WorldWideScience

Sample records for calcium increase triggers

  1. Early calcium increase triggers the formation of olfactory long-term memory in honeybees

    Directory of Open Access Journals (Sweden)

    Matsumoto Yukihisa

    2009-06-01

    Full Text Available Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+ plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward. Results By modulating the intracellular Ca2+ concentration ([Ca2+]i in the brain, we show that: (i blocking [Ca2+]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii conversely, increasing [Ca2+]i during single-trial conditioning triggers long-term memory formation; and finally, (iii as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca2+]i increase depends on de novo protein synthesis. Conclusion Altogether our data suggest that during olfactory conditioning Ca2+ is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca2+ therefore appears to act as a switch between short- and long-term storage of learned information.

  2. Sulfite triggers sustained calcium overload in cultured cortical neurons via a redox-dependent mechanism.

    Science.gov (United States)

    Wang, Xiao; Cao, Hui; Guan, Xin-Lei; Long, Li-Hong; Hu, Zhuang-Li; Ni, Lan; Wang, Fang; Chen, Jian-Guo; Wu, Peng-Fei

    2016-09-01

    Sulfite is a compound commonly used as preservative in foods and pharmaceuticals. Many studies have examined the neurotoxicity of sulfite, but its effect on neuronal calcium homeostasis has not yet been reported. Here, we observed the effect of sulfite on the cytosolic free calcium concentration ([Ca(2+)]i) in cultured cortical neurons using Fura-2/AM based calcium imaging technique. Sulfite (250-1000μM) caused a sustained increase in [Ca(2+)]i in the neurons via a dose-dependent manner. In Ca(2+)-free solution, sulfite failed to increase [Ca(2+)]i. After the depletion of the intracellular calcium store, the effect of sulfite on the [Ca(2+)]i was largely abolished. Pharmacological inhibition of phospholipase C (PLC)-inositol 1,4,5-triphosphate (IP3) signaling pathway blocked sulfite-induced increase of [Ca(2+)]i. Interestingly, antioxidants such as trolox and dithiothreitol, abolished the increase of [Ca(2+)]i induced by sulfite. Exposure to sulfite triggered generation of sulfur- and oxygen-centered free radicals in neurons and increased oxidative stress both in the cultured cortical neurons and the prefrontal cortex of rats. Furthemore, sulfite decreased cell viability in cultured cortical neurons via a calcium-dependent manner. Thus, our current study suggests that the redox-dependent calcium overload triggered by sulfite in cortical neuronsmay be involved in its neurotoxicity. PMID:27313092

  3. Cellular Mechanisms of Calcium-Mediated Triggered Activity

    Science.gov (United States)

    Song, Zhen

    Life-threatening cardiac arrhythmias continue to pose a major health problem. Ventricular fibrillation, which is a complex form of electrical wave turbulence in the lower chambers of the heart, stops the heart from pumping and is the largest cause of natural death in the United States. Atrial fibrillation, a related form of wave turbulence in the upper heart chambers, is in turn the most common arrhythmia diagnosed in clinical practice. Despite extensive research to date, mechanisms of cardiac arrhythmias remain poorly understood. It is well established that both spatial disorder of the refractory period of heart cells and triggered activity (TA) jointly contribute to the initiation and maintenance of arrhythmias. TA broadly refers to the abnormal generation of a single or a sequence of abnormal excitation waves from a small submillimeter region of the heart in the interval of time between two normal waves generated by the heart's natural pacemaker (the sinoatrial node). TA has been widely investigated experimentally and occurs in several pathological conditions where the intracellular concentration of free Ca2+ ions in heart cells becomes elevated. Under such conditions, Ca2+ can be spontaneously released from intracellular stores, thereby driving an electrogenic current that exchanges 3Na+ ions for one Ca2+ ion across the cell membrane. This current in turn depolarizes the membrane of heart cells after a normal excitation. If this calcium-mediated "delayed after depolarization'' (DAD) is sufficiently large, it can generate an action potential. While the arrhythmogenic importance of spontaneous Ca2+ release and DADs is well appreciated, the conditions under which they occur in heart pathologies remain poorly understood. Calcium overload is only one factor among several other factors that can promote DADs, including sympathetic nerve stimulation, different expression levels of membrane ion channels and calcium handling proteins, and different mutations of those

  4. Increased absolute calcium binding to albumin in hypoalbuminaemia.

    OpenAIRE

    Besarab, A; Caro, J F

    1981-01-01

    The amount of calcium bound to protein was measured in 30 patients with differing diseases and varying degrees of hypoalbuminaemia. Total serum calcium increased directly with both serum albumin and ultrafilterable calcium concentrations. The estimated amount of calcium bound per gram of albumin varied inversely with the albumin concentration, decreasing from 2.1 to 1.0 mg calcium/g albumin as albumin concentration increased from 1.7 to 3.1 g/dl. Circulating parathyroid hormone (PTH) concentr...

  5. Calcium signaling triggered by ouabain protects the embryonic kidney from adverse developmental programming.

    Science.gov (United States)

    Khodus, Georgiy R; Kruusmägi, Markus; Li, Juan; Liu, Xiao-Li; Aperia, Anita

    2011-09-01

    The kidney is extraordinarily sensitive to adverse fetal programming. Malnutrition, the most common form of developmental challenge, retards formation of the kidney's functional units, the nephrons. The resulting low nephron endowment increases susceptibility to renal injury and disease. Using explanted rat embryonic kidneys, we found that the sodium-potassium-adenosine triphosphatase (Na, K-ATPase) ligand ouabain triggers, via the Na, K-ATPase/ inositol 1,4,5-trisphosphate receptor signalosome, a calcium-nuclear factor-kappa B (NF-κB) signal that protects kidney development from adverse effects of malnutrition. Serum deprivation resulted in severe retardation of nephron formation and robust increase in apoptotic rate, but in ouabain-exposed kidneys, no adverse effects of serum deprivation were observed. Depletion of intracellular calcium stores and inhibition of NF-κB activity abolished the rescuing effect of ouabain. Proof of principle that ouabain rescues development of embryonic kidneys exposed to malnutrition was obtained from studies on pregnant rats given low-protein diets and treated with ouabain or vehicle throughout pregnancy. PMID:21424905

  6. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

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    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.

  7. Osteoblasts detect pericellular calcium concentration increase via neomycin-sensitive voltage gated calcium channels.

    Science.gov (United States)

    Sun, Xuanhao; Kishore, Vipuil; Fites, Kateri; Akkus, Ozan

    2012-11-01

    The mechanisms underlying the detection of critically loaded or micro-damaged regions of bone by bone cells are still a matter of debate. Our previous studies showed that calcium efflux originates from pre-failure regions of bone matrix and MC3T3-E1 osteoblasts respond to such efflux by an increase in the intracellular calcium concentration. The mechanisms by which the intracellular calcium concentration increases in response to an increase in the pericellular calcium concentration are unknown. Elevation of the intracellular calcium may occur via release from the internal calcium stores of the cell and/or via the membrane bound channels. The current study applied a wide range of pharmaceutical inhibitors to identify the calcium entry pathways involved in the process: internal calcium release from endoplasmic reticulum (ER, inhibited by thapsigargin and TMB-8), calcium receptor (CaSR, inhibited by calhex), stretch-activated calcium channel (SACC, inhibited by gadolinium), voltage-gated calcium channels (VGCC, inhibited by nifedipine, verapamil, neomycin, and ω-conotoxin), and calcium-induced-calcium-release channel (CICRC, inhibited by ryanodine and dantrolene). These inhibitors were screened for their effectiveness to block intracellular calcium increase by using a concentration gradient induced calcium efflux model which mimics calcium diffusion from the basal aspect of cells. The inhibitor(s) which reduced the intracellular calcium response was further tested on osteoblasts seeded on mechanically loaded notched cortical bone wafers undergoing damage. The results showed that only neomycin reduced the intracellular calcium response in osteoblasts, by 27%, upon extracellular calcium stimulus induced by concentration gradient. The inhibitory effect of neomycin was more pronounced (75% reduction in maximum fluorescence) for osteoblasts seeded on notched cortical bone wafers loaded mechanically to damaging load levels. These results imply that the increase in

  8. Role of calcium as trigger in thermal beta-lactoglobulin aggregation

    NARCIS (Netherlands)

    Simons, J.W.F.A.; Kosters, H.A.; Visschers, R.W.; Jongh, de H.H.J.

    2002-01-01

    Divalent calcium ions have been suggested to be involved in intermolecular protein-Ca2+-protein cross-linking, intramolecular electrostatic shielding, or ion-induced protein conformational changes as a trigger for protein aggregation at elevated temperatures. To address the first two phenomena in th

  9. Calcium signaling as a mediator of cell energy demand and a trigger to cell death.

    Science.gov (United States)

    Bhosale, Gauri; Sharpe, Jenny A; Sundier, Stephanie Y; Duchen, Michael R

    2015-09-01

    Calcium signaling is pivotal to a host of physiological pathways. A rise in calcium concentration almost invariably signals an increased cellular energy demand. Consistent with this, calcium signals mediate a number of pathways that together serve to balance energy supply and demand. In pathological states, calcium signals can precipitate mitochondrial injury and cell death, especially when coupled to energy depletion and oxidative or nitrosative stress. This review explores the mechanisms that couple cell signaling pathways to metabolic regulation or to cell death. The significance of these pathways is exemplified by pathological case studies, such as those showing loss of mitochondrial calcium uptake 1 in patients and ischemia/reperfusion injury.

  10. Calcium and caffeine interaction in increased calcium balance in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Sandra Tavares da Silva

    2013-06-01

    Full Text Available OBJECTIVE: This study investigated the effects of caffeine intake associated with inadequate or adequate calcium intake in laparotomized or ovariectomized rats by means of the calcium balance. Forty adults Wistar rats were ovariectomized or laparotomized. METHODS: The animals (n=40 were randomly placed in eight groups receiving the AIN-93 diet with 100% or 50% of the recommended calcium intake with or without added caffeine (6mg/kg/day. The animals were kept in individuals metabolic cages at a temperature of 24°±2ºC, light/dark cycles of 12/12 hours, and deionized water available ad libitum. On the 8th week of the experiment, food consumption was measured and 24-hour urine and 4-day feces were collected to determine calcium balance [Balance=Ca intake-(Urinary Ca+Fecal Ca]. RESULTS: Animals with adequate calcium intake presented higher balances and rates of calcium absorption and retention (p<0.05 than those with inadequate calcium intake, regardless of caffeine intake (p<0.05. Caffeine intake did not affect urinary calcium excretion but increased balance (p<0.05 in the groups with adequate calcium intake. CONCLUSION: Adequate calcium intake attenuated the negative effects of estrogen deficiency and improved calcium balance even in the presence of caffeine.

  11. TRIGGER

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    W. Smith from contributions of C. Leonidopoulos, I. Mikulec, J. Varela and C. Wulz.

    Level-1 Trigger Hardware and Software Over the past few months, the Level-1 trigger has successfully recorded data with cosmic rays over long continuous stretches as well as LHC splash events, beam halo, and collision events. The L1 trigger hardware, firmware, synchronization, performance and readiness for beam operation were reviewed in October. All L1 trigger hardware is now installed at Point 5, and most of it is completely commissioned. While the barrel ECAL Trigger Concentrator Cards are fully operational, the recently delivered endcap ECAL TCC system is still being commissioned. For most systems there is a sufficient number of spares available, but for a few systems additional reserve modules are needed. It was decided to increase the overall L1 latency by three bunch crossings to increase the safety margin for trigger timing adjustments. In order for CMS to continue data taking during LHC frequency ramps, the clock distribution tree needs to be reset. The procedures for this have been tested. A repl...

  12. TRIGGER

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    Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software New Forward Scintillating Counters (FSC) for rapidity gap measurements have been installed and integrated into the Trigger recently. For the Global Muon Trigger, tuning of quality criteria has led to improvements in muon trigger efficiencies. Several subsystems have started campaigns to increase spares by recovering boards or producing new ones. The barrel muon sector collector test system has been reactivated, new η track finder boards are in production, and φ track finder boards are under revision. In the CSC track finder, an η asymmetry problem has been corrected. New pT look-up tables have also improved efficiency. RPC patterns were changed from four out of six coincident layers to three out of six in the barrel, which led to a significant increase in efficiency. A new PAC firmware to trigger on heavy stable charged particles allows looking for chamber hit coincidences in two consecutive bunch-crossings. The redesign of the L1 Trigger Emulator...

  13. TRIGGER

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    J. Alimena

    2013-01-01

    Trigger Strategy Group The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for the development of future High-Level Trigger menus, as well as of its DQM and validation, in collaboration and with the technical support of the PdmV group. Taking into account the beam energy and luminosity expected in 2015, a rough estimate of the trigger rates indicates a factor four increase with respect to 2012 conditions. Assuming that a factor two can be tolerated thanks to the increase in offline storage and processing capabilities, a toy menu has been developed using the new OpenHLT workflow to estimate the transverse energy/momentum thresholds that would halve the current trigger rates. The CPU time needed to run the HLT has been compared between data taken with 25 ns and 50 ns bunch spacing, for equivalent pile-up: no significant difference was observed on the global time per event distribution at the only available data point, corresponding to a pile-up of about 10 interactions. Using th...

  14. Serum Calcium Increase Correlates With Worsening of Lipid Profile

    Science.gov (United States)

    Gallo, Luigia; Faniello, Maria C.; Canino, Giovanni; Tripolino, Cesare; Gnasso, Agostino; Cuda, Giovanni; Costanzo, Francesco S.; Irace, Concetta

    2016-01-01

    Abstract Despite the well-documented role of calcium in cell metabolism, its role in the development of cardiovascular disease is still under heavy debate. Several studies suggest that calcium supplementation might be associated with an increased risk of coronary heart disease, whereas others underline a significant effect on lowering high blood pressure and hyperlipidemia. The purpose of this study was to investigate, in a large nonselected cohort from South Italy, if serum calcium levels correlate with lipid values and can therefore be linked to higher individual cardiovascular risk. Eight-thousand-six-hundred-ten outpatients addressed to the Laboratory of Clinical Biochemistry, University of Magna Græcia, Catanzaro, Italy from January 2012 to December 2013 for routine blood tests, were enrolled in the study. Total HDL-, LDL- and non-HDL colesterol, triglycerides, and calcium were determined with standard methods. We observed a significant association between total cholesterol, LDL-cholesterol, HDL-cholesterol, non-HDL cholesterol, triglycerides, and serum calcium in men and postmenopause women. Interestingly, in premenopause women, we only found a direct correlation between serum calcium, total cholesterol, and HDL-cholesterol. Calcium significantly increased while increasing total cholesterol and triglycerides in men and postmenopause women. Our results confirm that progressive increase of serum calcium level correlates with worsening of lipid profile in our study population. Therefore, we suggest that a greater caution should be used in calcium supplement prescription particularly in men and women undergoing menopause, in which an increase of serum lipids is already known to be associated with a higher cardiovascular risk. PMID:26937904

  15. Alpha hemolysin induces an increase of erythrocytes calcium: a FLIM 2-photon phasor analysis approach.

    Directory of Open Access Journals (Sweden)

    Susana Sanchez

    Full Text Available α-Hemolysin (HlyA from Escherichia coli is considered as the prototype of a family of toxins called RTX (repeat in toxin, a group of proteins that share genetic and structural features. HlyA is an important virulence factor in E. coli extraintestinal infections, such as meningitis, septicemia and urinary infections. High concentrations of the toxin cause the lysis of several cells such as erythrocytes, granulocytes, monocytes, endothelial and renal epithelial cells of different species. At low concentrations it induces the production of cytokines and apoptosis. Since many of the subcytolytic effects in other cells have been reported to be triggered by the increase of intracellular calcium, we followed the calcium concentration inside the erythrocytes while incubating with sublytic concentrations of HlyA. Calcium concentration was monitored using the calcium indicator Green 1, 2-photon excitation, and fluorescence lifetime imaging microscopy (FLIM. Data were analyzed using the phasor representation. In this report, we present evidence that, at sublytic concentrations, HlyA induces an increase of calcium concentration in rabbit erythrocytes in the first 10 s. Results are discussed in relation to the difficulties of measuring calcium concentrations in erythrocytes where hemoglobin is present, the contribution of the background and the heterogeneity of the response observed in individual cells.

  16. Calcium-Ion-Triggered Co-assembly of Peptide and Polysaccharide into a Hybrid Hydrogel for Drug Delivery

    OpenAIRE

    Xie, Yanyan; Zhao, Jun; Huang, Renliang; Qi, Wei; Wang, Yuefei; Su, Rongxin; He, Zhimin

    2016-01-01

    We report a new approach to constructing a peptide–polysaccharide hybrid hydrogel via the calcium-ion-triggered co-assembly of fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) peptide and alginate. Calcium ions triggered the self-assembly of Fmoc-FF peptide into nanofibers with diameter of about 30 nm. Meanwhile, alginate was rapidly crosslinked by the calcium ions, leading to the formation of stable hybrid hydrogel beads. Compared to alginate or Fmoc-FF hydrogel alone, the hybrid Fmoc-FF...

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

    DEFF Research Database (Denmark)

    Hsu, Yu-Juei; Dimke, Henrik Anthony; Schoeber, Joost P H;

    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....... Androgen deficiency increased the abundance of the renal mRNA and protein of both the luminal transient receptor potential vanilloid-subtype 5 (TRPV5) and intracellular calbindin-D(28K) transporters, which in turn were suppressed by testosterone treatment. There were no significant differences in serum...

  18. Calcium pretreatment increases thermotolerance of Laminaria japonica sporophytes

    Institute of Scientific and Technical Information of China (English)

    You Wang; Qingyun Yu; Xuexi Tang; Lili Wang

    2009-01-01

    Calcium is a secondary messenger in plant signaling,and its concentration changes spatially and temporally during the course of heat stress.In the present study,potassium antimonate was used to visualize calcium localization in blades of a marine macroalga,the juvenile Laminariajaponica sporophytes under heat stress (25 ℃).Result showed that loosely bound calcium was mainly distributed on the cell wall under normal conditions (10 ℃),and flowed into the cytoplasm when exposed to heat.The simutaneous assay on the antioxidant system changes was performed.Oxidative damage,as measured by generation of reactive oxygen species (ROS) malondialdehyde (MDA) content,increased significantly during heat stress,and calcium pretreatment alleviated oxidative damage.The assay on the activities of six antioxidant enzymes demonstrated that their enzymatic activities were inhibited when exposed to heat stress,but Ca2+ pretreatment effectively attenuated the inhibition.Results in the present study inferred that calcium homeostasis plays an essential role in L.japonica sporophyte when exposed to heat,and calcium pretreatment could improve its thermo-tolerance.

  19. Some Factors Trigger Increasing Foodborne Diseases Cases of Livestock Origin

    Directory of Open Access Journals (Sweden)

    Anni Kusumaningsih

    2012-09-01

    Full Text Available Food is an essential need for various human body activities. Consequently, food must be guaranteed to be free from biological, chemical, and physical contaminants and other hazardous substances that can obstruct health. The presence of various hazardous contaminants in food may result in the appearance of foodborne diseases, i.e. human diseases spread through contaminated food and drinks. Biological contaminants in food can be bacteria, viruses, parasites, moulds, or fungi. The most dangerous biological contaminants that may cause an epidemic disease in human are pathogenic bacteria such as Salmonella spp., Escherichia coli, Bacillus anthracis, Clostridium spp., Listeria monocytogenes, Campylobacter spp., Vibrio cholerae, Enterobacter sakazakii, Shigella, etc. Researchers believe that there are several factors that can be the trigger that increase of foodborne diseases cases such as community demography by increasing the individual groups that are more susceptible to pathogenic foodborne infections, human behaviour related to the changes in the community life style and consumption, the advances in industrial and technological sectors through the increase of large scale food industries concentrated in one location, the global trade or travel, and increasing bacterial resistances against antimicrobials as the result of the increasing the uses of antimicrobials for disease prevention and cure in animals and humans.

  20. TRIGGER

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    Wesley Smith

    Level-1 Trigger Hardware and Software The hardware of the trigger components has been mostly finished. The ECAL Endcap Trigger Concentrator Cards (TCC) are in production while Barrel TCC firmware has been upgraded, and the Trigger Primitives can now be stored by the Data Concentrator Card for readout by the DAQ. The Regional Calorimeter Trigger (RCT) system is complete, and the timing is being finalized. All 502 HCAL trigger links to RCT run without error. The HCAL muon trigger timing has been equalized with DT, RPC, CSC and ECAL. The hardware and firmware for the Global Calorimeter Trigger (GCT) jet triggers are being commissioned and data from these triggers is available for readout. The GCT energy sums from rings of trigger towers around the beam pipe beam have been changed to include two rings from both sides. The firmware for Drift Tube Track Finder, Barrel Sorter and Wedge Sorter has been upgraded, and the synchronization of the DT trigger is satisfactory. The CSC local trigger has operated flawlessly u...

  1. TRIGGER

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    Roberta Arcidiacono

    2013-01-01

    Trigger Studies Group (TSG) The Trigger Studies Group has just concluded its third 2013 workshop, where all POGs presented the improvements to the physics object reconstruction, and all PAGs have shown their plans for Trigger development aimed at the 2015 High Level Trigger (HLT) menu. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger menu development, path timing, Trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – this last task in collaboration with PdmV (Physics Data and Monte Carlo Validation group). In the last months the group has delivered several HLT rate estimates and comparisons, using the available data and Monte Carlo samples. The studies were presented at the Trigger workshops in September and December, and STEAM has contacted POGs and PAGs to understand the origin of the discrepancies observed between 8 TeV data and Monte Carlo simulations. The most recent results show what the...

  2. TRIGGER

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    Wesley Smith

    Level-1 Trigger Hardware and Software The trigger synchronization procedures for running with cosmic muons and operating with the LHC were reviewed during the May electronics week. Firmware maintenance issues were also reviewed. Link tests between the new ECAL endcap trigger concentrator cards (TCC48) and the Regional Calorimeter Trigger have been performed. Firmware for the energy sum triggers and an upgraded tau trigger of the Global Calorimeter Triggers has been developed and is under test. The optical fiber receiver boards for the Track-Finder trigger theta links of the DT chambers are now all installed. The RPC trigger is being made more robust by additional chamber and cable shielding and also by firmware upgrades. For the CSC’s the front-end and trigger motherboard firmware have been updated. New RPC patterns and DT/CSC lookup tables taking into account phi asymmetries in the magnetic field configuration are under study. The motherboard for the new pipeline synchronizer of the Global Trigg...

  3. TRIGGER

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    W. Smith

    2012-01-01

      Level-1 Trigger The Level-1 Trigger group is ready to deploy improvements to the L1 Trigger algorithms for 2012. These include new high-PT patterns for the RPC endcap, an improved CSC PT assignment, a new PT-matching algorithm for the Global Muon Trigger, and new calibrations for ECAL, HCAL, and the Regional Calorimeter Trigger. These should improve the efficiency, rate, and stability of the L1 Trigger. The L1 Trigger group also is migrating the online systems to SLC5. To make the data transfer from the Global Calorimeter Trigger to the Global Trigger more reliable and also to allow checking the data integrity online, a new optical link system has been developed by the GCT and GT groups and successfully tested at the CMS electronics integration facility in building 904. This new system is now undergoing further tests at Point 5 before being deployed for data-taking this year. New L1 trigger menus have recently been studied and proposed by Emmanuelle Perez and the L1 Detector Performance Group...

  4. TRIGGER

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    W. Smith

    At the March meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, the program of trigger pattern tests and vertical slice tests and planning for the Global Runs starting this summer. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and integration testing is in full swing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. After full checkout, trigger subsystems will be then operated in the CMS Global Runs. Continuous...

  5. TRIGGER

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    by Wesley Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The overall status of the L1 trigger has been excellent and the running efficiency has been high during physics fills. The timing is good to about 1%. The fine-tuning of the time synchronization of muon triggers is ongoing and will be completed after more than 10 nb-1 of data have been recorded. The CSC trigger primitive and RPC trigger timing have been refined. A new configuration for the CSC Track Finder featured modified beam halo cuts and improved ghost cancellation logic. More direct control was provided for the DT opto-receivers. New RPC Cosmic Trigger (RBC/TTU) trigger algorithms were enabled for collision runs. There is further work planned during the next technical stop to investigate a few of the links from the ECAL to the Regional Calorimeter Trigger (RCT). New firmware and a new configuration to handle trigger rate spikes in the ECAL barrel are also being tested. A board newly developed by the tracker group (ReTRI) has been installed and activated to block re...

  6. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The production of the trigger hardware is now basically finished, and in time for the turn-on of the LHC. The last boards produced are the Trigger Concentrator Cards for the ECAL Endcaps (TCC-EE). After the recent installation of the four EE Dees, the TCC-EE prototypes were used for their commissioning. Production boards are arriving and are being tested continuously, with the last ones expected in November. The Regional Calorimeter Trigger hardware is fully integrated after installation of the last EE cables. Pattern tests from the HCAL up to the GCT have been performed successfully. The HCAL triggers are fully operational, including the connection of the HCAL-outer and forward-HCAL (HO/HF) technical triggers to the Global Trigger. The HCAL Trigger and Readout (HTR) board firmware has been updated to permit recording of the tower “feature bit” in the data. The Global Calorimeter Trigger hardware is installed, but some firmware developments are still n...

  7. TRIGGER

    CERN Multimedia

    W. Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The Level-1 Trigger hardware has performed well during both the recent proton-proton and heavy ion running. Efforts were made to improve the visibility and handling of alarms and warnings. The tracker ReTRI boards that prevent fixed frequencies of Level-1 Triggers are now configured through the Trigger Supervisor. The Global Calorimeter Trigger (GCT) team has introduced a buffer cleanup procedure at stops and a reset of the QPLL during configuring to ensure recalibration in case of a switch from the LHC clock to the local clock. A device to test the cables between the Regional Calorimeter Trigger and the GCT has been manufactured. A wrong charge bit was fixed in the CSC Trigger. The ECAL group is improving crystal masking and spike suppression in the trigger primitives. New firmware for the Drift Tube Track Finder (DTTF) sorters was developed to improve fake track tagging and sorting. Zero suppression was implemented in the DT Sector Collector readout. The track finder b...

  8. TRIGGER

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    Wesley Smith

    Trigger Hardware The status of the trigger components was presented during the September CMS Week and Annual Review and at the monthly trigger meetings in October and November. Procedures for cold and warm starts (e.g. refreshing of trigger parameters stored in registers) of the trigger subsystems have been studied. Reviews of parts of the Global Calorimeter Trigger (GCT) and the Global Trigger (GT) have taken place in October and November. The CERN group summarized the status of the Trigger Timing and Control (TTC) system. All TTC crates and boards are installed in the underground counting room, USC55. The central clock system will be upgraded in December (after the Global Run at the end of November GREN) to the new RF2TTC LHC machine interface timing module. Migration of subsystem's TTC PCs to SLC4/ XDAQ 3.12 is being prepared. Work is on going to unify the access to Local Timing Control (LTC) and TTC CMS interface module (TTCci) via SOAP (Simple Object Access Protocol, a lightweight XML-based messaging ...

  9. TRIGGER

    CERN Multimedia

    W. Smith from contributions of C. Leonidopoulos

    2010-01-01

    Level-1 Trigger Hardware and Software Since nearly all of the Level-1 (L1) Trigger hardware at Point 5 has been commissioned, activities during the past months focused on the fine-tuning of synchronization, particularly for the ECAL and the CSC systems, on firmware upgrades and on improving trigger operation and monitoring. Periodic resynchronizations or hard resets and a shortened luminosity section interval of 23 seconds were implemented. For the DT sector collectors, an automatic power-off was installed in case of high temperatures, and the monitoring capabilities of the opto-receivers and the mini-crates were enhanced. The DTTF and the CSCTF now have improved memory lookup tables. The HCAL trigger primitive logic implemented a new algorithm providing better stability of the energy measurement in the presence of any phase misalignment. For the Global Calorimeter Trigger, additional Source Cards have been manufactured and tested. Testing of the new tau, missing ET and missing HT algorithms is underw...

  10. Calcium-Ion-Triggered Co-assembly of Peptide and Polysaccharide into a Hybrid Hydrogel for Drug Delivery.

    Science.gov (United States)

    Xie, Yanyan; Zhao, Jun; Huang, Renliang; Qi, Wei; Wang, Yuefei; Su, Rongxin; He, Zhimin

    2016-12-01

    We report a new approach to constructing a peptide-polysaccharide hybrid hydrogel via the calcium-ion-triggered co-assembly of fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) peptide and alginate. Calcium ions triggered the self-assembly of Fmoc-FF peptide into nanofibers with diameter of about 30 nm. Meanwhile, alginate was rapidly crosslinked by the calcium ions, leading to the formation of stable hybrid hydrogel beads. Compared to alginate or Fmoc-FF hydrogel alone, the hybrid Fmoc-FF/alginate hydrogel had much better stability in both water and a phosphate-buffered solution (PBS), probably because of the synergistic effect of noncovalent and ionic interactions. Furthermore, docetaxel was chosen as a drug model, and it was encapsulated by hydrogel beads to study the in vitro release behavior. The sustained and controlled docetaxel release was obtained by varying the concentration ratio between Fmoc-FF peptide and alginate. PMID:27067732

  11. Calcium-Ion-Triggered Co-assembly of Peptide and Polysaccharide into a Hybrid Hydrogel for Drug Delivery

    Science.gov (United States)

    Xie, Yanyan; Zhao, Jun; Huang, Renliang; Qi, Wei; Wang, Yuefei; Su, Rongxin; He, Zhimin

    2016-04-01

    We report a new approach to constructing a peptide-polysaccharide hybrid hydrogel via the calcium-ion-triggered co-assembly of fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) peptide and alginate. Calcium ions triggered the self-assembly of Fmoc-FF peptide into nanofibers with diameter of about 30 nm. Meanwhile, alginate was rapidly crosslinked by the calcium ions, leading to the formation of stable hybrid hydrogel beads. Compared to alginate or Fmoc-FF hydrogel alone, the hybrid Fmoc-FF/alginate hydrogel had much better stability in both water and a phosphate-buffered solution (PBS), probably because of the synergistic effect of noncovalent and ionic interactions. Furthermore, docetaxel was chosen as a drug model, and it was encapsulated by hydrogel beads to study the in vitro release behavior. The sustained and controlled docetaxel release was obtained by varying the concentration ratio between Fmoc-FF peptide and alginate.

  12. Calcium Signalling Triggered by NAADP in T Cells Determines Cell Shape and Motility During Immune Synapse Formation

    Science.gov (United States)

    Nebel, Merle; Zhang, Bo; Odoardi, Francesca; Flügel, Alexander; Potter, Barry V. L.; Guse, Andreas H.

    2016-01-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP) has been implicated as an initial Ca2+ trigger in T cell Ca2+ signalling, but its role in formation of the immune synapse in CD4+ effector T cells has not been analysed. CD4+ T cells are activated by the interaction with peptide-MHCII complexes on the surface of antigen-presenting cells. Establishing a two-cell system including primary rat CD4+ T cells specific for myelin basic protein and rat astrocytes enabled us to mirror this activation process in vitro and to analyse Ca2+ signalling, cell shape changes and motility in T cells during formation and maintenance of the immune synapse. After immune synapse formation, T cells showed strong, antigen-dependent increases in free cytosolic calcium concentration ([Ca2+]i). Analysis of cell shape and motility revealed rounding and immobilization of T cells depending on the amplitude of the Ca2+ signal. NAADP-antagonist BZ194 effectively blocked Ca2+ signals in T cells evoked by the interaction with antigen-presenting astrocytes. BZ194 reduced the percentage of T cells showing high Ca2+ signals thereby supporting the proposed trigger function of NAADP for global Ca2+ signalling. Taken together, the NAADP signalling pathway is further confirmed as a promising target for specific pharmacological intervention to modulate T cell activation. PMID:27747143

  13. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The final parts of the Level-1 trigger hardware are now being put in place. For the ECAL endcaps, more than half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are now available at CERN, such that one complete endcap can be covered. The Global Trigger now correctly handles ECAL calibration sequences, without being influenced by backpressure. The Regional Calorimeter Trigger (RCT) hardware is complete and working in USC55. Intra-crate tests of all 18 RCT crates and the Global Calorimeter Trigger (GCT) are regularly taking place. Pattern tests have successfully captured data from HCAL through RCT to the GCT Source Cards. HB/HE trigger data are being compared with emulator results to track down the very few remaining hardware problems. The treatment of hot and dead cells, including their recording in the database, has been defined. For the GCT, excellent agreement between the emulator and data has been achieved for jets and HF ET sums. There is still som...

  14. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The trigger system has been constantly in use in cosmic and commissioning data taking periods. During CRAFT running it delivered 300 million muon and calorimeter triggers to CMS. It has performed stably and reliably. During the abort gaps it has also provided laser and other calibration triggers. Timing issues, namely synchronization and latency issues, have been solved. About half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are installed, and the firmware is being worked on. The production of the other half has started. The HCAL Trigger and Readout (HTR) card firmware has been updated, and new features such as fast parallel zero-suppression have been included. Repairs of drift tube (DT) trigger mini-crates, optical links and receivers of sector collectors are under way and have been completed on YB0. New firmware for the optical receivers of the theta links to the drift tube track finder is being installed. In parallel, tests with new eta track finde...

  15. TRIGGER

    CERN Multimedia

    R. Carlin with contributions from D. Acosta

    2012-01-01

    Level-1 Trigger Data-taking continues at cruising speed, with high availability of all components of the Level-1 trigger. We have operated the trigger up to a luminosity of 7.6E33, where we approached 100 kHz using the 7E33 prescale column.  Recently, the pause without triggers in case of an automatic "RESYNC" signal (the "settle" and "recover" time) was reduced in order to minimise the overall dead-time. This may become very important when the LHC comes back with higher energy and luminosity after LS1. We are also preparing for data-taking in the proton-lead run in early 2013. The CASTOR detector will make its comeback into CMS and triggering capabilities are being prepared for this. Steps to be taken include improved cooperation with the TOTEM trigger system and using the LHC clock during the injection and ramp phases of LHC. Studies are being finalised that will have a bearing on the Trigger Technical Design Report (TDR), which is to be rea...

  16. The increasing of enamel calcium level after casein phosphopeptideamorphous calcium phosphate covering

    Directory of Open Access Journals (Sweden)

    Widyasri Prananingrum

    2012-06-01

    Full Text Available Background: Caries process is characterized by the presence of demineralization. Demineralization is caused by organic acids as a result of carbohydrate substrate fermentation. Remineralization is a natural repair process for non-cavitated lesions. Remineralization occurs if there are Ca2+ and PO43- ions in sufficient quantities. Casein-amorphous calcium phosphate phosphopeptide (CPP-ACP is a paste material containing milk protein (casein, that actually contains minerals, such as calcium and phosphate. The casein ability to stabilize calcium phosphate and enhance mineral solubility and bioavailability confers upon CPP potential to be biological delivery vehicles for calcium and phosphate. Purpose: The aim of this study was to determine the calcium levels in tooth enamel after being covered with CPP-ACP 2 times a day for 3, 14 and 28 days. Methods: Sample were bovine incisors of 3 year old cows divided into 4 groups, namely group I as control group, group II, III and IV as treatment groups covered with CPP-ACP 2 times a day. All of those teeth were then immersed in artificial saliva. Group II was immersed for 3 days, while group III was immersed for 14 days, and group IV was immersed for 28 days. One drop of CPP-ACP was used to cover the entire labial surface of teeth. The measurement of the calcium levels was then conducted by using titration method. All data were analyzed by One- Way ANOVA test with 5% degree of confidence. Results: The results showed significant difference of the calcium levels in tooth enamel of those groups after covered with CPP-ACP 2 times a day for 3, 14 and 28 days (p = 0.001. There is also significant difference of the calcium levels in tooth enamel of those treatment groups and the control group (p = 0.001. Conclusion: The calcium levels of tooth enamel are increased after covered with CPP-ACP 2 times a day for 3, 14 and 28 days.Latar belakang: Proses terjadinya karies gigi ditandai oleh adanya demineralisasi

  17. TRIGGER

    CERN Multimedia

    W. Smith

    At the December meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, and results from the Magnet Test and Cosmic Challenge (MTCC) phase II. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and moving towards integration testing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. This is combined with operations and testing without beam that will continue until startup. The plans for start-up, pilot and early running tri...

  18. TRIGGER

    CERN Multimedia

    W. Smith, from contributions of D. Acosta

    2012-01-01

      The L1 Trigger group deployed several major improvements this year. Compared to 2011, the single-muon trigger rate has been reduced by a factor of 2 and the η coverage has been restored to 2.4, with high efficiency. During the current technical stop, a higher jet seed threshold will be applied in the Global Calorimeter Trigger in order to significantly reduce the strong pile-up dependence of the HT and multi-jet triggers. The currently deployed L1 menu, with the “6E33” prescales, has a total rate of less than 100 kHz and operates with detector readout dead time of less than 3% for luminosities up to 6.5 × 1033 cm–2s–1. Further prescale sets have been created for 7 and 8 × 1033 cm–2s–1 luminosities. The L1 DPG is evaluating the performance of the Trigger for upcoming conferences and publication. Progress on the Trigger upgrade was reviewed during the May Upgrade Week. We are investigating scenarios for stagin...

  19. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The road map for the final commissioning of the level-1 trigger system has been set. The software for the trigger subsystems is being upgraded to run under CERN Scientific Linux 4 (SLC4). There is also a new release for the Trigger Supervisor (TS 1.4), which implies upgrade work by the subsystems. As reported by the CERN group, a campaign to tidy the Trigger Timing and Control (TTC) racks has begun. The machine interface was upgraded by installing the new RF2TTC module, which receives RF signals from LHC Point 4. Two Beam Synchronous Timing (BST) signals, one for each beam, can now be received in CMS. The machine group will define the exact format of the information content shortly. The margin on the locking range of the CMS QPLL is planned for study for different subsystems in the next Global Runs, using a function generator. The TTC software has been successfully tested on SLC4. Some TTC subsystems have already been upgraded to SLC4. The TTCci Trigger Supervisor ...

  20. TRIGGER

    CERN Multimedia

    R. Arcidiacono

    2013-01-01

      In 2013 the Trigger Studies Group (TSG) has been restructured in three sub-groups: STEAM, for the development of new HLT menus and monitoring their performance; STORM, for the development of HLT tools, code and actual configurations; and FOG, responsible for the online operations of the High Level Trigger. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger Menu development, path timing, trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – in collaboration and with the technical support of the PdmV group. Since the end of proton-proton data taking, the group has started preparing for 2015 data taking, with collisions at 13 TeV and 25 ns bunch spacing. The reliability of the extrapolation to higher energy is being evaluated comparing the trigger rates on 7 and 8 TeV Monte Carlo samples with the data taken in the past two years. The effect of 25 ns bunch spacing is being studied on the d...

  1. TRIGGER

    CERN Multimedia

    W. Smith

    2011-01-01

    Level-1 Trigger Hardware and Software Overall the L1 trigger hardware has been running very smoothly during the last months of proton running. Modifications for the heavy-ion run have been made where necessary. The maximal design rate of 100 kHz can be sustained without problems. All L1 latencies have been rechecked. The recently installed Forward Scintillating Counters (FSC) are being used in the heavy ion run. The ZDC scintillators have been dismantled, but the calorimeter itself remains. We now send the L1 accept signal and other control signals to TOTEM. Trigger cables from TOTEM to CMS will be installed during the Christmas shutdown, so that the TOTEM data can be fully integrated within the CMS readout. New beam gas triggers have been developed, since the BSC-based trigger is no longer usable at high luminosities. In particular, a special BPTX signal is used after a quiet period with no collisions. There is an ongoing campaign to provide enough spare modules for the different subsystems. For example...

  2. TRIGGER

    CERN Multimedia

    by Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software After the winter shutdown minor hardware problems in several subsystems appeared and were corrected. A reassessment of the overall latency has been made. In the TTC system shorter cables between TTCci and TTCex have been installed, which saved one bunch crossing, but which may have required an adjustment of the RPC timing. In order to tackle Pixel out-of-syncs without influencing other subsystems, a special hardware/firmware re-sync protocol has been introduced in the Global Trigger. The link between the Global Calorimeter Trigger and the Global Trigger with the new optical Global Trigger Interface and optical receiver daughterboards has been successfully tested in the Electronics Integration Centre in building 904. New firmware in the GCT now allows a setting to remove the HF towers from energy sums. The HF sleeves have been replaced, which should lead to reduced rates of anomalous signals, which may allow their inclusion after this is validated. For ECAL, improvements i...

  3. Lithium prevents early cytosolic calcium increase and secondary injurious calcium overload in glycolytically inhibited endothelial cells

    International Nuclear Information System (INIS)

    Highlights: •We investigate free calcium as a central signalling element in endothelial cells. •Inhibition of glycolysis with 2-deoxy-D-glucose reduces cellular ATP. •This manoeuvre leads to a biphasic increase and overload of free calcium. •Pre-treatment with lithium for 24 h abolishes both phases of the calcium increase. •This provides a new strategy to protect endothelial calcium homeostasis and barrier function. -- Abstract: Cytosolic free calcium concentration ([Ca2+]i) is a central signalling element for the maintenance of endothelial barrier function. Under physiological conditions, it is controlled within narrow limits. Metabolic inhibition during ischemia/reperfusion, however, induces [Ca2+]i overload, which results in barrier failure. In a model of cultured porcine aortic endothelial monolayers (EC), we addressed the question of whether [Ca2+]i overload can be prevented by lithium treatment. [Ca2+]i and ATP were analysed using Fura-2 and HPLC, respectively. The combined inhibition of glycolytic and mitochondrial ATP synthesis by 2-desoxy-D-glucose (5 mM; 2-DG) plus sodium cyanide (5 mM; NaCN) caused a significant decrease in cellular ATP content (14 ± 1 nmol/mg protein vs. 18 ± 1 nmol/mg protein in the control, n = 6 culture dishes, P 2+]i (278 ± 24 nM vs. 71 ± 2 nM in the control, n = 60 cells, P 2+]i response of EC was biphasic with a peak after 1 min (183 ± 6 nM vs. 71 ± 1 nM, n = 60 cells, P 2+]i. A 24-h pre-treatment with 10 mM of lithium chloride before the inhibition of ATP synthesis abolished both phases of the 2-DG-induced [Ca2+]i increase. This effect was not observed when lithium chloride was added simultaneously with 2-DG. We conclude that lithium chloride abolishes the injurious [Ca2+]i overload in EC and that this most likely occurs by preventing inositol 3-phosphate-sensitive Ca2+-release from the endoplasmic reticulum. Though further research is needed, these findings provide a novel option for therapeutic strategies to

  4. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware The CERN group is working on the TTC system. Seven out of nine sub-detector TTC VME crates with all fibers cabled are installed in USC55. 17 Local Trigger Controller (LTC) boards have been received from production and are in the process of being tested. The RF2TTC module replacing the TTCmi machine interface has been delivered and will replace the TTCci module used to mimic the LHC clock. 11 out of 12 crates housing the barrel ECAL off-detector electronics have been installed in USC55 after commissioning at the Electronics Integration Centre in building 904. The cabling to the Regional Calorimeter Trigger (RCT) is terminated. The Lisbon group has completed the Synchronization and Link mezzanine board (SLB) production. The Palaiseau group has fully tested and installed 33 out of 40 Trigger Concentrator Cards (TCC). The seven remaining boards are being remade. The barrel TCC boards have been tested at the H4 test beam, and good agreement with emulator predictions were found. The cons...

  5. Adolescence: How do we increase intestinal calcium absorption to allow for bone mineral mass accumulation?

    Science.gov (United States)

    An increase in calcium absorptive efficiency (fractional absorption of dietary calcium) during adolescence is associated with a rapid increase in total body bone mineral mass (BMM) accumulation. This increase occurs across a range of calcium intakes. It appears to be principally mediated by hormonal...

  6. Lithium prevents early cytosolic calcium increase and secondary injurious calcium overload in glycolytically inhibited endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Bosche, Bert, E-mail: bert.bosche@uk-essen.de [Department of Neurology, University of Duisburg-Essen (Germany); Max Planck Institute for Neurological Research with Klaus-Joachim-Zülch Laboratories of the Max Planck Society and the Medical Faculty of the University of Cologne (Germany); Schäfer, Matthias, E-mail: matthias.schaefer@sanofi.com [Institute of Physiology, Justus-Liebig-University Giessen (Germany); Graf, Rudolf, E-mail: rudolf.graf@nf.mpg.de [Max Planck Institute for Neurological Research with Klaus-Joachim-Zülch Laboratories of the Max Planck Society and the Medical Faculty of the University of Cologne (Germany); Härtel, Frauke V., E-mail: frauke.haertel@tu-dresden.de [Institute of Physiology, Medical Faculty Carl Gustav Carus, Technical University Dresden (Germany); Schäfer, Ute, E-mail: ute.schaefer@medunigraz.at [Research Unit for Experimental Neurotraumatology, Medical University of Graz (Austria); Noll, Thomas, E-mail: thomas.noll@tu-dresden.de [Institute of Physiology, Medical Faculty Carl Gustav Carus, Technical University Dresden (Germany)

    2013-05-03

    Highlights: •We investigate free calcium as a central signalling element in endothelial cells. •Inhibition of glycolysis with 2-deoxy-D-glucose reduces cellular ATP. •This manoeuvre leads to a biphasic increase and overload of free calcium. •Pre-treatment with lithium for 24 h abolishes both phases of the calcium increase. •This provides a new strategy to protect endothelial calcium homeostasis and barrier function. -- Abstract: Cytosolic free calcium concentration ([Ca{sup 2+}]{sub i}) is a central signalling element for the maintenance of endothelial barrier function. Under physiological conditions, it is controlled within narrow limits. Metabolic inhibition during ischemia/reperfusion, however, induces [Ca{sup 2+}]{sub i} overload, which results in barrier failure. In a model of cultured porcine aortic endothelial monolayers (EC), we addressed the question of whether [Ca{sup 2+}]{sub i} overload can be prevented by lithium treatment. [Ca{sup 2+}]{sub i} and ATP were analysed using Fura-2 and HPLC, respectively. The combined inhibition of glycolytic and mitochondrial ATP synthesis by 2-desoxy-D-glucose (5 mM; 2-DG) plus sodium cyanide (5 mM; NaCN) caused a significant decrease in cellular ATP content (14 ± 1 nmol/mg protein vs. 18 ± 1 nmol/mg protein in the control, n = 6 culture dishes, P < 0.05), an increase in [Ca{sup 2+}]{sub i} (278 ± 24 nM vs. 71 ± 2 nM in the control, n = 60 cells, P < 0.05), and the formation of gaps between adjacent EC. These observations indicate that there is impaired barrier function at an early state of metabolic inhibition. Glycolytic inhibition alone by 10 mM 2-DG led to a similar decrease in ATP content (14 ± 2 nmol/mg vs. 18 ± 1 nmol/mg in the control, P < 0.05) with a delay of 5 min. The [Ca{sup 2+}]{sub i} response of EC was biphasic with a peak after 1 min (183 ± 6 nM vs. 71 ± 1 nM, n = 60 cells, P < 0.05) followed by a sustained increase in [Ca{sup 2+}]{sub i}. A 24-h pre-treatment with 10 mM of lithium

  7. EGF receptor—mediated intracellular calcium increase in human hepatoma BEL—7404 cells

    Institute of Scientific and Technical Information of China (English)

    FUTAO; YONGHUAXU; 等

    1994-01-01

    Epidermal growth factor(EGF) induced intracellular free calcium ([Ca2+]i) response was studied in fura-2- or fluo-3-loaded human hepatoma cells of BEL-7404 cell line.Single cell[Ca2+]i analysis and [Ca2+]i measurement in cell populations revealed that EGF triggered a rapid[Ca2+]i increase in the dose-dependent and time-dependent manner.Pretreatment of cells with an endoplasmic reticulum(ER) Ca2+-ATPase inhibitor,thapsigargin(TG) at 100nM concentration for 20 min,completely abolished EGF-induced [Ca2+]i increase,and chelating extracellular calcium by excess EGTA partially inhibited the increase.Furthermore,the expression of antisense EGF receptor sequence in BEL-7404 cells suppressed the [Ca2+]i response to EGF.The results suggest that EGF receptor-mediated [Ca2+]i increase in the human hepatoma cells is essentially dependent on the Ca2+ storage in ER.

  8. Calcium and vitamin D supplementation increases spinal BMD in healthy, postmenopausal women

    DEFF Research Database (Denmark)

    Baeksgaard, L; Andersen, K P; Hyldstrup, Lars

    1998-01-01

    of treatment was 2 years. Bone mineral density (BMD) was measured at the lumbar spine, hip and forearm. A dietary questionnaire was administered twice during the study and revealed a fairly good calcium and vitamin D intake (919 mg calcium/day; 3.8 micrograms vitamin D/day). An increase in lumbar spine BMD......We undertook a double-masked, randomized, placebo-controlled trial to evaluate the effect of a calcium and vitamin D supplement and a calcium supplement plus multivitamins on bone loss at the hip, spine and forearm. The study was performed in 240 healthy women, 58-67 years of age. Duration....... Together with significant changes in serum calcium and serum parathyroid hormone, this indicates that a long-term calcium and vitamin supplement of 1 g elementary calcium (calcium carbonate) and 14 micrograms vitamin D3 increases intestinal calcium absorption. A positive effect on BMD was demonstrated...

  9. Calcium and vitamin D supplementation increases spinal BMD in healthy, postmenopausal women

    DEFF Research Database (Denmark)

    Baeksgaard, L; Andersen, K P; Hyldstrup, Lars

    1998-01-01

    We undertook a double-masked, randomized, placebo-controlled trial to evaluate the effect of a calcium and vitamin D supplement and a calcium supplement plus multivitamins on bone loss at the hip, spine and forearm. The study was performed in 240 healthy women, 58-67 years of age. Duration...... of treatment was 2 years. Bone mineral density (BMD) was measured at the lumbar spine, hip and forearm. A dietary questionnaire was administered twice during the study and revealed a fairly good calcium and vitamin D intake (919 mg calcium/day; 3.8 micrograms vitamin D/day). An increase in lumbar spine BMD....... Together with significant changes in serum calcium and serum parathyroid hormone, this indicates that a long-term calcium and vitamin supplement of 1 g elementary calcium (calcium carbonate) and 14 micrograms vitamin D3 increases intestinal calcium absorption. A positive effect on BMD was demonstrated...

  10. Phototropism and geotropism in maize coleoptiles are spatially correlated with increases in cytosolic free calcium.

    Science.gov (United States)

    Gehring, C A; Williams, D A; Cody, S H; Parish, R W

    1990-06-01

    Phototropism and gravitropism in the shoots and roots of higher plants are the result of asymmetric growth. This is explained by the redistribution of growth regulators following exposure to gravity or unilateral light (the Cholodny-Went hypothesis). The positive phototropism and the negative geotropism of grass seedling coleoptiles are believed to result from lateral movement of auxin from the irradiated to the shaded side and from the upper to the lower side, respectively. Many physiological processes in plants, including auxin-induced cell elongation, are reported to be under the control of calcium. Added auxin triggers oscillations in cytosolic free calcium ([Ca2+]cyt) and cytosolic pH (pHcyt) in epidermal cells of maize coleoptiles. Until recently, it has not been possible to visualize these changes spatially with the commonly used fluorescent cation indicators. Using a scanning laser confocal microscope, a new visible wavelength Ca2+ probe fluo-3 and the fluorescent pH indicator BCECF, we have recorded rapid light-induced increases in [Ca2+]cyt and a lowering of pHcyt of cells on the shaded side of maize coleoptiles. In horizontally orientated coleoptiles, [Ca2+]cyt increases and pHcyt decreases in the more rapidly elongating cells on the lower side. For the first time, rapid changes in [Ca2+]cyt and pHcyt are correlated directly with increases in cell elongation stimulated by light and gravity.

  11. Increasing Water Temperature Triggers Dominance of Small Freshwater Plankton

    OpenAIRE

    Serena Rasconi; Andrea Gall; Katharina Winter; Martin J Kainz

    2015-01-01

    Climate change scenarios predict that lake water temperatures will increase up to 4°C and rainfall events will become more intense and frequent by the end of this century. Concurrently, supply of humic substances from terrestrial runoff is expected to increase, resulting in darker watercolor ("brownification") of aquatic ecosystems. Using a multi-seasonal, low trophic state mesocosm experiment, we investigated how higher water temperature and brownification affect plankton community compositi...

  12. Calcium and caffeine interaction in increased calcium balance in ovariectomized rats

    OpenAIRE

    Sandra Tavares da Silva; Neuza Maria Brunoro Costa; Frederico Souzalima Caldoncelli Franco; Antônio José Natali

    2013-01-01

    OBJECTIVE: This study investigated the effects of caffeine intake associated with inadequate or adequate calcium intake in laparotomized or ovariectomized rats by means of the calcium balance. Forty adults Wistar rats were ovariectomized or laparotomized. METHODS: The animals (n=40) were randomly placed in eight groups receiving the AIN-93 diet with 100% or 50% of the recommended calcium intake with or without added caffeine (6mg/kg/day). The animals were kept in individuals metabolic cages a...

  13. Astrocyte glycogenolysis is triggered by store-operated calcium entry and provides metabolic energy for cellular calcium homeostasis

    DEFF Research Database (Denmark)

    Müller, Margit S; Fox, Rebecca; Schousboe, Arne;

    2014-01-01

    Astrocytic glycogen, the only storage form of glucose in the brain, has been shown to play a fundamental role in supporting learning and memory, an effect achieved by providing metabolic support for neurons. We have examined the interplay between glycogenolysis and the bioenergetics of astrocytic...... cultures of murine cerebellar and cortical astrocytes, and determined glycogen content to investigate the effects of SOCE on glycogen metabolism. By blocking glycogenolysis, we tested energetic dependency of SOCE-related Ca(2+) dynamics on glycogenolytic ATP. Our results show that SOCE triggers astrocytic...... glycogenolysis. Upon inhibition of adenylate cyclase with 2',5'-dideoxyadenosine, glycogen content was no longer significantly different from that in unstimulated control cells, indicating that SOCE triggers astrocytic glycogenolysis in a cAMP-dependent manner. When glycogenolysis was inhibited in cortical...

  14. Extracellular calcium triggers unique transcriptional programs and modulates staurosporine-induced cell death in Neurospora crassa

    Directory of Open Access Journals (Sweden)

    A. Pedro Gonçalves

    2014-08-01

    Full Text Available Alterations in the intracellular levels of calcium are a common response to cell death stimuli in animals and fungi and, particularly, in the Neurospora crassa response to staurosporine. We highlight the importance of the extracellular availability of Ca2+ for this response. Limitation of the ion in the culture medium further sensitizes cells to the drug and results in increased accumulation of reactive oxygen species (ROS. Conversely, an approximately 30-fold excess of external Ca2+ leads to increased drug tolerance and lower ROS generation. In line with this, distinct staurosporine-induced cytosolic Ca2+ signaling profiles were observed in the absence or presence of excessive external Ca2+. High-throughput RNA sequencing revealed that different concentrations of extracellular Ca2+ define distinct transcriptional programs. Our transcriptional profiling also pointed to two putative novel Ca2+-binding proteins, encoded by the NCU08524 and NCU06607 genes, and provides a reference dataset for future investigations on the role of Ca2+ in fungal biology.

  15. Intraoperative Autotriggered Pressure Support Ventilation Resistant to Increased Flow Trigger Threshold.

    Science.gov (United States)

    Benitez Lopez, Julio; Rao, Sripad P; McNeer, Richard R; Dudaryk, Roman

    2016-07-01

    Oscillations from cardiac pulsations are normally transmitted to mediastinal structures without any consequence. Autotriggering (AT) of mechanical ventilation occurs when an inspiratory trigger, typically negative inspiratory flow in anesthesia ventilators, is met in the absence of patient effort. AT can lead to respiratory alkalosis, opioid overdose, prolonged mechanical ventilation, and lung hyperinflation. This entity has been reported in both critical care and operating room environments. Increasing the flow trigger usually resolves AT in all cases. We report a case of AT that failed to respond to increasing the flow trigger threshold to its maximal value on the GE Datex-Ohmeda Avance S5® anesthesia station. PMID:27224041

  16. Spike-triggered dendritic calcium transients depend on synaptic activity in the cricket giant interneurons.

    Science.gov (United States)

    Ogawa, Hiroto; Baba, Yoshichika; Oka, Kotaro

    2002-02-15

    The relationship between electrical activity and spike-induced Ca2+ increases in dendrites was investigated in the identified wind-sensitive giant interneurons in the cricket. We applied a high-speed Ca2+ imaging technique to the giant interneurons, and succeeded in recording the transient Ca2+ increases (Ca2+ transients) induced by a single action potential, which was evoked by presynaptic stimulus to the sensory neurons. The dendritic Ca2+ transients evoked by a pair of action potentials accumulated when spike intervals were shorter than 100 ms. The amplitude of the Ca2+ transients induced by a train of spikes depended on the number of action potentials. When stimulation pulses evoking the same numbers of action potentials were separately applied to the ipsi- or contra-lateral cercal sensory nerves, the dendritic Ca2+ transients induced by these presynaptic stimuli were different in their amplitude. Furthermore, the side of presynaptic stimulation that evoked larger Ca2+ transients depended on the location of the recorded dendritic regions. This result means that the spike-triggered Ca2+ transients in dendrites depend on postsynaptic activity. It is proposed that Ca2+ entry through voltage-dependent Ca2+ channels activated by the action potentials will be enhanced by excitatory synaptic inputs at the dendrites in the cricket giant interneurons.

  17. Role of arachidonic acid in hyposmotic membrane stretch-induced increase in calcium-activated potassium currents in gastric myocytes

    Institute of Scientific and Technical Information of China (English)

    Meng YANG; Wen-xie XU; Xing-lan LI; Hui-ying XU; Jia-bin SUN; Bin MEI; Hai-feng ZHENG; Lian-hua PIAO; De-gang XING; Zhai-liu LI

    2005-01-01

    Aim: To study effects of arachidonic acid (AA) and its metabolites on the hyposmotic membrane stretch-induced increase in calcium-activated potassium currents (IKCa) in gastric myocytes. Methods: Membrane currents were recorded by using a conventional whole cell patch-clamp technique in gastric myocytes isolated with collagenase. Results: Hyposmotic membrane stretch and AA increased both IK(Ca) and spontaneous transient outward currents significantly.Exogenous AA could potentiate the hyposmotic membrane stretch-induced increase in IK(Ca). The hyposmotic membrane stretch-induced increase in IK(Ca) was significantly suppressed by dimethyleicosadienoic acid (100 μmol/L in pipette solution), an inhibitor of phospholipase A2. Nordihydroguaiaretic acid, a lipoxygenase inhibitor, significantly suppressed AA and hyposmotic membrane stretch-induced increases in IK(Ca). External calcium-free or gadolinium chloride, a blocker of stretch-activated channels, blocked the AA-induced increase in IK(Ca) significantly, but it was not blocked by nicardipine, an L-type calcium channel blocker. Ryanodine, a calcium-induced calcium release agonist, completely blocked the AA-induced increase in IK(Ca); however, heparin, a potent inhibitor of inositol triphosphate receptor, did not block the AA-induced increase in IK(Ca). Conclusion:Hyposmotic membrane stretch may activate phospholipase A2, which hydrolyzes membrane phospholipids to ultimately produce AA; AA as a second messenger mediates Ca2+ influx, which triggers Ca2+-induced Ca2+ release and elicits activation of IK(Ca) in gastric antral circular myocytes of the guinea pig.

  18. Vitamin D does not increase calcium absorption in young women: a randomized clinical trial.

    Science.gov (United States)

    Gallagher, J Christopher; Jindal, Prachi S; Smith, Lynette M

    2014-01-01

    It is commonly said that vitamin D should be used to increase calcium absorption. We tested this statement in a dose-response study of vitamin D on calcium absorption. A total of 198 white and African American women, aged 25 to 45 years, with vitamin D insufficiency, serum 25-hydroxyvitamin D (25OHD) ng/mL, were randomized in a double-blind study to vitamin D3 400, 800, 1600, 2400 IU, or placebo. A calcium supplement was given to increase mean calcium intake at baseline from 706 mg/d to 1031 mg/d. Calcium absorption was measured at baseline and after 12 months using a single isotope method with radiocalcium45 and 100 mg of calcium. Mean baseline serum 25OHD was 13.4 ng/mL (33.5 nmol/L) and increased to 40 ng/mL (100 nmol/L) on the highest dose of 2400 IU. Using a multivariate regression analysis with significant predictors, baseline absorption, calcium intake, and weight, there was no increase in 12-month calcium absorption compared with baseline on any dose of vitamin D in either whites or African Americans. There was no significant relationship between 12-month calcium absorption and final serum 25OHD. In an analysis of calcium absorption and serum 25OHD at baseline, serum 25OHD levels were divided into groups: 0 to 5, 6 to 10, 11 to 15, or 16 to 20 ng/mL. There was no evidence of a threshold decrease in calcium absorption or serum 1,25 dihydroxyvitamin D (1,25(OH)2 D) amongst the lowest groups. Vitamin D doses up to 2400 IU daily did not increase calcium absorption. No threshold level of serum 25OHD for calcium absorption was found at baseline or in the longitudinal study, suggesting that active transport of calcium is saturated at very low serum 25OHD levels ng/mL. There is no need to recommend vitamin D for increasing calcium absorption in normal subjects. Very efficient calcium absorption at very low levels of serum 25OHD explains why people do not develop osteomalacia provided that dietary intakes of calcium and phosphorus are adequate. PMID

  19. Calcium signaling and mitochondrial destabilization in the triggering of the NLRP3 inflammasome.

    Science.gov (United States)

    Horng, Tiffany

    2014-06-01

    The NLRP3 inflammasome is a cytosolic complex that activates Caspase-1, leading to maturation of interleukin-1β (IL-1β) and IL-18 and induction of proinflammatory cell death in sentinel cells of the innate immune system. Diverse stimuli have been shown to activate the NLRP3 inflammasome during infection and metabolic diseases, implicating the pathway in triggering both adaptive and maladaptive inflammation in various clinically important settings. Here I discuss the emerging model that signals associated with mitochondrial destabilization may critically activate the NLRP3 inflammasome. Together with studies indicating an important role for Ca2+ signaling, these findings suggest that many stimuli engage Ca2+ signaling as an intermediate step to trigger mitochondrial destabilization, generating the mitochondrion-associated ligands that activate the NLRP3 inflammasome.

  20. Vitamin D is positively associated with sperm motility and increases intracellular calcium in human spermatozoa

    DEFF Research Database (Denmark)

    Blomberg Jensen, Martin; Bjerrum, Poul J; Jessen, Torben E;

    2011-01-01

    BACKGROUND The vitamin D receptor (VDR) is expressed in human spermatozoa, and VDR-knockout mice and vitamin D (VD) deficiency in rodents results in impaired fertility, low sperm counts and a low number of motile spermatozoa. We investigated the role of activated VD (1,25(OH)(2)D(3)) in human...... spermatozoa and whether VD serum levels are associated with semen quality. METHODS Cross-sectional association study of semen quality and VD serum level in 300 men from the general population, and in vitro studies on spermatozoa from 40 men to investigate the effects of VD on intracellular calcium, sperm......M). 1,25(OH)(2)D(3) increased intracellular calcium concentration in human spermatozoa through VDR-mediated calcium release from an intracellular calcium storage, increased sperm motility and induced the acrosome reaction in vitro. CONCLUSIONS 1,25(OH)(2)D(3) increased intracellular calcium...

  1. Trigger Finger Appearing as Gradually Increasing Digital Nerve Disorder after Surgical Treatment

    Directory of Open Access Journals (Sweden)

    Hiroyuki Tsuchie

    2013-01-01

    Full Text Available Trigger finger is a common disease, and operative treatments are often applied for it. Digital nerve injury is one of the complications of this surgical treatment, and paresthesia and sensory disturbance occur early after the operation. This paper presents a case of trigger finger appearing gradually as increasing digital nerve disorder after surgical treatment. In the second surgery, scar tissue covered the palmar MP joint where the A1 pulley had existed before, and palmar digital neurovascular tissue of the ulnar side was found on the inside of the scar. The ulnar digital nerve showed swelling like a neuroma, and bilateral digital nerves existed nearer to the center of the flexor pollicis longus tendon than normal digital nerves. Even when we operate on trigger finger by open release, we should create an appropriate surgical space for observation and be careful of digital nerve injury.

  2. Model Vestibular Nuclei Neurons Can Exhibit a Boosting Nonlinearity Due to an Adaptation Current Regulated by Spike-Triggered Calcium and Calcium-Activated Potassium Channels

    Science.gov (United States)

    Schneider, Adam D.

    2016-01-01

    In vitro studies have previously found a class of vestibular nuclei neurons to exhibit a bidirectional afterhyperpolarization (AHP) in their membrane potential, due to calcium and calcium-activated potassium conductances. More recently in vivo studies of such vestibular neurons were found to exhibit a boosting nonlinearity in their input-output tuning curves. In this paper, a Hodgkin-Huxley (HH) type neuron model, originally developed to reproduce the in vitro AHP, is shown to produce a boosting nonlinearity similar to that seen in vivo for increased the calcium conductance. Indicative of a bifurcation, the HH model is reduced to a generalized integrate-and-fire (IF) model that preserves the bifurcation structure and boosting nonliearity. By then projecting the neuron model’s phase space trajectories into 2D, the underlying geometric mechanism relating the AHP and boosting nonlinearity is revealed. Further simplifications and approximations are made to derive analytic expressions for the steady steady state firing rate as a function of bias current, μ, as well as the gain (i.e. its slope) and the position of its peak at μ = μ*. Finally, although the boosting nonlinearity has not yet been experimentally observed in vitro, testable predictions indicate how it might be found. PMID:27427914

  3. Model Vestibular Nuclei Neurons Can Exhibit a Boosting Nonlinearity Due to an Adaptation Current Regulated by Spike-Triggered Calcium and Calcium-Activated Potassium Channels.

    Science.gov (United States)

    Schneider, Adam D

    2016-01-01

    In vitro studies have previously found a class of vestibular nuclei neurons to exhibit a bidirectional afterhyperpolarization (AHP) in their membrane potential, due to calcium and calcium-activated potassium conductances. More recently in vivo studies of such vestibular neurons were found to exhibit a boosting nonlinearity in their input-output tuning curves. In this paper, a Hodgkin-Huxley (HH) type neuron model, originally developed to reproduce the in vitro AHP, is shown to produce a boosting nonlinearity similar to that seen in vivo for increased the calcium conductance. Indicative of a bifurcation, the HH model is reduced to a generalized integrate-and-fire (IF) model that preserves the bifurcation structure and boosting nonliearity. By then projecting the neuron model's phase space trajectories into 2D, the underlying geometric mechanism relating the AHP and boosting nonlinearity is revealed. Further simplifications and approximations are made to derive analytic expressions for the steady steady state firing rate as a function of bias current, μ, as well as the gain (i.e. its slope) and the position of its peak at μ = μ*. Finally, although the boosting nonlinearity has not yet been experimentally observed in vitro, testable predictions indicate how it might be found. PMID:27427914

  4. Therapy for triggered acute risk prevention in subjects at increased cardiovascular risk.

    Science.gov (United States)

    Tofler, Geoffrey H; Spinaze, Monica; Shaw, Elizabeth; Buckley, Thomas

    2013-06-15

    Heavy physical exertion, emotional stress, heavy meals, and respiratory infection transiently increase the risk of myocardial infarction, sudden cardiac death, and stroke; however, it remains uncertain how to use this information for disease prevention. We determined whether it was feasible for those with either risk factors for cardiovascular disease (CVD) or known CVD to take targeted medication for the hazard duration of the triggering activity to reduce their risk. After a run-in of 1 month, 20 subjects (12 women and 8 men) aged 68.6 years (range 58 to 83) recorded for 2 months all episodes of physical and emotional stress, heavy meal consumption, and respiratory infection. For each episode, the subjects were instructed to take either aspirin 100 mg and propranolol 10 mg (for physical exertion and emotional stress) or aspirin 100 mg alone (for respiratory infection and heavy meal consumption) and to record their adherence. Adherence with taking the appropriate medication was 86% according to the diary entries, with 15 of 20 subjects (75%) achieving ≥80% adherence. Propranolol taken before exertion reduced the peak heart rate compared with similar exercise during the run-in period (118 ± 21 vs 132 ± 16 beats/min, p = 0.016). Most subjects (85%) reported that it was feasible to continue taking the medication in this manner. In conclusion, it is feasible for those with increased CVD risk to identify potential triggers of acute CVD and to take targeted therapy at the time of these triggers.

