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Sample records for granule cell layer

  1. Status epilepticus increases mature granule cells in the molecular layer of the dentate gyrus in rats★

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    Liang, Zhaoliang; Gao, Fei; Wang, Fajun; Wang, Xiaochen; Song, Xinyu; Liu, Kejing; Zhan, Ren-Zhi

    2013-01-01

    Enhanced neurogenesis in the dentate gyrus of the hippocampus following seizure activity, especially status epilepticus, is associated with ectopic residence and aberrant integration of newborn granule cells. Hilar ectopic granule cells may be detrimental to the stability of dentate circuitry by means of their electrophysiological properties and synaptic connectivity. We hypothesized that status epilepticus also increases ectopic granule cells in the molecular layer. Status epilepticus was induced in male Sprague-Dawley rats by intraperitoneal injection of pilocarpine. Immunostaining showed that many doublecortin-positive cells were present in the molecular layer and the hilus 7 days after the induction of status epilepticus. At least 10 weeks after status epilepticus, the estimated number of cells positive for both prospero homeobox protein 1 and neuron-specific nuclear protein in the hilus was significantly increased. A similar trend was also found in the molecular layer. These findings indicate that status epilepticus can increase the numbers of mature and ectopic newborn granule cells in the molecular layer. PMID:25206705

  2. Dynamic properties of sensory stimulation evoked responses in mouse cerebellar granule cell layer and molecular layer.

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    Bing, Yan-Hua; Zhang, Guang-Jian; Sun, Lei; Chu, Chun-Ping; Qiu, De-Lai

    2015-01-12

    Sensory information coming from climbing fiber and mossy fiber-granule cell pathways, generates motor-related outputs according to internal rules of integration and computation in the cerebellar cortex. However, the dynamic properties of sensory information processing in mouse cerebellar cortex are less understood. Here, we studied the dynamic properties of sensory stimulation-evoked responses in the cerebellar granule cell layer (GCL) and molecular layer (ML) by electrophysiological recordings method. Our data showed that air-puff stimulation (5-10 ms in duration) of the ipsilateral whisker pad evoked single-peak responses in the GCL and ML; whereas a duration of stimulation ≥30 ms in GCL and ≥60 ms in ML, evoked double-peak responses that corresponded with stimulation-on and -off responses via mossy fiber pathway. The highest frequency of stimulation train for evoking GCL responses was 33 Hz. In contrast, the highest frequency of stimulation train for evoking ML responses was 4 Hz. These results indicate that the cerebellar granule cells transfer the high-fidelity sensory information from mossy fibers, which is cut-off by molecular layer interneurons (MLIs). Our results suggest that the MLIs network acts as a low-pass filter during the processing of high-frequency sensory information. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Improved Light Conversion Efficiency Of Dye-Sensitized Solar Cell By Dispersing Submicron-Sized Granules Into The Nano-Sized TiO2 Layer

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    Song S.A.

    2015-06-01

    Full Text Available In this work, TiO2 nanoparticles and submicron-sized granules were synthesized by a hydrothermal method and spray pyrolysis, respectively. Submicron-sized granules were dispersed into the nano-sized TiO2 layer to improve the light conversion efficiency. Granules showed better light scattering, but lower in terms of the dye-loading quantity and recombination resistance compared with nanoparticles. Consequently, the nano-sized TiO2 layer had higher cell efficiency than the granulized TiO2 layer. When dispersed granules into the nanoparticle layer, the light scattering was enhanced without the loss of dye-loading quantities. The dispersion of granulized TiO2 led to increase the cell efficiency up to 6.51%, which was about 5.2 % higher than that of the electrode consisting of only TiO2 nanoparticles. Finally, the optimal hydrothermal temperature and dispersing quantity of granules were found to be 200°C and 20 wt%, respectively.

  4. Morphological Constraints on Cerebellar Granule Cell Combinatorial Diversity.

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    Gilmer, Jesse I; Person, Abigail L

    2017-12-13

    Combinatorial expansion by the cerebellar granule cell layer (GCL) is fundamental to theories of cerebellar contributions to motor control and learning. Granule cells (GrCs) sample approximately four mossy fiber inputs and are thought to form a combinatorial code useful for pattern separation and learning. We constructed a spatially realistic model of the cerebellar GCL and examined how GCL architecture contributes to GrC combinatorial diversity. We found that GrC combinatorial diversity saturates quickly as mossy fiber input diversity increases, and that this saturation is in part a consequence of short dendrites, which limit access to diverse inputs and favor dense sampling of local inputs. This local sampling also produced GrCs that were combinatorially redundant, even when input diversity was extremely high. In addition, we found that mossy fiber clustering, which is a common anatomical pattern, also led to increased redundancy of GrC input combinations. We related this redundancy to hypothesized roles of temporal expansion of GrC information encoding in service of learned timing, and we show that GCL architecture produces GrC populations that support both temporal and combinatorial expansion. Finally, we used novel anatomical measurements from mice of either sex to inform modeling of sparse and filopodia-bearing mossy fibers, finding that these circuit features uniquely contribute to enhancing GrC diversification and redundancy. Our results complement information theoretic studies of granule layer structure and provide insight into the contributions of granule layer anatomical features to afferent mixing. SIGNIFICANCE STATEMENT Cerebellar granule cells are among the simplest neurons, with tiny somata and, on average, just four dendrites. These characteristics, along with their dense organization, inspired influential theoretical work on the granule cell layer as a combinatorial expander, where each granule cell represents a unique combination of inputs

  5. MicroRNAs Promote Granule Cell Expansion in the Cerebellum Through Gli2.

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    Constantin, Lena; Wainwright, Brandon J

    2015-12-01

    MicroRNAs (miRNAs) are important regulators of cerebellar function and homeostasis. Their deregulation results in cerebellar neuronal degeneration and spinocerebellar ataxia type 1 and contributes to medulloblastoma. Canonical miRNA processing involves Dicer, which cleaves precursor miRNAs into mature double-stranded RNA duplexes. In order to address the role of miRNAs in cerebellar granule cell precursor development, loxP-flanked exons of Dicer1 were conditionally inactivated using the granule cell precursor-specific Atoh1-Cre recombinase. A reduction of 87% in Dicer1 transcript was achieved in this conditional Dicer knockdown model. Although knockdown resulted in normal survival, mice had disruptions to the cortical layering of the anterior cerebellum, which resulted from the premature differentiation of granule cell precursors in this region during neonatal development. This defect manifested as a thinner external granular layer with ectopic mature granule cells, and a depleted internal granular layer. We found that expression of the activator components of the Hedgehog-Patched pathway, the Gli family of transcription factors, was perturbed in conditional Dicer knockdown mice. We propose that loss of Gli2 mRNA mediated the anterior-restricted defect in conditional Dicer knockdown mice and, as proof of principle, were able to show that miR-106b positively regulated Gli2 mRNA expression. These findings confirm the importance of miRNAs as positive mediators of Hedgehog-Patched signalling during granule cell precursor development.

  6. Morphologic Integration of Hilar Ectopic Granule Cells into Dentate Gyrus Circuitry in the Pilocarpine Model of Temporal Lobe Epilepsy

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    Cameron, Michael C.; Zhan, Ren-Zhi; Nadler, J. Victor

    2014-01-01

    After pilocarpine-induced status epilepticus, many granule cells born into the postseizure environment migrate aberrantly into the dentate hilus. Hilar ectopic granule cells (HEGCs) are hyperexcitable and may therefore increase circuit excitability. This study determined the distribution of their axons and dendrites. HEGCs and normotopic granule cells were filled with biocytin during whole-cell patch clamp recording in hippocampal slices from pilocarpine-treated rats. The apical dendrite of 86% of the biocytin-labeled HEGCs extended to the outer edge of the dentate molecular layer. The total length and branching of HEGC apical dendrites that penetrated the molecular layer were significantly reduced compared with apical dendrites of normotopic granule cells. HEGCs were much more likely to have a hilar basal dendrite than normotopic granule cells. They were about as likely as normotopic granule cells to project to CA3 pyramidal cells within the slice, but were much more likely to send at least one recurrent mossy fiber into the molecular layer. HEGCs with burst capability had less well-branched apical dendrites than nonbursting HEGCs, their dendrites were more likely to be confined to the hilus, and some exhibited dendritic features similar to those of immature granule cells. HEGCs thus have many paths along which to receive synchronized activity from normotopic granule cells and to transmit their own hyperactivity to both normotopic granule cells and CA3 pyramidal cells. They may therefore contribute to the highly interconnected granule cell hubs that have been proposed as crucial to development of a hyperexcitable, potentially seizure-prone circuit. PMID:21455997

  7. Early x-irradiation of rats. Part 2. Effect of granule cells and their dendrodendritic synapses in the olfactory bulb

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    Halasz, N

    1987-01-01

    Low, repeated doses of X-rays from a Co/sup 60/ source were used to impair the development of the granule cells and their dendritic terminals in the olfactory bulb, and the resulting effect was studied under light and electron microscopes at 9 days of age. Irradiation of rats from embryonic day 18 (in utero) to postnatal day 5 resulted, among others, in maldevelopment of the (internal) granule cell and external plexiform layers. This was accompanied by a decrease in the number and the density of the granule cells, and the remaining granule cells contained less ribosomes, regardless of their position within the layer. This implies that both supposed subtypes of granule cells were effected. In the external plexiform layer, a reduced number of mature dendrodendritic synapses and signs of harmed granule gemmules were observed. The results suggest that intrauterinal plus postnatal irradiation with low, repeated doses of X-rays may be an effective tool impairing the development of prenatally forming neurons.

  8. Olfactory granule cell development in normal and hyperthyroid rats.

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    Brunjes, P C; Schwark, H D; Greenough, W T

    1982-10-01

    Dendritic development was examined in olfactory bulbs of both normal 7-, 14-, 21- and 60-day-old rats and littermates treated on postnatal days 1-4 with 1 microgram/g body weight of L-thyroxine sodium. Tissue was processed via the Golgi-Cox technique and subjected to quantitative analyses of mitral and internal layer granule cell development. These populations of granule cells were selected because their pattern of late proliferation suggested potentially greater susceptibility to postnatal hormonal alterations. Although neonatal hyperthyroidism induces widespread acceleration of maturation, including precocious chemosensitivity, granule cell development was unaffected relative to littermate controls. Both normal and hyperthyroid groups exhibited an inverted U-shaped pattern of cellular development, with rapid dendritic dendritic growth and expansion occurring during the earliest ages tested, but with loss of processes and dendritic field size occurring after day 21.

  9. Hilar mossy cell circuitry controlling dentate granule cell excitability

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    Seiichiro eJinde

    2013-02-01

    Full Text Available Glutamatergic hilar mossy cells of the dentate gyrus can either excite or inhibit distant granule cells, depending on whether their direct excitatory projections to granule cells or their projections to local inhibitory interneurons dominate. However, it remains controversial whether the net effect of mossy cell loss is granule cell excitation or inhibition. Clarifying this controversy has particular relevance to temporal lobe epilepsy, which is marked by dentate granule cell hyperexcitability and extensive loss of dentate hilar mossy cells. Two diametrically opposed hypotheses have been advanced to explain this granule cell hyperexcitability – the dormant basket cell and the irritable mossy cell hypotheses. The dormant basket cell hypothesis proposes that mossy cells normally exert a net inhibitory effect on granule cells and therefore their loss causes dentate granule cell hyperexcitability. The irritable mossy cell hypothesis takes the opposite view that mossy cells normally excite granule cells and that the surviving mossy cells in epilepsy increase their activity, causing granule cell excitation. The inability to eliminate mossy cells selectively has made it difficult to test these two opposing hypotheses. To this end, we developed a transgenic toxin-mediated, mossy cell-ablation mouse line. Using these mutants, we demonstrated that the extensive elimination of hilar mossy cells causes granule cell hyperexcitability, although the mossy cell loss observed appeared insufficient to cause clinical epilepsy. In this review, we focus on this topic and also suggest that different interneuron populations may mediate mossy cell-induced translamellar lateral inhibition and intralamellar recurrent inhibition. These unique local circuits in the dentate hilar region may be centrally involved in the functional organization of the dentate gyrus.

  10. Denervation-induced homeostatic dendritic plasticity in morphological granule cell models

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    Hermann Cuntz

    2014-03-01

    Full Text Available Neuronal death and subsequent denervation of target areas are major consequences of several neurological conditions such asischemia or neurodegeneration (Alzheimer's disease. The denervation-induced axonal loss results in reorganization of the dendritic tree of denervated neurons. The dendritic reorganization has been previously studied using entorhinal cortex lesion (ECL. ECL leads to shortening and loss of dendritic segments in the denervated outer molecular layer of the dentate gyrus. However, the functional importance of these long-term dendritic alterations is not yet understood and their impact on neuronal electrical properties remains unclear. Here we analyzed what happens to the electrotonic structure and excitability of dentate granule cells after lesion-induced alterations of their dendritic morphology, assuming all other parameters remain equal. We performed comparative electrotonic analysis in anatomically and biophysically realistic compartmental models of 3D-reconstructed healthy and denervated granule cells. Using the method of morphological modeling based on optimization principles minimizing the amount of wiring and maximizing synaptic democracy, we built artificial granule cells which replicate morphological features of their real counterparts. Our results show that somatofugal and somatopetal voltage attenuation in the passive cable model are strongly reduced in denervated granule cells. In line with these predictions, the attenuation both of simulated backpropagating action potentials and forward propagating EPSPs was significantly reduced in dendrites of denervated neurons. Intriguingly, the enhancement of action potential backpropagation occurred specifically in the denervated dendritic layers. Furthermore, simulations of synaptic f-I curves revealed a homeostatic increase of excitability in denervated granule cells. In summary, our morphological and compartmental modeling indicates that unless modified by changes of

  11. Morphological alterations in newly born dentate gyrus granule cells that emerge after status epilepticus contribute to make them less excitable.

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    Julián Tejada

    Full Text Available Computer simulations of external current stimulations of dentate gyrus granule cells of rats with Status Epilepticus induced by pilocarpine and control rats were used to evaluate whether morphological differences alone between these cells have an impact on their electrophysiological behavior. The cell models were constructed using morphological information from tridimensional reconstructions with Neurolucida software. To evaluate the effect of morphology differences alone, ion channel conductances, densities and distributions over the dendritic trees of dentate gyrus granule cells were the same for all models. External simulated currents were injected in randomly chosen dendrites belonging to one of three different areas of dentate gyrus granule cell molecular layer: inner molecular layer, medial molecular layer and outer molecular layer. Somatic membrane potentials were recorded to determine firing frequencies and inter-spike intervals. The results show that morphologically altered granule cells from pilocarpine-induced epileptic rats are less excitable than control cells, especially when they are stimulated in the inner molecular layer, which is the target area for mossy fibers that sprout after pilocarpine-induced cell degeneration. This suggests that morphological alterations may act as a protective mechanism to allow dentate gyrus granule cells to cope with the increase of stimulation caused by mossy fiber sprouting.

  12. Gamma-radiation produces abnormal Bergmann fibers and ectopic granule cells in mouse cerebellar cortex

    International Nuclear Information System (INIS)

    Inouye, Minoru; Hayasaka, Shizu; Funahashi, Atsushi; Yamamura, Hideki

    1992-01-01

    Morphological changes in Bergmann glial fibers in the developing cerebellar cortex produced by exposure to gamma-rays were investigated in association with ectopic granule cells. Six-day-old mice that had been exposed to 3 Gy of gamma-radiation were killed 6 hours after exposure or at 7 through 30 days of age. Their cerebella were examined histologically and immunohistochemically for glial fibrillary acidic protein in Bergmann fibers. Extensive cell death took place in the external granular layer (EGL) of the cerebellum from 6 through 24 hours after exposure. This led to the thinning of the EGL and a decrease in the number of migrating cells in the molecular layer. The number of Bergmann cells was not decreased, but the fibers in the molecular layer were distorted; whereas, in the control these fibers were straight and perpendicular to the pial surface. The EGL began to recover 2 days after exposure, and abnormally oriented migrating cells were seen. At 17 days of age, some cell clustering was observed in the molecular layer of the irradiated cerebellum. Distortion of the Bergmann fibers was marked in regions where ectopic granule cells appeared at 30 days of age. These findings suggest that the distortion of Bergmann fibers leads to the production of ectopic granule cells after exposure to gamma-radiation. (author)

  13. PTEN deletion from adult-generated dentate granule cells disrupts granule cell mossy fiber axon structure.

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    LaSarge, Candi L; Santos, Victor R; Danzer, Steve C

    2015-03-01

    Dysregulation of the mTOR-signaling pathway is implicated in the development of temporal lobe epilepsy. In mice, deletion of PTEN from hippocampal dentate granule cells leads to mTOR hyperactivation and promotes the rapid onset of spontaneous seizures. The mechanism by which these abnormal cells initiate epileptogenesis, however, is unclear. PTEN-knockout granule cells develop abnormally, exhibiting morphological features indicative of increased excitatory input. If these cells are directly responsible for seizure genesis, it follows that they should also possess increased output. To test this prediction, dentate granule cell axon morphology was quantified in control and PTEN-knockout mice. Unexpectedly, PTEN deletion increased giant mossy fiber bouton spacing along the axon length, suggesting reduced innervation of CA3. Increased width of the mossy fiber axon pathway in stratum lucidum, however, which likely reflects an unusual increase in mossy fiber axon collateralization in this region, offsets the reduction in boutons per axon length. These morphological changes predict a net increase in granule cell innervation of CA3. Increased diameter of axons from PTEN-knockout cells would further enhance granule cell communication with CA3. Altogether, these findings suggest that amplified information flow through the hippocampal circuit contributes to seizure occurrence in the PTEN-knockout mouse model of temporal lobe epilepsy. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Migration and distribution of two populations of hippocampal granule cell precursors during the perinatal and postnatal periods

    International Nuclear Information System (INIS)

    Altman, J.; Bayer, S.A.

    1990-01-01

    Methacrylate-embedded sections and short-survival thymidine radiograms of the hippocampal dentate gyrus were examined in perinatal and postnatal rats in order to trace the site of origin and migration of the precursors of granule cells and study the morphogenesis of the granular layer. The densely packed, spindle-shaped cells of the secondary dentate matrix (a derivative of the primary dentate neuroepithelium) stream in a subpial position towards the granular layer of the internal dentate limb during the perinatal and early postnatal periods. By an accretionary process, the crest of the granular layer forms on day E21 and on the subsequent days the granular layer of the internal dentate limb expands progressively in a lateral direction. Granule cells differentiation, as judged by the transformation of polymorph, darkly staining small cells into rounder, lightly staining larger granule cells, follows the same gradient from the external dentate limb to the internal dentate limb. The secondary dentate matrix is in a process of dissolution by day P5. This matrix is the source of what will later become the outer shell of the granular layer composed of early generated granule cells. The thicker inner shell of the granular layer, formed during the infantile and juvenile periods, derives from an intrinsic, tertiary germinal matrix. On day E22, the dentate migration of the secondary dentate matrix becomes partitioned into two components: (a) the subpial component of extradentate origin, referred to in this context as the first dentate migration, and (b) the second dentate migration. The latter is distributed in the basal polymorph layer throughout the entire dentate gyrus and is henceforth recognized as the tertiary dentate matrix. The tertiary dentate matrix is prominent between days P3 and P10

  15. Trajectory Analysis Unveils Reelin's Role in the Directed Migration of Granule Cells in the Dentate Gyrus.

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    Wang, Shaobo; Brunne, Bianka; Zhao, Shanting; Chai, Xuejun; Li, Jiawei; Lau, Jeremie; Failla, Antonio Virgilio; Zobiak, Bernd; Sibbe, Mirjam; Westbrook, Gary L; Lutz, David; Frotscher, Michael

    2018-01-03

    Reelin controls neuronal migration and layer formation. Previous studies in reeler mice deficient in Reelin focused on the result of the developmental process in fixed tissue sections. It has remained unclear whether Reelin affects the migratory process, migration directionality, or migrating neurons guided by the radial glial scaffold. Moreover, Reelin has been regarded as an attractive signal because newly generated neurons migrate toward the Reelin-containing marginal zone. Conversely, Reelin might be a stop signal because migrating neurons in reeler , but not in wild-type mice, invade the marginal zone. Here, we monitored the migration of newly generated proopiomelanocortin-EGFP -expressing dentate granule cells in slice cultures from reeler , reeler -like mutants and wild-type mice of either sex using real-time microscopy. We discovered that not the actual migratory process and migratory speed, but migration directionality of the granule cells is controlled by Reelin. While wild-type granule cells migrated toward the marginal zone of the dentate gyrus, neurons in cultures from reeler and reeler -like mutants migrated randomly in all directions as revealed by vector analyses of migratory trajectories. Moreover, live imaging of granule cells in reeler slices cocultured to wild-type dentate gyrus showed that the reeler neurons changed their directions and migrated toward the Reelin-containing marginal zone of the wild-type culture, thus forming a compact granule cell layer. In contrast, directed migration was not observed when Reelin was ubiquitously present in the medium of reeler slices. These results indicate that topographically administered Reelin controls the formation of a granule cell layer. SIGNIFICANCE STATEMENT Neuronal migration and the various factors controlling its onset, speed, directionality, and arrest are poorly understood. Slice cultures offer a unique model to study the migration of individual neurons in an almost natural environment. In the

  16. Layered growth with bottom-spray granulation for spray deposition of drug.

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    Er, Dawn Z L; Liew, Celine V; Heng, Paul W S

    2009-07-30

    The gap in scientific knowledge on bottom-spray fluidized bed granulation has emphasized the need for more studies in this area. This paper comparatively studied the applicability of a modified bottom-spray process and the conventional top-spray process for the spray deposition of a micronized drug during granulation. The differences in circulation pattern, mode of growth and resultant granule properties between the two processes were highlighted. The more ordered and consistent circulation pattern of particles in a bottom-spray fluidized bed was observed to give rise to layered granule growth. This resulted in better drug content uniformity among the granule batches and within a granule batch. The processes' sensitivities to wetting and feed material characteristics were also compared and found to differ markedly. Less robustness to differing process conditions was observed for the top-spray process. The resultant bottom-spray granules formed were observed to be less porous, more spherical and had good flow properties. The bottom-spray technique can thus be potentially applied for the spray deposition of drug during granulation and was observed to be a good alternative to the conventional technique for preparing granules.

  17. Vaccine adjuvants: Tailor-made mast-cell granules

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    Gunzer, Matthias

    2012-03-01

    Mast cells induce protective immune responses through secretion of stimulatory granules. Microparticles modelled after mast-cell granules are now shown to replicate and enhance the functions of their natural counterparts and to direct the character of the resulting immunity.

  18. Polyhydroxyalkanoate (PHA) Granules Have no Phospholipids

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    Bresan, Stephanie; Sznajder, Anna; Hauf, Waldemar; Forchhammer, Karl; Pfeiffer, Daniel; Jendrossek, Dieter

    2016-01-01

    Polyhydroxybutyrate (PHB) granules, also designated as carbonosomes, are supra-molecular complexes in prokaryotes consisting of a PHB polymer core and a surface layer of structural and functional proteins. The presence of suspected phospholipids in the surface layer is based on in vitro data of isolated PHB granules and is often shown in cartoons of the PHB granule structure in reviews on PHB metabolism. However, the in vivo presence of a phospholipid layer has never been demonstrated. We addressed this topic by the expression of fusion proteins of DsRed2EC and other fluorescent proteins with the phospholipid-binding domain (LactC2) of lactadherin in three model organisms. The fusion proteins specifically localized at the cell membrane of Ralstonia eutropha but did not co-localize with PHB granules. The same result was obtained for Pseudomonas putida, a species that accumulates another type of polyhydroxyalkanoate (PHA) granules related to PHB. Notably, DsRed2EC-LactC2 expressed in Magnetospirillum gryphiswaldense was detected at the position of membrane-enclosed magnetosome chains and at the cytoplasmic membrane but not at PHB granules. In conclusion, the carbonosomes of representatives of α-proteobacteria, β-proteobacteria and γ-proteobacteria have no phospholipids in vivo and we postulate that the PHB/PHA granule surface layers in natural producers generally are free of phospholipids and consist of proteins only. PMID:27222167

  19. The cerebellar Golgi cell and spatiotemporal organization of granular layer activity

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    Egidio eD‘Angelo

    2013-05-01

    Full Text Available The cerebellar granular layer has been suggested to perform a complex spatiotemporal reconfiguration of incoming mossy fiber signals. Central to this role is the inhibitory action exerted by Golgi cells over granule cells: Golgi cells inhibit granule cells through double feedforward and feedback inhibitory loops and generate a broad lateral inhibition that extends beyond the afferent synaptic field. This characteristic connectivity has recently been investigated in great detail and been correlated with specific functional properties of the neuron. These include theta-frequency pacemaking, network entrainment into coherent oscillations and phase resetting. Important advances have also been made in terms of determining the membrane and synaptic properties of the neuron, and clarifying the mechanisms of activation by input bursts. Moreover, voltage sensitive dye imaging and multi-electrode array recordings, combined with mathematical simulations based on realistic computational models, have improved our understanding of the impact of Golgi cell activity on granular layer circuit computations. These investigations have highlighted the critical role of Golgi cells in: generating dense clusters of granule cell activity organized in center-surround structures, implementing combinatorial operations on multiple mossy fiber inputs, regulating transmission gain and cut-off frequency, controlling spike timing and burst transmission, and determining the sign, intensity and extension of long-term synaptic plasticity at the mossy fiber-granule cell relay. This review considers recent advances in the field, highlighting the functional implications of Golgi cells for granular layer network computation and indicating new challenges for cerebellar research.

  20. UVC-induced stress granules in mammalian cells.

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    Mohamed Taha Moutaoufik

    Full Text Available Stress granules (SGs are well characterized cytoplasmic RNA bodies that form under various stress conditions. We have observed that exposure of mammalian cells in culture to low doses of UVC induces the formation of discrete cytoplasmic RNA granules that were detected by immunofluorescence staining using antibodies to RNA-binding proteins. UVC-induced cytoplasmic granules are not Processing Bodies (P-bodies and are bone fide SGs as they contain TIA-1, TIA-1/R, Caprin1, FMRP, G3BP1, PABP1, well known markers, and mRNA. Concomitant with the accumulation of the granules in the cytoplasm, cells enter a quiescent state, as they are arrested in G1 phase of the cell cycle in order to repair DNA damages induced by UVC irradiation. This blockage persists as long as the granules are present. A tight correlation between their decay and re-entry into S-phase was observed. However the kinetics of their formation, their low number per cell, their absence of fusion into larger granules, their persistence over 48 hours and their slow decay, all differ from classical SGs induced by arsenite or heat treatment. The induction of these SGs does not correlate with major translation inhibition nor with phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2α. We propose that a restricted subset of mRNAs coding for proteins implicated in cell cycling are removed from the translational apparatus and are sequestered in a repressed form in SGs.

  1. Platelet granule exocytosis: A comparison with chromaffin cells

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    Jennifer eFitch-Tewfik

    2013-06-01

    Full Text Available The rapid secretion of bioactive amines from chromaffin cells constitutes an important component of the fight or flight response of mammals to stress. Platelets respond to stresses within the vasculature by rapidly secreting cargo at sites of injury, inflammation, or infection. Although chromaffin cells derive from the neural crest and platelets from bone marrow megakaryocytes, both have evolved a heterogeneous assemblage of granule types and a mechanism for efficient release. This article will provide an overview of granule formation and exocytosis in platelets with an emphasis on areas in which the study of chromaffin cells has influenced that of platelets and on similarities between the two secretory systems. Commonalities include the use of transporters to concentrate bioactive amines and other cargos into granules, the role of cytoskeletal remodeling in granule exocytosis, and the use of granules to provide membrane for cytoplasmic projections. The SNAREs and SNARE accessory proteins used by each cell type will also be considered. Finally, we will discuss the newly appreciated role of dynamin family proteins in regulated fusion pore formation. This evaluation of the comparative cell biology of regulated exocytosis in platelets and chromaffin cells demonstrates a convergence of mechanisms between two disparate cell types both tasked with responding rapidly to physiological stimuli.

  2. Distorted secretory granule composition in mast cells with multiple protease deficiency.

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    Grujic, Mirjana; Calounova, Gabriela; Eriksson, Inger; Feyerabend, Thorsten; Rodewald, Hans-Reimer; Tchougounova, Elena; Kjellén, Lena; Pejler, Gunnar

    2013-10-01

    Mast cells are characterized by an abundance of secretory granules densely packed with inflammatory mediators such as bioactive amines, cytokines, serglycin proteoglycans with negatively charged glycosaminoglycan side chains of either heparin or chondroitin sulfate type, and large amounts of positively charged proteases. Despite the large biological impact of mast cell granules and their contents on various pathologies, the mechanisms that regulate granule composition are incompletely understood. In this study, we hypothesized that granule composition is dependent on a dynamic electrostatic interrelationship between different granule compounds. As a tool to evaluate this possibility, we generated mice in which mast cells are multideficient in a panel of positively charged proteases: the chymase mouse mast cell protease-4, the tryptase mouse mast cell protease-6, and carboxypeptidase A3. Through a posttranslational effect, mast cells from these mice additionally lack mouse mast cell protease-5 protein. Mast cells from mice deficient in individual proteases showed normal morphology. In contrast, mast cells with combined protease deficiency displayed a profound distortion of granule integrity, as seen both by conventional morphological criteria and by transmission electron microscopy. An assessment of granule content revealed that the distorted granule integrity in multiprotease-deficient mast cells was associated with a profound reduction of highly negatively charged heparin, whereas no reduction in chondroitin sulfate storage was observed. Taken together with previous findings showing that the storage of basic proteases conversely is regulated by anionic proteoglycans, these data suggest that secretory granule composition in mast cells is dependent on a dynamic interrelationship between granule compounds of opposite electrical charge.

  3. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

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    Huckleberry, Kylie A.; Kane, Gary A.; Mathis, Rita J.; Cook, Sarah G.; Clutton, Jonathan E.; Drew, Michael R.

    2015-01-01

    Thousands of neurons are born each day in the dentate gyrus (DG), but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in the DG. The immediate-early gene (IEG) zif268 appears to be an important mediator of these effects, as its expression can be induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Richardson et al., 1992; Veyrac et al., 2013). Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs). We first quantified zif268 expression in doublecortin-positive (DCX+) immature neurons and in the general granule cell population after brief exposure to a novel environment (NE). In the general granule cell population, zif268 expression peaked 1 h after NE exposure and returned to baseline by 8 h post-exposure. However, in the DCX+ cells, zif268 expression was suppressed relative to home cage for at least 8 h post-exposure. We next asked whether suppression of zif268 in DCX+ immature cells occurs in other behavioral paradigms that recruit the hippocampus. Exposure to Morris water maze (MWM) training, an enriched environment, or a NE caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 expression among the general granule cell population. The same behavioral procedures activated zif268 expression in 6-week-old BrdU-labeled adult-born neurons, indicating that zif268 suppression is specific to immature neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. NE exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly

  4. Abnormal ion content, hydration and granule expansion of the secretory granules from cystic fibrosis airway glandular cells

    International Nuclear Information System (INIS)

    Baconnais, S.; Delavoie, F.; Zahm, J.M.; Milliot, M.; Terryn, C.; Castillon, N.; Banchet, V.; Michel, J.; Danos, O.; Merten, M.; Chinet, T.; Zierold, K.; Bonnet, N.; Puchelle, E.; Balossier, G.

    2005-01-01

    The absence or decreased expression of cystic fibrosis transmembrane conductance regulator (CFTR) induces increased Na + absorption and hyperabsorption of the airway surface liquid (ASL) resulting in a dehydrated and hyperviscous ASL. Although the implication of abnormal airway submucosal gland function has been suggested, the ion and water content in the Cystic Fibrosis (CF) glandular secretory granules, before exocytosis, is unknown. We analyzed, in non-CF and CF human airway glandular cell lines (MM-39 and KM4, respectively), the ion content in the secretory granules by electron probe X-ray microanalysis and the water content by quantitative dark field imaging on freeze-dried cryosections. We demonstrated that the ion content (Na + , Mg 2+ , P, S and Cl - ) is significantly higher and the water content significantly lower in secretory granules from the CF cell line compared to the non-CF cell line. Using videomicroscopy, we observed that the secretory granule expansion was deficient in CF glandular cells. Transfection of CF cells with CFTR cDNA or inhibition of non-CF cells with CFTR inh -172, respectively restored or decreased the water content and granule expansion, in parallel with changes in ion content. We hypothesize that the decreased water and increased ion content in glandular secretory granules may contribute to the dehydration and increased viscosity of the ASL in CF

  5. Proneurotrophin-3 promotes cell cycle withdrawal of developing cerebellar granule cell progenitors via the p75 neurotrophin receptor.

    Science.gov (United States)

    Zanin, Juan Pablo; Abercrombie, Elizabeth; Friedman, Wilma J

    2016-07-19

    Cerebellar granule cell progenitors (GCP) proliferate extensively in the external granule layer (EGL) of the developing cerebellum prior to differentiating and migrating. Mechanisms that regulate the appropriate timing of cell cycle withdrawal of these neuronal progenitors during brain development are not well defined. The p75 neurotrophin receptor (p75(NTR)) is highly expressed in the proliferating GCPs, but is downregulated once the cells leave the cell cycle. This receptor has primarily been characterized as a death receptor for its ability to induce neuronal apoptosis following injury. Here we demonstrate a novel function for p75(NTR) in regulating proper cell cycle exit of neuronal progenitors in the developing rat and mouse EGL, which is stimulated by proNT3. In the absence of p75(NTR), GCPs continue to proliferate beyond their normal period, resulting in a larger cerebellum that persists into adulthood, with consequent motor deficits.

  6. Constitutively polarized granules prime KHYG-1 NK cells.

    Science.gov (United States)

    Suck, Garnet; Branch, Donald R; Aravena, Paola; Mathieson, Mark; Helke, Simone; Keating, Armand

    2006-09-01

    The major mechanism for NK cell lysis of tumor cells is granule-mediated cytotoxicity. Polarization of granules is a prelude to the release of their cytotoxic contents in response to target-cell binding. We describe the novel observation of constitutive granule polarization in the cytotoxic NK cell line, KHYG-1. Continuous degranulation of KHYG-1 cells, however, does not occur and still requires target-cell contact. Disruption of microtubules with colcemid is sufficient to disperse the granules in KHYG-1 and significantly decreases cytotoxicity. A similar effect is not obtained by inhibiting extracellular signal-related kinase 2 (ERK2), the most distal kinase investigated in the cytolytic pathway. Disruption of microtubules significantly down-regulates activation receptors, NKp44 and NKG2D, implicating them as potential microtubule-trafficking receptors. Such changes in upstream receptor expression may have caused deactivation of ERK2, since NKG2D cross-linking also leads to receptor down-regulation and diminished ERK phosphorylation. Thus, a functional role for NKG2D in KHYG-1 cytotoxicity is demonstrated. Moreover, the novel primed state may contribute to the high cytotoxicity exhibited by KHYG-1.

  7. Somatic Arc protein expression in hippocampal granule cells is increased in response to environmental change but independent of task-specific learning.

    Science.gov (United States)

    Cleland, J P; Willis, E F; Bartlett, P F; Vukovic, J

    2017-09-29

    Activated neurons express immediate-early genes, such as Arc. Expression of Arc in the hippocampal granule cell layer, an area crucial for spatial learning and memory, is increased during acquisition of spatial learning; however, it is unclear whether this effect is related to the task-specific learning process or to nonspecific aspects of the testing procedure (e.g. exposure to the testing apparatus and exploration of the environment). Herein, we show that Arc-positive cells numbers are increased to the same extent in the granule cell layer after both acquisition of a single spatial learning event in the active place avoidance task and exploration of the testing environment, as compared to naïve (i.e. caged) mice. Repeated exposure the testing apparatus and environment did not reduce Arc expression. Furthermore, Arc expression did not correlate with performance in both adult and aged animals, suggesting that exploration of the testing environment, rather than the specific acquisition of the active place avoidance task, induces Arc expression in the dentate granule cell layer. These findings thus suggest that Arc is an experience-induced immediate-early gene.

  8. Glomerular and Mitral-Granule Cell Microcircuits Coordinate Temporal and Spatial Information Processing in the Olfactory Bulb.

    Science.gov (United States)

    Cavarretta, Francesco; Marasco, Addolorata; Hines, Michael L; Shepherd, Gordon M; Migliore, Michele

    2016-01-01

    The olfactory bulb processes inputs from olfactory receptor neurons (ORNs) through two levels: the glomerular layer at the site of input, and the granule cell level at the site of output to the olfactory cortex. The sequence of action of these two levels has not yet been examined. We analyze this issue using a novel computational framework that is scaled up, in three-dimensions (3D), with realistic representations of the interactions between layers, activated by simulated natural odors, and constrained by experimental and theoretical analyses. We suggest that the postulated functions of glomerular circuits have as their primary role transforming a complex and disorganized input into a contrast-enhanced and normalized representation, but cannot provide for synchronization of the distributed glomerular outputs. By contrast, at the granule cell layer, the dendrodendritic interactions mediate temporal decorrelation, which we show is dependent on the preceding contrast enhancement by the glomerular layer. The results provide the first insights into the successive operations in the olfactory bulb, and demonstrate the significance of the modular organization around glomeruli. This layered organization is especially important for natural odor inputs, because they activate many overlapping glomeruli.

  9. Glomerular and mitral-granule cell microcircuits coordinate temporal and spatial information processing in the olfactory bulb

    Directory of Open Access Journals (Sweden)

    Francesco Cavarretta

    2016-07-01

    Full Text Available The olfactory bulb processes inputs from olfactory receptor neurons (ORNs through two levels: the glomerular layer at the site of input, and the granule cell level at the site of output to the olfactory cortex. The sequence of action of these two levels has not yet been examined. We analyze this issue using a novel computational framework that is scaled up, in three-dimensions (3D, with realistic representations of the interactions between layers, activated by simulated natural odors, and constrained by experimental and theoretical analyses. We suggest that the postulated functions of glomerular circuits have as their primary role transforming a complex and disorganized input into a contrast-enhanced and normalized representation, but cannot provide for synchronization of the distributed glomerular outputs. By contrast, at the granule cell layer, the dendrodendritic interactions mediate temporal decorrelation, which we show is dependent on the preceding contrast enhancement by the glomerular layer. The results provide the first insights into the successive operations in the olfactory bulb, and demonstrate the significance of the modular organization around glomeruli. This layered organization is especially important for natural odor inputs, because they activate many overlapping glomeruli.

  10. Study of light scattering by a granulated coated sphere - a model of granulated blood cells

    NARCIS (Netherlands)

    Yurkin, M.A.; de Kanter, D.; Hoekstra, A.G.

    2008-01-01

    We performed extensive simulations of light scattering by granulated coated sphere model using the discrete dipole approximation and varying model parameters in the ranges of sizes and refractive indices of granulated blood cells. We compared these results with predictions of Maxwell-Garnett

  11. Biochemical and microscopic evidence for the internalization and degradation of heparin-containing mast cell granules by bovine endothelial cells

    International Nuclear Information System (INIS)

    Atkins, F.M.; Friedman, M.M.; Metcalfe, D.D.

    1985-01-01

    Incubation of [ 35 S]heparin-containing mast cell granules with cultured bovine endothelial cells was followed by the appearance of 35 S-granule-associated radioactivity within the endothelial cells and a decrease in radioactivity in the extracellular fluid. These changes occurred during the first 24 hours of incubation and suggested ingestion of the mast cell granules by the endothelial cells. Periodic electron microscopic examination of the monolayers confirmed this hypothesis by demonstrating apposition of the granules to the plasmalemma of endothelial cells, which was followed by the engulfment of the granules by cytoplasmic projections. Under light microscopic examination, mast cell granules within endothelial cells then appeared to undergo degradation. The degradation of [ 35 S]heparin in mast cell granules was demonstrated by a decrease in the amount of intracellular [ 35 S]heparin proteoglycan after 24 hours and the appearance of free [ 35 S]sulfate in the extracellular compartment. Intact endothelial cells were more efficient at degrading [ 35 S]heparin than were cell lysates or cell supernatants. These data provide evidence of the ability of endothelial cells to ingest mast cell granules and degrade native heparin that is presented as a part of the mast cell granule

  12. Differential Structural Development of Adult-Born Septal Hippocampal Granule Cells in the Thy1-GFP Mouse, Nuclear Size as a New Index of Maturation.

    Directory of Open Access Journals (Sweden)

    Tijana Radic

    Full Text Available Adult neurogenesis is frequently studied in the mouse hippocampus. We examined the morphological development of adult-born, immature granule cells in the suprapyramidal blade of the septal dentate gyrus over the period of 7-77 days after mitosis with BrdU-labeling in 6-weeks-old male Thy1-GFP mice. As Thy1-GFP expression was restricted to maturated granule cells, it was combined with doublecortin-immunolabeling of immature granule cells. We developed a novel classification system that is easily applicable and enables objective and direct categorization of newborn granule cells based on the degree of dendritic development in relation to the layer specificity of the dentate gyrus. The structural development of adult-generated granule cells was correlated with age, albeit with notable differences in the time course of development between individual cells. In addition, the size of the nucleus, immunolabeled with the granule cell specific marker Prospero-related homeobox 1 gene, was a stable indicator of the degree of a cell's structural maturation and could be used as a straightforward parameter of granule cell development. Therefore, further studies could employ our doublecortin-staging system and nuclear size measurement to perform investigations of morphological development in combination with functional studies of adult-born granule cells. Furthermore, the Thy1-GFP transgenic mouse model can be used as an additional investigation tool because the reporter gene labels granule cells that are 4 weeks or older, while very young cells could be visualized through the immature marker doublecortin. This will enable comparison studies regarding the structure and function between young immature and older matured granule cells.

  13. Control over the morphology and segregation of Zebrafish germ cell granules during embryonic development

    Directory of Open Access Journals (Sweden)

    Nakkrasae La-Iad

    2008-05-01

    Full Text Available Abstract Background Zebrafish germ cells contain granular-like structures, organized around the cell nucleus. These structures share common features with polar granules in Drosophila, germinal granules in Xenopus and chromatoid bodies in mice germ cells, such as the localization of the zebrafish Vasa, Piwi and Nanos proteins, among others. Little is known about the structure of these granules as well as their segregation in mitosis during early germ-cell development. Results Using transgenic fish expressing a fluorescently labeled novel component of Zebrafish germ cell granules termed Granulito, we followed the morphology and distribution of the granules. We show that whereas these granules initially exhibit a wide size variation, by the end of the first day of development they become a homogeneous population of medium size granules. We investigated this resizing event and demonstrated the role of microtubules and the minus-end microtubule dependent motor protein Dynein in the process. Last, we show that the function of the germ cell granule resident protein the Tudor domain containing protein-7 (Tdrd7 is required for determination of granule morphology and number. Conclusion Our results suggest that Zebrafish germ cell granules undergo a transformation process, which involves germ cell specific proteins as well as the microtubular network.

  14. Mechanism of the formation of hollow spherical granules using a high shear granulator.

    Science.gov (United States)

    Asada, Takumi; Nishikawa, Mitsunori; Ochiai, Yasushi; Noguchi, Shuji; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2018-05-30

    Recently, we have developed a novel granulation technology to manufacture hollow spherical granules (HSGs) for controlled-release formulations; however, the mechanism of the granulation is still unclear. The aim of this study is to determine the mechanism of the formation of the HSGs using a high shear granulator. Samples of granulated material were collected at various times during granulation and were investigated using scanning electron microscope and X-ray computed tomography. It was observed that the granulation proceeded by drug layering to the polymer, followed by formation of a hollow in the granule. In addition, it was also found that generation of a crack in the adhered drug layer and air flow into the granules might be involved in forming the hollow in the structure. Observation of the granulation of formulations with different types of drugs and polymers indicated that negative pressure in the granules occurred and the granules caved in when the hollow was formed. The hollow-forming speed and the shell density of the hollow granules depended on the particular drug and polymer. Taken together, the granulation mechanism of HSGs was determined and this information will be valuable for HSGs technology development. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Acute ethanol exposure inhibits silencing of cerebellar Golgi cell firing induced by granule cell axon input

    Directory of Open Access Journals (Sweden)

    Paolo eBotta

    2014-02-01

    Full Text Available Golgi cells (GoCs are specialized interneurons that provide inhibitory input to granule cells in the cerebellar cortex. GoCs are pacemaker neurons that spontaneously fire action potentials, triggering spontaneous inhibitory postsynaptic currents in granule cells and also contributing to the generation tonic GABAA receptor-mediated currents in granule cells. In turn, granule cell axons provide feedback glutamatergic input to GoCs. It has been shown that high frequency stimulation of granule cell axons induces a transient pause in GoC firing in a type 2-metabotropic glutamate receptor (mGluR2-dependent manner. Here, we investigated the effect ethanol on the pause of GoC firing induced by high frequency stimulation of granule cell axons. GoC electrophysiological recordings were performed in parasagittal cerebellar vermis slices from postnatal day 23 to 26 rats. Loose-patch cell-attached recordings revealed that ethanol (40 mM reversibly decreases the pause duration. An antagonist of mGluR2 reduced the pause duration but did not affect the effect of ethanol. Whole-cell voltage-clamp recordings showed that currents evoked by an mGluR2 agonist were not significantly affected by ethanol. Perforated-patch experiments in which hyperpolarizing and depolarizing currents were injected into GoCs demonstrated that there is an inverse relationship between spontaneous firing and pause duration. Slight inhibition of the Na+/K+ pump mimicked the effect of ethanol on pause duration. In conclusion, ethanol reduces the granule cell axon-mediated feedback mechanism by reducing the input responsiveness of GoCs. This would result in a transient increase of GABAA receptor-mediated inhibition of granule cells, limiting information flow at the input stage of the cerebellar cortex.

  16. Pyramid-like basket cells in the granular layer of the dentate gyrus in the rat.

    Science.gov (United States)

    Seress, L

    1978-01-01

    Basket cells of the dentate gyrus were identified using Nissl (cresyl violet) staining. It has been found that the ratio between basket and granule cells is 1:150--210. Only a few glial cells, mainly astroglia, were found in the granular layer of the dentate gyrus. In accordance with earlier data it was found that the granule cells and glial cells originate mainly postnatally, but the basket cells, like the pyramidal cells of the hippocampus, originate prenatally. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:701192

  17. Proteome profiling of human neutrophil granule subsets, secretory vesicles, and cell membrane

    DEFF Research Database (Denmark)

    Rørvig, Sara; Østergaard, Ole; Heegaard, Niels Henrik Helweg

    2013-01-01

    granules, SVs, and plasma membrane has been performed before. Here, we performed subcellular fractionation on freshly isolated human neutrophils by nitrogen cavitation and density centrifugation on a four-layer Percoll gradient. Granule subsets were pooled and subjected to SDS-PAGE, and gel pieces were in...... subcellular proteome profiles presented here may be used as a database in combination with the mRNA array database to predict and test the presence and localization of proteins in neutrophil granules and membranes....

  18. Application of tumbling melt granulation (TMG) method to prepare controlled-release fine granules.

    Science.gov (United States)

    Maejima, T; Kubo, M; Osawa, T; Nakajima, K; Kobayashi, M

    1998-03-01

    The tumbling melt granulation (TMG) method was applied to prepare controlled-release fine granules of diltiazem hydrochloride (DH). The entire process, from the preparation of the cores by the adherence of DH to the sucrose crystal to the subsequent coating of the controlled-release layer, was performed without using any solvent. A mixture of meltable material, talc, and ethylcellulose was used for the controlled-release layer and controlled-release fine granules approximately 400 microns in diameter were obtained with excellent producibility. The dissolution rate of DH from these fine granules was similar to that of a once-a-day dosage form obtained in the market; further, the dependency of the dissolution profile on pH of the media was less. Thus, it was concluded that this TMG method was very useful for preparing not only controlled-release beads of granule size (usually 500 to 1400 microns) but also fine granules.

  19. Hilar Mossy Cell Degeneration Causes Transient Dentate Granule Cell Hyperexcitability and Impaired Pattern Separation

    Science.gov (United States)

    Jinde, Seiichiro; Zsiros, Veronika; Jiang, Zhihong; Nakao, Kazuhito; Pickel, James; Kohno, Kenji; Belforte, Juan E.; Nakazawa, Kazu

    2012-01-01

    Summary Although excitatory mossy cells of the hippocampal hilar region are known to project both to dentate granule cells and to interneurons, it is as yet unclear whether mossy cell activity’s net effect on granule cells is excitatory or inhibitory. To explore their influence on dentate excitability and hippocampal function, we generated a conditional transgenic mouse line, using the Cre/loxP system, in which diphtheria toxin receptor was selectively expressed in mossy cells. One week after injecting toxin into this line, mossy cells throughout the longitudinal axis were degenerated extensively, theta wave power of dentate local field potentials increased during exploration, and deficits occurred in contextual discrimination. By contrast, we detected no epileptiform activity, spontaneous behavioral seizures, or mossy-fiber sprouting 5–6 weeks after mossy cell degeneration. These results indicate that the net effect of mossy cell excitation is to inhibit granule cell activity and enable dentate pattern separation. PMID:23259953

  20. Expression of tryptophan 2,3-dioxygenase in mature granule cells of the adult mouse dentate gyrus

    Directory of Open Access Journals (Sweden)

    Ohira, Koji

    2010-09-01

    Full Text Available Abstract New granule cells are continuously generated in the dentate gyrus of the adult hippocampus. During granule cell maturation, the mechanisms that differentiate new cells not only describe the degree of cell differentiation, but also crucially regulate the progression of cell differentiation. Here, we describe a gene, tryptophan 2,3-dioxygenase (TDO, whose expression distinguishes stem cells from more differentiated cells among the granule cells of the adult mouse dentate gyrus. The use of markers for proliferation, neural progenitors, and immature and mature granule cells indicated that TDO was expressed in mature cells and in some immature cells. In mice heterozygous for the alpha-isoform of calcium/calmodulin-dependent protein kinase II, in which dentate gyrus granule cells fail to mature normally, TDO immunoreactivity was substantially downregulated in the dentate gyrus granule cells. Moreover, a 5-bromo-2'-deoxyuridine labeling experiment revealed that new neurons began to express TDO between 2 and 4 wk after the neurons were generated, when the axons and dendrites of the granule cells developed and synaptogenesis occurred. These findings indicate that TDO might be required at a late-stage of granule cell development, such as during axonal and dendritic growth, synaptogenesis and its maturation.

  1. The number of granule cells in rat hippocampus is reduced after chronic mild stress and re-established after chronic escitalopram treatment

    DEFF Research Database (Denmark)

    Jayatissa, Magdalena N; Bisgaard, Christina; West, Mark J

    2008-01-01

    mild stress and chronic escitalopram treatment. Furthermore, we investigated which classes of immature granule cells are affected by stress and targeted by escitalopram. Rats were initially exposed to 2weeks of CMS and 4weeks of escitalopram treatment with concurrent exposure to stress. The behavioral...... changes, indicating a decrease in sensitivity to a reward, were assessed in terms of sucrose consumption. We found a significant 22.4% decrease in the total number of granule cells in the stressed rats. This decrease was reversed in the stressed escitalopram treated rats that responded to the treatment......, but not in the rats that did not respond to escitalopram treatment. These changes were not followed by alterations in the volume of the granule cell layer. We also showed a differential regulation of dentate neurons, in different stages of development, by chronic stress and chronic escitalopram treatment. Our study...

  2. Measurement of oxide-layer thickness of internal granules in high-purity aluminium

    International Nuclear Information System (INIS)

    Takacs, S.; Ditroi, F.; Mahunka, I.

    1989-01-01

    Charged-particle activation analysis was used for the determination of bulk oxygen concentration in aluminium. High-purity aluminium samples and mixtures containing different amounts of alumina were irradiated by 13 MeV 3 He particles. The aim of the investigation was to determine the oxide-layer thickness on the surface of internal aluminium granules. The measurement was carried out by determining the bulk oxygen concentration in the samples, and calculating the oxide-layer thickness, by using model conditions about the microstructure of the aluminium samples. (author) 5 refs

  3. Formation of tRNA granules in the nucleus of heat-induced human cells

    International Nuclear Information System (INIS)

    Miyagawa, Ryu; Mizuno, Rie; Watanabe, Kazunori; Ijiri, Kenichi

    2012-01-01

    Highlights: ► tRNAs are tranlocated into the nucleus in heat-induced HeLa cells. ► tRNAs form the unique granules in the nucleus. ► tRNA ganules overlap with nuclear stress granules. -- Abstract: The stress response, which can trigger various physiological phenomena, is important for living organisms. For instance, a number of stress-induced granules such as P-body and stress granule have been identified. These granules are formed in the cytoplasm under stress conditions and are associated with translational inhibition and mRNA decay. In the nucleus, there is a focus named nuclear stress body (nSB) that distinguishes these structures from cytoplasmic stress granules. Many splicing factors and long non-coding RNA species localize in nSBs as a result of stress. Indeed, tRNAs respond to several kinds of stress such as heat, oxidation or starvation. Although nuclear accumulation of tRNAs occurs in starved Saccharomyces cerevisiae, this phenomenon is not found in mammalian cells. We observed that initiator tRNA Met (Meti) is actively translocated into the nucleus of human cells under heat stress. During this study, we identified unique granules of Meti that overlapped with nSBs. Similarly, elongator tRNA Met was translocated into the nucleus and formed granules during heat stress. Formation of tRNA granules is closely related to the translocation ratio. Then, all tRNAs may form the specific granules.

  4. Formation of tRNA granules in the nucleus of heat-induced human cells

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Ryu [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Department of Biological Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan); Mizuno, Rie [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Watanabe, Kazunori, E-mail: watanabe@ric.u-tokyo.ac.jp [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Ijiri, Kenichi [Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Department of Biological Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654 (Japan)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer tRNAs are tranlocated into the nucleus in heat-induced HeLa cells. Black-Right-Pointing-Pointer tRNAs form the unique granules in the nucleus. Black-Right-Pointing-Pointer tRNA ganules overlap with nuclear stress granules. -- Abstract: The stress response, which can trigger various physiological phenomena, is important for living organisms. For instance, a number of stress-induced granules such as P-body and stress granule have been identified. These granules are formed in the cytoplasm under stress conditions and are associated with translational inhibition and mRNA decay. In the nucleus, there is a focus named nuclear stress body (nSB) that distinguishes these structures from cytoplasmic stress granules. Many splicing factors and long non-coding RNA species localize in nSBs as a result of stress. Indeed, tRNAs respond to several kinds of stress such as heat, oxidation or starvation. Although nuclear accumulation of tRNAs occurs in starved Saccharomyces cerevisiae, this phenomenon is not found in mammalian cells. We observed that initiator tRNA{sup Met} (Meti) is actively translocated into the nucleus of human cells under heat stress. During this study, we identified unique granules of Meti that overlapped with nSBs. Similarly, elongator tRNA{sup Met} was translocated into the nucleus and formed granules during heat stress. Formation of tRNA granules is closely related to the translocation ratio. Then, all tRNAs may form the specific granules.

  5. The Prohormone VGF Regulates β Cell Function via Insulin Secretory Granule Biogenesis

    Directory of Open Access Journals (Sweden)

    Samuel B. Stephens

    2017-09-01

    Full Text Available The prohormone VGF is expressed in neuroendocrine and endocrine tissues and regulates nutrient and energy status both centrally and peripherally. We and others have shown that VGF-derived peptides have direct action on the islet β cell as secretagogues and cytoprotective agents; however, the endogenous function of VGF in the β cell has not been described. Here, we demonstrate that VGF regulates secretory granule formation. VGF loss-of-function studies in both isolated islets and conditional knockout mice reveal a profound decrease in stimulus-coupled insulin secretion. Moreover, VGF is necessary to facilitate efficient exit of granule cargo from the trans-Golgi network and proinsulin processing. It also functions to replenish insulin granule stores following nutrient stimulation. Our data support a model in which VGF operates at a critical node of granule biogenesis in the islet β cell to coordinate insulin biosynthesis with β cell secretory capacity.

  6. Measurement of the internal pH of mast cell granules using microvolumetric fluorescence and isotopic techniques

    International Nuclear Information System (INIS)

    De Young, M.B.; Nemeth, E.F.; Scarpa, A.

    1987-01-01

    The intragranular pH of isolated mast cell granules was measured. Because of the minute amounts of isolated granules available, two techniques were developed by modifying aminoacridine fluorescence and [ 14 C]methylamine accumulation techniques to permit measurements with microliter sample volumes. Granule purity was demonstrated by electron microscopy, ruthenium red exclusion, and biochemical (histamine, mast cell granule protease) analysis. The internal pH was determined to be 5.55 +/- 0.06, indicating that the pH environment within mast cell granules is not significantly different from that of previously studied granule types (i.e., chromaffin, platelet, pancreatic islet, and pituitary granules). Collapse of the pH gradient by NH+4 was demonstrated with both techniques. No evidence of Cl-/OH- or specific cation/H+ transport was found, and major chloride permeability could not be unequivocably demonstrated. Ca 2+ and Cl- at concentrations normally present extracellularly destabilized granules in the presence of NH+4, but this phenomenon does not necessarily indicate a role for these ions in the exocytotic release of granule contents from intact cells. The pH measurement techniques developed for investigating the properties of granules in mast cells may be useful for studying other granules that can be obtained only in limited quantities

  7. Colchicine induced intraneuronal free zinc accumulation and dentate granule cell degeneration.

    Science.gov (United States)

    Choi, Bo Young; Lee, Bo Eun; Kim, Jin Hee; Kim, Hyun Jung; Sohn, Min; Song, Hong Ki; Chung, Tae Nyoung; Suh, Sang Won

    2014-08-01

    Colchicine has been discovered to inhibit many inflammatory processes such as gout, familial Mediterranean fever, pericarditis and Behcet disease. Other than these beneficial anti-inflammatory effects, colchicine blocks microtubule-assisted axonal transport, which results in the selective loss of dentate granule cells of the hippocampus. The mechanism of the colchicine-induced dentate granule cell death and depletion of mossy fiber terminals still remains unclear. In the present study, we hypothesized that colchicine-induced dentate granule cell death may be caused by accumulation of labile intracellular zinc. 10 μg kg(-1) of colchicine was injected into the adult rat hippocampus and then brain sections were evaluated at 1 day or 1 week later. Neuronal cell death was evaluated by H&E staining or Fluoro-Jade B. Zinc accumulation and vesicular zinc were detected by N-(6-methoxy-8-quinolyl)-para-toluene sulfonamide (TSQ) staining. To test whether an extracellular zinc chelator can prevent this process, CaEDTA was injected into the hippocampus over a 5 min period with colchicine. To test whether other microtubule toxins also produce similar effects as colchicine, vincristine was injected into the hippocampus. The present study found that colchicine injection induced intracellular zinc accumulation in the dentate granule cells and depleted vesicular zinc from mossy fiber terminals. Injection of a zinc chelator, CaEDTA, did not block the zinc accumulation and neuronal death. Vincristine also produced intracellular zinc accumulation and neuronal death. These results suggest that colchicine-induced dentate granule cell death is caused by blocking axonal zinc flow and accumulation of intracellular labile zinc.

  8. Turnover of pigment granules: cyclic catabolism and anabolism of ommochromes within epidermal cells.

    Science.gov (United States)

    Insausti, T C; Casas, J

    2009-12-01

    Ommochromes are end products of the tryptophan metabolism in arthropods. While the anabolism of ommochromes has been well studied, the catabolism is totally unknown. In order to study it, we used the crab-spider Misumena vatia, which is able to change color reversibly in a few days, from yellow to white and back. Ommochromes is the only pigment class responsible for the body coloration in this animal. The aim of this study was to analyze the fine structure of the epidermal cells in bleaching spiders, in an attempt to correlate morphological changes with the fate of the pigment granules. Central to the process of bleaching is the lysis of the ommochrome granules. In the same cell, intact granules and granules in different degradation stages are found. The degradation begins with granule autolysis. Some components are extruded in the extracellular space and others are recycled via autophagy. Abundant glycogen appears associated to granulolysis. In a later stage of bleaching, ommochrome progranules, typical of white spiders, appear in the distal zone of the same epidermal cell. Catabolism and anabolism of pigment granules thus take place simultaneously in spider epidermal cells. A cyclic pathway of pigment granules formation and degradation, throughout a complete cycle of color change is proposed, together with an explanation for this turnover, involving photoprotection against UV by ommochromes metabolites. The presence of this turnover for melanins is discussed.

  9. Sequestration of highly expressed mRNAs in cytoplasmic granules, P-bodies, and stress granules enhances cell viability.

    Directory of Open Access Journals (Sweden)

    Anna Lavut

    Full Text Available Transcriptome analyses indicate that a core 10%-15% of the yeast genome is modulated by a variety of different stresses. However, not all the induced genes undergo translation, and null mutants of many induced genes do not show elevated sensitivity to the particular stress. Elucidation of the RNA lifecycle reveals accumulation of non-translating mRNAs in cytoplasmic granules, P-bodies, and stress granules for future regulation. P-bodies contain enzymes for mRNA degradation; under stress conditions mRNAs may be transferred to stress granules for storage and return to translation. Protein degradation by the ubiquitin-proteasome system is elevated by stress; and here we analyzed the steady state levels, decay, and subcellular localization of the mRNA of the gene encoding the F-box protein, UFO1, that is induced by stress. Using the MS2L mRNA reporter system UFO1 mRNA was observed in granules that colocalized with P-bodies and stress granules. These P-bodies stored diverse mRNAs. Granules of two mRNAs transported prior to translation, ASH1-MS2L and OXA1-MS2L, docked with P-bodies. HSP12 mRNA that gave rise to highly elevated protein levels was not observed in granules under these stress conditions. ecd3, pat1 double mutants that are defective in P-body formation were sensitive to mRNAs expressed ectopically from strong promoters. These highly expressed mRNAs showed elevated translation compared with wild-type cells, and the viability of the mutants was strongly reduced. ecd3, pat1 mutants also exhibited increased sensitivity to different stresses. Our interpretation is that sequestration of highly expressed mRNAs in P-bodies is essential for viability. Storage of mRNAs for future regulation may contribute to the discrepancy between the steady state levels of many stress-induced mRNAs and their proteins. Sorting of mRNAs for future translation or decay by individual cells could generate potentially different phenotypes in a genetically identical

  10. Stimulation of mast cells leads to cholesterol accumulation in macrophages in vitro by a mast cell granule-mediated uptake of low density lipoprotein

    International Nuclear Information System (INIS)

    Kokkonen, J.O.; Kovanen, P.T.

