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Sample records for ca influx arising

  1. Effects of several chinese crude drugs on 45Ca transmembrane influx in vascular smooth muscles

    International Nuclear Information System (INIS)

    The effects of several Chinese crude drugs including Crocus sativus, Carthamus tinctorius and Ginkgo biloba on Ca2+ transmembrane influx in rat aorta rings were studied. Resting 45Ca uptake was not markedly altered by these drugs, whereas the 45Ca influxes evoked by norepinephrine (1.2 μmol/L) and KCl (100 mmol/L) in rat aorta rings were significantly inhibited by Crocus and Carthamus in a concentration-dependent manner, not by Ginkgo. The results indicate that extracellular Ca2+ transmembrane influx through receptor-operated Ca2+ channels and potential-dependent Ca2+ channels can be blocked by Crocus and Carthamus

  2. Isoflurane inhibits synaptic vesicle exocytosis through reduced Ca2+ influx, not Ca2+-exocytosis coupling.

    Science.gov (United States)

    Baumgart, Joel P; Zhou, Zhen-Yu; Hara, Masato; Cook, Daniel C; Hoppa, Michael B; Ryan, Timothy A; Hemmings, Hugh C

    2015-09-22

    Identifying presynaptic mechanisms of general anesthetics is critical to understanding their effects on synaptic transmission. We show that the volatile anesthetic isoflurane inhibits synaptic vesicle (SV) exocytosis at nerve terminals in dissociated rat hippocampal neurons through inhibition of presynaptic Ca(2+) influx without significantly altering the Ca(2+) sensitivity of SV exocytosis. A clinically relevant concentration of isoflurane (0.7 mM) inhibited changes in [Ca(2+)]i driven by single action potentials (APs) by 25 ± 3%, which in turn led to 62 ± 3% inhibition of single AP-triggered exocytosis at 4 mM extracellular Ca(2+) ([Ca(2+)]e). Lowering external Ca(2+) to match the isoflurane-induced reduction in Ca(2+) entry led to an equivalent reduction in exocytosis. These data thus indicate that anesthetic inhibition of neurotransmitter release from small SVs occurs primarily through reduced axon terminal Ca(2+) entry without significant direct effects on Ca(2+)-exocytosis coupling or on the SV fusion machinery. Isoflurane inhibition of exocytosis and Ca(2+) influx was greater in glutamatergic compared with GABAergic nerve terminals, consistent with selective inhibition of excitatory synaptic transmission. Such alteration in the balance of excitatory to inhibitory transmission could mediate reduced neuronal interactions and network-selective effects observed in the anesthetized central nervous system. PMID:26351670

  3. The contractile vacuole in Ca2+-regulation in Dictyostelium: its essential function for cAMP-induced Ca2+-influx

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    Schlatterer Christina

    2006-06-01

    Full Text Available Abstract Background cAMP-induced Ca2+-influx in Dictyostelium is controlled by at least two non-mitochondrial Ca2+-stores: acidic stores and the endoplasmic reticulum (ER. The acidic stores may comprise the contractile vacuole network (CV, the endosomal compartment and acidocalcisomes. Here the role of CV in respect to function as a potential Ca2+-store was investigated. Results Dajumin-GFP labeled contractile vacuoles were purified 7-fold by anti-GFP-antibodies in a magnetic field. The purified CV were shown for the first time to accumulate and release Ca2+. Release of Ca2+ was elicited by arachidonic acid or the calmodulin antagonist W7, the latter due to inhibition of the pump. The characteristics of Ca2+-transport and Ca2+-release of CV were compared to similarly purified vesicles of the ER labeled by calnexin-GFP. Since the CV proved to be a highly efficient Ca2+-compartment we wanted to know whether or not it takes part in cAMP-induced Ca2+-influx. We made use of the LvsA--mutant expected to display reduced Ca2+-transport due to loss of calmodulin. We found a severe reduction of cAMP-induced Ca2+-influx into whole cells. Conclusion The contractile vacuoles in Dictyostelium represent a highly efficient acidic Ca2+-store that is required for cAMP-induced Ca2+-influx.

  4. Ca2+ influx and ATP release mediated by mechanical stretch in human lung fibroblasts

    International Nuclear Information System (INIS)

    Highlights: • Uniaxial stretching activates Ca2+ signaling in human lung fibroblasts. • Stretch-induced intracellular Ca2+ elevation is mainly via Ca2+ influx. • Mechanical strain enhances ATP release from fibroblasts. • Stretch-induced Ca2+ influx is not mediated by released ATP or actin cytoskeleton. - Abstract: One cause of progressive pulmonary fibrosis is dysregulated wound healing after lung inflammation or damage in patients with idiopathic pulmonary fibrosis and severe acute respiratory distress syndrome. The mechanical forces are considered to regulate pulmonary fibrosis via activation of lung fibroblasts. In this study, the effects of mechanical stretch on the intracellular Ca2+ concentration ([Ca2+]i) and ATP release were investigated in primary human lung fibroblasts. Uniaxial stretch (10–30% in strain) was applied to fibroblasts cultured in a silicone chamber coated with type I collagen using a stretching apparatus. Following stretching and subsequent unloading, [Ca2+]i transiently increased in a strain-dependent manner. Hypotonic stress, which causes plasma membrane stretching, also transiently increased the [Ca2+]i. The stretch-induced [Ca2+]i elevation was attenuated in Ca2+-free solution. In contrast, the increase of [Ca2+]i by a 20% stretch was not inhibited by the inhibitor of stretch-activated channels GsMTx-4, Gd3+, ruthenium red, or cytochalasin D. Cyclic stretching induced significant ATP releases from fibroblasts. However, the stretch-induced [Ca2+]i elevation was not inhibited by ATP diphosphohydrolase apyrase or a purinergic receptor antagonist suramin. Taken together, mechanical stretch induces Ca2+ influx independently of conventional stretch-sensitive ion channels, the actin cytoskeleton, and released ATP

  5. Ca{sup 2+} influx and ATP release mediated by mechanical stretch in human lung fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Naohiko [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Ito, Satoru, E-mail: itori@med.nagoya-u.ac.jp [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Furuya, Kishio [Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Takahara, Norihiro [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Naruse, Keiji [Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Okayama 700-8558 (Japan); Aso, Hiromichi; Kondo, Masashi [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Sokabe, Masahiro [Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan); Hasegawa, Yoshinori [Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya 466-8550 (Japan)

    2014-10-10

    Highlights: • Uniaxial stretching activates Ca{sup 2+} signaling in human lung fibroblasts. • Stretch-induced intracellular Ca{sup 2+} elevation is mainly via Ca{sup 2+} influx. • Mechanical strain enhances ATP release from fibroblasts. • Stretch-induced Ca{sup 2+} influx is not mediated by released ATP or actin cytoskeleton. - Abstract: One cause of progressive pulmonary fibrosis is dysregulated wound healing after lung inflammation or damage in patients with idiopathic pulmonary fibrosis and severe acute respiratory distress syndrome. The mechanical forces are considered to regulate pulmonary fibrosis via activation of lung fibroblasts. In this study, the effects of mechanical stretch on the intracellular Ca{sup 2+} concentration ([Ca{sup 2+}]{sub i}) and ATP release were investigated in primary human lung fibroblasts. Uniaxial stretch (10–30% in strain) was applied to fibroblasts cultured in a silicone chamber coated with type I collagen using a stretching apparatus. Following stretching and subsequent unloading, [Ca{sup 2+}]{sub i} transiently increased in a strain-dependent manner. Hypotonic stress, which causes plasma membrane stretching, also transiently increased the [Ca{sup 2+}]{sub i}. The stretch-induced [Ca{sup 2+}]{sub i} elevation was attenuated in Ca{sup 2+}-free solution. In contrast, the increase of [Ca{sup 2+}]{sub i} by a 20% stretch was not inhibited by the inhibitor of stretch-activated channels GsMTx-4, Gd{sup 3+}, ruthenium red, or cytochalasin D. Cyclic stretching induced significant ATP releases from fibroblasts. However, the stretch-induced [Ca{sup 2+}]{sub i} elevation was not inhibited by ATP diphosphohydrolase apyrase or a purinergic receptor antagonist suramin. Taken together, mechanical stretch induces Ca{sup 2+} influx independently of conventional stretch-sensitive ion channels, the actin cytoskeleton, and released ATP.

  6. Neuronal processing of noxious thermal stimuli mediated by dendritic Ca(2+) influx in Drosophila somatosensory neurons.

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    Terada, Shin-Ichiro; Matsubara, Daisuke; Onodera, Koun; Matsuzaki, Masanori; Uemura, Tadashi; Usui, Tadao

    2016-01-01

    Adequate responses to noxious stimuli causing tissue damages are essential for organismal survival. Class IV neurons in Drosophila larvae are polymodal nociceptors responsible for thermal, mechanical, and light sensation. Importantly, activation of Class IV provoked distinct avoidance behaviors, depending on the inputs. We found that noxious thermal stimuli, but not blue light stimulation, caused a unique pattern of Class IV, which were composed of pauses after high-frequency spike trains and a large Ca(2+) rise in the dendrite (the Ca(2+) transient). Both these responses depended on two TRPA channels and the L-type voltage-gated calcium channel (L-VGCC), showing that the thermosensation provokes Ca(2+) influx. The precipitous fluctuation of firing rate in Class IV neurons enhanced the robust heat avoidance. We hypothesize that the Ca(2+) influx can be a key signal encoding a specific modality. PMID:26880554

  7. Basophil response to antigen and anti-IgE 3. Ca(2+) influx and histamine release

    OpenAIRE

    Tanizaki,Yoshiro; Kitani,Hikaru; Okazaki, Morihiro; Mifune, Takashi; Mitsunobu, Fumihiro; Kimura,Ikuro

    1992-01-01

    The release mechanism of chemical mediators from basophils and mast cells was discussed when these cells were stimulated by different antigens and anti-IgE. 1. Ca(2+) influx into mast cells increased after stimulation by antigen. The increased Ca(2+) uptake by mast cells was inhibited by antiallergic agents, disodium cromoglycate (DSCG) and tranilast, and calcium antagonists, nifedipine and nicardipine. 2. The dose-response curve of histamine release by antigen was different from that by anti...

  8. Hair cells use active zones with different voltage dependence of Ca2+ influx to decompose sounds into complementary neural codes.

    Science.gov (United States)

    Ohn, Tzu-Lun; Rutherford, Mark A; Jing, Zhizi; Jung, Sangyong; Duque-Afonso, Carlos J; Hoch, Gerhard; Picher, Maria Magdalena; Scharinger, Anja; Strenzke, Nicola; Moser, Tobias

    2016-08-01

    For sounds of a given frequency, spiral ganglion neurons (SGNs) with different thresholds and dynamic ranges collectively encode the wide range of audible sound pressures. Heterogeneity of synapses between inner hair cells (IHCs) and SGNs is an attractive candidate mechanism for generating complementary neural codes covering the entire dynamic range. Here, we quantified active zone (AZ) properties as a function of AZ position within mouse IHCs by combining patch clamp and imaging of presynaptic Ca(2+) influx and by immunohistochemistry. We report substantial AZ heterogeneity whereby the voltage of half-maximal activation of Ca(2+) influx ranged over ∼20 mV. Ca(2+) influx at AZs facing away from the ganglion activated at weaker depolarizations. Estimates of AZ size and Ca(2+) channel number were correlated and larger when AZs faced the ganglion. Disruption of the deafness gene GIPC3 in mice shifted the activation of presynaptic Ca(2+) influx to more hyperpolarized potentials and increased the spontaneous SGN discharge. Moreover, Gipc3 disruption enhanced Ca(2+) influx and exocytosis in IHCs, reversed the spatial gradient of maximal Ca(2+) influx in IHCs, and increased the maximal firing rate of SGNs at sound onset. We propose that IHCs diversify Ca(2+) channel properties among AZs and thereby contribute to decomposing auditory information into complementary representations in SGNs. PMID:27462107

  9. Ca2+ influx and efflux in animal cells in the presence of panax notoginseng extracts: investigated by using 45Ca as a radioactive tracer

    International Nuclear Information System (INIS)

    In this paper, the influence of extracts of Panax notoginseng on Ca2+ influx and efflux in isolated rat visceral organs was investigated by using 45Ca as a radioactive tracer. The results indicated that both extracts, the total flavonoids and total saponins of Panax notoginseng had significant influence on Ca2+ influx and efflux in the isolated rat aorta, heart, and kidney, in those organs it could markedly block 45Ca entering into cell and could facilitate efflux of intracellular Ca2+. Compared with the total flavonoids, total saponins had stronger role in the regulation of Ca2+ influx and efflux. Also, regulation effects of Ca2+ influx and efflux of the total saponins were compared with positive drug Verapamil, or even better. This implies that the total flavonoids and total saponins of Panax notoginseng have calcium antagonistic effect, and both may be the active ingredients in Panax notoginseng for coronary heart disease treatment. (authors)

  10. Effects of the Ca agonist Bay K8644 on 45Ca influx and net Ca uptake into rabbit aortic smooth muscle

    International Nuclear Information System (INIS)

    The authors examined the effects of Bay K8644 and external K+ on isolated rings of rabbit aorta. Previous evidence has suggested that the Ca channel agonist, Bay K8644, preferentially opens the potential-sensitive Ca2+ channels (PSCs) rather than receptor-operated Ca2+ channels (ROCs). Bay K8644 stimulated 45Ca influx, net Ca gain and contractile tension were measured as a function of extracellular K+ concentration. The data are explained in terms of a calcium entry model consisting of membrane Ca2+ channels in series with a subplasmalemmal barrier consisting of superficial sarcoplasmic reticulum (SR). (Auth.)

  11. Spasmolytic Effect of Caulerpine Involves Blockade of Ca2+ Influx on Guinea Pig Ileum

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    Magna Suzana Alexandre-Moreira

    2013-05-01

    Full Text Available In this work, we investigated the spasmolytic effect of caulerpine, a bisindole alkaloid isolated from marine algae of the Caulerpa genus, on guinea pig ileum. Our findings indicated that caulerpine inhibited phasic contractions induced by carbachol (IC50 = 7.0 ± 1.9 × 10−5 M, histamine (IC50 = 1.3 ± 0.3 × 10−4 M and serotonin (IC50 = 8.0 ± 1.4 × 10−5 M in a non-selective manner. Furthermore, caulerpine concentration-dependently inhibited serotonin-induced cumulative contractions (pD′2 = 4.48 ± 0.08, shifting the curves to the right with Emax reduction and slope of 2.44 ± 0.21, suggesting a noncompetitive antagonism pseudo-irreversible. The alkaloid also relaxed the ileum pre-contracted by KCl (EC50 = 9.0 ± 0.9 × 10−5 M and carbachol (EC50 = 4.6 ± 0.7 × 10−5 M in a concentration-dependent manner. This effect was probably due to inhibition of Ca2+ influx through voltage-gated calcium channels (CaV, since caulerpine slightly inhibited the CaCl2-induced contractions in depolarizing medium without Ca2+, shifting the curves to the right and with Emax reduction. According to these results, the spasmolytic effect of caulerpine on guinea pig ileum seems to involve inhibition of Ca2+ influx through CaV. However, other mechanisms are not discarded.

  12. TRP, TRPL and cacophony channels mediate Ca2+ influx and exocytosis in photoreceptors axons in Drosophila.

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    Guadalupe Astorga

    Full Text Available In Drosophila photoreceptors Ca(2+-permeable channels TRP and TRPL are the targets of phototransduction, occurring in photosensitive microvilli and mediated by a phospholipase C (PLC pathway. Using a novel Drosophila brain slice preparation, we studied the distribution and physiological properties of TRP and TRPL in the lamina of the visual system. Immunohistochemical images revealed considerable expression in photoreceptors axons at the lamina. Other phototransduction proteins are also present, mainly PLC and protein kinase C, while rhodopsin is absent. The voltage-dependent Ca(2+ channel cacophony is also present there. Measurements in the lamina with the Ca(2+ fluorescent protein G-CaMP ectopically expressed in photoreceptors, revealed depolarization-induced Ca(2+ increments mediated by cacophony. Additional Ca(2+ influx depends on TRP and TRPL, apparently functioning as store-operated channels. Single synaptic boutons resolved in the lamina by FM4-64 fluorescence revealed that vesicle exocytosis depends on cacophony, TRP and TRPL. In the PLC mutant norpA bouton labeling was also impaired, implicating an additional modulation by this enzyme. Internal Ca(2+ also contributes to exocytosis, since this process was reduced after Ca(2+-store depletion. Therefore, several Ca(2+ pathways participate in photoreceptor neurotransmitter release: one is activated by depolarization and involves cacophony; this is complemented by internal Ca(2+ release and the activation of TRP and TRPL coupled to Ca(2+ depletion of internal reservoirs. PLC may regulate the last two processes. TRP and TRPL would participate in two different functions in distant cellular regions, where they are opened by different mechanisms. This work sheds new light on the mechanism of neurotransmitter release in tonic synapses of non-spiking neurons.

  13. Jujuboside B Reduces Vascular Tension by Increasing Ca2+ Influx and Activating Endothelial Nitric Oxide Synthase.

    Science.gov (United States)

    Zhao, Yixiu; Zhang, Xin; Li, Jiannan; Bian, Yu; Sheng, Miaomiao; Liu, Bin; Fu, Zidong; Zhang, Yan; Yang, Baofeng

    2016-01-01

    Jujuboside B has been reported to have protective effect on many cardiovascular diseases. However, the effects of Jujuboside B on vascular tension and endothelial function are unknown. The present study investigated the effects of Jujuboside B on reducing vascular tension, protecting endothelial function and the potential mechanisms. The tension of isolated rat thoracic aorta ring was measured by Wire myograph system. The concentration of nitric oxide (NO) and the activity of endothelial nitric oxide synthase (eNOS) in human aortic endothelial cells (HAECs) were determined by Griess reagent method and enzyme-linked immune sorbent assay. The protein levels of eNOS and p-eNOS at Serine-1177 were determined by western blot analysis. Intracellular Ca2+ concentration in HAECs was measured by laser confocal imaging microscopy. Results showed that Jujuboside B reduced the tension of rat thoracic aorta rings with intact endothelium in a dose-dependent manner. L-NAME, KN93, EGTA, SKF96365, iberiotoxin and glibenclamide significantly attenuated Jujuboside B-induced vasodilation in endothelium-intact tissues. In contrast, indometacin and 4-DAMP had no such effects. Jujuboside B also promoted NO generation and increased eNOS activity, which were attenuated by L-NAME, EGTA and SKF96365. Moreover, Jujuboside B increased intracellular Ca2+ concentration dose-dependently, which was inhibited by EGTA and SKF96365. Besides, Jujuboside B induced a rapid Ca2+ influx instantaneously after depleting intracellular Ca2+ store, which was significantly inhibited by SKF96365. In conclusion, this study preliminarily confirmed that Jujuboside B reduced vascular tension endothelium-dependently. The underlying mechanisms involved that Jujuboside B increased extracellular Ca2+ influx through endothelial transient receptor potential cation (TRPC) channels, phosphorylated eNOS and promoted NO generation in vascular endothelial cells. In addition, Jujuboside B-induced vasodilation involved

  14. Duck-billed platypus venom peptides induce Ca2+ influx in neuroblastoma cells.

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    Kita, Masaki; Black, David StC; Ohno, Osamu; Yamada, Kaoru; Kigoshi, Hideo; Uemura, Daisuke

    2009-12-23

    The duck-billed platypus (Ornithorhynchus anatinus) is one of the few venomous Australian mammals. We previously found that its crude venom potently induces Ca(2+) influx in human neuroblastoma IMR-32 cells. Guided by this bioassay, we identified 11 novel peptides, including the heptapeptide H-His-Asp-His-Pro-Asn-Pro-Arg-OH (1). Compounds 1-4 and 5-11 coincided with the 6-9 N-terminal residues of Ornithorhynchus venom C-type natriuretic peptide (OvCNP) and the 132-150 part of OvCNP precursor peptide, respectively. Heptapeptide 1, which is one of the primary components of the venom fluid (approximately 200 ng/microL), induced a significant increase in [Ca(2+)](i) in IMR-32 cells at 75 microM. To the best of our knowledge, this is the first example of the isolation of the N-terminal linear fragments of CNPs in any mammal. PMID:19928958

  15. Paraoxon Attenuates Vascular Smooth Muscle Contraction through Inhibiting Ca2+ Influx in the Rabbit Thoracic Aorta

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    Shouhong Zhou

    2010-01-01

    Full Text Available We investigated the effect of paraoxon on vascular contractility using organ baths in thoracic aortic rings of rabbits and examined the effect of paraoxon on calcium homeostasis using a whole-cell patch-clamp technique in isolated aortic smooth muscle cells of rabbits. The findings show that administration of paraoxon (30 μM attenuated thoracic aorta contraction induced by phenylephrine (1 μM and/or a high K+ environment (80 mM in both the presence and absence of thoracic aortic endothelium. This inhibitory effect of paraoxon on vasoconstrictor-induced contraction was abolished in the absence of extracellular Ca2+, or in the presence of the Ca2+ channel inhibitor, verapamil. But atropine had little effect on the inhibitory effect of paraoxon on phenylephrine-induced contraction. Paraoxon also attenuated vascular smooth muscle contraction induced by the cumulative addition of CaCl2 and attenuated an increase of intracellular Ca2+ concentration induced by K+ in vascular smooth muscle cells. Moreover, paraoxon (30 μM inhibited significantly L-type calcium current in isolated aortic smooth muscle cells of rabbits. In conclusion, our results demonstrate that paraoxon attenuates vasoconstrictor-induced contraction through inhibiting Ca2+ influx in the rabbits thoracic aorta.

  16. Ca2+influx insensitive to organic Ca2+entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aorta

    NARCIS (Netherlands)

    Gouw, M.A.M.; Wilffert, B.; Wermelskirchen, D.; Van Zwieten, P.A.

    1990-01-01

    We determined the contribution of intracellular Ca2+to the noradrenaline (NA, 3 x 10-5mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+release, we assumed that a Ca2+influx component contributes

  17. Jujuboside B Reduces Vascular Tension by Increasing Ca2+ Influx and Activating Endothelial Nitric Oxide Synthase.

    Directory of Open Access Journals (Sweden)

    Yixiu Zhao

    Full Text Available Jujuboside B has been reported to have protective effect on many cardiovascular diseases. However, the effects of Jujuboside B on vascular tension and endothelial function are unknown. The present study investigated the effects of Jujuboside B on reducing vascular tension, protecting endothelial function and the potential mechanisms. The tension of isolated rat thoracic aorta ring was measured by Wire myograph system. The concentration of nitric oxide (NO and the activity of endothelial nitric oxide synthase (eNOS in human aortic endothelial cells (HAECs were determined by Griess reagent method and enzyme-linked immune sorbent assay. The protein levels of eNOS and p-eNOS at Serine-1177 were determined by western blot analysis. Intracellular Ca2+ concentration in HAECs was measured by laser confocal imaging microscopy. Results showed that Jujuboside B reduced the tension of rat thoracic aorta rings with intact endothelium in a dose-dependent manner. L-NAME, KN93, EGTA, SKF96365, iberiotoxin and glibenclamide significantly attenuated Jujuboside B-induced vasodilation in endothelium-intact tissues. In contrast, indometacin and 4-DAMP had no such effects. Jujuboside B also promoted NO generation and increased eNOS activity, which were attenuated by L-NAME, EGTA and SKF96365. Moreover, Jujuboside B increased intracellular Ca2+ concentration dose-dependently, which was inhibited by EGTA and SKF96365. Besides, Jujuboside B induced a rapid Ca2+ influx instantaneously after depleting intracellular Ca2+ store, which was significantly inhibited by SKF96365. In conclusion, this study preliminarily confirmed that Jujuboside B reduced vascular tension endothelium-dependently. The underlying mechanisms involved that Jujuboside B increased extracellular Ca2+ influx through endothelial transient receptor potential cation (TRPC channels, phosphorylated eNOS and promoted NO generation in vascular endothelial cells. In addition, Jujuboside B-induced vasodilation

  18. Effect of selective blockade of oxygen consumption, glucose transport, and Ca2+ influx on thyroxine action in human mononuclear cells

    DEFF Research Database (Denmark)

    Kvetny, J; Matzen, L E

    1990-01-01

    The effect of selective blockade of cellular glucose transporters, Ca2+ influx, and mitochondrial oxygen consumption on thyroxine (T4)-stimulated oxygen consumption and glucose uptake was examined in human mononuclear blood cells. Blockade of glucose transporters by cytochalasin B (1 x 10(-5) mol...... had no effect on glucose uptake. We conclude that T4-stimulated glucose uptake in human mononuclear blood cells is dependent on intact glucose transporters and Ca2+ influx, but not on mitochondrial oxygen consumption. However, oxygen consumption is, in part, dependent on intact glucose uptake......./L) and of Ca2+ influx by alprenolol (1 x 10(-5) mol/L) and verapamil (4 x 10(-4) mol/L) inhibited T4-activated glucose uptaken and reduced T4-stimulated oxygen consumption by 20%. Uncoupling of mitochondrial oxygen consumption by azide (1 x 10(-3) mol/L) inhibited T4-stimulated oxygen consumption, but...

  19. Extracellular Ca2+ influx is crucial for the early embryonic development of the sea urchin Echinometra lucunter.

    Science.gov (United States)

    de Araújo Leite, Jocelmo Cássio; Marques-Santos, Luis Fernando

    2012-03-01

    The involvement of Ca(2+) in the activation of eggs and in the first steps of the embryonic development of several species is a well-known phenomenon. An association between Ca(2+) sources with the fate of the blastopore during embryonic development has been investigated by several authors. Ca(2+) influx mediated by voltage-gated channels and Ca(2+) mobilization from intracellular stores are the major sources of Ca(2+) to egg activation and succeeding cell divisions. Studies on sea urchins embryonic development show that intracellular Ca(2+) stores are responsible for egg activation and early embryogenesis. In the present work we investigated the involvement of extracellular Ca(2+) in the first stages of the embryonic development of the sea urchin Echinometra lucunter. Divalent cation chelators EDTA and EGTA strongly blocked the early embryonic development. Adding to this, we demonstrated the involvement of voltage-gated Ca(2+) channels in E. lucunter embryogenesis since Ca(2+) channel blockers powerfully inhibited the early embryonic development. Our data also revealed that Ca(2+) influx is crucial for embryonic development during only the first 40 min postfertilization. However, intracellular Ca(2+) remains mandatory to embryonic development 40 min postfertilization, seen that both the intracellular Ca(2+) chelator BAPTA-AM and calmodulin antagonists trifluoperazine and chlorpromazine inhibited the first stages of development when added to embryos culture 50 min postfertilization. Our work highlights the crucial role of extracellular Ca(2+) influx through voltage-gated Ca(2+) channels for the early embryonic development of the sea urchin E. lucunter and characterizes an exception in the phylum Echinodermata. PMID:22532474

  20. TRPV3 channels mediate Ca²⁺ influx induced by 2-APB in mouse eggs.

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    Lee, Hoi Chang; Yoon, Sook-Young; Lykke-Hartmann, Karin; Fissore, Rafael A; Carvacho, Ingrid

    2016-01-01

    Fertilization in mammals is initiated when a sperm fuses with a mature MII oocyte, also known as egg, and triggers a plethora of finely controlled processes identified as egg activation. The completion of all events of egg activation is driven by and depends on a series of repetitive calcium (Ca(2+)) increases (Ca(2+) oscillations), which rely on Ca(2+) influx from the extracellular media. Ca(2+) channels on the egg plasma membrane (PM) are thought to mediate this influx. The TRP Ca(2+) channel TRPV3 is differentially expressed during oocyte maturation, being most active at the MII stage. Specific stimulation of TRPV3 channels promotes Ca(2+) influx sufficient to induce egg activation and parthenogenesis. Here, we explore the function and distribution dynamics of the TRPV3 channel protein during maturation. Using dsRNA, TrpV3 overexpression, and inhibitors of protein synthesis, we modified the expression levels of the channel and showed that the TRPV3 protein is synthesized and translocated to the PM during maturation. We demonstrated that 2-APB at the concentrations used here to promote Ca(2+) influx in eggs, specifically and reversibly targets TRPV3 channels without blocking IP3R1. Finally, we found that the activity of TRPV3 channels is dependent upon an intact actin cytoskeleton, suggesting an actin-based regulation of its expression and/or function on the PM. Collectively, our results show TRPV3 is a target of 2-APB in eggs, a condition that can be used to induce parthenogenesis. The need of an intact actin cytoskeleton for the function of TRPV3 channels in oocytes is a novel finding and suggests the rearrangements of actin that occur during maturation could regulate both the presence on the PM and/or the function of TRPV3 and of other Ca(2+) channels involved in oocyte maturation and fertilization. PMID:26725171

  1. Effect of the dB-c-AMP and forskolin on 45Ca influx, net Ca uptake and tension on rabbit aortic smooth muscle

    International Nuclear Information System (INIS)

    The effect of dibutiryl-adenosine-3',5'-cyclic-monophosphate (dB-c-AMP) and forskolin on aortic tension and 45Ca influx were measured. dB-c-AMP reduced both the rate of force development and the maximal tension achieved in solutions containing various K+ concentrations. Stimulated 45Ca influx was also reduced however to a lesser extent than was the tension. Forskolin showed more marked effects of a similar nature. Thus, both these agents which increase intracellular c-AMP caused a rightward shift in the curve expressing force(ordinate) as a function of Ca influx (abscissa). Consequently, they found that dB-c-AMP stimulated more net Ca to be taken up by the sarcoplasmic reticulum(SR) at the same influx rate. The conclusion that c-AMP produced these effects by stimulating Ca uptake into the superficial SR was supported by the finding that dB-c-AMP increased the amount of Ca taken up into a caffeine releasable fraction

  2. Effect of dB-c-AMP and forskolin on the 45Ca influx, net Ca uptake and tension in rabbit aortic smooth muscle

    International Nuclear Information System (INIS)

    The effects of dibutyril-adenosine-3',5'-cyclic monophosphate (dB-c-AMP) and forskolin on aortic tension and 45Ca influx were measured. dB-c-AMP reduced both the rate of force development and the maximal tension achieved in solutions containing various K+ concentrations. Stimulated 45Ca influx was also reduced, however, to a lesser extent than was the tension. Forskolin showed more marked effects of a similar nature. Thus, both these agents which increase intracellular c-AMP caused a rightward shift in the curve expressing force (ordinate) as a function of Ca2+ influx (abscissa). Consequently, the authors found that dB-c-AMP stimulated more net Ca to be taken up by sarcoplasmic reticulum (SR) at the same influx rate. The conclusion that c-AMP produced these effects by stimulating Ca uptake into the superficial SR was supported by the finding that dB-c-AMP increased the amount of Ca taken up into a caffeine releasable fraction. (Auth.)

  3. Salvia miltiorrhiza Induces Tonic Contraction of the Lower Esophageal Sphincter in Rats via Activation of Extracellular Ca2+ Influx

    Directory of Open Access Journals (Sweden)

    Ching-Chung Tsai

    2015-08-01

    Full Text Available Up to 40% of patients with gastroesophageal reflux disease (GERD suffer from proton pump inhibitor refractory GERD but clinically the medications to strengthen the lower esophageal sphincter (LES to avoid irritating reflux are few in number. This study aimed to examine whether Salvia miltiorrhiza (SM extracts induce tonic contraction of rat LES ex vivo and elucidate the underlying mechanisms. To investigate the mechanism underlying the SM extract-induced contractile effects, rats were pretreated with atropine (a muscarinic receptor antagonist, tetrodotoxin (a sodium channel blocker, nifedipine (a calcium channel blocker, and Ca2+-free Krebs-Henseleit solution with ethylene glycol tetraacetic acid (EGTA, followed by administration of cumulative dosages of SM extracts. SM extracts induced dose-related tonic contraction of the LES, which was unaffected by tetrodotoxin, atropine, or nifedipine. However, the SM extract-induced LES contraction was significantly inhibited by Ca2+-free Krebs-Henseleit solution with EGTA. Next, SM extracts significantly induce extracellular Ca2+ entry into primary LES cells in addition to intracellular Ca2+ release and in a dose-response manner. Confocal fluorescence microscopy showed that the SM extracts consistently induced significant extracellular Ca2+ influx into primary LES cells in a time-dependent manner. In conclusion, SM extracts could induce tonic contraction of LES mainly through the extracellular Ca2+ influx pathway.

  4. Inhibitory effect of acteoside on melittin-induced catecholamine exocytosis through inhibition of Ca(2+)-dependent phospholipase A2 and extracellular Ca(2+) influx in PC12 cells.

    Science.gov (United States)

    Song, Ho Sun; Ko, Myung Soo; Jo, Young Soo; Whang, Wan Kyunn; Sim, Sang Soo

    2015-10-01

    To investigate the inhibitory effect of acteoside on the process of exocytosis induced by melittin, we measured Ca(2+) mobilization, arachidonic acid (AA) release and catecholamine exocytosis in PC12 chromaffin cells. Melittin significantly increased the intracellular Ca(2+) mobilization via receptor-operated calcium channel but not the intracellular Ca(2+) release. It caused AA release via activation of Ca(2+)-dependent phospholipase A2 (PLA2) and catecholamine secretion in a dose-dependent manner. Acteoside dose-dependently inhibited the release of AA and intracellular Ca(2+) mobilization induced by melittin. Acteoside reduced the catecholamine release and raised the amount of intracellular chromogranin A which is co-released with catecholamine from melittin-stimulated PC12 cells. Taken together, our results suggest that acteoside could suppress the exocytosis via inhibition of Ca(2+)-dependent PLA2 and extracellular Ca(2+) influx in PC12 cells stimulated by melittin. PMID:25899996

  5. Induces vasodilatation of rat mesenteric artery in vitro mainly by inhibiting receptor-mediated Ca(2+)-influx and Ca(2+)-release

    DEFF Research Database (Denmark)

    Cao, Yong-Xiao; Zheng, Jian-Pu; He, Jian-Yu;

    2005-01-01

    inhibited the contraction derived from NA and CaCI2 in Ca(2+)-free medium, in a concentration dependent manner, indicating the vasodilatation was related to the inhibition of extracellular Ca2+ influx through the receptor-operated calcium channels and intracellular Ca2+ release from the Ca2+ store. Atropine......-induced concentration-response curve to the right, in a non-parallel manner, suggesting the mechanism of atropine was not mediated via the (alpha1-adrenoreceptor. The beta-adrenoreceptor and ATP sensitive potassium channel, a voltage dependent calcium channel, were not involved in the vasodilatation. However, atropine...... had no effect on the caffeine-induced contraction in the artery segments, indicating the inhibition of intracellular Ca2+ release as a result of atropine most likely occurs via the IP3 pathway rather than the ryanodine receptors. Our results suggest that atropine-induced vasodilatation is mainly from...

  6. Reverse mode Na+/Ca2+ exchange mediated by STIM1 contributes to Ca2+ influx in airway smooth muscle following agonist stimulation

    Directory of Open Access Journals (Sweden)

    Fox Jane

    2010-12-01

    Full Text Available Abstract Background Agonist stimulation of airway smooth muscle (ASM results in IP3 mediated Ca2+ release from the sarcoplasmic reticulum followed by the activation of store operated and receptor operated non-selective cation channels. Activation of these non-selective channels also results in a Na+ influx. This localised increase in Na+ levels can potentially switch the Na+/Ca2+ exchanger into reverse mode and so result in a further influx of Ca2+. The aim of this study was to characterise the expression and physiological function of the Na+/Ca2+ exchanger in cultured human bronchial smooth muscle cells and determine its contribution to agonist induced Ca2+ influx into these cells. Methods The expression profile of NCX (which encodes the Na+/Ca2+ exchanger homologues in cultured human bronchial smooth muscle cells was determined by reverse transcriptase PCR. The functional activity of reverse mode NCX was investigated using a combination of whole cell patch clamp, intracellular Ca2+ measurements and porcine airway contractile analyses. KB-R7943 (an antagonist for reverse mode NCX and target specific siRNA were utilised as tools to inhibit NCX function. Results NCX1 protein was detected in cultured human bronchial smooth muscle cells (HBSMC cells and NCX1.3 was the only mRNA transcript variant detected. A combination of intracellular Na+ loading and addition of extracellular Ca2+ induced an outwardly rectifying current which was augmented following stimulation with histamine. This outwardly rectifying current was inhibited by 10 μM KB-R7943 (an antagonist of reverse mode NCX1 and was reduced in cells incubated with siRNA against NCX1. Interestingly, this outwardly rectifying current was also inhibited following knockdown of STIM1, suggesting for the first time a link between store operated cation entry and NCX1 activation. In addition, 10 μM KB-R7943 inhibited agonist induced changes in cytosolic Ca2+ and induced relaxation of porcine

  7. Nitric Oxide Blocks Blue Light-Induced K+ Influx by Elevating the Cytosolic Ca2+ Concentration in Vicia faba L.Guard Cells

    Institute of Scientific and Technical Information of China (English)

    Xiang Zhao; Yuan-Yuan Li; Hui-Li Xiao; Chang-Shui Xu; Xiao Zhang

    2013-01-01

    Ca2+ plays a pivotal role in nitric oxide (NO)-promoted stomatal closure.However,the function of Ca2+ in NO inhibition of blue light (BL)-induced stomatal opening remains largely unknown.Here,we analyzed the role of Ca2+ in the crosstalk between BL and NO signaling in Vicia faba L.guard cells.Extracellular Ca2+ modulated the BL-induced stomatal opening in a dose-dependent manner,and an application of 5 μM Ca2+ in the pipette solution significantly inhibited BL-activated K+ influx.Sodium nitroprusside (SNP),a NO donor,showed little effect on BL-induced K+ influx and stomatal opening response in the absence of extracellular Ca2+,but K+ influx and stomatal opening were inhibited by SNP when Ca2+ was added to the bath solution.Interestingly,although both SNP and BL could activate the plasma membrane Ca2+ channels and induce the rise of cytosolic Ca2+,the change in levels of Ca2+ channel activity and cytosolic Ca2+ concentration were different between SNP and BL treatments.SNP at 100 μM obviously activated the plasma membrane Ca2+ channels and induced cytosolic Ca2+ rise by 102.4%.In contrast,a BL pulse (100 μmol/m2 per s for 30 s) slightly activated the Ca2+ channels and resulted in a Ca2+ rise of only 20.8%.Consistently,cytosolic Ca2+ promoted K+ influx at 0.5 μM or below,and significantly inhibited K+ influx at 5 μM or above.Taken together,our findings indicate that Ca2+ plays dual and distinctive roles in the crosstalk between BL and NO signaling in guard cells,mediating both the BL-induced K+ influx as an activator at a lower concentration and the NO-blocked K+ influx as an inhibitor at a higher concentration.

  8. Cch1p Mediates Ca2+ Influx to Protect Saccharomyces cerevisiae against Eugenol Toxicity

    OpenAIRE

    Roberts, Stephen K.; Martin McAinsh; Lisa Widdicks

    2012-01-01

    Eugenol has antifungal activity and is recognised as having therapeutic potential. However, little is known of the cellular basis of its antifungal activity and a better understanding of eugenol tolerance should lead to better exploitation of eugenol in antifungal therapies. The model yeast, Saccharomyces cerevisiae, expressing apoaequorin was used to show that eugenol induces cytosolic Ca(2+) elevations. We investigated the eugenol Ca(2+) signature in further detail and show that exponential...

  9. Antagonism of Ca2+ influx via L-type Ca2+ channels mediates the vasorelaxant effect of Catharanthus roseus-derived vindorosine in rat renal artery.

    Science.gov (United States)

    Wu, Xiao-Lin; Cheang, Wai San; Zhang, Dong-Mei; Li, Yong; Lau, Chi-Wai; Wang, Guo-Cai; Huang, Yu; Ye, Wen-Cai

    2014-12-01

    Catharanthus roseus is a traditional herbal medicine used in Asian and African countries for the treatment of various diseases including hypertension. The present study examined possible cellular mechanisms for the relaxation of rat renal arteries induced by vindorosine extracted from C. roseus. Intrarenal arteries were isolated from 200-300 g male Sprague-Dawley rats and treated with different pharmacological blockers and inhibitors for the measurement of vascular reactivity on a Multi Myograph System. Fluorescence imaging by laser scanning confocal microscopy was utilized to determine the intracellular Ca(2+) level in the vascular smooth muscles of the renal arteries. Vindorosine in micromolar concentrations relaxes renal arteries precontracted by KCl, phenylephrine, 11-dideoxy-9α,11α-epoxymethanoprostaglandin F2α, and serotonin. Vindorosine-induced relaxations were unaffected by endothelium denudation or by treatment with the nitric oxide synthase inhibitor N (G)-nitro-L-arginine methyl ester hydrochloride, the guanylyl cyclase inhibitor 1H-[1, 2, 4]oxadiazolo[4,3-a]quinoxalin-1-one, the cyclooxygenase inhibitor indomethacin, or K(+) channel blockers such as tetraethylammonium ions, glibenclamide, and BaCl2. Vindorosine-induced relaxations were attenuated in the presence of 0.1 µM nifedipine (an L-type Ca(2+) channel blocker). Vindorosine also concentration-dependently suppressed contractions induced by CaCl2 (0.01-5 mM) in Ca-free 60 mM KCl solution. Furthermore, fluorescence imaging using fluo-4 demonstrated that 30 min incubation with 100 µM vindorosine reduced the 60 mM KCl-stimulated Ca(2+) influx in the smooth muscles of rat renal arteries. The present study is probably the first report of blood vessel relaxation by vindorosine and the possible underlying mechanisms involving the inhibition of Ca(2+) entry via L-type Ca(2+) channels in vascular smooth muscles. PMID:25340466

  10. Counteracting effect of TRPC1-associated Ca2+ influx on TNF-α-induced COX-2-dependent prostaglandin E2 production in human colonic myofibroblasts.

    Science.gov (United States)

    Hai, Lin; Kawarabayashi, Yasuhiro; Imai, Yuko; Honda, Akira; Inoue, Ryuji

    2011-08-01

    TNF-α-NF-κB signaling plays a central role in inflammation, apoptosis, and neoplasia. One major consequence of this signaling in the gut is increased production of prostaglandin E(2) (PGE(2)) via cyclooxygenase-2 (COX-2) induction in myofibroblasts, which has been reported to be dependent on Ca(2+). In this study, we explored a potential role of canonical transient receptor potential (TRPC) proteins in this Ca(2+)-mediated signaling using a human colonic myofibroblast cell line CCD-18Co. In CCD-18Co cell, treatment with TNF-α greatly enhanced Ca(2+) influx induced by store depletion along with increased cell-surface expression of TRPC1 protein (but not of the other TRPC isoforms) and induction of a Gd(3+)-sensitive nonselective cationic conductance. Selective inhibition of TRPC1 expression by small interfering RNA (siRNA) or functionally effective TRPC1 antibody targeting the near-pore region of TRPC1 (T1E3) antagonized the enhancement of store-dependent Ca(2+) influx by TNF-α, whereas potentiated TNF-α induced PGE(2) production. Overexpression of TRPC1 in CCD-18Co produced opposite consequences. Inhibitors of NF-κB (curcumin, SN-50) attenuated TNF-α-induced enhancement of TRPC1 expression, store-dependent Ca(2+) influx, and COX-2-dependent PGE(2) production. In contrast, inhibition of calcineurin-nuclear factor of activated T-cell proteins (NFAT) signaling by FK506 or NFAT Activation Inhibitor III enhanced the PGE(2) production without affecting TRPC1 expression and the Ca(2+) influx. Finally, the suppression of store-dependent Ca(2+) influx by T1E3 antibody or siRNA knockdown significantly facilitated TNF-α-induced NF-κB nuclear translocation. In aggregate, these results strongly suggest that, in colonic myofibroblasts, NF-κB and NFAT serve as important positive and negative transcriptional regulators of TNF-α-induced COX-2-dependent PGE(2) production, respectively, at the downstream of TRPC1-associated Ca(2+) influx. PMID:21546578

  11. Antidiarrheal and Antispasmodic Activities of Buddleja polystachya are Mediated Through Dual Inhibition of Ca(++) Influx and Phosphodiesterase Enzyme.

    Science.gov (United States)

    Rehman, Najeeb-ur; Gilani, Anwarul-Hassan; Khan, Aslam; Nazneen, Maryam; El Gamal, Ali A; Fawzy, Ghada A; Al-Ati, Hanan Y; Abdel-kader, Maged S

    2015-08-01

    This study describes the antidiarrheal and antispasmodic activities of the hydro-alcoholic extract of Buddleja polystachya (Bp.Cr) with possible mode of action explored along with activity-directed fractionation. Bp.Cr and its aqueous (Bp.Aq) and organic fractions, petroleum ether (Bp.Pet), dichloromethane (Bp.DCM), ethylacetate (Bp.EtAc) and butanol (Bp.But), were tested using the in-vivo and in-vitro assays. The crude extract (100-300 mg/kg) showed 20 and 60% protection of castor oil-induced diarrhea in mice. In isolated rabbit jejunum, Bp.Cr like papaverine inhibited spontaneous and high K(+) (80 mM)-induced contractions equi-potently. In guinea-pig ileum, Bp.Cr showed a moderate spasmogenic effect. The activity-directed fractionation revealed that the spasmolytic activity was concentrated in the organic fractions and spasmogenic component in the aqueous fraction. Amongst the organic fractions, BP.DCM and Bp.Pet inhibited spontaneous and high K(+) -induced contractions equi-potently, while Bp.But, like verapamil was more potent against high K(+) . The crude extract and its organic fractions caused rightward shift in the Ca(++) -concentration response curves (CRCs), similar to verapamil, and all except Bp.But potentiated the isoprenaline-inhibitory CRCs to the left, similar to papaverine. The results of this study indicate that the crude extract of B. polystachya possesses antidiarrheal and antispasmodic activities, mediated possibly through dual inhibition of Ca(++) influx and phospodiesterase enzyme. PMID:25975350

  12. Ca2+ Influx through Store-operated Calcium Channels Replenishes the Functional Phosphatidylinositol 4,5-Bisphosphate Pool Used by Cysteinyl Leukotriene Type I Receptors.

    Science.gov (United States)

    Alswied, Abdullah; Parekh, Anant B

    2015-12-01

    Oscillations in cytoplasmic Ca(2+) concentration are a universal mode of signaling following physiological levels of stimulation with agonists that engage the phospholipase C pathway. Sustained cytoplasmic Ca(2+) oscillations require replenishment of the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2), the source of the Ca(2+)-releasing second messenger inositol trisphosphate. Here we show that cytoplasmic Ca(2+) oscillations induced by cysteinyl leukotriene type I receptor activation run down when cells are pretreated with Li(+), an inhibitor of inositol monophosphatases that prevents PIP2 resynthesis. In Li(+)-treated cells, cytoplasmic Ca(2+) signals evoked by an agonist were rescued by addition of exogenous inositol or phosphatidylinositol 4-phosphate (PI4P). Knockdown of the phosphatidylinositol 4-phosphate 5 (PIP5) kinases α and γ resulted in rapid loss of the intracellular Ca(2+) oscillations and also prevented rescue by PI4P. Knockdown of talin1, a protein that helps regulate PIP5 kinases, accelerated rundown of cytoplasmic Ca(2+) oscillations, and these could not be rescued by inositol or PI4P. In Li(+)-treated cells, recovery of the cytoplasmic Ca(2+) oscillations in the presence of inositol or PI4P was suppressed when Ca(2+) influx through store-operated Ca(2+) channels was inhibited. After rundown of the Ca(2+) signals following leukotriene receptor activation, stimulation of P2Y receptors evoked prominent inositol trisphosphate-dependent Ca(2+) release. Therefore, leukotriene and P2Y receptors utilize distinct membrane PIP2 pools. Our findings show that store-operated Ca(2+) entry is needed to sustain cytoplasmic Ca(2+) signaling following leukotriene receptor activation both by refilling the Ca(2+) stores and by helping to replenish the PIP2 pool accessible to leukotriene receptors, ostensibly through control of PIP5 kinase activity. PMID:26468289

  13. PA1b, a plant peptide, induces intracellular [Ca2+] in- crease via Ca2+ influx through the L-type Ca2+ channel and triggers secretion in pancreatic β cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using alginic acid to adsorb polypeptides at pH 2.7, we isolated a peptide pea albumin 1b (PA1b) from pea seeds. The PA1b is a single chain peptide consisting of 37 amino acid residues with 6 cysteines which constitutes the cystine-knot structure. Using microfluorometry and patch clamp techniques, we found that PA1b significantly elevated the intracellular calcium level ([Ca2+ ]i) and elicited membrane capacitance increase in the primary rat pancreatic β cells. The PA1b effect on [Ca2+]i elevation was abolished in the absence of extracellular Ca2+ or in the presence of L-type Ca2+ channel blocker, ni- modipine. Interestingly, we found that PA1b significantly depolarized membrane potential, which could lead to the opening of voltage-dependent L-type Ca2+ channels and influx of extracellular Ca2+, and then evoke robust secretion. In this study we identified the plant peptide PA1b which is capable of affecting the excitability and function of mammalian pancreatic β cell.

  14. Calcium influx pathways in rat pancreatic ducts

    DEFF Research Database (Denmark)

    Hug, M J; Pahl, C; Novak, I

    1996-01-01

    A number of agonists increase intracellular Ca2+ activity, [Ca2+]i, in pancreatic ducts, but the influx/efflux pathways and intracellular Ca2+ stores in this epithelium are unknown. The aim of the present study was to characterise the Ca2+ influx pathways, especially their pH sensitivity, in nati...

  15. Downregulation of transcription factor Oct4 induces an epithelial-to-mesenchymal transition via enhancement of Ca{sup 2+} influx in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jiajia; Qin, Kunhua; Zhang, Yan [Medical School of Nankai University, 94 Weijin Road, Tianjin 300071 (China); Gong, Junbo [Tianjin Key Laboratory of Modern Drug Delivery and High Efficiency in Tianjin University, 92 Weijin Road, Tianjin 300072 (China); Li, Na; Lv, Dan; Xiang, Rong [Medical School of Nankai University, 94 Weijin Road, Tianjin 300071 (China); Tan, Xiaoyue, E-mail: xiaoyuetan@nankai.edu.cn [Medical School of Nankai University, 94 Weijin Road, Tianjin 300071 (China)

    2011-08-12

    Highlights: {yields} We examine the role of Oct4 in metastasis in cultured MCF-7 cells. {yields} The down regulation of Oct4 induces EMT and increases the capability of migration and invasion in MCF-7 cells. {yields} TGF-{beta}1 inhibits Oct4 expression in both time- and dose-dependent manners. {yields} The EMT induced by TGF-{beta}1 or down regulation of Oct4 could be abrogated by inhibitor of SOCE. {yields} The down regulation of STIM1 (one of the major components of the CRAC channel) alleviates the EMT induce by Oct4 silencing down. -- Abstract: The stem cell-related transcription factor Oct4 regulates tumor proliferation and apoptosis, but its role in tumor migration and invasion is still undefined. Here, we compared Oct4 expression in MCF-7 and MDA-MB-231 cells, two breast cancer cell lines with similar epithelial origins, but distinct invasive and metastatic characteristics. We found MCF-7 cells to express very high levels of Oct4, while no obvious expression was detected in MDA-MB-231 cells. We then downregulated Oct4 expression using small interfering RNA (siRNA) to explore its effects on migration and invasion. Transwell assays showed that silencing Oct4 in MCF-7 cells improved their migration and invasion capabilities. Reverse-transcriptase PCR and western blots showed that E-cadherin expression decreased, and {alpha}-smooth muscle actin expression increased with Oct4 downregulation, which suggests that epithelial-to-mesenchymal transition (EMT) occurred. A potent EMT stimulus, TGF-{beta}1, significantly inhibited Oct4 expression in both dose- and time course-dependent manners. Silencing Oct4 also upregulated expression of two major components of store-operated Ca{sup 2+} entry channels (SOCs), STIM1 and Orai1, and enhanced SOC-directed Ca{sup 2+} influx. Silencing STIM1 blocked the Ca{sup 2+} influx and rescued the EMT initiated by Oct4 downregulation. In conclusion, silencing Oct4 promotes invasion and metastasis in breast cancer cells by inducing EMT

  16. Endothelin-1 induces intracellular [Ca2+] increase via Ca2+ influx through the L-type Ca2+ channel, Ca2+-induced Ca2+ release and a pathway involving ETA receptors, PKC, PKA and AT1 receptors in cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    ZENG QingHua; LI XingTing; ZHONG GuoGan; ZHANG WenJie; SUN ChengWen

    2009-01-01

    Using fura-2-acetoxymethyl eater (AM) fluorescence imaging and patch clamp techniques, we found that endothelin-1 (ET-1) significantly elevated the intracellular calcium level ([Ca2+]1) in a dose-dependent manner and activated the L-type Ca2+ channel in cardiomyocytes isolated from rats.The effect of ET-1 on [Ca2+]1 elevation was abolished in the presence of the ETA receptor blocker BQ123,but was not affected by the ETa receptor blocker BQ788. ET-1-induced an increase in [Ca2+]1, which was inhibited 46.7% by pretreatment with a high concentration of ryanodine (10 μmol/L), a blocker of the ryanodine receptor. The ET-1-induced [Ca2+]i increase was also inhibited by the inhibltors of protein kinase A (PKA), protein kinase C (PKC) and angiotensin type 1 receptor (AT1 receptor). We found that ET-1 induced an enhancement of the amplitude of the whole cell L-type Ca2+ channel current and an Increase of open-state probability (NPo) of an L-type single Ca2+ channel. BQ123 completely blocked the ET-1-induced increase in calcium channel open-state probability. In this study we demonstrated that ET-1 regulates calcium overload through a series of mechanisms that include L-type Ca2+ channel activation and Ca2+-induced Ca2+ release (CICR). ETa receptors, PKC, PKA and AT1 receptors may also contribute to this pathway.

  17. Endothelin-1 induces intracellular [Ca2+] increase via Ca2+ influx through the L-type Ca2+ channel, Ca2+-induced Ca2+ release and a pathway involving ETA receptors, PKC, PKA and AT1 receptors in cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Using fura-2-acetoxymethyl ester (AM) fluorescence imaging and patch clamp techniques, we found that endothelin-1 (ET-1) significantly elevated the intracellular calcium level ([Ca2+]i) in a dose-dependent manner and activated the L-type Ca2+ channel in cardiomyocytes isolated from rats. The effect of ET-1 on [Ca2+]i elevation was abolished in the presence of the ETA receptor blocker BQ123, but was not affected by the ETB receptor blocker BQ788. ET-1-induced an increase in [Ca2+]i, which was inhibited 46.7% by pretreatment with a high concentration of ryanodine (10 μmol/L), a blocker of the ryanodine receptor. The ET-1-induced [Ca2+]i increase was also inhibited by the inhibitors of protein kinase A (PKA), protein kinase C (PKC) and angiotensin type 1 receptor (AT1 receptor). We found that ET-1 induced an enhancement of the amplitude of the whole cell L-type Ca2+ channel current and an increase of open-state probability (NPo) of an L-type single Ca2+ channel. BQ123 completely blocked the ET-1-induced increase in calcium channel open-state probability. In this study we demonstrated that ET-1 regulates calcium overload through a series of mechanisms that include L-type Ca2+ channel activation and Ca2+-induced Ca2+ release (CICR). ETA receptors, PKC, PKA and AT1 receptors may also contribute to this pathway.

  18. A STIM1-dependent 'trafficking trap' mechanism regulates Orai1 plasma membrane residence and Ca²⁺ influx levels.

    Science.gov (United States)

    Hodeify, Rawad; Selvaraj, Senthil; Wen, Jennifer; Arredouani, Abdelilah; Hubrack, Satanay; Dib, Maya; Al-Thani, Sara N; McGraw, Timothy; Machaca, Khaled

    2015-08-15

    The key proteins mediating store-operated Ca(2+) entry (SOCE) are the endoplasmic reticulum (ER) Ca(2+) sensor STIM1 and the plasma membrane Ca(2+)-selective channel Orai1. Here, we quantitatively dissect Orai1 trafficking dynamics and show that Orai1 recycles rapidly at the plasma membrane (Kex≃0.1 min(-1)), with ∼40% of the total Orai1 pool localizing to the plasma membrane at steady state. A subset of intracellular Orai1 localizes to a sub-plasmalemal compartment. Store depletion is coupled to Orai1 plasma membrane enrichment in a STIM1-dependent fashion. This is due to trapping of Orai1 into cortical ER STIM1 clusters, leading to its removal from the recycling pool and enrichment at the plasma membrane. Interestingly, upon high STIM1 expression, Orai1 is trapped into STIM1 clusters intracellularly, thus preventing its plasma membrane enrichment following store depletion. Consistent with this, STIM1 knockdown prevents trapping of excess Orai1 into limiting STIM1 clusters in the cortical ER. SOCE-dependent Ca(2+) influx shows a similar biphasic dependence on the Orai1:STIM1 ratio. Therefore, a STIM1-dependent Orai1 'trafficking trap' mechanism controls Orai1 plasma membrane enrichment and SOCE levels, thus modulating the SOCE 'bandwidth' for downstream signaling. PMID:26116575

  19. Wallerian Degeneration Is Executed by an NMN-SARM1-Dependent Late Ca(2+) Influx but Only Modestly Influenced by Mitochondria.

    Science.gov (United States)

    Loreto, Andrea; Di Stefano, Michele; Gering, Martin; Conforti, Laura

    2015-12-22

    Axon injury leads to rapid depletion of NAD-biosynthetic enzyme NMNAT2 and high levels of its substrate, NMN. We proposed a key role for NMN in Wallerian degeneration but downstream events and their relationship to other mediators remain unclear. Here, we show, in vitro and in vivo, that axotomy leads to a late increase in intra-axonal Ca(2+), abolished by pharmacological or genetic reduction of NMN levels. NMN requires the pro-degenerative protein SARM1 to stimulate Ca(2+) influx and axon degeneration. While inhibition of NMN synthesis and SARM1 deletion block Ca(2+) rise and preserve axonal integrity, they fail to prevent early mitochondrial dynamic changes. Furthermore, depolarizing mitochondria does not alter the rate of Wallerian degeneration. These data reveal that NMN and SARM1 act in a common pathway culminating in intra-axonal Ca(2+) increase and fragmentation and dissociate mitochondrial dysfunctions from this pathway, elucidating which steps may be most effective as targets for therapy. PMID:26686637

  20. Wallerian Degeneration Is Executed by an NMN-SARM1-Dependent Late Ca2+ Influx but Only Modestly Influenced by Mitochondria

    Directory of Open Access Journals (Sweden)

    Andrea Loreto

    2015-12-01

    Full Text Available Axon injury leads to rapid depletion of NAD-biosynthetic enzyme NMNAT2 and high levels of its substrate, NMN. We proposed a key role for NMN in Wallerian degeneration but downstream events and their relationship to other mediators remain unclear. Here, we show, in vitro and in vivo, that axotomy leads to a late increase in intra-axonal Ca2+, abolished by pharmacological or genetic reduction of NMN levels. NMN requires the pro-degenerative protein SARM1 to stimulate Ca2+ influx and axon degeneration. While inhibition of NMN synthesis and SARM1 deletion block Ca2+ rise and preserve axonal integrity, they fail to prevent early mitochondrial dynamic changes. Furthermore, depolarizing mitochondria does not alter the rate of Wallerian degeneration. These data reveal that NMN and SARM1 act in a common pathway culminating in intra-axonal Ca2+ increase and fragmentation and dissociate mitochondrial dysfunctions from this pathway, elucidating which steps may be most effective as targets for therapy.

  1. Capsaicin sensitizes TRAIL-induced apoptosis through Sp1-mediated DR5 up-regulation: Involvement of Ca2+ influx

    International Nuclear Information System (INIS)

    Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various malignant cells, several cancers including human hepatocellular carcinoma (HCC) exhibit potent resistance to TRAIL-induced cell death. The aim of this study is to evaluate the anti-cancer potential of capsaicin in TRAIL-induced cancer cell death. As indicated by assays that measure phosphatidylserine exposure, mitochondrial activity and activation of caspases, capsaicin potentiated TRAIL-resistant cells to lead to cell death. In addition, we found that capsaicin induces the cell surface expression of TRAIL receptor DR5, but not DR4 through the activation Sp1 on its promoter region. Furthermore, we investigated that capsaicin-induced DR5 expression and apoptosis are inhibited by calcium chelator or inhibitors for calmodulin-dependent protein kinase. Taken together, our data suggest that capsaicin sensitizes TRAIL-mediated HCC cell apoptosis by DR5 up-regulation via calcium influx-dependent Sp1 activation. Highlights: ► Capsaicin sensitizes TRAIL-induced apoptosis through activation of caspases. ► Capsaicin induces expression of DR5 through Sp1 activation. ► Capsaicin activates calcium signaling pathway.

  2. Frequency dependence of CA3 spike phase response arising from h-current properties

    Directory of Open Access Journals (Sweden)

    Hyun Jae Jang

    2013-12-01

    Full Text Available The phase of firing of hippocampal neurons during theta oscillations encodes spatial information. Moreover, the spike phase response to synaptic inputs in individual cells depends on the expression of the hyperpolarisation-activated mixed cation current (Ih, which differs between CA3 and CA1 pyramidal neurons. Here, we compared the phase response of these two cell types, as well as their intrinsic membrane properties. We found that both CA3 and CA1 pyramidal neurons show a voltage sag in response to negative current steps but that this voltage sag is significantly smaller in CA3 cells. Moreover, CA3 pyramidal neurons have less prominent resonance properties compared to CA1 pyramidal neurons. This is consistent with differential expression of Ih by the two cell types. Despite their distinct intrinsic membrane properties, both CA3 and CA1 pyramidal neurons displayed bidirectional spike phase control by excitatory conductance inputs during theta oscillations. In particular, excitatory inputs delivered at the descending phase of a dynamic clamp-induced membrane potential oscillation delayed the subsequent spike by nearly 50 mrad. The effect was shown to be mediated by Ih and was counteracted by increasing inhibitory conductance driving the membrane potential oscillation. Using our experimental data to feed a computational model, we showed that differences in Ih between CA3 and CA1 pyramidal neurons could predict frequency-dependent differences in phase response properties between these cell types. We confirmed experimentally such frequency-dependent spike phase control in CA3 neurons. Therefore, a decrease in theta frequency, which is observed in intact animals during novelty, might switch the CA3 spike phase response from unidirectional to bidirectional and thereby promote encoding of the new context.

  3. Insulin Activates Vagal Afferent Neurons Including those Innervating Pancreas via Insulin Cascade and Ca(2+ Influx: Its Dysfunction in IRS2-KO Mice with Hyperphagic Obesity.

    Directory of Open Access Journals (Sweden)

    Yusaku Iwasaki

    Full Text Available Some of insulin's functions, including glucose/lipid metabolism, satiety and neuroprotection, involve the alteration of brain activities. Insulin could signal to the brain via penetrating through the blood-brain barrier and acting on the vagal afferents, while the latter remains unproved. This study aimed to clarify whether insulin directly regulates the nodose ganglion neurons (NGNs of vagal afferents in mice. NGs expressed insulin receptor (IR and insulin receptor substrate-2 (IRS2 mRNA, and some of NGNs were immunoreactive to IR. In patch-clamp and fura-2 microfluorometric studies, insulin (10(-12∼10(-6 M depolarized and increased cytosolic Ca(2+ concentration ([Ca(2+]i in single NGNs. The insulin-induced [Ca(2+]i increases were attenuated by L- and N-type Ca(2+ channel blockers, by phosphatidylinositol 3 kinase (PI3K inhibitor, and in NGNs from IRS2 knockout mice. Half of the insulin-responsive NGNs contained cocaine- and amphetamine-regulated transcript. Neuronal fibers expressing IRs were distributed in/around pancreatic islets. The NGNs innervating the pancreas, identified by injecting retrograde tracer into the pancreas, responded to insulin with much greater incidence than unlabeled NGNs. Insulin concentrations measured in pancreatic vein was 64-fold higher than that in circulation. Elevation of insulin to 10(-7 M recruited a remarkably greater population of NGNs to [Ca(2+]i increases. Systemic injection of glibenclamide rapidly released insulin and phosphorylated AKT in NGs. Furthermore, in IRS2 knockout mice, insulin action to suppress [Ca(2+]i in orexigenic ghrelin-responsive neurons in hypothalamic arcuate nucleus was intact while insulin action on NGN was markedly attenuated, suggesting a possible link between impaired insulin sensing by NGNs and hyperphagic obese phenotype in IRS2 knockout mice These data demonstrate that insulin directly activates NGNs via IR-IRS2-PI3K-AKT-cascade and depolarization-gated Ca(2+ influx. Pancreas

  4. Effects of Cl(-) substitution on electrophysiological properties, Ca(2+) influx and prolactin secretion of rat lactotropes in vitro.

    Science.gov (United States)

    Garcia, L; Couderc, B; Odessa, M F; Dufy-Barbe, L; Sartor, P

    1999-11-01

    In this study, we compared the effects of different chloride (Cl(-)) substitutes - methane sulfonate (CH(3)SO(-)(3)), bromide (Br(-)), nitrate (NO(-)(3)), thiocyanate (SCN(-)) and perchlorate (ClO(-)(4)) - on the secretory activity and calcium current activation of rat lactotropes in primary culture. We observed that CH(3)SO(-)(3) decreased basal prolactin (PRL) secretion. Br(-) had no effect, whereas the more lyotropic anions, such as NO(-3), SCN(-) and C1O(-4), increased basal PRL secretion. The latter three substitutes induced a significant shift in the voltage dependence of T-type calcium channel activation towards hyperpolarized values. However, this shift alone cannot explain the increase in secretion. Anion permeability studies also demonstrated that the organic anion CH(3)SO(-3) was less permeant than Cl(-), whereas monovalent inorganic anions were more permeant, with the following anion permeability sequence: SCN(-) > ClO(-4) > NO(-3) > Br(-). In conclusion, deprivation of Cl(-) ions has converse consequences on basal and induced secretion; permeating anions result in a transient increase in intracellular Ca(2+) ions. This process involves voltage-dependent Ca(2+) channels. We propose that an alteration in intracellular anion concentrations may influence the activation of internal effectors such as G proteins or channel proteins and, therefore, interfere with exocytosis. These effects are correlated with an external action of lyotropic anions, particularly NO(-3), ClO(-4) and SCN(-), on the gating properties of T-type calcium channels, probably through changes in cell surface charges. The results demonstrate the modulatory effect of anions on the secretory activity of rat lactotropes and underline the specific role played by chloride in stimulus-secretion coupling. PMID:10567859

  5. EF-hand protein Ca²⁺ buffers regulate Ca²⁺ influx and exocytosis in sensory hair cells

    OpenAIRE

    Pangršič, Tina; Gabrielaitis, Mantas; Michanski, Susann; Schwaller, Beat; Wolf, Fred; Strenzke, Nicola; Moser, Tobias

    2015-01-01

    EF-hand Ca²⁺-binding proteins are thought to shape the spatiotemporal properties of cellular Ca²⁺ signaling and are prominently expressed in sensory hair cells in the ear. Here, we combined genetic disruption of parvalbumin-α, calbindin-D28k, and calretinin in mice with patch-clamp recording, in vivo physiology, and mathematical modeling to study their role in Ca²⁺ signaling, exocytosis, and sound encoding at the synapses of inner hair cells (IHCs). IHCs lacking all three proteins showed exce...

  6. Tumor promoter phorbol myristate acetate inhibits Ca2+ influx through voltage-gated Ca2+ channels in two secretory cell lines, PC12 and RINm5F

    International Nuclear Information System (INIS)

    Protein kinase C is known to be involved both in initiation and termination of cellular responses due to phosphoinositide breakdown. The authors report that in PC12 cells (a line of neurosecretory cells derived from a rat pheochromocytoma, pretreatment with nanomolar concentrations of phorbol myristate acetate, PMA, which is believed to specifically activate protein kinase C, inhibits the cytosolic-free Ca2+ concentration rise induced by depolarizing agents. In contrast, plasma membrane potential and 45Ca efflux from preloaded cells were unaffected by PMA pretreatment. Inhibition by PMA and diacylglycerol of the cytosolic-free Ca2+ concentration rise induced by depolarization was observed also in another cell line, the insulin secreting line RINm5F. These results raise the possibility that the voltage-gated Ca2+ channel is under inhibitory control by protein kinase C

  7. Preproglucagon neurons in the hindbrain have IL-6 receptor-α and show Ca2+ influx in response to IL-6.

    Science.gov (United States)

    Anesten, Fredrik; Holt, Marie K; Schéle, Erik; Pálsdóttir, Vilborg; Reimann, Frank; Gribble, Fiona M; Safari, Cecilia; Skibicka, Karolina P; Trapp, Stefan; Jansson, John-Olov

    2016-07-01

    Neuronal circuits in the hypothalamus and hindbrain are of importance for control of food intake, energy expenditure, and fat mass. We have recently shown that treatment with exendin-4 (Ex-4), an analog of the proglucagon-derived molecule glucagon-like peptide 1 (GLP-1), markedly increases mRNA expression of the cytokine interleukin-6 (IL-6) in the hypothalamus and hindbrain and that this increase partly mediates the suppression of food intake and body weight by Ex-4. Endogenous GLP-1 in the central nervous system (CNS) is produced by preproglucagon (PPG) neurons of the nucleus of the solitary tract (NTS) in the hindbrain. These neurons project to various parts of the brain, including the hypothalamus. Outside the brain, IL-6 stimulates GLP-1 secretion from the gut and pancreas. In this study, we aim to investigate whether IL-6 can affect GLP-1-producing PPG neurons in the nucleus of the solitary tract (NTS) in mouse hindbrain via the ligand binding part of the IL-6 receptor, IL-6 receptor-α (IL-6Rα). Using immunohistochemistry, we found that IL-6Rα was localized on PPG neurons of the NTS. Recordings of these neurons in GCaMP3/GLP-1 reporter mice showed that IL-6 enhances cytosolic Ca(2+) concentration in neurons capable of expressing PPG. We also show that the Ca(2+) increase originates from the extracellular space. Furthermore, we found that IL-6Rα was localized on cells in the caudal hindbrain expressing immunoreactive NeuN (a neuronal marker) or CNP:ase (an oligodendrocyte marker). In summary, IL-6Rα is present on PPG neurons in the NTS, and IL-6 can stimulate these cells by increasing influx of Ca(2+) to the cytosol from the extracellular space. PMID:27097661

  8. A Single Amino Acid Deletion (ΔF1502 in the S6 Segment of CaV2.1 Domain III Associated with Congenital Ataxia Increases Channel Activity and Promotes Ca2+ Influx.