  5. Imaging the recruitment and loss of proteins and lipids at single sites of calcium-triggered exocytosis.

    Science.gov (United States)

    Trexler, Adam J; Sochacki, Kem A; Taraska, Justin W

    2016-08-01

    How and when the dozens of molecules that control exocytosis assemble in living cells to regulate the fusion of a vesicle with the plasma membrane is unknown. Here we image with two-color total internal reflection fluorescence microscopy the local changes of 27 proteins at single dense-core vesicles undergoing calcium-triggered fusion. We identify two broad dynamic behaviors of exocytic molecules. First, proteins enriched at exocytic sites are associated with DCVs long before exocytosis, and near the time of membrane fusion, they diffuse away. These proteins include Rab3 and Rab27, rabphilin3a, munc18a, tomosyn, and CAPS. Second, we observe a group of classical endocytic proteins and lipids, including dynamins, amphiphysin, syndapin, endophilin, and PIP2, which are rapidly and transiently recruited to the exocytic site near the time of membrane fusion. Dynamin mutants unable to bind amphiphysin were not recruited, indicating that amphiphysin is involved in localizing dynamin to the fusion site. Expression of mutant dynamins and knockdown of endogenous dynamin altered the rate of cargo release from single vesicles. Our data reveal the dynamics of many key proteins involved in exocytosis and identify a rapidly recruited dynamin/PIP2/BAR assembly that regulates the exocytic fusion pore of dense-core vesicles in cultured endocrine beta cells. PMID:27307587

  6. Acetate transiently inhibits myocardial contraction by increasing mitochondrial calcium uptake

    OpenAIRE

    Schooley, James F.; Namboodiri, Aryan M.A.; Cox, Rachel T.; Bünger, Rolf; Flagg, Thomas P

    2014-01-01

    Background There is a close relationship between cardiovascular disease and cardiac energy metabolism, and we have previously demonstrated that palmitate inhibits myocyte contraction by increasing Kv channel activity and decreasing the action potential duration. Glucose and long chain fatty acids are the major fuel sources supporting cardiac function; however, cardiac myocytes can utilize a variety of substrates for energy generation, and previous studies demonstrate the acetate is rapidly ta...

  7. Plum and soy aglycon extracts superior at increasing bone calcium retention in ovariectomized Sprague Dawley rats.

    Science.gov (United States)

    Pawlowski, Jessica W; Martin, Berdine R; McCabe, George P; Ferruzzi, Mario G; Weaver, Connie M

    2014-07-01

    Plant-derived polyphenols have been shown to influence bone turnover and bone properties in the estrogen-depleted state. We used a crossover design in ovariectomized rats (n = 16 rats for each diet) to investigate the effect of supplementation of two doses each of blueberry, plum, grape, grape seed extract, and resveratrol on bone. We tested the aglycon and glucoside forms of genistein to quantify differences in efficacy on bone calcium retention. Rats were given an intravenous dose of ⁴⁵Ca to prelabel bone, and bone calcium retention was assessed by urinary excretion of ⁴⁵Ca:Ca ratio during an intervention period compared with nonintervention. Genistein aglycon increased bone calcium retention significantly (pcalcium retention by 20% (p=0.0153) and 14% (p=0.0012), respectively. Several polyphenolic-rich diets improved bone calcium retention.

  8. Nondigestible oligosaccharides increase calcium absorption and suppress bone resorption in ovariectomized rats.

    Science.gov (United States)

    Zafar, Tasleem A; Weaver, Connie M; Zhao, Yongdong; Martin, Berdine R; Wastney, Meryl E

    2004-02-01

    Nondigestible oligosaccharides (NDO) including inulin and fructooligosaccharides (FOS) have been reported to stimulate calcium absorption. Here we report the effect of a mixture of inulin and FOS (Raftilose Synergy 1, Orafti) on calcium and bone metabolism in ovariectomized (OVX) rats. OVX rats (6 mo old) were fed a semipurified diet for 3 mo in our animal care laboratory for stabilization after ovariectomy. They were then divided into two groups (n = 13/group) and fed either a control or a NDO-supplemented diet (55 g/kg) for 21 d. Catheters were placed in their jugular veins. After 2 d, a tracer ((45)Ca) was administered by gavage or i.v. and blood was sampled for up to 300 min. Urine and fecal samples were collected for 4 d after (45)Ca administration. Femurs were measured for bone mineral density (BMD), breaking strength, and total calcium. Calcium absorption, femoral calcium content, BMD, and bone balance (V(bal)) were significantly increased (P calcium absorption and retention in ovariectomized rats.

  9. Altered ATP-sensitive potassium channels may underscore obesity-triggered increase in blood pressure

    Institute of Scientific and Technical Information of China (English)

    Li-hong FAN; Hong-yan TIAN; Ai-qun MA; Zhi HU; Jian-hua HUO; Yong-xiao CAO

    2008-01-01

    Aim:To determine whether ATP-sensitive potassium channels are altered in VSMC from arotas and mesenteric arteries of obese rat,and their association with obesity-triggered increase in blood pressure.Methods:Obesity was induced by 24 weeks of high-fat diet feeding in male Sprague-Dawley rats.Control rats were fed with standard laboratory rat chow.Blood pressure and body weight of these rats were measured every 4 weeks.At the end of 24 weeks,KATP channel-mediated relaxation responses in the aortas and mesenteric arteries,KATP channel current,and gene expression were examined,respectively.Results:Blood pres-sure and body weight were increased in rats fed with high-fat diet.KATP channel-mediated relaxation responses,currents,and KATP expression in VSMC of both aortas and mesenteric arteries were inhibited in these rats.Conclusion:Altered ATP-sensitive potassium channels in obese rats may underscore obesity-triggered increase in blood pressure.

  10. Increasing serotonin concentrations alter calcium and energy metabolism in dairy cows.

    Science.gov (United States)

    Laporta, Jimena; Moore, Spencer A E; Weaver, Samantha R; Cronick, Callyssa M; Olsen, Megan; Prichard, Austin P; Schnell, Brian P; Crenshaw, Thomas D; Peñagaricano, Francisco; Bruckmaier, Rupert M; Hernandez, Laura L

    2015-07-01

    A 4×4 Latin square design in which varied doses (0, 0.5, 1.0, and 1.5 mg/kg) of 5-hydroxy-l-tryptophan (5-HTP, a serotonin precursor) were intravenously infused into late-lactation, non-pregnant Holstein dairy cows was used to determine the effects of serotonin on calcium and energy metabolism. Infusion periods lasted 4 days, with a 5-day washout between periods. Cows were infused at a constant rate for 1 h each day. Blood was collected pre- and 5, 10, 30, 60, 90, and 120 min post-infusion, urine was collected pre- and post-infusion, and milk was collected daily. All of the 5-HTP doses increased systemic serotonin as compared to the 0 mg/kg dose, and the 1.0 and 1.5 mg/kg doses increased circulating glucose and non-esterified fatty acids (NEFA) and decreased beta-hydroxybutyrate (βHBA) concentrations. Treatment of cows with either 1.0 or 1.5 mg/kg 5-HTP doses decreased urine calcium elimination, and the 1.5 mg/kg dose increased milk calcium concentrations. No differences were detected in the heart rates, respiration rates, or body temperatures of the cows; however, manure scores and defecation frequency were affected. Indeed, cows that received 5-HTP defecated more, and the consistency of their manure was softer. Treatment of late-lactation dairy cows with 5-HTP improved energy metabolism, decreased loss of calcium into urine, and increased calcium secretion into milk. Further research should target the effects of increasing serotonin during the transition period to determine any benefits for post-parturient calcium and glucose metabolism. PMID:26099356

  11. An automatic machine learning system for coronary calcium scoring in clinical non-contrast enhanced, ECG-triggered cardiac CT

    Science.gov (United States)

    Wolterink, Jelmer M.; Leiner, Tim; Takx, Richard A. P.; Viergever, Max A.; Išgum, Ivana

    2014-03-01

    Presence of coronary artery calcium (CAC) is a strong and independent predictor of cardiovascular events. We present a system using a forest of extremely randomized trees to automatically identify and quantify CAC in routinely acquired cardiac non-contrast enhanced CT. Candidate lesions the system could not label with high certainty were automatically identified and presented to an expert who could relabel them to achieve high scoring accuracy with minimal effort. The study included 200 consecutive non-contrast enhanced ECG-triggered cardiac CTs (120 kV, 55 mAs, 3 mm section thickness). Expert CAC annotations made as part of the clinical routine served as the reference standard. CAC candidates were extracted by thresholding (130 HU) and 3-D connected component analysis. They were described by shape, intensity and spatial features calculated using multi-atlas segmentation of coronary artery centerlines from ten CTA scans. CAC was identified using a randomized decision tree ensemble classifier in a ten-fold stratified cross-validation experiment and quantified in Agatston and volume scores for each patient. After classification, candidates with posterior probability indicating uncertain labeling were selected for further assessment by an expert. Images with metal implants were excluded. In the remaining 164 images, Spearman's p between automatic and reference scores was 0.94 for both Agatston and volume scores. On average 1.8 candidate lesions per scan were subsequently presented to an expert. After correction, Spearman's p was 0.98. We have described a system for automatic CAC scoring in cardiac CT images which is able to effectively select difficult examinations for further refinement by an expert.

  12. Increased pressure from rising bubbles as a mechanism for remotely triggered seismicity

    Science.gov (United States)

    Linde, A.T.; Sacks, I.S.; Johnston, M.J.S.; Hill, D.P.; Bilham, R.G.

    1994-01-01

    Aftershocks of large earthquakes tend to occur close to the main rupture zone, and can be used to constrain its dimensions. But following the 1992 Landers earthquake (magnitude M(w) = 7.3) in southern California, many aftershocks were reported in areas remote from the mainshock. Intriguingly, this remote seismicity occurred in small clusters near active volcanic and geothermal systems. For one of these clusters (Long Valley, about 400 km from the Landers earthquake), crustal deformation associated with the seismic activity was also monitored. Here we argue that advective overpressure provides a viable mechanism for remote seismicity triggered by the Landers earthquake. Both the deformation and seismicity data are consistent with pressure increases owing to gas bubbles rising slowly within a volume of magma. These bubbles may have been shaken loose during the passage of seismic waves generated by the mainshock.

  13. Increase of a Calcium Independent Transglutaminase Activity in the Erythrocyte during the Infection with Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Wasserman Moisés

    1999-01-01

    Full Text Available We have studied the activity of a calcium dependent transglutaminase (EC 2.3.2.13 during the growth of the parasite Plasmodium falciparum inside the infected human erythrocyte. There is only one detectable transglutaminase in the two-cell-system, and its origin is erythrocytic. No activity was detected in preparations of the parasite devoid of erythrocyte cytoplasm. The Michaelis Menten constants (Km of the enzyme for the substrates N'N'dimethylcaseine and putrescine were undistinguishable whether the cell extracts used in their determination were obtained from normal or from infected red cells. The total activity of transglutaminase in stringently synchronized cultures, measured at 0.5mM Ca2+, decreased with the maturation of the parasite. However, a fraction which became irreversibly activated and independent of calcium concentration was detected. The proportion of this fraction grew with maturation; it represented only 20% of the activity in 20 hr-old-trophozoites while in 48-hr-schizonts it was more than 85% of the total activity. The activation of this fraction of transglutaminase did not depend on an increase in the erythrocyte cytoplasmic calcium, since most of the calcium was shown to be located in the parasite.

  14. Calcium gluconate in phosphate buffered saline increases gene delivery with adenovirus type 5.

    Directory of Open Access Journals (Sweden)

    Marko T Ahonen

    Full Text Available BACKGROUND: Adenoviruses are attractive vectors for gene therapy because of their stability in vivo and the possibility of production at high titers. Despite exciting preclinical data with various approaches, there are only a few examples of clear efficacy in clinical trials. Effective gene delivery to target cells remains the key variable determining efficacy and thus enhanced transduction methods are important. METHODS/RESULTS: We found that heated serum could enhance adenovirus 5 mediated gene delivery up to twentyfold. A new protein-level interaction was found between fiber knob and serum transthyretin, but this was not responsible for the observed effect. Instead, we found that heating caused the calcium and phosphate present in the serum mix to precipitate, and this was responsible for enhanced gene delivery. This finding could have relevance for designing preclinical experiments with adenoviruses, since calcium and phosphate are present in many solutions. To translate this into an approach potentially testable in patients, we used calcium gluconate in phosphate buffered saline, both of which are clinically approved, to increase adenoviral gene transfer up to 300-fold in vitro. Gene transfer was increased with or without heating and in a manner independent from the coxsackie-adenovirus receptor. In vivo, in mouse studies, gene delivery was increased 2-, 110-, 12- and 13-fold to tumors, lungs, heart and liver and did not result in increased pro-inflammatory cytokine induction. Antitumor efficacy of a replication competent virus was also increased significantly. CONCLUSION: In summary, adenoviral gene transfer and antitumor efficacy can be enhanced by calcium gluconate in phosphate buffered saline.

  15. Calcium Gluconate in Phosphate Buffered Saline Increases Gene Delivery with Adenovirus Type 5

    Science.gov (United States)

    Ahonen, Marko T.; Diaconu, Iulia; Pesonen, Sari; Kanerva, Anna; Baumann, Marc; Parviainen, Suvi T.; Spiller, Brad

    2010-01-01

    Background Adenoviruses are attractive vectors for gene therapy because of their stability in vivo and the possibility of production at high titers. Despite exciting preclinical data with various approaches, there are only a few examples of clear efficacy in clinical trials. Effective gene delivery to target cells remains the key variable determining efficacy and thus enhanced transduction methods are important. Methods/Results We found that heated serum could enhance adenovirus 5 mediated gene delivery up to twentyfold. A new protein-level interaction was found between fiber knob and serum transthyretin, but this was not responsible for the observed effect. Instead, we found that heating caused the calcium and phosphate present in the serum mix to precipitate, and this was responsible for enhanced gene delivery. This finding could have relevance for designing preclinical experiments with adenoviruses, since calcium and phosphate are present in many solutions. To translate this into an approach potentially testable in patients, we used calcium gluconate in phosphate buffered saline, both of which are clinically approved, to increase adenoviral gene transfer up to 300-fold in vitro. Gene transfer was increased with or without heating and in a manner independent from the coxsackie-adenovirus receptor. In vivo, in mouse studies, gene delivery was increased 2-, 110-, 12- and 13-fold to tumors, lungs, heart and liver and did not result in increased pro-inflammatory cytokine induction. Antitumor efficacy of a replication competent virus was also increased significantly. Conclusion In summary, adenoviral gene transfer and antitumor efficacy can be enhanced by calcium gluconate in phosphate buffered saline. PMID:20927353

  16. Analysis of Seismicity Risk Increase Triggered by Longtan Reservoir, China, Using a Fully Coupled Poroelastic Model

    Science.gov (United States)

    Deng, K.; Zhang, S.; Guo, Y.; Zhou, S.; Liu, Y.

    2015-12-01

    Impoundment of reservoirs can lead to increase in crustal pore pressure and Coulomb stress, and promotes nearby faults to fail. Abnormal seismicity increase around reservoir is often thought to be triggered by the water impounded behind the dam. In this study, we analyze the impact of Longtan reservoir in Guangxi province, southwest China, on local seismicity, which has increased significantly since the initial impoundment in October, 2006. Most of the earthquakes cluster around the reservoir according to local seismic network and CEA reports, and the greatest earthquake is of magnitude 4.2. We introduce an improved Bayesian method to show that the temporal variation of b-value is inversely correlated with the seasonal fluctuation of reservoir water level. Upon extracting background seismicity using the Epidemic Type Aftershock Sequence (ETAS) model, we show that background seismicity variation is highly related to the filling rate and volume We further investigate the mechanism of seismicity increase and reservoir impoundment by performing a fully coupled 3-D poroelastic model with the reservoir loading history as a dynamic boundary condition. An optimally oriented fault plane is chosen according to the regional stress field and GPS deformation data when calculating the induced Coulomb stress. Our results demonstrate that most earthquakes occurred within positive Coulomb stress regime, and the seismicity rate is highly related to the rate of pore pressure increase. In the next step we plan to apply the coupled poroelastic model to understand hydraulic fracturing induced earthquakes in shale gas exploration, such as the recent Fox Creek event cluster, in the western Canada sedimentary basin.

  17. Comparative Detection of Calcium Fluctuations in Single Female Sex Cells of Tobacco to Distinguish Calcium Signals Triggered by in vitro Fertilization

    Institute of Scientific and Technical Information of China (English)

    Xiong-Bo Peng; Meng-Xiang Sun; Hong-Yuan Yang

    2009-01-01

    Double fertilization is a key process of sexual reproduction in higher plants. The role of calcium In the activation of female sex cells through fertilization has recently received a great deal of attention. The establishment of a Ca-imaging technique for living, single, female sex cells is a difficult but necessary prerequisite for evaluating the role of Ca in the transduction of external stimuli, including the fusion with the sperm cell, to internal cellular processes. The present study describes the use of Fluo-3 for reporting the Ca signal in isolated, single, female sex cells, egg cells and central cells, of tobacco plants. A suitable loading protocol was optimized by loading the cells at pH 5.6 with 2 μM Fluo-3 for 30 min at 30℃. Under theseconditions, several key factors related to in vitro fertilization were also investigated in order to test their possible effects onthe [Ca] of the female sex cells. The results indicated that the bovine serum albumin-fusion system was superior to the polyethlene glycol.fusion system for detecting calcium fluctuations in female sex cells during fertilization. The central cell was fertilized with the sperm cell in bovine serum albumin; however, no evident calcium dynamic was detected, implying that a transient calcium rise might be a specific signal for egg cell fertilization.

  18. Formaldehyde increases intracellular calcium concentration in primary cultured hippocampal neurons partly through NMDA receptors and T-type calcium channels

    Institute of Scientific and Technical Information of China (English)

    Ye-Nan Chi; Xu Zhang; Jie Cai; Feng-Yu Liu; Guo-Gang Xing; You Wan

    2012-01-01

    Objective Formaldehyde at high concentrations is a contributor to air pollution.It is also an endogenous metabolic product in cells,and when beyond physiological concentrations,has pathological effects on neurons.Formaldehyde induces mis-folding and aggregation of neuronal tau protein,hippocampal neuronal apoptosis,cognitive impairment and loss of memory functions,as well as excitation of peripheral nociceptive neurons in cancer pain models.Intracellular calcium ([Ca2+]i) is an important intracellular messenger,and plays a key role in many pathological processes.The present study aimed to investigate the effect of formaldehyde on [Ca2+]i and the possible involvement of N-methyl-D-aspartate receptors (NMDARs) and T-type Ca2+ channels on the cell membrane.Methods Using primary cultured hippocampal neurons as a model,changes of [Ca2+]i in the presence of formaldehyde at a low concentration were detected by confocal laser scanning microscopy.Results Formaldehyde at 1 mmol/L approximately doubled [Ca2+]i.(2R)-amino-5-phosphonopentanoate (AP5,25 μtmol/L,an NMDAR antagonist) and mibefradil (MIB,1 μtmol/L,a T-type Ca2+ channel blocker),given 5 min after formaldehyde perfusion,each partly inhibited the formaldehyde-induced increase of [Ca2+]i,and this inhibitory effect was reinforced by combined application of AP5 and MIB.When applied 3 min before formaldehyde perfusion,AP5 (even at 50 μmol/L) did not inhibit the formaldehyde-induced increase of [Ca2+]i,but MIB (1 μmol/L) significantly inhibited this increase by 70%.Conclusion These results suggest that formaldehyde at a low concentration increases [Ca2+]i in cultured hippocampal neurons; NMDARs and T-type Ca2+ channels may be involved in this process.

  19. Activation of calcium-sensing receptor increases TRPC3 expression in rat cardiomyocytes

    International Nuclear Information System (INIS)

    Research highlights: → Calcium-sensing receptor (CaR) activation stimulates TRP channels. → CaR promoted transient receptor potential C3 (TRPC3) expression. → Adult rat ventricular myocytes display capacitative calcium entry (CCE), which was operated by TRPCs. → TRPC channels activation induced by CaR activator sustained the increased [Ca2+]i to evoke cardiomyocytes apoptosis. -- Abstract: Transient receptor potential (TRP) channels are expressed in cardiomyocytes, which gate a type of influx of extracellular calcium, the capacitative calcium entry. TRP channels play a role in mediating Ca2+ overload in the heart. Calcium-sensing receptors (CaR) are also expressed in rat cardiac tissue and promote the apoptosis of cardiomyocytes by Ca2+ overload. However, data about the link between CaR and TRP channels in rat heart are few. In this study, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting were used to examine the expression of the TRP canonical proteins TRPC1 and TRPC3 in adult and neonatal rat cardiomyocytes. Laser scan confocal microscopy was used to detect intracellular [Ca2+]i levels in isolated adult rat ventricular myocytes. The results showed that, in adult rat cardiomyocytes, the depletion of Ca2+ stores in the endoplasmic/sarcoplasmic reticulum (ER/SR) by thapsigargin induced a transient increase in [Ca2+]i in the absence of [Ca2+]o and the subsequent restoration of [Ca2+]o sustained the increased [Ca2+]i for a few minutes, whereas, the persisting elevation of [Ca2+]i was reduced in the presence of the TRPC inhibitor SKF96365. The stimulation of CaR by its activator gadolinium chloride (GdCl3) or spermine also resulted in the same effect and the duration of [Ca2+]i increase was also shortened in the absence of [Ca2+]o. In adult and neonatal rat cardiomyocytes, GdCl3 increased the expression of TRPC3 mRNA and protein, which were reversed by SKF96365 but not by inhibitors of the L-type channels and the Na+/Ca2+ exchangers

  20. Activation of calcium-sensing receptor increases TRPC3 expression in rat cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shan-Li [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China); Sun, Ming-Rui [Department of Pharmacology, Qiqihaer Medical College, Qiqihaer 160001 (China); Li, Ting-Ting; Yin, Xin [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China); Xu, Chang-Qing [Department of Pathophysiology, Harbin Medical University, Harbin 150086 (China); Sun, Yi-Hua, E-mail: syh200415@126.com [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China)

    2011-03-11

    Research highlights: {yields} Calcium-sensing receptor (CaR) activation stimulates TRP channels. {yields} CaR promoted transient receptor potential C3 (TRPC3) expression. {yields} Adult rat ventricular myocytes display capacitative calcium entry (CCE), which was operated by TRPCs. {yields} TRPC channels activation induced by CaR activator sustained the increased [Ca{sup 2+}]{sub i} to evoke cardiomyocytes apoptosis. -- Abstract: Transient receptor potential (TRP) channels are expressed in cardiomyocytes, which gate a type of influx of extracellular calcium, the capacitative calcium entry. TRP channels play a role in mediating Ca{sup 2+} overload in the heart. Calcium-sensing receptors (CaR) are also expressed in rat cardiac tissue and promote the apoptosis of cardiomyocytes by Ca{sup 2+} overload. However, data about the link between CaR and TRP channels in rat heart are few. In this study, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting were used to examine the expression of the TRP canonical proteins TRPC1 and TRPC3 in adult and neonatal rat cardiomyocytes. Laser scan confocal microscopy was used to detect intracellular [Ca{sup 2+}]{sub i} levels in isolated adult rat ventricular myocytes. The results showed that, in adult rat cardiomyocytes, the depletion of Ca{sup 2+} stores in the endoplasmic/sarcoplasmic reticulum (ER/SR) by thapsigargin induced a transient increase in [Ca{sup 2+}]{sub i} in the absence of [Ca{sup 2+}]{sub o} and the subsequent restoration of [Ca{sup 2+}]{sub o} sustained the increased [Ca{sup 2+}]{sub i} for a few minutes, whereas, the persisting elevation of [Ca{sup 2+}]{sub i} was reduced in the presence of the TRPC inhibitor SKF96365. The stimulation of CaR by its activator gadolinium chloride (GdCl{sub 3}) or spermine also resulted in the same effect and the duration of [Ca{sup 2+}]{sub i} increase was also shortened in the absence of [Ca{sup 2+}]{sub o}. In adult and neonatal rat cardiomyocytes, GdCl{sub 3

  1. Infrared laser pulse triggers increased singlet oxygen production in tumour cells

    Science.gov (United States)

    Sokolovski, S. G.; Zolotovskaya, S. A.; Goltsov, A.; Pourreyron, C.; South, A. P.; Rafailov, E. U.

    2013-12-01

    Photodynamic therapy (PDT) is a technique developed to treat the ever-increasing global incidence of cancer. This technique utilises singlet oxygen (1O2) generation via a laser excited photosensitiser (PS) to kill cancer cells. However, prolonged sensitivity to intensive light (6-8 weeks for lung cancer), relatively low tissue penetration by activating light (630 nm up to 4 mm), and the cost of PS administration can limit progressive PDT applications. The development of quantum-dot laser diodes emitting in the highest absorption region (1268 nm) of triplet oxygen (3O2) presents the possibility of inducing apoptosis in tumour cells through direct 3O2 --> 1O2 transition. Here we demonstrate that a single laser pulse triggers dose-dependent 1O2 generation in both normal keratinocytes and tumour cells and show that tumour cells yield the highest 1O2 far beyond the initial laser pulse exposure. Our modelling and experimental results support the development of direct infrared (IR) laser-induced tumour treatment as a promising approach in tumour PDT.

  2. GABA(A) Increases Calcium in Subventricular Zone Astrocyte-Like Cells Through L- and T-Type Voltage-Gated Calcium Channels

    DEFF Research Database (Denmark)

    Young, Stephanie Z; Platel, Jean-Claude; Nielsen, Jakob V;

    2010-01-01

    induced Ca(2+) increases in 40-50% of SVZ astrocytes. GABA(A)-induced Ca(2+) increases were prevented with nifedipine and mibefradil, blockers of L- and T-type voltage-gated calcium channels (VGCC). The L-type Ca(2+) channel activator BayK 8644 increased the percentage of GABA(A)-responding astrocyte...

  3. Cumulative Stressors Trigger Increased Vulnerability of Diatom Communities to Additional Disturbances.

    Science.gov (United States)

    Morin, Soizic; Bonet, Berta; Corcoll, Natàlia; Guasch, Helena; Bottin, Marius; Coste, Michel

    2015-10-01

    Chronic, non-lethal stressors occurring gradually (in space or time) can result in cumulative impacts that are more dramatic than higher intensities or occasional critical levels of any single one of these stressors. The negative effects of the chronic stressors trigger lasting impacts that may grow in intensity and become problematic over time and/or to higher trophic levels. In rivers, aquatic organisms experience this type of cumulative stress along the up- to downstream gradient in natural and anthropogenic contaminants generally observed in inhabited watersheds. Diatoms are a major component of the periphyton in rivers; their richness and diversity in natural communities are directly related to their varied ecological preferences and sensitivity to disturbance. In this study, we monitored from 2003 to 2008 the changes in the diversity of taxonomic and non-taxonomic features along a small river (Riou-Mort, South West France), at three sites: one site upstream considered as a reference for this watershed, one intermediate site with high nutrient load, and one downstream site exposed to both nutrient and metal pollution. The cumulative impacts of nutrients plus metals led to a gradual decrease in species richness and diversity, and in a potential capacity to cope with additional stresses, e.g., climate change-related ones. This is reflected by a decrease in species richness downstream, more dramatic in the hot summer of 2003 than in cooler summers. With the increasingly protective environmental regulations (e.g., Water Framework Directive in Europe), accumulation of stresses on aquatic resources are recommended to receive increasing attention, in particular considering the expected changes in climate.

  4. The mountains that triggered the Late Neoproterozoic increase in oxygen: The Second Great Oxidation Event

    Science.gov (United States)

    Campbell, Ian H.; Squire, Richard J.

    2010-08-01

    supermountains were higher than those produced during the assembly of earlier supercontinents and that rapid erosion of these mountains released a large flux of essential nutrients, including Fe and P, into the rivers and oceans, which triggered an explosion of algae and cyanobacteria. This, in turn, produced a marked increase in the production rate of photosynthetic O 2. Rapid sedimentation during this period promoted high rates of burial of biogenic pyrite and organic matter generated during photosynthesis so that they could not back react with O 2, leading to a sustained increase in atmospheric O 2.

  5. ORALLY LACTATE CALCIUM AND SWIMMING DECREASE OSTEOCLAST AND INCREASE OSTEOBLAST IN RADIAL PERIMENOPAUSAL MICE (MUS MUSCULUS BONE

    Directory of Open Access Journals (Sweden)

    Muliani **

    2013-04-01

    Full Text Available Calcium and moderate intensity swimming exercise can increase bone density. The aim of this research is to see the effect of orally calcium consumption and swimming activity to decrease osteoclast and increase osteoblast in radial perimenopausal mice (Mus musculus bone. Pretest and pos#est control group design was used in this research. Research subject used 15-16 aged mice (Mus musculus which divided into 4 groups (each group consisted of 13 mice, that was control, lactate calcium, swimming and lactate calcium and swimming. Treatment was given 90 days. This study showed a significant difference of the mean of the pos#est osteoblast between control and experimental groups (P<0.05. There was no significant difference between lactate calcium and swimming groups (P>0.05. Enhancement of osteoblast mean in combination group was greater than the other experimental groups. There was a significant difference of the mean of the pos#est  osteoclast between control and experimental groups (P<0.05, without significant difference between lactate calcium,   swimming groups and combination of lactate calcium and swimming group (P>0.05.  Conclusion: either lactate calcium or swimming decreases osteoclast and increases osteoblast of the mice but the osteoblast enhancement will be bigger when they are given together at once

  6. Proteolysis of the human DNA polymerase delta smallest subunit p12 by μ-calpain in calcium-triggered apoptotic HeLa cells.

    Directory of Open Access Journals (Sweden)

    Xiaoting Fan

    Full Text Available Degradation of p12 subunit of human DNA polymerase delta (Pol δ that results in an interconversion between Pol δ4 and Pol δ3 forms plays a significant role in response to replication stress or genotoxic agents triggered DNA damage. Also, the p12 is readily degraded by human calpain in vitro. However, little has been done for the investigation of its degree of participation in any of the more common apoptosis. Here, we first report that the p12 subunit is a substrate of μ-calpain. In calcium-triggered apoptotic HeLa cells, the p12 is degraded at 12 hours post-induction (hpi, restored thereafter by 24 hpi, and then depleted again after 36 hpi in a time-dependent manner while the other three subunits are not affected. It suggests a dual function of Pol δ by its interconversion between Pol δ4 and Pol δ3 that is involved in a novel unknown apoptosis mechanism. The proteolysis of p12 could be efficiently blocked by both calpain inhibitor ALLN and proteasome inhibitor MG132. In vitro pull down and co-immunoprecipitation assays show that the μ-calpain binds to p12 through the interaction of μ-calpain with Pol δ other three subunits, not p12 itself, and PCNA, implying that the proteolysis of p12 by μ-calpain might be through a Pol δ4/PCNA complex. The p12 cleavage sites by μ-calpain are further determined as the location within a 16-amino acids peptide 28-43 by in vitro cleavage assays. Thus, the p12/Pol δ is a target as a nuclear substrate of μ-calpain in a calcium-triggered apoptosis and appears to be a potential marker in the study of the chemotherapy of cancer therapies.

  7. Triiodothyronine increases calcium loss in a bed rest antigravity model for space flight.

    Science.gov (United States)

    Smith, Steven R; Lovejoy, Jennifer C; Bray, George A; Rood, Jennifer; Most, Marlene M; Ryan, Donna H

    2008-12-01

    Bed rest has been used as a model to simulate the effects of space flight on bone metabolism. Thyroid hormones accelerate bone metabolism. Thus, supraphysiologic doses of this hormone might be used as a model to accelerate bone metabolism during bed rest and potentially simulate space flight. The objective of the study was to quantitate the changes in bone turnover after low doses of triiodothyronine (T(3)) added to short-term bed rest. Nine men and 5 women were restricted to bed rest for 28 days with their heads positioned 6 degrees below their feet. Subjects were randomly assigned to receive either placebo or oral T(3) at doses of 50 to 75 microg/d in a single-blind fashion. Calcium balance was measured over 5-day periods; and T(3), thyroxine, thyroid-stimulating hormone, immunoreactive parathyroid hormone, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline were measured weekly. Triiodothyronine increased 2-fold in the men and 5-fold in the women during treatment, suppressing both thyroxine and thyroid-stimulating hormone. Calcium balance was negative by 300 to 400 mg/d in the T(3)-treated volunteers, primarily because of the increased fecal loss that was not present in the placebo group. Urinary deoxypyridinoline to creatinine ratio, a marker of bone resorption, increased 60% in the placebo group during bed rest, but more than doubled in the T(3)-treated subjects (P < .01), suggesting that bone resorption was enhanced by treatment with T(3). Changes in serum osteocalcin and bone-specific alkaline phosphatase, markers of bone formation, were similar in T(3)- and placebo-treated subjects. Triiodothyronine increases bone resorption and fecal calcium loss in subjects at bed rest.

  8. HEPARIN-INSENSITIVE CALCIUM-RELEASE FROM INTRACELLULAR STORES TRIGGERED BY THE RECOMBINANT HUMAN PARATHYROID-HORMONE RECEPTOR

    NARCIS (Netherlands)

    SEUWEN, K; BODDEKE, HGWM

    1995-01-01

    1 In the present study we have characterized the parathyroid hormone (PTH)-induced calcium signalling in 293 cells stably transfected with the human PTH receptor cDNA. In these cells, human PTH-I(1-38) strongly stimulates adenosine 3':5'-cyclic monophosphate (cyclic AMP) formation (EC(50) = 0.39 nM)

  9. Resveratrol inhibits the intracellular calcium increase and angiotensin/endothelin system activation induced by soluble uric acid in mesangial cells

    Energy Technology Data Exchange (ETDEWEB)

    Albertoni, G.; Schor, N. [Divisão de Nefrologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

    2014-10-24

    Resveratrol (Resv) is natural polyphenol found in grapes. This study evaluated the protective effect of Resv against the effects of uric acid (UA) in immortalized human mesangial cells (ihMCs). ihMCs were preincubated with Resv (12.5 µM) for 1 h and treated with UA (10 mg/dL) for 6 or 12 h. The intracellular calcium concentration [Ca{sup 2+}]i was quantified by fluorescence using flow cytometry. Angiotensinogen (AGT) and pre-pro endothelin-1 (ppET-1) mRNA were assayed by quantitative real-time RT-PCR. Angiotensin II (AII) and endothelin-1 (ET-1) were assayed by ELISA. UA significantly increased [Ca{sup 2+}]i. Pre-incubation with Resv significantly reduced the change in [Ca{sup 2+}]i induced by UA. Incubation with UA for 6 or 12 h also increased AGT mRNA expression and AII protein synthesis. Resv blunted these increases in AGT mRNA expression and AII protein. Incubation with UA in the ihMCs increased ppET-1 expression and ET-1 protein synthesis at 6 and 12 h. When ihMCs were pre-incubated with Resv, UA had a significantly diminished effect on ppET-1 mRNA expression and ET-1 protein synthesis at 6 and 12 h, respectively. Our results suggested that UA triggers reactions including AII and ET-1 production in mesangial cells. The renin-angiotensin system may contribute to the pathogenesis of renal function and chronic kidney disease. Resv can minimize the impact of UA on AII, ET-1 and the increase of [Ca{sup 2+}]i in mesangial cells, suggesting that, at least in part, Resv can prevent the effects of soluble UA in mesangial cells.

  10. Noradrenaline activates a calcium-activated chloride conductance and increases the voltage-dependent calcium current in cultured single cells of rat portal vein.

    Science.gov (United States)

    Pacaud, P; Loirand, G; Mironneau, C; Mironneau, J

    1989-05-01

    1. Membrane responses were recorded by a patch pipette technique in cultured cells isolated from rat portal vein. Using the whole-cell mode, pressure ejections of noradrenaline evoked depolarization (current clamp) and inward current (voltage clamp) at membrane potentials of -60 to -70 mV. The noradrenaline-induced response was reversibly blocked by prazosin indicating that the response was mediated by alpha 1-adrenoceptors. 2. The ionic mechanism of the noradrenaline-induced inward current was investigated in potassium-free caesium-containing solutions. Alteration of the chloride equilibrium potential produced similar changes in the reversal potential of the noradrenaline-induced current, indicating that noradrenaline opened chloride-selective channels. There was no evidence implicating sodium or calcium as the charge-carrying ion. 3. Caffeine applied in the bathing solution also induced a transient increase in chloride conductance but the noradrenaline-induced response was lost after application of caffeine. This is interpreted to mean that the increase in chloride conductance induced by noradrenaline and caffeine can occur as a consequence of a rise in intracellular calcium concentration depending on release of calcium from the same intracellular stores. 4. In the presence of caffeine, noradrenaline increased both the voltage-dependent calcium and chloride membrane conductances during application of repetitive depolarizing pulses. It is concluded that in isolated cells of the rat portal vein the depolarization in response to noradrenaline is mediated by an increase in chloride conductance depending on both the calcium release from intracellular stores and the increase of the voltage-dependent calcium current. PMID:2470458

  11. Release of intracellular Calcium increase production of mitochondrial reactive oxygen species in renal distal epithelial cells

    DEFF Research Database (Denmark)

    Bjerregaard, Henning F.

    was inhibited by buffering of intracellular calcium with BAPTA, by the antioxidant N-acetylcysteine and by uncoupling of mitochondrial oxidative phosphorylation from respiration with CCCP. These results indicate that Cd generate a prompt initiation of ROS production from mitochondria due to an increase...... peroxide (H2O2) has traditionally been regarded as toxic by-products of aerobic metabolism. However, recent findings indicate that H2O2 act as a signalling molecule. The aim of the present study was to monitor, in real time, the rates of ROS generation in order to directly determine their production...

  12. Serum Calcium Increase Correlates With Worsening of Lipid Profile: An Observational Study on a Large Cohort From South Italy.

    Science.gov (United States)

    Gallo, Luigia; Faniello, Maria C; Canino, Giovanni; Tripolino, Cesare; Gnasso, Agostino; Cuda, Giovanni; Costanzo, Francesco S; Irace, Concetta

    2016-02-01

    Despite the well-documented role of calcium in cell metabolism, its role in the development of cardiovascular disease is still under heavy debate. Several studies suggest that calcium supplementation might be associated with an increased risk of coronary heart disease, whereas others underline a significant effect on lowering high blood pressure and hyperlipidemia. The purpose of this study was to investigate, in a large nonselected cohort from South Italy, if serum calcium levels correlate with lipid values and can therefore be linked to higher individual cardiovascular risk.Eight-thousand-six-hundred-ten outpatients addressed to the Laboratory of Clinical Biochemistry, University of Magna Græcia, Catanzaro, Italy from January 2012 to December 2013 for routine blood tests, were enrolled in the study. Total HDL-, LDL- and non-HDL colesterol, triglycerides, and calcium were determined with standard methods.We observed a significant association between total cholesterol, LDL-cholesterol, HDL-cholesterol, non-HDL cholesterol, triglycerides, and serum calcium in men and postmenopause women. Interestingly, in premenopause women, we only found a direct correlation between serum calcium, total cholesterol, and HDL-cholesterol. Calcium significantly increased while increasing total cholesterol and triglycerides in men and postmenopause women.Our results confirm that progressive increase of serum calcium level correlates with worsening of lipid profile in our study population. Therefore, we suggest that a greater caution should be used in calcium supplement prescription particularly in men and women undergoing menopause, in which an increase of serum lipids is already known to be associated with a higher cardiovascular risk.

  13. Elevated Intracellular Calcium Increases Ferritin H Expression Through an NFAT-Independent Posttranscriptional Mechanism Involving mRNA Stabilization

    OpenAIRE

    MacKenzie, Elizabeth L.; Tsuji, Yoshiaki

    2008-01-01

    An increase in intracellular Ca2+ is one of the initiating events in T cell activation. A calcium-mediated signaling cascade in T cells involves activation of calcineurin and the dephosphorylation and translocation of Nuclear Factor of Activated T-cells (NFAT), resulting in the transcriptional activation of target genes such as IL-2. In the present study, we found that increased intracellular calcium leads to induction of the antioxidant protein ferritin H. We previously reported that the fer...

  14. Calcium intake is not associated with increased coronary artery calcification: The Framingham Study

    Science.gov (United States)

    Adequate calcium intake is known to protect the skeleton. However, studies that have reported adverse effects of calcium supplementation on vascular events have raised widespread concern. We assessed the association between calcium intake (from diet and supplements) and coronary artery calcification...

  15. Prostaglandin A1 inhibits increases in intracellular calcium concentration, TXA2 production and platelet activation

    Institute of Scientific and Technical Information of China (English)

    Yi ZHU; Zhen-lun GU; Zhong-qin LIANG; Hui-lin ZHANG; Zheng-hong QIN

    2006-01-01

    Aim: In our previous studies we found that cyclopentenane prostaglandin A1 (PGA1) had neuroprotective effects in a rodent ischemic model. In the present study we aimed to investigate the inhibitory effect of PGA1 on platelet function. Method: The rate of aggregation of human platelets was measured by using turbidimetry. The rate of adhesion of platelets to cultured endothelial cells was determined by using [3H]-adenine labeled platelets. 5-Hydroxytryptamine release from platelets was measured with O-phthaldialdehyde fluorospectrophotometry. The levels of TXB2, a stable metabolite of TXA2, were determined by radioimmunoassay. Alternations in platelet morphology were observed using an electron microscope, and the intraplatelet free calcium concentrations were measured with Fluo-3/AM FCM assay. Results: PGA1 significantly inhibited thrombin-collagen-and ADP-induced aggregation and adhesion of platelets. The morphological changes of platelets induced by thrombin were blocked by PGA1. PGA1 inhibited the release of 5-hydroxytyptamine from dense granules and the synthesis of TXA2. Conclusion: PGA1 inhibits the activation of platelets probably through blocking increases in intracellular calcium concentration and TXA2 synthesis.

  16. Riboflavin and vitamin E increase brain calcium and antioxidants, and microsomal calcium-ATP-ase values in rat headache models induced by glyceryl trinitrate.

    Science.gov (United States)

    Bütün, Ayşe; Nazıroğlu, Mustafa; Demirci, Serpil; Çelik, Ömer; Uğuz, Abdulhadi Cihangir

    2015-04-01

    The essential use of riboflavin is the prevention of migraine headaches, although its effect on migraines is considered to be associated with the increased mitochondrial energy metabolism. Oxidative stress is also important in migraine pathophysiology. Vitamin E is a strong antioxidant in nature and its analgesic effect is not completely clear in migraines. The current study aimed to investigate the effects of glyceryl trinitrate (GTN)-sourced exogen nitric oxide (NO), in particular, and also riboflavin and/or vitamin E on involved in the headache model induced via GTN-sourced exogen NO on oxidative stress, total brain calcium levels, and microsomal membrane Ca(2+)-ATPase levels. GTN infusion is a reliable method to provoke migraine-like headaches in experimental animals and humans. GTN resulted in a significant increase in brain cortex and microsomal lipid peroxidation levels although brain calcium, vitamin A, vitamin C, and vitamin E, and brain microsomal-reduced glutathione (GSH), glutathione peroxidase (GSH-Px), and plasma-membrane Ca(2+)-ATPase values decreased through GTN. The lipid peroxidation, GSH, vitamin A, β-carotene, vitamin C, and vitamin E, and calcium concentrations, GSH-Px, and the Ca(2+)-ATPase activities were increased both by riboflavin and vitamin E treatments. Brain calcium and vitamin A concentrations increased through riboflavin only. In conclusion, riboflavin and vitamin E had a protective effect on the GTN-induced brain injury by inhibiting free radical production, regulation of calcium-dependent processes, and supporting the antioxidant redox system. However, the effects of vitamin E on the values seem more important than in riboflavin.

  17. Intracellular calcium levels are differentially regulated in T lymphocytes triggered by anti-CD2 and anti-CD3 monoclonal antibodies.

    Science.gov (United States)

    Spinozzi, F; Agea, E; Bistoni, O; Belia, S; Travetti, A; Gerli, R; Muscat, C; Bertotto, A

    1995-03-01

    Antigen and/or mitogen-driven T-cell activation is mediated by a rise in intracellular free Ca2+, as second messenger. A regulatory key role for this process is represented by membrane-associated [Ca2+/Mg2+] ATP-ase that is mainly devoted to extrusion of intracellular ion excess. In the present study we have investigated the kinetics of CA2+ fluxes in both resting and already activated (Jurkat T-cell line) T lymphocytes after CD3 and CD2 (T11(2) and T11(3)) triggering and focused our attention on plasma membrane [Ca2+/Mg2+] ATP-ase activity. In both resting T cells and Jurkat cell line, the CD2 stimulation was able to determine a rise in intracellular free Ca2+ higher than that observed after CD3 triggering. In addition, this calcium signal was independent of negative feedback control exerted by [Ca2+/Mg2+] ATP-ase, as well as of IP3 generation. Thus the CD2 molecular system may, together with cell-adhesion properties, act as an amplifier of Ca2+ signals that, if delivered in the context of other molecular systems, such as CD3 or MHC class II antigens, are essentially devoted to the polyclonal co-stimulatory recruitment of a larger cellular repertoire. PMID:7662514

  18. Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT

    International Nuclear Information System (INIS)

    To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT. One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 kV, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD). The estimated effective dose was 1.5 ± 0.2 mSv. The mean heart rate was 63 ± 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 ± 4.5 kg/m2 (range, 15.5-42.3 kg/m2). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 ± 4 Hounsfield unit (HU) (range, 8-25 HU). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level. The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0.05).

  19. Activation of a P2Y4-like purinoceptor triggers an increase in cytosolic [Ca2+] in the red blood cells of the lizard Ameiva ameiva (Squamata, Teiidae

    Directory of Open Access Journals (Sweden)

    Sartorello R.

    2005-01-01

    Full Text Available An increasing number of pathophysiological roles for purinoceptors are emerging, some of which have therapeutic potential. Erythrocytes are an important source of purines, which can be released under physiological and physiopathological conditions, acting on purinergic receptors associated with the same cell or with neighboring cells. Few studies have been conducted on lizards, and have been limited to ATP agonist itself. We have previously shown that the red blood cells (RBCs of the lizard Ameiva ameiva store Ca2+ in the endoplasmic reticulum (ER and that the purinergic agonist ATP triggers a rapid and transient increase of [Ca2+]c by mobilization of the cation from internal stores. We also reported the ability of the second messenger IP3 to discharge the ER calcium pool of the ER. Here we characterize the purinoceptor present in the cytoplasmic membrane of the RBCs of the lizard Ameiva ameiva by the selective use of ATP analogues and pyrimidine nucleotides. The nucleotides UTP, UDP, GTP, and ATPgammaS triggered a dose-dependent response, while interestingly 2MeSATP, 2ClATP, alpha, ß-ATP, and ADP failed to do so in a 1- to 200-µm con- centration. The EC50 obtained for the compounds tested was 41.77 µM for UTP, 48.11 µM for GTP, 53.11 µM for UDP, and 30.78 µM for ATPgammaS. The present data indicate that the receptor within the RBCs of Ameiva ameiva is a P2Y4-like receptor due to its pharmacological similarity to the mammalian P2Y4 receptor.

  20. Activation of a P2Y4-like purinoceptor triggers an increase in cytosolic [Ca2+] in the red blood cells of the lizard Ameiva ameiva (Squamata, Teiidae).

    Science.gov (United States)

    Sartorello, R; Garcia, C R S

    2005-01-01

    An increasing number of pathophysiological roles for purinoceptors are emerging, some of which have therapeutic potential. Erythrocytes are an important source of purines, which can be released under physiological and physiopathological conditions, acting on purinergic receptors associated with the same cell or with neighboring cells. Few studies have been conducted on lizards, and have been limited to ATP agonist itself. We have previously shown that the red blood cells (RBCs) of the lizard Ameiva ameiva store Ca2+ in the endoplasmic reticulum (ER) and that the purinergic agonist ATP triggers a rapid and transient increase of [Ca2+]c by mobilization of the cation from internal stores. We also reported the ability of the second messenger IP3 to discharge the ER calcium pool of the ER. Here we characterize the purinoceptor present in the cytoplasmic membrane of the RBCs of the lizard Ameiva ameiva by the selective use of ATP analogues and pyrimidine nucleotides. The nucleotides UTP, UDP, GTP, and ATPgammaS triggered a dose-dependent response, while interestingly 2MeSATP, 2ClATP, alpha, ss-ATP, and ADP failed to do so in a 1- to 200-microm con- centration. The EC50 obtained for the compounds tested was 41.77 microM for UTP, 48.11 microM for GTP, 53.11 microM for UDP, and 30.78 microM for ATPgammaS. The present data indicate that the receptor within the RBCs of Ameiva ameiva is a P2Y4-like receptor due to its pharmacological similarity to the mammalian P2Y4 receptor. PMID:15665982

  1. Does adding an appended oncology module to the Global Trigger Tool increase its value?

    DEFF Research Database (Denmark)

    Mattsson, Thea Otto; Knudsen, Janne Lehmann; Brixen, Kim;

    2014-01-01

    OBJECTIVE: To determine any additional value in the evaluation of safety levels by adding an appended oncology module to the Institute for Healthcare Improvement's Global Trigger Tool (GTT). DESIGN: Comparison of two independent retrospective chart reviews: one review team using the general GTT...... method and one using the general GTT method plus the appended oncology module on the same inpatient charts. SETTING: The Department of Clinical Oncology at a Danish University Hospital (1000 beds). PARTICIPANTS: All inpatients admitted to the hospital in 2010, n = 3692, biweekly sample of 10 admission...... per 1000 admission days. RESULTS: No significant (95% confidence interval) difference was found between review teams using the general GTT versus the general GTT plus the appended oncology module on the total number of identified AEs, AEs per 100 admissions, AEs per 1000 admission days...

  2. Induction of defence gene expression by oligogalacturonic acid requires increases in both cytosolic calcium and hydrogen peroxide in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Xiang Yang HU; Steven J NEILL; Wei Ming CAI; Zhang Cheng TANG

    2004-01-01

    Responses to oligogalacturonic acid (OGA) were determined in transgenic Arabidopsis thaliana seedlings expressing the calcium reporter protein aequorin. OGA stimulated a rapid, substantial and transient increase in the concentration of cytosolic calcium ([Ca2+]cyt) that peaked after ca. 15 s. This increase was dose-dependent, saturating at ca. 50 μg Gal equiv/ml of OGA. OGA also stimulated a rapid generation of H2O2. A small, rapid increase in H2O2 content was followed by a much larger oxidative burst, with H2O2 content peaking after ca. 60 min and declining thereafter. Induction of the oxidative burst by OGA was also dose-dependent, with a maximum response again being achieved at ca. 50 μg Gal equiv/mL. Inhibitors of calcium fluxes inhibited both increases in [Ca2+]cyt and [H2O2], whereas inhibitors of NADPH oxidase blocked only the oxidative burst. OGA increased strongly the expression of the defence-related genes CHS,GST, PAL and PR-1. This induction was suppressed by inhibitors of calcium flux or NADPH oxidase, indicating that increases in both cytosolic calcium and H2O2 are required for OGA-induced gene expression.

  3. Oxidative damage increases intracellular free calcium [Ca2+]i concentration in human erythrocytes incubated with lead.

    Science.gov (United States)

    Quintanar-Escorza, M A; González-Martínez, M T; del Pilar, Intriago-Ortega Ma; Calderón-Salinas, J V

    2010-08-01

    One important effect of lead toxicity in erythrocytes consists of increasing [Ca(2+)](i) which in turn may cause alterations in cell shape and volume and it is associated with cellular rigidity, hemolysis, senescence and apoptosis. In this work, we proposed the use of erythrocytes incubated with Pb(2+) to assess association of the mechanisms of lead erythrocyte oxidative damage and calcium homeostasis. Lead incubation produced an increase in [Ca(2+)](i) dose- and time-dependent, which mainly involved Ca(2+) entry mechanism. Additionally, in this in vitro model alterations similar to erythrocytes of lead-exposed workers were produced: Increase in Ca(2+) influx, decrease in (Ca(2+)-Mg(2+))-ATPase activity and GSH/GSGG ratio; increase in lipoperoxidation, protein carbonylation and osmotic fragility accompanied of dramatic morphological changes. Co-incubation with trolox, a soluble vitamin-E analog is able to prevent these alterations indicating that lead damage mechanism is strongly associated with oxidative damage with an intermediate toxic effect via [Ca(2+)](i) increase. Furthermore, erythrocytes oxidation induced with a free radical generator (APPH) showed effects in [Ca(2+)](i) and oxidative damage similar to those found in erythrocytes incubated with lead. Co-incubation with trolox prevents the oxidative effects induced by AAPH in erythrocytes. These results suggest that increase of [Ca(2+)](i) depends on the oxidative status of the erythrocytes incubated with lead. We consider that this model contributes in the understanding of the relation between oxidative damage induced by lead exposure and Ca(2+) homeostasis, the consequences related to these phenomena and the molecular basis of lead toxicity in no excitable cells. PMID:20460147

  4. Recombinant erythropoietin increases blood pressure in experimental hypertension and uraemia without change in vascular cytosolic calcium.

    Science.gov (United States)

    Roger, S D; Fluck, R J; McMahon, A C; Raine, A E

    1996-01-01

    The mechanism of erythropoietin-induced hypertension in dialysis patients is unclear. Intracellular calcium ([Ca2+]i) may be altered in both hypertension and uraemia, and the effects of both uraemia and r-HuEPO on vascular smooth muscle [Ca2+]i and blood pressure (BP) in Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) were therefore studied. Male WKY and SHR underwent partial nephrectomy or sham operation. Three weeks later a 28-day period of treatment with either r-HuEPO 100 U/kg, s.c., 3 times/week or buffer was commenced (n = 10-12 for each subgroup). BP was measured weekly, by noninvasive Doppler tail-cuff assessment. [Ca2+]i was measured following loading with fura-2 in pooled, primary aortic vascular smooth muscle cells (VSMC). Serum urea and creatinine rose 3- to 4-fold after partial nephrectomy. Treatment with r-HuEPO did not change renal function further in either uraemic or control WKY or SHR. Haemoglobin increased in both non-uraemic WKY (16.2-20.3 g/dl) and SHR (16.4-20.5 g/dl) and uraemic animals (WKY 13.9-20.9; SHR 13.8-18.8 g/dl; p < 0.01 for all changes) following 4 weeks of r-HuEPO treatment. BP was unaffected by r-HuEPO in WKY but increased in nonuraemic SHR (210-250; p < 0.01) and in uraemic SHR (224-251 mm Hg; p < 0.001) at 4 weeks. VSMC [Ca2+]i was higher in SHR than WKY (121 vs. 83 nmol/l; MANOVA p < 0.05) but no effect of uraemia or r-HuEPO on [Ca2+]i was detected. In conclusion, the hypertensive effects of r-HuEPO are augmented both in a genetic model of hypertension and in uraemia. Although VSMC [Ca2+]i was elevated in SHR, the further increase in BP induced by r-HuEPO was not associated with alterations in VSMC cytosolic calcium. PMID:8773347

  5. Increased long-flight activity triggered in beet armyworm by larval feeding on diet containing Cry1Ac protoxin.

    Directory of Open Access Journals (Sweden)

    Xing Fu Jiang

    Full Text Available Evaluating ecological safety and conducting pest risk analysis for transgenic crops are vitally important before their commercial planting. The beet armyworm, Spodoptera exigua, a long-distance migratory insect pest, is not a direct target of transgenic Cry1Ac-expressing cotton in China, but nevertheless it has recently become an important pest. Migrants leaving their natal field arrive in other appropriate habitat far away in a short time, often followed by larval outbreaks. S. exigua has low susceptibility to Cry1Ac. However, our results from laboratory experiments identified (i sublethal effects of Cry1Ac protoxin on larval development rate, larval and pupal weight, and adult lifetime fecundity, and (ii increased long-flight behavior triggered by Cry1Ac which may contribute to larval outbreaks elsewhere. No significant differences in larval mortality, pupation rate, adult emergence rate, longevity, pre-oviposition period, or oviposition period were observed between controls and larvae fed on artificial diet incorporating a low concentration of Cry1Ac protoxin. The negative sublethal effects on some developmental and reproductive traits and lack of effect on others suggest they do not contribute to the observed severity of S. exigua outbreaks after feeding on Cry1Ac cotton. Interestingly, the percentage of long fliers increased significantly when larvae were reared on diet containing either of two low-dose treatments of Cry1Ac, suggesting a possible increased propensity to disperse long distances triggered by Cry1Ac. We hypothesize that negative effects on development and reproduction caused by Cry1Ac in the diet are offset by increased flight propensity triggered by the poor food conditions, thereby improving the chances of escaping adverse local conditions before oviposition. Increased long-flight propensity in turn may amplify the area damaged by outbreak populations. This phenomenon might be common in other migratory insect pests receiving

  6. Interleukin-2 stimulates osteoclastic activity: Increased acid production and radioactive calcium release

    International Nuclear Information System (INIS)

    Recombinant human interleukin-2 (IL-2) was studied to determine effects on acid production by individual osteoclasts in situ on mouse calvarial bones. This analysis was performed using a microspectrofluorimetric technique to quantify acid production in individual cells. Radioactive calcium release was determined using calvarial bones in a standard tissue culture system. This allowed us to correlate changes in acid production with a measure of bone resorption. IL-2 stimulated acid production and bone resorbing activity. Both effects were inhibited by calcitonin. No stimulation of bone resorption occurred when IL-2-containing test media was incubated with a specific anti-IL-2 antibody and ultrafiltered. Our data demonstrated a correlation between acid production and bone resorbing activity in mouse calvaria exposed to parathyroid hormone (PTH). The data obtained from cultured mouse calvaria exposed to IL-2 demonstrated similar stimulatory effects to those seen during PTH exposure. These data suggest that calvaria exposed to IL-2 in vitro have increased osteoclastic acid production corresponding with increased bone resorption. (author)

  7. Hunting Increases Phosphorylation of Calcium/Calmodulin-Dependent Protein Kinase Type II in Adult Barn Owls

    Directory of Open Access Journals (Sweden)

    Grant S. Nichols

    2015-01-01

    Full Text Available Juvenile barn owls readily adapt to prismatic spectacles, whereas adult owls living under standard aviary conditions do not. We previously demonstrated that phosphorylation of the cyclic-AMP response element-binding protein (CREB provides a readout of the instructive signals that guide plasticity in juveniles. Here we investigated phosphorylation of calcium/calmodulin-dependent protein kinase II (pCaMKII in both juveniles and adults. In contrast to CREB, we found no differences in pCaMKII expression between prism-wearing and control juveniles within the external nucleus of the inferior colliculus (ICX, the major site of plasticity. For prism-wearing adults that hunted live mice and are capable of adaptation, expression of pCaMKII was increased relative to prism-wearing adults that fed passively on dead mice and are not capable of adaptation. This effect did not bear the hallmarks of instructive information: it was not localized to rostral ICX and did not exhibit a patchy distribution reflecting discrete bimodal stimuli. These data are consistent with a role for CaMKII as a permissive rather than an instructive factor. In addition, the paucity of pCaMKII expression in passively fed adults suggests that the permissive default setting is “off” in adults.

  8. Application of different qualities of X-rays by X-ray microradiography to increase the detection efficiency of calcium

    International Nuclear Information System (INIS)

    It was the goal of this work to evaluate quantitatively the suitability of the radiation quality of tungsten, copper, titanium and scandium anodes for the generation of contrastful microradiographs and thus to increase the detection sensitivity of calcium. Halfwidth determinations were made with aluminium absorbers in air to characterize the different X-ray radiation qualities. Furthermore the dependence of the dose load of the absorber width and the type of the tube was determined in the radiation field for 20 kV anode voltage. Reference step-models were established in order to transfer these results to the calcium detection in microradiograph technology. (orig./HBR)

  9. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure.

    Science.gov (United States)

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C; van Meer, Berend; Ward-van Oostwaard, Dorien; Passier, Robert; Tertoolen, Leon G J; Mummery, Christine L; Casini, Simona

    2015-11-27

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation.

  10. Can occupational exposure to antineoplastic drugs increase levels of an inflammatory trigger?

    OpenAIRE

    T. Kamalasundar; Padmaja Udaykumar; Prabin Shah

    2015-01-01

    Background: Antineoplastic drugs (AND) are known to cause collateral damage to normal cells by oxidative stress. This study was conducted to check for oxidative stress in occupational exposure to these drugs using advanced oxidation protein products (AOPP). Methods: Cross-sectional comparison of serum AOPP levels of 33 nurses occupationally exposed and serum AOPP levels of 30 nurses not exposed using modified AOPP method. Results: Serum AOPP levels were significantly increased (p

  11. Increases in myocardial workload induced by rapid atrial pacing trigger alterations in global metabolism.

    Directory of Open Access Journals (Sweden)

    Aslan T Turer

    Full Text Available To determine whether increases in cardiac work lead to alterations in the plasma metabolome and whether such changes arise from the heart or peripheral organs.There is growing evidence that the heart influences systemic metabolism through endocrine effects and affecting pathways involved in energy homeostasis.Nineteen patients referred for cardiac catheterization were enrolled. Peripheral and selective coronary sinus (CS blood sampling was performed at serial timepoints following the initiation of pacing, and metabolite profiling was performed by liquid chromatography-mass spectrometry (LC-MS.Pacing-stress resulted in a 225% increase in the median rate·pressure product from baseline. Increased myocardial work induced significant changes in the peripheral concentration of 43 of 125 metabolites assayed, including large changes in purine [adenosine (+99%, p = 0.006, ADP (+42%, p = 0.01, AMP (+79%, p = 0.004, GDP (+69%, p = 0.003, GMP (+58%, p = 0.01, IMP (+50%, p = 0.03, xanthine (+61%, p = 0.0006], and several bile acid metabolites. The CS changes in metabolites qualitatively mirrored those in the peripheral blood in both timing and magnitude, suggesting the heart was not the major source of the metabolite release.Isolated increases in myocardial work can induce changes in the plasma metabolome, but these changes do not appear to be directly cardiac in origin. A number of these dynamic metabolites have known signaling functions. Our study provides additional evidence to a growing body of literature on metabolic 'cross-talk' between the heart and other organs.

  12. Adequate dietary vitamin D and calcium are both required to reduce bone turnover and increased bone mineral volume.

    Science.gov (United States)

    Lee, Alice M C; Sawyer, Rebecca K; Moore, Alison J; Morris, Howard A; O'Loughlin, Peter D; Anderson, Paul H

    2014-10-01

    Clinical studies indicate that the combination of vitamin D and dietary calcium supplementation is more effective for reducing fracture risk than either supplement alone. Our previous dietary studies demonstrated that an adequate serum 25-hydroxyvitamin D3 (25D) of 80nmol/L or more reduces bone RANKL expression, osteoclastogenesis and maintains the optimal levels of trabecular bone volume (BV/TV%) in young rats. The important clinical question of the interaction between vitamin D status, dietary calcium intake and age remains unclear. Hence, 9 month-old female Sprague-Dawley rats (n=5-6/group) were pair-fed a semi-synthetic diet containing varying levels of vitamin D (0, 2, 12 or 20IU/day) and dietary calcium (0.1% or 1%) for 6 months. At 15 months of age, animals were killed, for biochemical and skeletal analyses. While changes to serum 25D were determined by both dietary vitamin D and calcium levels, changes to serum 1,25-dihydroxyvitamin D3 (1,25D) were consistently raised in animals fed 0.1% Ca regardless of dietary vitamin D or vitamin D status. Importantly, serum cross-laps levels were significantly increased in animals fed 0.1% Ca only when combined with 0 or 2 IUD/day of vitamin D, suggesting a contribution of both dietary calcium and vitamin D in determining bone resorption activity. Serum 25(OH)D3 levels were positively correlated with both femoral mid-diaphyseal cortical bone volume (R(2)=0.24, PTV% (R(2)=0.23, Pnegative determinant of CBV (R(2)=0.24, PTV% levels. These data support clinical data that reduced bone resorption and increased bone volume can only be achieved with adequate 25D levels in combination with high dietary calcium and low serum 1,25D levels. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. PMID:24309068

  13. Increased expression of fatty-acid and calcium metabolism genes in failing human heart.

    Directory of Open Access Journals (Sweden)

    Vanessa García-Rúa

    Full Text Available BACKGROUND: Heart failure (HF involves alterations in metabolism, but little is known about cardiomyopathy-(CM-specific or diabetes-independent alterations in gene expression of proteins involved in fatty-acid (FA uptake and oxidation or in calcium-(Ca(2+-handling in the human heart. METHODS: RT-qPCR was used to quantify mRNA expression and immunoblotting to confirm protein expression in left-ventricular myocardium from patients with HF (n = 36 without diabetes mellitus of ischaemic (ICM, n = 16 or dilated (DCM, n = 20 cardiomyopathy aetiology, and non-diseased donors (CTL, n = 6. RESULTS: Significant increases in mRNA of genes regulating FA uptake (CD36 and intracellular transport (Heart-FA-Binding Protein (HFABP were observed in HF patients vs CTL. Significance was maintained in DCM and confirmed at protein level, but not in ICM. mRNA was higher in DCM than ICM for peroxisome-proliferator-activated-receptor-alpha (PPARA, PPAR-gamma coactivator-1-alpha (PGC1A and CD36, and confirmed at the protein level for PPARA and CD36. Transcript and protein expression of Ca(2+-handling genes (Two-Pore-Channel 1 (TPCN1, Two-Pore-Channel 2 (TPCN2, and Inositol 1,4,5-triphosphate Receptor type-1 (IP3R1 increased in HF patients relative to CTL. Increases remained significant for TPCN2 in all groups but for TPCN1 only in DCM. There were correlations between FA metabolism and Ca(2+-handling genes expression. In ICM there were six correlations, all distinct from those found in CTL. In DCM there were also six (all also different from those found in CTL: three were common to and three distinct from ICM. CONCLUSION: DCM-specific increases were found in expression of several genes that regulate FA metabolism, which might help in the design of aetiology-specific metabolic therapies in HF. Ca(2+-handling genes TPCN1 and TPCN2 also showed increased expression in HF, while HF- and CM-specific positive correlations were found among several FA and Ca(2

  14. Infrared laser pulse triggers increased singlet oxygen production in tumour cells

    OpenAIRE

    Sokolovski, S. G.; Zolotovskaya, S. A.; Goltsov, A.; Pourreyron, C; South, A P; Rafailov, E. U.

    2013-01-01

    Photodynamic therapy (PDT) is a technique developed to treat the ever-increasing global incidence of cancer. This technique utilises singlet oxygen (1O2) generation via a laser excited photosensitiser (PS) to kill cancer cells. However, prolonged sensitivity to intensive light (6–8 weeks for lung cancer), relatively low tissue penetration by activating light (630 nm up to 4 mm), and the cost of PS administration can limit progressive PDT applications. The development of quantum-dot laser diod...