    1987-01-01

    The uptake of low density lipoprotein (LDL) by cultured mouse macrophages was markedly promoted by isolated rat mast cell granules present in the culture medium. The granule-mediated uptake of 125 I-LDL enhanced the rate of cholesteryl ester synthesis in the macrophages, the result being accumulation of cholesteryl esters in these cells. Binding of LDL to the granules was essential for the granule-mediated uptake of LDL by macrophages, for the uptake process was prevented by treating the granules with avidin or protamine chloride or by treating LDL with 1,2-cyclohexanedione, all of which inhibit the binding of LDL to the granules. Inhibition of granule phagocytosis by the macrophages with cytochalasin B also abolished the granule-mediated uptake of LDL. Finally, mouse macrophage monolayers and LDL were incubated in the presence of isolated rat serosal mast cells. Stimulation of the mast cells with compound 48/80, a degranulating agent, resulted in dose-dependent release of secretory granules from the mast cells and a parallel increase in 14 C cholesteryl ester synthesis in the macrophages. The results show that, in this in vitro model, the sequence of events leading to accumulation of cholesteryl esters in macrophages involves initial stimulation of mast cells, subsequent release of their secretory granules, binding of LDL to the exocytosed granules, and, finally, phagocytosis of the LDL-containing granules by macrophages

  11. Evidence for evoked release of adenosine and glutamate from cultured cerebellar granule cells

    International Nuclear Information System (INIS)

    Schousboe, A.; Frandsen, A.; Drejer, J.

    1989-01-01

    Evoked release of [ 3 H]-D-aspartate which labels the neurotransmitter glutamate pool in cultured cerebellar granule cells was compared with evoked release of adenosine from similar cultures. It was found that both adenosine and [3H]-D-aspartate could be released from the neurons in a calcium dependent manner after depolarization of the cells with either 10-100 microM glutamate or 50 mM KCl. Cultures of cerebellar granule cells treated with 50 microM kainate to eliminate GABAergic neurons behaved in the same way. This together with the observation that cultured astrocytes did not exhibit a calcium dependent, potassium stimulated adenosine release strongly suggest that cerebellar granule cells release adenosine in a neurotransmitter-like fashion together with glutamate which is the classical neurotransmitter of these neurons. Studies of the metabolism of adenosine showed that in the granule cells adenosine is rapidly metabolized to ATP, ADP, and AMP, but in spite of this, adenosine was found to be released preferential to ATP

  12. Sensorimotor Representations in Cerebellar Granule Cells in Larval Zebrafish Are Dense, Spatially Organized, and Non-temporally Patterned.

    Science.gov (United States)

    Knogler, Laura D; Markov, Daniil A; Dragomir, Elena I; Štih, Vilim; Portugues, Ruben

    2017-05-08

    A fundamental question in neurobiology is how animals integrate external sensory information from their environment with self-generated motor and sensory signals in order to guide motor behavior and adaptation. The cerebellum is a vertebrate hindbrain region where all of these signals converge and that has been implicated in the acquisition, coordination, and calibration of motor activity. Theories of cerebellar function postulate that granule cells encode a variety of sensorimotor signals in the cerebellar input layer. These models suggest that representations should be high-dimensional, sparse, and temporally patterned. However, in vivo physiological recordings addressing these points have been limited and in particular have been unable to measure the spatiotemporal dynamics of population-wide activity. In this study, we use both calcium imaging and electrophysiology in the awake larval zebrafish to investigate how cerebellar granule cells encode three types of sensory stimuli as well as stimulus-evoked motor behaviors. We find that a large fraction of all granule cells are active in response to these stimuli, such that representations are not sparse at the population level. We find instead that most responses belong to only one of a small number of distinct activity profiles, which are temporally homogeneous and anatomically clustered. We furthermore identify granule cells that are active during swimming behaviors and others that are multimodal for sensory and motor variables. When we pharmacologically change the threshold of a stimulus-evoked behavior, we observe correlated changes in these representations. Finally, electrophysiological data show no evidence for temporal patterning in the coding of different stimulus durations. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  13. N-methyl-D-aspartate promotes the survival of cerebellar granule cells in culture

    DEFF Research Database (Denmark)

    Balázs, R; Jørgensen, Ole Steen; Hack, N

    1988-01-01

    Our previous studies on the survival-promoting influence of elevated concentrations of extracellular K+ ([K+]e) on cultured cerebellar granule cells led to the proposal that depolarization in vitro mimics the effect of the earliest afferent inputs received by the granule cells in vivo. This, in t...

  14. Synchronization in primate cerebellar granule cell layer local field potentials: Basic anisotropy and dynamic changes during active expectancy

    Directory of Open Access Journals (Sweden)

    Richard Courtemanche

    2009-07-01

    Full Text Available The cerebellar cortex is remarkable for its organizational regularity, out of which task-related neural networks should emerge. So, in Purkinje cells, both complex and simple spike network patterns are evident in sensorimotor behavior. However, task-related patterns of activity in the granule cell layer (GCL have been less studied. We recorded local field potential (LFP activity simultaneously in pairs of GCL sites in monkeys performing an active expectancy (lever-press task, in passive expectancy, and at rest. LFP sites were selected when they showed strong 10-25 Hz oscillations; pair orientation was in stereotaxic sagittal and coronal (mainly, and diagonal. As shown previously, LFP oscillations at each site were modulated during the lever-press task. Synchronization across LFP pairs showed an evident basic anisotropy at rest: sagittal pairs of LFPs were better synchronized (more than double the cross-correlation coefficients than coronal pairs, and more than diagonal pairs. On the other hand, this basic anisotropy was modifiable: during the active expectancy condition, where sagittal and coronal orientations were tested, synchronization of LFP pairs would increase just preceding movement, most notably for the coronal pairs. This lateral extension of synchronization was not observed in passive expectancy. The basic pattern of synchronization at rest, favoring sagittal synchrony, thus seemed to adapt in a dynamic fashion, potentially extending laterally to include more cerebellar cortex elements. This dynamic anisotropy in LFP synchronization could underlie GCL network organization in the context of sensorimotor tasks.

  15. Light scattering on PHA granules protects bacterial cells against the harmful effects of UV radiation.

    Science.gov (United States)

    Slaninova, Eva; Sedlacek, Petr; Mravec, Filip; Mullerova, Lucie; Samek, Ota; Koller, Martin; Hesko, Ondrej; Kucera, Dan; Marova, Ivana; Obruca, Stanislav

    2018-02-01

    Numerous prokaryotes accumulate polyhydroxyalkanoates (PHA) in the form of intracellular granules. The primary function of PHA is the storage of carbon and energy. Nevertheless, there are numerous reports that the presence of PHA granules in microbial cells enhances their stress resistance and fitness when exposed to various stress factors. In this work, we studied the protective mechanism of PHA granules against UV irradiation employing Cupriavidus necator as a model bacterial strain. The PHA-accumulating wild type strain showed substantially higher UV radiation resistance than the PHA non-accumulating mutant. Furthermore, the differences in UV-Vis radiation interactions with both cell types were studied using various spectroscopic approaches (turbidimetry, absorption spectroscopy, and nephelometry). Our results clearly demonstrate that intracellular PHA granules efficiently scatter UV radiation, which provides a substantial UV-protective effect for bacterial cells and, moreover, decreases the intracellular level of reactive oxygen species in UV-challenged cells. The protective properties of the PHA granules are enhanced by the fact that granules specifically bind to DNA, which in turn provides shield-like protection of DNA as the most UV-sensitive molecule. To conclude, the UV-protective action of PHA granules adds considerable value to their primary storage function, which can be beneficial in numerous environments.

  16. A Role for Serglycin Proteoglycan in Mast Cell Apoptosis Induced by a Secretory Granule-mediated Pathway*

    Science.gov (United States)

    Melo, Fabio Rabelo; Waern, Ida; Rönnberg, Elin; Åbrink, Magnus; Lee, David M.; Schlenner, Susan M.; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Turk, Boris; Wernersson, Sara; Pejler, Gunnar

    2011-01-01

    Mast cell secretory granules (secretory lysosomes) contain large amounts of fully active proteases bound to serglycin proteoglycan. Damage to the granule membrane will thus lead to the release of serglycin and serglycin-bound proteases into the cytosol, which potentially could lead to proteolytic activation of cytosolic pro-apoptotic compounds. We therefore hypothesized that mast cells are susceptible to apoptosis induced by permeabilization of the granule membrane and that this process is serglycin-dependent. Indeed, we show that wild-type mast cells are highly sensitive to apoptosis induced by granule permeabilization, whereas serglycin-deficient cells are largely resistant. The reduced sensitivity of serglycin−/− cells to apoptosis was accompanied by reduced granule damage, reduced release of proteases into the cytosol, and defective caspase-3 activation. Mechanistically, the apoptosis-promoting effect of serglycin involved serglycin-dependent proteases, as indicated by reduced sensitivity to apoptosis and reduced caspase-3 activation in cells lacking individual mast cell-specific proteases. Together, these findings implicate serglycin proteoglycan as a novel player in mast cell apoptosis. PMID:21123167

  17. Sorption of short-lived radionuclides in a layer of sorbent with spherical granules

    International Nuclear Information System (INIS)

    Karlin, Yu.V.

    1993-01-01

    Sorption methods have found wide application in the purification of liquid radioactive wastes. The working element in sorption methods for this purpose is usually a sorption column with a fixed layer of sorbent. Continuous-action equipment with a moving layer of sorbent is very seldom used. When a fixed layer of sorbent is used its wear and prolonged mixing in the sorption column are reduced to a minimum, and maximum purification is achieved due to the advantages of the dynamic method of sorption over the static method. The time of protective action of the sorbent layer is determined by the time taken for the radionuclide to pass through the sorption column, and for the majority of radionuclides is determined by numerous parameters, including the type of sorbent and radionuclide, the rate of flow through the sorbent, the size of the sorbent granules, etc. The physical and chemical aspects of this process have been investigated in detail, and numerous methods for modeling it mathematically have been developed and have been used to develop methods of designing sorption column apparatus. The specific nature of the radionuclides as unstable materials enables the hypothetical case of a open-quotes perpetualclose quotes sorption filter to be represented. In fact, to achieve this it is only necessary to assume that the half-life of the radionuclide is so small that the rate of decay of the radionuclide in the sorption column (both in the sorbed state and in the aqueous phase of the sorption layer) is equal to the rate that it is fed into the column in the flow of liquid radioactive waste. In this case the sorption front of the radionuclide in the column wall remains fixed after a certain initial period. In this paper, a mathematical model of such a hypothetical filter for the case of spherical sorbent granules is considered

  18. Direct conversion of injury-site myeloid cells to fibroblast-like cells of granulation tissue.

    Science.gov (United States)

    Sinha, Mithun; Sen, Chandan K; Singh, Kanhaiya; Das, Amitava; Ghatak, Subhadip; Rhea, Brian; Blackstone, Britani; Powell, Heather M; Khanna, Savita; Roy, Sashwati

    2018-03-05

    Inflammation, following injury, induces cellular plasticity as an inherent component of physiological tissue repair. The dominant fate of wound macrophages is unclear and debated. Here we show that two-thirds of all granulation tissue fibroblasts, otherwise known to be of mesenchymal origin, are derived from myeloid cells which are likely to be wound macrophages. Conversion of myeloid to fibroblast-like cells is impaired in diabetic wounds. In cross-talk between keratinocytes and myeloid cells, miR-21 packaged in extracellular vesicles (EV) is required for cell conversion. EV from wound fluid of healing chronic wound patients is rich in miR-21 and causes cell conversion more effectively compared to that by fluid from non-healing patients. Impaired conversion in diabetic wound tissue is rescued by targeted nanoparticle-based delivery of miR-21 to macrophages. This work introduces a paradigm wherein myeloid cells are recognized as a major source of fibroblast-like cells in the granulation tissue.

  19. COUP-TFI mitotically regulates production and migration of dentate granule cells and modulates hippocampal Cxcr4 expression.

    Science.gov (United States)

    Parisot, Joséphine; Flore, Gemma; Bertacchi, Michele; Studer, Michèle

    2017-06-01

    Development of the dentate gyrus (DG), the primary gateway for hippocampal inputs, spans embryonic and postnatal stages, and involves complex morphogenetic events. We have previously identified the nuclear receptor COUP-TFI as a novel transcriptional regulator in the postnatal organization and function of the hippocampus. Here, we dissect its role in DG morphogenesis by inactivating it in either granule cell progenitors or granule neurons. Loss of COUP-TFI function in progenitors leads to decreased granule cell proliferative activity, precocious differentiation and increased apoptosis, resulting in a severe DG growth defect in adult mice. COUP-TFI-deficient cells express high levels of the chemokine receptor Cxcr4 and migrate abnormally, forming heterotopic clusters of differentiated granule cells along their paths. Conversely, high COUP-TFI expression levels downregulate Cxcr4 expression, whereas increased Cxcr4 expression in wild-type hippocampal cells affects cell migration. Finally, loss of COUP-TFI in postmitotic cells leads to only minor and transient abnormalities, and to normal Cxcr4 expression. Together, our results indicate that COUP-TFI is required predominantly in DG progenitors for modulating expression of the Cxcr4 receptor during granule cell neurogenesis and migration. © 2017. Published by The Company of Biologists Ltd.

  20. Wolfram syndrome 1 gene (WFS1) product localizes to secretory granules and determines granule acidification in pancreatic beta-cells.

    Science.gov (United States)

    Hatanaka, Masayuki; Tanabe, Katsuya; Yanai, Akie; Ohta, Yasuharu; Kondo, Manabu; Akiyama, Masaru; Shinoda, Koh; Oka, Yoshitomo; Tanizawa, Yukio

    2011-04-01

    Wolfram syndrome is an autosomal recessive disorder characterized by juvenile-onset insulin-dependent diabetes mellitus and optic atrophy. The gene responsible for the syndrome (WFS1) encodes an endoplasmic reticulum (ER) resident transmembrane protein. The Wfs1-null mouse exhibits progressive insulin deficiency causing diabetes. Previous work suggested that the function of the WFS1 protein is connected to unfolded protein response and to intracellular Ca(2+) homeostasis. However, its precise molecular function in pancreatic β-cells remains elusive. In our present study, immunofluorescent and electron-microscopic analyses revealed that WFS1 localizes not only to ER but also to secretory granules in pancreatic β-cells. Intragranular acidification was assessed by measuring intracellular fluorescence intensity raised by the acidotrophic agent, 3-[2,4-dinitroanilino]-3'-amino-N-methyldipropyramine. Compared with wild-type β-cells, there was a 32% reduction in the intensity in WFS1-deficient β-cells, indicating the impairment of granular acidification. This phenotype may, at least partly, account for the evidence that Wfs1-null islets have impaired proinsulin processing, resulting in an increased circulating proinsulin level. Morphometric analysis using electron microscopy evidenced that the density of secretory granules attached to the plasma membrane was significantly reduced in Wfs1-null β-cells relative to that in wild-type β-cells. This may be relevant to the recent finding that granular acidification is required for the priming of secretory granules preceding exocytosis and may partly explain the fact that glucose-induced insulin secretion is profoundly impaired in young prediabetic Wfs1-null mice. These results thus provide new insights into the molecular mechanisms of β-cell dysfunction in patients with Wolfram syndrome.

  1. Conditional induction of Math1 specifies embryonic stem cells to cerebellar granule neuron lineage and promotes differentiation into mature granule neurons.

    Science.gov (United States)

    Srivastava, Rupali; Kumar, Manoj; Peineau, Stéphane; Csaba, Zsolt; Mani, Shyamala; Gressens, Pierre; El Ghouzzi, Vincent

    2013-04-01

    Directing differentiation of embryonic stem cells (ESCs) to specific neuronal subtype is critical for modeling disease pathology in vitro. An attractive means of action would be to combine regulatory differentiation factors and extrinsic inductive signals added to the culture medium. In this study, we have generated mature cerebellar granule neurons by combining a temporally controlled transient expression of Math1, a master gene in granule neuron differentiation, with inductive extrinsic factors involved in cerebellar development. Using a Tetracyclin-On transactivation system, we overexpressed Math1 at various stages of ESCs differentiation and found that the yield of progenitors was considerably increased when Math1 was induced during embryonic body stage. Math1 triggered expression of Mbh1 and Mbh2, two target genes directly involved in granule neuron precursor formation and strong expression of early cerebellar territory markers En1 and NeuroD1. Three weeks after induction, we observed a decrease in the number of glial cells and an increase in that of neurons albeit still immature. Combining Math1 induction with extrinsic factors specifically increased the number of neurons that expressed Pde1c, Zic1, and GABAα6R characteristic of mature granule neurons, formed "T-shaped" axons typical of granule neurons, and generated synaptic contacts and action potentials in vitro. Finally, in vivo implantation of Math1-induced progenitors into young adult mice resulted in cell migration and settling of newly generated neurons in the cerebellum. These results show that conditional induction of Math1 drives ESCs toward the cerebellar fate and indicate that acting on both intrinsic and extrinsic factors is a powerful means to modulate ESCs differentiation and maturation into a specific neuronal lineage. Copyright © 2012 AlphaMed Press.

  2. Dipeptidyl peptidase IV is sorted to the secretory granules in pancreatic islet A-cells

    DEFF Research Database (Denmark)

    Poulsen, Mona Dam; Hansen, Gert Helge; Dabelsteen, Erik

    1993-01-01

    Dipeptidyl peptidase IV (DP IV:EC 3.4.14.5) was localized in endocrine cells of pig pancreas by immunohistochemical and enzyme histochemical methods. Immunolight microscopy with both monoclonal and polyclonal antibodies demonstrated DP IV immunoreactivity in cells located in the peripheral part...... of the islets of Langerhans. The antigen is enzymatically active, as shown by enzyme histochemical analysis with a synthetic DP IV substrate. By immunoelectron microscopy (immunogold labeling), the labeling of DP IV in the islets was associated with the secretory granules of the A-cells, as identified by double...... labeling using a monoclonal glucagon antibody as the second primary antibody. These results show that DP IV is sorted to secretory granules in the pig pancreatic islet A-cells. Furthermore, this secretory granule enzyme, as opposed to intestinal brush border DP IV, is suggested to be a soluble protein...

  3. Three-dimensional ultrastructural analyses of anterior pituitary gland expose spatial relationships between endocrine cell secretory granule localization and capillary distribution.

    Science.gov (United States)

    Yoshitomi, Munetake; Ohta, Keisuke; Kanazawa, Tomonoshin; Togo, Akinobu; Hirashima, Shingo; Uemura, Kei-Ichiro; Okayama, Satoko; Morioka, Motohiro; Nakamura, Kei-Ichiro

    2016-10-31

    Endocrine and endothelial cells of the anterior pituitary gland frequently make close appositions or contacts, and the secretory granules of each endocrine cell tend to accumulate at the perivascular regions, which is generally considered to facilitate secretory functions of these cells. However, three-dimensional relationships between the localization pattern of secretory granules and blood vessels are not fully understood. To define and characterize these spatial relationships, we used scanning electron microscopy (SEM) three-dimensional reconstruction method based on focused ion-beam slicing and scanning electron microscopy (FIB/SEM). Full three-dimensional cellular architectures of the anterior pituitary tissue at ultrastructural resolution revealed that about 70% of endocrine cells were in apposition to the endothelial cells, while almost 30% of endocrine cells were entirely isolated from perivascular space in the tissue. Our three-dimensional analyses also visualized the distribution pattern of secretory granules in individual endocrine cells, showing an accumulation of secretory granules in regions in close apposition to the blood vessels in many cases. However, secretory granules in cells isolated from the perivascular region tended to distribute uniformly in the cytoplasm of these cells. These data suggest that the cellular interactions between the endocrine and endothelial cells promote an uneven cytoplasmic distribution of the secretory granules.

  4. Mathematical modeling and statistical analysis of calcium-regulated insulin granule exocytosis in ß-cells from mice and humans

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Cortese, Giuliana; Eliasson, Lena

    2011-01-01

    Insulin is released from pancreatic ß-cells as a result of Ca2+-evoked exocytosis of dense-core granules. Secretion is biphasic, which has been suggested to correspond to the release of different granule pools. Here we review and carefully reanalyze previously published patch-clamp data on depola......Insulin is released from pancreatic ß-cells as a result of Ca2+-evoked exocytosis of dense-core granules. Secretion is biphasic, which has been suggested to correspond to the release of different granule pools. Here we review and carefully reanalyze previously published patch-clamp data...... on depolarization-evoked Ca2+-currents and corresponding capacitance measurements. Using a statistical mixed-effects model, we show that the data indicate that pool depletion is negligible in response to short depolarizations in mouse ß-cells. We then review mathematical models of granule dynamics and exocytosis...

  5. Poly (ADP-ribose polymerase plays an important role in intermittent hypoxia-induced cell death in rat cerebellar granule cells

    Directory of Open Access Journals (Sweden)

    Chiu Sheng-Chun

    2012-03-01

    Full Text Available Abstract Background Episodic cessation of airflow during sleep in patients with sleep apnea syndrome results in intermittent hypoxia (IH. Our aim was to investigate the effects of IH on cerebellar granule cells and to identify the mechanism of IH-induced cell death. Methods Cerebellar granule cells were freshly prepared from neonatal Sprague-Dawley rats. IH was created by culturing the cerebellar granule cells in the incubators with oscillating O2 concentration at 20% and 5% every 30 min for 1-4 days. The results of this study are based on image analysis using a confocal microscope and associated software. Cellular oxidative stress increased with increase in IH. In addition, the occurrence of cell death (apoptosis and necrosis increased as the duration of IH increased, but decreased in the presence of an iron chelator (phenanthroline or poly (ADP-ribose polymerase (PARP inhibitors [3-aminobenzamide (3-AB and DPQ]. The fluorescence of caspase-3 remained the same regardless of the duration of IH, and Western blots did not detect activation of caspase-3. However, IH increased the ratio of apoptosis-inducing factor (AIF translocation to the nucleus, while PARP inhibitors (3-AB reduced this ratio. Results According to our findings, IH increased oxidative stress and subsequently leading to cell death. This effect was at least partially mediated by PARP activation, resulting in ATP depletion, calpain activation leading to AIF translocation to the nucleus. Conclusions We suggest that IH induces cell death in rat primary cerebellar granule cells by stimulating oxidative stress PARP-mediated calpain and AIF activation.

  6. Host cell subversion by Toxoplasma GRA16, an exported dense granule protein that targets the host cell nucleus and alters gene expression.

    Science.gov (United States)

    Bougdour, Alexandre; Durandau, Eric; Brenier-Pinchart, Marie-Pierre; Ortet, Philippe; Barakat, Mohamed; Kieffer, Sylvie; Curt-Varesano, Aurélie; Curt-Bertini, Rose-Laurence; Bastien, Olivier; Coute, Yohann; Pelloux, Hervé; Hakimi, Mohamed-Ali

    2013-04-17

    After invading host cells, Toxoplasma gondii multiplies within a parasitophorous vacuole (PV) that is maintained by parasite proteins secreted from organelles called dense granules. Most dense granule proteins remain within the PV, and few are known to access the host cell cytosol. We identify GRA16 as a dense granule protein that is exported through the PV membrane and reaches the host cell nucleus, where it positively modulates genes involved in cell-cycle progression and the p53 tumor suppressor pathway. GRA16 binds two host enzymes, the deubiquitinase HAUSP and PP2A phosphatase, which exert several functions, including regulation of p53 and the cell cycle. GRA16 alters p53 levels in a HAUSP-dependent manner and induces nuclear translocation of the PP2A holoenzyme. Additionally, certain GRA16-deficient strains exhibit attenuated virulence, indicating the importance of these host alterations in pathogenesis. Therefore, GRA16 represents a potentially emerging subfamily of exported dense granule proteins that modulate host function. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Novel insights into pericarp, protein body globoids of aleurone layer, starchy granules of three cereals gained using atomic force microscopy and environmental scanning electronic microscopy.

    Science.gov (United States)

    Antonini, Elena; Zara, Carolina; Valentini, Laura; Gobbi, Pietro; Ninfali, Paolino; Menotta, Michele

    2018-02-05

    In this study, we applied Environmental Scanning Electron Microscopy-Energy Dispersive Spectroscopy (ESEM-EDS) and Atomic Force Microscopy (AFM) analysis to three different cereal caryopses: barley, oat and einkorn wheat. The morphological structures, chemical elemental composition and surface characteristics of the three cereals were described. Regarding the morphology, barley showed the thickest pericarp, providing a strong barrier digestion and absorption of nutrients. The aleurone layer of each cereal type contained protein body globoids within its cells. Large type-A and small type-B starchy granules were revealed in the endosperm of barley and einkorn wheat, whereas irregular starchy granules were found in oats. The starchy granule elemental composition, detected by ESEM-EDS, was rather homogenous in the three cereals, whereas the pericarp and protein body globoids showed heterogeneity. In the protein body globoids, oats showed higher P and K concentrations than barley and einkorn wheat. Regarding the topographic profiles, detected by AFM, einkorn wheat starchy granules showed a surface profile that differed significantly from that of oats and barley, which were quite similar to one another. The present work provides insights into the morphological and chemical makeup of the three grains shedding light on the higher bio-accessibility of einkorn wheat nutrients compared to barley and oats, providing important suggestions for human nutrition and technological standpoints.

  8. Novel insights into pericarp, protein body globoids of aleurone layer, starchy granules of three cereals gained using atomic force microscopy and environmental scanning electronic microscopy

    Science.gov (United States)

    Antonini, Elena; Zara, Carolina; Valentini, Laura; Gobbi, Pietro; Menotta, Michele

    2018-01-01

    In this study, we applied Environmental Scanning Electron Microscopy-Energy Dispersive Spectroscopy (ESEM-EDS) and Atomic Force Microscopy (AFM) analysis to three different cereal caryopses: barley, oat and einkorn wheat. The morphological structures, chemical elemental composition and surface characteristics of the three cereals were described. Regarding the morphology, barley showed the thickest pericarp, providing a strong barrier to digestion and absorption of nutrients. The aleurone layer of each cereal type contained protein body globoids within its cells. Large type-A and small type-B starchy granules were revealed in the endosperm of barley and einkorn wheat, whereas irregular starchy granules were found in oats. The starchy granule elemental composition, detected by ESEM-EDS, was rather homogenous in the three cereals, whereas the pericarp and protein body globoids showed heterogeneity. In the protein body globoids, oats showed higher P and K concentrations than barley and einkorn wheat. Regarding the topographic profiles, detected by AFM, einkorn wheat starchy granules showed a surface profile that differed significantly from that of oats and barley, which were quite similar to one another. The present work provides insights into the morphological and chemical makeup of the three grains shedding light on the higher bio-accessibility of einkorn wheat nutrients compared to barley and oats, providing important suggestions for human nutrition and technological standpoints. PMID:29569870

  9. The Stress Granule RNA-Binding Protein TIAR-1 Protects Female Germ Cells from Heat Shock in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Gabriela Huelgas-Morales

    2016-04-01

    Full Text Available In response to stressful conditions, eukaryotic cells launch an arsenal of regulatory programs to protect the proteome. One major protective response involves the arrest of protein translation and the formation of stress granules, cytoplasmic ribonucleoprotein complexes containing the conserved RNA-binding proteins TIA-1 and TIAR. The stress granule response is thought to preserve mRNA for translation when conditions improve. For cells of the germline—the immortal cell lineage required for sexual reproduction—protection from stress is critically important for perpetuation of the species, yet how stress granule regulatory mechanisms are deployed in animal reproduction is incompletely understood. Here, we show that the stress granule protein TIAR-1 protects the Caenorhabditis elegans germline from the adverse effects of heat shock. Animals containing strong loss-of-function mutations in tiar-1 exhibit significantly reduced fertility compared to the wild type following heat shock. Analysis of a heat-shock protein promoter indicates that tiar-1 mutants display an impaired heat-shock response. We observed that TIAR-1 was associated with granules in the gonad core and oocytes during several stressful conditions. Both gonad core and oocyte granules are dynamic structures that depend on translation; protein synthesis inhibitors altered their formation. Nonetheless, tiar-1 was required for the formation of gonad core granules only. Interestingly, the gonad core granules did not seem to be needed for the germ cells to develop viable embryos after heat shock. This suggests that TIAR-1 is able to protect the germline from heat stress independently of these structures.

  10. The Stress Granule RNA-Binding Protein TIAR-1 Protects Female Germ Cells from Heat Shock in Caenorhabditis elegans.

    Science.gov (United States)

    Huelgas-Morales, Gabriela; Silva-García, Carlos Giovanni; Salinas, Laura S; Greenstein, David; Navarro, Rosa E

    2016-04-07

    In response to stressful conditions, eukaryotic cells launch an arsenal of regulatory programs to protect the proteome. One major protective response involves the arrest of protein translation and the formation of stress granules, cytoplasmic ribonucleoprotein complexes containing the conserved RNA-binding proteins TIA-1 and TIAR. The stress granule response is thought to preserve mRNA for translation when conditions improve. For cells of the germline-the immortal cell lineage required for sexual reproduction-protection from stress is critically important for perpetuation of the species, yet how stress granule regulatory mechanisms are deployed in animal reproduction is incompletely understood. Here, we show that the stress granule protein TIAR-1 protects the Caenorhabditis elegans germline from the adverse effects of heat shock. Animals containing strong loss-of-function mutations in tiar-1 exhibit significantly reduced fertility compared to the wild type following heat shock. Analysis of a heat-shock protein promoter indicates that tiar-1 mutants display an impaired heat-shock response. We observed that TIAR-1 was associated with granules in the gonad core and oocytes during several stressful conditions. Both gonad core and oocyte granules are dynamic structures that depend on translation; protein synthesis inhibitors altered their formation. Nonetheless, tiar-1 was required for the formation of gonad core granules only. Interestingly, the gonad core granules did not seem to be needed for the germ cells to develop viable embryos after heat shock. This suggests that TIAR-1 is able to protect the germline from heat stress independently of these structures. Copyright © 2016 Huelgas-Morales et al.

  11. Stimulus-dependent state transition between synchronized oscillation and randomly repetitive burst in a model cerebellar granular layer.

    Directory of Open Access Journals (Sweden)

    Takeru Honda

    2011-07-01

    Full Text Available Information processing of the cerebellar granular layer composed of granule and Golgi cells is regarded as an important first step toward the cerebellar computation. Our previous theoretical studies have shown that granule cells can exhibit random alternation between burst and silent modes, which provides a basis of population representation of the passage-of-time (POT from the onset of external input stimuli. On the other hand, another computational study has reported that granule cells can exhibit synchronized oscillation of activity, as consistent with observed oscillation in local field potential recorded from the granular layer while animals keep still. Here we have a question of whether an identical network model can explain these distinct dynamics. In the present study, we carried out computer simulations based on a spiking network model of the granular layer varying two parameters: the strength of a current injected to granule cells and the concentration of Mg²⁺ which controls the conductance of NMDA channels assumed on the Golgi cell dendrites. The simulations showed that cells in the granular layer can switch activity states between synchronized oscillation and random burst-silent alternation depending on the two parameters. For higher Mg²⁺ concentration and a weaker injected current, granule and Golgi cells elicited spikes synchronously (synchronized oscillation state. In contrast, for lower Mg²⁺ concentration and a stronger injected current, those cells showed the random burst-silent alternation (POT-representing state. It is suggested that NMDA channels on the Golgi cell dendrites play an important role for determining how the granular layer works in response to external input.

  12. Intracisternal granules in the adipokinetic cells of locusts are not degraded and apparently function as supplementary stores of secretory material.

    Science.gov (United States)

    Harthoorn, L F; Diederen, J H; Oudejans, R C; Verstegen, M M; Vullings, H G; Van der Horst, D J

    2000-01-01

    The intracisternal granules in locust adipokinetic cells appear to represent accumulations of secretory material within cisternae of the rough endoplasmic reticulum. An important question is whether these granules are destined for degradation or represent stores of (pro)hormones. Two strategies were used to answer this question. First, cytochemistry was applied to elucidate the properties of intracisternal granules. The endocytic tracers horseradish peroxidase and wheat-germ agglutinin-conjugated horseradish peroxidase were used to facilitate the identification of endocytic, autophagic, and lysosomal organelles, which may be involved in the degradation of intracisternal granules. No intracisternal granules could be found within autophagosomes, and granules fused with endocytic and lysosomal organelles were not observed, nor could tracer be found within the granules. The lysosomal enzyme acid phosphatase was absent from the granules. Second, biochemical analysis of the content of intracisternal granules revealed that these granules contain prohormones as well as hormones. Prohormones were present in relatively higher amounts compared with ordinary secretory granules. Since the intracisternal granules in locust adipokinetic cells are not degraded and contain intact (pro)hormones it is concluded that they function as supplementary stores of secretory material.

  13. Organization of spinocerebellar projection map in three types of agranular cerebellum: Purkinje cells vs. granule cells as organizer element

    International Nuclear Information System (INIS)

    Arsenio Nunes, M.L.; Sotelo, C.; Wehrle, R.

    1988-01-01

    The organization of the spinocerebellar projection was analysed by the anterograde axonal WGA-HRP (horseradish peroxidase-wheat germ agglutinin conjugate) tracing method in three different types of agranular cerebellar cortex either induced experimentally by X-irradiation or occurring spontaneously in weaver (wv/wv) and staggerer (sg/sg) mutant mice. The results of this study show that in the X-irradiated rat and weaver mouse, in both of which the granule cells are directly affected and die early in development, the spinal axons reproduce, with few differences, the normal spinocerebellar pattern. Conversely, in staggerer mouse, in which the Purkinje cells are intrinsically affected and granule neurons do not seem to be primarily perturbed by the staggerer gene action, the spinocerebellar organization is severely modified. These findings appear somewhat paradoxical because if granule cells, the synaptic targets of mossy spinocerebellar fibers, were necessary for the organization of spinocerebellar projection, the staggerer cerebellum would exhibit a much more normal projectional map than the weaver and the X-irradiated cerebella. It is, therefore, obvious that granule cells, and even specific synaptogenesis, are not essential for the establishment of the normal spinocerebellar topography. On the other hand, the fact that the Purkinje cells are primarily affected in the unique agranular cortex in which the spinocerebellar organization is severely modified suggests that these neurons could be the main element in the organization of the spinocerebellar projection map. This hypothesis is discussed in correlation with already-reported findings on the zonation of the cerebellar cortex by biochemically different clusters of Purkinje cells

  14. Surface Modification of Porous Titanium Granules for Improving Bioactivity.

    Science.gov (United States)

    Karaji, Zahra Gorgin; Houshmand, Behzad; Faghihi, Shahab

    The highly porous titanium granules are currently being used as bone substitute material and for bone tissue augmentation. However, they suffer from weak bone bonding ability. The aim of this study was to create a nanostructured surface oxide layer on irregularly shaped titanium granules to improve their bioactivity. This could be achieved using optimized electrochemical anodic oxidation (anodizing) and heat treatment processes. The anodizing process was done in an ethylene glycol-based electrolyte at an optimized condition of 60 V for 3 hours. The anodized granules were subsequently annealed at 450°C for 1 hour. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) were used to characterize the surface structure and morphology of the granules. The in vitro bioactivity of the samples was evaluated by immersion of specimens in simulated body fluid (SBF) for 1, 2, and 3 weeks. The human osteoblastic sarcoma cell line, MG63, was used to evaluate cell viability on the samples using dimethylthiazol-diphenyl tetrazolium bromide (MTT) assay. The results demonstrated the formation of amorphous nanostructured titanium oxide after anodizing, which transformed to crystalline anatase and rutile phases upon heat treatment. After immersion in SBF, spherical aggregates of amorphous calcium phosphate were formed on the surface of the anodized sample, which turned into crystalline hydroxyapatite on the surface of the anodized annealed sample. No cytotoxicity was detected among the samples. It is suggested that anodic oxidation followed by heat treatment could be used as an effective surface treatment procedure to improve bioactivity of titanium granules implemented for bone tissue repair and augmentation.

  15. KIF20A-Mediated RNA Granule Transport System Promotes the Invasiveness of Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Keisuke Taniuchi

    2014-12-01

    Full Text Available Pancreatic cancers are aggressive because they are highly invasive and highly metastatic; moreover, effective treatments for aggressive pancreatic cancers are lacking. Here, we report that the motor kinesin protein KIF20A promoted the motility and invasiveness of pancreatic cancer cells through transporting the RNA-binding protein IGF2BP3 and IGF2BP3-bound transcripts toward cell protrusions along microtubules. We previously reported that IGF2BP3 and its target transcripts are assembled into cytoplasmic stress granules of pancreatic cancer cells, and that IGF2BP3 promotes the motility and invasiveness of pancreatic cancer cells through regulation of localized translation of IGF2BP3-bound transcripts in cell protrusions. We show that knockdown of KIF20A inhibited accumulation of IGF2BP3-containing stress granules in cell protrusions and suppressed local protein expression from specific IGF2BP3-bound transcripts, ARF6 and ARHGEF4, in the protrusions. Our results provide insight into the link between regulation of KIF20A-mediated trafficking of IGF2BP3-containing stress granules and modulation of the motility and invasiveness in pancreatic cancers.

  16. On the origins of the universal dynamics of endogenous granules in mammalian cells.

    Science.gov (United States)

    Vanapalli, Siva A; Li, Yixuan; Mugele, Frieder; Duits, Michel H G

    2009-12-01

    Endogenous granules (EGs) that consist of lipid droplets and mitochondria have been commonly used to assess intracellular mechanical properties via multiple particle tracking microrheology (MPTM). Despite their widespread use, the nature of interaction of EGs with the cytoskeletal network and the type of forces driving their dynamics--both of which are crucial for the interpretation of the results from MPTM technique--are yet to be resolved. In this report, we study the dynamics of endogenous granules in mammalian cells using particle tracking methods. We find that the ensemble dynamics of EGs is diffusive in three types of mammalian cells (endothelial cells, smooth muscle cells and fibroblasts), thereby suggesting an apparent universality in their dynamical behavior. Moreover, in a given cell, the amplitude of the mean-squared displacement for EGs is an order of magnitude larger than that of injected particles. This observation along with results from ATP depletion and temperature intervention studies suggests that cytoskeletal active forces drive the dynamics of EGs. To elucidate the dynamical origin of the diffusive-like nonthermal motion, we consider three active force generation mechanisms--molecular motor transport, actomyosin contractility and microtubule polymerization forces. We test these mechanisms using pharmacological interventions. Experimental evidence and model calculations suggest that EGs are intimately linked to microtubules and that microtubule polymerization forces drive their dynamics. Thus, endogenous granules could serve as non-invasive probes for microtubule network dynamics in mammalian cells.

  17. Influence of Spray-dried Hydroxyapatite-5-Fluorouracil Granules on Cell Lines Derived from Tissues of Mesenchymal Origin

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    Tim Scharnweber

    2008-11-01

    Full Text Available In our previous work we described the preparation and characterization of spray dried hydroxyapatite micro granules loaded with 5-fluorouracil (5-FU. These loaded particles are used as a model drug delivery system (DDS. In this study we examined the in vitro response of two cell lines derived from different tissues to 5-FU loaded granules (LG. Both cell lines, either L929 cells of a mouse fibroblast lineage or cells originating from a rat osteosarcoma (ROS 17/2.8 showed a dose dependent decrease in cell proliferation in response to 5-FU-, either dissolved in the culture medium or loaded onto particles. The response of the two cell lines to loaded and nonloaded particles was different. The effect of LG and of a corresponding concentration of free 5-FU was practically the same for the ROS 17/2.8 cells indicating that ROS 17/2.8 cells were not affected by the carrier material. In contrast, L929 cells showed a slight decrease in cell proliferation also in the presence of granules not loaded with 5-FU. This is thought to be attributed to the inhibition of mitogenesis by phosphocitrates, already demonstrated in fibroblasts. In summary, we found that the loaded 5-FU kept its effectivity after the spray drying process and that the response towards the granules varied with cell type. This is the first step towards a tissue specific DDS.

  18. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

    Directory of Open Access Journals (Sweden)

    Kylie A. Huckleberry

    2015-08-01

    Full Text Available Thousands of neurons are born each day in the dentate gyrus (DG, but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in DG. The immediate-early gene (IEG zif268 is an important mediator of these effects, as its expression is induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Veyrac et al., 2013. Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs. In the general granule cell population, zif268 expression peaked 1 hour after novel environment exposure and returned to baseline by 8 hours post-exposure. However, in the doublecortin-positive (DCX+ immature neurons, zif268 expression was suppressed relative to home cage for at least 8 hours post-exposure. We next determined that exposure to water maze training, an enriched environment, or a novel environment caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 in the general DGC population and in 6-week-old adult-born neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. Novel environment exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly suppressed zif268 expression in 3-week-old neurons. In summary, behavioral experience transiently activated expression of zif268 in mature DGCs but caused a more long-lasting suppression of zif268 expression in immature, adult-born DGCs. We hypothesize that zif268 suppression inhibits memory-related synaptic plasticity in immature DGCs or mediates learning-induced apoptosis of immature adult

  19. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Morphometry of Hilar Ectopic Granule Cells in the Rat

    Science.gov (United States)

    Pierce, Joseph P.; McCloskey, Daniel P.; Scharfman, Helen E.

    2014-01-01

    Granule cell (GC) neurogenesis in the dentate gyrus (DG) does not always proceed normally. After severe seizures (e.g., status epilepticus [SE]) and some other conditions, newborn GCs appear in the hilus. Hilar ectopic GCs (EGCs) can potentially provide insight into the effects of abnormal location and seizures on GC development. Additionally, hilar EGCs that develop after SE may contribute to epileptogenesis and cognitive impairments that follow SE. Thus, it is critical to understand how EGCs differ from normal GCs. Relatively little morphometric information is available on EGCs, especially those restricted to the hilus. This study quantitatively analyzed the structural morphology of hilar EGCs from adult male rats several months after pilocarpineinduced SE, when they are considered to have chronic epilepsy. Hilar EGCs were physiologically identified in slices, intracellularly labeled, processed for light microscopic reconstruction, and compared to GC layer GCs, from both the same post-SE tissue and the NeuroMorpho database (normal GCs). Consistently, hilar EGC and GC layer GCs had similar dendritic lengths and field sizes, and identifiable apical dendrites. However, hilar EGC dendrites were topologically more complex, with more branch points and tortuous dendritic paths. Three-dimensional analysis revealed that, remarkably, hilar EGC dendrites often extended along the longitudinal DG axis, suggesting increased capacity for septotemporal integration. Axonal reconstruction demonstrated that hilar EGCs contributed to mossy fiber sprouting. This combination of preserved and aberrant morphological features, potentially supporting convergent afferent input to EGCs and broad, divergent efferent output, could help explain why the hilar EGC population could impair DG function. PMID:21344409

  1. Giant renin secretory granules in beige mouse renal afferent arterioles

    DEFF Research Database (Denmark)

    Jensen, B L; Rasch, Ruth; Nyengaard, Jens Randel

    1997-01-01

    The mutant beige mouse (C57BL/6 bg) has a disease characterised by abnormally enlarged cytoplasmic granules in a variety of cells. With the purpose of establishing a suitable cellular model for studying renin secretion, the present study was undertaken to compare renin granule morphology in beige...... (average granular volume 0.681 microm3), whereas 1-2 large granules were present per cell in beige mice. The volume of afferent arteriole that contained secretory granules was lower in the beige mice. We conclude that the beige mouse synthesizes, stores and releases active renin. Renin secretory granules...... in beige mice are grossly enlarged with 1-2 granules per juxtaglomerular cell. Compared with control mice, a similar amount of total renin granule volume per afferent arteriole is contained in a smaller part of beige mouse afferent arteriole. Granular cells from beige mice could therefore be a valuable...

  2. Cellular and Axonal Diversity in Molecular Layer Heterotopia of the Rat Cerebellar Vermis

    Directory of Open Access Journals (Sweden)

    Sarah E. Van Dine

    2013-01-01

    Full Text Available Molecular layer heterotopia of the cerebellar primary fissure are a characteristic of many rat strains and are hypothesized to result from defect of granule cells exiting the external granule cell layer during cerebellar development. However, the cellular and axonal constituents of these malformations remain poorly understood. In the present report, we use histochemistry and immunocytochemistry to identify neuronal, glial, and axonal classes in molecular layer heterotopia. In particular, we identify parvalbumin-expressing molecular layer interneurons in heterotopia as well as three glial cell types including Bergmann glia, Olig2-expressing oligodendrocytes, and Iba1-expressing microglia. In addition, we document the presence of myelinated, serotonergic, catecholaminergic, and cholinergic axons in heterotopia indicating possible spinal and brainstem afferent projections to heterotopic cells. These findings are relevant toward understanding the mechanisms of normal and abnormal cerebellar development.

  3. Effects of x irradiation on the postnatally-forming granule cell populations in the olfactory bulb, hippocampus, and cerebellum of the rat

    International Nuclear Information System (INIS)

    Bayer, S.A.; Altman, J.

    1975-01-01

    Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to low-level x irradiation (150 to 200 R) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss was assessed with two quantitative techniques. First, the total number of granule cells was determined to estimate the magnitude of permanent loss. Secondly, the number of labeled granule cells were counted on day 60 after a 3 H-thymidine injection given on either day 15 or on day 20 to estimate differential rates of cell proliferation during the recovery period. Permanent loss of granule cells was sustained in all regions by all schedules of irradiation. The time for the most effective exposures was earlier in the hippocampus and olfactory bulb than in the cerebellum. In all regions, both the irradiated groups and the controls showed a decrease in the level of cell proliferation between 15 and 20 days. The number of cells that could be labeled after either the 15 or 20 day injection was below control levels for all groups in the hippocampus, at control levels for all groups in the cerebellum, and either at (2X and 4X) or below (6X) control levels in the olfactory bulb. These results are discussed in the light of the formation time of the granule cells in each region

  4. Effects of x-irradiation on the postnatally-forming granule cell populations in the olfactory bulb, hippocampus, and cerebellum of the rat

    International Nuclear Information System (INIS)

    Bayer, S.A.; Altman, J.

    1975-01-01

    Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to low-level x irradiation (150-200 r) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss was assessed with two quantitative techniques. First, the total number of granule cells was determined to estimate the magnitude of permanent loss. Secondly, the number of labeled granule cells were counted on day 60 after a 3 H-thymidine injection given on either day 15 or on day 20 to estimate differential rates of cell proliferation during the recovery period. Permanent loss of granule cells was sustained in all regions by all schedules of irradiation. The time for the most effective exposures was earlier in the hippocampus and olfactory bulb than in the cerebellum. In all regions, both the irradiated groups and the controls showed a decrease in the level of cell proliferation between 15 and 20 days. The number of cells that could be labeled after either the 15 or 20 day injection was below control levels for all groups in the hippocampus, at control levels for all groups in the cerebellum, and either at (2X and 4X) or below (6X) control levels in the olfactory bulb. These results are discussed in the light of the formation time of the granule cells in each region

  5. Spontaneous calcium waves in granule cells in cerebellar slice cultures

    DEFF Research Database (Denmark)

    Apuschkin, Mia; Ougaard, Maria; Rekling, Jens C

    2013-01-01

    Multiple regions in the CNS display propagating correlated activity during embryonic and postnatal development. This activity can be recorded as waves of increased calcium concentrations in spiking neurons or glia cells, and have been suggested to be involved in patterning, axonal guidance and es......, that the propagating wave activity is carried through the tissue by axonal collaterals formed by neighboring granule cells, and further suggest that the correlated activity may be related to processes that ensure correct postnatal wiring of the cerebellar circuits....

  6. Loss of Melanin by Eye Retinal Pigment Epithelium Cells Is Associated with Its Oxidative Destruction in Melanolipofuscin Granules.

    Science.gov (United States)

    Dontsov, A E; Sakina, N L; Ostrovsky, M A

    2017-08-01

    The effect of superoxide radicals on melanin destruction and degradation of melanosomes isolated from cells of retinal pigment epithelium (RPE) of the human eye was studied. We found that potassium superoxide causes destruction of melanin in melanosomes of human and bovine RPE, as well as destruction of melanin from the ink bag of squid, with the formation of fluorescent decay products having an emission maximum at 520-525 nm. The initial kinetics of the accumulation of the fluorescent decay products is linear. Superoxide radicals lead simultaneously to a decrease in the number of melanosomes and to a decrease in concentration of paramagnetic centers in them. Complete degradation of melanosomes leads to the formation of a transparent solution containing dissolved proteins and melanin degradation products that do not exhibit paramagnetic properties. To completely degrade one melanosome of human RPE, 650 ± 100 fmol of superoxide are sufficient. The concentration of paramagnetic centers in a melanolipofuscin granule of human RPE is on average 32.5 ± 10.4% (p melanin undergoing a destruction process in these granules. RPE cells also contain intermediate granules that have an EPR signal with a lower intensity than that of melanolipofuscin granules, but higher than that of lipofuscin granules. This signal is due to the presence of residual melanin in these granules. Irradiation of a mixture of melanosomes with lipofuscin granules with blue light (450 nm), in contrast to irradiation of only melanosomes, results in the appearance of fluorescent melanin degradation products. We suggest that one of the main mechanisms of age-related decrease in melanin concentration in human RPE cells is its destruction in melanolipofuscin granules under the action of superoxide radicals formed during photoinduced oxygen reduction by lipofuscin fluorophores.

  7. The life cycle of platelet granules.

    Science.gov (United States)

    Sharda, Anish; Flaumenhaft, Robert

    2018-01-01

    Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types-dense granules, α-granules, and lysosomes-although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the trans -Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.

  8. Weaver mutant mouse cerebellar granule cells respond normally to chronic depolarization

    DEFF Research Database (Denmark)

    Bjerregaard, Annette; Mogensen, Helle Smidt; Hack, N

    1997-01-01

    We studied the effects of chronic K(+)-induced membrane depolarization and treatment with N-methyl-D-aspartate (NMDA) on cerebellar granule cells (CGCs) from weaver mutant mice and non-weaver litter-mates. The weaver mutation is a Gly-to-Ser substitution in a conserved region of the Girk2 G prote...

  9. Respiration Gates Sensory Input Responses in the Mitral Cell Layer of the Olfactory Bulb

    Science.gov (United States)

    Short, Shaina M.; Morse, Thomas M.; McTavish, Thomas S.; Shepherd, Gordon M.; Verhagen, Justus V.

    2016-01-01

    Respiration plays an essential role in odor processing. Even in the absence of odors, oscillating excitatory and inhibitory activity in the olfactory bulb synchronizes with respiration, commonly resulting in a burst of action potentials in mammalian mitral/tufted cells (MTCs) during the transition from inhalation to exhalation. This excitation is followed by inhibition that quiets MTC activity in both the glomerular and granule cell layers. Odor processing is hypothesized to be modulated by and may even rely on respiration-mediated activity, yet exactly how respiration influences sensory processing by MTCs is still not well understood. By using optogenetics to stimulate discrete sensory inputs in vivo, it was possible to temporally vary the stimulus to occur at unique phases of each respiration. Single unit recordings obtained from the mitral cell layer were used to map spatiotemporal patterns of glomerular evoked responses that were unique to stimulations occurring during periods of inhalation or exhalation. Sensory evoked activity in MTCs was gated to periods outside phasic respiratory mediated firing, causing net shifts in MTC activity across the cycle. In contrast, odor evoked inhibitory responses appear to be permitted throughout the respiratory cycle. Computational models were used to further explore mechanisms of inhibition that can be activated by respiratory activity and influence MTC responses. In silico results indicate that both periglomerular and granule cell inhibition can be activated by respiration to internally gate sensory responses in the olfactory bulb. Both the respiration rate and strength of lateral connectivity influenced inhibitory mechanisms that gate sensory evoked responses. PMID:28005923

  10. Amyloid β-mediated Zn2+ influx into dentate granule cells transiently induces a short-term cognitive deficit.

    Directory of Open Access Journals (Sweden)

    Atsushi Takeda

    Full Text Available We examined an idea that short-term cognition is transiently affected by a state of confusion in Zn2+ transport system due to a local increase in amyloid-β (Aβ concentration. A single injection of Aβ (25 pmol into the dentate gyrus affected dentate gyrus long-term potentiation (LTP 1 h after the injection, but not 4 h after the injection. Simultaneously, 1-h memory of object recognition was affected when the training was performed 1 h after the injection, but not 4 h after the injection. Aβ-mediated impairments of LTP and memory were rescued in the presence of zinc chelators, suggesting that Zn2+ is involved in Aβ action. When Aβ was injected into the dentate gyrus, intracellular Zn2+ levels were increased only in the injected area in the dentate gyrus, suggesting that Aβ induces the influx of Zn2+ into cells in the injected area. When Aβ was added to hippocampal slices, Aβ did not increase intracellular Zn2+ levels in the dentate granule cell layer in ACSF without Zn2+, but in ACSF containing Zn2+. The increase in intracellular Zn2+ levels was inhibited in the presence of CaEDTA, an extracellular zinc chelator, but not in the presence of CNQX, an AMPA receptor antagonist. The present study indicates that Aβ-mediated Zn2+ influx into dentate granule cells, which may occur without AMPA receptor activation, transiently induces a short-term cognitive deficit. Extracellular Zn2+ may play a key role for transiently Aβ-induced cognition deficits.

  11. Amyloid β-mediated Zn2+ influx into dentate granule cells transiently induces a short-term cognitive deficit.

    Science.gov (United States)

    Takeda, Atsushi; Nakamura, Masatoshi; Fujii, Hiroaki; Uematsu, Chihiro; Minamino, Tatsuya; Adlard, Paul A; Bush, Ashley I; Tamano, Haruna

    2014-01-01

    We examined an idea that short-term cognition is transiently affected by a state of confusion in Zn2+ transport system due to a local increase in amyloid-β (Aβ) concentration. A single injection of Aβ (25 pmol) into the dentate gyrus affected dentate gyrus long-term potentiation (LTP) 1 h after the injection, but not 4 h after the injection. Simultaneously, 1-h memory of object recognition was affected when the training was performed 1 h after the injection, but not 4 h after the injection. Aβ-mediated impairments of LTP and memory were rescued in the presence of zinc chelators, suggesting that Zn2+ is involved in Aβ action. When Aβ was injected into the dentate gyrus, intracellular Zn2+ levels were increased only in the injected area in the dentate gyrus, suggesting that Aβ induces the influx of Zn2+ into cells in the injected area. When Aβ was added to hippocampal slices, Aβ did not increase intracellular Zn2+ levels in the dentate granule cell layer in ACSF without Zn2+, but in ACSF containing Zn2+. The increase in intracellular Zn2+ levels was inhibited in the presence of CaEDTA, an extracellular zinc chelator, but not in the presence of CNQX, an AMPA receptor antagonist. The present study indicates that Aβ-mediated Zn2+ influx into dentate granule cells, which may occur without AMPA receptor activation, transiently induces a short-term cognitive deficit. Extracellular Zn2+ may play a key role for transiently Aβ-induced cognition deficits.

  12. Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation

    Directory of Open Access Journals (Sweden)

    Hourinaz Behesti

    2013-01-01

    BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival.

  13. Simulating spinal border cells and cerebellar granule cells under locomotion--a case study of spinocerebellar information processing.

    Directory of Open Access Journals (Sweden)

    Anton Spanne

    Full Text Available The spinocerebellar systems are essential for the brain in the performance of coordinated movements, but our knowledge about the spinocerebellar interactions is very limited. Recently, several crucial pieces of information have been acquired for the spinal border cell (SBC component of the ventral spinocerebellar tract (VSCT, as well as the effects of SBC mossy fiber activation in granule cells of the cerebellar cortex. SBCs receive monosynaptic input from the reticulospinal tract (RST, which is an important driving system under locomotion, and disynaptic inhibition from Ib muscle afferents. The patterns of activity of RST neurons and Ib afferents under locomotion are known. The activity of VSCT neurons under fictive locomotion, i.e. without sensory feedback, is also known, but there is little information on how these neurons behave under actual locomotion and for cerebellar granule cells receiving SBC input this is completely unknown. But the available information makes it possible to simulate the interactions between the spinal and cerebellar neuronal circuitries with a relatively large set of biological constraints. Using a model of the various neuronal elements and the network they compose, we simulated the modulation of the SBCs and their target granule cells under locomotion and hence generated testable predictions of their general pattern of modulation under this condition. This particular system offers a unique opportunity to simulate these interactions with a limited number of assumptions, which helps making the model biologically plausible. Similar principles of information processing may be expected to apply to all spinocerebellar systems.

  14. Granule cell potentials in the dentate gyrus of the hippocampus: coping behavior and stress ulcers in rats.

    Science.gov (United States)

    Henke, P G

    1990-01-01

    Evoked population potentials of the granule cells in the dentate gyrus of the hippocampus were increased in stress-resistant rats and decreased in stress-susceptible rats, as indexed by restraint-induced gastric ulcers. Inescapable, uncontrollable shock stimulation also suppressed granule cell population spikes and interfered with subsequent coping responses when escape was possible, i.e. the so-called helplessness effect. The data were interpreted to indicate that the hippocampus is part of a coping system in stressful situations.

  15. Balloon cells associated with granule cell dispersion in the dentate gyrus in hippocampal sclerosis.

    Science.gov (United States)

    Thom, M; Martinian, L; Caboclo, L O; McEvoy, A W; Sisodiya, S M

    2008-06-01

    Granule cell dispersion (GCD) is a common finding in hippocampal sclerosis in patients with intractable focal epilepsy. It is considered to be an acquired, post-developmental rather than a pre-existing abnormality, involving dispersion of either mature or newborn neurones, but the precise factors regulating it and its relationship to seizures are unknown. We present two cases of GCD with associated CD34-immunopositive balloon cells, a cell phenotype associated with focal cortical dysplasia type IIB, considered to be a developmental cortical lesion promoting epilepsy. This observation opens up the debate regarding the origin of balloon cells and CD34 expression and their temporal relationship to seizures.

  16. Facilitation of granule cell epileptiform activity by mossy fiber-released zinc in the pilocarpine model of temporal lobe epilepsy.

    Science.gov (United States)

    Timofeeva, Olga; Nadler, J Victor

    2006-03-17

    Recurrent mossy fiber synapses in the dentate gyrus of epileptic brain facilitate the synchronous firing of granule cells and may promote seizure propagation. Mossy fiber terminals contain and release zinc. Released zinc inhibits the activation of NMDA receptors and may therefore oppose the development of granule cell epileptiform activity. Hippocampal slices from rats that had experienced pilocarpine-induced status epilepticus and developed a recurrent mossy fiber pathway were used to investigate this possibility. Actions of released zinc were inferred from the effects of chelation with 1 mM calcium disodium EDTA (CaEDTA). When granule cell population bursts were evoked by mossy fiber stimulation in the presence of 6 mM K(+) and 30 microM bicuculline, CaEDTA slowed the rate at which evoked bursting developed, but did not change the magnitude of the bursts once they had developed fully. The effects of CaEDTA were then studied on the pharmacologically isolated NMDA receptor- and AMPA/kainate receptor-mediated components of the fully developed bursts. CaEDTA increased the magnitude of NMDA receptor-mediated bursts and reduced the magnitude of AMPA/kainate receptor-mediated bursts. CaEDTA did not affect the granule cell bursts evoked in slices from untreated rats by stimulating the perforant path in the presence of bicuculline and 6 mM K(+). These results suggest that zinc released from the recurrent mossy fibers serves mainly to facilitate the recruitment of dentate granule cells into population bursts.

  17. The presence of PHB granules in cytoplasm protects non-halophilic bacterial cells against the harmful impact of hypertonic environments.

    Science.gov (United States)

    Obruca, Stanislav; Sedlacek, Petr; Mravec, Filip; Krzyzanek, Vladislav; Nebesarova, Jana; Samek, Ota; Kucera, Dan; Benesova, Pavla; Hrubanova, Kamila; Milerova, Miluse; Marova, Ivana

    2017-10-25

    Numerous prokaryotes accumulate polyhydroxybutyrate (PHB) intracellularly as a storage material. It has also been proposed that PHB accumulation improves bacterial stress resistance. Cupriavidus necator and its PHB non-accumulating mutant were employed to investigate the protective role of PHB under hypertonic conditions. The presence of PHB granules enhanced survival of the bacteria after exposure to hypertonic conditions. Surprisingly, when coping with such conditions, the bacteria did not utilize PHB to harvest carbon or energy, suggesting that, in the osmotic upshock of C. necator, the protective mechanism of PHB granules is not associated with their hydrolysis. The presence of PHB granules influenced the overall properties of the cells, since challenged PHB-free cells underwent massive plasmolysis accompanied by damage to the cell membrane and the leakage of cytoplasm content, while no such effects were observed in PHB containing bacteria. Moreover, PHB granules demonstrated "liquid-like" properties indicating that they can partially repair and stabilize cell membranes by plugging small gaps formed during plasmolysis. In addition, the level of dehydration and changes in intracellular pH in osmotically challenged cells were less pronounced for PHB-containing cultures, demonstrating the important role of PHB for bacterial survival under hyperosmotic conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Identification of the Polyhydroxybutyrate Granules in Mammalian Cultured Cells

    OpenAIRE

    Elustondo, Pia; Zakharian, Eleonora; Pavlov, Evgeny

    2012-01-01

    Poly-3-hydroxybutyrate (PHB) is a biological polyester present in bacteria and eukaryotic cells. Long-chain (or storage) sPHB (up to 100,000 residues) is typically present in PHB-accumulating bacteria and localized in specialized granules known as carbonosomes. In these organisms, sPHB plays a major role as carbon and energy storage. On the other hand, short-chain (or complexed) cPHB (10–100 residues) is present in eukaryotic organisms, including mammals as well as in many bacteria. Previous ...