    Directory of Open Access Journals (Sweden)

    Maria Isabel Bahamonde

    Full Text Available Mutations in the CACNA1A gene, encoding the pore-forming CaV2.1 (P/Q-type channel α1A subunit, result in heterogeneous human neurological disorders, including familial and sporadic hemiplegic migraine along with episodic and progressive forms of ataxia. Hemiplegic Migraine (HM mutations induce gain-of-channel function, mainly by shifting channel activation to lower voltages, whereas ataxia mutations mostly produce loss-of-channel function. However, some HM-linked gain-of-function mutations are also associated to congenital ataxia and/or cerebellar atrophy, including the deletion of a highly conserved phenylalanine located at the S6 pore region of α1A domain III (ΔF1502. Functional studies of ΔF1502 CaV2.1 channels, expressed in Xenopus oocytes, using the non-physiological Ba2+ as the charge carrier have only revealed discrete alterations in channel function of unclear pathophysiological relevance. Here, we report a second case of congenital ataxia linked to the ΔF1502 α1A mutation, detected by whole-exome sequencing, and analyze its functional consequences on CaV2.1 human channels heterologously expressed in mammalian tsA-201 HEK cells, using the physiological permeant ion Ca2+. ΔF1502 strongly decreases the voltage threshold for channel activation (by ~ 21 mV, allowing significantly higher Ca2+ current densities in a range of depolarized voltages with physiological relevance in neurons, even though maximal Ca2+ current density through ΔF1502 CaV2.1 channels is 60% lower than through wild-type channels. ΔF1502 accelerates activation kinetics and slows deactivation kinetics of CaV2.1 within a wide range of voltage depolarization. ΔF1502 also slowed CaV2.1 inactivation kinetic and shifted the inactivation curve to hyperpolarized potentials (by ~ 28 mV. ΔF1502 effects on CaV2.1 activation and deactivation properties seem to be of high physiological relevance. Thus, ΔF1502 strongly promotes Ca2+ influx in response to either single or

  9. Plasma membrane protein OsMCA1 is involved in regulation of hypo-osmotic shock-induced Ca2+ influx and modulates generation of reactive oxygen species in cultured rice cells

    Directory of Open Access Journals (Sweden)

    Kurusu Takamitsu

    2012-01-01

    Full Text Available Abstract Background Mechanosensing and its downstream responses are speculated to involve sensory complexes containing Ca2+-permeable mechanosensitive channels. On recognizing osmotic signals, plant cells initiate activation of a widespread signal transduction network that induces second messengers and triggers inducible defense responses. Characteristic early signaling events include Ca2+ influx, protein phosphorylation and generation of reactive oxygen species (ROS. Pharmacological analyses show Ca2+ influx mediated by mechanosensitive Ca2+ channels to influence induction of osmotic signals, including ROS generation. However, molecular bases and regulatory mechanisms for early osmotic signaling events remain poorly elucidated. Results We here identified and investigated OsMCA1, the sole rice homolog of putative Ca2+-permeable mechanosensitive channels in Arabidopsis (MCAs. OsMCA1 was specifically localized at the plasma membrane. A promoter-reporter assay suggested that OsMCA1 mRNA is widely expressed in seed embryos, proximal and apical regions of shoots, and mesophyll cells of leaves and roots in rice. Ca2+ uptake was enhanced in OsMCA1-overexpressing suspension-cultured cells, suggesting that OsMCA1 is involved in Ca2+ influx across the plasma membrane. Hypo-osmotic shock-induced ROS generation mediated by NADPH oxidases was also enhanced in OsMCA1-overexpressing cells. We also generated and characterized OsMCA1-RNAi transgenic plants and cultured cells; OsMCA1-suppressed plants showed retarded growth and shortened rachises, while OsMCA1-suppressed cells carrying Ca2+-sensitive photoprotein aequorin showed partially impaired changes in cytosolic free Ca2+ concentration ([Ca2+]cyt induced by hypo-osmotic shock and trinitrophenol, an activator of mechanosensitive channels. Conclusions We have identified a sole MCA ortholog in the rice genome and developed both overexpression and suppression lines. Analyses of cultured cells with altered

  10. Targeted overexpression of tumor necrosis factor-α increases cyclin-dependent kinase 5 activity and TRPV1-dependent Ca2+ influx in trigeminal neurons.

    Science.gov (United States)

    Rozas, Pablo; Lazcano, Pablo; Piña, Ricardo; Cho, Andrew; Terse, Anita; Pertusa, Maria; Madrid, Rodolfo; Gonzalez-Billault, Christian; Kulkarni, Ashok B; Utreras, Elias

    2016-06-01

    We reported earlier that TNF-α, a proinflammatory cytokine implicated in many inflammatory disorders causing orofacial pain, increases the activity of Cdk5, a key kinase involved in brain development and function and recently found to be involved in pain signaling. To investigate a potential mechanism underlying inflammatory pain in trigeminal ganglia (TGs), we engineered a transgenic mouse model (TNF) that can conditionally overexpresses TNF-α upon genomic recombination by Cre recombinase. TNF mice were bred with Nav1.8-Cre mouse line that expresses the Cre recombinase in sensory neurons to obtain TNF-α:Nav1.8-Cre (TNF-α cTg) mice. Although TNF-α cTg mice appeared normal without any gross phenotype, they displayed a significant increase in TNF-α levels after activation of NFκB signaling in the TG. IL-6 and MCP-1 levels were also increased along with intense immunostaining for Iba1 and GFAP in TG, indicating the presence of infiltrating macrophages and the activation of satellite glial cells. TNF-α cTg mice displayed increased trigeminal Cdk5 activity, and this increase was associated with elevated levels of phospho-T407-TRPV1 and capsaicin-evocated Ca influx in cultured trigeminal neurons. Remarkably, this effect was prevented by roscovitine, an inhibitor of Cdk5, which suggests that TNF-α overexpression induced sensitization of the TRPV1 channel. Furthermore, TNF-α cTg mice displayed more aversive behavior to noxious thermal stimulation (45°C) of the face in an operant pain assessment device as compared with control mice. In summary, TNF-α overexpression in the sensory neurons of TNF-α cTg mice results in inflammatory sensitization and increased Cdk5 activity; therefore, this mouse model would be valuable for investigating the mechanism of TNF-α involved in orofacial pain. PMID:26894912

  11. NLRP3 inflammasome signaling is activated by low-level lysosome disruption but inhibited by extensive lysosome disruption: roles for K+ efflux and Ca2+ influx.

    Science.gov (United States)

    Katsnelson, Michael A; Lozada-Soto, Kristen M; Russo, Hana M; Miller, Barbara A; Dubyak, George R

    2016-07-01

    Nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) is a cytosolic protein that nucleates assembly of inflammasome signaling platforms, which facilitate caspase-1-mediated IL-1β release and other inflammatory responses in myeloid leukocytes. NLRP3 inflammasomes are assembled in response to multiple pathogen- or environmental stress-induced changes in basic cell physiology, including the destabilization of lysosome integrity and activation of K(+)-permeable channels/transporters in the plasma membrane (PM). However, the quantitative relationships between lysosome membrane permeabilization (LMP), induction of increased PM K(+) permeability, and activation of NLRP3 signaling are incompletely characterized. We used Leu-Leu-O-methyl ester (LLME), a soluble lysosomotropic agent, to quantitatively track the kinetics and extent of LMP in relation to NLRP3 inflammasome signaling responses (ASC oligomerization, caspase-1 activation, IL-1β release) and PM cation fluxes in murine bone marrow-derived dendritic cells (BMDCs). Treatment of BMDCs with submillimolar (≤1 mM) LLME induced slower and partial increases in LMP that correlated with robust NLRP3 inflammasome activation and K(+) efflux. In contrast, supramillimolar (≥2 mM) LLME elicited extremely rapid and complete collapse of lysosome integrity that was correlated with suppression of inflammasome signaling. Supramillimolar LLME also induced dominant negative effects on inflammasome activation by the canonical NLRP3 agonist nigericin; this inhibition correlated with an increase in NLRP3 ubiquitination. LMP elicited rapid BMDC death by both inflammasome-dependent pyroptosis and inflammasome-independent necrosis. LMP also triggered Ca(2+) influx, which attenuated LLME-stimulated NLRP3 inflammasome signaling but potentiated LLME-induced necrosis. Taken together, these studies reveal a previously unappreciated signaling network that defines the coupling between LMP, changes

  12. Paliperidone Protects SH-SY5Y Cells Against MK-801-Induced Neuronal Damage Through Inhibition of Ca(2+) Influx and Regulation of SIRT1/miR-134 Signal Pathway.

    Science.gov (United States)

    Zhu, Dexiao; Zhang, Jing; Wu, Jintao; Li, Guibao; Yao, Wei; Hao, Jing; Sun, Jinhao

    2016-05-01

    Schizophrenia is a serious psychotic disease. Recently, increasing evidences support that neurodegeneration occurs in the brain of schizophrenia patients with progressive morphological changes. Paliperidone, an atypical antipsychotic drug, could attenuate psychotic symptom and protect neurons from different stressors. However, the underlying mechanisms are largely unknown. In this study, we used SH-SY5Y cells to evaluate the neuroprotective capability of paliperidone against the neurotoxicity induced by N-methyl-D-aspartate receptor antagonist, MK-801. And, we also explored the possible molecular mechanism. Neurotoxicity of 100 μM MK-801, which reduced the cell viability, was diminished by 100 μM paliperidone using MTT and LDH assays (both p paliperidone effectively blocked the Ca(2+) influx through inhibiting the voltage-gated calcium channels (p paliperidone significantly reversed MK-801 induced increase of SIRT1 and decrease of miR-134 expression (both p paliperidone could protect SH-SY5Y cells against MK-801 induced neurotoxicity via inhibition of Ca(2+) influx and regulation of SIRT1/miR-134 pathway, providing a promising and potential therapeutic target for schizophrenia. PMID:26055227

  13. Activation of KCNN3/SK3/K(Ca)2.3 channels attenuates enhanced calcium influx and inflammatory cytokine production in activated microglia.

    Science.gov (United States)

    Dolga, Amalia M; Letsche, Till; Gold, Maike; Doti, Nunzianna; Bacher, Michael; Chiamvimonvat, Nipavan; Dodel, Richard; Culmsee, Carsten

    2012-12-01

    In neurons, small-conductance calcium-activated potassium (KCNN/SK/K(Ca)2) channels maintain calcium homeostasis after N-methyl-D-aspartate (NMDA) receptor activation, thereby preventing excitotoxic neuronal death. So far, little is known about the function of KCNN/SK/K(Ca)2 channels in non-neuronal cells, such as microglial cells. In this study, we addressed the question whether KCNN/SK/K(Ca)2 channels activation affected inflammatory responses of primary mouse microglial cells upon lipopolysaccharide (LPS) stimulation. We found that N-cyclohexyl-N-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-4-pyrimidinamine (CyPPA), a positive pharmacological activator of KCNN/SK/K(Ca)2 channels, significantly reduced LPS-stimulated activation of microglia in a concentration-dependent manner. The general KCNN/SK/K(Ca)2 channel blocker apamin reverted these effects of CyPPA on microglial proliferation. Since calcium plays a central role in microglial activation, we further addressed whether KCNN/SK/K(Ca)2 channel activation affected the changes of intracellular calcium levels, [Ca(2+)](i), in microglial cells. Our data show that LPS-induced elevation of [Ca(2+)](i) was attenuated following activation of KCNN2/3/K(Ca)2.2/K(Ca)2.3 channels by CyPPA. Furthermore, CyPPA reduced downstream events including tumor necrosis factor alpha and interleukin 6 cytokine production and nitric oxide release in activated microglia. Further, we applied specific peptide inhibitors of the KCNN/SK/K(Ca)2 channel subtypes to identify which particular channel subtype mediated the observed anti-inflammatory effects. Only inhibitory peptides targeting KCNN3/SK3/K(Ca)2.3 channels, but not KCNN2/SK2/K(Ca)2.2 channel inhibition, reversed the CyPPA-effects on LPS-induced microglial proliferation. These findings revealed that KCNN3/SK3/K(Ca)2.3 channels can modulate the LPS-induced inflammatory responses in microglial cells. Thus, KCNN3/SK3/K(Ca)2.3 channels may serve as a therapeutic target for reducing microglial

  14. Cannabinoid CB(1) receptor activation stimulates neurite outgrowth and inhibits capsaicin-induced Ca(2+) influx in an in vitro model of diabetic neuropathy.

    Science.gov (United States)

    Zhang, Fan; Challapalli, Sarat C; Smith, Paula J W

    2009-08-01

    Cannabinoid CB(1) receptors mediate, in part, the neuroprotectant properties of endocannabinoids, and altered signalling via the CB(1) receptor may contribute to the pathogenesis of diabetic neuropathy. We investigated CB(1) receptor function in PC12 cells differentiated into a neuronal phenotype with nerve growth factor (NGF, 50 ng/ml) in 5.5 and 50 mM concentrations of glucose. High glucose was associated with impaired NGF-induced neurite outgrowth (P HU210 (0.03-3 microM) increased neurite length in a concentration-dependent manner (P HU210 (1 microM) inhibited capsaicin-induced calcium transients to a similar degree in cells cultured in high glucose (40%) versus normal (43%) (P HU210-mediated rescue of neurite outgrowth and inhibition of calcium influx was blocked by the selective CB(1) antagonist AM251 (1 microM), but not by the selective CB(2) antagonist AM630 (1 microM), confirming the role of CB(1) receptors. High glucose treatment did not significantly elevate endocannabinoid levels. These results suggest that high glucose concentrations are associated with decreased expression, but preserved function of CB(1) receptors in nerve cells. PMID:19501110

  15. Capsaicin sensitizes TRAIL-induced apoptosis through Sp1-mediated DR5 up-regulation: Involvement of Ca{sup 2+} influx

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Dong-Oh [Department of Biology Education, Daegu University, Gyungsan, Gyeongbuk 712–714 (Korea, Republic of); Kang, Chang-Hee; Kang, Sang-Hyuck [Department of Marine Life Sciences, Jeju National University, Jeju 690–756 (Korea, Republic of); Choi, Yung-Hyun [Department of Biochemistry, College of Oriental Medicine, Dongeui University, Busan 614–054 (Korea, Republic of); Hyun, Jin-Won; Chang, Weon-Young; Kang, Hee-Kyoung; Koh, Young-Sang; Maeng, Young-Hee; Kim, Young-Ree [School of Medicine, Jeju National University, Jeju-si 690–756 (Korea, Republic of); Kim, Gi-Young, E-mail: immunkim@jejunu.ac.kr [Department of Marine Life Sciences, Jeju National University, Jeju 690–756 (Korea, Republic of)

    2012-02-15

    Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various malignant cells, several cancers including human hepatocellular carcinoma (HCC) exhibit potent resistance to TRAIL-induced cell death. The aim of this study is to evaluate the anti-cancer potential of capsaicin in TRAIL-induced cancer cell death. As indicated by assays that measure phosphatidylserine exposure, mitochondrial activity and activation of caspases, capsaicin potentiated TRAIL-resistant cells to lead to cell death. In addition, we found that capsaicin induces the cell surface expression of TRAIL receptor DR5, but not DR4 through the activation Sp1 on its promoter region. Furthermore, we investigated that capsaicin-induced DR5 expression and apoptosis are inhibited by calcium chelator or inhibitors for calmodulin-dependent protein kinase. Taken together, our data suggest that capsaicin sensitizes TRAIL-mediated HCC cell apoptosis by DR5 up-regulation via calcium influx-dependent Sp1 activation. Highlights: ► Capsaicin sensitizes TRAIL-induced apoptosis through activation of caspases. ► Capsaicin induces expression of DR5 through Sp1 activation. ► Capsaicin activates calcium signaling pathway.

  16. 5-(2-Cyclohexylideneethyl)-5-ethyl barbituric acid (CHEB): correlation of hypnotic and convulsant properties with alterations of synaptosomal 45Ca2+ influx

    International Nuclear Information System (INIS)

    Male ICR mice were given either 5-(2-cyclohexylideneethyl)-5-ethyl barbituric acid (CHEB) alone or CHEB after a 1 h pretreatment with phenobarbital CHEB alone produced excitatory behavior but not convulsive seizures. Higher doses produced convulsive seizures resulting in death. Pretreatment with phenobarbital prevented seizure activity. In vitro, CHEB significantly inhibited 'fast-phase' K+-stimulated 45Ca2+ uptake into cerebrocortical synaptosomes. CHEB also significantly increased basal 45Ca2+ uptake. The addition of CHEB or pentobarbital to striatal synaptosomes inhibited 'fast-phase' K+-stimulated 45Ca2+ uptake and endogenous dopamine release. CHEB, but not pentobarbital, produced a time- and dose-dependent increase in the resulting release of endogenous dopamine from striatal synaptosomes. The results of this study show that CHEB possesses hypnotic activity if its lethal convulsant actions are blocked. The hypnotic actions of CHEB appear to correlate with inhibition of voltage-dependent calcium channels in brain synaptosomes. (Auth.)

  17. Ca2+ influx and tyrosine kinases trigger Bordetella adenylate cyclase toxin (ACT endocytosis. Cell physiology and expression of the CD11b/CD18 integrin major determinants of the entry route.

    Directory of Open Access Journals (Sweden)

    Kepa B Uribe

    Full Text Available Humans infected with Bordetella pertussis, the whooping cough bacterium, show evidences of impaired host defenses. This pathogenic bacterium produces a unique adenylate cyclase toxin (ACT which enters human phagocytes and catalyzes the unregulated formation of cAMP, hampering important bactericidal functions of these immune cells that eventually cause cell death by apoptosis and/or necrosis. Additionally, ACT permeabilizes cells through pore formation in the target cell membrane. Recently, we demonstrated that ACT is internalised into macrophages together with other membrane components, such as the integrin CD11b/CD18 (CR3, its receptor in these immune cells, and GM1. The goal of this study was to determine whether ACT uptake is restricted to receptor-bearing macrophages or on the contrary may also take place into cells devoid of receptor and gain more insights on the signalling involved. Here, we show that ACT is rapidly eliminated from the cell membrane of either CR3-positive as negative cells, though through different entry routes, which depends in part, on the target cell physiology and characteristics. ACT-induced Ca(2+ influx and activation of non-receptor Tyr kinases into the target cell appear to be common master denominators in the different endocytic strategies activated by this toxin. Very importantly, we show that, upon incubation with ACT, target cells are capable of repairing the cell membrane, which suggests the mounting of an anti-toxin cell repair-response, very likely involving the toxin elimination from the cell surface.

  18. Calcium influx determines the muscular response to electrotransfer

    DEFF Research Database (Denmark)

    Møller, Pernille Højman; Brolin, Camilla; Gissel, Hanne

    2012-01-01

    Cell membrane permeabilization by electric pulses (electropermeabilization), results in free exchange of ions across the cell membrane. The role of electrotransfer-mediated Ca(2+)-influx on muscle signaling pathways involved in degeneration (β-actin and MurF), inflammation (IL-6 and TNF-α), and...... low-voltage pulse (HVLV), either alone or in combination with injection of DNA. Mice and rats were anesthetized before pulsing. At the times given, animals were killed, and intact tibialis cranialis muscles were excised for analysis. Uptake of Ca(2+) was assessed using (45)Ca as a tracer. Using gene...... expression analyses and histology, we showed a clear association between Ca(2+) influx and muscular response. Moderate Ca(2+) influx induced by HVLV pulses results in activation of pathways involved in immediate repair and hypertrophy. This response could be attenuated by intramuscular injection of EGTA...

  19. The effect of glutamate on cytosolic Ca2+ concentration and Ca2+ influx induced by ATP in cultured calf middle cerebral artery smooth muscle cells%谷氨酸对牛大脑中动脉平滑肌细胞胞浆静息Ca2+和ATP触发的Ca2+内流的影响

    Institute of Scientific and Technical Information of China (English)

    宜全; 关永源; 贺华

    2001-01-01

    目的观察谷氨酸对牛大脑中动脉平滑肌细胞有无直接的激动作用以及对ATP触发的Ca2+内流有无影响?方法采用Fura-2荧光法测定胞浆内Ca2+变化技术,在培养的乳牛大脑中动脉平滑肌细胞上观察药物的作用. 结果谷氨酸(10~200 μmol*L-1)不能增加或减少细胞胞浆静息游离Ca2+浓度([Ca2+]i)和ATP触发的Ca2+内流(谷氨酸:10~400 μmol*L-1).结论谷氨酸对大脑中动脉平滑肌细胞信息Ca2+水平和Ca2+内流均无直接的影响.谷氨酸可能没有直接参与脑血管张力的调节.

  20. Correlations between locked modes and impurity influxes

    Energy Technology Data Exchange (ETDEWEB)

    Fishpool, G.M. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Lawson, K.D. [UKAEA Culham Lab., Abingdon (United Kingdom)

    1994-07-01

    An analysis of pulses that were disturbed by medium Z impurity influxes (Cl, Cr, Fe and Ni) recorded during the 91/92 JET operations, has demonstrated that such influxes can result in MHD modes which subsequently ``lock``. A correlation is found between the power radiated by the influx and the time difference between the start of the influx and the beginning of the locked mode. The growth in the amplitude of the locked mode itself can lead to further impurity influxes. A correlation is noted between intense influxes (superior to 10 MW) and the mode ``unlocking``. (authors). 4 refs., 4 figs.

  1. Effect of Midazolam on Ca2+transsarcolemmal influx and Ca2+ release function of reticulum in human's uterine smooth muscle cells%咪达唑仑对子宫平滑肌细胞钙离子移动的影响

    Institute of Scientific and Technical Information of China (English)

    黄穗萍; 黄晓雷; 李元涛; 曹君; 孟馨; 苏娇玲; 胡薇

    2011-01-01

    : Healthy full-term pregnancy from maternal uterine smooth muscle, with collagenase digestion of cultured human uterine smooth muscle cells. The cells were divided into four groups, each of 10 uterine smooth muscle cells; the control group (group C),low concentration midazolam 1 (final concentration of 1μmol/L) M] group (m=10), middle concentration midazolam (final concentration of 3μmol/L) M2 group (n= 10).high concentration midazolam (final concentration of 15umol/L) M3 group (n = 10), with Fluo-3AM calcium fluoresceent indicator staining, respectively Hank's liquid, midazolam (final concentration of lpmol/L), midazolam (final concentration of 3μmol/L) , midazolam (final concentration of15umol/L). Then they were respectively preconditioned with 40mmol/L KC1 . Using a confocal laser scanning microscope for determination of intracellular calcium fluorescence intensity of the dynamic changes, reflecting the intracellular free Ca2+ concentration ([Ca2+] I) changes. The second section; the empirical procedure was similar to the first Section except for 20mmol/L caffeine instead of 40mmol/L KCL. Results: The first Section:The[Ca2+]I in Group M1 M2 and M3 were not statistically significant difference compared to group C(P>0. 05>.The[Ca2+]I in OHCs after addition of KC1 were increased (p0. 05). The[Ca2+]I in OHCs after addition of caffeine were increased(P0. 05). Conclusion: Midazolam decreases Ca2+ transsarcoletnmal influx through calcium channel in uterine smooth muscle cells , But it is not relate to ryanodine-sensitive Ca2+stores of endoplasmic reticulum.

  2. ATP stimulates calcium influx in primary astrocyte cultures

    International Nuclear Information System (INIS)

    The effect of ATP and other purines on 45Ca uptake was studied in primary cultures of rat astrocytes. Treatment of the cells with ATP for 1 to 30 min brought about an increase in cellular 45Ca. Stimulation of calcium influx by ATP was investigated using a 90 sec exposure to 45Ca and over a concentration range of 0.1 nM to 3 mM; a biphasic dose-response curve was obtained with EC50 values of 0.3 nM and 9 uM, indicating the presence of low and high affinity purinergic binding sites. Similar levels of 45Ca influx at 90 sec were observed with ATP, ADP and adenosine (all at 100 uM). Prior treatment of the cultures with LaCl3 blocked the purine-induced 45Ca influx. These findings indicate that one pathway for calcium entry in astrocytes involves purinergic receptor-operated, calcium channels

  3. Abnormal mitochondrial function impairs calcium influx in diabetic mouse pancreatic beta cells

    Institute of Scientific and Technical Information of China (English)

    LI Fei; D. Marshall Porterfield; ZHENG Xi-yan; WANG Wen-jun; XU Yue; ZHANG Zong-ming

    2012-01-01

    Background Abnormal insulin secretion of pancreatic beta cells is now regarded as the more primary defect than the insulin function in the etiology of type 2 diabetes.Previous studies found impaired mitochondrial function and impaired Ca2+ influx in beta cells in diabetic patients and animal models,suggesting a role for these processes in proper insulin secretion.The aim of this study was to investigate the detailed relationship of mitochondrial function,Ca2+ influx,and defective insulin secretion.Methods We investigated mitochondrial function and morphology in pancreatic beta cell of diabetic KK-Ay mice and C57BL/6J mice.Two types of Ca2+ channel activities,L-type and store-operated Ca2+ (SOC),were evaluated using whole-cell patch-clamp recording.The glucose induced Ca2+ influx was measured by a non-invasive micro-test technique (NMT).Results Mitochondria in KK-Ay mice pancreatic beta cells were swollen with disordered cristae,and mitochondrial function decreased compared with C57BL/6J mice.Ca2+ channel activity was increased and glucose induced Ca2+ influx was impaired,but could be recovered by genipin.Conclusion Defective mitochondrial function in diabetic mice pancreatic beta cells is a key cause of abnormal insulin secretion by altering Ca2+ influx,but not via Ca2+ channel activity.

  4. Process for capturing CO{sub 2} arising from the calcination of the CaCO{sub 3} used in cement manufacture

    Energy Technology Data Exchange (ETDEWEB)

    N. Rodriguez; M. Alonso; G. Grasa; J. Carlos Abanades [Instituto Nacional del Carbon, INCAR-CSIC, Oviedo (Spain)

    2008-09-15

    This paper outlines a new CaCO{sub 3} calcination method for producing a stream of CO{sub 2} (suitable for permanent geological storage after purification and compression). The process is based on the use of very hot CaO particles (T {gt} 1000{sup o}C) to transfer heat from a circulating fluidized bed combustor (CFBC) to a calciner (fluidized with CO{sub 2} and/or steam). Since the fluidized bed combustor and calciner have separate atmospheres, the CO{sub 2} resulting from the decomposition of CaCO{sub 3} can be captured, while the CO{sub 2} generated in the combustion of the fuel in air is emitted to the atmosphere. We demonstrate that with this system it is possible to reduce the CO{sub 2} emissions of a cement plant by around 60%. Furthermore, since the key pieces of equipment are similar to the commercial CFBCs used in power generation plants, it is possible to establish the additional investment required for the system and to estimate the cost per ton of CO{sub 2} avoided for this process to be about 19 $/tCO{sub 2} avoided. 19 refs., 4 figs.

  5. Pharmacologic study of calcium influx pathways in rabbit aortic smooth muscle

    International Nuclear Information System (INIS)

    Functional characteristics and pharmacologic domains of receptor-operated and potential-sensitive calcium (Ca2+) channels (ROCs and PSCs, respectively) were derived via measurements of 45Ca2+ influx (M/sup Ca/) during activation by the neurotransmitters norepinephrine (NE), histamine (HS), and serotonin (5-HT) and by elevated extracellular potassium (K+) in the individual or combined presence of organic Ca2+ channel antagonists (CAts), calmodulin antagonists (Calm-ants), lanthanum (La3+), and agents that increase intracellular levels of cyclic AMP

  6. GABAergic synaptic transmission regulates calcium influx during spike-timing dependent plasticity

    Directory of Open Access Journals (Sweden)

    Trevor Balena

    2010-06-01

    Full Text Available Coincident pre- and postsynaptic activity of hippocampal neurons alters the strength of gamma-aminobutyric acid (GABAA-mediated inhibition through a Ca2+-dependent regulation of cation-chloride cotransporters. This long-term synaptic modulation is termed GABAergic spike-timing dependent plasticity (STDP. In the present study, we examined whether the properties of the GABAergic synapses themselves modulate the required postsynaptic Ca2+ influx during GABAergic STDP induction. To do this we first identified GABAergic synapses between cultured hippocampal neurons based on their relatively long decay time constants and their reversal potentials which lay close to the resting membrane potential. GABAergic STDP was then induced by coincidentally (± 1 ms firing the pre- and postsynaptic neurons at 5 Hz for 30 seconds, while postsynaptic Ca2+ was imaged with the Ca2+-sensitive fluorescent dye Fluo4-AM. In all cases, the induction of GABAergic STDP increased postsynaptic Ca2+ above resting levels. We further found that the magnitude of this increase correlated with the amplitude and polarity of the GABAergic postsynaptic current (GPSC; hyperpolarizing GPSCs reduced the Ca2+ influx in comparison to both depolarizing GPSCs, and postsynaptic neurons spiked alone. This relationship was influenced by both the driving force for Cl- and GABAA conductance (which had positive correlations with the Ca2+ influx. The spike-timing order during STDP induction did not influence the correlation between GPSC amplitude and Ca2+ influx, which is likely accounted for by the symmetrical GABAergic STDP window.

  7. Effects of AMPK on high glucose stimulated apoptosis of endothelial cells via regulation of calcium influx

    Directory of Open Access Journals (Sweden)

    Ting LU

    2015-11-01

    Full Text Available Objective To investigate the inhibitory effect of adenosine monophosphate (AMP-dependent protein kinase (AMPK on high glucose-stimulated endothelial cell apoptosis and its mechanism. Methods MS-1 endothelial cells were cultured in vitro, and they were treated with AMPK agonist, AMPK inhibitor, 2-APB (a blocker of store operated Ca2+ channel (SOCC and (or high glucose, and a control group without any intervention were set up. TUNEL assay was performed to determine apoptotic cells. Laser scanning confocal microscopy was used to assess the Ca2+ influx into cells, and Western-blotting was performed to determine the expressions of Stim1 and Orai1 of the store operated Ca2+ channel (SOCC proteins. Results Apoptosis of endothelial cells was induced significantly, and the expressions of Stim1 and Orai1 were upregulated in high glucose group compared with that in control group (P<0.05. The rate of apoptosis of high glucose-induced endothelial cell was found to be increased in AMPK inhibitor group and decreased in AMPK agonist group, and the expressions of Stim1 and Orai1 were found to be down-regulated in AMPK agonist group as compared with that in high glucose group (P<0.05. Compared with the control group, high glucose stimulation significantly induced the Ca2+ influx to endothelial cells; compared with high glucose group, 2-APB significantly inhibited high glucose-induced Ca2+ influx to endothelial cells, and blocked the inducing effect of high-glucose on endothelial cell apoptosis. Compared with high glucose group, AMPK agonist significantly inhibited high glucose-induced cell Ca2+ influx. Conclusion By reducing the expressions of Stim1 and Orai1, AMPK may inhibit SOCC-mediated Ca2+ influx, and block the high glucose-stimulated endothelial cell apoptosis, thus play an important protective role in sustaining endothelial cell function. DOI: 10.11855/j.issn.0577-7402.2015.10.01

  8. EGF stimulates Mg{sup 2+} influx in mammary epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Trapani, Valentina; Arduini, Daniela; Luongo, Francesca; Wolf, Federica I., E-mail: federica.wolf@rm.unicatt.it

    2014-11-28

    Highlights: • EGF stimulation potentiates Mg{sup 2+} influx into epithelial cells. • EGF-induced Mg{sup 2+} influx does not depend on the concomitantly induced Ca{sup 2+} signal. • EGF-induced Ca{sup 2+} signal is dependent on the presence of extracellular Mg{sup 2+}. • New players in EGF-mediated signaling might be exploited as therapeutic targets. - Abstract: Magnesium is well established as a fundamental factor that regulates cell proliferation. However, the molecular mechanisms linking mitogenic signals, extracellular magnesium availability and intracellular effectors are still largely unknown. In the present study we sought to determine whether EGF regulates magnesium homeostasis in normal HC11 mammary epithelial cells. To this end, we measured Mg{sup 2+} and Ca{sup 2+} fluxes by confocal imaging in live cells loaded with specific fluorescent ion indicators (Mag-Fluo-4 and Fluo-4, respectively). EGF stimulation induces a rapid and sustained increase in intracellular Mg{sup 2+}, concomitantly with a rise in intracellular calcium. The increase in intracellular Mg{sup 2+} derives from an influx from the extracellular compartment, and does not depend on Ca{sup 2+}. On the contrary, the increase in intracellular Ca{sup 2+} derives from intracellular stores, and is impaired in the absence of extracellular magnesium. Inhibition of the EGF receptor tyrosine kinase by Tyrphostin AG1478 markedly inhibits EGF-induced Mg{sup 2+} and Ca{sup 2+} signals. These findings demonstrate that not only does Mg{sup 2+} influx represent an important step in the physiological response of epithelial cells to EGF, but unexpectedly the EGF-induced Mg{sup 2+} influx is essential for the Ca{sup 2+} signal to occur.

  9. Characterization of Na+ influx mediated by ATP(4-)-activated P2 purinoceptors in PC12 cells.

    OpenAIRE

    Choi, S. Y.; Kim, K. T.

    1996-01-01

    1. Micromolar levels of extracellular ATP increased cytosolic Na+ concentration ([Na+]i) as well as cytosolic Ca2+ concentration ([Ca2+]i) in PC12 cells. 2. Pretreatment of cells with tetrodotoxin, benzamil or thapsigargin did not alter the ATP-induced Na+ influx. 3. Increased extracellular Mg2+ concentration decreased the ATP effect. Furthermore, when the extracellular ATP pool was treated to contain corresponding calculated concentrations of ATP4-, the increase in [Na+]i stayed linked to th...

  10. Excess influx of Zn(2+) into dentate granule cells affects object recognition memory via attenuated LTP.

    Science.gov (United States)

    Suzuki, Miki; Fujise, Yuki; Tsuchiya, Yuka; Tamano, Haruna; Takeda, Atsushi

    2015-08-01

    The influx of extracellular Zn(2+) into dentate granule cells is nonessential for dentate gyrus long-term potentiation (LTP) and the physiological significance of extracellular Zn(2+) dynamics is unknown in the dentate gyrus. Excess increase in extracellular Zn(2+) in the hippocampal CA1, which is induced with excitation of zincergic neurons, induces memory deficit via excess influx of Zn(2+) into CA1 pyramidal cells. In the present study, it was examined whether extracellular Zn(2+) induces object recognition memory deficit via excess influx of Zn(2+) into dentate granule cells. KCl (100 mM, 2 µl) was locally injected into the dentate gyrus. The increase in intracellular Zn(2+) in dentate granule cells induced with high K(+) was blocked by co-injection of CaEDTA and CNQX, an extracellular Zn(2+) chelator and an AMPA receptor antagonist, respectively, suggesting that high K(+) increases the influx of Zn(2+) into dentate granule cells via AMPA receptor activation. Dentate gyrus LTP induction was attenuated 1 h after KCl injection into the dentate gyrus and also attenuated when KCl was injected 5 min after the induction. Memory deficit was induced when training of object recognition test was performed 1 h after KCl injection into the dentate gyrus and also induced when KCl was injected 5 min after the training. High K(+)-induced impairments of LTP and memory were rescued by co-injection of CaEDTA. These results indicate that excess influx of Zn(2+) into dentate granule cells via AMPA receptor activation affects object recognition memory via attenuated LTP induction. Even in the dentate gyrus where is scarcely innervated by zincergic neurons, it is likely that extracellular Zn(2+) homeostasis is strictly regulated for cognition. PMID:26044210

  11. Inhibition of 22Na influx by tricyclic and tetracyclic antidepressants and binding of [3H]imipramine in bovine adrenal medullary cells

    International Nuclear Information System (INIS)

    In bovine adrenal medullary cells we investigated the effects of antidepressants on ionic channels and secretion of catecholamines. Tricyclic (imipramine, amitriptyline and nortriptyline) and tetracyclic (maprotiline and mianserin) antidepressants inhibited carbachol-induced influx of 22Na, 45Ca and secretion of catecholamines (IC50, 14-96 microM). Influx of 22Na, 45Ca and secretion of catecholamines due to veratridine also were inhibited by these drugs (IC50, 10-17 microM). However, antidepressants did not suppress high concentration of K-induced 45Ca influx and catecholamine secretion, suggesting that antidepressants do not inhibit voltage-dependent Ca channels. [3H]Imipramine bound specifically to adrenal medullary cells. Binding was saturable, reversible and with two different equilibrium dissociation constants (13.3 and 165.0 microM). Tricyclic and tetracyclic antidepressants competed for the specific binding of [3H]imipramine at the same concentrations as they inhibited 22Na influx caused by carbachol or veratridine. Carbachol, d-tubocurarine, hexamethonium, tetrodotoxin, veratridine and scorpion venom did not inhibit the specific binding of [3H]imipramine. These results suggest that tricyclic and tetracyclic antidepressants bind to two populations of binding sites which are functionally associated with nicotinic receptor-associated ionic channels and with voltage-dependent Na channels, and inhibit Na influx. Inhibition of Na influx leads to the reduction of Ca influx and catecholamine secretion caused by carbachol or veratridine

  12. Modulation of agonist-activated calcium influx by extracellular pH in rat pancreatic acini

    International Nuclear Information System (INIS)

    The biochemical and Ca2+ transport pathways involved in generating the hormone-evoked Ca2+ signal are reported to be influenced by pH. The present study was designed to determine the effect of extracellular pH (pHo) and intracellular pH (pHi) on hormone-stimulated Ca2+ transport. We used rat pancreatic acini and measured free cytosolic Ca2+ concentration ([Ca2+]i) with fura-2, pHi with 2,7-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF), and Ca2+ fluxes with 45Ca2+. In the presence of external Ca2+, increasing pHo increased steady-state [Ca2+]i during sustained agonist stimulation; in the absence of external Ca2+, this increase in [Ca2+]i did not occur. The addition of an antagonist or blocking plasma membrane Ca2+ influx with La3+ in stimulated cells suspended at pHo 8.2 resulted in a reduction in [Ca2+]i. Increasing pHo increased the rate and extent of 45Ca2+ uptake into stimulated cells and the rate and extent of Ca2+ reloading of intracellular stores. The increased Ca2+ content of the intracellular stores with increased pHo indicated that at physiological pHo and pHi the agonist-mobilizable internal stores are not saturated with Ca2+. Changes in pHo affected pHi. However, changes in pHi at constant pHo had no effect on hormone-evoked [Ca2+]i increase, reduction in [Ca2+]i after hormone stimulation, or reloading of intracellular stores. We conclude that the hormone-activated plasma membrane Ca2+ entry pathway responsible for Ca2+ reloading is directly modulated by external H+

  13. The Arising of Results

    DEFF Research Database (Denmark)

    Sobisch, Jan-Ulrich

    2013-01-01

    Some Buddhist scholars have periodized the expected lifetime of the Buddha's teachings. According to them, these periods of 500 years each have different characteristics. The first is called 'the period of the results'. Therefore some scholars have claimed that only in the first 500 years after the...... Buddha results can arise. Kyobpa Jigten Sumgön has argued that results arise through practise as long as Dharma and Sangha exist....

  14. Intracellular pH changes induced by calcium influx during electrical activity in molluscan neurons

    OpenAIRE

    1980-01-01

    Simultaneous measurements of electrical activity and light absorbance have been made on nerve cell bodies from Archidoris monteryensis injected with indicator dyes. pH indicators, phenol red and bromocresol purple, and arsenazo III, which under normal conditions is primarily a calcium indicator have been employed. Voltage clamp pulses which induced calcium influx caused an absorbance decrease of the pH dyes indicating an internal acidification. The onset of the pH drop lagged the onset of Ca2...

  15. Calcium influx through CRAC channels controls actin organization and dynamics at the immune synapse

    Science.gov (United States)

    Hartzell, Catherine A; Jankowska, Katarzyna I; Burkhardt, Janis K; Lewis, Richard S

    2016-01-01

    T cell receptor (TCR) engagement opens Ca2+ release-activated Ca2+ (CRAC) channels and triggers formation of an immune synapse between T cells and antigen-presenting cells. At the synapse, actin reorganizes into a concentric lamellipod and lamella with retrograde actin flow that helps regulate the intensity and duration of TCR signaling. We find that Ca2+ influx is required to drive actin organization and dynamics at the synapse. Calcium acts by promoting actin depolymerization and localizing actin polymerization and the actin nucleation promotion factor WAVE2 to the periphery of the lamellipod while suppressing polymerization elsewhere. Ca2+-dependent retrograde actin flow corrals ER tubule extensions and STIM1/Orai1 complexes to the synapse center, creating a self-organizing process for CRAC channel localization. Our results demonstrate a new role for Ca2+ as a critical regulator of actin organization and dynamics at the synapse, and reveal potential feedback loops through which Ca2+ influx may modulate TCR signaling. DOI: http://dx.doi.org/10.7554/eLife.14850.001 PMID:27440222

  16. Calcium influx through CRAC channels controls actin organization and dynamics at the immune synapse.

    Science.gov (United States)

    Hartzell, Catherine A; Jankowska, Katarzyna I; Burkhardt, Janis K; Lewis, Richard S

    2016-01-01

    T cell receptor (TCR) engagement opens Ca(2+) release-activated Ca(2+) (CRAC) channels and triggers formation of an immune synapse between T cells and antigen-presenting cells. At the synapse, actin reorganizes into a concentric lamellipod and lamella with retrograde actin flow that helps regulate the intensity and duration of TCR signaling. We find that Ca(2+) influx is required to drive actin organization and dynamics at the synapse. Calcium acts by promoting actin depolymerization and localizing actin polymerization and the actin nucleation promotion factor WAVE2 to the periphery of the lamellipod while suppressing polymerization elsewhere. Ca(2+)-dependent retrograde actin flow corrals ER tubule extensions and STIM1/Orai1 complexes to the synapse center, creating a self-organizing process for CRAC channel localization. Our results demonstrate a new role for Ca(2+) as a critical regulator of actin organization and dynamics at the synapse, and reveal potential feedback loops through which Ca(2+) influx may modulate TCR signaling. PMID:27440222

  17. Calcium influx through stretch-activated channels mediates microfilament reorganization in osteoblasts under simulated weightlessness

    Science.gov (United States)

    Luo, Mingzhi; Yang, Zhouqi; Li, Jingbao; Xu, Huiyun; Li, Shengsheng; Zhang, Wei; Qian, Airong; Shang, Peng

    2013-06-01

    We have explored the role of Ca2+ signaling in microfilament reorganization of osteoblasts induced by simulated weightlessness using a random positioning machine (RPM). The RPM-induced alterations of cell morphology, microfilament distribution, cell proliferation, cell migration, cytosol free calcium concentration ([Ca2+]i), and protein expression in MG63 osteoblasts were investigated. Simulated weightlessness reduced cell size, disrupted microfilament, inhibited cellular proliferation and migration, and induced an increase in [Ca2+]i in MG63 human osteosarcoma cells. Gadolinium chloride (Gd), an inhibitor for stretch-activated channels, attenuated the increase in [Ca2+]i and microfilament disruption. Further, the expression of calmodulin was significantly increased by simulated weightlessness, and an inhibitor of calmodulin, W-7, aggravated microfilament disruption. Our findings demonstrate that simulated weightlessness induces Ca2+ influx through stretch-activated channels, then results in microfilament disruption.

  18. A cosmic dust influx model. III

    Science.gov (United States)

    Lebedinets, V. N.; Begkhanov, M.

    A model of cosmic dust influx is developed using results of radar and photographic studies of meteors and bolides, micrometeor impact data obtained during space missions, and the available experimental data on dust particles as small as 10 to the -17th g. It is shown, in particular, that particles of all sizes occurring above 30 km are mainly of meteor origin. Above 140 km, the earth atmosphere contains only primary cosmic particles of all sizes whose concentrations are equal to those observed in the interplanetary space but whose flux densities are twice as high. Above 30 km and below 100 km, the atmosphere contains primary micrometeor particles with masses less than 10 to the -8th g and particles of the same mass formed as a result of the fragmentation of large meteoric bodies.

  19. Simultaneous measurements of magnesium, calcium and sodium influxes in perfused squid giant axons under membrane potential control.

    Science.gov (United States)

    Rojas, E; Taylor, R E

    1975-10-01

    1. Giant axons from the squids Dosidicus gigas, Loligo forbesi and Loligo vulgaris were internally perfused with 550 or 275 mM KF plus sucrose and bathed in artificial sea water containing 45Ca, 28Mg or mixtures of 45Ca-28Mg or 45Ca-22Na. Resting influxes and extra influxes during voltage-clamp pulses were measured by collecting and counting the internal perfusate. 2. For Dosidicus axons in 10 mM-CaCl2 the resting influx of calcium was 0-016 +/- 0-007 p-mole/cm2 sec and a linear function of external concentration. For two experiments in 10 and 84-7 mM-CaCl2, 100 nM tetrodotoxin had no effect. Resting calcium influx in 10 mM-CaCl2 was 0-017 +/- 0-013 p-mole/cm2 sec for Loligo axons. 3. With 55 mM-MgCl2 outside the average resting magnesium influx was 0-124 +/- 0-080 p-mole/cm2 sec for Loligo axons. Discarding one aberrant point the value is 0-105 +/- 0-046 which is not significantly different from the resting calcium influx for Dosidicus fibres in 55 mM-CaCl2, given as 0-094 p-mole/cm2 sec by the regression line shown in Fig. 1. In two experiments 150 nM tetrodotoxin had no effect. 4. With 430 mM-NaCl outside 100 nM tetrodotoxin reduced the average resting influx of sodium in Dosidicus axon from 27-7 +/- 4-5 to 25-1 +/- 6-2 p-mole/cm2 sec and for Loligo fibres in 460 mM-NaCl from 50-5 +/- 4 to 20 +/- 8 p-mole/cm2 sec. 5. Using depolarizing pulses of various durations, the extra calcium influx occurred in two phases. The early phase was eliminated by external application of tetrodotoxin. The results of analysis are consistent with, but do not rigorously demonstrate, the conclusion that the tetrodotoxin sensitive calcium entry is flowing through the normal sodium channels (cf. Baker, Hodgkin & Ridgway, 1971). 6. Measurements of extra influxes using 22Na and 45Ca simultaneously indicate that the time courses of tetrodotoxin sensitive calcium and sodium entry are similar but not necessarily identical. It is very doubtful that any significant calcium entry occurs before

  20. A dynamic model of interactions of Ca2+, calmodulin, and catalytic subunits of Ca2+/calmodulin-dependent protein kinase II.

    Directory of Open Access Journals (Sweden)

    Shirley Pepke

    2010-02-01

    Full Text Available During the acquisition of memories, influx of Ca2+ into the postsynaptic spine through the pores of activated N-methyl-D-aspartate-type glutamate receptors triggers processes that change the strength of excitatory synapses. The pattern of Ca2+influx during the first few seconds of activity is interpreted within the Ca2+-dependent signaling network such that synaptic strength is eventually either potentiated or depressed. Many of the critical signaling enzymes that control synaptic plasticity,including Ca2+/calmodulin-dependent protein kinase II (CaMKII, are regulated by calmodulin, a small protein that can bindup to 4 Ca2+ ions. As a first step toward clarifying how the Ca2+-signaling network decides between potentiation or depression, we have created a kinetic model of the interactions of Ca2+, calmodulin, and CaMKII that represents our best understanding of the dynamics of these interactions under conditions that resemble those in a postsynaptic spine. We constrained parameters of the model from data in the literature, or from our own measurements, and then predicted time courses of activation and autophosphorylation of CaMKII under a variety of conditions. Simulations showed that species of calmodulin with fewer than four bound Ca2+ play a significant role in activation of CaMKII in the physiological regime,supporting the notion that processing of Ca2+ signals in a spine involves competition among target enzymes for binding to unsaturated species of CaM in an environment in which the concentration of Ca2+ is fluctuating rapidly. Indeed, we showed that dependence of activation on the frequency of Ca2+ transients arises from the kinetics of interaction of fluctuating Ca2+with calmodulin/CaMKII complexes. We used parameter sensitivity analysis to identify which parameters will be most beneficial to measure more carefully to improve the accuracy of predictions. This model provides a quantitative base from which to build more complex dynamic

  1. Ethanol induces calcium influx via the Cch1-Mid1 transporter in Saccharomyces cerevisiae.

    Science.gov (United States)

    Courchesne, William E; Vlasek, Christopher; Klukovich, Rachel; Coffee, Sara

    2011-05-01

    Yeast suffers from a variety of environmental stresses, such as osmotic pressure and ethanol produced during fermentation. Since calcium ions are protective for high concentrations of ethanol, we investigated whether Ca(2+) flux occurs in response to ethanol stress. We find that exposure of yeast to ethanol induces a rise in the cytoplasmic concentration of Ca(2+). The response is enhanced in cells shifted to high-osmotic media containing proline, galactose, sorbitol, or mannitol. Suspension of cells in proline and galactose-containing media increases the Ca(2+) levels in the cytoplasm independent of ethanol exposure. The enhanced ability for ethanol to induce Ca(2+) flux after the hypertonic shift is transient, decreasing rapidly over a period of seconds to minutes. There is partial recovery of the response after zymolyase treatment, suggesting that cell wall integrity affects the ethanol-induced Ca(2+) flux. Acetate inhibits the Ca(2+) accumulation elicited by the ethanol/osmotic stress. The Ca(2+) flux is primarily via the Cch1 Ca(2+) influx channel because strains carrying deletions of the cch1 and mid1 genes show greater than 90% reduction in Ca(2+) flux. Furthermore, a functional Cch1 channel reduced growth inhibition by ethanol. PMID:21259000

  2. Quantitative study on La3+ influx mediated by sodium-calcium exchanger in human lymphocytes

    Institute of Scientific and Technical Information of China (English)

    WEI; Chunying(魏春英); YANG; Pin(杨频)

    2002-01-01

    Whether La3+ can enter human peripheral blood lymphocytes by the Na+/Ca2+ exchanger or not and the effect of La3+ on the Na+/Ca2+ exchanger activity are examined by fura-2 technique. And that whether La3+ is sequestered by intracellular organelles (mainly endoplasmic reticulum and mitochondria) is studied by this method. La3+ uptake is obviously stimulated by pretreating the cells with ouabain and by removing extracellular Na+, and intracellular La3+ concentration ([La3+]i) is directly proportional to its extracellular concentration ([La3+]o). But when [La3+]o exceeds 0.4 mmol/L, the 340/380 nm ratio of fluorescence is no longer varied and the maximum [La3+]i is 1.5×10-12 mol@L-1. The higher concentration of La3+ (0.1 mmol/L) increases Na+/Ca2+ exchange-mediated calcium influx, but lower concentration (10 mmol/L) appears to block calcium influx. The results also suggest that cytosolic La3+ is transported by the ATP-dependent Ca2+ pump. Intracellular Ca2+ stores are depleted by ionomycin, and then ionomycin is added again during the period of La3+ uptake, the 340/380 nm ratio of fluorescence is also increased, these results indicate that La3+ is sequestered by intracellular organelles. A characterization of fura-2-La3+ interaction in solution simulating intracellular ionic composition (pH 7.05) shows that La3+ forms a 1:1 fura-2-La3+complex, and the apparent dissociation constant of La3+ for fura-2 (Kd) is 1.7×10-12 mol@L-1. In addition, the limit of detection of fura-2 for La3+ and Ca2+ is 10?12 and 10?8 mol@L-1 respectively.

  3. Involvement of plasma membrane calcium influx in bacterial induction of the K+/H+ and hypersensitive responses in tobacco

    International Nuclear Information System (INIS)

    An early event in the hypersensitive response of tobacco to Pseudomonas syringae pv syringae is the initiation of a K+/H+ response characterized by specific plasma membrane K+ efflux, extracellular alkalinization, and intracellular acidification. We investigated the role of calcium in induction of these host responses. Suspension-cultured tobacco cells exhibited a baseline Ca2+ influx of 0.02 to 0.06 micromole per gram per hour as determined from 45Ca2+ uptake. Following bacterial inoculation, uptake rates began to increase coincidently with onset of the K+/H+ response. Rates increased steadily for 2 to 3 hours, reaching 0.5 to 1 micromole per gram per hour. This increased Ca2+ influx was prevented by EGTA and calcium channel blockers such as La3+, Co2+, and Cd2+ but not by verapamil and nifedipine. Lanthanum, cobalt, cadmium, and EGTA inhibited the K+/H+ response in both suspension-cultured cells and leaf discs and prevented hypersensitive cell death in leaf discs. We conclude that increase plasmalemma Ca2+ influx is required for the K+/H+ and hypersensitive responses in tobacco

  4. Nelfinavir inhibits intra-mitochondrial calcium influx and protects brain against hypoxic-ischemic injury in neonatal mice.

    Directory of Open Access Journals (Sweden)

    Irina V Utkina-Sosunova

    Full Text Available Nelfinavir (NLF, an antiretroviral agent, preserves mitochondrial membranes integrity and protects mature brain against ischemic injury in rodents. Our study demonstrates that in neonatal mice NLF significantly limits mitochondrial calcium influx, the event associated with protection of the brain against hypoxic-ischemic insult (HI. Compared to the vehicle-treated mice, cerebral mitochondria from NLF-treated mice exhibited a significantly greater tolerance to the Ca(2+-induced membrane permeabilization, greater ADP-phosphorylating activity and reduced cytochrome C release during reperfusion. Pre-treatment with NLF or Ruthenium red (RuR significantly improved viability of murine hippocampal HT-22 cells, reduced Ca(2+ content and preserved membrane potential (Ψm in mitochondria following oxygen-glucose deprivation (OGD. Following histamine-stimulated Ca(2+ release from endoplasmic reticulum, in contrast to the vehicle-treated cells, the cells treated with NLF or RuR also demonstrated reduced Ca(2+ content in their mitochondria, the event associated with preserved Ψm. Because RuR inhibits mitochondrial Ca(2+ uniporter, we tested whether the NLF acts via the mechanism similar to the RuR. However, in contrast to the RuR, in the experiment with direct interaction of these agents with mitochondria isolated from naïve mice, the NLF did not alter mitochondrial Ca(2+ influx, and did not prevent Ca(2+ induced collapse of the Ψm. These data strongly argues against interaction of NLF and mitochondrial Ca(2+ uniporter. Although the exact mechanism remains unclear, our study is the first to show that NLF inhibits intramitochondrial Ca(2+ flux and protects developing brain against HI-reperfusion injury. This novel action of NLF has important clinical implication, because it targets a fundamental mechanism of post-ischemic cell death: intramitochondrial Ca(2+ overload → mitochondrial membrane permeabilization → secondary energy failure.

  5. Regulatory effects of anandamide on intracellular Ca2+ concentration increase in trigeminal ganglion neurons

    OpenAIRE

    ZHANG Yi; Xie, Hong; Lei, Gang; Li, Fen; Pan, Jianping; Liu, Changjin; Liu, Zhiguo; Liu, Lieju; Cao, Xuehong

    2014-01-01

    Activation of cannabinoid receptor type 1 on presynaptic neurons is postulated to suppress neurotransmission by decreasing Ca2+ influx through high voltage-gated Ca2+ channels. However, recent studies suggest that cannabinoids which activate cannabinoid receptor type 1 can increase neurotransmitter release by enhancing Ca2+ influx in vitro. The aim of the present study was to investigate the modulation of intracellular Ca2+ concentration by the cannabinoid receptor type 1 agonist anandamide, ...

  6. Characterization of a novel, hydrophilic dihydropyridine, NKY-722, as a Ca2+ antagonist in bovine cultured adrenal chromaffin cells.

    OpenAIRE

    Ohue, T.; Lee, K; Koshimura, K.; Miwa, S

    1991-01-01

    1. To characterize NKY-722, a novel hydrophilic dihydropyridine derivative, as a Ca2+ antagonist, we examined its effects on 45Ca2+ influx, intracellular free Ca2+ concentrations [( Ca2+]i), and release of noradrenaline and adrenaline in bovine cultured adrenal chromaffin cells. 2. NKY-722 had little effect on basal 45Ca2+ influx into the resting cells, but inhibited high K+ (35.9 mM)-evoked 45Ca2+ influx in a concentration-dependent manner with an IC50 value of 5.2 nM. 3. NKY-722 inhibited h...

  7. Influx of pyrophosphate ions into calvaria in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Neuman, M.W. (Univ. of Rochester, NY); Neuman, W.F.; Fleisch, H.

    1978-01-01

    The flux of /sup 32/P-labeled inorganic pyrophosphate (PP/sub i/) into bone was studied in vitro using Ussing chamber techniques and calvaria from newborn rat pups. Because insignificant hydrolysis and backflux of PP/sub i/ took place under experimental conditions, it was possible to study the penetration of bone membranes by PP/sub i/ unambiguously. At physiological concentrations, the influx was found to be linearly concentration dependent and to follow first order kinetics, apparently a simple diffusion process. In magnitude, the intrinsic constant for influx was found to be approximately one-half that of inorganic phosphate ions under comparable conditions.

  8. Massive Ca-induced Membrane Fusion and Phospholipid Changes Triggered by Reverse Na/Ca Exchange in BHK Fibroblasts

    OpenAIRE

    Yaradanakul, Alp; Wang, Tzu-Ming; Lariccia, Vincenzo; Lin, Mei-Jung; Shen, Chengcheng; Liu, Xinran; Hilgemann, Donald W.

    2008-01-01

    Baby hamster kidney (BHK) fibroblasts increase their cell capacitance by 25–100% within 5 s upon activating maximal Ca influx via constitutively expressed cardiac Na/Ca exchangers (NCX1). Free Ca, measured with fluo-5N, transiently exceeds 0.2 mM with total Ca influx amounting to ∼5 mmol/liter cell volume. Capacitance responses are half-maximal when NCX1 promotes a free cytoplasmic Ca of 0.12 mM (Hill coefficient ≈ 2). Capacitance can return to baseline in 1–3 min, and responses can be repeat...

  9. Essential adaptation of the calcium influx assay into liposomes with entrapped arsenazo III for studies on the possible calcium translocating properties of acidic phospholipids

    NARCIS (Netherlands)

    Smaal, Erik B.; Mandersloot, Jacqueline G.; Kruijff, B. de; Gier, Johannes de

    1985-01-01

    An adapted version of the Ca2+ influx assay of Weissmann et al. (Weissmann, G., Anderson, P., Serhan, C., Samuelson, E. and Goodman, E. (1980) Proc. Natl. Acad. Sci. USA 77, 1506–1510) is presented for studies on the possible ionophoretic properties of acidic phospholipids. This method is based on t

  10. CB1 cannabinoid receptor stimulation modulates transient receptor potential vanilloid receptor 1 activities in calcium influx and substande P release in cultured rat dorsal root ganglion cells

    OpenAIRE

    Ohshita, Kyoko

    2005-01-01

    Cannabinoids have been reported to have analgesic properties in animals of acute nociception or of inflammatory and neuropathic pain models, but the mechanisms by which they exert such alleviative effects are not yet fully understood. We investigated whether the CB1- cannabinoid-receptor agonist HU210 modulates the capsaicin-induced 45Ca2+ influx and substance P like-immunoreactivity (SPLI) release in cultured rat dorsal root ganglion (DRG) cells. HU210 attenuated the capsaicin-induced 45Ca2+...

  11. Glucose- and interleukin-1beta-induced beta-cell apoptosis requires Ca2+ influx and extracellular signal-regulated kinase (ERK) 1/2 activation and is prevented by a sulfonylurea receptor 1/inwardly rectifying K+ channel 6.2 (SUR/Kir6.2) selective potassium channel opener in human islets

    DEFF Research Database (Denmark)

    Maedler, Kathrin; Størling, Joachim; Sturis, Jeppe;

    2004-01-01

    -regulated kinase (ERK) 1/2, an effect that was abrogated by 3 micromol/l NN414. Similarly, 1 micromol/l of the mitogen-activated protein kinase/ERK kinase 1/2 inhibitor PD098059 or 1 micromol/l of the l-type Ca(2+) channel blocker nimodipine prevented glucose- and IL-1beta-induced ERK activation, beta......Increasing evidence indicates that a progressive decrease in the functional beta-cell mass is the hallmark of both type 1 and type 2 diabetes. The underlying causes, beta-cell apoptosis and impaired secretory function, seem to be partly mediated by macrophage production of interleukin (IL)-1beta...... and/or high-glucose-induced beta-cell production of IL-1beta. Treatment of type 1 and type 2 diabetic patients with the potassium channel opener diazoxide partially restores insulin secretion. Therefore, we studied the effect of diazoxide and of the novel potassium channel opener NN414, selective for...

  12. Calcium influx rescues adenylate cyclase-hemolysin from rapid cell membrane removal and enables phagocyte permeabilization by toxin pores.

    Directory of Open Access Journals (Sweden)

    Radovan Fiser

    Full Text Available Bordetella adenylate cyclase toxin-hemolysin (CyaA penetrates the cytoplasmic membrane of phagocytes and employs two distinct conformers to exert its multiple activities. One conformer forms cation-selective pores that permeabilize phagocyte membrane for efflux of cytosolic potassium. The other conformer conducts extracellular calcium ions across cytoplasmic membrane of cells, relocates into lipid rafts, translocates the adenylate cyclase enzyme (AC domain into cells and converts cytosolic ATP to cAMP. We show that the calcium-conducting activity of CyaA controls the path and kinetics of endocytic removal of toxin pores from phagocyte membrane. The enzymatically inactive but calcium-conducting CyaA-AC⁻ toxoid was endocytosed via a clathrin-dependent pathway. In contrast, a doubly mutated (E570K+E581P toxoid, unable to conduct Ca²⁺ into cells, was rapidly internalized by membrane macropinocytosis, unless rescued by Ca²⁺ influx promoted in trans by ionomycin or intact toxoid. Moreover, a fully pore-forming CyaA-ΔAC hemolysin failed to permeabilize phagocytes, unless endocytic removal of its pores from cell membrane was decelerated through Ca²⁺ influx promoted by molecules locked in a Ca²⁺-conducting conformation by the 3D1 antibody. Inhibition of endocytosis also enabled the native B. pertussis-produced CyaA to induce lysis of J774A.1 macrophages at concentrations starting from 100 ng/ml. Hence, by mediating calcium influx into cells, the translocating conformer of CyaA controls the removal of bystander toxin pores from phagocyte membrane. This triggers a positive feedback loop of exacerbated cell permeabilization, where the efflux of cellular potassium yields further decreased toxin pore removal from cell membrane and this further enhances cell permeabilization and potassium efflux.

  13. Adenosarcoma arising in hepatic endometriosis

    International Nuclear Information System (INIS)

    We report a case of adenosarcoma arising in hepatic endometriosis. Both CT and MR scans demontrated a huge heterogeneous mass containing septated, thick-walled cystic lesions. After enlarged right hepatectomy, the patient was asymptomatic with no abnormalities at liver and abdominal CT scan at 2-year follow-up. (orig.)

  14. Adenosarcoma arising in hepatic endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    N' Senda, P.; Dahan, H.; Tubiana, J.M.; Arrive, L. [Service de Radiologie, Hopital Saint-Antoine, 75 - Paris (France); Wendum, D. [Service d' Anatomie Pathologie, Hopital Saint-Antoine, 75 - Paris (France); Balladur, P. [Service de Chirurgie Digestive et Generale, Hopital Saint-Antoine, 75 - Paris (France)

    2000-08-01

    We report a case of adenosarcoma arising in hepatic endometriosis. Both CT and MR scans demontrated a huge heterogeneous mass containing septated, thick-walled cystic lesions. After enlarged right hepatectomy, the patient was asymptomatic with no abnormalities at liver and abdominal CT scan at 2-year follow-up. (orig.)

  15. Influx mechanisms in the embryonic and adult rat choroid plexus

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld;

    2015-01-01

    The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analyzed by functional groups of influx transporters, particularly solute carrier (SLC) transporters. RNA-Seq was performed at embryonic day (E) 15 and a...... studies suggests that the choroid plexus in embryonic brain plays a major role in supplying the developing brain with essential nutrients.......The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analyzed by functional groups of influx transporters, particularly solute carrier (SLC) transporters. RNA-Seq was performed at embryonic day (E) 15 and...... in the adult plexus were expressed at higher levels than in embryos. These results are compared with earlier published physiological studies of amino acid and monocarboxylate transport in developing rodents. This comparison shows correlation of high expression of some transporters in the developing...

  16. Regulated release of Ca2+ from respiring mitochondria by Ca2+/2H+ antiport.

    Science.gov (United States)

    Fiskum, G; Lehninger, A L

    1979-07-25

    Simultaneous measurements of oxygen consumption and transmembrane transport of Ca2+, H+, and phosphate show that the efflux of Ca2+ from respiring tightly coupled rat liver mitochondria takes place by an electroneutral Ca2+/2H+ antiport process that is ruthenium red-insensitive and that is regulated by the oxidation-reduction state of the mitochondrial pyridine nucleotides. When mitochondrial pyridine nucleotides are kept in a reduced steady state, the efflux of Ca2+ is inhibited; when they are in an oxidized state, Ca2+ efflux is activated. These processes were demonstrated by allowing phosphate-depleted mitochondria respiring on succinate in the presence of rotenone to take up Ca2+ from the medium. Upon subsequent addition of ruthenium red to block Ca2+ transport via the electrophoretic influx pathway, and acetoacetate, to bring mitochondrial pyridine nucleotides into the oxidized state, Ca2+ efflux and H+ influx ensued. The observed H+ influx/Ca2+ efflux ratio was close to the value 2.0 predicted for the operation of an electrically neutral Ca2+/2H+ antiport process. PMID:36390

  17. Sodium influxes in internally perfused squid giant axon during voltage clamp.

    Science.gov (United States)

    Atwater, I; Bezanilla, F; Rojas, E

    1969-05-01

    1. An experimental method for measuring ionic influxes during voltage clamp in the giant axon of Dosidicus is described; the technique combines intracellular perfusion with a method for controlling membrane potential.2. Sodium influx determinations were carried out while applying rectangular pulses of membrane depolarization. The ratio ;measured sodium influx/computed ionic flux during the early current' is 0.92 +/- 0.12.3. Plots of measured sodium influx and computed ionic flux during the early current against membrane potential are very similar. There was evidence that the membrane potential at which the sodium influx vanishes is the potential at which the early current reverses. PMID:5767887

  18. Structures of CaV2 Ca2+/CaM-IQ Domain Complexes Reveal Binding Modes That Underlie Calcium-Dependent Inactivation And Facilitation

    International Nuclear Information System (INIS)

    Calcium influx drives two opposing voltage-activated calcium channel (CaV) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca2+/calmodulin (Ca2+/CaM) lobes produce CDI and CDF through interactions with the CaVα1 subunit IQ domain. Curiously, Ca2+/CaM lobe modulation polarity appears inverted between CaV1s and CaV2s. Here, we present crystal structures of CaV2.1, CaV2.2, and CaV2.3 Ca2+/CaM-IQ domain complexes. All display binding orientations opposite to CaV1.2 with a physical reversal of the CaM lobe positions relative to the IQ α-helix. Titration calorimetry reveals lobe competition for a high-affinity site common to CaV1 and CaV2 IQ domains that is occupied by the CDI lobe in the structures. Electrophysiological experiments demonstrate that the N-terminal CaV2 Ca2+/C-lobe anchors affect CDF. Together, the data unveil the remarkable structural plasticity at the heart of CaV feedback modulation and indicate that CaV1 and CaV2 IQ domains bear a dedicated CDF site that exchanges Ca2+/CaM lobe occupants

  19. Enhancement of rat bladder contraction by artificial sweeteners via increased extracellular Ca2+ influx

    International Nuclear Information System (INIS)

    Introduction: Consumption of carbonated soft drinks has been shown to be independently associated with the development of overactive bladder symptoms (OR 1.62, 95% CI 1.18, 2.22) [Dallosso, H.M., McGrother, C.W., Matthews, R.J., Donaldson, M.M.K., 2003. The association of diet and other lifestyle factors with overactive bladder and stress incontinence: a longitudinal study in women. BJU Int. 92, 69-77]. We evaluated the effects of three artificial sweeteners, acesulfame K, aspartame and sodium saccharin, on the contractile response of isolated rat detrusor muscle strips. Methods: Strips of detrusor muscle were placed in an organ bath and stimulated with electrical field stimulation (EFS) in the absence and presence of atropine, and with α,β methylene ATP, potassium, calcium and carbachol. Results: Sweeteners 10-7 M to 10-2 M enhanced the contractile response to 10 Hz EFS compared to control (p -6 M, aspartame 10-7 M and sodium saccharin 10-7 M. Acesulfame K 10-6 M increased the maximum contractile response to α,β methylene ATP by 35% (± 9.6%) (p -6 M increased the log EC5 from -2.79 (± 0.037) to -3.03 (± 0.048, p -7 M from -2.74 (± 0.03) to 2.86 (± 0.031, p +2 channels

  20. A conotoxin from Conus textile with unusual posttranslational modifications reduces presynaptic Ca2+ influx

    DEFF Research Database (Denmark)

    Rigby, A C; Lucas-Meunier, E; Kalume, D E;

    1999-01-01

    Cone snails are gastropod mollusks of the genus Conus that live in tropical marine habitats. They are predators that paralyze their prey by injection of venom containing a plethora of small, conformationally constrained peptides (conotoxins). We report the identification, characterization, and...... structure of a gamma-carboxyglutamic acid-containing peptide, conotoxin epsilon-TxIX, isolated from the venom of the molluscivorous cone snail, Conus textile. The disulfide bonding pattern of the four cysteine residues, an unparalleled degree of posttranslational processing including bromination......2+ in a slow and reversible fashion. The three-dimensional structure, determined by two-dimensional 1H NMR spectroscopy, identifies an electronegative patch created by the side chains of two gamma-carboxyglutamic acid residues that extend outward from a cavernous cleft. The glycosylated threonine...

  1. Jujuboside B Reduces Vascular Tension by Increasing Ca2+ Influx and Activating Endothelial Nitric Oxide Synthase

    OpenAIRE

    Zhao, Yixiu; Zhang, Xin; Li, Jiannan; Bian, Yu; Sheng, Miaomiao; Liu, Bin; Fu, Zidong; Zhang, Yan; Yang, Baofeng

    2016-01-01

    Jujuboside B has been reported to have protective effect on many cardiovascular diseases. However, the effects of Jujuboside B on vascular tension and endothelial function are unknown. The present study investigated the effects of Jujuboside B on reducing vascular tension, protecting endothelial function and the potential mechanisms. The tension of isolated rat thoracic aorta ring was measured by Wire myograph system. The concentration of nitric oxide (NO) and the activity of endothelial nitr...

  2. Calcium Influx of Mast Cells Is Inhibited by Aptamers Targeting the First Extracellular Domain of Orai1

    Science.gov (United States)

    Sun, Renshan; Yang, Yongqiang; Ran, Xinze; Yang, Tao

    2016-01-01

    Using the systematic evolution of ligands by exponential enrichment (SELEX) method, we identified oligonucleotides that bind to the first extracellular domain of the Orai1 protein with high affinities and high specificities. These ligands were isolated from a random single-strand DNA (ssDNA) library with 40 randomized sequence positions, using synthesized peptides with amino acid sequences identical to the first extracellular domain of the Orai1 protein as the targets for SELEX selection. Seven aptamers were obtained after 12 rounds of SELEX. An enzyme-linked oligonucleotide assay (ELONA) was performed to determine the affinities of the aptamers. Aptamer Y1 had the highest affinity (Kd = 1.72×10−8 mol/L) and was selected for functional experiments in mast cells. Using LAD2 cells with the human high-affinity IgE receptor and Ca2+ release activation channel (CRAC), we demonstrated that Aptamer Y1 blocked IgE-mediated β-hexosaminidase release from cells triggered by biotin-IgE and streptavidin. A specific binding assay showed that Aptamer Y1 not only bound the Orai1 peptide specifically but also that the Orai1 peptide did not bind significantly to other random oligonucleotide molecules. Furthermore, Aptamer Y1 regulation of intracellular Ca2+ mobilization was investigated by probing intracellular Ca2+ with a Fluo-4-AM fluorescent probe. We found that Aptamer Y1 inhibits Ca2+ influx into antigen-activated mast cells. These results indicate that the target of Aptamer Y1 in the degranulation pathway is upstream of Ca2+ influx. Therefore, these oligonucleotide agents represent a novel class of CRAC inhibitors that may be useful in the fight against allergic diseases. PMID:27390850

  3. Fas mRNA expression and calcium influx change in H2O2-induced apoptotic hepatocytes in vitro

    Institute of Scientific and Technical Information of China (English)

    Qi-Ping Lu; Lei Tian

    2005-01-01

    AIM: To investigate the relationship between Fas gene expression and calcium influx change in peroxide-induced apoptotic hepatocytes and the possible molecular mechanism of Rxa in protecting hepatocytes.METHODS: Single-cell Fas mRNA expression in H2O2-exposed L02 hepatocytes with or without treatment of Rxa,an extract from an anti-peroxidant, Radix Salviae Miltiorrhizae,was determined by all-cell patch clamp and single-cell reverse transcriptase polymerase chain reaction (RT-PCR). Transient calcium influx change ([Ca2+]i) in the cells was evaluated with all-cell patch clamp micro-fluorescence single-cytosolic free Ca2+ concentration technique. Fas protein expression, early apoptotic index (annexin-V+) and cell membrane change inthe cells were evaluated by immunohistochemistry, flow cytometry (FCM) and scan electron microscopy respectively.RESULTS: In cells exposed to H2O2 for 2 h, the specific lane for Fas mRNA was vivid on electrophoresis, with increased Fas protein expression, [Ca2+]i (from 143.66±34.21 to 1115.28±227.16), annexin-V+ index (from 4.00±0.79 to 16.18±0.72) and membrane vesicle formation. However, in cells exposed to H2O2 but pre-treated with Rxa, there was no increase in Fas mRNA or protein expression and [Ca2+]i (103.56±28.92). Annexin-V+ index (8.92±1.44) was lower than the controls (P<0.01), and the cell membrane was intact.CONCLUSION: H2O2 induces apoptosis of L02 cells by increasing cytosolic [Ca2+]i, and inducing Fas mRNA and protein expression. Rxa protects the L02 cells from apoptosis through anti-peroxidation, inhibition of calcium overloading and prevention of the activation of cytosolic Fas signal pathway.