  15. Effect of increasing the colloidal calcium phosphate of milk on the texture and microstructure of yogurt.

    Science.gov (United States)

    Ozcan, T; Horne, D; Lucey, J A

    2011-11-01

    The effect of increasing the colloidal calcium phosphate (CCP) content on the physical, rheological, and microstructural properties of yogurt was investigated. The CCP content of heated (85°C for 30 min) milk was increased by increasing the pH by the addition of alkali (NaOH). Alkalized milk was dialyzed against pasteurized skim milk at approximately 4°C for 72 h to attempt to restore the original pH and soluble Ca content. By adjustment of the milk to pH values 7.45, 8.84, 10.06, and 10.73, the CCP content was increased to approximately 107, 116, 123, and 128%, respectively, relative to the concentration in heated milk. During fermentation of milk, the storage modulus (G') and loss tangent values of yogurts were measured using dynamic oscillatory rheology. Large deformation rheological properties were also measured. The microstructure of yogurt was observed using fluorescence microscopy, and whey separation was determined. Acid-base titration was used to evaluate changes in the CCP content in milk. Total Ca and casein-bound Ca increased with an increase in the pH value of alkalization. During acidification, elevated buffering occurred in milk between pH values 6.7 to 5.2 with an increase in the pH of alkalization. When acidified milk was titrated with alkali, elevated buffering occurred in milk between pH values 5.6 to 6.4 with an increase in the pH of alkalization. The high residual pH of milk after dialysis could be responsible for the decreased contents of soluble Ca in these milks. The pH of gelation was higher in all dialyzed samples compared with the heated control milk, and the gelation pH was higher with an increase in CCP content. The sample with highest CCP content (128%) exhibited gelation at very high pH (6.3), which could be due to alkali-induced CN micellar disruption. The G' values at pH 4.6 were similar in gels with CCP levels up to 116%; at higher CCP levels, the G' values at pH 4.6 greatly decreased. Loss tangent values at pH 5.1 were similar

  16. Mitoenergetic Dysfunction Triggers a Rapid Compensatory Increase in Steady-State Glucose Flux.

    Science.gov (United States)

    Liemburg-Apers, Dania C; Schirris, Tom J J; Russel, Frans G M; Willems, Peter H G M; Koopman, Werner J H

    2015-10-01

    ATP can be produced in the cytosol by glycolytic conversion of glucose (GLC) into pyruvate. The latter can be metabolized into lactate, which is released by the cell, or taken up by mitochondria to fuel ATP production by the tricarboxylic acid cycle and oxidative phosphorylation (OXPHOS) system. Altering the balance between glycolytic and mitochondrial ATP generation is crucial for cell survival during mitoenergetic dysfunction, which is observed in a large variety of human disorders including cancer. To gain insight into the kinetic properties of this adaptive mechanism we determined here how acute (30 min) inhibition of OXPHOS affected cytosolic GLC homeostasis. GLC dynamics were analyzed in single living C2C12 myoblasts expressing the fluorescent biosensor FLII(12)Pglu-700μδ6 (FLII). Following in situ FLII calibration, the kinetic properties of GLC uptake (V1) and GLC consumption (V2) were determined independently and used to construct a minimal mathematical model of cytosolic GLC dynamics. After validating the model, it was applied to quantitatively predict V1 and V2 at steady-state (i.e., when V1 = V2 = Vsteady-state) in the absence and presence of OXPHOS inhibitors. Integrating model predictions with experimental data on lactate production, cell volume, and O2 consumption revealed that glycolysis and mitochondria equally contribute to cellular ATP production in control myoblasts. Inhibition of OXPHOS induced a twofold increase in Vsteady-state and glycolytic ATP production flux. Both in the absence and presence of OXPHOS inhibitors, GLC was consumed at near maximal rates, meaning that GLC consumption is rate-limiting under steady-state conditions. Taken together, we demonstrate here that OXPHOS inhibition increases steady-state GLC uptake and consumption in C2C12 myoblasts. This activation fully compensates for the reduction in mitochondrial ATP production, thereby maintaining the balance between cellular ATP supply and demand. PMID:26445438

  17. Imatinib triggers mesenchymal-like conversion of CML cells associated with increased aggressiveness

    Institute of Scientific and Technical Information of China (English)

    Alexandre Puissant; Yann Chéli; Jill-Patrice Cassuto; Sophie Raynaud; Laurence Legros; Jean-Max Pasquet; Francois-Xavier Mahon; Frédéric Luciano; Patrick Auberger; Maeva Dufies; Nina Fenouille; Issam Ben Sahra; Arnaud Jacquel; Guillaume Robert; Thomas Cluzeau; Marcel Deckert; Mélanie Tichet

    2012-01-01

    Chronic myelogenous leukemia (CML) is a cytogenetic disorder resulting from the expression of p210BCR-ABL Imatinib,an inhibitor of BCR-ABL,has emerged as the leading compound to treat CML patients.Despite encouraging clinical results,resistance to imatinib represents a major drawback for therapy,as a substantial proportion of patients are refractory to this treatment.Recent publications have described the existence of a small cancer cell population with the potential to exhibit the phenotypic switch responsible for chemoresistance.To investigate the existence of such a chemoresistant cellular subpopulation in CML,we used a two-step approach of pulse and continuous selection by imatinib in different CML cell lines that allowed the emergence of a subpopulation of adherent cells (IM-R Adh) displaying an epithelial-mesenchymal transition (EMT)-like phenotype.Overexpression of several EMT markers was observed in this CML subpopulation,as well as in CD34+ CML primary cells from patients who responded poorly to imatinib treatment.In response to imatinib,this CD44high/CD24low IM-R Adh subpopulation exhibited increased adhesion,transmigration and invasion in vitro and in vivo through specific overexpression of the αVβ3 receptor.FAK/Akt pathway activation following integrin β3 (ITGβ3) engagement mediated the migration and invasion of IM-R Adh cells,whereas persistent activation of ERK counteracted BCR-ABL inhibition by imatinib,promoting cell adhesion-mediated resistance.

  18. Nucleus accumbens corticotropin-releasing factor increases cue-triggered motivation for sucrose reward: paradoxical positive incentive effects in stress?

    Directory of Open Access Journals (Sweden)

    Schulkin Jay

    2006-04-01

    Full Text Available Abstract Background Corticotropin-releasing factor (CRF is typically considered to mediate aversive aspects of stress, fear and anxiety. However, CRF release in the brain is also elicited by natural rewards and incentive cues, raising the possibility that some CRF systems in the brain mediate an independent function of positive incentive motivation, such as amplifying incentive salience. Here we asked whether activation of a limbic CRF subsystem magnifies the increase in positive motivation for reward elicited by incentive cues previously associated with that reward, in a way that might exacerbate cue-triggered binge pursuit of food or other incentives? We assessed the impact of CRF microinjections into the medial shell of nucleus accumbens using a pure incentive version of Pavlovian-Instrumental transfer, a measure specifically sensitive to the incentive salience of reward cues (which it separates from influences of aversive stress, stress reduction, frustration and other traditional explanations for stress-increased behavior. Rats were first trained to press one of two levers to obtain sucrose pellets, and then separately conditioned to associate a Pavlovian cue with free sucrose pellets. On test days, rats received microinjections of vehicle, CRF (250 or 500 ng/0.2 μl or amphetamine (20 μg/0.2 μl. Lever pressing was assessed in the presence or absence of the Pavlovian cues during a half-hour test. Results Microinjections of the highest dose of CRF (500 ng or amphetamine (20 μg selectively enhanced the ability of Pavlovian reward cues to trigger phasic peaks of increased instrumental performance for a sucrose reward, each peak lasting a minute or so before decaying after the cue. Lever pressing was not enhanced by CRF microinjections in the baseline absence of the Pavlovian cue or during the presentation without a cue, showing that the CRF enhancement could not be explained as a result of generalized motor arousal, frustration or stress

  19. Spontaneous calcium waves in Bergman glia increase with age and hypoxia and may reduce tissue oxygen

    DEFF Research Database (Denmark)

    Mathiesen, Claus; Brazhe, Alexey; Thomsen, Kirsten Joan;

    2013-01-01

    Glial calcium (Ca(2+)) waves constitute a means to spread signals between glial cells and to neighboring neurons and blood vessels. These waves occur spontaneously in Bergmann glia (BG) of the mouse cerebellar cortex in vivo. Here, we tested three hypotheses: (1) aging and reduced blood oxygen sa...

  20. Increased calcium oxalate monohydrate crystal binding to injured renal tubular epithelial cells in culture

    NARCIS (Netherlands)

    C.F. Verkoelen; B.G. van der Boom (Burt); A.B. Houtsmuller (Adriaan); F.H. Schröder (Fritz); J.C. Romijn (Johannes)

    1998-01-01

    textabstractThe retention of crystals in the kidney is considered to be a crucial step in the development of a renal stone. This study demonstrates the time-dependent alterations in the extent of calcium oxalate (CaOx) monohydrate (COM) crystal binding to Madin-Darby ca

  1. Prohexadione-calcium modifies growth and increases photosynthesis in strawberry nursery plants

    NARCIS (Netherlands)

    Reekie, J.Y.; Hicklenton, P.; Struik, P.C.

    2005-01-01

    Prohexadione-calcium (ProCa) at an active ingredient concentration of 62.5 mg L-1 was applied as a foliar spray to Camarosa and Sweet Charlie strawberry (Fragaria x ananassa Duchesne) plants in growth chambers to assess its effects on dry weight allocation and growth over 42 d. The height, leaf numb

  2. Calcium isotope evidence for pulses of increased continental weathering during the early Toarcian (Early Jurassic)

    Science.gov (United States)

    Suan, Guillaume; Brazier, Jean-Michel; Balter, Vincent; Simon, Laurent; Mattioli, Emanuela

    2014-05-01

    The Toarcian interval is punctuated by a number of episodes of environmental changes and mass extinctions that are considered as some of the most severe of the Mesozoic era. Significantly, the corresponding strata record marked negative carbon isotope excursions that point to pulses of massive injection of isotopically light carbon to the superficial reservoirs. Potential causes of these perturbations include gas hydrate dissociation, wildfires, and massive inputs of thermogenic and volcanogenic carbon related to the onset of volcanic activity of the Karoo-Ferrar province. All these scenarii imply large increases in chemical weathering rate as key drivers of the accompanying biotic and environmental perturbations (e.g., productivity-driven anoxia and coastal eutrophication). Nevertheless, detailed examination of most likely cause(s) of these events has been hampered by the uncertainty surrounding the timing and intensity of coeval changes in continental weathering. In this study, we reconstruct changes in continental weathering during the Toarcian using new calcium isotope ratios δ44/42Ca of brachiopods and bulk rock sediments from the Peniche section in Portugal. The data reveal two marked (>0.4permil) negative Ca-isotope excursions near the Pliensbachian-Toarcian transition (Pl-To) and at the base of the levisoni ammonite Zone recording the Early Toarcian Oceanic Anoxic Event (T-OAE). The comparison of the brachiopod and bulk rock Ca isotope data indicates that these excursions reflect changes in the global Ca-isotope composition of seawater rather than changes in the dominant mineralogy of calcifying organisms. Mass balance calculations suggest that the Ca-isotope excursions recorded across the Pl-To transition and T-OAE interval can be explained by the Ca inputs from rivers corresponding respectively to 90% and 34% of the initial mass of oceanic Ca. Based on these values, the injection of tens of thousands of gigatons of carbon with a C-isotope composition

  3. Activation of NADPH Oxidase 1 Increases Intracellular Calcium and Migration of Smooth Muscle Cells

    OpenAIRE

    Zimmerman, Matthew C.; Takapoo, Maysam; Jagadeesha, Dammanahalli K.; Stanic, Bojana; Banfi, Botond; Bhalla, Ramesh C; Miller, Francis J.

    2011-01-01

    Redox-dependent migration and proliferation of vascular smooth muscle cells (SMCs) are central events in the development of vascular proliferative diseases; however, the underlying intracellular signaling mechanisms are not fully understood. We tested the hypothesis that activation of Nox1 NADPH oxidase modulates intracellular calcium levels ([Ca2+]i). Using cultured SMCs from wild type (WT) and Nox1 null (Nox1−/y) mice, we confirmed that thrombin-dependent generation of ROS requires Nox1. Th...

  4. Spontaneous calcium waves in Bergman glia increase with age and hypoxia and may reduce tissue oxygen

    OpenAIRE

    Mathiesen, Claus; Brazhe, Alexey; Thomsen, Kirsten; Lauritzen, Martin

    2012-01-01

    Glial calcium (Ca2+) waves constitute a means to spread signals between glial cells and to neighboring neurons and blood vessels. These waves occur spontaneously in Bergmann glia (BG) of the mouse cerebellar cortex in vivo. Here, we tested three hypotheses: (1) aging and reduced blood oxygen saturation alters wave activity; (2) glial Ca2+ waves change cerebral oxygen metabolism; and (3) neuronal and glial wave activity is correlated. We used two-photon microscopy in the cerebellar cortexes of...

  5. Hunting Increases Phosphorylation of Calcium/Calmodulin-Dependent Protein Kinase Type II in Adult Barn Owls

    OpenAIRE

    Nichols, Grant S.; DeBello, William M.

    2015-01-01

    Juvenile barn owls readily adapt to prismatic spectacles, whereas adult owls living under standard aviary conditions do not. We previously demonstrated that phosphorylation of the cyclic-AMP response element-binding protein (CREB) provides a readout of the instructive signals that guide plasticity in juveniles. Here we investigated phosphorylation of calcium/calmodulin-dependent protein kinase II (pCaMKII) in both juveniles and adults. In contrast to CREB, we found no differences in pCaMKII e...

  6. External bioenergy-induced increases in intracellular free calcium concentrations are mediated by Na+/Ca2+ exchanger and L-type calcium channel.

    Science.gov (United States)

    Kiang, Juliann G; Ives, John A; Jonas, Wayne B

    2005-03-01

    External bioenergy (EBE, energy emitted from a human body) has been shown to increase intracellular calcium concentration ([Ca2+]i, an important factor in signal transduction) and regulate the cellular response to heat stress in cultured human lymphoid Jurkat T cells. In this study, we wanted to elucidate the underlying mechanisms. A bioenergy specialist emitted bioenergy sequentially toward tubes of cultured Jurkat T cells for one 15-minute period in buffers containing different ion compositions or different concentrations of inhibitors. [Ca2+], was measured spectrofluorometrically using the fluorescent probe fura-2. The resting [Ca2+]i in Jurkat T cells was 70 +/- 3 nM (n = 130) in the normal buffer. Removal of external calcium decreased the resting [Ca2+]i to 52 +/- 2 nM (n = 23), indicating that Ca2+ entry from the external source is important for maintaining the basal level of [Ca2+]i. Treatment of Jurkat T cells with EBE for 15 min increased [Ca2+]i by 30 +/- 5% (P EBE did not attenuate [Ca2+]i responsiveness to EBE. Removal of external Ca2+ or Na+, but not Mg2+, inhibited the EBE-induced increase in [Ca2+]i. Dichlorobenzamil, an inhibitor of Na+/Ca2+ exchangers, also inhibited the EBE-induced increase in [Ca2+]i in a concentration-dependent manner with an IC50 of 0.11 +/- 0.02 nM. When external [K+] was increased from 4.5 mM to 25 mM, EBE decreased [Ca2+]i. The EBE-induced increase was also blocked by verapamil, an L-type voltage-gated Ca2+ channel blocker. These results suggest that the EBE-induced [Ca2+]i increase may serve as an objective means for assessing and validating bioenergy effects and those specialists claiming bioenergy capability. The increase in [Ca2+]i is mediated by activation of Na+/Ca2+ exchangers and opening of L-type voltage-gated Ca2+ channels.

  7. Calcium-Mediated Abiotic Stress Signaling in Roots.

    Science.gov (United States)

    Wilkins, Katie A; Matthus, Elsa; Swarbreck, Stéphanie M; Davies, Julia M

    2016-01-01

    Roots are subjected to a range of abiotic stresses as they forage for water and nutrients. Cytosolic free calcium is a common second messenger in the signaling of abiotic stress. In addition, roots take up calcium both as a nutrient and to stimulate exocytosis in growth. For calcium to fulfill its multiple roles must require strict spatio-temporal regulation of its uptake and efflux across the plasma membrane, its buffering in the cytosol and its sequestration or release from internal stores. This prompts the question of how specificity of signaling output can be achieved against the background of calcium's other uses. Threats to agriculture such as salinity, water availability and hypoxia are signaled through calcium. Nutrient deficiency is also emerging as a stress that is signaled through cytosolic free calcium, with progress in potassium, nitrate and boron deficiency signaling now being made. Heavy metals have the capacity to trigger or modulate root calcium signaling depending on their dose and their capacity to catalyze production of hydroxyl radicals. Mechanical stress and cold stress can both trigger an increase in root cytosolic free calcium, with the possibility of membrane deformation playing a part in initiating the calcium signal. This review addresses progress in identifying the calcium transporting proteins (particularly channels such as annexins and cyclic nucleotide-gated channels) that effect stress-induced calcium increases in roots and explores links to reactive oxygen species, lipid signaling, and the unfolded protein response. PMID:27621742

  8. Porcine Circovirus Type 2 Activates CaMMKβ to Initiate Autophagy in PK-15 Cells by Increasing Cytosolic Calcium

    Science.gov (United States)

    Gu, Yuanxing; Qi, Baozhu; Zhou, Yingshan; Jiang, Xiaowu; Zhang, Xian; Li, Xiaoliang; Fang, Weihuan

    2016-01-01

    Porcine circovirus type 2 (PCV2) induces autophagy via the 5′ adenosine monophosphate-activated protein kinase (AMPK)/extracellular signal-regulated kinase (ERK)/tuberous sclerosis complex 2 (TSC2)/mammalian target of rapamycin (mTOR) pathway in pig kidney PK-15 cells. However, the underlying mechanisms of AMPK activation in autophagy induction remain unknown. With specific inhibitors and RNA interference (RNAi), we show that PCV2 infection upregulated calcium/calmodulin-dependent protein kinase kinase-beta (CaMKKβ) by increasing cytosolic Ca2+ via inositol 1,4,5-trisphosphate receptor (IP3R). Elevation of cytosolic calcium ion (Ca2+) did not seem to involve inositol 1,4,5-trisphosphate (IP3) release from phosphatidylinositol 4,5-bisphosphate (PIP2) by phosphoinositide phospholipase C-gamma (PLC-γ). CaMKKβ then activated both AMPK and calcium/calmodulin-dependent protein kinase I (CaMKI). PCV2 employed CaMKI and Trp-Asp (WD) repeat domain phosphoinositide-interacting protein 1 (WIPI1) as another pathway additional to AMPK signaling in autophagy initiation. Our findings could help better understanding of the signaling pathways of autophagy induction as part of PCV2 pathogenesis. Further research is warranted to study if PCV2 interacts directly with IP3R or indirectly with the molecules that antagonize IP3R activity responsible for increased cytosolic Ca2+ both in PK-15 cells and PCV2-targeted primary cells from pigs. PMID:27213427

  9. Porcine Circovirus Type 2 Activates CaMMKβ to Initiate Autophagy in PK-15 Cells by Increasing Cytosolic Calcium

    Directory of Open Access Journals (Sweden)

    Yuanxing Gu

    2016-05-01

    Full Text Available Porcine circovirus type 2 (PCV2 induces autophagy via the 5′ adenosine monophosphate-activated protein kinase (AMPK/extracellular signal-regulated kinase (ERK/tuberous sclerosis complex 2 (TSC2/mammalian target of rapamycin (mTOR pathway in pig kidney PK-15 cells. However, the underlying mechanisms of AMPK activation in autophagy induction remain unknown. With specific inhibitors and RNA interference (RNAi, we show that PCV2 infection upregulated calcium/calmodulin-dependent protein kinase kinase-beta (CaMKKβ by increasing cytosolic Ca2+ via inositol 1,4,5-trisphosphate receptor (IP3R. Elevation of cytosolic calcium ion (Ca2+ did not seem to involve inositol 1,4,5-trisphosphate (IP3 release from phosphatidylinositol 4,5-bisphosphate (PIP2 by phosphoinositide phospholipase C-gamma (PLC-γ. CaMKKβ then activated both AMPK and calcium/calmodulin-dependent protein kinase I (CaMKI. PCV2 employed CaMKI and Trp-Asp (WD repeat domain phosphoinositide-interacting protein 1 (WIPI1 as another pathway additional to AMPK signaling in autophagy initiation. Our findings could help better understanding of the signaling pathways of autophagy induction as part of PCV2 pathogenesis. Further research is warranted to study if PCV2 interacts directly with IP3R or indirectly with the molecules that antagonize IP3R activity responsible for increased cytosolic Ca2+ both in PK-15 cells and PCV2-targeted primary cells from pigs.

  10. Immunoglobulin Fc gamma receptor promotes immunoglobulin uptake, immunoglobulin-mediated calcium increase, and neurotransmitter release in motor neurons

    Science.gov (United States)

    Mohamed, Habib A.; Mosier, Dennis R.; Zou, Ling L.; Siklos, Laszlo; Alexianu, Maria E.; Engelhardt, Jozsef I.; Beers, David R.; Le, Wei-dong; Appel, Stanley H.

    2002-01-01

    Receptors for the Fc portion of immunoglobulin G (IgG; FcgammaRs) facilitate IgG uptake by effector cells as well as cellular responses initiated by IgG binding. In earlier studies, we demonstrated that amyotrophic lateral sclerosis (ALS) patient IgG can be taken up by motor neuron terminals and transported retrogradely to the cell body and can alter the function of neuromuscular synapses, such as increasing intracellular calcium and spontaneous transmitter release from motor axon terminals after passive transfer. In the present study, we examined whether FcgammaR-mediated processes can contribute to these effects of ALS patient immunoglobulins. F(ab')(2) fragments (which lack the Fc portion) of ALS patient IgG were not taken up by motor axon terminals and were not retrogradely transported. Furthermore, in a genetically modified mouse lacking the gamma subunit of the FcR, the uptake of whole ALS IgG and its ability to enhance intracellular calcium and acetylcholine release were markedly attenuated. These data suggest that FcgammaRs appear to participate in IgG uptake into motor neurons as well as IgG-mediated increases in intracellular calcium and acetylcholine release from motor axon terminals. Copyright 2002 Wiley-Liss, Inc.

  11. EPITHELIAL-CELL PROLIFERATION IN THE SIGMOID COLON OF PATIENTS WITH ADENOMATOUS POLYPS INCREASES DURING ORAL CALCIUM SUPPLEMENTATION

    NARCIS (Netherlands)

    KLEIBEUKER, JH; WELBERG, JWM; MULDER, NH; VANDERMEER, R; CATS, A; LIMBURG, AJ; KREUMER, WMT; HARDONK, MJ; DEVRIES, EGE

    1993-01-01

    To study the effect of oral supplemental calcium on colonic epithelial proliferation, 17 adenomatous polyp patients received 1.5 g Ca2+ as calcium carbonate daily during 12 weeks, while on a calcium constant diet, based on the patients' habitual diet. Seven subsequently continued calcium supplementa

  12. IgG from Amyotrophic Lateral Sclerosis Patients Increases Current Through P-Type Calcium Channels in Mammalian Cerebellar Purkinje Cells and in Isolated Channel Protein in Lipid Bilayer

    Science.gov (United States)

    Llinas, R.; Sugimori, M.; Cherksey, B. D.; Smith, R. Glenn; Delbono, O.; Stefani, E.; Appel, S.

    1993-12-01

    The effect of the IgG from amyotrophic lateral sclerosis (ALS) patients was tested on the voltage-dependent barium currents (IBa) in mammalian dissociated Purkinje cells and in isolated P-type calcium channels in lipid bilayers. Whole cell clamp of Purkinje cells demonstrates that ALS IgG increases the amplitude of IBa without modifying their voltage kinetics. This increased IBa could be blocked by a purified nonpeptide toxin from Agelenopsis aperta venom (purified funnel-web spider toxin) or by a synthetic polyamine analog (synthetic funnel-web spider toxin) and by a peptide toxin from the same spider venom, ω-Aga-IVA. Similar results were obtained on single-channel recordings from purified P channel protein. The addition of ALS IgG increased single-channel IBa open time without affecting slope conductance. The results described above were not seen with normal human IgG nor with boiled ALS IgG. It is concluded that ALS IgG enhances inward current through P-type calcium channels. Since P-type Ca2+ channels are present in motoneuron axon terminals, we propose that the enhanced calcium current triggered by ALS IgG may contribute to neuronal damage in ALS.

  13. Neural substrate of an increase in sensory sampling triggered by a motor command in a gymnotid fish.

    Science.gov (United States)

    Comas, Virginia; Borde, Michel

    2010-10-01

    Despite recent advances that have elucidated the effects of collateral of motor commands on sensory processing structures, the neural mechanisms underlying the modulation of active sensory systems by internal motor-derived signals remains poorly understood. This study deals with the neural basis of the modulation of the motor component of an active sensory system triggered by a central motor command in a gymnotid fish. In Gymnotus omarorum, activation of Mauthner cells, a pair of reticulospinal neurons responsible for the initiation of escape responses in most teleosts, evokes an abrupt and prolonged increase in the rate of the electric organ discharge (EOD), the output signal of the electrogenic component of the active electrosensory system. We show here that prepacemaker neural structures (PPs) that control the discharge of the command nucleus for EODs are key elements of this modulation. Retrograde labeling combined with injections of glutamate at structures that contain labeled neurons showed that PPs are composed of a bilateral group of dispersed brain stem neurons that extend from the diencephalon to the caudal medulla. Blockade of discrete PPs regions during the Mauthner cell-initiated electrosensory modulation indicate that the long duration of this modulation relied on activation of diencephalic PPs, whereas its peak amplitude depended on the recruitment of medullary PPs. Temporal correlation of motor and sensory consequences of Mauthner cell activation suggests that the Mauthner cell-initiated enhancement of electrosensory sampling is involved in the selection of escape trajectory. PMID:20719924

  14. Nitric oxide enhances increase in cytosolic Ca(2+) and promotes nicotine-triggered MAPK pathway in PC12 cells.

    Science.gov (United States)

    Kajiwara, Aya; Tsuchiya, Yukihiro; Takata, Tsuyoshi; Nyunoya, Mayumi; Nozaki, Naohito; Ihara, Hideshi; Watanabe, Yasuo

    2013-11-01

    The purpose of this study was to investigate the roles of neuronal nitric oxide synthase (nNOS), Ca(2+)/calmodulin (CaM)-dependent protein kinases (CaMKs), and protein kinase C (PKC) in nicotine-induced extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) activation. Treatment with nicotine stimulated ERK1/2 and p38 MAPK phosphorylation in the PC12 cells expressing nNOS (NPC12 cells) as compared with that in control PC12 cells. An inhibitor of L-type voltage-sensitive Ca(2+) channel suppressed the nicotine-induced phosphorylation of p38 MAPK. The inhibition of CaMK-kinase, the upstream activator of CaMKI and CaMKIV, did not inhibit the enhanced their phosphorylation. ERK1/2 phosphorylation was attenuated by inhibitors of p38 MAPK, PKC, and MAPK-kinase 1/2, indicating the involvement of these protein kinases upstream of ERK1/2. Furthermore, we found that nNOS expression enhances the nicotine-induced increase in the intracellular concentration of Ca(2+), using the Ca(2+)-sensitive fluorescent probe Fura2. These data suggest that NO promotes nicotine-triggered Ca(2+) transient in PC12 cells to activate possibly CaMKII, leading to sequential phosphorylation of p38 MAPK and ERK1/2.

  15. Two forms of the membrane-bound state of the first C2 domain (C2A) of synaptotagminⅠand calcium-triggered membrane insertion

    Institute of Scientific and Technical Information of China (English)

    HE Yuhong; LI Xianghui; WANG Fu; XUE Yi; SUI Senfang

    2003-01-01

    The synaptic vesicle protein synaptotagminⅠ (sytⅠ) is a vesicle trans membrane protein present in synaptic vesicles, which has been proposed as the Ca 2+ sensor that regulates secretion. The C2A domain is the membrane proximal part of its cytoplasmic domain. The interaction between C2A and lipid bilayer has be en considered to be essential for triggering neurotransmitter release. In the pr esent work, the measurements of membrane surface tension and surface concentrati on showed that the C2A domain of sytⅠexhibited two membrane-bound states: the s urface adsorption state and the membrane insertion state. The surface absorption state formed in a Ca2+-independent manner with lower affinity, while the membra ne insertion state formed with high affinity was only found in the presence of C a2+. Both the Ca2+-independent and Ca2+-dependent sytⅠ- membrane interactions r equired anionic phospholipids, such as phosphatidylserine (PS). When expressed i nto rat pheochromocytoma (PC12) cells and human embryonic kidney (HEK-293) cells , as demonstrated by immunofluorescence staining and subcellular fractionation, most of the C2A was found at the plasma membrane, even when the cells were deple ted of Ca2+ by incubation with EGTA. These results suggested a new molecular mec hanism of sytⅠas a Ca2+ sensor in membrane fusion. Ca2+-independent surface ads orption might attach sytⅠto the release site during the docking or priming step . When intracellular Ca2+ increased, sytⅠtriggered the neurotransmitter release following the Ca2+-dependent penetration into the target membrane.

  16. Elevated extracellular calcium increases expression of bone morphogenetic protein-2 gene via a calcium channel and ERK pathway in human dental pulp cells

    International Nuclear Information System (INIS)

    Dental pulp cells, which have been shown to share phenotypical features with osteoblasts, are capable of differentiating into odontoblast-like cells and generating a dentin-like mineral structure. Elevated extracellular Ca2+Cao2+ has been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of Cao2+ signaling in odontogenesis remains unclear. We found that elevated Cao2+ increases bone morphogenetic protein (BMP)-2 gene expression in human dental pulp cells. The increase was modulated not only at a transcriptional level but also at a post-transcriptional level, because treatment with Ca2+ increased the stability of BMP-2 mRNA in the presence of actinomycin D, an inhibitor of transcription. A similar increase in BMP-2 mRNA level was observed in other human mesenchymal cells from oral tissue; periodontal ligament cells and gingival fibroblasts. However, the latter cells exhibited considerably lower expression of BMP-2 mRNA compared with dental pulp cells and periodontal ligament cells. The BMP-2 increase was markedly inhibited by pretreatment with an extracellular signal-regulated kinase (ERK) inhibitor, PD98059, and partially inhibited by the L-type Ca2+ channels inhibitor, nifedipine. However, pretreatment with nifedipine had no effect on ERK1/2 phosphorylation triggered by Ca2+, suggesting that the Ca2+ influx from Ca2+ channels may operate independently of ERK signaling. Dental pulp cells do not express the transcript of Ca2+-sensing receptors (CaSR) and only respond slightly to other cations such as Sr2+ and spermine, suggesting that dental pulp cells respond to Cao2+ to increase BMP-2 mRNA expression in a manner different from CaSR and rather specific for Cao2+ among cations.

  17. Does the long-term application of calcium superphosphate lead to an increase of the soil rare earth element contents?

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun; DENG Li-bin; YE Wan-Hui

    2006-01-01

    In order to test whether the long-term application of calcium superphosphate leads to an increase of the soil rare earth element contents, superphosphate fertilized soils were sampled and compared with superphosphate-free soils. Spectrophlame inductively coupled argon plasma atomic emission spectrophotometer (ICP-AES) was applied to quantify the rare earth elements (REEs). The total rare earth element contents in calcium superphosphate from Zhijin County, west part of Guizhou Province, China (produced by the sulphuric acid treatment of the apatites) are about 2.54 mg/g. Between 38 and 189 gREEs/hm2 per year (available for plants, estimated by 2% citric acid) will be introduced into the soil solution when applying 320 kg superphosphate/hm2 per year. The long-term application of the latter will increase the REE content by about 18% in the soil surface layer in these areas. A statistically significant increase of the content of the rare earths in some cultivated soils should not be neglected.

  18. Parvalbumin overexpression alters immune-mediated increases in intracellular calcium, and delays disease onset in a transgenic model of familial amyotrophic lateral sclerosis

    Science.gov (United States)

    Beers, D. R.; Ho, B. K.; Siklos, L.; Alexianu, M. E.; Mosier, D. R.; Mohamed, A. H.; Otsuka, Y.; Kozovska, M. E.; McAlhany, R. E.; Smith, R. G.; Appel, S. H.

    2001-01-01

    Intracellular calcium is increased in vulnerable spinal motoneurons in immune-mediated as well as transgenic models of amyotrophic lateral sclerosis (ALS). To determine whether intracellular calcium levels are influenced by the calcium-binding protein parvalbumin, we developed transgenic mice overexpressing parvalbumin in spinal motoneurons. ALS immunoglobulins increased intracellular calcium and spontaneous transmitter release at motoneuron terminals in control animals, but not in parvalbumin overexpressing transgenic mice. Parvalbumin transgenic mice interbred with mutant SOD1 (mSOD1) transgenic mice, an animal model of familial ALS, had significantly reduced motoneuron loss, and had delayed disease onset (17%) and prolonged survival (11%) when compared with mice with only the mSOD1 transgene. These results affirm the importance of the calcium binding protein parvalbumin in altering calcium homeostasis in motoneurons. The increased motoneuron parvalbumin can significantly attenuate the immune-mediated increases in calcium and to a lesser extent compensate for the mSOD1-mediated 'toxic-gain-of-function' in transgenic mice.

  19. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueqian [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen, The Netherlands and Center for Medical Imaging – North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Greuter, Marcel J. W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Groen, Jaap M. [Department of Radiology, Zaans Medical Center, 1500EE Zaandam (Netherlands); Bock, Geertruida H. de [Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Oudkerk, Matthijs [Center for Medical Imaging – North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, University of Utrecht, 3584CX Utrecht (Netherlands); Vliegenthart, Rozemarijn [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen, The Netherlands and Center for Medical Imaging – North East Netherlands, Department of Radiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands)

    2013-08-15

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT.Methods: Three artificial coronary arteries containing calcifications of different densities (high, medium, and low), and sizes (large, medium, and small), were studied in a moving cardiac phantom. Two 64-detector CT systems were used. The phantom moved at 0–90 mm/s in nontriggered low-dose CT as index test, and at 0–30 mm/s in ECG-triggered CT as reference. Differences in calcium scores between nontriggered and ECG-triggered CT were analyzed by t-test and 95% confidence interval. The sensitivity to detect calcification was calculated as the percentage of positive calcium scores.Results: Overall, calcium scores in nontriggered CT were not significantly different to those in ECG-triggered CT (p > 0.05). Calcium scores in nontriggered CT were within the 95% confidence interval of calcium scores in ECG-triggered CT, except predominantly at higher velocities (≥50 mm/s) for the high-density and large-size calcifications. The sensitivity for a nonzero calcium score was 100% for large calcifications, but 46%± 11% for small calcifications in nontriggered CT.Conclusions: When performing multiple measurements, good agreement in positive calcium scores is found between nontriggered thoracic and ECG-triggered cardiac CT. Agreement decreases with increasing coronary velocity. From this phantom study, it can be concluded that a high calcium score can be detected by nontriggered CT, and thus, that nontriggered CT likely can identify individuals at high risk of cardiovascular disease. On the other hand, a zero calcium score in nontriggered CT does not reliably exclude coronary calcification.

  20. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    International Nuclear Information System (INIS)

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT.Methods: Three artificial coronary arteries containing calcifications of different densities (high, medium, and low), and sizes (large, medium, and small), were studied in a moving cardiac phantom. Two 64-detector CT systems were used. The phantom moved at 0–90 mm/s in nontriggered low-dose CT as index test, and at 0–30 mm/s in ECG-triggered CT as reference. Differences in calcium scores between nontriggered and ECG-triggered CT were analyzed by t-test and 95% confidence interval. The sensitivity to detect calcification was calculated as the percentage of positive calcium scores.Results: Overall, calcium scores in nontriggered CT were not significantly different to those in ECG-triggered CT (p > 0.05). Calcium scores in nontriggered CT were within the 95% confidence interval of calcium scores in ECG-triggered CT, except predominantly at higher velocities (≥50 mm/s) for the high-density and large-size calcifications. The sensitivity for a nonzero calcium score was 100% for large calcifications, but 46%± 11% for small calcifications in nontriggered CT.Conclusions: When performing multiple measurements, good agreement in positive calcium scores is found between nontriggered thoracic and ECG-triggered cardiac CT. Agreement decreases with increasing coronary velocity. From this phantom study, it can be concluded that a high calcium score can be detected by nontriggered CT, and thus, that nontriggered CT likely can identify individuals at high risk of cardiovascular disease. On the other hand, a zero calcium score in nontriggered CT does not reliably exclude coronary calcification

  1. Increase in cone biomass and terpenophenolics in hops ( Humulus lupulus L.) by treatment with prohexadione-calcium.

    Science.gov (United States)

    Kavalier, Adam R; Pitra, Nicholi J; Koelling, Jared M; Coles, Mark C; Kennelly, Edward J; Matthews, Paul D

    2011-06-22

    Humulus lupulus L. (hop), a specialty crop bred for flavor characteristics of the inflorescence, is an essential ingredient in beer. Hop inflorescences, commonly known as hop cones, contain terpenophenolic compounds, which are important for beer flavoring and of interest in biomedical research. Hop breeders focus their efforts on increasing cone biomass and terpenophenolic content. As an alternative to traditional breeding, hops were treated with prohexadione-calcium (Pro-Ca), a growth inhibitor previously shown to have positive agronomic effects in several crops. Application of Pro-Ca to hop plants during cone maturation induced increases in cone biomass production by 1.5-19.6% and increased terpenophenolic content by 9.1-87.3%; however, some treatments also induced significant decreases in terpenophenolic content. Induced changes in cone biomass production and terpenophenolic accumulation were most dependent on cultivar and the developmental stage at which plants were treated. PMID:21598976

  2. Increased strontium uptake in trabecular bone of ovariectomized calcium-deficient rats treated with strontium ranelate or strontium chloride.

    Science.gov (United States)

    Pemmer, Bernhard; Hofstaetter, Jochen G; Meirer, Florian; Smolek, Stephan; Wobrauschek, Peter; Simon, Rolf; Fuchs, Robyn K; Allen, Matthew R; Condon, Keith W; Reinwald, Susan; Phipps, Roger J; Burr, David B; Paschalis, Eleftherios P; Klaushofer, Klaus; Streli, Christina; Roschger, Paul

    2011-11-01

    Based on clinical trials showing the efficacy to reduce vertebral and non-vertebral fractures, strontium ranelate (SrR) has been approved in several countries for the treatment of postmenopausal osteoporosis. Hence, it is of special clinical interest to elucidate how the Sr uptake is influenced by dietary Ca deficiency as well as by the formula of Sr administration, SrR versus strontium chloride (SrCl(2)). Three-month-old ovariectomized rats were treated for 90 days with doses of 25 mg kg(-1) d(-1) and 150 mg kg(-1) d(-1) of SrR or SrCl(2) at low (0.1% Ca) or normal (1.19% Ca) Ca diet. Vertebral bone tissue was analysed by confocal synchrotron-radiation-induced micro X-ray fluorescence and by backscattered electron imaging. Principal component analysis and k-means clustering of the acquired elemental maps of Ca and Sr revealed that the newly formed bone exhibited the highest Sr fractions and that low Ca diet increased the Sr uptake by a factor of three to four. Furthermore, Sr uptake in bone of the SrCl(2)-treated animals was generally lower compared with SrR. The study clearly shows that inadequate nutritional calcium intake significantly increases uptake of Sr in serum as well as in trabecular bone matrix. This indicates that nutritional calcium intake as well as serum Ca levels are important regulators of any Sr treatment.

  3. Nicotine enhancement of dopamine release by a calcium-dependent increase in the size of the readily releasable pool of synaptic vesicles.

    Science.gov (United States)

    Turner, Timothy J

    2004-12-15

    A major factor underlying compulsive tobacco use is nicotine-induced modulation of dopamine release in the mesolimbic reward pathway (Wise and Rompre, 1989). An established biochemical mechanism for nicotine-enhanced dopamine release is by activating presynaptic nicotinic acetylcholine receptors (nAChRs) (Wonnacott, 1997). Prolonged application of 10(-7) to 10(-5) m nicotine to striatal synaptosomes promoted a sustained efflux of [3H]dopamine. This nicotine effect was mediated by non-alpha7 nAChRs, because it was blocked by 5 mum mecamylamine but was resistant to 100 nm alpha-bungarotoxin (alphaBgTx). Dopamine release was diminished by omitting Na+ or by applying peptide calcium channel blockers, indicating that nAChRs trigger release by depolarizing the nerve terminals. However, because alpha7 receptors rapidly desensitize in the continuous presence of agonists, a repetitive stimulation protocol was used to evaluate the possible significance of desensitization. This protocol produced a transient increase in [3H]dopamine released by depolarization and a significant increase in the response to hypertonic solutions that measure the size of the readily releasable pool (RRP) of synaptic vesicles. The nicotine-induced increase in the size of the readily releasable pool was blocked by alphaBgTx and by the calmodulin antagonist calmidazolium, suggesting that Ca2+ entry through alpha7 nAChRs specifically enhances synaptic vesicle mobilization at dopamine terminals. Thus, nicotine enhances dopamine release by two complementary actions mediated by discrete nAChR subtypes and suggest that the alpha7 nAChR-mediated pathway is tightly and specifically coupled to refilling of the RRP of vesicles in dopamine terminals.

  4. The zinc sensing receptor, ZnR/GPR39, triggers metabotropic calcium signalling in colonocytes and regulates occludin recovery in experimental colitis.

    Science.gov (United States)

    Sunuwar, Laxmi; Medini, Michal; Cohen, Limor; Sekler, Israel; Hershfinkel, Michal

    2016-08-01

    Impaired epithelial barrier function is a hallmark of inflammatory bowel diseases, such as colitis, contributing to diarrhoea and perpetuating inflammation. We show that the zinc sensing receptor, ZnR/GPR39, triggers intracellular Ca(2+) signalling in colonocytes thereby inducing occludin expression. Moreover, ZnR/GPR39 is essential for epithelial barrier recovery in the dextran sodium sulfate (DSS) ulcerative colitis model. Loss of ZnR/GPR39 results in increased susceptibility to DSS-induced inflammation, owing to low expression of the tight junction protein occludin and impaired epithelial barrier. Recovery of wild-type (WT) mice from the DSS insult was faster than that of ZnR/GPR39 knockout (KO) mice. Enhanced recovery of the epithelial layer and increased crypt regeneration were observed in WT mice compared with ZnR/GPR39 KO, suggesting that ZnR/GPR39 is promoting epithelial barrier integrity following DSS insult. Indeed, cell proliferation and apical expression of occludin, following the DSS-induced epithelial erosion, were increased in WT tissue but not in ZnR/GPR39 KO tissue. Importantly, survival following DSS treatment was higher in WT mice compared with ZnR/GPR39 KO mice. Our results support a direct role for ZnR/GPR39 in promoting epithelial renewal and barrier function following DSS treatment, thereby affecting the severity of the disease. We suggest ZnR/GPR39 as a novel therapeutic target that can improve epithelial barrier function in colitis.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. PMID:27377730

  5. 鳕鱼皮胶原蛋白肽的促钙吸收作用%Calcium absorption increasing effect of collagen peptide from skin of Walleye Pollock

    Institute of Scientific and Technical Information of China (English)

    卢玉坤; 姜慧明; 王景峰; 王珊珊; 杨霞; 李八方

    2013-01-01

    目的 探究鳕鱼皮胶原蛋白酶解制得梯级多肽的促钙吸收作用.方法 从鳕鱼皮中提取胶原蛋白并酶解制得不同分子量段的胶原多肽,采用低钙饮食建造大鼠缺钙模型,检测大鼠骨钙含量、钙代谢指标和血清钙磷指标,探讨其促钙吸收作用.结果 与加钙组相比,各受试物均能提高大鼠骨钙含量;高低剂量的高分子量胶原多肽能显著提高钙吸收率(P<0.05),高低剂量的低中分子量胶原多肽能极显著提高钙吸收率(P<0.01);而高低剂量的中分子量胶原多肽还能显著提高钙储留率(P<0.05),高低剂量的低分子量胶原多肽能极显著提高钙储留率(P<0.01);同时,各受试物也能相应的提高大鼠的血清钙磷含量.结论 鳕鱼皮胶原蛋白多肽能明显提高大鼠对钙的吸收率和储留率,分子量越小,其促钙吸收效果越好.%Objective To investigate the calcium absorption increasing effect of collagen enzymatic cascade polypeptide from skin of Walleye Pollock.Methods The collagen was extracted from skin of Walleye Pollock and then broken down by enzymes into collagen peptide.The rat calcium deficiency model induced by low calcium diet was used to investigate the calcium absorption increasing effect by detecting the bone calcium content,the calcium metabolism indicators and the serum calcium and phosphorus indicators.Results Compared with calcium-fortified group,all the test substance samples increased the bone calcium content.The high and low doses of high molecular weight collagen peptide significantly increased the calcium absorption rate (P<0.05);the high and low doses of medium molecular weight collagen peptide and low molecular weight collagen peptide more significantly increased the calcium absorption rate (P<0.01).The high and low doses of medium molecular weight collagen peptide also significantly increased the calcium retention rate (P<0.05);the high and low doses of low molecular weight

  6. Elevated extracellular calcium increases expression of bone morphogenetic protein-2 gene via a calcium channel and ERK pathway in human dental pulp cells

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Hiroyuki [Division of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Nemoto, Eiji, E-mail: e-nemoto@umin.ac.jp [Division of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Kanaya, Sousuke; Hamaji, Nozomu; Sato, Hisae; Shimauchi, Hidetoshi [Division of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan)

    2010-04-16

    Dental pulp cells, which have been shown to share phenotypical features with osteoblasts, are capable of differentiating into odontoblast-like cells and generating a dentin-like mineral structure. Elevated extracellular Ca{sup 2+}Ca{sub o}{sup 2+} has been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of Ca{sub o}{sup 2+} signaling in odontogenesis remains unclear. We found that elevated Ca{sub o}{sup 2+} increases bone morphogenetic protein (BMP)-2 gene expression in human dental pulp cells. The increase was modulated not only at a transcriptional level but also at a post-transcriptional level, because treatment with Ca{sup 2+} increased the stability of BMP-2 mRNA in the presence of actinomycin D, an inhibitor of transcription. A similar increase in BMP-2 mRNA level was observed in other human mesenchymal cells from oral tissue; periodontal ligament cells and gingival fibroblasts. However, the latter cells exhibited considerably lower expression of BMP-2 mRNA compared with dental pulp cells and periodontal ligament cells. The BMP-2 increase was markedly inhibited by pretreatment with an extracellular signal-regulated kinase (ERK) inhibitor, PD98059, and partially inhibited by the L-type Ca{sup 2+} channels inhibitor, nifedipine. However, pretreatment with nifedipine had no effect on ERK1/2 phosphorylation triggered by Ca{sup 2+}, suggesting that the Ca{sup 2+} influx from Ca{sup 2+} channels may operate independently of ERK signaling. Dental pulp cells do not express the transcript of Ca{sup 2+}-sensing receptors (CaSR) and only respond slightly to other cations such as Sr{sup 2+} and spermine, suggesting that dental pulp cells respond to Ca{sub o}{sup 2+} to increase BMP-2 mRNA expression in a manner different from CaSR and rather specific for Ca{sub o}{sup 2+} among cations.

  7. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting.

    Directory of Open Access Journals (Sweden)

    Manoocher Soleimani

    Full Text Available Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2 and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2 in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of

  8. Spatial Distribution of the Increased Porosity of Cement Paste due to Calcium Leaching

    Institute of Scientific and Technical Information of China (English)

    WAN Keshu; LI Lin; XU Qiong; SUN Wei

    2015-01-01

    Using the tomography image, a method to characterize the 3D spatial distributions of increased porosity was proposed, and the increased porosity distributions of cement pastes with different leaching degrees were given using the current method. The leaching processes of CH/C-S-H and the contribution of CH/C-S-H leaching to porosity evolution were discussed. The proposed method can be applied to all cement-based materials with any leaching degrees. From the quantitative increased porosity results, we ifnd that the CH leaching ifnished quickly on the sharp CH leaching front.

  9. Reduction of exchangeable calcium and magnesium in soil with increasing pH

    Directory of Open Access Journals (Sweden)

    Miyazawa Mário

    2001-01-01

    Full Text Available A laboratory study was conducted with soil samples and synthetic solutions to investigate possible mechanisms related with reduction in KCl exchangeable Ca and Mg with increasing pH. Increasing soil pH over 5.3 with CaCO3 added to the soil and with NaOH solution added to soil/KCl suspension increased adsorptions of Ca and Mg. The reduction of Mg was greater than Ca and was related to the concentration of soil exchangeable Al. The decreases of soluble Ca and Mg following addition of Al in synthetic solution were at pH > 7.5. The isomorphic coprecipitation reaction with Al compounds may be the most possible mechanism responsible for the decrease of exchangeable Ca and Mg with increasing pH. Possible chemical reactions are presented.

  10. A Specific Transitory Increase in Intracellular Calcium Induced by Progesterone Promotes Acrosomal Exocytosis in Mouse Sperm.

    Science.gov (United States)

    Romarowski, Ana; Sánchez-Cárdenas, Claudia; Ramírez-Gómez, Héctor V; Puga Molina, Lis del C; Treviño, Claudia L; Hernández-Cruz, Arturo; Darszon, Alberto; Buffone, Mariano G

    2016-03-01

    During capacitation, sperm acquire the ability to undergo the acrosome reaction (AR), an essential step in fertilization. Progesterone produced by cumulus cells has been associated with various physiological processes in sperm, including stimulation of AR. An increase in intracellular Ca(2+) ([Ca(2+)]i) is necessary for AR to occur. In this study, we investigated the spatiotemporal correlation between the changes in [Ca(2+)]i and AR in single mouse spermatozoa in response to progesterone. We found that progesterone stimulates an [Ca(2+)]i increase in five different patterns: gradual increase, oscillatory, late transitory, immediate transitory, and sustained. We also observed that the [Ca(2+)]i increase promoted by progesterone starts at either the flagellum or the head. We validated the use of FM4-64 as an indicator for the occurrence of the AR by simultaneously detecting its fluorescence increase and the loss of EGFP in transgenic EGFPAcr sperm. For the first time, we have simultaneously visualized the rise in [Ca(2+)]i and the process of exocytosis in response to progesterone and found that only a specific transitory increase in [Ca(2+)]i originating in the sperm head promotes the initiation of AR. PMID:26819478

  11. Young adolescents who respond to an inulin-type fructan substantially increase total absorbed calcium and daily calcium accretion to the skeleton

    Science.gov (United States)

    Calcium absorption and whole-body bone mineral content are greater in young adolescents who receive 8 g/d of Synergy, a mixture of inulin-type fructans (ITF), compared with those who received a maltodextrin control. Not all adolescents responded to this intervention, however. We evaluated 32 respond...

  12. Increased calcium content and inhomogeneity of mineralization render bone toughness in osteoporosis: mineralization, morphology and biomechanics of human single trabeculae.

    Science.gov (United States)

    Busse, Björn; Hahn, Michael; Soltau, Markus; Zustin, Jozef; Püschel, Klaus; Duda, Georg N; Amling, Michael

    2009-12-01

    The differentiation and degree of the effects of mineral content and/or morphology on bone quality remain, to a large extent, unanswered due to several microarchitectural particularities in spatial measuring fields (e.g., force transfer, trajectories, microcalli). Therefore, as the smallest basic component of cancellous bone, we focused on single trabeculae to investigate the effects of mineralization and structure, both independently and in superposition. Transiliac Bordier bone cores and T12 vertebrae were obtained from 20 females at autopsy for specimen preparation, enabling radiographical analyses, histomorphometry, Bone Mineral Density Distribution (BMDD) analyses, and trabecular singularization to be performed. Evaluated contact X-rays and histomorphometric limits from cases with osteoporotic vertebral fractures generated two subdivisions, osteoporotic (n=12, Ø 78 years) and non-osteoporotic (n=8, Ø 49 years) cases, based on fracture appearance and bone volume (BV/TV). Measurements of trabecular number (Tb.N.), trabecular separation (Tb.Sp.), trabecular thickness (Tb.Th.), trabecular bone pattern factor (TBPf) and eroded surface (ES/BS) were carried out to provide detailed structural properties of the investigated groups. The mechanical properties of 400 rod-like single vertebral trabeculae, assessed by three-point bending, were matched with mineral properties as quantified by BMDD analyses of cross-sectioned rod-like and plate-like trabeculae, both in superposition and independently. Non-osteoporotic iliac crests and vertebrae displayed linear dependency on structure parameters, whereas osteoporotic compartments proved to be non-correlated with bone structure. Independent of trabecular thickness, osteoporotic rod-like trabeculae showed decreases in Young's modulus, fracture load, yield strength, ultimate stress, work to failure and bending stiffness, along with significantly increased mean calcium content and calcium width. Non-osteoporotic trabeculae

  13. An increase in intracelluar free calcium ions modulated by cholinergic receptors in rat facial nucleus

    Institute of Scientific and Technical Information of China (English)

    SUN Da-wei; ZHOU Rui; LI Na; ZHANG Qiu-gui; ZHU Fu-gao

    2009-01-01

    Background Ca2+in the central nervous system plays important roles in brain physiology, including neuronal survival and regeneration in rats with injured facial motoneurons. The present research was to study the modulations of intracellular free Ca2+ concentrations by cholinergic receptors in rat facial nucleus, and the mechanisms of the modulations. Methods The fluorescence intensity of facial nucleus in Fluo-3 AM loaded acute brainstem slices was detected by applying intracellular free Ca2+ measurement technique via confocal laser scanning microscope. The changes of fluorescence intensity of facial nucleus indicate the average changes of intracellular free Ca2+ levels of the neurons. Results Acetylcholine was effective at increasing the fluorescence intensity of facial nucleus. Muscarine chlorlde induced a marked increase of fluorescence intensity in a concentration dependent fashion. The enhancement of fluorescence intensity by muscarine chloride was significantly reduced by thapsigargin (depletor of intracellular Ca2+ store; P0.05). And the increase of fluorescence intensity was also significantly inhibited by pirenzepine (M1 subtype selective antagonist; P0.05).Conclusions The data provide the evidence that muscarinic receptors may induce the increase of intracellular free Ca2+ levels through the Ca2+ release of intracellular Ca2+ stores, in a manner related to M1 and M3 subtypes of muscarinic receptors in rat facial nucleus. Nicotine may increase intracellular free Ca2+ concentrations via the influx of extracellular Ca2+ mainly across L-type voltage-gated Ca2+ channels, in a manner related to the α4β2 subtype of nicotinic receptors.

  14. Trigger finger

    Science.gov (United States)

    Digital stenosing tenosynovitis; Trigger digit; Trigger finger release ... JH. Carpal tunnel syndrome, ulnar tunnel syndrome, and stenosing tenosynovitis. In: Canale ST, Beaty JH, eds. Campbell's Operative ...

  15. Failure to reproduce increased calcium uptake in human lymphocytes at purported cyclotron resonance exposure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, A.V.; Miller, M.W.; Azadniv, M.; Brayman, A.A. (Rochester Univ., NY (USA). Dept. of Biophysics); Carstensen, E.L. (Rochester Univ., NY (USA). Dept. of Electrical Engineering); Cox, C. (Rochester Univ., NY (USA). Dept. of Biostatistics)

    1991-10-01

    An attempt was made to verify a report (Liboff et al. 1987) that a unique combination of DC and AC magnetic field exposures at room temperature results in a 3-fold increase in {sup 45}Ca{sup 2+} uptake by human lymphocytes in vitro. Exposures at 'resonance condition', as well as at frequencies and amplitudes above and below the reported effective exposure conditions, were without effect, as were exposures at 37deg C. Treatment with ionomycin (0.25 {mu}M), a positive control, resulted in a highly significant increase {sup 45}Ca{sup 2+} uptake. Some experiments were performed simultaneously by different investigators. Their results did not differ significantly. All experiments were conducted 'double blindly'. (orig.).

  16. Histamine H1 receptor induces cytosolic calcium increase and aquaporin translocation in human salivary gland cells.

    Science.gov (United States)

    Kim, Ji-Hyun; Park, Seong-Hae; Moon, Young Wha; Hwang, Sungmin; Kim, Donghoon; Jo, Su-Hyun; Oh, Seog Bae; Kim, Joong Soo; Jahng, Jeong Won; Lee, Jong-Ho; Lee, Sung Joong; Choi, Se-Young; Park, Kyungpyo

    2009-08-01

    One of the common side effects of antihistamine medicines is xerostomia (dry mouth). The current consensus is that antihistamine-induced xerostomia comes from an antimuscarinic effect. Although the effect of antihistamines on salivary secretion is both obvious and significant, the cellular mechanism whereby this happens is still unclear because of the lack of knowledge of histamine signaling in human salivary glands. Here, we have studied histamine receptors and the effect of antihistamines on human submandibular acinar cells. In primary cultured human submandibular gland and a HSG cell line, histamine increased the intracellular Ca(2+) concentration. The histamine-induced cytosolic free Ca(2+) concentration ([Ca(2+)](i)) increase was inhibited by histamine H1 receptor-specific antagonists, and the expression of the functional histamine H1 receptor was confirmed by reverse transcription-polymerase chain reaction. Interestingly, histamine pretreatment did not inhibit a subsequent carbachol-induced [Ca(2+)](i) rise without "heterologous desensitization." Chlorpheniramine inhibited a carbachol-induced [Ca(2+)](i) increase at a 100-fold greater concentration than histamine receptor antagonism, whereas astemizole and cetrizine showed more than 1000-fold difference, which in part explains the xerostomia-inducing potency among the antihistamines. Notably, histamine resulted in translocation of aquaporin-5 to the plasma membrane in human submandibular gland cells and green fluorescent protein-tagged aquaporin-5 expressing HSG cells. We found that histidine decarboxylase and the histamine H1 receptor are broadly distributed in submandibular gland cells, whereas choline acetyltransferase is localized only at the parasympathetic terminals. Our results suggest that human salivary gland cells express histamine H1 receptors and histamine-synthesizing enzymes, revealing the cellular mechanism of antihistamine-induced xerostomia. PMID:19443731

  17. Important role of PLC-γ1 in hypoxic increase in intracellular calcium in pulmonary arterial smooth muscle cells.

    Science.gov (United States)

    Yadav, Vishal R; Song, Tengyao; Joseph, Leroy; Mei, Lin; Zheng, Yun-Min; Wang, Yong-Xiao

    2013-02-01

    An increase in intracellular calcium concentration ([Ca(2+)](i)) in pulmonary arterial smooth muscle cells (PASMCs) induces hypoxic cellular responses in the lungs; however, the underlying molecular mechanisms remain incompletely understood. We report, for the first time, that acute hypoxia significantly enhances phospholipase C (PLC) activity in mouse resistance pulmonary arteries (PAs), but not in mesenteric arteries. Western blot analysis and immunofluorescence staining reveal the expression of PLC-γ1 protein in PAs and PASMCs, respectively. The activity of PLC-γ1 is also augmented in PASMCs following hypoxia. Lentiviral shRNA-mediated gene knockdown of mitochondrial complex III Rieske iron-sulfur protein (RISP) to inhibit reactive oxygen species (ROS) production prevents hypoxia from increasing PLC-γ1 activity in PASMCs. Myxothiazol, a mitochondrial complex III inhibitor, reduces the hypoxic response as well. The PLC inhibitor U73122, but not its inactive analog U73433, attenuates the hypoxic vasoconstriction in PAs and hypoxic increase in [Ca(2+)](i) in PASMCs. PLC-γ1 knockdown suppresses its protein expression and the hypoxic increase in [Ca(2+)](i). Hypoxia remarkably increases inositol 1,4,5-trisphosphate (IP(3)) production, which is blocked by U73122. The IP(3) receptor (IP(3)R) antagonist 2-aminoethoxydiphenyl borate (2-APB) or xestospongin-C inhibits the hypoxic increase in [Ca(2+)](i). PLC-γ1 knockdown or U73122 reduces H(2)O(2)-induced increase in [Ca(2+)](i) in PASMCs and contraction in PAs. 2-APB and xestospongin-C produce similar inhibitory effects. In conclusion, our findings provide novel evidence that hypoxia activates PLC-γ1 by increasing RISP-dependent mitochondrial ROS production in the complex III, which causes IP(3) production, IP(3)R opening, and Ca(2+) release, playing an important role in hypoxic Ca(2+) and contractile responses in PASMCs.

  18. Infrasound increases intracellular calcium concentration and induces apoptosis in hippocampi of adult rats.

    Science.gov (United States)

    Liu, Zhaohui; Gong, Li; Li, Xiaofang; Ye, Lin; Wang, Bin; Liu, Jing; Qiu, Jianyong; Jiao, Huiduo; Zhang, Wendong; Chen, Jingzao; Wang, Jiuping

    2012-01-01

    In the present study, we determined the effect of infrasonic exposure on apoptosis and intracellular free Ca²⁺ ([Ca²⁺]i) levels in the hippocampus of adult rats. Adult rats were randomly divided into the control and infrasound exposure groups. For infrasound treatment, animals received infrasonic exposure at 90 (8 Hz) or 130 dB (8 Hz) for 2 h per day. Hippocampi were dissected, and isolated hippocampal neurons were cultured. The [Ca²⁺]i levels in hippocampal neurons from adult rat brains were determined by Fluo-3/AM staining with a confocal microscope system on days 1, 7, 14, 21 and 28 following infrasonic exposure. Apoptosis was evaluated by Annexin V-FITC and propidium iodide double staining. Positive cells were sorted and analyzed by flow cytometry. Elevated [Ca²⁺]i levels were observed on days 14 and 21 after rats received daily treatment with 90 or 130 dB sound pressure level (SPL) infrasonic exposure (pinfrasound exposure, and significantly increased on day 14. Upon 130 dB infrasound treatment, apoptosis was first observed on day 14, whereas the number of apoptotic cells gradually decreased thereafter. Additionally, a marked correlation between cell apoptosis and [Ca²⁺]i levels was found on day 14 and 21 following daily treatment with 90 and 130 dB SPL, respectively. These results demonstrate that a period of infrasonic exposure induced apoptosis and upregulated [Ca²⁺]i levels in hippocampal neurons, suggesting that infrasound may cause damage to the central nervous system (CNS) through the Ca²⁺‑mediated apoptotic pathway in hippocampal neurons. PMID:21946944

  19. Calcium polycarbophil, a water absorbing polymer, increases bowel movement and prevents sennoside-induced diarrhea in dogs.

    Science.gov (United States)

    Saito, T; Yamada, T; Iwanaga, Y; Morikawa, K; Nagata, O; Kato, H; Mizumoto, A; Itoh, Z

    2000-07-01

    The effects of calcium polycarbophil (CP), a water-absorbing polymer, on bowel movement were examined in comparison with known laxatives and anti-diarrheal agents in dogs, a species that resembles humans for stool output. CP increased stool frequency, fecal water content and fecal weight in a dose-dependent manner, but did not induce diarrhea. Sennoside and carboxymethylcellulose sodium (CMC-Na) increased fecal water content and induced diarrhea at lower doses than that which enhanced stool frequency. Trimebutine decreased stool frequency, fecal weight and fecal water content, resulting in inhibition rather than stimulation of defecation. In sennoside-induced diarrhea, loperamide and CP improved stool consistency and this was accompanied by reduced fecal moisture and frequency of diarrhea. In contrast, CMC-Na aggravated stool consistency with increased fecal water content and frequency of diarrhea, and trimebutine had little noticeable effect apart from reducing fecal weight. Our results show that CP has both laxative and anti-diarrheal effects in dogs and differed from conventional laxatives and anti-diarrheal agents. CP may be a suitable agent for treatment of idiopathic constipation, secretory diarrhea and irritable bowel syndrome with alternating constipation and diarrhea and with either predominating in terms of less side effects such as diarrhea or constipation.

  20. Dynamic triggering

    Science.gov (United States)

    Hill, David P.; Prejean, Stephanie; Schubert, Gerald

    2015-01-01

    Dynamic stresses propagating as seismic waves from large earthquakes trigger a spectrum of responses at global distances. In addition to locally triggered earthquakes in a variety of tectonic environments, dynamic stresses trigger tectonic (nonvolcanic) tremor in the brittle–plastic transition zone along major plate-boundary faults, activity changes in hydrothermal and volcanic systems, and, in hydrologic domains, changes in spring discharge, water well levels, soil liquefaction, and the eruption of mud volcanoes. Surface waves with periods of 15–200 s are the most effective triggering agents; body-wave trigger is less frequent. Triggering dynamic stresses can be < 1 kPa.

  1. Activation of the adenosine A2A receptor attenuates experimental autoimmune encephalomyelitis and is associated with increased intracellular calcium levels.

    Science.gov (United States)

    Liu, Yumei; Zou, Haifeng; Zhao, Ping; Sun, Bo; Wang, Jinghua; Kong, Qingfei; Mu, Lili; Zhao, Sihan; Wang, Guangyou; Wang, Dandan; Zhang, Yao; Zhao, Jiaying; Yin, Pengqi; Liu, Lei; Zhao, Xiuli; Li, Hulun

    2016-08-25

    Multiple sclerosis (MS) is a common autoimmune disease that inevitably causes inflammatory nerve demyelination. However, an effective approach to prevent its course is still lacking and urgently needed. Recently, the adenosine A2A receptor (A2AR) has emerged as a novel inflammation regulator. Manipulation of A2AR activity may suppress the MS process and protect against nerve damage. To test this hypothesis, we treated murine experimental autoimmune encephalomyelitis (EAE), a model for MS, with the selective A2AR agonist, CGS21680 (CGS). We evaluated the effects of CGS on the pathological features of EAE progression, including CNS cellular infiltration, inflammatory cytokine expression, lymphocyte proliferation, and cell surface markers. Treatment with CGS significantly suppressed specific lymphocyte proliferation, reduced infiltration of CD4(+) T lymphocytes, and attenuated the expression of inflammatory cytokines, which in turn inhibited the EAE progression. For the first time, we demonstrate that CGS can increase the intracellular calcium concentration ([Ca(2+)]i) in murine lymphocytes, which may be the mechanism underlying the suppressive effects of CGS-induced A2AR activation on EAE progression. Our findings strongly suggest that A2AR is a potential therapeutic target for MS and provide insight into the mechanism of action of A2AR agonists, which may offer a therapeutic option for this disease. PMID:27217214

  2. Indole-3-acetic acid-induced oxidative burst and an increase in cytosolic calcium ion concentration in rice suspension culture.

    Science.gov (United States)

    Nguyen, Hieu T H; Umemura, Kenji; Kawano, Tomonori

    2016-08-01

    Indole-3-acetic acid (IAA) is the major natural auxin involved in the regulation of a variety of growth and developmental processes such as division, elongation, and polarity determination in growing plant cells. It has been shown that dividing and/or elongating plant cells accompanies the generation of reactive oxygen species (ROS) and a number of reports have suggested that hormonal actions can be mediated by ROS through ROS-mediated opening of ion channels. Here, we surveyed the link between the action of IAA, oxidative burst, and calcium channel activation in a transgenic cells of rice expressing aequorin in the cytosol. Application of IAA to the cells induced a rapid and transient generation of superoxide which was followed by a transient increase in cytosolic Ca(2+) concentration ([Ca(2+)]c). The IAA-induced [Ca(2+)]c elevation was inhibited by Ca(2+) channel blockers and a Ca(2+) chelator. Furthermore, ROS scavengers effectively blocked the action of IAA on [Ca(2+)]c elevation. PMID:27149194

  3. Melatonin increases intracellular calcium in the liver, muscle, white adipose tissues and pancreas of diabetic obese rats.

    Science.gov (United States)

    Agil, A; Elmahallawy, E K; Rodríguez-Ferrer, J M; Adem, A; Bastaki, S M; Al-Abbadi, I; Fino Solano, Y A; Navarro-Alarcón, M

    2015-08-01

    Melatonin, a widespread substance with antioxidant and anti-inflammatory properties, has been found to act as an antidiabetic agent in animal models, regulating the release and action of insulin. However, the molecular bases of this antidiabetic action are unknown, limiting its application in humans. Several studies have recently shown that melatonin can modify calcium (Ca(2+)) in diabetic animals, and Ca(2+) has been reported to be involved in glucose homeostasis. The objective of the present study was to assess whether the antidiabetic effect of chronic melatonin at pharmacological doses is established via Ca(2+) regulation in different tissues in an animal model of obesity-related type 2 diabetes, using Zücker diabetic fatty (ZDF) rats and their lean littermates, Zücker lean (ZL) rats. After the treatments, flame atomic absorption spectrometry was used to determine Ca(2+) levels in the liver, muscle, main types of internal white adipose tissue, subcutaneous lumbar fat, pancreas, brain, and plasma. This study reports for the first time that chronic melatonin administration (10 mg per kg body weight per day for 6 weeks) increases Ca(2+) levels in muscle, liver, different adipose tissues, and pancreas in ZDF rats, although there were no significant changes in their brain or plasma Ca(2+) levels. We propose that this additional peripheral dual action mechanism underlies the improvement in insulin sensitivity and secretion previously documented in samples from the same animals. According to these results, indoleamine may be a potential candidate for the treatment of type 2 diabetes mellitus associated with obesity.

  4. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to lactose and increase in calcium absorption leading to an increase in calcium retention (ID 668) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of health...... claims in relation to lactose and increase in calcium absorption leading to an increase in calcium retention. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member...... that the claimed effect (improved nutrient absorption) is only considered beneficial where absorption is a limiting factor for the maintenance of adequate status of the nutrient and where increased absorption leads to increased retention. The Panel considers that an increase in calcium absorption leading...

  5. DMSO triggers the generation of ROS leading to an increase in artemisinin and dihydroartemisinic acid in Artemisia annua shoot cultures

    OpenAIRE

    Mannan, Abdul; Liu, Chunzhao; Arsenault, Patrick R.; Towler, Melissa J.; Vail, Dan R.; Lorence, Argelia; Weathers, Pamela J.

    2009-01-01

    The antimalarial sesquiterpene, artemisinin, is in short supply; demand is not being met, and the role of artemisinin in the plant is not well established. Prior work showed that addition of dimethyl sulfoxide (DMSO) to seedlings increased artemisinin in their shoots and this study further investigated that serendipitous observation. When in vitro-cultured Artemisia annua rooted shoots were fed different amounts of DMSO (0–2.0% v/v), artemisinin levels doubled and showed biphasic optima at 0....

  6. Deletion of Wiskott-Aldrich syndrome protein triggers Rac2 activity and increased cross-presentation by dendritic cells.

    Science.gov (United States)

    Baptista, Marisa A P; Keszei, Marton; Oliveira, Mariana; Sunahara, Karen K S; Andersson, John; Dahlberg, Carin I M; Worth, Austen J; Liedén, Agne; Kuo, I-Chun; Wallin, Robert P A; Snapper, Scott B; Eidsmo, Liv; Scheynius, Annika; Karlsson, Mikael C I; Bouma, Gerben; Burns, Siobhan O; Forsell, Mattias N E; Thrasher, Adrian J; Nylén, Susanne; Westerberg, Lisa S

    2016-01-01

    Wiskott-Aldrich syndrome (WAS) is caused by loss-of-function mutations in the WASp gene. Decreased cellular responses in WASp-deficient cells have been interpreted to mean that WASp directly regulates these responses in WASp-sufficient cells. Here, we identify an exception to this concept and show that WASp-deficient dendritic cells have increased activation of Rac2 that support cross-presentation to CD8(+) T cells. Using two different skin pathology models, WASp-deficient mice show an accumulation of dendritic cells in the skin and increased expansion of IFNγ-producing CD8(+) T cells in the draining lymph node and spleen. Specific deletion of WASp in dendritic cells leads to marked expansion of CD8(+) T cells at the expense of CD4(+) T cells. WASp-deficient dendritic cells induce increased cross-presentation to CD8(+) T cells by activating Rac2 that maintains a near neutral pH of phagosomes. Our data reveals an intricate balance between activation of WASp and Rac2 signalling pathways in dendritic cells. PMID:27425374

  7. The effect of GlycoPEGylation on the physical stability of human rFVIIa with increasing calcium chloride concentration

    DEFF Research Database (Denmark)

    Plesner, Bitten; Westh, Peter; Hvidt, Søren;

    2011-01-01

    The effects of calcium chloride on the structural, kinetic and thermal stability of recombinant human factor VIIa (rFVIIa) were investigated using rFVIIa and two GlycoPEGylated recombinant human FVIIa derivatives, a linear 10 kDa PEG and a branched 40 kDa PEG, respectively. Three different CaCl(2...