  19. Granulated wood ash to forest soils. Effects on microorganisms, phosphorus availability, and spatial relationships in the humus layer

    International Nuclear Information System (INIS)

    Clarholm, Marianne

    1999-01-01

    The report summarises effects on microorganisms, phosphorus (P) availability and spatial relationships in the humus layer of two spruce forests in south-western Sweden four to seven years after application of 3.2 tonnes (t) (Skogaby), alternatively three or six t (Torup) of granulated wood ash. There were tendencies for increases in pH and in numbers of ciliates, flagellates and small nematodes while no effects were observed for naked amoebae, the major consumers of bacteria among the protozoa. After seven years, the amount of P in microbial biomass in the humus layer in the wood ash treatment (A) in Skogaby was significantly higher than in the control (C), increased amounts of microbial nitrogen and carbon were also recorded. Observations over time indicated that the P availability in the soil first decreased after the ash addition, but later increased above that in the control. The time course was most readily seen in the microbial biomass, which contained 50% of total P in the humus layer, an amount equal to ten times the yearly uptake in trees. The microbial biomass has a much higher P concentration as compared to the needles, the component of the tree with the highest concentration. The P in micro-organisms thus form a buffer against P deficiency for the trees. A test where the 32 P uptake rate of excised mycorrhizal fine roots in the laboratory is used to establish P availability in the field, indicated an increased P availability in (A), which was in contrast to reported decreased uptake of P in trees, decreased P concentration in needles and also in roots, as compared to (C). In six treatments investigated in Skogaby 32 P uptake rates were negatively correlated to the P/C of the microbial biomass. Acid phosphatase activity was always higher in (A) as compared to treatments where soluble P had been added and at two out of five times also higher than in (C ). High phosphatase activity levels were at least partly connected to large amounts of microbial biomass

  20. Glucose Toxic Effects on Granulation Tissue Productive Cells: The Diabetics’ Impaired Healing

    Directory of Open Access Journals (Sweden)

    Jorge Berlanga-Acosta

    2013-01-01

    Full Text Available Type 2 diabetes mellitus is a metabolic noncommunicable disease with an expanding pandemic magnitude. Diabetes predisposes to lower extremities ulceration and impairs the healing process leading to wound chronification. Diabetes also dismantles innate immunity favoring wound infection. Amputation is therefore acknowledged as one of the disease’s complications. Hyperglycemia is the proximal detonator of systemic and local toxic effectors including proinflammation, acute-phase proteins elevation, and spillover of reactive oxygen and nitrogen species. Insulin axis deficiency weakens wounds’ anabolism and predisposes to inflammation. The systemic accumulation of advanced glycation end-products irreversibly impairs the entire physiology from cells-to-organs. These factors in concert hamper fibroblasts and endothelial cells proliferation, migration, homing, secretion, and organization of a productive granulation tissue. Diabetic wound bed may turn chronically inflammed, procatabolic, and an additional source of circulating pro-inflammatory cytokines, establishing a self-perpetuating loop. Diabetic fibroblasts and endothelial cells may bear mitochondrial damages becoming prone to apoptosis, which impairs granulation tissue cellularity and perfusion. Endothelial progenitor cells recruitment and tubulogenesis are also impaired. Failure of wound reepithelialization remains a clinical challenge while it appears to be biologically multifactorial. Ulcer prevention by primary care surveillance, education, and attention programs is of outmost importance to reduce worldwide amputation figures.

  1. Visualization of cytolytic T cell differentiation and granule exocytosis with T cells from mice expressing active fluorescent granzyme B.

    Directory of Open Access Journals (Sweden)

    Pierre Mouchacca

    Full Text Available To evaluate acquisition and activation of cytolytic functions during immune responses we generated knock in (KI mice expressing Granzyme B (GZMB as a fusion protein with red fluorescent tdTomato (GZMB-Tom. As for GZMB in wild type (WT lymphocytes, GZMB-Tom was absent from naïve CD8 and CD4 T cells in GZMB-Tom-KI mice. It was rapidly induced in most CD8 T cells and in a subpopulation of CD4 T cells in response to stimulation with antibodies to CD3/CD28. A fraction of splenic NK cells expressed GZMB-Tom ex vivo with most becoming positive upon culture in IL-2. GZMB-Tom was present in CTL granules and active as a protease when these degranulated into cognate target cells, as shown with target cells expressing a specific FRET reporter construct. Using T cells from mice expressing GZMB-Tom but lacking perforin, we show that the transfer of fluorescent GZMB-Tom into target cells was dependent on perforin, favoring a role for perforin in delivery of GZMB at the target cells' plasma membranes. Time-lapse video microscopy showed Ca++ signaling in CTL upon interaction with cognate targets, followed by relocalization of GZMB-Tom-containing granules to the synaptic contact zone. A perforin-dependent step was next visualized by the fluorescence signal from the non-permeant dye TO-PRO-3 at the synaptic cleft, minutes before the labeling of the target cell nucleus, characterizing a previously undescribed synaptic event in CTL cytolysis. Transferred OVA-specific GZMB-Tom-expressing CD8 T cells acquired GZMB-Tom expression in Listeria monocytogenes-OVA infected mice as soon as 48h after infection. These GZMB-Tom positive CD8 T cells localized in the splenic T-zone where they interacted with CD11c positive dendritic cells (DC, as shown by GZMB-Tom granule redistribution to the T/DC contact zone. GZMB-Tom-KI mice thus also provide tools to visualize acquisition and activation of cytolytic function in vivo.

  2. Proliferation of granule cell precursors in the dentate gyrus of adult monkeys is diminished by stress

    Science.gov (United States)

    Gould, Elizabeth; Tanapat, Patima; McEwen, Bruce S.; Flügge, Gabriele; Fuchs, Eberhard

    1998-01-01

    Although granule cells continue to be added to the dentate gyrus of adult rats and tree shrews, this phenomenon has not been demonstrated in the dentate gyrus of adult primates. To determine whether neurons are produced in the dentate gyrus of adult primates, adult marmoset monkeys (Callithrix jacchus) were injected with BrdU and perfused 2 hr or 3 weeks later. BrdU is a thymidine analog that is incorporated into proliferating cells during S phase. A substantial number of cells in the dentate gyrus of adult monkeys incorporated BrdU and ≈80% of these cells had morphological characteristics of granule neurons and expressed a neuronal marker by the 3-week time point. Previous studies suggest that the proliferation of granule cell precursors in the adult dentate gyrus can be inhibited by stress in rats and tree shrews. To test whether an aversive experience has a similar effect on cell proliferation in the primate brain, adult marmoset monkeys were exposed to a resident-intruder model of stress. After 1 hr in this condition, the intruder monkeys were injected with BrdU and perfused 2 hr later. The number of proliferating cells in the dentate gyrus of the intruder monkeys was compared with that of unstressed control monkeys. We found that a single exposure to this stressful experience resulted in a significant reduction in the number of these proliferating cells. Our results suggest that neurons are produced in the dentate gyrus of adult monkeys and that the rate of precursor cell proliferation can be affected by a stressful experience. PMID:9501234

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

    Directory of Open Access Journals (Sweden)

    Yuichiro Hayashi

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

  4. The volume of Purkinje cells decreases in the cerebellum of acrylamide-intoxicated rats, but no cells are lost

    DEFF Research Database (Denmark)

    Larsen, Jytte Overgaard; Tandrup, T; Braendgaard, H

    1994-01-01

    The effects of acrylamide intoxication on the numbers of granule and Purkinje cells and the volume of Purkinje cell perikarya have been evaluated with stereological methods. The analysis was carried out in the cerebella of rats that had received a dose of 33.3 mg/kg acrylamide, twice a week, for 7.......5 weeks. The total numbers of cerebellar granule and Purkinje cells were estimated using the optical fractionator and the mean volume of the Purkinje cell perikarya was estimated with the vertical rotator technique. The volumes of the molecular layer, the granular cell layer and the white matter were...... estimated using the Cavalieri principle. The mean weight of the cerebellum of the intoxicated rats was 7% lower than that of the control rats (2P = 0.001). The numbers of the Purkinje cells and granule cells were the same in both groups, but the mean volume of the perikarya of the Purkinje cells...

  5. Secretory granule formation and membrane recycling by the trans-Golgi network in adipokinetic cells of Locusta migratoria in relation to flight and rest.

    Science.gov (United States)

    Diederen, J H; Vullings, H G

    1995-03-01

    The influence of flight activity on the formation of secretory granules and the concomitant membrane recycling by the trans-Golgi network in the peptidergic neurosecretory adipokinetic cells of Locusta migratoria was investigated by means of ultrastructural morphometric methods. The patterns of labelling of the trans-Golgi network by the exogenous adsorptive endocytotic tracer wheat-germ agglutinin-conjugated horse-radish peroxidase and by the endogenous marker enzyme acid phosphatase were used as parameters and were measured by an automatic image analysis system. The results show that endocytosed fragments of plasma membrane with bound peroxidase label were transported to the trans-Golgi network and used to build new secretory granules. The amounts of peroxidase and especially of acid phosphatase within the trans-Golgi network showed a strong tendency to be smaller in flight-stimulated cells than in non-stimulated cells. The amounts of acid phosphatase in the immature secretory granules originating from the trans-Golgi network were significantly smaller in stimulated cells. The number of immature secretory granules positive for acid phosphatase tended to be higher in stimulated cells. Thus, flight stimulation of adipokinetic cells for 1 h influences the functioning of the trans-Golgi network; this most probably results in a slight enhancement of the production of secretory granules by the trans-Golgi network.

  6. Preventing effect of L-type calcium channel blockade on electrophysiological alterations in dentate gyrus granule cells induced by entorhinal amyloid pathology.

    Directory of Open Access Journals (Sweden)

    Hamid Gholami Pourbadie

    Full Text Available The entorhinal cortex (EC is one of the earliest affected brain regions in Alzheimer's disease (AD. EC-amyloid pathology induces synaptic failure in the dentate gyrus (DG with resultant behavioral impairment, but there is little known about its impact on neuronal properties in the DG. It is believed that calcium dyshomeostasis plays a pivotal role in the etiology of AD. Here, the effect of the EC amyloid pathogenesis on cellular properties of DG granule cells and also possible neuroprotective role of L-type calcium channel blockers (CCBs, nimodipine and isradipine, were investigated. The amyloid beta (Aβ 1-42 was injected bilaterally into the EC of male rats and one week later, electrophysiological properties of DG granule cells were assessed. Voltage clamp recording revealed appearance of giant sIPSC in combination with a decrease in sEPSC frequency which was partially reversed by CCBs in granule cells from Aβ treated rats. EC amyloid pathogenesis induced a significant reduction of input resistance (Rin accompanied by a profound decreased excitability in the DG granule cells. However, daily administration of CCBs, isradipine or nimodipine (i.c.v. for 6 days, almost preserved the normal excitability against Aβ. In conclusion, lower tendency to fire AP along with reduced Rin suggest that DG granule cells might undergo an alteration in the membrane ion channel activities which finally lead to the behavioral deficits observed in animal models and patients with early-stage Alzheimer's disease.

  7. N-methyl-D-aspartate promotes the survival of cerebellar granule cells: pharmacological characterization

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1989-01-01

    The survival of cerebellar granule cells in culture is promoted by chronic exposure to N-methyl-D-aspartate (NMDA). The effect is due to the stimulation of 'conventional' NMDA receptor-ionophore complex: it is concentration dependent, voltage dependent and blocked by the selective antagonists D-2...

  8. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  9. High Plasticity of New Granule Cells in the Aging Hippocampus

    Directory of Open Access Journals (Sweden)

    Mariela F. Trinchero

    2017-10-01

    Full Text Available Summary: During aging, the brain undergoes changes that impair cognitive capacity and circuit plasticity, including a marked decrease in production of adult-born hippocampal neurons. It is unclear whether development and integration of those new neurons are also affected by age. Here, we show that adult-born granule cells (GCs in aging mice are scarce and exhibit slow development, but they display a remarkable potential for structural plasticity. Retrovirally labeled 3-week-old GCs in middle-aged mice were small, underdeveloped, and disconnected. Neuronal development and integration were accelerated by voluntary exercise or environmental enrichment. Similar effects were observed via knockdown of Lrig1, an endogenous negative modulator of neurotrophin receptors. Consistently, blocking neurotrophin signaling by Lrig1 overexpression abolished the positive effects of exercise. These results demonstrate an unparalleled degree of plasticity in the aging brain mediated by neurotrophins, whereby new GCs remain immature until becoming rapidly recruited to the network by activity. : Trinchero et al. show that development of new granule cells born in the adult hippocampus is strongly influenced by age. In the aging hippocampus, new neurons remain immature for prolonged intervals, yet voluntary exercise triggers their rapid growth and functional synaptogenesis. This extensive structural remodeling is mediated by neurotrophins. Keywords: adult neurogenesis, dentate gyrus, functional integration, neurotrophins, synaptogenesis, exercise

  10. Nonreutilizaton of adrenal chromaffin granule membranes following secretion

    International Nuclear Information System (INIS)

    Nobiletti, J.B.

    1985-01-01

    The intracellular postexocytotic fate of the adrenal chromaffin granule membrane (reutilization vs. nonreutilization) was addressed through two experimental approaches. First, ( 3 H) leucine pulse-chase labeling experiments were conducted in two systems - the isolated retrograde perfused cat adrenal gland and cultured bovine adrenal chromaffin cells to compare chromaffin granule soluble dopamine-B-hydroxylase (DBH) turnover (marker for granule soluble content turnover) to that of membrane-bound DBH (marker for granule membrane turnover). Experiments in cat adrenal glands showed that at all chase periods the granule distribution of radiolabeled DBH was in agreement with the DBH activity distribution (73% membrane-bound/27% soluble) - a result consistent with parallel turnover of soluble and membrane-bound DBH. Experiments in cultured bovine cells showed that labeled soluble and membrane-bound DBH had parallel turnover patterns and at all chase period, the distribution of radiolabeled DBH between the soluble contents and membranes was similar to the DBH activity distribution (50% soluble/50% membrane-bound). The above experiments showed that the soluble contents and membranes turnover in parallel and are consistent with nonreutilization of chromaffin granule membranes following exocytosis. Isolated retrograde perfused bovine adrenal glands were subjected to repetitive acetylcholine stimulation to induce exocytosis and then the dense and less-dense chromaffin granule fractions were isolated. Since both approaches gave results consistent with membrane nonreutilization, the authors conclude that once a chromaffin granule is involved in exocytosis, its membrane is not reutilized for the further synthesis, storage, and secretion of catecholamines

  11. AMP Kinase Activation Alters Oxidant-Induced Stress Granule Assembly by Modulating Cell Signaling and Microtubule Organization.

    Science.gov (United States)

    Mahboubi, Hicham; Koromilas, Antonis E; Stochaj, Ursula

    2016-10-01

    Eukaryotic cells assemble stress granules (SGs) when translation initiation is inhibited. Different cell signaling pathways regulate SG production. Particularly relevant to this process is 5'-AMP-activated protein kinase (AMPK), which functions as a stress sensor and is transiently activated by adverse physiologic conditions. Here, we dissected the role of AMPK for oxidant-induced SG formation. Our studies identified multiple steps of de novo SG assembly that are controlled by the kinase. Single-cell analyses demonstrated that pharmacological AMPK activation prior to stress exposure changed SG properties, because the granules became more abundant and smaller in size. These altered SG characteristics correlated with specific changes in cell survival, cell signaling, cytoskeletal organization, and the abundance of translation initiation factors. Specifically, AMPK activation increased stress-induced eukaryotic initiation factor (eIF) 2α phosphorylation and reduced the concentration of eIF4F complex subunits eIF4G and eIF4E. At the same time, the abundance of histone deacetylase 6 (HDAC6) was diminished. This loss of HDAC6 was accompanied by increased acetylation of α-tubulin on Lys40. Pharmacological studies further confirmed this novel AMPK-HDAC6 interplay and its importance for SG biology. Taken together, we provide mechanistic insights into the regulation of SG formation. We propose that AMPK activation stimulates oxidant-induced SG formation but limits their fusion into larger granules. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  12. Arachnoid granulation affected by subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    R.P. Chopard

    1993-11-01

    Full Text Available The purpose of this study was to investigate using light microscopy the fibro-cellular components of arachnoid granulations affected by mild and severe subarachnoid hemorrage. The erythrocytes were in the channels delimitated by collagenous and elastic bundles and arachnoid cells, showing their tortuous and intercommunicating row from the pedicle to the fibrous capsule. The core portion of the pedicle and the center represented a principal route to the bulk outflow of cerebrospinal fluid and erythrocytes. In the severe hemorrhage, the fibrocellular components are desorganized, increasing the extracellular channels. We could see arachnoid granulations without erythrocytes, which cells showed big round nucleous suggesting their transformation into phagocytic cells.

  13. Endothelin-1 stimulates the release of preloaded [3H]D-aspartate from cultured cerebellar granule cells

    International Nuclear Information System (INIS)

    Lin, W.W.; Lee, C.Y.; Chuang, D.M.

    1990-01-01

    We have recently reported that endothelin-1 (ET) induces phosphoinositide hydrolysis in primary cultures of rat cerebellar granule cells. Here we found that ET in a dose-dependent manner (1-30 nM) stimulated the release of preloaded [ 3 H]D-aspartate from granule cells. The ET-induced aspartate release was completely blocked in the absence of extracellular Ca 2+ , but was unaffected by 1 mM Co 2+ or 1 microM dihydropyridine derivatives (nisoldipine and nimodipine). At higher concentration (10 microM) of nisoldipine and nimodipine, the release was partially inhibited. Short-term pretreatment of cells with phorbol 12,13-dibutyrate (PDBu) potentiated the ET-induced aspartate release, while long-term pretreatment with PDBu attenuated the release. Long-term exposure of cells to pertussis toxin (PTX), on the other hand, potentiated the ET-induced effects. Our results suggest that ET has a neuromodulatory function in the central nervous system

  14. PHB granules are attached to the nucleoid via PhaM in Ralstonia eutropha.

    Science.gov (United States)

    Wahl, Andreas; Schuth, Nora; Pfeiffer, Daniel; Nussberger, Stephan; Jendrossek, Dieter

    2012-11-16

    Poly(3-hydroxybutyrate) (PHB) granules are important storage compounds of carbon and energy in many prokaryotes which allow survival of the cells in the absence of suitable carbon sources. Formation and subcellular localization of PHB granules was previously assumed to occur randomly in the cytoplasm of PHB accumulating bacteria. However, contradictionary results on subcellular localization of PHB granules in Ralstonia eutropha were published, recently. Here, we provide evidence by transmission electron microscopy that PHB granules are localized in close contact to the nucleoid region in R. eutropha during growth on nutrient broth. Binding of PHB granules to the nucleoid is mediated by PhaM, a PHB granule associated protein with phasin-like properties that is also able to bind to DNA and to phasin PhaP5. Over-expression of PhaM resulted in formation of many small PHB granules that were always attached to the nucleoid region. In contrast, PHB granules of ∆phaM strains became very large and distribution of granules to daughter cells was impaired. Association of PHB granules to the nucleoid region was prevented by over-expression of PhaP5 and clusters of several PHB granules were mainly localized near the cell poles. Subcellular localization of PHB granules is controlled in R. eutropha and depends on the presence and concentrations of at least two PHB granule associated proteins, PhaM and PhaP5.

  15. Performance of double-layer biofilter packed with coal fly ash ceramic granules in treating highly polluted river water.

    Science.gov (United States)

    Jing, Zhaoqian; Li, Yu-You; Cao, Shiwei; Liu, Yuyu

    2012-09-01

    To improve trickling filters' denitrification efficiency, a biofilter with a trickling upper layer and a submerged lower layer was developed and applied in treating highly polluted river water. It was packed with porous coal fly ash ceramic granules. Its start-up characteristics, influence of hydraulic loading rates (HLR), carbon/nitrogen (C/N) ratio and filter depth on pollutants removal were investigated. The results indicated this biofilter was started quickly in 16 days with river sediment as inoculum. Alternating nitrification and denitrification were achieved when water flowed downwards. COD and nitrogen were mainly removed in the upper layer and the lower layer, respectively. With HLR of 4.0-5.0m(3)/(m(2)d), chemical oxygen demand (COD), ammonium (NH(4)(+)-N) and total nitrogen (TN) in the effluent were below 50, 5 and 15 mg/L, respectively. This biofilter removed more than 80% of COD, 85% of NH(4)(+)-N and 60% of TN with C/N ratios ranging from 6 to 10. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. A review on granules initiation and development inside UASB Reactor and the main factors affecting granules formation process

    Energy Technology Data Exchange (ETDEWEB)

    Habeeb, S.A.; Latiff, Ab Aziz Bin Abdul; Daud, Zawawi Bin; Ahmad, Zulkifli Bin [Civil and Environmental Engineering, University Tun Hussein Onn Malaysia (Malaysia)

    2011-07-01

    Decades of investigations and explorations in the field of anaerobic wastewater treatment have resulted in significant indications about the role importance of sludge granules in biodegradation anaerobic process. It is believed that the development of anaerobic granules is reflecting an important role on the performance of reactor. An overview on the concept of up-flow anaerobic sludge bed (UASB) reactor operation as well as the main parts that reactor consists of is briefly explained in this paper, whereas the major theories of anaerobic granules formation are listed by related researchers. The correlations and compositions of such sludge granule have been specifically explained. It is believed that the extracellular polymer (ECP) is totally responsible of bacterial cell correlations and the formation of bacterial communities in the form of granules. In addition, the dependable factors for the performance of anaerobic granules formation process e.g. temperature, organic loading rate, pH, and alkalinity, nutrients, and cations and heavy metals have been discussed in this paper. Strong evidences proved that the process of gas production in the form of biogas is related to the methanogens activities, which are practically found in the core of granules. The aim of this review is to explore and assess the mechanisms of granules initiation and development inside UASB reactor.

  17. The survival of cultured mouse cerebellar granule cells is not dependent on elevated potassium-ion concentration

    DEFF Research Database (Denmark)

    Mogensen, Helle Smidt; Hack, N; Balázs, R

    1994-01-01

    The effects of K(+)-induced membrane depolarization were studied on the survival and biochemical parameters in mouse and rat cerebellar granule cells grown in micro-well cultures. Cell numbers were determined by estimating DNA content using the Hoechst 33258 fluorochrome binding assay. DNA from d...

  18. MMP-13 regulates growth of wound granulation tissue and modulates gene expression signatures involved in inflammation, proteolysis, and cell viability.

    Directory of Open Access Journals (Sweden)

    Mervi Toriseva

    Full Text Available Proteinases play a pivotal role in wound healing by regulating cell-matrix interactions and availability of bioactive molecules. The role of matrix metalloproteinase-13 (MMP-13 in granulation tissue growth was studied in subcutaneously implanted viscose cellulose sponge in MMP-13 knockout (Mmp13(-/- and wild type (WT mice. The tissue samples were harvested at time points day 7, 14 and 21 and subjected to histological analysis and gene expression profiling. Granulation tissue growth was significantly reduced (42% at day 21 in Mmp13(-/- mice. Granulation tissue in Mmp13(-/- mice showed delayed organization of myofibroblasts, increased microvascular density at day 14, and virtual absence of large vessels at day 21. Gene expression profiling identified differentially expressed genes in Mmp13(-/- mouse granulation tissue involved in biological functions including inflammatory response, angiogenesis, cellular movement, cellular growth and proliferation and proteolysis. Among genes linked to angiogenesis, Adamts4 and Npy were significantly upregulated in early granulation tissue in Mmp13(-/- mice, and a set of genes involved in leukocyte motility including Il6 were systematically downregulated at day 14. The expression of Pdgfd was downregulated in Mmp13(-/- granulation tissue in all time points. The expression of matrix metalloproteinases Mmp2, Mmp3, Mmp9 was also significantly downregulated in granulation tissue of Mmp13(-/- mice compared to WT mice. Mmp13(-/- mouse skin fibroblasts displayed altered cell morphology and impaired ability to contract collagen gel and decreased production of MMP-2. These results provide evidence for an important role for MMP-13 in wound healing by coordinating cellular activities important in the growth and maturation of granulation tissue, including myofibroblast function, inflammation, angiogenesis, and proteolysis.

  19. Performance of single carbon granules as perspective for larger scale capacitive bioanodes

    NARCIS (Netherlands)

    Borsje, Casper; Liu, Dandan; Sleutels, Tom H.J.A.; Buisman, Cees J.N.; Heijne, ter Annemiek

    2016-01-01

    The use of high surface area electrodes, like carbon-based felt or granules, in Bioelectrochemical Systems is crucial for high volumetric current production. In case activated carbon granules are used, charge can also be stored in the form of an electric double layer in the pores, which has been

  20. Autophagy meets fused in sarcoma-positive stress granules.

    Science.gov (United States)

    Matus, Soledad; Bosco, Daryl A; Hetz, Claudio

    2014-12-01

    Mutations in fused in sarcoma and/or translocated in liposarcoma (FUS, TLS or FUS) are linked to familial cases of amyotrophic lateral sclerosis (ALS). Mutant FUS selectively accumulates into discrete cytosolic structures known as stress granules under various stress conditions. In addition, mutant FUS expression can alter the dynamics and morphology of stress granules. Although the link between mutant FUS and stress granules is well established, the mechanisms modulating stress granule formation and disassembly in the context of ALS are poorly understood. In this issue of Neurobiology of Aging, Ryu et al. uncover the impact of autophagy on the potential toxicity of mutant FUS-positive stress granules. The authors provide evidence indicating that enhanced autophagy activity reduces the number of stress granules, which in the case of cells containing mutant FUS-positive stress granules, is neuroprotective. Overall, this study identifies an intersection between the proteostasis network and alterations in RNA metabolism in ALS through the dynamic assembly and disassembly of stress granules. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Progressive behavioral changes during the maturation of rats with early radiation-induced hypoplasia of fascia dentata granule cells

    International Nuclear Information System (INIS)

    Mickley, G.A.; Ferguson, J.L.; Mulvihill, M.A.; Nemeth, T.J.

    1989-01-01

    Localized exposure of the neonatal rat brain to X-rays produces neuronal hypoplasia specific to the granule cell layer of the hippocampal dentate gyrus. This brain damage causes locomotor hyperactivity, slowed acquisition of passive avoidance tasks and long bouts of spontaneous turning (without reversals) in a bowl apparatus. Here we report how these behavioral deficits change as a function of subject aging and behavioral test replications. Portions of the neonatal rat cerebral hemispheres were X-irradiated in order to selectively damage the granule cells of the dentate gyrus. The brains of experimental animals received a fractionated dose of X rays (13 Gy total) over postnatal days 1 to 16 and control animals were sham-irradiated. Rats between the ages of 71-462 days were tested 3 separate times on each of the following 3 behavioral tests: (1) spontaneous locomotion, (2) passive avoidance acquisition, and (3) spontaneous circling in a large plastic hemisphere. Rats with radiation-induced damage to the fascia dentata exhibited long bouts of slow turns without reversals. Once they began, irradiated subjects perseverated in turning to an extent significantly greater than sham-irradiated control subjects. This irradiation effect was significant during all test series. Moreover, in time, spontaneous perseverative turning was significantly potentiated in rats with hippocampal damage but increased only slightly in controls. Early radiation exposure produced locomotor hyperactivity in young rats. While activity levels of controls remained fairly stable throughout the course of the experiment, the hyperactivity of the irradiated animals decreased significantly as they matured

  2. Loss of protohaem IX farnesyltransferase in mature dentate granule cells impairs short-term facilitation at mossy fibre to CA3 pyramidal cell synapses.

    Science.gov (United States)

    Booker, Sam A; Campbell, Graham R; Mysiak, Karolina S; Brophy, Peter J; Kind, Peter C; Mahad, Don J; Wyllie, David J A

    2017-03-15

    Neurodegenerative disorders can exhibit dysfunctional mitochondrial respiratory chain complex IV activity. Conditional deletion of cytochrome c oxidase, the terminal enzyme in the respiratory electron transport chain of mitochondria, from hippocampal dentate granule cells in mice does not affect low-frequency dentate to CA3 glutamatergic synaptic transmission. High-frequency dentate to CA3 glutamatergic synaptic transmission and feedforward inhibition are significantly attenuated in cytochrome c oxidase-deficient mice. Intact presynaptic mitochondrial function is critical for the short-term dynamics of mossy fibre to CA3 synaptic function. Neurodegenerative disorders are characterized by peripheral and central symptoms including cognitive impairments which have been associated with reduced mitochondrial function, in particular mitochondrial respiratory chain complex IV or cytochrome c oxidase activity. In the present study we conditionally removed a key component of complex IV, protohaem IX farnesyltransferase encoded by the COX10 gene, in granule cells of the adult dentate gyrus. Utilizing whole-cell patch-clamp recordings from morphologically identified CA3 pyramidal cells from control and complex IV-deficient mice, we found that reduced mitochondrial function did not result in overt deficits in basal glutamatergic synaptic transmission at the mossy-fibre synapse because the amplitude, input-output relationship and 50 ms paired-pulse facilitation were unchanged following COX10 removal from dentate granule cells. However, trains of stimuli given at high frequency (> 20 Hz) resulted in dramatic reductions in short-term facilitation and, at the highest frequencies (> 50 Hz), also reduced paired-pulse facilitation, suggesting a requirement for adequate mitochondrial function to maintain glutamate release during physiologically relevant activity patterns. Interestingly, local inhibition was reduced, suggesting the effect observed was not restricted to synapses

  3. The influence of substrate transport limitation on porosity and methanogenic activity of anaerobic sludge granules

    Energy Technology Data Exchange (ETDEWEB)

    Alphenaar, P.A. (Agricultural Univ., Wageningen (Netherlands). Dept. of Environmental Technology); Perez, M.C. (Agricultural Univ., Wageningen (Netherlands). Dept. of Environmental Technology); Lettinga, G. (Agricultural Univ., Wageningen (Netherlands). Dept. of Environmental Technology)

    1993-05-01

    The relationship between porosity, diameter and methanogenic activity of anaerobic granules has been investigated. Experiments with different granular sludges revealed that substrate transport limitations increase with the diameter of the granules. As a consequence, autolysis can occur in the core of the granule, producing hollow granules. The porosity measurements revealed that the hollow centre is not available for substrate transport. Possibly as an effect of bacterial lysis, the porosity decreases in the more interior layers of the granules. This results in a inactive inner part of the large granules, which is not involved in the treatment process; the specific methanogenic activity decreases with granule size. No marked difference in substrate affinity is observed between granules of different sizes, which probably indicates that for large granules only the exterior is biological active. (orig.)

  4. Use of a continuous twin screw granulation and drying system during formulation development and process optimization.

    Science.gov (United States)

    Vercruysse, J; Peeters, E; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2015-01-01

    Since small scale is key for successful introduction of continuous techniques in the pharmaceutical industry to allow its use during formulation development and process optimization, it is essential to determine whether the product quality is similar when small quantities of materials are processed compared to the continuous processing of larger quantities. Therefore, the aim of this study was to investigate whether material processed in a single cell of the six-segmented fluid bed dryer of the ConsiGma™-25 system (a continuous twin screw granulation and drying system introduced by GEA Pharma Systems, Collette™, Wommelgem, Belgium) is predictive of granule and tablet quality during full-scale manufacturing when all drying cells are filled. Furthermore, the performance of the ConsiGma™-1 system (a mobile laboratory unit) was evaluated and compared to the ConsiGma™-25 system. A premix of two active ingredients, powdered cellulose, maize starch, pregelatinized starch and sodium starch glycolate was granulated with distilled water. After drying and milling (1000 μm, 800 rpm), granules were blended with magnesium stearate and compressed using a Modul™ P tablet press (tablet weight: 430 mg, main compression force: 12 kN). Single cell experiments using the ConsiGma™-25 system and ConsiGma™-1 system were performed in triplicate. Additionally, a 1h continuous run using the ConsiGma™-25 system was executed. Process outcomes (torque, barrel wall temperature, product temperature during drying) and granule (residual moisture content, particle size distribution, bulk and tapped density, hausner ratio, friability) as well as tablet (hardness, friability, disintegration time and dissolution) quality attributes were evaluated. By performing a 1h continuous run, it was detected that a stabilization period was needed for torque and barrel wall temperature due to initial layering of the screws and the screw chamber walls with material. Consequently, slightly deviating

  5. Early events of secretory granule formation in the rat parotid acinar cell under the influence of isoproterenol. An ultrastructural and lectin cytochemical study

    Directory of Open Access Journals (Sweden)

    F D’Amico

    2009-12-01

    Full Text Available The events involved in the maturation process of acinar secretory granules of rat parotid gland were investigated ultrastructurally and cytochemically by using a battery of four lectins [Triticum vulgaris agglutinin (WGA, Ulex europaeus agglutinin I (UEA-I, Glycine max agglutinin (SBA, Arachys hypogaea agglutinin (PNA]. In order to facilitate the study, parotid glands were chronically stimulated with isoproterenol to induce secretion. Specimens were embedded in the Lowicryl K4M resin. The trans-Golgi network (TGN derived secretory granules, which we refer to as immature secretory granules, were found to be intermediate structures in the biogenesis process of the secretory granules in the rat parotid acinar cell. These early structures do not seem to be the immediate precursor of the mature secretory granules: in fact, a subsequent interaction process between these early immature granule forms and TGN elements seems to occur, leading, finally, to the mature granules. These findings could explain the origin of the polymorphic subpopulations of the secretory granules in the normal acinar cells of the rat parotid gland. The lectin staining patterns were characteristic of each lectin. Immature and mature secretory gran- ules were labelled with WGA, SBA, PNA, and lightly with UEA-I. Cis and intermediate cisternae of the Golgi apparatus were labelled with WGA, and trans cisternae with WGA and SBA.

  6. Is Arc mRNA Unique: A Search for mRNAs That Localize to the Distal Dendrites of Dentate Gyrus Granule Cells Following Neural Activity

    Directory of Open Access Journals (Sweden)

    Christopher A. de Solis

    2017-10-01

    Full Text Available There have been several attempts to identify which RNAs are localized to dendrites; however, no study has determined which RNAs localize to the dendrites following the induction of synaptic activity. We sought to identify all RNA transcripts that localize to the distal dendrites of dentate gyrus granule cells following unilateral high frequency stimulation of the perforant pathway (pp-HFS using Sprague Dawley rats. We then utilized laser microdissection (LMD to very accurately dissect out the distal 2/3rds of the molecular layer (ML, which contains these dendrites, without contamination from the granule cell layer, 2 and 4 h post pp-HFS. Next, we purified and amplified RNA from the ML and performed an unbiased screen for 27,000 RNA transcripts using Affymetrix microarrays. We determined that Activity Regulated Cytoskeletal Protein (Arc/Arg3.1 mRNA, exhibited the greatest fold increase in the ML at both timepoints (2 and 4 h. In total, we identified 31 transcripts that increased their levels within the ML following pp-HFS across the two timepoints. Of particular interest is that one of these identified transcripts was an unprocessed micro-RNA (pri-miR132. Fluorescent in situ hybridization and qRT-PCR were used to confirm some of these candidate transcripts. Our data indicate Arc is a unique activity dependent gene, due to the magnitude that its activity dependent transcript localizes to the dendrites. Our study determined other activity dependent transcripts likely localize to the dendrites following neural activity, but do so with lower efficiency compared to Arc.

  7. Convergent evolution of germ granule nucleators: A hypothesis.

    Science.gov (United States)

    Kulkarni, Arpita; Extavour, Cassandra G

    2017-10-01

    Germ cells have been considered "the ultimate stem cell" because they alone, during normal development of sexually reproducing organisms, are able to give rise to all organismal cell types. Morphological descriptions of a specialized cytoplasm termed 'germ plasm' and associated electron dense ribonucleoprotein (RNP) structures called 'germ granules' within germ cells date back as early as the 1800s. Both germ plasm and germ granules are implicated in germ line specification across metazoans. However, at a molecular level, little is currently understood about the molecular mechanisms that assemble these entities in germ cells. The discovery that in some animals, the gene products of a small number of lineage-specific genes initiate the assembly (also termed nucleation) of germ granules and/or germ plasm is the first step towards facilitating a better understanding of these complex biological processes. Here, we draw on research spanning over 100years that supports the hypothesis that these nucleator genes may have evolved convergently, allowing them to perform analogous roles across animal lineages. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Zinc sulfide in intestinal cell granules of Ancylostoma caninum adults

    Energy Technology Data Exchange (ETDEWEB)

    Gianotti, A.J.; Clark, D.T.; Dash, J. (Portland State Univ., OR (USA))

    1991-04-01

    A source of confusion has existed since the turn of the century about the reddish brown, weakly birefringent 'sphaerocrystals' located in the intestines of strongyle nematodes, Strongylus and Ancylostoma. X-ray diffraction and energy dispersive spectrometric analyses were used for accurate determination of the crystalline order and elemental composition of the granules in the canine hookworm Ancylostoma caninum. The composition of the intestinal pigmented granules was identified unequivocally as zinc sulfide. It seems most probable that the granules serve to detoxify high levels of metallic ions (specifically zinc) present due to the large intake of host blood.

  9. Effect of sodium butyrate treatment on the granule morphology, histamine level and elemental content of the bone marrow-derived mast cell

    Energy Technology Data Exchange (ETDEWEB)

    Rydzynski, K. [Inst. of Occupational Medicine, Lodz (Poland); Dalen, H. [Bergen Univ. (Norway)

    1994-12-31

    Mast cells derived from the bone marrow of BALB/c mice (BMMC) were cultures and their growth ceased with sodium butyrate. Sodium butyrate treatment (1 mM, 4 days) caused maturation of the granules, and increased histamine content from approx. 1 pg/cell to 4 pg/cell. X-ray microanalysis revealed that maturation of the granules was accompanied by the increase in relative weight percent of sodium, phosphorus and sulphur, with concomitant decrease in chloride. The sulphur to potassium ratio increased three-fold in butyrate-treated mast cells. The existence of a different elemental composition during mast cell maturation may provide additional parameter for rapid discrimination of mast cell subpopulations. (author). 28 refs, 6 figs.

  10. Who Regulates Whom? An Overview of RNA Granules and Viral Infections

    Directory of Open Access Journals (Sweden)

    Natalia Poblete-Durán

    2016-06-01

    Full Text Available After viral infection, host cells respond by mounting an anti-viral stress response in order to create a hostile atmosphere for viral replication, leading to the shut-off of mRNA translation (protein synthesis and the assembly of RNA granules. Two of these RNA granules have been well characterized in yeast and mammalian cells, stress granules (SGs, which are translationally silent sites of RNA triage and processing bodies (PBs, which are involved in mRNA degradation. This review discusses the role of these RNA granules in the evasion of anti-viral stress responses through virus-induced remodeling of cellular ribonucleoproteins (RNPs.

  11. Somato-synaptic variation of GABA(A) receptors in cultured murine cerebellar granule cells: investigation of the role of the alpha6 subunit.

    Science.gov (United States)

    Mellor, J R; Wisden, W; Randall, A D

    2000-07-10

    Electrophysiological investigation of cultured cerebellar murine granule cells revealed differences between the GABA(A) receptors at inhibitory synapses and those on the cell body. Specifically, mIPSCs decayed more rapidly than cell body receptors deactivated, the mean single channel conductance at the synapse (32 pS) was greater than that at cell body (21 pS) and only cell body receptors were sensitive to Zn(2+) (150 microM), which depressed response amplitude by 82+/-5% and almost doubled the rate of channel deactivation. The GABA(A) receptor alpha6 subunit is selectively expressed in cerebellar granule cells. Although concentrated at synapses, it is also found on extrasynaptic membranes. Using a mouse line (Deltaalpha6lacZ) lacking this subunit, we investigated its role in the somato-synaptic differences in GABA(A) receptor function. All differences between cell body and synaptic GABA(A) receptors observed in wild-type (WT) granule cells persisted in Deltaalpha6lacZ cells, thus demonstrating that they are not specifically due to the cellular distribution of the alpha6 subunit. However, mIPSCs from WT and Deltaalpha6lacZ cells differed in both their kinetics (faster decay in WT cells) and underlying single channel conductance (32 pS WT, 25 pS Deltaalpha6lacZ). This provides good evidence for a functional contribution of the alpha6 subunit to postsynaptic GABA(A) receptors in these cells. Despite this, deactivation kinetics of mIPSCs in WT and Deltaalpha6lacZ granule cells exhibited similar benzodiazepene (BDZ) sensitivity. This suggests that the enhanced BDZ-induced ataxia seen in Deltaalpha6lacZ mice may reflect physiological activity at extrasynaptic receptors which, unlike those at synapses, display differential BDZ-sensitivity in WT and Deltaalpha6lacZ granule cells (Jones, A.M., Korpi, E.R., McKernan, R.M., Nusser, Z., Pelz, R., Makela, R., Mellor, J.R., Pollard, S., Bahn, S., Stephenson, F.A., Randall, A.D., Sieghart, W., Somogyi, P., Smith, A.J.H., Wisden

  12. Endothelin-1 stimulates the release of preloaded ( sup 3 H)D-aspartate from cultured cerebellar granule cells

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.W.; Lee, C.Y.; Chuang, D.M. (NIMH Neuroscience Center, Washington, DC (USA))

    1990-03-16

    We have recently reported that endothelin-1 (ET) induces phosphoinositide hydrolysis in primary cultures of rat cerebellar granule cells. Here we found that ET in a dose-dependent manner (1-30 nM) stimulated the release of preloaded ({sup 3}H)D-aspartate from granule cells. The ET-induced aspartate release was completely blocked in the absence of extracellular Ca{sup 2+}, but was unaffected by 1 mM Co{sup 2+} or 1 microM dihydropyridine derivatives (nisoldipine and nimodipine). At higher concentration (10 microM) of nisoldipine and nimodipine, the release was partially inhibited. Short-term pretreatment of cells with phorbol 12,13-dibutyrate (PDBu) potentiated the ET-induced aspartate release, while long-term pretreatment with PDBu attenuated the release. Long-term exposure of cells to pertussis toxin (PTX), on the other hand, potentiated the ET-induced effects. Our results suggest that ET has a neuromodulatory function in the central nervous system.

  13. Uric Acid Spherulites in the Reflector Layer of Firefly Light Organ

    Science.gov (United States)

    Goh, King-Siang; Sheu, Hwo-Shuenn; Hua, Tzu-En; Kang, Mei-Hua; Li, Chia-Wei

    2013-01-01

    Background In firefly light organs, reflector layer is a specialized tissue which is believed to play a key role for increasing the bioluminescence intensity through reflection. However, the nature of this unique tissue remains elusive. In this report, we investigated the role, fine structure and nature of the reflector layer in the light organ of adult Luciola cerata. Principal Findings Our results indicated that the reflector layer is capable of reflecting bioluminescence, and contains abundant uric acid. Electron microscopy (EM) demonstrated that the cytosol of the reflector layer's cells is filled with densely packed spherical granules, which should be the uric acid granules. These granules are highly regular in size (∼700 nm in diameter), and exhibit a radial internal structure. X-ray diffraction (XRD) analyses revealed that an intense single peak pattern with a d-spacing value of 0.320 nm is specifically detected in the light organ, and is highly similar to the diffraction peak pattern and d-spacing value of needle-formed crystals of monosodium urate monohydrate. However, the molar ratio evaluation of uric acid to various cations (K+, Na+, Ca2+ and Mg2+) in the light organ deduced that only a few uric acid molecules were in the form of urate salts. Thus, non-salt uric acid should be the source of the diffraction signal detected in the light organ. Conclusions In the light organ, the intense single peak diffraction signal might come from a unique needle-like uric acid form, which is different from other known structures of non-salt uric acid form. The finding of a radial structure in the granules of reflector layer implies that the spherical uric acid granules might be formed by the radial arrangement of needle-formed packing matter. PMID:23441187

  14. Adipose derived mesenchymal stem cells – Their osteogenicity and osteoblast in vitro mineralization on titanium granule carriers

    DEFF Research Database (Denmark)

    Dahl, Morten; Syberg, Susanne; Jørgensen, Niklas Rye

    2013-01-01

    Adipose derived mesenchymal stem cells (ADMSCs) may be osteogenic, may generate neoangiogenisis and may be progenitors for differentiated osteoblast mineralization. Titanium granules may be suitable as carriers for these cells. The aim was to demonstrate the osteogenic potential of ADMSCs...

  15. Cell labelling. Granule and platelet kinetics. Recent concepts

    International Nuclear Information System (INIS)

    Najean, Y.; Dresch, C.; Dassin, E.

    Some unsolved problems are reviewed concerning the lifetime of blood platelets, with special reference to excessive platelet consumption and its possible correction by anti-aggregation agents, in many vascular diseases. Regarding the production of platelets it is considered that the 75 Se-methionine labelling method alone offers a quantitative approach to the process and could be used for the physiological study of thrombopoietic factors. A short chapter is devoted to a survey of the points of agreement and disagreement regarding the lifetime of polynuclear cells and a tentative analysis of the reasons explaining the quite different results obtained with DFP and radiochromium labelling. Finally the methods used to study granule formation are criticized, though it is acknowledged that certain ideas useful in physiopathology have emerged from these different procedures [fr

  16. Iron and cell death in Parkinson's disease: a nuclear microscopic study into iron-rich granules in the parkinsonian substantia nigra of primate models

    Energy Technology Data Exchange (ETDEWEB)

    Thong, P.S.P.; Watt, F. E-mail: phywattf@nus.edu.sg; Ponraj, D.; Leong, S.K.; He, Y.; Lee, T.K.Y

    1999-09-02

    Parkinson's disease is a degenerative brain disease characterised by a loss of cells in the substantia nigra (SN) region of the brain and accompanying biochemical changes such as inhibition of mitochondrial function, increased iron concentrations and decreased glutathione levels in the parkinsonian SN. Though the aetiology of the disease is still unknown, the observed biochemical changes point to the involvement of oxidative stress. In particular, iron is suspected to play a role by promoting free radical production, leading to oxidative stress and cell death. The increase in iron in the parkinsonian SN has been confirmed by several research groups, both in human post-mortem brains and in brain tissue from parkinsonian animal models. However, the question remains as to whether the observed increase in iron is a cause or a consequence of the SN cell death process. Our previous study using unilaterally 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP)-lesioned monkeys in a time sequence experiment has shown that the increase in bulk iron concentrations follow rather than precede dopaminergic cell death. However, changes in the localised iron concentrations, which may play a more direct role in SN cell death, may not be reflected at the bulk level. Indeed, we have observed iron-rich granules in parkinsonian SNs. From this time sequence study into the iron content of iron-rich granules in the SNs of an untreated control and unilaterally MPTP-lesioned parkinsonian models, we present the following observations: (1) Iron-rich granules are found in both control and parkinsonian SNs and are variable in size and iron content in any one model. (2) These iron-rich granules may be associated with neuromelanin granules found in the SN and are known to accumulate transition metal ions such as iron. (3) The early onset of bulk SN cell loss (35%) was accompanied by a significant elevation of iron in granules found in the MPTP-injected SN compared to the contra-lateral SN

  17. Accumulation of PHA granules in Cupriavidus necator as seen by confocal fluorescence microscopy.

    Science.gov (United States)

    Mravec, Filip; Obruca, Stanislav; Krzyzanek, Vladislav; Sedlacek, Petr; Hrubanova, Kamila; Samek, Ota; Kucera, Dan; Benesova, Pavla; Nebesarova, Jana

    2016-05-01

    Many bacteria are capable of accumulating intracellular granules of polyhydroxyalkanoates (PHA). In this work, we developed confocal microscopy analysis of bacterial cells to study changes in the diameters of cells as well as PHA granules during growth and PHA accumulation in the bacterium Cupriavidus necator H16 (formerly Ralstonia eutropha). The cell envelope was stained by DiD(®) fluorescent probe and PHA granules by Nile Red. Signals from both probes were separated based on their spectral and fluorescence life-time properties. During growth and PHA accumulation, bacterial cells increased their length but the width of the cells remained constant. The volume fraction of PHA granules in cells increased during PHA accumulation, nevertheless, its value did not exceed 40 vol. % regardless of the PHA weight content. It seems that bacterial cultures lengthen the cells in order to control the PHA volume portion. However, since similar changes in cell length were also observed in a PHA non-accumulating mutant, it seems that there is no direct control mechanism, which regulates the prolongation of the cells with respect to PHA granules volume. It is more likely that PHA biosynthesis and the length of cells are influenced by the same external stimuli such as nutrient limitation. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Interaction between granulation and small-scale magnetic flux observed by Hinode

    International Nuclear Information System (INIS)

    Zhang Jun; Yang Shuhong; Jin Chunlan

    2009-01-01

    With the polarimetric observations obtained by the Spectro-Polarimeter on board Hinode, we study the relationship between granular development and magnetic field evolution in the quiet Sun. Six typical cases are displayed to exhibit interaction between granules and magnetic elements, and we have obtained the following results. (1) A granule develops centrosymmetrically when no magnetic flux emerges within the granular cell. (2) A granule develops and splits noncentrosymmetrically while flux emerges at an outer part of the granular cell. (3) Magnetic flux emergence in a cluster of mixed polarities is detected at the position of a granule as soon as the granule breaks up. (4) A dipole emerges accompanied by the development of a granule, and the two elements of the dipole are rooted in the adjacent intergranular lanes and face each other across the granule. Advected by the horizontal granular motion, the positive element of the dipole then cancels with the pre-existing negative flux. (5) Flux cancellation also takes place between a positive element, which is advected by granular flow, and its surrounding negative flux. (6) While magnetic flux cancellation takes place in a granular cell, the granule shrinks and then disappears. (7) Horizontal magnetic fields are enhanced at the places where dipoles emerge and where opposite polarities cancel each other, but only the horizontal fields between the dipolar elements point in an orderly way from the positive elements to the negative ones. Our results reveal that granules and small-scale magnetic fluxes influence each other. Granular flow advects magnetic flux, and magnetic flux evolution suppresses granular development. There exist extremely large Doppler blue-shifts at the site of one canceling magnetic element. This phenomenon may be caused by the upward flow produced by magnetic reconnection below the photosphere. (research papers)

  19. Statistical properties of solar granulation from the SOUP instrument on Spacelab 2

    International Nuclear Information System (INIS)

    Topka, K.; Title, A.; Tarbell, T.; Ferguson, S.; Shine, R.

    1988-01-01

    The Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 collected movies of solar granulation completely free from atmospheric blurring, and are not degraded by pointint jitter (the pointing stability was 0.003 sec root mean square). The movies illustrate that the solar five minute oscillation has a major role in the appearance of solar granulation and that exploding granules are a common feature of the granule evolution. Using 3-D Fourier filtering techniques the oscillations were removed and it was demonstrated that the autocorrelation lifetime of granulation is a factor of two greater in magnetic field regions than in field-free quiet sun. Horizontal velocities were measured and flow patterns were observed on the scale of meso- and super granulation. In quiet regions the mean flow velocity is 370 m/s while in the magnetic regions it is about 125 m/s. It was also found that the root mean square (RMS) fluctuating horizonal velocity field is substantially greater in quiet sun than in strong magnetic field regions. By superimposing the location of exploding granules on the average flow maps it was found that they appear almost exclusively in the center of mesogranulation size flow cells. Because of the nonuniformity of the distribution of exploding granules, the evolution of the granulation pattern in mesogranule cell centers and boundaries differs fundamentally. It is clear from this study there is neither a typical granule nor a typical granule evolution

  20. Statistical properties of solar granulation from the SOUP instrument on Spacelab 2

    Science.gov (United States)

    Topka, K.; Title, A.; Tarbell, T.; Ferguson, S.; Shine, R.

    1988-11-01

    The Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 collected movies of solar granulation completely free from atmospheric blurring, and are not degraded by pointint jitter (the pointing stability was 0.003 sec root mean square). The movies illustrate that the solar five minute oscillation has a major role in the appearance of solar granulation and that exploding granules are a common feature of the granule evolution. Using 3-D Fourier filtering techniques the oscillations were removed and it was demonstrated that the autocorrelation lifetime of granulation is a factor of two greater in magnetic field regions than in field-free quiet sun. Horizontal velocities were measured and flow patterns were observed on the scale of meso- and super granulation. In quiet regions the mean flow velocity is 370 m/s while in the magnetic regions it is about 125 m/s. It was also found that the root mean square (RMS) fluctuating horizonal velocity field is substantially greater in quiet sun than in strong magnetic field regions. By superimposing the location of exploding granules on the average flow maps it was found that they appear almost exclusively in the center of mesogranulation size flow cells. Because of the nonuniformity of the distribution of exploding granules, the evolution of the granulation pattern in mesogranule cell centers and boundaries differs fundamentally. It is clear from this study there is neither a typical granule nor a typical granule evolution.

  1. Chromospheric impact of an exploding solar granule

    Science.gov (United States)

    Fischer, C. E.; Bello González, N.; Rezaei, R.

    2017-06-01

    Context. Observations of multi-wavelength and therefore height-dependent information following events throughout the solar atmosphere and unambiguously assigning a relation between these rapidly evolving layers are rare and difficult to obtain. Yet, they are crucial for our understanding of the physical processes that couple the different regimes in the solar atmosphere. Aims: We characterize the exploding granule event with simultaneous observations of Hinode spectroplarimetric data in the solar photosphere and Hinode broadband Ca II H images combined with Interface Region Imaging Spectrograph (IRIS) slit spectra. We follow the evolution of an exploding granule and its connectivity throughout the atmosphere and analyze the dynamics of a magnetic element that has been affected by the abnormal granule. Methods: In addition to magnetic flux maps we use a local correlation tracking method to infer the horizontal velocity flows in the photosphere and apply a wavelet analysis on several IRIS chromospheric emission features such as Mg II k2v and Mg II k3 to detect oscillatory phenomena indicating wave propagation. Results: During the vigorous expansion of the abnormal granule we detect radially outward horizontal flows, causing, together with the horizontal flows from the surrounding granules, the magnetic elements in the bordering intergranular lanes to be squeezed and elongated. In reaction to the squeezing, we detect a chromospheric intensity and velocity oscillation pulse which we identify as an upward traveling hot shock front propagating clearly through the IRIS spectral line diagnostics of Mg II h&k. Conclusions: Exploding granules can trigger upward-propagating shock fronts that dissipate in the chromosphere. Movies associated to Figs. A.1 and A.2 are available in electronic form at http://www.aanda.org

  2. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation

    DEFF Research Database (Denmark)

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie

    2016-01-01

    Twin-screw granulation is a promising wet granulation technique for the continuous manufacturing of pharmaceutical solid dosage forms. A twin screw granulator displays a short residence time. Thus, the solid-liquid mixing must be achieved quickly by appropriate arrangement of transport and kneading...

  3. The biology and dynamics of mammalian cortical granules

    Directory of Open Access Journals (Sweden)

    Liu Min

    2011-11-01

    Full Text Available Abstract Cortical granules are membrane bound organelles located in the cortex of unfertilized oocytes. Following fertilization, cortical granules undergo exocytosis to release their contents into the perivitelline space. This secretory process, which is calcium dependent and SNARE protein-mediated pathway, is known as the cortical reaction. After exocytosis, the released cortical granule proteins are responsible for blocking polyspermy by modifying the oocytes' extracellular matrices, such as the zona pellucida in mammals. Mammalian cortical granules range in size from 0.2 um to 0.6 um in diameter and different from most other regulatory secretory organelles in that they are not renewed once released. These granules are only synthesized in female germ cells and transform an egg upon sperm entry; therefore, this unique cellular structure has inherent interest for our understanding of the biology of fertilization. Cortical granules are long thought to be static and awaiting in the cortex of unfertilized oocytes to be stimulated undergoing exocytosis upon gamete fusion. Not till recently, the dynamic nature of cortical granules is appreciated and understood. The latest studies of mammalian cortical granules document that this organelle is not only biochemically heterogeneous, but also displays complex distribution during oocyte development. Interestingly, some cortical granules undergo exocytosis prior to fertilization; and a number of granule components function beyond the time of fertilization in regulating embryonic cleavage and preimplantation development, demonstrating their functional significance in fertilization as well as early embryonic development. The following review will present studies that investigate the biology of cortical granules and will also discuss new findings that uncover the dynamic aspect of this organelle in mammals.

  4. Intrinsic neurophysiological properties of hilar ectopic and normotopic dentate granule cells in human temporal lobe epilepsy and a rat model.

    Science.gov (United States)

    Althaus, A L; Sagher, O; Parent, J M; Murphy, G G

    2015-02-15

    Hilar ectopic dentate granule cells (DGCs) are a salient feature of aberrant plasticity in human temporal lobe epilepsy (TLE) and most rodent models of the disease. Recent evidence from rodent TLE models suggests that hilar ectopic DGCs contribute to hyperexcitability within the epileptic hippocampal network. Here we investigate the intrinsic excitability of DGCs from humans with TLE and the rat pilocarpine TLE model with the objective of comparing the neurophysiology of hilar ectopic DGCs to their normotopic counterparts in the granule cell layer (GCL). We recorded from 36 GCL and 7 hilar DGCs from human TLE tissue. Compared with GCL DGCs, hilar DGCs in patient tissue exhibited lower action potential (AP) firing rates, more depolarized AP threshold, and differed in single AP waveform, consistent with an overall decrease in excitability. To evaluate the intrinsic neurophysiology of hilar ectopic DGCs, we made recordings from retrovirus-birthdated, adult-born DGCs 2-4 mo after pilocarpine-induced status epilepticus or sham treatment in rats. Hilar DGCs from epileptic rats exhibited higher AP firing rates than normotopic DGCs from epileptic or control animals. They also displayed more depolarized resting membrane potential and wider AP waveforms, indicating an overall increase in excitability. The contrasting findings between disease and disease model may reflect differences between the late-stage disease tissue available from human surgical specimens and the earlier disease stage examined in the rat TLE model. These data represent the first neurophysiological characterization of ectopic DGCs from human hippocampus and prospectively birthdated ectopic DGCs in a rodent TLE model. Copyright © 2015 the American Physiological Society.

  5. Differential gene expression in dentate granule cells in mesial temporal lobe epilepsy with and without hippocampal sclerosis.

    Science.gov (United States)

    Griffin, Nicole G; Wang, Yu; Hulette, Christine M; Halvorsen, Matt; Cronin, Kenneth D; Walley, Nicole M; Haglund, Michael M; Radtke, Rodney A; Skene, J H Pate; Sinha, Saurabh R; Heinzen, Erin L

    2016-03-01

    Hippocampal sclerosis is the most common neuropathologic finding in cases of medically intractable mesial temporal lobe epilepsy. In this study, we analyzed the gene expression profiles of dentate granule cells of patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis to show that next-generation sequencing methods can produce interpretable genomic data from RNA collected from small homogenous cell populations, and to shed light on the transcriptional changes associated with hippocampal sclerosis. RNA was extracted, and complementary DNA (cDNA) was prepared and amplified from dentate granule cells that had been harvested by laser capture microdissection from surgically resected hippocampi from patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis. Sequencing libraries were sequenced, and the resulting sequencing reads were aligned to the reference genome. Differential expression analysis was used to ascertain expression differences between patients with and without hippocampal sclerosis. Greater than 90% of the RNA-Seq reads aligned to the reference. There was high concordance between transcriptional profiles obtained for duplicate samples. Principal component analysis revealed that the presence or absence of hippocampal sclerosis was the main determinant of the variance within the data. Among the genes up-regulated in the hippocampal sclerosis samples, there was significant enrichment for genes involved in oxidative phosphorylation. By analyzing the gene expression profiles of dentate granule cells from surgically resected hippocampal specimens from patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis, we have demonstrated the utility of next-generation sequencing methods for producing biologically relevant results from small populations of homogeneous cells, and have provided insight on the transcriptional changes associated with this pathology. Wiley Periodicals, Inc. © 2016

  6. Molecular and functional characterization of GAD67-expressing, newborn granule cells in mouse dentate gyrus

    Directory of Open Access Journals (Sweden)

    Carolina eCabezas

    2013-04-01

    Full Text Available Dentate gyrus granule cells (GCs have been suggested to synthesize both GABA and glutamate immediately after birth and under pathological conditions in the adult. Expression of the GABA synthesizing enzyme GAD67 by GCs during the first few weeks of postnatal development may then allow for transient GABA synthesis and synaptic release from these cells. Here, using the GAD67-EGFP transgenic strain G42, we explored the phenotype of GAD67-expressing GCs in the mouse dentate gyrus. We report a transient, GAD67-driven EGFP expression in differentiating GCs throughout ontogenesis. EGFP expression correlates with the expression of GAD and molecular markers of GABA release and uptake in 2-4 weeks postmitotic GCs. These rather immature cells are able to fire action potentials and are synaptically integrated in the hippocampal network. Yet they show physiological properties that differentiate them from mature GCs. Finally, GAD67-expressing GCs express a specific complement of GABAA receptor subunits as well as distinctive features of synaptic and tonic GABA signaling. Our results reveal that GAD67 expression in dentate gyrus granule cells is a transient marker of late differentiation that persists throughout life and the G42 strain may be used to visualize newborn GCs at a specific, well-defined differentiation stage.