  4. Spectroscopic Measurement of Neutral Particle Influx Ratio on EAST

    International Nuclear Information System (INIS)

    The spectra of HeI (587.6 nm), Hα (656.28 nm) and Dα (656.1 nm) of the helium discharges as well as the normal deuterium discharges have been measured with two optical spectroscopic multi-channel analysis (OMA) systems on the experimental advanced superconducting tokamak (EAST). The influx ratio of the sum of H and D to He spectral lines and the influx ratio of H to D are given. In this way the ratio of hydrogen/deuterium ion (S/XB)H/D to (S/XB)He as well as (S/XB)H/D is not very sensitive to the variation in the edge density and temperature. The low-density helium discharges are operated in order to reduce the recycling hydrogen fluxes; however, the effect is not obvious. The possible reason is that the number of helium discharges is not enough and the content of hydrogen in the wall is still very abundant, which is caused by frequent wall conditionings and the vacuum leakage. The H/(H+D) ratio decreases quickly after one lithium coating and reduces to less than 10% using several accumulated lithium wall conditioning. It is found that the deposited He atoms on the carbon wall will remain at a low level after several D2 discharges.

  5. Observation of impurity accumulation and concurrent impurity influx in PBX

    International Nuclear Information System (INIS)

    Impurity studies in L- and H-mode discharges in PBX have shown that both types of discharges can evolve into either an impurity accumulative or nonaccumulative case. In a typical accumulative discharge, Zeff peaks in the center to values of about 5. The central metallic densities can be high, n/sub met//n/sub e/ ≅ 0.01, resulting in central radiated power densities in excess of 1 W/cm3, consistent with bolometric estimates. The radial profiles of metals obtained independently from the line radiation in the soft x-ray and the VUV regions are very peaked. Concurrent with the peaking, an increase in the impurity influx coming from the edge of the plasma is observed. At the beginning of the accumulation phase the inward particle flux for titanium has values of 6 x 1010 and 10 x 1010 particles/cm2s at minor radii of 6 and 17 cm. At the end of the accumulation phase, this particle flux is strongly increased to values of 3 x 1012 and 1 x 1012 particles/cm2s. This increased flux is mainly due to influx from the edge of the plasma and to a lesser extent due to increased convective transport. Using the measured particle flux, an estimate of the diffusion coefficient D and the convective velocity v is obtained

  6. Dust arising during steelmaking processes

    Directory of Open Access Journals (Sweden)

    P. Popielska-Ostrowska

    2012-12-01

    Full Text Available Purpose: This paper describes the dust arising during steelmaking processes.Design/methodology/approach: Steelmaking dusts may be a viable alternative for obtaining valuable and widely used metal which is zinc. On the other hand, heavy metals, it was as dangerous to the environment, and this in turn means that development of steelmaking dusts in the best possible way.Findings: The analysis of the formation of steelmaking dust.Research limitations/implications: Understanding the mechanism of steelmaking dusts will help to increase the participation of zinc recycling from wastes.Practical implications: Contained zinc in the dust can be recovered from the positive economic effect, and neutralization of hazardous waste to the desired environmental effect.Originality/value: Description of the mechanism of steelmaking dust, with particular emphasis on the distribution of zinc. The information is very important in the development of metal recovery technology from waste.

  7. Stretch induced endothelin-1 secretion by adult rat astrocytes involves calcium influx via stretch-activated ion channels (SACs)

    Energy Technology Data Exchange (ETDEWEB)

    Ostrow, Lyle W., E-mail: lostrow1@jhmi.edu [Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205 (United States); Suchyna, Thomas M.; Sachs, Frederick [Department of Physiology and Biophysical Sciences, State University of New York at Buffalo, Buffalo, NY 14214 (United States)

    2011-06-24

    Highlights: {yields} Endothelin-1 expression by adult rat astrocytes correlates with cell proliferation. {yields} Stretch-induced ET-1 is inhibited by GsMtx-4, a specific inhibitor of Ca{sup 2+} permeant SACs. {yields} The less specific SAC inhibitor streptomycin also inhibits ET-1 secretion. {yields} Stretch-induced ET-1 production depends on a calcium influx. {yields} SAC pharmacology may provide a new class of therapeutic agents for CNS pathology. -- Abstract: The expression of endothelins (ETs) and ET-receptors is often upregulated in brain pathology. ET-1, a potent vasoconstrictor, also inhibits the expression of astrocyte glutamate transporters and is mitogenic for astrocytes, glioma cells, neurons, and brain capillary endothelia. We have previously shown that mechanical stress stimulates ET-1 production by adult rat astrocytes. We now show in adult astrocytes that ET-1 production is driven by calcium influx through stretch-activated ion channels (SACs) and the ET-1 production correlates with cell proliferation. Mechanical stimulation using biaxial stretch (<20%) of a rubber substrate increased ET-1 secretion, and 4 {mu}M GsMTx-4 (a specific inhibitor of SACs) inhibited secretion by 30%. GsMTx-4 did not alter basal ET-1 levels in the absence of stretch. Decreasing the calcium influx by lowering extracellular calcium also inhibited stretch-induced ET-1 secretion without effecting ET-1 secretion in unstretched controls. Furthermore, inhibiting SACs with the less specific inhibitor streptomycin also inhibited stretch-induced ET-1 secretion. The data can be explained with a simple model in which ET-1 secretion depends on an internal Ca{sup 2+} threshold. This coupling of mechanical stress to the astrocyte endothelin system through SACs has treatment implications, since all pathology deforms the surrounding parenchyma.

  8. Carbon influx studies in the main chamber of ASDEX Upgrade

    International Nuclear Information System (INIS)

    Carbon sources in the main chamber of ASDEX Upgrade, especially the 12 guard limiters at the low field side (LFS), were determined spectroscopically using recently installed lines of sight. Absolute photon fluxes were measured for spectral lines in the visible wavelength range referring to all spin systems of C+1 and C+2. A simple transport model for carbon enabled the simulation of the radial distribution of carbon radiation and the determination of the effective inverse photon efficiency, which was used for the evaluation of ion fluxes. The model also predicts the fraction of eroded particles that are transported out of the plasma before further ionization occurs. Comparison of the calculated losses with measurements showed good agreement in L-mode cases, whereas in H-mode cases the CIII/CII radiation ratio was too high by a factor 1.5. The contribution of each spin system to the ion flux was independently measured. For C+1 and C+2 the spin system distribution was found to be close to equilibrium. The line-of-sight-integrated photon fluxes were spatially separated for many lines of sight by Zeeman-analysis and differential measurements. This allowed us to determine the total influx from the high field side and LFS. Surprisingly, the carbon source at the inner heat shield was larger than the carbon influx from the limiter source at the LFS. This is very pronounced for the H-mode case investigated, where 60-80% of the carbon atoms emerge from the heat shield. This source is due to recycling or re-erosion of carbon, which probably originates from the limiters, because approximately 85% of the heat shield area consisted of tungsten coated tiles

  9. Carbon influx studies in the main chamber of ASDEX Upgrade

    Science.gov (United States)

    Pütterich, T.; Dux, R.; Gafert, J.; Kallenbach, A.; Neu, R.; Pugno, R.; Yoon, S. W.; ASDEX Upgrade Team

    2003-10-01

    Carbon sources in the main chamber of ASDEX Upgrade, especially the 12 guard limiters at the low field side (LFS), were determined spectroscopically using recently installed lines of sight. Absolute photon fluxes were measured for spectral lines in the visible wavelength range referring to all spin systems of C+1 and C+2. A simple transport model for carbon enabled the simulation of the radial distribution of carbon radiation and the determination of the effective inverse photon efficiency, which was used for the evaluation of ion fluxes. The model also predicts the fraction of eroded particles that are transported out of the plasma before further ionization occurs. Comparison of the calculated losses with measurements showed good agreement in L-mode cases, whereas in H-mode cases the CIII/CII radiation ratio was too high by a factor 1.5. The contribution of each spin system to the ion flux was independently measured. For C+1 and C+2 the spin system distribution was found to be close to equilibrium. The line-of-sight-integrated photon fluxes were spatially separated for many lines of sight by Zeeman-analysis and differential measurements. This allowed us to determine the total influx from the high field side and LFS. Surprisingly, the carbon source at the inner heatshield was larger than the carbon influx from the limiter source at the LFS. This is very pronounced for the H-mode case investigated, where 60-80% of the carbon atoms emerge from the heatshield. This source is due to recycling or re-erosion of carbon, which probably originates from the limiters, because ap85% of the heatshield area consisted of tungsten coated tiles.

  10. CO2 Biogenic vs Anthropogenic Sectoral Contribution for INFLUX

    Science.gov (United States)

    Lopez-Coto, I.; Prasad, K.; Hu, H.; Whetstone, J. R.; Miles, N. L.; Richardson, S.; Lauvaux, T.; Davis, K. J.; Turnbull, J. C.; Karion, A.; Sweeney, C.; Brewer, A.; Hardesty, M.; Cambaliza, M. O. L.; Shepson, P. B.; Patarasuk, R.; Gurney, K. R.

    2014-12-01

    The Indianapolis Flux Experiment (INFLUX) aims to use a top-down inversion methodology to quantify sources of Greenhouse Gas (GHG) emissions over an urban domain with high spatial and temporal resolution. This project is an experimental test bed which is intended to establish reliable methods for quantifying and validating GHG emissions independently of the inventory methods typically used for Measurement, Reporting and Verification (MRV) of pollution sources. Analyzing the contribution of different source types or sectors is a fundamental step in order to achieve an accuracy level desired for such MRV applications. This is especially challenging when attempting to determine anthropogenic emissions during the growing season since biological GHG fluxes reach a maximum at this time. To this end, the Weather Research and Forecasting Model (WRF-ARW) version 3.5.1 was used along with a modified version of the Green House Gases chemistry module for simulating the CO2 mole fraction transport during September and October 2013. Sectoral anthropogenic CO2 emissions were obtained from Hestia 2012 and from Vulcan 2002 beyond the spatial coverage of Hestia. Biogenic CO2 emissions were simulated by using an augmented version of the "Vegetation Photosynthesis and Respiration Model" (VPRM) included in WRF-CHEM. An implementation of the unconstrained nonlinear global optimization method of Nelder and Mead was employed to find the optimum values for the VPRM parameters for each vegetation category by using data from Ameriflux eddy covariance flux towers. Here we present a preliminary assessment of the relative contribution of biological vs sectoral anthropogenic CO2 fluxes on the INFLUX measurements network. The simulations are compared to tower and aircraft measurements that include trace gases with the capacity to distinguish observationally anthropogenic and biogenic CO2 sources and sinks. In addition, an evaluation of the sensitivity of the sectoral attribution to meteorological

  11. Ca2+ current facilitation is CaMKII-dependent and has arrhythmogenic consequences

    Directory of Open Access Journals (Sweden)

    DonaldMBers

    2014-06-01

    Full Text Available The cardiac voltage gated Ca2+ current (ICa is critical to the electrophysiological properties, excitation-contraction coupling, mitochondrial energetics and transcriptional regulation in heart. Thus, it is not surprising that cardiac ICa is regulated by numerous pathways. This review will focus on changes in ICa that occur during the cardiac action potential (AP, with particular attention to Ca2+-dependent inactivation (CDI, Ca2+-dependent facilitation (CDF and how calmodulin (CaM and Ca2+-CaM dependent protein kinase (CaMKII participate in the regulation of Ca2+ current during the cardiac AP. CDI depends on CaM pre-bound to the C-terminal of the L-type Ca2+ channel, such that Ca2+ influx and Ca2+ released from the sarcoplasmic reticulum bind to that CaM and cause CDI. In cardiac myocytes CDI normally predominates over voltage-dependent inactivation. The decrease in ICa via CDI provides direct negative feedback on the overall Ca2+ influx during a single beat, when myocyte Ca2+ loading is high. CDF builds up over several beats, depends on CaMKII-dependent Ca2+ channel phosphorylation and results in a staircase of increasing ICa peak, with progressively slower inactivation. CDF and CDI co-exist and in combination may fine-tune the ICa waveform during the cardiac AP. CDF may partially compensate for the tendency for Ca2+ channel availability to decrease at higher heart rates because of accumulating inactivation. CDF may also allow some reactivation of ICa during long duration cardiac APs, and contribute to early afterdepolarizations, a form of triggered arrhythmias.

  12. Ca2+ sparks evoked by depolarization of rat ventricular myocytes involve multiple release sites

    Institute of Scientific and Technical Information of China (English)

    ZANGWei-Jin; YUXiao-Jiang; ZANGYi-Min

    2003-01-01

    AIM:To investigate the fundamental nature of calcium release events (Ca2+‘sparks’) evoked in rat ventricular myocytes during excitation-contraction (E-C) coupling. METHODS: High-resolution line-scan confocal imaging with the fluorescent calcium indicator and patch-clamp techniques were used to study the spontaneous Ca2+ sparks and sparks evoked by depolarization. RESULTS: 1)Line scans oriented along the length of the cell showed that both spontaneous sparks and sparks evoked by depolarization to -35mV appeared to arise at single sites spacing about 1.80μm apart (ie, the sarcomere length), and measurements of their longitudinal spread (full-width at halfmaximal amplitude:FWHM) followed single Gaussian distributions with means of 2.6μm. 2)Different to this,transverse line scans often revealed spontaneous and evoked sparks that appeared to arise near-synchronously from paired sites. Measurements of transverse FWHM of both spontaneous and evoked sparks showed bimodal distributions, which were fit well by the sums of two Gaussian curves with means of 1.8 and 2.9μm for spontaneous sparks and ith means of 1.9 and 3.1 μm for evoked sparks. Relative areas under the two Gaussian curves were 1.73:1 and 1.85:1, respectively, for spontaneous and evoked sparks. CONCLUSIONS: Ca2+ sparks evoked by depolarization are not ′unitary′ events, but often involve multiple sites of origin along Z-lines, as previously shown for spontaneous sparks. Thus, Ca2+ released during sparks directly triggered by influx through L-type Ca2+ channels may, in turn, trigger neighboring sites. The restricted involvement of only a few transverse release sites preserves the essential feature of the ‘local control’ theory of E-C coupling.

  13. Modeling the contributions of Ca2+ flows to spontaneous Ca2+ oscillations and cortical spreading depression-triggered Ca2+ waves in astrocyte networks.

    Directory of Open Access Journals (Sweden)

    Bing Li

    Full Text Available Astrocytes participate in brain functions through Ca(2+ signals, including Ca(2+ waves and Ca(2+ oscillations. Currently the mechanisms of Ca(2+ signals in astrocytes are not fully clear. Here, we present a computational model to specify the relative contributions of different Ca(2+ flows between the extracellular space, the cytoplasm and the endoplasmic reticulum of astrocytes to the generation of spontaneous Ca(2+ oscillations (CASs and cortical spreading depression (CSD-triggered Ca(2+ waves (CSDCWs in a one-dimensional astrocyte network. This model shows that CASs depend primarily on Ca(2+ released from internal stores of astrocytes, and CSDCWs depend mainly on voltage-gated Ca(2+ influx. It predicts that voltage-gated Ca(2+ influx is able to generate Ca(2+ waves during the process of CSD even after depleting internal Ca(2+ stores. Furthermore, the model investigates the interactions between CASs and CSDCWs and shows that the pass of CSDCWs suppresses CASs, whereas CASs do not prevent the generation of CSDCWs. This work quantitatively analyzes the generation of astrocytic Ca(2+ signals and indicates different mechanisms underlying CSDCWs and non-CSDCWs. Research on the different types of Ca(2+ signals might help to understand the ways by which astrocytes participate in information processing in brain functions.

  14. Citrus bergamia Risso Elevates Intracellular Ca2+ in Human Vascular Endothelial Cells due to Release of Ca2+ from Primary Intracellular Stores

    Directory of Open Access Journals (Sweden)

    Purum Kang

    2013-01-01

    , which was partially inhibited by a nonselective Ca2+ channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased [Ca2+]i in a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced [Ca2+]i increase was partially inhibited by a Ca2+-induced Ca2+ release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3-gated Ca2+ channel blocker, 2-aminoethoxydiphenyl borane (2-APB. BEO also increased [Ca2+]i in the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+ uptake. In addition, store-operated Ca2+ entry (SOC was potentiated by BEO. These results suggest that BEO mobilizes Ca2+ from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+ release and affect promotion of Ca2+ influx, likely via an SOC mechanism.

  15. Signaling between intracellular Ca2+ stores and depletion-activated Ca2+ channels generates [Ca2+]i oscillations in T lymphocytes

    OpenAIRE

    1994-01-01

    Stimulation through the antigen receptor (TCR) of T lymphocytes triggers cytosolic calcium ([Ca2+]i) oscillations that are critically dependent on Ca2+ entry across the plasma membrane. We have investigated the roles of Ca2+ influx and depletion of intracellular Ca2+ stores in the oscillation mechanism, using single-cell Ca2+ imaging techniques and agents that deplete the stores. Thapsigargin (TG; 5-25 nM), cyclopiazonic acid (CPA; 5-20 microM), and tert- butylhydroquinone (tBHQ; 80-200 micro...

  16. Glucosamine suppresses platelet-activating factor-induced activation of microglia through inhibition of store-operated calcium influx.

    Science.gov (United States)

    Park, Jae-Hyung; Kim, Jeong-Nam; Jang, Byeong-Churl; Im, Seung-Soon; Song, Dae-Kyu; Bae, Jae-Hoon

    2016-03-01

    Microglia activation and subsequent release of inflammatory mediators are implicated in the pathophysiology of neurodegenerative diseases. Platelet-activating factor (PAF), a potent lipid mediator synthesized by microglia, is known to stimulate microglia functional responses. In this study, we determined that endogenous PAF exert autocrine effects on microglia activation, as well as the underlying mechanism involved. We also investigated the effect of d-glucosamine (GlcN) on PAF-induced cellular activation in human HMO6 microglial cells. PAF induced sustained intracellular Ca(2+) ([Ca(2+)]i) increase through store-operated Ca(2+) channels (SOC) and reactive oxygen species (ROS) generation. PAF also induced pro-inflammatory markers through NFκB/COX-2 signaling. GlcN significantly inhibited PAF-induced Ca(2+) influx and ROS generation without significant cytotoxicity. GlcN downregulated excessive expression of pro-inflammatory markers and promoted filopodia formation through NFκB/COX-2 inhibition in PAF-stimulated HMO6 cells. Taken together, these data suggest that GlcN may offer substantial therapeutic potential for treating inflammatory and neurodegenerative diseases accompanied by microglial activation. PMID:26745504

  17. Design of impurity influx monitor (divertor) for ITER

    International Nuclear Information System (INIS)

    Because of the changes of interfaces between ITER and the Impurity Influx Monitor (divertor) accompanied with the change of the ITER design to a reduced size machine, changes in the design of the monitor are required. In this design work, optics compatible with new interfaces, a calibration system and an alignment system of the optical axis and the focus were designed and investigated. The design of the optical systems was simplified to save the cost. To simplify the optics, the design of the collection optics was changed from an off-axis aspherical mirror system, which is a previous design, to a simple Cassegrain telescope system composed of simple spherical mirrors and lenses. In addition, a micro lens array is inserted just in front of the fiber bundle to increase the light detected. The ray-trace analysis shows that the spatial resolution of ITER requirement (50 mm) will be achieved by these optical systems designed here. The in-situ sensitivity calibration will be realized by applying the light on a micro retro-reflector array installed in front of the plasma facing first mirror from the outside the vacuum chamber through the same optics for plasma measurement and measuring the intensity of the reflected light from the array by using the same optics. In addition, optical design of an adjustment system and a focusing system, and a conceptual design of the shutter system of the monitor were carried out. Moreover, the detector system for the monitor was investigated and designed. (author)

  18. Granule-specific ATP requirements for Ca2+-induced exocytosis in human neutrophils. Evidence for substantial ATP-independent release

    OpenAIRE

    Theander, Sten; Lew, Daniel Pablo; Nusse, Olivier

    2002-01-01

    Ca2+-induced exocytosis in neuronal and neuroendocrine cells involves ATP-dependent steps believed to 'prime' vesicles for exocytosis. Primed, docked vesicles are released in response to Ca2+ influx through voltage-gated Ca2+ channels. Neutrophils, however, do not possess voltage-gated Ca2+ channels and appear to have no docked vesicles. Furthermore, neutrophils have several types of granules with markedly different Ca2+ requirements for exocytosis. These differential Ca2+ dependencies were u...

  19. Stretch induced endothelin-1 secretion by adult rat astrocytes involves calcium influx via stretch-activated ion channels (SACs)

    International Nuclear Information System (INIS)

    Highlights: → Endothelin-1 expression by adult rat astrocytes correlates with cell proliferation. → Stretch-induced ET-1 is inhibited by GsMtx-4, a specific inhibitor of Ca2+ permeant SACs. → The less specific SAC inhibitor streptomycin also inhibits ET-1 secretion. → Stretch-induced ET-1 production depends on a calcium influx. → SAC pharmacology may provide a new class of therapeutic agents for CNS pathology. -- Abstract: The expression of endothelins (ETs) and ET-receptors is often upregulated in brain pathology. ET-1, a potent vasoconstrictor, also inhibits the expression of astrocyte glutamate transporters and is mitogenic for astrocytes, glioma cells, neurons, and brain capillary endothelia. We have previously shown that mechanical stress stimulates ET-1 production by adult rat astrocytes. We now show in adult astrocytes that ET-1 production is driven by calcium influx through stretch-activated ion channels (SACs) and the ET-1 production correlates with cell proliferation. Mechanical stimulation using biaxial stretch (2+ threshold. This coupling of mechanical stress to the astrocyte endothelin system through SACs has treatment implications, since all pathology deforms the surrounding parenchyma.

  20. Graded Ca2+/calmodulin-dependent coupling of voltage-gated CaV1.2 channels

    Science.gov (United States)

    Dixon, Rose E; Moreno, Claudia M; Yuan, Can; Opitz-Araya, Ximena; Binder, Marc D; Navedo, Manuel F; Santana, Luis F

    2015-01-01

    In the heart, reliable activation of Ca2+ release from the sarcoplasmic reticulum during the plateau of the ventricular action potential requires synchronous opening of multiple CaV1.2 channels. Yet the mechanisms that coordinate this simultaneous opening during every heartbeat are unclear. Here, we demonstrate that CaV1.2 channels form clusters that undergo dynamic, reciprocal, allosteric interactions. This ‘functional coupling’ facilitates Ca2+ influx by increasing activation of adjoined channels and occurs through C-terminal-to-C-terminal interactions. These interactions are initiated by binding of incoming Ca2+ to calmodulin (CaM) and proceed through Ca2+/CaM binding to the CaV1.2 pre-IQ domain. Coupling fades as [Ca2+]i decreases, but persists longer than the current that evoked it, providing evidence for ‘molecular memory’. Our findings suggest a model for CaV1.2 channel gating and Ca2+-influx amplification that unifies diverse observations about Ca2+ signaling in the heart, and challenges the long-held view that voltage-gated channels open and close independently. DOI: http://dx.doi.org/10.7554/eLife.05608.001 PMID:25714924

  1. Stoichiometry of Na/Ca antiport obtained by magnesium inhibition in cultured vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Cultured smooth muscle cells from rat aorta were loaded with Na, and Na/Ca antiport was assayed by measuring the initial rates of 45Ca influx and 22Na efflux. The replacement of extracellular Na with other monovalent ions, usually N-methyl-D-glucamine (NMG), was essential for obtaining significant antiport activity. Mg competitively inhibited 45Ca influx via the antiporter (Ki = 100 uM). External Ca stimulated 22Na efflux as expected for antiport activity. Mg did not stimulate 22Na efflux indicating that Mg is not transported by the antiporter. Mg inhibited Ca-stimulated 22Na efflux as expected from the 45Ca influx data. The stoichiometry of the antiporter was calculated from the changes in the rates of 45Ca influx and 22Na efflux at 3 Mg concentrations: 2.87 +/- 0.25 (mean +/- SE, n=5). The replacement of external NMG with potassium, but not other monovalent ions (choline, Li), decreased the potency of Mg as an inhibitor of Na/Ca antiport by about 6 fold. Other divalent cations (Co, Mn, Cd, Ba) inhibited Na/Ca antiport and high external potassium decreased the potency of each by about 6 fold. The order of effectiveness of the divalent cations as inhibitors of Na/Ca antiport (Cd>Mn>Co>Ba>Mg) correlated with the crystal ionic radius of the cation

  2. Auxin influx carriers control vascular patterning and xylem differentiation in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Norma Fàbregas

    2015-04-01

    Full Text Available Auxin is an essential hormone for plant growth and development. Auxin influx carriers AUX1/LAX transport auxin into the cell, while auxin efflux carriers PIN pump it out of the cell. It is well established that efflux carriers play an important role in the shoot vascular patterning, yet the contribution of influx carriers to the shoot vasculature remains unknown. Here, we combined theoretical and experimental approaches to decipher the role of auxin influx carriers in the patterning and differentiation of vascular tissues in the Arabidopsis inflorescence stem. Our theoretical analysis predicts that influx carriers facilitate periodic patterning and modulate the periodicity of auxin maxima. In agreement, we observed fewer and more spaced vascular bundles in quadruple mutants plants of the auxin influx carriers aux1lax1lax2lax3. Furthermore, we show AUX1/LAX carriers promote xylem differentiation in both the shoot and the root tissues. Influx carriers increase cytoplasmic auxin signaling, and thereby differentiation. In addition to this cytoplasmic role of auxin, our computational simulations propose a role for extracellular auxin as an inhibitor of xylem differentiation. Altogether, our study shows that auxin influx carriers AUX1/LAX regulate vascular patterning and differentiation in plants.

  3. Primary extradural meningioma arising from the calvarium

    Directory of Open Access Journals (Sweden)

    N Ravi

    2013-06-01

    Full Text Available Meningiomas are the most common intracranial tumours. Meningiomas arising at other locations are termed primary extradural meningiomas (EDM and are rare. Here we report a case of EDM arising from the calvarium – a primary calvarial meningioma (PCM.

  4. CaMKII binding to GluN2B is important for massed spatial learning in the Morris water maze

    OpenAIRE

    Stein, Ivar S.; Donaldson, Michaela S.; Hell, Johannes W

    2014-01-01

    Learning and memory as well as long-term potentiation (LTP) depend on Ca 2+ influx through the NMDA-type glutamate receptor (NMDAR) and the resulting activation of the Ca 2+ and calmodulin-dependent protein kinase (CaMKII). Ca 2+ influx via the NMDAR triggers CaMKII binding to the NMDAR for enhanced CaMKII accumulation at post-synaptic sites that experience heightened activity as occurring during LTP. Previously, we generated knock-in (KI) mice in which we replaced two residues in the NMDAR G...

  5. Effect of Hypoxia on Ca2+ Concentration in Broiler's Cardiac Muscle Cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The purpose of this research was to study the effect of hypoxia on the Ca2+ concentration in broiler's cardiac muscle cells (CMCs). The concentration of Ca2+ in the CMC was observed using a laser scanning confocal microscope (LSCM). The results showed that hypoxia could significantly increase intracellular Ca2+ (normal oxygen, 99.3 ± 13.1; hypoxia, 129.4±24.3, P<0.01) in CMCs. The Ca2+ antagonist (nifedipine, verapamil) could significantly restrain the Ca2+ influx across the cell membrane of CMC treated by hypoxia (CMC: hypoxia + verapamil, 100.9 ± 28.2; hypoxia + nifedipine, 107.6± 27.7;P < 0.01). The results showed hypoxia could increase intracellular Ca2+ concentration of CMC, and the Ca2+ antagonist could restrain the Ca2+ influx across the cell membrane of CMC treated by hypoxia.

  6. Calcium antagonistic effects of Chinese crude drugs: Preliminary investigation and evaluation by 45Ca

    International Nuclear Information System (INIS)

    Coronary and other diseases in cardiac or brain blood vessels are considered to be due to the excessive influx of Ca2+ into cytoplasm. If Ca2+ channels in cell membrane are blocked by medicines or other substances with considerable calcium antagonistic effects, these diseases might be cured or controlled. The influence of some Chinese crude drugs, including Crocus sativus, Carthamus tinctorius, Ginkgo biloba and Bulbus allii macrostemi on Ca2+ influx in isolated rat aortas was investigated by using 45Ca as a radioactive tracer, and their calcium antagonistic effects were evaluated. It can be noted that Ca2+ uptake in isolated rat aorta rings in normal physiological status was not markedly altered by these drugs, whereas the Ca2+ influxes induced by norepinephrine of 1.2 μmol/L and KCl of 100 mmol/L were significantly inhibited by Crocus, Carthamus and Bulbus in a concentration-dependent manner, but not by Ginkgo. The results show that extracellular Ca2+ influx through receptor-operated Ca2+channels and potential-dependent Ca2+channels can be blocked by Crocus, Carthamus and Bulbus. This implies that these Chinese crude drugs have obvious calcium antagonistic effects

  7. Structures of Ca(V) Ca**2+/CaM-IQ Domain Complexes Reveal Binding Modes That Underlie Calcium-Dependent Inactivation And Facilitation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E.Y.; Rumpf, C.H.; Fujiwara, Y.; Cooley, E.S.; Petegem, F.Van; Minor, D.L., Jr.

    2009-05-20

    Calcium influx drives two opposing voltage-activated calcium channel (Ca{sub V}) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca{sup 2+}/calmodulin (Ca{sup 2+}/CaM) lobes produce CDI and CDF through interactions with the Ca{sub V}{alpha}{sub 1} subunit IQ domain. Curiously, Ca{sup 2+}/CaM lobe modulation polarity appears inverted between Ca{sub V}1s and Ca{sub V}2s. Here, we present crystal structures of Ca{sub V}2.1, Ca{sub V}2.2, and Ca{sub V}2.3 Ca{sup 2+}/CaM-IQ domain complexes. All display binding orientations opposite to Ca{sub V}1.2 with a physical reversal of the CaM lobe positions relative to the IQ {alpha}-helix. Titration calorimetry reveals lobe competition for a high-affinity site common to Ca{sub V}1 and Ca{sub V}2 IQ domains that is occupied by the CDI lobe in the structures. Electrophysiological experiments demonstrate that the N-terminal Ca{sub V}2 Ca{sup 2+}/C-lobe anchors affect CDF. Together, the data unveil the remarkable structural plasticity at the heart of Ca{sub V} feedback modulation and indicate that Ca{sub V}1 and Ca{sub V}2 IQ domains bear a dedicated CDF site that exchanges Ca{sup 2+}/CaM lobe occupants.

  8. Extracellular ATP-dependent activation of plasma membrane Ca2+ pump in HEK-293 cells

    OpenAIRE

    Qi, Z.; Murase, K.; Obata, S.; Sokabe, M

    2000-01-01

    It is well known that extracellular ATP (ATPo) elevates the intracellular Ca2+ concentration ([Ca2+]i) by inducing Ca2+ influx or mobilizing Ca2+ from internal stores via activation of purinoceptors in the plasma membrane. This study shows that ATPo also activates the plasma membrane Ca2+ pumps (PMCPs) to bring the elevated [Ca2+]i back to the resting level in human embryonic kidney-293 (HEK-293) cells.The duration of ATPo-induced intracellular Ca2+ transients was significantly increased by P...

  9. Energy-linked potassium influx as related to cell potential in corn roots

    International Nuclear Information System (INIS)

    Cell potentials and K+ (86Rb) influx were determined for corn roots over a wide range of external K+ activity (K0) under control, anoxic, and uncoupled conditions. The data were analyzed using Goldman theory for the contribution of passive influx to total influx. For anoxic and uncoupled roots the K+ influx shows the functional relationship with K0 predicted with constant passive permeability, although K+ permeability in uncoupled roots is about twice that of anoxic roots. In control roots the equation fails to describe K+ infux at low K0, but does so at high K0, with a gradual transition over the region where the electrical potential becomes equal to the equilibrium potential for K+ (psi = E/sub K/). In the low K0 range, where net K+ infux is energetically uphill, participation of an energy-linked K+ carrier is indicated. In the high K0 range, K+ influx becomes passive down the electrical gradient established by the cell potential. Since the cell potential includes a substantial electrogenic component, anoxia or uncoupling reduces passive influx

  10. The role of Ca pathway in Cd uptake and translocation by the hyperaccumulator Sedum alfredii.

    Science.gov (United States)

    Lu, Lingli; Tian, Shengke; Zhang, Min; Zhang, Jie; Yang, Xiaoe; Jiang, Hong

    2010-11-15

    Effect of Ca on plant growth, Cd uptake and translocation in the hyperaccumulator Sedum alfredii was investigated, as to reveal the possible pathway of Cd entry into the plants system. High Ca increased plant growth under Cd stress after 7 d, and significantly affected the total Cd influx and translocation rate. Short-term kinetics of (109)Cd influx performed using radiotracers confirmed a significant inhibition of (109)Cd influx into the roots induced by high Ca. Under exposure of 5.0 mM Ca, K(m) of (109)Cd influx into roots was 2-fold higher in the hyperaccumulator, although the V(max) value remained at similar level, when compared with the treatments of 0.5 mM Ca. Calcium concentrations in xylem sap of the hyperaccumulator decreased with the increasing Cd levels and significant negative correlationship between the two elements was observed. However, increased xylem loading of Cd was observed in the hyperaccumulator in response to the increasing exogenous Ca level from 0.5 to 4.0 mM, but reverse effect was observed when higher Ca levels (8-32 mM) were presented in the solutions. These results suggest that Cd uptake and translocation in the hyperaccumulator S. alfredii plants is positively associated with Ca pathway. PMID:20674155

  11. The role of Ca pathway in Cd uptake and translocation by the hyperaccumulator Sedum alfredii

    Energy Technology Data Exchange (ETDEWEB)

    Lu Lingli, E-mail: linglilulu@gmail.com [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Huajiachi Campus, Hangzhou 310029 (China); Tian Shengke; Zhang Min; Zhang Jie [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Huajiachi Campus, Hangzhou 310029 (China); Yang Xiaoe, E-mail: xyang571@yahoo.com [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Huajiachi Campus, Hangzhou 310029 (China); Jiang Hong [MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Huajiachi Campus, Hangzhou 310029 (China)

    2010-11-15

    Effect of Ca on plant growth, Cd uptake and translocation in the hyperaccumulator Sedum alfredii was investigated, as to reveal the possible pathway of Cd entry into the plants system. High Ca increased plant growth under Cd stress after 7 d, and significantly affected the total Cd influx and translocation rate. Short-term kinetics of {sup 109}Cd influx performed using radiotracers confirmed a significant inhibition of {sup 109}Cd influx into the roots induced by high Ca. Under exposure of 5.0 mM Ca, K{sub m} of {sup 109}Cd influx into roots was 2-fold higher in the hyperaccumulator, although the V{sub max} value remained at similar level, when compared with the treatments of 0.5 mM Ca. Calcium concentrations in xylem sap of the hyperaccumulator decreased with the increasing Cd levels and significant negative correlationship between the two elements was observed. However, increased xylem loading of Cd was observed in the hyperaccumulator in response to the increasing exogenous Ca level from 0.5 to 4.0 mM, but reverse effect was observed when higher Ca levels (8-32 mM) were presented in the solutions. These results suggest that Cd uptake and translocation in the hyperaccumulator S. alfredii plants is positively associated with Ca pathway.

  12. Store-operated Ca2+ Entry Modulates the Expression of Enamel Genes.

    Science.gov (United States)

    Nurbaeva, M K; Eckstein, M; Snead, M L; Feske, S; Lacruz, R S

    2015-10-01

    Dental enamel formation is an intricate process tightly regulated by ameloblast cells. The correct spatiotemporal patterning of enamel matrix protein (EMP) expression is fundamental to orchestrate the formation of enamel crystals, which depend on a robust supply of Ca2+. In the extracellular milieu, Ca2+ -EMP interactions occur at different levels. Despite its recognized role in enamel development, the molecular machinery involved in Ca2+ homeostasis in ameloblasts remains poorly understood. A common mechanism for Ca2+ influx is store-operated Ca2+ entry (SOCE). We evaluated the possibility that Ca2+ influx in enamel cells might be mediated by SOCE and the Ca2+ release-activated Ca2+ (CRAC) channel, the prototypical SOCE channel. Using ameloblast-like LS8 cells, we demonstrate that these cells express Ca2+ -handling molecules and mediate Ca2+ influx through SOCE. As a rise in the cytosolic Ca2+ concentration is a versatile signal that can modulate gene expression, we assessed whether SOCE in enamel cells had any effect on the expression of EMPs. Our results demonstrate that stimulating LS8 cells or murine primary enamel organ cells with thapsigargin to activate SOCE leads to increased expression of Amelx, Ambn, Enam, Mmp20. This effect is reversed when cells are treated with a CRAC channel inhibitor. These data indicate that Ca2+ influx in LS8 cells and enamel organ cells is mediated by CRAC channels and that Ca2+ signals enhance the expression of EMPs. Ca2+ plays an important role not only in mineralizing dental enamel but also in regulating the expression of EMPs. PMID:26232387

  13. The Mg2+ transporter CNNM4 regulates sperm Ca2+ homeostasis and is essential for reproduction.

    Science.gov (United States)

    Yamazaki, Daisuke; Miyata, Haruhiko; Funato, Yosuke; Fujihara, Yoshitaka; Ikawa, Masahito; Miki, Hiroaki

    2016-05-01

    Ca(2+) influx triggers sperm capacitation; however, the underlying regulatory mechanisms remain incompletely understood. Here, we show that CNNM4, a Mg(2+) transporter, is required for Ca(2+) influx during capacitation. We find that Cnnm4-deficient male mice are almost infertile because of sperm dysfunction. Motion analyses show that hyperactivation, a qualitative change in the mode of sperm motility during capacitation, is abrogated in Cnnm4-deficient sperm. In contrast, tyrosine phosphorylation of flagellar proteins, a hallmark of capacitation, is excessively augmented. These seemingly paradoxical phenotypes of Cnnm4-deficient sperm are very similar to those of sperm lacking a functional cation channel of sperm (CatSper) channel, which plays an essential role in Ca(2+) influx during sperm capacitation. Ca(2+) imaging analyses demonstrate that Ca(2+) influx is perturbed in Cnnm4-deficient sperm, and forced Ca(2+) entry into these sperm normalizes the level of tyrosine phosphorylation. Furthermore, we confirm the importance of CNNM4 in sperm by generating germ-cell-specific Cnnm4-deficient mice. These results suggest a new role of CNNM4 in sperm Ca(2+) homeostasis. PMID:27006114

  14. Ethanol enhances GABA-induced 36Cl-influx in primary spinal cord cultured neurons

    International Nuclear Information System (INIS)

    Ethanol has a pharmacological profile similar to other centrally acting drugs, which facilitate GABAergic transmission. GABA is known to produce its effects by increasing the conductance to Cl- ions. In this study, we have examined the effect of ethanol on GABA-induced 36Cl-influx in primary spinal cord cultured neurons. GABA produces a concentration-dependent, and saturable effect on 36Cl-influx in these neurons. Ethanol potentiates the effect of GABA on 36Cl-influx in these neurons. GABA (20 microM) increased the 36Cl-influx by 75% over the basal value, and in the presence of 50 mM ethanol, the observed increase was 142%. Eadie-Hoffstee analysis of the saturation curves indicated that ethanol decreases the Km value of GABA (10.6 microM to 4.2 microM), and also increases the Vmax. Besides potentiating the effect of GABA, ethanol also appears to have a direct effect in the absence of added GABA. These results suggest that ethanol enhances GABA-induced 36Cl-influx and indicate a role of GABAergic system in the actions of ethanol. These results also support the behavioral and electrophysiological studies, which have implicated GABA systems in the actions of ethanol. The potential mechanism(s) and the role of direct effect of ethanol is not clear at this time, but is currently being investigated

  15. The influx of amino acids into the heart of the rat

    International Nuclear Information System (INIS)

    The influx of nineteen amino acids into the heart of the living rat was studied by a method specially devised for experiments under controlled conditions in vivo. When, in separate experiments, the concentration of each amino acid in turn was artificially raised in the circulation, the influx of that amino acid into the heart increased. The data indicate that at least ten of these amino acids enter the heart in vivo by means of saturable carrier-mediated transport systems. The transport rates conform, at least approximately, to Michaelis kinetics and the transport systems are clearly, in the case of many amino acids, active, i.e. energy-dependent. The amino acids which were studied had rates of influx into the heart which differed from each other over a range of more than 10 to 1, even when allowances were made for the differences in their concentration in the circulating blood. These differences in influx were not related to such factors as the molecular size of the individual amino acids. The amino acids which have a high influx into the heart are mainly those which are needed either to re-synthesize contractile protein or as oxidizable substrates. (author)

  16. Induction of nitrate transport in maize roots, and kinetics of influx, measured with nitrogen-13

    International Nuclear Information System (INIS)

    Unlike phosphate or potassium transport, uptake of nitrate by roots is induced, in part, by contact with the substrate ion. Plasmalemma influx of 13N-labeled nitrate in maize roots was studied in relation to induction of the uptake system, and the influence of short-term N starvation. Maize (Zea mays) roots not previously exposed to nitrate had a constitutive transport system (state 1), but influx increased 250% during six hours of contact with 100 micromolar nitrate, by which time the transport mechanism appeared to be fully synthesized (state 2). A three-day period of N starvation prior to induction and measurement of nitrate influx resulted in a greater capacity to transport nitrate than in unstarved controls, but this was fully expressed only if roots were kept in contact with nitrate for the six hours needed for full induction (state 2E). A kinetic analysis indicated a 160% increase in maximum influx in N-starved, induced roots with a small decrease in Km. The inducible component to nitrate influx was induced only by contact with nitrate. Full expression of the nitrate inducible transport system was dependent upon mRNA synthesis. An inhibitor of cytoplasmic protein synthesis (cycloheximide) eliminated the formation of the transport system while inhibition by chloramphenicol of mitochondrial- or plastid-coded protein synthesis had no effect. Poisoning of membrane-bound proteins effectively disabled both the constitutive and induced transport systems

  17. Characterization of Ca(2+)-activated 86Rb+ fluxes in rat C6 glioma cells: a system for identifying novel IKCa-channel toxins.

    OpenAIRE

    de-Allie, F. A.; Bolsover, S. R.; Nowicky, A. V.; Strong, P N

    1996-01-01

    1. The pharmacological characteristics of a putative Ca2+ activated K+ channel (IKCa channel) in rat glioma C6 cells were studied in the presence of the Ca2+ ionophore, ionomycin and various K+ channel blockers, 86Rb+ being used as a radioisotopic tracer for K+. 2. The resting 86Rb+ influx into C6 cells was 318 +/- 20 pmol s-1. The threshold for ionomycin activation of 86Rb+ influx was approx. 100 nM. At ionomycin concentrations above the activation threshold, the initial rate of 86Rb+ influx...

  18. Extracellular ATP induces spikes in cytosolic free Ca(2+) but not in NADPH oxidase activity in neutrophils

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Olsen, Lars Folke; Hallett, Maurice B

    2011-01-01

    In order to establish whether non-mitochondrial oxidase activity in human neutrophils is tightly related to cytosolic Ca(2+) concentration, we simultaneously measured Ca(2+) oscillations induced by ATP and oxidant production in single adherent neutrophils using confocal microscopy. ATP induced fast...... damped Ca(2+) spikes with a period of 15s and slower irregular spikes with a period greater than 50s. Spikes in Ca(2+) occurred in the absence of Ca(2+) influx, but the amplitude was damped by inhibition of Ca(2+) influx. Using the oxidation of hydroethidine as a cytosolic marker of oxidant production......, we show that the generation of reactive oxygen species by neutrophils adherent to glass was accelerated by ATP. The step-up in NADPH oxidase activity followed the first elevation of cytosolic Ca(2+) but, despite subsequent spikes in Ca(2+) concentration, no oscillations in oxidase activity could be...

  19. Extracellular ATP induces spikes in cytosolic free Ca2+ but not in NADH oxidase activity in neutrophils

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Olsen, Lars Folke; Hallett, Maurice B.

    2011-01-01

    In order to establish whether non-mitochondrial oxidase activity in human neutrophils is tightly related to cytosolic Ca2+ concentration, we simultaneously measured Ca2+ oscillations induced by ATP and oxidant production in single adherent neutrophils using confocal microscopy. ATP induced fast...... damped Ca2+ spikes with a period of 15 s and slower irregular spikes with a period greater than 50 s. Spikes in Ca2+ occurred in the absence of Ca2+ influx, but the amplitude was damped by inhibition of Ca2+ influx. Using the oxidation of hydroethidine as a cytosolic marker of oxidant production, we show...... that the generation of reactive oxygen species by neutrophils adherent to glass was accelerated by ATP. The step-up in NADPH oxidase activity followed the first elevation of cytosolic Ca2+ but, despite subsequent spikes in Ca2+ concentration, no oscillations in oxidase activity could be detected. ATP...

  20. ARISE: American renaissance in science education

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-14

    The national standards and state derivatives must be reinforced by models of curricular reform. In this paper, ARISE presents one model based on a set of principles--coherence, integration of the sciences, movement from concrete ideas to abstract ones, inquiry, connection and application, sequencing that is responsive to how people learn.

  1. Temperature-dependence of 45Ca fluxes and contraction in vascular smooth muscle cells of rabbit ear artery

    International Nuclear Information System (INIS)

    The effect of cooling from 35 to 200C on the 45Ca-exchange and on the contractile response of rabbit ear artery has been investigated. The amplitude of the contraction induced by K-depolarization at 200C is reduced to about 60% of its value at 350C, whereas the response to noradrenaline is not significantly affected. Cooling induces a 2 to 4-fold reduction of the 45Ca-efflux rate. This effect also occurs in Ca-free medium and in solutions containing 1 mM La. It also occurs in Na-free medium and in tissues in which the transmembrane Na-gradient has been reduced. At 200C, the 45Ca-influx in unstimulated tissues and in K-depolarized preparations is significantly lower than at 350C. In Ca-depleted tissues, the 45Ca-influx is not significantly affected by cooling. The gradual depletion of the noradrenaline-sensitive Ca-store in Ca-free solutions is at 200C much slower than at 350C. The amount of Ca released by noradrenaline is not affected by cooling, whereas for the same amount of Ca released the contractile response is higher at 200C. These findings indicate that temperature affects the transmembrane Ca-extrusion and the Ca-influx through voltage-dependent channels. The properties of the noradrenaline-sensitive Ca-store are less sensitive to temperature. (orig./MG)

  2. Comparison between effects of caffeine and ryanodine on electromechanical coupling in myocardium of hibernating chipmunks: role of internal Ca stores.

    OpenAIRE

    Kondo, N

    1988-01-01

    1. To clarify the cause of uncoupling of Ca influx through Ca channels and the contractility of the myocardium in hibernating chipmunks, the electromechanical effects of two different internal Ca store inhibitors, caffeine and ryanodine, and a cardiotonic agent, isoprenaline, were investigated in papillary muscles of hibernating animals. 2. Ryanodine (10(-6) M), an inhibitor of internal Ca release, abolished the contraction with a marked inhibition of the action potential plateau (APp). In su...

  3. TRPM8-independent menthol-induced Ca2+ release from endoplasmic reticulum and Golgi

    OpenAIRE

    Mahieu, Frank; Owsianik, Grzegorz; Verbert, Leen; Janssens, Annelies; De Smedt, Humbert; Nilius, Bernd; Voets, Thomas

    2007-01-01

    Menthol, a secondary alcohol produced by the peppermint herb, Mentha piperita, is widely used in the food and pharmaceutical industries as a cooling/ soothing compound and odorant. It induces Ca2+ influx in a subset of sensory neurons from dorsal root and trigeminal ganglia, due to activation of TRPM8, a Ca2+-permeable, cold-activated member of the TRP superfamily of cation channels. Menthol also induces Ca2+ release from intracellular stores in several TRPM8-expressing cell types, which has ...

  4. Effect of staphylococcal alpha-toxin on intracellular Ca2+ in polymorphonuclear leukocytes.

    OpenAIRE

    Suttorp, N; Habben, E

    1988-01-01

    Staphylococcal alpha-toxin, a channel-forming protein, stimulates leukotriene B4 formation in rabbit polymorphonuclear leukocytes (PMN) (N. Suttorp, W. Seeger, J. Zucker-Reimann, L. Roka, and S. Bhakdi, Infect. Immun. 55:104-110, 1987). The concept was advanced that transmembrane toxin pores act as Ca2+ gates allowing passive Ca2+ influx into the cell, thus initiating stimulus response coupling. A critical step in this hypothesis is the demonstration of an increase in the cytosolic free Ca2+ ...

  5. Ameloblastic Fibrosarcoma Arising in the Maxilla

    Science.gov (United States)

    Pillay, Rachael R.; Bilski, Arthur; Batstone, Martin

    2016-01-01

    Background: Ameloblastic fibrosarcoma (AFS) is a rare odontogenic neoplasm of the jaw that usually arises de novo or through a malignant change in the mesenchymal component of a preexisting or recurrent benign fibroma. The majority of AFS cases reported in the literature arise in the mandible. Case Report: A 35-year-old male presented with an asymptomatic left maxillary mass that on imaging was found to be effacing most of his maxillary sinus. He underwent a left maxillectomy with free-flap reconstruction and adjuvant radiotherapy to the tumor bed. Conclusion: Wide local excision remains the treatment of choice for AFS, given the poor survival rates of patients with recurrent disease. However, long-term studies and follow-up are needed to elucidate the role of adjuvant therapies in the primary treatment of AFS. PMID:27303223

  6. Parametrial and rectovaginal adenocarcinoma arising from endometriosis.

    Science.gov (United States)

    Ulrich, U; Rhiem, K; Kaminski, M; Wardelmann, E; Trog, D; Valter, M; Richter, O N

    2005-01-01

    Malignant extragonadal tumors arising from endometriosis are rare. We report on two cases. A 41-year-old gravida 1, para 1 (G1P1), with adenocarcinoma of the right parametrium arising from endometriosis and a 51-year-old G1P1 with endometriosis-associated rectovaginal adenocarcinoma were treated. Treatment included radical surgery plus radiation therapy. While the former patient was doing well 2 years after the primary diagnosis, the latter suffered a local pelvic recurrence 2 years later. Although there are no randomized controlled studies, radical surgery followed by radiation therapy seems generally to be the treatment of choice. The analysis of PTEN in various forms of endometriosis and its malignant transformation may help in understanding the early steps of tumorigenesis. PMID:16343215

  7. An organism arises from every nucleus.

    OpenAIRE

    Nurullah Keklikoglu

    2009-01-01

    The fact that, cloning using somatic cell nuclear transfer (SCNT) method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which c...

  8. Activations of the Ca dependent K channel by Ca released from the sarcoplasmic reticulum of mammalian smooth muscles.

    Science.gov (United States)

    Kitamura, K; Sakai, T; Kajioka, S; Kuriyama, H

    1989-01-01

    In mammalian smooth muscles, the outward K current recorded using the whole cell voltage clamp or patch clamp methods can be classified into the Ca-dependent and independent K currents. The former is sub-classified into the extra- and intra-cellular Ca dependent K current. The intra-cellular Ca dependent K current has a close relation to Ca released from the sarcoplasmic reticulum, i.e. Ca released by inositol 1,4,5-trisphosphate (InsP3), ryanodine or Ca ionophores (A23187 or ionomycin) modify the appearance of the K current. The transient (Ca dependent) outward current evoked by depolarization pulses, as measured using the whole cell voltage clamp method, is closely related with after-hyperpolarization of the action potential as recorded using the microelectrode method and is postulated to be due to activations of the Ca-induced Ca release mechanism in the sarcoplasmic reticulum. The oscillatory (Ca dependent) outward K current is closely related with the amount of Ca released from the sarcoplasmic reticulum during the long depolarization induced by electrical stimulation (command pulse) or applications of Ca releasers such as InsP3 or ryanodine. In this review, the Ca dependent K current recorded from smooth muscle cells is compared with the influx and release of Ca. PMID:2667516

  9. Hypothermia rescues hippocampal CA1 neurons and attenuates down-regulation of the AMPA receptor GluR2 subunit after forebrain ischemia

    OpenAIRE

    Colbourne, Frederick; Grooms, Sonja Y.; Zukin, R. Suzanne; Buchan, Alastair M.; Bennett, Michael V. L.

    2003-01-01

    Brief forebrain ischemia in rodents induces selective and delayed neuronal death, particularly of hippocampal CA1 pyramidal neurons. Neuronal death is preceded by down-regulation specific to CA1 of GluR2, the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit that limits Ca2+ influx. This alteration is hypothesized to cause neurodegeneration by permitting a lethal influx of Ca2+ and/or Zn2+ through newly formed GluR2-lacking AMPA receptors. Two days of mild hypotherm...

  10. When Isolated at Full Receptivity, in Vitro Fertilized Wheat (Triticum aestivum, L. Egg Cells Reveal [Ca2+]cyt Oscillation of Intracellular Origin

    Directory of Open Access Journals (Sweden)

    Zsolt Pónya

    2014-12-01

    Full Text Available During in vitro fertilization of wheat (Triticum aestivum, L. in egg cells isolated at various developmental stages, changes in cytosolic free calcium ([Ca2+]cyt were observed. The dynamics of [Ca2+]cyt elevation varied, reflecting the difference in the developmental stage of the eggs used. [Ca2+]cyt oscillation was exclusively observed in fertile, mature egg cells fused with the sperm cell. To determine how [Ca2+]cyt oscillation in mature egg cells is generated, egg cells were incubated in thapsigargin, which proved to be a specific inhibitor of the endoplasmic reticulum (ER Ca2+-ATPase in wheat egg cells. In unfertilized egg cells, the addition of thapsigargin caused an abrupt transient increase in [Ca2+]cyt in the absence of extracellular Ca2+, suggesting that an influx pathway for Ca2+ is activated by thapsigargin. The [Ca2+]cyt oscillation seemed to require the filling of an intracellular calcium store for the onset of which, calcium influx through the plasma membrane appeared essential. This was demonstrated by omitting extracellular calcium from (or adding GdCl3 to the fusion medium, which prevented [Ca2+]cyt oscillation in mature egg cells fused with the sperm. Combined, these data permit the hypothesis that the first sperm-induced transient increase in [Ca2+]cyt depletes an intracellular Ca2+ store, triggering an increase in plasma membrane Ca2+ permeability, and this enhanced Ca2+ influx results in [Ca2+]cyt oscillation.

  11. Amyloid-β Peptide Aβ3pE-42 Induces Lipid Peroxidation, Membrane Permeabilization, and Calcium Influx in Neurons.

    Science.gov (United States)

    Gunn, Adam P; Wong, Bruce X; Johanssen, Timothy; Griffith, James C; Masters, Colin L; Bush, Ashley I; Barnham, Kevin J; Duce, James A; Cherny, Robert A

    2016-03-18

    Pyroglutamate-modified amyloid-β (pE-Aβ) is a highly neurotoxic amyloid-β (Aβ) isoform and is enriched in the brains of individuals with Alzheimer disease compared with healthy aged controls. Pyroglutamate formation increases the rate of Aβ oligomerization and alters the interactions of Aβ with Cu(2+) and lipids; however, a link between these properties and the toxicity of pE-Aβ peptides has not been established. We report here that Aβ3pE-42 has an enhanced capacity to cause lipid peroxidation in primary cortical mouse neurons compared with the full-length isoform (Aβ(1-42)). In contrast, Aβ(1-42) caused a significant elevation in cytosolic reactive oxygen species, whereas Aβ3pE-42 did not. We also report that Aβ3pE-42 preferentially associates with neuronal membranes and triggers Ca(2+) influx that can be partially blocked by the N-methyl-d-aspartate receptor antagonist MK-801. Aβ3pE-42 further caused a loss of plasma membrane integrity and remained bound to neurons at significantly higher levels than Aβ(1-42) over extended incubations. Pyroglutamate formation was additionally found to increase the relative efficiency of Aβ-dityrosine oligomer formation mediated by copper-redox cycling. PMID:26697885

  12. State-dependent firing determines intrinsic dendritic Ca2+ signaling in thalamocortical neurons.

    Science.gov (United States)

    Errington, Adam C; Renger, John J; Uebele, Victor N; Crunelli, Vincenzo

    2010-11-01

    Activity-dependent dendritic Ca(2+) signals play a critical role in multiple forms of nonlinear cellular output and plasticity. In thalamocortical neurons, despite the well established spatial separation of sensory and cortical inputs onto proximal and distal dendrites, respectively, little is known about the spatiotemporal dynamics of intrinsic dendritic Ca(2+) signaling during the different state-dependent firing patterns that are characteristic of these neurons. Here we demonstrate that T-type Ca(2+) channels are expressed throughout the entire dendritic tree of rat thalamocortical neurons and that they mediate regenerative propagation of low threshold spikes, typical of, but not exclusive to, sleep states, resulting in global dendritic Ca(2+) influx. In contrast, actively backpropagating action potentials, typical of wakefulness, result in smaller Ca(2+) influxes that can temporally summate to produce dendritic Ca(2+) accumulations that are linearly related to firing frequency but spatially confined to proximal dendritic regions. Furthermore, dendritic Ca(2+) transients evoked by both action potentials and low-threshold spikes are shaped by Ca(2+) uptake by sarcoplasmic/endoplasmic reticulum Ca(2+) ATPases but do not rely on Ca(2+)-induced Ca(2+) release. Our data demonstrate that thalamocortical neurons are endowed with intrinsic dendritic Ca(2+) signaling properties that are spatially and temporally modified in a behavioral state-dependent manner and suggest that backpropagating action potentials faithfully inform proximal sensory but not distal corticothalamic synapses of neuronal output, whereas corticothalamic synapses only "detect" Ca(2+) signals associated with low-threshold spikes. PMID:21048143

  13. Mass Influx of Cosmic Dust Estimated From Vertical Transport of Meteoric Metals

    Science.gov (United States)

    Liu, Alan Z.; Guo, Yafang; Gardner, Chester S.

    2016-04-01

    The mesospheric metal layers are formed by the vaporization of high-speed cosmic dust particles in the lower thermosphere and upper mesosphere. The vaporized atoms and ions are transported downward by waves and turbulence to chemical sinks below 85 km, where they form stable compounds. These compounds condense onto meteoric smoke particles and are then transported to the winter pole where they eventually settle onto the surface. The downward fluxes of the metal atoms are directly related to their meteoric influxes and chemical loss rates. In this paper we use Doppler lidar measurements of Na and Fe fluxes made by the University of Illinois and University of Colorado groups, and a chemical ablation model (CABMOD) developed at the University of Leeds, to constrain the velocity/mass distribution of the meteoroids entering the atmosphere and to derive an improved estimate for the global influx of cosmic dust. We find that the particles responsible for injecting a large fraction of the ablated material into the Earth's upper atmosphere, enter at relatively slow speeds and originate primarily from the Jupiter Family of Comets. The global mean Na influx is 21,500±1,100 atoms/cm2/s, which equals 372±18 kg/d for the global input of Na vapor and 186±24 t/d for the global influx of cosmic dust. The global mean Fe influx is 131,000±36,000 atoms/cm2/s, which equals 5.5±1.5 t/d for the global input of Na vapor.

  14. Effective water influx control in gas reservoir development: Problems and countermeasures

    Directory of Open Access Journals (Sweden)

    Xi Feng

    2015-03-01

    Full Text Available Because of the diversity of geological characteristics and the complexity of percolation rules, many problems are found ineffective water influx control in gas reservoir development. The problems mainly focus on how to understand water influx rules, to establish appropriate countermeasures, and to ensure the effectiveness of technical measures. It is hard to obtain a complete applicable understanding through the isolated analysis of an individual gas reservoir due to many factors such as actual gas reservoir development phase, research work, pertinence and timeliness of measures, and so on. Over the past four decades, the exploration, practicing and tracking research have been conducted on water control in gas reservoir development in the Sichuan Basin, and a series of comprehensive water control technologies were developed integrating advanced concepts, successful experiences, specific theories and mature technologies. Though the development of most water-drive gas reservoirs was significantly improved, water control effects were quite different. Based on this background, from the perspective of the early-phase requirements of water influx control, the influencing factors of a water influx activity, the dynamic analysis method of water influx performance, the optimizing strategy of a water control, and the water control experience of typical gas reservoirs, this paper analyzed the key problems of water control, evaluated the influencing factors of water control effect, explored the practical water control strategies, and proposed that it should be inappropriate to apply the previous water control technological model to actual work but the pertinence should be improved according to actual circumstances. The research results in the paper provide technical reference for the optimization of water-invasion gas reservoir development.

  15. Angiomyolipoma arising in the gluteal region

    Institute of Scientific and Technical Information of China (English)

    Emmanouil Pikoulis; Constantine Bramis; Othon Mich; George Liapis; Evangelos Felekourasx; Vassiliki Kyriakou; John Griniatsos

    2007-01-01

    @@ Angiomyolipoma (AML) is a tumour of uncertain histogenesis originally believed to be a hamartomatous lesion, but recently recognized as a usually benign clonal mesenchymal neoplasm.1 Along with lymphagiomyomatosis (LAM), clear cell "sugar"tumour (CCST) and clear cell myelomelanocytic tumour (CCMMT), AML was classified in the so called perivascular epithelioid cell (PEComa) neoplasm family.1 Kidney constitutes the principal site of its development.Extrarenal AMLs are rare and to the best of our knowledge, only two cases of AML development in the soft tissues have been reported so far.2,3 We presented a 23 years old female patient with an AML arising in the left gluteal region.

  16. Malignant Insulinoma Arising from Intrasplenic Heterotopic Pancreas

    Directory of Open Access Journals (Sweden)

    Ismael Domínguez

    2009-05-01

    Full Text Available Context Heterotopic pancreas is defined as ectopic pancreatic tissue without vascular or anatomic continuity with the normal pancreas. The spleen is a rare site of origin. This case report describes a patient with a malignant insulinoma which originated from an intrasplenic heterotopic pancreas. Case report A 46-year-old man with three previous episodes of neuroglucopenic and adrenergic symptoms was referred to our hospital. A fasting test was performed and discontinued due to hypoglycemic symptoms. Preoperative studies failed to demonstrate any pancreatic lesions. However, a heterogeneous encapsulated tumor in the spleen was found on MRI. During surgery, only the splenic tumor was found, with neither vascular nor anatomical connections to the normal pancreas. Pathology reported a malignant insulinoma. Insulin and proinsulin were documented by immunohistochemistry. After one year of follow up, the patient is free of symptoms and no recurrent disease has been documented. Discussion Only seven cases of splenic heterotopic pancreas have been reported, six with cystic mucinous neoplasms. In addition, only one case of a malignant insulinoma arising from heterotopic pancreas has previously been described. This is the second case reported of an insulinoma arising from heterotopic pancreas and the first to originate from intrasplenic heterotopia.

  17. Altered calcium metabolism in aging CA1 hippocampal pyramidal neurons

    OpenAIRE

    Oh, M. Matthew; Oliveira, Fernando A.; Waters, Jack; Disterhoft, John F.

    2013-01-01

    Altered neuronal calcium homeostasis is widely hypothesized to underlie cognitive deficits in normal aging subjects, but the mechanisms that underlie this change are unknown, possibly due to a paucity of direct measurements from aging neurons. Using CCD and two-photon calcium imaging techniques on CA1 pyramidal neurons from young and aged rats, we show that calcium influx across the plasma membrane increases with aging, and that this change is countered by increased intracellular calcium buff...

  18. Optimization problems arising in robust stability theory

    Energy Technology Data Exchange (ETDEWEB)

    Polyak, B.

    1994-12-31

    Robustness is one of the main topics in modern control theory. We consider one aspect of the theme - robust stability analysis under parametric uncertainty. It deals with stability problems for linear time-invariant differential or difference equations with uncertainties in their coefficients. Various optimization problems concerning {open_quotes}the largest{close_quotes} admissible uncertainty naturally arise. Examples: (1) Find the largest cube inscribed in stability domain; (2) Find the box with the largest volume preserving stability; (3) Describe a boundary of a two-dimensional image of a box under linear or nonlinear transformation; (4) Find a sum or a project of sets on a complex plane, e.g., find a product of n discs. These problems require new duality results and new necessary conditions of optimality.

  19. Radioisotopes: problems of responsibility arising from medicine

    International Nuclear Information System (INIS)

    Radioisotopes have brought about great progress in the battle against illnesses of mainly tumoral origin, whether in diagnosis (nuclear medicine) or in treatment (medical radiotherapy). They are important enough therefore to warrant investigation. Such a study is attempted here, with special emphasis, at a time when medical responsibility proceedings are being taken more and more often on the medicolegal problems arising from their medical use. It is hoped that this study on medical responsibility in the use of radioisotopes will have shown: that the use of radioisotopes for either diagnosis or therapy constitutes a major banch of medicine; that this importance implies an awareness by the practitioner of a vast responsibility, especially in law where legislation to ensure protection as strict as in the field of ionizing radiations is lacking. The civil responsibility of doctors who use radioisotopes remains to be defined, since for want of adequate jurisprudence we are reduced to hypotheses based on general principles

  20. Degenerate Diffusion Operators Arising in Population Biology

    CERN Document Server

    Epstein, Charles L

    2011-01-01

    We analyze a class of partial differential equations that arise as "backwards Kolmogorov operators" in infinite population limits of the Wright-Fisher models in population genetics and in mathematical finance. These are degenerate elliptic operators defined on manifolds with corners. The classical example is the Kimura diffusion operator, which acts on functions defined on the simplex in R^n. We introduce anisotropic Holder spaces, and prove existence, uniqueness and regularity results for the heat and resolvent equations defined by this class of operators. This suffices to prove that the C^0-graph closure generates a strongly continuous semigroup, and that the associated Martingale problem has a unique solution. We give a detailed description of the nullspace of the forward Kolmogorov operator.

  1. Electric current arising from unpolarized polyvinyl formal

    Indian Academy of Sciences (India)

    P K Khare; P L Jain; R K Pandey

    2000-10-01

    An appreciable electric current is observed in a system consisting of a polyvinyl formal (PVF) film in a sandwich configuration, in the temperature range 30–110°C. The maximum value of the current during first heating is found to be of the order of 10–10 A and its thermograms exhibit one transition (i.e. current peak) at around 60°C. The position of the current peak in thermal spectrum shifts with the heating rate. A temperature dependence of the open circuit voltage is also observed. The activation energy of the process responsible for the current is determined. The magnitude of the current is more in the case of dissimilar electrode systems. It is proposed that the electric current arising from unpolarized metal–polymer–metal system is a water activated phenomenon, which is influenced by the transitional changes of the polymer.

  2. Juxtacortical chondromyxoid fibroma arising in an apophysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Ho; Kong, Keun Young; Chung, Hye Won; Kang, Heung Sik [Dept. of Radiology, Seoul National University College of Medicine (Korea); Kim, Chong Jai [Dept. of Pathology, Seoul National University College of Medicine, Seoul (Korea); Lee, Sang Hoon [Dept. of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul (Korea)

    2000-08-01

    We present a rare case of juxtacortical chondromyxoid fibroma arising in the lesser trochanter of the right femur which corresponds to an apophysis. Radiography showed a well-defined expansive lesion with a sclerotic margin measuring 5 x 3.5 cm in diameter in the lesser trochanter. On spin echo T1-weighted images, the lesion revealed low signal intensity similar to muscle. On spin echo T2-weighted images, the lesion revealed high heterogeneous signal intensity, which after gadolinium injection showed heterogeneous enhancement. The inner margin of the cortex was intact and adjacent bone marrow was of normal signal intensity. The outer margin of the lesion was also clearly defined and extension into adjacent soft tissue beyond the exophytic cortical outgrowth was not evident. (orig.)

  3. Periorbital nodular fasciitis arising during pregnancy

    Directory of Open Access Journals (Sweden)

    Brandon N Phillips

    2014-01-01

    Full Text Available Nodular fasciitis (NF is a benign proliferation of fibroblasts and myofibroblasts that rarely occurs in the periorbital region. We report what we believe to be the first case of periorbital NF associated with pregnancy. A case of intravascular fasciitis, a NF variant, has been reported during pregnancy, but it was not located in the periorbital region. A weak presence of estrogen receptors has been reported in NF. This may make it more susceptible to the hormone-related changes during pregnancy and contribute to the development of the lesion by stimulating fibroblasts and smooth muscle cell types. Although rare, NF should be considered in the differential diagnosis of periorbital soft-tissue masses arising during pregnancy.

  4. Ca2+ entry into neurons is facilitated by cooperative gating of clustered CaV1.3 channels

    Science.gov (United States)

    Moreno, Claudia M; Dixon, Rose E; Tajada, Sendoa; Yuan, Can; Opitz-Araya, Ximena; Binder, Marc D; Santana, Luis F

    2016-01-01

    CaV1.3 channels regulate excitability in many neurons. As is the case for all voltage-gated channels, it is widely assumed that individual CaV1.3 channels behave independently with respect to voltage-activation, open probability, and facilitation. Here, we report the results of super-resolution imaging, optogenetic, and electrophysiological measurements that refute this long-held view. We found that the short channel isoform (CaV1.3S), but not the long (CaV1.3L), associates in functional clusters of two or more channels that open cooperatively, facilitating Ca2+ influx. CaV1.3S channels are coupled via a C-terminus-to-C-terminus interaction that requires binding of the incoming Ca2+ to calmodulin (CaM) and subsequent binding of CaM to the pre-IQ domain of the channels. Physically-coupled channels facilitate Ca2+ currents as a consequence of their higher open probabilities, leading to increased firing rates in rat hippocampal neurons. We propose that cooperative gating of CaV1.3S channels represents a mechanism for the regulation of Ca2+ signaling and electrical activity. DOI: http://dx.doi.org/10.7554/eLife.15744.001 PMID:27187148

  5. Influx of CO2 from Soil Incubated Organic Residues at Constant Temperature

    Directory of Open Access Journals (Sweden)

    Shoukat Ali Abro

    2016-06-01

    Full Text Available Temperature induced CO2 from genotypic residue substances is still less understood. Two types of organic residues (wheat- maize were incubated at a constant temperature (25°C to determine the rate and cumulative influx of CO2 in laboratory experiment for 40 days. Further, the effect of surface and incorporated crop residues with and without phosphorus addition was also studied. Results revealed that mixing of crop residues increased CO2-C evolution significantly & emission rare was 37% higher than that of control. At constant temperature, soil mixed residues, had higher emission rates CO2-C than the residues superimposed. There was linear correlation of CO2-C influxed for phosphorus levels and residue application ways with entire incubation at constant temperature. The mixing of organic residues to soil enhanced SOC levels and biomass of microbially bound N; however to little degree ammonium (NH4-N and nitrate NO3-N nitrogen were decreased.

  6. Individual aggregates of amyloid beta induce temporary calcium influx through the cell membrane of neuronal cells

    Science.gov (United States)

    Drews, Anna; Flint, Jennie; Shivji, Nadia; Jönsson, Peter; Wirthensohn, David; De Genst, Erwin; Vincke, Cécile; Muyldermans, Serge; Dobson, Chris; Klenerman, David

    2016-01-01

    Local delivery of amyloid beta oligomers from the tip of a nanopipette, controlled over the cell surface, has been used to deliver physiological picomolar oligomer concentrations to primary astrocytes or neurons. Calcium influx was observed when as few as 2000 oligomers were delivered to the cell surface. When the dosing of oligomers was stopped the intracellular calcium returned to basal levels or below. Calcium influx was prevented by the presence in the pipette of the extracellular chaperone clusterin, which is known to selectively bind oligomers, and by the presence a specific nanobody to amyloid beta. These data are consistent with individual oligomers larger than trimers inducing calcium entry as they cross the cell membrane, a result supported by imaging experiments in bilayers, and suggest that the initial molecular event that leads to neuronal damage does not involve any cellular receptors, in contrast to work performed at much higher oligomer concentrations. PMID:27553885

  7. Calcium influx is sufficient to induce muscular dystrophy through a TRPC-dependent mechanism

    OpenAIRE

    Millay, Douglas P.; Goonasekera, Sanjeewa A.; Sargent, Michelle A.; Maillet, Marjorie; Aronow, Bruce J; Molkentin, Jeffery D.

    2009-01-01

    Muscular dystrophy is a general term encompassing muscle disorders that cause weakness and wasting, typically leading to premature death. Membrane instability, as a result of a genetic disruption within the dystrophin-glycoprotein complex (DGC), is thought to induce myofiber degeneration, although the downstream mechanism whereby membrane fragility leads to disease remains controversial. One potential mechanism that has yet to be definitively proven in vivo is that unregulated calcium influx ...