  8. Pharmacological evaluation of the mechanisms involved in increased adiposity in zebrafish triggered by the environmental contaminant tributyltin.

    Science.gov (United States)

    Ouadah-Boussouf, Nafia; Babin, Patrick J

    2016-03-01

    One proposed contributing factor to the rise in overweight and obesity is exposure to endocrine disrupting chemicals. Tributyltin chloride (TBT), an organotin, induces adipogenesis in cell culture models and may increases adipose mass in vivo in vertebrate model organisms. It has been hypothesized that TBT acts via the peroxisome proliferator activated receptor (PPAR)γ-dependent pathway. However, the mechanisms involved in the effects of TBT exposure on in vivo adipose tissue metabolism remain unexplored. Semitransparent zebrafish larvae, with their well-developed white adipose tissue, offer a unique opportunity for studying the effects of toxicant chemicals and pharmaceuticals on adipocyte biology and whole-organism adiposity in a vertebrate model. Within hours, zebrafish larvae, treated at environmentally-relevant nanomolar concentrations of TBT, exhibited a remarkable increase in adiposity linked to adipocyte hypertrophy. Under the experimental conditions used, we also demonstrated that zebrafish larvae adipose tissue proved to be highly responsive to selected human nuclear receptor agonists and antagonists. Retinoid X receptor (RXR) homodimers and RXR/liver X receptor heterodimers were suggested to be in vivo effectors of the obesogenic effect of TBT on zebrafish white adipose tissue. RXR/PPARγ heterodimers may be recruited to modulate adiposity in zebrafish but were not a necessary requirement for the short term in vivo TBT obesogenic effect. Together, the present results suggest that TBT may induce the promotion of triacylglycerol storage in adipocytes via RXR-dependent pathways without necessary using PPAR isoforms. PMID:26812627

  9. Increase in intracellular calcium and activation of protein kinase C in the expression of lymphokine receptors and the proliferation of murine B-cells

    Energy Technology Data Exchange (ETDEWEB)

    Proust, J.; Filburn, C.; Chrest, F.; Buchholz, M.; Nordin, A.

    1986-03-01

    BCGF dependent B cell proliferation requires costimulation by anti-..mu.. whereas IL2 dependent B cell proliferation requires preactivation by both anti-..mu.. and LPS. These studies show that in the BCGF dependent pathway the activation signal delivered by anti-..mu.. can be mimicked by an increase in intracellular calcium ((Ca/sup 2 +/)i) induced by the calcium ionophore, Ionomycin. In the IL2 dependent pathway, the additional signal delivered by LPS that leads to IL2 receptors expression and cell proliferation, can be replaced by the phorbol ester PMA as well as the diacylglycerol sn-1,2-dioctanoyl glycerol (DiC8), both shown to induce protein kinase C (PKc) activation. In agreement with these observations they show that LPS activates PKc with no concomitant increase in intracellular calcium ((Ca/sup 2 +/)i), while anti-..mu.. induces an increase in (Ca/sup 2 +/)i but no PKc activation. (Ca/sup 2 +/)i increase and PKc activation are both critical for the expression of IL2 receptor and the subsequent IL2 proliferation whereas an increase in (Ca/sup 2 +/)i is sufficient to induce BCGF dependent proliferation. These results suggest that the activation signals leading to BCGF and IL2 dependent proliferation proceed through 2 different biochemical pathways.

  10. The mechanism of hetero-synaptic interaction based on spatiotemporal intracellular calcium dynamics.

    Directory of Open Access Journals (Sweden)

    Daiki Futagi

    2014-03-01

    Full Text Available In recent physiological experiments focusing on synaptic plasticity, it is shown that synaptic modifications induced at one synapse are accompanied by hetero-synaptic changes at neighbor sites (Bi, 2002. These evidences imply that the hetero-synaptic interaction plays an important role in reconfiguration of synaptic connections to form and maintain functional neural circuits (Takahashi et al., 2012. Although the mechanism of the interaction is still unclear, some physiological studies suggest that the hetero-synaptic interaction could be caused by propagation of intracellular calcium signals (Nishiyama et al., 2000. Concretely, a spike-triggered calcium increase initiates calcium ion propagation along a dendrite through activation of molecular processes at neighboring sites. Here we hypothesized that the mechanism of the hetero-synaptic interaction was based on the intracellular calcium signaling, which is regulated by interactions between NMDA receptors (NMDARs, voltage-dependent calcium channels (VDCCs and Ryanodine receptors (RyRs on endoplasmic reticulum (ER. To assess realizability of the hypothesized interaction mechanism, we simulated intracellular calcium dynamics at a cellular level, using the computational model that integrated the model of intracellular calcium dynamics (Keizer and Levine, 1996 and the multi-compartment neuron model (Poirazi et al., 2003. Using the proposed computational model, we induced calcium influxes at a local site in postsynaptic dendrite by controlling the spike timings of pre- and postsynaptic neurons. As a result, synchronized calcium influxes through NMDARs and VDCCs caused calcium release from ER. According to the phase plane analysis, RyR-mediated calcium release occurred when the calcium concentration in cytoplasm sufficiently increased under the condition of a high calcium concentration in ER. An NMDAR-mediated calcium influx was slow and persistent, consequently responsible for maintaining a high

  11. Metabotropic glutamate receptor 6 signaling enhances TRPM1 calcium channel function and increases melanin content in human melanocytes

    OpenAIRE

    Devi, Sulochana; Markandeya, Yogananda; Maddodi, Nityanand; Dhingra, Anuradha; Vardi, Noga; Ravi C Balijepalli; Setaluri, Vijayasaradhi

    2013-01-01

    Mutations in TRPM1, a calcium channel expressed in retinal bipolar cells and epidermal melanocytes, cause complete congenital stationary night blindness with no discernible skin phenotype. In the retina, TRPM1 activity is negatively coupled to metabotropic glutamate receptor 6 (mGluR6) signaling through Gαo and TRPM1 mutations result in the loss of responsiveness of TRPM1 to mGluR6 signaling. Here, we show that human melanocytes express mGluR6 and treatment of melanocytes with L-AP4, a type I...

  12. Acidosis and Urinary Calcium Excretion

    DEFF Research Database (Denmark)

    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 inhibition of calcium transport processes within the renal tubule. The mechanisms whereby acid alters the integrity and stability of bone have been examined extensively in the published literature. Here, after briefly reviewing this literature, we consider the effects of acid on calcium transport...

  13. Microdamage induced calcium efflux from bone matrix activates intracellular calcium signaling in osteoblasts via L-type and T-type voltage-gated calcium channels.

    Science.gov (United States)

    Jung, Hyungjin; Best, Makenzie; Akkus, Ozan

    2015-07-01

    Mechanisms by which bone microdamage triggers repair response are not completely understood. It has been shown that calcium efflux ([Ca(2+)]E) occurs from regions of bone undergoing microdamage. Such efflux has also been shown to trigger intracellular calcium signaling ([Ca(2+)]I) in MC3T3-E1 cells local to damaged regions. Voltage-gated calcium channels (VGCCs) are implicated in the entry of [Ca(2+)]E to the cytoplasm. We investigated the involvement of VGCC in the extracellular calcium induced intracellular calcium response (ECIICR). MC3T3-E1 cells were subjected to one dimensional calcium efflux from their basal aspect which results in an increase in [Ca(2+)]I. This increase was concomitant with membrane depolarization and it was significantly reduced in the presence of Bepridil, a non-selective VGCC inhibitor. To identify specific type(s) of VGCC in ECIICR, the cells were treated with selective inhibitors for different types of VGCC. Significant changes in the peak intensity and the number of [Ca(2+)]I oscillations were observed when L-type and T-type specific VGCC inhibitors (Verapamil and NNC55-0396, respectively) were used. So as to confirm the involvement of L- and T-type VGCC in the context of microdamage, cells were seeded on devitalized notched bone specimen, which were loaded to induce microdamage in the presence and absence of Verapamil and NNC55-0396. The results showed significant decrease in [Ca(2+)]I activity of cells in the microdamaged regions of bone when L- and T-type blockers were applied. This study demonstrated that extracellular calcium increase in association with damage depolarizes the cell membrane and the calcium ions enter the cell cytoplasm by L- and T-type VGCCs.

  14. Calcium signaling mediates cold sensing in insect tissues.

    Science.gov (United States)

    Teets, Nicholas M; Yi, Shu-Xia; Lee, Richard E; Denlinger, David L

    2013-05-28

    The ability to rapidly respond to changes in temperature is a critical adaptation for insects and other ectotherms living in thermally variable environments. In a process called rapid cold hardening (RCH), insects significantly enhance cold tolerance following brief (i.e., minutes to hours) exposure to nonlethal chilling. Although the ecological relevance of RCH is well-established, the underlying physiological mechanisms that trigger RCH are poorly understood. RCH can be elicited in isolated tissues ex vivo, suggesting cold-sensing and downstream hardening pathways are governed by brain-independent signaling mechanisms. We previously provided preliminary evidence that calcium is involved in RCH, and here we firmly establish that calcium signaling mediates cold sensing in insect tissues. In tracheal cells of the freeze-tolerant goldenrod gall fly, Eurosta solidaginis, chilling to 0 °C evoked a 40% increase in intracellular calcium concentration as determined by live-cell confocal imaging. Downstream of calcium entry, RCH conditions significantly increased the activity of calcium/calmodulin-dependent protein kinase II (CaMKII) while reducing phosphorylation of the inhibitory Thr306 residue. Pharmacological inhibitors of calcium entry, calmodulin activation, and CaMKII activity all prevented ex vivo RCH in midgut and salivary gland tissues, indicating that calcium signaling is required for RCH to occur. Similar results were obtained for a freeze-intolerant species, adults of the flesh fly, Sarcophaga bullata, suggesting that calcium-mediated cold sensing is a general feature of insects. Our results imply that insect tissues use calcium signaling to instantly detect decreases in temperature and trigger downstream cold-hardening mechanisms.

  15. Is vaccenic acid (18:1t n-7) associated with an increased incidence of hip fracture? An explanation for the calcium paradox.

    Science.gov (United States)

    Hamazaki, Kei; Suzuki, Nobuo; Kitamura, Kei-Ichiro; Hattori, Atsuhiko; Nagasawa, Tetsuro; Itomura, Miho; Hamazaki, Tomohito

    2016-06-01

    High calcium intake may increase hip fracture (HF) incidence. This phenomenon, known as the calcium paradox, might be explained by vaccenic acid (18:1t n-7, VA), the highly specific trans fatty acid (TFA) present in dairy products. First, we ecologically investigated the relationship between 18:1 TFA intake and HF incidence using data from 12 to 13 European countries collected before 2000; then we measured the effects of VA and elaidic acid (18:1t n-9, EA) on osteoblasts from goldfish scales (tissues very similar to mammalian bone), with alkaline phosphatase as a marker; and finally we measured the effect of VA on mRNA expression in the scales for the major bone proteins type I collagen and osteocalcin. HF incidence was significantly correlated with 18:1 TFA intake in men (r=0.57) and women (r=0.65). Incubation with 1μmol/L VA and EA for 48h significantly decreased alkaline phosphatase activity by 25% and 21%, respectively. Incubation of scales with 10μmol/L VA for 48h significantly decreased mRNA expression for type I collagen and osteocalcin (by about 50%). In conclusion, VA may be causatively related to HF and could explain the calcium paradox. It may be prudent to reduce 18:1 TFA intake, irrespective of trans positions, to prevent HF.

  16. Is vaccenic acid (18:1t n-7) associated with an increased incidence of hip fracture? An explanation for the calcium paradox.

    Science.gov (United States)

    Hamazaki, Kei; Suzuki, Nobuo; Kitamura, Kei-Ichiro; Hattori, Atsuhiko; Nagasawa, Tetsuro; Itomura, Miho; Hamazaki, Tomohito

    2016-06-01

    High calcium intake may increase hip fracture (HF) incidence. This phenomenon, known as the calcium paradox, might be explained by vaccenic acid (18:1t n-7, VA), the highly specific trans fatty acid (TFA) present in dairy products. First, we ecologically investigated the relationship between 18:1 TFA intake and HF incidence using data from 12 to 13 European countries collected before 2000; then we measured the effects of VA and elaidic acid (18:1t n-9, EA) on osteoblasts from goldfish scales (tissues very similar to mammalian bone), with alkaline phosphatase as a marker; and finally we measured the effect of VA on mRNA expression in the scales for the major bone proteins type I collagen and osteocalcin. HF incidence was significantly correlated with 18:1 TFA intake in men (r=0.57) and women (r=0.65). Incubation with 1μmol/L VA and EA for 48h significantly decreased alkaline phosphatase activity by 25% and 21%, respectively. Incubation of scales with 10μmol/L VA for 48h significantly decreased mRNA expression for type I collagen and osteocalcin (by about 50%). In conclusion, VA may be causatively related to HF and could explain the calcium paradox. It may be prudent to reduce 18:1 TFA intake, irrespective of trans positions, to prevent HF. PMID:27269708

  17. INHIBITING MAP KINASE ACTIVITY PREVENTS CALCIUM TRANSIENTS AND MITOSIS ENTRY IN EARLY SEA URCHIN EMBRYOS

    OpenAIRE

    Philipova, Rada; Larman, Mark G.; Leckie, Calum P.; Harrison, Patrick K.; Groigno, Laurence; Whitaker, Michael

    2005-01-01

    A transient calcium increase triggers nuclear envelope breakdown (mitosis entry) in sea urchin embryos. Cdk1/cyclin B kinase activation is also known to be required for mitosis entry. More recently MAP kinase activity has also been shown to increase during mitosis. In sea urchin embryos both kinases show a similar activation profile, peaking at the time of mitosis entry.

  18. Calmodulin activation by calcium transients in the postsynaptic density of dendritic spines.

    Directory of Open Access Journals (Sweden)

    Daniel X Keller

    Full Text Available The entry of calcium into dendritic spines can trigger a sequence of biochemical reactions that begins with the activation of calmodulin (CaM and ends with long-term changes to synaptic strengths. The degree of activation of CaM can depend on highly local elevations in the concentration of calcium and the duration of transient increases in calcium concentration. Accurate measurement of these local changes in calcium is difficult because the spaces are so small and the numbers of molecules are so low. We have therefore developed a Monte Carlo model of intracellular calcium dynamics within the spine that included calcium binding proteins, calcium transporters and ion channels activated by voltage and glutamate binding. The model reproduced optical recordings using calcium indicator dyes and showed that without the dye the free intracellular calcium concentration transient was much higher than predicted from the fluorescent signal. Excitatory postsynaptic potentials induced large, long-lasting calcium gradients across the postsynaptic density, which activated CaM. When glutamate was released at the synapse 10 ms before an action potential occurred, simulating activity patterns that strengthen hippocampal synapses, the calcium gradient and activation of CaM in the postsynaptic density were much greater than when the order was reversed, a condition that decreases synaptic strengths, suggesting a possible mechanism underlying the induction of long-term changes in synaptic strength. The spatial and temporal mechanisms for selectivity in CaM activation demonstrated here could be used in other signaling pathways.

  19. Triggering Klystrons

    Energy Technology Data Exchange (ETDEWEB)

    Stefan, Kelton D.; /Purdue U. /SLAC

    2010-08-25

    To determine if klystrons will perform to the specifications of the LCLS (Linac Coherent Light Source) project, a new digital trigger controller is needed for the Klystron/Microwave Department Test Laboratory. The controller needed to be programmed and Windows based user interface software needed to be written to interface with the device over a USB (Universal Serial Bus). Programming the device consisted of writing logic in VHDL (VHSIC (Very High Speed Integrated Circuits) hardware description language), and the Windows interface software was written in C++. Xilinx ISE (Integrated Software Environment) was used to compile the VHDL code and program the device, and Microsoft Visual Studio 2005 was used to compile the C++ based Windows software. The device was programmed in such a way as to easily allow read/write operations to it using a simple addressing model, and Windows software was developed to interface with the device over a USB connection. A method of setting configuration registers in the trigger device is absolutely necessary to the development of a new triggering system, and the method developed will fulfill this need adequately. More work is needed before the new trigger system is ready for use. The configuration registers in the device need to be fully integrated with the logic that will generate the RF signals, and this system will need to be tested extensively to determine if it meets the requirements for low noise trigger outputs.

  20. Calcium - urine

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003603.htm Calcium - urine To use the sharing features on this ... enable JavaScript. This test measures the amount of calcium in urine. All cells need calcium in order ...

  1. Calcium supplements

    Science.gov (United States)

    ... 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 ...

  2. The Journal of Nutrition, Volume 106, 1976: Decreased absorption of calcium, magnesium, zinc and phosphorus by humans due to increased fiber and phosphorus consumption as wheat bread.

    Science.gov (United States)

    Reinhold, J G; Faradji, B; Abadi, P; Ismail-Beigi, F

    1991-07-01

    During a 20 day period of high fiber consumption in the form of bread made partly from wheaten wholemeal, two men developed negative balances of calcium, magnesium, zinc and phosphorus due to increased fecal excretion of each element. The fecal losses correlated closely with fecal dry matter and phosphorus. Fecal dry matter, in turn, was directly proportional to fecal fiber excretion. Balances of nitrogen remained positive. Mineral elements were well-utilized by the same subjects during a 20 day period of white bread consumption.

  3. Optogenetic measurement of presynaptic calcium transients using conditional genetically encoded calcium indicator expression in dopaminergic neurons.

    Directory of Open Access Journals (Sweden)

    Carmelo Sgobio

    Full Text Available Calcium triggers dopamine release from presynaptic terminals of midbrain dopaminergic (mDA neurons in the striatum. However, calcium transients within mDA axons and axon terminals are difficult to study and little is known about how they are regulated. Here we use a newly-developed method to measure presynaptic calcium transients (PreCaTs in axons and terminals of mDA neurons with a genetically encoded calcium indicator (GECI GCaMP3 expressed in transgenic mice. Using a photomultiplier tube-based system, we measured electrical stimulation-induced PreCaTs of mDA neurons in dorsolateral striatum slices from these mice. Single-pulse stimulation produced a transient increase in fluorescence that was completely blocked by a combination of N- and P/Q-type calcium channel blockers. DA and cholinergic, but not serotoninergic, signaling pathways modulated the PreCaTs in mDA fibers. These findings reveal heretofore unexplored dynamic modulation of presynaptic calcium in nigrostriatal terminals.

  4. Mitochondrial Calcium Uptake Modulates Synaptic Vesicle Endocytosis in Central Nerve Terminals.

    Science.gov (United States)

    Marland, Jamie Roslin Keynes; Hasel, Philip; Bonnycastle, Katherine; Cousin, Michael Alan

    2016-01-29

    Presynaptic calcium influx triggers synaptic vesicle (SV) exocytosis and modulates subsequent SV endocytosis. A number of calcium clearance mechanisms are present in central nerve terminals that regulate intracellular free calcium levels both during and after stimulation. During action potential stimulation, mitochondria rapidly accumulate presynaptic calcium via the mitochondrial calcium uniporter (MCU). The role of mitochondrial calcium uptake in modulating SV recycling has been debated extensively, but a definitive conclusion has not been achieved. To directly address this question, we manipulated the expression of the MCU channel subunit in primary cultures of neurons expressing a genetically encoded reporter of SV turnover. Knockdown of MCU resulted in ablation of activity-dependent mitochondrial calcium uptake but had no effect on the rate or extent of SV exocytosis. In contrast, the rate of SV endocytosis was increased in the absence of mitochondrial calcium uptake and slowed when MCU was overexpressed. MCU knockdown did not perturb activity-dependent increases in presynaptic free calcium, suggesting that SV endocytosis may be controlled by calcium accumulation and efflux from mitochondria in their immediate vicinity.

  5. Calcium signaling and epilepsy.

    Science.gov (United States)

    Steinlein, Ortrud K

    2014-08-01

    Calcium signaling is involved in a multitude of physiological and pathophysiological mechanisms. Over the last decade, it has been increasingly recognized as an important factor in epileptogenesis, and it is becoming obvious that the excess synchronization of neurons that is characteristic for seizures can be linked to various calcium signaling pathways. These include immediate effects on membrane excitability by calcium influx through ion channels as well as delayed mechanisms that act through G-protein coupled pathways. Calcium signaling is able to cause hyperexcitability either by direct modulation of neuronal activity or indirectly through calcium-dependent gliotransmission. Furthermore, feedback mechanisms between mitochondrial calcium signaling and reactive oxygen species are able to cause neuronal cell death and seizures. Unravelling the complexity of calcium signaling in epileptogenesis is a daunting task, but it includes the promise to uncover formerly unknown targets for the development of new antiepileptic drugs.

  6. Measurements of intracellular calcium

    International Nuclear Information System (INIS)

    Intracellular calcium concentration ([Ca2+]i) has been measured in cultured cells by using Fura-2 load cells and a computer-controlled Perkin Elmer LS-5B spectrofluorometer. Increased [Ca2+]i in cells exposed to extracellular bilirubin was observed both with and without extracellular calcium. However, the increase was considerable larger with extracellular calcium. The enhancement of [Ca2+]i became smaller with decreasing bilirubin/BSA (bovine serum albumine) ratio. 5 refs., 5 figs

  7. Carbachol increases basolateral K+ conductance in T84 cells. Simultaneous measurements of cell [Ca] and gK explore calcium's role.

    Science.gov (United States)

    Wong, S M; Tesfaye, A; DeBell, M C; Chase, H S

    1990-12-01

    To explore the role of calcium in mediating the action of carbachol in chloride-secreting epithelia, we simultaneously measured intracellular free [Ca] ([Ca]i) and the potassium conductance (gK) of the basolateral membrane in T84 cells grown on collagen-coated filters. [Ca]i was measured with fura-2 and fluorescence microscopy and expressed as a relative value ([Ca]'i) normalized to control. To assess changes in basolateral gK, we measured the short circuit current (Isc) in the presence of luminal amphotericin and a transepithelial mucosa-to-serosa K+ gradient (Germann, W. J., M. E. Lowy, S. A. Ernst, and D. C. Dawson. 1986. J. Gen. Physiol. 88:237-251). Treatment of the monolayers with carbachol resulted in a parallel increase and then decrease in [Ca]'i and gK. The carbachol-induced changes in gK appeared to be dependent on the increase in [Ca]i because stimulation of gK was significantly diminished when the hormone-induced increase in [Ca]'i was blunted, either by loading the cells with BAPTA or by reducing the extracellular [Ca]. The carbachol-stimulated increase in gK appeared to be the direct result of the increase in steady-state [Ca]'i. The changes in gK and [Ca]'i after stimulation with carbachol were correlated and ionomycin also increased gK and [Ca]'i in a parallel manner. The carbachol-induced delta gK per delta[Ca]'i, however, was greater than that after ionomycin. Because ionomycin and carbachol appear to open the same channel, a conclusion based on inhibitor and selectivity experiments, carbachol may have a second action that amplifies the effect of calcium on gK. PMID:2126802

  8. Antitranspirant-induced increases in leaf water potential increase tuber calcium and decrease tuber necrosis in water-stressed potato plants.

    Science.gov (United States)

    Win, K; Berkowitz, G A; Henninger, M

    1991-05-01

    Experiments were undertaken with field-grown potato (Solanum tuberosum L.) plants to test the hypothesis that altering leaf:tuber water potential gradients within a plant subjected to low soil moisture will allow greater Ca accumulation in tubers and reverse Ca deficiency-related tuber necrosis. Antitranspirant formulations containing a wax emulsion and a spreader/sticker surfactant increased leaf water potential during a drought episode, significantly reducing the potential gradient that develops between leaf and tuber during a period of stress. Increased leaf water potential in treated plants was associated with decreased leaf Ca and increased tuber Ca. Tuber necrosis was found to be reduced in treated plants, thus increasing tuber quality.

  9. Urinary calcium and oxalate excretion in healthy adult cats are not affected by increasing dietary levels of bone meal in a canned diet.

    Directory of Open Access Journals (Sweden)

    Nadine Passlack

    Full Text Available This study aimed to investigate the impact of dietary calcium (Ca and phosphorus (P, derived from bone meal, on the feline urine composition and the urinary pH, allowing a risk assessment for the formation of calcium oxalate (CaOx uroliths in cats. Eight healthy adult cats received 3 canned diets, containing 12.2 (A, 18.5 (B and 27.0 g Ca/kg dry matter (C and 16.1 (A, 17.6 (B and 21.1 g P/kg dry matter (C. Each diet was fed over 17 days. After a 7 dayś adaptation period, urine and faeces were collected over 2×4 days (with a two-day rest between, and blood samples were taken. Urinary and faecal minerals, urinary oxalate (Ox, the urinary pH and the concentrations of serum Ca, phosphate and parathyroid hormone (PTH were analyzed. Moreover, the urine was microscopically examined for CaOx uroliths. The results demonstrated that increasing levels of dietary Ca led to decreased serum PTH and Ca and increased faecal Ca and P concentrations, but did not affect the urinary Ca or Ox concentrations or the urinary fasting pH. The urinary postprandial pH slightly increased when the diet C was compared to the diet B. No CaOx crystals were detected in the urine of the cats. In conclusion, urinary Ca excretion in cats seems to be widely independent of the dietary Ca levels when Ca is added as bone meal to a typical canned diet, implicating that raw materials with higher contents of bones are of subordinate importance as risk factors for the formation of urinary CaOx crystals.

  10. The role of calcium in endotoxin-induced release of calcitonin gene-related peptide (CGRP) from rat spinal cord

    Institute of Scientific and Technical Information of China (English)

    唐跃明; 韩启德; 王宪

    1997-01-01

    In the present study, the role of calcium in endotoxin-induced CGRP release was studied. 2 .5-50 μg/mL endotoxin and 1 -10 mmol/L caffeine caused concentration-dependent increase of CGRP release from rat spinal cord in vitro. However, no additive effect could he found when caffeine and endotoxin were concomitantly incubated. By using capsaicin, Ca2+-free medium, Omega-Conotoxin, nifedipine, W-7, ryanodine, MgCl2, Tris-ATP, rutheni-um red, the results indicate that the release of CGRP evoked by endotoxin from the sensory fibers of rat spinal cord is dependent on extracellular calcium. After entering into the cell through the N-type calcium channel, calcium binds to calmodulin, and triggers calcium release from intracellular calcium store by activating the caffeine-sensitive but ryan-odine-insensitive mechanism.

  11. Triggering Artefacts

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst; Robinson, Mike

    1995-01-01

    The paper presents a general critique of the use of conceptual frameworks in design, illustrated by the well known synchronous/asynchronous, co-located/non-co-located framework. It argues that while frameworks are a necessary and inevitable starting point for design, the business of tailoring and...... adapting them to specific situations need not be ad hoc.Triggering artefacts are a way of systematically challenging both designers' preunderstandings and the conservatism of work practice. Experiences from the Great Belt tunnel and bridge project are used to illustrate howtriggering artefacts change...

  12. A sensor for calcium uptake

    OpenAIRE

    Collins, Sean; Meyer, Tobias

    2010-01-01

    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.

  13. Low-calcium diets increase both production and clearance of 1,25-dihydroxyvitamin D3 in rats

    International Nuclear Information System (INIS)

    Administration of large doses of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] to animals induces 1,25(OH)2D3 side-chain oxidative pathways. This study determined if the elevated plasma 1,25(OH)2D3 seen in rats fed low-Ca diets is associated not only with an increased production rate (PR) but also with an increased metabolic clearance rate (MCR) of the hormone. In vitamin D-replete rats fed a Ca-deficient diet for 3-4 wk, the PR increased 21-fold, plasma levels 15-fold, and the MCR by 37%. The increased MCR in Ca-deficient rats was associated with a 48% increase in hepatic microsomal UDP glucuronyl transferase enzyme activity, whereas 1,25(OH)2D3 catabolism by homogenates of liver and small intestinal mucosa was unchanged. In contrast to the effects of low-Ca diets, acute (7 h) pharmacological elevation of plasma 1,25(OH)2D3 to 1.5 ng/ml in normal rats did not influence the MCR. Thus chronically elevated 1,25(OH)2D3 levels are necessary to stimulate clearance. In conclusion, 1,25(OH)2D3 clearance in rats can be stimulated not only by chronic pharmacological doses of 1,25(OH)2D3 but also by the physiological stimulus of a low-Ca diet. Hence, plasma 1,25(OH)2D3 levels can be regulated by changes in both PR and MCR

  14. An Intracellular Calcium Oscillations Model Including Mitochondrial Calcium Cycling

    Institute of Scientific and Technical Information of China (English)

    SHI Xiao-Min; LIU Zeng-Rong

    2005-01-01

    @@ Calcium is a ubiquitous second messenger. Mitochondria contributes significantly to intracellular Ca2+ dynamics.The experiment of Kaftan et al. [J. Biol. Chem. 275(2000) 25465] demonstrated that inhibiting mitochondrial Ca2+ uptake can reduce the frequency of cytosolic Ca2+ concentration oscillations of gonadotropes. By considering the mitochondrial Ca2+ cycling we develop a three-variable model of intracellular Ca2+ oscillations based on the models of Atri et al. [Biophys. J. 65 (1993) 1727] and Falcke et al. [Biophys. J. 77 (1999) 37]. The model reproduces the fact that mitochondrial Ca2+ cycling increases the frequency of cytosolic Ca2+ oscillations, which accords with Kaftan's results. Moreover the model predicts that when the mitochondria overload with Ca2+, the cytosolic Ca2+ oscillations vanish, which may trigger apoptosis.

  15. Heterotrimeric G protein participated in modulation of cytoplasmic calcium concentration in pollen cells

    Institute of Scientific and Technical Information of China (English)

    SHANG Zhonglin; MA Ligeng; WANG Xuechen; SUN Daye

    2003-01-01

    Cytoplasmic free calcium concentration([Ca2+]c) in pollen cells of Lilium daviddi is measured with confocal laser scanning microscopy to investigate the effect of heterotrimeric G protein (G protein) on [Ca2+]c and the possible signal transduction pathway of G protein triggering cellular calcium signal. After application, cholera toxin (CTX), an agonist of G protein, triggers a transient increase of [Ca2+]c in pollen cells, and evokes a spatial-temporal characteristic calcium dynamics; while pertussis toxin (PTX), a G protein antagonist, leads to the decrease of [Ca2+]c. Both L-type Ca2+ channel blocker verapamil and inhibitor of IP3 receptor heparin inhibit CTX-induced [Ca2+]c increase. The results show that G protein may play a role in the modulation of [Ca2+]c through enhancing the extracellular Ca2+ influx and releasing of Ca2+ from intracellular stores.

  16. Angiotensin II rapidly increases phosphatidate-phosphoinositide synthesis and phosphoinositide hydrolysis and mobilizes intracellular calcium in cultured arterial muscle cells.

    OpenAIRE

    Smith, J B; Smith, L; Brown, E R; Barnes, D; Sabir, M A; Davis, J S; Farese, R V

    1984-01-01

    Smooth muscle cells were cultured from rat thoracic aorta and labeled to a stable specific activity with 45Ca2+, myo-[2-3H]inositol, or 32Pi. The efflux of 45Ca2+ was monitored over 10-sec intervals. Angiotensin II (AII) increased the amount of 45Ca2+ lost by 5-fold in the first 10-sec interval after the addition of AII and by 10-fold in the second 10-sec interval. AII-stimulated 45Ca2+ release was blocked by the angiotensin antagonist [1-sarcosine, 8-leucine]AII and by La3+. The removal of e...

  17. Smoking, calcium, calcium antagonists, and aging.

    Science.gov (United States)

    Nicita-Mauro, V

    1990-01-01

    Aging is characterized, besides other changes, by a progressive increase in calcium content in the arterial wall, which is enhanced by diabetes mellitus, osteoporosis, arterial hypertension, and tabagism. As to tabagism, experiments in animals have shown that nicotine can increase calcium content of the arterial wall, and clinical studies have demonstrated that cigarette smoking induces peripheral vasoconstriction, with consequent increase in blood pressure levels. In order to study the role of calcium ions in the pathogenesis of the vasoconstrictive lesions caused by "acute" smoking, the author has studied the peripheral vascular effects of the calcium-channel antagonist nifedipine, a dihydropyridine derivative, and calcitonin, a hypocalcemizing hormone which possess vasoactive actions on 12 elderly regular smokers (mean age 65.8 years). The results demonstrated that both nifedipine (10 mg sublingually 20 min before smoking) and salmon calcitonin (100 MRC U/daily intramuscularly for three days) are able to prevent peripheral vasoconstriction evaluated by Doppler velocimetry, as well as the increase of blood pressure induced by smoking. On the basis of our results, the author proposes that cigarette smoking-induced vasoconstriction is a calcium-mediated process, which can be hindered by drugs with calcium antagonist action. PMID:2226675

  18. Calcium addition at the Hubbard Brook Experimental Forest increases sugar storage, antioxidant activity and cold tolerance in native red spruce (Picea rubens).

    Science.gov (United States)

    Halman, Joshua M; Schaberg, Paul G; Hawley, Gary J; Eagar, Christopher

    2008-06-01

    In fall (November 2005) and winter (February 2006), we collected current-year foliage of native red spruce (Picea rubens Sarg.) growing in a reference watershed and in a watershed treated in 1999 with wollastonite (CaSiO(3), a slow-release calcium source) to simulate preindustrial soil calcium concentrations (Ca-addition watershed) at the Hubbard Brook Experimental Forest (Thornton, NH). We analyzed nutrition, soluble sugar concentrations, ascorbate peroxidase (APX) activity and cold tolerance, to evaluate the basis of recent (2003) differences between watersheds in red spruce foliar winter injury. Foliar Ca and total sugar concentrations were significantly higher in trees in the Ca-addition watershed than in trees in the reference watershed during both fall (P=0.037 and 0.035, respectively) and winter (P=0.055 and 0.036, respectively). The Ca-addition treatment significantly increased foliar fructose and glucose concentrations in November (P=0.013 and 0.007, respectively) and foliar sucrose concentrations in winter (P=0.040). Foliar APX activity was similar in trees in both watersheds during fall (P=0.28), but higher in trees in the Ca-addition watershed during winter (P=0.063). Cold tolerance of foliage was significantly greater in trees in the Ca-addition watershed than in trees in the reference watershed (Pcold tolerance in trees in the reference watershed contributed to their high vulnerability to winter injury in 2003. Because the reference watershed reflects forest conditions in the region, the consequences of impaired physiological function caused by soil Ca depletion may have widespread implications for forest health. PMID:18381266

  19. Trigger and decision processors

    International Nuclear Information System (INIS)

    In recent years there have been many attempts in high energy physics to make trigger and decision processes faster and more sophisticated. This became necessary due to a permanent increase of the number of sensitive detector elements in wire chambers and calorimeters, and in fact it was possible because of the fast developments in integrated circuits technique. In this paper the present situation will be reviewed. The discussion will be mainly focussed upon event filtering by pure software methods and - rather hardware related - microprogrammable processors as well as random access memory triggers. (orig.)

  20. Firearm trigger assembly

    Science.gov (United States)

    Crandall, David L.; Watson, Richard W.

    2010-02-16

    A firearm trigger assembly for use with a firearm includes a trigger mounted to a forestock of the firearm so that the trigger is movable between a rest position and a triggering position by a forwardly placed support hand of a user. An elongated trigger member operatively associated with the trigger operates a sear assembly of the firearm when the trigger is moved to the triggering position. An action release assembly operatively associated with the firearm trigger assembly and a movable assembly of the firearm prevents the trigger from being moved to the triggering position when the movable assembly is not in the locked position.

  1. Physiological increases in lactate inhibit intracellular calcium transients, acidify myocytes and decrease force in term pregnant rat myometrium.

    Science.gov (United States)

    Hanley, Jacqui-Ann; Weeks, Andrew; Wray, Susan

    2015-10-15

    Lactate is increased in myometrial capillary blood from women in slow or non-progressive labour (dystocia), suggesting that it is detrimental to uterine contractions. There are, however, no studies of the effect of lactate on the myometrium. We therefore investigated its effects and mechanism of action on myometrial strips from term pregnant rats. The effects on spontaneous and oxytocin-induced contractility in response to sodium lactate and other weak acids (1-20 mM) were studied. In some experiments, simultaneous force and intracellular Ca(2+) or pH (pH(i)) were measured with Indo-1 or Carboxy-SNARF, respectively. Statistical differences were tested using non-parametric tests. Lactate significantly decreased spontaneous contractility with an EC50 of 3.9 mM. Propionate, butyrate and pyruvate also reduced contractions with similar potency. The effects of lactate were reduced in the presence of oxytocin but remained significant. Lactate decreased pH(i) and nulling the decrease in pH(i) abolished its effects. We also show that lactate inhibited Ca(2+) transients, with these changes mirroring those produced on force. If Ca(2+) entry was enhanced by depolarization (high KCl) or applying the Ca(2+) channel agonist, Bay K 4644, the effects of lactate were abolished. Taken together, these data show that lactate in the physiological range potently decreases myometrial contractility as a result of its inhibition of Ca(2+) transients, which can be attributed to the induced acidification. The present study suggests that the accumulation of extracellular lactate will reduce myometrial contractions and could therefore contribute to labour dystocia. PMID:26223765

  2. Mechanism of store-operated calcium entry

    Indian Academy of Sciences (India)

    Devkanya Dutta

    2000-12-01

    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 store-operated calcium entry or capacitative calcium entry. Capacitative calcium current plays a key role in replenishing calcium stores and activating various physiological processes. Despite considerable efforts, very little is known about the molecular nature of the capacitative channel and the signalling pathway that activates it. This review summarizes our current knowledge about store operated calcium entry and suggests possible hypotheses for its mode of activation.

  3. Calcium D-saccharate

    DEFF Research Database (Denmark)

    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...

  4. 12(S)-HETE increases intracellular Ca(2+) in lymph-endothelial cells disrupting their barrier function in vitro; stabilization by clinical drugs impairing calcium supply.

    Science.gov (United States)

    Nguyen, Chi Huu; Brenner, Stefan; Huttary, Nicole; Li, Yuanfang; Atanasov, Atanas Georgiev; Dirsch, Verena M; Holzner, Silvio; Stadler, Serena; Riha, Juliane; Krieger, Sigurd; Milovanovic, Danijela; Fristiohardy, Adryan; Simonitsch-Klupp, Ingrid; Dolznig, Helmut; Saiko, Philipp; Szekeres, Thomas; Giessrigl, Benedikt; Jäger, Walter; Krupitza, Georg

    2016-09-28

    Secretion of 12(S)-HETE by breast cancer emboli provokes "circular chemorepellent induced defects" (CCIDs) in the adjacent lymphatic vasculature facilitating their intravasation and lymph node metastasis which determines prognosis. Therefore, elucidating the mechanism of lymph endothelial cell (LEC) wall disintegration may provide cues for anti-metastatic intervention. The role of intracellular free Ca(2+) for CCID formation was investigated in LECs using MCF-7 or MDA-MB231 breast cancer cell spheroids in a three-dimensional cell co-culture model. 12(S)-HETE elevated the Ca(2+) level in LEC by activating PLC/IP3. Downstream, the Ca(2+)-calmodulin kinase MYLK contributed to the phosphorylation of Ser19-MLC2, LEC contraction and CCID formation. Approved clinical drugs, lidoflazine, ketotifen, epiandrosterone and cyclosporine, which reportedly disturb cellular calcium supply, inhibited 12(S)-HETE-induced Ca(2+) increase, Ser19-MLC2 phosphorylation and CCID formation. This treatment strategy may reduce spreading of breast cancer through lymphatics. PMID:27390016

  5. The paradoxical role of urinary macromolecules in the aggregation of calcium oxalate: a further plea to increase diuresis in stone metaphylaxis.

    Science.gov (United States)

    Baumann, J M; Affolter, B

    2016-08-01

    This study was designed to get information on aggregation (AGN) of urinary calcium oxalate crystals (CaOx) which seems to occur in stone formation despite a protecting coat of urinary macromolecules (UMs). CaOx crystallization was directly produced in urine, control and albumin solution by Ox titration and was spectrophotometrically followed. A rapid decrease of optical density indicating AGN was absent in 14 of 15 freshly voided urines of 5 healthy controls. However, in the presence of UM-coated hydroxyapatite all urines with relative high sodium concentration, being an indicator of concentrated urine, showed a pronounced AGN which was abolished when these urines were diluted. Albumin relatively found to be an inhibitor of AGN showed after temporary adsorption on Ca Phosphate (CaP) massive self-AGN and changed to a promoter of CaOx AGN. Self-AGN after adsorption on surfaces especially of CaP, being an important compound of Randall's plaques, can thus explain this paradoxical behavior of UMs. Aggregated UMs probably bridge zones of electrostatic repulsion between UM-coated crystals with identical electrical surface charge. These zones extend by urine dilution which decreases ionic strength. Diminution of urinary concentration by increasing diuresis seems, therefore, to be important in stone metaphylaxis.

  6. Lipoxin A4 stimulates calcium-activated chloride currents and increases airway surface liquid height in normal and cystic fibrosis airway epithelia.

    LENUS (Irish Health Repository)

    2012-01-01

    Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl(-) secretion which in the lung leads to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA(4) is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA(4) are reported to be decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA(4) produced a rapid and transient increase in intracellular Ca(2+). We have investigated, the effect of LXA(4) on Cl(-) secretion and the functional consequences on ASL generation in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA(4) stimulated a rapid intracellular Ca(2+) increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA(4) stimulated whole-cell Cl(-) currents which were inhibited by NPPB (calcium-activated Cl(-) channel inhibitor), BAPTA-AM (chelator of intracellular Ca(2+)) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA(4) increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA(4) effect on ASL height was sensitive to bumetanide, an inhibitor of transepithelial Cl(-) secretion. The LXA(4) stimulation of intracellular Ca(2+), whole-cell Cl(-) currents, conductances and ASL height were inhibited by Boc-2, a specific antagonist of the ALX\\/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA(4) in the stimulation of intracellular Ca(2+) signalling leading to Ca(2+)-activated Cl(-) secretion and enhanced ASL height in non-CF and CF bronchial epithelia.

  7. Arginine vasopressin increases cellular free calcium concentration and adenosine 3',5'-monophosphate production in rat renal papillary collecting tubule cells in culture

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, S.; Okada, K.; Saito, T.

    1988-09-01

    The role of calcium (Ca) in the cellular action of arginine vasopressin (AVP) was examined in rat renal papillary collecting tubule cells in culture. AVP increased both the cellular free Ca concentration ((Ca2+)i) using fura-2, and cAMP production in a dose-dependent manner. AVP-induced cellular Ca mobilization was totally blocked by the antagonist to the antidiuretic action of AVP, and somewhat weakened by the antagonist to the vascular action of AVP. 1-Deamino-8-D-AVP (dDAVP). an antidiuretic analog of AVP, also increased (Ca2+) significantly. Cellular Ca mobilization was not obtained with cAMP, forskolin (a diterpene activator of adenylate cyclase), or phorbol-12-myristate-13-acetate. The early phase of (Ca2+)i depended on the intracellular Ca pool, since an AVP-induced rise in (Ca2+)i was obtained in cells pretreated with Ca-free medium containing 1 mM EGTA, verapamil, or cobalt, which blocked cellular Ca uptake. Also, AVP increased /sup 45/Ca2+ influx during the initial 10 min, which initiated the sustained phase of cellular Ca mobilization. However, cellular cAMP production induced by AVP during the 10-min observation period was diminished in the cells pretreated with Ca-free medium, verapamil, or cobalt, but was still significantly higher than the basal level. This was also diminished by a high Ca concentration in medium. These results indicate that 1) AVP concomitantly regulates cellular free Ca as well as its second messenger cAMP production; 2) AVP-induced elevation of cellular free Ca is dependent on both the cellular Ca pool and extracellular Ca; and 3) there is an optimal level of extracellular Ca to modulate the AVP action in renal papillary collecting tubule cells.

  8. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau

    2014-04-01

    connect ion conformationally rearranged, thus passing the signal through the chain of intermediaries. The most important function of calcium is its participation in many cell signaling pathways. Channels, pumps, gene expression, synthesis of alkaloids, protective molecules, NO etc. respond to changes in [Ca2+]cyt, while transductors are represented by a number of proteins. The universality of calcium is evident in the study in connection with other signaling systems, such as NO, which is involved in the immune response and is able to control the feedback activity of protein activators channels, producing nitric oxide. Simulation of calcium responses can determine the impact of key level and their regulation, and also depends on the type of stimulus and the effector protein that specifically causes certain changes. Using spatiotemporal modeling, scientists showed that the key components for the formation of Ca2+ bursts are the internal and external surfaces of the nucleus membrane. The research was aimed at understanding of the mechanisms of influence of Ca2+-binding components on Ca2+ oscillations. The simulation suggests the existence of a calcium depot EPR with conjugated lumen of the nucleus which releases its contents to nucleoplasm. With these assumptions, the mathematical model was created and confirmed experimentally. It describes the oscillation of nuclear calcium in root hairs of Medicago truncatula at symbiotic relationship of plants and fungi (rhizobia. Calcium oscillations are present in symbiotic relationships of the cortical layer of plant root cells. Before penetration of bacteria into the cells, slow oscillations of Ca2+ are observed, but with their penetration into the cells the oscillation frequency increases. These processes take place by changing buffer characteristics of the cytoplasm caused by signals from microbes, such as Nod-factor available after penetration of bacteria through the cell wall. Thus, the basic known molecular mechanisms for

  9. The discrimination filters to increase the reliability of EEW association on the location using geometric distribution of triggered stations with upgrading a travel time model.

    Science.gov (United States)

    Chi, H. C.; Park, J. H.; Lim, I. S.; Seong, Y. J.

    2015-12-01

    In operation of Earthquake Early Warning System (EEWS), the alerting criteria are one of the most important parameters in optimizing acceptable warning system. During early stage of testing EEW systems from 2011 to 2013, we adapted ElarmS by UC Berkeley BSL to Korean seismic network and applied very simple criteria for event alerting with the combination of the numbers of station and magnitude. As a result of the testing we found out that the real-time test result of Earthquake Early Warning (EEW) system in Korea showed that all events located within seismic network with bigger than magnitude 3.0 were well detected. However, two events located at sea between land and island gave false results with magnitude over 4.0 related to the teleseismic waves and one event located in land gave false results with magnitude over 3.0 related to the teleseismic waves. These teleseismic-relevant false events were caused by logical co-relation during association procedure and the corresponding geometric distribution of associated stations is crescent-shaped. Seismic stations are not deployed uniformly, so the expected bias ratio varies with evaluated epicentral location. This ratio is calculated in advance and stored into database, called as TrigDB, for the discrimination of teleseismic-origin false alarm. We developed a method, so called 'TrigDB back filling', updating location with supplementary association of stations comparing triggered times between sandwiched stations which was not associated previously based on predefined criteria such as travel-time. Because EEW program assume that all events are local, teleseismic-relevant events can give more triggered stations by using back filling of the unassociated stations than the normal association. And we also developed a travel time curve (K-SEIS-1DTT2015) to reduce split event for EEWS. After applying the K-SEIS-1DTT2015 model, these teleseismic-relevant false events are reduced. As a result of these methods we could get more

  10. MARCKS protein is phosphorylated and regulates calcium mobilization during human acrosomal exocytosis.

    Directory of Open Access Journals (Sweden)

    Marcelo J Rodriguez Peña

    Full Text Available Acrosomal exocytosis is a calcium-regulated exocytosis that can be triggered by PKC activators. The involvement of PKC in acrosomal exocytosis has not been fully elucidated, and it is unknown if MARCKS, the major substrate for PKC, participates in this exocytosis. Here, we report that MARCKS is expressed in human spermatozoa and localizes to the sperm head and the tail. Calcium- and phorbol ester-triggered acrosomal exocytosis in permeabilized sperm was abrogated by different anti-MARCKS antibodies raised against two different domains, indicating that the protein participates in acrosomal exocytosis. Interestingly, an anti-phosphorylated MARCKS antibody was not able to inhibit secretion. Similar results were obtained using recombinant proteins and phospho-mutants of MARCKS effector domain (ED, indicating that phosphorylation regulates MARCKS function in acrosomal exocytosis. It is known that unphosphorylated MARCKS sequesters PIP2. This phospholipid is the precursor for IP3, which in turn triggers release of calcium from the acrosome during acrosomal exocytosis. We found that PIP2 and adenophostin, a potent IP3-receptor agonist, rescued MARCKS inhibition in permeabilized sperm, suggesting that MARCKS inhibits acrosomal exocytosis by sequestering PIP2 and, indirectly, MARCKS regulates the intracellular calcium mobilization. In non-permeabilized sperm, a permeable peptide of MARCKS ED also inhibited acrosomal exocytosis when stimulated by a natural agonist such as progesterone, and pharmacological inducers such as calcium ionophore and phorbol ester. The preincubation of human sperm with the permeable MARCKS ED abolished the increase in calcium levels caused by progesterone, demonstrating that MARCKS regulates calcium mobilization. In addition, the phosphorylation of MARCKS increased during acrosomal exocytosis stimulated by the same activators. Altogether, these results show that MARCKS is a negative modulator of the acrosomal exocytosis

  11. Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in response to adrenergic stimulation.

    Directory of Open Access Journals (Sweden)

    Jerry Curran

    Full Text Available Spontaneous calcium waves in cardiac myocytes are caused by diastolic sarcoplasmic reticulum release (SR Ca(2+ leak through ryanodine receptors. Beta-adrenergic (β-AR tone is known to increase this leak through the activation of Ca-calmodulin-dependent protein kinase (CaMKII and the subsequent phosphorylation of the ryanodine receptor. When β-AR drive is chronic, as observed in heart failure, this CaMKII-dependent effect is exaggerated and becomes potentially arrhythmogenic. Recent evidence has indicated that CaMKII activation can be regulated by cellular oxidizing agents, such as reactive oxygen species. Here, we investigate how the cellular second messenger, nitric oxide, mediates CaMKII activity downstream of the adrenergic signaling cascade and promotes the generation of arrhythmogenic spontaneous Ca(2+ waves in intact cardiomyocytes. Both SCaWs and SR Ca(2+ leak were measured in intact rabbit and mouse ventricular myocytes loaded with the Ca-dependent fluorescent dye, fluo-4. CaMKII activity in vitro and immunoblotting for phosphorylated residues on CaMKII, nitric oxide synthase, and Akt were measured to confirm activity of these enzymes as part of the adrenergic cascade. We demonstrate that stimulation of the β-AR pathway by isoproterenol increased the CaMKII-dependent SR Ca(2+ leak. This increased leak was prevented by inhibition of nitric oxide synthase 1 but not nitric oxide synthase 3. In ventricular myocytes isolated from wild-type mice, isoproterenol stimulation also increased the CaMKII-dependent leak. Critically, in myocytes isolated from nitric oxide synthase 1 knock-out mice this effect is ablated. We show that isoproterenol stimulation leads to an increase in nitric oxide production, and nitric oxide alone is sufficient to activate CaMKII and increase SR Ca(2+ leak. Mechanistically, our data links Akt to nitric oxide synthase 1 activation downstream of β-AR stimulation. Collectively, this evidence supports the hypothesis

  12. Both serum 25-hydroxyvitamin D and calcium levels may increase the risk of incident prostate cancer in Caribbean men of African ancestry.

    Science.gov (United States)

    Jackson, Maria D; Tulloch-Reid, Marshall K; Lindsay, Carole M; Smith, Garrett; Bennett, Franklyn I; McFarlane-Anderson, Norma; Aiken, William; Coard, Kathleen C M

    2015-06-01

    Circulating 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with both higher and lower risk of prostate cancer (PCa), whereas elevated levels of circulating calcium has been related to higher risks. However, there are few studies that account for effects of both calcium and 25(OH)D concentrations on incident PCa in a black population. We examined these relationships in a case-control study of men 40-80 years old with newly diagnosed, histologically confirmed PCa in Jamaica, a tropical country. Mean serum calcium concentrations was higher among cases (2.32 ± 0.19 mmol/L) than controls, (2.27 ± 0.30 mmol/L) (P = 0.023) however, there were no differences in 25(OH)D by cancer status (cases, 33.67 ± 12.71 ng/mL; controls (32.25 ± 12.59 ng/mL). Serum calcium was not correlated with 25(OH)D (partial correlation: r, 0.06; P = 0.287). Multivariable-adjusted models showed a positive linear relationship between PCa and serum calcium (OR, 1.12; CI, 1.00-1.25 per 0.1 nmol/L). Serum 25(OH)D concentration also showed a positive association with PCa (OR, 1.23; CI, 1.01-1.49 per 10 ng/mL). The odds of PCa in men with serum 25(OH)D tertile 2 was OR, 2.18; CI, 1.04-4.43 and OR, 2.47 CI, 1.20-4.90 for tertile 3 (P(trend) = 0.013). Dietary intakes of calcium showed no relationship with PCa. Despite the strong relationship between serum calcium and vitamin D the mechanism by which each affects prostate cancer risk in men of African ancestry needs additional investigation. PMID:25858172

  13. The speed of swelling kinetics modulates cell volume regulation and calcium signaling in astrocytes: A different point of view on the role of aquaporins.

    Science.gov (United States)

    Mola, Maria Grazia; Sparaneo, Angelo; Gargano, Concetta Domenica; Spray, David C; Svelto, Maria; Frigeri, Antonio; Scemes, Eliana; Nicchia, Grazia Paola

    2016-01-01

    Regulatory volume decrease (RVD) is a process by which cells restore their original volume in response to swelling. In this study, we have focused on the role played by two different Aquaporins (AQPs), Aquaporin-4 (AQP4), and Aquaporin-1 (AQP1), in triggering RVD and in mediating calcium signaling in astrocytes under hypotonic stimulus. Using biophysical techniques to measure water flux through the plasma membrane of wild-type (WT) and AQP4 knockout (KO) astrocytes and of an astrocyte cell line (DI TNC1) transfected with AQP4 or AQP1, we here show that AQP-mediated fast swelling kinetics play a key role in triggering and accelerating RVD. Using calcium imaging, we show that AQP-mediated fast swelling kinetics also significantly increases the amplitude of calcium transients inhibited by Gadolinium and Ruthenium Red, two inhibitors of the transient receptor potential vanilloid 4 (TRPV4) channels, and prevented by removing extracellular calcium. Finally, inhibition of TRPV4 or removal of extracellular calcium does not affect RVD. All together our study provides evidence that (1) AQP influenced swelling kinetics is the main trigger for RVD and in mediating calcium signaling after hypotonic stimulus together with TRPV4, and (2) calcium influx from the extracellular space and/or TRPV4 are not essential for RVD to occur in astrocytes.

  14. The speed of swelling kinetics modulates cell volume regulation and calcium signaling in astrocytes: A different point of view on the role of aquaporins.

    Science.gov (United States)

    Mola, Maria Grazia; Sparaneo, Angelo; Gargano, Concetta Domenica; Spray, David C; Svelto, Maria; Frigeri, Antonio; Scemes, Eliana; Nicchia, Grazia Paola

    2016-01-01

    Regulatory volume decrease (RVD) is a process by which cells restore their original volume in response to swelling. In this study, we have focused on the role played by two different Aquaporins (AQPs), Aquaporin-4 (AQP4), and Aquaporin-1 (AQP1), in triggering RVD and in mediating calcium signaling in astrocytes under hypotonic stimulus. Using biophysical techniques to measure water flux through the plasma membrane of wild-type (WT) and AQP4 knockout (KO) astrocytes and of an astrocyte cell line (DI TNC1) transfected with AQP4 or AQP1, we here show that AQP-mediated fast swelling kinetics play a key role in triggering and accelerating RVD. Using calcium imaging, we show that AQP-mediated fast swelling kinetics also significantly increases the amplitude of calcium transients inhibited by Gadolinium and Ruthenium Red, two inhibitors of the transient receptor potential vanilloid 4 (TRPV4) channels, and prevented by removing extracellular calcium. Finally, inhibition of TRPV4 or removal of extracellular calcium does not affect RVD. All together our study provides evidence that (1) AQP influenced swelling kinetics is the main trigger for RVD and in mediating calcium signaling after hypotonic stimulus together with TRPV4, and (2) calcium influx from the extracellular space and/or TRPV4 are not essential for RVD to occur in astrocytes. PMID:26413835

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Increasing weight-bearing physical activity and calcium-rich foods to promote bone mass gains among 9–11 year old girls: outcomes of the Cal-Girls study

    Directory of Open Access Journals (Sweden)

    Hannan Peter

    2005-07-01

    Full Text Available Abstract Background A two-year, community-based, group-randomized trial to promote bone mass gains among 9–11 year-old girls through increased intake of calcium-rich foods and weight-bearing physical activity was evaluated. Methods Following baseline data collection, 30 5th-grade Girl Scout troops were randomized to a two-year behavioral intervention program or to a no-treatment control group. Evaluations were conducted at baseline, one year, and two years. Measures included bone mineral content, density, and area (measured by DXA, dietary calcium intake (24-hour recall, and weight-bearing physical activity (physical activity checklist interview. Mixed-model regression was used to evaluate treatment-related changes in bone mineral content (g for the total body, lumbar spine (L1-L4, proximal femur, one-third distal radius, and femoral neck. Changes in eating and physical activity behavioral outcomes were examined. Results Although the intervention was implemented with high fidelity, no significant intervention effects were observed for total bone mineral content or any specific bone sites. Significant intervention effects were observed for increases in dietary calcium. No significant intervention effects were observed for increases in weight-bearing physical activity. Conclusion Future research needs to identify the optimal dosage of weight-bearing physical activity and calcium-rich dietary behavior change required to maximize bone mass gains in pre-adolescent and adolescent girls.

  17. Phosphatidylinositol 3-Kinase Couples Localised Calcium Influx to Activation of Akt in Central Nerve Terminals.

    Science.gov (United States)

    Nicholson-Fish, Jessica C; Cousin, Michael A; Smillie, Karen J

    2016-03-01

    The efficient retrieval of synaptic vesicle membrane and cargo in central nerve terminals is dependent on the efficient recruitment of a series of endocytosis modes by different patterns of neuronal activity. During intense neuronal activity the dominant endocytosis mode is activity-dependent endocytosis (ADBE). Triggering of ADBE is linked to calcineurin-mediated dynamin I dephosphorylation since the same stimulation intensities trigger both. Dynamin I dephosphorylation is maximised by a simultaneous inhibition of its kinase glycogen synthase kinase 3 (GSK3) by the protein kinase Akt, however it is unknown how increased neuronal activity is transduced into Akt activation. To address this question we determined how the activity-dependent increases in intracellular free calcium ([Ca(2+)]i) control activation of Akt. This was achieved using either trains of high frequency action potentials to evoke localised [Ca(2+)]i increases at active zones, or a calcium ionophore to raise [Ca(2+)]i uniformly across the nerve terminal. Through the use of either non-specific calcium channel antagonists or intracellular calcium chelators we found that Akt phosphorylation (and subsequent GSK3 phosphorylation) was dependent on localised [Ca(2+)]i increases at the active zone. In an attempt to determine mechanism, we antagonised either phosphatidylinositol 3-kinase (PI3K) or calmodulin. Activity-dependent phosphorylation of both Akt and GSK3 was arrested on inhibition of PI3K, but not calmodulin. Thus localised calcium influx in central nerve terminals activates PI3K via an unknown calcium sensor to trigger the activity-dependent phosphorylation of Akt and GSK3.

  18. Both serum 25-hydroxyvitamin D and calcium levels may increase the risk of incident prostate cancer in Caribbean men of African ancestry

    OpenAIRE

    Jackson, Maria D; Marshall K. Tulloch-Reid; Lindsay, Carole M; Smith, Garrett; Bennett, Franklyn I.; McFarlane-Anderson, Norma; Aiken, William; Coard, Kathleen C. M.

    2015-01-01

    Circulating 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with both higher and lower risk of prostate cancer (PCa), whereas elevated levels of circulating calcium has been related to higher risks. However, there are few studies that account for effects of both calcium and 25(OH)D concentrations on incident PCa in a black population. We examined these relationships in a case–control study of men 40–80 years old with newly diagnosed, histologically confirmed PCa in Jamaica, ...

  19. Optically triggered infrared photodetector.

    Science.gov (United States)

    Ramiro, Íñigo; Martí, Antonio; Antolín, Elisa; López, Esther; Datas, Alejandro; Luque, Antonio; Ripalda, José M; González, Yolanda

    2015-01-14

    We demonstrate a new class of semiconductor device: the optically triggered infrared photodetector (OTIP). This photodetector is based on a new physical principle that allows the detection of infrared light to be switched ON and OFF by means of an external light. Our experimental device, fabricated using InAs/AlGaAs quantum-dot technology, demonstrates normal incidence infrared detection in the 2-6 μm range. The detection is optically triggered by a 590 nm light-emitting diode. Furthermore, the detection gain is achieved in our device without an increase of the noise level. The novel characteristics of OTIPs open up new possibilities for third generation infrared imaging systems ( Rogalski, A.; Antoszewski, J.; Faraone, L. J. Appl. Phys. 2009, 105 (9), 091101).

  20. Electroconvulsive stimulations prevent chronic stress-induced increases in L-type calcium channel mRNAs in the hippocampus and basolateral amygdala

    DEFF Research Database (Denmark)

    Maigaard, Katrine; Pedersen, Ida Hageman; Jørgensen, Anders;

    2012-01-01

    Although affective disorders have high prevalence, morbidity and mortality, we do not fully understand disease etiopathology, nor have we determined the exact mechanisms by which treatment works. Recent research indicates that intracellular calcium ion dysfunction might be involved. Here we use...

  1. Supplemental calcium attenuates the colitis-related increase in diarrhea, intestinal permeability, and extracellular matrix breakdown in HLA-B27 transgenic rats.

    NARCIS (Netherlands)

    Schepens, M.A.; Schonewille, A.J.; Vink, C.; Schothorst, E.M. van; Kramer, E.; Hendriks, T.; Brummer, R.J.; Keijer, J.; Meer, R. van der; Bovee-Oudenhoven, I.M.

    2009-01-01

    We have shown in several controlled rat and human infection studies that dietary calcium improves intestinal resistance and strengthens the mucosal barrier. Reinforcement of gut barrier function may alleviate inflammatory bowel disease (IBD). Therefore, we investigated the effect of supplemental cal

  2. HYPERTHERMIA, INTRACELLULAR FREE CALCIUM AND CALCIUM IONOPHORES

    NARCIS (Netherlands)

    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 calciu

  3. Calcium Carbonate

    Science.gov (United States)

    ... before being swallowed; do not swallow them whole. Drink a full glass of water after taking either the regular or chewable tablets or capsules. Some liquid forms of calcium carbonate must be shaken well before use.Do not ...

  4. Calcium Calculator

    Science.gov (United States)

    ... Latvia - Lebanon - Libya - Lithuania - Luxembourg - Macedonia, Republic of - Malaysia - Malta - Mexico - Moldova - Morocco - Netherlands - New Zealand - Nigeria - ... and Statistics Popular content Calcium content of common foods What is Osteoporosis? The Board Introduction to Bone ...

  5. Calcium Electroporation

    DEFF Research Database (Denmark)

    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. Using elevated CO2 to increase the biomass of a Sorghum vulgare x Sorghum vulgare var. sudanense hybrid and Trifolium pratense L. and to trigger hyperaccumulation of cesium

    International Nuclear Information System (INIS)

    The most important challenge to use phytoremediation is how to improve its efficiency by increasing the accumulation of metals in plants, or by improving key plant biological traits that should enhance metal uptake. In this paper, we used open-top chambers to investigate the effects of elevated CO2 (860 μL L-1) on biomass and Cs uptake by a Sorghum vulgare x Sorghum vulgare var. sudanense hybrid and Trifolium pratense L. growing on soils spiked with various levels of cesium (0, 300, 1500 and 3000 mg Cs kg-1). The results showed that elevated CO2 not only increased aboveground biomass of the Sorghum and Trifolium species by 32-111%, and by 8-11%, respectively, compared to the ambient CO2 treatment, but also caused more accumulation of Cs by Sorghum species (up to 73%) than Trifolium species (up to 43%). It was speculated that the increase in biomass and the improvement in Cs accumulation ability at elevated CO2 could be related to lowered soil pH values, and changes in number and kind of microorganisms in the rhizospheres of the two tested species. This is the first report of a link among elevated CO2, increased biomass and hyperaccumulation of Cs by Sorghum and Trifolium species.

  7. Identifying asthma triggers.

    Science.gov (United States)

    McCarty, Justin C; Ferguson, Berrylin J

    2014-02-01

    Asthma has many triggers including rhinosinusitis; allergy; irritants; medications (aspirin in aspirin-exacerbated respiratory disease); and obesity. Paradoxic vocal fold dysfunction mimics asthma and may be present along with asthma. This article reviews each of these triggers, outlining methods of recognizing the trigger and then its management. In many patients more than one trigger may be present. Full appreciation of the complexity of these relationships and targeted therapy to the trigger is needed to best care for the patient with asthma.

  8. Virus and calcium: an unexpected tandem to optimize insecticide efficacy.

    Science.gov (United States)

    Apaire-Marchais, Véronique; Ogliastro, Mylène; Chandre, Fabrice; Pennetier, Cédric; Raymond, Valérie; Lapied, Bruno

    2016-04-01

    The effective control of insect pests is based on the rational use of the most efficient and safe insecticide treatments. To increase the effects of classical insecticides and to avoid the ability of certain pest insects to develop resistance, it is essential to propose novel strategies. Previous studies have shown that calcium-dependent phosphorylation/dephosphorylation is now considered as a new cellular mechanism for increasing the target sensitivity to insecticides. Because it is known that virus entry is correlated with intracellular calcium concentration rise, this report attempts to present the most important data relevant to the feasibility of combining an insect virus such as baculovirus or densovirus with an insecticide. In this case, the insect virus is not used as a bioinsecticide but acts as a synergistic agent able to trigger calcium rise and to activate calcium-dependent intracellular signalling pathways involved in the increase of the membrane receptors and/or ion channels sensitivity to insecticides. This virus-insecticide mixture represents a promising alternative to optimize the efficacy of insecticides against insect pests while reducing the doses. PMID:26743399

  9. Activation of a P2Y4-like purinoceptor triggers an increase in cytosolic [Ca2+] in the red blood cells of the lizard Ameiva ameiva (Squamata, Teiidae)

    OpenAIRE

    Sartorello R.; Garcia C.R.S.

    2005-01-01

    An increasing number of pathophysiological roles for purinoceptors are emerging, some of which have therapeutic potential. Erythrocytes are an important source of purines, which can be released under physiological and physiopathological conditions, acting on purinergic receptors associated with the same cell or with neighboring cells. Few studies have been conducted on lizards, and have been limited to ATP agonist itself. We have previously shown that the red blood cells (RBCs) of the lizard ...

  10. Cardiovascular Effects of Calcium Supplements

    Directory of Open Access Journals (Sweden)

    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.

  11. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to beta-palmitate and increased calcium absorption pursuant to Article 14 of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    -palmitate and increased calcium absorption. The scope of the application was proposed to fall under a health claim referring to children’s development and health. The food constituent that is the subject of the health claim is beta-palmitate, a structured triglyceride with a high content of palmitic acid at the sn-2......Following an application from IDACE, submitted pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of France, the Panel on Dietetic Products, Nutrition and Allergies was asked to deliver an opinion on the scientific substantiation of a health claim related to beta......, including healthy infants consuming follow-on formula, preterm infants and infants needing foods for particular nutritional uses including foods for special medical purposes. The Panel considers that an increase in calcium absorption might be a beneficial physiological effect. In weighing the evidence...

  12. Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Pich, Claus Tröger [Campus de Araranguá, Universidade Federal de Santa Catarina, Araranguá (Brazil); Ferreira, Eduardo Antonio [Universidade de Brasília, Faculdade de Ceilândia, DF (Brazil); Filho, Danilo Wilhelm [Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Verrax, Julien; Calderon, Pedro Buc [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels (Belgium); Pedrosa, Rozangela Curi, E-mail: rozangelapedrosa@gmail.com [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil)

    2013-01-18

    Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC{sub 50} fell to 3.3 μM. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

  13. The Central Trigger Processor (CTP)

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It makes the Level-1 decision (L1A) based on a trigger menu.

  14. Calcium concentration and movement in the diadic cleft space of the cardiac ventricular cell.

    OpenAIRE

    Langer, G. A.; Peskoff, A

    1996-01-01

    We model the space between the junctional sarcoplasmic reticulum (JSR) membrane and the inner leaflet of the transverse tubular ("T") sarcolemmal (SL) membrane, the diadic cleft, with respect to calcium (Ca) concentration and movement. The model predicts the following: 1) Ca influx via the "L" channel increases [Ca] to 1 microM within a distance of 50 nm from the channel mouth in < 500 microseconds. This is sufficient to trigger Ca release from a domain of 9 "feet." 2) By contrast, "reverse" ...