  7. Analysis of carbohydrate storage granules in the diazotrophic cyanobacterium Cyanothece sp. PCC 7822

    Energy Technology Data Exchange (ETDEWEB)

    Welkie, David G. [Purdue Univ., West Lafayette, IN (United States); Sherman, Debra M. [Purdue Univ., West Lafayette, IN (United States); Chrisler, William B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Orr, Galya [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sherman, Louis A. [Purdue Univ., West Lafayette, IN (United States)

    2013-10-19

    The unicellular diazotrophic cyanobacteria of the genus Cyanothece demonstrate oscillations in nitrogenase activity and H2 production when grown under 12h light-12h dark cycles. We established that Cyanothece sp. PCC 7822 allows for the construction of knock-out mutants and our objective was to improve the growth characteristics of this strain and to identify the nature of the intracellular storage granules. We report the physiological and morphological effects of reduction in nitrate and phosphate concentrations in BG-11 media on this strain. We developed a series of BG-11-derived growth media and monitored batch culture growth, nitrogenase activity and nitrogenase-mediated hydrogen production, culture synchronicity, and intracellular storage content. Reduction in NaNO3 and K2HPO4 concentrations from 17.6 and 0.23 mM to 4.41 and 0.06 mM, respectively, improved growth characteristics such as cell size and uniformity, and enhanced the rate of cell division. Cells grown in this low NP BG-11 were less complex, a parameter that related to the composition of the intracellular storage granules. Cells grown in low NP BG-11 had less polyphosphate, fewer polyhydroxybutyrate granules and many smaller granules became evident. Biochemical analysis and transmission electron microscopy using the histocytochemical PATO technique demonstrated that these small granules contained glycogen. The glycogen levels and the number of granules per cell correlated nicely with a 2.3 to 3.3-fold change from the minimum at L0 to the maximum at D0. The differences in granule morphology and enzymes between Cyanothece ATCC 51142 and Cyanothece PCC 7822 provide insights into the formation of large starch-like granules in some cyanobacteria.

  8. The life cycle of platelet granules [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Anish Sharda

    2018-02-01

    Full Text Available Platelet granules are unique among secretory vesicles in both their content and their life cycle. Platelets contain three major granule types—dense granules, α-granules, and lysosomes—although other granule types have been reported. Dense granules and α-granules are the most well-studied and the most physiologically important. Platelet granules are formed in large, multilobulated cells, termed megakaryocytes, prior to transport into platelets. The biogenesis of dense granules and α-granules involves common but also distinct pathways. Both are formed from the trans-Golgi network and early endosomes and mature in multivesicular bodies, but the formation of dense granules requires trafficking machinery different from that of α-granules. Following formation in the megakaryocyte body, both granule types are transported through and mature in long proplatelet extensions prior to the release of nascent platelets into the bloodstream. Granules remain stored in circulating platelets until platelet activation triggers the exocytosis of their contents. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE proteins, located on both the granules and target membranes, provide the mechanical energy that enables membrane fusion during both granulogenesis and exocytosis. The function of these core fusion engines is controlled by SNARE regulators, which direct the site, timing, and extent to which these SNAREs interact and consequently the resulting membrane fusion. In this review, we assess new developments in the study of platelet granules, from their generation to their exocytosis.

  9. Serglycin proteoglycan is not implicated in localizing exocrine pancreas enzymes to zymogen granules

    DEFF Research Database (Denmark)

    Niemann, Carsten U; Cowland, Jack B; Ralfkiaer, Elisabeth

    2009-01-01

    Storage and release of proteins from granules forms the basis of cellular functions as diverse as cell mediated cytotoxicity, neuronal communication, activation of muscle fibres, and release of hormones or digestive enzymes from endocrine and exocrine glands, such as the pancreas. Serglycin...... is the major intracellular proteoglycan of haematopoietic cells. Serglycin is important for localization of proteins in granules of different haematopoietic cell types. Previous reports have indicated a role for serglycin in granule formation and localization of zymogens in granules of the exocrine pancreas...... in rat. We here present data showing that serglycin is not present at the protein level in human or murine pancreas. Furthermore, the amount and localization of three exocrine pancreas zymogens (amylase, trypsinogen, and carboxypeptidase A) is not affected by the absence of serglycin in a serglycin knock...

  10. MORPHOLOGICAL AND ANATOMICAL STUDY OF GRANULES WITH SEEDS EPIDERMIS OF PLANTAGO OVATA FORSSK

    Directory of Open Access Journals (Sweden)

    J. V. Daironas

    2017-01-01

    of the raw material and granules of Plantago ovata seed husks were established. The structure of epidermal cells filled with mucus, starch grains and the presence of fragments of the inner pigment layer of the skin and endosperm belong to them. The obtained results are consistent with the literature data. It can be used in the development of a normative document for granules of Plantago ovata seed husks. 

  11. Granule size control and targeting in pulsed spray fluid bed granulation.

    Science.gov (United States)

    Ehlers, Henrik; Liu, Anchang; Räikkönen, Heikki; Hatara, Juha; Antikainen, Osmo; Airaksinen, Sari; Heinämäki, Jyrki; Lou, Honxiang; Yliruusi, Jouko

    2009-07-30

    The primary aim of the study was to investigate the effects of pulsed liquid feed on granule size. The secondary aim was to increase knowledge of this technique in granule size targeting. Pulsed liquid feed refers to the pump changing between on- and off-positions in sequences, called duty cycles. One duty cycle consists of one on- and off-period. The study was performed with a laboratory-scale top-spray fluid bed granulator with duty cycle length and atomization pressure as studied variables. The liquid feed rate, amount and inlet air temperature were constant. The granules were small, indicating that the powder has only undergone ordered mixing, nucleation and early growth. The effect of atomizing pressure on granule size depends on inlet air relative humidity, with premature binder evaporation as a reason. The duty cycle length was of critical importance to the end product attributes, by defining the extent of intermittent drying and rewetting. By varying only the duty cycle length, it was possible to control granule nucleation and growth, with a wider granule size target range in increased relative humidity. The present study confirms that pulsed liquid feed in fluid bed granulation is a useful tool in end product particle size targeting.

  12. Incorporation of a circulating protein into megakaryocyte and platelet granules

    Science.gov (United States)

    Handagama, P. J.; George, J. N.; Shuman, M. A.; McEver, R. P.; Bainton, D. F.

    1987-01-01

    To determine whether or not proteins circulating in plasma can be incorporated into megakaryocytes and platelets, horseradish peroxidase (HRP) was injected intravenously into guinea pigs and these cells were examined for its uptake by electron microscopy and cytochemistry. Enriched samples of megakaryocytes enabled ultrastructural analysis of large numbers of these rare cells. In megakaryocytes, 50% of alpha granules contained HRP between 75 min and 7 hr after injection. At 24 hr, 25% of the megakaryocyte granules were peroxidase-positive, less were positive by 48 hr, and there were none at 4 days. Thus, the findings demonstrate that a circulating protein can be endocytosed by megakaryocytes and rapidly packaged into alpha granules. Platelet granules also contain HRP by 7 hr after injection, and they can secrete it in response to thrombin. Unfortunately, our present studies do not allow us to distinguish between direct endocytosis by the platelet and/or shedding of new platelets from recently labeled megakaryocytes. It is concluded that while some alpha granule proteins are synthesized by megakaryocytes, others may be acquired from plasma by endocytosis. In addition to providing evidence that some of the proteins of alpha granules may be of exogenous origin, this study has allowed the definition of a pathway whereby plasma proteins may be temporarily sequestered in megakaryocytes before reentering the circulation in platelets.

  13. Granules Harboring Translationally Active mRNAs Provide a Platform for P-Body Formation following Stress

    Directory of Open Access Journals (Sweden)

    Jennifer Lui

    2014-11-01

    Full Text Available The localization of mRNA to defined cytoplasmic sites in eukaryotic cells not only allows localized protein production but also determines the fate of mRNAs. For instance, translationally repressed mRNAs localize to P-bodies and stress granules where their decay and storage, respectively, are directed. Here, we find that several mRNAs are localized to granules in unstressed, actively growing cells. These granules play a key role in the stress-dependent formation of P-bodies. Specific glycolytic mRNAs are colocalized in multiple granules per cell, which aggregate during P-body formation. Such aggregation is still observed under conditions or in mutants where P-bodies do not form. In unstressed cells, the mRNA granules appear associated with active translation; this might enable a coregulation of protein expression from the same pathways or complexes. Parallels can be drawn between this coregulation and the advantage of operons in prokaryotic systems.

  14. Phleum pratense pollen starch granules induce humoral and cell-mediated immune responses in a rat model of allergy.

    Science.gov (United States)

    Motta, A; Peltre, G; Dormans, J A M A; Withagen, C E T; Lacroix, G; Bois, F; Steerenberg, P A

    2004-02-01

    Timothy grass (Phleum pratense) pollen allergens are an important cause of allergic symptoms. However, pollen grains are too large to penetrate the deeper airways. Grass pollen is known to release allergen-bearing starch granules (SG) upon contact with water. These granules can create an inhalable allergenic aerosol capable of triggering an early asthmatic response and are implicated in thunderstorm-associated asthma. We studied the humoral (IgE) and bronchial lymph node cells reactivities to SG from timothy grass pollen in pollen-sensitized rats. Brown-Norway rats were sensitized (day 0) and challenged (day 21) intratracheally with intact pollen and kept immunized by pollen intranasal instillation by 4 weeks intervals during 3 months. Blood and bronchial lymph nodes were collected 7 days after the last intranasal challenge. SG were purified from fresh timothy grass pollen using 5 microm mesh filters. To determine the humoral response (IgE) to SG, we developed an original ELISA inhibition test, based on competition between pollen allergens and purified SG. The cell-mediated response to SG in the bronchial lymph node cells was determined by measuring the uptake of [3H]thymidine in a proliferation assay. An antibody response to SG was induced, and purified SG were able to inhibit the IgE ELISA absorbance by 45%. Pollen extract and intact pollen gave inhibitions of 55% and 52%, respectively. A cell-mediated response was also found, as pollen extract, intact pollen and SG triggered proliferation of bronchial lymph node cells. It was confirmed that timothy grass pollen contains allergen-loaded SG, which are released upon contact with water. These granules were shown to be recognized by pollen-sensitized rats sera and to trigger lymph node cell proliferation in these rats. These data provide new arguments supporting the implication of grass pollen SG in allergic asthma.

  15. Synthetic mast-cell granules as adjuvants to promote and polarize immunity in lymph nodes

    Science.gov (United States)

    St. John, Ashley L.; Chan, Cheryl Y.; Staats, Herman F.; Leong, Kam W.; Abraham, Soman N.

    2012-03-01

    Granules of mast cells (MCs) enhance adaptive immunity when, on activation, they are released as stable particles. Here we show that submicrometre particles modelled after MC granules augment immunity when used as adjuvants in vaccines. The synthetic particles, which consist of a carbohydrate backbone with encapsulated inflammatory mediators such as tumour necrosis factor, replicate attributes of MCs in vivo including the targeting of draining lymph nodes and the timed release of the encapsulated mediators. When used as an adjuvant during vaccination of mice with haemagglutinin from the influenza virus, the particles enhanced adaptive immune responses and increased survival of mice on lethal challenge. Furthermore, differential loading of the particles with the cytokine IL-12 directed the character of the response towards Th1 lymphocytes. The synthetic MC adjuvants replicate and enhance the functions of MCs during vaccination, and can be extended to polarize the resulting immunity.

  16. Combined role of seizure-induced dendritic morphology alterations and spine loss in newborn granule cells with mossy fiber sprouting on the hyperexcitability of a computer model of the dentate gyrus.

    Science.gov (United States)

    Tejada, Julian; Garcia-Cairasco, Norberto; Roque, Antonio C

    2014-05-01

    Temporal lobe epilepsy strongly affects hippocampal dentate gyrus granule cells morphology. These cells exhibit seizure-induced anatomical alterations including mossy fiber sprouting, changes in the apical and basal dendritic tree and suffer substantial dendritic spine loss. The effect of some of these changes on the hyperexcitability of the dentate gyrus has been widely studied. For example, mossy fiber sprouting increases the excitability of the circuit while dendritic spine loss may have the opposite effect. However, the effect of the interplay of these different morphological alterations on the hyperexcitability of the dentate gyrus is still unknown. Here we adapted an existing computational model of the dentate gyrus by replacing the reduced granule cell models with morphologically detailed models coming from three-dimensional reconstructions of mature cells. The model simulates a network with 10% of the mossy fiber sprouting observed in the pilocarpine (PILO) model of epilepsy. Different fractions of the mature granule cell models were replaced by morphologically reconstructed models of newborn dentate granule cells from animals with PILO-induced Status Epilepticus, which have apical dendritic alterations and spine loss, and control animals, which do not have these alterations. This complex arrangement of cells and processes allowed us to study the combined effect of mossy fiber sprouting, altered apical dendritic tree and dendritic spine loss in newborn granule cells on the excitability of the dentate gyrus model. Our simulations suggest that alterations in the apical dendritic tree and dendritic spine loss in newborn granule cells have opposing effects on the excitability of the dentate gyrus after Status Epilepticus. Apical dendritic alterations potentiate the increase of excitability provoked by mossy fiber sprouting while spine loss curtails this increase.

  17. Soft x-ray imaging of intracellular granules of filamentous cyanobacterium generating musty smell in Lake Biwa

    International Nuclear Information System (INIS)

    Takemoto, K; Mizuta, G; Namba, H; Yamamoto, A; Kihara, H; Yoshimura, M; Ichise, S

    2013-01-01

    A planktonic blue-green algae, which are currently identified as Phormidium tenue, was observed by a soft x-ray microscopy (XM) for comparing a musty smell generating green strain (PTG) and a non-smell brown strain (PTB). By XM, cells were clearly imaged, and several intracellular granules which could not be observed under a light microscope were visualized. The diameter of granules was about 0.5–1 μm, and one or a few granules were seen in a cell. XM analyses showed that width of cells and sizes of intracellular granules were quite different between PTG and PTB strains. To study the granules observed by XM, transmission in more detail, transmission electron microscopy (TEM) and indirect fluorescent-antibody technique (IFA) were applied. By TEM, carboxysomes, thylakoids and polyphosphate granules were observed. IFA showed the presence of carboxysomes. Results lead to the conclusion that intracellular granules observed under XM are carboxysomes or polyphosphate granules. These results demonstrate that soft XM is effective for analyzing fine structures of small organisms such as cyanobacterium, and for discriminating the strains which generates musty smells from others

  18. Regularities of formation of granules at granulation of powdered materials in drum devices

    International Nuclear Information System (INIS)

    Kelbaliyev, G.I; Samedli, V.M.

    2008-01-01

    Full text:Granulation of powdered materials in the presence of binding agent is widely used in the most multi-tankage productions of chemical, food, pharmaceutical, metallurgical and agrarian technology. Granulation of powdered materials with participation of liquid phase is carried out in screw, disk, plase-shaped and drum devices and also in devices with mixers. In all cases a formation and growth of granules takes place owing to wetting of separate particles of powder leading to agglomeration and coagulation of particles in their contact with each other. It is apparent that in early stage of granule formation a growth and formation of granules takes place owing to adherence of small particles and agglomerates to larger granules. The content of liquid phase owing to which are appeared adhesive, capillary and surface forces, keeping particles on surface of granule exerts an essential influence on process of granule formation. Besides composition of mixture, its moisture and physical-chemical properties of initial components a mixing frequency degree of filling and angle of inclination of the device, ratio of liquid and hard phases which defines finally qualitative characteristics of the process exert an essential influence on formation of granules as a result of agglomeration of particles of powder. Powder lamination on granule surface is as consequence of its consolidation whereas as a result of consolidation and compression, a binding agent containing in pores squeezed out to a surface, which increases a possibility and probability of further sticking of dry particles of powder. In all cases the further growth and completeness of form of granule is determined by distribution of concentration of binding agent in volume of granule, i.e. moisture content or moisture of granule surface

  19. Amylolytic hydrolysis of native starch granules affected by granule surface area.

    Science.gov (United States)

    Kim, J C; Kong, B W; Kim, M J; Lee, S H

    2008-11-01

    Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, alpha-amylase from Bacillus subtilis, glucoamylase I (GA-I) and II (GA-II) from Aspergillus niger, and beta-amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver-Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule.

  20. Localization of SERBP1 in stress granules and nucleoli.

    Science.gov (United States)

    Lee, Yu-Jen; Wei, Hung-Ming; Chen, Ling-Yun; Li, Chuan

    2014-01-01

    SERPINE1 mRNA-binding protein 1 (SERBP1) is an arginine-methylated RNA-binding protein whose modification affects protein interaction and intracellular localization. In the present study, we show that, under normal growth conditions without stress, SERBP1 interacts with arginine-methylated and stress granule-associated proteins such as heterogeneous nuclear ribonucleoprotein A1, fragile X mental retardation protein and fragile X mental retardation syndrome-related protein 1 in an RNA-dependent manner. We also show that, after arsenite treatment, a proportion of full-length SERBP1 protein co-localizes with the typical stress granule marker T-cell intracellular antigen-1 in the cytoplasmic stress granules. Truncated SERBP1 with an N-terminal, central RG or C-terminal deletion, or single-domain segments comprising the N-terminal, central or C-terminal region, were recruited to stress granules upon arsenite treatment but with reduced efficiency. In addition, upon arsenite treatment, the localization of SERBP1 changed from a diffuse cytoplasmic localization to nuclear-dominant (concentrated in the nucleolus) A similar distribution was observed when cells were treated with the methylation inhibitor adenosine periodate, and was also detected for N- or C-terminal domain deletions and all three single-domain fragments even without stress induction. We further demonstrate that adenosine periodate treatment delays the association/dissociation of SERBP1 with stress granules. Hypomethylation retains SERBP1 in the nucleus/nucleolus regardless of arsenite treatment. Our study indicates that arginine methylation is correlated with recruitment of SERBP to stress granules and nucleoli and its retention therein. To our knowledge, this is the first report of an RNA-binding protein that is shifted simultaneously to cytoplasmic stress granules and nucleoli, two ribonucleoprotein-enriched subcellular compartments, upon stress. © 2013 FEBS.

  1. CSR-1 and P granules suppress sperm-specific transcription in the C. elegans germline.

    Science.gov (United States)

    Campbell, Anne C; Updike, Dustin L

    2015-05-15

    Germ granules (P granules) in C. elegans are required for fertility and function to maintain germ cell identity and pluripotency. Sterility in the absence of P granules is often accompanied by the misexpression of soma-specific proteins and the initiation of somatic differentiation in germ cells. To investigate whether this is caused by the accumulation of somatic transcripts, we performed mRNA-seq on dissected germlines with and without P granules. Strikingly, we found that somatic transcripts do not increase in the young adult germline when P granules are impaired. Instead, we found that impairing P granules causes sperm-specific mRNAs to become highly overexpressed. This includes the accumulation of major sperm protein (MSP) transcripts in germ cells, a phenotype that is suppressed by feminization of the germline. A core component of P granules, the endo-siRNA-binding Argonaute protein CSR-1, has recently been ascribed with the ability to license transcripts for germline expression. However, impairing CSR-1 has very little effect on the accumulation of its mRNA targets. Instead, we found that CSR-1 functions with P granules to prevent MSP and sperm-specific mRNAs from being transcribed in the hermaphrodite germline. These findings suggest that P granules protect germline integrity through two different mechanisms, by (1) preventing the inappropriate expression of somatic proteins at the level of translational regulation, and by (2) functioning with CSR-1 to limit the domain of sperm-specific expression at the level of transcription. © 2015. Published by The Company of Biologists Ltd.

  2. LXR agonist rescued the deficit in the proliferation of the cerebellar granule cells induced by dexamethasone

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Xuting; Zhong, Hongyu; Li, Fen; Cai, Yulong; Li, Xin; Wang, Lian; Fan, Xiaotang, E-mail: fanxiaotang2005@163.com

    2016-09-02

    Dexamethasone (DEX) exposure during early postnatal life produces permanent neuromotor and intellectual deficits and stunts cerebellar growth. The liver X receptor (LXR) plays important roles in CNS development. However, the effects of LXR on the DEX-mediated impairment of cerebellar development remain undetermined. Thus, mice were pretreated with LXR agonist TO901317 (TO) and were later exposed to DEX to evaluate its protective effects on DEX-mediated deficit during cerebellar development. The results showed that an acute exposure of DEX on postnatal day 7 resulted in a significant impairment in cerebellar development and decreased the proliferation of granule neuron precursors in the external granule layer of cerebellum. This effect was attenuated by pretreatment with TO. We further found that the decrease in the proliferation caused by DEX occurred via up-regulation of glucocorticoid receptor and p27kip1, which could be partially prevented by LXR agonist pretreatment. Overall, our results suggest that LXR agonist pretreatment could protect against DEX-induced deficits in cerebellar development in postnatal mice and may thus be perspective recruited to counteract such GC side effects.

  3. LXR agonist rescued the deficit in the proliferation of the cerebellar granule cells induced by dexamethasone

    International Nuclear Information System (INIS)

    Bian, Xuting; Zhong, Hongyu; Li, Fen; Cai, Yulong; Li, Xin; Wang, Lian; Fan, Xiaotang

    2016-01-01

    Dexamethasone (DEX) exposure during early postnatal life produces permanent neuromotor and intellectual deficits and stunts cerebellar growth. The liver X receptor (LXR) plays important roles in CNS development. However, the effects of LXR on the DEX-mediated impairment of cerebellar development remain undetermined. Thus, mice were pretreated with LXR agonist TO901317 (TO) and were later exposed to DEX to evaluate its protective effects on DEX-mediated deficit during cerebellar development. The results showed that an acute exposure of DEX on postnatal day 7 resulted in a significant impairment in cerebellar development and decreased the proliferation of granule neuron precursors in the external granule layer of cerebellum. This effect was attenuated by pretreatment with TO. We further found that the decrease in the proliferation caused by DEX occurred via up-regulation of glucocorticoid receptor and p27kip1, which could be partially prevented by LXR agonist pretreatment. Overall, our results suggest that LXR agonist pretreatment could protect against DEX-induced deficits in cerebellar development in postnatal mice and may thus be perspective recruited to counteract such GC side effects.

  4. Recent results and prospects on superheated superconducting granules detectors

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, L.; Perret-Gallix, D.

    1987-11-01

    The basic properties of superheated superconducting granules (SSG) detectors are reviewed. Recent results are presented and discussed. Granule samples of different sizes (10 μm -8 Ω.cm -6 Ω.cm) exhibit encouraging sensitivity to low energy β and γ sources (down to 55 Fe 6 KeV γ'S). All tests were performed with real-time read-out electronics, detecting single granule flips under the action of individual particles. Sensitivity is shown to depend on normal state resistivity. Irradiation of very large tin granules (45 μm ≤ Φ ≤ 400 μm) with α particles ( 241 Am, E ≅ 5.5 MeV) shows evidence for local heating, where the observed energy threshold is far below the one predicted by equilibrium thermodynamical calculations. Tests made at lower temperatures (T ≥ 450 mK) show the absence of avalanche effect (seen by other authors in different conditions) for several samples of tin granules. A theoretical discussion of the avalanche effect is presented. The understanding of the role of heat exchanges in the composite medium leads to the concept of 'localized micro-avalanche' and opens the way to drastic improvements of SSG performance for particle detection. Such a phenomenon should be obtained by a better thermal matching between dielectric and granules, working at temperatures where the released latent heat is slightly positive. Estimates of the behavior of the detector at very low T are also given, where a thin layer of normal electrons near the surface is shown to contribute to the heat capacity of a superheated granule. We discuss the main points to be studied in the near future, and give a brief evaluation of the present status of feasibility investigation for several proposed experiments (solar neutrinos, monopoles, dark matter, double β,...). An updated working program for SSG development is proposed

  5. Effects of Chinese Formula Jueyin Granules on Psoriasis in an Animal Model

    Directory of Open Access Journals (Sweden)

    Tian Ma

    2014-01-01

    Full Text Available Although Traditional Chinese medicine (TCM is known to be effective for psoriasis patients, the responsible mechanisms still remain poorly understood. In this study, we aimed to evaluate the effect of one formula, named Jueyin granules (JYG in the mouse model of the vaginal epithelium and tail epidermis. Additionally, we also determined the anti-inflammatory effects of JYG in an imiquimod- (IMQ- induced psoriasis-like skin mouse model. Our results show that JYG can attenuate the IMQ-induced psoriasis-like inflammation, accompanied with increased epidermal hyperplasia. We also measured estrogenic stage mitosis of vaginal epithelial cells and the formation of granular cell layers in male mouse tails per 100 scales, as well as the tissue nitric oxide (NO and malondialdehyde (MDA levels using the ELISA method. The results suggest that JYG significantly inhibited mitosis in mouse vaginal epithelial cells, promoted the formation of the squamous epidermal granular layer in mice tails, and reduced the levels of NO and MDA in an imiquimod-induced psoriasis-like skin mouse model after 14 d (P<0.05. These results demonstrate that JYG might be an effective clinical treatment for psoriasis and the effects may be related to inhibited keratinocytes proliferation, improved parakeratotic epidermal cells, and reduced expression of NO and MDA.

  6. Mast cell granules modulate alveolar macrophage respiratory-burst activity and eicosanoid metabolism.

    Science.gov (United States)

    Rock, M J; Despot, J; Lemanske, R F

    1990-10-01

    Alveolar macrophages (AMs) and mast cells reside in the airway, and both have been demonstrated to contribute independently to allergic inflammatory responses through the generation of respiratory-burst metabolites and the release of biologically active mediators, respectively. Since mast cell granules (MCGs) contain mediators that could potentially interact with the AM respiratory burst, we investigated the effects of isolated MCGs on this important inflammatory pathway of the AM. MCGs and AMs were obtained by peritoneal and tracheoalveolar lavage, respectively, of Sprague-Dawley rats. First, the overall respiratory-burst activity was measured by luminal-enhanced chemiluminescence (CL), and second, the individual oxygen species contributing to CL (superoxide anion [O2-], hydrogen peroxide [H2O2], and hypochlorous acid) were measured. MCGs alone enhanced AM CL responses to an equivalent degree compared to zymosan-stimulated AMs. However, AMs preincubated with MCGs followed by zymosan stimulation significantly and synergistically enhanced the CL responses. This enhanced CL was not due to an increased production of O2-, H2O2, or hypochlorous acid; in fact, there were decreased measured amounts of O2- and H2O2 from zymosan-stimulated AMs in the presence of MCGs, most likely caused by the content of granules of superoxide dismutase and peroxidase, respectively. The lipoxygenase inhibitor, nordihydroguaiaretic acid, completely abolished the enhanced CL of AM preincubated with MCGs and subsequently stimulated by zymosan, but O2- production was not affected by nordihydroguaiaretic acid. Taken together, these results suggest that derivatives of arachidonic acid metabolism, most likely those of the lipoxygenase pathway, are responsible for the enhanced AM CL response observed in the presence of MCGs. Thus, mast cell-macrophage interactions may be important within the airway in enhancing the generation of mediators that contribute to tissue inflammation and bronchospasm.

  7. The granule cell density of the dentate gyrus following administration of Urtica dioica extract to young diabetic rats.

    Science.gov (United States)

    Fazeli, S A; Gharravi, A M; Ghafari, S; Jahanshahi, M; Golalipour, M J

    2008-08-01

    Urtica dioica L. Stinging nettle has long been known worldwide as a medicinal plant. To study the benefits of the nettle in diabetic encephalopathy, the granule cell density of the dentate gyrus of diabetic rats was studied following administration of Urtica dioica extract. A total of 24 male albino Wistar rats were allocated equally to normal, diabetic, preventive and treatment groups. Hyperglycaemia was induced by streptozotocin (80 mg/kg) in the animals of the diabetic and treatment groups. One week after injection of the streptozotocin the animals in the treatment group received a hydroalcoholic extract of Urtica dioica (100 mg/kg/day) for 4 weeks intraperitoneally. The rats of the preventive group received hydroalcoholic extract of U. dioica (100 mg/kg/day) IP for the first 5 days and an injection of streptozotocin (80 mg/kg) on the 6th day. After 5 weeks of study all the rats were sacrificed and coronal sections were taken from the dorsal hippocampal formation of the right cerebral hemispheres and stained with cresyl violet. The area densities of the granule cells were measured and compared in the four groups. The density was lower in the diabetic rats compared with the controls (p > 0.05). The preventive group showed lower cell density than the controls (p > 0.05). The densities in the treated rats were higher than in the diabetic rats (p > 0.05). Furthermore, the control and treated rats showed similar densities (p > 0.05). It seems that U. dioica extract can help compensate for granule cell loss in the diabetic rat dentate gyrus, which can ameliorate cognitive impairment in diabetes. However, preventive use of the extract showed no significant benefit.

  8. Aspergillus oryzae AoSO is a novel component of stress granules upon heat stress in filamentous fungi.

    Directory of Open Access Journals (Sweden)

    Hsiang-Ting Huang

    Full Text Available Stress granules are a type of cytoplasmic messenger ribonucleoprotein (mRNP granule formed in response to the inhibition of translation initiation, which typically occurs when cells are exposed to stress. Stress granules are conserved in eukaryotes; however, in filamentous fungi, including Aspergillus oryzae, stress granules have not yet been defined. For this reason, here we investigated the formation and localization of stress granules in A. oryzae cells exposed to various stresses using an EGFP fusion protein of AoPab1, a homolog of Saccharomyces cerevisiae Pab1p, as a stress granule marker. Localization analysis showed that AoPab1 was evenly distributed throughout the cytoplasm under normal growth conditions, and accumulated as cytoplasmic foci mainly at the hyphal tip in response to stress. AoSO, a homolog of Neurospora crassa SO, which is necessary for hyphal fusion, colocalized with stress granules in cells exposed to heat stress. The formation of cytoplasmic foci of AoSO was blocked by treatment with cycloheximide, a known inhibitor of stress granule formation. Deletion of the Aoso gene had effects on the formation and localization of stress granules in response to heat stress. Our results suggest that AoSO is a novel component of stress granules specific to filamentous fungi. The authors would specially like to thank Hiroyuki Nakano and Kei Saeki for generously providing experimental and insightful opinions.

  9. On the so-called membrane coating granules in keratinized lichen planus lesions of the buccal mucosa.

    Science.gov (United States)

    El-Labban, N G; Wood, R D

    1982-11-01

    Serial sections of the so-called membrane-coating granules have been examined in keratinized oral epithelium of lichen planus lesions. As with 'granules' apparent in non-keratinized epithelium, it is found they do not represent specialized intra-cytoplasmic organelles, but are the result of sectioning at different areas, levels and planes through the plasma membrane of interdigitating cell processes. Such 'granules' appear mostly in the superficial, but not deep, part of the cytoplasm of the upper prickle cells. This is considered to be due to topographic differences between the upper and under surfaces of these cells and the presence of narrower intercellular spaces than those between deeper epithelial cells. Such arrangement often results in cell processes in sections appearing free in the superficial part of the cell below. The appearance of 'granules' arises when the plane of section is not at right angles to the two plasma membranes surrounding these processes.

  10. THE STUDY OF THE KINETIC OF NATURAL ZEOLITE GRANULES GROWTH AT DIFFERENT WAYS OF GRANULATION

    Directory of Open Access Journals (Sweden)

    Rybachuk VD

    2016-12-01

    Full Text Available Introduction. Active substances and excipients used in the manufacture of medicines in tablet form, in most cases, have poor technological properties. This fact determines the need for prior granulation of mass before compression. Granulators of various sizes and designs, running on different modes, made the formation, growth and consolidation of the powder particles that lead to obtain pellets of different shapes and sizes. From the literature it is known that granulation leads to two forms of granules: isodiametric and nonisodiametric. The first group of particles forms has globular shape with a smooth surface and the proportion in which the length, thickness and height are about the same. They are usually made by fluidized bed granulation, spray drying, pelletizing and granulation in dragee pan. Granules of nonisodiametric form in which length is several times the width and height are made mostly by extrusion and compacting. The geometrical parameters of obtained granules are affected by the properties of raw materials, the granulation modes, type and amount of added humidifier and so on. The shape and size of granules, from a technological point of view, are the key factors that contribute, except organoleptic characteristics of the product, its technological properties such as particle size distribution, bulk volume, the ability of the material to shrinkage, porosity, fluidity, mechanical strength and so on. Properly selected for specific conditions granulation method is able to provide the finished product with the specified technological parameters depending on the needs. The aim of this work was to study the effect of granulation method and its conditions on the kinetics of growth of the natural zeolite granules and some quality characteristics of obtained granules. Material & methods. As objects of study served the natural zeolite pellets produced using 3%, 5%, 7% and 10% potato starch paste and solution of polyvinylpyrrolidone (PVP

  11. TIA-1 Self-Multimerization, Phase Separation, and Recruitment into Stress Granules Are Dynamically Regulated by Zn2.

    Science.gov (United States)

    Rayman, Joseph B; Karl, Kevin A; Kandel, Eric R

    2018-01-02

    Stress granules are non-membranous structures that transiently form in the cytoplasm during cellular stress, where they promote translational repression of non-essential RNAs and modulate cell signaling by sequestering key signal transduction proteins. These and other functions of stress granules facilitate an adaptive cellular response to environmental adversity. A key component of stress granules is the prion-related RNA-binding protein, T cell intracellular antigen-1 (TIA-1). Here, we report that recombinant TIA-1 undergoes rapid multimerization and phase separation in the presence of divalent zinc, which can be reversed by the zinc chelator, TPEN. Similarly, the formation and maintenance of TIA-1-positive stress granules in arsenite-treated cells are inhibited by TPEN. In addition, Zn 2+ is released in cells treated with arsenite, before stress granule formation. These findings suggest that Zn 2+ is a physiological ligand of TIA-1, acting as a stress-inducible second messenger to promote multimerization of TIA-1 and subsequent localization into stress granules. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Identification of a multifunctional protein, PhaM, that determines number, surface to volume ratio, subcellular localization and distribution to daughter cells of poly(3-hydroxybutyrate), PHB, granules in Ralstonia eutropha H16.

    Science.gov (United States)

    Pfeiffer, Daniel; Wahl, Andreas; Jendrossek, Dieter

    2011-11-01

    A two-hybrid approach was applied to screen for proteins with the ability to interact with PHB synthase (PhaC1) of Ralstonia eutropha. The H16_A0141 gene (phaM) was identified in the majority of positive clones. PhaM (26.6 kDa) strongly interacted with PhaC1 and with phasin PhaP5 but not with PhaP1 or other PHB granule-associated proteins. A ΔphaM mutant accumulated only one or two large PHB granules instead of three to six medium-sized PHB granules of the wild type, and distribution of granules to daughter cells was disordered. All three phenotypes (number, size and distribution of PHB granules) were reversed by reintroduction of phaM. Purified PhaM revealed DNA-binding properties in gel mobility shift experiments. Expression of a fusion of the yellow fluorescent protein (eYfp) with PhaM resulted in formation of many small fluorescent granules that were bound to the nucleoid region. Remarkably, an eYfp-PhaP5 fusion localized at the cell poles in a PHB-negative background and overexpression of eYfp-PhaP5 in the wild type conferred binding of PHB granules to the cell poles. In conclusion, subcellular localization of PHB granules in R. eutropha depends on a concerted expression of at least three PHB granule-associated proteins, namely PhaM, PhaP5 and PHB synthase PhaC1. © 2011 Blackwell Publishing Ltd.

  13. Stimulation of the N-methyl-D-aspartate receptor has a trophic effect on differentiating cerebellar granule cells

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1988-01-01

    N-methyl-D-aspartate (NMDA) supplementation of cerebellar cultures enriched in granule neurones (about 90%) prevented the extensive cell loss which occurs when cultivation takes place, in serum containing media, in the presence of 'low' K+ (5-15 mM). Estimation of tetanus toxin receptors and N-CA...

  14. Difference in distribution of membrane proteins between low- and high-density secretory granules in parotid acinar cells

    International Nuclear Information System (INIS)

    Fujita-Yoshigaki, Junko; Katsumata, Osamu; Matsuki, Miwako; Yoshigaki, Tomoyoshi; Furuyama, Shunsuke; Sugiya, Hiroshi

    2006-01-01

    Secretory granules (SGs) are considered to be generated as immature granules and to mature by condensation of their contents. In this study, SGs of parotid gland were separated into low-, medium-, and high-density granule fractions by Percoll-density gradient centrifugation, since it was proposed that the density corresponds to the degree of maturation. The observation with electron microscopy showed that granules in the three fractions were very similar. The average diameter of high-density granules was a little but significantly larger than that of low-density granules. Although the three fractions contained amylase, suggesting that they are all SGs, distribution of membrane proteins was markedly different. Syntaxin6 and VAMP4 were localized in the low-density granule fraction, while VAMP2 was concentrated in the high-density granule fraction. Immunoprecipitation with anti-syntaxin6 antibody caused coprecipitation of VAMP2 from the medium-density granule fraction without solubilization, but not from Triton X-100-solubilized fraction, while VAMP4 was coprecipitated from both fractions. Therefore, VAMP2 is present on the same granules, but is separated from syntaxin6 and VAMP4, which are expected to be removed from immature granules. These results suggest that the medium-density granules are intermediates from low- to high-density granules, and that the membrane components of SGs dynamically change by budding and fusion during maturation

  15. TIA-1 Self-Multimerization, Phase Separation, and Recruitment into Stress Granules Are Dynamically Regulated by Zn2+

    Directory of Open Access Journals (Sweden)

    Joseph B. Rayman

    2018-01-01

    Full Text Available Summary: Stress granules are non-membranous structures that transiently form in the cytoplasm during cellular stress, where they promote translational repression of non-essential RNAs and modulate cell signaling by sequestering key signal transduction proteins. These and other functions of stress granules facilitate an adaptive cellular response to environmental adversity. A key component of stress granules is the prion-related RNA-binding protein, T cell intracellular antigen-1 (TIA-1. Here, we report that recombinant TIA-1 undergoes rapid multimerization and phase separation in the presence of divalent zinc, which can be reversed by the zinc chelator, TPEN. Similarly, the formation and maintenance of TIA-1-positive stress granules in arsenite-treated cells are inhibited by TPEN. In addition, Zn2+ is released in cells treated with arsenite, before stress granule formation. These findings suggest that Zn2+ is a physiological ligand of TIA-1, acting as a stress-inducible second messenger to promote multimerization of TIA-1 and subsequent localization into stress granules. : Rayman et al. show that Zn2+ is a stress-inducible second messenger that triggers self-multimerization and phase separation of TIA-1 and regulates dynamic recruitment of TIA-1 into stress granules. This mechanism is part of an adaptive cellular response to environmental adversity. Keywords: TIA-1, TIA1, stress granules, cellular stress, functional prion, phase separation, zinc regulation

  16. The functional morphology of color changing in a spider: development of ommochrome pigment granules.

    Science.gov (United States)

    Insausti, Teresita C; Casas, Jérôme

    2008-03-01

    Studies on the formation of ommochrome pigment granules are very few, despite their generalized occurrence as screening pigments in insect eyes. This is particularly true for ommochrome granules responsible for epidermal coloration. The aims of this study were to characterize the localization of major body pigments in a color changing mimetic spider, Misumena vatia (Thomisidae), and to describe the formation and location of ommochrome pigment granules responsible for the spider's color change from white to yellow. The unpigmented cuticula of this spider is transparent. Both the guanine localized in guanine cells in the opisthosoma and the uric acid localized in epidermis cells in the prosoma are responsible for the white coloration. The bright yellow color is due to the combination of ommochrome pigment granules and the white reflectance from coincident guanine and/or uric acid. The formation of ommochrome pigment granules in epidermis cells proceeds via three distinctive steps. Translucent, UV fluorescent, progranules (type I) are produced by a dense network of endoplasmic reticulum associated with numerous mitochondria and glycogen rosettes. These progranules are present in white spiders only, and regularly distributed in the cytoplasm. The merging of several progranules of type I into a transient state (progranule type II) leads to the formation of granules (type III) characterized by their lack of fluorescence, their spherical sections and their osmophilic-electron-dense contents. They are found in yellow spiders and in the red stripes on the body sides. Their color varies from yellow to red. Thus, white spiders contain only type I granules, yellow tinted spiders contain type II and III granules and bright yellow spiders contain only type III granules. We present a synthetic view of the ontogeny of ommochrome granules. We discuss the physiology of color changing and the nature of the chemical compounds in the different types of granules. Extended studies on the

  17. Distribution of binder in granules produced by means of twin screw granulation

    DEFF Research Database (Denmark)

    Fonteyne, Margot; Fussell, Andrew Luke; Vercruysse, Jurgen

    2014-01-01

    According to the quality by design principle processes may not remain black-boxes and full process understanding is required. The granule size distribution of granules produced via twin screw granulation is often found to be bimodal. The aim of this study was to gain a better understanding...

  18. In vivo Anomalous Diffusion and Weak Ergodicity Breaking of Lipid Granules

    DEFF Research Database (Denmark)

    Jeon, J.-H.; Tejedor, V.; Burov, S.

    2011-01-01

    Combining extensive single particle tracking microscopy data of endogenous lipid granules in living fission yeast cells with analytical results we show evidence for anomalous diffusion and weak ergodicity breaking. Namely we demonstrate that at short times the granules perform subdiffusion...... according to the laws of continuous time random walk theory. The associated violation of ergodicity leads to a characteristic turnover between two scaling regimes of the time averaged mean squared displacement. At longer times the granule motion is consistent with fractional Brownian motion....

  19. Cdk5 regulates accurate maturation of newborn granule cells in the adult hippocampus.

    Directory of Open Access Journals (Sweden)

    Sebastian Jessberger

    2008-11-01

    Full Text Available Newborn granule cells become functionally integrated into the synaptic circuitry of the adult dentate gyrus after a morphological and electrophysiological maturation process. The molecular mechanisms by which immature neurons and the neurites extending from them find their appropriate position and target area remain largely unknown. Here we show that single-cell-specific knockdown of cyclin-dependent kinase 5 (cdk5 activity in newborn cells using a retrovirus-based strategy leads to aberrant growth of dendritic processes, which is associated with an altered migration pattern of newborn cells. Even though spine formation and maturation are reduced in cdk5-deficient cells, aberrant dendrites form ectopic synapses onto hilar neurons. These observations identify cdk5 to be critically involved in the maturation and dendrite extension of newborn neurons in the course of adult neurogenesis. The data presented here also suggest a mechanistic dissociation between accurate dendritic targeting and subsequent synapse formation.

  20. The paradox of high shear granulation : the formation of non-homogeneous granules

    NARCIS (Netherlands)

    Dries, Kaspar van den

    2004-01-01

    Wet granulation is a process used for the particle size enlargement of primary powders. The mixing of a liquid with the powder glues the primary particles together, which results in the formation of the granules. The mixing action can be performed in many ways, like tumbling (drum granulation),

  1. Effects of dissolved oxygen and pH on nitrous oxide production rates in autotrophic partial nitrification granules.

    Science.gov (United States)

    Rathnayake, Rathnayake M L D; Oshiki, Mamoru; Ishii, Satoshi; Segawa, Takahiro; Satoh, Hisashi; Okabe, Satoshi

    2015-12-01

    The effects of dissolved oxygen (DO) and pH on nitrous oxide (N2O) production rates and pathways in autotrophic partial nitrification (PN) granules were investigated at the granular level. N2O was primarily produced by betaproteobacterial ammonia-oxidizing bacteria, mainly Nitrosomonas europaea, in the oxic surface layer (production increased with increasing bulk DO concentration owing to activation of the ammonia (i.e., hydroxylamine) oxidation in this layer. The highest N2O emissions were observed at pH 7.5, although the ammonia oxidation rate was unchanged between pH 6.5 and 8.5. Overall, the results of this study suggest that in situ analyses of PN granules are essential to gaining insight into N2O emission mechanisms in a granule. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Lipopolysaccharide-binding protein: localization in secretory granules of Paneth cells in the mouse small intestine

    DEFF Research Database (Denmark)

    Hansen, Gert H; Rasmussen, Karina; Niels-Christiansen, Lise-Lotte

    2009-01-01

    Lipopolysaccharide (LPS)-binding protein (LBP) is an acute-phase protein involved in the host's response to endotoxin and mainly synthesized and secreted to the blood by the liver. But in addition, LBP is also made by extrahepatic cells, including the enterocyte-like cell line Caco-2. To study...... in closer detail the synthesis and storage of LBP in the intestinal mucosal epithelium, we performed an immunolocalization of LBP in mouse small intestine. By immunofluorescence microscopy, an antibody recognizing the 58-60 kDa protein of LBP distinctly labeled a small population of cells located deep...... into the crypts. This cell population was also positive for lysozyme and alpha-defensin 4, identifying Paneth cells as the main intestinal LBP-producing cells. By immunogold electron microscopy, intense labeling was observed in the secretory granules of these cells. We conclude that Paneth cells express LBP...

  3. Maintained LTP and Memory Are Lost by Zn2+ Influx into Dentate Granule Cells, but Not Ca2+ Influx.

    Science.gov (United States)

    Takeda, Atsushi; Tamano, Haruna; Hisatsune, Marie; Murakami, Taku; Nakada, Hiroyuki; Fujii, Hiroaki

    2018-02-01

    The idea that maintained LTP and memory are lost by either increase in intracellular Zn 2+ in dentate granule cells or increase in intracellular Ca 2+ was examined to clarify significance of the increases induced by excess synapse excitation. Both maintained LTP and space memory were impaired by injection of high K + into the dentate gyrus, but rescued by co-injection of CaEDTA, which blocked high K + -induced increase in intracellular Zn 2+ but not high K + -induced increase in intracellular Ca 2+ . High K + -induced disturbances of LTP and intracellular Zn 2+ are rescued by co-injection of 6-cyano-7-nitroquinoxakine-2,3-dione, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor antagonist, but not by co-injection of blockers of NMDA receptors, metabotropic glutamate receptors, and voltage-dependent calcium channels. Furthermore, AMPA impaired maintained LTP and the impairment was also rescued by co-injection of CaEDTA, which blocked increase in intracellular Zn 2+ , but not increase in intracellular Ca 2+ . NMDA and glucocorticoid, which induced Zn 2+ release from the internal stores, did not impair maintained LTP. The present study indicates that increase in Zn 2+ influx into dentate granule cells through AMPA receptors loses maintained LTP and memory. Regulation of Zn 2+ influx into dentate granule cells is more critical for not only memory acquisition but also memory retention than that of Ca 2+ influx.

  4. Reduction of the immunostainable length of the hippocampal dentate granule cells' primary cilia in 3xAD-transgenic mice producing human A{beta}{sub 1-42} and tau

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarthy, Balu, E-mail: Balu.Chakravarthy@nrc-cnrc.gc.ca [Human Health Therapeutics, National Research Council of Canada, Ottawa, ON (Canada); Gaudet, Chantal; Menard, Michel; Brown, Leslie; Atkinson, Trevor [Human Health Therapeutics, National Research Council of Canada, Ottawa, ON (Canada); LaFerla, Frank M. [Department of Neurobiology and Behavior, University of California, Irvine, CA (United States); Ito, Shingo [Human Health Therapeutics, National Research Council of Canada, Ottawa, ON (Canada); Armato, Ubaldo; Dal Pra, Ilaria [Department of Life and Reproduction Sciences, University of Verona Medical School, Verona (Italy); Whitfield, James [Human Health Therapeutics, National Research Council of Canada, Ottawa, ON (Canada)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A{beta} and tau-induced neurofibrillary tangles play a key role in Alzheimer's disease. Black-Right-Pointing-Pointer A{beta}{sub 1-42} and mutant tau protein together reduce the primary cilium length. Black-Right-Pointing-Pointer This shortening likely reduces cilium-dependent neurogenesis and memory function. Black-Right-Pointing-Pointer This provides a model of an A{beta}/tau targeting of a neuronal signaling organelle. -- Abstract: The hippocampal dentate gyrus is one of the two sites of continuous neurogenesis in adult rodents and humans. Virtually all dentate granule cells have a single immobile cilium with a microtubule spine or axoneme covered with a specialized cell membrane loaded with receptors such as the somatostatin receptor 3 (SSTR3), and the p75 neurotrophin receptor (p75{sup NTR}). The signals from these receptors have been reported to stimulate neuroprogenitor proliferation and the post-mitotic maturation of newborn granule cells into functioning granule cells. We have found that in 6-24-months-old triple transgenic Alzheimer's disease model mice (3xTg-AD) producing both A{beta}{sub 1-42} and the mutant human tau protein tau{sub P301L,} the dentate granule cells still had immunostainable SSTR3- and p75{sup NTR}-bearing cilia but they were only half the length of the immunostained cilia in the corresponding wild-type mice. However, the immunostainable length of the granule cell cilia was not reduced either in 2xTg-AD mice accumulating large amounts of A{beta}{sub 1-42} or in mice accumulating only a mutant human tau protein. Thus it appears that a combination of A{beta}{sub 1-42} and tau protein accumulation affects the levels of functionally important receptors in 3xTg-AD mice. These observations raise the important possibility that structural and functional changes in granule cell cilia might have a role in AD.

  5. Effects of x-irradiation induced loss of cerebellar granule cells on the synaptosomal levels and the high affinity uptake of amino acids

    International Nuclear Information System (INIS)

    Rohde, B.H.; Rea, M.A.; Simon, J.R.; McBride, W.J.

    1979-01-01

    Crude synaptosomal (P 2 ) preparations were obtained from the cerebella of rats in which the granule cell population had been selectively reduced by X-irradiation treatment and from the cerebella of control animals. In the P 2 fraction form control cerebella, the level of glutamate was greater than any other of the 5 amino acids measured and was 2-fold higher than taurine. The content of taurine, GABA, glycine, and alanine were not changed by the X-irradiation treatment. The uptake of 1.0 micrometers-L-[ 3 H]glutamate and L-[ 3 H]aspartate was reduced approx 20% by X-irradiation treatment, whereas the uptake of 1.0 micrometers-[ 3 H]GABA and [ 3 H]taurine was unchanged. In a second study, the uptake of L-[ 3 H]glutamate, L-[ 3 H]aspartate and [ 3 H]GABA was measured using P 2 fractions obtained from the cerebella of rats in which the population of granule, stellate and basket cells had been reduced by X-irradiation treatment. The uptake of 1.0 micrometers-L-[ 3 H]glutamate, L-[ 3 H]aspartate and [ 3 H]GABA was significantly (P < 0.05) reduced to 57.68 and 59% respectively, of control values. The data are discussed in terms of glutamate being the excitatory neurotransmitter released from granule cells and GABA being the inhibitory neurotransmitter released from basket cells. (author)

  6. The GABAA Antagonist DPP-4-PIOL Selectively Antagonises Tonic over Phasic GABAergic Currents in Dentate Gyrus Granule Cells

    DEFF Research Database (Denmark)

    Boddum, Kim; Frølund, Bente; Kristiansen, Uffe

    2014-01-01

    that phasic and tonic GABAA receptor currents can be selectively inhibited by the antagonists SR 95531 and the 4-PIOL derivative, 4-(3,3-diphenylpropyl)-5-(4-piperidyl)-3-isoxazolol hydrobromide (DPP-4-PIOL), respectively. In dentate gyrus granule cells, SR 95531 was found approximately 4 times as potent...

  7. Neutrophil glycoprotein Mo1 is an integral membrane protein of plasma membranes and specific granules

    International Nuclear Information System (INIS)

    Stevenson, K.B.; Nauseef, W.M.; Clark, R.A.

    1987-01-01

    The glucoprotein Mo1 has previously been demonstrated to be on the cell surface and in the specific granule fraction of neutrophils and to be translocated to the cell surface during degranulation. It is not known, however, whether Mo1 is an integral membrane protein or a soluble, intragranular constituent loosely associated with the specific granule membrane. Purified neutrophils were disrupted by nitrogen cavitation and separated on Percoll density gradients into four fractions enriched for azurophilic granules, specific granules, plasma membrane, and cytosol, respectively. The glycoproteins in these fractions were labeled with 3 H-borohydride reduction, extracted with Triton X-114, and immunoprecipitated with 60.3, an anti-Mo1 monoclonal antibody. Mo1 was detected only in the specific granule and plasma membrane fractions and partitioned exclusively into the detergent-rich fraction consistent with Mo1 being an integral membrane protein. In addition, treatment of specific granule membranes with a high salt, high urea buffer to remove adsorbed or peripheral proteins failed to dissociate Mo1. These data support the hypothesis that Mo1 is an integral membrane protein of plasma and specific granule membranes in human neutrophils

  8. Anti-virus effect of traditional Chinese medicine Yi-Fu-Qing granule on acute respiratory tract infections.

    Science.gov (United States)

    Li, Anyuan; Xie, Yanying; Qi, Fanghua; Li, Jie; Wang, Peng; Xu, Shulan; Zhao, Lin

    2009-08-01

    Yi-Fu-Qing granule is a traditional Chinese medicine for the treatment of acute respiratory tract infections. The present study sought to investigate the anti-virus effects of Yi-Fu-Qing granule on acute respiratory infections with respiratory syncytial virus (RSV) and human adenoviruses type 3 (Ad3). The cytotoxicity of Yi-Fu-Qing granule was evaluated by the neutral red assay on HeLa cells. The antiviral effect of Yi-Fu-Qing granule was tested by observing the cytopathogenic effect (CPE) with a compound mixture of Isatis leaf as the positive control drug. The results indicated that the highest non-toxicity concentration of Yi-Fu-Qing granule on Hela cells was 1:100. The CPE reduction assay showed that Yi-Fu-Qing granule inhibited RSV and Ad3 replication at a concentration of 1:100. Thus, Yi-Fu-Qing granule may have a significant antivirus effect on acute respiratory tract infections with RSV and Ad3 infections and this could prove useful for further antivirus research on acute respiratory tract infections.

  9. Chronic Fluoxetine Induces the Enlargement of Perforant Path-Granule Cell Synapses in the Mouse Dentate Gyrus

    Science.gov (United States)

    Kitahara, Yosuke; Ohta, Keisuke; Hasuo, Hiroshi; Shuto, Takahide; Kuroiwa, Mahomi; Sotogaku, Naoki; Togo, Akinobu; Nakamura, Kei-ichiro; Nishi, Akinori

    2016-01-01

    A selective serotonin reuptake inhibitor is the most commonly prescribed antidepressant for the treatment of major depression. However, the mechanisms underlying the actions of selective serotonin reuptake inhibitors are not fully understood. In the dentate gyrus, chronic fluoxetine treatment induces increased excitability of mature granule cells (GCs) as well as neurogenesis. The major input to the dentate gyrus is the perforant path axons (boutons) from the entorhinal cortex (layer II). Through voltage-sensitive dye imaging, we found that the excitatory neurotransmission of the perforant path synapse onto the GCs in the middle molecular layer of the mouse dentate gyrus (perforant path-GC synapse) is enhanced after chronic fluoxetine treatment (15 mg/kg/day, 14 days). Therefore, we further examined whether chronic fluoxetine treatment affects the morphology of the perforant path-GC synapse, using FIB/SEM (focused ion beam/scanning electron microscopy). A three-dimensional reconstruction of dendritic spines revealed the appearance of extremely large-sized spines after chronic fluoxetine treatment. The large-sized spines had a postsynaptic density with a large volume. However, chronic fluoxetine treatment did not affect spine density. The presynaptic boutons that were in contact with the large-sized spines were large in volume, and the volumes of the mitochondria and synaptic vesicles inside the boutons were correlated with the size of the boutons. Thus, the large-sized perforant path-GC synapse induced by chronic fluoxetine treatment contains synaptic components that correlate with the synapse size and that may be involved in enhanced glutamatergic neurotransmission. PMID:26788851

  10. Effervescent Granules Prepared Using Eucommia ulmoides Oliv. and Moso Bamboo Leaves: Hypoglycemic Activity in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Xiang-Zhou Li

    2016-01-01

    Full Text Available Eucommia ulmoides Oliv. (E. ulmoides Oliv. and moso bamboo (Phyllostachys pubescens leaves are used as folk medicines in central-western China to treat diabetes. To investigate the hypoglycemic activity of the effervescent granules prepared using E. ulmoides Oliv. and moso bamboo leaves (EBEG in HepG2 cells, EBEG were prepared with 5% of each of polysaccharides and chlorogenic acids from moso bamboo and E. ulmoides Oliv. leaves, respectively. HepG2 cells cultured in a high-glucose medium were classified into different groups. The results displayed EBEG-treated cells showed better glucose utilization than the negative controls; thus, the hypoglycemic effect of EBEG was much greater than that of granules prepared using either component alone, thereby indicating that this effect was due to a synergistic action of the components. Further, glucose consumption levels in the cells treated with EBEG (156.35% at 200 μg/mL and the positive controls (metformin, 162.29%; insulin, 161.52% were similar. Thus, EBEG exhibited good potential for use as a natural antidiabetic agent. The hypoglycemic effect of EBEG could be due to the synergistic action of polysaccharides from the moso bamboo leaves and chlorogenic acids from E. ulmoides Oliv. leaves via the inhibition of alpha-glucosidase and glucose-6-phosphate displacement enzyme.

  11. Expression of the GABA(A) receptor alpha6 subunit in cultured cerebellar granule cells is developmentally regulated by activation of GABA(A) receptors

    DEFF Research Database (Denmark)

    Carlson, B X; Belhage, B; Hansen, Gert Helge

    1997-01-01

    Da (alpha6 subunit) radioactive peaks in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In contrast, THIP-treated granule cells at 8 DIV demonstrated a small but significant decrease from control cultures in the photoincorporation of [3H]Ro15-4513 in the 51-kDa peak; however...... that the major effect of THIP was to increase alpha6 subunit clustering on granule cell bodies as well as neurites, 15-fold and sixfold, respectively. Using in situ hybridization, a small THIP-induced increase in alpha6 mRNA was detected at 4 DIV; however, no effect was apparent at 8 DIV. These data suggest...

  12. Hybrid window layer for photovoltaic cells

    Science.gov (United States)

    Deng, Xunming

    2010-02-23

    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  13. Localization of poly(3-hydroxybutyrate) (PHB) granule-associated proteins during PHB granule formation and identification of two new phasins, PhaP6 and PhaP7, in Ralstonia eutropha H16.

    Science.gov (United States)

    Pfeiffer, Daniel; Jendrossek, Dieter

    2012-11-01

    Poly(3-hydroxybutyrate) (PHB) granules are covered by a surface layer consisting of mainly phasins and other PHB granule-associated proteins (PGAPs). Phasins are small amphiphilic proteins that determine the number and size of accumulated PHB granules. Five phasin proteins (PhaP1 to PhaP5) are known for Ralstonia eutropha. In this study, we identified three additional potential phasin genes (H16_B1988, H16_B2296, and H16_B2326) by inspection of the R. eutropha genome for sequences with "phasin 2 motifs." To determine whether the corresponding proteins represent true PGAPs, fusions with eYFP (enhanced yellow fluorescent protein) were constructed. Similar fusions of eYFP with PhaP1 to PhaP5 as well as fusions with PHB synthase (PhaC1), an inactive PhaC1 variant (PhaC1-C319A), and PhaC2 were also made. All fusions were investigated in wild-type and PHB-negative backgrounds. Colocalization with PHB granules was found for all PhaC variants and for PhaP1 to PhaP5. Additionally, eYFP fusions with H16_B1988 and H16_B2326 colocalized with PHB. Fusions of H16_B2296 with eYFP, however, did not colocalize with PHB granules but did colocalize with the nucleoid region. Notably, all fusions (except H16_B2296) were soluble in a ΔphaC1 strain. These data confirm that H16_B1988 and H16_B2326 but not H16_B2296 encode true PGAPs, for which we propose the designation PhaP6 (H16_B1988) and PhaP7 (H16_B2326). When localization of phasins was investigated at different stages of PHB accumulation, fusions of PhaP6 and PhaP7 were soluble in the first 3 h under PHB-permissive conditions, although PHB granules appeared after 10 min. At later time points, the fusions colocalized with PHB. Remarkably, PHB granules of strains expressing eYFP fusions with PhaP5, PhaP6, or PhaP7 localized predominantly near the cell poles or in the area of future septum formation. This phenomenon was not observed for the other PGAPs (PhaP1 to PhaP4, PhaC1, PhaC1-C319A, and PhaC2) and indicated that some phasins

  14. The F-actin modifier villin regulates insulin granule dynamics and exocytosis downstream of islet cell autoantigen 512

    Directory of Open Access Journals (Sweden)

    Hassan Mziaut

    2016-08-01

    Full Text Available Objective: Insulin release from pancreatic islet β cells should be tightly controlled to avoid hypoglycemia and insulin resistance. The cortical actin cytoskeleton is a gate for regulated exocytosis of insulin secretory granules (SGs by restricting their mobility and access to the plasma membrane. Prior studies suggest that SGs interact with F-actin through their transmembrane cargo islet cell autoantigen 512 (Ica512 (also known as islet antigen 2/Ptprn. Here we investigated how Ica512 modulates SG trafficking and exocytosis. Methods: Transcriptomic changes in Ica512−/− mouse islets were analyzed. Imaging as well as biophysical and biochemical methods were used to validate if and how the Ica512-regulated gene villin modulates insulin secretion in mouse islets and insulinoma cells. Results: The F-actin modifier villin was consistently downregulated in Ica512−/− mouse islets and in Ica512-depleted insulinoma cells. Villin was enriched at the cell cortex of β cells and dispersed villin−/− islet cells were less round and less deformable. Basal mobility of SGs in villin-depleted cells was enhanced. Moreover, in cells depleted either of villin or Ica512 F-actin cages restraining cortical SGs were enlarged, basal secretion was increased while glucose-stimulated insulin release was blunted. The latter changes were reverted by overexpressing villin in Ica512-depleted cells, but not vice versa. Conclusion: Our findings show that villin controls the size of the F-actin cages restricting SGs and, thus, regulates their dynamics and availability for exocytosis. Evidence that villin acts downstream of Ica512 also indicates that SGs directly influence the remodeling properties of the cortical actin cytoskeleton for tight control of insulin secretion. Keywords: F-actin, Granules, Ica512, Insulin, Secretion, Villin

  15. Structure of gels layers with cells

    Science.gov (United States)

    Pokusaev, B. G.; Karlov, S. P.; Vyazmin, A. V.; Nekrasov, D. A.; Zakharov, N. S.; Khramtsov, D. P.; Skladnev, D. A.; Tyupa, D. V.