  8. Migration "crisis" in Europe. An overview of the influx of refugees and migrants

    OpenAIRE

    Nadarzyński, Kamil, 1987-

    2016-01-01

    The influx of foreign migrants into Europe as well as dramatic events on the Mediterranean Sea in the recent months has attracted attention of the public, political and academic spheres in Europe. Media’s coverage on migration and public debate constituted to popularization and dissemination of few key terms which are often confused or misunderstood. The most fundamental definitions come from UN, Red Cross and IOM. Migration can be dated back to the beginning of the human species. With the ap...

  9. Auxin influx inhibitors 1-NOA, 2-NOA, and CHPAA interfere with membrane dynamics in tobacco cells

    OpenAIRE

    Laňková, M. (Martina); Smith, R. S.; Pešek, B. (Bedřich); Kubeš, M. (Martin); Zažímalová, E. (Eva); Petrášek, J. (Jan); Hoyerová, K.

    2010-01-01

    The phytohormone auxin is transported through the plant body either via vascular pathways or from cell to cell by specialized polar transport machinery. This machinery consists of a balanced system of passive diffusion combined with the activities of auxin influx and efflux carriers. Synthetic auxins that differ in the mechanisms of their transport across the plasma membrane together with polar auxin transport inhibitors have been used in many studies on particular auxin carriers and their ro...

  10. Schistosoma mansoni cercariae experience influx of macromolecules during skin penetration

    OpenAIRE

    Thornhill, J.; Coelho, P. M. Z.; McVeigh, P.; Maule, A.; Jurberg, A.D.; Kusel, J.R.

    2009-01-01

    We have observed that when cercariae penetrate the skin of mice, there is influx into their tissues of Lucifer Yellow and certain labelled molecules of up to 20 kDa molecular weight. This observation was made using a variety of fluorescent membrane-impermeant compounds injected into the skin before the application of cercariae. This unexpected phenomenon was investigated further by transforming cercariae in vitro in the presence of the membrane-impermeant compounds and examining the distribut...

  11. Auxin influx inhibitors 1-NOA, 2-NOA, and CHPAA interfere with membrane dynamics in tobacco cells

    Czech Academy of Sciences Publication Activity Database

    Laňková, Martina; Smith, R. S.; Pešek, Bedřich; Kubeš, Martin; Zažímalová, Eva; Petrášek, Jan; Hoyerová, Klára

    2010-01-01

    Roč. 61, č. 13 (2010), s. 3589-3598. ISSN 0022-0957 R&D Projects: GA AV ČR KJB600380702; GA MŠk(CZ) LC06034 Grant ostatní: _(CZ) CZ.2.16/3.1.00/21159 Institutional research plan: CEZ:AV0Z50380511 Keywords : Auxin efflux carrier * auxin influx carrier * auxin transport Subject RIV: EF - Botanics Impact factor: 4.818, year: 2010

  12. Potassium ion influx measurements on cultured Chinese hamster cells exposed to 60-hertz electromagnetic fields

    International Nuclear Information System (INIS)

    Potassium ion influx was measured by monitoring 42KCl uptake by Chinese hamster ovary (CHO) cells grown in suspension culture and exposed in the culture medium to 60-Hz electromagnetic fields up to 2.85 V/m. In the presence of the field CHO cells exhibited two components of uptake, the same as previously observed for those grown under normal conditions; both these components of influx were decreased when compared to sham-exposed cells. Although decreases were consistently observed in exposed cells when plotted as loge of uptake, the differences between the means of the calculated fluxes of exposed and sham-exposed cells were quite small (on the order of 4-7%). When standard deviations were calculated, there was no significant difference between these means; however, when time-paired uptake data were analyzed, the differences were found to be statistically significant. Cells exposed only to the magnetic field exhibited similar small decreases in influx rates when compared to sham-exposed cells, suggesting that the reduction in K+ uptake could be attributed to the magnetic field. Additionally, intracellular K+ levels were measured over a prolonged exposure period (96 h), and no apparent differences in intracellular K+ levels were observed between field-exposed and sham-exposed cultures. These results indicate that high-strength electric fields have a small effect on the rate of transport of potassium ions but no effect on long-term maintenance of intracellular K+

  13. Relationship between NaCl- and H2O2-Induced Cytosolic Ca2+ Increases in Response to Stress in Arabidopsis

    OpenAIRE

    Jiang, Zhonghao; Zhu, Shan; Ye, Rui; Xue, Yan; Chen, Amelia; An, Lizhe; Pei, Zhen-Ming

    2013-01-01

    Salinity is among the environmental factors that affect plant growth and development and constrain agricultural productivity. Salinity stress triggers increases in cytosolic free Ca2+ concentration ([Ca2+]i) via Ca2+ influx across the plasma membrane. Salinity stress, as well as other stresses, induces the production of reactive oxygen species (ROS). It is well established that ROS also triggers increases in [Ca2+]i. However, the relationship and interaction between salinity stress-induced [C...

  14. Simulation of spontaneous Ca2+ oscillations in astrocytes mediated by voltage-gated calcium channels.

    Science.gov (United States)

    Zeng, Shuai; Li, Bing; Zeng, Shaoqun; Chen, Shangbin

    2009-11-01

    The purpose of this computational study was to investigate the possible role of voltage-gated Ca(2+) channels in spontaneous Ca(2+) oscillations of astrocytes. By incorporating different types of voltage-gated Ca(2+) channels and a previous model, this study reproduced typical Ca(2+) oscillations in silico. Our model could mimic the oscillatory phenomenon under a wide range of experimental conditions, including resting membrane potential (-75 to -60 mV), extracellular Ca(2+) concentration (0.1 to 1500 muM), temperature (20 to 37 degrees C), and blocking specific Ca(2+) channels. By varying the experimental conditions, the amplitude and duration of Ca(2+) oscillations changed slightly (both astrocytes might be an all-or-none process, which might be frequency-encoded in signaling. Moreover, the properties of Ca(2+) oscillations were found to be related to the dynamics of Ca(2+) influx, and not only to a constant influx. Therefore, calcium channels dynamics should be used in studying Ca(2+) oscillations. This work provides a platform to explore the still unclear mechanism of spontaneous Ca(2+) oscillations in astrocytes. PMID:19883585

  15. Accretion rate of extraterrestrial 41Ca in Antarctic snow samples

    Science.gov (United States)

    Gómez-Guzmán, J. M.; Bishop, S.; Faestermann, T.; Famulok, N.; Fimiani, L.; Hain, K.; Jahn, S.; Korschinek, G.; Ludwig, P.; Rodrigues, D.

    2015-10-01

    Interplanetary Dust Particles (IDPs) are small grains, generally less than a few hundred micrometers in size. Their main source is the Asteroid Belt, located at 3 AU from the Sun, between Mars and Jupiter. During their flight from the Asteroid Belt to the Earth they are irradiated by galactic and solar cosmic rays (GCR and SCR), thus radionuclides are formed, like 41Ca and 53Mn. Therefore, 41Ca (T1/2 = 1.03 × 105 yr) can be used as a key tracer to determine the accretion rate of IDPs onto the Earth because there are no significant terrestrial sources for this radionuclide. The first step of this study consisted to calculate the production rate of 41Ca in IDPs accreted by the Earth during their travel from the Asteroid Belt. This production rate, used in accordance with the 41Ca/40Ca ratios that will be measured in snow samples from the Antarctica will be used to calculate the amount of extraterrestrial material accreted by the Earth per year. There challenges for this project are, at first, the much longer time for the flight needed by the IDPs to travel from the Asteroid Belt to the Earth in comparison with the 41Ca half-life yields an early saturation for the 41Ca/40Ca ratio, and second, the importance of selecting the correct sampling site to avoid a high influx of natural 40Ca, preventing dilution of the 41Ca/40Ca ratio, the quantity measured by AMS.

  16. How Does the Ca2+-paradox Injury Induce Contracture in the Heart?—A Combined Study of the Intracellular Ca2+ Dynamics and Cell Structures in Perfused Rat Hearts—

    International Nuclear Information System (INIS)

    The calcium (Ca2+)-paradox injury of the heart, induced by restoration of extracellular Ca2+ after its short-term depletion, is known to provoke cardiomyocyte contracture. However, undetermined is how the Ca2+-paradox provokes such a distinctive presentation of myocytes in the heart. To address this, we imaged sequential intracellular Ca2+ dynamics and concomitant structures of the subepicardial ventricular myocytes in fluo3-loaded, Langendorff-perfused rat hearts produced by the Ca2+ paradox. Under rapid-scanning confocal microscopy, repletion of Ca2+ following its depletion produced high-frequency Ca2+ waves in individual myocytes with asynchronous localized contractions, resulting in contracture within 10 min. Such alterations of myocytes were attenuated by 5-mM NiCl2, but not by verapamil, SEA0400, or combination of ryanodine and thapsigargin, indicating a contribution of non-specific transmembrane Ca2+ influx in the injury. However, saponin-induced membrane permeabilization of Ca2+ showed no apparent contracture despite the emergence of high-frequency Ca2+ waves, indicating an essential role of myocyte-myocyte and myocyte-extracellular matrix (ECM) mechanical connections in the Ca2+ paradox. In immunohistochemistry Ca2+ depletion produced separation of the intercalated disc that expresses cadherin and dissipation of β-dystroglycan located along the sarcolemma. Taken together, along with the trans-sarcolemmal Ca2+ influx, disruption of cell-cell and cell-ECM connections is essential for contracture in the Ca2+-paradox injury

  17. Chemodectomas arising in temporal bone structures

    Energy Technology Data Exchange (ETDEWEB)

    Dickens, W.J.; Million, R.R.; Cassisi, N.J.; Singleton, G.T.

    1982-02-01

    Eighteen patients with chemodectomas arising in temporal bone structures were evaluated and treated at the University of Florida. Seventeen patients have each been followed a minimum of 3 years. Patients were retrospectively staged as having ''local'' or ''advanced'' disease, depending on the presence or absence of bone destruction and/or cranial nerve involvement. Fourteen of the patients received radiation therapy as all or part of their therapy; 6 patients were treated with radiation therapy alone, 3 patients were irradiated immediately postoperatively for residual disease, and 5 patients had radiation therapy for recurrence after operation. They were treated with cobalt-60 radiation with doses ranging from 3760 to 5640 rad. All irradiated patients demonstrated evidence of tumor regression, and none have had tumor recurrence with followup of 3-12 years. Of the 8 patients with cranial nerve paralysis prior to therapy, 5 had return of function of 1 or more cranial nerves. One of 6 patients treated initially with radiation therapy had a complication, while 6 of 8 patients irradiated postoperatively had complications. None of the complications were fatal. Three patients treated by operation for early disease limited to the hypotympanum had the disease controlled for 11-12 years. Guidelines for the selection of initial therapy are discussed.

  18. An organism arises from every nucleus.

    Directory of Open Access Journals (Sweden)

    Nurullah Keklikoglu

    2009-12-01

    Full Text Available The fact that, cloning using somatic cell nuclear transfer (SCNT method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which can be applied with SCNT, showed us that it may be possible to obtain different versions of the original genetic constitution of a cell. Because of this opportunity which is provided by SCNT, in reproductive cloning, it would be possible to clone enhanced organisms which can adapt to different environmental conditions and survive. Furthermore, regaining the genetic characteristics of ancestors or reverse herediter variations would be possible. On the other hand, in therapeutic cloning, more precise and easily obtainable alternatives for cell replacement therapy could be presented. However, while producing healthier or different organisms from a nucleus, it is hard to foresee the side effects influencing natural processes in long term is rather difficult.

  19. Chemodectomas arising in temporal bone structures

    International Nuclear Information System (INIS)

    Eighteen patients with chemodectomas arising in temporal bone structures were evaluated and treated at the University of Florida. Seventeen patients have each been followed a minimum of 3 years. Patients were retrospectively staged as having ''local'' or ''advanced'' disease, depending on the presence or absence of bone destruction and/or cranial nerve involvement. Fourteen of the patients received radiation therapy as all or part of their therapy; 6 patients were treated with radiation therapy alone, 3 patients were irradiated immediately postoperatively for residual disease, and 5 patients had radiation therapy for recurrence after operation. They were treated with cobalt-60 radiation with doses ranging from 3760 to 5640 rad. All irradiated patients demonstrated evidence of tumor regression, and none have had tumor recurrence with followup of 3-12 years. Of the 8 patients with cranial nerve paralysis prior to therapy, 5 had return of function of 1 or more cranial nerves. One of 6 patients treated initially with radiation therapy had a complication, while 6 of 8 patients irradiated postoperatively had complications. None of the complications were fatal. Three patients treated by operation for early disease limited to the hypotympanum had the disease controlled for 11-12 years. Guidelines for the selection of initial therapy are discussed

  20. Radiological emergencies arising from accidents in Italy

    International Nuclear Information System (INIS)

    The Nuclear Safety and Health Protection Directorate (DISP) of ENEA has organized a structure of officers and technicians on call whenever an accident related to the activity of ENEA-DISP should occur. The most frequent events arise from natural misfortunes, crime, and deficiencies in public services. As regards technical operations such as measurements, removals, decontaminations and transport, DISP requests utilization of the different structures and equipment available to ENEA research centres and, in particular and most frequently, of the Safety and Radioprotection Division of the main ENEA centre: the Casaccia Research Centre. The technicians of this division are always available via telephone or radio, with the firm duty to be present within one hour from the call. The co-operation between these two structures enables timely and efficient intervention in many circumstances so that population and environmental risks can be avoided. Typical accidental situations are earthquakes, adverse atmospheric events, landslides, collapses, railway and road accidents, lost sources discovery, and seizure of illegally detained sources by judicial power. The paper briefly describes some of the situations which have occurred, and the actions carried out to recover sources and to re-establish safe environmental conditions. (author)

  1. Chemical hazards arising from shale gas extraction

    Directory of Open Access Journals (Sweden)

    Daria Pakulska

    2015-02-01

    Full Text Available The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extremely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction. Med Pr 2015;66(1:99–117

  2. Hypotonicity-induced TRPV4 function in renal collecting duct cells: modulation by progressive cross-talk with Ca2+-activated K+ channels

    Science.gov (United States)

    Jin, Min; Berrout, Jonathan; Chen, Ling; O’Neil, Roger G.

    2011-01-01

    The mouse cortical collecting duct (CCD) M-1 cells were grown to confluency on coverslips to assess the interaction between TRPV4 and Ca2+-activated K+ channels. Immunocytochemistry demonstrated strong expression of TRPV4, along with the CCD marker, aquaporin-2, and the Ca2+-activated K+ channels, the small conductance SK3 (KCa2.3) channel and large conductance BKα channel (KCa1.1). TRPV4 overexpression studies demonstrated little physical dependency of the K+ channels on TRPV4. However, activation of TRPV4 by hypotonic swelling (or GSK1016790A, a selective agonist) or inhibition by the selective antagonist, HC-067047, demonstrated a strong dependency of SK3 and BK-α activation on TRPV4-mediated Ca2+ influx. Selective inhibition of BK-α channel (Iberiotoxin) or SK3 channel (apamin), thereby depolarizing the cells, further revealed a significant dependency of TRPV4-mediated Ca2+ influx on activation of both K+ channels. It is concluded that a synergistic cross-talk exists between the TRPV4 channel and SK3 and BK-α channels to provide a tight functional regulation between the channel groups. This cross-talk may be progressive in nature where the initial TRPV4-mediated Ca2+ influx would first activate the highly Ca2+-sensitive SK3 channel which, in turn, would lead to enhanced Ca2+ influx and activation of the less Ca2+-sensitive BK channel. PMID:22204737

  3. RIGHT SUPERIOR POLAR ARTERY ARISING FROM AORTA

    Directory of Open Access Journals (Sweden)

    Sreekanth

    2013-05-01

    Full Text Available ABSTRACT: The renal vasculature was always a subject of varia tions both in the number and pattern of portal of entry into kidney and Perihilar placement of the artery, vein and pelvis. Good anatomical insight is an essential prerequisite besides the surgical expertise. The cadaveric dissection at Shadan Institute of Medical Sciences, Teaching Hospital and Research Centre, revealed superior / upper polar artery arising from the lateral aspect of the aorta just proximal to the origin of Main Renal Artery (MRA. T he main renal artery and the accessory renal artery had almost a common point of origin. Th e peri-hilar segmentation of the main renal artery was a fork like pattern. One of the segmental arteries was long and had its portal of entry into the kidney by perforating the capsule of the ant erior substance of the kidney. The remaining segmental branches had their portal of ent ry through the hilum. The lower two segmental branches were placed anterior to the main renal vein causing altered hilar anatomy. A thorough knowledge of the frequently to the rarel y occurring wide range of variations of renal vasculature has significance in exploration and trea tment of renal trauma, renal transplantation, renal artery embolization, surgery for abdominal ao rtic aneurysm and conservative or radical renal surgery. Such a rare variation including the combination of extra renal peri-hilar segmentation of MRA with superior polar artery is wor thy of concern to the urologists harvesting kidneys from the live donors for performi ng transplantation procedures, partial nephrectomies for the hilar tumors and for Radiologi sts during interpretation of the angiograms

  4. Impact of freshwater influx on the cyclogenesis, tracks of cyclones and air-sea coupling over the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Sarma, M.S.S.; Jenson, G.V.; Vidya, P.J.

    caused by freshwater influx and precipitation. It is found that the zone of higher EOLC, characterized by warmer temperature, lower surface salinity, higher heat potential and higher specific humidity in the surface air, couples with the zone of intense...

  5. A real-time, non-invasive, micro-optrode technique for detecting seed viability by using oxygen influx.

    Science.gov (United States)

    Xin, Xia; Wan, Yinglang; Wang, Wenjun; Yin, Guangkun; McLamore, Eric S; Lu, Xinxiong

    2013-01-01

    Quantifying seed viability is required for seed bank maintenance. The classical methods for detecting seed viability are time consuming and frequently cause seed damage and unwanted germination. We have established a novel micro-optrode technique (MOT) to measure seed viability in a quick and non-invasive manner by measuring the oxygen influxes of intact seeds, approximately 10 seconds to screen one seed. Here, we used soybean, wheat, and oilseed rape as models to test our method. After 3-hour imbibition, oxygen influxes were recorded in real-time with the total measurement taking less than 5 minutes. The results indicated a significantly positive correlation between oxygen influxes and viability in all 3 seed types. We also established a linear equation between oxygen influxes and seed viability for each seed type. For measurements, seeds were kept in the early imbibition stage without germination. Thus, MOT is a reliable, quick, and low-cost seed viability detecting technique. PMID:24162185

  6. Tidal propagation in the Mandovi-Zuari Estuarine network, west coast of India: Impact of freshwater influx

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Shetye, S.R.; Gouveia, A.D.

    The Mandovi-Zuari estuarine network on the west coast of India consists of shallow strongly converging channels, that receive large seasonal influx of fresh water due to the monsoons. The main channels, the Mandovi and Zuari estuaries, connect...

  7. ARISE - Advanced Radio Interferometry Between Space and Earth

    Science.gov (United States)

    Ulvestad, J. S.; Linfield, R. P.; Wannier, P. G.; Preston, R. A.; Hirabayashi, H.; Zensus, J. A.; Veal, G. R.

    1995-01-01

    A mission is described called ARISE, Advanced Radio Interferometry between Space and Earth. ARISE will will provide affordable very long baseline interferometry (VLBI) using second- generation VLBI and one or more inflatable space radio telescopes.

  8. A morphologic study of the influx of neutrophils into dog lung alveoli after lavage with sterile saline.

    OpenAIRE

    Damiano, V. V.; Cohen, A; Tsang, A. L.; Batra, G.; Petersen, R

    1980-01-01

    The appearance of neutrophils in the alveoli of the lung is a common result of pulmonary infection, although the route of neutrophil migration across the alveolar wall has not been demonstrated in normal animals. Recently, however, several methods of stimulating the influx of neutrophils into alveoli have been developed. In the present study, the lung wash model was used to attract large numbers of neutrophils into the airways in order to identify the site of influx of alveolar neutrophils. T...

  9. Squamous cell carcinoma arising in an odontogenic cyst

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jae Jung; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of); Choi, Jeong Hee [Chonnam National University College of Medicine, Kwangju (Korea, Republic of)

    2003-12-15

    Squamous cell carcinoma arising in an odontogenic cyst is uncommon. The diagnosis of carcinoma arising in a cyst requires that there must be an area of microscopic transition from the benign epithelial cyst lining to the invasive squamous cell carcinoma. We report a histopathologically proven case of squamous cell carcinoma arising in a residual mandibular cyst in a 54-year-old woman.

  10. Fenvalerate-induced Ca2+ transients via both intracellular and extracellular way in mouse GC-2spd (ts) cells

    International Nuclear Information System (INIS)

    Fenvalerate (Fen) is a widely used synthetic pyrethroid insecticide which is considered to impede the male reproductive function. However, little is known about its underlying mechanism. In this study, we found that fenvalerate affected the Ca2+ homeostasis, inducing Ca2+ transients via both intracellular Ca2+ release and extracellular Ca2+ influx. Ca2+ influx was via store-operated channel (SOC). Therefore, the effects of fenvalerate on Ryanodine receptors (RyRs) and Inositol (1,4,5)-trisphosphate receptors (IP3Rs) which involved in forming Ca2+ transient was assessed by pharmacological way. We also demonstrated that fenvalerate affected the expression of both receptors and hindered cell proliferation as well. In addition, we discovered that 2-APB, an antagonist of IP3Rs, inhibited GC-2spd (ts) cells (GC-2 cells) proliferation. Cell cycle analysis of GC-2 cells treated with fenvalerate and 2-APB indicated that both of which showed a slight S-phase accumulation. In conclusion, our results demonstrate that fenvalerate-induced Ca2+ transients from both calcium release through RyRs or IP3Rs and calcium influx via SOC. IP3Rs seem to serve a predominant role in triggering Ca2+ transients which could participate to the regulation of GC-2 cell proliferation.

  11. Ablation of triadin causes loss of cardiac Ca2+ release units, impaired excitation–contraction coupling, and cardiac arrhythmias

    OpenAIRE

    Chopra, Nagesh; Yang, Tao; Asghari, Parisa; Moore, Edwin D.; Huke, Sabine; Akin, Brandy; Cattolica, Robert A.; Perez, Claudio F.; Hlaing, Thinn; Knollmann-Ritschel, Barbara E. C.; Jones, Larry R.; Pessah, Isaac N; Allen, Paul D.; Franzini-Armstrong, Clara; Knollmann, Björn C.

    2009-01-01

    Heart muscle excitation–contraction (E-C) coupling is governed by Ca2+ release units (CRUs) whereby Ca2+ influx via L-type Ca2+ channels (Cav1.2) triggers Ca2+ release from juxtaposed Ca2+ release channels (RyR2) located in junctional sarcoplasmic reticulum (jSR). Although studies suggest that the jSR protein triadin anchors cardiac calsequestrin (Casq2) to RyR2, its contribution to E-C coupling remains unclear. Here, we identify the role of triadin using mice with ablation of the Trdn gene (...

  12. Ca2+ signal is generated only once in the mating pheromone response pathway in Saccharomyces cerevisiae.

    Science.gov (United States)

    Nakajima-Shimada, J; Sakaguchi, S; Tsuji, F I; Anraku, Y; Iida, H

    2000-04-01

    The mating pheromone, alpha-factor, of the yeast Saccharomyces cerevisiae binds to the heterotrimeric G protein-coupled cell surface receptor of MATa cells and induces cellular responses necessary for mating. In higher eukaryotic cells, many hormones and growth factors rapidly mobilize a second messenger, Ca2+, by means of receptor-G protein signaling. Although striking similarities between the mechanisms of the receptor-G protein signaling in yeast and higher eukaryotes have long been known, it is still uncertain whether the pheromone rapidly mobilizes Ca2+ necessary for early events of the pheromone response. Here we reexamine this problem using sensitive methods for detecting Ca2+ fluxes and mobilization, and find no evidence that there is rapid Ca2+ influx leading to a rapid increase in the cytosolic free Ca2+ concentration. In addition, the yeast PLC1 deletion mutant lacking phosphoinositide-specific phospholipase C, a key enzyme for generating Ca2+ signals in higher eukaryotic cells, responds normally to the pheromone. These findings suggest that the receptor-G protein signaling does not utilize Ca2+ as a second messenger in the early stage of the pheromone response pathway. Since the receptor-G protein signaling does stimulate Ca2+ influx after early events have finished and this stimulation is essential for late events in the pheromone response pathway [Iida et al., (1990) J. Biol. Chem., 265: 13391-13399] Ca2+ may be used only once in the signal transduction pathway in unicellular eukaryotes such as yeast. PMID:10885582

  13. Low energy 40Ca + 40Ca collisions

    International Nuclear Information System (INIS)

    This paper deals with the classical microscopic study of 40Ca + 40Ca collisions. Fusion cross-sections (σsub(CF)) for various incident energies, energy variations with time, shape deformation and the life time of resonance scattering (T) have been studied. Comparison of 40Ca + 40Ca results with those of 16O + 16O have also been made. (author)

  14. Ca²⁺ signaling and regulation of fluid secretion in salivary gland acinar cells.

    Science.gov (United States)

    Ambudkar, Indu S

    2014-06-01

    Neurotransmitter stimulation of plasma membrane receptors stimulates salivary gland fluid secretion via a complex process that is determined by coordinated temporal and spatial regulation of several Ca(2+) signaling processes as well as ion flux systems. Studies over the past four decades have demonstrated that Ca(2+) is a critical factor in the control of salivary gland function. Importantly, critical components of this process have now been identified, including plasma membrane receptors, calcium channels, and regulatory proteins. The key event in activation of fluid secretion is an increase in intracellular [Ca(2+)] ([Ca(2+)]i) triggered by IP3-induced release of Ca(2+) from ER via the IP3R. This increase regulates the ion fluxes required to drive vectorial fluid secretion. IP3Rs determine the site of initiation and the pattern of [Ca(2+)]i signal in the cell. However, Ca(2+) entry into the cell is required to sustain the elevation of [Ca(2+)]i and fluid secretion. This Ca(2+) influx pathway, store-operated calcium influx pathway (SOCE), has been studied in great detail and the regulatory mechanisms as well as key molecular components have now been identified. Orai1, TRPC1, and STIM1 are critical components of SOCE and among these, Ca(2+) entry via TRPC1 is a major determinant of fluid secretion. The receptor-evoked Ca(2+) signal in salivary gland acinar cells is unique in that it starts at the apical pole and then rapidly increases across the cell. The basis for the polarized Ca(2+) signal can be ascribed to the polarized arrangement of the Ca(2+) channels, transporters, and signaling proteins. Distinct localization of these proteins in the cell suggests compartmentalization of Ca(2+) signals during regulation of fluid secretion. This chapter will discuss new concepts and findings regarding the polarization and control of Ca(2+) signals in the regulation of fluid secretion. PMID:24646566

  15. Differential potassium influx influences growth of two cotton varieties in hydroponics

    International Nuclear Information System (INIS)

    Potassium uptake rate of two cotton (Gossypium hirsutum L.) varieties viz., NIBGE-2 and MNH-786 was investigated in nutrient solution culture having deficient K at the rate 0.3 mM and deficient K+ Na at the rate 0.3 +2.7 mM. Depletion of K from solution was monitored over a period of 24 h at regular time intervals after 0, 0.5, 1.0, 1.5, 2, 3, 4, 5, 6, 8, 10, 12 and 24 h to estimate K uptake kinetics of the roots i.e. maximum influx, I/sub max/ and the Michaelis-Menten constant, Km. NIBGE-2 had about 2-fold higher (2.0 mg g rdw-1 hr-1) I/sub max/ value for K uptake rate at deficient K+Na than that (1.207 mg g rdw-1 hr-1) for MNH-786. Higher, Michaelis-Menten constant, Km (12.82 ppm) for K uptake rate was observed in both cultivars NIBGE-2 and MNH-786 at deficient K+Na than that at deficient K. Main effects of treatments and varieties had significant (p< 0.05) effect on shoot dry matter, root dry matter, total dry matter and leaf area per plant. Maximum K influx in NIBGE-2 at deficient K and deficient K +Na was attributed to enhanced growth response as compared to that in MNH-786. (author)

  16. Spontaneous Ca2+ oscillations in subcellular compartments of vascular smooth muscle cells rely on different Ca2+ pools

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Spontaneous Ca2+ oscillations in vascular smooth muscle cells have been modeled using a single Ca2+ pool. This report describes spontaneous Ca2+ oscillations dependent on two separate Ca2+ sources for the nuclear versus cytoplasmic compartments. Changes in free intracellular Ca2+ were monitored with ratiometric Ca2+- fluorophores using confocal microscopy. On average, spontaneous oscillations developed in 79% of rat aortic smooth muscle cells that were synchronous between the cytoplasm and nucleus. Reduction of extracellular Ca2+ (< 1 μM) decreased the frequency and amplitude of the cytoplasmic oscillations with 48% of the oscillations asynchronous between the nuclear and cytoplasmic compartments. Similar results were obtained with the Ca2+ channel blockers, nimodipine and diltiazem.Arg-vasopressin (AVP) induced a rapid release of intracellular Ca2+ stores that was greater in the nuclear compartment (4.20 ± 0.23 ratio units, n = 56) than cytoplasm (2.54 ± 0.28) in cells that had spontaneously developed prior oscillations.Conversely, cells in the same conditions lacking oscillations had a greater AVP-induced Ca2+ transient in the cytoplasm (4.99 ± 0.66, n = 17) than in the nucleus (2.67 ± 0.29). Pre-treatment with Ca2+ channel blockers depressed the AVP responses in both compartments with the cytoplasmic Ca2+ most diminished. Depletion of internal Ca2+ stores prior to AVP exposure blunted the nuclear response, mimicking the response of cells that lacked prior oscillations. Spontaneous oscillating cells had a greater sarcoplasmic reticulum network than cells that did not oscillate. We propose that spontaneous nuclear oscillations rely on perinuclear sarcoplasmic reticulum stores, while the cytoplasmic oscillations rely on Ca2+ influx.

  17. Ca-mediated and independent effects of arachidonic acid on gap junctions and Ca-independent effects of oleic acid and halothane.

    Science.gov (United States)

    Lazrak, A; Peres, A; Giovannardi, S; Peracchia, C

    1994-09-01

    In Novikoff hepatoma cell pairs studied by double perforated patch clamp (DPPC), brief (20 s) exposure to 20 microM arachidonic acid (AA) induced a rapid and reversible uncoupling. In pairs studied by double whole-cell clamp (DWCC), uncoupling was completely prevented by effective buffering of Cai2+ with BAPTA. Similarly, AA (20 s) had no effect on coupling in cells perfused with solutions containing no added Ca2+ (SES-no-Ca) and studied by DPPC, suggesting that Ca2+ influx plays an important role. Parallel experiments monitoring [Ca2+]i with fura-2 showed that [Ca2+]i increases with AA to 0.7-1.5 microM in normal [Ca2+]o, and to approximately 400 nM in SES-no-Ca solutions. The rate of [Ca2+]i increase matched that of Gj decrease, but [Ca2+]i recovery was faster. In cells studied by DWCC with 2 mM BAPTA in the pipette solution and superfused with SES-no-Ca, long exposure (1 min) to 20 microM AA caused a slow and virtually irreversible uncoupling. This result suggests that AA has a dual mechanism of uncoupling: one dominant, fast, reversible, and Ca(2+)-dependent, the other slow, poorly reversible, and Ca(2+)-independent. In contrast, uncoupling by oleic acid (OA) or halothane was insensitive to internal buffering with BAPTA, suggesting a Ca(2+)-independent mechanism only. PMID:7811915

  18. Adenocarcinoma arising from the tailgut cyst: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung Jae; Lee, Young Rae [Kangbuk Samsung Hospital, Samsung Medical Center, Seoul (Korea, Republic of)

    1995-09-15

    Tailgut cyst is a rare congenital anomaly arising in the retrorectal space. Malignancy arising from the tailgut cyst is very rare. We experienced a case of adenocarcinoma arising from the tailgut cyst. The findings of this rare tumor are bony destruction of the sacrum on plain radiograph, a cystic mass on ultrasound, a low attenuation mass with calcification and enhancement on CT, and a multiseptated cystic mass containing solid component on MRI.

  19. Wilms tumor arising in extracoelomic paravertebral soft tissues.

    LENUS (Irish Health Repository)

    Mulligan, Linda

    2012-02-01

    Extrarenal Wilms tumor (ERWT) is a well-established entity which most commonly arises within the genitourinary tract, including intracoelomic paranephric soft tissue. Rarely, ERWT arises within teratoma, and it tends to occur predominantly in distinct settings, such as females with spinal defects and males with testicular teratomas. We report a unique ERWT arising within an extracoelomic teratoma of the paraspinal musculature, thereby expanding the range of reported locations for this unusual tumor.

  20. Intestinal-Type Adenocarcinoma Arising in a Mature Cystic Teratoma of the Ovary.

    Science.gov (United States)

    Clark, Mary E; Will, Micah D

    2016-07-01

    Here, we present a rare case of intestinal type adenocarcinoma arising in mature cystic teratoma (MCT) and review all previously reported similar cases with emphasis on the immunohistochemical characteristics of prior cases. Nine prior cases of intestinal type adenocarcinoma arising in MCT have been previously reported. Two of the prior cases as well as this case have been associated with CA19-9 elevation. CK20 is consistently strongly positive and CK7 is usually negative in cases of intestinal type adenocarcinoma arising in MCT. This contrasts with mucinous tumors of the ovary which are known to be usually CK7 strongly positive and inconsistently CK20 positive. The pattern of strong CK20 staining and often negative or weak CK7 staining is common to mucinous neoplasms arising in MCT. These findings suggest that the less common subset of primary mucinous ovarian tumors that have strong CK20 staining and partial or negative CK7 staining may represent a group of tumors with germ cell origin rather than the more common surface epithelial origin. PMID:26937866

  1. ADAPTATION OF THE CARTER-TRACY WATER INFLUX CALCULATION TO GROUNDWATER FLOW SIMULTATION.

    Science.gov (United States)

    Kipp, Kenneth L.

    1986-01-01

    The Carter-Tracy calculation for water influx is adapted to groundwater flow simulation with additional clarifying explanation not present in the original papers. The Van Everdingen and Hurst aquifer-influence functions for radial flow from an outer aquifer region are employed. This technique, based on convolution of unit-step response functions, offers a simple but approximate method for embedding an inner region of groundwater flow simulation within a much larger aquifer region where flow can be treated in an approximate fashion. The use of aquifer-influence functions in groundwater flow modeling reduces the size of the computational grid with a corresponding reduction in computer storage and execution time. The Carter-Tracy approximation to the convolution integral enables the aquifer influence function calculation to be made with an additional storage requirement of only two times the number of boundary nodes more than that required for the inner region simulation.

  2. Polyamines interact with hydroxyl radicals in activating Ca(2+) and K(+) transport across the root epidermal plasma membranes.

    Science.gov (United States)

    Zepeda-Jazo, Isaac; Velarde-Buendía, Ana María; Enríquez-Figueroa, René; Bose, Jayakumar; Shabala, Sergey; Muñiz-Murguía, Jesús; Pottosin, Igor I

    2011-12-01

    Reactive oxygen species (ROS) are integral components of the plant adaptive responses to environment. Importantly, ROS affect the intracellular Ca(2+) dynamics by activating a range of nonselective Ca(2+)-permeable channels in plasma membrane (PM). Using patch-clamp and noninvasive microelectrode ion flux measuring techniques, we have characterized ionic currents and net K(+) and Ca(2+) fluxes induced by hydroxyl radicals (OH(•)) in pea (Pisum sativum) roots. OH(•), but not hydrogen peroxide, activated a rapid Ca(2+) efflux and a more slowly developing net Ca(2+) influx concurrent with a net K(+) efflux. In isolated protoplasts, OH(•) evoked a nonselective current, with a time course and a steady-state magnitude similar to those for a K(+) efflux in intact roots. This current displayed a low ionic selectivity and was permeable to Ca(2+). Active OH(•)-induced Ca(2+) efflux in roots was suppressed by the PM Ca(2+) pump inhibitors eosine yellow and erythrosine B. The cation channel blockers gadolinium, nifedipine, and verapamil and the anionic channel blockers 5-nitro-2(3-phenylpropylamino)-benzoate and niflumate inhibited OH(•)-induced ionic currents in root protoplasts and K(+) efflux and Ca(2+) influx in roots. Contrary to expectations, polyamines (PAs) did not inhibit the OH(•)-induced cation fluxes. The net OH(•)-induced Ca(2+) efflux was largely prolonged in the presence of spermine, and all PAs tested (spermine, spermidine, and putrescine) accelerated and augmented the OH(•)-induced net K(+) efflux from roots. The latter effect was also observed in patch-clamp experiments on root protoplasts. We conclude that PAs interact with ROS to alter intracellular Ca(2+) homeostasis by modulating both Ca(2+) influx and efflux transport systems at the root cell PM. PMID:21980172

  3. Polyamines as mediators of insulin's action on pyruvate dehydrogenase, 45Ca2+ fluxes, and membrane transport

    International Nuclear Information System (INIS)

    Insulin (IN) induces a rapid stimulation of Ca2+ fluxes and membrane transport in mouse kidney cortex which involves rapid polyamine synthesis. 1.3 nM (IN) induced an early (45Ca2+ influx and efflux peaked at 1-2 min and returned to basal levels by 5-10 min. The ODC inhibitor α-difluoromethylornithine (DFMO, 5 mM) abolished IN stimulation of PDH, 45Ca2+ fluxes and membrane transport, and putrescine (.5 mM) nullified DFMO inhibition. IN (50 mUnits/kg) in rats induced an early (2+ fluxes, and membrane transport

  4. Earth's influx of different populations of sporadic meteoroids from photographic and television data

    International Nuclear Information System (INIS)

    Precise photographic and television double- and multi-station data on 3624 sporadic meteors in the mass range from 2 x 10-5 grams to 2 x 107 grams form the basis of this paper. The applied classification criteria and procedures are defined and described. A survey of 7 different populations of sporadic meteoroids known so far is presented. The total numbers and masses of meteoroids as a function of mass are given for individual groups and for all sporadic meteors. The absolute calibration of the influx to the Earth was carried out by comparison with the results of Halliday et al. (1984). The comparison with the visual and cratering data revealed good agreement in the narrow ''visual'' interval of masses, and disagreement in the extrapolated parts of the visual and cratering flux curves. The slope of the cumulative number curve for the meteorite-dropping fireballs (type I) with masses larger than 1 kg was found as -0.69 in perfect agreement with the results of Halliday et al. (1984). The final mass scale derived in this paper is situated between the scale of McCrosky and the scale of Halliday. The relative significance of the different groups of meteoroids changes with the mass quite dramatically. The total influx of sporadic meteoroids in the mass interval of 12 orders from 2 x 107 to 2 x 10-5 grams resulted in 5 x 109 grams per year for the entire Earth's surface. Most of this mass comes in the form of larger meteoroids. Bulk densities and ablation coefficient are presented for the individual meteor groups depending on different ablation models of several authors and some extreme concepts of this problem are discussed. (author). 3 figs., 6 tabs., 38 refs

  5. Disruptions in AUX1-Dependent Auxin Influx Alter Hypocotyl Phototropism in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Bethany B.Stone; Emily L.Stowe-Evans; Reneé M.Harper; R.Brandon Celaya; Karin Ljung; G(o)ran Sandberg; Emmanuel Liscum

    2008-01-01

    Phototropism represents a differential growth response by which plant organs can respond adaptively to changes in the direction of incident light to optimize leaf/stem positioning for photosynthetic light capture and root growth orientation for water/nutrient acquisition. Studies over the past few years have identified a number of components in the signaling pathway(s) leading to development of phototropic curvatures in hypocotyls. These include the phototropin photoreceptors (phot1 and phot2) that perceive directional blue-light (BL) cues and then stimulate signaling,leading to relocalization of the plant hormone auxin, as well as the auxin response factor NPH4/ARF7 that responds to changes in local auxin concentrations to directly mediate expression of genes likely encoding proteins necessary for development of phototropic curvatures. While null mutations in NPH4/ARF7 condition an aphototropic response to unidirectional BL, seedlings carrying the same mutations recover BL-dependent phototropic responsiveness if coirradiated with red light (RL) or pre-treated with either ethylene. In the present study, we identify second-site enhancer mutations in the nph4 background that abrogate these recovery responses. One of these mutations-map1 ((m)odifier of (a)rf7 (p)henotypes (1))-was found to represent a missense allele of AUX1-a gene encoding a high-affinity auxin influx carrier previously associated with a number of root responses. Pharmocological studies and analyses of additional aux1 mutants confirmed that AUX1 functions as a modulator of hypocotyl phototropism. Moreover, we have found that the strength of dependence of hypocotyl phototropism on AUX1-mediated auxin influx is directly related to the auxin responsiveness of the seedling in question.

  6. Distinct Properties of \\(Ca^{2+}\\)-Calmodulin Binding to N- and C-Terminal Regulatory Regions of the TRPV1 Channel

    OpenAIRE

    Gaudet, Rachelle; Lau, Sze-Yi; Procko, Erik

    2012-01-01

    Transient receptor potential (TRP) vanilloid 1 (TRPV1) is a molecular pain receptor belonging to the TRP superfamily of nonselective cation channels. As a polymodal receptor, TRPV1 responds to heat and a wide range of chemical stimuli. The influx of calcium after channel activation serves as a negative feedback mechanism leading to TRPV1 desensitization. The cellular calcium sensor calmodulin (CaM) likely participates in the desensitization of TRPV1. Two CaM-binding sites are identified in TR...

  7. Apo-states of calmodulin and CaBP1 control CaV1 voltage-gated calcium channel function through direct competition for the IQ domain

    Science.gov (United States)

    Findeisen, Felix; Rumpf, Christine; Minor, Daniel L.

    2013-01-01

    In neurons, binding of calmodulin (CaM) or calcium-binding protein 1 (CaBP1) to the CaV1 (L-type) voltage-gated calcium channel IQ domain endows the channel with diametrically opposed properties. CaM causes calcium-dependent inactivation (CDI) and limits calcium entry, whereas CaBP1 blocks CDI and allows sustained calcium influx. Here, we combine isothermal titration calorimetry (ITC) with cell-based functional measurements and mathematical modeling to show that these calcium sensors behave in a competitive manner that is explained quantitatively by their apo-state binding affinities for the IQ domain. This competition can be completely blocked by covalent tethering of CaM to the channel. Further, we show that Ca2+/CaM has a sub-picomolar affinity for the IQ domain that is achieved without drastic alteration of calcium binding properties. The observation that the apo-forms of CaM and CaBP1 compete with each other demonstrates a simple mechanism for direct modulation of CaV1 function and suggests a means by which excitable cells may dynamically tune CaV activity. PMID:23811053

  8. Dissociation of Ca sup 2+ entry and Ca sup 2+ mobilization responses to angiotensin II in bovine adrenal chromaffin cells

    Energy Technology Data Exchange (ETDEWEB)

    Stauderman, K.A.; Pruss, R.M. (Merrell Dow Research Institute, Cincinnati, OH (USA))

    1989-11-05

    In fura-2-loaded bovine adrenal chromaffin cells, 0.5 microM angiotensin II (AII) stimulated a 185 +/- 19 nM increase of intracellular-free calcium (( Ca2+)i) approximately 3 s after addition. The time from the onset of the response until achieving 50% recovery (t 1/2) was 67 +/- 10 s. Concomitantly, AII stimulated both the release of 45Ca2+ from prelabeled cells, and a 4-5-fold increase of (3H)inositol 1,4,5-trisphosphate (( 3H)Ins(1,4,5)P3) levels. In the presence of 50 microM LaCl3, or when extracellular-free Ca2+ (( Ca2+)o) was less than 100 nM, AII still rapidly increased (Ca2+)i by 95-135 nM, but the t 1/2 for recovery was then only 23-27 s. In medium with 1 mM MnCl2 present, AII also stimulated a small amount of Mn2+ influx, as judged by quenching of the fura-2 signal. When (Ca2+)o was normal (1.1 mM) or low (less than 60 nM), 1-2 microM ionomycin caused (Ca2+)i to increase 204 +/- 26 nM, while also releasing 45-55% of bound 45Ca2+. With low (Ca2+)o, ionomycin pretreatment abolished both the (Ca2+)i increase and 45Ca2+ release stimulated by AII. However, after ionomycin pretreatment in normal medium, AII produced a La3+-inhibitable increase of (Ca2+)i (103 +/- 13 nM) with a t 1/2 of 89 +/- 8 s, but no 45Ca2+ release. No pretreatment condition altered AII-induced formation of (3H)Ins(1,4,5)P3. We conclude that AII increased (Ca2+)i via rapid and transient Ca2+ mobilization from Ins(1,4,5)P3- and ionomycin-sensitive stores, accompanied (and/or followed) by Ca2+ entry through a La3+-inhibitable divalent cation pathway. Furthermore, the ability of AII to activate Ca2+ entry in the absence of Ca2+ mobilization (i.e. after ionomycin pretreatment) suggests a receptor-linked stimulus other than Ca2+ mobilization initiates Ca2+ entry.

  9. On the nature and origin of the calcium asymmetry arising during gravitropic response in etiolated pea epicotyls

    Science.gov (United States)

    Migliaccio, F.; Galston, A. W.

    1987-01-01

    Seven day old etiolated pea epicotyls were loaded symmetrically with 3H-indole 3-acetic acid (IAA) or 45Ca2+, then subjected to 1.5 hours of 1g gravistimulation. Epidermal peels taken from top and bottom surfaces after 90 minutes showed an increase in IAA on the lower side and of Ca2+ on the upper side. Inhibitors of IAA movement (TIBA, 9-hydroxyfluorene carboxylic acid) block the development of both IAA and Ca2+ asymmetries, but substances known to interfere with normal Ca2+ transport (nitrendipine, nisoldipine, Bay K 8644, A 23187) do not significantly alter either IAA or Ca2+ asymmetries. These substances, however, are active in modifying both Ca2+ uptake and efflux through oat and pea leaf protoplast membranes. We conclude that the 45Ca2+ fed to pea epicotyls occurs largely in the cell wall, and that auxin movement is primary and Ca2+ movement secondary in gravitropism. We hypothesize that apoplastic Ca2+ changes during graviresponse because it is displaced by H+ secreted through auxin-induced proton release. This proposed mechanism is supported by localized pH experiments, in which filter paper soaked in various buffers was applied to one side of a carborundum-abraded epicotyls. Buffer at pH 3 increases calcium loss from the side to which it is applied, whereas pH 7 buffer decreases it. Moreover, 10 micromolar IAA and 1 micromolar fusicoccin, which promote H+ efflux, increase Ca2+ release from pea epicotyl segments, whereas cycloheximide, which inhibits H+ efflux, has the reverse effect. We suggest that Ca2+ does not redistribute actively during gravitropism: the asymmetry arises because of its release from the wall adjacent to the region of high IAA concentration, proton secretion, and growth. Thus, the asymmetric distribution of Ca2+ appears to be a consequence of growth stimulation, not a critical step in the early phase of the graviresponse.

  10. Estrone-1-sulphate (E1S) has impact on the kinetics parameters of transporter mediated taurine and glutamate influx in Caco-2 cells

    DEFF Research Database (Denmark)

    Steffansen, Bente; El-Sayed, F

    membrane transporters. The aim was therefore to investigate if addition of E1S to the growth medium of Caco-2 cells before but not during the influx study, change the kinetic parameters of transporter-mediated influx of taurine and glutamate by respective TAUT and EAAT transporters. The results show that 4...... days pretreatment with E1S change the concentration dependent influx curves and Km for transporter mediated taurine and Km and Jmax for glutamate influx although the effects on Km and Jmax are not significant....

  11. Hypoxic remodelling of Ca{sup 2+} stores does not alter human cardiac myofibroblast invasion

    Energy Technology Data Exchange (ETDEWEB)

    Riches, K.; Hettiarachchi, N.T.; Porter, K.E. [Leeds Institute for Genetics, Health and Therapeutics, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT (United Kingdom); Peers, C., E-mail: c.s.peers@leeds.ac.uk [Leeds Institute for Genetics, Health and Therapeutics, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2010-12-17

    Research highlights: {yields} Bradykinin promotes migration and proliferation of myofibroblasts. {yields} Such activity is Ca{sup 2+}-dependent and occurs under hypoxic conditions. {yields} Hypoxia increased myofibroblast Ca{sup 2+} stores but not influx evoked by bradykinin. {yields} Myofibroblast migration and proliferation was unaffected by hypoxia. -- Abstract: Cardiac fibroblasts are the most abundant cell type in the heart, and play a key role in the maintenance and repair of the myocardium following damage such as myocardial infarction by transforming into a cardiac myofibroblast (CMF) phenotype. Repair occurs through controlled proliferation and migration, which are Ca{sup 2+} dependent processes, and often requires the cells to operate within a hypoxic environment. Angiotensin converting enzyme (ACE) inhibitors reduce infarct size through the promotion of bradykinin (BK) stability. Although CMF express BK receptors, their activity under the reduced O{sub 2} conditions that occur following infarct are entirely unexplored. Using Fura-2 microfluorimetry on primary human CMF, we found that hypoxia significantly increased the mobilisation of Ca{sup 2+} from intracellular stores in response to BK whilst capacitative Ca{sup 2+} entry (CCE) remained unchanged. The enhanced store mobilisation was due to a striking increase in CMF intracellular Ca{sup 2+}-store content under hypoxic conditions. However, BK-induced CMF migration or proliferation was not affected following hypoxic exposure, suggesting that Ca{sup 2+} influx rather than mobilisation is of primary importance in CMF migration and proliferation.

  12. Modulation of Ca2+ oscillation and melatonin secretion by BKCa channel activity in rat pinealocytes.

    Science.gov (United States)

    Mizutani, Hiroya; Yamamura, Hisao; Muramatsu, Makoto; Hagihara, Yumiko; Suzuki, Yoshiaki; Imaizumi, Yuji

    2016-05-01

    The pineal glands regulate circadian rhythm through the synthesis and secretion of melatonin. The stimulation of nicotinic acetylcholine receptor due to parasympathetic nerve activity causes an increase in intracellular Ca(2+) concentration and eventually downregulates melatonin production. Our previous report shows that rat pinealocytes have spontaneous and nicotine-induced Ca(2+) oscillations that are evoked by membrane depolarization followed by Ca(2+) influx through voltage-dependent Ca(2+) channels (VDCCs). These Ca(2+) oscillations are supposed to contribute to the inhibitory mechanism of melatonin secretion. Here we examined the involvement of large-conductance Ca(2+)-activated K(+) (BKCa) channel conductance on the regulation of Ca(2+) oscillation and melatonin production in rat pinealocytes. Spontaneous Ca(2+) oscillations were markedly enhanced by BKCa channel blockers (1 μM paxilline or 100 nM iberiotoxin). Nicotine (100 μM)-induced Ca(2+) oscillations were also augmented by paxilline. In contrast, spontaneous Ca(2+) oscillations were abolished by BKCa channel opener [3 μM 12,14-dichlorodehydroabietic acid (diCl-DHAA)]. Under whole cell voltage-clamp configurations, depolarization-elicited outward currents were significantly activated by diCl-DHAA and blocked by paxilline. Expression analyses revealed that the α and β3 subunits of BKCa channel were highly expressed in rat pinealocytes. Importantly, the activity of BKCa channels modulated melatonin secretion from whole pineal gland of the rat. Taken together, BKCa channel activation attenuates these Ca(2+) oscillations due to depolarization-synchronized Ca(2+) influx through VDCCs and results in a recovery of reduced melatonin secretion during parasympathetic nerve activity. BKCa channels may play a physiological role for melatonin production via a negative-feedback mechanism. PMID:26791489

  13. Odorant-regulated Ca2+ gradients in rat olfactory neurons

    OpenAIRE

    1993-01-01

    Olfactory neurons respond to odors with a change in conductance that mediates an influx of cations including Ca2+. The concomitant increase in [Cai] has been postulated to play a role in the adaptation to maintained odorant stimulation (Kurahashi, T., and T. Shibuya. 1990. Brain Research. 515:261-268. Kramer, R. H., and S. A. Siegelbaum. 1992. Neuron. 9:897-906. Zufall, F., G. M. Shepherd, and S. Firestein. 1991. Proceedings of the Royal Society of London, B. 246:225-230.) We have imaged the ...

  14. Store-Operated Ca2+ Release-Activated Ca2+ Channels Regulate PAR2-Activated Ca2+ Signaling and Cytokine Production in Airway Epithelial Cells.

    Science.gov (United States)

    Jairaman, Amit; Yamashita, Megumi; Schleimer, Robert P; Prakriya, Murali

    2015-09-01

    The G-protein-coupled protease-activated receptor 2 (PAR2) plays an important role in the pathogenesis of various inflammatory and auto-immune disorders. In airway epithelial cells (AECs), stimulation of PAR2 by allergens and proteases triggers the release of a host of inflammatory mediators to regulate bronchomotor tone and immune cell recruitment. Activation of PAR2 turns on several cell signaling pathways of which the mobilization of cytosolic Ca(2+) is likely a critical but poorly understood event. In this study, we show that Ca(2+) release-activated Ca(2+) (CRAC) channels encoded by stromal interaction molecule 1 and Orai1 are a major route of Ca(2+) entry in primary human AECs and drive the Ca(2+) elevations seen in response to PAR2 activation. Activation of CRAC channels induces the production of several key inflammatory mediators from AECs including thymic stromal lymphopoietin, IL-6, and PGE2, in part through stimulation of gene expression via nuclear factor of activated T cells (NFAT). Furthermore, PAR2 stimulation induces the production of many key inflammatory mediators including PGE2, IL-6, IL-8, and GM-CSF in a CRAC channel-dependent manner. These findings indicate that CRAC channels are the primary mechanism for Ca(2+) influx in AECs and a vital checkpoint for the induction of PAR2-induced proinflammatory cytokines. PMID:26238490

  15. Legalizing File-Sharing: An Idea Whose Time Has Come - Or Gone? Report from the Information Influx Conference 2014

    NARCIS (Netherlands)

    J.P. Quintais

    2014-01-01

    On 2-4 July 2014 Information Influx, the 25th anniversary conference of the Institute for Information Law (IViR) was held in Amsterdam. Integrated in the conference, on Friday, 4 July a panel entitled "Legalizing file-sharing: an idea whose time has come - or gone?" met. The panel’s moderator was Pr

  16. Squamous cell carcinoma arising in mature cystic teratoma of ovary

    Directory of Open Access Journals (Sweden)

    Ranu Patni

    2014-01-01

    Full Text Available Squamous cell carcinoma of the ovary is a rare condition and usually arises in mature cystic teratoma (MCT or dermoid cyst of the ovary. The reported incidence of malignant transformation in MCT is approximately 2%. A case of squamous cell carcinoma arising in a dermoid cyst of the ovary presenting at an early stage is presented here. A 53-year-old postmenopausal lady, presented with the complaint of pain in right lower abdomen since one month and a large complex abdomino-pelvic mass on examination and investigations. Final histopathology was reported as squamous cell carcinoma of left ovary arising from dermoid cyst and a benign dermoid cyst in the right ovary. The patient was assigned to squamous cell carcinoma of the ovary arising in a mature cystic teratoma, surgical stage Ic2. In view of the poor prognosis, adjuvant chemotherapy was started.

  17. Localised fibrous mesothelioma arising in an intralobar pulmonary sequestration.

    OpenAIRE

    Paksoy, N.; Demircan, A.; Altiner, M; Artvinli, M

    1992-01-01

    A localised fibrous mesothelioma arising from an intralobar lung sequestration occurred in a 64 year old Turkish woman. This appears to be the first report of a mesothelioma occurring within a pulmonary sequestration.

  18. Malignant melanoma arising in mature cystic teratoma of the ovary

    OpenAIRE

    Heidi E Godoy; Kesterson, Joshua P.; Kasznica, John M.; Lele, Shashikant

    2011-01-01

    ► Teratomas are composed of elements of all three germ layers, all potentially capable of undergoing malignant transformation. ► A case of malignant melanoma arising in a mature teratoma is presented.

  19. Identities involving Bessel polynomials arising from linear differential equations

    OpenAIRE

    Kim, Taekyun; Kim, Dae San

    2016-01-01

    In this paper, we study linear di?erential equations arising from Bessel polynomials and their applications. From these linear differential equations, we give some new and explicit identities for Bessel polynomials.

  20. Secondary osteosarcoma arising after treatment for childhood hematologic malignancies

    OpenAIRE

    Okada, Atsushi; Hatori, Masahito; Hosaka, Masami; Watanuki, Munenori; Itoi, Eiji

    2009-01-01

    Secondary osteosarcoma arising after the treatment of hematologic malignancies other than Hodgkin's lymphoma is rare. We report two cases of secondary osteosarcoma arising after treatment for childhood hematologic malignancies (non-Hodgkin's lymphoma and lymphoblastic leukemia). A 10-year-old boy, at the age of 3, was diagnosed with non-Hodgkin's lymphoma. He received chemotherapy, radiation, and bone-marrow transplantation and then was in complete remission. At 6 years, he complained of incr...

  1. MYC Amplification in Angiosarcoma Arising from an Arteriovenous Graft Site

    Directory of Open Access Journals (Sweden)

    Kristen M. Paral

    2015-01-01

    Full Text Available Angiosarcoma arising in association with an arteriovenous graft (AVG or fistula is a unique clinicopathologic scenario that appears to be gaining recognition in the literature. Among reported cases, none has described high-level MYC gene amplification, a genetic aberration that is increasingly unifying the various clinicopathologic subdivisions of angiosarcoma. We therefore report the MYC gene status in a case of angiosarcoma arising at an AVG site.

  2. Number theory arising from finite fields analytic and probabilistic theory

    CERN Document Server

    Knopfmacher, John

    2001-01-01

    ""Number Theory Arising from Finite Fields: Analytic and Probabilistic Theory"" offers a discussion of the advances and developments in the field of number theory arising from finite fields. It emphasizes mean-value theorems of multiplicative functions, the theory of additive formulations, and the normal distribution of values from additive functions. The work explores calculations from classical stages to emerging discoveries in alternative abstract prime number theorems.

  3. Multiple Ectopic Hepatocellular Carcinomas Arising in the Abdominal Cavity

    OpenAIRE

    Miyake, Toru; Hoshino, Seiichiro; Yoshida, Yoichiro; AISU, NAOYA; Tanimura, Syu; Hisano, Satoshi; Kuno, Nobuaki; Sohda, Tetsuro; Sakisaka, Shotaro; Yamashita, Yuichi

    2012-01-01

    Ectopic hepatocellular carcinoma (HCC) is a very rare clinical entity that is defined as HCC arising from extrahepatic liver tissue. This report presents a case of ectopic multiple HCC arising in the abdominal cavity. A 42-year-old otherwise healthy male presented with liver dysfunction at a general health checkup. Both HCV antibody and hepatitis B surface antigen were negative. Laboratory examination showed elevations in serum alpha-fetoprotein and PIVKA-II. Ultrasonography and computed tomo...

  4. Effect of pH on contractile state and transsarcolemmal Ca flux in cultured heart cells

    International Nuclear Information System (INIS)

    The mechanism of pH-induced changes in cardiac contractile state was investigated using spontaneously beating cultured chick embryo ventricular cells. Cells were equilibrated in HEPES-buffered medium at pH 7.4 and then exposed to pH 6.0, 7.4 or 8.8 medium. pH-induced changes in Ca uptake were insensitive to 1 μM verapamil but were sensitive to changes in Na gradient. pH 6.0 inhibited and pH 8.8 stimulated Na/sub i/-dependent Ca uptake. Replacement of Na in the efflux medium with choline during 45Ca efflux did not affect the pH-induced changes in Ca efflux, suggesting that pH alters Ca efflux via sarcolemmal Ca-ATPase. Intracellular alkalinization or acidification produced by NH4Cl (20 mM) altered contractile state by +140% or -60%, respectively, but failed to alter significantly the 45Ca influx or efflux rates. The authors conclude that pH-induced alteration in contractile state is due in part to changes in transsarcolemmal Ca movement via Na/Ca exchange as well as sarcolemmal Ca pump activity. pH/sub i/-induced alteration in contractile state is due to changes in Ca movements within the cell and/or in Ca sensitivity of myofibrils

  5. Carbon influx in He and D plasmas in DIII-D

    International Nuclear Information System (INIS)

    Differences in the carbon behavior between He and D plasmas during VH-mode, L-mode and L-mode with excess gas puffing are reported and inferences on the importance of the various carbon sources during these modes of operation are discussed. During a VH-mode phase, VUV and visible charge exchange spectroscopy indicates that for both He and D operation the carbon behavior is very similar. In the edge plasma, carbon build up is quite rapid, and the carbon influx represents a large fraction of the total plasma density increase until the termination of the VH phase. During cold divertor operation induced by puffing the primary fueling gas, D and He discharges show a difference in the carbon behavior. The core carbon density is seen to be approximately constant during a D discharge as it transitions from an attached to a cold divertor. However in a He discharge, the core carbon density disappears soon after the cold divertor transition. Arguments are made that the primary carbon source in the ELM free H-mode period is physical sputtering by ion impact at the divertor strike point. In L-mode, both attached and cold divertor, the primary source is from the divertor region and two possibilities for this source are chemical sputtering or charge neutral sputtering. Existing data supports charge exchange neutrals as dominant

  6. Toll-like receptor 4-mediated lymphocyte influx induces neonatal necrotizing enterocolitis.

    Science.gov (United States)

    Egan, Charlotte E; Sodhi, Chhinder P; Good, Misty; Lin, Joyce; Jia, Hongpeng; Yamaguchi, Yukihiro; Lu, Peng; Ma, Congrong; Branca, Maria F; Weyandt, Samantha; Fulton, William B; Niño, Diego F; Prindle, Thomas; Ozolek, John A; Hackam, David J

    2016-02-01

    The nature and role of the intestinal leukocytes in necrotizing enterocolitis (NEC), a severe disease affecting premature infants, remain unknown. We now show that the intestine in mouse and human NEC is rich in lymphocytes that are required for NEC development, as recombination activating gene 1–deficient (Rag1–/–) mice were protected from NEC and transfer of intestinal lymphocytes from NEC mice into naive mice induced intestinal inflammation. The intestinal expression of the lipopolysaccharide receptor TLR4, which is higher in the premature compared with full-term human and mouse intestine, is required for lymphocyte influx through TLR4-mediated upregulation of CCR9/CCL25 signaling. TLR4 also mediates a STAT3-dependent polarization toward increased proinflammatory CD3+CD4+IL-17+ and reduced tolerogenic Foxp3+ Treg lymphocytes (Tregs). Th17 lymphocytes were required for NEC development, as inhibition of STAT3 or IL-17 receptor signaling attenuated NEC in mice, while IL-17 release impaired enterocyte tight junctions, increased enterocyte apoptosis, and reduced enterocyte proliferation, leading to NEC. Importantly, TLR4-dependent Th17 polarization could be reversed by the enteral administration of retinoic acid, which induced Tregs and decreased NEC severity. These findings identify an important role for proinflammatory lymphocytes in NEC development via intestinal epithelial TLR4 that could be reversed through dietary modification. PMID:26690704

  7. Modeling the Global micrometeor influx into the Mesosphere/Lower Thermosphere using radar measurements

    Science.gov (United States)

    Janches, D.; Heinselman, C.; Chandran, A.; Chau, J. L.

    We discuss initial results from an effort to model the annual and global micrometeor influx into the Mesosphere Lower Thermosphere MLT atmospheric region based on very precise meteor head-echo radar observations The principal goal of this effort is to construct a new and more precise sporadic meteoric input function needed for the subsequent modeling of the atmospheric chemistry of the meteoric material and the origin and formation of metal layers in the MLT Modeling this function requires precise knowledge of the meteor directionality velocity distributions mass flux and diurnal and or annual variability of the sporadic micrometeoroid environment The model is constructed based on meteor radar observations obtained with the 430 MHz dual-beam Arecibo AO radar in Puerto Rico and the 50 MHz Jicamarca JRO radar in Peru We also compare the modeled fluxes with observations from the 1 29 GHz Sondrestrom radar in Greenland thus utilizing almost the entire NSF ISR chain The model uses Monte Carlo simulation techniques and at present assumes that most of the detected particles originate from three radiant distributions The most dominant meteor source has a radiant distribution concentrated around the Earth s apex The other two sources are centered 80 degrees in ecliptic longitude to each side of the Apex and are commonly known as Helion and Anti-Helion Each source is introduced with its characteristic particle geocentric velocity distribution To reproduce the measurements the Apex source flux was set to three times as many particles as the

  8. A Semi-Annual Study of the Micrometeor Influx in the Mesopause

    Science.gov (United States)

    Janches, D.; Nolan, M. C.; Mathews, J. D.; Meisel, D. D.

    2003-12-01

    We present and discuss results from the first six months of a year-long observation campaign of the micrometeor influx in the upper atmosphere using the dual-beam 430 MHz Arecibo Observatory radar. The AO radar detects decelerating particles in the size range 0.5-100 microns for which precise altitude; instantaneous Doppler velocity (rms errors of the order of 10-100 m/sec) and (constant) deceleration are obtained. This provides a tool for the study of a mass-region of the interplanetary dust distribution and its influence to the mesopause that was previously inaccessible to ground-based instruments and helps bridge the gap between spacecraft dust measurements and traditional meteor radar capabilities. The meteor rate detected inside the 305 m-diameter radar beam peaks at sunrise ( ˜40 events per minute) when the radar points near the apex. We find the meteor flux rate as well as the geocentric velocity distribution to be strongly dependent on the topocentric declination implying a function with radiant ecliptic latitude. In addition, we present estimations of the total micrometeor mass flux derived from these observations, resulting in ˜2000 tons of meteoric material deposited over the whole earth each year in the 80-120 km altitude region. Preliminary results also show that the mass flux peaks in June (i.e. a function of ecliptic longitude) in agreement with diurnal measurements of metallic densities derived from lidar observations.

  9. Lysophosphatidylethanolamine increases intracellular Ca(2+) through LPA(1) in PC-12 neuronal cells.

    Science.gov (United States)

    Lee, Jung-Min; Park, Soo-Jin; Im, Dong-Soon

    2015-05-29

    G protein-coupled receptors (GPCRs) have been implicated in lysophosphatidylethanolamine (LPE)-induced increases in intracellular Ca(2+) ([Ca(2+)]i), but in different cell types, this response may be dependent or independent of lysophosphatidic acid (LPA) GPCR. The effects of LPEs from Grifola frondosa on the neuronal differentiation and apoptosis of PC-12 neuronal cells have been previously reported. In the present study, the authors sought to identify the mechanism responsible for the effects of LPEs in PC-12 neuronal cells. LPE increase [Ca(2+)]i concentration-dependently in PC-12 neuronal cells, but this LPE-induced [Ca(2+)]i increase was less than that elicited by LPA. Studies using specific inhibitors showed that LPE-induced Ca(2+) response was mediated via pertussis toxin-sensitive Gi/o proteins, edelfosine-sensitive phospholipase C, and 2-APB-sensitive IP3 receptor and by Ca(2+) influx across the cell membrane, and that this did not involve the conversion of LPE to LPA. Furthermore, LPE- and LPA-induced responses were found to show homologous and heterologous desensitization in PC-12 cells. VPC32183 and Ki16425 (antagonists of LPA1 and LPA3) inhibited LPE-induced [Ca(2+)]i increases. Furthermore, AM-095 (a specific inhibitor of LPA1) inhibited LPE-induced Ca(2+) response completely in PC-12 cells. These findings indicate LPE increases [Ca(2+)]i via a LPA1/Gi/o proteins/phospholipase C/IP3/Ca(2+) rise/Ca(2+) influx pathway in PC-12 neuronal cells. PMID:25888792

  10. Effect of 1,25(OH)2 vitamin D3 and ionized Ca2+ on 45Ca uptake by primary cultures of aortic myocytes of spontaneously hypertensive and Wistar Kyoto normotensive rats

    International Nuclear Information System (INIS)

    The effect of several regulators of whole animal Ca2+ homeostasis on 45Ca uptake by primary cultures of aortic myocytes isolated from spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats was examined. Exposure of confluent cells to 1.0, 1.25 or 1.50 mM ionized Ca2+ in serum-free medium for seven days resulted in increased 45Ca uptake at the higher concentrations of Ca2+ in cells of the SHR but not the WKY. 1,25 (OH)2 vitamin D3 (1 ng/ml) for 7 days caused enhanced influx in cells from both the SHR and WKY while parathyroid hormone (1-34) (1 ng/ml) was without effect. The data indicate that humoral factors that serve to regulate whole animal Ca2+ homeostasis may also play a role in the regulation of Ca2+ metabolism of the vascular smooth muscle cell

  11. Up-Regulation of Pressure-activated Ca2+-permeable Cation Channel in Intact Vascular Endothelium of Hypertensive Rats

    Science.gov (United States)

    Hoyer, J.; Kohler, R.; Haase, W.; Distler, A.

    1996-10-01

    In endothelial cells, stretch-activated cation channels have been proposed to act as mechanosensors for changes in hemodynamic forces. We have identified a novel mechanosensitive pressure-activated channel in intact endothelium from rat aorta and mesenteric artery. The 18-pS cation channel responded with a multifold increase in channel activity when positive pressure was applied to the luminal cell surface with the patch pipette and inactivated at negative pipette pressure. Channel permeability ratio for K+, Na+, and Ca2+ ions was 1:0.98:0.23. Ca2+ influx through the channel was sufficient to activate a neighboring Ca2+-dependent K+ channel. Hemodynamic forces are chronically disturbed in arterial hypertension. Endothelial cell dysfunction has been implicated in the pathogenesis of arterial hypertension. In two comparative studies, density of the pressure-activated channel was found to be significantly higher in spontaneously hypertensive rats and renovascular hypertensive rats compared with their respective normotensive controls. Channel activity presumably leads to mechanosensitive Ca2+ influx and induces cell hyperpolarization by K+ channel activity. Both Ca2+ influx and hyperpolarization are known to induce a vasodilatory endothelial response by stimulating endothelial nitric oxide (NO) production. Up-regulation of channel density in hypertension could, therefore, represent a counterregulatory mechanism of vascular endothelium.

  12. An increase in the Ca2+ permeability of the plasma membrane caused by the radiation-induced thymocyte apopthosis

    International Nuclear Information System (INIS)

    Parameters of the Ca2+-permeability (the 45Ca influx rate in the presence of orthovanadate blocking the Ca2+-APThase, and the initial rate of the 45Ca uptake) and the DNA fragmentation were determined in rat thymocytes after γ-irradiation-induced (with a dose of 5 Gy) apopthosis. It is shown that modification of the membrane Ca2+ permeability in the irradiated thymocytes precedes a stage of initiation of the DNA degradation. A decrease of disturbance of the membrane passive permeability increases as the thymocyte apopthosis progresses. The obtained data suggest that disturbance of the passive Ca2+ permeability and the intracellular Ca2+ homeostasis are responsible for the apopthosis of lethally irradiated thymocytes. 28 refs., 3 figs

  13. Early postischemic 45Ca accumulation in rat dentate hilus

    International Nuclear Information System (INIS)

    Several studies have found postischemic regional accumulation of calcium to be time-dependent and coincident with the progression of ischemic cell change. In the most vulnerable cells in the hippocampus one would therefore expect to find a primary and specific early uptake of calcium after ischemia. Autoradiograms of 45Ca and 3H-inulin distribution were investigated before and 1 h after 20 min ischemia in the rat hippocampus. Two different methodological approaches were used for administration of 45Ca: (a) administration via microdialysis probes, (b) intraventricular injection. During control conditions the 45Ca autoradiograms showed variations in distribution volume in accordance with 3H-inulin determination of extracellular space size. One hour after ischemia a massive accumulation of 45Ca was found in the dentate hilus. No change in the distribution pattern of 3H-inulin could be demonstrated 1 h after ischemia. We suggest that 45Ca accumulation in dentate hilus 1 h after ischemia is a result of increased Ca2+ uptake before irreversible cell damage occurs and is not due to passive influx of calcium across a leaky plasma membrane

  14. Triclocarban-induced change in intracellular Ca²⁺ level in rat thymocytes: cytometric analysis with Fluo-3 under Zn²⁺-free conditions.