  15. Familial hypocalciuric hypercalcemia and calcium sensing receptor

    DEFF Research Database (Denmark)

    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...

  16. Early pre- and postsynaptic calcium signaling abnormalities mask underlying synaptic depression in presymptomatic Alzheimer’s disease mice

    Science.gov (United States)

    Chakroborty, Shreaya; Kim, Joyce; Schneider, Corinne; Jacobson, Christopher; Molgó, Jordi; Stutzmann, Grace E.

    2012-01-01

    Alzheimer’s disease (AD)-linked presenilin mutations result in pronounced endoplasmic reticulum (ER) calcium disruptions that occur prior to detectable histopathology and cognitive deficits. More subtly, these early AD-linked calcium alterations also reset neurophysiological homeostasis, such that calcium-dependent pre- and postsynaptic signaling appear functionally normal yet are actually operating under aberrant calcium signaling systems. In these 3xTg-AD mouse brains, upregulated RyR activity is associated with a shift towards synaptic depression, likely through a reduction in presynaptic vesicle stores and increased postsynaptic outward currents through SK2 channels. The deviant RyR-calcium involvement in the 3xTg-AD mice also compensates for an intrinsic predisposition for hippocampal LTD and reduced LTP. In this study we detail the impact of disrupted ryanodine receptor (RyR)-mediated calcium stores on synaptic transmission properties, long term depression (LTD) and calcium-activated membrane channels of hippocampal CA1 pyramidal neurons in presymptomatic 3xTg-AD mice. Using electrophysiological recordings in young 3xTg-AD and NonTg hippocampal slices, we show that increased RyR-evoked calcium release in 3xTg-AD mice ‘normalizes’ an altered synaptic transmission system operating under a shifted homeostatic state that is not present in NonTg mice. In the process, we uncover compensatory signaling mechanisms recruited early in the disease process which counterbalance the disrupted RyR-calcium dynamics, namely increases in presynaptic spontaneous vesicle release, altered probability of vesicle release, and upregulated postsynaptic SK channel activity. As AD is increasingly recognized as a ‘synaptic disease’, calcium-mediated signaling alterations may serve as a proximal trigger for the synaptic degradation driving the cognitive loss in AD. PMID:22699914

  17. Change perspective to increase diagnostic accuracy of ultrasonography in calcium pyrophosphate dihydrate deposition disease! A new approach: the axial scan of the meniscus

    Directory of Open Access Journals (Sweden)

    G. Filippou

    2015-03-01

    Full Text Available Ultrasonography (US is a relevant tool in the study of calcium pyrophosphate dihydrate (CPP deposition disease. However, differential diagnosis of hyperechoic deposits within the fibrocartilage can be difficult; moreover, US study is limited by the need of an adequate acoustic window. We describe a US scanning technique that offers a new viewpoint in the study of knee meniscal structure: a longitudinal scan performed according to the long axis of meniscus. This technique proves to be particularly useful for the identification of CPP deposition, but could also improve the US diagnostic utility and accuracy in other meniscal pathologies.

  18. Towards evidence-based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 4: Alpha blockers v calcium blockers to increase spontaneous passage of renal calculi.

    Science.gov (United States)

    Stewart, Alexander; Ferguson, Craig

    2013-02-01

    A short cut review was carried out to establish the administration of an alpha-1 receptor antagonist or a calcium channel blocker would facilitate the most rapid and successful expulsion of a stone from a patient with uncomplicated renal colic. 597 articles were found using the reported search, of which five trials were selected as providing the best evidence to answer this question. The authors, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that in a patient with an uncomplicated ureteric calculus tamsulosin is more effective than nifedipine in promoting speedy and successful expulsion of the stone.

  19. Carbachol increases basolateral K+ conductance in T84 cells. Simultaneous measurements of cell [Ca] and gK explore calcium's role

    OpenAIRE

    1990-01-01

    To explore the role of calcium in mediating the action of carbachol in chloride-secreting epithelia, we simultaneously measured intracellular free [Ca] ([Ca]i) and the potassium conductance (gK) of the basolateral membrane in T84 cells grown on collagen-coated filters. [Ca]i was measured with fura-2 and fluorescence microscopy and expressed as a relative value ([Ca]'i) normalized to control. To assess changes in basolateral gK, we measured the short circuit current (Isc) in the presence of lu...

  20. Asthma triggers (image)

    Science.gov (United States)

    ... things make your asthma worse. These are called asthma "triggers". Avoiding them is your first step toward feeling better. The most common asthma triggers are mold, pets, dust, grasses, pollen, cockroaches, odors ...

  1. Global Trigger Upgrade firmware architecture for the level-1 Trigger of the CMS experiment

    Science.gov (United States)

    Rahbaran, B.; Arnold, B.; Bergauer, H.; Wittmann, J.; Matsushita, T.

    2015-02-01

    The Global Trigger (GT) is the final step of the CMS Level-1 Trigger and implements the ``menu'' of triggers, which is a set of selection requirements applied to the final list of objects (such as muons, electrons or jets) to trigger the readout of the detector and serve as basis for further calculations by the High Level Trigger. Operational experience in developing trigger menus from the first LHC run has shown that the requirements increased as the luminosity and pile-up increased. The new GT (μGT) is designed based on Xilinx Virtex-7 FPGAs, which combine unsurpassed flexibility with regard to scalability and high robustness. Furthermore, a custom board which receives signals from legacy electronics and basic binary inputs from less complex trigger sources is presented. Additionally, this paper describes the architecture of a distributed testing framework and the Trigger Menu Editor.

  2. Aging and calcium as an environmental factor.

    Science.gov (United States)

    Fujita, T

    1985-12-01

    Calcium deficiency is a constant menace to land-abiding animals, including mammals. Humans enjoying exceptional longevity on earth are especially susceptible to calcium deficiency in old age. Low calcium and vitamin D intake, short solar exposure, decreased intestinal absorption, and falling renal function with insufficient 1,25(OH)2 vitamin D biosynthesis all contribute to calcium deficiency, secondary hyperparathyroidism, bone loss and possibly calcium shift from the bone to soft tissue, and from the extracellular to the intracellular compartment, blunting the sharp concentration gap between these compartments. The consequences of calcium deficiency might thus include not only osteoporosis, but also arteriosclerosis and hypertension due to the increase of calcium in the vascular wall, amyotrophic lateral sclerosis and senile dementia due to calcium deposition in the central nervous system, and a decrease in cellular function, because of blunting of the difference in extracellular-intracellular calcium, leading to diabetes mellitus, immune deficiency and others (Fig. 6). PMID:2943880

  3. Quantitative proteomic analysis reveals metabolic alterations, calcium dysregulation, and increased expression of extracellular matrix proteins in laminin α2 chain-deficient muscle.

    Science.gov (United States)

    de Oliveira, Bruno Menezes; Matsumura, Cintia Y; Fontes-Oliveira, Cibely C; Gawlik, Kinga I; Acosta, Helena; Wernhoff, Patrik; Durbeej, Madeleine

    2014-11-01

    Congenital muscular dystrophy with laminin α2 chain deficiency (MDC1A) is one of the most severe forms of muscular disease and is characterized by severe muscle weakness and delayed motor milestones. The genetic basis of MDC1A is well known, yet the secondary mechanisms ultimately leading to muscle degeneration and subsequent connective tissue infiltration are not fully understood. In order to obtain new insights into the molecular mechanisms underlying MDC1A, we performed a comparative proteomic analysis of affected muscles (diaphragm and gastrocnemius) from laminin α2 chain-deficient dy(3K)/dy(3K) mice, using multidimensional protein identification technology combined with tandem mass tags. Out of the approximately 700 identified proteins, 113 and 101 proteins, respectively, were differentially expressed in the diseased gastrocnemius and diaphragm muscles compared with normal muscles. A large portion of these proteins are involved in different metabolic processes, bind calcium, or are expressed in the extracellular matrix. Our findings suggest that metabolic alterations and calcium dysregulation could be novel mechanisms that underlie MDC1A and might be targets that should be explored for therapy. Also, detailed knowledge of the composition of fibrotic tissue, rich in extracellular matrix proteins, in laminin α2 chain-deficient muscle might help in the design of future anti-fibrotic treatments. All MS data have been deposited in the ProteomeXchange with identifier PXD000978 (http://proteomecentral.proteomexchange.org/dataset/PXD000978).

  4. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  5. Calcium carbonate overdose

    Science.gov (United States)

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Some products that contain calcium carbonate are certain: ... and mineral supplements Other products may also contain calcium ...

  6. Get Enough Calcium

    Science.gov (United States)

    ... Calcium Print This Topic En español Get Enough Calcium Browse Sections The Basics Overview Foods and Vitamins ... 2 of 4 sections Take Action! Take Action: Calcium Sources Protect your bones – get plenty of calcium ...

  7. Structures of apicomplexan calcium-dependent protein kinases reveal mechanism of activation by calcium

    Energy Technology Data Exchange (ETDEWEB)

    Wernimont, Amy K; Artz, Jennifer D.; Jr, Patrick Finerty; Lin, Yu-Hui; Amani, Mehrnaz; Allali-Hassani, Abdellah; Senisterra, Guillermo; Vedadi, Masoud; Tempel, Wolfram; Mackenzie, Farrell; Chau, Irene; Lourido, Sebastian; Sibley, L. David; Hui, Raymond (Toronto); (WU-MED)

    2010-09-21

    Calcium-dependent protein kinases (CDPKs) have pivotal roles in the calcium-signaling pathway in plants, ciliates and apicomplexan parasites and comprise a calmodulin-dependent kinase (CaMK)-like kinase domain regulated by a calcium-binding domain in the C terminus. To understand this intramolecular mechanism of activation, we solved the structures of the autoinhibited (apo) and activated (calcium-bound) conformations of CDPKs from the apicomplexan parasites Toxoplasma gondii and Cryptosporidium parvum. In the apo form, the C-terminal CDPK activation domain (CAD) resembles a calmodulin protein with an unexpected long helix in the N terminus that inhibits the kinase domain in the same manner as CaMKII. Calcium binding triggers the reorganization of the CAD into a highly intricate fold, leading to its relocation around the base of the kinase domain to a site remote from the substrate binding site. This large conformational change constitutes a distinct mechanism in calcium signal-transduction pathways.

  8. Potassium conductances mediate bidirectional state-dependent modulation of action potential evoked dendritic calcium signals in dentate gyrus granule cells

    Directory of Open Access Journals (Sweden)

    János Brunner

    2014-03-01

    Full Text Available Backpropagating action potentials (bAPs and local calcium signals that they trigger are fundamental for dendritic functions. Here we addressed the question what extent the changes of local dendritic membrane properties can contribute to the shaping of the coupling between dendritic action potentials and the local calcium responses. Using a combination of in vitro electrophysiological and confocal imaging techniques we found that activation of dendritic GIRK channels via mGlu2 or GABAB receptors enhanced the bAP¬-triggered calcium signals in the dendrites of dentate gyrus granule cells (GCs. The enhancement of calcium signals was significant only in those dendritic regions, where these receptors are predominantly expressed. Similarly to GIRK channel activation, somatic hyperpolarization by DC current injection (from -64 mV to -77 mV, significantly increased bAP-associated calcium signals in the proximal dendrites. The hyperpolarization was associated with a decrease in the input resistance due to the rectification of the membrane potential of GCs. The effect of hyperpolarization on the calcium signals was maintained when T-type calcium currents were blocked but it decreased when GIRK channels were inhibited. Simultaneous dual somato-dendritic recordings from GCs showed that somatic hyperpolarization accelerated the repolarization phase of dendritic bAP in the proximal region whereas the rising phase and peak amplitude was not affected. We hypothesize that the larger driving force for calcium ions during the faster repolarization can contribute to the increasing in calcium signals. Employment of previously recorded dendritic bAP waveforms from hyperpolarized membrane potential as voltage command evoked larger calcium currents in nucleated patches compared to bAP waveform from the same recording at depolarized membrane potential. Furthermore, addition of native, high-voltage activated, inactivating potassium conductance by somatic dynamic clamp

  9. Combination of low calcium with Y-27632 rock inhibitor increases the proliferative capacity, expansion potential and lifespan of primary human keratinocytes while retaining their capacity to differentiate into stratified epidermis in a 3D skin model.

    Directory of Open Access Journals (Sweden)

    Xanthe L Strudwick

    Full Text Available Human keratinocytes are difficult to isolate and have a limited lifespan. Traditionally, immortalised keratinocyte cell lines are used in vitro due to their ability to bypass senescence and survive indefinitely. However these cells do not fully retain their ability to differentiate in vitro and they are unable to form a normal stratum corneum in organotypic culture. Here we aimed to generate a pool of phenotypically similar keratinocytes from human donors that could be used in monolayer culture, without a fibroblast feeder layer, and in 3D human skin equivalent models. Primary human neonatal epidermal keratinocytes (HEKn were cultured in low calcium, (0.07 mM media, +/-10 μM Y-27632 ROCK inhibitor (HEKn-CaY. mRNA and protein was extracted and expression of differentiation markers Keratin 14 (K14, Keratin 10 (K10 and Involucrin (Inv assessed by qRT-PCR and Western blotting. The differentiation potential of the HEKn-CaY cultures was assessed by increasing calcium levels and removing the Y-27632 for 72 hrs prior to assessment of K14, K10 and Inv. The ability of the HEKn-CaY, to form a stratified epithelium was assessed using a human skin equivalent (HSE model in the absence of Y-27632. Increased proliferative capacity, expansion potential and lifespan of HEKn was observed with the combination of low calcium and 10 μM ROCK inhibitor Y-27632. The removal of Y-27632 and the addition of high calcium to induce differentiation allowed the cells to behave as primary keratinocytes even after extended serial passaging. Prolonged lifespan HEK-CaYs were capable of forming an organised stratified epidermis in 3D HSE cultures, demonstrating their ability to fully stratify and retain their original, primary characteristics. In conclusion, the use of 0.07 mM Calcium and 10 μM Y-27632 in HEKn monocultures provides the opportunity to culture primary human keratinocytes without a cell feeder layer for extended periods of culture whilst retaining their ability to

  10. Lactulose stimulates calcium absorption in postmenopausal women

    NARCIS (Netherlands)

    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 po

  11. Modulation of elementary calcium release mediates a transition from puffs to waves in an IP3R cluster model.

    Directory of Open Access Journals (Sweden)

    Martin Rückl

    2015-01-01

    Full Text Available The oscillating concentration of intracellular calcium is one of the most important examples for collective dynamics in cell biology. Localized releases of calcium through clusters of inositol 1,4,5-trisphosphate receptor channels constitute elementary signals called calcium puffs. Coupling by diffusing calcium leads to global releases and waves, but the exact mechanism of inter-cluster coupling and triggering of waves is unknown. To elucidate the relation of puffs and waves, we here model a cluster of IP3R channels using a gating scheme with variable non-equilibrium IP3 binding. Hybrid stochastic and deterministic simulations show that puffs are not stereotyped events of constant duration but are sensitive to stimulation strength and residual calcium. For increasing IP3 concentration, the release events become modulated at a timescale of minutes, with repetitive wave-like releases interspersed with several puffs. This modulation is consistent with experimental observations we present, including refractoriness and increase of puff frequency during the inter-wave interval. Our results suggest that waves are established by a random but time-modulated appearance of sustained release events, which have a high potential to trigger and synchronize activity throughout the cell.

  12. Calcium Forms,Subcelluar Distribution and Ultrastructure of Pulp Cells as Influenced by Calcium Deficiency in Apple (Malus pumila) Fruits

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-hui; ZHOU Wei

    2004-01-01

    Calcium in Red Fuji and Starkrimson apples during storage were fractionated by sequent extracting. Localization and distribution of calcium and influence of calcium nutrition on cell ultrastructure were observed by transmission electron microscopy combined with in situ precipitation of calcium with an improved method of potassium pyroantimonate technique. Results indicated that spraying calcium solution on surface of young fruits increased contents of calcium in all forms. During storage, contents of soluble calcium and pectic calcium declined and thosein calcium phosphate, calcium oxalate and calcium silicate increased. Calcium contents of Red Fuji in all forms were higher than those of Starkrimson, indicating that calcium accumulating capability of Red Fuji fruits preceded that of Starkrimson. Under transmission electron microscopy, calcium antimonite precipitates (CaAP) was mainly distributed in cell wall, tonoplast, nuclear membrane and nucleoplasm,much more CaAP deposited in vacuole. Calcium deficiency during storage leads to decrease of CaAP in locations mentioned above, disappearance of compartmentation, and entrance of CaAP to cytoplasm. Transformation from soluble calcium and pectic calcium to calcium phosphate,oxalate and damages of biomembranes structuraly and functionally resulted from calcium deficiency during storage were the crucial causation of physiological disorder.

  13. Is Earthquake Triggering Driven by Small Earthquakes?

    OpenAIRE

    Helmstetter, Agnes

    2002-01-01

    Using a catalog of seismicity for Southern California, we measure how the number of triggered earthquakes increases with the earthquake magnitude. The trade-off between this relation and the distribution of earthquake magnitudes controls the relative role of small compared to large earthquakes. We show that seismicity triggering is driven by the smallest earthquakes, which trigger fewer events than larger earthquakes, but which are much more numerous. We propose that the non-trivial scaling o...

  14. Stay away from asthma triggers

    Science.gov (United States)

    Asthma triggers - stay away from; Asthma triggers - avoiding; Reactive airway disease - triggers; Bronchial asthma - triggers ... to them. Have someone who does not have asthma cut the grass, or wear a facemask if ...

  15. Calcium paradox and calcium entry blockers

    NARCIS (Netherlands)

    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, exhausti

  16. Tidal triggering of earthquakes

    OpenAIRE

    Heaton, Thomas H.

    1982-01-01

    Analysis of the tidal stress tensor at the time of moderate to large earthquakes strongly suggests that shallow (< 30 km) larger magnitude oblique-slip and dip-slip earthquakes are triggered by tidal stresses. No corresponding triggering effect is seen for shallow strike-slip earthquakes or for any type of intermediate or deep focus earthquakes which have been studied. Tidal triggering is also discussed from the viewpoint of the ‘dilatancy-diffusion’ model. Specifically, the model as usually ...

  17. Increased osteoinductivity and mineralization by minimal concentration of bone morphogenetic protein-2 loaded onto biphasic calcium phosphate in a rabbit sinus

    Science.gov (United States)

    2016-01-01

    Purpose The purpose of the present study was to evaluate the effectiveness of a minimal concentration of bone morphogenetic protein-2 (BMP-2) in terms of quantitative and qualitative analyses of newly formed bone in a rabbit maxillary sinus model. Methods In 7 rabbits, sinus windows were prepared bilaterally. Biphasic calcium phosphate (BCP) loaded with 0.05 mg/mL BMP-2 was grafted into one sinus (the BMP group) and saline-soaked BCP was placed into the other (the control group) in each animal. The animals were allowed an 8-week healing period before being sacrificed. Specimens including the augmented area and surrounding tissues were then removed and evaluated both radiographically and histologically. Results There was a difference in the mineralization of new bone between the groups. In the BMP group, the greater part of the new bone consisted of mature lamellar bone with an evident trabecular pattern, whereas the control group showed mostly woven bone, consisting only partially of lamellar bone. Histometrically, the area of new bone was significantly greater (4.55±1.35 mm2 vs. 2.99±0.86 mm2) in the BMP group than in the control group (Pmineralization in a rabbit sinus model using a BCP carrier. PMID:27800217

  18. The ATLAS b-jet Trigger

    CERN Document Server

    Ferreira de Lima, D E; The ATLAS collaboration

    2011-01-01

    The ATLAS b-jet Trigger The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is presently contributing to the event selection for the 2011 running. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and performance on real data is presented in this poster.

  19. Commissioning of the ATLAS Muon Trigger Selection

    CERN Document Server

    Musto, Elisa

    2010-01-01

    The performance of the three-level ATLAS muon trigger as evaluated by using LHC data is presented. Events have been selected by using only the hardware-based Level-1 trigger in order to commission and to subsequently enable the (software-based) selections of the High Level Trigger. Studies aiming at selecting prompt muons from J/{\\psi} and at reducing non prompt muon contamination have been performed. A brief overview on how the muon triggers evolve with increasing luminosity is given.

  20. Local calcium elevation and cell elongation initiate guided motility in electrically stimulated osteoblast-like cells.

    Directory of Open Access Journals (Sweden)

    Nurdan Ozkucur

    Full Text Available BACKGROUND: Investigation of the mechanisms of guided cell migration can contribute to our understanding of many crucial biological processes, such as development and regeneration. Endogenous and exogenous direct current electric fields (dcEF are known to induce directional cell migration, however the initial cellular responses to electrical stimulation are poorly understood. Ion fluxes, besides regulating intracellular homeostasis, have been implicated in many biological events, including regeneration. Therefore understanding intracellular ion kinetics during EF-directed cell migration can provide useful information for development and regeneration. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the initial events during migration of two osteogenic cell types, rat calvarial and human SaOS-2 cells, exposed to strong (10-15 V/cm and weak (< or = 5 V/cm dcEFs. Cell elongation and perpendicular orientation to the EF vector occurred in a time- and voltage-dependent manner. Calvarial osteoblasts migrated to the cathode as they formed new filopodia or lamellipodia and reorganized their cytoskeleton on the cathodal side. SaOS-2 cells showed similar responses except towards the anode. Strong dcEFs triggered a rapid increase in intracellular calcium levels, whereas a steady state level of intracellular calcium was observed in weaker fields. Interestingly, we found that dcEF-induced intracellular calcium elevation was initiated with a local rise on opposite sides in calvarial and SaOS-2 cells, which may explain their preferred directionality. In calcium-free conditions, dcEFs induced neither intracellular calcium elevation nor directed migration, indicating an important role for calcium ions. Blocking studies using cadmium chloride revealed that voltage-gated calcium channels (VGCCs are involved in dcEF-induced intracellular calcium elevation. CONCLUSION/SIGNIFICANCE: Taken together, these data form a time scale of the morphological and physiological

  1. The effect of calcium gluconate and other calcium supplements as a dietary calcium source on magnesium absorption in rats.

    Science.gov (United States)

    Chonan, O; Takahashi, R; Yasui, H; Watanuki, M

    1997-01-01

    The effects of commercially available calcium supplements (calcium carbonate, calcium gluconate, oyster shell preparation and bovine bone preparation) and gluconic acid on the absorption of calcium and magnesium were evaluated for 30 days in male Wistar rats. There were no differences in the apparent absorption ratio of calcium among rats fed each calcium supplement; however, the rats fed the calcium gluconate diet had a higher apparent absorption ratio of magnesium than the rats fed the other calcium supplements. Dietary gluconic acid also more markedly stimulated magnesium absorption than the calcium carbonate diet, and the bone (femur and tibia) magnesium contents of rats fed the gluconic acid diet were significantly higher than those of the rats fed the calcium carbonate diet. Furthermore, the weight of cecal tissue and the concentrations of acetic acid and butyric acid in cecal digesta of rats fed the calcium gluconate diet or the gluconic acid diet were significantly increased. We speculate that the stimulation of magnesium absorption in rats fed the calcium gluconate diet is a result of the gluconic acid component and the effect of gluconic acid on magnesium absorption probably results from cecal hypertrophy, magnesium solubility in the large intestine and the effects of volatile fatty acids on magnesium absorption.

  2. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    Energy Technology Data Exchange (ETDEWEB)

    Bizzozero, Julien, E-mail: julien.bizzozero@gmail.com; Scrivener, Karen L.

    2015-10-15

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  3. Increasing extracellular H2O2 produces a bi-phasic response in intracellular H2O2, with peroxiredoxin hyperoxidation only triggered once the cellular H2O2-buffering capacity is overwhelmed.

    Science.gov (United States)

    Tomalin, Lewis Elwood; Day, Alison Michelle; Underwood, Zoe Elizabeth; Smith, Graham Robert; Dalle Pezze, Piero; Rallis, Charalampos; Patel, Waseema; Dickinson, Bryan Craig; Bähler, Jürg; Brewer, Thomas Francis; Chang, Christopher Joh-Leung; Shanley, Daryl Pierson; Veal, Elizabeth Ann

    2016-06-01

    Reactive oxygen species, such as H2O2, can damage cells but also promote fundamental processes, including growth, differentiation and migration. The mechanisms allowing cells to differentially respond to toxic or signaling H2O2 levels are poorly defined. Here we reveal that increasing external H2O2 produces a bi-phasic response in intracellular H2O2. Peroxiredoxins (Prx) are abundant peroxidases which protect against genome instability, ageing and cancer. We have developed a dynamic model simulating in vivo changes in Prx oxidation. Remarkably, we show that the thioredoxin peroxidase activity of Prx does not provide any significant protection against external rises in H2O2. Instead, our model and experimental data are consistent with low levels of extracellular H2O2 being efficiently buffered by other thioredoxin-dependent activities, including H2O2-reactive cysteines in the thiol-proteome. We show that when extracellular H2O2 levels overwhelm this buffering capacity, the consequent rise in intracellular H2O2 triggers hyperoxidation of Prx to thioredoxin-resistant, peroxidase-inactive form/s. Accordingly, Prx hyperoxidation signals that H2O2 defenses are breached, diverting thioredoxin to repair damage. PMID:26944189

  4. AMY trigger system

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yoshihide [National Laboratory for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1989-04-01

    A trigger system of the AMY detector at TRISTAN e{sup +}e{sup -} collider is described briefly. The system uses simple track segment and shower cluster counting scheme to classify events to be triggered. It has been operating successfully since 1987.

  5. Osteogenic Differentiation of MSC through Calcium Signaling Activation: Transcriptomics and Functional Analysis.

    Directory of Open Access Journals (Sweden)

    Federica Viti

    Full Text Available The culture of progenitor mesenchymal stem cells (MSC onto osteoconductive materials to induce a proper osteogenic differentiation and mineralized matrix regeneration represents a promising and widely diffused experimental approach for tissue-engineering (TE applications in orthopaedics. Among modern biomaterials, calcium phosphates represent the best bone substitutes, due to their chemical features emulating the mineral phase of bone tissue. Although many studies on stem cells differentiation mechanisms have been performed involving calcium-based scaffolds, results often focus on highlighting production of in vitro bone matrix markers and in vivo tissue ingrowth, while information related to the biomolecular mechanisms involved in the early cellular calcium-mediated differentiation is not well elucidated yet. Genetic programs for osteogenesis have been just partially deciphered, and the description of the different molecules and pathways operative in these differentiations is far from complete, as well as the activity of calcium in this process. The present work aims to shed light on the involvement of extracellular calcium in MSC differentiation: a better understanding of the early stage osteogenic differentiation program of MSC seeded on calcium-based biomaterials is required in order to develop optimal strategies to promote osteogenesis through the use of new generation osteoconductive scaffolds. A wide spectrum of analysis has been performed on time-dependent series: gene expression profiles are obtained from samples (MSC seeded on calcium-based scaffolds, together with related microRNAs expression and in vivo functional validation. On this basis, and relying on literature knowledge, hypotheses are made on the biomolecular players activated by the biomaterial calcium-phosphate component. Interestingly, a key role of miR-138 was highlighted, whose inhibition markedly increases osteogenic differentiation in vitro and enhance ectopic bone

  6. Osteogenic Differentiation of MSC through Calcium Signaling Activation: Transcriptomics and Functional Analysis.

    Science.gov (United States)

    Viti, Federica; Landini, Martina; Mezzelani, Alessandra; Petecchia, Loredana; Milanesi, Luciano; Scaglione, Silvia

    2016-01-01

    The culture of progenitor mesenchymal stem cells (MSC) onto osteoconductive materials to induce a proper osteogenic differentiation and mineralized matrix regeneration represents a promising and widely diffused experimental approach for tissue-engineering (TE) applications in orthopaedics. Among modern biomaterials, calcium phosphates represent the best bone substitutes, due to their chemical features emulating the mineral phase of bone tissue. Although many studies on stem cells differentiation mechanisms have been performed involving calcium-based scaffolds, results often focus on highlighting production of in vitro bone matrix markers and in vivo tissue ingrowth, while information related to the biomolecular mechanisms involved in the early cellular calcium-mediated differentiation is not well elucidated yet. Genetic programs for osteogenesis have been just partially deciphered, and the description of the different molecules and pathways operative in these differentiations is far from complete, as well as the activity of calcium in this process. The present work aims to shed light on the involvement of extracellular calcium in MSC differentiation: a better understanding of the early stage osteogenic differentiation program of MSC seeded on calcium-based biomaterials is required in order to develop optimal strategies to promote osteogenesis through the use of new generation osteoconductive scaffolds. A wide spectrum of analysis has been performed on time-dependent series: gene expression profiles are obtained from samples (MSC seeded on calcium-based scaffolds), together with related microRNAs expression and in vivo functional validation. On this basis, and relying on literature knowledge, hypotheses are made on the biomolecular players activated by the biomaterial calcium-phosphate component. Interestingly, a key role of miR-138 was highlighted, whose inhibition markedly increases osteogenic differentiation in vitro and enhance ectopic bone formation in vivo

  7. PKA controls calcium influx into motor neurons during a rhythmic behavior.

    Directory of Open Access Journals (Sweden)

    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.

  8. Effect of lowering dietary calcium intake on fractional whole body calcium retention

    Energy Technology Data Exchange (ETDEWEB)

    Dawson-Hughes, B.; Stern, D.T.; Shipp, C.C.; Rasmussen, H.M.

    1988-07-01

    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 /sup 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.

  9. Research on seismic stress triggering

    Institute of Scientific and Technical Information of China (English)

    万永革; 吴忠良; 周公威; 黄静; 秦立新

    2002-01-01

    This paper briefly reviews basic theory of seismic stress triggering. Recent development on seismic stress triggering has been reviewed in the views of seismic static and dynamic stress triggering, application of viscoelastic model in seismic stress triggering, the relation between earthquake triggering and volcanic eruption or explosion, other explanation of earthquake triggering, etc. And some suggestions for further study on seismic stress triggering in near future are given.

  10. Fast kinetics of calcium signaling and sensor design.

    Science.gov (United States)

    Tang, Shen; Reddish, Florence; Zhuo, You; Yang, Jenny J

    2015-08-01

    Fast calcium signaling is regulated by numerous calcium channels exhibiting high spatiotemporal profiles which are currently measured by fluorescent calcium sensors. There is still a strong need to improve the kinetics of genetically encoded calcium indicators (sensors) to capture calcium dynamics in the millisecond time frame. In this review, we summarize several major fast calcium signaling pathways and discuss the recent developments and application of genetically encoded calcium indicators to detect these pathways. A new class of genetically encoded calcium indicators designed with site-directed mutagenesis on the surface of beta-barrel fluorescent proteins to form a pentagonal bipyramidal-like calcium binding domain dramatically accelerates calcium binding kinetics. Furthermore, novel genetically encoded calcium indicators with significantly increased fluorescent lifetime change are advantageous in deep-field imaging with high light-scattering and notable morphology change.

  11. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-01

    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. PMID:7488645

  12. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-01

    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.

  13. The ATLAS Muon and Tau Trigger

    CERN Document Server

    Dell'Asta, L; The ATLAS collaboration

    2013-01-01

    [Muon] The ATLAS experiment at CERN's Large Hadron Collider (LHC) deploys a three-levels processing scheme for the trigger system. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 (L2) trigger followed by an event filter (EF) for a staged trigger approach. It has access to the data of the precision muon detectors and other detector elements to refine the muon hypothesis. Trigger-specific algorithms were developed and are used for the L2 to increase processing speed for instance by making use of look-up tables and simpler algorithms, while the EF muon triggers mostly benefit from offline reconstruction software to obtain most precise determination of the track parameters. There are two algorithms with different approaches, namely inside-out and outside-in...

  14. Calcium source (image)

    Science.gov (United States)

    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 ...

  15. Calcium hydroxide poisoning

    Science.gov (United States)

    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 ...

  16. Calcium and bones (image)

    Science.gov (United States)

    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. Coronary Calcium Scan

    Science.gov (United States)

    ... the NHLBI on Twitter. What Is a Coronary Calcium Scan? A coronary calcium scan is a test ... you have calcifications in your coronary arteries. Coronary Calcium Scan Figure A shows the position of the ...

  18. Calcium Pyrophosphate Deposition (CPPD)

    Science.gov (United States)

    ... 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 ...

  19. LHCb Topological Trigger Reoptimization

    Science.gov (United States)

    Likhomanenko, Tatiana; Ilten, Philip; Khairullin, Egor; Rogozhnikov, Alex; Ustyuzhanin, Andrey; Williams, Michael

    2015-12-01

    The main b-physics trigger algorithm used by the LHCb experiment is the so- called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger, which utilized a custom boosted decision tree algorithm, selected a nearly 100% pure sample of b-hadrons with a typical efficiency of 60-70%; its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and neural networks. The topological trigger algorithm is designed to select all ’interesting” decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. Methods studied include cascading, ensembling and blending techniques. Furthermore, novel boosting techniques have been implemented that will help reduce systematic uncertainties in Run 2 measurements. We demonstrate that the reoptimized topological trigger is expected to significantly improve on the Run 1 performance for a wide range of b-hadron decays.

  20. The LHCb Trigger

    CERN Document Server

    van Herwijnen, Eric

    2010-01-01

    The Large Hadron Collider beauty experiment (LHCb) is a dedicated heavy flavour physics experiment at the LHC. The trigger system employs the finite lifetime and relative large mass of charm and beauty hadrons to distinguish heavy flavour and background from inelastic pp-scattering. The LHCb trigger is a two level system. The first level is implemented in hardware, it reduces the visible interaction rate to a maximum of 1MHz, at which the whole detector can be readout. The second trigger level is a C++ application running on an Event Filter Farm composed of several thousand CPU nodes. The full trigger is operational in the experiment. In this talk, an overview of the LHCb trigger system will be given. We put special emphasis on the experience obtained with the initial data taking at the LHC, and the commissioning and monitoring of the software trigger. The method to obtain the efficiency of the trigger from real data will be described, and first results will be presented.

  1. Software for implementing trigger algorithms on the upgraded CMS Global Trigger System

    Science.gov (United States)

    Matsushita, Takashi; Arnold, Bernhard

    2015-12-01

    The Global Trigger is the final step of the CMS Level-1 Trigger and implements a trigger menu, a set of selection requirements applied to the final list of trigger objects. The conditions for trigger object selection, with possible topological requirements on multiobject triggers, are combined by simple combinatorial logic to form the algorithms. The LHC has resumed its operation in 2015, the collision-energy will be increased to 13 TeV with the luminosity expected to go up to 2x1034 cm-2s-1. The CMS Level-1 trigger system will be upgraded to improve its performance for selecting interesting physics events and to operate within the predefined data-acquisition rate in the challenging environment expected at LHC Run 2. The Global Trigger will be re-implemented on modern FPGAs on an Advanced Mezzanine Card in MicroTCA crate. The upgraded system will benefit from the ability to process complex algorithms with DSP slices and increased processing resources with optical links running at 10 Gbit/s, enabling more algorithms at a time than previously possible and allowing CMS to be more flexible in how it handles the trigger bandwidth. In order to handle the increased complexity of the trigger menu implemented on the upgraded Global Trigger, a set of new software has been developed. The software allows a physicist to define a menu with analysis-like triggers using intuitive user interface. The menu is then realised on FPGAs with further software processing, instantiating predefined firmware blocks. The design and implementation of the software for preparing a menu for the upgraded CMS Global Trigger system are presented.

  2. FocusStack and StimServer: a new open source MATLAB toolchain for visual stimulation and analysis of two-photon calcium neuronal imaging data

    OpenAIRE

    Dylan Richard Muir; Björn Kampa

    2015-01-01

    Two-photon calcium imaging of neuronal responses is an increasingly accessible technology for probing population responses in cortex at single cell resolution, and with reasonable and improving temporal resolution. However, analysis of two-photon data is usually performed using ad-hoc solutions. To date, no publicly available software exists for straightforward analysis of stimulus-triggered two-photon imaging experiments. In addition, the increasing data rates of two-photon acquisition syste...

  3. Pharmacological profile of the ATP-mediated increase in L-type calcium current amplitude and activation of a non-specific cationic current in rat ventricular cells.

    OpenAIRE

    Scamps, F.; Vassort, G

    1994-01-01

    1. The pharmacological profile of the ATP-induced increase in ICa amplitude and of ATP activation of a non-specific cationic current, IATP, was investigated in rat ventricular cells. 2. The EC50 values for ICa increase and IATP activation were 0.36 microM and 0.76 microM respectively. Suramin (10 microM) and cibacron blue (1 microM) competitively antagonized both effects of ATP. 3. The rank order of efficacy and potency of ATP analogues in increasing ICa amplitude was 2-methylthio-ATP approxi...

  4. Calo trigger acquisition system

    CERN Multimedia

    Franchini, Matteo

    2016-01-01

    Calo trigger acquisition system - Evolution of the acquisition system from a multiple boards system (upper, orange cables) to a single board one (below, light blue cables) where all the channels are collected in a single board.

  5. Sensitivity to calcium intake in calcium stone forming patients.

    Science.gov (United States)

    Heilberg, I P; Martini, L A; Draibe, S A; Ajzen, H; Ramos, O L; Schor, N

    1996-01-01

    The absorptive or renal origin of hypercalciuria can be discriminated using an acute oral calcium load test (ACLT). Of 86 patients with calcium oxalate kidney stones, 28 (23%) were found to be hypercalciuric (HCa) and 58 (67%) normocalciuric (NCa) on their customary free diet, containing 542 +/- 29 mg/day (mean +/- SE) of calcium. Since the apparently normal 24-hour calcium excretion of many calcium stone formers (CSF) may be due to a combination of high calcium absorption with moderately low calcium intake, all patients were investigated by ACLT. Of 28 HCa patients, 13 (46%) were classified as absorptive (AH) and 15 (54%) as renal hypercalciuria (RH). Of the 58 NCa patients, 38 (65%) presented features of intestinal hyperabsorption and were therefore designated as AH-like, and 20 (35%) as RH-like. To further elucidate the role of dietary calcium in these CSF, a chronic calcium load test (CCLT), consisting of 1 g/day of oral Ca for 7 days, was designed. A positive response to the CCLT was considered to occur when urinary calcium (uCa) was > or = 4 mg/ kg/24 h on the 7th day. Among NCa patients, 29% of AH-like subjects responded to the CCLT and 71% did not; 50% of RH-like subjects also responded and 50% did not. In HCa patients, 85% of AH and 67% of RH subjects maintained uCa > or = 4 mg/kg/24 h after the CCLT and 15% of AH and 23% of RH subjects did not. However, a significant additional increase in mean uCa was not observed among HCa patients. All patients were submitted to a second evaluation of fasting calciuria (Ca/Cr). A modification of this parameter was noticed in 89% of RH-like and 78% of RH patients. In conclusion, these data suggest the presence of subpopulations of patients sensitive or not to calcium intake, regardless of whether the acute response to a calcium overload test suggested AH or RH. The CCLT disclosed dietary hypercalciuria in 21/58 (36%) of previously NCa patients. In these NCa patients, the ACLT may be replaced by the CCLT. The distinction

  6. Topological Trigger Developments

    CERN Multimedia

    Likhomanenko, Tatiana

    2015-01-01

    The main b-physics trigger algorithm used by the LHCb experiment is the so-called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger utilized a custom boosted decision tree algorithm, selected an almost 100% pure sample of b-hadrons with a typical efficiency of 60-70%, and its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and uBoost. The topological trigger algorithm is designed to select all "interesting" decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. These inclu...

  7. The VERITAS Trigger System

    CERN Document Server

    Weinstein, A

    2007-01-01

    The VERITAS gamma-ray observatory, situated in southern Arizona, is an array of four 12m diameter imaging Cherenkov telescopes, each with a 499-pixel photomultiplier-tube camera. The instrument is designed to detect astrophysical gamma rays at energies above 100 GeV. At the low end of the VERITAS energy range, fluctuations in the night sky background light and single muons from cosmic-ray showers constitute significant backgrounds. VERITAS employs a three-tier trigger system to reduce the rate of these background events: an initial trigger which acts at the single pixel level, a pattern trigger which acts on the relative timing and pixel level, a pattern trigger which acts on the relative timing and distribution of pixel-level triggers within a single telescope camera, and an array-level trigger which requires simultaneous observation of an air-shower event in multiple telescopes. This final coincidence requirement significantly reduces the rate of background events, particularly those due to single muons. In...

  8. The LHCb Trigger System

    Science.gov (United States)

    Rodrigues, E.; LHCb Collaboration

    2007-08-01

    The LHCb detector has been conceived to study with high precision CP violation and rare decays of b-flavoured hadrons produced at the LHC. The LHCb trigger is of crucial importance in selecting the collisions of interest for b-physics studies. The trigger is based on a two-level system. The first level, Level-0, is implemented in hardware and uses information from the calorimeter, muon and pile-up systems to select events containing particles with relatively large transverse momentum, typically above 1-2 GeV. The Level-0 trigger accepts events at a rate of 1 MHz. All the detector information is then read out and fed into the High Level Trigger. This software trigger runs in the event-filter farm composed of about 1800 CPU nodes. Events are selected at a rate of 2 kHz and sent for mass storage and subsequent offline reconstruction and analysis. The current status and expected performance of the trigger system are described.

  9. LHCb Topological Trigger Reoptimization

    CERN Document Server

    Likhomanenko, Tatiana; Khairullin, Egor; Rogozhnikov, Alex; Ustyuzhanin, Andrey; Williams, Michael

    2015-01-01

    The main b-physics trigger algorithm used by the LHCb experiment is the so-called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger, which utilized a custom boosted decision tree algorithm, selected a nearly 100% pure sample of b-hadrons with a typical efficiency of 60-70%; its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and neural networks. The topological trigger algorithm is designed to select all "interesting" decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. ...

  10. Dynamic Triggering Stress Modeling

    Science.gov (United States)

    Gonzalez-Huizar, H.; Velasco, A. A.

    2008-12-01

    It has been well established that static (permanent) stress changes can trigger nearby earthquakes, within a few fault lengths from the causative event, whereas triggering by dynamic (transient) stresses carried by seismic waves both nearby and at remote distances has not been as well documented nor understood. An analysis of the change in the local stress caused by the passing of surfaces waves is important for the understanding of this phenomenon. In this study, we modeled the change in the stress that the passing of Rayleigh and Loves waves causes on a fault plane of arbitrary orientation, and applied a Coulomb failure criteria to calculate the potential of these stress changes to trigger reverse, normal or strike-slip failure. We preliminarily test these model results with data from dynamically triggering earthquakes in the Australian Bowen Basin. In the Bowen region, the modeling predicts a maximum triggering potential for Rayleigh waves arriving perpendicularly to the strike of the reverse faults present in the region. The modeled potentials agree with our observations, and give us an understanding of the dynamic stress orientation needed to trigger different type of earthquakes.

  11. Calcium-linked increase in coupled cAMP synthesis and hydrolysis is an early event in cholinergic and. beta. -adrenergic stimulation of parotid secretion

    Energy Technology Data Exchange (ETDEWEB)

    Deeg, M.A.; Graeff, R.M.; Walseth, T.F.; Goldberg, N.D. (Univ. of Minnesota, Minneapolis (USA))

    1988-11-01

    The dynamics and compartmental characteristics of cAMP metabolism were examined by {sup 18}O labeling of cellular adenine nucleotide {alpha} phosphoryls in rat parotid gland stimulated to secrete with {beta}-adrenergic and cholinergic agents. The secretory response occurred in association with a rapidly increased rate of cAMP hydrolysis apparently coordinated with an equivalent increase in the rate of cAMP synthesis, since the cellular concentration of cAMP remained unchanged. The magnitude of this metabolic response was equivalent to the metabolism of 10-75 times the cellular content of cAMP within the first minute of stimulation. This increased metabolic rate occurred only during the early (1-3 min) period of stimulation, in what appeared to be an exclusive cellular compartment distinguished by a unique distribution of {sup 18}O among adenine nucleotide {alpha} phosphoryls. This {sup 18}O distribution contrasted with that produced by forskolin, which increased cellular cAMP concentration and elicited only a delayed response missing the early secretory component. The early acceleration of cAMP metabolism appeared linked to a stimulus-induced increase in intracellular Ca{sup 2+} concentration, since the Ca{sup 2+} ionophore ionomycin produced the same metabolic response in association with secretion. These observations suggest that cAMP metabolism is involved in stimulus-secretion coupling by a Ca{sup 2+}-linked mechanism different from that in which cAMP plays the role of a second messenger.

  12. The ATLAS b-jet Trigger

    CERN Document Server

    Hansson Adrian, P; The ATLAS collaboration

    2011-01-01

    The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is presently contributing to the event selection for the 2011 running. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and performance on real data is presented in this contribution.

  13. ATLAS FTK: Fast Track Trigger

    CERN Document Server

    Volpi, Guido; The ATLAS collaboration

    2015-01-01

    An overview of the ATLAS Fast Tracker processor is presented, reporting the design of the system, its expected performance, and the integration status. The next LHC runs, with a significant increase in instantaneous luminosity, will provide a big challenge to the trigger and data acquisition systems of all the experiments. An intensive use of the tracking information at the trigger level will be important to keep high efficiency in interesting events, despite the increase in multiple p-p collisions per bunch crossing (pile-up). In order to increase the use of tracks within the High Level Trigger (HLT), the ATLAS experiment planned the installation of an hardware processor dedicated to tracking: the Fast TracKer (FTK) processor. The FTK is designed to perform full scan track reconstruction at every Level-1 accept. To achieve this goal, the FTK uses a fully parallel architecture, with algorithms designed to exploit the computing power of custom VLSI chips, the Associative Memory, as well as modern FPGAs. The FT...

  14. Nonlinear dynamical triggering of slow slip

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paul A [Los Alamos National Laboratory; Knuth, Matthew W [WISCONSIN; Kaproth, Bryan M [PENN STATE; Carpenter, Brett [PENN STATE; Guyer, Robert A [Los Alamos National Laboratory; Le Bas, Pierre - Yves [Los Alamos National Laboratory; Daub, Eric G [Los Alamos National Laboratory; Marone, Chris [PENN STATE

    2010-12-10

    Among the most fascinating, recent discoveries in seismology have been the phenomena of triggered slip, including triggered earthquakes and triggered-tremor, as well as triggered slow, silent-slip during which no seismic energy is radiated. Because fault nucleation depths cannot be probed directly, the physical regimes in which these phenomena occur are poorly understood. Thus determining physical properties that control diverse types of triggered fault sliding and what frictional constitutive laws govern triggered faulting variability is challenging. We are characterizing the physical controls of triggered faulting with the goal of developing constitutive relations by conducting laboratory and numerical modeling experiments in sheared granular media at varying load conditions. In order to simulate granular fault zone gouge in the laboratory, glass beads are sheared in a double-direct configuration under constant normal stress, while subject to transient perturbation by acoustic waves. We find that triggered, slow, silent-slip occurs at very small confining loads ({approx}1-3 MPa) that are smaller than those where dynamic earthquake triggering takes place (4-7 MPa), and that triggered slow-slip is associated with bursts of LFE-like acoustic emission. Experimental evidence suggests that the nonlinear dynamical response of the gouge material induced by dynamic waves may be responsible for the triggered slip behavior: the slip-duration, stress-drop and along-strike slip displacement are proportional to the triggering wave amplitude. Further, we observe a shear-modulus decrease corresponding to dynamic-wave triggering relative to the shear modulus of stick-slips. Modulus decrease in response to dynamical wave amplitudes of roughly a microstrain and above is a hallmark of elastic nonlinear behavior. We believe that the dynamical waves increase the material non-affine elastic deformation during shearing, simultaneously leading to instability and slow-slip. The inferred

  15. Enhancement of macrophage candidacidal activity by interferon-gamma. Increased phagocytosis, killing, and calcium signal mediated by a decreased number of mannose receptors.

    Science.gov (United States)

    Maródi, L; Schreiber, S; Anderson, D C; MacDermott, R P; Korchak, H M; Johnston, R B

    1993-01-01

    In contrast to its macrophage-activating capacity, IFN-gamma downregulates expression of the macrophage mannose receptor (MMR), which mediates uptake of Candida and other microorganisms. We found that IFN-gamma induced a concentration-dependent increase in the capacity of human monocyte-derived macrophages to ingest and kill both opsonized and unopsonized Candida albicans and to release superoxide anion upon stimulation with Candida. Mannan or mannosylated albumin inhibited this activated uptake of unopsonized Candida, but glucan did not. Addition of mAb to complement receptor (CR) 3 did not inhibit ingestion; macrophages that lacked CR3 (leukocyte adhesion defect) showed normal upregulation of ingestion by IFN-gamma. The increased candidacidal activity of IFN-gamma-activated macrophages was associated with reduced expression of MMR by a mean of 79% and decreased pinocytic uptake of 125I-mannosylated BSA by 73%; K(uptake) of pinocytosis was not changed. Exposure of resident macrophages to unopsonized Candida did not elicit a transient increase in intracellular free Ca2+ ([Ca2+]i); macrophages activated by IFN-gamma expressed a brisk increase in [Ca2+]i on exposure to Candida. These data suggest that macrophage activation by IFN-gamma can enhance resistance to C. albicans infection in spite of downregulation of the MMR, perhaps through enhanced coupling of the MMR to microbicidal functions. PMID:8390485

  16. NMDAR1 mRNA expression and glutamate receptor stimulated increase in cytosolic calcium concentration in rat and mouse cerebellar granule cells

    DEFF Research Database (Denmark)

    Mogensen, H S; Jørgensen, Ole Steen

    1996-01-01

    concentration of mRNA for the obligatory NMDA receptor subunit, NMDAR1, and (b) the glutamate/NMDA stimulated increase in cytosolic Ca(2+)-ion concentration in cultures at physiological or elevated K(+)-ion concentration. The expression of NMDAR1 mRNA was measured by competitive PCR of reversely transcribed m......RNA and was normalized to that of the constitutively expressed H3.3 histone mRNA. The glutamate and NMDA stimulated increase in cytosolic Ca(2+)-ion concentration was measured using the fluorescent Ca(2+)-chelator Fluo3. In contrast to the hypothesis, we found NMDAR1 mRNA expression to be lower in mouse...... than in rat granule cells cultured for 4 days at physiological K(+)-ion concentration. However, the NMDA stimulated increase in cytosolic Ca(2+)-ion concentration did not differ in 4-day rat and mouse cultures. Although the glutamate-stimulated increase in cytosolic Ca(2+)-ion concentration in 2-day...

  17. Aqueous extract of tamarind seeds selectively increases glucose transporter-2, glucose transporter-4, and islets' intracellular calcium levels and stimulates β-cell proliferation resulting in improved glucose homeostasis in rats with streptozotocin-induced diabetes mellitus.

    Science.gov (United States)

    Sole, Sushant Shivdas; Srinivasan, B P

    2012-08-01

    Tamarindus indica Linn. has been in use for a long time in Asian food and traditional medicine for different diseases including diabetes and obesity. However, the molecular mechanisms of these effects have not been fully understood. In view of the multidimensional activity of tamarind seeds due to their having high levels of polyphenols and flavonoids, we hypothesized that the insulin mimetic effect of aqueous tamarind seed extract (TSE) might increase glucose uptake through improvement in the expression of genes of the glucose transporter (GLUT) family and sterol regulatory element-binding proteins (SREBP) 1c messenger RNA (mRNA) in the liver. Daily oral administration of TSE to streptozotocin (STZ)-induced (90 mg/kg intraperitoneally) type 2 diabetic male Wistar rats at different doses (120 and 240 mg/kg body weight) for 4 weeks showed positive correlation with intracellular calcium and insulin release in isolated islets of Langerhans. Tamarind seed extract supplementation significantly improved the GLUT-2 protein and SREBP-1c mRNA expression in the liver and GLUT-4 protein and mRNA expression in the skeletal muscles of diabetic rats. The elevated levels of serum nitric oxide (NO), glycosylated hemoglobin level (hemoglobin (A1c)) and tumor necrosis factor α (TNF-α) decreased after TSE administration. Immunohistochemical findings revealed that TSE abrogated STZ-induced apoptosis and increased β-cell neogenesis, indicating its effect on islets and β-cell mass. In conclusion, it was found that the antidiabetic effect of TSE on STZ-induced diabetes resulted from complex mechanisms of β-cell neogenesis, calcium handling, GLUT-2, GLUT-4, and SREBP-1c. These findings show the scope for formulating a new herbal drug for diabetes therapy.

  18. Hardware, firmware and software developments for the upgrade of the ATLAS Level-1 Central Trigger Processor

    CERN Document Server

    Ghibaudi, M; The ATLAS collaboration; Spiwoks, R; Anders, G; Bertelsen, H; Boisen, A; Childers, T; Dam, M; Ellis, N; Farthouat, P; Gabaldon Ruiz, C; Gorini, B; Kaneda, M; Ohm, C; Silva Oliveira, M; Pauly, T; Pottgen, R; Schmieden, K; Xella, S

    2013-01-01

    The Central Trigger Processor (CTP) is the final stage of the ATLAS first level trigger system which reduces the collision rate of 40 MHz to a Level-1 event rate of 100 kHz. An upgrade of the CTP is currently underway to significantly increase the number of trigger inputs and trigger combinations, allowing additional flexibility for the trigger menu.\

  19. The ATLAS Level-1 Topological Trigger Performance

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00371751; The ATLAS collaboration

    2016-01-01

    The LHC will collide protons in the ATLAS detector with increasing luminosity through 2016, placing stringent operational and physical requirements to the ATLAS trigger system in order to reduce the 40 MHz collision rate to a manageable event storage rate of 1 kHz, while not rejecting interesting physics events. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system with an output rate of 100 kHz and decision latency smaller than 2.5 μs. It consists of a calorimeter trigger, muon trigger and a central trigger processor. During the LHC shutdown after the Run 1 finished in 2013, the Level-1 trigger system was upgraded including hardware, firmware and software updates. In particular, new electronics modules were introduced in the real-time data processing path: the Topological Processor System (L1Topo). It consists of a single AdvancedCTA shelf equipped with two Level-1 topological processor blades. They receive real-time information from the Level-1 calorimeter and muon triggers, which...

  20. The Run-2 ATLAS Trigger System

    CERN Document Server

    Ruiz-Martinez, Aranzazu; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger systems, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. At hand of a few examples, we will show the ...

  1. The Run-2 ATLAS Trigger System

    CERN Document Server

    Ruiz-Martinez, Aranzazu; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger successfully collected collision data during the first run of the LHC between 2009-2013 at different centre-of-mass energies between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software-based high level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV and higher luminosity, resulting in roughly five times higher trigger rates. A brief review of the ATLAS trigger system upgrades that were implemented between Run-1 and Run-2, allowing to cope with the increased trigger rates while maintaining or even improving the efficiency to select physics processes of interest, will be given. This includes changes to the Level-1 calorimeter and muon trigger systems, the introduction of a new Level-1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. A ...

  2. Effect of increasing dietary calcium through supplements and dairy food on body weight and body composition: a meta-analysis of randomised controlled trials.

    Science.gov (United States)

    Booth, Alison O; Huggins, Catherine E; Wattanapenpaiboon, Naiyana; Nowson, Caryl A

    2015-10-14

    This meta-analysis of randomised controlled trials assessed the effect of Ca on body weight and body composition through supplementation or increasing dairy food intake. Forty-one studies met the inclusion criteria (including fifty-one trial arms; thirty-one with dairy foods (n 2091), twenty with Ca supplements (n 2711). Ca intake was approximately 900 mg/d higher in the supplement groups compared with control. In the dairy group, Ca intake was approximately 1300 mg/d. Ca supplementation did not significantly affect body weight (mean change ( - 0·17, 95% CI - 0·70, 0·37) kg) or body fat (mean change ( - 0·19, 95% CI - 0·51, 0·13) kg) compared to control. Similarly, increased dairy food intake did not affect body weight ( - 0·06, 95% CI - 0·54, 0·43) kg or body fat change ( - 0·36, 95% CI - 0·80, 0·09) kg compared to control. Sub-analyses revealed that dairy supplementation resulted in no change in body weight (nineteen studies, n 1010) ( - 0·32, 95% CI - 0·93, 0·30 kg, P= 0·31), but a greater reduction in body fat (thirteen studies, n 564) ( - 0·96, 95% CI - 1·46, - 0·46 kg, P energy restriction over a mean of 4 months compared to control. Increasing dietary Ca intake by 900 mg/d as supplements or increasing dairy intake to approximately 3 servings daily (approximately 1300 mg of Ca/d) is not an effective weight reduction strategy in adults. There is, however, an indication that approximately 3 servings of dairy may facilitate fat loss on weight reduction diets in the short term.

  3. Absorptive activity of calcium in the isolated cecal epithelium adaptively increased by 2 week's feeding of difructose anhydride III in rats.

    OpenAIRE

    Mineo, Hitoshi; Amano, Midori; Chiji, Hideyuki; Shigematsu, Norihiro; Tomita, Fusao; Hara, Hiroshi

    2003-01-01

    We compared net Ca absorption and Lucifer Yellow (LY), a paracellular passage dye, permeability in the epithelium isolated from the rat small intestine, cecum, and colon after feeding with control and difructose anhydride (DFA) III diets for 14 days using the Ussing chamber system. Feeding of DFA III increased net Ca transport and LY passage in the cecal but not in small intestinal or colonic epithelium. Ability of paracellular Ca passage via Tight-junction (TJ) in the cecum was changed adapt...

  4. Calcium and Vitamin D

    Science.gov (United States)

    ... Home › Patients › Treatment › Calcium/Vitamin D Calcium/Vitamin D Getting enough calcium and vitamin D is essential ... counter medications and calcium supplements. What is Vitamin D and What Does it Do? Vitamin D plays ...

  5. A theory of Plasma Membrane Calcium Pump stimulation and activity

    CERN Document Server

    Graupner, M; Meyer-Hermann, M; Erler, Frido; Graupner, Michael; Meyer-Hermann, Michael

    2003-01-01

    The ATP-driven Plasma Membrane Calcium (PMCA) pump is characterized by a high affinity to calcium and a low transport rate compared to other transmembrane calcium transport proteins. It plays a crucial role for calcium extrusion from cells. Calmodulin is an intracellular calcium buffering protein which is capable in its Calcium-liganded form to stimulate the PMCA pump by increasing both, the affinity to calcium and the maximum calcium transport rate. We introduce a new model of this stimulation process and deduce analytical expressions for experimental observables in order to determine the model parameter on the basis of specific experiments. Furthermore a model for the pumping activity is developed. In contrast to the biological process we have to describe the pumping rate behavior by assuming a ATP:Calcium stoichiometry of 2 in order to reproduce experimental data. The conjunction of the description of calcium pumping and the stimulation model fully and correctly simulates PMCA pump function. Therewith the ...

  6. Calcium- and Phosphorus-Supplemented Diet Increases Bone Mass after Short-Term Exercise and Increases Bone Mass and Structural Strength after Long-Term Exercise in Adult Mice

    OpenAIRE

    Friedman, Michael A.; Bailey, Alyssa M.; Rondon, Matthew J.; McNerny, Erin M.; Sahar, Nadder D.; Kohn, David H.

    2016-01-01

    Exercise has long-lasting benefits to bone health that may help prevent fractures by increasing bone mass, bone strength, and tissue quality. Long-term exercise of 6-12 weeks in rodents increases bone mass and bone strength. However, in growing mice, a short-term exercise program of 3 weeks can limit increases in bone mass and structural strength, compared to non-exercised controls. Short-term exercise can, however, increase tissue strength, suggesting that exercise may create competition for...

  7. Stimulus conflict triggers behavioral avoidance.

    Science.gov (United States)

    Dignath, David; Eder, Andreas B

    2015-12-01

    According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

  8. Role of T3 surface molecules in human T-cell activation: T3-dependent activation results in an increase in cytoplasmic free calcium.

    OpenAIRE

    Weiss, A; Imboden, J; Shoback, D; Stobo, J.

    1984-01-01

    The human T-cell leukemia, Jurkat, and a T3-negative mutant of Jurkat (S.5) were used to study the role of T3 in human T-cell activation. Incubation of Jurkat with phytohemagglutinin (PHA) resulted in the production of interleukin 2, which was markedly increased by the addition of phorbol 12-myristate 13-acetate (PMA). Antibodies reactive with T3 could activate Jurkat only if added together with PMA. However, S.5 cells failed to produce interleukin 2 in response to PHA and produced 1/16th the...

  9. Hyperosmolar sodium chloride is toxic to cultured neurons and causes reduction of glucose metabolism and ATP levels, an increase in glutamate uptake, and a reduction in cytosolic calcium.

    Science.gov (United States)

    Morland, Cecilie; Pettersen, Mi Nguyen; Hassel, Bjørnar

    2016-05-01

    Elevation of serum sodium, hypernatremia, which may occur during dehydration or treatment with sodium chloride, may cause brain dysfunction and damage, but toxic mechanisms are poorly understood. We found that exposure to excess NaCl, 10-100mmol/L, for 20h caused cell death in cultured cerebellar granule cells (neurons). Toxicity was due to Na(+), since substituting excess Na(+) with choline reduced cell death to control levels, whereas gluconate instead of excess Cl(-) did not. Prior to cell death from hyperosmolar NaCl, glucose consumption and lactate formation were reduced, and intracellular aspartate levels were elevated, consistent with reduced glycolysis or glucose uptake. Concomitantly, the level of ATP became reduced. Pyruvate, 10mmol/L, reduced NaCl-induced cell death. The extracellular levels of glutamate, taurine, and GABA were concentration-dependently reduced by excess NaCl; high-affinity glutamate uptake increased. High extracellular [Na(+)] caused reduction in intracellular free [Ca(2+)], but a similar effect was seen with mannitol, which was not neurotoxic. We suggest that inhibition of glucose metabolism with ensuing loss of ATP is a neurotoxic mechanism of hyperosmolar sodium, whereas increased uptake of extracellular neuroactive amino acids and reduced intracellular [Ca(2+)] may, if they occur in vivo, contribute to the cerebral dysfunction and delirium described in hypernatremia. PMID:26994581

  10. Hyperosmolar sodium chloride is toxic to cultured neurons and causes reduction of glucose metabolism and ATP levels, an increase in glutamate uptake, and a reduction in cytosolic calcium.

    Science.gov (United States)

    Morland, Cecilie; Pettersen, Mi Nguyen; Hassel, Bjørnar

    2016-05-01

    Elevation of serum sodium, hypernatremia, which may occur during dehydration or treatment with sodium chloride, may cause brain dysfunction and damage, but toxic mechanisms are poorly understood. We found that exposure to excess NaCl, 10-100mmol/L, for 20h caused cell death in cultured cerebellar granule cells (neurons). Toxicity was due to Na(+), since substituting excess Na(+) with choline reduced cell death to control levels, whereas gluconate instead of excess Cl(-) did not. Prior to cell death from hyperosmolar NaCl, glucose consumption and lactate formation were reduced, and intracellular aspartate levels were elevated, consistent with reduced glycolysis or glucose uptake. Concomitantly, the level of ATP became reduced. Pyruvate, 10mmol/L, reduced NaCl-induced cell death. The extracellular levels of glutamate, taurine, and GABA were concentration-dependently reduced by excess NaCl; high-affinity glutamate uptake increased. High extracellular [Na(+)] caused reduction in intracellular free [Ca(2+)], but a similar effect was seen with mannitol, which was not neurotoxic. We suggest that inhibition of glucose metabolism with ensuing loss of ATP is a neurotoxic mechanism of hyperosmolar sodium, whereas increased uptake of extracellular neuroactive amino acids and reduced intracellular [Ca(2+)] may, if they occur in vivo, contribute to the cerebral dysfunction and delirium described in hypernatremia.

  11. ATLAS Muon Trigger

    CERN Document Server

    Woudstra, MJ; The ATLAS collaboration

    2013-01-01

    CERN’s Large Hadron Collider (LHC) is the highest energy proton-proton collider, providing also the highest instantaneous luminosity as a hadron collider. Bunch crossings occurred every 50 ns in 2012 runs. Amongst of which the online event selection system should reduce the event recording rate down to a few 100 Hz, while events are in a harsh condition with many overlapping proton-proton collisions occurring in a same bunch crossing. Muons often provide an important and clear signature of physics processes that are searched for, for instance as in the discovery of Higgs particle in year 2012. The ATLAS experiment deploys a three-levels processing scheme at online. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 (L2) trigger followed by an event filte...