    2017-11-01

    The structure of two-layer agarose gels containing yeast cells is investigated experimentally by spectrometry, to shed a light on the theoretical foundations for the development of bioreactors by the method of 3D bioprinting. Due to division, cells overcome the layer of the dispersion phase separating successively applied layers of the agarose gel. However a gel layer of 100 μm thick with a high concentration of silver nanoparticles completely excludes the infiltration of yeast cells through it. A special sort of agarose is suggested where the concentration of silver nanoparticles formed by cells from salt of silver can serve as an indicator of the state of the yeast cells in the volume of the gel.

  16. Distribution Profile of Inositol 1,4,5-Trisphosphate Receptor/Ca2+ Channels in α and β Cells of Pancreas: Dominant Localization in Secretory Granules and Common Error in Identification of Secretory Granule Membranes.

    Science.gov (United States)

    Hur, Yong Suk; Yoo, Seung Hyun

    2015-01-01

    The α and β cells of pancreatic islet release important hormones in response to intracellular Ca increases that result from Ca releases through the inositol 1,4,5-trisphoshate receptor (IP3R)/Ca channels. Yet no systematic studies on distribution of IP3R/Ca channels have been done, prompting us to investigate the distribution of all 3 IP3R isoforms. Immunogold electron microscopy was performed to determine the presence and the relative concentrations of all 3 IP3R isoforms in 2 major organelles secretory granules (SGs) and the endoplasmic reticulum of α and β cells of rat pancreas. All 3 IP3R isoforms were present in SG membranes of both cells, and the IP3R concentrations in SGs were ∼2-fold higher than those in the endoplasmic reticulum. Moreover, large halos shown in the electron microscope images of insulin-containing SGs of β cells were gap spaces that resulted from separation of granule membranes from the surrounding cytoplasm. These results strongly suggest the important roles of SGs in IP3-induced, Ca-dependent regulatory secretory pathway in pancreas. Moreover, the accurate location of SG membranes of β cells was further confirmed by the location of another integral membrane protein synaptotagmin V and of membrane phospholipid PI(4,5)P2.

  17. Zebrafish P54 RNA helicases are cytoplasmic granule residents that are required for development and stress resilience

    Directory of Open Access Journals (Sweden)

    Cecilia Zampedri

    2016-10-01

    Full Text Available Stress granules are cytoplasmic foci that directly respond to the protein synthesis status of the cell. Various environmental insults, such as oxidative stress or extreme heat, block protein synthesis; consequently, mRNA will stall in translation, and stress granules will immediately form and become enriched with mRNAs. P54 DEAD box RNA helicases are components of RNA granules such as P-bodies and stress granules. We studied the expression, in cytoplasmic foci, of both zebrafish P54 RNA helicases (P54a and P54b during development and found that they are expressed in cytoplasmic granules under both normal conditions and stress conditions. In zebrafish embryos exposed to heat shock, some proportion of P54a and P54b helicases move to larger granules that exhibit the properties of genuine stress granules. Knockdown of P54a and/or P54b in zebrafish embryos produces developmental abnormalities restricted to the posterior trunk; further, these embryos do not form stress granules, and their survival upon exposure to heat-shock conditions is compromised. Our observations fit the model that cells lacking stress granules have no resilience or ability to recover once the stress has ended, indicating that stress granules play an essential role in the way organisms adapt to a changing environment.

  18. Rab3A, a possible marker of cortical granules, participates in cortical granule exocytosis in mouse eggs

    Energy Technology Data Exchange (ETDEWEB)

    Bello, Oscar Daniel; Cappa, Andrea Isabel; Paola, Matilde de; Zanetti, María Natalia [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Fukuda, Mitsunori [Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Fissore, Rafael A. [Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003 (United States); Mayorga, Luis S. [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Michaut, Marcela A., E-mail: mmichaut@gmail.com [Instituto de Histología y Embriología, CONICET – Universidad Nacional de Cuyo, Av. Libertador 80, 5500 Mendoza (Argentina); Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo (Argentina)

    2016-09-10

    Fusion of cortical granules with the oocyte plasma membrane is the most significant event to prevent polyspermy. This particular exocytosis, also known as cortical reaction, is regulated by calcium and its molecular mechanism is still not known. Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in calcium-dependent exocytosis and is not yet clear whether Rab3A participates in cortical granules exocytosis. Here, we examine the involvement of Rab3A in the physiology of cortical granules, particularly, in their distribution during oocyte maturation and activation, and their participation in membrane fusion during cortical granule exocytosis. Immunofluorescence and Western blot analysis showed that Rab3A and cortical granules have a similar migration pattern during oocyte maturation, and that Rab3A is no longer detected after cortical granule exocytosis. These results suggested that Rab3A might be a marker of cortical granules. Overexpression of EGFP-Rab3A colocalized with cortical granules with a Pearson correlation coefficient of +0.967, indicating that Rab3A and cortical granules have almost a perfect colocalization in the egg cortical region. Using a functional assay, we demonstrated that microinjection of recombinant, prenylated and active GST-Rab3A triggered cortical granule exocytosis, indicating that Rab3A has an active role in this secretory pathway. To confirm this active role, we inhibited the function of endogenous Rab3A by microinjecting a polyclonal antibody raised against Rab3A prior to parthenogenetic activation. Our results showed that Rab3A antibody microinjection abolished cortical granule exocytosis in parthenogenetically activated oocytes. Altogether, our findings confirm that Rab3A might function as a marker of cortical granules and participates in cortical granule exocytosis in mouse eggs. - Highlights: • Rab3A has a similar migration pattern to cortical granules in mouse oocytes. • Rab3A can be a marker of

  19. Phenotypic properties and microbial diversity of methanogenic granules from a full-scale upflow anaerobic sludge bed reactor treating brewery wastewater.

    Science.gov (United States)

    Díaz, Emiliano E; Stams, Alfons J M; Amils, Ricardo; Sanz, José L

    2006-07-01

    Methanogenic granules from an anaerobic bioreactor that treated wastewater of a beer brewery consisted of different morphological types of granules. In this study, the microbial compositions of the different granules were analyzed by molecular microbiological techniques: cloning, denaturing gradient gel electrophoresis and fluorescent in situ hybridization (FISH), and scanning and transmission electron microscopy. We propose here that the different types of granules reflect the different stages in the life cycle of granules. Young granules were small, black, and compact and harbored active cells. Gray granules were the most abundant granules. These granules have a multilayer structure with channels and void areas. The core was composed of dead or starving cells with low activity. The brown granules, which were the largest granules, showed a loose and amorphous structure with big channels that resulted in fractured zones and corresponded to the older granules. Firmicutes (as determined by FISH) and Nitrospira and Deferribacteres (as determined by cloning and sequencing) were the predominant Bacteria. Remarkably, Firmicutes could not be detected in the brown granules. The methanogenic Archaea identified were Methanosaeta concilii (70 to 90% by FISH and cloning), Methanosarcina mazei, and Methanospirillum spp. The phenotypic appearance of the granules reflected the physiological condition of the granules. This may be valuable to easily select appropriate seed sludges to start up other reactors.

  20. Common spectrum of polypeptides occurs in secretion granule membranes of different exocrine glands

    International Nuclear Information System (INIS)

    Cameron, R.S.; Cameron, P.L.; Castle, J.D.

    1986-01-01

    A highly purified membrane preparation from rat parotid secretion granules has been used as a comparative probe to examine the extent of compositional overlap in granule membranes of three other exocrine secretory tissues - pancreatic, lacrimal, and submandibular - from several standpoints. First, indirect immunofluorescent studies using a polyclonal polyspecific anti-parotid granule membrane antiserum has indicated a selective staining of granule membrane profiles in all acinar cells of all tissues. Second, highly purified granule membrane subfractions have been isolated from each exocrine tissue; comparative two-dimensional (isoelectric focusing; SDS) PAGE of radioiodinated granule membranes has identified 10-15 polypeptides of identical pI and apparent molecular mass. These species are likely to be integral membrane components since they are not extracted by either saponin-sodium sulfate or sodium carbonate (pH 11.5) treatments, and they do not have counterparts in the granule content. Finally, the identity among selected parotid and pancreatic radioiodinated granule membrane polypeptides has been documented using two-dimensional peptide mapping of chymotryptic and tryptic digests. These findings clearly indicate that exocrine secretory granules, irrespective of the nature of stored secretion, comprise a type of vesicular carrier with a common (and probably refined) membrane composition. Conceivably, the polypeptides identified carry out general functions related to exocrine secretion

  1. Interactive effects involving different classes of excitatory amino acid receptors and the survival of cerebellar granule cells in culture

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1990-01-01

    Differentiating granule cells develop survival requirements in culture which can be met by treatment with high K+ or N-methyl-D-aspartate (NMDA) and, according to our recent findings, also with low concentrations of kainic acid (KA, 50 microM). We have now attempted to elucidate the mechanism(s) ...

  2. Snapin mediates insulin secretory granule docking, but not trans-SNARE complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Somanath, Sangeeta [Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT (United Kingdom); Partridge, Christopher J. [Diabetes Research Laboratories, Oxford Centre for Diabetes, Endocrinology and Churchill Hospital, University of Oxford, Oxford, OX3 7LJ (United Kingdom); Marshall, Catriona [Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT (United Kingdom); Rowe, Tony [CSL Limited, 45 Poplar Road, Parkville, Victoria 3052 (Australia); Turner, Mark D., E-mail: mark.turner@ntu.ac.uk [Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS (United Kingdom)

    2016-04-29

    Secretory granule exocytosis is a tightly regulated process requiring granule targeting, tethering, priming, and membrane fusion. At the heart of this process is the SNARE complex, which drives fusion through a coiled-coil zippering effect mediated by the granule v-SNARE protein, VAMP2, and the plasma membrane t-SNAREs, SNAP-25 and syntaxin-1A. Here we demonstrate that in pancreatic β-cells the SNAP-25 accessory protein, snapin, C-terminal H2 domain binds SNAP-25 through its N-terminal Sn-1 domain. Interestingly whilst snapin binds SNAP-25, there is only modest binding of this complex with syntaxin-1A under resting conditions. Instead synataxin-1A appears to be recruited in response to secretory stimulation. These results indicate that snapin plays a role in tethering insulin granules to the plasma membrane through coiled coil interaction of snapin with SNAP-25, with full granule fusion competency only resulting after subsequent syntaxin-1A recruitment triggered by secretory stimulation. - Highlights: • Snapin mediates granule docking. • Snapin binds SNAP-25. • SNARE complex forms downstream.

  3. Snapin mediates insulin secretory granule docking, but not trans-SNARE complex formation

    International Nuclear Information System (INIS)

    Somanath, Sangeeta; Partridge, Christopher J.; Marshall, Catriona; Rowe, Tony; Turner, Mark D.

    2016-01-01

    Secretory granule exocytosis is a tightly regulated process requiring granule targeting, tethering, priming, and membrane fusion. At the heart of this process is the SNARE complex, which drives fusion through a coiled-coil zippering effect mediated by the granule v-SNARE protein, VAMP2, and the plasma membrane t-SNAREs, SNAP-25 and syntaxin-1A. Here we demonstrate that in pancreatic β-cells the SNAP-25 accessory protein, snapin, C-terminal H2 domain binds SNAP-25 through its N-terminal Sn-1 domain. Interestingly whilst snapin binds SNAP-25, there is only modest binding of this complex with syntaxin-1A under resting conditions. Instead synataxin-1A appears to be recruited in response to secretory stimulation. These results indicate that snapin plays a role in tethering insulin granules to the plasma membrane through coiled coil interaction of snapin with SNAP-25, with full granule fusion competency only resulting after subsequent syntaxin-1A recruitment triggered by secretory stimulation. - Highlights: • Snapin mediates granule docking. • Snapin binds SNAP-25. • SNARE complex forms downstream.

  4. In vitro atrazine-exposure inhibits human natural killer cell lytic granule release

    International Nuclear Information System (INIS)

    Rowe, Alexander M.; Brundage, Kathleen M.; Barnett, John B.

    2007-01-01

    The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine exposure. These assays demonstrated no significant decrease in the level of target cell binding. However, the levels of NK intracellular lytic protein retained and the amount of lytic protein released were assessed following a 4-h incubation with K562 target cells. The relative level of intracellular lytic protein was 25-50% higher, and the amount of lytic protein released was 55-65% less in atrazine-treated cells than vehicle-treated cells following incubation with the target cells. These results indicate that ATR exposure inhibits the ability of NK cells to lyse target cells by blocking lytic granule release without affecting the ability of the NK cell to form stable conjugates with target cells

  5. The endocytic pathways of a secretory granule membrane protein in HEK293 cells: PAM and EGF traverse a dynamic multivesicular body network together.

    Science.gov (United States)

    Bäck, Nils; Kanerva, Kristiina; Kurutihalli, Vishwanatha; Yanik, Andrew; Ikonen, Elina; Mains, Richard E; Eipper, Betty A

    2017-08-01

    Peptidylglycine α-amidating monooxygenase (PAM) is highly expressed in neurons and endocrine cells, where it catalyzes one of the final steps in the biosynthesis of bioactive peptides. PAM is also expressed in unicellular organisms such as Chlamydomonas reinhardtii, which do not store peptides in secretory granules. As for other granule membrane proteins, PAM is retrieved from the cell surface and returned to the trans-Golgi network. This pathway involves regulated entry of PAM into multivesicular body intralumenal vesicles (ILVs). The aim of this study was defining the endocytic pathways utilized by PAM in cells that do not store secretory products in granules. Using stably transfected HEK293 cells, endocytic trafficking of PAM was compared to that of the mannose 6-phosphate (MPR) and EGF (EGFR) receptors, established markers for the endosome to trans-Golgi network and degradative pathways, respectively. As in neuroendocrine cells, PAM internalized by HEK293 cells accumulated in the trans-Golgi network. Based on surface biotinylation, >70% of the PAM on the cell surface was recovered intact after a 4h chase and soluble, bifunctional PAM was produced. Endosomes containing PAM generally contained both EGFR and MPR and ultrastructural analysis confirmed that all three cargos accumulated in ILVs. PAM containing multivesicular bodies made frequent dynamic tubular contacts with younger and older multivesicular bodies. Frequent dynamic contacts were observed between lysosomes and PAM containing early endosomes and multivesicular bodies. The ancient ability of PAM to localize to ciliary membranes, which release bioactive ectosomes, may be related to its ability to accumulate in ILVs and exosomes. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Cell-type-specific expression of NFIX in the developing and adult cerebellum.

    Science.gov (United States)

    Fraser, James; Essebier, Alexandra; Gronostajski, Richard M; Boden, Mikael; Wainwright, Brandon J; Harvey, Tracey J; Piper, Michael

    2017-07-01

    Transcription factors from the nuclear factor one (NFI) family have been shown to play a central role in regulating neural progenitor cell differentiation within the embryonic and post-natal brain. NFIA and NFIB, for instance, promote the differentiation and functional maturation of granule neurons within the cerebellum. Mice lacking Nfix exhibit delays in the development of neuronal and glial lineages within the cerebellum, but the cell-type-specific expression of this transcription factor remains undefined. Here, we examined the expression of NFIX, together with various cell-type-specific markers, within the developing and adult cerebellum using both chromogenic immunohistochemistry and co-immunofluorescence labelling and confocal microscopy. In embryos, NFIX was expressed by progenitor cells within the rhombic lip and ventricular zone. After birth, progenitor cells within the external granule layer, as well as migrating and mature granule neurons, expressed NFIX. Within the adult cerebellum, NFIX displayed a broad expression profile, and was evident within granule cells, Bergmann glia, and interneurons, but not within Purkinje neurons. Furthermore, transcriptomic profiling of cerebellar granule neuron progenitor cells showed that multiple splice variants of Nfix are expressed within this germinal zone of the post-natal brain. Collectively, these data suggest that NFIX plays a role in regulating progenitor cell biology within the embryonic and post-natal cerebellum, as well as an ongoing role within multiple neuronal and glial populations within the adult cerebellum.

  7. Plant RNA Regulatory Network and RNA Granules in Virus Infection

    Directory of Open Access Journals (Sweden)

    Kristiina Mäkinen

    2017-12-01

    Full Text Available Regulation of post-transcriptional gene expression on mRNA level in eukaryotic cells includes translocation, translation, translational repression, storage, mRNA decay, RNA silencing, and nonsense-mediated decay. These processes are associated with various RNA-binding proteins and cytoplasmic ribonucleoprotein complexes many of which are conserved across eukaryotes. Microscopically visible aggregations formed by ribonucleoprotein complexes are termed RNA granules. Stress granules where the translationally inactive mRNAs are stored and processing bodies where mRNA decay may occur present the most studied RNA granule types. Diverse RNP-granules are increasingly being assigned important roles in viral infections. Although the majority of the molecular level studies on the role of RNA granules in viral translation and replication have been conducted in mammalian systems, some studies link also plant virus infection to RNA granules. An increasing body of evidence indicates that plant viruses require components of stress granules and processing bodies for their replication and translation, but how extensively the cellular mRNA regulatory network is utilized by plant viruses has remained largely enigmatic. Antiviral RNA silencing, which is an important regulator of viral RNA stability and expression in plants, is commonly counteracted by viral suppressors of RNA silencing. Some of the RNA silencing suppressors localize to cellular RNA granules and have been proposed to carry out their suppression functions there. Moreover, plant nucleotide-binding leucine-rich repeat protein-mediated virus resistance has been linked to enhanced processing body formation and translational repression of viral RNA. Many interesting questions relate to how the pathways of antiviral RNA silencing leading to viral RNA degradation and/or repression of translation, suppression of RNA silencing and viral RNA translation converge in plants and how different RNA granules and

  8. Plant RNA Regulatory Network and RNA Granules in Virus Infection.

    Science.gov (United States)

    Mäkinen, Kristiina; Lõhmus, Andres; Pollari, Maija

    2017-01-01

    Regulation of post-transcriptional gene expression on mRNA level in eukaryotic cells includes translocation, translation, translational repression, storage, mRNA decay, RNA silencing, and nonsense-mediated decay. These processes are associated with various RNA-binding proteins and cytoplasmic ribonucleoprotein complexes many of which are conserved across eukaryotes. Microscopically visible aggregations formed by ribonucleoprotein complexes are termed RNA granules. Stress granules where the translationally inactive mRNAs are stored and processing bodies where mRNA decay may occur present the most studied RNA granule types. Diverse RNP-granules are increasingly being assigned important roles in viral infections. Although the majority of the molecular level studies on the role of RNA granules in viral translation and replication have been conducted in mammalian systems, some studies link also plant virus infection to RNA granules. An increasing body of evidence indicates that plant viruses require components of stress granules and processing bodies for their replication and translation, but how extensively the cellular mRNA regulatory network is utilized by plant viruses has remained largely enigmatic. Antiviral RNA silencing, which is an important regulator of viral RNA stability and expression in plants, is commonly counteracted by viral suppressors of RNA silencing. Some of the RNA silencing suppressors localize to cellular RNA granules and have been proposed to carry out their suppression functions there. Moreover, plant nucleotide-binding leucine-rich repeat protein-mediated virus resistance has been linked to enhanced processing body formation and translational repression of viral RNA. Many interesting questions relate to how the pathways of antiviral RNA silencing leading to viral RNA degradation and/or repression of translation, suppression of RNA silencing and viral RNA translation converge in plants and how different RNA granules and their individual

  9. Morphological study of the solar granulation. Pt. 2

    International Nuclear Information System (INIS)

    Kawaguchi, I.

    1980-01-01

    A time sequence of granulation images of 46 min long has allowed us to make a detailed study of the evolution of granules in an area of approximately 17 x 17 on the solar surface; It is found that the granules evolve by repeated fragmentation into smaller granules or merging with adjacent ones and that there are few granules which appear in the intergranular lanes as new granules (Table III). The statistical nature of granules is as follows: (1) A family of granules is defined as a group of granules produced from a single granule by fragmentation or merging. The lifetime is estimated for single granules and for families of granules. The lifetime shows a close correlation with the maximum size of a single granule or with that of the largest granule belonging to a family (Figures 5 and 7). (2) The smaller the size, the more probably a granule will disappear without further fragmentation or merging. The granule whose size is larger than 2 will certainly split or merge as the next evolutional step (Table IV.). (orig.)

  10. Competition from newborn granule cells does not drive axonal retraction of silenced old granule cells in the adult hippocampus

    Directory of Open Access Journals (Sweden)

    Carla M Lopez

    2012-11-01

    Full Text Available In the developing nervous system synaptic refinement, typified by the neuromuscular junction where supernumerary connections are eliminated by axon retraction leaving the postsynaptic target innervated by a single dominant input, critically regulates neuronal circuit formation. Whether such competition based pruning continues in established circuits of mature animals remains unknown. This question is particularly relevant in the context of adult neurogenesis where newborn cells must integrate into preexisting circuits, and thus, potentially compete with functionally mature synapses to gain access to their postsynaptic targets. The hippocampus plays an important role in memory formation/retrieval and the dentate gyrus subfield (DG exhibits continued neurogenesis into adulthood. Therefore, this region contains both mature granule cells (old GCs and immature recently born GCs that are generated throughout adult life (young GCs, providing a neurogenic niche model to examine the role of competition in synaptic refinement. Recent work from an independent group in developing animals indicated that embryonically/early postnatal generated GCs placed at a competitive disadvantage by selective expression of tetanus toxin (TeTX to prevent synaptic release rapidly retracted their axons, and that this retraction was driven by competition from newborn GCs lacking TeTX. In contrast, following 3-6 months of selective TeTX expression in old GCs of adult mice we did not observe any evidence of axon retraction. Indeed ultrastructural analyses indicated that the terminals of silenced GCs even maintained synaptic contact with their postsynaptic targets. Furthermore, we did not detect any significant differences in the electrophysiological properties between old GCs in control and TeTX conditions. Thus, our data demonstrate a remarkable stability in the face of a relatively prolonged period of altered synaptic competition between two populations of neurons within the

  11. Investigation of Physicochemical Drug Properties to Prepare Fine Globular Granules Composed of Only Drug Substance in Fluidized Bed Rotor Granulation.

    Science.gov (United States)

    Mise, Ryohei; Iwao, Yasunori; Kimura, Shin-Ichiro; Osugi, Yukiko; Noguchi, Shuji; Itai, Shigeru

    2015-01-01

    The effect of some drug properties (wettability and particle size distribution) on granule properties (mean particle size, particle size distribution, sphericity, and granule strength) were investigated in a high (>97%) drug-loading formulation using fluidized bed rotor granulation. Three drugs: acetaminophen (APAP); ibuprofen (IBU); and ethenzamide (ETZ) were used as model drugs based on their differences in wettability and particle size distribution. Granules with mean particle sizes of 100-200 µm and a narrow particle size distribution (PSD) could be prepared regardless of the drug used. IBU and ETZ granules showed a higher sphericity than APAP granules, while APAP and ETZ granules exhibited higher granule strength than IBU. The relationship between drug and granule properties suggested that the wettability and the PSD of the drugs were critical parameters affecting sphericity and granule strength, respectively. Furthermore, the dissolution profiles of granules prepared with poorly water-soluble drugs (IBU and ETZ) showed a rapid release (80% release in 20 min) because of the improved wettability with granulation. The present study demonstrated for the first time that fluidized bed rotor granulation can prepare high drug-loaded (>97%) globular granules with a mean particle size of less than 200 µm and the relationship between physicochemical drug properties and the properties of the granules obtained could be readily determined, indicating the potential for further application of this methodology to various drugs.

  12. Multimodal approach to characterization of hydrophilic matrices manufactured by wet and dry granulation or direct compression methods.

    Science.gov (United States)

    Kulinowski, Piotr; Woyna-Orlewicz, Krzysztof; Obrał, Jadwiga; Rappen, Gerd-Martin; Haznar-Garbacz, Dorota; Węglarz, Władysław P; Jachowicz, Renata; Wyszogrodzka, Gabriela; Klaja, Jolanta; Dorożyński, Przemysław P

    2016-02-29

    The purpose of the research was to investigate the effect of the manufacturing process of the controlled release hydrophilic matrix tablets on their hydration behavior, internal structure and drug release. Direct compression (DC) quetiapine hemifumarate matrices and matrices made of powders obtained by dry granulation (DG) and high shear wet granulation (HS) were prepared. They had the same quantitative composition and they were evaluated using X-ray microtomography, magnetic resonance imaging and biorelevant stress test dissolution. Principal results concerned matrices after 2 h of hydration: (i) layered structure of the DC and DG hydrated tablets with magnetic resonance image intensity decreasing towards the center of the matrix was observed, while in HS matrices layer of lower intensity appeared in the middle of hydrated part; (ii) the DC and DG tablets retained their core and consequently exhibited higher resistance to the physiological stresses during simulation of small intestinal passage than HS formulation. Comparing to DC, HS granulation changed properties of the matrix in terms of hydration pattern and resistance to stress in biorelevant dissolution apparatus. Dry granulation did not change these properties-similar hydration pattern and dissolution in biorelevant conditions were observed for DC and DG matrices. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. PD-1 blocks lytic granule polarization with concomitant impairment of integrin outside-in signaling in the natural killer cell immunological synapse.

    Science.gov (United States)

    Huang, Yu; Chen, Zhiying; Jang, Joon Hee; Baig, Mirza S; Bertolet, Grant; Schroeder, Casey; Huang, Shengjian; Hu, Qian; Zhao, Yong; Lewis, Dorothy E; Qin, Lidong; Zhu, Michael Xi; Liu, Dongfang

    2018-04-18

    The inhibitory receptor programmed cell death protein 1 (PD-1) is upregulated on a variety of immune cells, including natural killer (NK) cells, during chronic viral infection and tumorigenesis. Blockade of PD-1 or its ligands produces durable clinical responses with tolerable side effects in patients with a broad spectrum of cancers. However, the underlying molecular mechanisms of how PD-1 regulates NK cell function remain poorly characterized. We sought to determine the effect of PD-1 signaling on NK cells. PD-1 was overexpressed in CD16-KHYG-1 (a human NK cell line with both antibody-dependent cellular cytotoxicity through CD16 and natural cytotoxicity through NKG2D) cells and stimulated by exposing the cells to NK-sensitive target cells expressing programmed death ligand 1 (PD-L1). PD-1 engagement by PD-L1 specifically blocked NK cell-mediated cytotoxicity without interfering with the conjugation between NK cells and target cells. Further examination showed that PD-1 signaling blocked lytic granule polarization in NK cells, which was accompanied by failure of integrin-linked kinase, a key molecule in the integrin outside-in signaling pathway, to accumulate in the immunological synapse after NK-target cell conjugation. Our results suggest that NK cell cytotoxicity is inhibited by PD-1 engagement, which blocks lytic granule polarization to the NK cell immunological synapse with concomitant impairment of integrin outside-in signaling. This study provides novel mechanistic insights into how PD-1 inhibition disrupts NK cell function. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Comparative evaluation of different calcium phosphate-based bone graft granules - an in vitro study with osteoblast-like cells.

    Science.gov (United States)

    Bernhardt, Anne; Lode, Anja; Peters, Fabian; Gelinsky, Michael

    2013-04-01

    Granule-shaped calcium phosphate-based bone graft materials are often required for bone regeneration especially in implant dentistry. Two newly developed bone graft materials are Ceracell(®) , an open-celled highly porous bioceramic from β-tricalcium phosphate (β-TCP) under addition of bioglass and Osseolive(®) , an open porous glass ceramic with the general formula Ca2 KNa(PO4 )2 . The goal of this study was to characterize different modifications of the two bone graft materials in vitro in comparison to already established ceramic bone grafts Cerasorb M(®) , NanoBone(®) and BONIT Matrix(®) . Adhesion and proliferation of SaOS-2 osteoblast-like cells were evaluated quantitatively by determining DNA content and lactate dehydrogenase (LDH) activity and qualitatively by scanning electron microscopy (SEM). In addition, MTT cell-vitality staining was applied to confirm the attachment of viable cells to the different materials. Osteogenic differentiation was evaluated by measurement of alkaline phosphatase (ALP) activity as well as gene expression analysis of osteogenic markers using reverse transcriptase PCR. DNA content and LDH activity revealed good cell attachment and proliferation for Ceracell and Cerasorb M. When pre-incubated with cell-culture medium, also Osseolive showed good cell attachment and proliferation. Attachment and proliferation of osteoblast-like cells on NanoBone and BONIT Matrix was very low, even after pre-incubation with cell-culture medium. Specific ALP activity on Ceracell(®) , Osseolive (®) and Cerasorb M(®) increased with time and expression of bone-related genes ALP, osteonectin, osteopontin and bone sialoprotein II was demonstrated. Ceracell as well as Osseolive granules support proliferation and osteogenic differentiation in vitro and may be promising candidates for in vivo applications. © 2011 John Wiley & Sons A/S.

  15. Roles of EDTA washing and Ca{sup 2+} regulation on the restoration of anammox granules inhibited by copper(II)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zheng-Zhe; Cheng, Ya-Fei; Zhou, Yu-Huang; Buayi, Xiemuguli [Department of Environmental Science and Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou 310036 (China); Jin, Ren-Cun, E-mail: jrczju@aliyun.com [Department of Environmental Science and Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, Hangzhou Normal University, Hangzhou 310036 (China)

    2016-01-15

    Highlights: • 80.5% of the Cu in anammox granules was introduced via adsorption. • Cu(II) internalized on/into AnAOB cells plays a crucial role in toxicity. • EDTA washing contributes to the detoxification of anammox granules. • Ca{sup 2+} can stimulate the re-growth of damaged anammox consortium. - Abstract: We investigated the feasibility of using ethylene diamine tetraacetic acid (EDTA) washing followed by Ca{sup 2+} enhancement for the recovery of anammox reactors inhibited by Cu(II). Kinetic experiments and batch activity assays were employed to determine the optimal concentration of EDTA and washing time; and the performance and physiological dynamics were tracked by continuous-flow monitoring to evaluate the long-term effects. The two-step desorption process revealed that the Cu in anammox granules was primarily introduced via adsorption (approximately, 80.5%), and the portion of Cu in the dispersible layer was predominant (accounting for 71.1%). Afterwards, the Cu internalized in the cells (approximately, 14.7%) could diffuse out of the cells and be gradually washed out of the reactor over the next 20 days. The Ca{sup 2+} addition that followed led to an accelerated nitrogen removal rate recovery slope (0.1491 kgN m{sup −3} d{sup −2}) and a normal biomass growth rate (0.054 d{sup −1}). The nitrogen removal rate returned to normal levels within 90 days and gradual improvements in granular characteristics were also achieved. Therefore, this study provides a new insight that externally removing the adsorbed heavy metals followed by internally repairing the metabolic system may represent an optimal restoration strategy for anammox consortium damaged by heavy metals.

  16. Intracellular production of hydrogels and synthetic RNA granules by multivalent molecular interactions

    Science.gov (United States)

    Nakamura, Hideki; Lee, Albert A.; Afshar, Ali Sobhi; Watanabe, Shigeki; Rho, Elmer; Razavi, Shiva; Suarez, Allister; Lin, Yu-Chun; Tanigawa, Makoto; Huang, Brian; Derose, Robert; Bobb, Diana; Hong, William; Gabelli, Sandra B.; Goutsias, John; Inoue, Takanari

    2018-01-01

    Some protein components of intracellular non-membrane-bound entities, such as RNA granules, are known to form hydrogels in vitro. The physico-chemical properties and functional role of these intracellular hydrogels are difficult to study, primarily due to technical challenges in probing these materials in situ. Here, we present iPOLYMER, a strategy for a rapid induction of protein-based hydrogels inside living cells that explores the chemically inducible dimerization paradigm. Biochemical and biophysical characterizations aided by computational modelling show that the polymer network formed in the cytosol resembles a physiological hydrogel-like entity that acts as a size-dependent molecular sieve. We functionalize these polymers with RNA-binding motifs that sequester polyadenine-containing nucleotides to synthetically mimic RNA granules. These results show that iPOLYMER can be used to synthetically reconstitute the nucleation of biologically functional entities, including RNA granules in intact cells.

  17. Granule Associated Serine Proteases of Hematopoietic Cells - An Analysis of Their Appearance and Diversification during Vertebrate Evolution.

    Directory of Open Access Journals (Sweden)

    Srinivas Akula

    Full Text Available Serine proteases are among the most abundant granule constituents of several hematopoietic cell lineages including mast cells, neutrophils, cytotoxic T cells and NK cells. These proteases are stored in their active form in the cytoplasmic granules and in mammals are encoded from four different chromosomal loci: the chymase locus, the met-ase locus, the T cell tryptase and the mast cell tryptase locus. In order to study their appearance during vertebrate evolution we have performed a bioinformatic analysis of related genes and gene loci from a large panel of metazoan animals from sea urchins to placental mammals for three of these loci: the chymase, met-ase and granzyme A/K loci. Genes related to mammalian granzymes A and K were the most well conserved and could be traced as far back to cartilaginous fish. Here, the granzyme A and K genes were found in essentially the same chromosomal location from sharks to humans. However in sharks, no genes clearly identifiable as members of the chymase or met-ase loci were found. A selection of these genes seemed to appear with bony fish, but sometimes in other loci. Genes related to mammalian met-ase locus genes were found in bony fish. Here, the most well conserved member was complement factor D. However, genes distantly related to the neutrophil proteases were also identified in this locus in several bony fish species, indicating that this locus is also old and appeared at the base of bony fish. In fish, a few of the chymase locus-related genes were found in a locus with bordering genes other than the mammalian chymase locus and some were found in the fish met-ase locus. This indicates that a convergent evolution rather than divergent evolution has resulted in chymase locus-related genes in bony fish.

  18. Breakage and drying behaviour of granules in a continuous fluid bed dryer: Influence of process parameters and wet granule transfer.

    Science.gov (United States)

    De Leersnyder, F; Vanhoorne, V; Bekaert, H; Vercruysse, J; Ghijs, M; Bostijn, N; Verstraeten, M; Cappuyns, P; Van Assche, I; Vander Heyden, Y; Ziemons, E; Remon, J P; Nopens, I; Vervaet, C; De Beer, T

    2018-03-30

    Although twin screw granulation has already been widely studied in recent years, only few studies addressed the subsequent continuous drying which is required after wet granulation and still suffers from a lack of detailed understanding. The latter is important for optimisation and control and, hence, a cost-effective practical implementation. Therefore, the aim of the current study is to increase understanding of the drying kinetics and the breakage and attrition phenomena during fluid bed drying after continuous twin screw granulation. Experiments were performed on a continuous manufacturing line consisting of a twin-screw granulator, a six-segmented fluid bed dryer, a mill, a lubricant blender and a tablet press. Granulation parameters were fixed in order to only examine the effect of drying parameters (filling time, drying time, air flow, drying air temperature) on the size distribution and moisture content of granules (both of the entire granulate and of size fractions). The wet granules were transferred either gravimetrically or pneumatically from the granulator exit to the fluid bed dryer. After a certain drying time, the moisture content reached an equilibrium. This drying time was found to depend on the applied airflow, drying air temperature and filling time. The moisture content of the granules decreased with an increasing drying time, airflow and drying temperature. Although smaller granules dried faster, the multimodal particle size distribution of the granules did not compromise uniform drying of the granules when the target moisture content was achieved. Extensive breakage of granules was observed during drying. Especially wet granules were prone to breakage and attrition during pneumatic transport, either in the wet transfer line or in the dry transfer line. Breakage and attrition of granules during transport and drying should be anticipated early on during process and formulation development by performing integrated experiments on the granulator

  19. The mysterious case of the C. elegans gut granule: death fluorescence, anthranilic acid and the kynurenine pathway

    Directory of Open Access Journals (Sweden)

    David eGems

    2013-08-01

    Full Text Available Despite decades of research on the nematode C. elegans, it still contains many hidden secrets. One such is the function of the prominent organelles known as gut granules, which are numerous in the intestinal cells of nematodes throughout the suborder Rhabditina. A striking feature of gut granules is the blue fluorescence that they emit under ultraviolet light. Clues to gut granule function include their acidic interior and capacity for endocytosis, both lysosome-like features (though gut granules are much bigger than normal lysosomes. This and the fluorescent material within identify gut granules as lysosome-like organelles (LROs, akin to pigment-containing melanosomes in mammals and eye pigment granules in Drosophila. Thus, the identity of the blue fluorescent substance could provide a key to understanding gut granule function.

  20. Layer-by-layer self-assembled active electrodes for hybrid photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Kniprath, Rolf

    2008-11-18

    Solar cells based on thin organic/inorganic heterofilms are currently in the focus of research, since they represent promising candidates for cost-efficient photovoltaic energy conversion. In this type of cells, charges are separated at a heterointerface between dissimilar electrode materials. These materials either absorb light themselves, or they are sensitized by an additional absorber layer at the interface. The present work investigates photovoltaic cells which are composed of nanoporous TiO{sub 2} combined with conjugated polymers and semiconductor quantum dots (QDs). The method of layer-by-layer self-assembly of oppositely charged nanoparticles and polymers is used for the fabrication of such devices. This method allows to fabricate nanoporous films with controlled thicknesses in the range of a few hundred nanometers to several micrometers. Investigations with scanning electron (SEM) and atomic force microscopy (AFM) reveal that the surface morphology of the films depends only on the chemical structure of the polyions used in the production process, and not on their molecular weight or conformation. From dye adsorption at the internal surface of the electrodes one can estimate that the internal surface area of a 1 {mu}m thick film is up to 120 times larger than the projection plane. X-ray photoelectron spectroscopy (XPS) is used to demonstrate that during the layer-by-layer self-assembly at least 40% of the TiO{sub 2} surface is covered with polymers. This feature allows to incorporate polythiophene derivatives into the films and to use them as sensitizers for TiO{sub 2}. Further, electrodes containing CdSe or CdTe quantum dots (QDs) as sensitizers are fabricated. For the fabrication of photovoltaic cells the layer-by-layer grown films are coated with an additional polymer layer, and Au back electrodes are evaporated on top. The cells are illuminated through transparent doped SnO{sub 2} front electrodes. The I/V curves of all fabricated cells show diode

  1. Single-layer versus double-layer laparoscopic intracorporeally sutured gastrointestinal anastomoses in the canine model.

    Science.gov (United States)

    Tavakoli, Azine; Bakhtiari, Jalal; Khalaj, Ali Reza; Gharagozlou, Mohammad Javad; Veshkini, Abbas

    2010-01-01

    The objective of this study was to compare the gross and histopathologic changes following 1- versus 2-layer hand-sewn suture techniques in laparoscopic gastrointestinal anastomosis in dogs. This was an experimental prospective study of 16 healthy mixed breed male and female dogs. Animals were randomly divided into 2 groups. Two-layer side-to-side hand-sewn laparoscopic gastrojejunostomies were performed in group A, so that simple interrupted sutures were placed in the outer layer and simple continuous suture was used in the inner layer. The 1-layer simple continuous anastomosis between the stomach and jejunum was done in group B precisely. Specimen were collected from the sites of anastomosis, and H&E statining was performed for light microscopic studies. All animals survived the surgery. There was no gross inflammation, ischemia, apparent granulation tissue, abscess or fistula formation, leakage or stricture formation, and all sites of anastomosis were patent. Several adhesion formations were found in the abdomen with the higher incidence in the control group. Mean scores of leukocyte infiltration and granulation tissue formation at the sites of anastomosis were statistically insignificant between groups (P>0.05). Gross and histopathologic findings revealed that hand-sewn laparoscopic gastrointestinal anastomosis with the 1-layer suture technique is comparable to the 2-layer suture technique.

  2. Layer-by-Layer Bioprinting of Stem Cells for Retinal Tissue Regeneration

    Science.gov (United States)

    2016-12-01

    Precision Tissue Models”, Distinguished Seminar, Eli and Edythe Broad CIRM Center for Regenerative Medicine and Stem Cell Research, University of...in vitro drug screening and potential in vivo retinal neuron repair. The expansion of ganglion cells is tightly related to the spatial arrangement of...AWARD NUMBER: W81XWH-14-1-0522 TITLE: Layer-by-Layer Bioprinting of Stem Cells for Retinal Tissue Regeneration PRINCIPAL INVESTIGATOR

  3. Twin screw wet granulation: Binder delivery.

    Science.gov (United States)

    Saleh, Mohammed F; Dhenge, Ranjit M; Cartwright, James J; Hounslow, Michael J; Salman, Agba D

    2015-06-20

    The effects of three ways of binder delivery into the twin screw granulator (TSG) on the residence time, torque, properties of granules (size, shape, strength) and binder distribution were studied. The binder distribution was visualised through the transparent barrel using high speed imaging as well as quantified using offline technique. Furthermore, the effect of binder delivery and the change of screw configuration (conveying elements only and conveying elements with kneading elements) on the surface velocity of granules across the screw channel were investigated using particle image velocimetry (PIV). The binder was delivered in three ways; all solid binder incorporated with powder mixture, 50% of solid binder mixed with powder mixture and 50% mixed with water, all the solid binder dissolved in water. Incorporation of all solid binder with powder mixture resulted in the relatively longer residence time and higher torque, narrower granule size distribution, more spherical granules, weaker big-sized granules, stronger small-sized granules and better binder distribution compared to that in other two ways. The surface velocity of granules showed variation from one screw to another as a result of uneven liquid distribution as well as shown a reduction while introducing the kneading elements into the screw configuration. Copyright © 2015. Published by Elsevier B.V.

  4. Surface modified zeolite-based granulates for the sustained release of diclofenac sodium.

    Science.gov (United States)

    Serri, Carla; de Gennaro, Bruno; Quagliariello, Vincenzo; Iaffaioli, Rosario Vincenzo; De Rosa, Giuseppe; Catalanotti, Lilia; Biondi, Marco; Mayol, Laura

    2017-03-01

    In this study, a granulate for the oral controlled delivery of diclofenac sodium (DS), an anionic sparingly soluble nonsteroidal anti-inflammatory drug, has been realized by wet granulation, using a surface modified natural zeolite (SMNZ) as an excipient. The surface modification of the zeolite has been achieved by means of a cationic surfactant, so as to allow the loading of DS through ionic interaction and bestow a control over the drug release mechanism. The granules possessed a satisfactory dosage uniformity, a flowability suitable for an oral dosage form manufacturing, along with a sustained drug release up to 9h, driven by both ion exchange and transport kinetics. Furthermore, the obtained granulate did not elicit a significant cytotoxicity and could also induce a prolonged anti-inflammatory effect on RAW264.7 cells. Taking also into account that natural zeolites are generally abundant and economic, SMNZ can be considered as an attracting alternative excipient for the production of granules with sustained release features. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Revisiting the single cell protein application of Cupriavidus necator H16 and recovering bioplastic granules simultaneously.

    Directory of Open Access Journals (Sweden)

    Balakrishnan Kunasundari

    Full Text Available Cupriavidus necator H16 (formerly known as Hydrogenomonas eutropha was famous as a potential single cell protein (SCP in the 1970s. The drawback however was the undesirably efficient accumulation of non-nutritive polyhydroxybutyrate (PHB storage compound in the cytoplasm of this bacterium. Eventually, competition from soy-based protein resulted in SCP not receiving much attention. Nevertheless, C. necator H16 remained in the limelight as a producer of PHB, which is a material that resembles commodity plastics such as polypropylene. PHB is a 100% biobased and biodegradable polyester. Although tremendous achievements have been attained in the past 3 decades in the efficient production of PHB, this bioplastic is still costly. One of the main problems has been the recovery of PHB from the cell cytoplasm. In this study, we showed for the first time that kilogram quantities of PHB can be easily recovered in the laboratory without the use of any solvents and chemicals, just by using the cells as SCP. In addition, the present study also demonstrated the safety and tolerability of animal model used, Sprague Dawley given lyophilized cells of C. necator H16. The test animals readily produced fecal pellets that were whitish in color, as would be expected of PHB granules. The pellets were determined to contain about 82-97 wt% PHB and possessed molecular mass of around 930 kg/mol. The PHB granules recovered biologically possessed similar molecular mass compared to chloroform extracted PHB [950 kg/mol]. This method now allows the production and purification of substantial quantities of PHB for various experimental trials. The method reported here is easy, does not require expensive instrumentation, scalable and does not involve extensive use of solvents and strong chemicals.

  6. [Removal of PO4(3-) from solution, wastewater and seawater by modification and granulation magnesium and aluminium layered double hydroxide].

    Science.gov (United States)

    Xing, Kun; Wang, Hai-Zeng

    2013-04-01

    Powder layered double hydroxide of Mg-Al LDH were prepared by hydrothermal technology with 500 kg x batch(-1), modified and granulated (MG Mg-Al CLDH) by deposition method. After the modification and granulation, the fixed bed can not be accumulated and clogged by the adsorbents. The PO4(3-) is removed from aqueous solution, wastewater and seawater by MG Mg-Al CLDH with column experiments. It shows that MG Mg-Al CLDH is an effective adsorbent. After removal, the water quality can satisfy with the first degree of integrated wastewater discharge or seawater standards. The mechanism of removal PO4(3-) is ion exchange and 'memory effect'. The breakthrough adsorption capacity of PO4(3-) from solution is 13.49 mg x g(-1), more than 6 times higher than that by Mg-Al LDH without modification. The exhausted MG Mg-Al CLDH can be desorbed with 0.1 mol x L(-1) NaOH and 3 mol x L(-1) NaCl and regenerated with 25% MgCl2. The regeneration rate is 126.24%. The breakthrough curves are influenced by bed depth, flow rate, initial concentration and initial pH. The adsorption processes are controlled by film diffusion. When the initial concentration is as low as 0.38 micromol x L(-1), PO4(3-) can be removed from seawater to satisfy with the first degree of seawater quality. So this work is very useful for the practical application of Mg-Al LDH and the removal of phosphorus.

  7. Bizarre (pseudomalignant) granulation-tissue reactions following ionizing-radiation exposure. A microscopic, immunohistochemical, and flow-cytometric study

    International Nuclear Information System (INIS)

    Weidner, N.; Askin, F.B.; Berthrong, M.; Hopkins, M.B.; Kute, T.E.; McGuirt, F.W.

    1987-01-01

    Two patients developed extremely bizarre (pseudomalignant) granulation-tissue reactions in the larynx and facial sinuses, following radiation therapy for carcinoma. Containing pleomorphic spindle cells and numerous (sometimes atypical) mitotic figures, both tumefactive lesions simulated high grade malignancies. While the pleomorphic cells contained vimentin immunoreactivity, they were nonreactive for low or high molecular weight keratin. Flowcytometric study of paraffin-embedded tissues revealed DNA indexes of 0.75 and 1.0. Neither recurred locally nor spread distantly after therapy. Their granulation-tissue growth pattern, and the presence of stromal and endothelial cells showing similar degrees of cytologic atypia were central to their recognition as benign. These findings show that severely atypical, sometimes aneuploid, granulation-tissue reactions can occur following radiation exposure. Care should be taken not to misinterpret these lesions as malignant

  8. Research advances in Huai′er granules combined with transarterial chemoembolization in treatment of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    DONG Deshuo

    2017-10-01

    Full Text Available Hepatocellular carcinoma (HCC has an insidious onset and when a confirmed diagnosis is made, most patients lose the chance for surgery and are given transarterial chemoembolization (TACE as palliative treatment. However, repeated TACE may lead to overexpression of hypoxia-inducible factor 1α (HIF-1α and vascular endothelial growth factor (VEGF, liver injury, and reduced immune function and has poor long-term efficacy. The introduction of Huai′er granules may help to change the current status. Studies in China and foreign countries have shown that Huai′er granules exert a remarkable anti-tumor effect by blocking cell cycle, inducing cell apoptosis, inhibiting cell proliferation and invasion, and blocking the hepatitis B-hepatocellular carcinoma pathway. Meanwhile, as an adjuvant drug for HCC, Huai′er granules cover the shortcomings of TACE from multiple aspects and can effectively inhibit the overexpression of HIF-1α and VEGF, improve liver injury and immunity, enhance the effect of chemotherapy drugs, and reverse drug resistance. Many clinical studies have confirmed the remarkable advantages of Huai′er granules combined with TACE, and their synergistic effect helps to enhance anti-tumor effect and improve short- and long-term survival rates.

  9. Layered granule chute flow near the angle of repose

    International Nuclear Information System (INIS)

    Pitts, J.H.; Walton, O.R.

    1985-01-01

    A natural, two-layered gravity flow of sand can be obtained on chutes inclined at angles slightly above the angle of repose of the sand. The top-surface layer is free-flowing, is thin, and moves rapidly at supercritical velocity. The velocity depends mainly on the character of the sand and the chute inclination angle. The bottom layer is thick and moves more slowly, with the flow controlled by adjustable weirs at the chute exit. The velocity profile in the thick bottom layer is curved; as much as an order of magnitude higher velocity occurs in the upper portion of the layer than occurs along the bottom wall of the chute. This study has applications to the cascade inertial fusion concept

  10. APPLICATION OF GRANULATION TECHNOLOGY IN VARIOUS INDUSTRIES

    Directory of Open Access Journals (Sweden)

    B. V. YEGOROV

    2017-10-01

    Full Text Available Science and practice proved the high efficiency of granulated mixed fodders. This article presents an overview of granulation technologies for various industries. This article discusses the application of granulation technologies in various industries. The processes of granulation are mass technological processes currently used in a wide range of industries: feed industry, food industry, pharmaceutical industry, fertilizer production, polyethylene, metal production, mining, etc. A wide range of different materials are granulated, including chemicals, iron ore, mixed fodder, and much more. Granulation is a process of pressing or shaping a material in the form of granulesGranulation is widely used in the production of pigments, dyes, synthetic detergents, catalysts, plastics, soot, chemical reagents, etc. The use of granular raw materials in the metallurgical industry helps not only to mechanize processes, but also to increase their intensity by increasing the contact surface of interacting media. Granular fertilizers retain their properties for a long time. In the mining industry, granulation processes are used at the stage of preparation and enrichment of raw materials and release of the finished product.  Particular attention is paid to the feed industry. Granulation allows to ensure stable homogeneity, to improve sanitary and hygienic parameters, to increase nutritional value, to increase the storage period, improve the physical properties. However, despite all the advantages, the existing granulation production lines have a relatively high productivity and, at the same time, a high energy intensity. In this regard, this article proposes a technology for improving the granulation of mixed fodders. According to a preliminary literary review, It should be concluded that improving the technology of the granulation process for feed production is a topical issue in the feed industry today. The development of technology for improving the

  11. Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

    Science.gov (United States)

    Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

    2014-04-01

    Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All

  12. Cascade reactor: granule fabrication processes

    International Nuclear Information System (INIS)

    Erlandson, O.D.; Winkler, E.O.; Maya, I.; Pitts, J.H.

    1985-01-01

    A key feature of Cascade is the granular blanket. Of the many blanket material options open to Cascade, fabrication of Li 2 O granules was felt to offer the greatest challenge. The authors explored available methods for initial Li 2 O granule fabrication. They identified three cost-effective processes for fabricating Li 2 O granules: the VSM drop-melt furnace process, which is based on melting and spheroidizing irregularly shaped Li 2 O feed granules; the LiOH process, which spheroidizes liquefied LiOH and uses GA Technologies' sphere-forming procedures; and the Li 2 CO 3 sol-gel process, used for making spherical fuel particles for the high-temperature gas-cooled reactor (HTGR). Each process is described below

  13. Selective stimulation of excitatory amino acid receptor subtypes and the survival of cerebellar granule cells in culture: effect of kainic acid

    DEFF Research Database (Denmark)

    Balázs, R; Hack, N; Jørgensen, Ole Steen

    1990-01-01

    Our previous studies showed that the survival of cerebellar granule cells in culture is promoted by treatment with N-methyl-D-aspartate. Here we report on the influence of another glutamate analogue, kainic acid, which, in contrast to N-methyl-D-aspartate, is believed to stimulate transmitter rec...

  14. Granule fraction inhomogeneity of calcium carbonate/sorbitol in roller compacted granules

    DEFF Research Database (Denmark)

    Bacher, Charlotte; Olsen, P.M.; Bertelsen, P.

    2008-01-01

    The granule fraction inhomogeneity of roller compacted granules was examined on mixtures of three different morphologic forms of calcium carbonate and three particle sizes of sorbitol. The granule fraction inhomogeneity was determined by the distribution of the calcium carbonate in each of the 10...... size fractions between 0 and 2000 µm and by calculating the demixing potential. Significant inhomogeneous occurrence of calcium carbonate in the size fractions was demonstrated, depending mostly on the particles sizes of sorbitol but also on the morphological forms of calcium carbonate......, the ability of the powder to agglomerate in the roller compactor was demonstrated to be related to the ability of the powder to be compacted into a tablet, thus the most compactable calcium carbonate and the smallest sized sorbitol improved the homogeneity by decreasing the demixing potential....

  15. Crystallization and initial X-ray analysis of polyhydroxyalkanoate granule-associated protein from Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Minglian; Li, Zhenguo; Zheng, Wei; Lou, Zhiyong [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Chen, Guo-Qiang, E-mail: chengq@stu.edu.cn [MOE Key Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084 (China); Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong (China)

    2006-08-01

    The phasin PhaP{sub Ah} from A. hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were discovered in PHA-accumulating bacteria. They play a crucial role as a structural protein during initial PHA-granule formation and granule growth and also serve as interfaces for granule stabilization in vivo. The phasin PhaP{sub Ah} from Aeromonas hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Single crystals were cryocooled for X-ray diffraction analysis. The phasin crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 80.8, b = 108.9, c = 134.4 Å.

  16. Human iPSC Derived GABA Ergic Precursor Cell Therapy for Chronic Epilepsy

    Science.gov (United States)

    2016-10-01

    of hMGE progenitors (obtained from hPSCs expanded from human embryonic stem cells) that were transduced with DREADDs through CRISPR/Cas9 technology...regions and cell layers of the hippocampus, which include the subgranular zone and the dentate hilus in the dentate gyrus, and strata oriens and...have migrated extensively in the dentate hilus (A3) and into different layers of the CA1 subfield. DG, dentate gyrus; DH, dentate hilus; GCL, granule

  17. Sorting of a HaloTag protein that has only a signal peptide sequence into exocrine secretory granules without protein aggregation.

    Science.gov (United States)

    Fujita-Yoshigaki, Junko; Matsuki-Fukushima, Miwako; Yokoyama, Megumi; Katsumata-Kato, Osamu

    2013-11-15

    The mechanism involved in the sorting and accumulation of secretory cargo proteins, such as amylase, into secretory granules of exocrine cells remains to be solved. To clarify that sorting mechanism, we expressed a reporter protein HaloTag fused with partial sequences of salivary amylase protein in primary cultured parotid acinar cells. We found that a HaloTag protein fused with only the signal peptide sequence (Met(1)-Ala(25)) of amylase, termed SS25H, colocalized well with endogenous amylase, which was confirmed by immunofluorescence microscopy. Percoll-density gradient centrifugation of secretory granule fractions shows that the distributions of amylase and SS25H were similar. These results suggest that SS25H is transported to secretory granules and is not discriminated from endogenous amylase by the machinery that functions to remove proteins other than granule cargo from immature granules. Another reporter protein, DsRed2, that has the same signal peptide sequence also colocalized with amylase, suggesting that the sorting to secretory granules is not dependent on a characteristic of the HaloTag protein. Whereas Blue Native PAGE demonstrates that endogenous amylase forms a high-molecular-weight complex, SS25H does not participate in the complex and does not form self-aggregates. Nevertheless, SS25H was released from cells by the addition of a β-adrenergic agonist, isoproterenol, which also induces amylase secretion. These results indicate that addition of the signal peptide sequence, which is necessary for the translocation in the endoplasmic reticulum, is sufficient for the transportation and storage of cargo proteins in secretory granules of exocrine cells.

  18. Microtubule-dependent association of AKAP350A and CCAR1 with RNA stress granules

    International Nuclear Information System (INIS)

    Kolobova, Elena; Efimov, Andrey; Kaverina, Irina; Rishi, Arun K.; Schrader, John W.; Ham, Amy-Joan; Larocca, M. Cecilia; Goldenring, James R.

    2009-01-01

    Recent investigations have highlighted the importance of subcellular localization of mRNAs to cell function. While AKAP350A, a multifunctional scaffolding protein, localizes to the Golgi apparatus and centrosomes, we have now identified a cytosolic pool of AKAP350A. Analysis of AKAP350A scaffolded complexes revealed two novel interacting proteins, CCAR1 and caprin-1. CCAR1, caprin-1 and AKAP350A along with G3BP, a stress granule marker, relocate to RNA stress granules after arsenite treatment. Stress also caused loss of AKAP350 from the Golgi and fragmentation of the Golgi apparatus. Disruption of microtubules with nocodazole altered stress granule formation and changed their morphology by preventing fusion of stress granules. In the presence of nocodazole, arsenite induced smaller granules with the vast majority of AKAP350A and CCAR1 separated from G3BP-containing granules. Similar to nocodazole treatment, reduction of AKAP350A or CCAR1 expression also altered the size and number of G3BP-containing stress granules induced by arsenite treatment. A limited set of 69 mRNA transcripts was immunoisolated with AKAP350A even in the absence of stress, suggesting the association of AKAP350A with mRNA transcripts. These results provide the first evidence for the microtubule dependent association of AKAP350A and CCAR1 with RNA stress granules

  19. The natural scorpion peptide, BmK NT1 activates voltage-gated sodium channels and produces neurotoxicity in primary cultured cerebellar granule cells.

    Science.gov (United States)

    Zou, Xiaohan; He, Yuwei; Qiao, Jinping; Zhang, Chunlei; Cao, Zhengyu

    2016-01-01

    The scorpion Buthus martensii Karsch has been used in Traditional Chinese Medicine to treat neuronal diseases such as neuropathic pain, paralysis and epilepsy for thousands of years. Studies have demonstrated that scorpion venom is the primary active component. Although scorpion venom can effectively attenuate pain in the clinic, it also produces neurotoxic response. In this study, toxicity guided purification led to identify a mammalian toxin termed BmK NT1 comprising of 65 amino acid residues and an amidated C-terminus, a mature peptide encoded by the nucleotide sequence (GenBank No. AF464898). In contract to the recombinant product of the same nucleotide sequence, BmK AGAP, which displayed analgesic and anti-tumor effect, intravenous injection (i.v.) of BmK NT1 produced acute toxicity in mice with an LD50 value of 1.36 mg/kg. In primary cultured cerebellar granule cells, BmK NT1 produced a concentration-dependent cell death with an IC50 value of 0.65 μM (0.41-1.03 μM, 95% Confidence Intervals, 95% CI) which was abolished by TTX, a voltage-gated sodium channel (VGSC) blocker. We also demonstrated that BmK NT1 produced modest sodium influx in cerebellar granule cell cultures with an EC50 value of 2.19 μM (0.76-6.40 μM, 95% CI), an effect similar to VGSC agonist, veratridine. The sodium influx response was abolished by TTX suggesting that BmK NT1-induced sodium influx is solely through activation of VGSC. Considered these data together, we demonstrated that BmK NT1 activated VGSC and produced neurotoxicity in cerebellar granule cell cultures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. InP solar cell with window layer

    Science.gov (United States)

    Jain, Raj K. (Inventor); Landis, Geoffrey A. (Inventor)

    1994-01-01

    The invention features a thin light transmissive layer of the ternary semiconductor indium aluminum arsenide (InAlAs) as a front surface passivation or 'window' layer for p-on-n InP solar cells. The window layers of the invention effectively reduce front surface recombination of the object semiconductors thereby increasing the efficiency of the cells.

  1. Phospho-Rasputin Stabilization by Sec16 Is Required for Stress Granule Formation upon Amino Acid Starvation

    NARCIS (Netherlands)

    Aguilera-Gomez, Angelica; Zacharogianni, Margarita; van Oorschot, Marinke M.; Genau, Heide; Grond, Rianne; Veenendaal, Tineke; Sinsimer, Kristina S.; Gavis, Elisabeth A.; Behrends, Christian; Rabouille, Catherine

    2017-01-01

    Most cellular stresses induce protein translation inhibition and stress granule formation. Here, using Drosophila S2 cells, we investigate the role of G3BP/Rasputin in this process. In contrast to arsenite treatment, where dephosphorylated Ser142 Rasputin is recruited to stress granules, we find

  2. Long-term potentiation in hilar circuitry modulates gating by the dentate gyrus.

    Science.gov (United States)

    Wright, Brandon J; Jackson, Meyer B

    2014-07-16

    The dentate gyrus serves as a gateway to the hippocampus, filtering and processing sensory inputs as an animal explores its environment. The hilus occupies a strategic position within the dentate gyrus from which it can play a pivotal role in these functions. Inputs from dentate granule cells converge on the hilus, and excitatory hilar mossy cells redistribute these signals back to granule cells to transform a pattern of cortical input into a new pattern of output to the hippocampal CA3 region. Using voltage-sensitive dye to image electrical activity in rat hippocampal slices, we explored how long-term potentiation (LTP) of different excitatory synapses modifies the flow of information. Theta burst stimulation of the perforant path potentiated responses throughout the molecular layer, but left responses in the CA3 region unchanged. By contrast, theta burst stimulation of the granule cell layer potentiated responses throughout the molecular layer, as well as in the CA3 region. Theta burst stimulation of the granule cell layer potentiated CA3 responses not only to granule cell layer stimulation but also to perforant path stimulation. Potentiation of responses in the CA3 region reflected NMDA receptor-dependent LTP of upstream synapses between granule cells and mossy cells, with no detectable contribution from NMDA receptor-independent LTP of local CA3 mossy fiber synapses. Potentiation of transmission to the CA3 region required LTP in both granule cell→mossy cell and mossy cell→granule cell synapses. This bidirectional plasticity enables hilar circuitry to regulate the flow of information through the dentate gyrus and on to the hippocampus. Copyright © 2014 the authors 0270-6474/14/349743-11$15.00/0.