    Science.gov (United States)

    Miura, Yukari; Chen, Xiaohui; Yamada, Saki; Sugihara, Aya; Enkhjargal, Molomjamts; Sun, Yuanzhi; Kuroda, Keiko; Satoh, Masaya; Oyama, Yasuo

    2014-03-01

    Triclocarban (TCC) is an antimicrobial used in personal hygiene products. Recent health concerns arose after TCC was detected in the blood of human subjects who showered with soap containing TCC. In this study, the effect of TCC on intracellular Ca(2+) concentration in rat thymocytes was examined using Fluo-3, an indicator of intracellular Ca(2+). TCC at concentrations ranging from 0.1 μM to 3 μM increased intracellular Ca(2+) concentration biphasically: first by releasing Ca(2+) from intracellular Ca(2+) stores and then inducing Ca(2+) influx through store-operated Ca(2+) channels. The threshold TCC concentration to increase intracellular Ca(2+) concentration in this study was lower than the maximum TCC concentrations reported in human blood samples. Therefore, we anticipate that TCC at concentrations reported in human blood samples might disturb intracellular Ca(2+) signaling in human lymphocytes. PMID:24562054

  15. Mechanisms of pyrethroid insecticide-induced stimulation of calcium influx in neocortical neurons

    Science.gov (United States)

    Pyrethroid insecticides bind to voltage-gated sodium channels (VGSCs) and modify their gating kinetics, thereby disrupting neuronal function. Pyrethroids have also been reported to alter the function of other channel types, including activation of voltage-gated Ca2+ calcium chann...

  16. Automated Kick Control Procedure for an Influx in Managed Pressure Drilling Operations

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    2016-01-01

    Full Text Available Within drilling of oil and gas wells, the Managed Pressure Drilling (MPD method with active control of wellbore pressure during drilling has partly evolved from conventional well control procedures. However, for MPD operations the instrumentation is typically more extensive compared to conventional drilling. Despite this, any influx of formation fluids (commonly known as a kick during MPD operations is typically handled by conventional well control methods, at least if the kick is estimated to be larger than a threshold value. Conventional well control procedures rely on manual control of the blow out preventer, pumps, and choke valves and do not capitalize on the benefits from the instrumentation level associated with MPD. This paper investigates two alternative well control procedures specially adapted to backpressure MPD: the dynamic shut-in (DSI procedure and the automatic kick control (AKC procedure. Both methods capitalize on improvements in Pressure While Drilling (PWD technology. A commercially available PWD tool buffers high-resolution pressure measurements, which can be used in an automated well control procedure. By using backpressure MPD, the choke valve opening is tuned automatically using a feedback-feedforward control method. The two procedures are evaluated using a high fidelity well flow model and cases from a North Sea drilling operation are simulated. The results show that using AKC procedure reduces the time needed to establish control of the well compared to DSI procedure. It also indicates that the AKC procedure reduces the total kick size compared to the DSI procedure, and thereby reduces the risk of lost circulation.

  17. Diagnostic Reference Level Arising from Dental Panoramic Radiography

    International Nuclear Information System (INIS)

    The present work describes a study in which, based on patient dose measurements, thermoluminescent dosimeters were used to obtain the diagnostic reference level arising from panoramic radiography. Ten panoramic units and a sample of 15 patients per X-ray unit were studied. Two thermoluminescent dosimeter chips were placed on the skin surface of selected organs. Mean value of two ESDs was taken as the measured representation dose at the point of interest. Mean ESD on parotid glands derived from panoramic radiography was equal to 369.2 μGy. Individual patients' dose value varied from 180.1 to 470.3 μGy. Third quartile of mean absorbed dose distribution arising from a particular examination has been adopted as diagnostic reference level. Based on this definition, local diagnostic reference level arising from panoramic radiography of the greater Khorasan province is equal to 400 μG.

  18. Four Different Tumors Arising in a Nevus Sebaceous

    Science.gov (United States)

    Namiki, Takeshi; Miura, Keiko; Ueno, Makiko; Arima, Yumi; Nishizawa, Aya; Yokozeki, Hiroo

    2016-01-01

    Nevus sebaceous is known by its association with one or more secondary tumors, but more than three multiple tumors arising from a nevus sebaceous is extremely rare. A 67-year-old female presented with a light brown plaque on the back of her head that contained a dome-shaped black node and an erosive lesion. Histopathological examination showed atypical basaloid cells in the black node. At the periphery of that node, structures resembling follicular germs extruded from interlacing cords in the upper portion and tumor nests with sebocytes were in the lower portion. In the erosive lesion, papillated structures with an apocrine epithelium were observed. In the light brown plaque, enlargement of sebaceous lobules was noted. From those histopathological features, a diagnosis of syringocystadenoma papilliferum, sebaceoma, trichoblastoma and basal cell carcinoma arising from a nevus sebaceous was made. We discuss the rarity of multiple tumors arising from a nevus sebaceous. PMID:27194974

  19. Four Different Tumors Arising in a Nevus Sebaceous

    Directory of Open Access Journals (Sweden)

    Takeshi Namiki

    2016-04-01

    Full Text Available Nevus sebaceous is known by its association with one or more secondary tumors, but more than three multiple tumors arising from a nevus sebaceous is extremely rare. A 67-year-old female presented with a light brown plaque on the back of her head that contained a dome-shaped black node and an erosive lesion. Histopathological examination showed atypical basaloid cells in the black node. At the periphery of that node, structures resembling follicular germs extruded from interlacing cords in the upper portion and tumor nests with sebocytes were in the lower portion. In the erosive lesion, papillated structures with an apocrine epithelium were observed. In the light brown plaque, enlargement of sebaceous lobules was noted. From those histopathological features, a diagnosis of syringocystadenoma papilliferum, sebaceoma, trichoblastoma and basal cell carcinoma arising from a nevus sebaceous was made. We discuss the rarity of multiple tumors arising from a nevus sebaceous.

  20. Four Different Tumors Arising in a Nevus Sebaceous.

    Science.gov (United States)

    Namiki, Takeshi; Miura, Keiko; Ueno, Makiko; Arima, Yumi; Nishizawa, Aya; Yokozeki, Hiroo

    2016-01-01

    Nevus sebaceous is known by its association with one or more secondary tumors, but more than three multiple tumors arising from a nevus sebaceous is extremely rare. A 67-year-old female presented with a light brown plaque on the back of her head that contained a dome-shaped black node and an erosive lesion. Histopathological examination showed atypical basaloid cells in the black node. At the periphery of that node, structures resembling follicular germs extruded from interlacing cords in the upper portion and tumor nests with sebocytes were in the lower portion. In the erosive lesion, papillated structures with an apocrine epithelium were observed. In the light brown plaque, enlargement of sebaceous lobules was noted. From those histopathological features, a diagnosis of syringocystadenoma papilliferum, sebaceoma, trichoblastoma and basal cell carcinoma arising from a nevus sebaceous was made. We discuss the rarity of multiple tumors arising from a nevus sebaceous. PMID:27194974

  1. Laparoscopic resection of a retroperitoneal hemangioma arising from ovarian vessels.

    Science.gov (United States)

    Choi, Youn Seok; Oh, Hoon Kyu

    2009-01-01

    Hemangiomas are known to be common benign tumors. However, hemangiomas of female genital organs are very rare. Furthermore, a retroperitoneal hemangioma arising from ovarian vessels has never been reported. Here we report a case of a 29-year-old woman with a retroperitoneal cavernous hemangioma arising from the ovarian vessels of infundibulopelvic ligament, which was treated with laparoscopic resection. The operating time was 30 minutes, and resection was carried out with minimal blood loss. The postoperative period was uneventful, and the patient was discharged on postoperative day 3. Laparoscopic resection of this type of hemangioma is feasible. PMID:19896610

  2. Papillary Carcinoma Arising from the Pyramidal Lobe of the Thyroid

    International Nuclear Information System (INIS)

    The authors present a rare case of papillary carcinoma arising from the pyramidal lobe of the thyroid in a 54-year-old woman, who presented with a right submental palpable mass. An ultrasound evaluation depicted a 3 cm mixed echoic mass from the thyroid cartilage level without a focal lesion in the thyroid gland. Surgical specimens obtained during bilateral thyroidectomy confirmed papillary carcinoma of the pyramidal lobe. To the authors' knowledge, this is the first case report to describe papillary carcinoma arising from the pyramidal lobe of the thyroid gland

  3. Gastrointestinal Stromal Tumor Arising From a Gastric Duplication Cyst.

    Science.gov (United States)

    Fernandez, Diego Cabrera; Machicado, Jorge; Davogustto, Giovanni

    2016-04-01

    Gastric duplication cysts (GDC) are rarely diagnosed in adults, but previous cases have been associated with malignancy. We present a case of gastrointestinal stromal tumor (GIST) arising from a GDC in a 71-year-old woman who presented with 3 years of early satiety, anorexia, abdominal distention, and weight loss. Abdominal CT showed a 9.3 x 5.2 x 9.5-cm well-circumscribed cystic mass arising 3 cm above the gastroduodenal junction. The cyst was resected, and histopathology was consistent with GDC. Future studies are needed to clarify the malignant potential of GDC and the molecular pathways for its development. PMID:27144196

  4. 17ß-Estradiol and progesterone inhibit l-type Ca2+ current of rat aorta smooth muscle cells

    OpenAIRE

    E. Cairrão; J. Carvas; A.J. Santos-Silva; Alvarez, E.; Verde, I.

    2006-01-01

    Sex hormones like 17ß-estradiol (ßES) and progesterone have shown rapid non-genomic vasodilator effects, which could be involved in the protection of cardiovascular system. However, the precise mechanism by which this effect occurs has not been elucidated yet, even if Ca2+ influx inhibition seems to be implicated. The aim of this study was to study the influence of ßES and progesterone on the L-type Ca2+ current measured by whole cell voltage-clamp in A7r5 cells. Voltage-operated Ca2+ current...

  5. 17 Beta-Estradiol and progesterone inhibit L-type Ca2+ current of rat aorta smooth muscle cells

    OpenAIRE

    Verde, Ignacio; Cairrão, Elisa; J. Carvas; Santos-Silva, António José; Alvarez, Ezequiel

    2010-01-01

    Sex hormones like 17ß-estradiol (ßES) and progesterone have shown rapid non-genomic vasodilator effects, which could be involved in the protection of cardiovascular system. However, the precise mechanism by which this effect occurs has not been elucidated yet, even if Ca2+ influx inhibition seems to be implicated. The aim of this study was to study the influence of ßES and progesterone on the L-type Ca2+ current measured by whole cell voltage-clamp in A7r5 cells. Voltage-operated Ca2+ current...

  6. N-cadherin modulates voltage activated calcium influx via RhoA, p120-catenin, and myosinactin interaction

    OpenAIRE

    Marrs, Glen S.; Theisen, Christopher S.; Brusés, Juan L.

    2008-01-01

    N-cadherin is a transmembrane adhesion receptor that contributes to neuronal development and synapse formation through homophilic interactions that provide structural-adhesive support to contacts between cell membranes. In addition, N-cadherin homotypic binding may initiate cell signaling that regulates neuronal physiology. In this study, we investigated signaling capabilities of N-cadherin that control voltage activated calcium influx. Using whole-cell voltage clamp recording of isolated inw...

  7. A real-time, non-invasive, micro-optrode technique for detecting seed viability by using oxygen influx

    OpenAIRE

    Xin, Xia; Wan, Yinglang; Wang, Wenjun; Yin, Guangkun; McLamore, Eric S.; Lu, Xinxiong

    2013-01-01

    Quantifying seed viability is required for seed bank maintenance. The classical methods for detecting seed viability are time consuming and frequently cause seed damage and unwanted germination. We have established a novel micro-optrode technique (MOT) to measure seed viability in a quick and non-invasive manner by measuring the oxygen influxes of intact seeds, approximately 10 seconds to screen one seed. Here, we used soybean, wheat, and oilseed rape as models to test our method. After 3-hou...

  8. Electron temperature, ion density and energy influx measurements in a tubular plasma reactor for powder surface modification

    International Nuclear Information System (INIS)

    The tubular plasma reactor was designed for the continuous surface modification of fine powders in non-equilibrium RF discharges. So far, little has been known about the plasma characteristics of this inductively coupled reactor system. Therefore, moderate pressure argon-oxygen discharges, commonly used for powder processing, are investigated with tailor-made probe techniques. The influence of plasma power, system pressure, gas composition and mean gas velocity on the axial profiles of plasma parameters was studied. Electron temperature and positive ion density profiles were measured with a Langmuir double probe and the energy influx due to the plasma was determined by a new type of calorimetric probe. The limits for the E-H-mode transition are provided and photographs of the discharge are presented to illustrate the relationship between process parameters and plasma characteristics. Both, ion density and energy influx increased with rising plasma power. The axial energy influx profiles were in addition strongly influenced by the mean gas velocity. Based on these profiles the maximum transient particle temperature was calculated as a function of the particle diameter. Particle temperatures in the order of 100 °C were estimated, whereas the thermal load of the substrates rises with increasing plasma power, residence time and pressure.

  9. Orthophosphate influx and efflux rates of Chlorella fusca measured in a continuous turbidostat culture with 32P under various conditions

    International Nuclear Information System (INIS)

    The main objective of the experiments with Chlorella fusca strain 211-8b was to measure the unidirectional influx rates of phosphate into non-phosphate-starved algae under different steady-state conditions (light, temperature, 3-phosphoglycerate influence) or following the addition of several photosynthesis and phosphate transport inhibitors. For a continuous steady-state culture grown in the light (250C) the unidirectional influx rate measured with 32P is 260 times higher than the net uptake rate calculated from the mass balance using the data of this culture. In all experiments except the controls, the specific activity of the intracellular inorganic orthophosphate compartment oscillates around a constant mean value which never reaches the specific activity of the nutrient medium within the duration of the short-term experiments. The inhibitors strongly affect the characteristics of the oscillations. The unidirectional influx rates are constant. Oscillating flushing rates with unlabelled phosphate from a storage compartment have been postulated to explain the oscillations. Oscillating rates from the individual cells are apparently synchronized by an unknown mechanism. (orig./MG)

  10. Inhibition of Calcium Influx Reduces Dysfunction and Apoptosis in Lipotoxic Pancreatic β-Cells via Regulation of Endoplasmic Reticulum Stress.

    Directory of Open Access Journals (Sweden)

    Yuren Zhou

    Full Text Available Lipotoxicity plays an important role in pancreatic β-cell failure during the development of type 2 diabetes. Prolonged exposure of β-cells to elevated free fatty acids level could cause deterioration of β-cell function and induce cell apoptosis. Therefore, inhibition of fatty acids-induced β-cell dysfunction and apoptosis might provide benefit for the therapy of type 2 diabetes. The present study examined whether regulation of fatty acids-triggered calcium influx could protect pancreatic β-cells from lipotoxicity. Two small molecule compounds, L-type calcium channel blocker nifedipine and potassium channel activator diazoxide were used to inhibit palmitic acid-induced calcium influx. And whether the compounds could reduce palmitic acid-induced β-cell failure and the underlying mechanism were also investigated. It was found that both nifedipine and diazoxide protected MIN6 pancreatic β-cells and primary cultured murine islets from palmitic acid-induced apoptosis. Meanwhile, the impaired insulin secretion was also recovered to varying degrees by these two compounds. Our results verified that nifedipine and diazoxide could reduce palmitic acid-induced endoplasmic reticulum stress to generate protective effects on pancreatic β-cells. More importantly, it suggested that regulation of calcium influx by small molecule compounds might provide benefits for the prevention and therapy of type 2 diabetes.

  11. Fast adaptation and Ca2+-sensitivity of the mechanotransducer require myosin-XVa in inner but not outer cochlear hair cells

    OpenAIRE

    Stepanyan, Ruben; Frolenkov, Gregory I.

    2009-01-01

    In inner ear hair cells, activation of mechotransduction channels is followed by extremely rapid deactivation that depends on the influx of Ca2+ through these channels. Although the molecular mechanisms of this “fast” adaptation are largely unknown, the predominant models assume Ca2+ sensitivity as an intrinsic property of yet unidentified mechanotransduction channels. Here we examined mechanotransduction in the hair cells of young postnatal shaker 2 mice (Myo15sh2/sh2). These mice have no fu...

  12. Ablation of triadin causes loss of cardiac Ca2+ release units, impaired excitation-contraction coupling, and cardiac arrhythmias.

    Science.gov (United States)

    Chopra, Nagesh; Yang, Tao; Asghari, Parisa; Moore, Edwin D; Huke, Sabine; Akin, Brandy; Cattolica, Robert A; Perez, Claudio F; Hlaing, Thinn; Knollmann-Ritschel, Barbara E C; Jones, Larry R; Pessah, Isaac N; Allen, Paul D; Franzini-Armstrong, Clara; Knollmann, Björn C

    2009-05-01

    Heart muscle excitation-contraction (E-C) coupling is governed by Ca(2+) release units (CRUs) whereby Ca(2+) influx via L-type Ca(2+) channels (Cav1.2) triggers Ca(2+) release from juxtaposed Ca(2+) release channels (RyR2) located in junctional sarcoplasmic reticulum (jSR). Although studies suggest that the jSR protein triadin anchors cardiac calsequestrin (Casq2) to RyR2, its contribution to E-C coupling remains unclear. Here, we identify the role of triadin using mice with ablation of the Trdn gene (Trdn(-/-)). The structure and protein composition of the cardiac CRU is significantly altered in Trdn(-/-) hearts. jSR proteins (RyR2, Casq2, junctin, and junctophilin 1 and 2) are significantly reduced in Trdn(-/-) hearts, whereas Cav1.2 and SERCA2a remain unchanged. Electron microscopy shows fragmentation and an overall 50% reduction in the contacts between jSR and T-tubules. Immunolabeling experiments show reduced colocalization of Cav1.2 with RyR2 and substantial Casq2 labeling outside of the jSR in Trdn(-/-) myocytes. CRU function is impaired in Trdn(-/-) myocytes, with reduced SR Ca(2+) release and impaired negative feedback of SR Ca(2+) release on Cav1.2 Ca(2+) currents (I(Ca)). Uninhibited Ca(2+) influx via I(Ca) likely contributes to Ca(2+) overload and results in spontaneous SR Ca(2+) releases upon beta-adrenergic receptor stimulation with isoproterenol in Trdn(-/-) myocytes, and ventricular arrhythmias in Trdn(-/-) mice. We conclude that triadin is critically important for maintaining the structural and functional integrity of the cardiac CRU; triadin loss and the resulting alterations in CRU structure and protein composition impairs E-C coupling and renders hearts susceptible to ventricular arrhythmias. PMID:19383796

  13. Ecknomic benefits arising from the Canadian nuclear industry

    International Nuclear Information System (INIS)

    This document is a collection of surveys of the Canadian nuclear industry, with forecasts covering a number of possible scenarios. Topics covered include uranium mining and processing; economic benefits arising from the design, manufacture and construction of CANDU generating stations; employment and economic activity in the Canadian nqclear industry; and an overview of the remainder of the industry

  14. Synovial sarcoma arising in association with a popliteal cyst

    International Nuclear Information System (INIS)

    Synovial sarcoma is a relatively common soft tissue sarcoma particularly in the adolescent and young adult. We report an unusual case of a synovial sarcoma arising within a popliteal cyst in a 13-year-old female presenting with bilateral popliteal cysts. MR imaging demonstrated the cyst with evidence of subacute haemorrhage and a discrete nodule of tumour. (orig.)

  15. Synovial sarcoma arising in association with a popliteal cyst

    Energy Technology Data Exchange (ETDEWEB)

    Ayoub, K.S.; Grimer, R.J. [Royal Orthopaedic Hospital, Birmingham (United Kingdom). Dept. of Orthopaedic Oncology; Davies, A.M. [MRI Centre, Royal Orthopaedic Hospital, Birmingham (United Kingdom); Mangham, D.C. [Dept. of Pathology, Royal Orthopaedic Hospital, Birmingham (United Kingdom); Twiston Davies, C.W. [Jersey General Hospital (United Kingdom). Dept. of Orthopaedic Surgery

    2000-12-01

    Synovial sarcoma is a relatively common soft tissue sarcoma particularly in the adolescent and young adult. We report an unusual case of a synovial sarcoma arising within a popliteal cyst in a 13-year-old female presenting with bilateral popliteal cysts. MR imaging demonstrated the cyst with evidence of subacute haemorrhage and a discrete nodule of tumour. (orig.)

  16. Squamous cell carcinoma arising in a mature cystic teratoma

    Directory of Open Access Journals (Sweden)

    Gupta Vishwanath

    2009-04-01

    Full Text Available Two cases of squamous cell carcinoma (SCC arising in a mature cystic teratoma (MCT are being discussed for their rarity and pattern of infiltration of tumor cells in the stroma (alpha mode, beta mode and gamma mode, which is a key factor in deciding the prognosis and patient survival.

  17. Dioxins: diagnostic and prognostic challenges arising from complex mechanisms

    DEFF Research Database (Denmark)

    Rysavy, Noel M.; Maaetoft-Udsen, Kristina; Turner, Helen

    2013-01-01

    Dioxins are ubiquitous environmental challenges to humans, with a pervasiveness that arises from 200?years of rapid industrialization and mechanization of Western societies and which is now extending into the developing world. In spite of their penetrance of the human biota, these compounds are p...

  18. Transcultural Knowledge and Skills Transfer: Issues Arising from Evaluation Processes

    Science.gov (United States)

    Green, Anita J.; Holloway, David G.

    2007-01-01

    The transfer of knowledge, policy and practice between nations increasingly involves knowledge of the theory and practice of evaluation. This article examines issues arising from the transcultural evaluation of a drug and alcohol misuse knowledge and skills transfer programme for nurses, nurse teachers and medical staff in the narcology service in…

  19. Squamous Cell Carcinoma arising in a Cystic Teratoma

    Directory of Open Access Journals (Sweden)

    Ruchi Khajuria, Madalsa Bargotra,Rubey Bhat, V.K.Dubey

    2000-04-01

    Full Text Available Malignant transformation in a benign cystic teratoma occurs in 1-3% of cases. A rare case of squamouscell carcinoma arising in a benign cystic teratoma ofovary in a 37 year old f~male is reported. The patientpresented with increasing abdominal girth and pain abdomen and was cl inically diagnosed having a largeovarian cyst.

  20. Transitional cell carcinoma arising in a tailgut cyst.

    Science.gov (United States)

    Sheikh, Adnan A; Rotimi, Olorundi; Jacob, Deepa; Hyland, Racheal; Sagar, Peter M

    2015-01-01

    Malignant transformation in tailgut cysts (TGCs) is extremely rare, with no reports of transitional cell carcinoma arising in them in the UK literature. Here, we discuss a case of a patient with a malignant TGC encapsulating the rectum. This case report highlights the pathological and diagnostic considerations and discusses its management. PMID:26217002

  1. Adenocarcinoma arising in a tailgut cyst: a case report.

    Science.gov (United States)

    Rammeh, S; Ben Abdelkrim, S; Khalifa, M H Ben Hadj; Letaief, R; Mokni, M

    2013-12-01

    Tailgut cyst (TGC), also called retrorectal hamartoma, is a rare congenital lesion arising from persistent remnants of the postanal gut. Malignant transformation of TGC is exceedingly uncommon. We report herein the clinicopathologic features and the follow-up of a new case of a TGC with adenocarcinomatous transformation occurring in a 61 year-old woman. PMID:24730339

  2. Transitional cell carcinoma arising in a tailgut cyst

    OpenAIRE

    Sheikh, Adnan A.; Rotimi, Olorundi; Jacob, Deepa; Hyland, Racheal; Sagar, Peter M.

    2015-01-01

    Malignant transformation in tailgut cysts (TGCs) is extremely rare, with no reports of transitional cell carcinoma arising in them in the UK literature. Here, we discuss a case of a patient with a malignant TGC encapsulating the rectum. This case report highlights the pathological and diagnostic considerations and discusses its management.

  3. A 2,4-dichlorophenoxyacetic acid analog screened using a maize coleoptile system potentially inhibits indole-3-acetic acid influx in Arabidopsis thaliana

    OpenAIRE

    Suzuki, Hiromi; Matano, Naoyuki; Nishimura, Takeshi; Koshiba, Tomokazu

    2014-01-01

    Studies using inhibitors of indole-3-acetic acid (IAA) transport, not only for efflux but influx carriers, provide many aspects of auxin physiology in plants. 1-Naphtoxyacetic acid (1-NOA), an analog of the synthetic auxin 1-N-naphtalene acetic acid (NAA), inhibits the IAA influx carrier AUX1. However, 1-NOA also shows auxin activity because of its structural similarity to NAA. In this study, we have identified another candidate inhibitor of the IAA influx carrier. The compound, “7-B3; ethyl ...

  4. Tests of Transport Theory and Reduced Impurity Influx with Highly Radiative Plasmas in TFTR

    Science.gov (United States)

    Hill, K. W.

    1997-11-01

    ,(M. Kotschenreuther, W. Dorland, M. A. Beer, and G. W. Hammett, Phys. Plasmas 2, 2381 (1995)) which has strong marginal-stability behavior, are reasonable; more detailed comparisons are in progress. Use of high-Z radiators did not impair fusion performance, confirming they can be used to reduce the heat flux to the plasma facing components with minimal ion dilution. At input power level s of 30-33 MW, enhanced radiation through krypton and xenon puffing eliminated serious carbon influx (carbon ``blooms") which occurred in comparable plasmas without impurity puffing.

  5. Ca2+-dependent functions in peptidoglycan-stimulated mouse dendritic cells.

    Science.gov (United States)

    Xuan, Nguyen T; Shumilina, Ekaterina; Matzner, Nicole; Zemtsova, Irina M; Biedermann, Tilo; Goetz, Friedrich; Lang, Florian

    2009-01-01

    Peptidoglycans (PGN) from bacterial cell walls may modify the course of an infection with bacterial pathogens. The present study explored the effect of PGN on cytosolic Ca2+ activity, cytokine production and phagocytosis of mouse dendritic cells (DCs), essential cells in the initiation and direction of antigen-specific T cell responses. Exposure of DCs to PGN was followed by a rapid increase in cytosolic Ca2+ activity ([Ca2+]i), which was due to Ca2+ release from intracellular stores and influx of extracellular Ca2+ across the cell membrane. In DCs isolated from Toll-like receptor 2 (TLR2) deficient mice the effect of PGN on [Ca2+]i was dramatically impaired. The PGN-induced increase of [Ca2+]i was dependent on voltage-gated K+ (Kv) channel activity. PGN-induced increase of [Ca2+]i was significantly blunted by margatoxin (MgTx) and perhexiline maleate (PM), inhibitors of Kv1.3 and Kv1.5, respectively. PGN further stimulated the release of tumour necrosis factor alpha (TNFalpha), interleukin-12 (IL-12) and interleukin-10 (IL-10), an effect significantly blunted by PM and the specific blocker of store-operated Ca2+ channels SKF-96365. Moreover, phagocytic capacity was dramatically increased in PGN-stimulated DCs in the presence of either Kv channel inhibitors or SKF-96365. The observations disclose Ca2+ and Kv channel-dependent cytokine production and phagocytosis in PGN-stimulated DCs. PMID:19710531

  6. EGF raises cytosolic Ca2+ in A431 and Swiss 3T3 cells by a dual mechanism

    International Nuclear Information System (INIS)

    The changes in Ca2+ homeostasis and phosphoinositide hydrolysis induced by EGF were studied in human epidermoid carcinoma A431 cells both when attached to a substratum and after detachment and suspension. The cytosolic Ca2+ concentration was measured by the conventional fluorimetric technique, using the specific probe, quin2, as well as by a new microscopic technique in which single cells are investigated after loading with another probe, fura-2. EGF applied in the complete, Ca2+-containing medium caused a rapid rise in the cytosolic 45Ca2+ concentration, that remained elevated for several minutes. In Ca2+-free, EGTA-containing medium, part of this response persisted, as revealed by quin2 results in suspended cells and microscopic results with fura-2. These results, as well as additional microscopic fura-2 results in Swiss 3T3 fibroblasts, demonstrate that the Ca2+ signal elicited by EGF is due to two components: redistribution from an intracellular store and stimulated influx across the plasmalemma. This latter process was not detected in 3T3 cells treated with either PDGF or bombesin. It is therefore suggested that the 45Ca2+ influx effect of EGF is under the control of a separate, as yet unidentified mechanism

  7. Passive transport pathways for Ca2+ and Co2+ in human red blood cells

    DEFF Research Database (Denmark)

    Simonsen, Lars Ole; Harbak, Henrik; Bennekou, Poul

    2011-01-01

    (exposed to iodoacetamide), consistent with the notion that Co(2+) is not transported by the Ca-pump. The transporter is thus neither SH-group nor ATP or phosphorylation dependent. The (57)Co uptake shows several similarities with the (45)Ca uptake in ATP-depleted cells supplemented with tetrathionate...... is inhibited by Co(2+). The (57)Co and (45)Ca uptake are both insensitive to the 1,4-dihydropyridine Ca-channel blocker nifedipine, even at 100µM. The (57)Co uptake is increased at high negative membrane potentials, indicating that the uptake is at least partially electrogenic. The (57)Co influx amounts...... to about half the (45)Ca influx in ATP-depleted cells. It is speculated that the basal Ca(2+) and Co(2+) uptake could be mediated by a common transporter, probably with a channel-like and a carrier-mediated component, and that (57)Co could be useful as a tracer for at least the channel-like Ca(2+) entry...

  8. Alterations of Intracellular Ca2+ Concentration and Ultrastructure in Spruce Apical Bud Cells during Seasonal Transition

    Institute of Scientific and Technical Information of China (English)

    Jian Lingcheng; Sun Delan; Deng Jiangming; Song Yanmei; Paul H. Li

    2004-01-01

    Potassium antimonite was used to localize Ca2+ in the apical bud cells of spruce from July 1999 to May 2000. During the period of active growth (July 14), Calcium precipitates, an indication of Ca2+ localization, were mainly distributed in vacuoles, intercellular spaces and cell walls. Few Ca2+ deposits localized in the cytosol and nucleus, showing a low level of the cytosolic and nuclear Ca2+ concentration in the warm summer. In August, some Ca2+ deposits appeared in the cytosol and nuclei, indicating that Ca2+ influx occurred in the cytosol and nucleus as the day length became shorter. From September to November, high levels of the cytosolic and nuclear Ca2+ remained. During the mid-winter (December and January), the distribution of Ca2+ deposits and the ultrastructures in the cells were altered dramatically. Plasmolysis occurred in many cells due to the protoplasmic dehydration. In addition plasmalemma invagination and nuclear chromatin aggregation also occurred. A large number of Ca2+ deposits appeared in the space between the plasmalemma and the cell wall. And also some Ca2+ deposits were distributed in the plastids. However, few Ca2+ deposits were observed in the cytosol and nuclei. By spring of the next year (May), when plants were de-acclimated and resumed active growth, Ca2+ subcellular localization essentially restored to that observed in July of the last year, i.e., the cells contained low cytosolic and nuclear Ca2+ concentrations; Ca2+ deposits were mainly distributed in the vacuoles, cell walls and intercellular spaces. The relationships between the seasonal changes of intracellular Ca2+ concentration and the development of dormancy/cold acclimation, as well as plasmolysis associated with dormancy and cold hardiness were discussed.

  9. Effect of the ostreolysin A/pleurotolysin B pore-forming complex on intracellular Ca2+ activity in the vascular smooth muscle cell line A10.

    Science.gov (United States)

    Vrecl, Milka; Babnik, Monika; Sepčić, Kristina; Žužek, Monika C; Maček, Peter; Diacci, Uroš; Frangež, Robert

    2015-12-01

    Ostreolysin A/pleurotolysin B (OlyA/PlyB) is a binary pore-forming protein complex that produces a rapid cardiorespiratory arrest. Increased tonus of the coronary vascular wall produced by OlyA/PlyB may lead to ischemia, arrhythmias, the hypoxic injury of cardiomyocytes and cardiotoxicity. We evaluated the effects of OlyA/PlyB in cultured vascular smooth muscle A10 cells. Fluorometric measurements using the Ca(2+) indicator Fluo-4 AM and Fura-2 AM revealed that nanomolar concentrations of OlyA/PlyB increased the intracellular Ca(2+) activity [Ca(2+)]i in A10 cells. This effect was absent in a Ca(2+)-free medium, indicating that OlyA/PlyB-induced [Ca(2+)]i increase was dependent on Ca(2+) influx into cells. The increase in [Ca(2+)]i by OlyA/PlyB was partially prevented by: i) the calcium channel blockers verapamil and La(3+), ii) the inhibitor of the sodium-calcium exchanger (NCX) benzamil, and iii) the iso-osmotic replacement of NaCl by sucrose. The pre-treatment of cells with the Ca(2+)-ATPase inhibitor thapsigargin reduced the [Ca(2+)]i increase evoked by OlyA/PlyB, whereas the plasma membrane depolarization with high K(+) in the medium did not prevent OlyA/PlyB-induced [Ca(2+)]i. In summary, our data could suggest that the OlyA/PlyB-induced increase in [Ca(2+)]i is due to an influx of Ca(2+) through a variety of co-existing plasma membrane Ca(2+)-permeable channels, Ca(2+) entry through non-selective ion permeable pores formed de novo by OlyA/PlyB in the plasma membrane and calcium-induced intracellular Ca(2+) release, altogether leading to disturbed Ca(2+) homeostasis in A10 cells. PMID:26320834

  10. Cellular Pathophysiology of an Adrenal Adenoma-Associated Mutant of the Plasma Membrane Ca(2+)-ATPase ATP2B3.

    Science.gov (United States)

    Tauber, Philipp; Aichinger, B; Christ, C; Stindl, J; Rhayem, Y; Beuschlein, F; Warth, R; Bandulik, S

    2016-06-01

    Adrenal aldosterone-producing adenomas (APAs) are a main cause for primary aldosteronism leading to arterial hypertension. Physiologically, aldosterone production in the adrenal gland is stimulated by angiotensin II and high extracellular potassium. These stimuli lead to a depolarization of the plasma membrane and, as a consequence, an increase of intracellular Ca(2+). Mutations of the plasma membrane Ca(2+)-ATPase ATP2B3 have been found in APAs with a prevalence of 0.6%-3.1%. Here, we investigated the effects of the APA-associated ATP2B3(Leu425_Val426del) mutation in adrenocortical NCI-H295R and human embryonic kidney (HEK-293) cells. Ca(2+) measurements revealed a higher basal Ca(2+) level in cells expressing the mutant ATP2B3. This rise in intracellular Ca(2+) was even more pronounced under conditions with high extracellular Ca(2+) pointing to an increased Ca(2+) influx associated with the mutated protein. Furthermore, cells with the mutant ATP2B3 appeared to have a reduced capacity to export Ca(2+) suggesting a loss of the physiological pump function. Surprisingly, expression of the mutant ATP2B3 caused a Na(+)-dependent inward current that strongly depolarized the plasma membrane and compromised the cytosolic cation composition. In parallel to these findings, mRNA expression of the cytochrome P450, family 11, subfamily B, polypeptide 2 (aldosterone synthase) was substantially increased and aldosterone production was enhanced in cells overexpressing mutant ATP2B3. In summary, the APA-associated ATP2B3(Leu425_Val426del) mutant promotes aldosterone production by at least 2 different mechanisms: 1) a reduced Ca(2+) export due to the loss of the physiological pump function; and 2) an increased Ca(2+) influx due to opening of depolarization-activated Ca(2+) channels as well as a possible Ca(2+) leak through the mutated pump. PMID:27035656

  11. From blue to black: Anthropogenic forcing of carbon and nitrogen influx to mangrove-lined estuaries in the South China Sea.

    Science.gov (United States)

    Lee, S Y

    2016-08-30

    Southeast Asia is the global centre of mangrove development but human activities have dramatically reduced mangrove area in the region. An analysis is made of the shift in carbon and nitrogen influxes into the South China Sea (SCS) resulting from three anthropogenic nutrient sources: domestic sewage discharge, fertilizer use in rice agriculture and environmental loss from mariculture, between 1997 and 2010. Anthropogenic C and N influxes were, respectively, 1.81× and 1.43× those in 1997, with coastal aquaculture contributing most to the increase. In contrast, fringing mangroves provided ~44% of the C but only ~3% of the N from anthropogenic sources in 2010. In 1997, influx from mangroves was 113% and 6% of anthropogenic influx for C and N, respectively. This dominance by relatively labile anthropogenic nutrients over mangrove sources would change nearshore trophodynamics, with negative implications for the resilience of mangroves and nutrient-intolerant systems such as corals. PMID:26781456

  12. Angiosarcoma Arising in an Ovarian Fibroma: A Case Report

    Directory of Open Access Journals (Sweden)

    Eduardo Cambruzzi

    2010-01-01

    Full Text Available Primary ovarian angiosarcoma is a very rare gynaecological sarcoma, with poor prognosis. These tumors are though to arise from carcinosarcomas, teratomas, or the ovarian vasculature and occur at any age. There are only a few cases reported in the international literature, most commonly associated to surface epithelial-stromal or germ cell tumours. Herein, the authors report the clinicopathologic features of an angiosarcoma arising in an ovarian fibroma. A 65-year-old patient was admitted with a palpable mass in the hypogastrium. Grossly, the removed ovary was completely replaced by a solid tumor mass. On histological analysis, the lesion revealed the typical histological features of angiosarcoma with sinusoidal patterns and anaplastic cells, admixed with spindle-shaped cells arranged in fascicles or in a storiform pattern, compatible with a fibroma. The vascular component was strongly immunopositive for CD31 and CD34. The patient was submitted to chemotherapy, and she was alive for two months after surgical proceedings.

  13. Angiosarcoma arising in an ovarian fibroma: a case report.

    Science.gov (United States)

    Cambruzzi, Eduardo; Pegas, Karla Lais; Milani, Daniel Marini; Cruz, Ricardo Pedrini; Guerra, Enilde Heloena; Ferrari, Márcio Balbinotti

    2010-01-01

    Primary ovarian angiosarcoma is a very rare gynaecological sarcoma, with poor prognosis. These tumors are though to arise from carcinosarcomas, teratomas, or the ovarian vasculature and occur at any age. There are only a few cases reported in the international literature, most commonly associated to surface epithelial-stromal or germ cell tumours. Herein, the authors report the clinicopathologic features of an angiosarcoma arising in an ovarian fibroma. A 65-year-old patient was admitted with a palpable mass in the hypogastrium. Grossly, the removed ovary was completely replaced by a solid tumor mass. On histological analysis, the lesion revealed the typical histological features of angiosarcoma with sinusoidal patterns and anaplastic cells, admixed with spindle-shaped cells arranged in fascicles or in a storiform pattern, compatible with a fibroma. The vascular component was strongly immunopositive for CD31 and CD34. The patient was submitted to chemotherapy, and she was alive for two months after surgical proceedings. PMID:21151524

  14. Invasive breast carcinoma arising in microglandular adenosis: two case reports.

    Science.gov (United States)

    Choi, Jung Eun; Bae, Young Kyung

    2013-12-01

    Microglandular adenosis (MGA) is a rare benign disease that shows an infiltrative growth pattern of small glands, and it may progress to include atypia and carcinoma. Here we report two cases of breast carcinoma arising in MGA. Case 1 was a 44-year-old woman with a previous history of ductal carcinoma in situ in her right breast. During a follow-up, a 1.8 cm mass-like lesion was found in her left breast. An excisional biopsy suggested that the lesion was breast carcinoma. Case 2 was a 57-year-old woman with a 2.9 cm mass in her right breast. A core needle biopsy of the lesion suggested invasive carcinoma. Both patients underwent modified radical mastectomy with sentinel lymph node biopsy. Both tumors lacked a myoepithelial cell layer and stained positively for S-100, lysozyme, and α1-antitrypsin, which is typical of MGA. Both cases showed invasive carcinoma arising in MGA. PMID:24454466

  15. [A solitary neurofibroma arising from the temporal fossa].

    Science.gov (United States)

    Tian, Xiaoyan; Luo, Gui; Zhu, Xinhua

    2014-07-01

    Neurofibromas are benign nerve sheath tumors that arise from the nonmyelinating Schwann cells. Generally, neurofibromas can be categorized into dermal and plexiform subtypes. The former subtype is usually associated with a lone peripheral nerve in the integumentary system, while plexiform tumors are associated with many nerve bundles and can originate internally. Rarely, the plexiform tumors can undergo malignant transformation. Neurofibromas are usually found in individuals with neurofibromatosis, which is an autosomal dominant disease. On occasion, an isolated neurofibroma can transpire without being associated with neurofibromatosis. Mostly, these solitary tumors tend to occur in the gastrointestinal system, and neurofibromas of the head and neck are not uncommon, but very rarely they have been reported to occur in the temporal fossa. In this report, we describe a case of a solitary neurofibroma arising from the temporal fossa. PMID:25248275

  16. Acute Lymphoblastic Leukemia Arising in CALR Mutated Essential Thrombocythemia

    Directory of Open Access Journals (Sweden)

    Stephen E. Langabeer

    2016-01-01

    Full Text Available The development of acute lymphoblastic leukemia in an existing myeloproliferative neoplasm is rare with historical cases unable to differentiate between concomitant malignancies or leukemic transformation. Molecular studies of coexisting JAK2 V617F-positive myeloproliferative neoplasms and mature B cell malignancies indicate distinct disease entities arising in myeloid and lymphoid committed hematopoietic progenitor cells, respectively. Mutations of CALR in essential thrombocythemia appear to be associated with a distinct phenotype and a lower risk of thrombosis yet their impact on disease progression is less well defined. The as yet undescribed scenario of pro-B cell acute lymphoblastic leukemia arising in CALR mutated essential thrombocythemia is presented. Intensive treatment for the leukemia allowed for expansion of the original CALR mutated clone. Whether CALR mutations in myeloproliferative neoplasms predispose to the acquisition of additional malignancies, particularly lymphoproliferative disorders, is not yet known.

  17. Basal Cell Carcinoma Arising in a Tattooed Eyebrow

    OpenAIRE

    Lee, Jong-Sun; Park, Jin; Kim, Seong-min; Yun, Seok-Kweon; Kim, Han-Uk

    2009-01-01

    Malignant skin tumors, including squamous cell carcinoma and malignant melanoma, have occurred in tattoos. Seven documented cases of basal cell carcinoma associated with tattoos have also been reported in the medical literature. We encountered a patient with basal cell carcinoma in a tattooed eyebrow. We report on this case as the eighth reported case of a patient with basal cell carcinoma arising in a tattooed area.

  18. Carcinosarcoma arising in a dermoid cyst of the ovary.

    OpenAIRE

    Arora, D S; Haldane, S

    1996-01-01

    A case of carcinosarcoma arising within an otherwise benign cystic teratoma is reported. The patient, a 78 year old nulliparous woman, presented with right sided abdominal pain of short duration and subsequently underwent a bilateral salphingo-oophorectomy. Slicing of the left ovary revealed a unilocular cyst containing hair admixed with soft yellow material with a thin wall apart from a solid area at one pole. Extensive areas of necrosis and cystic degeneration were present within this mass....

  19. Serous adenocarcinoma of the sigmoid mesentery arising in cystic endosalpingiosis

    OpenAIRE

    McCoubrey, A.; Houghton, O; McCallion, K; McCluggage, W G

    2005-01-01

    This case report describes a Mullerian serous adenocarcinoma arising within a multoloculated cyst lined by ciliated serous-type epithelium located in the sigmoid mesentery. Twenty years previously the patient underwent a hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. The ovaries contained bilateral serous cystadenofibromas, and multiple cysts lined by ciliated serous-type epithelium were present in the omentum. The resection specimen 20 years later contained a 14 cm multilocu...

  20. Sebaceous Carcinoma Arising in Mature Cystic Teratoma of Ovary

    OpenAIRE

    An, Hyo Jeong; Jung, Yong Han; Yoon, Hye Kyoung; Jung, Soo Jin

    2013-01-01

    Roughly 1% of mature cystic teratomas undergo malignant transformation. In particular, cutaneous-type adnexal neoplasms may occur in mature cystic teratomas. Sebaceous carcinomas, which arise from mature cystic teratomas, have rarely been observed, with only seven cases previously reported. Here, we present a case of a 69-year-old female who had pelvic pain for two weeks and who subsequently underwent bilateral salpingo-oophorectomy and hysterectomy. Her left ovary showed a unilocular cyst, m...

  1. A Case of Endometrioid Adenocarcinoma Arising from Adenomyosis

    OpenAIRE

    Shigeki Taga; Mari Sawada; Aya Nagai; Dan Yamamoto; Ryoji Hayase

    2014-01-01

    Malignant changes in endometriosis are often reported, but those in adenomyosis are rare. We report a case of endometrioid adenocarcinoma arising from adenomyosis. Case Presentation. A 57-year-old woman presenting with vaginal bleeding was referred to our hospital. Cytological tests of endometrium revealed atypical glandular cells. Fractional endometrial curettage revealed normal endometrium without atypia. Magnetic resonance imaging (MRI) revealed multiple myomas. The endometrium was slightl...

  2. Some Questions Arising from the Homogeneous Banach Space Problem

    OpenAIRE

    Casazza, Peter G.

    1992-01-01

    We review the current state of the homogeneous Banach space problem. We then formulate several questions which arise naturally from this problem, some of which seem to be fundamental but new. We give many examples defining the bounds on the problem. We end with a simple construction showing that every infinite dimensional Banach space contains a subspace on which weak properties have become stable (under passing to further subspaces). Implications of this construction are considered.

  3. Thyroid gland metastasis arising from breast cancer: A case report

    OpenAIRE

    Yang, Mei; WANG, WEI; ZHANG, CHENFANG

    2013-01-01

    The thyroid gland is an uncommon site for metastasis to develop and thus metastases arising from breast cancer are rarely observed. In the present study, we describe a case of a 45-year-old female with a three-year history of breast cancer who presented with a thyroid mass that was diagnosed as metastatic breast carcinoma by histopathological analysis of the subtotal thyroidectomy specimen. To ascertain the diagnosis of metastatic breast cancer, we evaluated two types of markers; those that p...

  4. Papillary carcinoma arising from a thyroglossal duct cyst

    International Nuclear Information System (INIS)

    This report describes a case of papillary carcinoma arising from a thyroglossal duct cyst (TDC) in a young woman. Imaging showed a heterogeneous cystic lesion at the level of the hyoid, with calcifications and enhancing septae. We compared the USG, CT scan, and MRI findings with those reported previously in literature and we conclude that the presence of a midline cystic lesion with calcification in a young adult should arouse suspicion of papillary carcinoma in a TDC

  5. Acute Lymphoblastic Leukemia Arising in CALR Mutated Essential Thrombocythemia

    OpenAIRE

    Langabeer, Stephen E.; Karl Haslam; David O’Brien; Johanna Kelly; Claire Andrews; Ciara Ryan; Richard Flavin; Hayden, Patrick J.; Bacon, Christopher L.

    2016-01-01

    The development of acute lymphoblastic leukemia in an existing myeloproliferative neoplasm is rare with historical cases unable to differentiate between concomitant malignancies or leukemic transformation. Molecular studies of coexisting JAK2 V617F-positive myeloproliferative neoplasms and mature B cell malignancies indicate distinct disease entities arising in myeloid and lymphoid committed hematopoietic progenitor cells, respectively. Mutations of CALR in essential thrombocythemia appear to...

  6. Nephrogenic adenoma arising from the urinary bladder: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Sun Hee; Lee, Sun Wha; Han, Woon Seup [Ewha Womans Univ. College of Medicine, Seoul (Korea, Republic of)

    2001-03-01

    Nephrogenic adenoma is a benign metaplastic lesion of the urinary tract occurring most frequently at the urinary bladder. It is very rare, especially in children. We describe the US, CT and MRI findings of nephrogenic adenoma arising from the urinary bladder in an 8-year-old girl who suffered rupture of the bladder, urethra and vagina after a traffic accident and whose condition was complicated by urethral stricture and vesicoureteral reflux.

  7. Unusual gestational choriocarcinoma arising in an interstitial pregnancy

    OpenAIRE

    Sawsen Meddeb; Mohamed Salah Rhim; Wissal Zarrouk; Mohamed Bibi; Mohamed Tahar Yacoubi; Hedi Khairi

    2014-01-01

    INTRODUCTION: Choriocarcinoma is a highly malignant trophoblastic neoplasm. Its association with ectopic pregnancy is very rare and usually with aggressive behavior. PRESENTATION OF CASE: We report a new case arising in an interstitial pregnancy occurring in a 46-year-old woman. The patient was admitted for severe pelvic pain and abundant metrorrhagia. One month ago, she had had a laparoscopic resection of an interstitial pregnancy subsequent to failure of chemotherapy by methotrexate. The...

  8. Intercellular ultrafast Ca(2+) wave in vascular smooth muscle cells: numerical and experimental study.

    Science.gov (United States)

    Quijano, J C; Raynaud, F; Nguyen, D; Piacentini, N; Meister, J J

    2016-01-01

    Vascular smooth muscle cells exhibit intercellular Ca(2+) waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca(2+) wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca(2+) wave and it was suggested to be the result of the interplay between membrane potential and Ca(2+) dynamics which depended on influx of extracellular Ca(2+), cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca(2+) wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca(2+) wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca(2+) wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca(2+) waves in smooth muscle cells. PMID:27507785

  9. Intercellular ultrafast Ca2+ wave in vascular smooth muscle cells: numerical and experimental study

    Science.gov (United States)

    Quijano, J. C.; Raynaud, F.; Nguyen, D.; Piacentini, N.; Meister, J. J.

    2016-01-01

    Vascular smooth muscle cells exhibit intercellular Ca2+ waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca2+ wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca2+ wave and it was suggested to be the result of the interplay between membrane potential and Ca2+ dynamics which depended on influx of extracellular Ca2+, cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca2+ wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca2+ wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca2+ wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca2+ waves in smooth muscle cells. PMID:27507785

  10. Cation transport in oxidant-stressed human erythrocytes: heightened N-ethylmaleimide activation of passive K+ influx after mild peroxidation.

    Science.gov (United States)

    Sheerin, H E; Snyder, L M; Fairbanks, G

    1989-07-24

    Normal and chronically dehydrated (hereditary xerocytosis) human red cells were subjected to mild peroxidative treatment (315 microM hydrogen peroxide (H2O2), 15 min) in the presence of azide. The subsequent expression of passive (ouabain-resistant) K+ transport activities was analyzed by measurement of 86Rb+ influx. Peroxidation of normal red cells did not affect basal K+ transport activity, but the increment in K+ influx elicited by 0.5 mM N-ethylmaleimide (NEM) was increased 3-fold. The enhanced K+ influx was chloride-dependent, but only partially inhibited by 0.1 mM furosemide. Stimulated activity declined progressively after NEM activation, but could be restored by a second NEM treatment. Prior conversion of hemoglobin to the carbonmonoxy form abolished the response to peroxide, while 200 microM butylated hydroxytoluene (BHT) exerted only partial inhibition, suggesting that the effect of H2O2 requires interaction of activated, unstable hemoglobin species with the membrane, but that lipid peroxidation is not sufficient. Peroxidation following NEM treatment also enhanced NEM activation, indicating that enhancement does not require altered NEM reactions with stimulatory or inhibitory sites. Passive K+ transport in hereditary xerocytosis red cells was not activated by NEM, with or without H2O2 pretreatment. The results demonstrate that modest peroxidative damage to red cells can heighten the activation of a transport system that is thought to be capable of mediating net K+ efflux and volume reduction in cells that express it. Models are proposed in which the effects of NEM, H2O2, cell swelling and other factors are mediated by conformational changes in a postulated subpopulation of anion channel (Band 3) molecules that bind the K+ transporter. PMID:2758051

  11. Antitumor activity of 7-aminocarboxycoumarin derivatives, a new class of potent inhibitors of lactate influx but not efflux.

    Science.gov (United States)

    Draoui, Nihed; Schicke, Olivier; Seront, Emmanuel; Bouzin, Caroline; Sonveaux, Pierre; Riant, Olivier; Feron, Olivier

    2014-06-01

    High lactate concentration in tumors is associated with bad prognosis. Lactate is released by glycolytic cells in tumors and recaptured by oxidative cancer cells to feed the tricarboxylic acid (TCA) cycle after conversion into pyruvate. Monocarboxylate transporters (MCT) mediate these fluxes of proton-linked lactate and represent attractive targets to interrupt lactate shuttle and to inhibit tumor growth. Here, we investigated the properties of 7-aminocarboxycoumarins (7ACC) developed to selectively interfere with lactate fluxes in the lactate-rich tumor microenvironment. The pharmacologic properties of two compounds of this family, including their effects on lactate influx and efflux and antitumor activity, were investigated using human cancer cell lines and mouse xenograft models. Contrary to the reference MCT1 inhibitor AR-C155858, 7ACC unexpectedly inhibited lactate influx but not efflux in tumor cells expressing MCT1 and MCT4 transporters. 7ACC delayed the growth of cervix SiHa tumors, colorectal HCT116 tumors, and orthoptopic MCF-7 breast tumors. MCT target engagement was confirmed by the lack of activity of 7ACC on bladder UM-UC-3 carcinoma that does not express functional MCT. 7ACC also inhibited SiHa tumor relapse after treatment with cisplatin. Finally, we found that contrary to AR-C155858, 7ACC did not prevent the cell entry of the substrate-mimetic drug 3-bromopyruvate (3BP) through MCT1, and contributed to the inhibition of tumor relapse after 3BP treatment. In conclusion, our results indicate that 7ACC selectively affects a single part of the MCT symporter translocation cycle, leading to strict inhibition of lactate influx. This singular activity is associated with antitumor effects less prone to resistance and side effects. PMID:24672058

  12. Beta-blockers, left and right ventricular function, and in-vivo calcium influx in muscular dystrophy cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Alison Blain

    Full Text Available Beta-blockers are used to treat acquired heart failure in adults, though their role in early muscular dystrophy cardiomyopathy is unclear. We treated 2 different dystrophic mouse models which have an associated cardiomyopathy (mdx: model for Duchenne Muscular Dystrophy, and Sgcd-/-: model for limb girdle muscular dystrophy type 2F and wild type controls (C57 Bl10 with the beta blocker metoprolol or placebo for 8 weeks at an early stage in the development of the cardiomyopathy. Left and right ventricular function was assessed with cardiac magnetic resonance imaging (MRI and in-vivo myocardial calcium influx with manganese enhanced MRI. In the mdx mice at baseline there was reduced stroke volume, cardiac index, and end-diastolic volume with preserved left ventricular ejection fraction. These abnormalities were no longer evident after treatment with beta-blockers. Right ventricular ejection fraction was reduced and right ventricular end-systolic volume increased in the mdx mice. With metoprolol there was an increase in right ventricular end-diastolic and end-systolic volumes. Left and right ventricular function was normal in the Sgcd-/- mice. Metroprolol had no significant effects on left and right ventricular function in these mice, though heart/body weight ratios increased after treatment. In-vivo myocardial calcium influx with MEMRI was significantly elevated in both models, though metoprolol had no significant effects on either. In conclusion, metoprolol treatment at an early stage in the development of cardiomyopathy has deleterious effects on right ventricular function in mdx mice and in both models no effect on increased in-vivo calcium influx. This suggests that clinical trials need to carefully monitor not just left ventricular function but also right ventricular function and other aspects of myocardial metabolism.

  13. CA 19-9 (Cancer Antigen 19-9)

    Science.gov (United States)

    ... as a tumor marker : To help differentiate between cancer of the pancreas and other conditions, such as pancreatitis To monitor ... levels of CA 19-9 are seen in cancer of the exocrine pancreas. This cancer arises in the tissues that produce ...

  14. Influx of Thyroid Hormones into Rat Liver In Vivo: DIFFERENTIAL AVAILABILITY OF THYROXINE AND TRIIODOTHYRONINE BOUND BY PLASMA PROTEINS

    OpenAIRE

    Pardridge, William M.; Mietus, Lawrence J.

    1980-01-01

    The transport of [125I]thyroxine (T4) and [125I]triiodothyronine (T3) into liver was investigated with a tissue sampling-portal vein injection technique in the anesthetized rat. The method allows the investigation of the effects of plasma proteins in human serum on the unidirectional influx of T4 or T3 into liver cells. The percent extraction of unidirectional clearance of T3 and T4 was 77±2% and 43±2%, respectively, after portal injection of a bolus of Ringer's solution. Cell membrane transp...

  15. In vivo quantification of the unidirectional influx constant for Gd-DTPA diffusion across the myocardial capillaries with MR imaging

    DEFF Research Database (Denmark)

    Larsson, H B; Stubgaard, M; Søndergaard, Lise; Henriksen, O

    1994-01-01

    The authors present an in vivo method for measuring the unidirectional influx constant (Ki) for gadolinium diethylenetriaminepentaacetic acid (DTPA) diffusion across the capillary membrane in the human myocardium with magnetic resonance imaging. Ki is related to the extraction fraction (E) and the...... using inversion-recovery Turbo-FLASH (fast low-angle shot) images obtained in real time. The results were comparable to those obtained from studies with positron emission tomography in humans and invasive studies in animals. A method for obtaining the input function noninvasively is also presented...

  16. Polyamines cause plasma membrane depolarization, activate Ca2+-, and modulate H+-ATPase pump activity in pea roots.

    Science.gov (United States)

    Pottosin, Igor; Velarde-Buendía, Ana María; Bose, Jayakumar; Fuglsang, Anja T; Shabala, Sergey

    2014-06-01

    Polyamines regulate a variety of cation and K(+) channels, but their potential effects on cation-transporting ATPases are underexplored. In this work, noninvasive microelectrode ion flux estimation and conventional microelectrode techniques were applied to study the effects of polyamines on Ca(2+) and H(+) transport and membrane potential in pea roots. Externally applied spermine or putrescine (1mM) equally activated eosin yellow (EY)-sensitive Ca(2+) pumping across the root epidermis and caused net H(+) influx or efflux. Proton influx induced by spermine was suppressed by EY, supporting the mechanism in which Ca(2+) pump imports 2 H(+) per each exported Ca(2+). Suppression of the Ca(2+) pump by EY diminished putrescine-induced net H(+) efflux instead of increasing it. Thus, activities of Ca(2+) and H(+) pumps were coupled, likely due to the H(+)-pump inhibition by intracellular Ca(2+). Additionally, spermine but not putrescine caused a direct inhibition of H(+) pumping in isolated plasma membrane vesicles. Spermine, spermidine, and putrescine (1mM) induced membrane depolarization by 70, 50, and 35 mV, respectively. Spermine-induced depolarization was abolished by cation transport blocker Gd(3+), was insensitive to anion channels' blocker niflumate, and was dependent on external Ca(2+). Further analysis showed that uptake of polyamines but not polyamine-induced cationic (K(+)+Ca(2+)+H(+)) fluxes were a main cause of membrane depolarization. Polyamine increase is a common component of plant stress responses. Activation of Ca(2+) efflux by polyamines and contrasting effects of polyamines on net H(+) fluxes and membrane potential can contribute to Ca(2+) signalling and modulate a variety of transport processes across the plasma membrane under stress. PMID:24723394

  17. Temperature and Ca2+-dependence of the sarcoplasmic reticulum Ca2(+)-ATPase in haddock, salmon, rainbow trout and zebra cichlid

    DEFF Research Database (Denmark)

    Godiksen, Helene; Jessen, Flemming

    2002-01-01

    Temperature dependence of Ca2+-ATPase from the sarcoplasmic reticulum (SR) in rabbit muscle has been widely studied, and it is generally accepted that a break point in Arrhenius plot exist at approximately 20 degreesC. Whether the break point arises as a result of temperature dependent changes in...

  18. Evaluation of cellular mechanisms for modulation of calcium transients using a mathematical model of fura-2 Ca2+ imaging in Aplysia sensory neurons.

    Science.gov (United States)

    Blumenfeld, H; Zablow, L; Sabatini, B

    1992-10-01

    A theoretical model of [Ca++]i diffusion, buffering, and extrusion was developed for Aplysia sensory neurons, and integrated with the measured optical transfer function of our fura-2 microscopic recording system, in order to fully simulate fura-2 video or photomultiplier tube measurements of [Ca++]i. This allowed an analysis of the spatial and temporal distortions introduced during each step of fura-2 measurements of [Ca++]i in cells. In addition, the model was used to evaluate the plausibility of several possible mechanisms for modulating [Ca++]i transients evoked by action potentials. The results of the model support prior experimental work (Blumenfeld, Spira, Kandel, and Siegelbaum, 1990. Neuron. 5: 487-499), suggesting that 5-HT and FMRFamide modulate action potential-induced [Ca++]i transients in Aplysia sensory neurons through changes in Ca++ influx, and not through changes in [Ca++]i homeostasis or release from internal stores. PMID:1420931

  19. The CANDU-PHW generating system waste arisings

    International Nuclear Information System (INIS)

    In this report, the volume of material and level of contained radioactive nuclides are tabulated for wastes arising from four fuel cycles which might be operated in CANDU-PHW (CANada Deuterium Uranium - Pressurized Heavy Water) reactors. The data presented, based on Canadian experience and/or studies, cover the range of conditioned waste volumes which could be expected from steady-state (no growth), CANDU-PHW-powered electrical generating systems. The wastes arising from operation and decommissioning of facilities in each phase of each fuel cycle are estimated. Each fuel cycle is considered to operate in isolation with the data given in terms of quantities per gigawatt-year of electricity produced. Three of the fuel cycles for which data are presented, the natural uranium once-through cycle, the plutonium-enriched uranium cycle (plutonium recycle) and the low-burnup uranium-enriched thorium cycle (thorium and uranium recycle), were studied by INFCE WG.7 (the International Nuclear Fuel Cycle Evaluation, Working Group 7) as fuel cycles 4, 5 and 6. The high-burnup uranium-enriched thorium cycle is included for comparison. INFCE WG.7 selected many common reference parameters which are applied uniformly to all seven INFCE WG.7 reference fuel cycles in determining waste arisings. Where these parameters differ from the data of Canadian origin given in the body of this report, the INFCE WG.7 data are given in an appendix. The waste management costs associated with operation of each INFCE WG.7 reference fuel cycle were calculated and compared by the working group. An arbitrary set of costing parameters and disposal technologies was selected by the working group for application to each of the reference fuel cycles. The waste management and disposal costs for the PHW reactor fuel cycles based on these arbitrary cost parameters are given in an appendix. (author)

  20. A functional equation arising from multiplication of quantum integers

    OpenAIRE

    Nathanson, Melvyn B.

    2002-01-01

    For the quantum integer $[n]_q = 1+q+...+q^{n-1}$ there is a natural polynomial multiplication $*_q$ such that $[m]_q *_q [n]_q = [mn]_q$. This multiplication leads to the functional equation $f_{mn}(q) = f_m(q)f_n(q^m),$ defined on a given sequence $\\mathcal(F)=\\{f_n(q)\\}_{n=1}^{\\infty}$ of polynomials. This paper contains various results concerning the classification and construction of polynomial sequences that satisfy the functional equation, as well as a list of open problems that arise ...

  1. Renal cell carcinoma arising in ipsilateral duplex system.

    Science.gov (United States)

    Mohan, Harsh; Kundu, Reetu; Dalal, Usha

    2014-09-01

    Congenital anomalies of the kidney and urinary tract are common and include a wide anatomic spectrum. Duplex systems are one of the more common renal anomalies, with the majority being asymptomatic. Little is known about the molecular pathogenesis of these anomalies; however, certain causative genes have been implicated. The finding of renal cell carcinoma arising in a kidney with the duplication of pelvicalyceal system and ureters, as in the present case, is uncommon. The association between a duplex system and renal cell carcinoma may be more than a coincidence, requiring a deeper insight and further elucidation. PMID:26328175

  2. Radiologic findings of malignant tumors arising from ovarian endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ju; Joo, Hee Jae [Ajou Univ. College of Medicine, Suwon (Korea, Republic of); Kim, Bo Hyun [SungkyunKwan Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-11-01

    To determine the radiologic characteristics of malignant tumors arising from ovarian endometriosis. The radiologic findings of eleven patients with pelvic masses histologically confirmed as malignant ovarian tumors arising from endometriosis were retrospectively reviewed. All patients underwent MR, and six underwent ultrasonography. The findings were evaluated with regard to tumor size and shape, locularity, thickness and enhancement of the wall and septa, the presence of papillary nodule or solid portion, signal intensity of the locule, the presence of mass in contralateral ovary, ascites, local invasion, distant metastases, and the Pathologic diagnosis included clear cell carcinoma in six cases, endometrioid carcinoma in three, and mucinous cystadenocarcinoma of borderline malignancy and endometrial stromal sarcoma in one case each. Tumor size ranged from 8 to 20 (mean, 12.7)cm. The tumors were mixed in four cases, entirely cystic in three, predominantly cystic in three, and predominantly solid in one. Six cases were unilocular and five were multilocular. The wall and septa varied in thickness and regularity and were well enhanced in all but one case. In all cases papillary nodules or solid portions with similar enhancement to uterine myometrium were seen. On T1WI, the signal intensity of fluid was seen to be high in eight cases, low or intermediate in two, and of differing intensity in one. Ten cases showed high signal intensity on T2WI, whereas in one case in which high signal intensity was seen on T1WI, there was low signal intensity(shading). In three cases the contralateral ovary contained an endometrioma. Other features included ascites in seven cases and peritoneal seeding in one. Malignant ovarian tumors arising from endometriosis showed radiologic features of malignancy:they were larger than 10cm, there was enhancement of the wall and septa, and a papillary nodule or solid portion was present. However, the presence of hyperintense fluid, as seen on T1WI

  3. Radiologic findings of malignant tumors arising from ovarian endometriosis

    International Nuclear Information System (INIS)

    To determine the radiologic characteristics of malignant tumors arising from ovarian endometriosis. The radiologic findings of eleven patients with pelvic masses histologically confirmed as malignant ovarian tumors arising from endometriosis were retrospectively reviewed. All patients underwent MR, and six underwent ultrasonography. The findings were evaluated with regard to tumor size and shape, locularity, thickness and enhancement of the wall and septa, the presence of papillary nodule or solid portion, signal intensity of the locule, the presence of mass in contralateral ovary, ascites, local invasion, distant metastases, and the Pathologic diagnosis included clear cell carcinoma in six cases, endometrioid carcinoma in three, and mucinous cystadenocarcinoma of borderline malignancy and endometrial stromal sarcoma in one case each. Tumor size ranged from 8 to 20 (mean, 12.7)cm. The tumors were mixed in four cases, entirely cystic in three, predominantly cystic in three, and predominantly solid in one. Six cases were unilocular and five were multilocular. The wall and septa varied in thickness and regularity and were well enhanced in all but one case. In all cases papillary nodules or solid portions with similar enhancement to uterine myometrium were seen. On T1WI, the signal intensity of fluid was seen to be high in eight cases, low or intermediate in two, and of differing intensity in one. Ten cases showed high signal intensity on T2WI, whereas in one case in which high signal intensity was seen on T1WI, there was low signal intensity(shading). In three cases the contralateral ovary contained an endometrioma. Other features included ascites in seven cases and peritoneal seeding in one. Malignant ovarian tumors arising from endometriosis showed radiologic features of malignancy:they were larger than 10cm, there was enhancement of the wall and septa, and a papillary nodule or solid portion was present. However, the presence of hyperintense fluid, as seen on T1WI

  4. Knowledge Protection and Input Complexity Arising from Open Innovation

    DEFF Research Database (Denmark)

    Peeters, Thijs; Sofka, Wolfgang

    Controlling unique knowledge is of increasing importance to firms. Therefore, firms use knowledge protection mechanisms to prevent competitors from imitating their knowledge. We study the effects of the complexity of knowledge inputs that arises from open innovation on the importance of two widely...... used protection mechanisms: patents and trademarks. We argue that this complexity makes the threat of imitation less predictable, and thus makes knowledge protection more important. By analyzing survey data of 938 German firms, we find that patents are more important for firms in industries with higher...... knowledge input complexity. Furthermore, we show that the dynamics and not the level of knowledge input complexity positively affect the importance of trademarks....

  5. Review of radioactive gaseous and liquid effluent arisings in CAGR

    International Nuclear Information System (INIS)

    The sources of the active nuclides present in gaseous and liquid effluents arising during the normal operation of CAGR power stations are identified. The methods of calculation used to predict the activity of nuclides present in effluents discharged during normal station operation are outlined. The results of calculations based on these methods are compared with operating station measurements to obtain an indication of their accuracy. Reasonable consistency between prediction and measurement is obtained in general, but where appropriate the comparison is used to make corrections to input data and the calculational route. (author)

  6. Dealing with uncertainty arising out of probabilistic risk assessment

    International Nuclear Information System (INIS)

    In addressing the area of safety goal implementation, the question of uncertainty arises. This report suggests that the Nuclear Regulatory Commission (NRC) should examine how other regulatory organizations have addressed the issue. Several examples are given from the chemical industry, and comparisons are made to nuclear power risks. Recommendations are made as to various considerations that the NRC should require in probabilistic risk assessments in order to properly treat uncertainties in the implementation of the safety goal policy. 40 references, 7 figures, 5 tables

  7. On the modular functions arising from the Theta constants

    OpenAIRE

    Ugur S. Kirmaci

    2003-01-01

    Some modular functions arising from the theta constants $ \\vartheta_2(\\tau)$, $ \\vartheta_3(\\tau)$, $ \\vartheta_4(\\tau)$ are investigated. Let $n$ be an odd square-free positive integer as in [4,7]. It is obtained a necessary and sufficient condition that $ \\varphi_{\\delta,\\rho,3}(\\tau)=\\prod_{\\delta|n,\\rho|n}\\Big({\\vartheta_3(\\delta\\tau) \\over\\vartheta_3(\\rho\\tau)}\\Big)^{r_\\delta}$  is invariant with respect to transformations in $ \\theta(n)$. Also, It is deduced that $ \\varphi_{\\delta,\\rho,...

  8. The Mechanism of Safrole-Induced [Ca²⁺]i Rises and Non-Ca²⁺-Triggered Cell Death in SCM1 Human Gastric Cancer Cells.

    Science.gov (United States)

    Hung, Tzu-Yi; Chou, Chiang-Ting; Sun, Te-Kung; Liang, Wei-Zhe; Cheng, Jin-Shiung; Fang, Yi-Chien; Li, Yih-Do; Shieh, Pochuen; Ho, Chin-Man; Kuo, Chun-Chi; Lin, Jia-Rong; Kuo, Daih-Huang; Jan, Chung-Ren

    2015-10-31

    Safrole is a carcinogen found in plants. The effect of safrole on cytosolic free Ca²⁺ concentrations ([Ca²⁺](i)) and viability in SCM1 human gastric cancer cells was explored. The Ca²⁺-sensitive fluorescent dye fura-2 was applied to measure [Ca²⁺](i). Safrole at concentrations of 150-450 μM induced a [Ca²⁺](i) rise in a concentration-dependent manner. The response was reduced by 60% by removing extracellular Ca²⁺. Safrole-evoked Ca²⁺ entry was not altered by nifedipine, econazole, SKF96365, and protein kinase C activator or inhibitor. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) abolished safrole-evoked [Ca²⁺](i) rises. Conversely, treatment with safrole abolished thapsigargin or BHQ-evoked [Ca²⁺](i) rises. Inhibition of phospholipase C (PLC) with U73122 abolished safrole-induced [Ca²⁺](i) rises. At 250-550 μM, safrole decreased cell viability concentration-dependently, which was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxy methyl (BAPTA/AM). Annexin V/propidium iodide staining data suggest that safrole (350-550 μM) induced apoptosis concentration-dependently. These studies suggest that in SCM1 human gastric cancer cells, safrole induced [Ca²⁺](i) rises by inducing PLC-dependent Ca²⁺ release from the endoplasmic reticulum and Ca²⁺ influx via non-store-operated Ca²⁺ entry pathways. Safrole-induced cell death may involve apoptosis. PMID:26387654

  9. Electron-impact excitation and ionization of W3+ for the determination of tungsten influx in a fusion plasma

    Science.gov (United States)

    Ballance, C. P.; Loch, S. D.; Pindzola, M. S.; Griffin, D. C.