  12. The CMS trigger system

    CERN Document Server

    Khachatryan, Vardan; CMS Collaboration; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Knünz, Valentin; König, Axel; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Schöfbeck, Robert; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Lauwers, Jasper; Luyckx, Sten; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Van Parijs, Isis; Barria, Patrizia; Brun, Hugues; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Fasanella, Giuseppe; Favart, Laurent; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Maerschalk, Thierry; Marinov, Andrey; Perniè, Luca; Randle-conde, Aidan; Reis, Thomas; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Crucy, Shannon; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Poyraz, Deniz; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Mertens, Alexandre; Musich, Marco; Nuttens, Claude; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Beliy, Nikita; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Hamer, Matthias; Hensel, Carsten; Mora Herrera, Clemencia; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; De Souza Santos, Angelo; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Cheng, Tongguang; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Micanovic, Sasa; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; El Sawy, Mai; Elgammal, Sherif; Ellithi Kamel, Ali; Mahmoud, Mohammed; Calpas, Betty; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Dahms, Torsten; Davignon, Olivier; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Lisniak, Stanislav; Mastrolorenzo, Luca; Miné, Philippe; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Merlin, Jeremie Alexandre; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Edelhoff, Matthias; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schulte, Jan-Frederik; Verlage, Tobias; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Künsken, Andreas; Lingemann, Joschka; Nehrkorn, Alexander; Nowack, Andreas; Nugent, Ian Michael; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asin, Ivan; Bartosik, Nazar; Behnke, Olaf; Behrens, Ulf; Bell, Alan James; Borras, Kerstin; Burgmeier, Armin; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Korol, Ievgen; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Schröder, Matthias; Seitz, Claudia; Spannagel, Simon; Trippkewitz, Karim Damun; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Gonzalez, Daniel; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Nowatschin, Dominik; Ott, Jochen; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Pietsch, Niklas; Poehlsen, Jennifer; Rathjens, Denis; Sander, Christian; Scharf, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schwandt, Joern; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Fink, Simon; Frensch, Felix; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Lobelle Pardo, Patricia; Maier, Benedikt; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Sieber, Georg; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Strologas, John; Bencze, Gyorgy; Hajdu, Csaba; Hazi, Andras; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Makovec, Alajos; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Mal, Prolay; Mandal, Koushik; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutta, Suchandra; Jain, Sandhya; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukherjee, Swagata; Mukhopadhyay, Supratik; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Mahakud, Bibhuprasad; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sarkar, Tanmay; Sur, Nairit; Sutar, Bajrang; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Kothekar, Kunal; Sharma, Seema; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Bacchetta, Nicola; Bellato, Marco; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Montecassiano, Fabio; Passaseo, Marina; Pazzini, Jacopo; Pegoraro, Matteo; Pozzobon, Nicola; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Vanini, Sara; Ventura, Sandro; Zanetti, Marco; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Schizzi, Andrea; Zanetti, Anna; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Sakharov, Alexandre; Son, Dong-Chul; Brochero Cifuentes, Javier Andres; Kim, Hyunsoo; Kim, Tae Jeong; Song, Sanghyeon; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Park, Sung Keun; Roh, Youn; Yoo, Hwi Dong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Casimiro Linares, Edgar; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Khurshid, Taimoor; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Pozniak, Krzysztof; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Leonardo, Nuno; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Konoplyanikov, Viktor; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Vlasov, Evgueni; Zhokin, Alexander; Bylinkin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Kaminskiy, Alexandre; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Soares, Mara Senghi; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Palencia Cortezon, Enrique; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; De Castro Manzano, Pablo; Duarte Campderros, Jordi; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Berruti, Gaia Maria; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Castello, Roberto; Cerminara, Gianluca; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dorney, Brian; Du Pree, Tristan; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Franzoni, Giovanni; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kirschenmann, Henning; Kortelainen, Matti J; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Nemallapudi, Mythra Varun; Neugebauer, Hannes; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Piparo, Danilo; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Ruan, Manqi; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Seidel, Markus; Sharma, Archana; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Takahashi, Yuta; Treille, Daniel; Triossi, Andrea; Tsirou, Andromachi; Veres, Gabor Istvan; Wardle, Nicholas; Wöhri, Hermine Katharina; Zagoździńska, Agnieszka; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Casal, Bruno; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Eller, Philipp; Grab, Christoph; Heidegger, Constantin; Hits, Dmitry; Hoss, Jan; Kasieczka, Gregor; Lustermann, Werner; Mangano, Boris; Marionneau, Matthieu; Martinez Ruiz del Arbol, Pablo; Masciovecchio, Mario; Meister, Daniel; Micheli, Francesco; Musella, Pasquale; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pata, Joosep; Pauss, Felicitas; Perrozzi, Luca; Quittnat, Milena; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Tavolaro, Vittorio Raoul; Theofilatos, Konstantinos; Wallny, Rainer; Aarrestad, Thea Klaeboe; Amsler, Claude; Caminada, Lea; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Galloni, Camilla; Hinzmann, Andreas; Hreus, Tomas; Kilminster, Benjamin; Lange, Clemens; Ngadiuba, Jennifer; Pinna, Deborah; Robmann, Peter; Ronga, Frederic Jean; Salerno, Daniel; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Doan, Thi Hien; Jain, Shilpi; Khurana, Raman; Konyushikhin, Maxim; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Yu, Shin-Shan; Kumar, Arun; Bartek, Rachel; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Fiori, Francesco; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Liu, Yueh-Feng; Lu, Rong-Shyang; Miñano Moya, Mercedes; Petrakou, Eleni; Tsai, Jui-fa; Tzeng, Yeng-Ming; Asavapibhop, Burin; Kovitanggoon, Kittikul; Singh, Gurpreet; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Demiroglu, Zuhal Seyma; Dozen, Candan; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Guler, Yalcin; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Onengut, Gulsen; Ozdemir, Kadri; Polatoz, Ayse; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Zorbilmez, Caglar; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Isildak, Bora; Karapinar, Guler; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Kaya, Mithat; Kaya, Ozlem; Yetkin, Elif Asli; Yetkin, Taylan; Cakir, Altan; Cankocak, Kerem; Sen, Sercan; Vardarlı, Fuat Ilkehan; Grynyov, Boris; Levchuk, Leonid; Sorokin, Pavel; Aggleton, Robin; Ball, Fionn; Beck, Lana; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Sakuma, Tai; Seif El Nasr-storey, Sarah; Senkin, Sergey; Smith, Dominic; Smith, Vincent J; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Calligaris, Luigi; Cieri, Davide; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Williams, Thomas; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Bundock, Aaron; Burton, Darren; Casasso, Stefano; Citron, Matthew; Colling, David; Corpe, Louie; Cripps, Nicholas; Dauncey, Paul; Davies, Gavin; De Wit, Adinda; Della Negra, Michel; Dunne, Patrick; Elwood, Adam; Ferguson, William; Fulcher, Jonathan; Futyan, David; Hall, Geoffrey; Iles, Gregory; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Richards, Alexander; Rose, Andrew; Seez, Christopher; Tapper, Alexander; Uchida, Kirika; Vazquez Acosta, Monica; Virdee, Tejinder; Zenz, Seth Conrad; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Borzou, Ahmad; Call, Kenneth; Dittmann, Jay; Hatakeyama, Kenichi; Liu, Hongxuan; Pastika, Nathaniel; Charaf, Otman; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; Arcaro, Daniel; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Gastler, Daniel; Lawson, Philip; Rankin, Dylan; Richardson, Clint; Rohlf, James; St John, Jason; Sulak, Lawrence; Zou, David; Alimena, Juliette; Berry, Edmund; Bhattacharya, Saptaparna; Cutts, David; Dhingra, Nitish; Ferapontov, Alexey; Garabedian, Alex; Hakala, John; Heintz, Ulrich; Laird, Edward; Landsberg, Greg; Mao, Zaixing; Narain, Meenakshi; Piperov, Stefan; Sagir, Sinan; Syarif, Rizki; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Gardner, Michael; Ko, Winston; Lander, Richard; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Ricci-Tam, Francesca; Shalhout, Shalhout; Smith, John; Squires, Michael; Stolp, Dustin; Tripathi, Mani; Wilbur, Scott; Yohay, Rachel; Cousins, Robert; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Saltzberg, David; Takasugi, Eric; Valuev, Vyacheslav; Weber, Matthias; Burt, Kira; Clare, Robert; Ellison, John Anthony; Gary, J William; Hanson, Gail; Heilman, Jesse; Paneva, Mirena Ivova; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Luthra, Arun; Malberti, Martina; Olmedo Negrete, Manuel; Shrinivas, Amithabh; Wei, Hua; Wimpenny, Stephen; Yates, Brent; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; D'Agnolo, Raffaele Tito; Derdzinski, Mark; Holzner, André; Kelley, Ryan; Klein, Daniel; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tadel, Matevz; Vartak, Adish; Wasserbaech, Steven; Welke, Charles; Würthwein, Frank; Yagil, Avraham; Zevi Della Porta, Giovanni; Bradmiller-Feld, John; Campagnari, Claudio; Dishaw, Adam; Dutta, Valentina; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Gouskos, Loukas; Gran, Jason; Incandela, Joe; Mccoll, Nickolas; Mullin, Sam Daniel; Richman, Jeffrey; Stuart, David; Suarez, Indara; West, Christopher; Yoo, Jaehyeok; Anderson, Dustin; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Duarte, Javier; Mott, Alexander; Newman, Harvey B; Pena, Cristian; Pierini, Maurizio; Spiropulu, Maria; Vlimant, Jean-Roch; Xie, Si; Zhu, Ren-Yuan; Andrews, Michael Benjamin; Azzolini, Virginia; Calamba, Aristotle; Carlson, Benjamin; Ferguson, Thomas; Paulini, Manfred; Russ, James; Sun, Menglei; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Ford, William T; Gaz, Alessandro; Jensen, Frank; Johnson, Andrew; Krohn, Michael; Mulholland, Troy; Nauenberg, Uriel; Stenson, Kevin; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Chaves, Jorge; Chu, Jennifer; Dittmer, Susan; Eggert, Nicholas; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Rinkevicius, Aurelijus; Ryd, Anders; Skinnari, Louise; Soffi, Livia; Sun, Werner; Tan, Shao Min; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Weng, Yao; Wittich, Peter; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Banerjee, Sunanda; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Jung, Andreas Werner; Klima, Boaz; Kreis, Benjamin; Kwan, Simon; Lammel, Stephan; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Martinez Outschoorn, Verena Ingrid; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mishra, Kalanand; Mrenna, Stephen; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Yang, Fan; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Carnes, Andrew; Carver, Matthew; Curry, David; Das, Souvik; Di Giovanni, Gian Piero; Field, Richard D; Furic, Ivan-Kresimir; Gleyzer, Sergei V; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Low, Jia Fu; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Milenovic, Predrag; Mitselmakher, Guenakh; Rank, Douglas; Rossin, Roberto; Shchutska, Lesya; Snowball, Matthew; Sperka, David; Terentyev, Nikolay; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Jordon Rowe; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Khatiwada, Ajeeta; Prosper, Harrison; Weinberg, Marc; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Kalakhety, Himali; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Kurt, Pelin; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Wu, Zhenbin; Zakaria, Mohammed; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Anderson, Ian; Barnett, Bruce Arnold; Blumenfeld, Barry; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Osherson, Marc; Roskes, Jeffrey; Cocoros, Alice; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; Xin, Yongjie; You, Can; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Bruner, Christopher; Kenny III, Raymond Patrick; Majumder, Devdatta; Malek, Magdalena; Murray, Michael; Sanders, Stephen; Stringer, Robert; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Toda, Sachiko; Lange, David; Rebassoo, Finn; Wright, Douglas; Anelli, Christopher; Baden, Drew; Baron, Owen; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Ferraioli, Charles; Gomez, Jaime; Hadley, Nicholas John; Jabeen, Shabnam; Kellogg, Richard G; Kolberg, Ted; Kunkle, Joshua; Lu, Ying; Mignerey, Alice; Shin, Young Ho; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Baty, Austin; Bierwagen, Katharina; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; Demiragli, Zeynep; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Varma, Mukund; Velicanu, Dragos; Veverka, Jan; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Yang, Mingming; Zhukova, Victoria; Dahmes, Bryan; Evans, Andrew; Finkel, Alexey; Gude, Alexander; Hansen, Peter; Kalafut, Sean; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Fangmeier, Caleb; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Keller, Jason; Knowlton, Dan; Kravchenko, Ilya; Meier, Frank; Monroy, Jose; Ratnikov, Fedor; Siado, Joaquin Emilo; Snow, Gregory R; Alyari, Maral; Dolen, James; George, Jimin; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Kaisen, Josh; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Teixeira De Lima, Rafael; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Zhang, Jinzhong; Hahn, Kristan Allan; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Brinkerhoff, Andrew; Dev, Nabarun; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Lynch, Sean; Marinelli, Nancy; Meng, Fanbo; Mueller, Charles; Musienko, Yuri; Pearson, Tessa; Planer, Michael; Reinsvold, Allison; Ruchti, Randy; Smith, Geoffrey; Taroni, Silvia; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Hart, Andrew; Hill, Christopher; Hughes, Richard; Ji, Weifeng; Kotov, Khristian; Ling, Ta-Yung; Liu, Bingxuan; Luo, Wuming; Puigh, Darren; Rodenburg, Marissa; Winer, Brian L; Wulsin, Howard Wells; Driga, Olga; Elmer, Peter; Hardenbrook, Joshua; Hebda, Philip; Koay, Sue Ann; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Palmer, Christopher; Piroué, Pierre; Saka, Halil; Stickland, David; Tully, Christopher; Zuranski, Andrzej; Malik, Sudhir; Barnes, Virgil E; Benedetti, Daniele; Bortoletto, Daniela; Gutay, Laszlo; Jha, Manoj; Jones, Matthew; Jung, Kurt; Miller, David Harry; Neumeister, Norbert; Radburn-Smith, Benjamin Charles; Shi, Xin; Shipsey, Ian; Silvers, David; Sun, Jian; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Chen, Zhenyu; Ecklund, Karl Matthew; Geurts, Frank JM; Guilbaud, Maxime; Li, Wei; Michlin, Benjamin; Northup, Michael; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Rorie, Jamal; Tu, Zhoudunming; Zabel, James; Betchart, Burton; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Harel, Amnon; Hindrichs, Otto; Khukhunaishvili, Aleko; Petrillo, Gianluca; Tan, Ping; Verzetti, Mauro; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Lath, Amitabh; Nash, Kevin; Panwalkar, Shruti; Park, Michael; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Foerster, Mark; Riley, Grant; Rose, Keith; Spanier, Stefan; York, Andrew; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Kamon, Teruki; Krutelyov, Vyacheslav; Mueller, Ryan; Osipenkov, Ilya; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Rose, Anthony; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Undleeb, Sonaina; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Ni, Hong; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Wood, John; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Sarangi, Tapas; Savin, Alexander; Sharma, Archana; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

    2016-01-01

    This paper describes the CMS trigger system and its performance during Run 1 of the LHC. The trigger system consists of two levels designed to select events of potential physics interest from a GHz (MHz) interaction rate of proton-proton (heavy ion) collisions. The first level of the trigger is implemented in hardware, and selects events containing detector signals consistent with an electron, photon, muon, $\\tau$ lepton, jet, or missing transverse energy. A programmable menu of up to 128 object-based algorithms is used to select events for subsequent processing. The trigger thresholds are adjusted to the LHC instantaneous luminosity during data taking in order to restrict the output rate to 100 kHz, the upper limit imposed by the CMS readout electronics. The second level, implemented in software, further refines the purity of the output stream, selecting an average rate of 400 Hz for offline event storage. The objectives, strategy and performance of the trigger system during the LHC Run 1 are described.

  13. The CMS trigger system

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, Vardan; et al.

    2016-09-08

    This paper describes the CMS trigger system and its performance during Run 1 of the LHC. The trigger system consists of two levels designed to select events of potential physics interest from a GHz (MHz) interaction rate of proton-proton (heavy ion) collisions. The first level of the trigger is implemented in hardware, and selects events containing detector signals consistent with an electron, photon, muon, tau lepton, jet, or missing transverse energy. A programmable menu of up to 128 object-based algorithms is used to select events for subsequent processing. The trigger thresholds are adjusted to the LHC instantaneous luminosity during data taking in order to restrict the output rate to 100 kHz, the upper limit imposed by the CMS readout electronics. The second level, implemented in software, further refines the purity of the output stream, selecting an average rate of 400 Hz for offline event storage. The objectives, strategy and performance of the trigger system during the LHC Run 1 are described.

  14. Homodimeric anoctamin-1, but not homodimeric anoctamin-6, is activated by calcium increases mediated by the P2Y1 and P2X7 receptors.

    Science.gov (United States)

    Stolz, Michaela; Klapperstück, Manuela; Kendzierski, Thomas; Detro-Dassen, Silvia; Panning, Anna; Schmalzing, Günther; Markwardt, Fritz

    2015-10-01

    The P2X7 receptor (P2X7R) is a ligand-gated ion channel that conducts Na(+), K(+), and Ca(2+) when activated by extracellular ATP. In various cell types, such as secretory epithelia, the P2X7R is co-expressed with Ca(2+)-dependent Cl(-) channels of the TMEM16/anoctamin family. Here, we studied whether the P2X7R and TMEM16A/anoctamin-1 (Ano1) or TMEM16F/anoctamin-6 (Ano6) interact functionally and physically, using oocytes of Xenopus laevis and Ambystoma mexicanum (Axolotl) for heterologous expression. As a control, we co-expressed anoctamin-1 with the P2Y1 receptor (P2Y1R), which induces the release of Ca(2+) from intracellular stores via activating phospholipase C through coupling to Gαq. We found that co-expression of anoctamin-1 with the P2Y1R resulted in a small transient increase in Cl(-) conductance in response to ATP. Co-expression of anoctamin-1 with the P2X7R resulted in a large sustained increase in Cl(-) conductance via Ca(2+) influx through the ATP-opened P2X7R in Xenopus and in Axolotl oocytes, which lack endogenous Ca(2+)-dependent Cl(-) channels. P2Y1R- or P2X7R-mediated stimulation of Ano1 was primarily functional, as demonstrated by the absence of a physically stable interaction between Ano1 and the P2X7R. In the pancreatic cell line AsPC-1, we found the same functional Ca(2+)-dependent interaction of P2X7R and Ano1. The P2X7R-mediated sustained activation of Ano1 may be physiologically relevant to the time course of stimulus-secretion coupling in secretory epithelia. No such increase in Cl(-) conductance could be elicited by activating the P2X7 receptor in either Xenopus oocytes or Axolotl oocytes co-expressing Ano6. The lack of function of Ano6 can, at least in part, be explained by its poor cell-surface expression, resulting from a relatively inefficient exit of the homodimeric Ano6 from the endoplasmic reticulum. PMID:25592660

  15. Homodimeric anoctamin-1, but not homodimeric anoctamin-6, is activated by calcium increases mediated by the P2Y1 and P2X7 receptors.

    Science.gov (United States)

    Stolz, Michaela; Klapperstück, Manuela; Kendzierski, Thomas; Detro-Dassen, Silvia; Panning, Anna; Schmalzing, Günther; Markwardt, Fritz

    2015-10-01

    The P2X7 receptor (P2X7R) is a ligand-gated ion channel that conducts Na(+), K(+), and Ca(2+) when activated by extracellular ATP. In various cell types, such as secretory epithelia, the P2X7R is co-expressed with Ca(2+)-dependent Cl(-) channels of the TMEM16/anoctamin family. Here, we studied whether the P2X7R and TMEM16A/anoctamin-1 (Ano1) or TMEM16F/anoctamin-6 (Ano6) interact functionally and physically, using oocytes of Xenopus laevis and Ambystoma mexicanum (Axolotl) for heterologous expression. As a control, we co-expressed anoctamin-1 with the P2Y1 receptor (P2Y1R), which induces the release of Ca(2+) from intracellular stores via activating phospholipase C through coupling to Gαq. We found that co-expression of anoctamin-1 with the P2Y1R resulted in a small transient increase in Cl(-) conductance in response to ATP. Co-expression of anoctamin-1 with the P2X7R resulted in a large sustained increase in Cl(-) conductance via Ca(2+) influx through the ATP-opened P2X7R in Xenopus and in Axolotl oocytes, which lack endogenous Ca(2+)-dependent Cl(-) channels. P2Y1R- or P2X7R-mediated stimulation of Ano1 was primarily functional, as demonstrated by the absence of a physically stable interaction between Ano1 and the P2X7R. In the pancreatic cell line AsPC-1, we found the same functional Ca(2+)-dependent interaction of P2X7R and Ano1. The P2X7R-mediated sustained activation of Ano1 may be physiologically relevant to the time course of stimulus-secretion coupling in secretory epithelia. No such increase in Cl(-) conductance could be elicited by activating the P2X7 receptor in either Xenopus oocytes or Axolotl oocytes co-expressing Ano6. The lack of function of Ano6 can, at least in part, be explained by its poor cell-surface expression, resulting from a relatively inefficient exit of the homodimeric Ano6 from the endoplasmic reticulum.

  16. Elevated extracellular calcium increases fibroblast growth factor-2 gene and protein expression levels via a cAMP/PKA dependent pathway in cementoblasts.

    Science.gov (United States)

    Kanaya, Sousuke; Nemoto, Eiji; Ebe, Yukari; Somerman, Martha J; Shimauchi, Hidetoshi

    2010-09-01

    Cementoblasts, tooth root lining cells, are responsible for laying down cementum on the root surface, a process that is indispensable for establishing a functional periodontal ligament. Cementoblasts share phenotypical features with osteoblasts. Elevated levels of extracellular Ca(2+) have been implicated in osteogenesis by stimulating the proliferation and differentiation of osteoblasts; however, the role of extracellular Ca(2+) signaling in cementogenesis has not been examined. Using RT-PCR, we found that elevated levels of extracellular Ca(2+) increase fibroblast growth factor (FGF)-2 gene expression with a peak at 6h. Pretreatment with a protein kinase A (PKA) inhibitor, H89, or an adenylate cyclase inhibitor, MDL-12,330A, inhibited Ca(2+)-stimulated Fgf-2 expression. In contrast, pretreatment with the protein kinase C (PKC) inhibitor GF-109203X or the phospholipase C (PLC) inhibitor U73122 did not affect the expression of Fgf-2 transcripts, suggesting that the increase in Fgf-2 expression was dependent on the PKA but not the PLC/PKC signaling pathway. Treatment with an activator of adenylate cyclase, forskolin, or a cell-permeable analog of cAMP, 8-Br-cAMP, enhanced Ca(2+)-stimulated Fgf-2 expression, but a single treatment with forskolin or 8-Br-cAMP did not, suggesting that cAMP generation is indispensable but not sufficient for Ca(2+)-stimulated FGF2 expression. Next, we examined the cation specificity of the putative receptor and showed that treatment with trivalent/divalent inorganic ions, Ca(2+), Gd(3+), Sr(2+), or Al(3+), caused a dose-dependent increase in Fgf-2 mRNA levels in a cAMP-dependent fashion, whereas Mg(2+) and the organic ions neomycin and spermine had no effect on Fgf-2 gene expression levels. These findings suggest that an extracellular Ca(2+)-sensing mechanism is present in cementoblasts and its activation leads to FGF-2 stimulation in a cAMP/PKA dependent fashion. Understanding the pathway regulating key genes involved in modulating the

  17. Salicylic acid alleviates aluminum toxicity in rice seedlings better than magnesium and calcium by reducing aluminum uptake, suppressing oxidative damage and increasing antioxidative defense.

    Science.gov (United States)

    Pandey, Poonam; Srivastava, Rajneesh Kumar; Dubey, R S

    2013-05-01

    Aluminum toxicity is a major constraint to crop production in acid soils. The present study was undertaken to examine the comparative ameliorating effects of salicylic acid, Ca and Mg on Al toxicity in rice (Oryza sativa L.) seedlings grown in hydroponics. Al treatment (0.5 mM AlCl3) caused decrease in plant vigour, loss of root plasma membrane integrity, increased contents of O 2 (∙-) , H2O2, lipid peroxidation, protein carbonyls and decline in the level of protein thiol. Al treatment caused significant changes in activity of antioxidative enzymes in rice seedlings. Exogenously added salicylic acid (60 μM), Ca (1 mM) and Mg (0.25 mM) significantly alleviated Al toxicity effects in the seedlings marked by restoration of growth, suppression of Al uptake, restoration of root plasma membrane integrity and decline in O 2 (∙-) , H2O2, lipid peroxidation and protein carbonyl contents. Salicylic acid, Ca and Mg suppressed Al-induced increase in SOD, GPX and APX activities while it elevated Al-induced decline in CAT activity. By histochemical staining of O 2 (∙-) using NBT and H2O2 using DAB, it was further confirmed that added salicylic acid, Ca or Mg decreased Al-induced accumulation of O 2 (∙-) and H2O2 in the leaf tissues. Results indicate that exogenously added salicylic acid, Ca or Mg alleviates Al toxicity in rice seedlings by suppressing Al uptake, restoring root membrane integrity, reducing ROS level and ROS induced oxidative damage and regulating the level of antioxidative enzyme activities. Further salicylic appears to be superior to Mg and Ca in alleviating Al toxicity effects in rice plants.

  18. Increasing physical activity and decreasing sedentary activity in adolescent girls – The Incorporating More Physical Activity and Calcium in Teens (IMPACT study

    Directory of Open Access Journals (Sweden)

    Hergenroeder Albert

    2008-08-01

    Full Text Available Abstract Background Lack of regular physical activity and consequent sub-optimal bone mass acquisition in youth has been implicated as a primary cause of adult-onset osteoporosis. IMPACT was a behavioral theory-based 1 1/2 year randomized controlled field study aimed at increasing bone accretion in middle school girls. The objective of this study was to determine the intervention effects of the IMPACT program upon key physical and sedentary activity endpoints among schools that participated in the IMPACT study. Endpoints examined included weight bearing physical activity (WBPA; moderate to vigorous physical activity (MVPA; vigorous physical activity (VPA; MET (metabolic equivalent – weighted WBPA and MVPA; sedentary activity; before/after-school physical activity; and weekend physical activity. Methods Primary data analysis using a pretest-posttest control group design was conducted utilizing mixed model analysis of covariance. Data gathered from the IMPACT cohort from 2000–2002 were analyzed to determine baseline versus follow-up differences in activity endpoints. Confounders investigated included ethnicity, body mass index, menarcheal status, participation in 7th grade PE/athletics, friend/familial support and neighborhood safety. Results Follow-up means were higher for participating intervention schools relative to control schools for all physical activity variables but were statistically significant only for the following variables: daily minutes of vigorous physical activity (mean difference between Intervention (I and Control (C = 6.00↑ minutes, 95% CI = 5.82–6.18, p = 0.05, daily after school activity minutes (mean difference between I and C = 8.95↑ minutes, 95% CI = 8.69–9.21, p = 0.04, and daily weekend activity minutes (mean difference between I and C = 19.00↑ minutes, 95% CI = 18.40–19.60, p = 0.05. The intervention significantly reduced duration of student daily TV/Video watching (mean difference between I and C = 12

  19. Comparison of triggering systems for neonatal patient triggered ventilation.

    OpenAIRE

    Hird, M F; Greenough, A

    1991-01-01

    The efficacy of two triggering systems was compared during neonatal patient triggered ventilation: the Graseby MR10 respiration monitor and airway pressure changes. Ten preterm infants were studied, median gestational age 33 weeks (range 28-35). Patient triggered ventilation was administered via the SLE ventilator at a series of inflation times (0.24, 0.3, and 0.4 seconds). Comparison was made between the trigger systems of the trigger delay, inflation volume delivered, and proportion of spon...

  20. Is Earthquake Triggering Driven by Small Earthquakes?

    CERN Document Server

    Helmstetter, A

    2002-01-01

    Using a catalog of seismicity for Southern California, we measure how the number of triggered earthquakes increases with the earthquake magnitude. The trade-off between this scaling and the distribution of earthquake magnitudes controls the relative role of small compared to large earthquakes. We show that seismicity triggering is driven by the smallest earthquakes, which trigger fewer aftershocks than larger earthquakes, but which are much more numerous. We propose that the non-trivial scaling of the number of aftershocks emerges from the fractal spatial distribution of aftershocks.

  1. Cilioplasm is a cellular compartment for calcium signaling in response to mechanical and chemical stimuli.

    Science.gov (United States)

    Jin, Xingjian; Mohieldin, Ashraf M; Muntean, Brian S; Green, Jill A; Shah, Jagesh V; Mykytyn, Kirk; Nauli, Surya M

    2014-06-01

    Primary cilia with a diameter of ~200 nm have been implicated in development and disease. Calcium signaling within a primary cilium has never been directly visualized and has therefore remained a speculation. Fluid-shear stress and dopamine receptor type-5 (DR5) agonist are among the few stimuli that require cilia for intracellular calcium signal transduction. However, it is not known if these stimuli initiate calcium signaling within the cilium or if the calcium signal originates in the cytoplasm. Using an integrated single-cell imaging technique, we demonstrate for the first time that calcium signaling triggered by fluid-shear stress initiates in the primary cilium and can be distinguished from the subsequent cytosolic calcium response through the ryanodine receptor. Importantly, this flow-induced calcium signaling depends on the ciliary polycystin-2 calcium channel. While DR5-specific agonist induces calcium signaling mainly in the cilioplasm via ciliary CaV1.2, thrombin specifically induces cytosolic calcium signaling through the IP3 receptor. Furthermore, a non-specific calcium ionophore triggers both ciliary and cytosolic calcium responses. We suggest that cilia not only act as sensory organelles but also function as calcium signaling compartments. Cilium-dependent signaling can spread to the cytoplasm or be contained within the cilioplasm. Our study thus provides the first model to understand signaling within the cilioplasm of a living cell.

  2. ALICE High Level Trigger

    CERN Multimedia

    Alt, T

    2013-01-01

    The ALICE High Level Trigger (HLT) is a computing farm designed and build for the real-time, online processing of the raw data produced by the ALICE detectors. Events are fully reconstructed from the raw data, analyzed and compressed. The analysis summary together with the compressed data and a trigger decision is sent to the DAQ. In addition the reconstruction of the events allows for on-line monitoring of physical observables and this information is provided to the Data Quality Monitor (DQM). The HLT can process event rates of up to 2 kHz for proton-proton and 200 Hz for Pb-Pb central collisions.

  3. Calcium channel as a potential anticancer agent.

    Science.gov (United States)

    Kriazhev, L

    2009-11-01

    Anticancer treatment in modern clinical practices includes chemotherapy and radiation therapy with or without surgical interventions. Efficiency of both methods varies greatly depending on cancer types and stages. Besides, chemo- and radiotherapy are toxic and damaging that causes serious side effects. This fact prompts the search for alternative methods of antitumor therapy. It is well known that prolonged or high increase of intracellular calcium concentration inevitably leads to the cell death via apoptosis or necrosis. However, stimulation of cell calcium level by chemical agents is hardly achievable because cells have very sophisticated machinery for maintaining intracellular calcium in physiological ranges. This obstacle can be overridden, nevertheless. It was found that calcium channels in so called calcium cells in land snails are directly regulated by extracellular calcium concentration. The higher the concentration the higher the calcium intake is through the channels. Bearing in mind that extracellular/intracellular calcium concentration ratio in human beings is 10,000-12,000 fold the insertion of the channel into cancer cells would lead to fast and uncontrollable by the cells calcium intake and cell death. Proteins composing the channel may be extracted from plasma membrane of calcium cells and sequenced by mass-spectrometry or N-terminal sequencing. Either proteins or corresponding genes could be used for targeted delivery into cancer cells.

  4. Remotely triggered earthquakes following moderate main shocks

    Science.gov (United States)

    Hough, S.E.

    2007-01-01

    Since 1992, remotely triggered earthquakes have been identified following large (M > 7) earthquakes in California as well as in other regions. These events, which occur at much greater distances than classic aftershocks, occur predominantly in active geothermal or volcanic regions, leading to theories that the earthquakes are triggered when passing seismic waves cause disruptions in magmatic or other fluid systems. In this paper, I focus on observations of remotely triggered earthquakes following moderate main shocks in diverse tectonic settings. I summarize evidence that remotely triggered earthquakes occur commonly in mid-continent and collisional zones. This evidence is derived from analysis of both historic earthquake sequences and from instrumentally recorded M5-6 earthquakes in eastern Canada. The latter analysis suggests that, while remotely triggered earthquakes do not occur pervasively following moderate earthquakes in eastern North America, a low level of triggering often does occur at distances beyond conventional aftershock zones. The inferred triggered events occur at the distances at which SmS waves are known to significantly increase ground motions. A similar result was found for 28 recent M5.3-7.1 earthquakes in California. In California, seismicity is found to increase on average to a distance of at least 200 km following moderate main shocks. This supports the conclusion that, even at distances of ???100 km, dynamic stress changes control the occurrence of triggered events. There are two explanations that can account for the occurrence of remotely triggered earthquakes in intraplate settings: (1) they occur at local zones of weakness, or (2) they occur in zones of local stress concentration. ?? 2007 The Geological Society of America.

  5. Effects of calcium gluconate on the utilization of magnesium and the nephrocalcinosis in rats fed excess dietary phosphorus and calcium.

    Science.gov (United States)

    Chonan, O; Takahashi, R; Kado, S; Nagata, Y; Kimura, H; Uchida, K; Watanuki, M

    1996-08-01

    The effects of calcium gluconate on the utilization of magnesium and nephrocalcinosis in male Wistar rats made magnesium-deficient by adding excess dietary phosphorus (1.195 g of phosphorus/100 g of diet) and calcium (1.04 g of calcium/100 g of diet) were compared with the effects of calcium carbonate. The effects of dietary magnesium concentration on the magnesium status and nephrocalcinosis were also examined. Adding excess dietary phosphorus and calcium decreased the apparent magnesium absorption ratios and the concentrations of magnesium in the serum and femur and increased the deposition of calcium in the kidney, and the low magnesium condition (0.024 g of magnesium/100 g of diet) aggravated the deposition of calcium and the low magnesium status. The apparent magnesium absorption ratios and femur magnesium concentration in the rats fed a calcium gluconate diet (an equimolar mixture of calcium gluconate and calcium carbonate was used as a source of calcium) were significantly higher than in the rats fed a calcium carbonate diet (only calcium carbonate was used as a source of calcium), irrespective of dietary magnesium concentration. Dietary calcium gluconate lessened the accumulation of calcium in the kidney and increased the serum magnesium concentration compared with dietary calcium carbonate, when the rats were fed the normal magnesium diet (0.049 g of magnesium/100 g of diet) but not the low magnesium diet. We speculate that the increased utilization of magnesium by feeding the calcium gluconate diet to a limited extent prevented the low magnesium status and the severity of nephrocalcinosis caused by adding excess dietary phosphorus and calcium.

  6. Performance of the ATLAS trigger system

    Science.gov (United States)

    Casadei, Diego

    2012-12-01

    The ATLAS trigger has been used very successfully to collect collision data during 2009-2011 LHC running at centre of mass energies between 900 GeV and 7 TeV. The three-level trigger system reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 300 Hz. The first level uses custom electronics to reject most background events, in less than 2.5 μs, using information from the calorimeter and muon detectors. The upper two trigger levels are software-based triggers. The trigger system selects events by identifying signatures of muon, electron, photon, tau lepton, jet, and B meson candidates, as well as using global event signatures, such as missing transverse energy. We give an overview of the performance of these trigger selections based on extensive online running during the 2011 LHC run and discuss issues encountered during 2011 operations. We describe how the trigger has evolved with increasing LHC luminosity coping with pile-up conditions close to LHC design luminosity.

  7. Upgrade of the CMS Global Muon Trigger

    CERN Document Server

    Lingemann, Joschka; Sakulin, Hannes; Jeitler, Manfred; Stahl, Achim

    2015-01-01

    The increase in center-of-mass energy and luminosity for Run 2 of the Large Hadron Collider pose new challenges for the trigger systems of the experiments. To keep triggering with a similar performance as in Run 1, the CMS muon trigger is currently being upgraded. The new algorithms will provide higher resolution, especially for the muon transverse momentum and will make use of isolation criteria that combine calorimeter with muon information already in the level-1 trigger. The demands of the new algorithms can only be met by upgrading the level-1 trigger system to new powerful FPGAs with high bandwidth I/O. The processing boards will be based on the new microTCA standard. We report on the planned algorithms for the upgraded Global Muon Trigger (GMT) which combines information from the muon trigger sub-systems and assigns the isolation variable. The upgraded GMT will be implemented using a Master Processor 7 card, built by Imperial College, that features a large Xilinx Virtex 7 FPGA. Up to 72 optical links at...

  8. Upgrade of the CMS Global Muon Trigger

    CERN Document Server

    Jeitler, Manfred; Rabady, Dinyar; Sakulin, Hannes; Stahl, Achim

    2015-01-01

    The increase in center-of-mass energy and luminosity for Run-II of the Large Hadron Collider poses new challenges for the trigger systems of the experiments. To keep triggering with a similar performance as in Run-I, the CMS muon trigger is currently being upgraded. The new algorithms will provide higher resolution, especially for the muon transverse momentum and will make use of isolation criteria that combine calorimeter with muon information already in the level-1 trigger. The demands of the new algorithms can only be met by upgrading the level-1 trigger system to new powerful FPGAs with high bandwidth I/O. The processing boards will be based on the new μTCA standard. We report on the planned algorithms for the upgraded Global Muon Trigger (μGMT) which sorts and removes duplicates from boundaries of the muon trigger sub-systems. Furthermore, it determines how isolated the muon candidates are based on calorimetric energy deposits. The μGMT will be implemented using a processing board that features a larg...

  9. Disambiguating Syntactic Triggers

    Science.gov (United States)

    Sakas, William Gregory; Fodor, Janet Dean

    2012-01-01

    We present data from an artificial language domain that suggest new contributions to the theory of syntactic triggers. Whether a learning algorithm is capable of matching the achievements of child learners depends in part on how much parametric ambiguity there is in the input. For practical reasons this cannot be established for the domain of all…

  10. Common Asthma Triggers

    Science.gov (United States)

    ... air pollution can trigger an asthma attack. This pollution can come from factories, cars, and other sources. Pay attention to air quality forecasts on radio, television, and the Internet and check your newspaper to plan ... levels will be low. Cockroach Allergen Cockroaches and ...

  11. The ALFA Trigger Simulator

    CERN Document Server

    Dziedzic B

    2015-01-01

    The paper presents basic information about ALFA detectors used in the ATLAS experiment, and the structure of currently developed device used to test a new ALFA trigger interface. It discusses the block diagram of the device, principle of its operation, implementation details and future plans for developing the Simulator.

  12. Calcium handling by vascular myocytes in hypertension

    Directory of Open Access Journals (Sweden)

    R.C.A. Tostes

    1997-03-01

    Full Text Available Calcium ions (Ca2+ trigger the contraction of vascular myocytes and the level of free intracellular Ca2+ within the myocyte is precisely regulated by sequestration and extrusion mechanisms. Extensive evidence indicates that a defect in the regulation of intracellular Ca2+ plays a role in the augmented vascular reactivity characteristic of clinical and experimental hypertension. For example, arteries from spontaneously hypertensive rats (SHR have an increased contractile sensitivity to extracellular Ca2+ and intracellular Ca2+ levels are elevated in aortic smooth muscle cells of SHR. We hypothesize that these changes are due to an increase in membrane Ca2+ channel density and possibly function in vascular myocytes from hypertensive animals. Several observations using various experimental approaches support this hypothesis: 1 the contractile activity in response to depolarizing stimuli is increased in arteries from hypertensive animals demonstrating increased voltage-dependent Ca2+ channel activity in hypertension; 2 Ca2+ channel agonists such as Bay K 8644 produce contractions in isolated arterial segments from hypertensive rats and minimal contraction in those from normotensive rats; 3 intracellular Ca2+ concentration is abnormally increased in vascular myocytes from hypertensive animals following treatment with Ca2+ channel agonists and depolarizing interventions, and 4 using the voltage-clamp technique, the inward Ca2+ current in arterial myocytes from hypertensive rats is nearly twice as large as that from myocytes of normotensive rats. We suggest that an alteration in Ca2+ channel function and/or an increase in Ca2+ channel density, resulting from increased channel synthesis or reduced turnover, underlies the increased vascular reactivity characteristic of hypertension

  13. Polarity Alteration of a Calcium Site Induces a Hydrophobic Interaction Network and Enhances Cel9A Endoglucanase Thermostability.

    Science.gov (United States)

    Wang, Hsiu-Jung; Hsiao, Yu-Yuan; Chen, Yu-Pei; Ma, Tien-Yang; Tseng, Ching-Ping

    2016-03-01

    Structural calcium sites control protein thermostability and activity by stabilizing native folds and changing local conformations. Alicyclobacillus acidocaldarius survives in thermal-acidic conditions and produces an endoglucanase Cel9A (AaCel9A) which contains a calcium-binding site (Ser465 to Val470) near the catalytic cleft. By superimposing the Ca(2+)-free and Ca(2+)-bounded conformations of the calcium site, we found that Ca(2+) induces hydrophobic interactions between the calcium site and its nearby region by driving a conformational change. The hydrophobic interactions at the high-B-factor region could be enhanced further by replacing the surrounding polar residues with hydrophobic residues to affect enzyme thermostability and activity. Therefore, the calcium-binding residue Asp468 (whose side chain directly ligates Ca(2+)), Asp469, and Asp471 of AaCel9A were separately replaced by alanine and valine. Mutants D468A and D468V showed increased activity compared with those of the wild type with 0 mM or 10 mM Ca(2+) added, whereas the Asp469 or Asp471 substitution resulted in decreased activity. The D468A crystal structure revealed that mutation D468A triggered a conformational change similar to that induced by Ca(2+) in the wild type and developed a hydrophobic interaction network between the calcium site and the neighboring hydrophobic region (Ala113 to Ala117). Mutations D468V and D468A increased 4.5°C and 5.9°C, respectively, in melting temperature, and enzyme half-life at 75°C increased approximately 13 times. Structural comparisons between AaCel9A and other endoglucanases of the GH9 family suggested that the stability of the regions corresponding to the AaCel9A calcium site plays an important role in GH9 endoglucanase catalysis at high temperature. PMID:26729722

  14. Effects of modulation of calcium levels and calcium fluxes on ABA- induced gene expression in barley aleurone

    NARCIS (Netherlands)

    Meulen, R.M. van der; Visser, K.; Wang, M.

    1996-01-01

    We present data to elucidate the involvement of calcium ions in abscisic acid (ABA)-induced gene expression. Modulation of external calcium concentrations was able to affect ABA-induced specific RAB gene expression. At a constant ABA level with increasing extracellular calcium level, an increasing R

  15. The Topo-trigger: a new concept of stereo trigger system for imaging atmospheric Cherenkov telescopes

    CERN Document Server

    López-Coto, Rubén; Paoletti, Riccardo; Bigas, Oscar Blanch; Cortina, Juan

    2016-01-01

    Imaging atmospheric Cherenkov telescopes (IACTs) such as the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes endeavor to reach the lowest possible energy threshold. In doing so the trigger system is a key element. Reducing the trigger threshold is hampered by the rapid increase of accidental triggers generated by ambient light, the so-called Night Sky Background (NSB). In this paper we present a topological trigger, dubbed Topo-trigger, which rejects events on the basis of their relative orientation in the telescope cameras. We have simulated and tested the trigger selection algorithm in the MAGIC telescopes. The algorithm was tested using MonteCarlo simulations and shows a rejection of 85% of the accidental stereo triggers while preserving 99 % of the gamma rays. A full implementation of this trigger system would achieve an increase in collection area between 10 and 20% at the energy threshold. The analysis energy threshold of the instrument is expected to decrease by ?8 %. The selection alg...

  16. Glial calcium signaling in physiology and pathophysioilogy

    Institute of Scientific and Technical Information of China (English)

    Alexei VERKHRASKY

    2006-01-01

    Neuronal-glial circuits underlie integrative processes in the nervous system.Function of glial syncytium is,to a very large extent,regulated by the intracellular calcium signaling system.Glial calcium signals are triggered by activation of multiple receptors,expressed in glial membrane,which regulate both Ca2+ entry and Ca2+ release from the endoplasmic reticulum.The endoplasmic reticulum also endows glial cells with intracellular excitable media,which is able to produce and maintain long-ranging signaling in a form of propagating Ca2+ waves.In pathological conditions,calcium signals regulate glial response to injury,which might have both protective and detrimental effects on the nervous tissue.

  17. Khz (fusion of Ganoderma lucidum and Polyporus umbellatus mycelia induces apoptosis by increasing intracellular calcium levels and activating JNK and NADPH oxidase-dependent generation of reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Tae Hwan Kim

    Full Text Available Khz is a compound derived from the fusion of Ganoderma lucidum and Polyporus umbellatus mycelia that inhibits the growth of cancer cells. The results of the present study show that Khz induced apoptosis preferentially in transformed cells and had only minimal effects on non-transformed cells. Furthermore, Khz induced apoptosis by increasing the intracellular Ca(2+ concentration ([Ca(2+](i and activating JNK to generate reactive oxygen species (ROS via NADPH oxidase and the mitochondria. Khz-induced apoptosis was caspase-dependent and occurred via a mitochondrial pathway. ROS generation by NADPH oxidase was critical for Khz-induced apoptosis, and although mitochondrial ROS production was also required, it appeared to occur secondary to ROS generation by NADPH oxidase. Activation of NADPH oxidase was demonstrated by the translocation of regulatory subunits p47(phox and p67(phox to the cell membrane and was necessary for ROS generation by Khz. Khz triggered a rapid and sustained increase in [Ca(2+](i, which activated JNK. JNK plays a key role in the activation of NADPH oxidase because inhibition of its expression or activity abrogated membrane translocation of the p47(phox and p67(phox subunits and ROS generation. In summary, these data indicate that Khz preferentially induces apoptosis in cancer cells, and the signaling mechanisms involve an increase in [Ca(2+](i, JNK activation, and ROS generation via NADPH oxidase and mitochondria.

  18. Vitamin K Supplement Along with Vitamin D and Calcium Reduced Serum Concentration of Undercarboxylated Osteocalcin While Increasing Bone Mineral Density in Korean Postmenopausal Women over Sixty-Years-Old

    OpenAIRE

    Je, Sang Hyeon; Joo, Nam-Seok; Choi, Beom-hee; Kim, Kwang-Min; Kim, Bom-Taeck; Park, Sat-Byul; Cho, Doo-Yeoun; Kim, Kyu-Nam; Lee, Duck-Joo

    2011-01-01

    There are inconsistent findings on the effects of vitamin K on bone mineral density (BMD) and undercarboxylated osteocalcin (UcOC). The present intervention study evaluated the effect in subjects over 60-yr-old. The vitamin K group (vitamin K + vitamin D + calcium supplement; 15 mg of vitamin K2 [menatetrenone] three times daily, 400 IU of vitamin D once a day, and 315 mg of calcium twice daily) and the control group (vitamin D + calcium supplement) were randomly assigned. During the six mont...

  19. Effects of Calcium Spikes in the Layer 5 Pyramidal Neuron on Coincidence Detection and Activity Propagation

    Science.gov (United States)

    Chua, Yansong; Morrison, Abigail

    2016-01-01

    The role of dendritic spiking mechanisms in neural processing is so far poorly understood. To investigate the role of calcium spikes in the functional properties of the single neuron and recurrent networks, we investigated a three compartment neuron model of the layer 5 pyramidal neuron with calcium dynamics in the distal compartment. By performing single neuron simulations with noisy synaptic input and occasional large coincident input at either just the distal compartment or at both somatic and distal compartments, we show that the presence of calcium spikes confers a substantial advantage for coincidence detection in the former case and a lesser advantage in the latter. We further show that the experimentally observed critical frequency phenomenon, in which action potentials triggered by stimuli near the soma above a certain frequency trigger a calcium spike at distal dendrites, leading to further somatic depolarization, is not exhibited by a neuron receiving realistically noisy synaptic input, and so is unlikely to be a necessary component of coincidence detection. We next investigate the effect of calcium spikes in propagation of spiking activities in a feed-forward network (FFN) embedded in a balanced recurrent network. The excitatory neurons in the network are again connected to either just the distal, or both somatic and distal compartments. With purely distal connectivity, activity propagation is stable and distinguishable for a large range of recurrent synaptic strengths if the feed-forward connections are sufficiently strong, but propagation does not occur in the absence of calcium spikes. When connections are made to both the somatic and the distal compartments, activity propagation is achieved for neurons with active calcium dynamics at a much smaller number of neurons per pool, compared to a network of passive neurons, but quickly becomes unstable as the strength of recurrent synapses increases. Activity propagation at higher scaling factors can be

  20. Optimizing calcium selective fluorimetric nanospheres.

    Science.gov (United States)

    Kisiel, Anna; Kłucińska, Katarzyna; Gniadek, Marianna; Maksymiuk, Krzysztof; Michalska, Agata

    2015-11-01

    Recently it was shown that optical nanosensors based on alternating polymers e.g. poly(maleic anhydride-alt-1-octadecene) were characterized by a linear dependence of emission intensity on logarithm of concentration over a few of orders of magnitude range. In this work we focus on the material used to prepare calcium selective nanosensors. It is shown that alternating polymer nanosensors offer competitive performance in the absence of calcium ionophore, due to interaction of the nanospheres building blocks with analyte ions. The emission increase corresponds to increase of calcium ions contents in the sample within the range from 10(-4) to 10(-1) M. Further improvement in sensitivity (from 10(-6) to 10(-1) M) and selectivity can be achieved by incorporating calcium ionophore in the nanospheres. The optimal results were obtained for core-shell nanospheres, where the core was prepared from poly(styrene-co-maleic anhydride) and the outer layer from poly(maleic anhydride-alt-1-octadecene). Thus obtained chemosensors were showing linear dependence of emission on logarithm of calcium ions concentration within the range from 10(-7) to 10(-1) M. PMID:26452839

  1. Effects of Adding Chymosin to Milk on Calcium Homeostasis

    DEFF Research Database (Denmark)

    Møller, Ulla Kristine; Jensen, Lars Thorbjørn; Mosekilde, Leif;

    2014-01-01

    Calcium intake and absorption is important for bone health. In a randomized double-blind cross-over trial, we investigated effects of adding chymosin to milk on the intestinal calcium absorption as measured by renal calcium excretion and indices of calcium homeostasis. The primary outcome...... of the study was 24-h renal calcium excretion that is considered a proxy measure of the amount of calcium absorbed from the intestine. We studied 125 healthy men and women, aged 34 (25-45) years on two separate days. On each day, a light breakfast was served together with 500 ml of semi-skimmed milk to which...... not depend on plasma 25-hydroxyvitamin D levels. Chymosin added to milk increases renal calcium excretion in the hours following intake without affecting plasma levels of calcium or calciotropic hormones. The effect most likely represents enhanced intestinal calcium absorption shortly after intake. Further...

  2. Inulin and fructooligosaccharide affect in vitro calcium uptake and absorption from calcium-enriched gluten-free bread.

    Science.gov (United States)

    Krupa-Kozak, U; Swiątecka, D; Bączek, N; Brzóska, M M

    2016-04-01

    Compromised intestinal calcium absorption affecting a deterioration of bone state is a sign of coeliac disease. Experimental calcium-fortified gluten-free bread (GFB) of improved calcium bioavailability could increase calcium content in the diets of coeliac disease patients, allowing them to obtain the amount of calcium they need for therapeutic use. Prebiotics, including inulin-type fructans (IFs) have a beneficial effect on calcium bioavailability. In the present study, the in vitro model composed of the intestinal-like Caco-2 cells and the human intestinal bacteria (Lactobacillus, Enterococcus and Enterobacteriaceae) were used to analyse the effect of inulin and fructooligosaccharide (FOS) of different chain lengths, on calcium uptake and absorption from experimental GFB. Analysed IFs, especially short-chain FOS, significantly (p < 0.05) increased cellular calcium uptake from GFB digest and stimulated the intestinal bacteria applied in the cultures to the intensive synthesis of organic acids. In particular, the concentration of butyric, valeric and lactic acids increased significantly. Similarly, in the calcium absorption experiment, IFs increased the cellular calcium retention but concomitantly reduced its content in basolateral filtrates. The results obtained suggest that the applied IFs affected differentially calcium uptake and absorption from the experimental calcium-enriched GFB, therefore a further study is needed to assess whether these observations made in vitro contribute to IF effects on calcium absorption from experimental GFB in vivo.

  3. Inulin and fructooligosaccharide affect in vitro calcium uptake and absorption from calcium-enriched gluten-free bread.

    Science.gov (United States)

    Krupa-Kozak, U; Swiątecka, D; Bączek, N; Brzóska, M M

    2016-04-20

    Compromised intestinal calcium absorption affecting a deterioration of bone state is a sign of coeliac disease. Experimental calcium-fortified gluten-free bread (GFB) of improved calcium bioavailability could increase calcium content in the diets of coeliac disease patients, allowing them to obtain the amount of calcium they need for therapeutic use. Prebiotics, including inulin-type fructans (IFs) have a beneficial effect on calcium bioavailability. In the present study, the in vitro model composed of the intestinal-like Caco-2 cells and the human intestinal bacteria (Lactobacillus, Enterococcus and Enterobacteriaceae) were used to analyse the effect of inulin and fructooligosaccharide (FOS) of different chain lengths, on calcium uptake and absorption from experimental GFB. Analysed IFs, especially short-chain FOS, significantly (p < 0.05) increased cellular calcium uptake from GFB digest and stimulated the intestinal bacteria applied in the cultures to the intensive synthesis of organic acids. In particular, the concentration of butyric, valeric and lactic acids increased significantly. Similarly, in the calcium absorption experiment, IFs increased the cellular calcium retention but concomitantly reduced its content in basolateral filtrates. The results obtained suggest that the applied IFs affected differentially calcium uptake and absorption from the experimental calcium-enriched GFB, therefore a further study is needed to assess whether these observations made in vitro contribute to IF effects on calcium absorption from experimental GFB in vivo. PMID:26965706

  4. Graphics Processing Units for HEP trigger systems

    Science.gov (United States)

    Ammendola, R.; Bauce, M.; Biagioni, A.; Chiozzi, S.; Cotta Ramusino, A.; Fantechi, R.; Fiorini, M.; Giagu, S.; Gianoli, A.; Lamanna, G.; Lonardo, A.; Messina, A.; Neri, I.; Paolucci, P. S.; Piandani, R.; Pontisso, L.; Rescigno, M.; Simula, F.; Sozzi, M.; Vicini, P.

    2016-07-01

    General-purpose computing on GPUs (Graphics Processing Units) is emerging as a new paradigm in several fields of science, although so far applications have been tailored to the specific strengths of such devices as accelerator in offline computation. With the steady reduction of GPU latencies, and the increase in link and memory throughput, the use of such devices for real-time applications in high-energy physics data acquisition and trigger systems is becoming ripe. We will discuss the use of online parallel computing on GPU for synchronous low level trigger, focusing on CERN NA62 experiment trigger system. The use of GPU in higher level trigger system is also briefly considered.

  5. Causative and preventive action of calcium in cataractogenesis

    Institute of Scientific and Technical Information of China (English)

    Purshottam Das GUPTA; Kaid JOHAR; Abhay VASAVADA

    2004-01-01

    Calcium and Ca-dependent enzymes play specific role in the development of human cataracts. Entry of Ca2+ into the lens epithelial cells (LEC) is highly regulated by quantum of receptors. The Ca2+ level controls homeostasis and growth of entire lens. Intracellular overload of Ca2+ in the LEC trigger a series of events such as activation of Ca-dependent enzymes, irreversible breakdown of important structural proteins and cell death. Proper maintenance of Ca2+ levels by regulating activity of Ca-pumps and Ca-channels and inhibition of Ca-dependent enzymes can help in prevention of cataract. Induction of cell death in the LEC by increase in the intracellular Ca2+ may be utilized for the prevention of posterior capsular opacification.

  6. Calcium channel blocker overdose

    Science.gov (United States)

    ... 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 ...

  7. Fenoprofen calcium overdose

    Science.gov (United States)

    ... 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 ...

  8. Calcium Regulation of Hemorrhagic Fever Virus Budding: Mechanistic Implications for Host-Oriented Therapeutic Intervention.

    Directory of Open Access Journals (Sweden)

    Ziying Han

    2015-10-01

    Full Text Available Hemorrhagic fever viruses, including the filoviruses (Ebola and Marburg and arenaviruses (Lassa and Junín viruses, are serious human pathogens for which there are currently no FDA approved therapeutics or vaccines. Importantly, transmission of these viruses, and specifically late steps of budding, critically depend upon host cell machinery. Consequently, strategies which target these mechanisms represent potential targets for broad spectrum host oriented therapeutics. An important cellular signal implicated previously in EBOV budding is calcium. Indeed, host cell calcium signals are increasingly being recognized to play a role in steps of entry, replication, and transmission for a range of viruses, but if and how filoviruses and arenaviruses mobilize calcium and the precise stage of virus transmission regulated by calcium have not been defined. Here we demonstrate that expression of matrix proteins from both filoviruses and arenaviruses triggers an increase in host cytoplasmic Ca2+ concentration by a mechanism that requires host Orai1 channels. Furthermore, we demonstrate that Orai1 regulates both VLP and infectious filovirus and arenavirus production and spread. Notably, suppression of the protein that triggers Orai activation (Stromal Interaction Molecule 1, STIM1 and genetic inactivation or pharmacological blockade of Orai1 channels inhibits VLP and infectious virus egress. These findings are highly significant as they expand our understanding of host mechanisms that may broadly control enveloped RNA virus budding, and they establish Orai and STIM1 as novel targets for broad-spectrum host-oriented therapeutics to combat these emerging BSL-4 pathogens and potentially other enveloped RNA viruses that bud via similar mechanisms.

  9. Calcium and Mitosis

    Science.gov (United States)

    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.

  10. The ARGUS vertex trigger

    International Nuclear Information System (INIS)

    A fast second level trigger has been developed for the ARGUS experiment which recognizes tracks originating from the interaction region. The processor compares the hits in the ARGUS Micro Vertex Drift Chamber to 245760 masks stored in random access memories. The masks which are fully defined in three dimensions are able to reject tracks originating in the wall of the narrow beampipe of 10.5 mm radius. (orig.)

  11. Trigger and data acquisition

    CERN Document Server

    Ellis, Nick

    2010-01-01

    The lectures address some of the issues of triggering and data acquisition in large high-energy physics experiments. Emphasis is placed on hadron-collider experiments that present a particularly challenging environment for event selection and data collection. However, the lectures also explain how T/DAQ systems have evolved over the years to meet new challenges. Some examples are given from early experience with LHC T/DAQ systems during the 2008 single-beam operations.

  12. Neural networks for triggering

    Energy Technology Data Exchange (ETDEWEB)

    Denby, B. (Fermi National Accelerator Lab., Batavia, IL (USA)); Campbell, M. (Michigan Univ., Ann Arbor, MI (USA)); Bedeschi, F. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy)); Chriss, N.; Bowers, C. (Chicago Univ., IL (USA)); Nesti, F. (Scuola Normale Superiore, Pisa (Italy))

    1990-01-01

    Two types of neural network beauty trigger architectures, based on identification of electrons in jets and recognition of secondary vertices, have been simulated in the environment of the Fermilab CDF experiment. The efficiencies for B's and rejection of background obtained are encouraging. If hardware tests are successful, the electron identification architecture will be tested in the 1991 run of CDF. 10 refs., 5 figs., 1 tab.

  13. Patient triggered ventilation using a flow triggered system.

    OpenAIRE

    Hird, M F; Greenough, A

    1991-01-01

    The role of patient triggered ventilation (PTV) for the newborn was assessed using a new patient triggered ventilator, the Draeger Bablylog 8000, which incorporates significant improvements in both ventilator performance and the triggering system. Thirty three infants, median gestational age 30 weeks and postnatal age 2.5 days, were entered into the study to compare blood gases obtained during conventional and patient triggered ventilation. Oxygenation did not improve with PTV in the group ov...

  14. Relationship of calcium absorption with 25(OH)D and calcium intake in children with rickets.

    Science.gov (United States)

    Thacher, Tom D; Abrams, Steven A

    2010-11-01

    Nutritional rickets has long been considered a disease caused by vitamin D deficiency, but recent data indicate that inadequate dietary calcium intake is an important cause of rickets, particularly in tropical countries. Children with rickets due to calcium deficiency do not have very low 25(OH)D concentrations, and serum 1,25(OH)(2) D values are markedly elevated. Studies of Nigerian children with rickets demonstrated they have high fractional calcium absorption. A high-phytate diet was demonstrated to increase calcium absorption compared with the fasting state, and enzymatic dephytinization did not significantly improve calcium absorption. When given vitamin D, children with rickets have a marked increase in 1,25(OH)(2) D concentrations without any change in fractional calcium absorption. No positive relationship was found between fractional calcium absorption and serum 25(OH)D concentrations in children on low-calcium diets. More research is needed to understand the interaction between calcium and vitamin D and the role of vitamin D in calcium absorption.

  15. Calcium en cardioplegie

    NARCIS (Netherlands)

    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 cardiop

  16. A trigger for beauty

    International Nuclear Information System (INIS)

    The possibility of B-meson experiments, in a fixed-target high-energy proton machine (Tevatron) is discussed. Compared to a B-meson factory experiment, it can produce 105, Banti B's per hour, using 108 protons per second, but it suffers from high background and needs high selectivity to cope with the million times higher interaction rate. To overcome these difficulties a technique called the 'optical trigger for beauty' is proposed, based on the detection of Cherenkov photons produced in a 2 mm thick LiF crystal, through a fast photodetector. Its virtue is that it is opaque to minimum-bias events originating in a small target, but sensitive to the high impact parameter B-meson decay charged particles from a secondary vertex. Calculations and first simulations results give a good efficiency for B-meson detection. A multistep trigger, combining the 'optical trigger' and a tracking detector, allows significant selection and a consequent enrichment of the data sample. Taking into account its fast response (∝ 1 ns), the above considerations can be extended to other hadronic machines, especially those with high-rate environments such as the LHC or SSC. (orig.)

  17. Resource Utilization by the ATLAS High Level Trigger during 2010 and 2011 LHC running

    CERN Document Server

    Schaefer, D; The ATLAS collaboration; Ospanov, R

    2012-01-01

    Since starting in 2010, the Large Hadron Collider (LHC) has produced collisions at an ever increasing rate. The ATLAS experiment successfully records the collision data with high efficiency and excellent data quality. Events are selected using a three-level trigger system, where each level makes a more re ned selection. The level-1 trigger (L1) consists of a custom-designed hardware trigger which seeds two higher software based trigger levels. Over 300 triggers compose a trigger menu which selects physics signatures such as electrons, muons, particle jets, etc. Each trigger consumes computing resources of the ATLAS trigger system and online storage. The LHC instantaneous luminosity conditions, desired physics goals of the collaboration, and the limits of the trigger infrastructure determine the composition of the ATLAS trigger menu. We describe a trigger monitoring framework for computing the costs of individual trigger algorithms such as data request rates and CPU consumption. This framework has been used to...

  18. The cardiac L-type calcium channel distal carboxy terminus autoinhibition is regulated by calcium.

    Science.gov (United States)

    Crump, Shawn M; Andres, Douglas A; Sievert, Gail; Satin, Jonathan

    2013-02-01

    The L-type calcium channel (LTCC) provides trigger Ca(2+) for sarcoplasmic reticulum Ca-release, and LTCC function is influenced by interacting proteins including the LTCC distal COOH terminus (DCT) and calmodulin. DCT is proteolytically cleaved and reassociates with the LTCC complex to regulate calcium channel function. DCT reduces LTCC barium current (I(Ba,L)) in reconstituted channel complexes, yet the contribution of DCT to LTCC Ca(2+) current (I(Ca,L)) in cardiomyocyte systems is unexplored. This study tests the hypothesis that DCT attenuates cardiomyocyte I(Ca,L). We measured LTCC current and Ca(2+) transients with DCT coexpressed in murine cardiomyocytes. We also heterologously coexpressed DCT and Ca(V)1.2 constructs with truncations corresponding to the predicted proteolytic cleavage site, Ca(V)1.2Δ1801, and a shorter deletion corresponding to well-studied construct, Ca(V)1.2Δ1733. DCT inhibited I(Ba,L) in cardiomyocytes, and in human embryonic kidney (HEK) 293 cells expressing Ca(V)1.2Δ1801 and Ca(V)1.2Δ1733. Ca(2+)-CaM relieved DCT block in cardiomyocytes and HEK cells. The selective block of I(Ba,L) combined with Ca(2+)-CaM effects suggested that DCT-mediated blockade may be relieved under conditions of elevated Ca(2+). We therefore tested the hypothesis that DCT block is dynamic, increasing under relatively low Ca(2+), and show that DCT reduced diastolic Ca(2+) at low stimulation frequencies but spared high frequency Ca(2+) entry. DCT reduction of diastolic Ca(2+) and relief of block at high pacing frequencies and under conditions of supraphysiological bath Ca(2+) suggests that a physiological function of DCT is to increase the dynamic range of Ca(2+) transients in response to elevated pacing frequencies. Our data motivate the new hypothesis that DCT is a native reverse use-dependent inhibitor of LTCC current.

  19. Preparation of calcium chloride-loaded solid lipid particles and heat-triggered calcium ion release

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Huangying; Kim, Jin-Chul [Kangwon National University, Chunchon (Korea, Republic of)

    2015-08-15

    CaCl{sub 2}-loaded solid lipid particles (SLPs) were prepared by a melt/emulsification/solidification method. CaCl{sub 2} microparticles (1-5 μm) could be obtained in a mortar with aid of the dispersant (Tween 80/Span80 (35/65, w/w)) when the ratio of CaCl{sub 2} to dispersant was 2 : 0.1 (w/w). SLP was prepared by dispersing 0.42 g of micronized CaCl{sub 2} particles in 2 g of molten PBSA, emulsifying the mixture at 85 .deg. C in 40 ml of Tween 20 solution (0.5% w/v), and quenching the emulsion in an ice bath. The diameter of CaCl{sub 2}-loaded SLP was 10-150 μm. The unenveloped CaCl{sub 2} could be removed by dialysis and the specific loading of CaCl{sub 2} in SLP was 0.036mg/mg. An EDS spectrum of CaCl{sub 2}-loaded SLP, which was dialyzed, showed that the unenveloped CaCl{sub 2} was completely removed. Any excipients (dispersant, Tween 20, CaCl{sub 2}) had little effect on the melting point of SLPs. No appreciable amount of Ca2+ was released in 20-50 .deg. C for 22 h. But the release degree at 60 .deg. C was significant (about 2.3%) during the same period. The matrix of the lipid particle was in a liquid state at 60 .deg. C, so CaCl{sub 2} particles could move freely and contact the surrounding water, leading to the release. At 70 .deg. C, the release degree at a given time was a few times higher than that obtained at 60 .deg. C.

  20. Calcium signaling in pluripotent stem cells.

    Science.gov (United States)

    Apáti, Ágota; Pászty, Katalin; Erdei, Zsuzsa; Szebényi, Kornélia; Homolya, László; Sarkadi, Balázs

    2012-04-28

    Pluripotent stem cells represent a new source of biological material allowing the exploration of signaling phenomena during normal cell development and differentiation. Still, the calcium signaling pathways and intracellular calcium responses to various ligands or stress conditions have not been sufficiently explored as yet in embryonic or induced pluripotent stem cells and in their differentiated offspring. This is partly due to the special culturing conditions of these cell types, the rapid morphological and functional changes in heterogeneous cell populations during early differentiation, and methodological problems in cellular calcium measurements. In this paper, we review the currently available data in the literature on calcium signaling in pluripotent stem cells and discuss the potential shortcomings of these studies. Various assay methods are surveyed for obtaining reliable data both in undifferentiated embryonic stem cells and in specific, stem cell-derived human tissues. In this paper, we present the modulation of calcium signaling in human embryonic stem cells (hESC) and in their derivates; mesenchymal stem cell like (MSCl) cells and cardiac tissues using the fluorescent calcium indicator Fluo-4 and confocal microscopy. LPA, trypsin and angiotensin II were effective in inducing calcium signals both in HUES9 and MSCl cells. Histamine and thrombin induced calcium signal exclusively in the MSCl cells, while ATP was effective only in HUES9 cells. There was no calcium signal evoked by GABA, even at relatively high concentrations. In stem cell-derived cardiomyocytes a rapid increase in the beating rate and an increase of the calcium signal peaks could be observed after the addition of adrenaline, while verapamil led to a strong decrease in cellular calcium and stopped spontaneous contractions in a relaxed state.

  1. Level-1 Jets and Sums Trigger Performance

    CERN Document Server

    CMS Collaboration

    2016-01-01

    After the first long shutdown, the LHC has restarted at a centre-of-mass energy of 13 TeV. The LHC is expected to achieve an instantaneous luminosity larger than $10^{34} \\rm{cm}^{-2} \\rm{s}^{-1}$ and an average number of pile-up interactions of at least 40. The CMS Level-1 trigger architecture has undergone a full upgrade in order to maintain and improve the trigger performance under these new conditions. It will allow CMS to keep the trigger rate under control and to avoid a significant increase in trigger thresholds that would have a negative impact on the CMS physics programme. First studies of the performance of the calorimeter trigger upgrade for jets and energy sums are shown. Details of the algorithms and commissioning may be found in CMS-DP-2015-051 and the CMS Technical Design Report for the Level-1 Trigger upgrade: CERN-LHCC-2013-011, CMS-TDR-12 (2013)

  2. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    NARCIS (Netherlands)

    Xie, Xueqian; Greuter, Marcel J. W.; Groen, Jaap M.; de Bock, Geertruida H.; Oudkerk, Matthijs; de Jong, Pim A.; Vliegenthart, Rozemarijn

    2013-01-01

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontr

  3. A mathematical model of T lymphocyte calcium dynamics derived from single transmembrane protein properties

    Directory of Open Access Journals (Sweden)

    Christine Dorothee Schmeitz

    2013-09-01

    Full Text Available Fate decision processes of T lymphocytes are crucial for health and disease. Whether a T lymphocyte is activated, divides, gets anergic or initiates apoptosis depends on extracellular triggers and intracellular signalling. Free cytosolic calcium dynamics plays an important role in this context. The relative contributions of store-derived calcium entry and calcium entry from extracellular space to T lymphocyte activation are still a matter of debate. Here we develop a quantitative mathematical model of T lymphocyte calcium dynamics in order to establish a tool which allows to disentangle cause-effect relationships between ion fluxes and observed calcium time courses. The model is based on single transmembrane protein characteristics which have been determined in independent experiments. This reduces the number of unknown parameters in the model to a minimum and ensures the predictive power of the model. Simulation results are subsequently used for an analysis of whole cell calcium dynamics measured under various experimental conditions. The model accounts for a variety of these conditions, which supports the suitability of the modelling approach. The simulation results suggest a model in which calcium dynamics dominantly relies on the opening of channels in calcium stores while calcium entry through calcium-release activated channels (CRAC is more associated with the maintenance of the T lymphocyte calcium levels and prevents the cell from calcium depletion. Our findings indicate that CRAC guarantees a long-term stable calcium level which is required for cell survival and sustained calcium enhancement.

  4. Apoptosis-mediated endothelial toxicity but not direct calcification or functional changes in anti-calcification proteins defines pathogenic effects of calcium phosphate bions

    Science.gov (United States)

    Kutikhin, Anton G.; Velikanova, Elena A.; Mukhamadiyarov, Rinat A.; Glushkova, Tatiana V.; Borisov, Vadim V.; Matveeva, Vera G.; Antonova, Larisa V.; Filip’Ev, Dmitriy E.; Golovkin, Alexey S.; Shishkova, Daria K.; Burago, Andrey Yu.; Frolov, Alexey V.; Dolgov, Viktor Yu.; Efimova, Olga S.; Popova, Anna N.; Malysheva, Valentina Yu.; Vladimirov, Alexandr A.; Sozinov, Sergey A.; Ismagilov, Zinfer R.; Russakov, Dmitriy M.; Lomzov, Alexander A.; Pyshnyi, Dmitriy V.; Gutakovsky, Anton K.; Zhivodkov, Yuriy A.; Demidov, Evgeniy A.; Peltek, Sergey E.; Dolganyuk, Viatcheslav F.; Babich, Olga O.; Grigoriev, Evgeniy V.; Brusina, Elena B.; Barbarash, Olga L.; Yuzhalin, Arseniy E.

    2016-06-01

    Calcium phosphate bions (CPB) are biomimetic mineralo-organic nanoparticles which represent a physiological mechanism regulating the function, transport and disposal of calcium and phosphorus in the human body. We hypothesised that CPB may be pathogenic entities and even a cause of cardiovascular calcification. Here we revealed that CPB isolated from calcified atherosclerotic plaques and artificially synthesised CPB are morphologically and chemically indistinguishable entities. Their formation is accelerated along with the increase in calcium salts-phosphates/serum concentration ratio. Experiments in vitro and in vivo showed that pathogenic effects of CPB are defined by apoptosis-mediated endothelial toxicity but not by direct tissue calcification or functional changes in anti-calcification proteins. Since the factors underlying the formation of CPB and their pathogenic mechanism closely resemble those responsible for atherosclerosis development, further research in this direction may help us to uncover triggers of this disease.