  3. Oscillating behavior of carbohydrate granule formation and dinitrogen fixation in the cyanobacterium Cyanothece sp. strain ATCC 51142

    Science.gov (United States)

    Schneegurt, M. A.; Sherman, D. M.; Nayar, S.; Sherman, L. A.; Mitchell, C. A. (Principal Investigator)

    1994-01-01

    It has been shown that some aerobic, unicellular, diazotrophic cyanobacteria temporally separate photosynthetic O2 evolution and oxygen-sensitive N2 fixation. Cyanothece sp. ATCC strain 51142 is an aerobic, unicellular, diazotrophic cyanobacterium that fixes N2 during discrete periods of its cell cycle. When the bacteria are maintained under diurnal light-dark cycles, N2 fixation occurs in the dark. Similar cycling is observed in continuous light, implicating a circadian rhythm. Under N2-fixing conditions, large inclusion granules form between the thylakoid membranes. Maximum granulation, as observed by electron microscopy, occurs before the onset of N2 fixation, and the granules decrease in number during the period of N2 fixation. The granules can be purified from cell homogenates by differential centrifugation. Biochemical analyses of the granules indicate that these structures are primarily carbohydrate, with some protein. Further analyses of the carbohydrate have shown that it is a glucose polymer with some characteristics of glycogen. It is proposed that N2 fixation is driven by energy and reducing power stored in these inclusion granules. Cyanothece sp. strain ATCC 51142 represents an excellent experimental organism for the study of the protective mechanisms of nitrogenase, metabolic events in cyanobacteria under normal and stress conditions, the partitioning of resources between growth and storage, and biological rhythms.

  4. Ultrastructural study on the embryonic development of the orthokeratinized epithelium and its cornified layer (lingual nail) on the ventral surface of the lingual apex in the domestic duck (Anas platyrhynchos f. domestica).

    Science.gov (United States)

    Skieresz-Szewczyk, Kinga; Jackowiak, Hanna; Ratajczak, Marlena

    2018-02-01

    The lingual nail as the cornified layer of the orthokeratinized epithelium in birds is responsible for the collection of solid food by pecking. The aim of the present study is to determine the manner of orthokeratinized epithelium development and assess the degree of readiness of the epithelium to fulfill its mechanical function at hatching. Three developmental phases are distinguished, i.e. embryonic, transformation and pre-hatching stage. In the embryonic stage lasting until day 13 of incubation the epithelium is composed of several layers of undifferentiated cells. During the transformation stage, from day 14 to 20 of incubation, the epithelium becomes differentiated to form three layers. A characteristic feature is the formation of osmophilic granules in the superficial layer, referred to as periderm granules. Until the pre-hatching stage the fibrous cytoskeleton of epithelial cells and an impermeable epithelial barrier are gradually developed. In the pre-hatching stage, a cornified lingual nail is formed, while the periderm is exfoliated. At hatching the orthokeratinized epithelium and lingual nail are fully developed and ready to perform feeding activities. The presence of periderm, similarly as in the epidermis, indicates the ectodermal derivation of the oral cavity epithelium. Moreover, occurrence of osmophilic granules may be considered as evidence for the phylogenetic affinity of birds and reptiles. Copyright © 2018 Elsevier GmbH. All rights reserved.

  5. Factors Involved in Sludge Granulation under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-03-01

    Full Text Available This paper investigates the effects of factors involved in sludge anaerobic granulation. Granulated sludge formation is the main parameter contributing to the success of UASB reactors. Anaerobic granulation leads to reduced reactor size, space requirement, and investment costs. Operation costs are also greatly reduced due to lack of aeration. An important parameter affecting process performance is the size of sludge granules; the factors involved in granule size will be investigated. Some of the important parameters of anaerobic sludge granulation are: existence of growth cores as inert particles or granulated sludge, process operational conditions (Sludge Loading Rate and Organic Loading Rate, Loading rate increase and …, and environment conditions (nutrients, temperature, pH, combination and ….

  6. Early x-irradiation of rats

    International Nuclear Information System (INIS)

    Halasz, N.

    1987-01-01

    Low, repeated doses of X-rays from a Co 60 source were used to impair the development of the granule cells and their dendritic terminals in the olfactory bulb, and the resulting effect was studied under light and electron microscopes at 9 days of age. Irradiation of rats from embryonic day 18 (in utero) to postnatal day 5 resulted, among others, in maldevelopment of the (internal) granule cell and external plexiform layers. This was accompanied by a decrease in the number and the density of the granule cells, and the remaining granule cells contained less ribosomes, regardless of their position within the layer. This implies that both supposed subtypes of granule cells were effected. In the external plexiform layer, a reduced number of mature dendrodendritic synapses and signs of harmed granule gemmules were observed. The results suggest that intrauterinal plus postnatal irradiation with low, repeated doses of X-rays may be an effective tool impairing the development of prenatally forming neurons. (author)

  7. High resolution of heterogeneity among human neutrophil granules: physical, biochemical, and ultrastructural properties of isolated fractions.

    Science.gov (United States)

    Rice, W G; Kinkade, J M; Parmley, R T

    1986-08-01

    -TCH-SP staining of isolated granule fractions revealed patterns similar to those of granules in intact neutrophils at different stages of development. Granules from human acute promyelocytic leukemia cells (HL-60) exhibited a surprisingly low density compared with typical azurophil granules from normal, mature neutrophils. The data suggest that both functional and maturational differences contribute to granule heterogeneity, and provide a new practical and conceptual framework for further defining the phenomenon of neutrophil granule heterogeneity.

  8. gamma-Aminobutyric acid- and benzodiazepine-induced modulation of [35S]-t-butylbicyclophosphorothionate binding to cerebellar granule cells

    International Nuclear Information System (INIS)

    Gallo, V.; Wise, B.C.; Vaccarino, F.; Guidotti, A.

    1985-01-01

    t-Butylbicyclophosphorothionate (TBPS) is a bicyclophosphate derivative with potent picrotoxin-like convulsant activity that binds with high affinity and specificity to a Cl- channel-modulatory site of the gamma-aminobutyric acid (GABA)/benzodiazepine receptor complex. Using intact cerebellar granule cells maintained in primary culture, the authors have studied the modifications induced by GABA and diazepam on the ion channel-modulatory binding site labeled by [ 35 S]TBPS. At 25 degrees C, and in a modified Locke solution, the [ 35 S]TBPS specific binding, determined by displacing the radioligand with an excess (10(-4) M) of picrotoxin, was approximately 70% of the total radioactivity bound to the cells. [ 35 S]TBPS specific binding was saturable with a Kd of approximately 100 nM, a Bmax of approximately 440 fmol/mg of protein, and a Hill coefficient of 1.18. Neither cerebellar astrocytes maintained in culture for 2 weeks nor a neuroblastoma cell line (NB-2A) exhibited any specific [ 35 S]TBPS binding. Muscimol (0.3 to 5 microM) enhanced and bicuculline (0.1 to 5 microM) inhibited [ 35 S]TBPS specific binding to intact cerebellar granule cells. The effect of muscimol and bicuculline on [ 35 S]TBPS binding was noncompetitive. Muscimol (0.1 to 5 microM) reversed bicuculline inhibition in a dose-dependent fashion but failed to reverse picrotoxin-induced inhibition. [ 35 S]TBPS binding was also modulated by benzodiazepine receptor ligands. The binding was increased by diazepam and decreased by 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylic acid methylester. Muscimol (0.05 microM) failed to reverse bicuculline inhibition in the absence of diazepam, but it became effective in the presence of 0.1 to 1 microM diazepam

  9. The type II cGMP dependent protein kinase regulates GluA1 levels at the plasma membrane of developing cerebellar granule cells

    Science.gov (United States)

    Incontro, Salvatore; Ciruela, Francisco; Ziff, Edward; Hofmann, Franz; Sánchez-Prieto, José; Torres, Magdalena

    2014-01-01

    Trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) is regulated by specific interactions with other proteins and by post-translational mechanisms, such as phosphorylation. We have found that the type II cGMP-dependent protein kinase (cGKII) phosphorylates GluA1 (formerly GluR1) at S845, augmenting the surface expression of AMPARs at both synaptic and extrasynaptic sites. Activation of cGKII by 8-Br-cGMP enhances the surface expression of GluA1, whereas its inhibition or suppression effectively diminished the expression of this protein at the cell surface. In granule cells, NMDA receptor activation (NMDAR) stimulates nitric oxide and cGMP production, which in turn activates cGKII and induces the phosphorylation of GluA1, promoting its accumulation in the plasma membrane. GluA1 is mainly incorporated into calcium permeable AMPARs as exposure to 8-Br-cGMP or NMDA activation enhanced AMPA-elicited calcium responses that are sensitive to NASPM inhibition. We summarize evidence for an increase of calcium permeable AMPA receptors downstream of NMDA receptor activation that might be relevant for granule cell development and plasticity. PMID:23545413

  10. Joint Effects of Granule Size and Degree of Substitution on Octenylsuccinated Sweet Potato Starch Granules As Pickering Emulsion Stabilizers.

    Science.gov (United States)

    Li, Jinfeng; Ye, Fayin; Lei, Lin; Zhou, Yun; Zhao, Guohua

    2018-05-02

    The granules of sweet potato starch were size fractionated into three portions with significantly different median diameters ( D 50 ) of 6.67 (small-sized), 11.54 (medium-sized), and 16.96 μm (large-sized), respectively. Each portion was hydrophobized at the mass-based degrees of substitution (DS m ) of approximately 0.0095 (low), 0.0160 (medium), and 0.0230 (high). The Pickering emulsion-stabilizing capacities of modified granules were tested, and the resultant emulsions were characterized. The joint effects of granule size and DS m on emulsifying capacity (EC) were investigated by response surface methodology. For small-, medium-, and large-sized fractions, their highest emulsifying capacities are comparable but, respectively, encountered at high (0.0225), medium (0.0158), and low (0.0095) DS m levels. The emulsion droplet size increased with granule size, and the number of freely scattered granules in emulsions decreased with DS m . In addition, the term of surface density of the octenyl succinic group (SD -OSG ) was first proposed for modified starch granules, and it was proved better than DS m in interpreting the emulsifying capacities of starch granules with varying sizes. The present results implied that, as the particulate stabilizers, the optimal DS m of modified starch granules is size specific.

  11. Casein Kinase 1δ Is an APC/CCdh1 Substrate that Regulates Cerebellar Granule Cell Neurogenesis

    Directory of Open Access Journals (Sweden)

    Clara Penas

    2015-04-01

    Full Text Available Although casein kinase 1δ (CK1δ is at the center of multiple signaling pathways, its role in the expansion of CNS progenitor cells is unknown. Using mouse cerebellar granule cell progenitors (GCPs as a model for brain neurogenesis, we demonstrate that the loss of CK1δ or treatment of GCPs with a highly selective small molecule inhibits GCP expansion. In contrast, CK1δ overexpression increases GCP proliferation. Thus, CK1δ appears to regulate GCP neurogenesis. CK1δ is targeted for proteolysis via the anaphase-promoting complex/cyclosome (APC/CCdh1 ubiquitin ligase, and conditional deletion of the APC/CCdh1 activator Cdh1 in cerebellar GCPs results in higher levels of CK1δ. APC/CCdh1 also downregulates CK1δ during cell-cycle exit. Therefore, we conclude that APC/CCdh1 controls CK1δ levels to balance proliferation and cell-cycle exit in the developing CNS. Similar studies in medulloblastoma cells showed that CK1δ holds promise as a therapeutic target.

  12. Signaling from the secretory granule to the nucleus: Uhmk1 and PAM.

    Science.gov (United States)

    Francone, Victor P; Ifrim, Marius F; Rajagopal, Chitra; Leddy, Christopher J; Wang, Yanping; Carson, John H; Mains, Richard E; Eipper, Betty A

    2010-08-01

    Neurons and endocrine cells package peptides in secretory granules (large dense-core vesicles) for storage and stimulated release. Studies of peptidylglycine alpha-amidating monooxygenase (PAM), an essential secretory granule membrane enzyme, revealed a pathway that can relay information from secretory granules to the nucleus, resulting in alterations in gene expression. The cytosolic domain (CD) of PAM, a type 1 membrane enzyme essential for the production of amidated peptides, is basally phosphorylated by U2AF homology motif kinase 1 (Uhmk1) and other Ser/Thr kinases. Proopiomelanocortin processing in AtT-20 corticotrope tumor cells was increased when Uhmk1 expression was reduced. Uhmk1 was concentrated in the nucleus, but cycled rapidly between nucleus and cytosol. Endoproteolytic cleavage of PAM releases a soluble CD fragment that localizes to the nucleus. Localization of PAM-CD to the nucleus was decreased when PAM-CD with phosphomimetic mutations was examined and when active Uhmk1 was simultaneously overexpressed. Membrane-tethering Uhmk1 did not eliminate its ability to exclude PAM-CD from the nucleus, suggesting that cytosolic Uhmk1 could cause this response. Microarray analysis demonstrated the ability of PAM to increase expression of a small subset of genes, including aquaporin 1 (Aqp1) in AtT-20 cells. Aqp1 mRNA levels were higher in wild-type mice than in mice heterozygous for PAM, indicating that a similar relationship occurs in vivo. Expression of PAM-CD also increased Aqp1 levels whereas expression of Uhmk1 diminished Aqp1 expression. The outlines of a pathway that ties secretory granule metabolism to the transcriptome are thus apparent.

  13. Mutant human FUS Is ubiquitously mislocalized and generates persistent stress granules in primary cultured transgenic zebrafish cells.

    Directory of Open Access Journals (Sweden)

    Jamie Rae Acosta

    Full Text Available FUS mutations can occur in familial amyotrophic lateral sclerosis (fALS, a neurodegenerative disease with cytoplasmic FUS inclusion bodies in motor neurons. To investigate FUS pathology, we generated transgenic zebrafish expressing GFP-tagged wild-type or fALS (R521C human FUS. Cell cultures were made from these zebrafish and the subcellular localization of human FUS and the generation of stress granule (SG inclusions examined in different cell types, including differentiated motor neurons. We demonstrate that mutant FUS is mislocalized from the nucleus to the cytosol to a similar extent in motor neurons and all other cell types. Both wild-type and R521C FUS localized to SGs in zebrafish cells, demonstrating an intrinsic ability of human FUS to accumulate in SGs irrespective of the presence of disease-associated mutations or specific cell type. However, elevation in relative cytosolic to nuclear FUS by the R521C mutation led to a significant increase in SG assembly and persistence within a sub population of vulnerable cells, although these cells were not selectively motor neurons.

  14. Diffusion inside living human cells

    DEFF Research Database (Denmark)

    Leijnse, N.; Jeon, J. -H.; Loft, Steffen

    2012-01-01

    of the cell or within the nucleus. Also, granules in cells which are stressed by intense laser illumination or which have attached to a surface for a long period of time move in a more restricted fashion than those within healthy cells. For granules diffusing in healthy cells, in regions away from the cell...... cells. For these cells the exact diffusional pattern of a particular granule depends on the physiological state of the cell and on the localization of the granule within the cytoplasm. Granules located close to the actin rich periphery of the cell move less than those located towards to the center...

  15. Highly doped layer for tunnel junctions in solar cells

    Science.gov (United States)

    Fetzer, Christopher M.

    2017-08-01

    A highly doped layer for interconnecting tunnel junctions in multijunction solar cells is presented. The highly doped layer is a delta doped layer in one or both layers of a tunnel diode junction used to connect two or more p-on-n or n-on-p solar cells in a multijunction solar cell. A delta doped layer is made by interrupting the epitaxial growth of one of the layers of the tunnel diode, depositing a delta dopant at a concentration substantially greater than the concentration used in growing the layer of the tunnel diode, and then continuing to epitaxially grow the remaining tunnel diode.

  16. Hilar granule cells of the mouse dentate gyrus: effects of age, septotemporal location, strain, and selective deletion of the proapoptotic gene BAX.

    Science.gov (United States)

    Bermudez-Hernandez, Keria; Lu, Yi-Ling; Moretto, Jillian; Jain, Swati; LaFrancois, John J; Duffy, Aine M; Scharfman, Helen E

    2017-09-01

    The dentate gyrus (DG) principal cells are glutamatergic granule cells (GCs), and they are located in a compact cell layer. However, GCs are also present in the adjacent hilar region, but have been described in only a few studies. Therefore, we used the transcription factor prospero homeobox 1 (Prox1) to quantify GCs at postnatal day (PND) 16, 30, and 60 in a common mouse strain, C57BL/6J mice. At PND16, there was a large population of Prox1-immunoreactive (ir) hilar cells, with more in the septal than temporal hippocampus. At PND30 and 60, the size of the hilar Prox1-ir cell population was reduced. Similar numbers of hilar Prox1-expressing cells were observed in PND30 and 60 Swiss Webster mice. Prox1 is usually considered to be a marker of postmitotic GCs. However, many Prox1-ir hilar cells, especially at PND16, were not double-labeled with NeuN, a marker typically found in mature neurons. Most hilar Prox1-positive cells at PND16 co-expressed doublecortin (DCX) and calretinin, markers of immature GCs. Double-labeling with a marker of actively dividing cells, Ki67, was not detected. These results suggest that, surprisingly, a large population of cells in the hilus at PND16 are immature GCs (Type 2b and Type 3 cells). We also asked whether hilar Prox1-ir cell numbers are modifiable. To examine this issue, we conditionally deleted the proapoptotic gene BAX in Nestin-expressing cells at a time when there are numerous immature GCs in the hilus, PND2-8. When these mice were examined at PND60, the numbers of Prox1-ir hilar cells were significantly increased compared to control mice. However, deletion of BAX did not appear to change the proportion that co-expressed NeuN, suggesting that the size of the hilar Prox1-expressing population is modifiable. However, deleting BAX, a major developmental disruption, does not appear to change the proportion that ultimately becomes neurons.

  17. Human Cytotoxic T Lymphocytes Form Dysfunctional Immune Synapses with B Cells Characterized by Non-Polarized Lytic Granule Release

    Directory of Open Access Journals (Sweden)

    Anna Kabanova

    2016-04-01

    Full Text Available Suppression of the cytotoxic T cell (CTL immune response has been proposed as one mechanism for immune evasion in cancer. In this study, we have explored the underlying basis for CTL suppression in the context of B cell malignancies. We document that human B cells have an intrinsic ability to resist killing by freshly isolated cytotoxic T cells (CTLs, but are susceptible to lysis by IL-2 activated CTL blasts and CTLs isolated from immunotherapy-treated patients with chronic lymphocytic leukemia (CLL. Impaired killing was associated with the formation of dysfunctional non-lytic immune synapses characterized by the presence of defective linker for activation of T cells (LAT signaling and non-polarized release of the lytic granules transported by ADP-ribosylation factor-like protein 8 (Arl8. We propose that non-lytic degranulation of CTLs are a key regulatory mechanism of evasion through which B cells may interfere with the formation of functional immune synapses by CTLs.

  18. Phospho-Rasputin Stabilization by Sec16 Is Required for Stress Granule Formation upon Amino Acid Starvation

    Directory of Open Access Journals (Sweden)

    Angelica Aguilera-Gomez

    2017-07-01

    Full Text Available Most cellular stresses induce protein translation inhibition and stress granule formation. Here, using Drosophila S2 cells, we investigate the role of G3BP/Rasputin in this process. In contrast to arsenite treatment, where dephosphorylated Ser142 Rasputin is recruited to stress granules, we find that, upon amino acid starvation, only the phosphorylated Ser142 form is recruited. Furthermore, we identify Sec16, a component of the endoplasmic reticulum exit site, as a Rasputin interactor and stabilizer. Sec16 depletion results in Rasputin degradation and inhibition of stress granule formation. However, in the absence of Sec16, pharmacological stabilization of Rasputin is not enough to rescue the assembly of stress granules. This is because Sec16 specifically interacts with phosphorylated Ser142 Rasputin, the form required for stress granule formation upon amino acid starvation. Taken together, these results demonstrate that stress granule formation is fine-tuned by specific signaling cues that are unique to each stress. These results also expand the role of Sec16 as a stress response protein.

  19. Medical image of the week: granulation tissue

    Directory of Open Access Journals (Sweden)

    Ganesh A

    2014-03-01

    Full Text Available A 57 year old woman presented with a tickling sensation in the back of throat and intermittent bleeding from the healing stoma one month after decannulation of her tracheostomy tube. On bronchoscopy a granuloma with surrounding granulation tissue was present in the subglottic space (Figure 1. Argon plasma coagulation (APC was performed to cauterize the granulation tissue (Figure 2. Formation of granulation tissue after tracheostomy is a common complication which can result in tracheal stenosis. APC and electrocautery using flexible bronchoscopy has been shown to safely and effectively remove the granulation tissue.

  20. 21 CFR 520.905b - Fenbendazole granules.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fenbendazole granules. 520.905b Section 520.905b... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.905b Fenbendazole granules. (a) Specifications. Each gram of granules contains 222 milligrams (mg) fenbendazole. (b) Sponsor. See...

  1. Increased accuracy of starch granule type quantification using mixture distributions

    OpenAIRE

    Tanaka, Emi; Ral, Jean-Phillippe F.; Li, Sean; Gaire, Raj; Cavanagh, Colin R.; Cullis, Brian R.; Whan, Alex

    2017-01-01

    Background The proportion of granule types in wheat starch is an important characteristic that can affect its functionality. It is widely accepted that granule types are either large, disc-shaped A-type granules or small, spherical B-type granules. Additionally, there are some reports of the tiny C-type granules. The differences between these granule types are due to its carbohydrate composition and crystallinity which is highly, but not perfectly, correlated with the granule size. A majority...

  2. Enhanced Inhibitory Effect of Ultra-Fine Granules of Red Ginseng on LPS-induced Cytokine Expression in the Monocyte-Derived Macrophage THP-1 Cells

    Directory of Open Access Journals (Sweden)

    Hong-Yeoul Kim

    2008-08-01

    Full Text Available Red ginseng is one of the most popular traditional medicines in Korea because its soluble hot-water extract is known to be very effective on enhancing immunity as well as inhibiting inflammation. Recently, we developed a new technique, called the HACgearshift system, which can pulverize red ginseng into the ultra-fine granules ranging from 0.2 to 7.0 μm in size. In this study, the soluble hot-water extract of those ultra-fine granules of red ginseng (URG was investigated and compared to that of the normal-sized granules of red ginseng (RG. The high pressure liquid chromatographic analyses of the soluble hot-water extracts of both URG and RG revealed that URG had about 2-fold higher amounts of the ginsenosides, the biologically active components in red ginseng, than RG did. Using quantitative RT-PCR, cytokine profiling against the Escherichia coli lipopolysaccharide (LPS in the monocyte-derived macrophage THP-1 cells demonstrated that the URG-treated cells showed a significant reduction in cytokine expression than the RG-treated ones. Transcription expression of the LPS-induced cytokines such as TNF-α, IL-1β, IL-6, IL-8, IL-10, and TGF-β was significantly inhibited by URG compared to RG. These results suggest that some biologically active and soluble components in red ginseng can be more effectively extracted from URG than RG by standard hot-water extraction.

  3. Treatment of hyper-granulated limb wounds in horses

    Directory of Open Access Journals (Sweden)

    O. A. Bader

    2011-01-01

    Full Text Available This study was performed to investigate the different methods of treating hyper granulation tissue on experimentally induced wounds in equine limbs. Wounds were induced by removal of a skin patch and subcutaneous tissue for about 5-7 cm width and 6-8 cm in length from the dorsal and lateral aspect of the fore and hind limbs below the carpal and tarsal joints. The wounds were left open without treatment and the animals were trained 2-2.5 hours every day for about 3-5 weeks until hyper granulation tissue was developed. The schedule for the treatment of hyper granulation was divided into five groups each contained eight wounds of hyper granulation tissue; each main group was divided into two subgroups. The subgroups of first, second, third, fourth and fifth groups were treated by the following schedules: bandage alone; copper sulphate ointment 10%; silver nitrate ointment 2%; red mercury ointment 11%; and laser therapy (at a total dose of 9.72 Joule / cm2 respectively. While the second subgroups were treated by surgical resection of the hyper granulation tissue, followed by the same treatments applied on the first subgroup. The bandage for all experimental groups was changed every 48 hours until healing was occurred. The clinical and histological observation of the first group revealed that the healing take long period comparing with other groups. The mean of wound healing were 65 days in non surgical removal of hyper granulation tissue subgroup, while 57 days in surgical removed of hyper granulation tissue subgroup. The results of the second, third, fourth groups revealed that the caustic material especially red mercury has a role in healing processes through depressing the hyper granulation tissue. The mean of wound healing of the second group was 42.25 days in non surgical removal of hyper granulation tissue subgroup while 37.25 days in surgically removed hyper granulation tissue subgroup. In the third group the mean of wound healing was 45

  4. Methylmercury disrupts the balance between phosphorylated and non-phosphorylated cofilin in primary cultures of mice cerebellar granule cells A proteomic study

    International Nuclear Information System (INIS)

    Vendrell, Iolanda; Carrascal, Montserrat; Campos, Francisco; Abian, Joaquin; Sunol, Cristina

    2010-01-01

    Methylmercury is an environmental contaminant that is particularly toxic to the developing central nervous system; cerebellar granule neurons are especially vulnerable. Here, primary cultures of cerebellar granule cells (CGCs) were continuously exposed to methylmercury for up to 16 days in vitro (div). LC50 values were 508 ± 199, 345 ± 47, and 243 ± 45 nM after exposure for 6, 11, and 16 div, respectively. Proteins from cultured mouse CGCs were separated by 2DE. Seventy-one protein spots were identified by MALDI-TOF PMF and MALDI-TOF/TOF sequencing. Prolonged exposure to a subcytotoxic concentration of methylmercury significantly increased non-phosphorylated cofilin both in cell protein extracts (1.4-fold; p < 0.01) and in mitochondrial-enriched fractions (1.7-fold; p < 0.01). The decrease in P-cofilin induced by methylmercury was concentration-dependent and occurred after different exposure times. The percentage of P-cofilin relative to total cofilin significantly decreased to 49 ± 13% vs. control cells after exposure to 300 nM methylmercury for 5 div. The balance between the phosphorylated and non-phosphorylated form of cofilin regulates actin dynamics and facilitates actin filament turnover. Filamentous actin dynamics and reorganization are responsible of neuron shape change, migration, polarity formation, regulation of synaptic structures and function, and cell apoptosis. An alteration of the complex regulation of the cofilin phosphorylation/dephosphorylation pathway could be envisaged as an underlying mechanism compatible with reported signs of methylmercury-induced neurotoxicity.

  5. Effects of different feeder layers on culture of bovine embryonic stem cell-like cells in vitro.

    Science.gov (United States)

    Cong, Shan; Cao, Guifang; Liu, Dongjun

    2014-12-01

    To find a suitable feeder layer is important for successful culture conditions of bovine embryonic stem cell-like cells. In this study, expression of pluripotency-related genes OCT4, SOX2 and NANOG in bovine embryonic stem cell-like cells on mouse embryonic fibroblast feeder layers at 1-5 passages were monitored in order to identify the possible reason that bovine embryonic stem cell-like cells could not continue growth and passage. Here, we developed two novel feeder layers, mixed embryonic fibroblast feeder layers of mouse and bovine embryonic fibroblast at different ratios and sources including mouse fibroblast cell lines. The bovine embryonic stem cell-like cells generated in our study displayed typical stem cell morphology and expressed specific markers such as OCT4, stage-specific embryonic antigen 1 and 4, alkaline phosphatase, SOX2, and NANOG mRNA levels. When feeder layers and cell growth factors were removed, the bovine embryonic stem cell-like cells formed embryoid bodies in a suspension culture. Furthermore, we compared the expression of the pluripotent markers during bovine embryonic stem cell-like cell in culture on mixed embryonic fibroblast feeder layers, including mouse fibroblast cell lines feeder layers and mouse embryonic fibroblast feeder layers by real-time quantitative polymerase chain reaction. Results suggested that mixed embryonic fibroblast and sources including mouse fibroblast cell lines feeder layers were more suitable for long-term culture and growth of bovine embryonic stem cell-like cells than mouse embryonic fibroblast feeder layers. The findings may provide useful experimental data for the establishment of an appropriate culture system for bovine embryonic stem cell lines.

  6. A realistic large-scale model of the cerebellum granular layer predicts circuit spatio-temporal filtering properties

    Directory of Open Access Journals (Sweden)

    Sergio Solinas

    2010-05-01

    Full Text Available The way the cerebellar granular layer transforms incoming mossy fiber signals into new spike patterns to be related to Purkinje cells is not yet clear. Here, a realistic computational model of the granular layer was developed and used to address four main functional hypotheses: center-surround organization, time-windowing, high-pass filtering in responses to spike bursts and coherent oscillations in response to diffuse random activity. The model network was activated using patterns inspired by those recorded in vivo. Burst stimulation of a small mossy fiber bundle resulted in granule cell bursts delimited in time (time windowing and space (center-surround by network inhibition. This burst-burst transmission showed marked frequency-dependence configuring a high-pass filter with cut-off frequency around 100 Hz. The contrast between center and surround properties was regulated by the excitatory-inhibitory balance. The stronger excitation made the center more responsive to 10-50 Hz input frequencies and enhanced the granule cell output (with spike occurring earlier and with higher frequency and number compared to the surround. Finally, over a certain level of mossy fiber background activity, the circuit generated coherent oscillations in the theta-frequency band. All these processes were fine-tuned by NMDA and GABA-A receptor activation and neurotransmitter vesicle cycling in the cerebellar glomeruli. This model shows that available knowledge on cellular mechanisms is sufficient to unify the main functional hypotheses on the cerebellum granular layer and suggests that this network can behave as an adaptable spatio-temporal filter coordinated by theta-frequency oscillations.

  7. Effect of duration and severity of migraine on retinal nerve fiber layer, ganglion cell layer, and choroidal thickness.

    Science.gov (United States)

    Abdellatif, Mona K; Fouad, Mohamed M

    2018-03-01

    To investigate the factors in migraine that have the highest significance on retinal and choroidal layers' thickness. Ninety patients with migraine and 40 age-matched healthy participants were enrolled in this observational, cross-sectional study. After full ophthalmological examination, spectral domain-optical coherence tomography was done for all patients measuring the thickness of ganglion cell layer and retinal nerve fiber layer. Enhanced depth imaging technique was used to measure the choroidal thickness. There was significant thinning in the superior and inferior ganglion cell layers, all retinal nerve fiber layer quadrants, and all choroidal quadrants (except for the central subfield) in migraineurs compared to controls. The duration of migraine was significantly correlated with ganglion cell layer, retinal nerve fiber layer, and all choroidal quadrants, while the severity of migraine was significantly correlated with ganglion cell layer and retinal nerve fiber layer only. Multiregression analysis showed that the duration of migraine is the most important determinant factor of the superior retinal nerve fiber layer quadrant (β = -0.375, p = 0.001) and in all the choroidal quadrants (β = -0.531, -0.692, -0.503, -0.461, -0.564, respectively, p  layer quadrants (β = -0.256, -0.335, -0.308; p  = 0.036, 0.005, 0.009, respectively) and the inferior ganglion cell layer hemisphere (β = -0.377 and p = 0.001). Ganglion cell layer, retinal nerve fiber layer, and choroidal thickness are significantly thinner in patients with migraine. The severity of migraine has more significant influence in the thinning of ganglion cell layer and retinal nerve fiber layer, while the duration of the disease affected the choroidal thickness more.

  8. Sonic hedgehog-induced histone deacetylase activation is required for cerebellar granule precursor hyperplasia in medulloblastoma.

    Directory of Open Access Journals (Sweden)

    Seung Joon Lee

    Full Text Available Medulloblastoma, the most common pediatric brain tumor, is thought to arise from deregulated proliferation of cerebellar granule precursor (CGP cells. Sonic hedgehog (Shh is the primary mitogen that regulates proliferation of CGP cells during the early stages of postnatal cerebellum development. Aberrant activation of Shh signaling during this time has been associated with hyperplasia of CGP cells and eventually may lead to the development of medulloblastoma. The molecular targets of Shh signaling involved in medulloblastoma formation are still not well-understood. Here, we show that Shh regulates sustained activation of histone deacetylases (HDACs and that this activity is required for continued proliferation of CGP cells. Suppression of HDAC activity not only blocked the Shh-induced CGP proliferation in primary cell cultures, but also ameliorated aberrant CGP proliferation at the external germinal layer (EGL in a medulloblastoma mouse model. Increased levels of mRNA and protein of several HDAC family members were found in medulloblastoma compared to wild type cerebellum suggesting that HDAC activity is required for the survival/progression of tumor cells. The identification of a role of HDACs in the early steps of medulloblastoma formation suggests there may be a therapeutic potential for HDAC inhibitors in this disease.

  9. Maintaining sufficient nanos is a critical function for polar granule component in the specification of primordial germ cells.

    Science.gov (United States)

    Deshpande, Girish; Spady, Emma; Goodhouse, Joe; Schedl, Paul

    2012-11-01

    Primordial germ cells (PGC) are the precursors of germline stem cells. In Drosophila, PGC specification is thought to require transcriptional quiescence and three genes, polar granule component (pgc), nanos (nos), and germ cell less (gcl) function to downregulate Pol II transcription. While it is not understood how nos or gcl represses transcription, pgc does so by inhibiting the transcription elongation factor b (P-TEFb), which is responsible for phosphorylating Ser2 residues in the heptad repeat of the C-terminal domain (CTD) of the largest Pol II subunit. In the studies reported here, we demonstrate that nos are a critical regulatory target of pgc. We show that a substantial fraction of the PGCs in pgc embryos have greatly reduced levels of Nos protein and exhibit phenotypes characteristic of nos PGCs. Lastly, restoring germ cell-specific expression of Nos is sufficient to ameliorate the pgc phenotype.

  10. Azurophil granule proteins constitute the major mycobactericidal proteins in human neutrophils and enhance the killing of mycobacteria in macrophages

    DEFF Research Database (Denmark)

    Jena, Prajna; Mohanty, Soumitra; Mohanty, Tirthankar

    2012-01-01

    Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil...... and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule...... proteins (AZP) were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane...

  11. Back contact buffer layer for thin-film solar cells

    Science.gov (United States)

    Compaan, Alvin D.; Plotnikov, Victor V.

    2014-09-09

    A photovoltaic cell structure is disclosed that includes a buffer/passivation layer at a CdTe/Back contact interface. The buffer/passivation layer is formed from the same material that forms the n-type semiconductor active layer. In one embodiment, the buffer layer and the n-type semiconductor active layer are formed from cadmium sulfide (CdS). A method of forming a photovoltaic cell includes the step of forming the semiconductor active layers and the buffer/passivation layer within the same deposition chamber and using the same material source.

  12. Endocytosis of Cytotoxic Granules Is Essential for Multiple Killing of Target Cells by T Lymphocytes.

    Science.gov (United States)

    Chang, Hsin-Fang; Bzeih, Hawraa; Schirra, Claudia; Chitirala, Praneeth; Halimani, Mahantappa; Cordat, Emmanuelle; Krause, Elmar; Rettig, Jens; Pattu, Varsha

    2016-09-15

    CTLs are serial killers that kill multiple target cells via exocytosis of cytotoxic granules (CGs). CG exocytosis is tightly regulated and has been investigated in great detail; however, whether CG proteins are endocytosed following exocytosis and contribute to serial killing remains unknown. By using primary CTLs derived from a knock-in mouse of the CG membrane protein Synaptobrevin2, we show that CGs are endocytosed in a clathrin- and dynamin-dependent manner. Following acidification, endocytosed CGs are recycled through early and late, but not recycling endosomes. CGs are refilled with granzyme B at the late endosome stage and polarize to subsequent synapses formed between the CTL and new target cells. Importantly, inhibiting CG endocytosis in CTLs results in a significant reduction of their cytotoxic activity. Thus, our data demonstrate that continuous endocytosis of CG membrane proteins is a prerequisite for efficient serial killing of CTLs and identify key events in this process. Copyright © 2016 by The American Association of Immunologists, Inc.

  13. Biomass conversion inhibitors furfural and 5-hydroxymethylfurfural induce formation of messenger RNP granules and attenuate translation activity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Iwaki, Aya; Kawai, Takao; Yamamoto, Yosuke; Izawa, Shingo

    2013-03-01

    Various forms of stress can cause an attenuation of bulk translation activity and the accumulation of nontranslating mRNAs into cytoplasmic messenger RNP (mRNP) granules termed processing bodies (P-bodies) and stress granules (SGs) in eukaryotic cells. Furfural and 5-hydroxymethylfurfural (HMF), derived from lignocellulosic biomass, inhibit yeast growth and fermentation as stressors. Since there is no report regarding their effects on the formation of cytoplasmic mRNP granules, here we investigated whether furfural and HMF cause the assembly of yeast P-bodies and SGs accompanied by translational repression. We found that furfural and HMF cause the attenuation of bulk translation activity and the assembly of cytoplasmic mRNP granules in Saccharomyces cerevisiae. Notably, a combination of furfural and HMF induced the remarkable repression of translation initiation and SG formation. These findings provide new information about the physiological effects of furfural and HMF on yeast cells, and also suggest the potential usefulness of cytoplasmic mRNP granules as a warning sign or index of the deterioration of cellular physiological status in the fermentation of lignocellulosic hydrolysates.

  14. In vitro utilization of amylopectin and high-amylose maize (Amylomaize) starch granules by human colonic bacteria.

    Science.gov (United States)

    Wang, X; Conway, P L; Brown, I L; Evans, A J

    1999-11-01

    It has been well established that a certain amount of ingested starch can escape digestion in the human small intestine and consequently enters the large intestine, where it may serve as a carbon source for bacterial fermentation. Thirty-eight types of human colonic bacteria were screened for their capacity to utilize soluble starch, gelatinized amylopectin maize starch, and high-amylose maize starch granules by measuring the clear zones on starch agar plates. The six cultures which produced clear zones on amylopectin maize starch- containing plates were selected for further studies for utilization of amylopectin maize starch and high-amylose maize starch granules A (amylose; Sigma) and B (Culture Pro 958N). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to detect bacterial starch-degrading enzymes. It was demonstrated that Bifidobacterium spp., Bacteroides spp., Fusobacterium spp., and strains of Eubacterium, Clostridium, Streptococcus, and Propionibacterium could hydrolyze the gelatinized amylopectin maize starch, while only Bifidobacterium spp. and Clostridium butyricum could efficiently utilize high-amylose maize starch granules. In fact, C. butyricum and Bifidobacterium spp. had higher specific growth rates in the autoclaved medium containing high-amylose maize starch granules and hydrolyzed 80 and 40% of the amylose, respectively. Starch-degrading enzymes were cell bound on Bifidobacterium and Bacteroides cells and were extracellular for C. butyricum. Active staining for starch-degrading enzymes on SDS-PAGE gels showed that the Bifidobacterium cells produced several starch-degrading enzymes with high relative molecular (M(r)) weights (>160,000), medium-sized relative molecular weights (>66,000), and low relative molecular weights (spp. and C. butyricum degraded and utilized granules of amylomaize starch.

  15. A Survey of Sludge Granulation Theories Under Anaerobic Conditions

    Directory of Open Access Journals (Sweden)

    Jalal Shayegan

    2011-01-01

    Full Text Available This paper surveys the different theories developed on anaerobic sludge granulation. The theories are generally categorized as physical, microbial, and thermodynamic approaches. In the physical approach to the granulation process, granulation is described by such physical conditions of the reactor as upflow velocity of gas and liquid streams, suspended solids in the effluent flow, and excess sludge removal. Microbial theories are based on the properties of specific organisms and on granule properties (granule structure and its microbiology. The thermodynamic approach studies such factors as hydrophobia, electrophoretic mobility, effective energy in granule adhesion process, and effect of proton transferring activities on bacterial membrane surfaces.

  16. Oligodendrocyte ablation affects the coordinated interaction between granule and Purkinje neurons during cerebellum development

    International Nuclear Information System (INIS)

    Collin, Ludovic; Doretto, Sandrine; Malerba, Monica; Ruat, Martial; Borrelli, Emiliana

    2007-01-01

    Oligodendrocytes (OLs) are the glial cells of the central nervous system (CNS) classically known to be devoted to the formation of myelin sheaths around most axons of the vertebrate brain. We have addressed the role of these cells during cerebellar development, by ablating OLs in vivo. Previous analyses had indicated that OL ablation during the first six postnatal days results into a striking cerebellar phenotype, whose major features are a strong reduction of granule neurons and aberrant Purkinje cells development. These two cell types are highly interconnected during cerebellar development through the production of molecules that help their proliferation, differentiation and maintenance. In this article, we present data showing that OL ablation has major effects on the physiology of Purkinje (PC) and granule cells (GC). In particular, OL ablation results into a reduction of sonic hedgehog (Shh), Brain Derived Neurotrophic Factor (BDNF), and Reelin (Rln) expression. These results indicate that absence of OLs profoundly alters the normal cerebellar developmental program

  17. PHYSICAL PROPERTIES OF LARGE AND SMALL GRANULES IN SOLAR QUIET REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    Yu Daren; Xie Zongxia; Hu Qinghua [Harbin Institute of Technology, Harbin 150001 (China); Yang Shuhong; Zhang Jun; Wang Jingxiu, E-mail: caddiexie@hotmail.com, E-mail: zjun@ourstar.bao.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2011-12-10

    The normal mode observations of seven quiet regions obtained by the Hinode spacecraft are analyzed to study the physical properties of granules. An artificial intelligence technique is introduced to automatically find the spatial distribution of granules in feature spaces. In this work, we investigate the dependence of granular continuum intensity, mean Doppler velocity, and magnetic fields on granular diameter. We recognized 71,538 granules by an automatic segmentation technique and then extracted five properties: diameter, continuum intensity, Doppler velocity, and longitudinal and transverse magnetic flux density to describe the granules. To automatically explore the intrinsic structures of the granules in the five-dimensional parameter space, the X-means clustering algorithm and one-rule classifier are introduced to define the rules for classifying the granules. It is found that diameter is a dominating parameter in classifying the granules and two families of granules are derived: small granules with diameters smaller than 1.''44, and large granules with diameters larger than 1.''44. Based on statistical analysis of the detected granules, the following results are derived: (1) the averages of diameter, continuum intensity, and Doppler velocity in the upward direction of large granules are larger than those of small granules; (2) the averages of absolute longitudinal, transverse, and unsigned flux density of large granules are smaller than those of small granules; (3) for small granules, the average of continuum intensity increases with their diameters, while the averages of Doppler velocity, transverse, absolute longitudinal, and unsigned magnetic flux density decrease with their diameters. However, the mean properties of large granules are stable; (4) the intensity distributions of all granules and small granules do not satisfy Gaussian distribution, while that of large granules almost agrees with normal distribution with a peak at 1.04 I

  18. Phospho-Rasputin Stabilization by Sec16 Is Required for Stress Granule Formation upon Amino Acid Starvation.

    Science.gov (United States)

    Aguilera-Gomez, Angelica; Zacharogianni, Margarita; van Oorschot, Marinke M; Genau, Heide; Grond, Rianne; Veenendaal, Tineke; Sinsimer, Kristina S; Gavis, Elizabeth R; Behrends, Christian; Rabouille, Catherine

    2017-07-25

    Most cellular stresses induce protein translation inhibition and stress granule formation. Here, using Drosophila S2 cells, we investigate the role of G3BP/Rasputin in this process. In contrast to arsenite treatment, where dephosphorylated Ser142 Rasputin is recruited to stress granules, we find that, upon amino acid starvation, only the phosphorylated Ser142 form is recruited. Furthermore, we identify Sec16, a component of the endoplasmic reticulum exit site, as a Rasputin interactor and stabilizer. Sec16 depletion results in Rasputin degradation and inhibition of stress granule formation. However, in the absence of Sec16, pharmacological stabilization of Rasputin is not enough to rescue the assembly of stress granules. This is because Sec16 specifically interacts with phosphorylated Ser142 Rasputin, the form required for stress granule formation upon amino acid starvation. Taken together, these results demonstrate that stress granule formation is fine-tuned by specific signaling cues that are unique to each stress. These results also expand the role of Sec16 as a stress response protein. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. Poliovirus infection induces the co-localization of cellular protein SRp20 with TIA-1, a cytoplasmic stress granule protein.

    Science.gov (United States)

    Fitzgerald, Kerry D; Semler, Bert L

    2013-09-01

    Different types of environmental stress cause mammalian cells to form cytoplasmic foci, termed stress granules, which contain mRNPs that are translationally silenced. These foci are transient and dynamic, and contain components of the cellular translation machinery as well as certain mRNAs and RNA binding proteins. Stress granules are known to be induced by conditions such as hypoxia, nutrient deprivation, and oxidative stress, and a number of cellular factors have been identified that are commonly associated with these foci. More recently it was discovered that poliovirus infection also induces the formation of stress granules, although these cytoplasmic foci appear to be somewhat compositionally unique. Work described here examined the punctate pattern of SRp20 (a host cell mRNA splicing protein) localization in the cytoplasm of poliovirus-infected cells, demonstrating the partial co-localization of SRp20 with the stress granule marker protein TIA-1. We determined that SRp20 does not co-localize with TIA-1, however, under conditions of oxidative stress, indicating that the close association of these two proteins during poliovirus infection is not representative of a general response to cellular stress. We confirmed that the expression of a dominant negative version of TIA-1 (TIA-1-PRD) results in the dissociation of stress granules. Finally, we demonstrated that expression of wild type TIA-1 or dominant negative TIA-1-PRD in cells during poliovirus infection does not dramatically affect viral translation. Taken together, these studies provide a new example of the unique cytoplasmic foci that form during poliovirus infection. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Poliovirus infection induces the co-localization of cellular protein SRp20 with TIA-1, a cytoplasmic stress granule protein

    Science.gov (United States)

    Fitzgerald, Kerry D.; Semler, Bert L.

    2013-01-01

    Different types of environmental stress cause mammalian cells to form cytoplasmic foci, termed stress granules, which contain mRNPs that are translationally silenced. These foci are transient and dynamic, and contain components of the cellular translation machinery as well as certain mRNAs and RNA binding proteins. Stress granules are known to be induced by conditions such as hypoxia, nutrient deprivation, and oxidative stress, and a number of cellular factors have been identified that are commonly associated with these foci. More recently it was discovered that poliovirus infection also induces the formation of stress granules, although these cytoplasmic foci appear to be somewhat compositionally unique. Work described here examined the punctate pattern of SRp20 (a host cell mRNA splicing protein) localization in the cytoplasm of poliovirus-infected cells, demonstrating the partial co-localization of SRp20 with the stress granule marker protein TIA-1. We determined that SRp20 does not co-localize with TIA-1, however, under conditions of oxidative stress, indicating that the close association of these two proteins during poliovirus infection is not representative of a general response to cellular stress. We confirmed that the expression of a dominant negative version of TIA-1 (TIA-1-PRD) results in the dissociation of stress granules. Finally, we demonstrated that expression of wild type TIA-1 or dominant negative TIA-1-PRD in cells during poliovirus infection does not dramatically affect viral translation. Taken together, these studies provide a new example of the unique cytoplasmic foci that form during poliovirus infection. PMID:23830997

  1. The critical role of Golgi cells in regulating spatio-temporal integration and plasticity at the cerebellum input stage

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available After the discovery at the end of the 19th century (Golgi, 1883, the Golgi cell was precisely described by S.R. y Cajal (see Cajal, 1987, 1995 and functionally identified as an inhibitory interneuron 50 years later by J.C. Eccles and colleagues (Eccles e al., 1967. Then, its role has been casted by Marr (1969 within the Motor Learning Theory as a codon size regulator of granule cell activity. It was immediately clear that Golgi cells had to play a critical role, since they are the main inhibitory interneuron of the granular layer and control activity of as many as 100 millions granule cells. In vitro, Golgi cells show pacemaking, resonance, phase-reset and rebound-excitation in the theta-frequency band. These properties are likely to impact on their activity in vivo, which shows irregular spontaneous beating modulated by sensory inputs and burst responses to punctuate stimulation followed by a silent pause. Moreover, investigations have given insight into Golgi cells connectivity within the cerebellar network and on their impact on the spatio-temporal organization of activity. It turns out that Golgi cells can control both the temporal dynamics and the spatial distribution of information transmitted through the cerebellar network. Moreover, Golgi cells regulate the induction of long-term synaptic plasticity at the mossy fiber - granule cell synapse. Thus, the concept is emerging that Golgi cells are of critical importance for regulating granular layer network activity bearing important consequences for cerebellar computation as a whole.

  2. Studies on the influence of laser beams on wound granulation

    International Nuclear Information System (INIS)

    Brunner, R.

    1982-01-01

    The influence of laser light of law energy on wound healing was tested on 204 rats in a blind study. The growth of granulation tissue in a polyvinylchloride cylinder implanted on the backs of the animals served as parameter for wound healing. Irradiation was carried out with a helium-neon laser (wavelength 632.8 nm) at daily doses of 0.5 J/cm 2 , 1.5 J/cm 2 , 4 J/cm 2 , 10 J/cm 2 and 20 J/cm 2 , and with incoherent non-linear polarized red light (wavelength 630 nm) with a daily dose of 4 J/cm 2 . This was repeated 8 times. Laser irradiation caused a statistically significant increase in wet and dry granulation tissue weight of 25% in the dose range 1.5 J/cm 2 to 20 J/cm 2 . At 0.5 J/cm 2 the effect was less, but the least effect was achieved by non-linear polarized incoherent red light. Bacteriological evaluation of wound germ counts revealed a marginally lower presence of high germ cell densities. In irradiated animals, histological and enzyme cytochemical findings revealed, in addition to a significant findings revealed, in addition to a significant increase in mast cells, a smaller increase in fibroblast count and a slight decrease in granulocytic and histiocytic elements. The biochemical evaluation of granulation tissue revealed no differences in collagen content between irradiated and unirradiated animals. (orig.) [de

  3. Digestion of Starch Granules from Maize, Potato and Wheat by Larvae of the the Yellow Mealworm, Tenebrio molitor and the Mexican Bean Weevil, Zabrotes subfasciatus

    Science.gov (United States)

    Meireles, Elaine A.; Carneiro, Cíntia N. B.; DaMatta, Renato A.; Samuels, Richard I.; Silva, Carlos P.

    2009-01-01

    Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut α-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One α-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other α-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chromatography., Digested starch granules from larvae fed on maize, potato or wheat were isolated from midgut contents. Combinations of starch granules with isolated α-amylases from both species showed similar patterns of granule degradation. In vitro enzymatic degradation of maize starch granules by the three different α-amylase fractions began by creating small holes and crater-like areas on the surface of the granules. Over time, these holes increased in number and area resulting in extensive degradation of the granule structure. Granules from potato did not show formation of pits and craters on their surface, but presented extensive erosion in their interior. For all types of starch, as soon as the interior of the starch granule was reached, the inner layers of amylose and amylopectin were differentially hydrolyzed, resulting in a striated pattern. These data support the hypothesis that the pattern of starch degradation depends more on the granule type than on the α-amylase involved. PMID:19619014

  4. [Protective effect and mechanism of compound Ginkgo biloba granules on oxidative stress injury of HUVEC].

    Science.gov (United States)

    Li, Qi; Chen, Xi; Kan, Xiao-Xi; Li, Yu-Jie; Yang, Qing; Wang, Ya-Jie; Chen, Ying; Weng, Xiao-Gang; Cai, Wei-Yan; Huang, He-Fei; Zhu, Xiao-Xin

    2016-02-01

    To reveal the protective and anti-apoptosis effect of compound Ginkgo biloba granules on oxidative stress injury of human umbilical vein endothelial cells (HUVEC). Negative control group, H2O2 model group and 4 drug pretreatment groups (80, 160, 320, 640 mg• L⁻¹) were established. The cell proliferation, morphological changes in each group after oxidative stress injury was detected by MTT assay and through microscope observation respectively. The content of LDH, MDA, SOD and NO and SOD activity in supernatant were detected to judge the protection effect of the drugs on endothelial cells. The protective effect on HUVEC apoptosis was analyzed by Caspase-3 activity test and Annexin V-FITC/PI staining. Western blot was used to observe the expression of apoptosis-related proteins Bcl-2 and Bax. Results showed that 1 200 μmol• L⁻¹ H2O2 can induce oxidative stress injury in endothelial cells and reduce the cell survival rate; cell proliferation inhibition degree is positively correlated with the effect time of H2O2. Besides, 80, 160, 320 640 mg•L⁻¹ compound Ginkgo biloba granules can protect HUVEC from oxidative stress injury, recover the normal proliferation level of cells, improve their state, prohibit cell apoptosis, and can up-regulate and down-regulate the expression level of Bcl-2 and Bax respectively. In conclusion, compound G. biloba granules can protect HUVEC from the oxidative stress injury induced by H2O2, its mechanism may be correlated with inhibition of the mitochondrial apoptotic pathway in HUVEC. Copyright© by the Chinese Pharmaceutical Association.

  5. Impact of fill-level in twin-screw granulation on critical quality attributes of granules and tablets.

    Science.gov (United States)

    Meier, Robin; Moll, Klaus-Peter; Krumme, Markus; Kleinebudde, Peter

    2017-06-01

    In a previous study a change of the fill-level in the barrel exerted a huge influence on the twin-screw granulation (TSG) process of a high drug loaded, simplified formulation. The present work investigated this influence systematically. The specific feed load (SFL) indicating the mass per revolution as surrogate parameter for the fill-level was applied and the correlation to the real volumetric fill level of an extruder could be demonstrated by a newly developed method. A design of experiments was conducted to examine the combined influence of SFL and screw speed on the process and on critical quality attributes of granules and tablets. The same formulation was granulated at constant liquid level with the same screw configuration and led to distinctively different results by only changing the fill-level and the screw speed. The power consumption of the extruder increased at higher SFLs with hardly any influence of screw speed. At low SFL the median residence time was mainly fill-level dependent and at higher SFL mainly screw speed dependent. Optimal values for the product characteristics were found at medium values for the SFL. Granule size distributions shifted from mono-modal and narrow shape to broader and even bimodal distributions of larger median granule sizes, when exceeding or falling below a certain fill-level. Deviating from the optimum fill-level, tensile strength of tablets decreased by about 25% and disintegration times of tablets increased for more than one third. At low fill-levels, material accumulation in front of the kneading zone was detected by pressure measurements and was assumed to be responsible for the unfavored product performance. At high fill-levels, granule consolidation due to higher propensity of contact with the result of higher material temperature was accounted for inferior product performance. The fill-level was found to be an important factor in assessment and development of twin-screw granulation processes as it impacted

  6. Posttraining ablation of adult-generated olfactory granule cells degrades odor-reward memories.

    Science.gov (United States)

    Arruda-Carvalho, Maithe; Akers, Katherine G; Guskjolen, Axel; Sakaguchi, Masanori; Josselyn, Sheena A; Frankland, Paul W

    2014-11-19

    Proliferation of neural progenitor cells in the subventricular zone leads to the continuous generation of new olfactory granule cells (OGCs) throughout life. These cells synaptically integrate into olfactory bulb circuits after ∼2 weeks and transiently exhibit heightened plasticity and responses to novel odors. Although these observations suggest that adult-generated OGCs play important roles in olfactory-related memories, global suppression of olfactory neurogenesis does not typically prevent the formation of odor-reward memories, perhaps because residual OGCs can compensate. Here, we used a transgenic strategy to selectively ablate large numbers of adult-generated OGCs either before or after learning in mice. Consistent with previous studies, pretraining ablation of adult-generated OGCs did not prevent the formation of an odor-reward memory, presumably because existing OGCs can support memory formation in their absence. However, ablation of a similar cohort of adult-generated OGCs after training impaired subsequent memory expression, indicating that if these cells are available at the time of training, they play an essential role in subsequent expression of odor-reward memories. Memory impairment was associated with the loss of adult-generated OGCs that were >10 d in age and did not depend on the developmental stage in which they were generated, suggesting that, once sufficiently mature, OGCs generated during juvenility and adulthood play similar roles in the expression of odor-reward memories. Finally, ablation of adult-generated OGCs 1 month after training did not produce amnesia, indicating that adult-generated OGCs play a time-limited role in the expression of odor-reward memories. Copyright © 2014 the authors 0270-6474/14/3415793-11$15.00/0.

  7. Clarithromycin highly-loaded gastro-floating fine granules prepared by high-shear melt granulation can enhance the efficacy of Helicobacter pylori eradication.

    Science.gov (United States)

    Aoki, Hajime; Iwao, Yasunori; Mizoguchi, Midori; Noguchi, Shuji; Itai, Shigeru

    2015-05-01

    In an effort to develop a new gastro-retentive drug delivery system (GRDDS) without a large amount of additives, 75% clarithromycin (CAM) loaded fine granules were prepared with three different hydrophobic binders by high-shear melt granulation and their properties were evaluated. Granules containing the higher hydrophobic binder showed sustained drug release and were able to float over 24h. The synchrotron X-ray CT measurement indicated that both the high hydrophobicity of the binder and the void space inside the granules might be involved in their buoyancy. In an in vivo experiment, the floating granules more effectively eradicated Helicobacter pylori than a CAM suspension by remaining in the stomach for a longer period. In short, CAM highly-loaded gastro-floating fine granules can enhance the eradication efficiency of H. pylori compared with CAM alone. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. The Optical Fractionator Technique to Estimate Cell Numbers in a Rat Model of Electroconvulsive Therapy

    DEFF Research Database (Denmark)

    Olesen, Mikkel Vestergaard; Needham, Esther Kjær; Pakkenberg, Bente

    2017-01-01

    present the optical fractionator in conjunction with BrdU immunohistochemistry to estimate the production and survival of newly-formed neurons in the granule cell layer (including the sub-granular zone) of the rat hippocampus following electroconvulsive stimulation, which is among the most potent...

  9. Increased accuracy of starch granule type quantification using mixture distributions.

    Science.gov (United States)

    Tanaka, Emi; Ral, Jean-Phillippe F; Li, Sean; Gaire, Raj; Cavanagh, Colin R; Cullis, Brian R; Whan, Alex

    2017-01-01

    The proportion of granule types in wheat starch is an important characteristic that can affect its functionality. It is widely accepted that granule types are either large, disc-shaped A-type granules or small, spherical B-type granules. Additionally, there are some reports of the tiny C-type granules. The differences between these granule types are due to its carbohydrate composition and crystallinity which is highly, but not perfectly, correlated with the granule size. A majority of the studies that have considered granule types analyse them based on a size threshold rather than chemical composition. This is understandable due to the expense of separating starch into different types. While the use of a size threshold to classify granule type is a low-cost measure, this results in misclassification. We present an alternative, statistical method to quantify the proportion of granule types by a fit of the mixture distribution, along with an R package, a web based app and a video tutorial for how to use the web app to enable its straightforward application. Our results show that the reliability of the genotypic effects increase approximately 60% using the proportions of the A-type and B-type granule estimated by the mixture distribution over the standard size-threshold measure. Although there was a marginal drop in reliability for C-type granules. The latter is likely due to the low observed genetic variance for C-type granules. The determination of the proportion of granule types from size-distribution is better achieved by using the mixing probabilities from the fit of the mixture distribution rather than using a size-threshold.

  10. Layer-by-Layer Heparinization of the Cell Surface by Using Heparin-Binding Peptide Functionalized Human Serum Albumin.

    Science.gov (United States)

    Song, Guowei; Hu, Yaning; Liu, Yusheng; Jiang, Rui

    2018-05-20

    Layer-by-layer heparinization of therapeutic cells prior to transplantation is an effective way to inhibit the instant blood-mediated inflammatory reactions (IBMIRs), which are the major cause of early cell graft loss during post-transplantation. Here, a conjugate of heparin-binding peptide (HBP) and human serum albumin (HSA), HBP-HSA, was synthesized by using heterobifunctional crosslinker. After the first heparin layer was coated on human umbilical vein endothelial cells (HUVECs) by means of the HBP-polyethylene glycol-phospholipid conjugate, HBP-HSA and heparin were then applied to the cell surface sequentially to form multiple layers. The immobilization and retention of heparin were analyzed by confocal microscopy and flow cytometry, respectively, and the cytotoxity of HBP-HSA was further evaluated by cell viability assay. Results indicated that heparin was successfully introduced to the cell surface in a layer-by-layer way and retained for at least 24 h, while the cytotoxity of HBP-HSA was negligible at the working concentration. Accordingly, this conjugate provides a promising method for co-immobilization of heparin and HSA to the cell surface under physiological conditions with improved biocompatibility.

  11. Mathematical model of melt flow channel granulator

    Directory of Open Access Journals (Sweden)

    A. A. Kiselev

    2016-01-01

    Full Text Available Granulation of carbohydrate-vitamin-mineral supplements based on molasses is performed at a high humidity (26 %, so for a stable operation of granulator it is necessary to reveal its melt flow pattern. To describe melt non-isothermal flow in the granulator a mathematical model with following initial equations: continuity equation, motion equation and rheological equation – was developed. The following assumptions were adopted: the melt flow in the granulator is a steady laminar flow; inertial and gravity forces can be ignored; melt is an incompressible fluid; velocity gradient in the flow direction is much smaller than in the transverse direction; the pressure gradient over the cross section of the channel is constant; the flow is hydrodynamically fully developed; effects impact on the channel inlet and outlet may be neglected. Due to the assumptions adopted, it can be considered that in this granulator only velocity components in the x-direction are significant and all the members of the equation with the components and their derivatives with respect to the coordinates y and z can be neglected. The resulting solutions were obtained: the equation for the mean velocity, the equation for determining the volume flow, the formula for calculating of mean time of the melt being in the granulator, the equation for determining the shear stress, the equation for determining the shear rate and the equation for determining the pressure loss. The results of calculations of the equations obtained are in complete agreement with the experimental data; deviation range is 16–19 %. The findings about the melt movement pattern in granulator allowed developing a methodology for calculating a rational design of the granulator molding unit.