    2013-03-01

    Tungsten will be employed as a plasma facing material in the ITER fusion reactor under construction in Cadarache, France; therefore, there is a significant need for accurate electron-impact excitation and ionization data for the ions of tungsten. We report on the results of extensive calculations of ionization and excitation for W3+ that are intended to provide the atomic data needed for the determination of impurity influx diagnostics of tungsten in several existing tokamak reactors. The electron-impact excitation rate coefficients for this study were determined using the relativistic R-matrix method. The contribution to direct electron-impact ionization was determined using the distorted-wave approximation, the accuracy of which was verified by an R-matrix with pseudo states calculation. Contributions to total ionization from excitation autoionization were also generated from the relativistic R-matrix method. These results were then employed to calculate values of ionization per emitted photon, or SXB ratios, for four carefully selected spectral lines; these data will allow the determination of impurity influx from tungsten facing surfaces. For the range of densities of importance in the edge region of a tokamak reactor, these SXB ratios are found to be nearly independent of electron density but vary significantly with electron temperature.

  10. Ca2+ sensitization and Ca2+ entry in the control of blood pressure and adrenergic vasoconstriction in conscious Wistar-Kyoto and spontaneously hypertensive rats

    Czech Academy of Sciences Publication Activity Database

    Behuliak, Michal; Pintérová, Mária; Bencze, Michal; Petrová, M.; Líšková, Silvia; Karen, Petr; Kuneš, Jaroslav; Vaněčková, Ivana; Zicha, Josef

    2013-01-01

    Roč. 31, č. 10 (2013), s. 2025-2035. ISSN 0263-6352 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GA305/09/0336; GA ČR(CZ) GAP304/12/0259 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : Ca2+ influx * nifedipine * RhoA/Rho kinase * fasudil * sympathetic vasoconstriction Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.222, year: 2013

  11. Regulation of store-operated and voltage-operated Ca2+ channels in the proliferation and death of oligodendrocyte precursor cells by golli proteins

    Directory of Open Access Journals (Sweden)

    Pablo M Paez

    2009-04-01

    Full Text Available OPCs (oligodendrocyte precursor cells) express golli proteins which, through regulation of Ca2+ influx, appear to be important in OPC process extension/retraction and migration. The aim of the present study was to examine further the role of golli in regulating OPC development. The effects of golli ablation and overexpression were examined in primary cultures of OPCs prepared from golli-KO (knockout) and JOE (golli J37-overexpressing) mice. In OPCs lacking golli, or overexpressing golli, differentiation induced by growth factor withdrawal was impaired. Proliferation analysis in the presence of PDGF (platelet-derived growth factor), revealed that golli enhanced the mitogen-stimulated proliferation of OPCs through activation of SOCCs (store-operated Ca2+ channels). PDGF treatment induced a biphasic increase in OPC intracellular Ca2+, and golli specifically increased Ca2+ influx during the second SOCC-dependent phase that followed the initial release of Ca2+ from intracellular stores. This store-operated Ca2+ uptake appeared to be essential for cell division, since specific SOCC antagonists completely blocked the effects of PDGF and golli on OPC proliferation. Additionally, in OPCs overexpressing golli, increased cell death was observed after mitogen withdrawal. This phenomenon could be prevented by exposure to VOCC (voltage-operated Ca2+ channel) blockers, indicating that the effect of golli on cell death involved increased Ca2+ influx through VOCCs. The results showed a clear effect of golli on OPC development and support a role for golli in modulating multiple Ca2+-regulatory events through VOCCs and SOCCs. Our results also suggest that PDGF engagement of its receptor resulting in OPC proliferation proceeds through activation of SOCCs.

  12. Poorly Differentiated Squamous Cell Carcinoma Arising in Tattooed Skin

    Directory of Open Access Journals (Sweden)

    Deba P. Sarma

    2010-01-01

    Full Text Available Introduction. Tattoos have increasingly become accepted by mainstream Western society. As a result, the incidence of tattoo-associated dermatoses is on the rise. The presence of a poorly differentiated squamous cell carcinoma in an old tattooed skin is of interest as it has not been previously documented. Case Presentation. A 79-year-old white homeless man of European descent presented to the dermatology clinic with a painless raised nodule on his left forearm arising in a tattooed area. A biopsy of the lesion revealed a poorly differentiated squamous cell carcinoma infiltrating into a tattoo. The lesion was completely excised and the patient remains disease-free one year later. Conclusion. All previous reports of squamous cell carcinomas arising in tattoos have been well-differentiated low-grade type or keratoacanthoma-type and are considered to be coincidental rather than related to any carcinogenic effect of the tattoo pigments. Tattoo-associated poorly differentiated invasive carcinoma appears to be extremely rare.

  13. Sebaceous carcinoma arising in mature cystic teratoma of ovary.

    Science.gov (United States)

    An, Hyo Jeong; Jung, Yong Han; Yoon, Hye Kyoung; Jung, Soo Jin

    2013-08-01

    Roughly 1% of mature cystic teratomas undergo malignant transformation. In particular, cutaneous-type adnexal neoplasms may occur in mature cystic teratomas. Sebaceous carcinomas, which arise from mature cystic teratomas, have rarely been observed, with only seven cases previously reported. Here, we present a case of a 69-year-old female who had pelvic pain for two weeks and who subsequently underwent bilateral salpingo-oophorectomy and hysterectomy. Her left ovary showed a unilocular cyst, measuring 22.0 cm in diameter, filled with sebaceous material and a few hairs. A luminally-protruding solid mass measuring 4.0 cm in diameter was also noted. Microscopic findings revealed lobular or diffusely arranged basophilic, atypical sebaceous cells connected to a typical mature cystic teratoma. Tumor cells demonstrated positive immunoreactivity for high molecular weight cytokeratin, cytokeratin 7, cytokeratin 19, epithelial membrane antigen, and carcinoembryonic antigen. Here, we present a case of sebaceous carcinoma arising from a mature cystic teratoma along with a review of previously published reports. PMID:24009635

  14. Multiple Ectopic Hepatocellular Carcinomas Arising in the Abdominal Cavity

    Directory of Open Access Journals (Sweden)

    Toru Miyake

    2012-09-01

    Full Text Available Ectopic hepatocellular carcinoma (HCC is a very rare clinical entity that is defined as HCC arising from extrahepatic liver tissue. This report presents a case of ectopic multiple HCC arising in the abdominal cavity. A 42-year-old otherwise healthy male presented with liver dysfunction at a general health checkup. Both HCV antibody and hepatitis B surface antigen were negative. Laboratory examination showed elevations in serum alpha-fetoprotein and PIVKA-II. Ultrasonography and computed tomography revealed multiple nodular lesions in the abdominal cavity with ascites without a possible primary tumor. Exploratory laparoscopy was performed, which revealed bloody ascites and multiple brown nodular tumors measuring approximately 10 mm in size that were disseminated on the perineum and mesentery. A postoperative PET-CT scan was performed but it did not reveal any evidence of a tumor in the liver. The tumors resected from the peritoneum were diagnosed as HCC. The present case of HCC was thought to have possibly developed from ectopic liver on the peritoneum or mesentery.

  15. Nipple adenoma arising from axillary accessory breast: a case report

    Directory of Open Access Journals (Sweden)

    Shioi Yoshihiro

    2012-11-01

    Full Text Available Abstract Nipple adenoma is a relatively rare benign breast neoplasm, and cases of the disease arising from the axillary accessory breast have very seldom been reported in the English literature. We report a case of nipple adenoma arising from axillary accessory breast including clinical and pathological findings. An 82-year-old woman presented with the complaint of a small painful mass in the right axilla. Physical examination confirmed a well-defined eczematous crusted mass that was 8 mm in size. The diagnosis of nipple adenoma was made from an excisional specimen on the basis of characteristic histological findings. Microscopic structural features included a compact proliferation of small tubules lined by epithelial and myoepithelial cells, and the merging of glandular epithelial cells of the adenoma into squamous epithelial cells in the superficial epidermal layer. Because clinically nipple adenoma may resemble Paget’s disease and pathologically can be misinterpreted as tubular carcinoma, the correct identification of nipple adenoma is an important factor in the differential diagnosis for axillary tumor neoplasms. Virtual slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1186821489769063

  16. Altered distribution of ICa impairs Ca release at the t-tubules of ventricular myocytes from failing hearts.

    Science.gov (United States)

    Bryant, Simon M; Kong, Cherrie H T; Watson, Judy; Cannell, Mark B; James, Andrew F; Orchard, Clive H

    2015-09-01

    In mammalian cardiac ventricular myocytes, Ca influx and release occur predominantly at t-tubules, ensuring synchronous Ca release throughout the cell. Heart failure is associated with disrupted t-tubule structure, but its effect on t-tubule function is less clear. We therefore investigated Ca influx and release at the t-tubules of ventricular myocytes isolated from rat hearts ~18weeks after coronary artery ligation (CAL) or corresponding Sham operation. L-type Ca current (ICa) was recorded using the whole-cell voltage-clamp technique in intact and detubulated myocytes; Ca release at t-tubules was monitored using confocal microscopy with voltage- and Ca-sensitive fluorophores. CAL was associated with cardiac and cellular hypertrophy, decreased ejection fraction, disruption of t-tubule structure and a smaller, slower Ca transient, but no change in ryanodine receptor distribution, L-type Ca channel expression, or ICa density. In Sham myocytes, ICa was located predominantly at the t-tubules, while in CAL myocytes, it was uniformly distributed between the t-tubule and surface membranes. Inhibition of protein kinase A with H-89 caused a greater decrease of t-tubular ICa in CAL than in Sham myocytes; in the presence of H-89, t-tubular ICa density was smaller in CAL than in Sham myocytes. The smaller t-tubular ICa in CAL myocytes was accompanied by increased latency and heterogeneity of SR Ca release at t-tubules, which could be mimicked by decreasing ICa using nifedipine. These data show that CAL decreases t-tubular ICa via a PKA-independent mechanism, thereby impairing Ca release at t-tubules and contributing to the altered excitation-contraction coupling observed in heart failure. PMID:26103619

  17. Regulation of free Ca2+ by liver mitochondria and endoplasmic reticulum.

    Science.gov (United States)

    Becker, G L; Fiskum, G; Lehninger, A L

    1980-10-10

    Electrode measurements were made of the free Ca2+ concentration maintained by suspensions of isolated rat liver mitochondria and microsomes, as well as by hepatocytes whose plasma membranes had been made permeable by treatment with digitonin. When the KCl, ATP, Mg2+, and phosphate concentrations were made similar to that of cytosol, the steady state free Ca2+ concentration in the presence of respiring mitochondria alone was about 0.5 microM. The additional presence of rat liver microsomes resulted in a steady state level of close to 0.2 microM, which was maintaied for greater than 1 h at 25 degrees C. This concentration of Ca2+ was also maintained by suspensions of hepatocytes permeabilized by digitonin and thus may approximate the actual cytosolic free Ca2+ concentration in vivo. The "set point" for free Ca2+ homeostasis in these systems is determined by mitochondrial Ca2+ influx-efflux cycling, which is dependent on the level of intramitochondrial Ca2+ and can be adjusted by sequestration of Ca2+ in microsomes. PMID:7410406

  18. The Relative Contribution of NMDARs to Excitatory Postsynaptic Currents is Controlled by Ca2+-Induced Inactivation

    Science.gov (United States)

    Valiullina, Fliza; Zakharova, Yulia; Mukhtarov, Marat; Draguhn, Andreas; Burnashev, Nail; Rozov, Andrei

    2016-01-01

    NMDA receptors (NMDARs) are important mediators of excitatory synaptic transmission and plasticity. A hallmark of these channels is their high permeability to Ca2+. At the same time, they are themselves inhibited by the elevation of intracellular Ca2+ concentration. It is unclear however, whether the Ca2+ entry associated with single NMDAR mediated synaptic events is sufficient to self-inhibit their activation. Such auto-regulation would have important effects on the dynamics of synaptic excitation in several central neuronal networks. Therefore, we studied NMDAR-mediated synaptic currents in mouse hippocampal CA1 pyramidal neurons. Postsynaptic responses to subthreshold Schaffer collateral stimulation depended strongly on the absence or presence of intracellular Ca2+ buffers. Loading of pyramidal cells with exogenous Ca2+ buffers increased the amplitude and decay time of NMDAR mediated EPSCs (EPSPs) and prolonged the time window for action potential (AP) generation. Our data indicate that the Ca2+ influx mediated by unitary synaptic events is sufficient to produce detectable self-inhibition of NMDARs even at a physiological Mg2+ concentration. Therefore, the contribution of NMDARs to synaptic excitation is strongly controlled by both previous synaptic activity as well as by the Ca2+ buffer capacity of postsynaptic neurons. PMID:26858606

  19. The Relative Contribution of NMDARs to Excitatory Postsynaptic Currents is Controlled by Ca(2+)-Induced Inactivation.

    Science.gov (United States)

    Valiullina, Fliza; Zakharova, Yulia; Mukhtarov, Marat; Draguhn, Andreas; Burnashev, Nail; Rozov, Andrei

    2016-01-01

    NMDA receptors (NMDARs) are important mediators of excitatory synaptic transmission and plasticity. A hallmark of these channels is their high permeability to Ca(2+). At the same time, they are themselves inhibited by the elevation of intracellular Ca(2+) concentration. It is unclear however, whether the Ca(2+) entry associated with single NMDAR mediated synaptic events is sufficient to self-inhibit their activation. Such auto-regulation would have important effects on the dynamics of synaptic excitation in several central neuronal networks. Therefore, we studied NMDAR-mediated synaptic currents in mouse hippocampal CA1 pyramidal neurons. Postsynaptic responses to subthreshold Schaffer collateral stimulation depended strongly on the absence or presence of intracellular Ca(2+) buffers. Loading of pyramidal cells with exogenous Ca(2+) buffers increased the amplitude and decay time of NMDAR mediated EPSCs (EPSPs) and prolonged the time window for action potential (AP) generation. Our data indicate that the Ca(2+) influx mediated by unitary synaptic events is sufficient to produce detectable self-inhibition of NMDARs even at a physiological Mg(2+) concentration. Therefore, the contribution of NMDARs to synaptic excitation is strongly controlled by both previous synaptic activity as well as by the Ca(2+) buffer capacity of postsynaptic neurons. PMID:26858606

  20. The relative contribution of NMDARs to excitatory postsynaptic currents is controlled by Ca2+-induced inactivation.

    Directory of Open Access Journals (Sweden)

    Fliza eValiullina

    2016-01-01

    Full Text Available NMDA receptors (NMDARs are important mediators of excitatory synaptic transmission and plasticity. A hallmark of these channels is their high permeability to Ca2+. At the same time, they are themselves inhibited by the elevation of intracellular Ca2+ concentration. It is unclear however, whether the Ca2+ entry associated with single NMDAR mediated synaptic events is sufficient to self-inhibit their activation. Such auto-regulation would have important effects on the dynamics of synaptic excitation in several central networks. Therefore, we studied NMDAR-mediated synaptic currents in mouse hippocampal CA1 pyramidal neurons. Postsynaptic responses to subthreshold Schaffer collateral stimulation depended strongly on the absence or presence of intracellular Ca2+ buffers. Loading of pyramidal cells with exogenous Ca2+ buffers increased the amplitude and decay time of NMDAR mediated EPSCs (EPSP and prolonged the time window for action potential generation.Our data indicate that the Ca2+ influx mediated by unitary synaptic events is sufficient to produce detectable self-inhibition of NMDARs even at a physiological Mg2+ concentration. Therefore, the contribution of NMDARs to synaptic excitation is strongly controlled by both previous synaptic activity as well as by the Ca2+ buffer capacity of postsynaptic neurons.

  1. Inhibition of anaphylactic histamine release from heterologously sensitized mast cells: differential effects of drugs which interfere with calcium influx.

    OpenAIRE

    Kurose, Masao

    1981-01-01

    Drug effects were studied on anaphylactic histamine release from rat mast cells sensitized in vitro with mouse IgE antibody. When histamine release was elicited by adding Ca-++ at various times after antigen-stimulation of sensitized cells in Ca++-free medium, the drugs to be tested were added shortly before each Ca++ addition. Quercetin was effective only when added before or immediately after antigen. Theophylline and disodium cromoglycate (DSCG) were active irrespective of the time interva...

  2. sup 86 Rb(K) influx and ( sup 3 H)ouabain binding by human platelets: Evidence for beta-adrenergic stimulation of Na-K ATPase activity

    Energy Technology Data Exchange (ETDEWEB)

    Turaihi, K.; Khokher, M.A.; Barradas, M.A.; Mikhailidis, D.P.; Dandona, P. (Royal Free Hospital and School of Medicine, London (England))

    1989-08-01

    Although active transport of potassium into human platelets has been demonstrated previously, there is hitherto no evidence that human platelets have an ouabain-inhibitable Na-K ATPase in their membrane. The present study demonstrates active rubidium (used as an index of potassium influx), {sup 86}Rb(K), influx into platelets, inhibitable by ouabain, and also demonstrates the presence of specific ({sup 3}H)ouabain binding by the human platelet. This {sup 86}Rb(K) influx was stimulated by adrenaline, isoprenaline, and salbutamol, but noradrenaline caused a mild inhibition. Active {sup 86}Rb(K) influx by platelets was inhibited markedly by timolol, mildly by atenolol, but not by phentolamine. Therefore, active {sup 86}Rb(K) influx in human platelets is enhanced by stimulation of beta adrenoceptors of the beta 2 subtype. The platelet may therefore replace the leukocyte in future studies of Na-K ATPase activity. This would be a considerable advantage in view of the ease and rapidity of preparation of platelets.

  3. Optimal control of switched systems arising in fermentation processes

    CERN Document Server

    Liu, Chongyang

    2014-01-01

    The book presents, in a systematic manner, the optimal controls under different mathematical models in fermentation processes. Variant mathematical models – i.e., those for multistage systems; switched autonomous systems; time-dependent and state-dependent switched systems; multistage time-delay systems and switched time-delay systems – for fed-batch fermentation processes are proposed and the theories and algorithms of their optimal control problems are studied and discussed. By putting forward novel methods and innovative tools, the book provides a state-of-the-art and comprehensive systematic treatment of optimal control problems arising in fermentation processes. It not only develops nonlinear dynamical system, optimal control theory and optimization algorithms, but can also help to increase productivity and provide valuable reference material on commercial fermentation processes.

  4. Carcinosarcoma arising from uterine adenomyosis: A case report.

    Science.gov (United States)

    Kiuchi, Kaori; Hasegawa, Kiyoshi; Kanamori, Anriko; Machida, Hiromi; Kojima, Masaru; Fukasawa, Ichio

    2016-03-01

    Carcinosarcoma arising from uterine adenomyosis is extremely rare. We encountered such a patient and herein provide a review of the literature. A 56-year-old woman was referred for a huge pelvic tumor, suspected to be an advanced uterine leiomyosarcoma. Intraoperative inspection revealed a mass, mainly located in the uterine myometrium, invading the uterine serosa. The tumor had previously spontaneously ruptured and disseminated to the pelvic cavity. Pathological and immunohistochemical examination revealed an infiltrative pattern of biphasic tumor cells composed of endometrioid adenocarcinoma and a nonepithelial component with rhabdomyosarcomatous differentiation. Benign endometrial glands with stromal cells were found adjacent to the area of the carcinosarcoma. The endometrium and both ovaries and fallopian tubes were microscopically free of tumor cells. The final diagnosis was heterologous type carcinosarcoma with rhabdomyosarcomatous differentiation, originating from uterine adenomyosis. PMID:26663238

  5. Irregular activity arises as a natural consequence of synaptic inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Terman, D., E-mail: terman@math.ohio-state.edu [Department of Mathematics, The Ohio State University, Columbus, Ohio 43210 (United States); Rubin, J. E., E-mail: jonrubin@pitt.edu [Department of Mathematics, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Diekman, C. O., E-mail: diekman@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

    2013-12-15

    Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects.

  6. Irregular activity arises as a natural consequence of synaptic inhibition

    Science.gov (United States)

    Terman, D.; Rubin, J. E.; Diekman, C. O.

    2013-12-01

    Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects.

  7. Multiple solutions for inhomogeneous elliptic problems arising in astrophysics

    International Nuclear Information System (INIS)

    By variational and topological methods we prove the existence of a positive interval Λ such that for all λ ε Λ there exists at least three positive solutions of (1.1) on Ω = DR {(x,y) ε R2+: x2 + y2 2}, where f: R → R is a function of type (tσ-tσ+α)χ(0,1)(t) with σ > 1 and α ≤ 1, h is a non negative bounded smooth function. Under some restrictions for f and h we show that Λ is independent of R, for R big enough. This type of problem arises in an astrophysical gravity free model of solar flares given by Heyvaerts et al. (author). 9 refs

  8. Nuclear waste management and problems arising from constitutional law

    International Nuclear Information System (INIS)

    The author discusses the problems arising in the field of nuclear waste management on account of the constitutional law. Especially the difficulties emanating from the conflict between the provisions of section 9a of the Atomic Energy Act and the provisions of constitutional law are dealt with in detail, referring to the monography of H. Hofmann, 'legal aspects of nuclear waste management'. The author comes to the conclusion that the reqquirements laid down in section 9a-9c of the Atomic Energy Act are in agreement with the Basic law. There is, he says, no unreasonable risk for future generations, as the provisions of the nuclear law provide for sufficient safety of sites and equipment selected for the final storage of nuclear waste, ensuring that radioactive leakage is excluded over long periods of time. In the second part of his lecture, the author discusses the problem of competency and delegation of authority with regard to the reprocessing of radioactive waste. (BW)

  9. Criminal prosecution arising from medical mishaps: a Japanese perspective.

    Science.gov (United States)

    Tsukamoto, Yasushi

    2005-12-01

    In Japan, the number of physicians being investigated on suspicion of medical malpractice has increased. Specifically, the criminal prosecutions arising from professional negligence resulting in bodily injury or death have also increased. Article 21 of the Japanese Physician's Act compels a doctor to notify the district police when he diagnoses a death to be 'unnatural'. Originally this provision was to increase public safety through crime detection, but one recent criminal case broadened the application of this article to include the death from a mishap during medical treatment. This criminal case made a tremendous impact on physicians, as the convictions and sentences forced physicians to notify the police even when it is not certain the patient died of the malady or of the medical misconduct itself. Besides, we wonder if such obligation of doctors to notify such 'unnatural' death from medical mishap may be against a person's privilege against self-incrimination which is assured by Japanese Constitutional Law (article 38). PMID:16440862

  10. Anomalous right coronary artery arising from left anterior descending artery

    Directory of Open Access Journals (Sweden)

    M.L. Sreenivas Kumar

    2012-07-01

    Full Text Available A 54-year-old male patient presented with acute myocardial infarction involving left anterior descending and right coronary artery territories. Coronary angiogram showed a single coronary artery with right coronary artery arising from left anterior descending artery (LAD, which coursed anterior to right ventricular outflow tract and thrombotic lesion in mid left anterior descending artery before origin of right coronary artery. The patient was treated with thrombolytic therapy and glycoprotein IIb/IIIa inhibitors. Anomalous origin of right coronary artery as a branch of LAD is a very rare type of congenital coronary artery anomalies. It is important to recognize this anomaly as it can be associated with extensive myocardial ischemia and sudden cardiac death in young persons even without atherosclerosis.

  11. Solitary fibrous tumor arising in an intrathoracic goiter

    DEFF Research Database (Denmark)

    Larsen, Stine Rosenkilde; Godballe, Christian; Krogdahl, Annelise

    2010-01-01

    BACKGROUND: Solitary fibrous tumor (SFT) is a rare spindle cell tumor most often found in the mediastinal pleura. Nineteen cases of SFT arising in the thyroid gland have been reported. We report a case of SFT of the thyroid gland with immunohistochemical and cytogenetic investigation. SUMMARY: A 58....... CONCLUSION: The histological appearance and immunohistochemical reaction pattern of SFT is characteristic. The entity should be considered when dealing with a spindle cell lesion in the thyroid gland. All cases of this site of origin reported have had a benign clinical course. As only a small number of cases......-year-old man had pulmonary symptoms, thought to be asthma. Computed tomographic scan revealed a large goiter with a solid hyperechoic nodule. The results of thyroid function tests were normal. Microscopically, the lesion was composed of fibroblast-like spindle cells in a patternless growth. Cellular...

  12. Extravasation Mucocele Arising from a Lingual Thyroglossal Duct Remnant

    Directory of Open Access Journals (Sweden)

    Mitsuhiko Nakahira

    2015-01-01

    Full Text Available Although a thyroglossal duct cyst is a congenital anomaly, it can also appear in adults. Despite the presence of embryological remnants, it is still unclear why the cyst should suddenly develop later in life. We report a case of a 46-year-old male with an extravasation mucocele arising from a long-standing lingual thyroglossal duct remnant. MRI demonstrated a lingual cystic lesion near the hyoid bone associated with a suprahyoid tract-like structure masquerading as a thyroglossal duct cyst. However, histopathological examination demonstrated a mucocele secondary to a rupture of a thyroglossal duct remnant with numerous intramural heterotopic salivary glands. We propose a new mechanism of an acquired cystic formation of this congenital disease that excessive production of mucus from heterotopic salivary glands and a physical trauma such as swallowing may lead to extravasation of mucus from the thyroglossal duct.

  13. Irregular activity arises as a natural consequence of synaptic inhibition

    International Nuclear Information System (INIS)

    Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects

  14. Unilateral Eye Blinking Arising From the Ictal Ipsilateral Occipital Area.

    Science.gov (United States)

    Falsaperla, Raffaele; Perciavalle, Valentina; Pavone, Piero; Praticò, Andrea Domenico; Elia, Maurizio; Ruggieri, Martino; Caraballo, Roberto; Striano, Pasquale

    2016-07-01

    We report on an 18-month-old boy with unilateral left eye blinking as a single ictal manifestation without facial twitching. The clinical onset of this phenomenon was first recorded (as an occasional event) at age 3 months, and it was overlooked. By age 6 months, the child's blinking increased to almost daily occurrence in clusters: during blinking the infant showed intact awareness and occasional jerks in the upper limbs and right leg. A video-electroencephalography (video-EEG) documented clinical correlation with a focal pattern arising from the left occipital region, and brain magnetic resonance imaging (MRI) revealed severe brain damage, consisting in poroencephalic hollows and increased spaces in the convexities involving a large area of the left cerebral hemisphere. The boy was prescribed sodium valproate (30 mg/kg/d), resulting in drastic reduction of his clinical seizures. Follow-up to his current age documented good general status, with persistent partial right hemilateral seizures. The blinking progressively disappeared, and is no longer recorded. The pathogenic hypotheses of the unilateral ictal blinking include involvement of the ipsilateral cerebral hemisphere and/or the cerebellar pathways. Review of previous reports of unilateral eye blinking, arising from the ictal ipsilateral brain, revealed that different damaged regions may give rise to blinking ictal phenomena, likely via the trigeminal fibres innervating the subdural intracranial structures and the pial vessels in the ipsilateral affected brain. The eye blinking in the present child represents a further example of an ictal phenomenon, which is predictive of the damaged brain region. PMID:25179638

  15. Teale CA. Counties

    Data.gov (United States)

    California Department of Resources — California Spatial Information System (CaSIL) is a project designed to improve access to geo-spatial and geo-spatial related data information throughout the state...

  16. Alteration of alpha 1 Na+,K(+)-ATPase 86Rb+ influx by a single amino acid substitution

    International Nuclear Information System (INIS)

    The sodium- and potassium-dependent adenosine triphosphatase (Na+,K(+)-ATPase) maintains the transmembrane Na+ gradient to which is coupled all active cellular transport systems. The R and S alleles of the gene encoding the Na+,K(+)-ATPase alpha 1 subunit isoform were identified in Dahl salt-resistant (DR) and Dahl salt-sensitive (DS) rats, respectively. Characterization of the S allele-specific Na+,K(+)-ATPase alpha 1 complementary DNA identified a leucine substitution of glutamine at position 276. This mutation alters the hydropathy profile of a region in proximity to T3(Na), the trypsin-sensitive site that is only detected in the presence of Na+. This mutation causes a decrease in the rubidium-86 influx of S allele-specific sodium pumps, thus marking a domain in the Na+,K(+)-ATPase alpha subunit important for K+ transport, and supporting the hypothesis of a putative role of these pumps in hypertension

  17. Leukotriene B4 mediates macrophage influx and pulmonary hypertension in bleomycin-induced chronic neonatal lung injury.

    Science.gov (United States)

    Ee, Mong Tieng; Kantores, Crystal; Ivanovska, Julijana; Wong, Mathew J; Jain, Amish; Jankov, Robert P

    2016-08-01

    Systemically-administered bleomycin causes inflammation, arrested lung growth, and pulmonary hypertension (PHT) in the neonatal rat, similar to human infants with severe bronchopulmonary dysplasia (BPD). Leukotrienes (LTs) are inflammatory lipid mediators produced by multiple cell types in the lung. The major LTs, LTB4 and cysteinyl LTs, are suggested to contribute to BPD, but their specific roles remain largely unexplored in experimental models. We hypothesized that LTs are increased in bleomycin-induced BPD-like injury, and that inhibition of LT production would prevent inflammatory cell influx and thereby ameliorate lung injury. Rat pups were exposed to bleomycin (1 mg·kg(-1)·day(-1) ip) or vehicle (control) from postnatal days 1-14 and were treated with either zileuton (5-lipoxygenase inhibitor), montelukast (cysteinyl LT1 receptor antagonist), or SC57461A (LTA4 hydrolase inhibitor) 10 mg·kg(-1)·day(-1) ip. Bleomycin led to increased lung content of LTB4, but not cysteinyl LTs. Bleomycin-induced increases in tissue neutrophils and macrophages and lung contents of LTB4 and tumor necrosis factor-α were all prevented by treatment with zileuton. Treatment with zileuton or SC57461A also prevented the hemodynamic and structural markers of chronic PHT, including raised pulmonary vascular resistance, increased Fulton index, and arterial wall remodeling. However, neither treatment prevented impaired alveolarization or vascular hypoplasia secondary to bleomycin. Treatment with montelukast had no effect on macrophage influx, PHT, or on abnormal lung structure. We conclude that LTB4 plays a crucial role in lung inflammation and PHT in experimental BPD. Agents targeting LTB4 or LTB4-mediated signaling may have utility in infants at risk of developing BPD-associated PHT. PMID:27317685

  18. Effect of dietary protein level on nitrogen utilization and ruminal influx of endogenous urea nitrogen in growing animals

    International Nuclear Information System (INIS)

    Three experiments were conducted to evaluate the impact of ruminal influx of blood urea nitrogen (BUN) on intestinal protein supply and nitrogen (N) metabolism in growing animals at both excess and growth-limiting protein intake. In Experiment 1, wether lambs were given diets, either high or low in protein, containing 25% cottonseed hulls and 75% corn-soybean meal hourly in 24 equal portions. Single injections of 14C- and 15N-urea, and 15N-ammonium sulfate (AS) were made into the BUN and ruminal ammonia N (RAN) pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. In Experiment 2, beef calves were given HP and LP diets containing 30% cottonseed hulls and 70% corn-soybean meal every 4 h in 6 equal portions. Single injections of 15N-urea and 15N-AS were made into the BUN and RAN pools, respectively, to measure rate of flux through, and transfer of N between these and the bacterial N pool. Abomasal N flow was 24% greater than intake in LP and 29% less than intake in HP. An inverse relationship may exist between level of N intake and rate of influx of BUN into the rumen. In Experiment 3 ruminal fluid samples were obtained. With HP, BUN-derived 15N-ammonia appeared to rapidly equilibrate with RAN in the primary digesta mass. In contrast, with LP, there appeared to be an enrichment gradient for both RAN and bacterial N, declining from the rumen wall toward the center of the digesta mass, suggesting that bacteria at or near the rumen wall may preferentially utilized some BUN-derived ammonia N entering through the rumen wall

  19. Heterogeneous abnormalities of in-vivo left ventricular calcium influx and function in mouse models of muscular dystrophy cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Greally Elizabeth

    2013-01-01

    Full Text Available Abstract Background Manganese-enhanced cardiovascular magnetic resonance (MECMR can non-invasively assess myocardial calcium influx, and calcium levels are known to be elevated in muscular dystrophy cardiomyopathy based on cellular studies. Methods Left ventricular functional studies and MECMR were performed in mdx mice (model of Duchenne Muscular Dystrophy, 24 and 40 weeks and Sgcd−/− mice (Limb Girdle Muscular Dystrophy 2 F, 16 and 32 weeks, compared to wild type controls (C57Bl/10, WT. Results Both models had left ventricular hypertrophy at the later age compared to WT, though the mdx mice had reduced stroke volumes and the Sgcd−/− mice increased heart rate and cardiac index. Especially at the younger ages, MECMR was significantly elevated in both models (both Pmdx mice (PSgcd−/− mice (PSgcd−/− mice had increased heart rates, to determine the role of heart rate in MECMR we studied the hyperpolarization-activated cyclic nucleotide-gated channel inhibitor ZD 7288 which selectively reduces heart rate. This reduced heart rate and MECMR in all mouse groups. However, when looking at the time course of reduction of MECMR in the Sgcd−/− mice at up to 5 minutes of the manganese infusion when heart rates were matched to the WT mice, MECMR was still significantly elevated in the Sgcd−/− mice (P Conclusions Despite both mouse models exhibiting increased in-vivo calcium influx at an early stage in the development of the cardiomyopathy before left ventricular hypertrophy, there are distinct phenotypical differences between the 2 models in terms of heart rates, hemodynamics and responses to calcium channel inhibitors.

  20. Better well control through safe drilling margin identification, influx analysis and direct bottom hole pressure control method for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Veeningen, Daan [National Oilwell Varco IntelliServ (NOV), Houston, TX (United States)

    2012-07-01

    Currently, well control events are almost exclusively detected by using surface measurements. Measuring a volume increase in the 'closed loop' mud circulation system; a standpipe pressure decrease; or changes in a variety of drilling parameters provide indicators of a kick. Especially in deep water, where the riser comprises a substantial section of the well bore, early kick detection is paramount for limiting the severity of a well bore influx and improve the ability to regain well control. While downhole data is presently available from downhole tools nearby the bit, available data rates are sparse as mud pulse telemetry bandwidth is limited and well bore measurements compete with transmission of other subsurface data. Further, data transfer is one-directional, latency is significant and conditions along the string are unknown. High-bandwidth downhole data transmission system, via a wired or networked drill string system, has the unique capability to acquire real-time pressure and temperature measurement at a number of locations along the drill string. This system provides high-resolution downhole data available at very high speed, eliminating latency and restrictions that typically limit the availability of downhole data. The paper describes well control opportunities for deep water operations through the use of downhole data independent from surface measurements. First, the networked drill string provides efficient ways to identify pore pressure, fracture gradient, and true mud weight that comprise the safe drilling margin. Second, the independent measurement capability provides early kick detection and improved ability to analyze an influx even with a heterogeneous mud column through distributed along-string annular pressure measurements. Third, a methodology is proposed for a direct measurement method using downhole real-time pressure for maintaining constant bottom hole pressure during well kills in deep water. (author)

  1. Involvement of both sodium influx and potassium efflux in ciguatoxin-induced nodal swelling of frog myelinated axons.

    Science.gov (United States)

    Mattei, César; Molgó, Jordi; Benoit, Evelyne

    2014-10-01

    Ciguatoxins, mainly produced by benthic dinoflagellate Gambierdiscus species, are responsible for a complex human poisoning known as ciguatera. Previous pharmacological studies revealed that these toxins activate voltage-gated Na+ channels. In frog nodes of Ranvier, ciguatoxins induce spontaneous and repetitive action potentials (APs) and increase axonal volume that may explain alterations of nerve functioning in intoxicated humans. The present study aimed determining the ionic mechanisms involved in Pacific ciguatoxin-1B (P-CTX-1B)-induced membrane hyperexcitability and subsequent volume increase in frog nodes of Ranvier, using electrophysiology and confocal microscopy. The results reveal that P-CTX-1B action is not dependent on external Cl- ions since it was not affected by substituting Cl- by methylsulfate ions. In contrast, substitution of external Na+ by Li+ ions suppressed spontaneous APs and prevented nodal swelling. This suggests that P-CTX-1B-modified Na+ channels are not selective to Li+ ions and/or are blocked by these ions, and that Na+ influx through Na+ channels opened during spontaneous APs is required for axonal swelling. The fact that the K+ channel blocker tetraethylammonium modified, but did not suppress, spontaneous APs and greatly reduced nodal swelling induced by P-CTX-1B indicates that K+ efflux might also be involved. This is supported by the fact that P-CTX-1B, when tested in the presence of both tetraethylammonium and the K+ ionophore valinomycin, produced the characteristic nodal swelling. It is concluded that, during the action of P-CTX-1B, water movements responsible for axonal swelling depend on both Na+ influx and K+ efflux. These results pave the way for further studies regarding ciguatera treatment. PMID:24950451

  2. Boosting of synaptic potentials and spine Ca transients by the peptide toxin SNX-482 requires alpha-1E-encoded voltage-gated Ca channels.

    Directory of Open Access Journals (Sweden)

    Andrew J Giessel

    Full Text Available The majority of glutamatergic synapses formed onto principal neurons of the mammalian central nervous system are associated with dendritic spines. Spines are tiny protuberances that house the proteins that mediate the response of the postsynaptic cell to the presynaptic release of glutamate. Postsynaptic signals are regulated by an ion channel signaling cascade that is active in individual dendritic spines and involves voltage-gated calcium (Ca channels, small conductance (SK-type Ca-activated potassium channels, and NMDA-type glutamate receptors. Pharmacological studies using the toxin SNX-482 indicated that the voltage-gated Ca channels that signal within spines to open SK channels belong to the class Ca(V2.3, which is encoded by the Alpha-1E pore-forming subunit. In order to specifically test this conclusion, we examined the effects of SNX-482 on synaptic signals in acute hippocampal slices from knock-out mice lacking the Alpha-1E gene. We find that in these mice, application of SNX-482 has no effect on glutamate-uncaging evoked synaptic potentials and Ca influx, indicating that that SNX-482 indeed acts via the Alpha-1E-encoded Ca(V2.3 channel.

  3. Variational problems arising in classical mechanics and nonlinear elasticity

    International Nuclear Information System (INIS)

    In this thesis we consider two different classes of variational problems. First, one-dimensional problems arising from classical mechanics where the problem is to determine whether there is a unique function η0(x) which minimises the energy functional of the form I(η) = ∫ab L(x,η(x), η'(x)) dx. We will investigate uniqueness by making a change of dependent and independent variables and showing that for a class of integrands L with a particular kind of scaling invariance the resulting integrand is completely convex. The change of variables arises by applying results from Lie group theory as applied in the study of differential equations and this work is motivated by [60] and [68]. Second, the problem of minimising energy functionals of the form E(u) = ∫A W(∇u(x)) dx in the case of a nonlinear elastic body occupying an annular region A contains R2 with u : A-bar → A-bar. This work is motivated by [57] (in particular the example of paragraph 4). We will consider rotationally symmetric deformations satisfying prescribed boundary conditions. We will show the existence of minimisers for stored energy functions of the form W(F) = g-tilde(vertical bar-F-vertical bar, det(F)) in a class of general rotationally symmetric deformations of a compressible annulus and for stored energy functions of the form W(F) = g-bar(vertical bar-F-vertical bar) in a class of rotationally symmetric deformations of an incompressible annulus. We will also show that in each case the minimisers are solutions of the full equilibrium equations. A model problem will be considered where the energy functional is the Dirichlet integral and it will be shown that the rotationally symmetric solution obtained is a minimiser among admissible non-rotationally symmetric deformations. In the case of an incompressible annulus, we will consider the Dirichlet integral as the energy functional and show that the rotationally symmetric equilibrium solutions in this case are weak local minimisers in a

  4. Risk analysis for renewable energy projects due to constraints arising

    Science.gov (United States)

    Prostean, G.; Vasar, C.; Prostean, O.; Vartosu, A.

    2016-02-01

    Starting from the target of the European Union (EU) to use renewable energy in the area that aims a binding target of 20% renewable energy in final energy consumption by 2020, this article illustrates the identification of risks for implementation of wind energy projects in Romania, which could lead to complex technical implications, social and administrative. In specific projects analyzed in this paper were identified critical bottlenecks in the future wind power supply chain and reasonable time periods that may arise. Renewable energy technologies have to face a number of constraints that delayed scaling-up their production process, their transport process, the equipment reliability, etc. so implementing these types of projects requiring complex specialized team, the coordination of which also involve specific risks. The research team applied an analytical risk approach to identify major risks encountered within a wind farm project developed in Romania in isolated regions with different particularities, configured for different geographical areas (hill and mountain locations in Romania). Identification of major risks was based on the conceptual model set up for the entire project implementation process. Throughout this conceptual model there were identified specific constraints of such process. Integration risks were examined by an empirical study based on the method HAZOP (Hazard and Operability). The discussion describes the analysis of our results implementation context of renewable energy projects in Romania and creates a framework for assessing energy supply to any entity from renewable sources.

  5. Novel ethical dilemmas arising in geriatric clinical practice.

    Science.gov (United States)

    Calleja-Sordo, Elisa Constanza; de Hoyos, Adalberto; Méndez-Jiménez, Jorge; Altamirano-Bustamante, Nelly F; Islas-Andrade, Sergio; Valderrama, Alejandro; García-Peña, Carmen; Altamirano-Bustamante, Myriam M

    2015-05-01

    The purpose of this study is to determine empirically the state of the art of the medical care, when healthcare personal is confronted with ethical dilemmas related with the care they give to the geriatric population. An observational, longitudinal, prospective and qualitative study was conducted by analyzing the correlation between healthcare personnel-patient relationship, and ethical judgments regarding dilemmas that arise in daily clinical practice with geriatric patients. Mexican healthcare personnel with current active practices were asked to write up an ethical dilemma that arose frequently or that had impacted their medical practice. From the narrative input, we were able to draw up a database with 421 dilemmas, and those corresponding to patients 60 years and older were selected (n = 54, 12.8 %). The axiological analysis of the narrative dilemmas of geriatric patients was made using dialectical empiricism. The axiological analysis values found most frequently were classified into three groups: the impact of healthcare, the roles of the physician, and refusal of therapy; the healthcare role of educator, caring for the patients' life and the risk of imminent death where the values found more often. The persistence and universality of certain dilemmas in geriatrics calls for awareness and requires a good training in the ethical discernment of these dilemmas. This would help to improve substantially the care and the life quality of this population. PMID:25185872

  6. Unicentric Castleman's Disease Arising from an Intrapulmonary Lymph Node

    Directory of Open Access Journals (Sweden)

    Hideki Ota

    2013-01-01

    Full Text Available Castleman's disease is an uncommon lymphoproliferative disorder of unknown etiology, most often involving the mediastinum. It has 2 distinct clinical forms: unicentric and multicentric. Unicentric Castleman's disease arising from an intrapulmonary lymph node is rare, and establishing a preoperative diagnosis of this disease is very difficult mainly due to a lack of specific imaging features. We report a case of intrapulmonary unicentric Castleman's disease in an asymptomatic 19-year-old male patient who was accurately diagnosed by preoperative computed tomography (CT. The mass was incidentally found on a routine chest X-ray. A subsequent dynamic CT showed a well-defined, hypervascular, soft-tissue mass with small calcifications located in the perihilar area of the right lower lung. Three-dimensional CT (3D-CT angiography indicated that the mass was receiving its blood supply through a vascular network at its surface that originated from 2 right bronchial arteries. The clinical history and CT findings were consistent with a diagnosis of unicentric Castleman's disease, and we safely and successfully removed the tumor via video-assisted thoracoscopic surgical lobectomy. This case shows that the imaging characteristics of these rare tumors on contrast-enhanced CT combined with 3D-CT angiography can be helpful in reliably establishing a correct preoperative diagnosis.

  7. Primary abdominal wall clear cell carcinoma arising from incisional endometriosis

    Institute of Scientific and Technical Information of China (English)

    Burcu Gundogdu; Isin Ureyen; Gunsu Kimyon; Hakan Turan; Nurettin Boran; Gokhan Tulunay; Dilek Bulbul; Taner Turan; M Faruk Kose

    2013-01-01

    A 49 year-old patient with the complaint of a mass located in the caesarean scar was admitted. There was a fixed mass 30í30 mm in diameter with regular contour located at the right corner of the pfannenstiel incision. Computed tomography revealed a (40í50í50) mm solid mass lesion with margins that cannot be distinguished from the uterus, bladder and small intestines and a heterogeneous mass lesion (50í45í55) mm in diameter, located in the right side of the anterior abdominal wall. Cytoreductive surgery including total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. Final pathology was clear cell carcinoma. Clear cell carcinoma arising from an extraovarian endometriotic focus was diagnosed and the patient received 6 cycles paclitaxel-carboplatin chemotherapy as adjuvant treatment. The patient who was lost to follow-up applied to our clinic 2 years after surgery with a recurrent mass in the left inguinal region. After 3 cycles of chemotherapy, the patient's tumoral mass in the left inguinal region was excised. The result of the pathology was carcinoma metastasis. It is decided that the following treatment of the patient should be palliative radiation therapy. The patient who underwent palliative radiation therapy died of disease after 4 months of the second operation.

  8. Malignant tumors arising in the maxillary region after radiation therapy

    International Nuclear Information System (INIS)

    Although radiotherapy has proven of great therapeutic value in the treatment of malignant tumors, it should also be borne in mind that radiation has a serious potential risk of giving rise to a secondary malignancy. We recently experienced 2 cases each of carcinoma and sarcoma arising in the irradiated areas long after radiation therapy for malignant tumors. In these 4 cases, 2 males and 2 females, the primary neoplastic diseases were squamous cell carcinoma, epidermoid carcinoma, carcinoma of unknown pathology and malignant lymphoma, and the secondary tumors were epidermoid carcinoma, squamous cell carcinoma, osteosarcoma and chondrosarcoma, respectively. The sites of occurrence of these malignancies were invariably in the maxillary region; the mean latent period was 15 years, aside from an infantile case with a latent period of 5 years. In view of the primary diseases being malignant tumors the following criteria were set up for the diagnosis of radiation-induced malignancies: (1) the site of occurrence is within the confines of a previously irradiated area, (2) the latent period is prolonged and (3) the malignancy occurs as a double tumor. Therapy was primarily by operation. The prognosis was exceedingly ominous, the average survival time being 22 months. This was probably and mainly because of rapidity of tumor growth. Thus, the secondary tumors had already spread back to inward by the time they were first discovered. This should be kept in mind during a long-term follow-up of patients receiving radiotherapy for malignancy. (author)

  9. Lyman-$\\alpha$ absorbers arising in galaxy clusters

    CERN Document Server

    Ortiz-Gill, A; Webb, J K; Barcons, X

    1997-01-01

    We present here new GHRS observations of Lyman-alpha absorption lines associated with groups or clusters toward the QSOs 1545+2101 and 0850+4400. In the first case we have identified at least eight distinct Lyman-alpha absorption features, with a mean redshift of = 0.2648 \\pm 0.0002 and a velocity dispersion of 163 \\pm 57 km/s. We have also identified a group or cluster of galaxies in the vicinity of this QSO with a mean redshift of = 0.2643 \\pm 0.0004 and velocity dispersion 223 \\pm 91 km/s . The spectrum of QSO 0850+4400, of poorer quality, reveals two Lyman-alpha absorption features at z=0.0909500 \\pm 0.0000070 (which is just resolved) and z=0.0948215 \\pm 0.0000090, separated by $\\sim 1060 km/s. A group or cluster of galaxies is also present in the vicinity of the QSO line-of-sight with a mean redshift =0.0901 \\pm 0.0007 and velocity dispersion of 530 \\pm 200 km/s. The results of this work establish that Lyman-alpha absorption can occur in denser than average galaxy environments, and that it arises in di...

  10. Treatment of High Level Waste Arising from Pyrochemical Processes

    International Nuclear Information System (INIS)

    The report describes the JSC «SSC RIAR» research experience on management high-level waste (HLW) arising from pyrochemical processes. The laboratory investigations including simulated and real waste forms generated as a result of the experimental reprocessings of spent nuclear fuel (SNF) of fast reactors are summarized. Pyrochemical processes are characterized by a few types and a small volume of the waste, their high specific activity and, practically, absence of the liquid process HLW. The main types of solid process wastes are phosphate and oxide precipitates and spent electrolytes. The investigation included the chemical and radionuclide composition, gas release, chemical durability, thermal stability of the precipitates and spent electrolytes. The results of the analysis suggest that the main waste forms of the pyrochemical processes can be stored for a long time in shielded containers without any chemical conversion and immobilization. To increase the efficiency of the shielded barrier for the purposes of the long-term geological storage, the waste forms of the pyrochemical processes can be transferred into more stable chemical forms. (author)

  11. Giant solitary fibrous tumor arising from greater omentum

    Institute of Scientific and Technical Information of China (English)

    Liang Zong; Ping Chen; Guang-Yao Wang; Qun-Shan Zhu

    2012-01-01

    Extrathoracic solitary fibrous tumors (SFTs) have been described at almost every anatomic location of human body,but reports of SFT in the abdominal cavity are rare.We herein present a rare case of SFT originating from greater omentum.Computed tomography revealed a 15.8 cm x 21.0 cm solid mass located at superior aspect of stomach.Open laparotomy confirmed its mesenchymal origin.Microscopically,its tissue was composed of non-organized and spindle-shaped cells exhibiting atypical nuclei,which were divided up by branching vessel and collagen bundles.Immunohistochemical staining showed that this tumor was negative for CD117,CD99,CD68,cytokeratin,calretinin,desmin,epithelial membrane antigen,F8 and S-100,but positive for CD34,bcl-2,α-smooth muscle actin and vimentin.The patient presented no evidence of recurrence during follow-up.SFT arising from abdominal cavity can be diagnosed by histological findings and immunohistochemical markers,especially for CD34 and bcl-2 positive cases.

  12. Giant lipoma arising from deep lobe of the parotid gland

    Directory of Open Access Journals (Sweden)

    Hsu Ying-Che

    2006-06-01

    Full Text Available Abstract Background Lipomas are common benign soft tissue neoplasms but they are found very rarely in the deep lobe of parotid gland. Surgical intervention in these tumors is challenging because of the proximity of the facial nerve, and thus knowledge of the anatomy and meticulous surgical technique are essential. Case presentation A 71-year-old female presented with a large asymptomatic mass, which had occupied the left facial area for over the past fifteen years, and she requested surgical excision for a cosmetically better facial appearance. The computed tomography (CT scan showed a well-defined giant lipoma arising from the left deep parotid gland. The lipoma was successfully enucleated after full exposure and mobilization of the overlying facial nerve branches. The surgical specimen measured 9 × 6 cm in size, and histopathology revealed fibrolipoma. The patient experienced an uneventful recovery, with a satisfying facial contour and intact facial nerve function. Conclusion Giant lipomas involving the deep parotid lobe are extremely rare. The high-resolution CT scan provides an accurate and cost-effective preoperative investigative method. Surgical management of deep lobe lipoma should be performed by experienced surgeons due to the need for meticulous dissection of the facial nerve branches. Superficial parotidectomy before deep lobe lipoma removal may be unnecessary in selected cases because preservation of the superficial lobe may contribute to a better aesthetic and functional result.

  13. Contribution to irradiation creep arising from gas-driven bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Woo, C.H. [Hong Kong Polytechnic Univ., Kowloon (Hong Kong); Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-03-01

    In a previous paper the relationship was defined between void swelling and irradiation creep arising from the interaction of the SIPA and SIG creep-driven deformation and swelling-driven deformation was highly interactive in nature, and that the two contributions could not be independently calculated and then considered as directly additive. This model could be used to explain the recent experimental observation that the creep-swelling coupling coefficient was not a constant as previously assumed, but declined continuously as the swelling rate increased. Such a model thereby explained the creep-disappearance and creep-damping anomalies observed in conditions where significant void swelling occurred before substantial creep deformation developed. At lower irradiation temperatures and high helium/hydrogen generation rates, such as found in light water cooled reactors and some fusion concepts, gas-filled cavities that have not yet exceeded the critical radius for bubble-void conversion should also exert an influence on irradiation creep. In this paper the original concept is adapted to include such conditions, and its predictions then compared with available data. It is shown that a measurable increase in the creep rate is expected compared to the rate found in low gas-generating environments. The creep rate is directly related to the gas generation rate and thereby to the neutron flux and spectrum.

  14. Is there a role for T-type Ca2+ channels in regulation of vasomotor tone in mesenteric arterioles?

    DEFF Research Database (Denmark)

    Jensen, Lars Jørn; Holstein-Rathlou, Niels-Henrik

    2009-01-01

    was predominantly expressed in endothelial cells. Voltage-dependent Ca2+ entry was inhibited by the new specific T-type blockers R(-)-efonidipine and NNC 55-0396. The effect of NNC 55-0396 persisted in depolarized arterioles, suggesting an unusually high activation threshold of mesenteric T......The largest peripheral blood pressure drop occurs in terminal arterioles (<40 microm lumen diameter). L-type voltage-dependent Ca2+ channels (VDCCs) are considered the primary pathway for Ca2+ influx during physiologic activation of vascular smooth muscle cells (VSMC). Recent evidence suggests that...... T-type VDCCs are expressed in renal afferent and efferent arterioles, mesenteric arterioles, and skeletal muscle arterioles. T-type channels are small-conductance, low voltage-activated, fast-inactivating channels. Thus, their role in supplying Ca2+ for contraction of VSMC has been disputed. However...

  15. Complex Patterns of Metabolic and Ca2+ Entrainment in Pancreatic Islets by Oscillatory Glucose

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Mosekilde, Erik; Polonsky, Kenneth S.; Luciani, Dan Seriano

    2013-01-01

    Glucose-stimulated insulin secretion is pulsatile and driven by intrinsic oscillations in metabolism, electrical activity, and Ca2+in pancreatic islets. Periodic variations in glucose can entrain islet Ca2+ and insulin secretion, possibly promoting interislet synchronization. Here, we used...... fluorescence microscopy to demonstrate that glucose oscillations can induce distinct 1:1 and 1:2 entrainment of oscillations (one and two oscillations for each period of exogenous stimulus, respectively) in islet Ca2+ , NAD(P)H, and mitochondrial membrane potential. To our knowledge, this is the first...... demonstration of metabolic entrainment in islets, and we found that entrainment of metabolic oscillations requires voltage-gated Ca2+ influx. We identified diverse patterns of 1:2 entrainment and showed that islet synchronization during entrainment involves adjustments of both oscillatory phase and period. All...

  16. A carcinoembryonic antigen-secreting adenocarcinoma arising in tailgut cyst: clinical implications of carcinoembryonic antigen.

    Science.gov (United States)

    Cho, Byoung Chul; Kim, Nam Kyu; Lim, Beom Jin; Kang, Sang Ook; Sohn, Ju Hyuk; Roh, Jae Kyung; Choi, Sang Tae; Kim, Sung Ai; Park, Se Eun

    2005-08-31

    Tailgut cysts (TGCs) are rare congenital cysts that occur in the retrorectal or presacral spaces. Although most tailgut cysts have been reported as benign, there have been at least 9 cases associated with malignant change. We report herein on an unusual case of a 40-year-old woman with a carcinoembryonic antigen (CEA)-producing adenocarcinoma arising within a TGC who underwent surgical resection and local radiation therapy. Despite the complete resection, metastatic adenocarcinoma developed five months after surgery. CEA-producing adenocarcinoma from a TGC is extremely rare and only two cases, including this case, have been reported in the English medical literature. Besides CEA, the serum levels of CA 19-9 became markedly elevated in this patient. Given that the serum CEA level decreased to the normal range after complete resection of tumor and that the tumor recurrence was associated with a rebound of the CEA serum level, our case shows that serial measurements of serum CEA can be used for treatment planning and for assessing the patient's treatment response for this rare disease. PMID:16127782

  17. Urban surface water pollution problems arising from misconnections.

    Science.gov (United States)

    Revitt, D Michael; Ellis, J Bryan

    2016-05-01

    The impacts of misconnections on the organic and nutrient loadings to surface waters are assessed using specific household appliance data for two urban sub-catchments located in the London metropolitan region and the city of Swansea. Potential loadings of biochemical oxygen demand (BOD), soluble reactive phosphorus (PO4-P) and ammoniacal nitrogen (NH4-N) due to misconnections are calculated for three different scenarios based on the measured daily flows from specific appliances and either measured daily pollutant concentrations or average pollutant concentrations for relevant greywater and black water sources obtained from an extensive review of the literature. Downstream receiving water concentrations, together with the associated uncertainties, are predicted from derived misconnection discharge concentrations and compared to existing freshwater standards for comparable river types. Consideration of dilution ratios indicates that these would need to be of the order of 50-100:1 to maintain high water quality with respect to BOD and NH4-N following typical misconnection discharges but only poor quality for PO4-P is likely to be achievable. The main pollutant loading contributions to misconnections arise from toilets (NH4-N and BOD), kitchen sinks (BOD and PO4-P) washing machines (PO4-P and BOD) and, to a lesser extent, dishwashers (PO4-P). By completely eliminating toilet misconnections and ensuring misconnections from all other appliances do not exceed 2%, the potential pollution problems due to BOD and NH4-N discharges would be alleviated but this would not be the case for PO4-P. In the event of a treatment option being preferred to solve the misconnection problem, it is shown that for an area the size of metropolitan Greater London, a sewage treatment plant with a Population Equivalent value approaching 900,000 would be required to efficiently remove BOD and NH4-N to safely dischargeable levels but such a plant is unlikely to have the capacity to deal

  18. Estimation of the Decommissioning Waste Arising for a PWR

    International Nuclear Information System (INIS)

    In Korea, Kori Unit 1(Pressurized Water Reactor, 587MW) began the first life extension operation since 2008 and Wolsong Unit 1(Canadian Deuterium Uranium Reactor, 679MW) has waited for the admission of life extension after license expiration since November 2012. However, after Fukushima Daichi nuclear power plant accident happened March 2011, the public support for the nuclear power plant life extension has been faded. This is reason why the preparation of nuclear power plant decommissioning is significant in this time. When it comes to the decommissioning cost estimation, the waste treatment and disposal possess about 17% ∼ 43% in the total decommissioning expense. Hence, the accurate analysis of the decommissioning cost has the immense influence on the determination of decommissioning strategy in later. Namely, as the fundamental investigation of the decommissioning outlay, the approach to the expected waste weight estimation is worth of study. In this study, the arising of waste weight during the decommissioning of Kori Unit 1 was estimated with some documents listed in the reference. Finally, the total expected waste amount during the Kori Unit 1 decommissioning is about 49,139 tons. Among them, assumed radioactive waste material is 1,915,214 kg(869 tons). Based on IAEA standard, these wastes are divided in HLW, ILW, LLW, VLLW and EW respectively. Future plan is to assess the radioactivity of primary side components and dose rate distribution of Kori Unit 1 using MCNP and ORIGEN-2 codes. This action will be helpful to design the reasonable decommissioning scenario in the future 4 session

  19. Classical Hodgkin Lymphoma Arising Adjacent to a Breast Implant.

    Science.gov (United States)

    Ryan, Ciara; Ged, Yasser; Quinn, Fiona; Walker, Jan; Kennedy, John; Gillham, Charles; Pittaluga, Stefania; McDermott, Ronan; Vandenberghe, Elisabeth; Grant, Cliona; Flavin, Richard

    2016-08-01

    Breast implant-associated lymphoma has recently gained wide recognition. Anaplastic large cell lymphoma (ALCL) is the most frequently diagnosed subtype in this setting but the spectrum is broadening. A 66-year-old woman developed swelling and itch around her saline implant 6 years after its insertion. Imaging revealed a fluid collection surrounding the implant with an adjacent mass. Microscopy showed sclerotic tissue punctuated by discrete cellular nodules comprising small lymphocytes, eosinophils and interspersed large atypical Hodgkin Reed-Sternberg (HRS)-like cells. The HRS-like cells stained positively for CD30 and CD15 by immunohistochemistry. Small T-lymphocytes formed rosettes around HRS-like cells. Appearances were consistent with classical Hodgkin lymphoma (HL). Multiplex polymerase chain reaction demonstrated no clonal rearrangements of immunoglobulin or T-cell receptor genes, however, a t(14;18)(q32;q21)BCL2-JH translocation involving the major breakpoint region of the bcl2 gene was present. Staging positron emission tomography-computed tomography scan revealed FDG-avid masses in the right axilla and pelvis. Subsequent pathological examination identified low-grade follicular lymphoma (FL) with a t(14;18) translocation at these sites. To our knowledge, this is the first case of HL arising adjacent to a breast implant. An awareness of this diagnosis is important as classical HL, with its prominent mixed inflammatory background, may be overlooked as a reactive process when histologically assessing capsulectomy specimens. It is also important in the differential diagnosis for implant-associated ALCL as both contain large atypical CD30-positive cells highlighting the need for full immunohistochemical and molecular workup in such cases. This case also adds to the large body of literature regarding the association between HL and FL. PMID:26888955

  20. Leptin signaling in Kiss1 neurons arises after pubertal development.

    Directory of Open Access Journals (Sweden)

    Roberta M Cravo

    Full Text Available The adipocyte-derived hormone leptin is required for normal pubertal maturation in mice and humans and, therefore, leptin has been recognized as a crucial metabolic cue linking energy stores and the onset of puberty. Several lines of evidence have suggested that leptin acts via kisspeptin expressing neurons of the arcuate nucleus to exert its effects. Using conditional knockout mice, we have previously demonstrated that deletion of leptin receptors (LepR from kisspeptin cells cause no puberty or fertility deficits. However, developmental adaptations and system redundancies may have obscured the physiologic relevance of direct leptin signaling in kisspeptin neurons. To overcome these putative effects, we re-expressed endogenous LepR selectively in kisspeptin cells of mice otherwise null for LepR, using the Cre-loxP system. Kiss1-Cre LepR null mice showed no pubertal development and no improvement of the metabolic phenotype, remaining obese, diabetic and infertile. These mice displayed decreased numbers of neurons expressing Kiss1 gene, similar to prepubertal control mice, and an unexpected lack of re-expression of functional LepR. To further assess the temporal coexpression of Kiss1 and Lepr genes, we generated mice with the human renilla green fluorescent protein (hrGFP driven by Kiss1 regulatory elements and crossed them with mice that express Cre recombinase from the Lepr locus and the R26-tdTomato reporter gene. No coexpression of Kiss1 and LepR was observed in prepubertal mice. Our findings unequivocally demonstrate that kisspeptin neurons are not the direct target of leptin in the onset of puberty. Leptin signaling in kisspeptin neurons arises only after completion of sexual maturation.

  1. Sewage sludge - arisings, composition, disposal capacities; Klaerschlamm - Mengen, Zusammensetzung, Entsorgungskapazitaeten

    Energy Technology Data Exchange (ETDEWEB)

    Faulstich, M.; Rabus, J. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Wasserguete- und Abfallwirtschaft; Urban, A.I.; Friedel, M. [Kassel Univ. (Gesamthochschule) (Germany). Fachgebiet Abfalltechnik

    1998-09-01

    One of the main disposal paths for sewage sludge in the past was landfilling. This option was severely restricted by the issue of the Technical Code on Household Waste in 1993. In its agricultural applications sewage sludge serves as a fertiliser and a soil improvement agent. Estimates on potential thermal treatment capacities have shown that there are enough public power plants to accommodate and provide thermal treatment for the total of sewage sludge arisings in Germany. As can be seen from the estimates presented in this paper, it would not even be necessary to restrict oneself to public power plant capacities. The paper points out possibilities of using plant capacities already existing in industrial firing plants and certain production sectors. It uses a comparison to show that sewage sludge would have to be dried in order to permit its thermal treatment in these private facilities. Aside from this, there are a number of new techniques entering the market which from the technical viewpoint also appear to be well suited for thermal sewage sludge treatment. [Deutsch] Ein wesentlicher Entsorgungsweg von Klaerschlamm war in der Vergangenheit die Verbringung auf eine Deponie. Diese Moeglichkeit ist durch die TA Siedlungsabfall von 1993 stark eingeschraenkt. Bei der landwirtschaftlichen Verwertung wird durch den Klaerschlamm eine Duengewirkung sowie eine Bodenverbesserung erreicht. Eine Abschaetzung der potentiellen thermischen Behandlungskapazitaeten zeigt, dass die gesamte bundesdeutsche Klaerschlammenge in oeffentlichen Kraftwerken unterzubringen und thermisch zu behandeln waere. Wie die hier dargestellten Abschaetzungen gezeigt haben, ist man durchaus nicht allein auf die Nutzung oeffentlicher Kraftwerkskapazitaeten angewiesen. Es wurden Moeglichkeiten zur Nutzung vorhandener Anlagenkapazitaeten in industriellen Feuerungsanlagen und in Produktionsbereichen aufgezeigt. Wie aus einem Vergleich erkennbar wird, ist allerdings eine Trocknung der Klaerschlaemme

  2. Calculation of forces arising from impacting projectiles upon yielding structures

    International Nuclear Information System (INIS)

    Calculations concerning the impact of airplanes upon nuclear power plant buildings usually imply that the building 'acts' as a rigid target. This assumption is justified for considerations concerning the structural integrity of the building being hit. However, for investigating induced vibrations of components within the structure, this approach might -in general- be too conservative. It is expected, that yielding of the structure during impact reduces the peak values of the loads and changes the temporal behavior of the load function which is obtained for a rigid target. To calculate the changes of the load function which are due to deformations of the structure, Riera's method is extended for the case of a yielding target. In view of the applications of the calculations to the impact of airplanes upon buildings which are constructed to withstand loads of this kind without serious damage and without large deformations, it is possible to simplify the calculations to some extent. That is, the investigations need not take into account in detail the behavior of the target during impact. The calculations are performed with a one-dimensional model for the projectile. The direction of impact is perpendicular to the target surface; direction of impact and projectile axis coincide. The calculations were performed for several initial velocities of the projectiles simulating a fast flying military airplane. Variations of the peak values of the load functions as compared to corresponding values for a rigid target do not exceed about 10%. The overall temporal behavior of the load curves turns out to be not very sensitive to the yielding of the target, though, in some cases displacements in time of the peak positions within a single load curve do arise

  3. Inhibitory effect of dibutyryl cyclic GMP on potassium-stimulated 45Ca uptake by synaptosomes from rat brain

    International Nuclear Information System (INIS)

    The effects of dibutyryl cyclic GMP (db-cGMP) and dibutyryl cyclic AMP (db-cAMP) on potassium-stimulated 45Ca uptake by the P2 fraction of Gray and Whittaker were investigated with the following results. (1)db-cGMP inhibited initial rate of potassium-stimulated 45Ca-uptake in a dose-dependent manner in 0.1 mM Ca0 medium, but had no effect on the uptake in low K+ medium. In 0.1 mM Ca0 medium, the concentration of db-cGMP causing 50% inhibition was about 3 mM. db-cAMP (5mM) had no effect on the uptake. (2) db-cGMP inhibited potassium-stimulated 45Ca uptake in 1 mM Ca0 medium, though less than in 0.1 mM Ca0 medium. (3) db-cGMP inhibited potassium-stimulated 45Ca uptake by synaptosomes (pinched-off nerve terminals) more than the uptakes by other subfractions of P2 fraction. It is suggested from the results that cGMP inhibits the Ca influx resulting from depolarization of the nerve endings in situ. (Auth.)

  4. Age-dependent impact of CaV 3.2 T-type calcium channel deletion on myogenic tone and flow-mediated vasodilatation in small arteries

    DEFF Research Database (Denmark)

    Mikkelsen, Miriam F; Björling, Karl; Jensen, Lars Jørn

    2016-01-01

    The myogenic response and flow-mediated vasodilatation are important regulators of local blood perfusion and total peripheral resistance, and are known to entail a calcium influx into vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), respectively. CaV 3.2 T-type calcium channels a......-mediated vasomotor responses to prevent excess arterial tone, protect against cardiovascular disease. This article is protected by copyright. All rights reserved....

  5. Expression of store-operated Ca2+ entry and transient receptor potential canonical and vanilloid-related proteins in rat distal pulmonary venous smooth muscle

    OpenAIRE

    Peng, Gongyong; Lu, Wenju; LI, XIAOYAN; Chen, Yuqin; Zhong, Nanshan; Ran, Pixin; Wang, Jian

    2010-01-01

    Chronic hypoxia causes remodeling and alters contractile responses in both pulmonary arteries and pulmonary veins. Although pulmonary arteries have been studied extensively in these disorders, the mechanisms by which pulmonary veins respond to hypoxia and whether these responses contribute to chronic hypoxic pulmonary hypertension remain poorly understood. In pulmonary arterial smooth muscle, we have previously demonstrated that influx of Ca2+ through store-operated calcium channels (SOCC) th...

  6. Mucinous adenocarcinoma arising at the anastomotic site after operation for hirschsprung's disease: case report

    International Nuclear Information System (INIS)

    To our knowledge, rectal cancer arising at the anastomotic site after surgery for Hirschsprung's disease has not been reported. We report a case of mucinous adenocarcinoma arising at the anastomotic site after Soave operation 26 years ago

  7. Non-Dioxin-Like Polychlorinated Biphenyls Inhibit G-Protein Coupled Receptor-Mediated Ca2+ Signaling by Blocking Store-Operated Ca2+ Entry.

    Directory of Open Access Journals (Sweden)

    Se-Young Choi

    Full Text Available Polychlorinated biphenyls (PCBs are ubiquitous pollutants which accumulate in the food chain. Recently, several molecular mechanisms by which non-dioxin-like (NDL PCBs mediate neurodevelopmental and neurobehavioral toxicity have been elucidated. However, although the G-protein coupled receptor (GPCR is a significant target for neurobehavioral disturbance, our understanding of the effects of PCBs on GPCR signaling remains unclear. In this study, we investigated the effects of NDL-PCBs on GPCR-mediated Ca2+ signaling in PC12 cells. We found that ortho-substituted 2,2',6-trichlorinated biphenyl (PCB19 caused a rapid decline in the Ca2+ signaling of bradykinin, a typical Gq- and phospholipase Cβ-coupled GPCR, without any effect on its inositol 1,4,5-trisphosphate production. PCB19 reduced thapsigargin-induced sustained cytosolic Ca2+ levels, suggesting that PCB19 inhibits SOCE. The abilities of other NDL-PCBs to inhibit store-operated Ca2+ entry (SOCE were also examined and found to be of similar potencies to that of PCB19. PCB19 also showed a manner equivalent to that of known SOCE inhibitors. PCB19-mediated SOCE inhibition was confirmed by demonstrating the ability of PCB19 to inhibit the SOCE current and thapsigargin-induced Mn2+ influx. These results imply that one of the molecular mechanism by which NDL-PCBs cause neurobehavioral disturbances involves NDL-PCB-mediated inhibition of SOCE, thereby interfering with GPCR-mediated Ca2+ signaling.

  8. Electrodeposition of Ca Metal in CaCl2-CaO Molten Salt

    Institute of Scientific and Technical Information of China (English)

    GUO; Jun-kang; WANG; Chang-shui; CAO; Long-hao; OUYANG; Ying-gen

    2013-01-01

    To realize the continuouscalciothermic reduction in molten salts,the electrodeposition behavior of Ca metal in CaCl2-CaO molten salt was investigated by cylic voltammetry.The cyclic voltammograms at the scan rate of 100 mV/s are shown in Fig.1.As is shown,the electrodeposition potential of Ca deviated from-1.66 V to-0.97 V after CaO was added to molten CaCl2 and the decomposition of CaO

  9. Ca2+ toxicity and mitochondrial damage in acute pancreatitis: translational overview.

    Science.gov (United States)

    Maléth, József; Hegyi, Péter

    2016-08-01

    Acute pancreatitis (AP) is a leading cause of hospitalization among non-malignant gastrointestinal disorders. The mortality of severe AP can reach 30-50%, which is most probably owing to the lack of specific treatment. Therefore, AP is a major healthcare problem, which urges researchers to identify novel drug targets. Studies from the last decades highlighted that the toxic cellular Ca(2+) overload and mitochondrial damage are key pathogenic steps in the disease development affecting both acinar and ductal cell functions. Moreover, recent observations showed that modifying the cellular Ca(2+) signalling might be beneficial in AP. The inhibition of Ca(2+) release from the endoplasmic reticulum or the activity of plasma membrane Ca(2+) influx channels decreased the severity of AP in experimental models. Similarly, inhibition of mitochondrial permeability transition pore (MPTP) opening also seems to improve the outcome of AP in in vivo animal models. At the moment MPTP blockers are under detailed clinical investigation to test whether interventions in MPTP openings and/or Ca(2+) homeostasis of the cells can be specific targets in prevention or treatment of cell damage in AP.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'. PMID:27377719

  10. Ca2+-Transport through Plasma Membrane as a Test of Auxin Sensitivity

    Directory of Open Access Journals (Sweden)

    Anastasia A. Kirpichnikova

    2014-03-01

    Full Text Available Auxin is one of the crucial regulators of plant growth and development. The discovered auxin cytosolic receptor (TIR1 is not involved in the perception of the hormone signal at the plasma membrane. Instead, another receptor, related to the ABP1, auxin binding protein1, is supposed to be responsible for the perception at the plasma membrane. One of the fast and sensitive auxin-induced reactions is an increase of Ca2+ cytosolic concentration, which is suggested to be dependent on the activation of Ca2+ influx through the plasma membrane. This investigation was carried out with a plasmalemma enriched vesicle fraction, obtained from etiolated maize coleoptiles. The magnitude of Ca2+ efflux through the membrane vesicles was estimated according to the shift of potential dependent fluorescent dye diS-C3-(5. The obtained results showed that during coleoptiles ageing (3rd, 4th and 5th days of seedling etiolated growth the magnitude of Ca2+ efflux from inside-out vesicles was decreased. Addition of ABP1 led to a recovery of Ca2+ efflux to the level of the youngest and most sensitive cells. Moreover, the efflux was more sensitive, responding from 10−8 to 10−6 M 1-NAA, in vesicles containing ABP1, whereas native vesicles showed the highest efflux at 10−6 M 1-NAA. We suggest that auxin increases plasma membrane permeability to Ca2+ and that ABP1 is involved in modulation of this reaction.