  5. Localization and pharmacological characterization of voltage dependent calcium channels in cultured neocortical neurons

    DEFF Research Database (Denmark)

    Timmermann, D B; Lund, Trine Meldgaard; Belhage, B;

    2001-01-01

    The physiological significance and subcellular distribution of voltage dependent calcium channels was defined using calcium channel blockers to inhibit potassium induced rises in cytosolic calcium concentration in cultured mouse neocortical neurons. The cytosolic calcium concentration was measured...... using the fluorescent calcium chelator fura-2. The types of calcium channels present at the synaptic terminal were determined by the inhibitory action of calcium channel blockers on potassium-induced [3H]GABA release in the same cell preparation. L-, N-, P-, Q- and R-/T-type voltage dependent calcium...... most important voltage dependent calcium channel in all parts of the neuron. After treatment with thapsigargin the increase in cytosolic calcium was halved, indicating that calcium release from thapsigargin sensitive intracellular calcium stores is an important component of the potassium induced rise...

  6. The Topo-trigger: A new stereo trigger for lowering the energy threshold of IACTs

    CERN Document Server

    López-Coto, R; Paoletti, R; Blanch, O; Cortina, J

    2015-01-01

    The purpose of the hardware presented in this contribution is to decrease the energy threshold of the MAGIC telescopes without significantly increasing the data acquisition rate. To achieve this purpose, we developed an additional level of trigger that relies on the location in both MAGIC cameras where the trigger is issued to rule out accidental events. This allows to decrease the Discriminator Threshold (DT), which results in a reduction of the energy threshold of the instrument. We simulated the Topo-trigger concept using the standard MAGIC Monte Carlo (MC) and tested it with real telescope data. In this paper we show the concept and results of these tests.

  7. Triggering filamentation using turbulence

    CERN Document Server

    Eeltink, D; Marchiando, N; Hermelin, S; Gateau, J; Brunetti, M; Wolf, J P; Kasparian, J

    2016-01-01

    We study the triggering of single filaments due to turbulence in the beam path for a laser of power below the filamenting threshold. Turbulence can act as a switch between the beam not filamenting and producing single filaments. This 'positive' effect of turbulence on the filament probability, combined with our observation of off-axis filaments suggests the underlying mechanism is modulation instability caused by transverse perturbations. We hereby experimentally explore the interaction of modulation instability and turbulence, commonly associated with multiple-filaments, in the single-filament regime.

  8. The UA1 upgrade calorimeter trigger processor

    International Nuclear Information System (INIS)

    The increased luminosity of the improved CERN Collider and the more subtle signals of second-generation collider physics demand increasingly sophisticated triggering. We have built a new first-level trigger processor designed to use the excellent granularity of the UA1 upgrade calorimeter. This device is entirely digital and handles events in 1.5 μs, thus introducing no deadtime. Its most novel feature is fast two-dimensional electromagnetic cluster-finding with the possibility of demanding an isolated shower of limited penetration. The processor allows multiple combinations of triggers on electromagnetic showers, hadronic jets and energy sums, including a total-energy veto of multiple interactions and a full vector sum of missing transverse energy. This hard-wired processor is about five times more powerful than its predecessor, and makes extensive use of pipelining techniques. It was used extensively in the 1988 and 1989 runs of the CERN Collider. (author)

  9. Dysbalance of astrocyte calcium under hyperammonemic conditions.

    Directory of Open Access Journals (Sweden)

    Nicole Haack

    Full Text Available Increased brain ammonium (NH4(+/NH3 plays a central role in the manifestation of hepatic encephalopathy (HE, a complex syndrome associated with neurological and psychiatric alterations, which is primarily a disorder of astrocytes. Here, we analysed the influence of NH4(+/NH3 on the calcium concentration of astrocytes in situ and studied the underlying mechanisms of NH4(+/NH3-evoked calcium changes, employing fluorescence imaging with Fura-2 in acute tissue slices derived from different regions of the mouse brain. In the hippocampal stratum radiatum, perfusion with 5 mM NH4(+/NH3 for 30 minutes caused a transient calcium increase in about 40% of astrocytes lasting about 10 minutes. Furthermore, the vast majority of astrocytes (∼ 90% experienced a persistent calcium increase by ∼ 50 nM. This persistent increase was already evoked at concentrations of 1-2 mM NH4(+/NH3, developed within 10-20 minutes and was maintained as long as the NH4(+/NH3 was present. Qualitatively similar changes were observed in astrocytes of different neocortical regions as well as in cerebellar Bergmann glia. Inhibition of glutamine synthetase resulted in significantly larger calcium increases in response to NH4(+/NH3, indicating that glutamine accumulation was not a primary cause. Calcium increases were not mimicked by changes in intracellular pH. Pharmacological inhibition of voltage-gated sodium channels, sodium-potassium-chloride-cotransporters (NKCC, the reverse mode of sodium/calcium exchange (NCX, AMPA- or mGluR5-receptors did not dampen NH4(+/NH3-induced calcium increases. They were, however, significantly reduced by inhibition of NMDA receptors and depletion of intracellular calcium stores. Taken together, our measurements show that sustained exposure to NH4(+/NH3 causes a sustained increase in intracellular calcium in astrocytes in situ, which is partly dependent on NMDA receptor activation and on release of calcium from intracellular stores. Our study

  10. Calcium absorption and achlorhydria

    International Nuclear Information System (INIS)

    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

  11. Effects of triggering mechanism on snow avalanche slope angles and slab depths from field data

    Science.gov (United States)

    McClung, David M.

    2013-04-01

    Field data from snow avalanche fracture lines for slope angle and slab depth (measured perpendicular to the weak layer) were analyzed for different triggering mechanisms. For slope angle, the results showed that the same probability density function (pdf) (of log-logistic type) and range (25 - 55 degrees) apply independent of triggering mechanism. For slab depth, the same pdf (generalized extreme value) applies independent of triggering mechanism. For both slope angle and slab depth, the data skewness differentiated between triggering mechanism and increased with applied triggering load. For slope angle, skewness is lowest for natural triggering by snow loads and highest for triggering from human intervention. For slab depth, the skewness is lowest for natural triggering and highest for a mix of triggers including explosive control with skier triggering being intermediate. The results reveal the effects of triggering mechanism which are important for risk analyses and to guide avalanche forecasting.

  12. TRPM8 and Nav1.8 sodium channels are required for transthyretin-induced calcium influx in growth cones of small-diameter TrkA-positive sensory neurons

    Directory of Open Access Journals (Sweden)

    Vincent Adele J

    2011-03-01

    Full Text Available Abstract Background Familial amyloidotic polyneuropathy (FAP is a peripheral neuropathy caused by the extracellular accumulation and deposition of insoluble transthyretin (TTR aggregates. However the molecular mechanism that underlies TTR toxicity in peripheral nerves is unclear. Previous studies have suggested that amyloidogenic proteins can aggregate into oligomers which disrupt intracellular calcium homeostasis by increasing the permeability of the plasma membrane to extracellular calcium. The aim of the present study was to examine the effect of TTR on calcium influx in dorsal root ganglion neurons. Results Levels of intracellular cytosolic calcium were monitored in dorsal root ganglion (DRG neurons isolated from embryonic rats using the calcium-sensitive fluorescent indicator Fluo4. An amyloidogenic mutant form of TTR, L55P, induced calcium influx into the growth cones of DRG neurons, whereas wild-type TTR had no significant effect. Atomic force microscopy and dynamic light scattering studies confirmed that the L55P TTR contained oligomeric species of TTR. The effect of L55P TTR was decreased by blockers of voltage-gated calcium channels (VGCC, as well as by blockers of Nav1.8 voltage-gated sodium channels and transient receptor potential M8 (TRPM8 channels. siRNA knockdown of TRPM8 channels using three different TRPM8 siRNAs strongly inhibited calcium influx in DRG growth cones. Conclusions These data suggest that activation of TRPM8 channels triggers the activation of Nav1.8 channels which leads to calcium influx through VGCC. We suggest that TTR-induced calcium influx into DRG neurons may contribute to the pathophysiology of FAP. Furthermore, we speculate that similar mechanisms may mediate the toxic effects of other amyloidogenic proteins such as the β-amyloid protein of Alzheimer's disease.

  13. Calcium Intake in Elderly Australian Women Is Inadequate

    Directory of Open Access Journals (Sweden)

    Colin W. Binns

    2010-09-01

    Full Text Available The role of calcium in the prevention of bone loss in later life has been well established but little data exist on the adequacy of calcium intakes in elderly Australian women. The aim of this study was to compare the dietary intake including calcium of elderly Australian women with the Australian dietary recommendation, and to investigate the prevalence of calcium supplement use in this population. Community-dwelling women aged 70–80 years were randomly recruited using the Electoral Roll for a 2-year protein intervention study in Western Australia. Dietary intake was assessed at baseline by a 3-day weighed food record and analysed for energy, calcium and other nutrients. A total of 218 women were included in the analysis. Mean energy intake was 7,140 ± 1,518 kJ/day and protein provided 19 ± 4% of energy. Mean dietary calcium intake was 852 ± 298 mg/day, which is below Australian recommendations. Less than one quarter of women reported taking calcium supplements and only 3% reported taking vitamin D supplements. Calcium supplements by average provided calcium 122 ± 427 mg/day and when this was taken into account, total calcium intake increased to 955 ± 504 mg/day, which remained 13% lower than the Estimated Average Requirement (EAR, 1,100 mg/day for women of this age group. The women taking calcium supplements had a higher calcium intake (1501 ± 573 mg compared with the women on diet alone (813 ± 347 mg. The results of this study indicate that the majority of elderly women were not meeting their calcium requirements from diet alone. In order to achieve the recommended dietary calcium intake, better strategies for promoting increased calcium, from both diet and calcium supplements appears to be needed.

  14. Intracellular calcium release modulates polycystin-2 trafficking

    Directory of Open Access Journals (Sweden)

    Miyakawa Ayako

    2013-02-01

    Full Text Available Abstract Background Polycystin-2 (PC2, encoded by the gene that is mutated in autosomal dominant polycystic kidney disease (ADPKD, functions as a calcium (Ca2+ permeable ion channel. Considerable controversy remains regarding the subcellular localization and signaling function of PC2 in kidney cells. Methods We investigated the subcellular PC2 localization by immunocytochemistry and confocal microscopy in primary cultures of human and rat proximal tubule cells after stimulating cytosolic Ca2+ signaling. Plasma membrane (PM Ca2+ permeability was evaluated by Fura-2 manganese quenching using time-lapse fluorescence microscopy. Results We demonstrated that PC2 exhibits a dynamic subcellular localization pattern. In unstimulated human or rat proximal tubule cells, PC2 exhibited a cytosolic/reticular distribution. Treatments with agents that in various ways affect the Ca2+ signaling machinery, those being ATP, bradykinin, ionomycin, CPA or thapsigargin, resulted in increased PC2 immunostaining in the PM. Exposing cells to the steroid hormone ouabain, known to trigger Ca2+ oscillations in kidney cells, caused increased PC2 in the PM and increased PM Ca2+ permeability. Intracellular Ca2+ buffering with BAPTA, inositol 1,4,5-trisphosphate receptor (InsP3R inhibition with 2-aminoethoxydiphenyl borate (2-APB or Ca2+/Calmodulin-dependent kinase inhibition with KN-93 completely abolished ouabain-stimulated PC2 translocation to the PM. Conclusions These novel findings demonstrate intracellular Ca2+-dependent PC2 trafficking in human and rat kidney cells, which may provide new insight into cyst formations in ADPKD.

  15. Latent myofascial trigger points.

    Science.gov (United States)

    Ge, Hong-You; Arendt-Nielsen, Lars

    2011-10-01

    A latent myofascial trigger point (MTP) is defined as a focus of hyperirritability in a muscle taut band that is clinically associated with local twitch response and tenderness and/or referred pain upon manual examination. Current evidence suggests that the temporal profile of the spontaneous electrical activity at an MTP is similar to focal muscle fiber contraction and/or muscle cramp potentials, which contribute significantly to the induction of local tenderness and pain and motor dysfunctions. This review highlights the potential mechanisms underlying the sensory-motor dysfunctions associated with latent MTPs and discusses the contribution of central sensitization associated with latent MTPs and the MTP network to the spatial propagation of pain and motor dysfunctions. Treating latent MTPs in patients with musculoskeletal pain may not only decrease pain sensitivity and improve motor functions, but also prevent latent MTPs from transforming into active MTPs, and hence, prevent the development of myofascial pain syndrome.

  16. b-jet triggering in ATLAS

    CERN Document Server

    Cavaliere, V; The ATLAS collaboration

    2012-01-01

    The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is in place from the beginning of the 2011 data-taking period and is contributing to keep the total bandwidth to an affordable rate. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and the performance on real data is presented in this contribution. Data-driven techniques to extract the online b-tagging efficiency and mis-tag rate, key ingredients f...

  17. Homer1a attenuates glutamate-induced oxidative injury in HT-22 cells through regulation of store-operated calcium entry

    Science.gov (United States)

    Rao, Wei; Peng, Cheng; Zhang, Lei; Su, Ning; Wang, Kai; Hui, Hao; Dai, Shu-hui; Yang, Yue-fan; Luo, Peng; Fei, Zhou

    2016-01-01

    Calcium disequilibrium is extensively involved in oxidative stress-induced neuronal injury. Although Homer1a is known to regulate several neuronal calcium pathways, its effects on, or its exact relationship with, oxidative stress-induced neuronal injury has not yet been fully elucidated. We found that Homer1a protected HT-22 cells from glutamate-induced oxidative stress injury by inhibiting final-phase intracellular calcium overload and mitochondrial oxidative stress. In these cells, stromal interactive molecule 1 (STIM1) puncta, but not the protein level, was significantly increased after glutamate treatment. Store-operated calcium entry (SOCE) inhibitors and cells in which a key component of SOCE (STIM1) was knocked out were used as glutamate-induced oxidative stress injury models. Both models demonstrated significant improvement of HT-22 cell survival after glutamate treatment. Additionally, increased Homer1a protein levels significantly inhibited SOCE and decreased the association of STIM1-Orai1 triggered by glutamate. These results suggest that up-regulation of Homer1a can protect HT-22 cells from glutamate-induced oxidative injury by disrupting the STIM1-Oria1 association, and then by inhibiting the SOCE-mediated final-phrase calcium overload. Thus, regulation of Homer1a, either alone or in conjunction with SOCE inhibition, may serve as key therapeutic interventional targets for neurological diseases in which oxidative stress is involved in the etiology or progression of the disease. PMID:27681296

  18. Calcium--a central regulator of keratinocyte differentiation in health and disease.

    Science.gov (United States)

    Elsholz, Floriana; Harteneck, Christian; Muller, Walter; Friedland, Kristina

    2014-01-01

    Regular keratinocyte differentiation is crucial for the formation of an intact epidermal barrier and is triggered by extracellular calcium. Disturbances of epidermal barrier formation and aberrant keratinocyte differentiation are involved in the pathophysiology of several skin diseases, such as psoriasis, atopic dermatitis, basal and squamous skin cancer, and genetic skin diseases such as Darier's disease and Olmstedt syndrome. In this review, we summarize current knowledge about the underlying molecular mechanisms of calcium-induced differentiation in keratinocytes. We provide an overview of calcium's genomic and non-genomic mechanisms to induce differentiation and discuss the calcium gradient in the epidermis, giving rise to cornified skin and lipid envelope formation. We focus on the calcium-sensing receptor, transient receptor potential channels, and STIM/Orai as the major constituents of calcium sensing and calcium entry in the keratinocytes. Finally, skin diseases linked to impaired differentiation will be discussed, paying special attention to disturbed TRP channel expression and TRP channel mutations.

  19. Consumption of calcium-fortified cereal bars to improve dietary calcium intake of healthy women: randomized controlled feasibility study.

    Directory of Open Access Journals (Sweden)

    Jennifer T Lee

    Full Text Available Calcium is an important structural component of the skeletal system. Although an adequate intake of calcium helps to maintain bone health and reduce the risk of osteoporosis, many women do not meet recommended daily intakes of calcium. Previous interventions studies designed to increase dietary intake of women have utilized primarily dairy sources of calcium or supplements. However, lactose intolerance, milk protein allergies, or food preferences may lead many women to exclude important dairy sources of dietary calcium. Therefore, we undertook a 9 week randomized crossover design trial to examine the potential benefit of including a non-dairy source of calcium in the diet of women. Following a 3 week run-in baseline period, 35 healthy women > 18 years were randomized by crossover design into either Group I or Group II. Group I added 2 calcium-fortified cereal bars daily (total of 400 mg calcium/day (intervention to their usual diet and Group II continued their usual diet (control. At the end of 3 weeks, diets were switched for another 3 weeks. Intakes of calcium and energy were estimated from 3-day diet and supplemental diaries. Wilcoxon signed-rank tests were used for within group comparisons and Mann Whitney U tests were used for between group comparisons of calcium and energy intake. Dietary calcium was significantly higher during intervention (1071 mg/d when participants consumed 2 calcium-fortified cereal bars daily than during the baseline (720 mg/d, P <0.0001 or control diets (775 mg/d, P = 0.0001 periods. Furthermore, the addition of 2 calcium-fortified cereal bars daily for the 3 week intervention did not significantly increase total energy intake or result in weight gain. In conclusion, consumption of calcium-fortified cereal bars significantly increased calcium intake of women. Further research examining the potential ability of fortified cereal bars to help maintain and improve bone health of women is warranted.ClinicalTrials.gov NCT

  20. Relationship between calcium decoding elements and plant abiotic-stress resistance

    Directory of Open Access Journals (Sweden)

    Wei-Yi Song, Zheng-Bin Zhang, Hong-Bo Shao, Xiu-Lin Guo, Hong-Xing Cao, Hong-Bin Zhao, Zheng-Yan Fu, Xiao-Jun Hu

    2008-01-01

    Full Text Available Serving as an important second messenger, calcium ion has unique properties and universal ability to transmit diverse signals that trigger primary physiological actions in cells in response to hormones, pathogens, light, gravity, and stress factors. Being a second messenger of paramount significance, calcium is required at almost all stages of plant growth and development, playing a fundamental role in regulating polar growth of cells and tissues and participating in plant adaptation to various stress factors. Many researches showed that calcium signals decoding elements are involved in ABA-induced stomatal closure and plant adaptation to drought, cold, salt and other abiotic stresses. Calcium channel proteins like AtTPC1 and TaTPC1 can regulate stomatal closure. Recently some new studies show that Ca2+ is dissolved in water in the apoplast and transported primarily from root to shoot through the transpiration stream. The oscillating amplitudes of [Ca2+]o and [Ca2+]i are controlled by soil Ca2+ concentrations and transpiration rates. Because leaf water use efficiency (WUE is determined by stomatal closure and transpiration rate, so there may be a close relationship between Ca2+ transporters and stomatal closure as well as WUE, which needs to be studied. The selection of varieties with better drought resistance and high WUE plays an increasing role in bio-watersaving in arid and semi-arid areas on the globe. The current paper reviews the relationship between calcium signals decoding elements and plant drought resistance as well as other abiotic stresses for further study.

  1. Calcium binding to low molecular weight compounds and health promoting products

    DEFF Research Database (Denmark)

    Vavrusova, Martina

    absorption. Therefore, calcium as an essential nutrient should not be underestimated in our diet. Milk and dairy products are good sources of bioavailable calcium due to specific protein binding. Other sources of calcium, apart from a balanced and healthy diet, are calcium supplements and calcium fortified...... food. Therefore, an understanding of the basic chemistry of calcium binding to low molecular weight compounds can contribute to a general knowledge about calcium bioavailability and also to product improvement. Calcium precipitation with palmitate was described by a first-order reaction for conditions...... of excess calcium in neutral aqueous solutions with a stoichiometry Ca:Pal lower than 1:2. Increasing pH during aging of the precipitate and solubility product determination lead to a suggestion of an initial precipitation of calcium hydroxy palmitate as a possible precursor phase. The binding of calcium...

  2. Effects of Exterior Abscisic Acid on Calcium Distribution of Mesophyll Cells and Calcium Concentration of Guard Cells in Maize Seedlings

    Institute of Scientific and Technical Information of China (English)

    GUO Xiu-lin; MA Yuan-yuan; LIU Zi-hui; LIU Bin-hui

    2008-01-01

    In this study, the direct effects of exterior abscisic acid (ABA) on both calcium distribution of mesophyll cells and cytosolic calcium concentration of guard cells were examined. The distribution of Ca2+ localization were observed with calcium antimonate precipitate-electromicroscopic-cyto-chemical methods after treated with ABA and pretreated with ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA), verapamil (Vp), and trifluoperazine (TFP). The laser scanning confocal microscopy was used to measure the cytosolic calcium concentrations of guard cells under different treatments. The results showed that the cytosolic Ca2+ concentration of mesophyll cells was induced to increase by ABA, but to decrease in both outside cell and the vacuoles within 10 min after treatments. The cytosolic calcium concentration of guard cells was increased gradually with the lag in treatment time. However, both EGTA and TFP could inverse those effects, indicating that the increase of cytosolic calcium induced by exterior ABA was mainly caused by calcium influx. The results also showed that calmodulin could influence both the calcium distribution of mesophyll cells and calcium concentration of guard cells. It shows that calmodulin participates in the process of ABA signal transduction, but the mechanism is not known as yet. The changes both calcium distribution of mesophyll cells and calcium concentration of guard cells further proved that the variations of cytosolic Ca2+ concentration induced by ABA were involved in the stomatal movements of maize seedlings.

  3. Performance and upgrade plans of the LHCb trigger system

    Science.gov (United States)

    Gligorov, V. V.; LHCb Collaboration

    2013-08-01

    The trigger of the LHCb experiment consists of two stages: an initial hardware trigger, and a high-level trigger implemented in a farm of parallel-processing CPUs. It reduces the event rate from an input of 15 MHz to an output rate of around 4 kHz. In order to maximize efficiencies and minimize biases, the trigger is designed around inclusive selection algorithms, culminating in a novel boosted decision tree which enables the efficient selection of beauty hadron decays based on a robust partial reconstruction of their decay products. In order to improve performance, the LHCb upgrade aims to significantly increase the rate at which the detector will be read out, and hence shift more of the workload onto the high-level trigger. It is demonstrated that the current high-level trigger architecture will be able to meet this challenge, and the expected efficiencies in several key channels are discussed in context of the LHCb upgrade.

  4. The upgrade of the ATLAS first-level calorimeter trigger

    Science.gov (United States)

    Yamamoto, Shimpei

    2016-07-01

    The first-level calorimeter trigger (L1Calo) had operated successfully through the first data taking phase of the ATLAS experiment at the CERN Large Hadron Collider. Towards forthcoming LHC runs, a series of upgrades is planned for L1Calo to face new challenges posed by the upcoming increases of the beam energy and the luminosity. This paper reviews the ATLAS L1Calo trigger upgrade project that introduces new architectures for the liquid-argon calorimeter trigger readout and the L1Calo trigger processing system.

  5. Effect of combining different calcium concentration dialysate on calcium balance in peritoneal dialysis patients

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hui-ping; WU Bei; LU Li-xia; QIAO Jie; WU Xiang-lan; WANG Mei

    2012-01-01

    Background Calcium and phosphorus metabolic disturbance are common in dialysis patients and associated with increased morbidity and mortality.Therefore,maintaining the balance of calcium and phosphate metabolism and suitable intact parathyroid hormone(iPTH)level has become the focus of attention.We investigated the effects of different peritoneal dialysate calcium concentrations on calcium phosphate metabolism and iPTH in continuous ambulatory peritoneal dialysis(CAPD)patients.Methods Forty stable CAPD patients with normal serum calcium were followed for six months of treatment with 1.25 mmol/L calcium dialysate(DCa1.25,PD4,22 patients)or a combination of 1.75 mmol/L calcium dialysate(DCa1.75,PD2)and PD4(18 patients)twice a day respectively.Total serum calcium(after albumin correction),serum phosphorus,iPTH,alkaline phosphatase(ALP)and blood pressure were recorded before and 1,3 and 6 months after treatment commenced.Results No significant difference was found in baseline serum calcium,phosphorus between the two patient groups,but the levels of iPTH were significantly different.No significant changes were found in the dosage of calcium carbonate and active vitamin D during 6 months.In the PD4 group,serum calcium level at the 1st,3rd,6th months were significantly lower than the baseline(P<0.05).There was no significant difference in serum phosphorus after 6 months treatment.iPTH was significantly higher(P<0.001)at the 1st,3rd,and 6th months compared with the baseline.No differences were seen in ALP and blood pressure.In the PD4+PD2 group,no significant changes in serum calcium,phosphorus,iPTH,ALP and BP during the 6-month follow-up period.Conclusions Treatment with 1.25 mmol/L calcium dialysate for six months can decrease serum calcium,increase iPTH,without change in serum phosphorus,ALP,and BP.The combining of PD4 and PD2 can stabilize the serum calcium and avoid fluctuations in iPTH levels.

  6. Minimum Bias Trigger in ATLAS

    International Nuclear Information System (INIS)

    Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.2 < |η| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presented. We also highlight the advantage of these triggers for particle correlation analyses. (author)

  7. Histopathology of tenosynovium in trigger fingers.

    Science.gov (United States)

    Uchihashi, Kazuyoshi; Tsuruta, Toshiyuki; Mine, Hiroko; Aoki, Shigehisa; Nishijima-Matsunobu, Aki; Yamamoto, Mihoko; Kuraoka, Akio; Toda, Shuji

    2014-06-01

    Stenosing flexor tenosynovitis, trigger finger, is a common clinical disorder causing painful locking or contracture of the involved digits, and most instances are idiopathic. This problem is generally caused by a size mismatch between the swollen flexor tendon and the thickened first annular pulley. Although hypertrophic pulleys have been histologically and ultrasonographically detected, little is known about the histopathology of the tenosynovium covering the tendons of trigger fingers. We identified chondrocytoid cells that produced hyaluronic acid in 23 (61%) fingers and hypocellular collagen matrix in 32 (84%) fingers around the tenosynovium among 38 specimens of tenosynovium from patients with trigger fingers. These chondrocytoid cells expressed the synovial B cell marker CD44, but not the chondrocyte marker S-100 protein. The incidence of these findings was much higher than that of conventional findings of synovitis, such as inflammatory infiltrate (37%), increased vascularity (37%), hyperplasia of synovial lining cells (21%), or fibrin exudation (5%). We discovered the following distinctive histopathological features of trigger finger: hyaluronic acid-producing chondrocytoid cells originated from fibroblastic synovial B cells, and a hypocellular collagen matrix surrounding the tenosynovium. Thus, an edematous extracellular matrix with active hyaluronic acid synthesis might increase pressure under the pulley and contribute to the progression of stenosis. PMID:24965110

  8. Myofacial trigger points in advanced cancer patients

    Directory of Open Access Journals (Sweden)

    Hideaki Hasuo

    2016-01-01

    Full Text Available Myofascial pain syndrome is started to be recognized as one of important factors of pain in cancer patients. However, no reports on features of myofascial trigger points were found in terminally-ill cancer populations. This time, we encountered 5 patients with myofascial pain syndrome and terminal cancer in whom delirium developed due to increased doses of opioid without a diagnosis of myofascial pain syndrome on initial presentation. The delirium subsided with dose reductions of opioid and treatment of myofascial pain syndrome. The common reason for a delayed diagnosis among the patients included an incomplete palpation of the painful sites, which led to unsuccessful myofascial trigger points identification. The features of myofascial trigger points included single onset in the cancer pain management site with opioid and the contralateral abdominal side muscles of the non-common sites. Withdrawal reflexes associated with cancer pain in the supine position, which are increasingly seen in the terminal cancer patients, were considered to have contributed to this siuation.We consider that careful palpation of the painful site is important, in order to obtain greater knowledge and understanding of the features of myofascial trigger points.

  9. Performance of the CMS High Level Trigger

    CERN Document Server

    Perrotta, Andrea

    2015-01-01

    The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increases in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. The increase in the number of interactions per bunch crossing, on average 25 in 2012, and expected to be around 40 in Run II, will be an additional complication. We present here the expected performance of the main triggers that will be used during the 2015 data taking campaign, paying particular attention to the new approaches that have been developed to cope with the challenges of the new run. This includes improvements in HLT electron and photon reconstruction as well as better performing muon triggers. We will also present the performance of the improved trac...

  10. GnRH agonist triggering

    DEFF Research Database (Denmark)

    Kol, Shahar; Humaidan, Peter; Al Humaidan, Peter Samir Heskjær

    2013-01-01

    The concept that a bolus of gonadotrophin-releasing hormone agonist (GnRHa) can replace human chorionic gonadotrophin (HCG) as a trigger of final oocyte maturation was introduced several years ago. Recent developments in the area strengthen this premise. GnRHa trigger offers important advantages...... triggering concept should be challenged and that the GnRHa trigger is the way to move forward with thoughtful consideration of the needs, safety and comfort of our patients. Routinely, human chorionic gonadotrophin (HCG) is used to induce ovulation in fertility treatments. This approach deviates...... significantly from physiology and often results in insufficient hormonal support in early pregnancy and in ovarian hyperstimulation syndrome (OHSS). An alternative approach is to use a gonadotrophin-releasing hormone (GnRH) agonist which allows a more physiological trigger of ovulation and, most importantly...

  11. Triggering requirements for SSC physics

    Energy Technology Data Exchange (ETDEWEB)

    Gilchriese, M.G.D. [Lawrence Berkeley Lab., CA (United States)

    1989-04-01

    Some aspects of triggering requirements for high P{sub T} physics processes at the Superconducting Super Collider (SSC) are described. A very wide range of trigger types will be required to enable detection of the large number of potential physics signatures possible at the SSC. Although in many cases trigger rates are not now well understood, it is possible to conclude that the ability to trigger on transverse energy, number and energy of jets, number and energy of leptons (electrons and muons), missing energy and combinations of these will be required. An SSC trigger system must be both highly flexible and redundant to ensure reliable detection of many new physics processes at the SSC.

  12. CDF trigger interface board 'FRED'

    International Nuclear Information System (INIS)

    We describe FASTBUS boards which interface sixteen different trigger interrupts to the Collider Detector Facility (CDF) data acquisition system. The boards are known to CDF by the acronym 'FRED'. The data acquisition scheme for CDF allows for up to 16 different parts of the detector, called 'Partitions', to run independently. Four partitions are reserved for physics runs and sophisticated calibration and debugging: they use the common Level 1 and Level 2 trigger logic and have access to information from all the components of the CDF detector. These four partitions are called ''CDF Partitions''. The remaining twelve partitions have no access to the common trigger logic and provide their own Level 1 and Level 2 signals: they are called ''Autonomous Partitions''. Fred collects and interprets signals from independent parts of the CDF trigger system and delivers Level 1 and Level 2 responses to the Trigger Supervisors (FASTBUS masters which control the data acquisition process in each partition)

  13. The ATLAS Hadronic Tau Trigger

    CERN Document Server

    Mahlstedt, J; The ATLAS collaboration

    2014-01-01

    During the 2012 run the Large Hadron Collider (LHC) reached instantaneous luminosities of nearly $10^{34}\\,cm^{-2}s^{-1}$, with bunch crossings occuring every 50 ns. In this difficult environment of several overlapping interactions per bunch crossing (pile-up) the trigger system of the ATLAS detector has the task of reducing the event rate from 40 MHz to a few hundred Hz while keeping the most interesting physics events. Being the heaviest of all leptons, the tau lepton plays an important role in many physics processes. The ability to trigger on events containing hadronically decaying taus is therefore of special interest. This paper summarizes the concept of the ATLAS tau trigger and the improvements made in 2012. Furthermore the performance of the triggers including efficiency and rate measurements are presented and an outlook towards future developments of the tau trigger algorithms is given.

  14. Calcium signals and calcium channels in osteoblastic cells

    Science.gov (United States)

    Duncan, R. L.; Akanbi, K. A.; Farach-Carson, M. C.

    1998-01-01

    Calcium (Ca2+) channels are present in non-excitable as well as in excitable cells. In bone cells of the osteoblast lineage, Ca2+ channels play fundamental roles in cellular responses to external stimuli including both mechanical forces and hormonal signals. They are also proposed to modulate paracrine signaling between bone-forming osteoblasts and bone-resorbing osteoclasts at local sites of bone remodeling. Calcium signals are characterized by transient increases in intracellular Ca2+ levels that are associated with activation of intracellular signaling pathways that control cell behavior and phenotype, including patterns of gene expression. Development of Ca2+ signals is a tightly regulated cellular process that involves the concerted actions of plasma membrane and intracellular Ca2+ channels, along with Ca2+ pumps and exchangers. This review summarizes the current state of knowledge concerning the structure, function, and role of Ca2+ channels and Ca2+ signals in bone cells, focusing on the osteoblast.

  15. Exocrine pancreatic enzyme and calcium secretion in health and pancreatitis.

    OpenAIRE

    Clain, J E; Barbezat, G O; Marks, I N

    1981-01-01

    Calcium, enzyme, and total protein secretion were measured in secretin stimulated pancreatic juice in health, "early" chronic pancreatitis, and in chronic calcific pancreatitis. Increased concentrations of trypsin, total protein, and calcium, and increased outputs of calcium and protein were shown to be present in the "early" stages of the disease, indicating that an environment conducive to the formation of protein plugs and possibly later calcification already exists.

  16. Should We Prescribe Calcium Supplements For Osteoporosis Prevention?

    OpenAIRE

    Reid, Ian R

    2014-01-01

    Advocacy for the use of calcium supplements arose at a time when there were no other effective interventions for the prevention of osteoporosis. Their promotion was based on the belief that increasing calcium intake would increase bone formation. Our current understandings of the biology of bone suggest that this does not occur, though calcium does act as a weak antiresorptive. Thus, it slows postmenopausal bone loss but, despite this, recent meta-analyses suggest no significant prevention of...

  17. Auranofin, an Anti-Rheumatic Gold Compound, Modulates Apoptosis by Elevating the Intracellular Calcium Concentration ([Ca2+]i in MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Elizabeth Varghese

    2014-11-01

    Full Text Available Auranofin, a transition metal complex is used for the treatment of rheumatoid arthritis but is also an effective anti-cancer drug. We investigate the effects of Auranofin in inducing cell death by apoptosis and whether these changes are correlated to changes of intracellular calcium concentration ([Ca2+]i in breast cancer cells (MCF-7. Cytotoxicity of Auranofin was evaluated using MTS assay and the Trypan blue dye exclusion method. With fluorescent dyes SR-FLICA and 7-AAD apoptotic death and necrotic death were differentiated by Flow cytometry. A concentration dependent decrease in the viability occurred and cells were shifted to the apoptotic phase. Intracellular calcium ([Ca2+]i was recorded using florescence microscopy and a calcium sensitive dye (Fluo-4 AM with a strong negative correlation (r = −0.713 to viability. Pharmacological modulators 2-APB (50 μM, Nimodipine (10 μM, Caffeine (10 mM, SKF 96365(20 μM were used to modify calcium entry and release. Auranofin induced a sustained increase of [Ca2+]i in a concentration and time dependent manner. The use of different blockers of calcium channels did not reveal the source for the rise of [Ca2+]i. Overall, elevation of [Ca2+]i by Auranofin might be crucial for triggering Ca2+-dependent apoptotic pathways. Therefore, in anti-cancer therapy, modulating [Ca2+]i should be considered as a crucial factor for the induction of cell death in cancer cells.

  18. A Multiplexed Fluorescent Calcium and NFAT Reporter Gene Assay to Identify GPCR Agonists

    OpenAIRE

    Sheth, Heeral; Gorey, Colleen; Roush, Nicole; Smallman, Shelly; Collantes, Elizabeth; Santoro, Maxine; Olson, Barbara; Fitzgerald, Laura; Paul H. Lee; Shen, Xiqiang John

    2013-01-01

    Intracellular calcium response and resulting calcium signaling to an agonist-GPCR interaction are important for the measurement of compound activity in the GPCR drug development. The increase in cytosol calcium concentration can be measured by the fluorescent calcium indicator dye such as Fluo-4 in a quick assay (in 3-5 minutes) using the fluorescence imaging plate reader. The calcium signaling through the transcription factors such as NFAT that induces gene expression can be measured by the ...

  19. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Maeda, Junpei; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software based high-level trigger that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the data-taking period of Run-2 the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. In these proceedings, we briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the Level-1 calorimeter and muon trigger system, the introduction of a new Level-1 topological trigger module and themerging of the previously two-level higher-level trigger system into a single even...

  20. Recording of calcium transient and analysis of calcium removal mechanisms in cardiac myocytes from rats and ground squirrels

    Institute of Scientific and Technical Information of China (English)

    王世强; 周曾铨; 钱洪

    2000-01-01

    With confocal microscopy, we recorded calcium transients and analyzed calcium removal rate at different temperatures in cardiac myocytes from the rat, a non-hibernator, and the ground squirrel, a hibernator. The results showed a remarkable increase of the diastolic level of calcium transients in the rat but no detectable change in the ground squirrel. Calcium transient of the ground squirrel, compared with that of the rat at the same temperature, had a shorter duration and showed a faster calcium removal. As indicated by the pharmacological effect of cyclopiazonic acid, calcium uptake by sarcoplasmic reticulum (SR) was the major mechanism of calcium removal, and was faster in the ground squirrel than in the rat. Our results confirmed the essential role of SR in hypothermia-tolerant adaptation, and negated the importance of Na-Ca exchange. We postulated the possibility to improve hypothermia-tolerance of the cardiac tissue of non-hibernating mammals.

  1. Astrocyte calcium signaling: the third wave.

    Science.gov (United States)

    Bazargani, Narges; Attwell, David

    2016-02-01

    The discovery that transient elevations of calcium concentration occur in astrocytes, and release 'gliotransmitters' which act on neurons and vascular smooth muscle, led to the idea that astrocytes are powerful regulators of neuronal spiking, synaptic plasticity and brain blood flow. These findings were challenged by a second wave of reports that astrocyte calcium transients did not mediate functions attributed to gliotransmitters and were too slow to generate blood flow increases. Remarkably, the tide has now turned again: the most important calcium transients occur in fine astrocyte processes not resolved in earlier studies, and new mechanisms have been discovered by which astrocyte [Ca(2+)]i is raised and exerts its effects. Here we review how this third wave of discoveries has changed our understanding of astrocyte calcium signaling and its consequences for neuronal function.

  2. Discrete stochastic modeling of calcium channel dynamics

    CERN Document Server

    Baer, M E; Levine, H; Tsimring, L S; Baer, Markus; Falcke, Martin; Levine, Herbert; Tsimring, Lev S.

    1999-01-01

    We propose a simple discrete stochastic model for calcium dynamics in living cells. Specifically, the calcium concentration distribution is assumed to give rise to a set of probabilities for the opening/closing of channels which release calcium thereby changing those probabilities. We study this model in one dimension, analytically in the mean-field limit of large number of channels per site N, and numerically for small N. As the number of channels per site is increased, the transition from a non-propagating region of activity to a propagating one changes in nature from one described by directed percolation to that of deterministic depinning in a spatially discrete system. Also, for a small number of channels a propagating calcium wave can leave behind a novel fluctuation-driven state, in a parameter range where the limiting deterministic model exhibits only single pulse propagation.

  3. Discrete Stochastic Modeling of Calcium Channel Dynamics

    International Nuclear Information System (INIS)

    We propose a discrete stochastic model for calcium dynamics in living cells. A set of probabilities for the opening/closing of calcium channels is assumed to depend on the calcium concentration. We study this model in one dimension, analytically in the limit of a large number of channels per site N , and numerically for small N . As the number of channels per site is increased, the transition from a nonpropagating region of activity to a propagating one changes from one described by directed percolation to that of deterministic depinning in a spatially discrete system. Also, for a small number of channels a propagating calcium wave can leave behind a novel fluctuation-driven state. (c) 2000 The American Physical Society

  4. Disaster triggers disaster: Earthquake triggering by tropical cyclones

    Science.gov (United States)

    Wdowinski, S.; Tsukanov, I.

    2011-12-01

    Three recent devastating earthquakes, the 1999 M=7.6 Chi-Chi (Taiwan), 2010 M=7.0 Leogane (Haiti), 2010 M=6.4 Kaohsiung (Taiwan), and additional three moderate size earthquakes (6hurricane or typhoon) hit the very same area. The most familiar example is Haiti, which was hit during the late summer of 2008 by two hurricanes and two tropical storms (Fay, Gustav, Hanna and Ike) within 25 days. A year an a half after this very wet hurricane season, the 2010 Leogane earthquake occurred in the mountainous Haiti's southern peninsula and caused the death of more than 300,000 people. The other cases are from Taiwan, which is characterized by a high seismicity level and frequent typhoon landfall. The three wettest typhoons in Taiwan's past 50 years were Morakot (in 2009, with 2885 mm or rain), Flossie (1969, 2162 mm) and Herb (1996, 1987 mm)[Lin et al., 2010]. Each of this three very wet storms was followed by one or two main-shock M>6 earthquake that occurred in the central mountainous area of Taiwan within three years after the typhoon. The 2009 Morakot typhoon was followed by 2009 M=6.2 Nantou and 2010 M=6.4 Kaohsiung earthquakes; the 1969 Flossie typhoon was followed by an M=6.3 earthquake in 1972; and the 1996 Herb typhoon by the 1998 M=6.2 Rueyli and 1999 M=7.6 Chi-Chi earthquakes. The earthquake catalog of Taiwan lists only two other M>6 main-shocks that occurred in Taiwan's central mountainous belt, one of them was in 1964 only four months after the wet Typhoon Gloria poured heavy rain in the same area. We suggest that the close proximity in time and space between wet tropical cyclones and earthquakes reflects a physical link between the two hazard types in which these earthquakes were triggered by rapid erosion induced by tropical cyclone's heavy rain. Based on remote sensing observations, meshfree finite element modeling, and Coulomb failure stress analysis, we show that the erosion induced by very wet cyclones increased the failure stresses at the hypocenters

  5. Bacillus thuringiensis Crystal Protein Cry6Aa Triggers Caenorhabditis elegans Necrosis Pathway Mediated by Aspartic Protease (ASP-1)

    Science.gov (United States)

    Zhang, Fengjuan; Peng, Donghai; Cheng, Chunsheng; Zhou, Wei; Ju, Shouyong; Wan, Danfeng; Yu, Ziquan; Shi, Jianwei; Deng, Yaoyao; Wang, Fenshan; Ye, Xiaobo; Hu, Zhenfei; Lin, Jian; Ruan, Lifang; Sun, Ming

    2016-01-01

    Cell death plays an important role in host-pathogen interactions. Crystal proteins (toxins) are essential components of Bacillus thuringiensis (Bt) biological pesticides because of their specific toxicity against insects and nematodes. However, the mode of action by which crystal toxins to induce cell death is not completely understood. Here we show that crystal toxin triggers cell death by necrosis signaling pathway using crystal toxin Cry6Aa-Caenorhabditis elegans toxin-host interaction system, which involves an increase in concentrations of cytoplasmic calcium, lysosomal lyses, uptake of propidium iodide, and burst of death fluorescence. We find that a deficiency in the necrosis pathway confers tolerance to Cry6Aa toxin. Intriguingly, the necrosis pathway is specifically triggered by Cry6Aa, not by Cry5Ba, whose amino acid sequence is different from that of Cry6Aa. Furthermore, Cry6Aa-induced necrosis pathway requires aspartic protease (ASP-1). In addition, ASP-1 protects Cry6Aa from over-degradation in C. elegans. This is the first demonstration that deficiency in necrosis pathway confers tolerance to Bt crystal protein, and that Cry6A triggers necrosis represents a newly added necrosis paradigm in the C. elegans. Understanding this model could lead to new strategies for nematode control. PMID:26795495

  6. Bacillus thuringiensis Crystal Protein Cry6Aa Triggers Caenorhabditis elegans Necrosis Pathway Mediated by Aspartic Protease (ASP-1.

    Directory of Open Access Journals (Sweden)

    Fengjuan Zhang

    2016-01-01

    Full Text Available Cell death plays an important role in host-pathogen interactions. Crystal proteins (toxins are essential components of Bacillus thuringiensis (Bt biological pesticides because of their specific toxicity against insects and nematodes. However, the mode of action by which crystal toxins to induce cell death is not completely understood. Here we show that crystal toxin triggers cell death by necrosis signaling pathway using crystal toxin Cry6Aa-Caenorhabditis elegans toxin-host interaction system, which involves an increase in concentrations of cytoplasmic calcium, lysosomal lyses, uptake of propidium iodide, and burst of death fluorescence. We find that a deficiency in the necrosis pathway confers tolerance to Cry6Aa toxin. Intriguingly, the necrosis pathway is specifically triggered by Cry6Aa, not by Cry5Ba, whose amino acid sequence is different from that of Cry6Aa. Furthermore, Cry6Aa-induced necrosis pathway requires aspartic protease (ASP-1. In addition, ASP-1 protects Cry6Aa from over-degradation in C. elegans. This is the first demonstration that deficiency in necrosis pathway confers tolerance to Bt crystal protein, and that Cry6A triggers necrosis represents a newly added necrosis paradigm in the C. elegans. Understanding this model could lead to new strategies for nematode control.

  7. Triggered Release from Polymer Capsules

    Energy Technology Data Exchange (ETDEWEB)

    Esser-Kahn, Aaron P. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Odom, Susan A. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry; Sottos, Nancy R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Materials Science and Engineering; White, Scott R. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Aerospace Engineering; Moore, Jeffrey S. [Univ. of Illinois, Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology and Dept. of Chemistry

    2011-07-06

    Stimuli-responsive capsules are of interest in drug delivery, fragrance release, food preservation, and self-healing materials. Many methods are used to trigger the release of encapsulated contents. Here we highlight mechanisms for the controlled release of encapsulated cargo that utilize chemical reactions occurring in solid polymeric shell walls. Triggering mechanisms responsible for covalent bond cleavage that result in the release of capsule contents include chemical, biological, light, thermal, magnetic, and electrical stimuli. We present methods for encapsulation and release, triggering methods, and mechanisms and conclude with our opinions on interesting obstacles for chemically induced activation with relevance for controlled release.

  8. Characteristics of plant calcium fractions for 25 species in Tengger Desert

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Little attention has been paid to plant calcium fractions in the desert.To address the characteristic of the calcium fractions of desert plants,we collected 25 plant species in Tengger Desert,observed the calcium crystals using an optical microscope and determined water soluble calcium,acetic acid soluble calcium,and hydrochloric acid soluble calcium.To do so,we used sequential fractionation procedures to probe the relationships among different functional groups,different growth forms,or different successional stages.The results showed that the psammophyte,the late successional plants,and the drought-resistant shrub and semi-shrub all held considerable calcium oxalate crystal compared to the grassland plants,the early successional plants,and the perennial herb.With the proceeding succession,the acetic acid soluble calcium decreased gradually,and the hydrochloric acid soluble calcium increased gradually.The perennial herb had more water soluble calcium,while shrub held greater hydrochloric acid soluble calcium.The grassland plants held more water soluble calcium,while psammophyte had greater hydrochloric acid soluble calcium.This implies that the plants that are relatively sensitive to drought hold more calcium ion,while the drought-resistance plants hold more calcium oxalate.Thus,the plant calcium components are in close relation to plant drought-resistance,and of important significance in plant physiology of the desert.

  9. Effect of calcium on moving-bed biofilm reactor biofilms.

    Science.gov (United States)

    Goode, C; Allen, D G

    2011-03-01

    The effect of calcium concentration on the biofilm structure, microbiology, and treatment performance was evaluated in a moving-bed biofilm reactor. Three experiments were conducted in replicate laboratory-scale reactors to determine if wastewater calcium is an important variable for the design and optimization of these reactors. Biofilm structural properties, such as thickness, oxygen microprofiles, and the composition of extracellular polymeric substances (EPS) were affected by increasing calcium concentrations. Above a threshold concentration of calcium between 1 and 50 mg/L, biofilms became thicker and denser, with a shift toward increasingly proteinaceous EPS at higher calcium concentrations up to 200 mgCa2+/L. At 300 mgCa2+/L, biofilms were found to become primarily composed of inorganic calcium precipitates. Microbiology was assessed through microscopy, denaturing grade gel electrophoresis, and enumeration of higher organisms. Higher calcium concentrations were found to change the bacterial community and promote the abundant growth of filamentous organisms and various protazoa and metazoan populations. The chemical oxygen demand removal efficiency was improved for reactors at calcium concentrations of 50 mg/L and above. Reactor effluents for the lowest calcium concentration (1 mgCa2+/L) were found to be turbid (>50 NTU), as a result of the detachment of small and poorly settling planktonic biomass, whereas higher concentrations promoted settling of the suspended phase. In general, calcium was found to be an important variable causing significant changes in biofilm structure and reactor function.

  10. Activation of protein kinase Ceta triggers cortical granule exocytosis in Xenopus oocytes.

    Science.gov (United States)

    Gundersen, Cameron B; Kohan, Sirus A; Chen, Qian; Iagnemma, Joseph; Umbach, Joy A

    2002-03-15

    Previous work has shown that phorbol esters or diacylglycerol trigger cortical granule exocytosis in Xenopus oocytes. We sought to identify the isoform(s) of protein kinase C (PKC) that mediate(s) this regulated secretory event. Because this process is initiated by lipid activators of PKC but is independent of calcium ions, we focused on the family of novel (calcium-independent) PKCs. Pharmacological investigations using Gö6976 and Gö6983 tended to exclude PKCdelta, epsilon and mu as secretory triggers. Subcellular fractionation and immunoblot data revealed that these oocytes expressed all five members of the novel PKC family, but it was only PKCeta that colocalized with cortical granules. Finally, expression of wild type or constitutively active forms of PKCdelta and eta strongly supported the conclusion that it is PKCeta that initiates cortical granule exocytosis in these cells. These observations represent an important step in identifying the mechanism of secretory triggering in this system. PMID:11884530

  11. Resource Utilization by the ATLAS High Level Trigger during 2010 and 2011 LHC running

    Science.gov (United States)

    Lipeles, Elliot; Ospanov, Rustem; Schaefer, Doug

    2012-12-01

    Since starting in 2010, the Large Hadron Collider (LHC) has produced collisions at an ever increasing rate. The ATLAS experiment successfully recorded the collision data with high efficiency and excellent data quality. Events were selected using a three-level trigger system, where each level made a more refined selection. The Level 1 (L1) trigger consisted of a custom-designed hardware trigger which seeded two higher software based trigger levels. Over 300 triggers composed a trigger menu which selected physics signatures such as electrons, muons, particle jets, etc. Each trigger consumed computing resources of the ATLAS Trigger system and offline storage. The LHC instantaneous luminosity conditions, desired physics goals of the collaboration, and the limits of the trigger infrastructure determined the composition of the ATLAS Trigger menu. We describe a trigger monitoring framework called the Cost Monitoring Framework for computing the costs of individual trigger algorithms such as data request rates and CPU consumption. This framework was used to prepare the ATLAS Trigger for data taking during increases of more than six orders of magnitude in the LHC luminosity and has been influential in guiding ATLAS Trigger computing upgrades.

  12. Differential Dendritic Integration of Synaptic Potentials and Calcium in Cerebellar Interneurons.

    Science.gov (United States)

    Tran-Van-Minh, Alexandra; Abrahamsson, Therése; Cathala, Laurence; DiGregorio, David A

    2016-08-17

    Dendritic voltage integration determines the transformation of synaptic inputs into output firing, while synaptic calcium integration drives plasticity mechanisms thought to underlie memory storage. Dendritic calcium integration has been shown to follow the same synaptic input-output relationship as dendritic voltage, but whether similar operations apply to neurons exhibiting sublinear voltage integration is unknown. We examined the properties and cellular mechanisms of these dendritic operations in cerebellar molecular layer interneurons using dendritic voltage and calcium imaging, in combination with synaptic stimulation or glutamate uncaging. We show that, while synaptic potentials summate sublinearly, concomitant dendritic calcium signals summate either linearly or supralinearly depending on the number of synapses activated. The supralinear dendritic calcium triggers a branch-specific, short-term suppression of neurotransmitter release that alters the pattern of synaptic activation. Thus, differential voltage and calcium integration permits dynamic regulation of neuronal input-output transformations without altering intrinsic nonlinear integration mechanisms.

  13. Differential Dendritic Integration of Synaptic Potentials and Calcium in Cerebellar Interneurons.

    Science.gov (United States)

    Tran-Van-Minh, Alexandra; Abrahamsson, Therése; Cathala, Laurence; DiGregorio, David A

    2016-08-17

    Dendritic voltage integration determines the transformation of synaptic inputs into output firing, while synaptic calcium integration drives plasticity mechanisms thought to underlie memory storage. Dendritic calcium integration has been shown to follow the same synaptic input-output relationship as dendritic voltage, but whether similar operations apply to neurons exhibiting sublinear voltage integration is unknown. We examined the properties and cellular mechanisms of these dendritic operations in cerebellar molecular layer interneurons using dendritic voltage and calcium imaging, in combination with synaptic stimulation or glutamate uncaging. We show that, while synaptic potentials summate sublinearly, concomitant dendritic calcium signals summate either linearly or supralinearly depending on the number of synapses activated. The supralinear dendritic calcium triggers a branch-specific, short-term suppression of neurotransmitter release that alters the pattern of synaptic activation. Thus, differential voltage and calcium integration permits dynamic regulation of neuronal input-output transformations without altering intrinsic nonlinear integration mechanisms. PMID:27537486

  14. Variability of calcium absorption

    International Nuclear Information System (INIS)

    Variability in calcium absorption was estimated in three groups of normal subjects in whom Ca absorption was measured by standard isotopic-tracer methods at interstudy intervals ranging from 1 to 4 mo. Fifty absorption tests were performed in 22 subjects. Each was done in the morning after an overnight fast with an identical standard breakfast containing a Ca load of approximately 250 mg. Individual fractional absorption values were normalized to permit pooling of the data. The coefficient of variation (CVs) for absorption for the three groups ranged from 10.57 to 12.79% with the size of the CV increasing with interstudy duration. One other published study presenting replicate absorption values was analyzed in a similar fashion and was found to have a CV of absorption of 9.78%. From these data we estimate that when the standard double-isotope method is used to measure Ca absorption there is approximately 10% variability around any given absorption value within an individual human subject and that roughly two-thirds of this represents real biological variability in absorption

  15. Intracellular calcium ions as regulators of renal tubular sodium transport.

    Science.gov (United States)

    Windhager, E; Frindt, G; Yang, J M; Lee, C O

    1986-09-15

    This review addresses the putative role of intracellular calcium ions in the regulation of sodium transport by renal tubules. Cytoplasmic calcium-ion activities in proximal tubules of Necturus are less than 10(-7) M and can be increased by lowering the electrochemical potential gradient for sodium ions across the peritubular cell membrane, or by addition of quinidine or ionomycin to peritubular fluid. Whereas lowering of the peritubular Na concentration increases cytosolic [Ca++] and [H+], ionomycin, a calcium ionophore, raises intracellular [Ca++] without decreasing pHi. The intracellular calcium-ion level is maintained by transport processes in the plasma membrane and membranes of intracellular organelles, as well as by calcium-binding proteins. Calcium ions inhibit net transport of sodium by reducing the rate of sodium entry across the luminal cell membrane. In the collecting tubule this inhibition is caused, at least in part, by an indirect reduction in the activity of the amiloride-sensitive sodium channel. PMID:2430134

  16. FERMIGTRIG - Fermi GBM Trigger Catalog

    Data.gov (United States)

    National Aeronautics and Space Administration — This table lists all of the triggers observed by one or more of the 14 GBM detectors (12 NaI and 2 BGO). Note that there are two Browse catalogs resulting from GBM...

  17. The relationship between calcium and the metabolism of plasma membrane phospholipids in hemolysis induced by brown spider venom phospholipase-D toxin.

    Science.gov (United States)

    Chaves-Moreira, Daniele; Souza, Fernanda N; Fogaça, Rosalvo T H; Mangili, Oldemir C; Gremski, Waldemiro; Senff-Ribeiro, Andrea; Chaim, Olga M; Veiga, Silvio S

    2011-09-01

    Brown spider venom phospholipase-D belongs to a family of toxins characterized as potent bioactive agents. These toxins have been involved in numerous aspects of cell pathophysiology including inflammatory response, platelet aggregation, endothelial cell hyperactivation, renal disorders, and hemolysis. The molecular mechanism by which these toxins cause hemolysis is under investigation; literature data have suggested that enzyme catalysis is necessary for the biological activities triggered by the toxin. However, the way by which phospholipase-D activity is directly related with human hemolysis has not been determined. To evaluate how brown spider venom phospholipase-D activity causes hemolysis, we examined the impact of recombinant phospholipase-D on human red blood cells. Using six different purified recombinant phospholipase-D molecules obtained from a cDNA venom gland library, we demonstrated that there is a correlation of hemolytic effect and phospholipase-D activity. Studying recombinant phospholipase-D, a potent hemolytic and phospholipase-D recombinant toxin (LiRecDT1), we determined that the toxin degrades synthetic sphingomyelin (SM), lysophosphatidylcholine (LPC), and lyso-platelet-activating factor. Additionally, we determined that the toxin degrades phospholipids in a detergent extract of human erythrocytes, as well as phospholipids from ghosts of human red blood cells. The products of the degradation of synthetic SM and LPC following recombinant phospholipase-D treatments caused hemolysis of human erythrocytes. This hemolysis, dependent on products of metabolism of phospholipids, is also dependent on calcium ion concentration because the percentage of hemolysis increased with an increase in the dose of calcium in the medium. Recombinant phospholipase-D treatment of human erythrocytes stimulated an influx of calcium into the cells that was detected by a calcium-sensitive fluorescent probe (Fluo-4). This calcium influx was shown to be channel

  18. Triggering tradeoffs for recording dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, R.P.; Laios, B.B.

    1997-04-01

    Dynamics recording devices (DRD) that monitor and record the transient or dynamic response of power systems are installed across power systems. DRDs that have been installed in the last decade have increasingly used digital computer implementation; these include digital relays, digital fault recorders, integrated electronic controls for substation automation, and many digitally implemented controls such as excitation system controls and stabilizers. The system dynamics of interest generally lie in the frequency range below 5 Hz and may require recordings up to 2 to 5 minutes. This timeframe includes the times for transient instability, oscillatory instability, and governing responses, as well as the initial responses of secondary controls including power plant controls and automatic generation control (AGC). In some applications, the frequency range may be greater for monitoring the faster dynamics associated with flexible alternating current transmission system (FACTS) devices and subsynchronous oscillatory interactions. Recordings from DRDs are used for event reconstruction, review of the action of control and protection systems, and detection of unexpected dynamics within the power system. In recent years, DRDs have been recognized as viable options for data to be used in control functions, including those associated with FACTS devices. DRDs and monitoring systems need triggering algorithms and settings that dependably and securely detect unusual events in the presence of normal power system events such as switching, customer load changes, and other routine operations. This article describes how to address these needs.

  19. Should we prescribe calcium supplements for osteoporosis prevention?

    Science.gov (United States)

    Reid, Ian R

    2014-02-01

    Advocacy for the use of calcium supplements arose at a time when there were no other effective interventions for the prevention of osteoporosis. Their promotion was based on the belief that increasing calcium intake would increase bone formation. Our current understandings of the biology of bone suggest that this does not occur, though calcium does act as a weak antiresorptive. Thus, it slows postmenopausal bone loss but, despite this, recent meta-analyses suggest no significant prevention of fractures. In sum, there is little substantive evidence of benefit to bone health from the use of calcium supplements. Against this needs to be balanced the likelihood that calcium supplement use increases cardiovascular events, kidney stones, gastrointestinal symptoms, and admissions to hospital with acute gastrointestinal problems. Thus, the balance of risk and benefit seems to be consistently negative. As a result, current recommendations are to obtain calcium from the diet in preference to supplements. Dietary calcium intake has not been associated with the adverse effects associated with supplements, probably because calcium is provided in smaller boluses, which are absorbed more slowly since they come together with quantities of protein and fat, resulting in a slower gastric transit time. These findings suggest that calcium supplements have little role to play in the modern therapeutics of osteoporosis, which is based around the targeting of safe and effective anti-resorptive drugs to individuals demonstrated to be at increased risk of future fractures. PMID:24707464

  20. Calcium binding by dietary fibre

    International Nuclear Information System (INIS)

    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)

  1. The salutary effect of dietary calcium on bone mass in a rat model of simulated weightlessness

    Science.gov (United States)

    Bikle, D. D.; Globus, R.; Halloran, B. P.; Morey-Holton, E.

    1985-01-01

    Whether supplementation of dietary calcium reduces the differences in bone mass of unweighed limbs and normally weighted limbs, and whether parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH)2D) respond differently to dietary calcium in unweighted animals in comparison with pair-fed controls was studied. The hind limbs of rats were unweighted by a tail suspension method and diets containing 0.1% to 2.4% calcium. After 2 weeks serum calcium, phosphorus, PTH and 1,25(OH)2D intestinal calcium transport were determined and bone mass, ash weight, and calcium in the tibia, L-1 vertebra, and humerus were measured. No significant differences in body weights were observed among the various groups. Suspended rats maintained constant levels of serum calcium and phosphate over the wide range of dietary calcium. Serum PTH and 1,25(OH)2D and intestinal calcium transport fell as dietary calcium was increased. Bone calcium in the tibia and vertebra from suspended rats remained less than that from pair-fed control. It is suggested that although no striking difference between suspended and control animals was observed in response to dieteary calcium, increasing dietary calcium may reduce the negative impact of unloading on the calcium content of the unweighted bones. The salutary effect of high dietary calcium appears to be due to inhibition of bone resorption rather than to stimulation of bone formation.

  2. B physics triggers at CMS

    OpenAIRE

    Starodumov, A.(Institute for Particle Physics, ETH Zurich, Zurich, Switzerland)

    2003-01-01

    The CMS detector is mainly designed to investigate hard events. Only few Level-1 Trigger conditions are suitable to select soft B-meson decays. The B-physics potential of CMS depends strongly on a selection strategy at High-Level Trigger. The selection algorithms for some benchmark B-decay channels that allow CMS to perform competitive B-physics program are presented.

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

    NARCIS (Netherlands)

    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 ab

  4. The ELETTRA Gun Trigger module

    International Nuclear Information System (INIS)

    The ELETTRA injector is a full energy Linac. The Linac and the pulsed magnets need to be synchronized with the beam in the storage ring in order to fill it with the proper bunch pattern. Most of the triggers for the timing system are generated by a module which is named Gun Trigger module. The gun is triggered in synchronism with a reference bucket of the storage ring. It can be programmed with a delay between 2 and 864 ns, a range which covers one revolution period of the storage ring, so any arbitrary bucket of the ring can be filled. The module generates also the gun trigger for working in FEL mode, which needs a repetition from 30 to 50 ns in a 10 μs window. The jitter of all these triggers is less than 50 ps. The Gun Trigger module is developed in VMEbus standard, using TTL and ECL technology. It is remotely programmable through the ELETTRA control system. The general architecture of the ELETTRA timing system is also described in the paper

  5. The ATLAS Trigger Muon "Vertical Slice"

    CERN Document Server

    Sidoti, A; Biglietti, M; Carlino, G; Cataldi, G; Conventi, F; Del Prete, T; Di Mattia, A; Falciano, S; Gorini, S; Kanaya, N; Kohno, T; Krasznahorkay, A; Lagouri, T; Luci, C; Luminari, L; Marzano, F; Nagano, K; Nisati, A; Panikashvili, N; Pasqualucci, E; Primavera, M; Scannicchio, D A; Spagnolo, S; Tarem, S; Tarem, Z; Tokushuku, K; Usai, G; Ventura, A; Vercesi, V; Yamazaki, Y; 10th Pisa Meeting on Advanced Detectors : Frontier Detectors For Frontier Physics

    2007-01-01

    The muon trigger system is a fundamental component of the ATLAS detector at the LHC collider. In this paper we describe the ATLAS multi-level trigger selecting events with muons: the Muon Trigger Slice.

  6. Triggering on hadronic tau decays: ATLAS meets the challenge

    Indian Academy of Sciences (India)

    Mark Scarcella; on behalf of the ATLAS Collaboration

    2012-11-01

    Hadronic tau decays play a crucial role in taking Standard Model (SM) measurements as well as in the search for physics beyond the SM. However, hadronic tau decays are difficult to identify and trigger on due to their resemblance to QCD jets. Given the large production crosssection of QCD processes, designing and operating a trigger system to efficiently select hadronic tau decays, while maintaining the rate within the bandwidth limits, is a difficult challenge. This contribution will summarize the status and performance of the ATLAS tau trigger system during the 2010–2011 data taking period. Different methods that have been explored to obtain the trigger efficiency curves from data will be shown. Finally, the status of the measurements, which include hadronic tau decays in the final state, will be summarized. In light of the vast statistics collected in 2011, future prospects for triggering on hadronic tau decays in this exciting new period of increased instantaneous luminosity will be presented.

  7. Climate warming shifts carbon allocation from stemwood to roots in calcium-depleted spruce forests

    Science.gov (United States)

    Lapenis, Andrei Gennady; Lawrence, Gregory B.; Heim, Alexander; Zheng, Chengyang; Shortle, Walter

    2013-01-01

    Increased greening of northern forests, measured by the Normalized Difference Vegetation Index (NDVI), has been presented as evidence that a warmer climate has increased both net primary productivity (NPP) and the carbon sink in boreal forests. However, higher production and greener canopies may accompany changes in carbon allocation that favor foliage or fine roots over less decomposable woody biomass. Furthermore, tree core data throughout mid- and northern latitudes have revealed a divergence problem (DP), a weakening in tree ring responses to warming over the past half century that is receiving increasing attention, but remains poorly understood. Often, the same sites exhibit trend inconsistency phenomenon (TIP), namely positive, or no trends in growing season NDVI where negative trends in tree ring indexes are observed. Here we studied growth of two Norway spruce (Picea abies) stands in western Russia that exhibited both the DP and TIP but were subject to soil acidification and calcium depletion of differing timing and severity. Our results link the decline in radial growth starting in 1980 to a shift in carbon allocation from wood to roots driven by a combination of two factors: (a) soil acidification that depleted calcium and impaired root function and (b) earlier onset of the growing season that further taxed the root system. The latter change in phenology appears to act as a trigger at both sites to push trees into nutrient limitation as the demand for Ca increased with the longer growing season, thereby causing the shift in carbon allocation.

  8. Role of calcium in growth inhibition induced by a novel cell surface sialoglycopeptide

    Science.gov (United States)

    Betz, N. A.; Westhoff, B. A.; Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    Our laboratory has purified an 18 kDa cell surface sialoglycopeptide growth inhibitor (CeReS-18) from intact bovine cerebral cortex cells. Evidence presented here demonstrates that sensitivity to CeReS-18-induced growth inhibition in BALB-c 3T3 cells is influenced by calcium, such that a decrease in the calcium concentration in the growth medium results in an increase in sensitivity to CeReS-18. Calcium did not alter CeReS-18 binding to its cell surface receptor and CeReS-18 does not bind calcium directly. Addition of calcium, but not magnesium, to CeReS-18-inhibited 3T3 cells results in reentry into the cell cycle. A greater than 3-hour exposure to increased calcium is required for escape from CeReS-18-induced growth inhibition. The calcium ionophore ionomycin could partially mimic the effect of increasing extracellular calcium, but thapsigargin was ineffective in inducing escape from growth inhibition. Increasing extracellular calcium 10-fold resulted in an approximately 7-fold increase in total cell-associated 45Ca+2, while free intracellular calcium only increased approximately 30%. However, addition of CeReS-18 did not affect total cell-associated calcium or the increase in total cell-associated calcium observed with an increase in extracellular calcium. Serum addition induced mobilization of intracellular calcium and influx across the plasma membrane in 3T3 cells, and pretreatment of 3T3 cells with CeReS-18 appeared to inhibit these calcium mobilization events. These results suggest that a calcium-sensitive step exists in the recovery from CeReS-18-induced growth inhibition. CeReS-18 may inhibit cell proliferation through a novel mechanism involving altering the intracellular calcium mobilization/regulation necessary for cell cycle progression.

  9. The ATLAS Trigger System: Ready for Run II

    CERN Document Server

    Czodrowski, Patrick; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger system has been used successfully for data collection in the 2009-2013 Run 1 operation cycle of the CERN Large Hadron Collider (LHC) at center-of-mass energies of up to 8 TeV. With the restart of the LHC for the new Run 2 data-taking period at 13 TeV, the trigger rates are expected to rise by approximately a factor of 5. The trigger system consists of a hardware-based first level (L1) and a software-based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of ~ 1kHz. This presentation will give an overview of the upgrades to the ATLAS trigger system that have been implemented during the LHC shutdown period in order to deal with the increased trigger rates while efficiently selecting the physics processes of interest. These upgrades include changes to the L1 calorimeter trigger, the introduction of a new L1 topological trigger module, improvements in the L1 muon system, and the merging of the previously two-level HLT ...

  10. The ATLAS Trigger System - Ready for Run-2

    CERN Document Server

    Backes, Moritz; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware based Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the course of the ongoing Run-2 data-taking campaign at 13 TeV centre-of-mass energy the trigger rates will be approximately 5 times higher compared to Run-1. In these proceedings we briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger system, the introduction of a new L1 topological trigger subsystem and the merging of the previously two-level HLT system into a single ev...

  11. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Backes, Moritz; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the next data-taking period starting in 2015 (Run-2) the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger system, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter fa...