  12. Protective Effect of Edaravone in Primary Cerebellar Granule Neurons against Iodoacetic Acid-Induced Cell Injury

    Directory of Open Access Journals (Sweden)

    Xinhua Zhou

    2015-01-01

    Full Text Available Edaravone (EDA is clinically used for treatment of acute ischemic stroke in Japan and China due to its potent free radical-scavenging effect. However, it has yet to be determined whether EDA can attenuate iodoacetic acid- (IAA- induced neuronal death in vitro. In the present study, we investigated the effect of EDA on damage of IAA-induced primary cerebellar granule neurons (CGNs and its possible underlying mechanisms. We found that EDA attenuated IAA-induced cell injury in CGNs. Moreover, EDA significantly reduced intracellular reactive oxidative stress production, loss of mitochondrial membrane potential, and caspase 3 activity induced by IAA. Taken together, EDA protected CGNs against IAA-induced neuronal damage, which may be attributed to its antiapoptotic and antioxidative activities.

  13. Effect of p-layer properties on nanocrystalline absorber layer and thin film silicon solar cells

    International Nuclear Information System (INIS)

    Chowdhury, Amartya; Adhikary, Koel; Mukhopadhyay, Sumita; Ray, Swati

    2008-01-01

    The influence of the p-layer on the crystallinity of the absorber layer and nanocrystalline silicon thin film solar cells has been studied. Boron doped Si : H p-layers of different crystallinities have been prepared under different power pressure conditions using the plasma enhanced chemical vapour deposition method. The crystalline volume fraction of p-layers increases with the increase in deposition power. Optical absorption of the p-layer reduces as the crystalline volume fraction increases. Structural studies at the p/i interface have been done by Raman scattering studies. The crystalline volume fraction of the i-layer increases as that of the p-layer increases, the effect being more prominent near the p/i interface. Grain sizes of the absorber layer decrease from 9.2 to 7.2 nm and the density of crystallites increases as the crystalline volume fraction of the p-layer increases and its grain size decreases. With increasing crystalline volume fraction of the p-layer solar cell efficiency increases

  14. Decreased surface expression of the δ subunit of the GABAA receptor contributes to reduced tonic inhibition in dentate granule cells in a mouse model of fragile X syndrome.

    Science.gov (United States)

    Zhang, Nianhui; Peng, Zechun; Tong, Xiaoping; Lindemeyer, A Kerstin; Cetina, Yliana; Huang, Christine S; Olsen, Richard W; Otis, Thomas S; Houser, Carolyn R

    2017-11-01

    While numerous changes in the GABA system have been identified in models of Fragile X Syndrome (FXS), alterations in subunits of the GABA A receptors (GABA A Rs) that mediate tonic inhibition are particularly intriguing. Considering the key role of tonic inhibition in controlling neuronal excitability, reduced tonic inhibition could contribute to FXS-associated disorders such as hyperactivity, hypersensitivity, and increased seizure susceptibility. The current study has focused on the expression and function of the δ subunit of the GABA A R, a major subunit involved in tonic inhibition, in granule cells of the dentate gyrus in the Fmr1 knockout (KO) mouse model of FXS. Electrophysiological studies of dentate granule cells revealed a marked, nearly four-fold, decrease in tonic inhibition in the Fmr1 KO mice, as well as reduced effects of two δ subunit-preferring pharmacological agents, THIP and DS2, supporting the suggestion that δ subunit-containing GABA A Rs are compromised in the Fmr1 KO mice. Immunohistochemistry demonstrated a small but statistically significant decrease in δ subunit labeling in the molecular layer of the dentate gyrus in Fmr1 KO mice compared to wildtype (WT) littermates. The discrepancy between the large deficits in GABA-mediated tonic inhibition in granule cells in the Fmr1 KO mice and only modest reductions in immunolabeling of the δ subunit led to studies of surface expression of the δ subunit. Cross-linking experiments followed by Western blot analysis demonstrated a small, non-significant decrease in total δ subunit protein in the hippocampus of Fmr1 KO mice, but a four-fold decrease in surface expression of the δ subunit in these mice. No significant changes were observed in total or surface expression of the α4 subunit protein, a major partner of the δ subunit in the forebrain. Postembedding immunogold labeling for the δ subunit demonstrated a large, three-fold, decrease in the number of symmetric synapses with

  15. A comparative study of the influence of alpha-lactose monohydrate particle morphology on granule and tablet properties after roll compaction/dry granulation.

    Science.gov (United States)

    Grote, Simon; Kleinebudde, Peter

    2018-05-29

    The influence of particle morphology and size of alpha-lactose monohydrate on dry granules and tablets was studied. Four different morphologies were investigated: Two grades of primary crystals, which differed in their particle size and structure (compact crystals vs. agglomerates). The materials were roll compacted at different specific compaction forces and changes in the particle size distribution and the specific surface area were measured. Afterwards, two fractions of granules were pressed to tablets and the tensile strength was compared to that from tablets compressed from the raw materials. The specific surface area was increased induced by roll compaction/dry granulation for all materials. At increased specific compaction forces, the materials showed sufficient size enlargement. The morphology of lactose determined the strength of direct compressed tablets. In contrast, the strength of granule tablets was leveled by the previous compression step during roll compaction/dry granulation. Thus, the tensile strength of tablets compressed directly from the powder mixtures determined whether materials exhibited a loss in tabletability after roll compaction/dry granulation or not. The granule size had only a slight influence on the strength of produced tablets. In some cases, the fraction of smaller granules showed a higher tensile strength compared to the larger fraction.

  16. Granulated wood ash to forest soils. Effects on microorganisms, phosphorus availability, and spatial relationships in the humus layer; Granulerad vedaska till skog paa fastmark. Paaverkan paa fosfortillgaang, mikroorganismer och rumsliga variationsmoenster

    Energy Technology Data Exchange (ETDEWEB)

    Clarholm, Marianne [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1999-07-01

    The report summarises effects on microorganisms, phosphorus (P) availability and spatial relationships in the humus layer of two spruce forests in south-western Sweden four to seven years after application of 3.2 tonnes (t) (Skogaby), alternatively three or six t (Torup) of granulated wood ash. There were tendencies for increases in pH and in numbers of ciliates, flagellates and small nematodes while no effects were observed for naked amoebae, the major consumers of bacteria among the protozoa. After seven years, the amount of P in microbial biomass in the humus layer in the wood ash treatment (A) in Skogaby was significantly higher than in the control (C), increased amounts of microbial nitrogen and carbon were also recorded. Observations over time indicated that the P availability in the soil first decreased after the ash addition, but later increased above that in the control. The time course was most readily seen in the microbial biomass, which contained 50% of total P in the humus layer, an amount equal to ten times the yearly uptake in trees. The microbial biomass has a much higher P concentration as compared to the needles, the component of the tree with the highest concentration. The P in micro-organisms thus form a buffer against P deficiency for the trees. A test where the {sup 32}P uptake rate of excised mycorrhizal fine roots in the laboratory is used to establish P availability in the field, indicated an increased P availability in (A), which was in contrast to reported decreased uptake of P in trees, decreased P concentration in needles and also in roots, as compared to (C). In six treatments investigated in Skogaby {sup 32}P uptake rates were negatively correlated to the P/C of the microbial biomass. Acid phosphatase activity was always higher in (A) as compared to treatments where soluble P had been added and at two out of five times also higher than in (C ). High phosphatase activity levels were at least partly connected to large amounts of

  17. New developments on transition radiation detectors using superconducting granules

    International Nuclear Information System (INIS)

    Yuan, L.C.L.

    1977-01-01

    By raising slightly either the temperature or the magnetic field to above that of the critical temperature or the critical magnetic field, the type I superconducting granules would still remain in the superconducting state which becomes a metastable state and is called the superheated superconducting state. If a relativistic charged particle incident on such a granule which is located in a colloidal suspension has imported to it an energy that is above the threshold energy (for state flipping) of the granule then it would flip to the normal state. The threshold energy of a granule is a function of the square of its radius, whereas the energy loss of a charged particle due to ionization is linearly proportional to the radius. The size of the granule can be pre-determined to be such that its threshold energy is slightly above the ionization loss of a relativistic charged particle. Then the traversal of the charged particle through such a granule would not affect the superconducting state of the granule unless a transition x-ray radiation is emitted at the surface of the granule by the traversing particle and the x-ray transition radiation is immediately absorbed either in total or partially by the metallic granule causing it to flip to the normal state. The total intensity of the x-ray transition radiation is linearly proportional to the Lorentz factor γ of the traversing particle, and the number of granules flipped would also be a measure of γ. Three methods for detecting the flipping of granules from the superconducting state to the normal state are described. They include the frequency measuring method, the SQUID method, and the pulse method with low noise amplifier system

  18. Disintegration of aerobic granules induced by trans-2-decenoic acid.

    Science.gov (United States)

    Cai, Pei-Jie; Xiao, Xiang; He, Yan-Rong; Li, Wen-Wei; Yu, Lei; Yu, Han-Qing

    2013-01-01

    One current major hurdle to practical implementation of aerobic granule technology is the frequent occurrence of granule disintegration during long-term operation. However, the mechanism behind this is largely unclear today. Here, 2-decenoic acid, which has been previously demonstrated to be released by Pseudomonas aeruginosa and disperse biofilms, was found to also induce the disintegration of aerobic granules. A comparison of the solution compositions from samples of only trans-2-decenoic acid, only aerobic granules, and granules added with trans-2-decenoic acid shows that bacteria and extracellular polymeric substances (EPS) were stripped from granule surface upon trans-2-decenoic acid dosing. Due to the possible toxicity of trans-2-decenoic acid at a saturation concentration, the disintegrated granules and the milky suspension in the disintegration test showed a significantly lower oxygen uptake rate than the un-integrated granules. This work suggests that trans-2-decenoic acid released by microbes might play a critical role in regulating the disintegration of aerobic granules. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Granulation of Cu-Al-Fe-Ni Bronze

    Directory of Open Access Journals (Sweden)

    Pisarek B.P.

    2014-08-01

    Full Text Available With the increase in wall thickness of the casting of iron-nickel-aluminium-bronze, by the reduction of the cooling rate the size of κII phase precipitates increases. This process, in the case of complex aluminium bronzes with additions of Cr, Mo and W is increased. Crystallization of big κII phase, during slow cooling of the casting, reduces the concentration of additives introduced to the bronze matrix and hardness. Undertaken research to develop technology of thick-walled products (g> 6 mm of complex aluminium bronzes. Particular attention was paid to the metallurgy of granules. As a result, a large cooling speed of the alloy, and also high-speed solidification casting a light weight of the granules allows: to avoid micro-and macrosegregation, decreasing the particle size, increase the dispersion of phases in multiphase alloys. Depending on the size granules as possible is to provide finished products with a wall thickness greater than 6 mm by infiltration of liquid alloy of granules (composites. Preliminary studies was conducted using drip method granulate of CuAl10Fe5Ni5 bronze melted in a INDUTHERM-VC 500 D Vacuum Pressure Casting Machine. This bronze is a starting alloy for the preparation of the complex aluminium bronzes with additions of Cr, Mo, W and C or Si. Optimizations of granulation process was carried out. As the process control parameters taken a casting temperature t (°C and the path h (mm of free-fall of the metal droplets in the surrounding atmosphere before it is intensively cooled in a container of water. The granulate was subjected to a sieve analysis. For the objective function was assume maximize of the product of Um*n, the percentage weight “Um” and the quantity of granules ‘n’ in the mesh fraction. The maximum value of the ratio obtained for mesh fraction a sieve with a mesh aperture of 6.3 mm. In the intensively cooled granule of bronze was identified microstructure composed of phases: β and fine bainite

  20. Active unjamming of confluent cell layers

    Science.gov (United States)

    Marchetti, M. Cristina

    Cell motion inside dense tissues governs many biological processes, including embryonic development and cancer metastasis, and recent experiments suggest that these tissues exhibit collective glassy behavior. Motivated by these observations, we have studied a model of dense tissues that combines self-propelled particle models and vertex models of confluent cell layers. In this model, referred to as self-propelled Voronoi (SPV), cells are described as polygons in a Voronoi tessellation with directed noisy cell motility and interactions governed by a shape energy that incorporates the effects of cell volume incompressibility, contractility and cell-cell adhesion. Using this model, we have demonstrated a new density-independent solid-liquid transition in confluent tissues controlled by cell motility and a cell-shape parameter measuring the interplay of cortical tension and cell-cell adhesion. An important insight of this work is that the rigidity and dynamics of cell layers depends sensitively on cell shape. We have also used the SPV model to test a new method developed by our group to determine cellular forces and tissue stresses from experimentally accessible cell shapes and traction forces, hence providing the spatio-temporal distribution of stresses in motile dense tissues. This work was done with Dapeng Bi, Lisa Manning and Xingbo Yang. MCM was supported by NSF-DMR-1305184 and by the Simons Foundation.

  1. Formulation of a poorly water-soluble drug in sustained-release hollow granules with a high viscosity water-soluble polymer using a fluidized bed rotor granulator.

    Science.gov (United States)

    Asada, Takumi; Yoshihara, Naoki; Ochiai, Yasushi; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2018-04-25

    Water-soluble polymers with high viscosity are frequently used in the design of sustained-release formulations of poorly water-soluble drugs to enable complete release of the drug in the gastrointestinal tract. Tablets containing matrix granules with a water-soluble polymer are preferred because tablets are easier to handle and the multiple drug-release units of the matrix granules decreases the influences of the physiological environment on the drug. However, matrix granules with a particle size of over 800 μm sometimes cause a content uniformity problem in the tableting process because of the large particle size. An effective method of manufacturing controlled-release matrix granules with a smaller particle size is desired. The aim of this study was to develop tablets containing matrix granules with a smaller size and good controlled-release properties, using phenytoin as a model poorly water-soluble drug. We adapted the recently developed hollow spherical granule granulation technology, using water-soluble polymers with different viscosities. The prepared granules had an average particle size of 300 μm and sharp particle size distribution (relative width: 0.52-0.64). The values for the particle strength of the granules were 1.86-1.97 N/mm 2 , and the dissolution profiles of the granules were not affected by the tableting process. The dissolution profiles and the blood concentration levels of drug released from the granules depended on the viscosity of the polymer contained in the granules. We succeeded in developing the desired controlled-release granules, and this study should be valuable in the development of sustained-release formulations of poorly water-soluble drugs. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. High-shear granulation as a manufacturing method for cocrystal granules

    DEFF Research Database (Denmark)

    Rehder, Sönke; Christensen, Niels Peter Aae; Rantanen, Jukka

    2013-01-01

    and the respective excipients). The drug release was slightly decreased by cocrystal formation, most likely due to the lower solubility of the cocrystal. In the presence of calcium hydrogenphosphate however, no influence of cocrystal formation on either compactability or on drug release were observed, compared...... with the reference tablets. It was concluded that high-shear wet granulation is a valuable, however complex, manufacturing method for cocrystals. Cocrystal formation may influence compactability and drug release and thus affect drug performance and should be investigated during pre-formulation.......Cocrystal formation allows the tailoring of physicochemical as well as of mechanical properties of an API. However, there is a lack of large-scale manufacturing methods of cocrystals. Therefore, the objective of this work was to examine the suitability of high-shear wet granulation...

  3. Technical note: A method for isolating glycogen granules from ruminal protozoa for further characterization.

    Science.gov (United States)

    Hall, Mary Beth

    2016-03-01

    Evaluation of physical, chemical, and enzymatic hydrolysis characteristics of protozoal glycogen is best performed on a pure substrate to avoid interference from other cell components. A method for isolating protozoal glycogen granules without use of detergents or other potentially contaminating chemicals was developed. Rumen inoculum was incubated anerobically in vitro with glucose. Glycogen-laden protozoa produced in the fermentation, primarily isotrichids, were allowed to sediment in a separatory funnel and were dispensed. The protozoa were processed through repeated centrifugations and sonication to isolate glycogen granules largely free of feed and cellular debris. The final water-insoluble lyophilized product analyzed as 98.3% α-glucan with very rare starch granules and 1.9% protein. Observed losses of glycogen granules during the clean-up process indicate that this procedure should not be used for quantitative assessment of protozoal glycogen from fermentations. Further optimization of this procedure to enhance the amount of glycogen obtained per fermentation may be possible. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Coating of waste containing ceramic granules

    International Nuclear Information System (INIS)

    Neumann, W.; Kofler, O.

    1979-01-01

    Simulated high-level waste granules produced by fluidized-bed calcination were overcoated by chemical vapor deposition (CVD) with pyrocarbon and nickel in laboratory-scale experiments. Successful development enables pyrocrbon deposition at temperatures of 600 to 800 0 K. The coated granules have excellent properties for long-term waste storage

  5. Downstream processing from melt granulation towards tablets: In-depth analysis of a continuous twin-screw melt granulation process using polymeric binders.

    Science.gov (United States)

    Grymonpré, W; Verstraete, G; Vanhoorne, V; Remon, J P; De Beer, T; Vervaet, C

    2018-03-01

    The concept of twin-screw melt granulation (TSMG) has steadily (re)-gained interest in pharmaceutical formulation development as an intermediate step during tablet manufacturing. However, to be considered as a viable processing option for solid oral dosage forms there is a need to understand all critical sources of variability which could affect this granulation technique. The purpose of this study was to provide an in-depth analysis of the continuous TSMG process in order to expose the critical process parameters (CPP) and elucidate the impact of process and formulation parameters on the critical quality attributes (CQA) of granules and tablets during continuous TSMG. A first part of the study dealt with the screening of various amorphous polymers as binder for producing high-dosed melt granules of two model drug (i.e. acetaminophen and hydrochlorothiazide). The second part of this study described a quality-by-design (QbD) approach for melt granulation of hydrochlorothiazide in order to thoroughly evaluate TSMG, milling and tableting stage of the continuous TSMG line. Using amorphous polymeric binders resulted in melt granules with high milling efficiency due to their brittle behaviour without producing excessive amounts of fines, providing high granule yields with low friability. Therefore, it makes them extremely suitable for further downstream processing. One of the most important CPP during TSMG with polymeric binders was the granulation-torque, which - in case of polymers with high T g - increased during longer granulation runs to critical levels endangering the continuous process flow. However, by optimizing both screw speed and throughput or changing to polymeric binders with lower T g it was possible to significantly reduce this risk. This research paper highlighted that TSMG must be considered as a viable option during formulation development of solid oral dosage forms based on the robustness of the CQA of both melt granules and tablets. Copyright © 2017

  6. Ambient Layer-by-Layer ZnO Assembly for Highly Efficient Polymer Bulk Heterojunction Solar Cells

    KAUST Repository

    Eita, Mohamed Samir

    2015-02-04

    The use of metal oxide interlayers in polymer solar cells has great potential because metal oxides are abundant, thermally stable, and can be used in fl exible devices. Here, a layer-by-layer (LbL) protocol is reported as a facile, room-temperature, solution-processed method to prepare electron transport layers from commercial ZnO nanoparticles and polyacrylic acid (PAA) with a controlled and tunable porous structure, which provides large interfacial contacts with the active layer. Applying the LbL approach to bulk heterojunction polymer solar cells with an optimized ZnO layer thickness of H25 nm yields solar cell power-conversion effi ciencies (PCEs) of ≈6%, exceeding the effi ciency of amorphous ZnO interlayers formed by conventional sputtering methods. Interestingly, annealing the ZnO/PAA interlayers in nitrogen and air environments in the range of 60-300 ° C reduces the device PCEs by almost 20% to 50%, indicating the importance of conformational changes inherent to the PAA polymer in the LbL-deposited fi lms to solar cell performance. This protocol suggests a new fabrication method for solution-processed polymer solar cell devices that does not require postprocessing thermal annealing treatments and that is applicable to fl exible devices printed on plastic substrates.

  7. RhoG protein regulates platelet granule secretion and thrombus formation in mice.

    Science.gov (United States)

    Goggs, Robert; Harper, Matthew T; Pope, Robert J; Savage, Joshua S; Williams, Christopher M; Mundell, Stuart J; Heesom, Kate J; Bass, Mark; Mellor, Harry; Poole, Alastair W

    2013-11-22

    Rho GTPases such as Rac, RhoA, and Cdc42 are vital for normal platelet function, but the role of RhoG in platelets has not been studied. In other cells, RhoG orchestrates processes integral to platelet function, including actin cytoskeletal rearrangement and membrane trafficking. We therefore hypothesized that RhoG would play a critical role in platelets. Here, we show that RhoG is expressed in human and mouse platelets and is activated by both collagen-related peptide (CRP) and thrombin stimulation. We used RhoG(-/-) mice to study the function of RhoG in platelets. Integrin activation and aggregation were reduced in RhoG(-/-) platelets stimulated by CRP, but responses to thrombin were normal. The central defect in RhoG(-/-) platelets was reduced secretion from α-granules, dense granules, and lysosomes following CRP stimulation. The integrin activation and aggregation defects could be rescued by ADP co-stimulation, indicating that they are a consequence of diminished dense granule secretion. Defective dense granule secretion in RhoG(-/-) platelets limited recruitment of additional platelets to growing thrombi in flowing blood in vitro and translated into reduced thrombus formation in vivo. Interestingly, tail bleeding times were normal in RhoG(-/-) mice, suggesting that the functions of RhoG in platelets are particularly relevant to thrombotic disorders.

  8. Detection and Analysis of the Quality of Ibuprofen Granules

    Science.gov (United States)

    Yu-bin, Ji; Xin, LI; Guo-song, Xin; Qin-bing, Xue

    2017-12-01

    The Ibuprofen Granules comprehensive quality testing to ensure that it is in accordance with the provisions of Chinese pharmacopoeia. With reference of Chinese pharmacopoeia, the Ibuprofen Granules is tested by UV, HPLC, in terms of grain size checking, volume deviation, weight loss on drying detection, dissolution rate detection, and quality evaluation. Results indicated that Ibuprofen Granules conform to the standards. The Ibuprofen Granules are qualified and should be permitted to be marketed.

  9. ALS mutant SOD1 interacts with G3BP1 and affects stress granule dynamics.

    Science.gov (United States)

    Gal, Jozsef; Kuang, Lisha; Barnett, Kelly R; Zhu, Brian Z; Shissler, Susannah C; Korotkov, Konstantin V; Hayward, Lawrence J; Kasarskis, Edward J; Zhu, Haining

    2016-10-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. Mutations in Cu/Zn superoxide dismutase (SOD1) are responsible for approximately 20 % of the familial ALS cases. ALS-causing SOD1 mutants display a gain-of-toxicity phenotype, but the nature of this toxicity is still not fully understood. The Ras GTPase-activating protein-binding protein G3BP1 plays a critical role in stress granule dynamics. Alterations in the dynamics of stress granules have been reported in several other forms of ALS unrelated to SOD1. To our surprise, the mutant G93A SOD1 transgenic mice exhibited pathological cytoplasmic inclusions that co-localized with G3BP1-positive granules in spinal cord motor neurons. The co-localization was also observed in fibroblast cells derived from familial ALS patient carrying SOD1 mutation L144F. Mutant SOD1, unlike wild-type SOD1, interacted with G3BP1 in an RNA-independent manner. Moreover, the interaction is specific for G3BP1 since mutant SOD1 showed little interaction with four other RNA-binding proteins implicated in ALS. The RNA-binding RRM domain of G3BP1 and two particular phenylalanine residues (F380 and F382) are critical for this interaction. Mutant SOD1 delayed the formation of G3BP1- and TIA1-positive stress granules in response to hyperosmolar shock and arsenite treatment in N2A cells. In summary, the aberrant mutant SOD1-G3BP1 interaction affects stress granule dynamics, suggesting a potential link between pathogenic SOD1 mutations and RNA metabolism alterations in ALS.

  10. Evaluation of granulated BGO, GSO:Ce, YAG:Ce, CaF2:Eu and ZnS:Ag for alpha/beta pulse shape discrimination in a flow-cell radiation detector

    International Nuclear Information System (INIS)

    DeVol, T.A.; Chotoo, S.B.; Fjeld, R.A.

    1999-01-01

    Granulated BGO, GSO:Ce, YAG:Ce, and CaF 2 :Eu; CaF 2 :Eu coated with a fluorescent polymer, and combinations of coated and uncoated CaF 2 :Eu with ZnS:Ag were evaluated for their ability to discriminate between alpha and beta particles in a flow-cell radiation detector. The evaluations were based on the analysis of pulse shape spectra. Various granulated scintillators were packed into flow cell detectors that were coils of 3.0 mm ODx1.5 mm ID fluorinated ethylene propylene Teflon[reg] tubing positioned between dual photomultiplier tubes for analysis. The best pulse shape discrimination was obtained for a combination of equal masses of uncoated CaF 2 :Eu (63-90 μm) and ZnS:Ag (10 μm), which had a 9% spillover. Additional research is needed to reduce the spillover

  11. Early effects of trimethyltin on the dentate gyrus basket cells: a morphological study

    Energy Technology Data Exchange (ETDEWEB)

    Chang, L.W.; Dyer, R.S.

    1985-01-01

    Electrophysiological evidence for reduction of recurrent inhibition in the dentate gyrus in animals exposed to trimethyltin (TMT) suggested alterations in the inhibitory neurons (basket cells) by TMT. The present study was designed to investigate the morphology of basket cells after TMT exposure. Long-Evans hooded rats were injected with TMT chloride in a dose of 6.0 mg/kg body weight (b.w.). Tissue samples from the dentate gyri were examined by both light and electron microscopy at 24 and 72 h after TMT exposure. Except for isolated basket cell damage at 72 h, no remarkable pathological changes were observed with light microscopy. Consistent with previous data, electron microscopy revealed that the basket cells of the dentate gyrus are large neurons situated just below the granule cell layer with characteristic large, infolded nuclei and intranuclear filamentous rods. Increased cytoplasmic density and degenerative changes of the Golgi complex were evident in the basket cells as early as 24 h after TMT exposure. By 72 h, neuronal vacuolation, accumulation of lysosomes, and occasional neuronal necrosis were observed. No significant pathological changes were found among the granule cells at this time. This report provides the first morphological evidence for early damage to the basket cells by TMT, which may account for the reduction of recurrent inhibition and hyperexcitability among the granule cells reported previously.

  12. Sodium phenylbutyrate coated granules (Pheburane). Defective urea synthesis: a welcome formulation.

    Science.gov (United States)

    2015-02-01

    Compared with Ammonaps granules, Pheburane coated granules mask the unpleasant taste of sodium phenylbutyrate. A more precise dosing device is provided with the coated granules than with the uncoated granules (Ammonaps).

  13. Granulation of snow: From tumbler experiments to discrete element simulations

    Science.gov (United States)

    Steinkogler, Walter; Gaume, Johan; Löwe, Henning; Sovilla, Betty; Lehning, Michael

    2015-06-01

    It is well known that snow avalanches exhibit granulation phenomena, i.e., the formation of large and apparently stable snow granules during the flow. The size distribution of the granules has an influence on flow behavior which, in turn, affects runout distances and avalanche velocities. The underlying mechanisms of granule formation are notoriously difficult to investigate within large-scale field experiments, due to limitations in the scope for measuring temperatures, velocities, and size distributions. To address this issue we present experiments with a concrete tumbler, which provide an appropriate means to investigate granule formation of snow. In a set of experiments at constant rotation velocity with varying temperatures and water content, we demonstrate that temperature has a major impact on the formation of granules. The experiments showed that granules only formed when the snow temperature exceeded -1∘C. No evolution in the granule size was observed at colder temperatures. Depending on the conditions, different granulation regimes are obtained, which are qualitatively classified according to their persistence and size distribution. The potential of granulation of snow in a tumbler is further demonstrated by showing that generic features of the experiments can be reproduced by cohesive discrete element simulations. The proposed discrete element model mimics the competition between cohesive forces, which promote aggregation, and impact forces, which induce fragmentation, and supports the interpretation of the granule regime classification obtained from the tumbler experiments. Generalizations, implications for flow dynamics, and experimental and model limitations as well as suggestions for future work are discussed.

  14. Development of granules from Phyllanthus niruri spray-dried extract

    Directory of Open Access Journals (Sweden)

    Tatiane Pereira de Souza

    2009-12-01

    Full Text Available The aim of this study was to develop granules from Phyllanthus niruri spray-dried extract using dry and wet granulation and to assess techniques to enable the production of granules with improved technological characteristics and yields. Granules were characterized by granulometry, reological parameters, compression and hygroscopic behavior. Independent of the granulation technique, technologically developed granules presented particle diameter, bulk and tapped densities and compressibility indexes suitable for a solid dosage form. The compression behavior showed plastic and fragmentary deformation for granules produced by the dry granulation technique and predominantly plastic deformation for wet granulation. Concerning the humidity sorption, the study showed that granules absorb less humidity than the spray-dried extract. However, granules with Eudragit® E 100 were the least hygroscopic.O objetivo deste estudo foi desenvolver grânulos de extrato Phyllantus niruri seco por aspersão e por granulação úmida e avaliar técnicas que possibilitem a produção de grânulos com características tecnológicas e rendimentos aperfeiçoados. Os grânulos foram caracterizados por granulometria, parâmetros reológicos, compressão e comportamento higroscópico. Independentemente da técnica de granulação, os grânulos tecnologicamente desenvolvidos apresentaram diâmetro de partículas, densidades aparente e compactada e índices de compressibilidade adequados para a formulação sólida. O comportamento de compressão mostrou deformação plástica e elástica para os grânulos produzidos por técnicas de granulação seca e, predominantemente, deformação plástica para a granulação úmida. Com relação à absorção da umidade, o estudo mostrou que os grânulos absorvem menos umidade do que o extrato seco por aspersão. Entretanto, os grânulos com Eudragit E 100 foram os menos higroscópicos.

  15. Cysteamine depletes prolactin (PRL) but does not alter the structure of PRL-containing granules in the anterior pituitary

    International Nuclear Information System (INIS)

    Weinstein, L.A.; Landis, D.M.; Sagar, S.M.; Millard, W.J.; Martin, J.B.

    1984-01-01

    Cysteamine causes a profound depletion of PRL in the anterior pituitary and in the systemic circulation, as measured by RIA and bioassay. However, electron microscopic study of PRL-containing cells in rat anterior pituitary does not reveal changes in secretory granule or cytoplasmic structure during the interval of depressed PRL content and of subsequent recovery to normal levels. In contrast to the results obtained by RIA, PRL-like immunoreactivity as detected by immunocyto-chemistry is present and similar to that of control preparations after cysteamine administration. We suggest that cysteamine alters PRL structure in secretory granules, probably by interacting with the disulfide bonds of PRL, thereby altering bioactivity and immunoreactivity. The presence of cysteamine-altered PRL in secretory granules does not seem to trigger degradation of granules by the lysosomal system

  16. Generation of organized germ layers from a single mouse embryonic stem cell.

    Science.gov (United States)

    Poh, Yeh-Chuin; Chen, Junwei; Hong, Ying; Yi, Haiying; Zhang, Shuang; Chen, Junjian; Wu, Douglas C; Wang, Lili; Jia, Qiong; Singh, Rishi; Yao, Wenting; Tan, Youhua; Tajik, Arash; Tanaka, Tetsuya S; Wang, Ning

    2014-05-30

    Mammalian inner cell mass cells undergo lineage-specific differentiation into germ layers of endoderm, mesoderm and ectoderm during gastrulation. It has been a long-standing challenge in developmental biology to replicate these organized germ layer patterns in culture. Here we present a method of generating organized germ layers from a single mouse embryonic stem cell cultured in a soft fibrin matrix. Spatial organization of germ layers is regulated by cortical tension of the colony, matrix dimensionality and softness, and cell-cell adhesion. Remarkably, anchorage of the embryoid colony from the 3D matrix to collagen-1-coated 2D substrates of ~1 kPa results in self-organization of all three germ layers: ectoderm on the outside layer, mesoderm in the middle and endoderm at the centre of the colony, reminiscent of generalized gastrulating chordate embryos. These results suggest that mechanical forces via cell-matrix and cell-cell interactions are crucial in spatial organization of germ layers during mammalian gastrulation. This new in vitro method could be used to gain insights on the mechanisms responsible for the regulation of germ layer formation.

  17. Phospho-Rasputin Stabilization by Sec16 Is Required for Stress Granule Formation upon Amino Acid Starvation

    OpenAIRE

    Aguilera-Gomez, Angelica; Zacharogianni, Margarita; van Oorschot, Marinke M; Genau, Heide; Grond, Rianne; Veenendaal, Tineke; Sinsimer, Kristina S; Gavis, Elizabeth R; Behrends, Christian; Rabouille, Catherine

    2017-01-01

    Most cellular stresses induce protein translation inhibition and stress granule formation. Here, using Drosophila S2 cells, we investigate the role of G3BP/Rasputin in this process. In contrast to arsenite treatment, where dephosphorylated Ser142 Rasputin is recruited to stress granules, we find that, upon amino acid starvation, only the phosphorylated Ser142 form is recruited. Furthermore, we identify Sec16, a component of the endoplasmic reticulum exit site, as a Rasputin interactor and sta...

  18. In vitro study of uptake and synthesis of creatine and its precursors by cerebellar granule cells and astrocytes suggests some hypotheses on the physiopathology of the inherited disorders of creatine metabolism

    Directory of Open Access Journals (Sweden)

    Carducci Claudia

    2012-04-01

    Full Text Available Abstract Background The discovery of the inherited disorders of creatine (Cr synthesis and transport in the last few years disclosed the importance of blood Cr supply for the normal functioning of the brain. These putatively rare diseases share a common pathogenetic mechanism (the depletion of brain Cr and similar phenotypes characterized by mental retardation, language disturbances, seizures and movement disorders. In the effort to improve our knowledge on the mechanisms regulating Cr pool inside the nervous tissue, Cr transport and synthesis and related gene transcripts were explored in primary cultures of rat cerebellar granule cells and astrocytes. Methods Cr uptake and synthesis were explored in vitro by incubating monotypic primary cultures of rat type I astrocytes and cerebellar granule cells with: a D3-Creatine (D3Cr and D3Cr plus β-guanidinopropionate (GPA, an inhibitor of Cr transporter, and b labelled precursors of Guanidinoacetate (GAA and Cr (Arginine, Arg; Glycine, Gly. Intracellular D3Cr and labelled GAA and Cr were assessed by ESI-MS/MS. Creatine transporter (CT1, L-arginine:glycine amidinotransferase (AGAT, and S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT gene expression was assessed in the same cells by real time PCR. Results D3Cr signal was extremely high in cells incubated with this isotope (labelled/unlabelled Cr ratio reached about 10 and 122, respectively in cerebellar granule cells and astrocytes and was reduced by GPA. Labelled Arg and Gly were taken up by the cells and incorporated in GAA, whose concentration paralleled that of these precursors both in the extracellular medium and inside the cells (astrocytes. In contrast, the increase of labelled Cr was relatively much more limited since labelled Cr after precursors' supplementation did not exceed 2,7% (cerebellar granule cells and 21% (astrocytes of unlabelled Cr. Finally, AGAT, GAMT and SLC6A8 were expressed in both kind of cells. Conclusions Our

  19. Transient degradation of NF-κB proteins in macrophages after interaction with mast cell granules

    Directory of Open Access Journals (Sweden)

    Noriko Ito

    1998-01-01

    Full Text Available The exposure of the macrophage cell line, J774 to mast cell granules (MCG led to the form ation of altered nuclear transcription factor proteins (NFκBx, which had faster electrophoretic mobility than the p50 homodimer of NF-κB, but retained comparable DNA binding capacity. Antibodies to N-terminal peptides of p50, p52, p65 or c-Rel supershifted only a fraction of NF-κBx. Western blot analyses revealed that nuclear p65 and c-Rel were progressively degraded after exposure to MCG, whereas nuclear p50 appeared to be unaffected. In contrast, cytoplasmic p50, p65, c-Rel as well as IkBα remained intact after MCG treatment, although p52 was clearly degraded. In comparison to J774 cells, incubation of m ouse peritoneal macrophages with MCG resulted in more extensive alterations to NF-κB proteins. The alterations in NF-κB proteins did not affect the expression of inducible nitric oxide synthase (iNOS or TNF-α mRNA in J774 cells. These data indicate that exposure of J774 cells to MCG leads to generation of altered nuclear p52, p65 and c-Rel, which retain intact N-terminal peptides, specific oligonucleotide binding and transactivating activity. On the other hand, in peritoneal macrophages, MCG induce more extensive modifications to NF-κB proteins with associated inhibition of iNOS or TNF-α mRNA expression.

  20. Identification of chondroitin sulfate E proteoglycans and heparin proteoglycans in the secretory granules of human lung mast cells

    International Nuclear Information System (INIS)

    Stevens, R.L.; Austen, K.F.; Fox, C.C.; Lichtenstein, L.M.

    1988-01-01

    The predominant subclasses of mast cells in both the rat and the mouse can be distinguished from one another by their preferential synthesis of 35 S-labeled proteoglycans that contain either heparin or oversulfated chondroitin sulfate glycosaminoglycans. Although [ 35 S]heparin proteoglycans have been isolated from human lung mast cells of 40-70% purity and from a skin biopsy specimen of a patient with urticaria pigmentosa, no highly sulfated chondroitin sulfate proteoglycan has been isolated from any enriched or highly purified population of human mast cells. The authors demonstrate that human lung mast cells of 96% purity incorporate [ 35 S]sulfate into separate heparin and chondroitin sulfate proteoglycans in an ∼2:1 ratio. As assessed by HPLC of the chondroitinase ABC digests, the chondroitin [ 35 S]sulfate proteoglycans isolated from these human lung mast cells contain the same unusual chondroitin sulfate E disaccharide that is present in proteoglycans produced by interleukin 3-dependent mucosal-like mouse mast cells. Both the chondroitin [ 35 S]sulfate E proteoglycans and the [ 35 S]heparin proteoglycans were exocytosed from the [ 35 S]sulfate-labeled cells via perturbation of the IgE receptor, indicating that both types of 35 S-labeled proteoglycans reside in the secretory granules of these human lung mast cells

  1. Reduction of the immunostainable length of the hippocampal dentate granule cells’ primary cilia in 3xAD-transgenic mice producing human Aβ1-42 and tau

    International Nuclear Information System (INIS)

    Chakravarthy, Balu; Gaudet, Chantal; Ménard, Michel; Brown, Leslie; Atkinson, Trevor; LaFerla, Frank M.; Ito, Shingo; Armato, Ubaldo; Dal Prà, Ilaria; Whitfield, James

    2012-01-01

    Highlights: ► Aβ and tau-induced neurofibrillary tangles play a key role in Alzheimer’s disease. ► Aβ 1-42 and mutant tau protein together reduce the primary cilium length. ► This shortening likely reduces cilium-dependent neurogenesis and memory function. ► This provides a model of an Aβ/tau targeting of a neuronal signaling organelle. -- Abstract: The hippocampal dentate gyrus is one of the two sites of continuous neurogenesis in adult rodents and humans. Virtually all dentate granule cells have a single immobile cilium with a microtubule spine or axoneme covered with a specialized cell membrane loaded with receptors such as the somatostatin receptor 3 (SSTR3), and the p75 neurotrophin receptor (p75 NTR ). The signals from these receptors have been reported to stimulate neuroprogenitor proliferation and the post-mitotic maturation of newborn granule cells into functioning granule cells. We have found that in 6–24-months-old triple transgenic Alzheimer’s disease model mice (3xTg-AD) producing both Aβ 1-42 and the mutant human tau protein tau P301L, the dentate granule cells still had immunostainable SSTR3- and p75 NTR -bearing cilia but they were only half the length of the immunostained cilia in the corresponding wild-type mice. However, the immunostainable length of the granule cell cilia was not reduced either in 2xTg-AD mice accumulating large amounts of Aβ 1-42 or in mice accumulating only a mutant human tau protein. Thus it appears that a combination of Aβ 1-42 and tau protein accumulation affects the levels of functionally important receptors in 3xTg-AD mice. These observations raise the important possibility that structural and functional changes in granule cell cilia might have a role in AD.

  2. Effects of different feeder layers on culture of bovine embryonic stem cell-like cells in vitro

    OpenAIRE

    Cong, Shan; Cao, Guifang; Liu, Dongjun

    2014-01-01

    To find a suitable feeder layer is important for successful culture conditions of bovine embryonic stem cell-like cells. In this study, expression of pluripotency-related genes OCT4, SOX2 and NANOG in bovine embryonic stem cell-like cells on mouse embryonic fibroblast feeder layers at 1–5 passages were monitored in order to identify the possible reason that bovine embryonic stem cell-like cells could not continue growth and passage. Here, we developed two novel feeder layers, mixed embryonic ...

  3. State of the art of aerobic granulation in continuous flow bioreactors.

    Science.gov (United States)

    Kent, Timothy R; Bott, Charles B; Wang, Zhi-Wu

    In the wake of the success of aerobic granulation in sequential batch reactors (SBRs) for treating wastewater, attention is beginning to turn to continuous flow applications. This is a necessary step given the advantages of continuous flow treatment processes and the fact that the majority of full-scale wastewater treatment plants across the world are operated with aeration tanks and clarifiers in a continuous flow mode. As in SBRs, applying a selection pressure, based on differences in either settling velocity or the size of the biomass, is essential for successful granulation in continuous flow reactors (CFRs). CFRs employed for aerobic granulation come in multiple configurations, each with their own means of achieving such a selection pressure. Other factors, such as bioaugmentation and hydraulic shear force, also contribute to aerobic granulation to some extent. Besides the formation of aerobic granules, long-term stability of aerobic granules is also a critical issue to be addressed. Inorganic precipitation, special inocula, and various operational optimization strategies have been used to improve granule long-term structural integrity. Accumulated studies reviewed in this work demonstrate that aerobic granulation in CFRs is capable of removing a wide spectrum of contaminants and achieving properties generally comparable to those in SBRs. Despite the notable research progress made toward successful aerobic granulation in lab-scale CFRs, to the best of our knowledge, there are only three full-scale tests of the technique, two being seeded with anammox-supported aerobic granules and the other with conventional aerobic granules; two other process alternatives are currently in development. Application of settling- or size-based selection pressures and feast/famine conditions are especially difficult to implement to these and similar mainstream systems. Future research efforts needs to be focused on the optimization of the granule-to-floc ratio, enhancement of

  4. Comparison of starch granule development and physicochemical properties of starches in wheat pericarp and endosperm.

    Science.gov (United States)

    Yu, Xurun; Zhou, Liang; Zhang, Jing; Yu, Heng; Xiong, Fei; Wang, Zhong

    2015-01-01

    The objectives of this study were: (i) to characterize structural development of starch granule in pericarp and endosperm during wheat caryopsis growth; (ii) to compare physicochemical properties of starches in pericarp and endosperm; (iii) to further discover the relationships between pericarp starches and endosperm starches. Wheat pericarp and endosperm at different development stages were observed by light microscopy and scanning electron microscopy, respectively. Structural properties of starches were determined using X-ray power diffraction and (13) C solid nuclear magnetic resonance. Pericarp starch granules (PSG) accumulated in amyloplasts and chloroplasts, and showed a typical accumulation peak at 5 days after fertilization (DAF), and then gradually decomposed during 5-22 DAF. PSG in the abdominal region showed a higher rate of decomposition compared to the dorsal region of pericarp. Endosperm starch granules (ESG) accumulated in amyloplasts, and occurred in endosperm cells at 5 DAF, then rapidly enriched the endosperm cells until 22 DAF. Compared with ESG, PSG were compound granules of irregular shape and small size distribution. The results also suggested lower amylose content and V-type single-helix content and higher proportions of double helices for PSG compared to ESG. Based on the structural development of PSG and ESG, we speculated that the saccharides resulting from decomposition of PSG, on one hand, enabled the pericarp to survive before maturity of wheat caryopsis and, on the other hand, provided extra nutrition for the growth of ESG. © 2014 Society of Chemical Industry.

  5. Colchicine may assist in reducing granulation tissue in junctional epidermolysis bullosa

    Directory of Open Access Journals (Sweden)

    Minhee Kim, MBBS

    2016-06-01

    Full Text Available Epidermolysis bullosa (EB is a rare, inherited blistering genodermatosis. Patients with junctional EB (JEB due to LAMB3 mutations have widespread blisters and erosions of skin, mucosae, and nails, creating significant physical, emotional, and psychosocial burdens. Here we report the use of colchicine for ameliorating hypergranulating wounds in a 41-year-old female with JEB generalized intermediate. Her skin wounds and granulation tissue gradually exacerbated under silicone dressings such that she became profoundly anemic. Subsequently, she was commenced on colchicine 500 μg daily on the basis that it may inhibit cell proliferation and be anti-inflammatory. After a 6-month trial of colchicine, she had an objective and subjective improvement in her validated EB Disease Activity and Scarring Index activity and damage scores and Quality Of Life in EB score with less skin erosions, granulation tissue, and erythema. In addition, her anemia resolved. She denied any gastrointestinal side effects. The exact mechanism of colchicine in assisting reduction of the blistering, erosions, and granulation in JEB is unclear, but the anti-inflammatory and antimitotic properties of colchicine may be partially responsible for this process.

  6. Multiphase flow in spout fluidized bed granulators

    NARCIS (Netherlands)

    Buijtenen, van M.S.

    2011-01-01

    Spout fluidized beds are frequently used for the production of granules or particles through granulation, which are widely applied, for example, in the production of detergents, pharmaceuticals, food and fertilizers (M¨orl et al. 2007). Spout fluidized beds have a number of advantageous properties,

  7. Hepatitis C virus (HCV) induces formation of stress granules whose proteins regulate HCV RNA replication and virus assembly and egress.

    Science.gov (United States)

    Garaigorta, Urtzi; Heim, Markus H; Boyd, Bryan; Wieland, Stefan; Chisari, Francis V

    2012-10-01

    Stress granules (SGs) are cytoplasmic structures that are induced in response to environmental stress, including viral infections. Here we report that hepatitis C virus (HCV) triggers the appearance of SGs in a PKR- and interferon (IFN)-dependent manner. Moreover, we show an inverse correlation between the presence of stress granules and the induction of IFN-stimulated proteins, i.e., MxA and USP18, in HCV-infected cells despite high-level expression of the corresponding MxA and USP18 mRNAs, suggesting that interferon-stimulated gene translation is inhibited in stress granule-containing HCV-infected cells. Finally, in short hairpin RNA (shRNA) knockdown experiments, we found that the stress granule proteins T-cell-restricted intracellular antigen 1 (TIA-1), TIA1-related protein (TIAR), and RasGAP-SH3 domain binding protein 1 (G3BP1) are required for efficient HCV RNA and protein accumulation at early time points in the infection and that G3BP1 and TIA-1 are required for intracellular and extracellular infectious virus production late in the infection, suggesting that they are required for virus assembly. In contrast, TIAR downregulation decreases extracellular infectious virus titers with little effect on intracellular RNA content or infectivity late in the infection, suggesting that it is required for infectious particle release. Collectively, these results illustrate that HCV exploits the stress granule machinery at least two ways: by inducing the formation of SGs by triggering PKR phosphorylation, thereby downregulating the translation of antiviral interferon-stimulated genes, and by co-opting SG proteins for its replication, assembly, and egress.

  8. Tar DNA binding protein-43 (TDP-43 associates with stress granules: analysis of cultured cells and pathological brain tissue.

    Directory of Open Access Journals (Sweden)

    Liqun Liu-Yesucevitz

    2010-10-01

    Full Text Available Tar DNA Binding Protein-43 (TDP-43 is a principle component of inclusions in many cases of frontotemporal lobar degeneration (FTLD-U and amyotrophic lateral sclerosis (ALS. TDP-43 resides predominantly in the nucleus, but in affected areas of ALS and FTLD-U central nervous system, TDP-43 is aberrantly processed and forms cytoplasmic inclusions. The mechanisms governing TDP-43 inclusion formation are poorly understood. Increasing evidence indicates that TDP-43 regulates mRNA metabolism by interacting with mRNA binding proteins that are known to associate with RNA granules. Here we show that TDP-43 can be induced to form inclusions in cell culture and that most TDP-43 inclusions co-localize with SGs. SGs are cytoplasmic RNA granules that consist of mixed protein-RNA complexes. Under stressful conditions SGs are generated by the reversible aggregation of prion-like proteins, such as TIA-1, to regulate mRNA metabolism and protein translation. We also show that disease-linked mutations in TDP-43 increased TDP-43 inclusion formation in response to stressful stimuli. Biochemical studies demonstrated that the increased TDP-43 inclusion formation is associated with accumulation of TDP-43 detergent insoluble complexes. TDP-43 associates with SG by interacting with SG proteins, such as TIA-1, via direct protein-protein interactions, as well as RNA-dependent interactions. The signaling pathway that regulates SGs formation also modulates TDP-43 inclusion formation. We observed that inclusion formation mediated by WT or mutant TDP-43 can be suppressed by treatment with translational inhibitors that suppress or reverse SG formation. Finally, using Sudan black to quench endogenous autofluorescence, we also demonstrate that TDP-43 positive-inclusions in pathological CNS tissue co-localize with multiple protein markers of stress granules, including TIA-1 and eIF3. These data provide support for accumulating evidence that TDP-43 participates in the SG pathway.

  9. Hydroxylated polychlorinated biphenyls increase reactive oxygen species formation and induce cell death in cultured cerebellar granule cells

    International Nuclear Information System (INIS)

    Dreiem, Anne; Rykken, Sidsel; Lehmler, Hans-Joachim; Robertson, Larry W.; Fonnum, Frode

    2009-01-01

    Polychlorinated biphenyls (PCBs) are persistent organic pollutants that bioaccumulate in the body, however, they can be metabolized to more water-soluble products. Although they are more readily excreted than the parent compounds, some of the metabolites are still hydrophobic and may be more available to target tissues, such as the brain. They can also cross the placenta and reach a developing foetus. Much less is known about the toxicity of PCB metabolites than about the parent compounds. In the present study, we have investigated the effects of eight hydroxylated (OH) PCB congeners (2'-OH PCB 3, 4-OH PCB 14, 4-OH PCB 34, 4'-OH PCB 35, 4-OH PCB 36, 4'-OH PCB 36, 4-OH PCB 39, and 4'-OH PCB 68) on reactive oxygen species (ROS) formation and cell viability in rat cerebellar granule cells. We found that, similar to their parent compounds, OH-PCBs are potent ROS inducers with potency 4-OH PCB 14 < 4-OH PCB 36 < 4-OH PCB 34 < 4'-OH PCB 36 < 4'-OH PCB 68 < 4-OH PCB 39 < 4'-OH PCB 35. 4-OH PCB 36 was the most potent cell death inducer, and caused apoptotic or necrotic morphology depending on concentration. Inhibition of ERK1/2 kinase with U0126 reduced both cell death and ROS formation, suggesting that ERK1/2 activation is involved in OH-PCB toxicity. The results indicate that the hydroxylation of PCBs may not constitute a detoxification reaction. Since OH-PCBs like their parent compounds are retained in the body and may be more widely distributed to sensitive tissues, it is important that not only the levels of the parent compounds but also the levels of their metabolites are taken into account during risk assessment of PCBs and related compounds.

  10. Venom Apparatus Structure and Conutoxins Granules formation in Cone Snail (Conus coronatus of Persian Gulf

    Directory of Open Access Journals (Sweden)

    Ferial Monsef

    2014-05-01

    Full Text Available Background: Today use conotoxin as a neurotoxin and cytotoxin in medical science is obvious. These compounds are produced by venomous cone snails. Toxins produced by the venom apparatus of this snail and injected into the prey. To obtain and identification of these toxins, study of venom apparatus and the manufacture formation is necessary. Materials and Methods: In order to study the organ, specimens of C. coronatus were collected from the Coast of Gheshm Island. After dissection were fixed in Bouin's for 48 hours and transferred to laboratory into 70% ethanol. After dehydration and Paraffin embedded were cutted by microtome and then collected on glass slides and stained then photographed and studied. Results: Observation showed that, the venom bulb was muscular and in their middle part a channel with epithelial cells was observable that secreted some material. Venom duct walls composed of 3 parts including the outer layer of connective tissue with muscle an inner layer of columnar epithelial cells with basal nucleus and the inner lumens which filled by the. Departed nucleus by secretion exist in all 3 part of venom duct. In radula sac sections, lots growing radula were observed. Conclusion: Venom bulb was a weak secretion role and venom duct near the pharynx have a more mature granule than the other part. Holocrine secretion happened in all part of venom duct. Most suitable part for extract the conotoxin was the venom bulb end part.

  11. In vitro evaluation of chondrosarcoma cells and canine chondrocytes on layer-by-layer (LbL) self-assembled multilayer nanofilms

    International Nuclear Information System (INIS)

    Shaik, J; Mohammed, J Shaikh; McShane, M J; Mills, D K

    2013-01-01

    Short-term cell–substrate interactions of two secondary chondrocyte cell lines (human chondrosarcoma cells, canine chondrocytes) with layer-by-layer self-assembled multilayer nanofilms were investigated for a better understanding of cellular-behaviour dependence on a number of nanofilm layers. Cell–substrate interactions were studied on polyelectrolyte multilayer nanofilms (PMNs) of eleven different biomaterials. Surface characterization of PMNs performed using AFM showed increasing surface roughness with increasing number of layers for most of the biomaterials. LDH-L and MTT assays were performed on chondrosarcoma cells and canine chondrocytes, respectively. A major observation was that 10-bilayer nanofilms exhibited lesser cytotoxicity towards human chondrosarcoma cells than their 5-bilayer counterparts. In the case of canine chondrocytes, BSA enhanced cell metabolic activity with increasing number of layers, underscoring the importance of the multilayer nanofilm architecture on cellular behaviour. (paper)

  12. TFB:TPDSi2 interfacial layer usable in organic photovoltaic cells

    Science.gov (United States)

    Marks, Iobin J [Evanston, IL; Hains, Alexander W [Evanston, IL

    2011-02-15

    The present invention, in one aspect, relates to a solar cell. In one embodiment, the solar cell includes an anode; an active organic layer comprising an electron-donating organic material and an electron-accepting organic material; and an interfacial layer formed between the anode and active organic layer, where the interfacial layer comprises a hole-transporting polymer characterized with a hole-mobility higher than that of the electron-donating organic material in the active organic layer, and a small molecule that has a high hole-mobility and is capable of crosslinking on contact with air.

  13. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

    International Nuclear Information System (INIS)

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-01-01

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing, between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection

  14. Aggregation of ALS-linked FUS mutant sequesters RNA binding proteins and impairs RNA granules formation

    Energy Technology Data Exchange (ETDEWEB)

    Takanashi, Keisuke; Yamaguchi, Atsushi, E-mail: atsyama@restaff.chiba-u.jp

    2014-09-26

    Highlights: • Aggregation of ALS-linked FUS mutant sequesters ALS-associated RNA-binding proteins (FUS wt, hnRNP A1, and hnRNP A2). • Aggregation of ALS-linked FUS mutant sequesters SMN1 in the detergent-insoluble fraction. • Aggregation of ALS-linked FUS mutant reduced the number of speckles in the nucleus. • Overproduced ALS-linked FUS mutant reduced the number of processing-bodies (PBs). - Abstract: Protein aggregate/inclusion is one of hallmarks for neurodegenerative disorders including amyotrophic lateral sclerosis (ALS). FUS/TLS, one of causative genes for familial ALS, encodes a multifunctional DNA/RNA binding protein predominantly localized in the nucleus. C-terminal mutations in FUS/TLS cause the retention and the inclusion of FUS/TLS mutants in the cytoplasm. In the present study, we examined the effects of ALS-linked FUS mutants on ALS-associated RNA binding proteins and RNA granules. FUS C-terminal mutants were diffusely mislocalized in the cytoplasm as small granules in transiently transfected SH-SY5Y cells, whereas large aggregates were spontaneously formed in ∼10% of those cells. hnRNP A1, hnRNP A2, and SMN1 as well as FUS wild type were assembled into stress granules under stress conditions, and these were also recruited to FUS mutant-derived spontaneous aggregates in the cytoplasm. These aggregates stalled poly(A) mRNAs and sequestered SMN1 in the detergent insoluble fraction, which also reduced the number of nuclear oligo(dT)-positive foci (speckles) in FISH (fluorescence in situ hybridization) assay. In addition, the number of P-bodies was decreased in cells harboring cytoplasmic granules of FUS P525L. These findings raise the possibility that ALS-linked C-terminal FUS mutants could sequester a variety of RNA binding proteins and mRNAs in the cytoplasmic aggregates, which could disrupt various aspects of RNA equilibrium and biogenesis.

  15. Study of granulated nickel alloy superplasticity

    International Nuclear Information System (INIS)

    Anoshkin, N.F.; Fatkullin, O.Kh.; Ermanok, M.Z.; Sharshagin, N.A.

    1982-01-01

    Peculiarities of the structure and properties of compact material obtained from granules of the EhI 698 and ZhS6U alloys in the form of pressed rods are investigated. It is shown, that granule metallurgy is the most rational technology method, ensuring the receipt of stable fine-grained structure in the initial blank. After appropriate thermal treatment the products obtained by the method of granule metallyrgy have more high strength characteristics at the room temperature and heat resistance, than typical for the products produced by traditional technology. Creation of specialized vertical presses providing low rates of deformation as well as their equipment by vacuum mechanizms which permit to use a tool from molybdenum alloys is necessary for successful introduction into production of the processes of plastic metal working under conditions of superplasticity

  16. Increased biogenesis of glucagon-containing secretory granules and glucagon secretion in BIG3-knockout mice

    Directory of Open Access Journals (Sweden)

    Hongyu Li

    2015-03-01

    Conclusions: Together with our previous studies, the current data reveal a conserved role for BIG3 in regulating alpha- and beta-cell functions. We propose that BIG3 negatively regulates hormone production at the secretory granule biogenesis stage and that such regulatory mechanism may be used in secretory pathways of other endocrine cells.

  17. In vitro proliferation of haemopoietic cells in the presence of adherent cell layers. II. Differential effect of adherent cell layers derived from various organs

    NARCIS (Netherlands)

    Reimann, J.; Burger, H.

    1979-01-01

    Mouse bone marrow-derived adherent cell populations promoted proliferation of haemopoietic cells in vitro in a liquid culture system for at least 4 weeks. Adherent cell layers derived from other haemopoietic organs (foetal liver, adult spleen) and fibroblasts from embryonic tissues did not maintain

  18. Semaphorin 5A inhibits synaptogenesis in early postnatal- and adult-born hippocampal dentate granule cells.

    Science.gov (United States)

    Duan, Yuntao; Wang, Shih-Hsiu; Song, Juan; Mironova, Yevgeniya; Ming, Guo-li; Kolodkin, Alex L; Giger, Roman J

    2014-10-14

    Human SEMAPHORIN 5A (SEMA5A) is an autism susceptibility gene; however, its function in brain development is unknown. In this study, we show that mouse Sema5A negatively regulates synaptogenesis in early, developmentally born, hippocampal dentate granule cells (GCs). Sema5A is strongly expressed by GCs and regulates dendritic spine density in a cell-autonomous manner. In the adult mouse brain, newly born Sema5A-/- GCs show an increase in dendritic spine density and increased AMPA-type synaptic responses. Sema5A signals through PlexinA2 co-expressed by GCs, and the PlexinA2-RasGAP activity is necessary to suppress spinogenesis. Like Sema5A-/- mutants, PlexinA2-/- mice show an increase in GC glutamatergic synapses, and we show that Sema5A and PlexinA2 genetically interact with respect to GC spine phenotypes. Sema5A-/- mice display deficits in social interaction, a hallmark of autism-spectrum-disorders. These experiments identify novel intra-dendritic Sema5A/PlexinA2 interactions that inhibit excitatory synapse formation in developmentally born and adult-born GCs, and they provide support for SEMA5A contributions to autism-spectrum-disorders.

  19. THE RELATIONSHIP BETWEEN BULK-DENSITY AND COMPACTIBILITY OF LACTOSE GRANULATIONS

    NARCIS (Netherlands)

    ZUURMAN, K; RIEPMA, KA; BOLHUIS, GK; VROMANS, H; LERK, CF

    1994-01-01

    The relationship between the bulk density and the compactibility of lactose granulations was studied. The granulations were prepared from different alpha-lactose monohydrate and roller dried beta-lactose powders by wet granulation, using different techniques with only water as a binder, or by

  20. Evaluation of granulated BGO, GSO:Ce, YAG:Ce, CaF sub 2 :Eu and ZnS:Ag for alpha/beta pulse shape discrimination in a flow-cell radiation detector

    CERN Document Server

    Devol, T A; Fjeld, R A

    1999-01-01

    Granulated BGO, GSO:Ce, YAG:Ce, and CaF sub 2 :Eu; CaF sub 2 :Eu coated with a fluorescent polymer, and combinations of coated and uncoated CaF sub 2 :Eu with ZnS:Ag were evaluated for their ability to discriminate between alpha and beta particles in a flow-cell radiation detector. The evaluations were based on the analysis of pulse shape spectra. Various granulated scintillators were packed into flow cell detectors that were coils of 3.0 mm ODx1.5 mm ID fluorinated ethylene propylene Teflon[reg] tubing positioned between dual photomultiplier tubes for analysis. The best pulse shape discrimination was obtained for a combination of equal masses of uncoated CaF sub 2 :Eu (63-90 mu m) and ZnS:Ag (10 mu m), which had a 9% spillover. Additional research is needed to reduce the spillover.

  1. Localization of MTT formazan in lipid droplets. An alternative hypothesis about the nature of formazan granules and aggregates

    Directory of Open Access Journals (Sweden)

    G Diaz

    2009-08-01

    Full Text Available MTT (3-(4, 5-dimethyl-2-thiazolyl-2, 5-dihphenyltetrazolium bromide assay is a widely used method to assess cell viability and proliferation. MTT is readily taken up by cells and enzymatically reduced to formazan, a dark compound which accumulates in cytoplasmic granules. Formazan is later eliminated by the cell by a mechanisms often indicated as exocytosis, that produces characteristic needle-like aggregates on the cell surface. The shape of formazan aggregates and the rate of exocytosis change in the presence of bioactive amyloid b peptides (Ab and cholesterol. Though the cellular mechanisms involved in MTT reduction have been extensively investigated, the exact nature of formazan granules and the process of exocytosis are still obscure. Using Nile Red, which stains differentially neutral and polar lipids, and a fluorescent analog of cholesterol (NBD-cholesterol, we found that formazan localized in lipid droplets, consistent with the lipophilic nature of formazan. However, formazan granules and aggregates were also found to form after killing cells with paraformaldehyde fixation. Moreover, formazan aggregates were also obtained in cell-free media, using ascorbic acid to reduce MTT. The density and shape of formazan aggregates obtained in cell-free media was sensitive to cholesterol and Ab. In cells, electron microscopy failed to detect the presence of secretory vesicles, but revealed unusual fibers of 50 nm of diameter extending throughout the cytoplasm. Taken together, these findings suggest that formazan efflux is driven by physico-chemical interactions at molecular level without involving higher cytological mechanisms.