  11. Influence of different spectral ranges of light and Ca2+ -channel blockers on Ca2+ and K+ levels in Phaseolus coccineus L. pulvini

    Directory of Open Access Journals (Sweden)

    Jan Białczyk

    2014-02-01

    Full Text Available The effect of different spectral ranges of light on the modification of transport processes in isolated parts of Phaseolus coccineus pulvini was analysed in a bath medium by determining the Ca2+ and K+ contents. After 1 h incubation of separated fragments of the extensor and flexor in solutions containing deionized water, medium, or medium with verapamil or nifedipine, the investigated material was irradiated with monochromatic light of different wavelengths. The concentration of Ca2+, K+ and the pH value were determined in the medium. The obtained results suggest the occurrence of a specific coupling between the concentration of Ca2+ and K+ dependend on the wavelength of the applied light and part of the pulvinus. Certain spectral ranges of light brought about opposite effects on ion transport in opposite parts of the pulvinus. Changes in the pH of mediums containing isolated parts of the pulvini part to different effects of blue, red, and far-red light on the activity of H+-pumps located in the motor cells. The use of verapamil and nifedipine, specific Ca2+-channel blockers, made it possible to demonstrate the significant effect of Ca2+ on the activity and functioning of K+ -channels. The two types of inhibitors decreased the influx of Ca2+ and K+ to motor cells of the pulvini, however they did not limit the efflux of ions to the medium. The obtained results suggest that Ca2+ ions take part in transduction of the light signal. It seems probable that the action of blue light is also mediated by part of the Ca2+ ions.

  12. Extracellular Adenosine Diphosphate Ribose Mobilizes Intracellular Ca2+ via Purinergic-Dependent Ca2+ Pathways in Rat Pulmonary Artery Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Chun Huang

    2015-11-01

    Full Text Available Background/Aims: Adenosine diphosphate ribose (ADPR, a product of β-NAD+ metabolism generated by the multifunctional enzyme CD38, is recognized as a novel signaling molecule. The catalytic site of CD38 orients extracellularly or intracellularly, capable of generating ADPR outside and inside the cells. CD38-dependent pathways have been characterized in pulmonary artery smooth muscle cells (PASMCs; however the physiological function of extracellular ADPR is unclear. Methods: Ca2+ mobilizing and proliferative effects of extracellular ADPR were characterized and compared with the ATP-induced responses in rat PASMCs; and the expression of purinergic receptor (P2X and P2Y subtypes were examined in pulmonary arteries. Results: ADPR elicited concentration-dependent increase in [Ca2+]i with a fast transient and a sustained phase in PASMCs. The sustained phase was abolished by Ca2+ removal and inhibited by the non-selective cation channel blocker SKF-96365, but was unaffected by TRPM2 antagonists or nifedipine. The purinergic receptor (P2X antagonist pyridoxal-phosphate-6-azophenyl-2', 4'-disulfonate inhibited partially the transient and the sustained Ca2+ response, while the P2(XY inhibitor suramin and the phospholipase C inhibitor U73122 abolished the sustained Ca2+ influx. The P2Y1 antagonist MRS2179 had no effect on the response. By contrast, ATP and ADP activated Ca2+ response exhibited a high and a low affinity component, and the pharmacological profile of ATP-induced Ca2+ response was distinctive from that of ADPR. BrdU incorporation assay showed that ADPR caused significant inhibition whereas ATP caused slight stimulation of PASMC proliferation. RT-PCR analysis found that almost all P2X and P2Y subtypes are expressed in PAs. Conclusion: ADPR and ATP activate Ca2+ responses through different combinations of multiple purinergic receptor subtypes; and extracellular ADPR may exert an autocrine/paracrine action via purinergic receptors on PASMCs.

  13. Epac2 contributes to PACAP-induced astrocytic differentiation through calcium ion influx in neural precursor cells.

    Science.gov (United States)

    Seo, Hyunhyo; Lee, Kyungmin

    2016-02-01

    Astrocytes play a critical role in normal brain functions and maintaining the brain microenvironment, and defects in astrocytogenesis during neurodevelopment could give rise to severe mental illness and psychiatric disorders. During neuro-embryogenesis, astrocytogenesis involves astrocytic differentiation of neural precursor cells (NPCs) induced by signals from ciliary neurotrophic factor (CNTF) or pituitary adenylate cyclase-activating peptide (PACAP). However, in contrast to the CNTF signaling pathway, the exact mechanism underlying astrocytic differentiation induced by PACAP is unknown. In the present study, we aimed to verify a signaling pathway specific to PACAP-induced astrocytogenesis, using exchange protein directly activated by cAMP2 (Epac2)-knockout mice. We found that PACAP could trigger astrocytic differentiation of NPCs via Epac2 activation and an increase in the intracellular calcium concentration via a calcium ion influx. Taken together, we concluded that astrocytogenesis stimulated by PACAP occurs through a novel signaling pathway independent from CNTF-JAK/STAT signaling, that is the well-known pathway of astrocytogenesis. [BMB Reports 2016; 49(2): 128-133]. PMID:26645637

  14. Shoot-supplied ammonium targets the root auxin influx carrier AUX1 and inhibits lateral root emergence in Arabidopsis

    KAUST Repository

    Li, Baohai

    2011-03-24

    Deposition of ammonium (NH4 +) from the atmosphere is a substantial environmental problem. While toxicity resulting from root exposure to NH4 + is well studied, little is known about how shoot-supplied ammonium (SSA) affects root growth. In this study, we show that SSA significantly affects lateral root (LR) development. We show that SSA inhibits lateral root primordium (LRP) emergence, but not LRP initiation, resulting in significantly impaired LR number. We show that the inhibition is independent of abscisic acid (ABA) signalling and sucrose uptake in shoots but relates to the auxin response in roots. Expression analyses of an auxin-responsive reporter, DR5:GUS, and direct assays of auxin transport demonstrated that SSA inhibits root acropetal (rootward) auxin transport while not affecting basipetal (shootward) transport or auxin sensitivity of root cells. Mutant analyses indicated that the auxin influx carrier AUX1, but not the auxin efflux carriers PIN-FORMED (PIN)1 or PIN2, is required for this inhibition of LRP emergence and the observed auxin response. We found that AUX1 expression was modulated by SSA in vascular tissues rather than LR cap cells in roots. Taken together, our results suggest that SSA inhibits LRP emergence in Arabidopsis by interfering with AUX1-dependent auxin transport from shoot to root. © 2011 Blackwell Publishing Ltd.

  15. Alterations in plasma membrane promote overexpression and increase of sodium influx through epithelial sodium channel in hypertensive platelets.

    Science.gov (United States)

    Cerecedo, D; Martínez-Vieyra, Ivette; Sosa-Peinado, Alejandro; Cornejo-Garrido, Jorge; Ordaz-Pichardo, Cynthia; Benítez-Cardoza, Claudia

    2016-08-01

    Platelets are small, anucleated cell fragments that activate in response to a wide variety of stimuli, triggering a complex series of intracellular pathways leading to a hemostatic thrombus formation at vascular injury sites. However, in essential hypertension, platelet activation contributes to causing myocardial infarction and ischemic stroke. Reported abnormalities in platelet functions, such as platelet hyperactivity and hyperaggregability to several agonists, contribute to the pathogenesis and complications of thrombotic events associated with hypertension. Platelet membrane lipid composition and fluidity are determining for protein site accessibility, structural arrangement of platelet surface, and response to appropriate stimuli. The present study aimed to demonstrate whether structural and biochemical abnormalities in lipid membrane composition and fluidity characteristic of platelets from hypertensive patients influence the expression of the Epithelial Sodium Channel (ENaC), fundamental for sodium influx during collagen activation. Wb, cytometry and quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) assays demonstrated ENaC overexpression in platelets from hypertensive subjects and in relation to control subjects. Additionally, our results strongly suggest a key role of β-dystroglycan as a scaffold for the organization of ENaC and associated proteins. Understanding of the mechanisms of platelet alterations in hypertension should provide valuable information for the pathophysiology of hypertension. PMID:27137675

  16. Noninvasive estimation of the net influx constant using standardized uptake value for quantification of FDG uptake of tumors

    International Nuclear Information System (INIS)

    To reduce the fluctuation of the standardized uptake value (SUV) as the indicator for the 2-(18F)fluoro-2-deoxy-D-glucose (FDG) uptake of tumors, the net influx constant (Ki) was estimated from SUV. The relation was used; Ki=SUV x kp x V0, kp: the elimination rate constant of FDG from plasma and V0: the initial distribution volume of FDG. V0, kp and SUV were calculated, then the estimated Ki was obtained. To enhance the accuracy, the estimated Ki was compared with the actual Ki from 8 patients with head and neck cancer. V0 based on the body weight was 0.1627±0.0329 (ml/g) and showed the weak correlation with the body weight. V0 based on the surface area was 5540±871 (ml/m2) and showed no correlation with the body weight. kp showed no correlation with the blood-sugar level. The high correlation was found between the actual Ki and the estimated Ki. It suggested that Ki is superior to SUV as an index of FDG uptake, and noninvasive estimation of the Ki is useful to standardize the quantification of diagnosis for tumor using FDG-PET. (K.H.)

  17. Neutrophils influx and proinflammatory cytokines inhibition by sodium salicylate, unlike aspirin, in Candida albicans-induced peritonitis model.

    Science.gov (United States)

    Pereira, Priscilla Aparecida Tártari; Bini, Daniel; Bovo, Fernanda; Faccioli, Lucia Helena; Monteiro, Marta Chagas

    2016-07-01

    Sodium salicylate (NaS) and aspirin (ASA) are known to have a variety of effects on microorganisms, such as fungus (C. albicans and C. neoformans), moreover, it have effects in leukocyte adhesion and migration in vitro. In this report, we investigated the effect of ASA and NaS in neutrophil migration and cytokine production in C. albicans-induced peritonitis murine model. For this, mice were treated intraperitoneally (i.p) or orally (po) with NaS or ASA; after they were stimulated i.p. with C. albicans, the cellular migration was evaluated 24 h after stimulation. NaS, in mice treated i.p., unlike ASA, was able to inhibit the neutrophil migration and proinflammatory cytokine production induced by C. albicans, such as TNF-α, IL-1, IFN-γ, IL-12, and IL-10, but did not alter the IL-4 levels in these animals. However, the po treatment with same the dose of NaS or ASA did not affect the influx of this cell for inflammatory site. These results suggest that the NaS inhibits cellular migration and proinflammatory cytokine by different anti-inflammatory mechanism compared to ASA. PMID:26762336

  18. Ketamine inhibits human sperm function by Ca(2+)-related mechanism.

    Science.gov (United States)

    He, Yuanqiao; Zou, Qianxing; Li, Bingda; Chen, Houyang; Du, Xiaohong; Weng, Shiqi; Luo, Tao; Zeng, Xuhui

    2016-09-01

    Ketamine, a dissociative anesthetic, which was widely used in human and animal medicine, has become a popular recreational drug, as it can induce hallucinatory effects. Ketamine abuse can cause serious damage to many aspects of the organism, mainly reflected in the nervous system and urinary system. It has also been reported that ketamine can impair the male genital system. However, the detailed effect of ketamine on human spermatozoa remains unclear. Thus, we investigated the in vitro effects of ketamine on human sperm functions, to elucidate the underlying mechanism. Human sperm were treated in vitro with different concentrations of ketamine (0, 0.125, 0.25, 0.5, 1 g/L). The results showed that 0.25-1 g/L ketamine inhibited sperm total motility, progressive motility and linear velocity, in a dose-dependent manner. In addition, the sperm's ability to penetrate viscous medium and the progesterone-induced acrosome reaction were significantly inhibited by ketamine. Ketamine did not affect sperm viability, capacitation and spontaneous acrosome reaction. The intracellular calcium concentration ([Ca(2+)]i), which is a central factor in the regulation of human sperm function, was decreased by ketamine (0.125-1 g/L) in a dose-dependent manner. Furthermore, the currents of the sperm-specific Ca(2+) channel, CatSper, which modulates Ca(2+) influx in sperm, were inhibited by ketamine (0.125-1 g/L) in a dose-dependent manner. Our findings suggest that ketamine induces its toxic effects on human sperm functions by reducing sperm [Ca(2+)]i through inhibition of CatSper channel. PMID:27143628

  19. Elevation difference of Ca2+ levels in young leaf cells of bromegrass and induced cold-tolerant enhancement under different controlled chilling temperatures

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The changes of Ca2+ levels in young leaf cells of bromegrass under different controlled chilling temperatures were inves-tigated by an antimonite precipitation eytochemical method. The main results were as follows: under 25/20℃ (day/night) tempera-ture and 14 h photoperiod, electron-dense Ca2+ antimonite precipitates, indicators of Ca2+ localization, were mainly localized in the vacuoles, cell walls and intercellular spaces; few Ca2+ deposits were observed in the cytosol and nuclei. After a 3℃ chilling treatment for 3 h, many Ca2+ precipitates appeared in the cytosol and nuclei, indicating that Ca2+ influx had occurred in the cytosol and nuclei.When the 3℃ treatment was prolonged to 8 h, more Ca2+ deposits appeared in the nuclei and cytosol, but the amount of Ca2+ depos-its in both the cytosol and nuclei decreased markedly after a 24 h treatment and most Ca2+ deposits were returned to the vacuoles and intercellular spaces after an 8 d treatment. When bromegrass was exposed to 7℃ for 3 h, the Ca2+ distribution in the cells had no visible changes, compared with that of the 25/20℃ grown control plants. However, when the chilling treatment of 7℃ was pro-longed to 8 h, a Ca2+ influx occurred, where many Ca2+ deposits were observed in the nuclei and cytosol. More Ca2+ deposits ap-peared in the nuclei and cytosol after a 24 h treatment, but the amount of Ca2+ deposits in the cytosol and nuclei was reduced mark-edly after an 8 d treatment. After a 14 d treatment, the remaining low level of Ca2+ was recovered in both the cytosol and nuclei andthe Ca2+ deposits were again located in the vacuoles and the intercellular spaces. The dynamics of subcellular Ca2+ localization in young leaf cells of bromegrass during a 12℃ chilling treatment were similar to those of the 7℃ treatment. Besides, the results showed that the frost tolerance of bromegrass exposed to 3℃ for 8 d increased by 6℃, for 7℃ and 8 d by 4℃ and for 12℃ and 14 d by 3℃, compared with the

  20. High K+-induced contraction requires depolarization-induced Ca2+ release from internal stores in rat gut smooth muscle

    Institute of Scientific and Technical Information of China (English)

    Timo KIRSCHSTEIN; Mirko REHBERG; Rika BAJORAT; Tursonjan TOKAY; Katrin PORATH; Rudiger KOHLING

    2009-01-01

    Aim: Depolarization-induced contraction of smooth muscle is thought to be mediated by Ca2+influx through voltage-gated L-type Ca2+channels. We describe a novel contraction mechanism that is independent of Ca2+ entry.Methods: Pharmacological experiments were carried out on isolated rat gut longitudinal smooth muscle preparations, measuring iso-metric contraction strength upon high K+-induced depolarization.Results: Treatment with verapamil, which presumably leads to a conformational change in the channel, completely abolished K+-induced contraction, while residual contraction still occurred when Ca2+ entry was blocked with Cd2+. These results were further con-firmed by measuring intracellular Ca2+ transients using Fura-2. Co-application of Cd2+ and the ryanodine receptor blocker DHBP further reduced contraction, albeit incompletely. Additional blockage of either phospholipase C (U 73122) or inositol 1,4,5-trisphophate (IP3)receptors (2-APB) abolished most contractions, while sole application of these blockers and Cd2+ (without parallel ryanodine receptor manipulation) also resulted in incomplete contraction block.Conclusion: We conclude that there are parallel mechanisms of depolarization-induced smooth muscle contraction via (a) Ca2+ entry and (b) Ca2+ entry-independent, depolarization-induced Ca2+-release through ryanodine receptors and IP3, with the latter being depen-dent on phospholipase C activation.

  1. C.A. Nothardbiblioteek

    Directory of Open Access Journals (Sweden)

    J. Swart

    1988-09-01

    Full Text Available As instructed by the Central Board of the South African Nursing Association during 1985, an investigation was launched into the function of the C.A. Not hard Library, namely to provide optimal information to members. The underlying philosophy concerned with the establishment of the library was to provide a service which is not available elsewhere. The investigation revealed however, that various training institutions in the country meet this need. As a result of the findings, as presented in the article, the C.A. Northard Library was closed on 1 December 1985 as a lending library. A unique Nursing reference library is being established in its place, with the emphasis in the future on the S. A. Nursing Association’s role in the promotion of Nursing research.

  2. Mobilisation of store Ca2+ activates tyrosine hydroxylase in bovine adrenal chromaffin cells

    International Nuclear Information System (INIS)

    Full text: Many receptor agonists are able to activate tyrosine hydroxylase (TOH) in bovine adrenal chromaffin cells. The majority of these are dependent on extracellular Ca2+ for this action. Entry of extracellular Ca2+ through voltage-operated Ca2+ channels is very effective at activating TOH. The contribution of the intracellular Ca2+ stores to TOH activation however is not known. Previous studies have shown that mobilisation of intracellular Ca2+ stores is effective at increasing phosphorylation of TOH, but its effect on TOH activity has not been studied. Therefore, in the present study, the effect of mobilisation of store Ca2+ on TOH activity was investigated using primary cultures of bovine adrenal chromaffin cells. Cells were prepared from abattoir tissue and cultured for 3-6 days. TOH activity was determined over 10 minutes, measuring the 14CO2 produced following the hydroxylation and rapid decarboxylation of 14C-tyrosine offered to intact cells. Caffeine increased TOH activity in a concentration-dependent manner with a maximum response of 100% increase at 20mM. This effect was not due to osmolarity since 20mM sucrose had no effect.Nor was it due to inhibition of phosphodiesterases, since the effect of caffeine was still seen in the presence of 1mM IBMX. However,caffeine-induced TOH activation was substantially reduced in the absence of extracellular Ca2+. The results suggest that TOH activity can be increased by mobilising intracellular Ca2+ stores, but that this effect involves extracellular Ca2+ influx, possibly through store-operated channels. Copyright (2001) Australian Neuroscience Society

  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. Experimental Establishment of the CaAl2O4–MgO and CaAl4O7–MgO Isoplethal Sections within the Al2O3–MgO–CaO Ternary System

    OpenAIRE

    Durán, Teresa; Serena Palomares, Sara; Peña, P.; Caballero Cuesta, Ángel; Aza Pendas, Salvador de; Aza Moya, Antonio H. de

    2008-01-01

    The isoplethal sections CaAl2O4–MgO and CaAl4O7–MgO of the Al2O3–MgO–CaO ternary system have been experimentally established at 1 bar total pressure and air of normal humidity. The sections obtained provide new data and information that are in disagreement with thermodynamic evaluations and optimizations of the Al2O3–MgO–CaO ternary system published to date. These differences arise mainly from the inclusion, or exclusion, of the binary compound Ca12Al14O33, mayenite, as a stable phase in the ...

  5. Coverage of crime and violence in Nigerian media: matters arising

    Directory of Open Access Journals (Sweden)

    E. O. Soola

    2011-08-01

    Full Text Available Nigerias socio-political and economic landscape has been blighted by the endemic twin evil of crime and violence. Social responsibility media, framing, and attribution theories provide the theoretical anchor for this paper. Nigerian consumers of media products, like their counterparts in other cultures, are insatiably interested in, and are at times shocked and fascinated by, crime and violence, as covered in the media. The Nigerian mass media, acting both as mirrors of society and business enterprises, provide a daily diet of these crimes, howbeit deficiently. This deficiency is traceable to their episodic rather than thematic approach, their individual, instead of societal blame, and cause, rather than solution. Nigerian media, in many instances, fail to turn their searchlight on the undercurrents of crime and violence: the Nigerian system of justice and the issues and grievances that give rise to crime and violence in the society. The paper, as matters arising, critically examines the often ignored, and at best-perfunctorily handled, aspects of coverage of crime and violence in Nigerian media.
    Nigeria’s socio-political and economic landscape has been blighted by the endemic twin evil of crime and violence of major, tragic and alarming proportions. The widespread frustration and deep sense of insecurity to life and property, occasioned by this epidemic, has become a matter of grave concern to government, security agencies and the Nigerian citizenry at large (Nwosu, 2003. The situation has become most critical, consequent upon the apparent helplessness of the law-enforcement agencies to stem the tide of the epidemic (Otudor, 2005, Adebayo, 2006, Adeyemi, 2006, Adeyemi, 2007, Iziguzo, 2007
    The state of insecurity in Nigeria today is such that it is not an overstatement to conclude that the Nigerian nation is under siege. And while the urban centres are more prone to crimes, neither the urban, the sub-urban nor the rural is immune to

  6. Pesticide adsorptivity of aged particulate matter arising from crop residue burns.

    Science.gov (United States)

    Yang, Yaning; Sheng, Guangyao

    2003-08-13

    Particulates (ashes) arising from the burning of crop residues are potentially effective adsorbents for pesticides in agricultural soils. To determine the long-term adsorptive sustainability of ashes, a wheat (Triticum aestivum L.) ash was aged under environmentally relevant conditions (in CaCl(2) solution at room temperature and pH 7) in soil extract for 1 month and in a soil (1% ash) for a period of up to 12 months. The aged ash and ash-amended soil were used to sorb diuron from water. The diuron sorption was also measured in the presence of atrazine as a competing pesticide. There was no observed microbial impact on the stability of the wheat ash in soil. All isotherms with the ash were nonlinear type-I curves, suggestive of the surface adsorption. On a unit mass basis, the ash in soil extract was 600-10000 times more effective than the soil in sorbing diuron. Adsorption of dissolved soil organic matter (DOM) during aging on the ash surfaces reduced the diuron adsorption by 50-60%. Surface competition from the atrazine adsorption also reduced the ash adsorption of diuron by 10-30%. A total of 55-67% reduction in diuron sorption by the ash-amended soil was observed. Due to its high initial adsorptivity, the ash fraction of the aged ash-amended soil contributed >50% to the total diuron sorption. Thus, the wheat ash aged in the soil remained highly effective in adsorbing diuron. As crop residues are frequently burned in the field, pesticides in agricultural soils may be highly immobilized due to the presence of ashes. PMID:12903968

  7. Inhibition of anaphylactic histamine release from heterologously sensitized mast cells: differential effects of drugs which interfere with calcium influx.

    Directory of Open Access Journals (Sweden)

    Kurose,Masao

    1981-11-01

    Full Text Available Drug effects were studied on anaphylactic histamine release from rat mast cells sensitized in vitro with mouse IgE antibody. When histamine release was elicited by adding Ca-++ at various times after antigen-stimulation of sensitized cells in Ca++-free medium, the drugs to be tested were added shortly before each Ca++ addition. Quercetin was effective only when added before or immediately after antigen. Theophylline and disodium cromoglycate (DSCG were active irrespective of the time interval between antigen and Ca++ addition. Verapamil was more effective when added before or simultaneously with antigen than when added later. When tested in the two-stage experiments, quercetin showed inhibition only in Stage 1 and verapamil was inhibitive primarily in Stage 1, while theophylline and DSCG wee only inhibitive in Stage 2. It seems that quercetin selectively and verapamil primarily act to block calcium-gate opening resulting from antigen-antibody interaction on the mast cell membrane, while theophylline and DSCG selectively inhibit the passage of calcium through open calcium channels.

  8. Seasonal Sr/Ca, and 44Ca/40Ca co-variation in Arctica islandica

    International Nuclear Information System (INIS)

    Full text: We have studied the Ca isotopic variations and Sr/Ca ratios within an A. islandica shell in relation to temperature fluctuations of the ambient seawater with sub-seasonal resolution. The long-lived bivalve A. islandica dwells at 10-200 m depth throughout much of the North Atlantic continental shelf. Its shells represent a promising SST archive for boreal marine settings. The A. islandica shell used for this study was collected at 60-m depth near the former position of the Nantucket Shoals Lightship. The years 1956-1958 were analyzed for both, Sr/Ca ratios and δ44/40Ca, with 1957 being the best resolved. The δ44/40Ca are highly correlated with Sr/Ca ratios (r= 0.92 for 1957). The positive correlation of Sr/Ca ratios and temperature in A. islandica is in accordance with published data on other bivalves, but contrary to thermodynamic expectations and e.g. coral data. The same inversion is found for Ca isotope fractionation: the δ44/40Ca correlation with temperature of A. islandica is negative, while all δ44/40Ca temperature gradients published so far (inorganic precipitates and foraminifera data) show varying degrees of positive correlation. Thus, as for Sr/Ca, the temperature correlation of δ44/40Ca in A. islandica is not under thermodynamic control. It appears inevitable to conclude that biological effects dominate both, Sr incorporation and Ca isotope fractionation in A. islandica. Growth rates and food supply are parameters that might relate Sr/Ca ratios as well as Ca isotopic compositions to vital activity and thus indirectly to temperature. In any case the high correlation of Sr/Ca ratios and Ca isotope fractionation indicates a common metabolic process for the observed variations. (author)

  9. Na+ Influx Induced by New Antimalarials Causes Rapid Alterations in the Cholesterol Content and Morphology of Plasmodium falciparum.

    Directory of Open Access Journals (Sweden)

    Sudipta Das

    2016-05-01

    Full Text Available Among the several new antimalarials discovered over the past decade are at least three clinical candidate drugs, each with a distinct chemical structure, that disrupt Na+ homeostasis resulting in a rapid increase in intracellular Na+ concentration ([Na+]i within the erythrocytic stages of Plasmodium falciparum. At present, events triggered by Na+ influx that result in parasite demise are not well-understood. Here we report effects of two such drugs, a pyrazoleamide and a spiroindolone, on intraerythrocytic P. falciparum. Within minutes following the exposure to these drugs, the trophozoite stage parasite, which normally contains little cholesterol, was made permeant by cholesterol-dependent detergents, suggesting it acquired a substantial amount of the lipid. Consistently, the merozoite surface protein 1 and 2 (MSP1 and MSP2, glycosylphosphotidylinositol (GPI-anchored proteins normally uniformly distributed in the parasite plasma membrane, coalesced into clusters. These alterations were not observed following drug treatment of P. falciparum parasites adapted to grow in a low [Na+] growth medium. Both cholesterol acquisition and MSP1 coalescence were reversible upon the removal of the drugs, implicating an active process of cholesterol exclusion from trophozoites that we hypothesize is inhibited by high [Na+]i. Electron microscopy of drug-treated trophozoites revealed substantial morphological changes normally seen at the later schizont stage including the appearance of partial inner membrane complexes, dense organelles that resemble "rhoptries" and apparent nuclear division. Together these results suggest that [Na+]i disruptor drugs by altering levels of cholesterol in the parasite, dysregulate trophozoite to schizont development and cause parasite demise.

  10. Improving and Assessing Aircraft-based Greenhouse Gas Emission Rate Measurements at Indianapolis as part of the INFLUX project.

    Science.gov (United States)

    Heimburger, A. M. F.; Shepson, P. B.; Stirm, B. H.; Susdorf, C.; Cambaliza, M. O. L.

    2015-12-01

    Since the Copenhagen accord in 2009, several countries have affirmed their commitment to reduce their greenhouse gas emissions. The United States and Canada committed to reduce their emissions by 17% below 2005 levels, by 2020, Europe by 14% and China by ~40%. To achieve such targets, coherent and effective strategies in mitigating atmospheric carbon emissions must be implemented in the next decades. Whether such goals are actually achieved, they require that reductions are "measurable", "reportable", and "verifiable". Management of greenhouse gas emissions must focus on urban environments since ~74% of CO2 emissions worldwide will be from cities, while measurement approaches are highly uncertain (~50% to >100%). The Indianapolis Flux Experiment (INFLUX) was established to develop, assess and improve top-down and bottom-up quantifications of urban greenhouse gas emissions. Based on an aircraft mass balance approach, we performed a series of experiments focused on the improvement of CO2, CH4 and CO emission rates quantification from Indianapolis, our final objective being to drastically improve the method overall uncertainty from the previous estimate of 50%. In November-December 2014, we conducted nine methodologically identical mass balance experiments in a short period of time (24 days, one downwind distance) for assumed constant total emission rate conditions, as a means to obtain an improved standard deviation of the mean determination. By averaging the individual emission rate determinations, we were able to obtain a method precision of 17% and 16% for CO2 and CO, respectively, at the 95%C.L. CH4 emission rates are highly variable day to day, leading to precision of 60%. Our results show that repetitive sampling can enable improvement in precision of the aircraft top-down methods through averaging.

  11. Capsaicin stimulates the non-store-operated Ca2+ entry but inhibits the store-operated Ca2+ entry in neutrophils

    International Nuclear Information System (INIS)

    Rat neutrophils express the mRNA encoding for transient receptor potential (TRP) V1. However, capsaicin-stimulated [Ca2+]i elevation occurred only at high concentrations (≥100 μM). This response was substantially decreased in a Ca2+-free medium. Vanilloids displayed similar patterns of Ca2+ response with the rank order of potency as follows: scutigeral>resiniferatoxin>capsazepine>capsaicin=olvanil>isovelleral. Arachidonyl dopamine (AAD), an endogenous ligand for TRPV1, failed to desensitize the subsequent capsaicin challenge. Capsaicin-induced Ca2+ response was not affected by 8-bromo-cyclic ADP-ribose (8-Br-cADPR), the ryanodine receptor blocker, but was slightly attenuated by 1-[6-[17β-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl] -1H-pyrrole-2,5-dione (U-73122), the inhibitor of phospholipase C-coupled processes, 1-[β-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole (SKF-96365), the blocker of receptor-gated and store-operated Ca2+ (SOC) channels, 2-aminoethyldiphenyl borate (2-APB), the blocker of D-myo-inositol 1,4,5-trisphospahte (IP3) receptor and Ca2+ influx, and by ruthenium red, a blocker of TRPV channels, and enhanced by the Ca2+ channels blocker, cis-N-(2-phenylcyclopentyl)azacyclotridec-1-en-2-amine (MDL-12330A) and Na+-deprivation. In addition, capsaicin had no effect on the plasma membrane Ca2+-ATPase activity or the production of nitric oxide (NO) and reactive oxygen intermediates (ROI) or on the total thiols content. Capsaicin (≥100 μM) inhibited the cyclopiazonic acid (CPA)-induced store-operated Ca2+ entry (SOCE). In the absence of external Ca2+, the robust Ca2+ entry after subsequent addition of Ca2+ was decreased by capsaicin in CPA-activated cells. Capsaicin alone increased the actin cytoskeleton, and also increased the actin filament content in cell activation with CPA. These results indicate that capsaicin activates a TRPV1-independent non-SOCE pathway in neutrophils. The reorganization of the actin cytoskeleton is

  12. Characteristics of 36C103- influx into nitrate reductase deficient mutant E1 pisum sativum seedlings: evidence for restricted ''induction'' by nitrate compared with wild type

    International Nuclear Information System (INIS)

    The characteristics of nitrate uptake into seedlings of Pisum sativum L. cv. Rondo mutant E1 defective for nitrate reductase (NR) and of its parent variety Rondo have been investigated using 36C103- as an analogue for nitrate. The apparent Michaelis Menten constants (Km) for 36ClO3- influx measured over 10 min were similar for mutant E1 and the wild type (Wt). There was a 28% increase in 36C103- into Wt seedlings following nitrate pretreatment but this was not found when mutant seedlings were used. N starvation increased 36C103- influx into both mutant and Wt seedlings, and the rate of cycling E/I was also enhanced to a similar extent. The results are discussed in terms of current ideas on the regulation of nitrate uptake and assimilation. (author)

  13. The mitochondrial Na+/Ca2+exchanger may reduce high glucose-induced oxidative stress and nucleotide-binding oligomerization domain receptor 3 inflammasome activation in endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Yuan ZU; Li-Juan WAN; Shao-Yuan CUI; Yan-Ping GONG; Chun-Lin LI

    2015-01-01

    Background The mitochondrial Na+/Ca2+exchanger, NCLX, plays an important role in the balance between Ca2+influx and efflux across the mitochondrial inner membrane in endothelial cells. Mitochondrial metabolism is likely to be affected by the activity of NCLX because Ca2+activates several enzymes of the Krebs cycle. It is currently believed that mitochondria are not only centers of energy produc-tion but are also important sites of reactive oxygen species (ROS) generation and nucleotide-binding oligomerization domain receptor 3 (NLRP3) inflammasome activation. Methods&Results This study focused on NCLX function, in rat aortic endothelial cells (RAECs), induced by glucose. First, we detected an increase in NCLX expression in the endothelia of rats with diabetes mellitus, which was induced by an injection of streptozotocin. Next, colocalization of NCLX expression and mitochondria was detected using confocal analysis. Suppression of NCLX expression, using an siRNA construct (siNCLX), enhanced mitochondrial Ca2+influx and blocked efflux induced by glucose. Un-expectedly, silencing of NCLX expression induced increased ROS generation and NLRP3 inflammasome activation. Conclusions These findings suggest that NCLX affects glucose-dependent mitochondrial Ca2+signaling, thereby regulating ROS generation and NLRP3 in-flammasome activation in high glucose conditions. In the early stages of high glucose stimulation, NCLX expression increases to compensate in order to self-protect mitochondrial maintenance, stability, and function in endothelial cells.

  14. Effect of Hypericin on Confocal Imaging of Ca2+ Signaling in Cultured Human Retinal Pigment Epithelium

    Institute of Scientific and Technical Information of China (English)

    Qianying Gao; Yannian Hui; Yusheng Wang; Lin Wang

    2001-01-01

    Purpose: To investigate the mechanism of the Ca2 + signaling in cultured human retinal pigment epithelial(RPE) cells with the protein kinase C(PKC) specific inhibitor-hypericin stimulation.Methods: Cultured human RPE cells were analyzed using the fluorescence Ca2+ dye fluo-3 AM and laser scanning confocal microscope(LSCM) after stimulation with 100nM phorbol 12-myristate 13-acetate(PMA) and (or)5 concentrations of hypericin(1, 2, 3, 4 and 5 μM).Results: The normal fluorescence in RPE cells was strong and distributed throughout the cells. The nucleus appeared to be more fluorescent than the cytoplasm. After stimulation with PMA alone or 5 concentrations of hypericin, a rapid decrease in flurescence intensity was observed. There was no obvious difference in decreased curve among 5concentrations. However, after stimulation with a 24 hr preincubation of PMA and 5 concentrations of hypericin, a further decrease was not observed.Conclusion: Fluo-3 AM appears to be a good indicator of the change in Ca2+ occurring in RPE cells and hypericin is a strong inhibitor of Ca2 + influx channel. Hypericin has potential as a therapeutic drug for proliferative vitreoretinopathy(PVR), the inhibitory effect on PVR might be caused by blocking the PKC activity and inhibiting Ca2+ influxpathway.

  15. Temporal and spatial changes in Ca2+ distribution during the programmed cell death of tracheary elements

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The changes in Ca2+ distribution in the tracheary elements (TEs) of the pepper leaves were studied using the cytochemical method of potassium antimonate. At the early stage of TEs formation, the vacuole and the nucleus held large volume, and antimonate Ca2+ deposits were observed mainly in the intercellular space and the cell wall. As the thickening of secondary wall occurred, the vacuole, nucleus and other organelles began to rupture, concomitant with the increase of calcium deposits in the cytosol, showing the influx of Ca2+ into the cell. With the further rupture of cytoplasm and other organelles, the number of calcium deposits at the non-thickening cell wall increased, but declined at the thickening bands of the secondary wall. When the cytoplasmic contents disappeared completely, the level of Ca2+ decreased at the non-thickening wall, but by contrast,increased at the thickening bands of the secondary wall.These observations indicated that the dynamic changes in Ca2+ distribution spatially and temporarily might have a close correlation with its distinct roles played during the formation of the secondary walls.

  16. An exact calculation of the N2+ and H2+ influx at cathode surface in N2–H2 discharges

    Directory of Open Access Journals (Sweden)

    K.S. Suraj

    2014-01-01

    Full Text Available An exact calculation of N2+ and H2+ influx, at cathode surface in N2–H2 discharge, has been derived using electron impact ionization cross-section at plasma sheath boundary. The analytical formula is very convenient in practical applications. Through the analysis of experimental parameters for glow discharge plasma nitriding, the formula explains, why treatment in an N2–H2 mixture with H2 percentage ∼70% gives most enhanced result.

  17. Magnetism of CaAs, CaP, and CaN half-metals

    International Nuclear Information System (INIS)

    First principles calculations indicate that CaAs, CaP, and CaN compounds are ferromagnets. Analysis of these and other II-V compounds that do not contain transition metal atoms shows that their magnetism derives from the spin polarization of the atomic p(anion) orbitals, which persists in the compounds of Ca, Sr, and Ba due to their large atomic radii

  18. Magnetism of CaAs, CaP, and CaN half-metals

    Energy Technology Data Exchange (ETDEWEB)

    Volnianska, O. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)]. E-mail: volnian@ifpan.edu.pl; Jakubas, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Boguslawski, P. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)

    2006-10-26

    First principles calculations indicate that CaAs, CaP, and CaN compounds are ferromagnets. Analysis of these and other II-V compounds that do not contain transition metal atoms shows that their magnetism derives from the spin polarization of the atomic p(anion) orbitals, which persists in the compounds of Ca, Sr, and Ba due to their large atomic radii.

  19. Endothelium- and smooth muscle-dependent vasodilator effects of Citrus aurantium L. var. amara: Focus on Ca(2+) modulation.

    Science.gov (United States)

    Kang, Purum; Ryu, Kang-Hyun; Lee, Jeong-Min; Kim, Hyo-Keun; Seol, Geun Hee

    2016-08-01

    Neroli, the essential oil of Citrus aurantium L. var. amara, is a well-characterized alleviative agent used to treat cardiovascular symptoms. However, because it has been found to have multiple effects, its mechanism of action requires further exploration. We sought to clarify the mechanism underlying the actions of neroli in mouse aorta. In aortic rings from mice precontracted with prostaglandin F2 alpha, neroli induced vasodilation. However, relaxation effect of neroli was decreased in endothelium-denuded ring or pre-incubation with the nitric oxide synthase inhibitor NG-Nitro-l-arginine-methyl ester (L-NAME). And also, neroli-induced relaxation was also partially reversed by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ), a soluble guanylyl cyclase (sGC) inhibitor. In addition, neroli inhibited extracellular Ca(2+)-dependent, depolarization-induced contraction, an effect that was concentration dependent. Pretreatment with the non-selective cation channel blocker, Ni(2+), attenuated neroli-induced relaxation, whereas the K(+) channel blocker, tetraethylammonium chloride, had no effect. In the presence of verapamil, added to prevent Ca(2+) influx via smooth muscle voltage-gated Ca(2+) channels, neroli-induced relaxation was reduced by the ryanodine receptor (RyR) inhibitor ruthenium red. Our findings further indicate that the endothelial component of neroli-induced vasodilation is partly mediated by the NO-sGC pathway, whereas the smooth muscle component involves modulation of intracellular Ca(2+) concentration through inhibition of cation channel-mediated extracellular Ca(2+) influx and store-operated Ca(2+) release mediated by the RyR signaling pathway. PMID:27470386

  20. Combination of Ca2+-activated K+ channel blockers inhibits acetylcholine-evoked nitric oxide release in rat superior mesenteric artery

    Science.gov (United States)

    Stankevičius, E; Lopez-Valverde, V; Rivera, L; Hughes, A D; Mulvany, M J; Simonsen, Ulf

    2006-01-01

    Background and purpose: The present study investigated whether calcium-activated K+ channels are involved in acetylcholine-evoked nitric oxide (NO) release and relaxation. Experimental approach: Simultaneous measurements of NO concentration and relaxation were performed in rat superior mesenteric artery and endothelial cell membrane potential and intracellular calcium ([Ca2+]i) were measured. Key results. A combination of apamin plus charybotoxin, which are, respectively, blockers of small-conductance and of intermediate- and large-conductance Ca2+-activated K channels abolished acetylcholine (10 μM)-evoked hyperpolarization of endothelial cell membrane potential. Acetylcholine-evoked NO release was reduced by 68% in high K+ (80 mM) and by 85% in the presence of apamin plus charybdotoxin. In noradrenaline-contracted arteries, asymmetric dimethylarginine (ADMA), an inhibitor of NO synthase inhibited acetylcholine-evoked NO release and relaxation. However, only further addition of oxyhaemoglobin or apamin plus charybdotoxin eliminated the residual acetylcholine-evoked NO release and relaxation. Removal of extracellular calcium or an inhibitor of calcium influx channels, SKF96365, abolished acetylcholine-evoked increase in NO concentration and [Ca2+]i. Cyclopiazonic acid (CPA, 30 μM), an inhibitor of sarcoplasmic Ca2+-ATPase, caused a sustained NO release in the presence, but only a transient increase in the absence, of extracellular calcium. Incubation with apamin and charybdotoxin did not change acetylcholine or CPA-induced increases in [Ca2+]i, but inhibited the sustained NO release induced by CPA. Conclusions and Implications: Acetylcholine increases endothelial cell [Ca2+]i by release of stored calcium and calcium influx resulting in activation of apamin and charybdotoxin-sensitive K channels, hyperpolarization and release of NO in the rat superior mesenteric artery. PMID:16967048

  1. Sustained calcium influx activated by basic fibroblast growth factor in Balb-c 3T3 fibroblasts.

    Science.gov (United States)

    Munaron, L; Distasi, C; Carabelli, V; Baccino, F M; Bonelli, G; Lovisolo, D

    1995-05-01

    1. We have investigated the ionic events elicited in Balb-c 3T3 fibroblasts by basic fibroblast growth factor (bFGF), a peptide that binds to membrane receptors with tyrosine kinase activity and has a mitogenic action on many cell types. The peptide (0.2-100 ng ml-1) caused the appearance of an inward current, as observed in whole-cell patch-clamp experiments at a holding potential of -50 mV, that could last for tens of minutes and had a peak density of 4.6 +/- 2.6 pA pF-1. The reversal potential was 18.8 +/- 16.7 mV. 2. The current was reversibly abolished by removal of bFGF from the external bath. Inhibition of low-affinity FGF receptors had no effect on the activation of the inward current; it was completely abolished when cells were pre-incubated with tyrphostin or 5'-methylthioadenosine (MTA), two inhibitors of the tyrosine kinase activity of the high-affinity FGF receptors. The inward current was not activated by the emptying of internal calcium stores, as tested with 200 nM thapsigargin. 3. Values of peak current density comparable to control ones were obtained when either all Na+ ions or all Ca2+ ions were removed from the external solution; when both ions were completely removed, no inward current could be observed. The inward current was not affected by 2 microM nifedipine, and was reversibly blocked by the imidazole derivative SK&F 96365-A. 4. Measurements of free intracellular calcium concentration ([Ca2+]i) with the dye fura-2 showed that bFGF elicited sustained increases in [Ca2+]i that were completely dependent on external calcium and on the presence of the agonist and could last more than 1 h. 5. Single channel currents (conductance 7.9 pS) in response to bFGF stimulation could be recorded in the cell-attached configuration with 100 mM CaCl2 in the pipette. When the resting potential was brought near to 0 mV by external perfusion in a high-K+ solution, Vrev was about 0 mV. 6. We conclude that in Balb-c 3T3 cells bFGF induces an inward current that

  2. Control of the neurovascular coupling by nitric oxide-dependent regulation of astrocytic Ca2+ signaling

    Directory of Open Access Journals (Sweden)

    Manuel Francisco Muñoz

    2015-03-01

    Full Text Available Neuronal activity must be tightly coordinated with blood flow to keep proper brain function, which is achieved by a mechanism known as neurovascular coupling. Then, an increase in synaptic activity leads to a dilation of local parenchymal arterioles that matches the enhanced metabolic demand. Neurovascular coupling is orchestrated by astrocytes. These glial cells are located between neurons and the microvasculature, with the astrocytic endfeet ensheathing the vessels, which allows fine intercellular communication. The neurotransmitters released during neuronal activity reach astrocytic receptors and trigger a Ca2+ signaling that propagates to the endfeet, activating the release of vasoactive factors and arteriolar dilation. The astrocyte Ca2+ signaling is coordinated by gap junction channels and hemichannels formed by connexins (Cx43 and Cx30 and channels formed by pannexins (Panx-1. The neuronal activity-initiated Ca2+ waves are propagated among neighboring astrocytes directly via gap junctions or through ATP release via connexin hemichannels or pannexin channels. In addition, Ca2+ entry via connexin hemichannels or pannexin channels may participate in the regulation of the astrocyte signaling-mediated neurovascular coupling. Interestingly, nitric oxide (NO can activate connexin hemichannel by S-nitrosylation and the Ca2+-dependent NO-synthesizing enzymes endothelial NO synthase (eNOS and neuronal NOS (nNOS are expressed in astrocytes. Therefore, the astrocytic Ca2+ signaling triggered in neurovascular coupling may activate NO production, which, in turn, may lead to Ca2+ influx through hemichannel activation. Furthermore, NO release from the hemichannels located at astrocytic endfeet may contribute to the vasodilation of parenchymal arterioles. In this review, we discuss the mechanisms involved in the regulation of the astrocytic Ca2+ signaling that mediates neurovascular coupling, with a special emphasis in the possible participation of NO in

  3. Adenocarcinoma arising from intrahepatic heterotopic pancreas: A case report and literature review

    OpenAIRE

    Yan, Mao-Lin; Wang, Yao-Dong; Tian, Yi-Feng; Lin, Ying

    2012-01-01

    Heterotopic pancreas is mostly found incidentally, and adenocarcinoma arising from heterotopic pancreas appears to be extremely rare. A case of a 46-year-old woman with adenocarcinoma arising from intrahepatic heterotopic pancreas is reported herein. Computed tomography demonstrated a mass located in the bile duct of the left hepatic lobe. Pathological examination revealed a moderately differentiated adenocarcinoma arising from intrahepatic heterotopic pancreas with nerve infiltration. This m...

  4. “Cutaneous‐type” angiosarcoma arising in a mature cystic teratoma of the ovary

    OpenAIRE

    den Bakker, M A; Ansink, A C; Ewing‐Graham, P C

    2006-01-01

    Benign and malignant somatic tumours arising in mature cystic teratomas of the ovary are a rare but recognised phenomenon. Squamous cell carcinoma is the most common somatic malignancy arising in ovarian teratomas, although many other types of tumour have been described. An angiosarcoma with “cutaneous” type typical features arising in a dermoid cyst of the ovary is reported. Vascular tumours have only rarely been described as secondary somatic tumours in ovarian teratomas. The diagnostic fea...

  5. Homeostatic and stimulus-induced coupling of the L-type Ca2+ channel to the ryanodine receptor in the hippocampal neuron in slices

    Science.gov (United States)

    Berrout, Jonathan; Isokawa, Masako

    2009-01-01

    Activity-dependent increase in cytosolic calcium ([Ca2+]i) is a prerequisite for many neuronal functions. We previously reported a strong direct depolarization, independent of glutamate receptors, effectively caused a release of Ca2+ from ryanodine sensitive stores and induced the synthesis of endogenous cannabinoids (eCBs) and eCB-mediated responses. However, the cellular mechanism that initiated the depolarization-induced Ca2+ release is not completely understood. In the present study, we optically recorded [Ca2+]i from CA1 pyramidal neurons in the hippocampal slice and directly monitored miniature Ca2+ activities and depolarization-induced Ca2+ signals in order to determine the source(s) and properties of [Ca2+]i-dynamics that could lead to a release of Ca2+ from the ryanodine receptor. In the absence of depolarizing stimuli, spontaneously-occurring miniature Ca2+ events were detected from a group of hippocampal neurons. This miniature Ca2+ event persisted in the nominal Ca2+-containing artificial cerebrospinal fluid (ACSF), and increased in frequency in response to the bath-application of caffeine and KCl. In contrast, nimodipine, the antagonist of the L-type Ca2+ channel (LTCC), a high concentration of ryanodine, the antagonist of the ryanodine receptor (RyR), and thapsigargin (TG) reduced the occurrence of the miniature Ca2+ events. When a brief puff-application of KCl was given locally to the soma of individual neurons in the presence of glutamate receptor antagonists, these neurons generated a transient increase in the [Ca2+]i in the dendrosomal region. This [Ca2+]i-transient was sensitive to nimodipine, TG, and ryanodine suggesting that the [Ca2+]i-transient was caused primarily by the LTCC-mediated Ca2+-influx and a release of Ca2+ from RyR. We observed little contribution from N-or P/Q-type Ca2+ channels. The coupling between LTCC and RyR was direct and independent of synaptic activities. Immunohistochemical study revealed a cellular localization of LTCC

  6. Soluble sperm extract specifically recapitulates the initial phase of the Ca2+ response in the fertilized oocyte of P. occelata following a G-protein/ PLCβ signaling pathway.

    Science.gov (United States)

    Nakano, Takeshi; Kyozuka, Keiichiro

    2015-12-01

    Matured oocytes of the annelidan worm Pseudopotamilla occelata are fertilized at the first metaphase of the meiotic division. During the activation by fertilizing spermatozoa, the mature oocyte shows a two-step intracellular Ca2+ increase. Whereas the first Ca2+ increase is localized and appears to utilize the inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ stores, the second Ca2+ increase is global and involves Ca2+ influx via voltage-gated Ca2+ channels on the entire surface of the oocyte. To study how sperm trigger the Ca2+ increases during fertilization, we prepared soluble sperm extract (SE) and examined its ability to induce Ca2+ increases in the oocyte. The SE could evoke a Ca2+ increase in the oocyte when it was added to the medium, but not when it was delivered by microinjection. However, the second-step Ca2+ increase leading to the resumption of meiosis did not follow in these eggs. Local application of SE induced a non-propagating Ca2+ increase and formed a cytoplasmic protrusion that was similar to that created by the fertilizing sperm at the first stage of the Ca2+ response, important for sperm incorporation into the oocyte. Our results suggest that the fertilizing spermatozoon may trigger the first-step Ca2+ increase before it fuses with the oocyte in a pathway that involves the G-protein-coupled receptor and phospholipase C. Thus, the first phase of the Ca2+ response in the fertilized egg of this species is independent of the second phase of the Ca2+ increase for egg activation. PMID:25318389

  7. Safety, efficacy and physiological actions of a lysine-free, arginine-rich formula to treat glutaryl-CoA dehydrogenase deficiency: focus on cerebral amino acid influx.

    Science.gov (United States)

    Strauss, Kevin A; Brumbaugh, Joan; Duffy, Alana; Wardley, Bridget; Robinson, Donna; Hendrickson, Christine; Tortorelli, Silvia; Moser, Ann B; Puffenberger, Erik G; Rider, Nicholas L; Morton, D Holmes

    2011-01-01

    Striatal degeneration from glutaryl-CoA dehydrogenase deficiency (glutaric aciduria type 1, GA1) is associated with cerebral formation and entrapment of glutaryl-CoA and its derivatives that depend on cerebral lysine influx. In 2006 we designed a lysine-free study formula enriched with arginine to selectively block lysine transport across cerebral endothelia and thereby limit glutaryl-CoA production by brain. Between 2006 and present, we treated twelve consecutive children with study formula (LYSx group) while holding all other treatment practices constant. Clinical and biochemical outcomes were compared to 25 GA1 patients (PROx group) treated between 1995 and 2005 with natural protein restriction (dietary lysine/arginine ratio of 1.7±0.3 mg:mg). We used published kinetic parameters of the y+and LAT1 blood-brain barrier transporters to model the influx of amino acids into the brain. Arginine fortification to achieve a mean dietary lysine/arginine ratio of 0.7±0.2 mg:mg was neuroprotective. All 12 LYSx patients are physically and neurologically healthy after 28 aggregate patient-years of follow up (current ages 28±21 months) and there were no adverse events related to formula use. This represents a 36% reduction of neurological risk (95% confidence interval 14-52%, p=0.018) that we can directly attribute to altered amino acid intake. During the first year of life, 20% lower lysine intake and two-fold higher arginine intake by LYSx patients were associated with 50% lower plasma lysine, 3-fold lower plasma lysine/arginine concentration ratio, 42% lower mean calculated cerebral lysine influx, 54% higher calculated cerebral arginine influx, 15-26% higher calculated cerebral influx of several anaplerotic precursors (isoleucine, threonine, methionine, and leucine), 50% less 3-hydroxyglutarate excretion, and a 3-fold lower hospitalization rate (0.8 versus 2.3 hospitalizations per patient per year). The relationship between arginine fortification and plasma lysine

  8. Follicle-stimulating hormone receptor-mediated uptake of 45Ca2+ by cultured rat Sertoli cells does not require activation of cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding proteins or adenylate cyclase

    International Nuclear Information System (INIS)

    We have previously reported that FSH stimulates flux of 45Ca2+ into cultured Sertoli cells from immature rats via voltage-sensitive and voltage-independent calcium channels. In the present study, we show that this effect of FSH does not require cholera toxin (CT)- or pertussis toxin (PT)-sensitive guanine nucleotide binding (G) protein or activation of adenylate cyclase (AC). Significant stimulation of 45Ca2+ influx was observed within 1 min, and maximal response (3.2-fold over basal levels) was achieved within 2 min after exposure to FSH. FSH-stimulated elevations in cellular cAMP paralleled increases in 45Ca2+ uptake, suggesting a possible coupling of AC activation to 45Ca2+ influx. (Bu)2cAMP, however, was not able to enhance 45Ca2+ uptake over basal levels at a final concentration of 1000 microM, although a concentration-related increase in androstenedione conversion to estradiol was evident. Exposure of Sertoli cells to CT (10 ng/ml) consistently stimulated basal levels of androstenedione conversion to estradiol but had no effect on basal levels of 45Ca2+ uptake. Similarly, CT had no effect on FSH-induced 45Ca2+ uptake, but potentiated FSH-stimulated estradiol synthesis. PT (10 ng/ml) augmented basal and FSH-stimulated estradiol secretion without affecting 45Ca2+ influx. The adenosine analog N6-phenylisopropyladenosine, which binds to Gi-coupled adenosine receptors on Sertoli cells, inhibited FSH-stimulated androgen conversion to estradiol in a dose-related (1-1000 nM) manner, but FSH-stimulated 45Ca2+ influx remained unchanged. Our results show that in contrast to FSH-stimulated estradiol synthesis, the flux of 45Ca2+ into Sertoli cells in response to FSH is not mediated either directly or indirectly by CT- or PT-sensitive G protein, nor does it require activation of AC. Our data further suggest that the FSH receptor itself may function as a calcium channel

  9. BOTANyCA

    OpenAIRE

    Armenta, Almudena; Guerrero, Teresa

    2012-01-01

    Esta publicación se realiza con motivo de la exposición titulada BOTANyCA celebrada en el Real Jardín Botánico de Madrid del 10 al 21 de octubre de 2012. Dicha exposición fue llevada a cabo por el Grupo de Investigación, Arte, Ciencia y Naturaleza de la Universidad Complutense de Madrid en colaboración con el Real Jardín Botánico. Comisariado de la exposición: Almudena Armenta y Teresa Guerrero. Coordinación técnica: Esther García Guillén y Marga Juárez Canga. Artistas participantes: Almudena...

  10. Phosphorescence quenching by mechanical stimulus in CaZnOS:Cu

    International Nuclear Information System (INIS)

    We have found that phosphorescence intensity of CaZnOS:Cu decreased visibly under an applied load. This mechanical quenching (MQ) of phosphorescence in CaZnOS:Cu corresponded to the mechanical stimuli. We have thus demonstrated that the MQ of CaZnOS:Cu could be used for visualizing stress distributions in practical applications. We propose that MQ arises from non-radiative recombination due to electron-transfer from trap levels to non-radiative centers as a result of the mechanical load.

  11. 45 CFR 73.735-1304 - Referral of matters arising under the standards of this part.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Referral of matters arising under the standards of this part. 73.735-1304 Section 73.735-1304 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION STANDARDS OF CONDUCT Reporting Violations § 73.735-1304 Referral of matters arising under the standards of this part. (a)...

  12. 31 CFR 535.335 - Claim arising out of events in Iran.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Claim arising out of events in Iran. 535.335 Section 535.335 Money and Finance: Treasury Regulations Relating to Money and Finance... General Definitions § 535.335 Claim arising out of events in Iran. For purposes of § 535.216, a claim...

  13. 26 CFR 301.6230(c)-1 - Claim arising out of erroneous computation, etc.

    Science.gov (United States)

    2010-04-01

    ... contained in 26 CFR part 1, revised April 1, 2001. ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Claim arising out of erroneous computation, etc....6230(c)-1 Claim arising out of erroneous computation, etc. (a) In general. A claim for refund...

  14. Localization of Rod Bipolar Cells in the Mammalian Retina Using an Antibody Against the α1c L-type Ca2+ Channel

    International Nuclear Information System (INIS)

    Bipolar cells transmit stimuli via graded changes in membrane potential and neurotransmitter release is modulated by Ca2+ influx through L-type Ca2+ channels. The purpose of this study was to determine whether the α1c subunit of L-type voltage-gated Ca2+ channel (α1c L-type Ca2+ channel) colocalizes with protein kinase C alpha (PKC-α), which labels rod bipolar cells. Retinal whole mounts and vertical sections from mouse, hamster, rabbit, and dog were immunolabeled with antibodies against PKC-α and α1c L-type Ca2+ channel, using fluorescein isothiocyanate (FITC) and Cy5 as visualizing agents. PKC-α-immunoreactive cells were morphologically identical to rod bipolar cells as previously reported. Their cell bodies were located within the inner nuclear layer, dendritic processes branched into the outer plexiform layer, and axons extended into the inner plexiform layer. Immunostaining showed that α1c L-type Ca2+ channel colocalized with PKC-α in rod bipolar cells. The identical expression of PKC-α and α1c L-type Ca2+ channel indicates that the α1c L-type Ca2+ channel has a specific role in rod bipolar cells, and the antibody against the α1c L-type Ca2+ channel may be a useful marker for studying the distribution of rod bipolar cells in mouse, hamster, rabbit, and dog retinas

  15. Evidence that Ca2+ within the microdomain of the L-type voltage gated Ca2+ channel activates ERK in MIN6 cells in response to glucagon-like peptide-1.

    Directory of Open Access Journals (Sweden)

    Joanne Selway

    Full Text Available Glucagon like peptide-1 (GLP-1 is released from intestinal L-cells in response to nutrient ingestion and acts upon pancreatic β-cells potentiating glucose-stimulated insulin secretion and stimulating β-cell proliferation, differentiation, survival and gene transcription. These effects are mediated through the activation of multiple signal transduction pathways including the extracellular regulated kinase (ERK pathway. We have previously reported that GLP-1 activates ERK through a mechanism dependent upon the influx of extracellular Ca(2+ through L-type voltage gated Ca(2+ channels (VGCC. However, the mechanism by which L-type VGCCs couple to the ERK signalling pathway in pancreatic β-cells is poorly understood. In this report, we characterise the relationship between L-type VGCC mediated changes in intracellular Ca(2+ concentration ([Ca(2+](i and the activation of ERK, and demonstrate that the sustained activation of ERK (up to 30 min in response to GLP-1 requires the continual activation of the L-type VGCC yet does not require a sustained increase in global [Ca(2+](i or Ca(2+ efflux from the endoplasmic reticulum. Moreover, sustained elevation of [Ca(2+](i induced by ionomycin is insufficient to stimulate the prolonged activation of ERK. Using the cell permeant Ca(2+ chelators, EGTA-AM and BAPTA-AM, to determine the spatial dynamics of L-type VGCC-dependent Ca(2+ signalling to ERK, we provide evidence that a sustained increase in Ca(2+ within the microdomain of the L-type VGCC is sufficient for signalling to ERK and that this plays an important role in GLP-1- stimulated ERK activation.

  16. Can Endocrine disrupters interfere with Ca2+ homeostasis in invertebrate cells?

    Directory of Open Access Journals (Sweden)

    L. Canesi

    2010-01-01

    Full Text Available A wide range of environmental chemicals have been shown to alter the endocrine system of both wildlife and humans. There is increasing evidence that many of these endocrine disruptors (EDs, in particular estrogenic chemicals, can rapidly affect cellular homeostasis and signaling in mammalian Ca2+ systems. In this work, in vitro and in vivo data are summarised on the effects of different compounds known or suspected as EDs on homeostasis in Ca2+ marine invertebrate, the blue mussel Mytilus spp. Both synthetic estrogens and different EDs (DES, BPA, NP, PCB congeners, etc. rapidly increased sytosolic [Ca2+] in mussel hemosytes, as evaluated by FURA2 single cell fluorescence microscopy. The observed [Ca2+] increase was unaffected by the antiestrogen Tamoxifen and was due to either increased influx or release from Ca2+ intracellular stores, depending on the compound. Moreover, different ED,s including the brominated flame retardant TBBPA (tetrabromo bisphenol A induced a dose-dependent inhibition of the plasma membrane Ca2+ -ATPase (PMCA activity from mussel gills in vitro, this supporting a direct effect on membrane pumps. The in vitro effects of EDs were observed at concentrations generally higher than those of E2. However, in vivo, mussel exposure to environmetal concentrations of Bisphenol A (BPA and of the polybrominated diphenyl ether TBDE-47 resulted in large inhibition of PMCA activity in the digestive gland. The results indicate that, in invertebrate like in mammalian systems, interference with Ca2+ homeostasis may represent a significant mode of action of a variety of EDs.

  17. Accessing the nuclear symmetry energy in Ca+Ca collisions

    International Nuclear Information System (INIS)

    The status of the analysis of the INDRA-VAMOS experiment performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35 AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions. (authors)

  18. Characterization of the substituted N-triazole oxindole TROX-1, a small-molecule, state-dependent inhibitor of Ca(V)2 calcium channels.

    Science.gov (United States)

    Swensen, Andrew M; Herrington, James; Bugianesi, Randal M; Dai, Ge; Haedo, Rodolfo J; Ratliff, Kevin S; Smith, McHardy M; Warren, Vivien A; Arneric, Stephen P; Eduljee, Cyrus; Parker, David; Snutch, Terrance P; Hoyt, Scott B; London, Clare; Duffy, Joseph L; Kaczorowski, Gregory J; McManus, Owen B

    2012-03-01

    Biological, genetic, and clinical evidence provide validation for N-type calcium channels (Ca(V)2.2) as therapeutic targets for chronic pain. A state-dependent Ca(V)2.2 inhibitor may provide an improved therapeutic window over ziconotide, the peptidyl Ca(V)2.2 inhibitor used clinically. Supporting this notion, we recently reported that in preclinical models, the state-dependent Ca(V)2 inhibitor (3R)-5-(3-chloro-4-fluorophenyl)-3-methyl-3-(pyrimidin-5-ylmethyl)-1-(1H-1,2,4-triazol-3-yl)-1,3-dihydro-2H-indol-2-one (TROX-1) has an improved therapeutic window compared with ziconotide. Here we characterize TROX-1 inhibition of Cav2.2 channels in more detail. When channels are biased toward open/inactivated states by depolarizing the membrane potential under voltage-clamp electrophysiology, TROX-1 inhibits Ca(V)2.2 channels with an IC(50) of 0.11 μM. The voltage dependence of Ca(V)2.2 inhibition was examined using automated electrophysiology. TROX-1 IC(50) values were 4.2, 0.90, and 0.36 μM at -110, -90, and -70 mV, respectively. TROX-1 displayed use-dependent inhibition of Ca(V)2.2 with a 10-fold IC(50) separation between first (27 μM) and last (2.7 μM) pulses in a train. In a fluorescence-based calcium influx assay, TROX-1 inhibited Ca(V)2.2 channels with an IC(50) of 9.5 μM under hyperpolarized conditions and 0.69 μM under depolarized conditions. Finally, TROX-1 potency was examined across the Ca(V)2 subfamily. Depolarized IC(50) values were 0.29, 0.19, and 0.28 μM by manual electrophysiology using matched conditions and 1.8, 0.69, and 1.1 μM by calcium influx for Ca(V)2.1, Ca(V)2.2, and Ca(V)2.3, respectively. Together, these in vitro data support the idea that a state-dependent, non-subtype-selective Ca(V)2 channel inhibitor can achieve an improved therapeutic window over the relatively state-independent Ca(V)2.2-selective inhibitor ziconotide in preclinical models of chronic pain. PMID:22188924

  19. Roles and mechanisms of the CD38/cyclic adenosine diphosphate ribose/Ca2+ signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Wenjie; Wei; Richard; Graeff; Jianbo; Yue

    2014-01-01

    Mobilization of intracellular Ca2+ stores is involved inmany diverse cell functions, including: cell proliferation;differentiation; fertilization; muscle contraction; secre-tion of neurotransmitters, hormones and enzymes;and lymphocyte activation and proliferation. Cyclic ad-enosine diphosphate ribose(cADPR) is an endogenousCa2+ mobilizing nucleotide present in many cell typesand species, from plants to animals. cADPR is formedby ADP-ribosyl cyclases from nicotinamide adenine di-nucleotide. The main ADP-ribosyl cyclase in mammalsis CD38, a multi-functional enzyme and a type Ⅱ mem-brane protein. It has been shown that many extracel-lular stimuli can induce cADPR production that leadsto calcium release or influx, establishing cADPR as asecond messenger. cADPR has been linked to a widevariety of cellular processes, but the molecular mecha-nisms regarding cADPR signaling remain elusive. Theaim of this review is to summarize the CD38/cADPR/Ca2+ signaling pathway, focusing on the recent advanc-es involving the mechanism and physiological functionsof cADPR-mediated Ca2+ mobilization.

  20. Influence of the 15-HETE on cytosolic [ Ca2+] i of the rabbit pulmonary artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Xiaobo Tang

    2008-04-01

    Full Text Available Extracellular Ca2+ influx was blocked by L-type Ca2+ channel blocker nifedipine to observe the effects of 15-hydroxyeicosatetraenoic acid on the constriction of rabbit pulmonary artery rings and on the changes of Ca2+ level in the rabbit pulmonary artery smooth muscle cells, and further to investigate the mechanism of the calcium mobilization induced by the 15-HETE under hypoxic conditions. The effect of extracellular Ca2+ on tension of the rabbit PA rings was also studied. Nifedipine (10 µ mol/L had no effect on 1 µ mol/L 15-hydroxyeicosatetraenoic acid induced vasoconstriction under normoxic and hypoxic conditions. Intracellular Ca2+ increased markedly in the 15-HETE group (cells were exposed to 1 µ mol/L 15-HETE for 8 min during culture compared to the control group (P < 0.05. The study demonstrated that the 15-HETE could induce the elevation of Ca2+ in the pulmonary artery smooth muscle cells and the elevated calcium came from the release of the intracellular calcium.

  1. Cessation of neutrophil influx in C5a-induced acute experimental arthritis is associated with loss of chemoattractant activity from the joint space

    International Nuclear Information System (INIS)

    Neutrophil emigration is a critical component of the inflammatory process and is generally thought to play a role in host defense as well as in the tissue injury that often accompanies inflammation. Most inflammatory reactions exhibit a sequence of emigrating cell types, thus clearly demonstrating that the neutrophil influx eventually ceases and that the neutrophils are then removed from the lesion. It has been our premise that in order to understand the processes that lead to the progressive inflammatory reactions that underly so many disease processes, it is important to determine the mechanism by which the ''normal'' inflammatory response resolves. The purpose of this study was to identify the time of cessation of neutrophil influx in experimental arthritis induced by the injection of C5 fragments (C5f) and to investigate mechanisms underlying the cessation process. The migration of i.v. delivery pulses to inflamed joints was assessed by lavage of the joint space and by external scintigraphy. We found no evidence for the development of inhibitory systems against chemotactic factors or ''desensitization'' of the inflamed site, because a second injection of C5f into joints which had been injected previously with C5f resulted in enhancement rather than inhibition of migration. Neither was evidence found for altered tissue barriers to migration or for desensitization of neutrophils as possible explanations for cessation of influx. The major mechanism appeared to be a loss of chemoattractant activity in the joint space between 2 h and 6 h after C5f injection which was detected by transfer into a fresh joint. Radiolabeled C5a des-Arg had a t1/2 of disappearance from the joint of less than 1 h, which suggested that the transferred chemoattractant must, in part, have been due to the generation of new chemotaxins by C5f injection

  2. Influx of Enterococci and Associated Antibiotic Resistance and Virulence Genes from Ready-To-Eat Food to the Human Digestive Tract▿

    OpenAIRE

    Macovei, Lilia; Zurek, Ludek

    2007-01-01

    The influx of enterococcal antibiotic resistance (AR) and virulence genes from ready-to-eat food (RTEF) to the human digestive tract was assessed. Three RTEFs (chicken salad, chicken burger, and carrot cake) were sampled from five fast-food restaurants five times in summer (SU) and winter (WI). The prevalence of enterococci was significantly higher in SU (92.0% of salad samples and 64.0% of burger samples) than in WI (64.0% of salad samples and 24.0% of burger samples). The overall concentrat...

  3. The Phenomenon of «Deep Water» Influx from the Earth's Interior and its Role in the Development of the Earth

    OpenAIRE

    A. I. Tikhonov; I. S. Kopylov

    2014-01-01

    The phenomenon of extensive permanent influx of the «deep-water» to the hydrosphere of the Earth characterized by a high content of various chemical components, including mineral and toxic elements of deep origin is considered. Results of analysis of large amount of experimental data suggest that «deep-water» is a source of formation and permanent supplement of the ocean water with stable salinity, chemical and isotopic composition, and the formation of various mineralized water deposits. «De...

  4. Fluvial influx and weathering history of the Himalayas since Last Glacial Maxima - Isotopic, sedimentological and magnetic records from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.; Patil, S.K.; Suneethi, J.

    augmented the fluvial influx of the Himalayan rivers. These events are also coeval with melt water pulses 1A and IB observed in sea - level r e- cords in which global sea - level had risen by 24 and 28 m respectively 17 . We, ther e fore, suggest... that augmented chlorite is produced under arid, cold climate due to higher magnitude of physical weathering. With increase in the precipitation, production of smectite ? illite ? kaolinite ? gibbsite in the increasing order is observed 35 . In the bay...

  5. The Phenomenon of «Deep Water» Influx from the Earth's Interior and its Role in the Development of the Earth

    Directory of Open Access Journals (Sweden)

    A. I. Tikhonov

    2014-12-01

    Full Text Available The phenomenon of extensive permanent influx of the «deep-water» to the hydrosphere of the Earth characterized by a high content of various chemical components, including mineral and toxic elements of deep origin is considered. Results of analysis of large amount of experimental data suggest that «deep-water» is a source of formation and permanent supplement of the ocean water with stable salinity, chemical and isotopic composition, and the formation of various mineralized water deposits. «Deep-water» can cause formation of substandard water clusters within the underground fresh water fields, affecting their ecological quality.