  12. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Nakahama, Yu; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the next data-taking period starting in early 2015 (Run-2) the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. We will review the upgrades to the ATLAS Trigger system that have been implemented during the shutdown and that will allow us to cope with these increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter trigger, the introduction of a new L1 topological trigger module, improvements in the L1 muon system and the merging of the prev...

  13. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    Science.gov (United States)

    Glatzer, Julian

    2015-12-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of two with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the factor of two increase in the number of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to three different subdetector combinations. An overview of the operational software framework of the L1CT system with particular emphasis on the configuration, controls and monitoring aspects is given. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition system. Trigger and dead-time rates are monitored coherently at all stages of processing and are logged by the online computing system for physics analysis, data quality assurance and operational debugging. In addition, the synchronisation of trigger inputs is watched based on bunch-by-bunch trigger information. Several software tools allow for efficient display of the relevant information in the control room in a way useful for shifters and experts. The design of the framework aims at reliability, flexibility, and robustness of the system and takes into account the operational experience gained during Run 1. The Level-1 Central Trigger was successfully operated with high efficiency during the cosmic-ray, beam-splash and first Run 2 data taking with the full ATLAS detector.

  14. Calcium and iron absorption: mechanism of action and nutritional importance.

    Science.gov (United States)

    Hallberg, L; Rossander-Hultén, L; Brune, M; Gleerup, A

    1992-05-01

    We investigated the inhibitory effect of calcium on iron absorption in 57 human subjects. Three studies suggested that the effect is not located in the gastrointestinal tract. The presence of phytate in a meal and formation of calcium-iron-phytate complexes is not a prerequisite for the inhibition. The relative increase in iron absorption by ascorbic acid was the same in meals with and without calcium, suggesting that calcium did not influence the balance between enhancing and inhibiting ligands in the gastrointestinal lumen. No inhibiting effect on iron absorption was seen when adding 3 mg calcium to 0.01 mg iron (molar ratio Ca/Fe = 420). Previous studies showing a marked inhibition by calcium had a lower molar ratio, but greater amounts of calcium were given. This suggests that a minimal concentration of calcium is needed to achieve an effect. The present results indirectly support our original hypothesis that the inhibitory effect of calcium on iron absorption is situated within the intestinal mucosal cells. The practical nutritional implications of the inhibitory effect of calcium are considerable since addition of milk, milkshake or cheese to common meals such as pizza or hamburger meals reduced iron absorption by 50-60%. It is recommended to reduce the intake of dairy products with the main meals providing most of the dietary iron, especially for those having the highest iron requirements i.e. children, teenagers and women at childbearing age. PMID:1600930

  15. Calcium-sensing receptor regulates stomatal closure through hydrogen peroxide and nitric oxide in response to extracellular calcium in Arabidopsis

    OpenAIRE

    Wang, Wen-Hua; Yi, Xiao-Qian; Han, Ai-Dong; Liu, Ting-Wu; Chen, Juan; Wu, Fei-Hua; Dong, Xue-Jun; He, Jun-Xian; Pei, Zhen-Ming; Zheng, Hai-Lei

    2011-01-01

    The Arabidopsis calcium-sensing receptor CAS is a crucial regulator of extracellular calcium-induced stomatal closure. Free cytosolic Ca2+ (Ca2+ i) increases in response to a high extracellular calcium (Ca2+ o) level through a CAS signalling pathway and finally leads to stomatal closure. Multidisciplinary approaches including histochemical, pharmacological, fluorescent, electrochemical, and molecular biological methods were used to discuss the relationship of hydrogen peroxide (H2O2) and nitr...

  16. Effects of calcium signaling on coagulation factor VIIa-induced proliferation and migration of the SW620 colon cancer cell line.

    Science.gov (United States)

    Wu, Ying; Wang, Jing; Zhou, Hong; Yu, Xiaoyan; Hu, Lichao; Meng, Fanlu; Jiang, Shuanghong

    2014-12-01

    Tissue factor (TF)/VIIa/protease‑activated receptor 2 (PAR2) has been shown to trigger the ERK1/2 signaling pathway. This was shown to be closely associated with the proliferation and migration of SW620 colon cancer cells; however, the detailed mechanisms remain unclear. The aim of the present study was to elucidate the effects of calcium signaling on the proliferation and migration of SW620 cells induced by coagulation factor VIIa. The results demonstrated that VIIa and PAR2 agonist PAR2‑AP increased [Ca2+]i in SW620 cells. In addition, VIIa‑and PAR2‑AP‑induced ERK1/2 activation was inhibited by thapsigargin (TG)‑induced depletion of intracellular Ca2+ stores and EGTA‑mediated removal of extracellular Ca2+. It was also identified that VIIa and PAR2‑AP‑induced proliferation and migration of SW620 cells was modulated by EGTA and TG. Taken together, the present results indicate that VIIa triggers calcium signaling in SW620 cells, in a TF‑dependent manner, which is critical for VIIa‑induced ERK1/2 activation in SW620 cells. These results suggested that calcium signaling had a vital role in the proliferation and migration of SW620 cells.

  17. Calcium and calcium isotope changes during carbon cycle perturbations at the end-Permian

    Science.gov (United States)

    Komar, Nemanja; Zeebe, Richard

    2016-04-01

    Negative carbon and calcium isotope excursions, as well as climate shifts, took place during the most severe mass extinction event in Earth's history, the end-Permian (˜252 Ma). Investigating the connection between carbon and calcium cycles during transient carbon cycle perturbation events, such as the end-Permian, may help resolve the intricacies between the coupled calcium-carbon cycles, as well as provide a tool for constraining the causes of mass extinction. Here, we identify the deficiencies of a simplified calcium model employed in several previous studies and we demonstrate the importance of a fully coupled carbon-cycle model when investigating the dynamics of carbon and calcium cycling. Simulations with a modified version of the LOSCAR model, which includes a fully coupled carbon-calcium cycle, indicate that increased weathering rates and ocean acidification (potentially caused by Siberian Trap volcanism) are not capable of producing trends observed in the record, as previously claimed. Our model results suggest that combined effects of carbon input via Siberian Trap volcanism (12,000 Pg C), the cessation of biological carbon export, and variable calcium isotope fractionation (due to a change in the seawater carbonate ion concentration) represents a more plausible scenario. This scenario successfully reconciles δ13C and δ44Ca trends observed in the sediment record, as well as the proposed warming of >6oC.

  18. Towards a Level-1 Tracking Trigger for the ATLAS Experiment

    CERN Document Server

    De Santo, A; The ATLAS collaboration

    2014-01-01

    Plans for a physics-driven upgrade of the LHC foresee staged increases of the accelerator's average instantaneous luminosity, of up to a factor of five compared to the original design. In order to cope with the sustained luminosity increase, and the resulting higher detector occupancy and particle interaction rates, the ATLAS experiment is planning phased upgrades of the trigger system and of the DAQ infrastructure. In the new conditions, maintaining an adequate signal acceptance for electro-weak processes will pose unprecedented challenges, as the default solution to cope with the higher rates would be to increase thresholds on the transverse momenta of physics objects (leptons, jets, etc). Therefore the possibility to apply fast processing at the first trigger level in order to use tracking information as early as possible in the trigger selection represents a most appealing opportunity, which can preserve the ATLAS trigger's selectivity without reducing its flexibility. Studies to explore the feasibility o...

  19. ATLAS Jet Trigger Update for the LHC Run II

    CERN Document Server

    Prince, Sebastien; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and centre of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The Jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  20. The updated ATLAS Jet Trigger for the LHC Run II

    CERN Document Server

    Prince, Sebastien; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and center of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  1. The updated ATLAS Jet Trigger for the LHC Run II

    CERN Document Server

    Prince, Sebastien

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and center of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High-Level Trigger, placed after a first hardware-based Level~1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  2. Influence of the calcium sulfate source on the rheological behaviour of calcium sulfoaluminate cement pastes

    OpenAIRE

    Santacruz, Isabel; García-Maté, Marta; G. Aranda, Miguel Ángel; De la Torre, Ángeles G.

    2013-01-01

    Calcium sulfoaluminate (CSA) cements are receiving increasing attention since their manufacture produces much less CO2 than ordinary Portland cement (OPC) [1]. In addition, they show interesting properties such as high early-age strengths, short setting times and impermeability. The main uses of these CSA cements are for quick repairs and pre-cast products or floor concrete applications. They are prepared by mixing the clinker with different amounts of a calcium sulfate set regulator such as ...

  3. Reactive oxygen species, inflammation and calcium oxalate nephrolithiasis

    OpenAIRE

    Khan, Saeed R.

    2014-01-01

    Calcium oxalate (CaOx) kidney stones are formed attached to Randall’s plaques (RPs) or Randall’s plugs. Mechanisms involved in the formation and growth are poorly understood. It is our hypothesis that stone formation is a form of pathological biomineralization or ectopic calcification. Pathological calcification and plaque formation in the body is triggered by reactive oxygen species (ROS) and the development of oxidative stress (OS). This review explores clinical and experimental data in sup...

  4. Unexpected link between polyketide synthase and calcium carbonate biomineralization

    OpenAIRE

    Hojo, Motoki; Omi, Ai; Hamanaka, Gen; Shindo, Kazutoshi; Shimada, Atsuko; Kondo, Mariko; Narita, Takanori; Kiyomoto, Masato; Katsuyama, Yohei; Ohnishi, Yasuo; Irie, Naoki; Takeda, Hiroyuki

    2015-01-01

    Introduction Calcium carbonate biominerals participate in diverse physiological functions. Despite intensive studies, little is known about how mineralization is initiated in organisms. Results We analyzed the medaka spontaneous mutant, ha, defective in otolith (calcareous ear stone) formation. ha lacks a trigger for otolith mineralization, and the causative gene was found to encode polyketide synthase (pks), a multifunctional enzyme mainly found in bacteria, fungi, and plant. Subsequent expe...

  5. ATP-triggered anticancer drug delivery

    Science.gov (United States)

    Mo, Ran; Jiang, Tianyue; Disanto, Rocco; Tai, Wanyi; Gu, Zhen

    2014-03-01

    Stimuli-triggered drug delivery systems have been increasingly used to promote physiological specificity and on-demand therapeutic efficacy of anticancer drugs. Here we utilize adenosine-5'-triphosphate (ATP) as a trigger for the controlled release of anticancer drugs. We demonstrate that polymeric nanocarriers functionalized with an ATP-binding aptamer-incorporated DNA motif can selectively release the intercalating doxorubicin via a conformational switch when in an ATP-rich environment. The half-maximal inhibitory concentration of ATP-responsive nanovehicles is 0.24 μM in MDA-MB-231 cells, a 3.6-fold increase in the cytotoxicity compared with that of non-ATP-responsive nanovehicles. Equipped with an outer shell crosslinked by hyaluronic acid, a specific tumour-targeting ligand, the ATP-responsive nanocarriers present an improvement in the chemotherapeutic inhibition of tumour growth using xenograft MDA-MB-231 tumour-bearing mice. This ATP-triggered drug release system provides a more sophisticated drug delivery system, which can differentiate ATP levels to facilitate the selective release of drugs.

  6. Triggering of Suicidal Erythrocyte Death by Pazopanib

    Directory of Open Access Journals (Sweden)

    Elena Signoretto

    2016-03-01

    Full Text Available Background/Aims: The multi-targeted kinase inhibitor pazopanib, a drug employed for the treatment of a wide variety of malignancies, has previously been shown to trigger apoptosis. Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Mechanisms involved in the triggering of eryptosis include Ca2+ entry, oxidative stress and ceramide. The present study explored, whether pazopanib induces eryptosis and, if so, whether it is effective by Ca2+ entry, oxidative stress and/or ceramide. Methods: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, reactive oxygen species (ROS formation from DCF dependent fluorescence, and ceramide abundance utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to pazopanib significantly increased the percentage of annexin-V-binding (≥ 25 µg/ml and of shrunken erythrocytes (≥ 50 µg/ml. Pazopanib treatment further resulted in significant hemolysis (≥ 25 µg/ml. The effect of pazopanib on annexin-V-binding was significantly blunted but not abolished by removal of extracellular Ca2+. Pazopanib significantly increased DCF fluorescence (50 µg/ml and ceramide abundance (50 µg/ml. Conclusions: Pazopanib triggers eryptosis, an effect involving Ca2+ entry, oxidative stress and ceramide.

  7. Yeast respond to hypotonic shock with a calcium pulse

    Science.gov (United States)

    Batiza, A. F.; Schulz, T.; Masson, P. H.

    1996-01-01

    We have used the transgenic AEQUORIN calcium reporter system to monitor the cytosolic calcium ([Ca2+]cyt) response of Saccharomyces cerevisiae to hypotonic shock. Such a shock generates an almost immediate and transient rise in [Ca2+]cyt which is eliminated by gadolinium, a blocker of stretch-activated channels. In addition, this transient rise in [Ca2+]cyt is initially insensitive to 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), an extracellular calcium chelator. However, BAPTA abruptly attenuates the maintenance of that transient rise. These data show that hypotonic shock generates a stretch-activated channel-dependent calcium pulse in yeast. They also suggest that the immediate calcium influx is primarily generated from intracellular stores, and that a sustained increase in [Ca2+]cyt depends upon extracellular calcium.

  8. Adaptative diversity of calcium metabolism in gammarus fossarum populations

    Energy Technology Data Exchange (ETDEWEB)

    Meyran, J.C. [Grenoble-1 Univ., 38 (France)

    1994-11-01

    Analysis of Gammarus fossarum populations from mountain torrents in the Grenoble region reveals some morphological and eco physiological diversity which appears to be related to the calcium concentration of the water after both field and laboratory experimentation. Animals from waters with a high calcium concentration (located in Chartreuse and Vercors) show larger size and a longer molt cycle than those from low calcium concentrated waters (located in Belledonne); their calcium balance during the molt cycle is different. Translocation experiments confirm these differences: a significant increase of the duration of the molt cycle is observed in animals translocated to lower calcium concentrated waters and vice-versa whereas no significant difference is observed between controls and animals translocated within comparably calcium concentrated waters. The causes of such an adaptative diversity between Gammarus fossarum populations will be researched at the genetic level, namely through mitochondrial DNA investigations. (author). 25 refs., 2 tabs., 2 figs.

  9. Adaptative diversity of calcium metabolism in gammarus fossarum populations

    International Nuclear Information System (INIS)

    Analysis of Gammarus fossarum populations from mountain torrents in the Grenoble region reveals some morphological and eco physiological diversity which appears to be related to the calcium concentration of the water after both field and laboratory experimentation. Animals from waters with a high calcium concentration (located in Chartreuse and Vercors) show larger size and a longer molt cycle than those from low calcium concentrated waters (located in Belledonne); their calcium balance during the molt cycle is different. Translocation experiments confirm these differences: a significant increase of the duration of the molt cycle is observed in animals translocated to lower calcium concentrated waters and vice-versa whereas no significant difference is observed between controls and animals translocated within comparably calcium concentrated waters. The causes of such an adaptative diversity between Gammarus fossarum populations will be researched at the genetic level, namely through mitochondrial DNA investigations. (author). 25 refs., 2 tabs., 2 figs

  10. FLIPR assays of intracellular calcium in GPCR drug discovery

    DEFF Research Database (Denmark)

    Hansen, Kasper Bø; Bräuner-Osborne, Hans

    2009-01-01

    Fluorescent dyes sensitive to changes in intracellular calcium have become increasingly popular in G protein-coupled receptor (GPCR) drug discovery for several reasons. First of all, the assays using the dyes are easy to perform and are of low cost compared to other assays. Second, most non......-Galpha(q)-coupled GPCRs can be tweaked to modulate intracellular calcium by co-transfection with promiscuous or chimeric/mutated G proteins making the calcium assays broadly applicable in GPCR research. Third, the price of instruments capable of measuring fluorescent-based calcium indicators has become significantly less...

  11. Anthropogenic Triggering of Large Earthquakes

    Science.gov (United States)

    Mulargia, Francesco; Bizzarri, Andrea

    2014-08-01

    The physical mechanism of the anthropogenic triggering of large earthquakes on active faults is studied on the basis of experimental phenomenology, i.e., that earthquakes occur on active tectonic faults, that crustal stress values are those measured in situ and, on active faults, comply to the values of the stress drop measured for real earthquakes, that the static friction coefficients are those inferred on faults, and that the effective triggering stresses are those inferred for real earthquakes. Deriving the conditions for earthquake nucleation as a time-dependent solution of the Tresca-Von Mises criterion applied in the framework of poroelasticity yields that active faults can be triggered by fluid overpressures < 0.1 MPa. Comparing this with the deviatoric stresses at the depth of crustal hypocenters, which are of the order of 1-10 MPa, we find that injecting in the subsoil fluids at the pressures typical of oil and gas production and storage may trigger destructive earthquakes on active faults at a few tens of kilometers. Fluid pressure propagates as slow stress waves along geometric paths operating in a drained condition and can advance the natural occurrence of earthquakes by a substantial amount of time. Furthermore, it is illusory to control earthquake triggering by close monitoring of minor ``foreshocks'', since the induction may occur with a delay up to several years.

  12. Effect of galactooligosaccharides on calcium absorption in rats.

    Science.gov (United States)

    Chonan, O; Watanuki, M

    1995-02-01

    The effect of transgalactosylated oligosaccharides (TOS), which are oligosaccharides that are unhydrolyzed in the small intestine and are fermented by the intestinal bacteria, on calcium absorption was examined in male Wistar rats for 10 days. The apparent calcium absorption ratios and the apparent retention ratios were significantly higher in the rats fed TOS-containing diets (5 or 10 g/100 g of diet). In the second experiment, the cecum was ligated in situ and calcium absorption from the cecum was observed after injecting TOS into the cecal lumen. Four hours after the injection, the calcium concentration in the cecal vein of the rats given TOS was significantly higher than that of the control. The calcium content in the liquid phase of the cecal lumen and the liquid phase weight were also increased by the injection of TOS into the cecum. Although the extent of calcium absorption from the cecum of rats fed TOS is due to overall calcium absorption is not known, under the experimental conditions used in the present study the stimulatory effect of TOS on calcium absorption may be partly associated with increased solubility of calcium and the fluid content in the intestinal lumen.

  13. Mitochondrial calcium uptake.

    Science.gov (United States)

    Williams, George S B; Boyman, Liron; Chikando, Aristide C; Khairallah, Ramzi J; Lederer, W J

    2013-06-25

    Calcium (Ca(2+)) uptake into the mitochondrial matrix is critically important to cellular function. As a regulator of matrix Ca(2+) levels, this flux influences energy production and can initiate cell death. If large, this flux could potentially alter intracellular Ca(2+) ([Ca(2+)]i) signals. Despite years of study, fundamental disagreements on the extent and speed of mitochondrial Ca(2+) uptake still exist. Here, we review and quantitatively analyze mitochondrial Ca(2+) uptake fluxes from different tissues and interpret the results with respect to the recently proposed mitochondrial Ca(2+) uniporter (MCU) candidate. This quantitative analysis yields four clear results: (i) under physiological conditions, Ca(2+) influx into the mitochondria via the MCU is small relative to other cytosolic Ca(2+) extrusion pathways; (ii) single MCU conductance is ∼6-7 pS (105 mM [Ca(2+)]), and MCU flux appears to be modulated by [Ca(2+)]i, suggesting Ca(2+) regulation of MCU open probability (P(O)); (iii) in the heart, two features are clear: the number of MCU channels per mitochondrion can be calculated, and MCU probability is low under normal conditions; and (iv) in skeletal muscle and liver cells, uptake per mitochondrion varies in magnitude but total uptake per cell still appears to be modest. Based on our analysis of available quantitative data, we conclude that although Ca(2+) critically regulates mitochondrial function, the mitochondria do not act as a significant dynamic buffer of cytosolic Ca(2+) under physiological conditions. Nevertheless, with prolonged (superphysiological) elevations of [Ca(2+)]i, mitochondrial Ca(2+) uptake can increase 10- to 1,000-fold and begin to shape [Ca(2+)]i dynamics.

  14. Effect of dairy calcium or supplementary calcium intake on postprandial fat metabolism, appetite, and subsequent energy intake

    DEFF Research Database (Denmark)

    Lorenzen, J.K.; Nielsen, S.; Holst, J.J.;

    2007-01-01

    Background: High calcium intake has been shown to increase fecal fat excretion. Objective: Our aim was to examine whether a high calcium intake from dairy products or from supplements affects postprandial fat metabolism and appetite through fat malabsorption. Design: Four different isocaloric meals...... were tested in 18 subjects according to a randomized crossover design. The test meals contained high (HC meal: 172 mg/MJ), medium (MC meal: 84 mg/MJ), or low (LC meal: 15 mg/MJ) amounts of calcium from dairy products or a high amount of calcium given as a calcium carbonate supplement (Suppl meal: 183...... and approximate to 15% lower after the MC meal (P = 0.0495) and approximate to 17% lower after the HC meal (P = 0.02) than after the Suppl meal. No consistent effects of calcium on appetite sensation, or on energy intake at the subsequent meal, or on the postprandial responses of cholecystokinin, glucagon...

  15. The ATLAS Hadronic Tau Trigger

    CERN Document Server

    Mahlstedt, J; The ATLAS collaboration

    2013-01-01

    During the 2012 run the Large Hadron Collider (LHC) reached instantaneous luminosities of nearly $10^{34} cm^{-2} s^{-1}$, with bunch crossings occurring every 50 ns. In this difficult environment of several overlapping interactions per bunch crossing (pile-up) the trigger system of the ATLAS detector has the task of reducing the event rate from 40 MHz to a few hundred Hz while keeping the most interesting physics events. Being the heaviest of all leptons, the tau lepton plays an important role in many physics processes. The ability to trigger on events containing hadronically decaying taus is therefore of special interest. In this poster the hadronic tau trigger is described and its performance during 2012 is shown.

  16. The CMS Level-1 Trigger for LHC Run II

    CERN Document Server

    Tapper, Alexander

    2016-01-01

    During LHC Run II the centre-of-mass energy of pp collisions has increased up to 13 TeV and the instantaneous luminosity has progressed towards 2E34 cmâ??2 sâ??1. In order to guarantee a successful and ambitious physics programme under these conditions, the CMS trigger system system has been upgraded. The upgraded CMS Level-1 trigger is designed to improve performance at high luminosity and large number of simultaneous inelastic collisions per crossing. The trigger design, implementation and commissioning are summarised and early performance results are described.

  17. Calcium and bone disorders in pregnancy

    Directory of Open Access Journals (Sweden)

    Shriraam Mahadevan

    2012-01-01

    Full Text Available Significant transplacental calcium transfer occurs during pregnancy, especially during the last trimester, to meet the demands of the rapidly mineralizing fetal skeleton. Similarly, there is an obligate loss of calcium in the breast milk during lactation. Both these result in considerable stress on the bone mineral homeostasis in the mother. The maternal adaptive mechanisms to conserve calcium are different in pregnancy and lactation. During pregnancy, increased intestinal absorption of calcium from the gut mainly due to higher generation of calcitriol (1,25 dihydroxy vitamin D helps in maintaining maternal calcium levels. On the other hand, during lactation, the main compensatory mechanism is skeletal resorption due to increased generation of parathormone related peptide (PTHrP from the breast. Previous studies suggest that in spite of considerable changes in bone mineral metabolism during pregnancy, parity and lactation are not significantly associated with future risk for osteoporosis. However, in India, the situation may not be the same as a significant proportion of pregnancies occur in the early twenties when peak bone mass is not yet achieved. Further, malnutrition, anemia and vitamin D deficiency are commonly encountered in this age group. This may have an impact on future bone health of the mother. It may also probably provide an opportunity for health care providers for prevention. Other metabolic bone diseases like hypoparathyroidism, hyperparathyroidism and pseudohypoparathyroidism are rarely encountered in pregnancy. Their clinical implications and management are also discussed.

  18. Triggering events with GPUs at ATLAS

    Science.gov (United States)

    Kama, S.; Soares, J. Augusto; Baines, J.; Bauce, M.; Bold, T.; Conde Muino, P.; Emeliyanov, D.; Goncalo, R.; Messina, A.; Negrini, M.; Rinaldi, L.; Sidoti, A.; Tavares Delgado, A.; Tupputi, S.; Vaz Gil Lopes, L.

    2015-12-01

    The growing complexity of events produced in LHC collisions demands increasing computing power both for the online selection and for the offline reconstruction of events. In recent years there have been significant advances in the performance of Graphics Processing Units (GPUs) both in terms of increased compute power and reduced power consumption that make GPUs extremely attractive for use in a complex particle physics experiments such as ATLAS. A small scale prototype of the full ATLAS High Level Trigger has been implemented that exploits reconstruction algorithms optimized for this new massively parallel paradigm. We discuss the integration procedure followed for this prototype and present the performance achieved and the prospects for the future.

  19. LHCb Run 2 Trigger Performance

    CERN Document Server

    Sciascia, Barbara

    2016-01-01

    During the first long shutdown of the LHC (2013-2014, LS1), the LHCb detector remained essentially unchanged, while the trigger system has been completely revisited. Upgrades to the LHCb computing infrastructure have allowed for high quality decay information to be calculated by the software trigger making a separate offline event reconstruction unnecessary. Reaching the ultimate precision of the LHCb experiment already in real time as the data arrive has the power to transform the experimental approach to processing large quantities of data

  20. Role of Calcium Hydroxide in Endodontics: A Review

    OpenAIRE

    Arun A; Sangameshwar Sajjanshetty; Deepak Jain; Saujanya KP; Mohammed Mustafa; Laxmi Uppin; Mahnoor Kadri

    2012-01-01

    Calcium hydroxide is a multipurpose agent, and there have been an increasing number of indications for its use in endodontics. Some of its indications include inter-appointment intracanal medicaments, endodontic sealers, pulp capping agents, apexification, pulpotomy and weeping canals. The purpose of this article is to review the properties, advantages, disadvantages and various indications for the use of calcium hydroxide in endodontics.

  1. EFFECTS OF PDGF-BB ON INTRACELLULAR CALCIUM CONCENTRATION AND PROLIFERATION IN CULTURED GLOMERULAR MESANGIAL CELLS

    Institute of Scientific and Technical Information of China (English)

    WEN Li-ping; ZHANG Chong; BIAN Fan; ZOU Jun; JIANG Geng-ru; ZHU Han-wei

    2006-01-01

    Objective To investigate the relationship between the alteration of intracellular calcium concentration and proliferation in cultured glomerular mesangial cells. Methods Rat mesangial cells were cultured.Intracellular calcium concentrations were measured by confocal Laser Scanning Microscopy and Fura-3 fluorescence dyeing techniques. Cell growth was measured by MTT assay. Results PDGF-BB increased intracellular calcium concentrations in a dose-dependent manner, and at the same time promote the proliferation of mesangial cells. After preincubation with calcium channel blocker nifedipine or angiotensin converting enzyme inhibitor captopril, both the increase of intracellular calcium concentrations and cell proliferations induced by PDGF-BB were inhibited. Tripterigium Wilfordii Glycosides (TMG) significantly inhibited the mesangial cell proliferations, but it had no significant effect on intracellular calcium concentrations. Conclusion There was a positive relationship between the elevation of intracellular calcium concentration and cell proliferation in glomerular mesangial cells, but the increase of in- tracellular calcium concentrations wasn't the only way for proliferation.

  2. CALCIUM-INDUCED SUPRAMOLECULAR STRUCTURES IN THE CALCIUM CASEINATE SYSTEM

    Science.gov (United States)

    The molecular details deciphering the spontaneous calcium-induced protein aggregation process in the calcium caseinate system remain obscure. Understanding this complex process could lead to potential new applications of this important food ingredient. In this work, we studied calcium-induced supra...

  3. Calcium binding proteins and calcium signaling in prokaryotes.

    Science.gov (United States)

    Domínguez, Delfina C; Guragain, Manita; Patrauchan, Marianna

    2015-03-01

    With the continued increase of genomic information and computational analyses during the recent years, the number of newly discovered calcium binding proteins (CaBPs) in prokaryotic organisms has increased dramatically. These proteins contain sequences that closely resemble a variety of eukaryotic calcium (Ca(2+)) binding motifs including the canonical and pseudo EF-hand motifs, Ca(2+)-binding β-roll, Greek key motif and a novel putative Ca(2+)-binding domain, called the Big domain. Prokaryotic CaBPs have been implicated in diverse cellular activities such as division, development, motility, homeostasis, stress response, secretion, transport, signaling and host-pathogen interactions. However, the majority of these proteins are hypothetical, and only few of them have been studied functionally. The finding of many diverse CaBPs in prokaryotic genomes opens an exciting area of research to explore and define the role of Ca(2+) in organisms other than eukaryotes. This review presents the most recent developments in the field of CaBPs and novel advancements in the role of Ca(2+) in prokaryotes.

  4. Synchronous and asynchronous modes of synaptic transmission utilize different calcium sources

    OpenAIRE

    Wen, Hua; Hubbard, Jeffrey M; Rakela, Benjamin; Linhoff, Michael W.; Mandel, Gail; Brehm, Paul

    2013-01-01

    eLife digest Neurons communicate with one another at junctions called synapses. The arrival of an electrical signal known as an action potential at the first (presynaptic) neuron causes calcium ions to flood into the cell. This in turn causes the neuron to release packages of chemicals called neurotransmitters into the synapse. These activate receptors on the second (postsynaptic) neuron, triggering a new action potential that travels down the axon to the next synapse. The ions that trigger t...

  5. Children's Bone Health and Calcium

    Science.gov (United States)

    ... Trials Resources and Publications Children's Bone Health and Calcium: Condition Information Skip sharing on social media links ... straight, walk, run, and lead an active life. Calcium is one of the key dietary building blocks ...

  6. Run-2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Winklmeier, Frank; The ATLAS collaboration

    2016-01-01

    The 2nd LHC run has started in June 2015 with a pp centre-of-mass collision energy of 13 TeV, and ATLAS has taken first data at this new energy. In this talk the improvements made to the ATLAS experiment during the 2-year shutdown 2013/2014 will be discussed, and first detector and trigger performance results from the Run-2 will be shown. In general, reconstruction algorithms of tracks, e/gamma, muons, taus, jets and flavour tag- ging have been improved for Run-2. The new reconstruction algorithms and their performance measured using the data taken in 2015 at sqrt(s)=13 TeV will be discussed. Reconstruction efficiency, isolation performance, transverse momentum resolution and momentum scales are measured in various regions of the detector and in momentum intervals enlarged with respect to those measured in the Run-1. This presentation will also give an overview of the upgrades to the ATLAS trigger system that have been implemented during the LHC shutdown in order to deal with the increased trigger rates (fact...

  7. ENSO-triggered floods in South America

    Science.gov (United States)

    Isla, Federico Ignacio

    2016-04-01

    ENSO-triggered floods altered completely the annual discharge of most watersheds of South America. Anomalous years as 1941, 1982-83 and 1997-98 signified enormous discharges of rivers draining toward the Pacific but also to the Atlantic Ocean. These floods affected large cities as Porto Alegre, Blumenau, Curitiba, Asunción, Santa Fe and Buenos Aires. Maximum discharge months are particular and easily distinguished at those watersheds located at the South American Arid Diagonal. At watersheds conditioned by precipitations delivered from the Atlantic or Pacific anticyclonic centers the ENSO-triggered floods are difficult to discern. The floods of 1941 affected 70,000 inhabitants in Porto Alegre. In 1983, Blumenau city was flooded during several days; and the Paraná River multiplied 15 times the width of its middle floodplain. The Colorado River in Northern Patagonia connected for the last time to the Desaguadero-Chadileuvú-Curacó system and therefore received saline water. ENSO years modify also the water balance of certain piedmont lakes of Southern Patagonia: the increases in snow accumulations cause high water levels with a lag of 13 months. The correlation between the maximum monthly discharges of 1982-83 and 1997-98 at different regions and watersheds indicates they can be forecasted for future floods triggered by same phenomena. South American rivers can be classified therefore into ENSO-affected, and ENSO-dominated, for those within the Arid Diagonal that are exclusively subject to high discharges during these years.

  8. Rapidly activated epidermal growth factor receptor mediates lipopolysaccharide-triggered migration of microglia.

    Science.gov (United States)

    Qu, Wen-Sheng; Liu, Jun-Li; Li, Chun-Yu; Li, Xiao; Xie, Min-Jie; Wang, Wei; Tian, Dai-Shi

    2015-11-01

    Previous reports have suggested that epidermal growth factor receptor (EGFR) is involved in microglia activation characterized by cell morphology changes, cytokine production and cell migration; and the biochemical regulation of the microglia migration is a potential therapeutic target following CNS inflammatory damages. However, the role of EGFR in microglia motility after inflammatory stimulation remains unknown. In the present study, lipopolysaccharide (LPS) was found to trigger rapid EGFR phosphorylation within 10 min, which was sustained during long-term stimulation in both primary microglial cells and the cultured BV2 microglial cells, furthermore, blocking EGFR phosphorylation by AG1478 significantly attenuated the LPS-induced chemotactic and chemokinetic migration of microglia. In addition, LPS could initiate calcium oscillation in microglia during live-cell recording, however, an intracellular calcium chelator and a selective inhibitor of calcium/calmodulin-dependent protein kinase II, but not an extracellular calcium chelator, remarkably suppressed the LPS-induced EGFR phosphorylation in BV2 microglia cells. As EGFR is not a traditional receptor for LPS, these findings suggest that the rapid phosphorylation of EGFR is attributed to the LPS-triggered intracellular calcium mobilization. By examining the downstream signals of EGFR, we further proved that extracellular signal-regulated kinase (ERK) is essential for EGFR-mediated microglia migration, because ERK inhibition attenuated the chemotactic and chemokinetic migration of microglia that had been induced by either LPS or EGF. Collectively, these results suggest that LPS could trigger the rapid phosphorylation of EGFR and subsequent ERK activation through mobilizing calcium activity, which underlies the microglia migration in an inflammatory condition.

  9. Molecular aspects of intestinal calcium absorption.

    Science.gov (United States)

    Diaz de Barboza, Gabriela; Guizzardi, Solange; Tolosa de Talamoni, Nori

    2015-06-21

    Intestinal Ca(2+) absorption is a crucial physiological process for maintaining bone mineralization and Ca(2+) homeostasis. It occurs through the transcellular and paracellular pathways. The first route comprises 3 steps: the entrance of Ca(2+) across the brush border membranes (BBM) of enterocytes through epithelial Ca(2+) channels TRPV6, TRPV5, and Cav1.3; Ca(2+) movement from the BBM to the basolateral membranes by binding proteins with high Ca(2+) affinity (such as CB9k); and Ca(2+) extrusion into the blood. Plasma membrane Ca(2+) ATPase (PMCA1b) and sodium calcium exchanger (NCX1) are mainly involved in the exit of Ca(2+) from enterocytes. A novel molecule, the 4.1R protein, seems to be a partner of PMCA1b, since both molecules co-localize and interact. The paracellular pathway consists of Ca(2+) transport through transmembrane proteins of tight junction structures, such as claudins 2, 12, and 15. There is evidence of crosstalk between the transcellular and paracellular pathways in intestinal Ca(2+) transport. When intestinal oxidative stress is triggered, there is a decrease in the expression of several molecules of both pathways that inhibit intestinal Ca(2+) absorption. Normalization of redox status in the intestine with drugs such as quercetin, ursodeoxycholic acid, or melatonin return intestinal Ca(2+) transport to control values. Calcitriol [1,25(OH)₂D₃] is the major controlling hormone of intestinal Ca(2+) transport. It increases the gene and protein expression of most of the molecules involved in both pathways. PTH, thyroid hormones, estrogens, prolactin, growth hormone, and glucocorticoids apparently also regulate Ca(2+) transport by direct action, indirect mechanism mediated by the increase of renal 1,25(OH)₂D₃ production, or both. Different physiological conditions, such as growth, pregnancy, lactation, and aging, adjust intestinal Ca(2+) absorption according to Ca(2+) demands. Better knowledge of the molecular details of intestinal Ca(2

  10. Acoustic Manifestations of Natural versus Triggered Lightning

    Science.gov (United States)

    Arechiga, R. O.; Johnson, J. B.; Edens, H. E.; Rison, W.; Thomas, R. J.; Eack, K.; Eastvedt, E. M.; Aulich, G. D.; Trueblood, J.

    2010-12-01

    Positive leaders are rarely detected by VHF lightning detection systems; positive leader channels are usually outlined only by recoil events. Positive cloud-to-ground (CG) channels are usually not mapped. The goal of this work is to study the types of thunder produced by natural versus triggered lightning and to assess which types of thunder signals have electromagnetic activity detected by the lightning mapping array (LMA). Towards this end we are investigating the lightning detection capabilities of acoustic techniques, and comparing them with the LMA. In a previous study we used array beam forming and time of flight information to locate acoustic sources associated with lightning. Even though there was some mismatch, generally LMA and acoustic techniques saw the same phenomena. To increase the database of acoustic data from lightning, we deployed a network of three infrasound arrays (30 m aperture) during the summer of 2010 (August 3 to present) in the Magdalena mountains of New Mexico, to monitor infrasound (below 20 Hz) and audio range sources due to natural and triggered lightning. The arrays were located at a range of distances (60 to 1400 m) surrounding the triggering site, called the Kiva, used by Langmuir Laboratory to launch rockets. We have continuous acoustic measurements of lightning data from July 20 to September 18 of 2009, and from August 3 to September 1 of 2010. So far, lightning activity around the Kiva was higher during the summer of 2009. We will present acoustic data from several interesting lightning flashes including a comparison between a natural and a triggered one.

  11. Calcium ion channel and epilepsy

    Institute of Scientific and Technical Information of China (English)

    Yudan Lü; Weihong Lin; Dihui Ma

    2006-01-01

    OBJECTIVE: To review the relationship between calcium ion channel and epilepsy for well investigating the pathogenesis of epilepsy and probing into the new therapeutic pathway of epilepsy.DATA SOURCES: A computer-based online research Calcium ion channel and epilepsy related articles published between January 1994 and December 2006 in the CKNI and Wanfang database with the key words of "calcium influxion, epilepsy, calcium-channel blocker". The language was limited to Chinese. At the same time,related articles published between January 1993 and December 2006 in Pubmed were searched for on online with the key words of "calcium influxion, epilepsy" in English.STUDY SELECTION: The materials were selected firstly. Inclusive criteria: ① Studies related to calcium ion channel and the pat1hogenesis of epilepsy. ② Studies on the application of calcium ion channel blocker in the treatment of epilepsy. Exclusive criteria: repetitive or irrelated studies.DATA EXTRACTION: According to the criteria, 123 articles were retrieved and 93 were excluded due to repetitive or irrelated studies. Altogether 30 articles met the inclusive criteria, 11 of them were about the structure and characters of calcium ion channel, 10 about calcium ion channel and the pathogenesis of epilepsy and 9 about calcium blocker and the treatment of epilepsy.DATA SYNTHESIS: Calcium ion channels mainly consist of voltage dependent calcium channel and receptor operated calcium channel. Depolarization caused by voltage gating channel-induced influxion is the pathological basis of epileptic attack, and it is found in many studies that many anti-epileptic drugs have potential and direct effect to rivalizing voltage-dependent calcium ion channel.CONCLUSION: Calcium influxion plays an important role in the seizure of epilepsy. Some calcium antagonists seen commonly are being tried in the clinical therapy of epilepsy that is being explored, not applied in clinical practice. If there are enough evidences to

  12. Solar Imagery - Chromosphere - Calcium

    Data.gov (United States)

    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...

  13. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    CERN Document Server

    Glatzer, Julian Maximilian Volker; The ATLAS collaboration

    2015-01-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of 2 with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the double amount of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to 3 different subdetector combinations. An overview of the operational software framework of the L1CT system with particular emphasis of the configuration, controls and monitoring aspects is given. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition. Trigger and dead-time rates are monitored coherently at...

  14. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    CERN Document Server

    Glatzer, Julian Maximilian Volker; The ATLAS collaboration

    2015-01-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of 2 with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the double amount of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to 3 different sub-detector combinations. In this contribution, we give an overview of the operational software framework of the L1CT system with particular emphasis of the configuration, controls and monitoring aspects. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition. Trigger and dead-time rates are m...

  15. Reactive oxygen species, inflammation and calcium oxalate nephrolithiasis.

    Science.gov (United States)

    Khan, Saeed R

    2014-09-01

    Calcium oxalate (CaOx) kidney stones are formed attached to Randall's plaques (RPs) or Randall's plugs. Mechanisms involved in the formation and growth are poorly understood. It is our hypothesis that stone formation is a form of pathological biomineralization or ectopic calcification. Pathological calcification and plaque formation in the body is triggered by reactive oxygen species (ROS) and the development of oxidative stress (OS). This review explores clinical and experimental data in support of ROS involvement in the formation of CaOx kidney stones. Under normal conditions the production of ROS is tightly controlled, increasing when and where needed. Results of clinical and experimental studies show that renal epithelial exposure to high oxalate and crystals of CaOx/calcium phosphate (CaP) generates excess ROS, causing injury and inflammation. Major markers of OS and inflammation are detectable in urine of stone patients as well as rats with experimentally induced CaOx nephrolithiasis. Antioxidant treatments reduce crystal and oxalate induced injury in tissue culture and animal models. Significantly lower serum levels of antioxidants, alpha-carotene, beta-carotene and beta-cryptoxanthine have been found in individuals with a history of kidney stones. A diet rich in antioxidants has been shown to reduce stone episodes. ROS regulate crystal formation, growth and retention through the timely production of crystallization modulators. In the presence of abnormal calcium, citrate, oxalate, and/or phosphate, however, there is an overproduction of ROS and a decrease in the antioxidant capacity resulting in OS, renal injury and inflammation. Cellular degradation products in the urine promote crystallization in the tubular lumen at a faster rate thus blocking the tubule and plugging the tubular openings at the papillary tips forming Randall's plugs. Renal epithelial cells lining the loops of Henle/collecting ducts may become osteogenic, producing membrane vesicles at

  16. Triggering of Suicidal Erythrocyte Death by Regorafenib

    Directory of Open Access Journals (Sweden)

    Jens Zierle

    2016-01-01

    Full Text Available Background/Aims: The multikinase inhibitor regorafenib is utilized for the treatment of malignancy. The substance is effective in part by triggering suicidal death or apoptosis of tumor cells. Side effects of regorafenib include anemia. At least in theory, regorafenib induced anemia could result from stimulated suicidal erythrocyte death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include increase of cytosolic Ca2+ activity ([Ca2+]i, oxidative stress and ceramide. The present study explored, whether regorafenib induces eryptosis and, if so, whether it is effective up- and/or downstream of Ca2+. Methods: To this end, phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, ROS formation from DCFDA dependent fluorescence, and ceramide abundance utilizing specific antibodies. Results: A 48 hours exposure of human erythrocytes to regorafenib (≥ 0.5 µg/ml significantly increased the percentage of annexin-V-binding cells, significantly decreased forward scatter (≥ 1.25 µg/ml, but did not significantly increase Fluo3-fluorescence, DCFDA fluorescence or ceramide abundance. The effect of regorafenib on annexin-V-binding and forward scatter was not significantly blunted by removal of extracellular Ca2+. Regorafenib (5 µg/ml significantly augmented the increase of annexin-V-binding, but significantly blunted the decrease of forward scatter following treatment with the Ca2+ ionophore ionomycin. Conclusions: Regorafenib triggers cell shrinkage and phospholipid scrambling of the erythrocyte cell membrane, an effect at least in part downstream of Ca2+.

  17. Calcium aluminate in alumina

    Science.gov (United States)

    Altay, Arzu

    The properties of ceramic materials are determined not only by the composition and structure of the phases present, but also by the distribution of impurities, intergranular films and second phases. The phase distribution and microstructure both depend on the fabrication techniques, the raw materials used, the phase-equilibrium relations, grain growth and sintering processes. In this dissertation research, various approaches have been employed to understand fundamental phenomena such as grain growth, impurity segregation, second-phase formation and crystallization. The materials system chosen was alumina intentionally doped with calcium. Atomic-scale structural analyses of grain boundaries in alumina were carried on the processed samples. It was found that above certain calcium concentrations, CA6 precipitated as a second phase at all sintering temperatures. The results also showed that abnormal grain growth can occur after precipitation and it is not only related to the calcium level, but it is also temperature dependent. In order to understand the formation mechanism of CA6 precipitates in calcium doped alumina samples, several studies have been carried out using either bulk materials or thin films The crystallization of CA2 and CA6 powders has been studied. Chemical processing techniques were used to synthesize the powders. It was observed that CA2 powders crystallized directly, however CA6 powders crystallized through gamma-Al 2O3 solid solution. The results of energy-loss near-edge spectrometry confirmed that gamma-Al2O3 can dissolve calcium. Calcium aluminate/alumina reaction couples have also been investigated. All reaction couples were heat treated following deposition. It was found that gamma-Al2O3 was formed at the interface as a result of the interfacial reaction between the film and the substrate. gamma-Al 2O3 at the interface was stable at much higher temperatures compared to the bulk gamma-Al2O3 formed prior to the CA6 crystallization. In order to

  18. Suicide Triggers Described by Herodotus

    Science.gov (United States)

    Auchincloss, Stephane; Ahmadi, Jamshid

    2016-01-01

    Objective: The aim of this study was to better understand the triggers of suicide, particularly among the ancient Greek and Persian soldiers and commanders. Method: ‘Herodotus:TheHistories’ is a history of the rulers and soldiery who participated in the Greco-Persian wars (492-449 BCE). A new translation (2013) of this manuscript was studied. Accounts of suicide were collected and collated, with descriptions of circumstances, methods, and probable triggers. Results: Nine accounts of suicide were identified. Eight of these were named individuals (4 Greeks and 4 Persians); of whom, seven were male. Only one (not the female) appeared to act in response to a mental disorder. Other triggers of suicide included guilt, avoidance of dishonour/punishment and altruism. Cutting/ stabbing was the most common method; others included hanging, jumping, poison, and burning (the single female). Conclusion: While soldiers at a time of war do not reflect the general community, they are nevertheless members of their society. Thus, this evidence demonstrates that suicide triggered by burdensome circumstances (in addition to mental disorder) was known to the Greek and Persian people more than two millennia ago. PMID:27437010

  19. Etiology of myofascial trigger points

    NARCIS (Netherlands)

    Bron, C.; Dommerholt, J.D.

    2012-01-01

    Myofascial pain syndrome (MPS) is described as the sensory, motor, and autonomic symptoms caused by myofascial trigger points (TrPs). Knowing the potential causes of TrPs is important to prevent their development and recurrence, but also to inactivate and eliminate existing TrPs. There is general ag

  20. The ATLAS Hadronic Tau Trigger

    CERN Document Server

    Brost, E; The ATLAS collaboration

    2014-01-01

    As proton-proton collisions at the LHC reach luminosities close to 10$^{\\mathrm{34}}$ cm$^{\\mathrm{-2}}$ s $^{\\mathrm{-1}}$, the strategies for triggering have become more important than ever for physics analyses. Simplistic single tau lepton triggers suffer from severe rate limitation, despite the sophisticated algorithms used in the tau identification. The development of further fast algorithms and the design of topological selections are the main challenges to allow a large program of physics analysis. The tau triggers provide many opportunities to study new physics beyond the Standard Model, and to get precise measurements of the properties of the Higgs boson decaying to tau-leptons. We present the performance of the hadronic tau trigger taken in Run 1 data with the ATLAS detector at $\\sqrt{s}$ = 8 TeV pp collision. One of the major challenges is to sustain high efficiencies in events with multiple interactions. To do this we introduced faster tracking methods, multivariate selection techniques, and new t...

  1. Hepatic Cell Apoptosis Was Triggerred by HBx Accumulation and Independent on Verapamil

    Institute of Scientific and Technical Information of China (English)

    王海平; 陈孝平; 白祥军

    2004-01-01

    Summary: In order to studythe roles of HBx and calcium inhibitor verapamil in apoptosis of human normal hepatic cells, L02-off, a pTet-off stably integrated human hepatic cell line was established,in which HBx expression was tightly induced by Doxycycline. The effect of different amounts of HBx and verapamil on apoptosis of human normal hepatic cells was detected. The study showed that apoptosis was triggered by accumulation of intracellular HBx, while verapamil had no effects on the apoptotic process. It was concluded that apoptosis mediated by HBx was dose-dependent but calcium-independent.

  2. Nicotinic acetylcholine receptor-mediated calcium signaling in the nervous system

    Institute of Scientific and Technical Information of China (English)

    Jian-xin SHEN; Jerrel L YAKEL

    2009-01-01

    Based on the composition of the five subunits forming functional neuronal nicotinic acetylcholine receptors (nAChRs), they are grouped into either heteromeric (comprising both α and β subunits) or homomeric (comprising only α subunits) recep-tors. The nAChRs are known to be differentially permeable to calcium ions, with the α7 nAChR subtype having one of the highest permeabilities to calcium. Calcium influx through nAChRs, particularly through the α-bungarotoxin-sensitive α7-containing nAChRs, is a very efficient way to raise cytoplasmic calcium levels. The activation of nAChRs can mediate three types of cytoplasmic calcium signals: (1) direct calcium influx through the nAChRs, (2) indirect calcium influx through voltage-dependent calcium channels (VDCCs) which are activated by the nAChR-mediated depolarization, and (3) calcium-induced calcium release (CICR) (triggered by the first two sources) from the endoplasmic reticulum (ER) through the ryanodine receptors and inositol (1,4,5)-triphosphate receptors (IP3Rs). Downstream signaling events mediated by nAChR-mediated calcium responses can be grouped into instantaneous effects (such as neurotransmitter release, which can occur in milliseconds after nAChR activation), short-term effects (such as the recovery of nAChR desensitization through cellular signaling cascades), and long-term effects (such as neuroprotection via gene expression). In addition, nAChR activity can be regulated by cytoplasmic calcium levels, suggesting a complex reciprocal relationship. Further advances in imaging techniques, animal models, and more potent and subtype-selective ligands for neuronal nAChRs would help in understand-ing the neuronal nAChR-mediated calcium signaling, and lead to the development of improved therapeutic treatments.

  3. Finite Element Model to Study One Dimensional Calcium Dyanmics in Cardiac Myocytes

    Science.gov (United States)

    Pathak, Kunal B.; Adlakha, Neeru

    2015-12-01

    The multi physical process involving calcium ions regulate expansion and contraction of cardiac myocytes. This mechanism of expansion and contraction of cardiac myocytes is responsible for contraction and expansion of heart for pumping of blood into arteries and receiving blood into heart from vein. Thus calcium dynamics in cardiac myocytes is responsible for the activities of the myocytes cells and functioning of the heart. The specific spatiotemporal calcium ion dynamics is required to trigger, sustain and terminate activity of the cell. In this paper an attempt has been done to propose a model to study calcium dynamics in cardiac myocytes for a one-dimensional unsteady state case. The model incorporates the process like diffusion, reaction involving source and excess buffers. Appropriate boundary conditions and initial conditions have been framed. The finite element method has been employed to obtain the solution. The numerical results have been used to study the effect of buffers and source influx on calcium dynamics in cardiac myocytes.

  4. Modeling of progesterone-induced intracellular calcium signaling in human spermatozoa.

    Science.gov (United States)

    Li, Long-Fei; Xiang, Cheng; Zhu, Ya-Bing; Qin, Kai-Rong

    2014-06-21

    Calcium ion is a secondary messenger of mammalian spermatozoa. The dynamic change of its concentration plays a vital role in the process of sperm motility, capacitation, acrosome and fertilization. Progesterone released by the cumulus cells, as a potent stimulator of fertilization, can activate the calcium channels on the plasma membrane, which in turn triggers the dynamic change of intracellular calcium concentration. In this paper, a mathematical model of calcium dynamic response in mammalian spermatozoa induced by progesterone is proposed and numerical simulation of the dynamic model is conducted. The results show that the dynamic response of calcium concentration predicted by the model is in accordance with experimental evidence. The proposed dynamic model can be used to explain the phenomena observed in the experiments and predict new phenomena to be revealed by experimental investigations, which will provide the basis to quantitatively investigate the fluid mechanics and biochemistry for the sperm motility induced by progesterone.

  5. Calcium flux assay in Xenopus oocytes.

    Science.gov (United States)

    Murphy, P M

    2001-05-01

    Many G protein-coupled receptors of interest to neuroscientists induce transient increases in [Ca(2+)](i), which can be used as a convenient measure of receptor activation in a variety of applications. This unit describes a simple calcium flux assay applied to Xenopus oocytes. PMID:18428482

  6. Calcium regulation of oxidative phosphorylation in rat skeletal muscle mitochondria.

    Science.gov (United States)

    Kavanagh, N I; Ainscow, E K; Brand, M D

    2000-02-24

    Activation of oxidative phosphorylation by physiological levels of calcium in mitochondria from rat skeletal muscle was analysed using top-down elasticity and regulation analysis. Oxidative phosphorylation was conceptually divided into three subsystems (substrate oxidation, proton leak and phosphorylation) connected by the membrane potential or the protonmotive force. Calcium directly activated the phosphorylation subsystem and (with sub-saturating 2-oxoglutarate) the substrate oxidation subsystem but had no effect on the proton leak kinetics. The response of mitochondria respiring on 2-oxoglutarate at two physiological concentrations of free calcium was quantified using control and regulation analysis. The partial integrated response coefficients showed that direct stimulation of substrate oxidation contributed 86% of the effect of calcium on state 3 oxygen consumption, and direct activation of the phosphorylation reactions caused 37% of the increase in phosphorylation flux. Calcium directly activated phosphorylation more strongly than substrate oxidation (78% compared to 45%) to achieve homeostasis of mitochondrial membrane potential during large increases in flux.

  7. The role of voltage-gated calcium channels in neurotransmitter phenotype specification: Coexpression and functional analysis in Xenopus laevis

    OpenAIRE

    Lewis, Brittany B.; Miller, Lauren E.; Herbst, Wendy A; Saha, Margaret S.

    2014-01-01

    Calcium activity has been implicated in many neurodevelopmental events, including the specification of neurotransmitter phenotypes. Higher levels of calcium activity lead to an increased number of inhibitory neural phenotypes, whereas lower levels of calcium activity lead to excitatory neural phenotypes. Voltage-gated calcium channels (VGCCs) allow for rapid calcium entry and are expressed during early neural stages, making them likely regulators of activity-dependent neurotransmitter phenoty...

  8. Effects of dietary clinoptilolite and calcium levels on uric acid and calcium blood concentrations and bone quality of commercial layers

    Directory of Open Access Journals (Sweden)

    DA Berto

    2013-06-01

    Full Text Available The objective of the present study was to evaluate the effect of clinoptilolite and calcium levels on uric acid and calcium blood profile and bone quality of commercial layers. A total of 576 birds were distributed according to a completely randomized experimental design in a 3x4 factorial arrangement (calcium levels of 2.5, 3.1, or 3.7% and clinoptilolite levels of 0.0, 0.15, 0.25, or 0.50%, into 12 treatments with six replicates of eight birds per cage (experimental unit. The experimental period was 112 days. The experimental diets were based on corn and soybean meal. Results were submitted to analysis of variance and means were compared by the test of Tukey at 5% significance level using SISVAR statistical package. Blood uric acid was significantly influenced by the interaction of the evaluated factors. Clinoptilolite levels significantly increased blood calcium levels. There was no effect of dietary calcium levels on any of the evaluated characteristics. It was concluded that feeding layers with up to 0.50% clinoptilolite does not benefit blood uric acid and calcium concentrations and does not affect their bone quality. When layers at the end of the first laying cycle are fed ad libitum and present 119.50g/hen/day average feed intake, 3.1% dietary calcium promotes 3.7g/hen/day calcium intake, which is sufficient to maintain adequate calcium blood levels and bone quality.

  9. Role of calcium conductance in firing behavior of retinal ganglion cells

    Institute of Scientific and Technical Information of China (English)

    Dan Wang; Qingli Qiao; Nan Xie

    2011-01-01

    Fohlmeister-Coleman-Miller model of retinal ganglion cells consists of five ion channels; these are sodium channels, calcium channels, and 3 types of potassium channels. An increasing number of studies have investigated sodium channels, voltage-gated potassium channels, and delayed rectifier potassium channels. However, little is known about calcium channels, and in particular the dynamics and computational models of calcium ions. Retinal prostheses have been designed to assist with sight recovery for the blind, and in the present study, the effects of calcium ions in retinal ganglion cell models were analyzed with regard to calcium channel potential and calcium-activated potassium potential. Using MATLAB software, calcium conductance and calcium current from the Fohlmeister-Coleman-Miller model, under clamped voltages, were numerically computed using backward Euler methods. Subsequently, the Fohlmeister-Coleman-Miller model was simulated with the absence of calcium-current (lc,) or calcium-activated potassium current (IK, ca). The model was also analyzed according to the phase plane method.The relationship curve between peak calcium current and clamped potentials revealed an inverted bell shape, and the calcium-activated potassium current increased the frequency of firing and the peak of membrane potential. Results suggested that calcium ion concentrations play an important role in controlling the peak and the magnitude of peak membrane voltage in retinal ganglion cells.

  10. Calcium-regulated in vivo protein phosphorylation in Zea mays L. root tips

    Science.gov (United States)

    Raghothama, K. G.; Reddy, A. S.; Friedmann, M.; Poovaiah, B. W.

    1987-01-01

    Calcium dependent protein phosphorylation was studied in corn (Zea mays L.) root tips. Prior to in vivo protein phosphorylation experiments, the effect of calcium, ethyleneglycol-bis-(beta-aminoethyl ether)-N-N' -tetraacetic acid (EGTA) and calcium ionophore (A-23187) on phosphorus uptake was studied. Calcium increased phosphorus uptake, whereas EGTA and A-23187 decreased it. Consequently, phosphorus concentration in the media was adjusted so as to attain similar uptake in different treatments. Phosphoproteins were analyzed by two-dimensional gel electrophoresis. Distinct changes in phosphorylation were observed following altered calcium levels. Calcium depletion in root tips with EGTA and A-23187 decreased protein phosphorylation. However, replenishment of calcium following EGTA and ionophore pretreatment enhanced phosphorylation of proteins. Preloading of the root tips with 32P in the presence of EGTA and A-23187 followed by a ten minute calcium treatment, resulted in increased phosphorylation indicating the involvement of calcium, calcium and calmodulin-dependent kinases. Calmodulin antagonist W-7 was effective in inhibiting calcium-promoted phosphorylation. These studies suggest a physiological role for calcium-dependent phosphorylation in calcium-mediated processes in plants.

  11. Respiratory metabolism and calorie restriction relieve persistent endoplasmic reticulum stress induced by calcium shortage in yeast.

    Science.gov (United States)

    Busti, Stefano; Mapelli, Valeria; Tripodi, Farida; Sanvito, Rossella; Magni, Fulvio; Coccetti, Paola; Rocchetti, Marcella; Nielsen, Jens; Alberghina, Lilia; Vanoni, Marco

    2016-06-16

    Calcium homeostasis is crucial to eukaryotic cell survival. By acting as an enzyme cofactor and a second messenger in several signal transduction pathways, the calcium ion controls many essential biological processes. Inside the endoplasmic reticulum (ER) calcium concentration is carefully regulated to safeguard the correct folding and processing of secretory proteins. By using the model organism Saccharomyces cerevisiae we show that calcium shortage leads to a slowdown of cell growth and metabolism. Accumulation of unfolded proteins within the calcium-depleted lumen of the endoplasmic reticulum (ER stress) triggers the unfolded protein response (UPR) and generates a state of oxidative stress that decreases cell viability. These effects are severe during growth on rapidly fermentable carbon sources and can be mitigated by decreasing the protein synthesis rate or by inducing cellular respiration. Calcium homeostasis, protein biosynthesis and the unfolded protein response are tightly intertwined and the consequences of facing calcium starvation are determined by whether cellular energy production is balanced with demands for anabolic functions. Our findings confirm that the connections linking disturbance of ER calcium equilibrium to ER stress and UPR signaling are evolutionary conserved and highlight the crucial role of metabolism in modulating the effects induced by calcium shortage.

  12. Trigger electronics for the ALICE PHOS detector

    CERN Document Server

    Müller, H; Musa, L; Yin, Z; Röhrich, D; Skaali, B; Sibiryak, Yu; Budnikov, D L

    2004-01-01

    The Photon Spectrometer of ALICE consists of 5 identical modules of 56 multiplied by 64 PWO crystals with a total of 100 degree azimuthal coverage of the barrel. The electronics required for implementing both the L0 trigger for high luminosity p-p physics and the L1 trigger for high p//T Pb+Pb physics has been studied. A full integration of the trigger logic into the detector's enclosure is based on analog transmission of fast trigger sums between stacks of front-end boards and trigger-router units. The latter contain 112 digitizer channels of 10bit, which are mapped into a single FPGA per trigger unit, covering areas of 24 multiplied by 16 crystals. The running modes allow for Level-0 trigger at 800ns and Level-1 at 6200ns trigger latencies. The design and status of the PHOS trigger electronics are outlined.

  13. Calcium signaling and T-type calcium channels in cancer cell cycling

    Institute of Scientific and Technical Information of China (English)

    James T Taylor; Xiang-Bin Zeng; Jonathan E Pottle; Kevin Lee; Alun R Wang; Stephenie G Yi; Jennifer A S Scruggs; Suresh S Sikka; Ming Li

    2008-01-01

    Regulation of intracellular calcium is an important signaling mechanism for cell proliferation in both normal and cancerous cells. In normal epithelial cells,free calcium concentration is essential for cells to enter and accomplish the S phase and the M phase of the cell cycle. In contrast, cancerous cells can pass these phases of the cell cycle with much lower cytoplasmic free calcium concentrations, indicating an alternative mechanism has developed for fulfilling the intracellular calcium requirement for an increased rate of DNA synthesis and mitosis of fast replicating cancerous cells. The detailed mechanism underlying the altered calcium loading pathway remains unclear;however, there is a growing body of evidence that suggests the T-type Ca2+ channel is abnormally expressed in cancerous cells and that blockade of these channels may reduce cell proliferation in addition to inducing apoptosis. Recent studies also show that the expression of T-type Ca2+ channels in breast cancer cells is proliferation state dependent, i.e. the channels are expressed at higher levels during the fast-replication period, and once the cells are in a non-proliferation state, expression of this channel isminimal. Therefore, selectively blocking calcium entry into cancerous cells may be a valuable approach for preventing tumor growth. Since T-type Ca2+ channels are not expressed in epithelial cells, selective T-type Ca2+ channel blockers may be useful in the treatment of certain types of cancers.

  14. In vivo calcium imaging of evoked calcium waves in the embryonic cortex

    Directory of Open Access Journals (Sweden)

    Mikhail eYuryev

    2016-01-01

    Full Text Available The dynamics of intracellular calcium fluxes are instrumental in the proliferation, differentiation and migration of neuronal cells. Knowledge thus far of the relationship between these calcium changes and physiological processes in the developing brain has derived principally from ex vivo and in vitro experiments. Here, we present a new method to image intracellular calcium flux in the cerebral cortex of live rodent embryos, whilst attached to the dam through the umbilical cord. Using this approach we demonstrate induction of calcium waves by laser stimulation. These waves are sensitive to ATP-receptor blockade and are significantly increased by pharmacological facilitation of intracellular-calcium release. This approach is the closest to physiological conditions yet achieved for imaging of calcium in the embryonic brain and as such opens new avenues for the study of prenatal brain development. Furthermore, the developed method could open the possibilities of preclinical translational studies in embryos particularly important for developmentally related diseases such as schizophrenia and autism.

  15. Childhood Asthma Management and Environmental Triggers.

    Science.gov (United States)

    Hollenbach, Jessica P; Cloutier, Michelle M

    2015-10-01

    Asthma is the most common chronic disease among children. It cannot be prevented but can be controlled. Industrialized countries experience high lifetime asthma prevalence that has increased over recent decades. Asthma has a complex interplay of genetic and environmental triggers. Studies have revealed complex interactions of lung structure and function genes with environmental exposures such as environmental tobacco smoke and vitamin D. Home environmental strategies can reduce asthma morbidity in children but should be tailored to specific allergens. Coupled with education and severity-specific asthma therapy, tailored interventions may be the most effective strategy to manage childhood asthma.

  16. Over-voltage trigger device for Marx generators

    International Nuclear Information System (INIS)

    For treatment of plant tissue with pulsed electric fields in large scale, synchronized operation of several Marx generators is required in order to minimize the low-field regions inside the electroporation reactor and to overcome the current limitations of a single pulse circuit. Hence, the Marx generators must be triggered. If long-term operation without service is to be achieved, these generators are triggered by over-volting the first spark gap without the use of an additional electrode for ignition, which would cause increased wear. A trigger device for over-volting the first spark gap of a Marx generator has been designed. It has been tailored to replace the charging coils between the 1st and the 2nd stage of an already existing Marx generator. In order to overcome the requirements for insulation to ground potential, the trigger device is powered by the charging current of the Marx generator. This paper describes some design issues.

  17. The ATLAS Transverse Momentum Trigger at the LHC

    CERN Document Server

    Mincer, Allen; The ATLAS collaboration; Struebig, Antonia; Schouwenberg, Jeroen; Beacham, James Baker

    2015-01-01

    The transverse momentum triggers of the ATLAS experiment at the CERN Large Hadron Collider (LHC) are designed to select collision events with non-interacting particles passing through the detector. Such events provide an interesting probe for new-physics interactions beyond the Standard Model, and also provide the basis for precise measurements of Standard Model parameters such as Higgs couplings. The transverse momentum used in the trigger system is calculated from calorimeter- based global energy sums and supplemented with information from the muon detection system. The trigger successfully operated during the first running period of the LHC. Starting in 2015 the LHC will produce collisions at higher energy and increased luminosity; improving on the trigger performance from the previous run period will be challenging.

  18. Over-voltage trigger device for Marx generators

    Energy Technology Data Exchange (ETDEWEB)

    Sack, M.; Staengle, R.; Mueller, G. [Karlsruhe Institute of Technology (KIT), Institute for Pulsed Power and Microwave Technology, Eggenstein-Leopoldshafen (Germany)

    2011-12-15

    For treatment of plant tissue with pulsed electric fields in large scale, synchronized operation of several Marx generators is required in order to minimize the low-field regions inside the electroporation reactor and to overcome the current limitations of a single pulse circuit. Hence, the Marx generators must be triggered. If long-term operation without service is to be achieved, these generators are triggered by over-volting the first spark gap without the use of an additional electrode for ignition, which would cause increased wear. A trigger device for over-volting the first spark gap of a Marx generator has been designed. It has been tailored to replace the charging coils between the 1st and the 2nd stage of an already existing Marx generator. In order to overcome the requirements for insulation to ground potential, the trigger device is powered by the charging current of the Marx generator. This paper describes some design issues.

  19. FocusStack and StimServer: A new open source MATLAB toolchain for visual stimulation and analysis of two-photon calcium neuronal imaging data

    Directory of Open Access Journals (Sweden)

    Dylan Richard Muir

    2015-01-01

    Full Text Available Two-photon calcium imaging of neuronal responses is an increasingly accessible technology for probing population responses in cortex at single cell resolution, and with reasonable and improving temporal resolution. However, analysis of two-photon data is usually performed using ad-hoc solutions. To date, no publicly available software exists for straightforward analysis of stimulus-triggered two-photon imaging experiments. In addition, the increasing data rates of two-photon acquisition systems imply increasing cost of computing hardware required for in-memory analysis. Here we present a Matlab toolbox, FocusStack, for simple and efficient analysis of two-photon calcium imaging stacks on consumer-level hardware, with minimal memory footprint. We also present a Matlab toolbox, StimServer, for generation and sequencing of visual stimuli, designed to be triggered over a network link from a two-photon acquisition system. FocusStack is compatible out of the box with several existing two-photon acquisition systems, and is simple to adapt to arbitrary binary file formats. Analysis tools such as stack alignment for movement correction, automated cell detection and peri-stimulus time histograms are already provided, and further tools can be easily incorporated. Both packages are available as publicly-accessible source-code repositories.

  20. FocusStack and StimServer: a new open source MATLAB toolchain for visual stimulation and analysis of two-photon calcium neuronal imaging data.

    Science.gov (United States)

    Muir, Dylan R; Kampa, Björn M

    2014-01-01

    Two-photon calcium imaging of neuronal responses is an increasingly accessible technology for probing population responses in cortex at single cell resolution, and with reasonable and improving temporal resolution. However, analysis of two-photon data is usually performed using ad-hoc solutions. To date, no publicly available software exists for straightforward analysis of stimulus-triggered two-photon imaging experiments. In addition, the increasing data rates of two-photon acquisition systems imply increasing cost of computing hardware required for in-memory analysis. Here we present a Matlab toolbox, FocusStack, for simple and efficient analysis of two-photon calcium imaging stacks on consumer-level hardware, with minimal memory footprint. We also present a Matlab toolbox, StimServer, for generation and sequencing of visual stimuli, designed to be triggered over a network link from a two-photon acquisition system. FocusStack is compatible out of the box with several existing two-photon acquisition systems, and is simple to adapt to arbitrary binary file formats. Analysis tools such as stack alignment for movement correction, automated cell detection and peri-stimulus time histograms are already provided, and further tools can be easily incorporated. Both packages are available as publicly-accessible source-code repositories.