  6. CFTR and Ca2+ signaling in cystic fibrosis

    Directory of Open Access Journals (Sweden)

    Fabrice eAntigny

    2011-10-01

    Full Text Available Among the diverse physiological functions exerted by calcium signaling in living cells, its role in the regulation of protein biogenesis and trafficking remains incompletely understood. In cystic fibrosis (CF disease the most common CFTR (Cystic Fibrosis Transmembrane conductance Regulator mutation, F508del-CFTR generates a misprocessed protein that is abnormally retained in the endoplasmic reticulum (ER compartment, rapidly degraded by the ubiquitine/proteasome pathway and hence absent at the plasma membrane of CF epithelial cells. Recent studies have demonstrated that intracellular calcium signals consequent to activation of apical G protein-coupled receptors (GPCRs by different agonists are increased in CF airway epithelia. Moreover, the regulation of various intracellular calcium storage compartments, such as ER is also abnormal in CF cells. Although the molecular mechanism to explain this increase remains puzzling in epithelial cells, the F508del-CFTR mutation is proposed to be the origin of abnormal Ca2+ influx linking the calcium signaling to CFTR pathobiology. This article reviews the relationships between CFTR and calcium signaling in the context of the genetic disease cystic fibrosis.

  7. Endometrial Stromal Sarcoma Arising in Colorectal Endometriosis: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Qiao Wang

    2015-01-01

    Full Text Available Extrauterine endometrial stromal sarcoma (ESS arising in endometriosis is extremely rare, particularly in the colorectum. It should always be included in the differential diagnosis of primary tumors originating from gastrointestinal tract in females, given that preoperative endoscopical biopsy may reveal no specific changes. We reported a case of ESS arising in colorectal endometriosis and reviewed the previous 7 cases reported in the English literature. Our patient, who was unavailable for tumor resection and refused further adjuvant therapy, played a role in representing the natural history of low-grade extragenital ESS. This case was the only death from ESS arising in colorectal endometriosis.

  8. Decreased Caffeine-Induced Locomotor Activity via Microinjection of CART Peptide into the Nucleus Accumbens Is Linked to Inhibition of the pCaMKIIa-D3R Interaction.

    Directory of Open Access Journals (Sweden)

    Qiang Fu

    Full Text Available The purpose of this study was to characterize the inhibitory modulation of cocaine- and amphetamine-regulated transcript (CART peptides, particularly with respect to the function of the D3 dopamine receptor (D3R, which is activated by its interaction with phosphorylated CaMKIIα (pCaMKIIα in the nucleus accumbens (NAc. After repeated oral administration of caffeine (30 mg/kg for five days, microinjection of CART peptide (0.08 μM/0.5 μl/hemisphere into the NAc affected locomotor behavior. The pCaMKIIα-D3R interaction, D3R phosphorylation and cAMP/PKA/phosphorylated CREB (pCREB signaling pathway activity were measured in NAc tissues, and Ca2+ influx and pCaMKIIα levels were measured in cultured NAc neurons. We found that CART attenuated the caffeine-mediated enhancement of depolarization-induced Ca2+ influx and CaMKIIα phosphorylation in cultured NAc neurons. Repeated microinjection of CART peptides into the NAc decreased the caffeine-induced enhancement of Ca2+ channels activity, pCaMKIIα levels, the pCaMKIIα-D3R interaction, D3R phosphorylation, cAMP levels, PKA activity and pCREB levels in the NAc. Furthermore, behavioral sensitization was observed in rats that received five-day administration of caffeine following microinjection of saline but not in rats that were treated with caffeine following microinjection of CART peptide. These results suggest that caffeine-induced CREB phosphorylation in the NAc was ameliorated by CART peptide due to its inhibition of D3R phosphorylation. These effects of CART peptides may play a compensatory role by inhibiting locomotor behavior in rats.

  9. Decreased Caffeine-Induced Locomotor Activity via Microinjection of CART Peptide into the Nucleus Accumbens Is Linked to Inhibition of the pCaMKIIa-D3R Interaction.

    Science.gov (United States)

    Fu, Qiang; Zhou, Xiaoyan; Dong, Yun; Huang, Yonghong; Yang, Jianhua; Oh, Ki-Wan; Hu, Zhenzhen

    2016-01-01

    The purpose of this study was to characterize the inhibitory modulation of cocaine- and amphetamine-regulated transcript (CART) peptides, particularly with respect to the function of the D3 dopamine receptor (D3R), which is activated by its interaction with phosphorylated CaMKIIα (pCaMKIIα) in the nucleus accumbens (NAc). After repeated oral administration of caffeine (30 mg/kg) for five days, microinjection of CART peptide (0.08 μM/0.5 μl/hemisphere) into the NAc affected locomotor behavior. The pCaMKIIα-D3R interaction, D3R phosphorylation and cAMP/PKA/phosphorylated CREB (pCREB) signaling pathway activity were measured in NAc tissues, and Ca2+ influx and pCaMKIIα levels were measured in cultured NAc neurons. We found that CART attenuated the caffeine-mediated enhancement of depolarization-induced Ca2+ influx and CaMKIIα phosphorylation in cultured NAc neurons. Repeated microinjection of CART peptides into the NAc decreased the caffeine-induced enhancement of Ca2+ channels activity, pCaMKIIα levels, the pCaMKIIα-D3R interaction, D3R phosphorylation, cAMP levels, PKA activity and pCREB levels in the NAc. Furthermore, behavioral sensitization was observed in rats that received five-day administration of caffeine following microinjection of saline but not in rats that were treated with caffeine following microinjection of CART peptide. These results suggest that caffeine-induced CREB phosphorylation in the NAc was ameliorated by CART peptide due to its inhibition of D3R phosphorylation. These effects of CART peptides may play a compensatory role by inhibiting locomotor behavior in rats. PMID:27404570

  10. A confocal study of mechanism of 5-hydroxytryptaminoinduced intracellular calcium dynamics in cultured ratstomach fundus smooth muscle cells with a new Ca2+indicator STDIn-AM

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Xiaoling; (张小玲); YAN; Hongtao; (阎宏涛)

    2002-01-01

    A new fluorescent Ca2+ indicator STDIn-AM for detecting i transients in cultured smooth muscle cells is presented. By making a comparison, the difference between STDIn and fluo-3 is discussed in detail. Using the new Ca2+ indicator, the mechanism of 5-hydroxytryptamino (5-HT) induced intracellular calcium dynamics in stomach fundus smooth muscle cells (SFSMC) of rats is investigated. It is shown that in contrast with fluo-3, STDIn is uniformly distributed in the cytosolic compartment but excluded from the nucleus, when it is transfected into cells. This feature makes it a real cytosol Ca2+ indicator and can reflect changes of cytosol more accurately than that of fluo-3. In addition, STDIn responds to the i transients more sensitive and faster than fluo-3. The results also show that, the L-type Ca2+ channel inhibitor Mn9202 and the PLC inhibitor Compound 48/80 can significantly inhibit the i elevation induced by 5-HT, while the PKC inhibitor D-Sphingosine can enhance the effect of 5-HT. The results suggest that 5-HT acts by the way of 5-HT2 receptors on SFSMC, then through 5-HT2 receptors coupled IP3/Ca2+ and GC/PKC double signal transduction pathways to make Ca2+ release from intracellular Ca2+ stores and Ca2+ influx possibly through L-type calcium channels.

  11. A Classical Realizability Model arising from a Stable Model of Untyped Lambda Calculus

    OpenAIRE

    Streicher, Thomas

    2014-01-01

    We study a classical realizability model (in the sense of J.-L. Krivine) arising from a model of untyped lambda calculus in coherence spaces. We show that this model validates countable choice using bar recursion and bar induction.

  12. Approximate Solutions for Local Fractional Linear Transport Equations Arising in Fractal Porous Media

    OpenAIRE

    2014-01-01

    We investigate the local fractional linear transport equations arising in fractal porous media by using the local fractional variational iteration method. Their approximate solutions within the nondifferentiable functions are obtained and their graphs are also shown.

  13. On a Linear Equation Arising in Isometric Embedding of Torus-like Surface

    Institute of Scientific and Technical Information of China (English)

    Chunhe LI

    2009-01-01

    The solvability of a linear equation and the regularity of the solution are discussed.The equation is arising in a geometric problem which is concerned with the realization of Alexandroff's positive annul in R3.

  14. Algebraic Bethe ansatz for integrable extended Hubbard models arising from supersymmetric group solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, Anthony J.; Ge Xiangyu; Gould, Mark D.; Links, Jon; Zhou Huanqiang [Centre for Mathematical Physics, University of Queensland, Brisbane, QLD (Australia)

    2001-06-01

    Integrable extended Hubbard models arising from symmetric group solutions are examined in the framework of the graded quantum inverse scattering method. The Bethe ansatz equations for all these models are derived by using the algebraic Bethe ansatz method. (author)

  15. Intra-articular ganglion arising from the meniscofemoral ligament of Humphrey

    International Nuclear Information System (INIS)

    We present a case of an intra-articular ganglion of the knee arising from the anterior meniscofemoral ligament of Humphrey. The MR imaging and arthroscopic appearance of the lesion are illustrated. (orig.)

  16. A pair of Fibonacci-like polynomials arising from a special mapping

    Science.gov (United States)

    Griffiths, Martin; Griffiths, Jonny

    2016-02-01

    We study here a pair of sequences of polynomials that arise from a particular iterated mapping on the plane. We show how these sequences come about, and give some of their interesting mathematical properties.

  17. Two cases of basal cell carcinoma arising from chronic radiation dermatitis

    International Nuclear Information System (INIS)

    A 48-year-old female and a 51-year-old male with basal cell carcinoma (BCC) arising from chronic radiation dermatitis are reviewed. They are treated with radiotherapy for hemangioma on their right cheek in their childhood. Review in the literature showed high incidence of the histological diagnosis of malignant skin tumors arising from chronic radiation dermatitis are follows: squamous cell carcinoma (SCC), BCC, sarcoma, and Bowen's disease. (author)

  18. Metastatic Pulmonary Adenocarcinoma Deposit Arising Within a Cutaneous Basal Cell Carcinoma: A Case Report

    OpenAIRE

    Carey, Elinor; Jones, Simon D; Griffiths, Paul; Baxter, Prue

    2011-01-01

    Skin metastases are rare complications of internal malignancies, and most commonly arise from primary lung carcinoma (Brownstein and Helwig in Arch Dermatol 105:82–68, 1972). Metastatic cutaneous lesions have not previously been documented to arise within other skin tumours. We report our experience of a solitary pulmonary adenocarcinoma metastasis that arose within a pre-existing basal cell carcinoma in a patient with undiagnosed lung cancer. Immunohistochemistry was invaluable in confirming...

  19. Clear Cell Adenocarcinoma Arising from Adenofibroma in a Patient with Endometriosis of the Ovary.

    Science.gov (United States)

    Cho, Inju; Lim, Sung-Chul

    2016-03-01

    Ovarian clear cell adenocarcinomas (CCACs) are frequently associated with endometriosis and, less often with clear cell adenofibromas (CCAFs). We encountered a case of ovarian CCAC arising from benign and borderline adenofibromas of the clear cell and endometrioid types with endometriosis in a 53-year-old woman. Regions of the adenofibromas showed transformation to CCAC and regions of the endometriosis showed atypical endometriotic cysts. This case demonstrates that CCAC can arise from CCAF or endometriosis. PMID:26498012

  20. Schwannomatosis with Cystic Degeneration Arising from a Single Intercostal Nerve: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun Woo; Lee, Young Kyung [Dept. of Radiology, Kyung Hee University College of Medicine, Seoul (Korea, Republic of); Kim, Dae Hyun [Dept. of Thoracic and Cardiovascular, Kyung Hee Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul (Korea, Republic of); Sung, Dong Wook [Dept. of Radiology, Kyung Hee Medical Center, Kyung Hee University College of Medicine, Seoul (Korea, Republic of)

    2012-03-15

    An intrathoracic schwannoma is a benign neurogenic tumor that arises from the posterior mediastinum and is commonly found to be solitary. Schwannomatosis that manifests as multiple cysts is extremely rare. In this case study, we report a rare case of a 36-year-old man with no respiratory symptoms, with multiple cystic tumors in the posterior chest wall and pathologically confirmed schwannomatosis with cystic degeneration arising from a single intercostal nerve.

  1. Multi-focal lobular carcinoma in situ arising in benign phylodes tumor: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taeg Ki; Choi, Chang Hwan; Kim, Youn Jeong; Kim, Mi Young; Lee, Kyung Hee; Cho, Soon Gu [Inha University Hospital, Incheon (Korea, Republic of)

    2015-08-15

    Coexistent breast malignancy arising in phyllodes tumor is extremely rare, and most of them are incidental reports after surgical excision. Coexistent malignancy in phyllodes tumor can vary from in-situ to invasive carcinoma. Lobular neoplasia is separated into atypical lobular hyperplasia and lobular carcinoma in situ (LCIS). LCIS is known to have a higher risk of developing invasive cancer. We reported imaging findings of multifocal LCIS arising in benign phyllodes tumor.

  2. [Primary metastatic well-differentiated neuroendocrine tumor arising in a tailgut cyst].

    Science.gov (United States)

    Wöhlke, M; Sauer, J; Dommisch, K; Görling, S; Valdix, A; Hinze, R

    2011-03-01

    Tailgut cysts are unusual benign cystic retrorectal malformations arising from persistent remnants of the postanal gut. Malignant transformation within this dysontogenetic lesion is very uncommon. We report the rare occurrence of a neuroendocrine tumor arising in a tailgut cyst with primary liver and lymph node metastases in a 55-year-old woman. The neuroendocrine differentiation of the tumor determines the therapeutic approach and prognosis. PMID:21046106

  3. Post-transplantation lymphoproliferative disorders arising in solid organ transplant recipients are usually of recipient origin.

    OpenAIRE

    Chadburn, A; Suciu-Foca, N; Cesarman, E.; Reed, E; Michler, R.E.; Knowles, D M

    1995-01-01

    Recent clinical, pathological, and molecular studies have increased our understanding of posttransplantation lymphoproliferative disorders (PT-LPDs). Studies have shown that the majority of PT-LPDs arising in bone marrow transplant recipients are of donor origin; however, the source (host or donor) of the lymphoid cells that make up PT-LPDs arising in solid organ transplant recipients has not been systemically investigated. In this study, 18 PT-LPDs occurring in 16 organ transplant recipients...

  4. Two cases of basal cell carcinoma arising from chronic radiation dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Wakamori, Takeshi; Takenaka, Hideya; Ueda, Eiichiro; Katoh, Norito; Kishimoto, Saburo [Kyoto Prefectural Univ. of Medicine (Japan)

    2003-04-01

    A 48-year-old female and a 51-year-old male with basal cell carcinoma (BCC) arising from chronic radiation dermatitis are reviewed. They are treated with radiotherapy for hemangioma on their right cheek in their childhood. Review in the literature showed high incidence of the histological diagnosis of malignant skin tumors arising from chronic radiation dermatitis are follows: squamous cell carcinoma (SCC), BCC, sarcoma, and Bowen's disease. (author)

  5. Variation of turbulence characteristics along the radius under different gas influx, ECRH power and plasma currents in T-10 tokamak

    International Nuclear Information System (INIS)

    The turbulence characteristics were investigated by means of correlation reflectometry and Langmuir probes. The ECRH discharges show the distinct transition from the core turbulence, having complex structure, to the unstructured one at periphery. It is explained as the transition from ITG/TEM to the resistive interchange instability. The core turbulence includes the 'broad band', 'quasi-coherent' feature, arising due to the excitation of rational surfaces with high poloidal m-numbers, 'low frequency', looking like 'streamers' and oscillations at 20 - 30 kHz, having properties of 'zonal flows'. The turbulence rotates like rigid body with constant angular velocity equal to that of m=2 mode rotation over all plasma radii in OH discharges. The decrease of the mean core turbulence wavelength, impurities peaking and decrease of ion heat conductivity were observed under transition of the OH discharge from SOC to IOC phase after gas puff cut off. The change of poloidal asymmetry was also registered. Significant variation of the turbulence characteristics were measured at the start of the central ECRH and after fast edge cooling by carbon flake. In all cases the change of the core turbulence were interpreted as interplay between ITG and DTEM instabilities. (author)

  6. Distinct properties of Ca2+-calmodulin binding to N- and C-terminal regulatory regions of the TRPV1 channel

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Sze-Yi; Procko, Erik; Gaudet, Rachelle [Harvard

    2012-11-01

    Transient receptor potential (TRP) vanilloid 1 (TRPV1) is a molecular pain receptor belonging to the TRP superfamily of nonselective cation channels. As a polymodal receptor, TRPV1 responds to heat and a wide range of chemical stimuli. The influx of calcium after channel activation serves as a negative feedback mechanism leading to TRPV1 desensitization. The cellular calcium sensor calmodulin (CaM) likely participates in the desensitization of TRPV1. Two CaM-binding sites are identified in TRPV1: the N-terminal ankyrin repeat domain (ARD) and a short distal C-terminal (CT) segment. Here, we present the crystal structure of calcium-bound CaM (Ca2+CaM) in complex with the TRPV1-CT segment, determined to 1.95-Å resolution. The two lobes of Ca2+CaM wrap around a helical TRPV1-CT segment in an antiparallel orientation, and two hydrophobic anchors, W787 and L796, contact the C-lobe and N-lobe of Ca2+CaM, respectively. This structure is similar to canonical Ca2+CaM-peptide complexes, although TRPV1 contains no classical CaM recognition sequence motif. Using structural and mutational studies, we established the TRPV1 C terminus as a high affinity Ca2+CaM-binding site in both the isolated TRPV1 C terminus and in full-length TRPV1. Although a ternary complex of CaM, TRPV1-ARD, and TRPV1-CT had previously been postulated, we found no biochemical evidence of such a complex. In electrophysiology studies, mutation of the Ca2+CaM-binding site on TRPV1-ARD abolished desensitization in response to repeated application of capsaicin, whereas mutation of the Ca2+CaM-binding site in TRPV1-CT led to a more subtle phenotype of slowed and reduced TRPV1 desensitization. In summary, our results show that the TRPV1-ARD is an important mediator of TRPV1 desensitization, whereas TRPV1-CT has higher affinity for CaM and is likely involved in separate regulatory mechanisms.

  7. Cadmium sorption, influx, and efflux at the mesophyll layer of leaves from ecotypes of the Zn/Cd hyperaccumulator Thlaspi caerulescens.

    Science.gov (United States)

    Ebbs, Stephen D; Zambrano, M Clemencia; Spiller, Shawna M; Newville, Matthew

    2009-01-01

    Differential sorption and transport characteristics of the leaf mesophyll layer of the Prayon and Ganges ecotypes of the hyperaccumulator Thlaspi caerulescens were examined. (109)Cd influx and efflux experiments were conducted with leaf sections, and X-ray absorption near edge structure (XANES) data were collected from leaves as a general comparison of in vivo cadmium (Cd) coordination. There were modest differences in cell wall sorption of Cd between ecotypes. There were obvious differences in time- and concentration-dependent Cd influx, including a greater V(MAX) for Prayon but a lower K(M) for Ganges for concentration-dependent Cd uptake and a notably greater Cd uptake by Ganges leaf sections at 1000 microm Cd. Leaf sections of Prayon had a greater Cd efflux than Ganges. The XANES spectra from the two ecotypes suggested differences in Cd coordination. The fundamental differences observed between the two ecotypes may reflect differential activity and/or expression of plasma membrane and tonoplast transporters. More detailed study of these transporters and the in vivo coordination of Cd are needed to determine the contribution of these processes to metal homeostasis and tolerance. PMID:19054336

  8. Cadmium sorption, influx, and efflux at the mesophyll layer of leaves from ecotypes of the Zn/Cd hyperaccumulator Thlaspi caerulescens

    Energy Technology Data Exchange (ETDEWEB)

    Ebbs, S.D.; Zambrano, M.C.; Spiller, S.M.; Newville, M. (SIU); (UC)

    2009-01-23

    Differential sorption and transport characteristics of the leaf mesophyll layer of the Prayon and Ganges ecotypes of the hyperaccumulator Thlaspi caerulescens were examined. {sup 109}Cd influx and efflux experiments were conducted with leaf sections, and X-ray absorption near edge structure (XANES) data were collected from leaves as a general comparison of in vivo cadmium (Cd) coordination. There were modest differences in cell wall sorption of Cd between ecotypes. There were obvious differences in time- and concentration-dependent Cd influx, including a greater V{sub MAX} for Prayon but a lower K{sub M} for Ganges for concentration-dependent Cd uptake and a notably greater Cd uptake by Ganges leaf sections at 1000 {micro}m Cd. Leaf sections of Prayon had a greater Cd efflux than Ganges. The XANES spectra from the two ecotypes suggested differences in Cd coordination. The fundamental differences observed between the two ecotypes may reflect differential activity and/or expression of plasma membrane and tonoplast transporters. More detailed study of these transporters and the in vivo coordination of Cd are needed to determine the contribution of these processes to metal homeostasis and tolerance.

  9. Connexin43-containing gap junctions potentiate extracellular Ca²⁺-induced odontoblastic differentiation of human dental pulp stem cells via Erk1/2.

    Science.gov (United States)

    Li, Shiting; He, Haitao; Zhang, Gang; Wang, Fei; Zhang, Ping; Tan, Yinghui

    2015-10-15

    Extracellular Ca(2+) can promote dentin sialophosphoprotein (DSPP) expression and odontoblastic differentiation of dental pulp stem cells (DPSCs). Gap junctions mediated by connexin43 (Cx43) allow diffusion of small molecules (such as Ca(2+)) among cells to regulate cell-to-cell communications. However, it is unclear whether Cx43 is required for the Ca(2+)-induced cell differentiation. Here, we found that the influx of extracellular Ca(2+) through L-type Ca(2+) channels increases intracellular free Ca(2+) levels to promote DSPP expression. Cx43 overexpression potentiated the extracellular Ca(2+)-induced DSPP expression via Erk1/2. Flow cytometry analyses showed that Cx43 increased the percentage of p-Erk1/2 positive cells in response to Ca(2+), indicating that Cx43 in DPSCs possibly acts as a traditional gap junction channel, which permits the sharing of signals among coupled cells to make more DPSCs respond to Ca(2+). Furthermore, inhibition of Cx43 function and gap junction communication decreased Ca(2+)-induced the expression of DSPP, suggesting that cell-to-cell contacts are required for Cx43 to promote the Ca(2+)-induced cell differentiation. Similarly, the study performed on DPSCs cultured at low-density and high-density revealed that intercellular contacts are required to potentiate Erk1/2 activity and DSPP expression. In total, this study indicates that Cx43 increases Ca(2+)-induced DSPP expression and odontoblastic differentiation of DPSCs via Erk1/2 through gap junction-mediated cell-to-cell contacts. PMID:26376117

  10. Aluminum toxicity and Ca depletion may enhance cell death of tobacco cells via similar syndrome.

    Science.gov (United States)

    Basset, Refat Abdel; Matsumoto, Hideaki

    2008-05-01

    The main objective of this work is to find out whether aluminum (Al) toxicity and Ca depletion cause cell death of tobacco cells via similar sequence of events. Tobacco cell suspension culture exhibited maximum fresh weight in the presence of a wide range of Ca concentrations between 0.1-1.0 mM whereas higher concentrations (>1.0-5.0 mM) gradually lowered cell fresh weight. However, this decrease in fresh weight does not imply a negative impact on cell viability since cell growth recommenced in fresh MS medium with rates mostly higher than those of low Ca. In addition, high Ca seems to be crucial for survival of Al-treated cells. On the other side, tobacco cells exhibited extreme sensitivity to complete deprivation of Ca. Without Ca, cells could not survive for 18 h and substantially lost their growth capability. Evans blue uptake proved membrane damage of Ca-depleted same as Al-treated cells; relative to maintained membrane intactness of calcium-supplemented (control) ones. Percentage of membrane damage and the growth capability (survival) of tobacco cells exhibited a clear negative correlation.Alterations in growth (fresh weight per aliquot) could not be ascribed neither to cell number nor to decreased dry matter allocation (dry weight/fresh weight percentage) but was mainly due to decreased cellular water content. In this context, Ca-depleted cells lost about half their original water content while 100 microM Al-treated ones retained most of it (ca 87%). This represented the single difference between the two treatments (discussed in the text). Nevertheless, such high water content of the Al-treated cells seems physiologically useless since it did not result in improved viability. Similarities, however, included negligible levels of growth capability, maximum levels of membrane damage, and comparable amounts of NO(3) (-) efflux. As well, both types of treatments led to a sharp decline in osmotic potential that is, in turn, needed for water influx. The above

  11. Estimation of doses to the residents arising from inhalation of Rn-222, Tn-220 and their decay products in high background radiation area of Yangjiang

    International Nuclear Information System (INIS)

    Objective: The author reports on the estimate of average annual effective dose of the residents and absorbed dose in some human tissues and organs arising from inhalation of Rn-222, Tn-220 and their decay products in investigated areas. Methods: In order to calculate equilibrium factor F for Rn-222 and equilibrium equivalent concentration of Tn-222, the authors measure concentration of Rn-222 and Tn-220 by discrete sampling. Meanwhile, the authors measure the concentration of decay products of Rn-222 and Tn-220. Based on the equilibrium factor F of Rn-222 and equilibrium equivalent concentration of Tn-220, and the occupancy factor, writer estimated average annual effective doses and absorbed doses in some tissues and organs to the residents arising from inhalation of Rn-222, Tn-220 and their decay products in investigated areas. Results: The data based upon the results of integrated measurements on the concentration of Rn-222, Tn-220 in investigated areas. The average indoor and outdoor concentration of Rn-222 are 49.61 Bq·m-3 and 17.30 Bq·m-3 in HBRA, respectively, and 18.1 and 11.7 Bq·m-3 in CA, respectively. The average indoor and outdoor concentrations of Tn-220 are 95.16 Bq·m-3 and 9.3 Bq·m-3 in HBRA, respectively, and 12.4 and 8.1 Bq·m-3 in CA, respectively. The averages of equilibrium factors of Rn-222 for indoors and outdoors in HBRA are 0.46 and 0.53, respectively. The values in CA are 0.62 for indoors and 0.63 for outdoors, respectively. The value of equilibrium equivalent concentration of Tn-220 for indoors and outdoors in HBRA are 6.51 Bq·m-'3 and 0.79 Bq·m-3, respectively, and the values for CA are 0.66 Bq·m-3 and 0.33 Bq·m-3, respectively. Conclusion: The estimate of average annual effective dose to the residents arising from inhalation of Rn-222, Tn-220 and their decay products was 3.28 mSv·a-1 in HBRA, while that in CA was 1.03 mSv·a-1. The trachea-bronchial tree has the maximum absorbed dose in HBRA, the value is 5.40 mGy·a-1; lung has

  12. CaPTC Biennial Meetings

    Science.gov (United States)

    CaPTC hosts the 'Biennial Science of Global Prostate Cancer Disparities in Black Men' conference to address the growing global public health problem of prostate cancer among Black men in industrialized and developing countries.

  13. Sonoma County, CA, 2013 Lidar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sonoma County Vegetation Mapping and LiDAR Consortium retained WSI to provide lidar and Orthophoto data and derived products in Sonoma County, CA. A classified LAS...

  14. CaWave user's guide

    International Nuclear Information System (INIS)

    CaWave User's Guide explains how to use the CaWave functions which were specifically written in PV-WAVE command language and C language for EPICS users. CaWave consists of a special set of external channel access functions which provides the PV-WAVE users with easy and flexible access of channel information across the IOC networks. It also provides a complete set of process variable event monitoring functions. This document also gives examples how a PV-WAVE user can interface to channel access devices. It is assumed that the user is already familiar with using PV-WAVE. Few simple example modules of using PV-WAVE command language with CaWave functions are also given in this document

  15. CA 242, a new tumour marker for pancreatic cancer: a comparison with CA 19-9, CA 50 and CEA.

    OpenAIRE

    Haglund, C.; Lundin, J; Kuusela, P.; Roberts, P. J.

    1994-01-01

    The serum expression of a novel tumour marker, CA 242, defined by monoclonal antibody C 242, was studied in 179 patients with pancreatic cancer. The results were compared with CA 19-9, CA 50 and CEA. CA 242 is a carbohydrate closely related, but not identical, to CA 19-9 and CA 50. The overall sensitivity of the CA 242 assay was 74%: 55% in stage I, 83% in stage II-III and 78% in stage IV disease. The specificity calculated from 112 patients with benign diseases was 91%. CA 19-9 had a higher ...

  16. Calcium antagonistic effects of Bambusa Rigida investigated by 45Ca and its protection on myocardial ischemia of rats

    Institute of Scientific and Technical Information of China (English)

    LIN Rushan; YE Ling; YANG Yuanyou; LIAO Jiali; MO Shangwu; LIU Ning

    2008-01-01

    An investigation was conducted using 45Ca as a radioactive tracer to evaluate calcium antagonistic effects of several extracts from Bambusa Rigida in living rats. The relationship between the flavonoid and saccharide contents of Bambusa Rigida and calcium antagonistic effects were also analyzed. The protective effects of the alkali extracts ofBambusa Rigida on myocardial ischemia were investigated in living rats. The results indicated that the alkali extracts of Bambusa Rigida had a prominent influence on Ca2+ influx and efflux in the isolated rat aorta and heart, as they could obviously block 45Ca entering into cells and stimulate efflux of intracellular Ca2+. Moreover, the alkali extracts of Bambusa Rigida had favorable protective effects on myocardial ischemia induced either by isoproterenol injection (ISO) or by the ligation of coronary artery. These results implied that the Bambusa Rigida had attractive potential for the treatment of heart, cerebrovascular and other diseases. However, the conclusion that whether the flavonoid or saccharide in Bambusa Rigida affected the calcium antagonistic effects and Ca2+ channels or not was hard to make within the results of the investigation.

  17. Effect of quercetin on colon contractility and L-type Ca(2+) channels in colon smooth muscle of guinea-pig.

    Science.gov (United States)

    Huang, Wei-Feng; Ouyang, Shou; Li, Shi-Ying; Lin, Yan-Fei; Ouyang, Hui; Zhang, Hui; Lu, Chun-Jing

    2009-12-25

    The aim of the present study was to investigate the effects of quercetin on colon contractility and voltage-dependent Ca(2+) channels in the single smooth muscle cell isolated from the proximal colon of guinea-pig and to clarify whether its effect on L-type Ca(2+) current (I(Ca,L)) would be related to its myorelaxing properties. Colon smooth muscle strips were used to take contractile tension recordings. Smooth muscle cells were freshly isolated from the proximal colon of guinea-pig by means of papain treatment. I(Ba,L) (barium instead of calcium as current carrier) was measured by using whole-cell patch-clamp techniques. The results showed that quercetin relaxed colon muscle strips in a concentration-dependent manner and antagonized the contractile effect of acetylcholine and neostigmine. Preincubation with indomethcin [cyclooxygenase (COX) inhibitor] and methylene blue [guanylate cyclase (GC) inhibitor] significantly attenuated the relaxing effect of quercetin, respectively. Quercetin increased I(Ba,L) in a concentration- [EC(50)= (7.59+/-0.38) mumol/L] and voltage-dependent pattern, and shifted the maximum of the current-voltage curve by 10 mV in the depolarizing direction without modifying the threshold potential for Ca(2+) influx. Quercetin shifted the steady-state inactivation curve toward more positive potentials by approximately 3.75 mV without affecting the slope of activation and inactivation curve. H-89 (PKA inhibitor) abolished quercetin-induced I(Ba,L) increase, while cAMP enhanced the quercetin-induced I(Ba,L) increase. The patch-clamp results proved that quercetin increased I(Ba,L) via PKA pathway. It is therefore suggested that the relaxing effect of quercetin attributes to the interaction of GC and COX stimulation, as well as the antagonism effect on acetylcholine, which hierarchically prevails over the increase in the Ca(2+) influx to be expected from I(Ca,L) stimulation. PMID:20029691

  18. Desensitization-resistant and -sensitive GPCR-mediated inhibition of GABA release occurs by Ca2+-dependent and -independent mechanisms at a hypothalamic synapse.

    Science.gov (United States)

    Pennock, Reagan L; Hentges, Shane T

    2016-06-01

    Whereas the activation of Gαi/o-coupled receptors commonly results in postsynaptic responses that show acute desensitization, the presynaptic inhibition of transmitter release caused by many Gαi/o-coupled receptors is maintained during agonist exposure. However, an exception has been noted where GABAB receptor (GABABR)-mediated inhibition of inhibitory postsynaptic currents (IPSCs) recorded in mouse proopiomelanocortin (POMC) neurons exhibit acute desensitization in ∼25% of experiments. To determine whether differential effector coupling confers sensitivity to desensitization, voltage-clamp recordings were made from POMC neurons to compare the mechanism by which μ-opioid receptors (MORs) and GABABRs inhibit transmitter release. Neither MOR- nor GABABR-mediated inhibition of release relied on the activation of presynaptic K(+) channels. Both receptors maintained the ability to inhibit release in the absence of external Ca(2+) or in the presence of ionomycin-induced Ca(2+) influx, indicating that inhibition of release can occur through a Ca(2+)-independent mechanism. Replacing Ca(2+) with Sr(2+) to disrupt G-protein-mediated inhibition of release occurring directly at the release machinery did not alter MOR- or GABAB -mediated inhibition of IPSCs, suggesting that reductions in evoked release can occur through the inhibition of Ca(2+) channels. Additionally, both receptors inhibited evoked IPSCs in the presence of selective blockers of N- or P/Q-type Ca(2+) channels. Altogether, the results show that MORs and GABABRs can inhibit transmitter release through the inhibition of calcium influx and by direct actions at the release machinery. Furthermore, since both the desensitizing and nondesensitizing presynaptic receptors are similarly coupled, differential effector coupling is unlikely responsible for differential desensitization of the inhibition of release. PMID:26912590

  19. Fucoidan protects ARPE-19 cells from oxidative stress via normalization of reactive oxygen species generation through the Ca²⁺-dependent ERK signaling pathway.

    Science.gov (United States)

    Li, Xiaoxia; Zhao, Haiyan; Wang, Qingfa; Liang, Hongyan; Jiang, Xiaofeng

    2015-05-01

    Diabetic retinopathy (DR) is a common complication of diabetes mellitus (DM) and it is the main cause of loss of vision. In previous years, interest in the biological activities of marine organisms has intensified. The effect of fucoidan from the seaweed Fucus vesiculosus on the molecular mechanisms of numerous diseases has been studied, while to date, its effect on DR was yet to be investigated. Therefore, the aim of the present study was to evaluate the role of fucoidan in DR. The human retinal pigment epithelial cell line ARPE‑19 was exposed to high D‑glucose in the presence or absence of fucoidan. Cell viability was monitored using MTT and lactate dehydrogenase assays. The intracellular reactive oxygen species (ROS) generation was measured using fluorescence spectrophotometry. Cell apoptosis was measured by flow cytometry using Annexin V‑fluorescein isothiocyanate staining. Ca2+ influx was measured with a calcium imaging system and the activation of the extracellular signal‑regulated kinase (ERK) protein was evaluated using western blot analysis. The non‑toxic fucoidan protected ARPE‑19 cells from high glucose‑induced cell death and normalized high glucose‑induced generation of ROS. Fucoidan also inhibited high glucose‑induced cell apoptosis, as well as the Ca2+ influx and ERK1/2 phosphorylation in ARPE‑19 cells. Taken together, these findings indicated that fucoidan protects ARPE‑19 cells against high glucose‑induced oxidative damage via normalization of ROS generation through the Ca2+‑dependent ERK signaling pathway. PMID:25606812

  20. Stimulation of human red blood cells leads to Ca2+-mediated intercellular adhesion

    CERN Document Server

    Steffen, Patrick; Nguyen, Duc Bach; Müller, Torsten; Bernhardt, Ingolf; Kaestner, Lars; Wagner, Christian

    2011-01-01

    Red blood cells (RBCs) are a major component of blood clots, which form physiologically as a response to injury or pathologically in thrombosis. The active participation of RBCs in thrombus solidification has been previously proposed but not yet experimentally proven. Holographic optical tweezers and single-cell force spectroscopy were used to study potential cell-cell adhesion between RBCs. Irreversible intercellular adhesion of RBCs could be induced by stimulation with lysophosphatidic acid (LPA), a compound known to be released by activated platelets. We identified Ca2+ as an essential player in the signaling cascade by directly inducing Ca2+ influx using A23187. Elevation of the internal Ca2+ concentration leads to an intercellular adhesion of RBCs similar to that induced by LPA stimulation. Using single-cell force spectroscopy, the adhesion of the RBCs was identified to be approximately 100 pN, a value large enough to be of significance inside a blood clot or in pathological situations like the vasco-occ...

  1. Deoxyschisandrin modulates synchronized Ca2+ oscillations and spontaneous synaptic transmission of cultured hippocampal neurons

    Institute of Scientific and Technical Information of China (English)

    Min FU; Zhao-hui SUN; Min ZONG; Xiang-ping HE; Huan-cong ZUO; Zuo-ping XIE

    2008-01-01

    Aim: Deoxyschisandrin is one of the most effective composites of Schisandra chinensis, a famous Chinese medicine widely used as an antistress, anti-aging, and neurological performance-improving herb. In this study, we examined its spe- cific mechanisms of action on cultured hippocampal neurons. Methods: Hippoc- ampal neurons, primarily cultured for 9-11 d in vitro, were used for this study. DS were dissolved in DMSO and applied to calcium imaging and whole-cell patch clamp. Results: The application of 3 mg/L DS decreased the frequency of sponta- neous and synchronous oscillations of intracellular Ca2+ to 72%±2% (mean±SEM), and the spontaneous inhibitory postsynaptic currents to 60%±3% (mean±SEM). The inhibitory concentraton 50% (IC50) for the effect of DS on calcium oscillations was 3.8 mg/L. DS also depressed the high voltage-gated Ca2+ channel and the voltage-gated Na+ channel currents at the same time point. It had no effect, however, on voltage-gated K+ and spontaneous excitatory postsynaptic currents. Conclusion: DS inhibited the spontaneous and synchronous oscillations of intra- cellular Ca2+ through the depression of influx of extracellular calcium and the initiation of action potential. By repressing the spontaneous neurotransmitter release, DS modulated the neuronal network activities.

  2. GDF-15 enhances intracellular Ca2+ by increasing Cav1.3 expression in rat cerebellar granule neurons

    Science.gov (United States)

    Lu, Jun-Mei; Wang, Chang-Ying; Hu, Changlong; Fang, Yan-Jia; Mei, Yan-Ai

    2016-01-01

    GDF-15 (growth/differentiation factor 15) is a novel member of the TGF (transforming growth factor)-β superfamily that has critical roles in the central and peripheral nervous systems. We reported previously that GDF-15 increased delayed rectifier outward K+ currents and Kv2.1 α subunit expression through TβRII (TGF-β receptor II) to activate Src kinase and Akt/mTOR (mammalian target of rapamycin) signalling in rat CGNs (cerebellar granule neurons). In the present study, we found that treatment of CGNs with GDF-15 for 24 h increased the intracellular Ca2+ concentration ([Ca2+]i) in response to membrane depolarization, as determined by Ca2+ imaging. Whole-cell current recordings indicated that GDF-15 increased the inward Ca2+ current (ICa) without altering steady-state activation of Ca2+ channels. Treatment with nifedipine, an inhibitor of L-type Ca2+ channels, abrogated GDF-15-induced increases in [Ca2+]i and ICa. The GDF-15-induced increase in ICa was mediated via up-regulation of the Cav1.3 α subunit, which was attenuated by inhibiting Akt/mTOR and ERK (extracellular-signal-regulated kinase) pathways and by pharmacological inhibition of Src-mediated TβRII phosphorylation. Given that Cav1.3 is not only a channel for Ca2+ influx, but also a transcriptional regulator, our data confirm that GDF-15 induces protein expression via TβRII and activation of a non-Smad pathway, and provide novel insight into the mechanism of GDF-15 function in neurons. PMID:27114559

  3. Rapid effects of 17beta-estradiol on TRPV5 epithelial Ca2+ channels in rat renal cells.

    LENUS (Irish Health Repository)

    Irnaten, Mustapha

    2009-08-01

    The renal distal tubules and collecting ducts play a key role in the control of electrolyte and fluid homeostasis. The discovery of highly calcium selective channels, Transient Receptor Potential Vanilloid 5 (TRPV5) of the TRP superfamily, has clarified the nature of the calcium entry channels. It has been proposed that this channel mediates the critical Ca(2+) entry step in transcellular Ca(2+) re-absorption in the kidney. The regulation of transmembrane Ca(2+) flux through TRPV5 is of particular importance for whole body calcium homeostasis.In this study, we provide evidence that the TRPV5 channel is present in rat cortical collecting duct (RCCD(2)) cells at mRNA and protein levels. We demonstrate that 17beta-estradiol (E(2)) is involved in the regulation of Ca(2+) influx in these cells via the epithelial Ca(2+) channels TRPV5. By combining whole-cell patch-clamp and Ca(2+)-imaging techniques, we have characterized the electrophysiological properties of the TRPV5 channel and showed that treatment with 20-50nM E(2) rapidly (<5min) induced a transient increase in inward whole-cell currents and intracellular Ca(2+) via TRPV5 channels. This rise was significantly prevented when cells were pre-treated with ruthenium red and completely abolished in cells treated with siRNA specifically targeting TRPV5.These data demonstrate for the first time, a novel rapid modulation of endogenously expressed TRPV5 channels by E(2) in kidney cells. Furthermore, the results suggest calcitropic effects of E(2). The results are discussed in relation to present concepts of non-genomic actions of E(2) in Ca(2+) homeostasis.

  4. Synthetic peptides corresponding to human follicle-stimulating hormone (hFSH)-beta-(1-15) and hFSH-beta-(51-65) induce uptake of 45Ca++ by liposomes: evidence for calcium-conducting transmembrane channel formation

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, P.; Santa-Coloma, T.A.; Reichert, L.E. Jr. (Department of Biochemistry, Albany Medical College, New York, NY (USA))

    1991-06-01

    We have previously described FSH receptor-mediated influx of 45Ca++ in cultured Sertoli cells from immature rats and receptor-enriched proteoliposomes via activation of voltage-sensitive and voltage-independent calcium channels. We have further shown that this effect of FSH does not require cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding protein or activation of adenylate cyclase. In the present study, we have identified regions of human FSH-beta-subunit which appear to be involved in mediating calcium influx. We screened 11 overlapping peptide amides representing the entire primary structure of hFSH-beta-subunit for their effects on 45Ca++ flux in FSH receptor-enriched proteoliposomes. hFSH-beta-(1-15) and hFSH-beta-(51-65) induced uptake of 45Ca++ in a concentration-related manner. This effect of hFSH-beta-(1-15) and hFSH-beta-(51-65) was also observed in liposomes lacking incorporated FSH receptor. Reducing membrane fluidity by incubating liposomes (containing no receptor) with hFSH-beta-(1-15) or hFSH-beta-(51-65) at temperatures lower than the transition temperatures of their constituent phospholipids resulted in no significant (P greater than 0.05) difference in 45Ca++ uptake. The effectiveness of the calcium ionophore A23187, however, was abolished. Ruthenium red, a voltage-independent calcium channel antagonist, was able to completely block uptake of 45Ca++ induced by hFSH-beta-(1-15) and hFSH-beta-(51-65) whereas nifedipine, a calcium channel blocker specific for L-type voltage-sensitive calcium channels, was without effect. These results suggest that in addition to its effect on voltage-sensitive calcium channel activity, interaction of FSH with its receptor may induce formation of transmembrane aqueous channels which also facilitate influx of extracellular calcium.

  5. Synthetic peptides corresponding to human follicle-stimulating hormone (hFSH)-beta-(1-15) and hFSH-beta-(51-65) induce uptake of 45Ca++ by liposomes: evidence for calcium-conducting transmembrane channel formation

    International Nuclear Information System (INIS)

    We have previously described FSH receptor-mediated influx of 45Ca++ in cultured Sertoli cells from immature rats and receptor-enriched proteoliposomes via activation of voltage-sensitive and voltage-independent calcium channels. We have further shown that this effect of FSH does not require cholera toxin- or pertussis toxin-sensitive guanine nucleotide binding protein or activation of adenylate cyclase. In the present study, we have identified regions of human FSH-beta-subunit which appear to be involved in mediating calcium influx. We screened 11 overlapping peptide amides representing the entire primary structure of hFSH-beta-subunit for their effects on 45Ca++ flux in FSH receptor-enriched proteoliposomes. hFSH-beta-(1-15) and hFSH-beta-(51-65) induced uptake of 45Ca++ in a concentration-related manner. This effect of hFSH-beta-(1-15) and hFSH-beta-(51-65) was also observed in liposomes lacking incorporated FSH receptor. Reducing membrane fluidity by incubating liposomes (containing no receptor) with hFSH-beta-(1-15) or hFSH-beta-(51-65) at temperatures lower than the transition temperatures of their constituent phospholipids resulted in no significant (P greater than 0.05) difference in 45Ca++ uptake. The effectiveness of the calcium ionophore A23187, however, was abolished. Ruthenium red, a voltage-independent calcium channel antagonist, was able to completely block uptake of 45Ca++ induced by hFSH-beta-(1-15) and hFSH-beta-(51-65) whereas nifedipine, a calcium channel blocker specific for L-type voltage-sensitive calcium channels, was without effect. These results suggest that in addition to its effect on voltage-sensitive calcium channel activity, interaction of FSH with its receptor may induce formation of transmembrane aqueous channels which also facilitate influx of extracellular calcium

  6. Vasorelaxant Effect of 5'-Methylthioadenosine Obtained from Candida utilis Yeast Extract through the Suppression of Intracellular Ca(2+) Concentration in Isolated Rat Aorta.

    Science.gov (United States)

    Kumrungsee, Thanutchaporn; Akiyama, Sayaka; Saiki, Tomomi; Omae, Masato; Hamasawa, Kazuhiro; Matsui, Toshiro

    2016-05-01

    Our study is the first to demonstrate the vasorelaxant effect of Candida utilis yeast extract on rat aorta (EC50 of 7.2 ± 3.2 mg/mL). Among five identified compounds, 5'-methylthioadenosine (MTA) exhibited comparable vasorelaxant effect (EC50 of 190 ± 40 μM) with adenosine, a known vasodilator, on 1 μM phenylephrine (PE)-contracted Sprague-Dawley rat aortic rings. MTA induced vasorelaxation in an endothelium-independent manner and independent of the adenosine receptors. MTA reduced a CaCl2-induced vasocontraction stimulated by 1 μM PE, whereas the effect was abolished in a 60 mM KCl-induced vasocontraction. This indicates that MTA was not involved in the suppression of extracellular Ca(2+) influx. MTA significantly (P < 0.01) attenuated the PE-induced activation of calmodulin-dependent kinase II (CaMK II) in aortic rings and inhibited the phosphorylation of L-type Ca(2+) channel (VDCC). In conclusion, the underlying mechanism(s) of MTA-induced vasorelaxation involves the inhibition of Ca(2+)/CaMK II/VDCC phosphorylation pathway, resulting in the suppression of intracellular Ca(2+) concentration in aortic rings. PMID:27066696

  7. Infiltrating adenocarcinoma arising in a villous adenoma of the anal canal

    Institute of Scientific and Technical Information of China (English)

    Marni Colvin; Aris Delis; Erika Bracamonte; Hugo Villar; Luis R Leon Jr

    2009-01-01

    Primary neoplasms arising in the anal canal are relatively unusual. In particular, adenomas and adenocarcinomas are distinctly rare entities in this region. We describe an infiltrating, well-differentiated adenocarcinoma arising in a villous adenoma from the distal anal canal, in an otherwise healthy patient at low risk for gastrointestinal malignancy. This is the case of an octogenarian man with a several year history of hemorrhoids and intermittent rectal bleeding, more recently complaining of continuous hematochezia. Examination revealed a blood-covered pedunculated mass with a long stalk protruding from the anus. The lesion was amputated at the bedside. Microscopic evaluation revealed an infiltrating well-differentiated adenocarcinoma, arising from a villous adenoma. This was further evaluated under anesthesia and complete excision of distal anal tissue was performed. Our report is the first describing the possible malignant degeneration of a villous adenoma in the anal canal.

  8. Mucinous adenocarcinoma arising at the anastomotic site after operation for hirschsprung's disease: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Soo; Yoon, Kwon Ha [College of Medicine, Wonkwang Univ., Iksan (Korea, Republic of)

    2004-02-01

    To our knowledge, rectal cancer arising at the anastomotic site after surgery for Hirschsprung's disease has not been reported. We report a case of mucinous adenocarcinoma arising at the anastomotic site after Soave operation 26 years ago.

  9. Hepatocellular carcinoma arising from hepatocellular adenoma in a hepatitis B virus-associated cirrhotic liver

    International Nuclear Information System (INIS)

    Hepatocellular adenoma (HCA) is a rare, benign proliferation of hepatocytes that occurs mostly in a normal liver and in extreme rare cases, occurs in a cirrhotic liver. Hepatocellular carcinomas (HCC) arising within HCA through malignant transformation is rare. The specific incidence and mechanism of malignant transformation has not been established, but the long term use of oral contraceptives is considered a causative agent. We report a case of HCC arising from HCA detected in a hepatitis B-related cirrhotic liver with serial radiologic images.

  10. Langerhans Cell Sarcoma Arising from Langerhans Cell Histiocytosis: A Case Report

    OpenAIRE

    Lee, Jong-Sil; Ko, Gyung Hyuck; Kim, Ho Cheol; Jang, In Seok; Jeon, Kyung-Nyeo; Lee, Jeong-Hee

    2006-01-01

    Langerhans cell sarcoma (LCS) is a neoplastic proliferation of Langerhans cells that have overtly malignant cytologic features. It is a very rare disease and theoretically, it can present de novo or progress from an antecedent Langerhans cell histiocytosis (LCH). However, to our knowledge, LCS arising from an antecedent LCH has not been reported on. We present here a case of LCS arising from a pulmonary LCH. A 34 yr-old man who was a smoker, had a fever and a chronic cough. Computed tomograph...

  11. Hepatocellular carcinoma arising from hepatocellular adenoma in a hepatitis B virus-associated cirrhotic liver

    Energy Technology Data Exchange (ETDEWEB)

    Seo, J.M. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Lee, S.J., E-mail: lucia@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, S.H. [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, C.K.; Ha, S.Y. [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2012-04-15

    Hepatocellular adenoma (HCA) is a rare, benign proliferation of hepatocytes that occurs mostly in a normal liver and in extreme rare cases, occurs in a cirrhotic liver. Hepatocellular carcinomas (HCC) arising within HCA through malignant transformation is rare. The specific incidence and mechanism of malignant transformation has not been established, but the long term use of oral contraceptives is considered a causative agent. We report a case of HCC arising from HCA detected in a hepatitis B-related cirrhotic liver with serial radiologic images.

  12. Operational management for radioactive effluents and wastes arising in nuclear power plants

    International Nuclear Information System (INIS)

    This Guide provides those involved in the management of radioactive wastes arising in nuclear power plants with operational management information and administrative recommendations on the handling, treatment, storage and transport of the wastes on site. It also provides information on the assessment of the provisions needed by the operating organization for measuring, evaluating and controlling the release of radioactive effluents from the plant during its commissioning and operating phases and to demonstrate compliance with any applicable requirement made by the regulatory body. This Guide does not cover the management of wastes arising during decommissioning, nor the disposal of any wastes other than effluents

  13. Adenocarcinomas arising from primary retroperitoneal mature teratomas: CT and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Li-Jen; Wong, Yon-Cheong [Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Taipei (Taiwan); Chu, Sheng-Hsien [Department of Urology, Chang Gung Memorial Hospital, Taipei (Taiwan); Ng, Kwai-Fong [Department of Pathology, Chang Gung Memorial Hospital, Taipei (Taiwan)

    2002-06-01

    An adenocarcinoma arising from mature teratoma is one form of teratoma with malignant transformation. It is extremely rare but highly malignant. The authors report two patients with adenocarcinomas arising from primary retroperitoneal teratomas. The CT and MRI findings of the tumors are presented with emphasis on imaging features implying the presence of malignant transformation and differing from those of pure benign mature teratoma. Correct diagnosis of the presence of malignant transformation from a benign mature teratoma can be made as early as possible by awareness of the imaging features. (orig.)

  14. CaWingz user's guide

    International Nuclear Information System (INIS)

    This document assumes that you have read and understood the Wingz user's manuals. CaWingz is an external Wingz program which, when combined with a set of script files, provides easy-to-use EPICS channel access interface functions for Wingz users. The external function run allows Wingz user to invoke any Unix processor within caWingz. Few additional functions for accessing static database field and monitoring of value change event is available for EPICS users after release 3.11. The functions, script files, and usage are briefly described in this document. The script files supplied here serve as examples only. Users are responsible for generating their own spreadsheet and script files. CaWingz communicates with IOC through channel access function calls

  15. Electron and local gas densities in diffuse interstellar clouds from measurements of Ca I absorption

    International Nuclear Information System (INIS)

    Electron and local gas densities in 12 diffuse interstellar clouds have been determined from absorption measurements of Ca I lambda4226 and Ca I lambda3934 and an assumed fractional ionization x/sub e/ = 3 x 10-4. Individual velocity components have been analyzed separately. The values for the electron density range from 0.055 to 0.57 cm-3, while the local gas densities are between 180 and 1900 cm-3. The large values for the electron and local gas densities toward iota, zeta, and perhaps 23 Ori, where few hydrogen molecules occur, may arise from recently compressed gas behind a shock

  16. Linear and nonlinear electrodynamic responses of bulk CaC6 in the microwave regime

    Science.gov (United States)

    Andreone, A.; Cifariello, G.; Di Gennaro, E.; Lamura, G.; Emery, N.; Hérold, C.; Marêché, J. F.; Lagrange, P.

    2007-08-01

    The linear and nonlinear responses to a microwave electromagnetic field of two c-axis oriented polycrystalline samples of the recently discovered superconductor CaC6 (TC≈11.5K ) is studied in the superconducting state down to 2K. The surface resistance RS and the third order intermodulation distortion, arising from a two-tone excitation, have been measured as a function of temperature and microwave circulating power. Experiments are carried out using a dielectrically loaded copper cavity operating at 7GHz in a "hot finger" configuration. The results confirm recent experimental findings that CaC6 behaves as a weakly coupled, fully gapped, superconductor.

  17. Temperature Dependence of IP3-Mediated Local and Global Ca2+ Signals

    OpenAIRE

    Dickinson, George D.; Parker, Ian

    2013-01-01

    We examined the effect of temperature (12–40°C) on local and global Ca2+ signals mediated by inositol trisphosphate receptor/channels (IP3R) in human neuroblastoma (SH-SY5Y) cells. The amplitudes and spatial spread of local signals arising from single IP3R (blips) and clusters of IP3R (puffs) showed little temperature dependence, whereas their kinetics (durations and latencies) were markedly accelerated by increasing temperature. In contrast, the amplitude of global Ca2+ waves increased appre...

  18. Airway smooth muscle relaxation results from a reduction in the frequency of Ca2+ oscillations induced by a cAMP-mediated inhibition of the IP3 receptor

    Directory of Open Access Journals (Sweden)

    Sanderson Michael J

    2006-02-01

    Full Text Available Abstract Background It has been shown that the contractile state of airway smooth muscle cells (SMCs in response to agonists is determined by the frequency of Ca2+ oscillations occurring within the SMCs. Therefore, we hypothesized that the relaxation of airway SMCs induced by agents that increase cAMP results from the down-regulation or slowing of the frequency of the Ca2+ oscillations. Methods The effects of isoproterenol (ISO, forskolin (FSK and 8-bromo-cAMP on the relaxation and Ca2+ signaling of airway SMCs contracted with methacholine (MCh was investigated in murine lung slices with phase-contrast and laser scanning microscopy. Results All three cAMP-elevating agents simultaneously induced a reduction in the frequency of Ca2+ oscillations within the SMCs and the relaxation of contracted airways. The decrease in the Ca2+ oscillation frequency correlated with the extent of airway relaxation and was concentration-dependent. The mechanism by which cAMP reduced the frequency of the Ca2+ oscillations was investigated. Elevated cAMP did not affect the re-filling rate of the internal Ca2+ stores after emptying by repetitive exposure to 20 mM caffeine. Neither did elevated cAMP limit the Ca2+ available to stimulate contraction because an elevation of intracellular Ca2+ concentration induced by exposure to a Ca2+ ionophore (ionomycin or by photolysis of caged-Ca2+ did not reverse the effect of cAMP. Similar results were obtained with iberiotoxin, a blocker of Ca2+-activated K+ channels, which would be expected to increase Ca2+ influx and contraction. By contrast, the photolysis of caged-IP3 in the presence of agonist, to further elevate the intracellular IP3 concentration, reversed the slowing of the frequency of the Ca2+ oscillations and relaxation of the airway induced by FSK. This result implied that the sensitivity of the IP3R to IP3 was reduced by FSK and this was supported by the reduced ability of IP3 to release Ca2+ in SMCs in the presence of

  19. Biomass gasification bottom ash as a source of CaO catalyst for biodiesel production via transesterification of palm oil

    International Nuclear Information System (INIS)

    Highlights: • CaO catalyst was successfully developed from wood gasification bottom ash. • CaCO3 in bottom ash can be converted to CaO catalyst by calcination. • CaO catalysts derived from bottom ash exhibited high activity towards transesterification. • CaO catalysts derived from bottom ash can be reutilized up to four times. - Abstract: The main aim of this research is to develop environmentally and economically benign heterogeneous catalysts for biodiesel production via transesterification of palm oil. For this propose, calcium oxide (CaO) catalyst has been developed from bottom ash waste arising from woody biomass gasification. Calcium carbonate was found to be the main component in bottom ash and can be transformed into the active CaO catalyst by simple calcination at 800 °C without any chemical treatment. The obtained CaO catalysts exhibit high biodiesel production activity, over 90% yield of methyl ester can be achieved at the optimized reaction condition. Experimental kinetic data fit well the pseudo-first order kinetic model. The activation energy (Ea) of the transesterification reaction was calculated to be 83.9 kJ mol−1. Moreover, the CaO catalysts derived from woody biomass gasification bottom ash can be reutilized up to four times, offering the efficient and low-cost CaO catalysts which could make biodiesel production process more economic and environmental friendly

  20. Where Cognitive Conflict Arises from?: The Structure of Creating Cognitive Conflict

    Science.gov (United States)

    Lee, Gyoungho; Yi, Jinseog

    2013-01-01

    In this study, our basic contention was that it is essential for researchers to answer the question, "Where does cognitive conflict really arise from?" with more precision than has heretofore been attempted. First, we examined how the term "cognitive conflict" has been treated in the existing literature and try to pinpoint some difficulties,…

  1. On the Linearized Darboux Equation Arising in Isometric Embedding of the Alexandrov Positive Annulus

    Institute of Scientific and Technical Information of China (English)

    Chunhe LI

    2013-01-01

    In the present paper,the solvability condition of the linearized Gauss-Codazzi system and the solutions to the homogenous system are given.In the meantime,the Solvability of a relevant linearized Darboux equation is given.The equations are arising in a geometric problem which is concerned with the realization of the Alexandrov's positive annulus in R3.

  2. Multicentric extra-abdominal desmoid tumors arising in bilateral lower limbs

    Directory of Open Access Journals (Sweden)

    Nobuhiro Fukushima

    2010-03-01

    Full Text Available Extra-abdominal desmoid tumors preferentially affect the shoulders, arms, backs, buttocks, and thighs of young adults. Multicentric occurrence is rather rare but seems to be another distinctive feature of extra-abdominal desmoid tumors. In this article we report a rare case of multicentric extra-abdominal desmoid tumors arising in bilateral lower limbs.

  3. Dynamics of neural recruitment surrounding the spontaneous arising of thoughts in experienced mindfulness practitioners.

    Science.gov (United States)

    Ellamil, Melissa; Fox, Kieran C R; Dixon, Matthew L; Pritchard, Sean; Todd, Rebecca M; Thompson, Evan; Christoff, Kalina

    2016-08-01

    Thoughts arise spontaneously in our minds with remarkable frequency, but tracking the brain systems associated with the early inception of a thought has proved challenging. Here we addressed this issue by taking advantage of the heightened introspective ability of experienced mindfulness practitioners to observe the onset of their spontaneously arising thoughts. We found subtle differences in timing among the many regions typically recruited by spontaneous thought. In some of these regions, fMRI signal peaked prior to the spontaneous arising of a thought - most notably in the medial temporal lobe and inferior parietal lobule. In contrast, activation in the medial prefrontal, temporopolar, mid-insular, lateral prefrontal, and dorsal anterior cingulate cortices peaked together with or immediately following the arising of spontaneous thought. We propose that brain regions that show antecedent recruitment may be preferentially involved in the initial inception of spontaneous thoughts, while those that show later recruitment may be preferentially involved in the subsequent elaboration and metacognitive processing of spontaneous thoughts. Our findings highlight the temporal dynamics of neural recruitment surrounding the emergence of spontaneous thoughts and may help account for some of spontaneous thought's peculiar qualities, including its wild diversity of content and its links to memory and attention. PMID:27114056

  4. Invariant measures for subshifts arising from substitutions of some primitive components

    CERN Document Server

    Hama, Masaki

    2010-01-01

    The class of substitutions of some primitive components is introduced. A bilateral subshift arising from a substitution of some primitive components is decomposed into pairwise disjoint, locally compact, shift-invariant sets, on each of which an invariant Radon measure is unique up to scaling. It is completely characterized in terms of eigenvalues of an incidence matrix when the unique invariant measure is finite.

  5. A case of clear cell carcinoma arising from the endometriosis of the paraovarian cyst

    OpenAIRE

    Lee, Jung-Yun; Im, Eun Seon; Kim, Sang-Wook; Kim, Haeryoung; Kim, Yong-Beom; Jeon, Yong-Tark

    2009-01-01

    Malignant transformation of endometriosis is an infrequent complication. Clear cell carcinoma from endometriosis is very rare in the paraovarian cyst. To date no cases have been reported. We report a case of clear cell carcinoma arising from endometriosis of the paraovarian cyst with a brief review of literature.

  6. Epithelioid sarcoma and squamous cell carcinoma arising in a burn scar

    Directory of Open Access Journals (Sweden)

    Kusum D Jashnani

    2011-01-01

    Full Text Available Development of a malignant tumor is a well known complication of a chronic burn scar. Most of these tumors are squamous cell carcinomas and only 28 cases of burn scar sarcomas have been reported in literature. We report the first occurrence of the combination of squamous cell carcinoma and epithelioid sarcoma arising in a burn scar.

  7. Single string planning problem arising in liner shipping industries: A heuristic approach

    DEFF Research Database (Denmark)

    Gelareh, Shahin; Neamatian Monemi, Rahimeh; Mahey, Philippe;

    2013-01-01

    We propose an efficient heuristic approach for solving instances of the Single String Planning Problem (SSPP) arising in the liner shipping industry. In the SSPP a Liner Service Provider (LSP) only revises one of its many operational strings, and it is assumed that the other strings are unchangea...

  8. Melanotic paraganglioma arising in the temporal horn following Langerhans cell histiocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jeong Hyun [Baylor College of Medicine, Neuroradiology Department, Houston, TX (United States); Ewha Womans University, Radiology Department, School of Medicine, Seoul (Korea); Rivera, Andreana [Baylor College of Medicine, Pathology Department, Houston, TX (United States); Naeini, Ramin M.; Yedururi, Sireesha; Megahead, Hatem [Baylor College of Medicine, Radiology Department, Houston, TX (United States); Bayindir, Petek [Ege Universitesi, Radiology Department, Lojmanlari (Turkey); Fuller, Gregory N. [MD Anderson Cancer Center, Pathology Department, Houston, TX (United States); Suh, Jeong Soo [Ewha Womans University, Radiology Department, School of Medicine, Seoul (Korea); Adesina, Adekunle M. [Baylor College of Medicine, Pathology Department, Houston, TX (United States); Texas Children' s Cancer Center, Houston, TX (United States); Hunter, Jill V. [Texas Children' s Cancer Center, Houston, TX (United States); Baylor College of Medicine, Neuroradiology Department, Houston, TX (United States)

    2008-05-15

    Intracerebral paragangliomas are rare because of the lack of paraganglial cells in the cerebral tissue. We report a rare case of melanotic paraganglioma arising from the temporal horn of the lateral ventricle in a patient with prior Langerhans cell histiocytosis (LCH) treated with chemotherapy and radiation. (orig.)

  9. Melanotic paraganglioma arising in the temporal horn following Langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Intracerebral paragangliomas are rare because of the lack of paraganglial cells in the cerebral tissue. We report a rare case of melanotic paraganglioma arising from the temporal horn of the lateral ventricle in a patient with prior Langerhans cell histiocytosis (LCH) treated with chemotherapy and radiation. (orig.)

  10. Chest wall secondary chondrosarcoma arising from enchondroma in a young Asian female

    Directory of Open Access Journals (Sweden)

    Chih Chiang Nieh

    2014-01-01

    CONCLUSION: Secondary chondrosarcoma in a young Asian female arising from a benign solitary enchondroma in the absence of multiple enchondromatosis, such as Ollier disease or Maffucci syndrome, is extremely rare. Regular follow up including physical assessment and radiological imaging can result in earlier detection of malignant transformation obviating the need for aggressive surgical treatment involving multiple rib resections.

  11. Varied presentations of ectopic breast - polymastia, fibroadenoma, and carcinoma arising from ectopic breast tissue

    Directory of Open Access Journals (Sweden)

    Yasmeen Khatib

    2015-01-01

    Full Text Available Ectopic breast is a congenital anomaly of the breast which can have varied presentations because of its different sites and pathologies arising from it. Lesions of ectopic breast tissue (EBT are commonly seen due to persistence of embryonic remnants along the milk line. They have also been reported from other sites like face, vulva, and perineum. They are prone to the same physiological and pathological alterations seen in the normal breast. Only 0.3% of breast carcinomas arise in the ectopic breast, whereas only a few cases of fibroadenoma have been reported at this site. We present a case of polymastia in a 21-year-old female in the inframammary region. We report two cases of fibroadenoma and carcinoma arising from EBT in the axilla of a 26 and 45-year females. Fibroadenoma was treated by simple excision while for carcinoma modified radical mastectomy was done followed by radiation and chemotherapy. Patient developed metastasis in the sternum. Carcinoma arising from EBT has a poorer prognosis and needs early diagnosis and treatment.

  12. 28 CFR 45.2 - Disqualification arising from personal or political relationship.

    Science.gov (United States)

    2010-07-01

    ..., a candidate (whether or not successful) for elective, public office, a political party, or a... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless...

  13. Aberrant ovarian artery arising from the common Iliac artery: Case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Yang, Seung Boo; Lee, Jae Myeong [Dept. of Radiology, Soonchunhyang University Gumi Hospital, Soonchunhyang University College of Medicine, Gumi (Korea, Republic of); Goo, Dong Erk; Kim, Yong Jae; Chang, Yun Woo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    A 46-year-old Vietnamese woman received embolization therapy in order to control postpartum hemorrhage. Angiography revealed an aberrant ovarian artery arising from the right common iliac artery. Superselective catheterization and subsequent embolization of the aberrant ovarian artery and bilateral uterine arteries were performed. Precise knowledge of the anatomic variations of the ovarian artery is important for successful embolization.

  14. In search of lost spacetime: philosophical issues arising in quantum gravity

    CERN Document Server

    Wuthrich, Christian

    2012-01-01

    This essay presents an accessible introduction to the basic motivations to seek a quantum theory of gravity. It focuses on one approach- loop quantum gravity - as an example of the rich philosophical issues that arise when we try to combine spacetime and quantum physics.

  15. Monotonicity of a Key Function Arised in Studies of Nematic Liquid Crystal Polymers

    Directory of Open Access Journals (Sweden)

    Hongyun Wang

    2007-01-01

    Full Text Available We revisit a key function arised in studies of nematic liquid crystal polymers. Previously, it was conjectured that the function is strictly decreasing and the conjecture was numerically confirmed. Here we prove the conjecture analytically. More specifically, we write the derivative of the function into two parts and prove that each part is strictly negative.

  16. Saliva DHEAS Changes in Patients Suffering from Psychopathological Disorders Arising from Bullying at Work

    Science.gov (United States)

    Lac, Gerard; Dutheil, Frederic; Brousse, Georges; Triboulet-Kelly, Celine; Chamoux, Alain

    2012-01-01

    Background: Psychological disorders arising from bullying at work (BW) are common. The relationship between these disorders and putative markers is not well established. Aims: To measure saliva dehydroepiandrosterone sulphate (DHEAS) and saliva cortisol as putative markers in individuals suffering from BW. Methods: Forty one subjects suffering…

  17. Techniques of treatment or conditioning for waste arising from 131I production

    International Nuclear Information System (INIS)

    Distillation, evaporation/crystallization, direct immobilization and some chemical like precipitation and reduction were studied as techniques of treatment or conditioning for waste arising from 131I production. The description of all techniques studied, as well as evaluation and discussion of the results are presented. (author)

  18. A rare case report of squamous-cell carcinoma arising from mature cystic teratoma of ovary

    OpenAIRE

    KALAMPOKAS, E.; BOUTAS, I.; KAIRI-VASILATOU, E.; SALAKOS, N.; PANOULIS, K.; ARAVANTINOS, L.; DAMASKOS, C.; KALAMPOKAS, T.; DELIGEOROGLOU, E.

    2014-01-01

    The most frequent ovarian germ cell tumors are mature cystic teratomas (MCTs), composing 10–25% of all ovarian neoplasms. MCTs have the potential of undergoing malignant transformation, typically in postmenopausal women, with a frequency of 0.17–3%, with squamous cell carcinoma being the most common malignant tumor arising from MCT.

  19. Modification of the Absorption Edge of GaAs Arising from Hot-Electron Effects

    DEFF Research Database (Denmark)

    McGroddy, J. C.; Christensen, Ove

    1973-01-01

    We have observed a large enhancement of the electric-field-induced optical absorption arising from hot-electron effects in n-type GaAs at 77 K. The magnitude and field dependence of the enhancement can be approximately accounted for by a theory attributing the effect to broadening of the final...

  20. Conventional protein kinase C isoforms differentially regulate ADP- and thrombin-evoked Ca²⁺ signalling in human platelets.

    Science.gov (United States)

    Lever, Robert A; Hussain, Azhar; Sun, Benjamin B; Sage, Stewart O; Harper, Alan G S

    2015-12-01

    Rises in cytosolic Ca(2+) concentration ([Ca(2+)]cyt) are central in platelet activation, yet many aspects of the underlying mechanisms are poorly understood. Most studies examine how experimental manipulations affect agonist-evoked rises in [Ca(2+)]cyt, but these only monitor the net effect of manipulations on the processes controlling [Ca(2+)]cyt (Ca(2+) buffering, sequestration, release, entry and removal), and cannot resolve the source of the Ca(2+) or the transporters or channels affected. To investigate the effects of protein kinase C (PKC) on platelet Ca(2+) signalling, we here monitor Ca(2+) flux around the platelet by measuring net Ca(2+) fluxes to or from the extracellular space and the intracellular Ca(2+) stores, which act as the major sources and sinks for Ca(2+) influx into and efflux from the cytosol, as well as monitoring the cytosolic Na(+) concentration ([Na(+)]cyt), which influences platelet Ca(2+) fluxes via Na(+)/Ca(2+) exchange. The intracellular store Ca(2+) concentration ([Ca(2+)]st) was monitored using Fluo-5N, the extracellular Ca(2+) concentration ([Ca(2+)]ext) was monitored using Fluo-4 whilst [Ca(2+)]cyt and [Na(+)]cyt were monitored using Fura-2 and SFBI, respectively. PKC inhibition using Ro-31-8220 or bisindolylmaleimide I potentiated ADP- and thrombin-evoked rises in [Ca(2+)]cyt in the absence of extracellular Ca(2+). PKC inhibition potentiated ADP-evoked but reduced thrombin-evoked intracellular Ca(2+) release and Ca(2+) removal into the extracellular medium. SERCA inhibition using thapsigargin and 2,5-di(tert-butyl) l,4-benzohydroquinone abolished the effect of PKC inhibitors on ADP-evoked changes in [Ca(2+)]cyt but only reduced the effect on thrombin-evoked responses. Thrombin evokes substantial rises in [Na(+)]cyt which would be expected to reduce Ca(2+) removal via the Na(+)/Ca(2+) exchanger (NCX). Thrombin-evoked rises in [Na(+)]cyt were potentiated by PKC inhibition, an effect which was not due to altered changes in non