  2. Nos2 inactivation promotes the development of medulloblastoma in Ptch1(+/- mice by deregulation of Gap43-dependent granule cell precursor migration.

    Directory of Open Access Journals (Sweden)

    Daniel Haag

    Full Text Available Medulloblastoma is the most common malignant brain tumor in children. A subset of medulloblastoma originates from granule cell precursors (GCPs of the developing cerebellum and demonstrates aberrant hedgehog signaling, typically due to inactivating mutations in the receptor PTCH1, a pathomechanism recapitulated in Ptch1(+/- mice. As nitric oxide may regulate GCP proliferation and differentiation, we crossed Ptch1(+/- mice with mice lacking inducible nitric oxide synthase (Nos2 to investigate a possible influence on tumorigenesis. We observed a two-fold higher medulloblastoma rate in Ptch1(+/- Nos2(-/- mice compared to Ptch1(+/- Nos2(+/+ mice. To identify the molecular mechanisms underlying this finding, we performed gene expression profiling of medulloblastomas from both genotypes, as well as normal cerebellar tissue samples of different developmental stages and genotypes. Downregulation of hedgehog target genes was observed in postnatal cerebellum from Ptch1(+/+ Nos2(-/- mice but not from Ptch1(+/- Nos2(-/- mice. The most consistent effect of Nos2 deficiency was downregulation of growth-associated protein 43 (Gap43. Functional studies in neuronal progenitor cells demonstrated nitric oxide dependence of Gap43 expression and impaired migration upon Gap43 knock-down. Both effects were confirmed in situ by immunofluorescence analyses on tissue sections of the developing cerebellum. Finally, the number of proliferating GCPs at the cerebellar periphery was decreased in Ptch1(+/+ Nos2(-/- mice but increased in Ptch1(+/- Nos2(-/ (- mice relative to Ptch1(+/- Nos2(+/+ mice. Taken together, these results indicate that Nos2 deficiency promotes medulloblastoma development in Ptch1(+/- mice through retention of proliferating GCPs in the external granular layer due to reduced Gap43 expression. This study illustrates a new role of nitric oxide signaling in cerebellar development and demonstrates that the localization of pre-neoplastic cells during

  3. Lamotrigine increases the number of BrdU-labeled cells in the rat hippocampus

    DEFF Research Database (Denmark)

    Kondziella, Daniel; Strandberg, Joakim; Lindquist, Catarina

    2011-01-01

    Antidepressant medication and electroconvulsive therapy stabilize mood symptoms and increase hippocampal neurogenesis. We examined whether lamotrigine, suggested to give rise to mood-stabilizing and antidepressant effects in addition to its antiepileptic properties, also increases the number of n...... in the granule cell layer of the dentate gyrus showed an increased number of newborn cells in rats receiving lamotrigine (42.6 ± 3.5 cells/slice) compared with valproate (31.6 ± 2.8) and controls (32.2 ± 3.1; P...

  4. CXCL12-mediated feedback from granule neurons regulates generation and positioning of new neurons in the dentate gyrus.

    Science.gov (United States)

    Abe, Philipp; Wüst, Hannah M; Arnold, Sebastian J; van de Pavert, Serge A; Stumm, Ralf

    2018-03-14

    Adult hippocampal neurogenesis is implicated in learning and memory processing. It is tightly controlled at several levels including progenitor proliferation as well as migration, differentiation and integration of new neurons. Hippocampal progenitors and immature neurons reside in the subgranular zone (SGZ) and are equipped with the CXCL12-receptor CXCR4 which contributes to defining the SGZ as neurogenic niche. The atypical CXCL12-receptor CXCR7 functions primarily by sequestering extracellular CXCL12 but whether CXCR7 is involved in adult neurogenesis has not been assessed. We report that granule neurons (GN) upregulate CXCL12 and CXCR7 during dentate gyrus maturation in the second postnatal week. To test whether GN-derived CXCL12 regulates neurogenesis and if neuronal CXCR7 receptors influence this process, we conditionally deleted Cxcl12 and Cxcr7 from the granule cell layer. Cxcl12 deletion resulted in lower numbers, increased dispersion and abnormal dendritic growth of immature GN and reduced neurogenesis. Cxcr7 ablation caused an increase in progenitor proliferation and progenitor numbers and reduced dispersion of immature GN. Thus, we provide a new mechanism where CXCL12-signals from GN prevent dispersion and support maturation of newborn GN. CXCR7 receptors of GN modulate the CXCL12-mediated feedback from GN to the neurogenic niche. © 2018 Wiley Periodicals, Inc.

  5. Overexpression of Lin28b in Neural Stem Cells is Insufficient for Brain Tumor Formation, but Induces Pathological Lobulation of the Developing Cerebellum.

    Science.gov (United States)

    Wefers, Annika K; Lindner, Sven; Schulte, Johannes H; Schüller, Ulrich

    2017-02-01

    LIN28B is a homologue of the RNA-binding protein LIN28A and regulates gene expression during development and carcinogenesis. It is strongly upregulated in a variety of brain tumors, such as medulloblastoma, embryonal tumor with multilayered rosettes (ETMR), atypical teratoid/rhabdoid tumor (AT/RT), or glioblastoma, but the effect of an in vivo overexpression of LIN28B on the developing central nervous system is unknown. We generated transgenic mice that either overexpressed Lin28b in Math1-positive cerebellar granule neuron precursors or in a broad range of Nestin-positive neural precursors. Sections of the cerebellar vermis from adult Math1-Cre::lsl-Lin28b mice had an additional subfissure in lobule IV. Vermes from p0 and p7 Nestin-Cre::lsl-Lin28b mice appeared normal, but we found a pronounced vermal hypersublobulation at p15 and p21 in these mice. Also, the external granule cell layer (EGL) was thicker at p15 than in controls, contained more proliferating cells, and persisted up to p21. Consistently, some Pax6- and NeuN-positive cells were present in the EGL of Nestin-Cre::lsl-Lin28b mice even at p21, and we detected more NeuN-positive granule neuron precursors in the molecular layer (ML) as compared to control. Finally, we found some residual Pax2-positive precursors of inhibitory interneurons in the ML of Nestin-Cre::lsl-Lin28b mice at p21, which have already disappeared in controls. We conclude that while overexpression of LIN28B in Nestin-positive cells does not lead to tumor formation, it results in a protracted development of granule cells and inhibitory interneurons and leads to a hypersublobulation of the cerebellar vermis.

  6. Electrophysiological mapping of the accessory olfactory bulb of the rabbit (Oryctolagus cuniculus).

    Science.gov (United States)

    van Groen, T; Ruardy, L; da Silva, F H

    1986-07-01

    Field potentials elicited by electrical stimulation of the vomeronasal nerve were measured in the accessory olfactory bulb of the rabbit. Maps were made of the distribution of surface field potentials and of the corresponding depth profiles. The surface maps followed closely the contours of the accessory olfactory bulb: at the frontal border the field potential tended to zero and at the center of the structure the field potential attained a maximum. Depth profiles of the field potentials through the accessory olfactory bulb presented a surface-negative wave and, in depth, a positive wave. The polarity reversal occurred at the deep part of the granule cell layer. The zero equipotential line followed closely the curvature of the granule cell layer. Current source density analysis of the depth profiles revealed a main sink at the external plexiform and granule cell layers. This indicates that the main activity in the accessory olfactory bulb is generated by the synapses between the mitral cells and the granule cells as is found in the main olfactory bulb.

  7. Interfacial Layer Engineering for Performance Enhancement in Polymer Solar Cells

    Directory of Open Access Journals (Sweden)

    Hao Zeng

    2015-02-01

    Full Text Available Improving power conversion efficiency and device performance stability is the most critical challenge in polymer solar cells for fulfilling their applications in industry at large scale. Various methodologies have been developed for realizing this goal, among them interfacial layer engineering has shown great success, which can optimize the electrical contacts between active layers and electrodes and lead to enhanced charge transport and collection. Interfacial layers also show profound impacts on light absorption and optical distribution of solar irradiation in the active layer and film morphology of the subsequently deposited active layer due to the accompanied surface energy change. Interfacial layer engineering enables the use of high work function metal electrodes without sacrificing device performance, which in combination with the favored kinetic barriers against water and oxygen penetration leads to polymer solar cells with enhanced performance stability. This review provides an overview of the recent progress of different types of interfacial layer materials, including polymers, small molecules, graphene oxides, fullerene derivatives, and metal oxides. Device performance enhancement of the resulting solar cells will be elucidated and the function and operation mechanism of the interfacial layers will be discussed.

  8. New gentle-wing high-shear granulator: impact of processing variables on granules and tablets characteristics of high-drug loading formulation using design of experiment approach.

    Science.gov (United States)

    Fayed, Mohamed H; Abdel-Rahman, Sayed I; Alanazi, Fars K; Ahmed, Mahrous O; Tawfeek, Hesham M; Al-Shdefat, Ramadan I

    2017-10-01

    The aim of this work was to study the application of design of experiment (DoE) approach in defining design space for granulation and tableting processes using a novel gentle-wing high-shear granulator. According to quality-by-design (QbD) prospective, critical attributes of granules, and tablets should be ensured by manufacturing process design. A face-centered central composite design has been employed in order to investigate the effect of water amount (X 1 ), impeller speed (X 2 ), wet massing time (X 3 ), and water addition rate (X 4 ) as independent process variables on granules and tablets characteristics. Acetaminophen was used as a model drug and granulation experiments were carried out using dry addition of povidone k30. The dried granules have been analyzed for their size distribution, density, and flow pattern. Additionally, the produced tablets have been investigated for; weight uniformity, breaking force, friability and percent capping, disintegration time, and drug dissolution. Results of regression analysis showed that water amount, impeller speed and wet massing time have significant (p tablets characteristics. However, the water amount had the most pronounced effect as indicated by its higher parameter estimate. On the other hand, water addition rate showed a minimal impact on granules and tablets properties. In conclusion, water amount, impeller speed, and wet massing time could be considered as critical process variables. Thus, understanding the relationship between these variables and quality attributes of granules and corresponding tablets provides the basis for adjusting granulation variables in order to optimize product performance.

  9. Role of calcium oxide in sludge granulation and methanogenesis for the treatment of palm oil mill effluent using UASB reactor

    International Nuclear Information System (INIS)

    Ahmad, Anwar; Ghufran, Rumana; Wahid, Zularisam Abd.

    2011-01-01

    Graphical abstract: SEM micrograph of granules; Outer surface of the granule; Scanning electron micrographs of the granule: Archaea (Methanosarcina sp.) showing the arrangement of bacterial cells in granule surrounded by extracellular polymeric substances (EPS), the seed sludge and granules sampled on day 150. Highlights: ► Examine the treatability of POME and effects of CaO–CKD on the granulation process in UASB reactors. ► The main objective was to determine the influent CaO–CKD concentration and the relationship between the CaO concentration in the feed and biomass accumulation, specific granulation, methanogenic activity, and the density and composition of granules. ► The biomass concentration profiles along the reactors and the size distribution of granules were also measured to track and to assess granulation, methanogenesis, and COD removal on levels at the industrial scale. ► SEM micrograph are showing smooth surface of granule with a large opening cavities likely for biogas escape. - Abstract: The granulation process in palm oil mill effluent using calcium oxide-cement kiln dust (CaO–CKD) provides an attractive and cost effective treatment option. In this study the efficiency of CaO–CKD at doses of 1.5–20 g/l was tested in batch experiments and found that 10 g of CaO/l caused the greatest degradation of VFA, butyrate and acetate. An upflow anaerobic sludge blanket (UASB) reactor was operated continuously at 35 °C for 150 days to investigate the effect of CaO–CKD on sludge granulation and methanogenesis during start-up. The treatment of POME emphasized the influence of varying organic loading rates (OLR). Up to 94.9% of COD was removed when the reactor was fed with the 15.5–65.5 g-COD g/l at an OLR of 4.5–12.5 kg-COD/m 3 d, suggesting the feasibility of using CaO in an UASB process to treat POME. The ratio of volatile solids/total solids (VS/TS) and volatile fatty acids in the anaerobic sludge in the UASB reactor decreased

  10. Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation

    International Nuclear Information System (INIS)

    Mazaheri, M.; Akhavan, O.; Simchi, A.

    2014-01-01

    Highlights: • Fabrication of flexible graphene oxide–chitosan nanocomposite layers was reported. • The flexibility of the chitosan layers were improved by adding graphene oxide sheets. • The nanocomposite layers with 1.5 wt% graphene oxide content showed yielded flexible and antibacterial surfaces for stem cell proliferation. - Abstract: Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)–chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs

  11. Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Mazaheri, M. [Department of Materials Science and Engineering, Sharif University of Technology, PO Box 11365-9466, Tehran (Iran, Islamic Republic of); Akhavan, O., E-mail: oakhavan@sharif.edu [Department of Physics, Sharif University of Technology, PO Box 11155-9161, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, PO Box 14588-89694, Tehran (Iran, Islamic Republic of); Simchi, A. [Department of Materials Science and Engineering, Sharif University of Technology, PO Box 11365-9466, Tehran (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, PO Box 14588-89694, Tehran (Iran, Islamic Republic of)

    2014-05-01

    Highlights: • Fabrication of flexible graphene oxide–chitosan nanocomposite layers was reported. • The flexibility of the chitosan layers were improved by adding graphene oxide sheets. • The nanocomposite layers with 1.5 wt% graphene oxide content showed yielded flexible and antibacterial surfaces for stem cell proliferation. - Abstract: Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)–chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs.

  12. Pelletizing of NaF granules as adsorbent for fluorides of nuclear fuel materials, (1)

    International Nuclear Information System (INIS)

    Kimura, Syojiro; Tsutsui, Tenson; Kanagawa, Akira.

    1976-01-01

    The pelletizing of NaF granules on laboratory scale used for recovery and purification of fluorides of nuclear fuel materials are investigated, particularity experimental studies on how to pelletize, fluidity of granules and flow rate of the granules in mortar of tablet machine are carried out. As result, added quantity of H 2 O as binder at granulation process of spherical NaF granule influence to yield of NaF granules. The proper quantity of H 2 O to NaF powder is about 18--19%. Friction coefficient of unfixed shape NaF granule is higher than that of spherical granule, in opposition, density of the former granule is lower. So fluidity of unfixed shape NaF granule is low, flow rate of the granules through feeder of tablet machine is slow, and arching on mortar of the tablet machine occurs. Then, some further operation for getting better fluidity needs for pelletizing of NaF granules using unfixed shape granule. The other hand, using spherical NaF granule, continuous pelletizing by commercial tablet machine can be carried out. (auth.)

  13. Phagocytosis of mast cell granules results in decreased macrophage superoxide production

    Directory of Open Access Journals (Sweden)

    Bobby A. Shah

    1995-01-01

    Full Text Available The mechanism by which phagocytosed mast cell granules (MCGs inhibit macrophage superoxide production has not been defined. In this study, rat peritoneal macrophages were co-incubated with either isolated intact MCGs or MCG-sonicate, and their respiratory burst capacity and morphology were studied. Co-incubation of macrophages with either intact MCGs or MCG-sonicate resulted in a dose-dependent inhibition of superoxide- mediated cytochrome c reduction. This inhibitory effect was evident within 5 min of incubation and with MCG-sonicate was completely reversed when macrophages were washed prior to activation with PMA. In the case of intact MCGs, the inhibitory effect was only partially reversed by washing after a prolonged co-incubation time. Electron microscopic analyses revealed that MCGs were rapidly phagocytosed by macrophages and were subsequently disintegrated within the phagolysosomes. Assay of MCGs for superoxide dismutase (SOD revealed the presence of significant activity of this enzyme. A comparison of normal macrophages and those containing phagocytosed MCGs did not reveal a significant difference in total SOD activity. It is speculated that, although there was no significant increase in total SOD activity in macrophages containing phagocytosed MCGs, the phagocytosed MCGs might cause a transient increase in SOD activity within the phagolysosomes. This transient rise in SOD results in scavenging of the newly generated superoxide. Alternatively, MCG inhibition of NADPH oxidase would explain the reported observations.

  14. Behavior of hollow balls containing granules bouncing repeatedly off the ground

    Science.gov (United States)

    Hu, Min; Mu, Qing-song; Luo, Ning; Li, Gang; Peng, Ning-bo

    2013-07-01

    An experimental study of the behavior of hollow balls filled with some granules (mung beans or millets) bouncing repeatedly off a static flat horizontal surface is presented. We observed that the bounce number of the ball is limited and decreases regularly with an increasing number of granules. Moreover, for two balls containing a different kind of granules, their bounce numbers are basically equal when the two balls have the same mass of granules. While there is no clear relationship between the first rebound height of one ball and the number of granules, there appears an exponential decay of the second rebound height with an increase of the granule number. Furthermore, a two-dimensional numerical model has been created to find out the law of the ball's rebound height and the dissipation law of the granule nested system. A generalized prediction equation to reasonably explain the law of the bounce number has also been proposed.

  15. Sustained-release progesterone vaginal suppositories 1--development of sustained-release granule--.

    Science.gov (United States)

    Nakayama, Ayako; Sunada, Hisakazu; Okamoto, Hirokazu; Furuhashi, Kaoru; Ohno, Yukiko; Ito, Mikio

    2009-02-01

    Progesterone (P) is an important hormone for the establishment of pregnancy, and its administration is useful for luteal insufficiency. Considering the problems of commercially available oral and injection drugs, hospital-formulated vaginal suppositories are clinically used. However, since the half-life of P suppositories is short, it is difficult to maintain its constant blood concentration. To sustain drug efficacy and prevent side-effects, we are attempting to develop sustained-release suppositories by examining the degree of sustained-release of active ingredients. In this study, we examined the combinations of granulation methods and release systems for the preparation of sustained-release granules of P, and produced 13 types of sustained-release granules. We also examined the diameter, content, and dissolution of each type of granules, and confirmed that the sustained-release of all types of granules was satisfactory. Among the sustained-release granules, we selected granules with a content and a degree of sustained-release suitable for sustained-release suppositories.

  16. The influence of granulating solvents on drug release from tablets ...

    African Journals Online (AJOL)

    ... significantly lower than the other wet granulated tablets, but higher than the matrix tablets. The granulating solvent influenced the release of drug which increased with increase in the water content. Key Words: Grewia gum: Granulating solvents; Release mechanisms. Journal of Pharmacy and Bioresources Vol.1(1) 2004: ...

  17. FMDV-induced stress granules are disrupted by the viral L-protease

    DEFF Research Database (Denmark)

    Polacek, Charlotta; Belsham, Graham; McInerney, Gerald

    2014-01-01

    Eukaryotic cells respond to environmental stress by entering a state of reduced protein synthesis, redirecting resources to damage control and defense. This reduced translation is closely linked to the formation of cytoplasmic stress granules (SGs). SGs are multicomponent foci, which contain...... stalled translation preinitiation complexes, including polyadenylated mRNAs, and several aggregation-prone RNA binding factors, such as the Ras-GAP SH3 domain-binding protein (G3BP) that enable their formation. Once the stress is lifted, the stalled complexes from the SGs are believed to re......-engage in translation, facilitating cellular recovery. A growing body of evidence shows that various viruses can trigger SG formation. However, the presence of SGs may not be beneficial to the virus and many viruses have found ways to circumvent, disrupt or even utilize these granules, suggesting a role for SGs...

  18. Layer-by-layer buildup of polysaccharide-containing films: Physico-chemical properties and mesenchymal stem cells adhesion.

    Science.gov (United States)

    Kulikouskaya, Viktoryia I; Pinchuk, Sergei V; Hileuskaya, Kseniya S; Kraskouski, Aliaksandr N; Vasilevich, Irina B; Matievski, Kirill A; Agabekov, Vladimir E; Volotovski, Igor D

    2018-03-22

    Layer-by-Layer assembled polyelectrolyte films offer the opportunity to control cell attachment and behavior on solid surfaces. In the present study, multilayer films based on negatively charged biopolymers (pectin, dextran sulfate, carboxymethylcellulose) and positively charged polysaccharide chitosan or synthetic polyelectrolyte polyethyleneimine has been prepared and evaluated. Physico-chemical properties of the formed multilayer films, including their growth, morphology, wettability, stability, and mechanical properties, have been studied. We demonstrated that chitosan-containing films are characterized by the linear growth, the defect-free surface, and predominantly viscoelastic properties. When chitosan is substituted for the polyethyleneimine in the multilayer system, the properties of the formed films are significantly altered: the rigidity and surface roughness increases, the film growth acquires the exponential character. The multilayer films were subsequently used for culturing mesenchymal stem cells. It has been determined that stem cells effectively adhered to chitosan-containing films and formed on them the monolayer culture of fibroblast-like cells with high viability. Our results show that cell attachment is a complex process which is not only governed by the surface functionality because one of the key parameter effects on cell adhesion is the stiffness of polyelectrolyte multilayer films. We therefore propose our Layer-by-Layer films for applications in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018. © 2018 Wiley Periodicals, Inc.

  19. Movement of beta-irradiated epidermal basal cells to the spinous-granular layers in the absence of cell division

    International Nuclear Information System (INIS)

    Etoh, H.; Taguchi, Y.H.; Tabachnick, J.

    1975-01-01

    Guinea-pig epidermis was irradiated with 3000 rad of beta rays 1 hr after two injections of [ 3 H]thymidine 5 hr apart (labeled cells in S phase and G 2 phase) or 18 hr after injection (labeled early G 1 cells). In nonirradiated epidermis labeled basal cells divided within 24 hr with daughter cells remaining in the basal layer, and approximately 50 percent of the labeled cells moved into the spinal layer by the 3rd day. Cell division in nonirradiated epidermis diluted the number of silver grains/nucleus, and lightly labeled cells were found in the granular layer by day 7. Beta irradiation inhibited cell division but it did not slow the rate of transit (ca 8 days) of irradiated labeled cells from basal to granular layer, some of these remaining heavily labeled. Although cell division may play some role in upward movement of basal cells in normal epidermis detachment of a basal cell from the basement membrane and its transit to the granular layer is unimpaired in the absence of cell division. These findings suggest that some radioresistant metabolic function(s), not cell division, is responsible for upward movement of basal cells. (auth)

  20. Impact of Interfacial Layers in Perovskite Solar Cells.

    Science.gov (United States)

    Cho, An-Na; Park, Nam-Gyu

    2017-10-09

    Perovskite solar cells (PCSs) are composed of organic-inorganic lead halide perovskite as the light harvester. Since the first report on a long-term-durable, 9.7 % efficient, solid-state perovskite solar cell, organic-inorganic halide perovskites have received considerable attention because of their excellent optoelectronic properties. As a result, a power conversion efficiency (PCE) exceeding 22 % was certified. Controlling the grain size, grain boundary, morphology, and defects of the perovskite layer is important for achieving high efficiency. In addition, interfacial engineering is equally or more important to further improve the PCE through better charge collection and a reduction in charge recombination. In this Review, the type of interfacial layers and their impact on photovoltaic performance are investigated for both the normal and the inverted cell architectures. Four different interfaces of fluorine-doped tin oxide (FTO)/electron-transport layer (ETL), ETL/perovskite, perovskite/hole-transport layer (HTL), and HTL/metal are classified, and their roles are investigated. The effects of interfacial engineering with organic or inorganic materials on photovoltaic performance are described in detail. Grain-boundary engineering is also included because it is related to interfacial engineering and the grain boundary in the perovskite layer plays an important role in charge conduction, recombination, and chargecarrier life time. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Glutamine granule-supplemented enteral nutrition maintains immunological function in severely burned patients.

    Science.gov (United States)

    Peng, Xi; Yan, Hong; You, Zhongyi; Wang, Pei; Wang, Shiliang

    2006-08-01

    Glutamine is an important energy source for immune cells. It is a necessary nutrient for cell proliferation, and serves as specific fuel for lymphocytes, macrophages, and enterocytes when it is present in appropriate concentrations. The purpose of this clinical study was to observe the effects of enteral nutrition supplemented with glutamine granules on immunologic function in severely burned patients. Forty-eight severely burned patients (total burn surface area 30-75%, full thickness burn area 20-58%) who met the requirements of the protocol joined this double-blind randomized controlled clinical trail. Patients were randomly divided into two groups: burn control group (B group, 23 patients) and glutamine treated group (Gln group, 25 patients). There was isonitrogenous and isocaloric intake in both groups, Gln and B group patents were given glutamine granules or placebo (glycine) at 0.5 g/kgd for 14 days with oral feeding or tube feeding, respectively. The plasma level of glutamine and several indices of immunologic function including lymphocyte transformation ratio, neutrophil phagocytosis index (NPI), CD4/CD8 ratio, the content of immunoglobulin, complement C3, C4 and IL-2 levels were determined. Moreover, wound healing rate of burn area was observed and then hospital stay was recorded. The results showed significantly reduced plasma glutamine and damaged immunological function after severe burn Indices of cellular immunity function were remarkably decreased from normal controls. After taking glutamine granules for 14 days, plasma glutamine concentration was significantly higher in Gln group than that in B group (607.86+/-147.25 micromol/L versus 447.63+/-132.38 micromol/L, P0.05). In addition, wound healing was better and hospital stay days were reduced in Gln group (46.59+/-12.98 days versus 55.68+/-17.36 days, Pburn; supplemented glutamine granules with oral feeding or tube feeding abate the degree of immunosuppression, improve immunological function

  2. Surface passivation of InP solar cells with InAlAs layers

    Science.gov (United States)

    Jain, Raj K.; Flood, Dennis J.; Landis, Geoffrey A.

    1993-01-01

    The efficiency of indium phosphide solar cells is limited by high values of surface recombination. The effect of a lattice-matched In(0.52)Al(0.48)As window layer material for InP solar cells, using the numerical code PC-1D is investigated. It was found that the use of InAlAs layer significantly enhances the p(+)n cell efficiency, while no appreciable improvement is seen for n(+)p cells. The conduction band energy discontinuity at the heterojunction helps in improving the surface recombination. An optimally designed InP cell efficiency improves from 15.4 percent to 23 percent AMO for a 10 nm thick InAlAs layer. The efficiency improvement reduces with increase in InAlAs layer thickness, due to light absorption in the window layer.

  3. Internal structure of normal maize starch granules revealed by chemical surface gelatinization.

    Science.gov (United States)

    Pan, D D; Jane, J I

    2000-01-01

    Normal maize starch was fractionated into two sizes: large granules with diameters more than 5 microns and small granules with diameters less than 5 microns. The large granules were surface gelatinized by treating them with an aqueous LiCl solution (13 M) at 22-23 degrees C. Surface-gelatinized remaining granules were obtained by mechanical blending, and gelatinized surface starch was obtained by grinding with a mortar and a pestle. Starches of different granular sizes and radial locations, obtained after different degrees of surface gelatinization, were subjected to scanning electron microscopy, iodine potentiometric titration, gel-permeation chromatography, and amylopectin branch chain length analysis. Results showed that the remaining granules had a rough surface with a lamella structure. Amylose was more concentrated at the periphery than at the core of the granule. Amylopectin had longer long B-chains at the core than at the periphery of the granule. Greater proportions of the long B-chains were present at the core than at the periphery of the granule.

  4. Assessment of physical properties of granules with paracetamol and caffeine

    Directory of Open Access Journals (Sweden)

    Michal Szumilo

    2017-09-01

    Full Text Available Caffeine increases the analgesic properties of acetaminophen and therefore it is reasonable to use both substances together in one drug form in stronger pain. Currently, there are no commercially available pharmaceutical combination products containing acetaminophen and caffeine, which is present as granules. The aim of the study was to obtain twelve different granules with these therapeutic substances and determine the effect of various excipients on the quality of the drug form. All the granules were made by wet granulation. Two types of binders were used: polyethylene glycol 6000 (PEG and polyvinylpyrrolidone K30 (PVP as well as different types of fillers. The physical properties of granules were assessed in accordance to the requirements of the European Pharmacopoeia 8th ed. The highest apparent density was found in preparations containing calcium hydrophosphate (0.609 g/mL and the lowest – containing mannitol (0.353 g/mL as a filler. The Hausner ratio of most prepared granules ranged from 1.05 to 1.11, while the compressibility index ranged from 4.59 to 10.48%. The evaluation of properties of individual granules helped to indicate formulation with good features, which perhaps will be a good alternative to currently available painkillers with caffeine and acetaminophen.

  5. Using a million cell simulation of the cerebellum: network scaling and task generality.

    Science.gov (United States)

    Li, Wen-Ke; Hausknecht, Matthew J; Stone, Peter; Mauk, Michael D

    2013-11-01

    Several factors combine to make it feasible to build computer simulations of the cerebellum and to test them in biologically realistic ways. These simulations can be used to help understand the computational contributions of various cerebellar components, including the relevance of the enormous number of neurons in the granule cell layer. In previous work we have used a simulation containing 12000 granule cells to develop new predictions and to account for various aspects of eyelid conditioning, a form of motor learning mediated by the cerebellum. Here we demonstrate the feasibility of scaling up this simulation to over one million granule cells using parallel graphics processing unit (GPU) technology. We observe that this increase in number of granule cells requires only twice the execution time of the smaller simulation on the GPU. We demonstrate that this simulation, like its smaller predecessor, can emulate certain basic features of conditioned eyelid responses, with a slight improvement in performance in one measure. We also use this simulation to examine the generality of the computation properties that we have derived from studying eyelid conditioning. We demonstrate that this scaled up simulation can learn a high level of performance in a classic machine learning task, the cart-pole balancing task. These results suggest that this parallel GPU technology can be used to build very large-scale simulations whose connectivity ratios match those of the real cerebellum and that these simulations can be used guide future studies on cerebellar mediated tasks and on machine learning problems. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Enteric coating of granules containing the probiotic Lactobacillus acidophilus

    Directory of Open Access Journals (Sweden)

    Pyar Hassan

    2014-06-01

    Full Text Available In the present study, a capsule formulation composed of enteric coated granules of Lactobacillus acidophilus ATCC 4962 was developed using Eudragit L30D-55 as enteric polymer. Optimization of the capsule formulation was achieved with a maximum viable cell count after 2 h of incubation in acid medium and disintegration time of 1 h in buffer pH 6.8. The amount of Eudragit L30D-55 in the capsules correlated with gastric juice resistance. The best protective qualities against artificial gastric juice were observed when capsules were prepared from granules composed of L. acidophilus, corn starch, lactose monohydrate, polyvinylpyrrolidone and coated with 12.5 % (m/V of Eudragit L30D-55. Capsule formulation of L. acidophilus in edible broth medium suspension serves as a cheap alternative to the expensive freeze-drying procedure for preparing L. acidophilus. In addition, the enteric coating using Eudragit L30D-55 could protect probiotics from the acidic gastric environment and enhance the bioactivity of probiotics along with replacement of pathogenic microbes in human intestine

  7. Comparison of Ca2+ and Mg2+ enhancing aerobic granulation in SBR

    International Nuclear Information System (INIS)

    Liu Lin; Gao Dawen; Zhang Min; Fu Yuan

    2010-01-01

    Two sequencing batch reactors (SBRs) were operated to investigate the effect of Ca 2+ and Mg 2+ augmentation on aerobic granulation. Reactor R1 was augmented with Ca 2+ at 40 mg/L, while Mg 2+ was added to the reactor R2 with 40 mg/L. Results showed that the reactor R1 had a faster granulation process compared with R2, and the mature granules in R1 showed better physical characteristics. However, the mature granules in R2 had the higher production yield of polysaccharides and proteins, and aerobic granules in R2 experienced a faster substrate biodegradation. Microbial and genetic characteristics in mature granules were analyzed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The results revealed that Mg 2+ addition led to higher microbial diversity in mature granules. In addition, an uncultured bacterium (AB447697) was major specie in R1, and β-proteobacterium was dominant in R2. It can be concluded that Ca 2+ had an important effect on physical properties of aerobic granules, while Mg 2+ played a key role on biological properties during the sludge granulation.

  8. Granule cell dispersion is not a predictor of surgical outcome in temporal lobe epilepsy with mesial temporal sclerosis.

    Science.gov (United States)

    da Costa Neves, Rafael Scarpa; Jardim, Anaclara Prada; Caboclo, Luís Otávio; Lancellotti, Carmen; Marinho, Taissa Ferrari; Hamad, Ana Paula; Marinho, Murilo; Centeno, Ricardo; Cavalheiro, Esper Abrão; Scorza, Carla Alessandra; Targas Yacubian, Elza Márcia

    2013-01-01

    The aim of this retrospective study of a series of patients with mesial temporal lobe epilepsy (MTLE) and mesial temporal sclerosis (MTS) was to analyze the association of granule cell dispersion (GCD) with surgical prognosis, patterns of MTS and clinical data. Hippocampal specimens from 66 patients with MTLE and unilateral MTS and from 13 controls were studied. Quantitative neuropathological evaluation was performed on NeuN-stained hippocampal sections. Patients' clinical data, types of MTS and surgical outcome were reviewed. GCD occurred in 45.5% of cases and was not correlated with clinical variable. More severe neuronal loss was observed in patients with GCD. Except for MTS Type 2 - observed only in four no- GCD patients - groups did not differ with respect to the types of MTS. Surgical outcome was similar in both groups. In conclusion, GCD was associated with the degree of hippocampal cell loss, but was not a predictor of surgical outcome.

  9. The histone demethylase Kdm6b regulates a mature gene expression program in differentiating cerebellar granule neurons.

    Science.gov (United States)

    Wijayatunge, Ranjula; Liu, Fang; Shpargel, Karl B; Wayne, Nicole J; Chan, Urann; Boua, Jane-Valeriane; Magnuson, Terry; West, Anne E

    2018-03-01

    The histone H3 lysine 27 (H3K27) demethylase Kdm6b (Jmjd3) can promote cellular differentiation, however its physiological functions in neurons remain to be fully determined. We studied the expression and function of Kdm6b in differentiating granule neurons of the developing postnatal mouse cerebellum. At postnatal day 7, Kdm6b is expressed throughout the layers of the developing cerebellar cortex, but its expression is upregulated in newborn cerebellar granule neurons (CGNs). Atoh1-Cre mediated conditional knockout of Kdm6b in CGN precursors either alone or in combination with Kdm6a did not disturb the gross morphological development of the cerebellum. Furthermore, RNAi-mediated knockdown of Kdm6b in cultured CGN precursors did not alter the induced expression of early neuronal marker genes upon cell cycle exit. By contrast, knockdown of Kdm6b significantly impaired the induction of a mature neuronal gene expression program, which includes gene products required for functional synapse maturation. Loss of Kdm6b also impaired the ability of Brain-Derived Neurotrophic Factor (BDNF) to induce expression of Grin2c and Tiam1 in maturing CGNs. Taken together, these data reveal a previously unknown role for Kdm6b in the postmitotic stages of CGN maturation and suggest that Kdm6b may work, at least in part, by a transcriptional mechanism that promotes gene sensitivity to regulation by BDNF. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Feline Calicivirus infection disrupts the assembly of cytoplasmic stress granules and induces G3BP1 cleavage

    NARCIS (Netherlands)

    Humoud, Majid N; Doyle, Nicole; Royall, Elizabeth; Willcocks, Margaret M; Sorgeloos, Frederic; van Kuppeveld, Frank; Roberts, Lisa O; Goodfellow, Ian G; Langereis, Martijn A; Locker, Nicolas

    In response to stress such as virus infection, cells can stall translation by storing mRNAs away in cellular compartments called stress granules (SGs). This defence mechanism favours cell survival by limiting the use of energy and nutrients until the stress is resolved. In some cases it may also

  11. Cycle length and COD/N ratio determine properties of aerobic granules treating high-nitrogen wastewater.

    Science.gov (United States)

    Cydzik-Kwiatkowska, Agnieszka; Bernat, Katarzyna; Zielińska, Magdalena; Wojnowska-Baryła, Irena

    2014-07-01

    Aerobic granule characteristic in sequencing batch reactors treating high-nitrogen digester supernatant was investigated at cycle lengths (t) of 6, 8 and 12 h with the COD/N ratios in the influent of 4.5 and 2.3. The biomass production (Y obs) correlated with the extracellular polymeric substances (EPS) in grams per COD removed. Denitrification efficiency significantly decreased as the amount of EPS in biomass increased, suggesting that organic assimilation in EPS hampers nitrogen removal. Granule hydrophobicity was highest at t of 8 h; the t has to be long enough to remove pollutants, but not so long that excessive biomass starvation causes extracellular protein consumption that decreases hydrophobicity. At a given t, reducing the COD/N ratio improved hydrophobicity that stimulates cell aggregation. At t of 6 h and the COD/N ratio of 2.3, the dominance of 0.5-1.0 mm granules favored simultaneous nitrification and denitrification and resulted in the highest nitrogen removal.

  12. Effect of granular activated carbon on the aerobic granulation of sludge and its mechanism.

    Science.gov (United States)

    Tao, Jia; Qin, Lian; Liu, Xiaoying; Li, Bolin; Chen, Junnan; You, Juan; Shen, Yitian; Chen, Xiaoguo

    2017-07-01

    The granulation of activated sludge and effect of granular activated carbon (GAC) was investigated under the alternative anaerobic and aerobic conditions. The results showed that GAC accelerated the granulation, but had no obvious effect on the bacterial community structure of granules. The whole granulation process could be categorized into three phases, i.e. lag, granulation and granule maturation phase. During lag period GAC provided nuclei for sludge to attach, and thus enhanced the morphological regularization of sludge. During granulation period the granule size increased significantly due to the growth of bacteria in granules. GAC reduced the compression caused by the inter-particle collisions and thus accelerate the granulation. GAC has no negative effect on the performance of SBR, and thus efficient simultaneous removal of COD, nitrogen and phosphorus were obtained during most of the operating time. Copyright © 2017. Published by Elsevier Ltd.

  13. Granular Cell Tumor

    African Journals Online (AJOL)

    1). Her packed cell volume was 40%, she was system, gastro-intestinal tract, brain, heart, and negative to human immunodeficiency virus. 2 female reproductive . ... histocytes and neurons at various times. They granules. The granules are probably of lysosmal were consequently termed granular cell origin and contain ...

  14. Anaerobic granule-based biofilms formation reduces propionate accumulation under high H2 partial pressure using conductive carbon felt particles.

    Science.gov (United States)

    Xu, Heng; Wang, Cuiping; Yan, Kun; Wu, Jing; Zuo, Jiane; Wang, Kaijun

    2016-09-01

    Syngas based co-digestion is not only more economically attractive than separate syngas methanation but also able to upgrade biogas and increase overall CH4 amount simultaneously. However, high H2 concentration in the syngas could inhibit syntrophic degradation of propionate, resulting in propionate accumulation and even failure of the co-digestion system. In an attempt to reduce propionate accumulation via enhancing both H2 interspecies transfer (HIT) and direct interspecies electron transfer (DIET) pathways, layered granule-based biofilms induced by conductive carbon felt particles (CCFP) was employed. The results showed that propionate accumulation was effectively reduced with influent COD load up to 7gL(-1)d(-1). Two types of granule-based biofilms, namely biofilm adhered to CCFP (B-CCFP) and granules formed by self-immobilization (B-SI) were formed in the reactor. Clostridium, Syntrophobacter, Methanospirillum were possibly involved in HIT and Clostridium, Geobacter, Anaerolineaceae, Methanosaeta in DIET, both of which might be responsible for the high-rate propionate degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Granule cell dispersion is associated with memory impairment in right mesial temporal lobe epilepsy.

    Science.gov (United States)

    Neves, Rafael Scarpa da Costa; de Souza Silva Tudesco, Ivanda; Jardim, Anaclara Prada; Caboclo, Luís Otávio Sales Ferreira; Lancellotti, Carmen; Ferrari-Marinho, Taíssa; Hamad, Ana Paula; Marinho, Murilo; Centeno, Ricardo Silva; Cavalheiro, Esper Abrão; Scorza, Carla Alessandra; Yacubian, Elza Márcia Targas

    2012-11-01

    We analyzed the association of granule cell dispersion (GCD) with memory performance, clinical data and surgical outcome in a series of patients with mesial temporal lobe epilepsy (MTLE) and mesial temporal sclerosis (MTS). Hippocampal specimens from 54 patients with MTLE (27 patients with right MTLE and 27 with left MTLE) and unilateral MTS, who were separated into GCD and no-GCD groups and thirteen controls were studied. Quantitative neuropathological evaluation was performed using hippocampal sections stained with NeuN. Patients' neuropsychological measures, clinical data, type of MTS and surgical outcome were reviewed. GCD occurred in 28 (51.9%) patients. No correlation between GCD and MTS pattern, clinical data or surgical outcome was found. The presence of GCD was correlated with worse visuospatial memory performance in right MTLE, but not with memory performance in left MTLE. GCD may be related to memory impairment in right MTLE-MTS patients. However, the role of GCD in memory function is not precisely defined. Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  16. Role of calcium oxide in sludge granulation and methanogenesis for the treatment of palm oil mill effluent using UASB reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Anwar, E-mail: anwarak218@yahoo.co.uk [Faculty of Civil Engineering and Earth Resources, University Malaysia Pahang (UMP), Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang (Malaysia); Ghufran, Rumana; Wahid, Zularisam Abd. [Faculty of Civil Engineering and Earth Resources, University Malaysia Pahang (UMP), Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang (Malaysia)

    2011-12-30

    Graphical abstract: SEM micrograph of granules; Outer surface of the granule; Scanning electron micrographs of the granule: Archaea (Methanosarcina sp.) showing the arrangement of bacterial cells in granule surrounded by extracellular polymeric substances (EPS), the seed sludge and granules sampled on day 150. Highlights: Black-Right-Pointing-Pointer Examine the treatability of POME and effects of CaO-CKD on the granulation process in UASB reactors. Black-Right-Pointing-Pointer The main objective was to determine the influent CaO-CKD concentration and the relationship between the CaO concentration in the feed and biomass accumulation, specific granulation, methanogenic activity, and the density and composition of granules. Black-Right-Pointing-Pointer The biomass concentration profiles along the reactors and the size distribution of granules were also measured to track and to assess granulation, methanogenesis, and COD removal on levels at the industrial scale. Black-Right-Pointing-Pointer SEM micrograph are showing smooth surface of granule with a large opening cavities likely for biogas escape. - Abstract: The granulation process in palm oil mill effluent using calcium oxide-cement kiln dust (CaO-CKD) provides an attractive and cost effective treatment option. In this study the efficiency of CaO-CKD at doses of 1.5-20 g/l was tested in batch experiments and found that 10 g of CaO/l caused the greatest degradation of VFA, butyrate and acetate. An upflow anaerobic sludge blanket (UASB) reactor was operated continuously at 35 Degree-Sign C for 150 days to investigate the effect of CaO-CKD on sludge granulation and methanogenesis during start-up. The treatment of POME emphasized the influence of varying organic loading rates (OLR). Up to 94.9% of COD was removed when the reactor was fed with the 15.5-65.5 g-COD g/l at an OLR of 4.5-12.5 kg-COD/m{sup 3} d, suggesting the feasibility of using CaO in an UASB process to treat POME. The ratio of volatile solids

  17. Ambient Layer-by-Layer ZnO Assembly for Highly Efficient Polymer Bulk Heterojunction Solar Cells

    KAUST Repository

    Eita, Mohamed Samir; El Labban, Abdulrahman; Cruciani, Federico; Usman, Anwar; Beaujuge, Pierre; Mohammed, Omar F.

    2015-01-01

    The use of metal oxide interlayers in polymer solar cells has great potential because metal oxides are abundant, thermally stable, and can be used in fl exible devices. Here, a layer-by-layer (LbL) protocol is reported as a facile, room

  18. UNCERTAINTY HANDLING IN DISASTER MANAGEMENT USING HIERARCHICAL ROUGH SET GRANULATION

    Directory of Open Access Journals (Sweden)

    H. Sheikhian

    2015-08-01

    Full Text Available Uncertainty is one of the main concerns in geospatial data analysis. It affects different parts of decision making based on such data. In this paper, a new methodology to handle uncertainty for multi-criteria decision making problems is proposed. It integrates hierarchical rough granulation and rule extraction to build an accurate classifier. Rough granulation provides information granules with a detailed quality assessment. The granules are the basis for the rule extraction in granular computing, which applies quality measures on the rules to obtain the best set of classification rules. The proposed methodology is applied to assess seismic physical vulnerability in Tehran. Six effective criteria reflecting building age, height and material, topographic slope and earthquake intensity of the North Tehran fault have been tested. The criteria were discretized and the data set was granulated using a hierarchical rough method, where the best describing granules are determined according to the quality measures. The granules are fed into the granular computing algorithm resulting in classification rules that provide the highest prediction quality. This detailed uncertainty management resulted in 84% accuracy in prediction in a training data set. It was applied next to the whole study area to obtain the seismic vulnerability map of Tehran. A sensitivity analysis proved that earthquake intensity is the most effective criterion in the seismic vulnerability assessment of Tehran.

  19. Roll Compaction/Dry Granulation of Dibasic Calcium Phosphate Anhydrous-Does the Morphology of the Raw Material Influence the Tabletability of Dry Granules?

    Science.gov (United States)

    Grote, Simon; Kleinebudde, Peter

    2018-04-01

    The influence of raw material particle morphology on the tabletabilty of dry granules was investigated. Therefore, dibasic calcium phosphate anhydrous was used as a model material. One milled grade, 2 agglomerated grades with different porosities, and a functionalized structure, that is, an agglomerate formed by very small primary particles, were included. Particle size, density, and specific surface area of raw materials were measured. The starting materials and 2 fractions of dry granules were compressed to tablets. The tabletability of granules was compared to that of the powders and the influence of specific compaction force, granule size, and lubrication on tablet tensile strength was evaluated. All materials showed a loss in tabletability induced by a previous compaction step but to a varying extent. Only in case of the functionalized calcium phosphate morphology, this effect depended on the specific compaction force. In contrast to the other materials, the tabletability of functionalized calcium phosphate was influenced by the granule size. This effect was not related to an overlubrication as internal and external lubrication resulted in similar tensile strengths. A clear influence of the particle morphology on tablet strength was demonstrated by the study. The functionalized structure showed aspects of a more plastic deformation behavior. The functionalized dibasic calcium phosphate and the more porous agglomerate performed as potential filler/binder in the field of roll compaction/dry granulation. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. Actinomyces associated with persistent vaginal granulation tissue.

    OpenAIRE

    Wai, Clifford Y; Nihira, Mikio A; Drewes, Peter G; Chang, Joe S; Siddiqui, Momin T; Hemsell, David L

    2005-01-01

    BACKGROUND: We report a case of symptomatic actinomycosis associated with vaginal suture erosion and granulation tissue refractory to conservative management, in an outpatient setting. CASE: Three months after total vaginal hysterectomy and uterosacral ligament vaginal vault suspension, a woman complained of painless, intermittent vaginal discharge and spotting. Despite cauterization of granulation tissue, vaginal spotting persisted for another month. On re-examination, braided polyester sutu...

  1. rab3 mediates cortical granule exocytosis in the sea urchin egg.

    Science.gov (United States)

    Conner, S; Wessel, G M

    1998-11-15

    Egg activation at fertilization in the sea urchin results in the exocytosis of approximately 15,000 cortical granules that are docked at the plasma membrane. Previously, we reported that several integral membrane proteins modeled in the SNARE hypothesis, synaptotagmin, VAMP, and syntaxin, in addition to a small GTPase of the ras superfamily, rab3, were present on cortical granules (Conner, S., Leaf, D., and Wessel, G., Mol. Reprod. Dev. 48, 1-13, 1997). Here we report that rab3 is associated with cortical granules throughout oogenesis, during cortical granule translocation, and while docked at the egg plasma membrane. Following cortical granule exocytosis, however, rab3 reassociates with a different population of vesicles, at least some of which are of endocytic origin. Because of its selective association with cortical granules in eggs and oocytes, we hypothesize that rab3 functions in cortical granule exocytosis. To test this hypothesis, we used a strategy of interfering with rab3 function by peptide competition with its effector domain, a conserved region within specific rab types. We first identified the effector domain sequence in Lytechinus variegatus eggs and find the sequence 94% identical to the effector domain of rab3 in Stronglocentrotus purpuratus. Then, with synthetic peptides to different regions of the rab3 protein, we find that cortical granule exocytosis is inhibited in eggs injected with effector domain peptides, but not with peptides from the hypervariable region or with a scrambled effector peptide. Additionally, effector-peptide-injected eggs injected with IP3 are blocked in their ability to exocytose cortical granules, suggesting that the inhibition is directly on the membrane fusion event and not the result of interference with the signal transduction mechanism leading to calcium release. We interpret these results to mean that rab3 functions in the regulation of cortical granule exocytosis following vesicle docking. Copyright 1998 Academic

  2. Microbial Community Composition and Ultrastructure of Granules from a Full-Scale Anammox Reactor

    KAUST Repository

    Gonzalez-Gil, Graciela

    2014-12-11

    Granules in anammox reactors contain besides anammox bacteria other microbial communities whose identity and relationship with the anammox bacteria are not well understood. High calcium concentrations are often supplied to anammox reactors to obtain sufficient bacterial aggregation and biomass retention. The aim of this study was to provide the first characterization of bacterial and archaeal communities in anammox granules from a full-scale anammox reactor and to explore on the possible role of calcium in such aggregates. High magnification imaging using backscattered electrons revealed that anammox bacteria may be embedded in calcium phosphate precipitates. Pyrosequencing of 16S rRNA gene fragments showed, besides anammox bacteria (Brocadiacea, 32 %), substantial numbers of heterotrophic bacteria Ignavibacteriacea (18 %) and Anaerolinea (7 %) along with heterotrophic denitrifiers Rhodocyclacea (9 %), Comamonadacea (3 %), and Shewanellacea (3 %) in the granules. It is hypothesized that these bacteria may form a network in which heterotrophic denitrifiers cooperate to achieve a well-functioning denitrification system as they can utilize the nitrate intrinsically produced by the anammox reaction. This network may provide a niche for the proliferation of archaea. Hydrogenotrophic methananogens, which scavenge the key fermentation product H2, were the most abundant archaea detected. Cells resembling the polygon-shaped denitrifying methanotroph Candidatus Methylomirabilis oxyfera were observed by electron microscopy. It is hypothesized that the anammox process in a full-scale reactor triggers various reactions overall leading to efficient denitrification and a sink of carbon as biomass in anammox granules.

  3. Microbial community composition and ultrastructure of granules from a full-scale anammox reactor.

    Science.gov (United States)

    Gonzalez-Gil, Graciela; Sougrat, Rachid; Behzad, Ali R; Lens, Piet N L; Saikaly, Pascal E

    2015-07-01

    Granules in anammox reactors contain besides anammox bacteria other microbial communities whose identity and relationship with the anammox bacteria are not well understood. High calcium concentrations are often supplied to anammox reactors to obtain sufficient bacterial aggregation and biomass retention. The aim of this study was to provide the first characterization of bacterial and archaeal communities in anammox granules from a full-scale anammox reactor and to explore on the possible role of calcium in such aggregates. High magnification imaging using backscattered electrons revealed that anammox bacteria may be embedded in calcium phosphate precipitates. Pyrosequencing of 16S rRNA gene fragments showed, besides anammox bacteria (Brocadiacea, 32%), substantial numbers of heterotrophic bacteria Ignavibacteriacea (18%) and Anaerolinea (7%) along with heterotrophic denitrifiers Rhodocyclacea (9%), Comamonadacea (3%), and Shewanellacea (3%) in the granules. It is hypothesized that these bacteria may form a network in which heterotrophic denitrifiers cooperate to achieve a well-functioning denitrification system as they can utilize the nitrate intrinsically produced by the anammox reaction. This network may provide a niche for the proliferation of archaea. Hydrogenotrophic methananogens, which scavenge the key fermentation product H2, were the most abundant archaea detected. Cells resembling the polygon-shaped denitrifying methanotroph Candidatus Methylomirabilis oxyfera were observed by electron microscopy. It is hypothesized that the anammox process in a full-scale reactor triggers various reactions overall leading to efficient denitrification and a sink of carbon as biomass in anammox granules.

  4. Mining the granule proteome

    DEFF Research Database (Denmark)

    Albrethsen, Jakob; Goetze, Jens P; Johnsen, Anders H

    2015-01-01

    Proteomics of secretory granules is an emerging strategy for identifying secreted proteins, including potentially novel candidate biomarkers and peptide hormones. In addition, proteomics can provide information about the abundance, localization and structure (post-translational modification) of g...

  5. Double-layered ZnO nanostructures for efficient perovskite solar cells

    KAUST Repository

    Mahmood, Khalid; S. Swain, Bhabani; Amassian, Aram

    2014-01-01

    To date, a single layer of TiO2 or ZnO has been the most successful implementations of any electron transport layer (ETL) in solution-processed perovskite solar cells. In a quest to improve the ETL, we explore a new nanostructured double-layer ZnO film for mesoscopic perovskite-based thin film photovoltaics. This approach yields a maximum power conversion efficiency of 10.35%, which we attribute to the morphology of oxide layer and to faster electron transport. The successful implementation of the low-temperature hydrothermally processed double-layer ZnO film as ETL in perovskite solar cells highlights the opportunities to further improve the efficiencies by focusing on the ETL in this rapidly developing field. This journal is

  6. Granulation for Coking Wastewater Treatment in a Coupled Anaerobic-Aerobic Reactor

    Science.gov (United States)

    Dong, Chunjuan; Lv, Bingnan

    2018-06-01

    A coupled anaerobic-aerobic granular bio-film reactor was employed with two operation stages: Stage I, granular sludge was formed from digestion sludge using brewery wastewater, and Stage II, granular sludge was acclimatized using coking wastewater. Two oxygenation methods (i.e. A and B) were employed to acclimatize the granules. For method A, dissolved O 2 was supplied through a continuous oxygenation way of 800-15000ml-min-1 . And for method B, dissolved O2 was supplied of 800-15000ml-min-1 18-12 times at 20-60min intervals, 1h each time. The experimental results showed that granules could quickly form in 10d in the EGSB reactor seeded with digestion sludge and little loose granules lack of nutrition, and it was the key factor for granules forming to add little loose granules. It took only about 6 months for granules acclimation using coking wastewater. Both oxygenation methods could run well when acclimatizing the granules. However, method A could have comparatively high and stable operation effect. The actual coking wastewater had distinct inhibition effect on the granules, but the supplement of some oxygen could promote the recovery of SMA, and NaHCO3 supplement could also weaken the inhibition effect of the CWW. Method A had more strongly activity recovery ability than method B.

  7. Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin

    OpenAIRE

    Johnson, Adam S; Garc?a, Dana M

    2007-01-01

    Abstract Background Inside bluegill (Lepomis macrochirus) retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog) is one example. Previous research indicates that the ca...

  8. Solid oxide fuel cells with bi-layered electrolyte structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinge; Robertson, Mark; Deces-Petit, Cyrille; Xie, Yongsong; Hui, Rob; Qu, Wei; Kesler, Olivera; Maric, Radenka; Ghosh, Dave [Institute for Fuel Cell Innovation, National Research Council Canada, 4250 Wesbrook Mall, Vancouver, B.C. V6T 1W5 (Canada)

    2008-01-10

    In this work, we have developed solid oxide fuel cells with a bi-layered electrolyte of 2 {mu}m SSZ and 4 {mu}m SDC using tape casting, screen printing, and co-firing processes. The cell reached power densities of 0.54 W cm{sup -2} at 650 C and 0.85 W cm{sup -2} at 700 C, with open circuit voltage (OCV) values larger than 1.02 V. The electrical leaking between anode and cathode through an SDC electrolyte has been blocked in the bi-layered electrolyte structure. However, both the electrolyte resistance (R{sub el}) and electrode polarization resistance (R{sub p,a+c}) increased in comparison to cells with single-layered SDC electrolytes. The formation of a solid solution of (Ce, Zr)O{sub 2-x} during sintering process and the flaws in the bi-layered electrolyte structure seem to be the main causes for the increase in the R{sub el} value (0.32 {omega} cm{sup 2}) at 650 C, which is almost one order of magnitude higher than the calculated value. (author)

  9. Solar cells with perovskite-based light sensitization layers

    Science.gov (United States)

    Kanatzidis, Mercouri G.; Chang, Robert P.H.; Stoumpos, Konstantinos; Lee, Byunghong

    2018-05-08

    Solar cells are provided which comprise an electron transporting layer and a light sensitizing layer of perovskite disposed over the surface of the electron transporting layer. The perovskite may have a formula selected from the group consisting of A2MX6, Z2MX6 or YMX6, wherein A is an alkali metal, M is a metal or a metalloid, X is a halide, Z is selected from the group consisting of a primary ammonium, an iminium, a secondary ammonium, a tertiary ammonium, and a quaternary ammonium, and Y has formula Mb(L)3, wherein Mb is a transition metal in the 2+ oxidation state L is an N--N neutral chelating ligand. Methods of making the solar cells are also provided, including methods based on electrospray deposition.

  10. A Review of Granulation Process for Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Yu Pengfei

    2016-01-01

    Full Text Available Molten slags of blast furnace is a second resources with great value of 1600~1 800 MJ sensible heat per ton. At present, water-quenching process plays a leading role in recovering waste heat of the molten slags. However, this method not only cost lots of water, but also recover little sensible heat and can pollute the surrounding environment. Dry granulation process, as an environmentally friendly method with high-efficiency heat recovery, have attracted widespread attentions. In this paper, the water quenching and dry granulation processes were discussed in detail. After a thorough comparative analysis of various treatment technologies, it can be concluded that centrifugal granulation affiliated with dry granulation is the optimum process, with smaller slag particle size (about 2mm, more glassy phase and higher recovery rate.

  11. Improved Efficiency of Polymer Solar Cells by means of Coating Hole Transporting Layer as Double Layer Deposition

    Science.gov (United States)

    Chonsut, T.; Kayunkid, N.; Rahong, S.; Rangkasikorn, A.; Wirunchit, S.; Kaewprajak, A.; Kumnorkaew, P.; Nukeaw, J.

    2017-09-01

    Polymer solar cells is one of the promising technologies that gain tremendous attentions in the field of renewable energy. Optimization of thickness for each layer is an important factor determining the efficiency of the solar cells. In this work, the optimum thickness of Poly(3,4-ethylenedioxythione): poly(styrenesulfonate) (PEDOT:PSS), a famous polymer widely used as hole transporting layer in polymer solar cells, is determined through the analyzing of device’s photovoltaic parameters, e.g. short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF) as well as power conversion efficiency (PCE). The solar cells were prepared with multilayer of ITO/PEDOT:PSS/PCDTBT:PC70BM/TiOx/Al by rapid convective deposition. In such preparation technique, the thickness of the thin film is controlled by the deposition speed. The faster deposition speed is used, the thicker film is obtained. Furthermore, double layer deposition of PEDOT:PSS was introduced as an approach to improve solar cell efficiency. The results obviously reveal that, with the increase of PEDOT:PSS thickness, the increments of Jsc and FF play the important role to improve PCE from 3.21% to 4.03%. Interestingly, using double layer deposition of PEDOT:PSS shows the ability to enhance the performance of the solar cells to 6.12% under simulated AM 1.5G illumination of 100 mW/cm2.

  12. Lipid raft localization of GABA A receptor and Na+, K+-ATPase in discrete microdomain clusters in rat cerebellar granule cells

    DEFF Research Database (Denmark)

    Dalskov, Stine-Mathilde; Immerdal, Lissi; Niels-Christiansen, Lise-Lotte W

    2005-01-01

    The microdomain localization of the GABA(A) receptor in rat cerebellar granule cells was studied by subcellular fractionation and fluorescence- and immunogold electron microscopy. The receptor resided in lipid rafts, prepared at 37 degrees C by extraction with the nonionic detergent Brij 98......, but the raft fraction, defined by the marker ganglioside GM(1) in the floating fractions following density gradient centrifugation, was heterogeneous in density and protein composition. Thus, another major raft-associated membrane protein, the Na(+), K(+)-ATPase, was found in discrete rafts of lower density......, reflecting clustering of the two proteins in separate membrane microdomains. Both proteins were observed in patchy "hot spots" at the cell surface as well as in isolated lipid rafts. Their insolubility in Brij 98 was only marginally affected by methyl-beta-cyclodextrin. In contrast, both the GABA(A) receptor...

  13. Epitaxially grown polycrystalline silicon thin-film solar cells on solid-phase crystallised seed layers

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei, E-mail: weili.unsw@gmail.com; Varlamov, Sergey; Xue, Chaowei

    2014-09-30

    Highlights: • Crystallisation kinetic is used to analyse seed layer surface cleanliness. • Simplified RCA cleaning for the seed layer can shorten the epitaxy annealing duration. • RTA for the seed layer can improve the quality for both seed layer and epi-layer. • Epitaxial poly-Si solar cell performance is improved by RTA treated seed layer. - Abstract: This paper presents the fabrication of poly-Si thin film solar cells on glass substrates using seed layer approach. The solid-phase crystallised P-doped seed layer is not only used as the crystalline template for the epitaxial growth but also as the emitter for the solar cell structure. This paper investigates two important factors, surface cleaning and intragrain defects elimination for the seed layer, which can greatly influence the epitaxial grown solar cell performance. Shorter incubation and crystallisation time is observed using a simplified RCA cleaning than the other two wet chemical cleaning methods, indicating a cleaner seed layer surface is achieved. Cross sectional transmission microscope images confirm a crystallographic transferal of information from the simplified RCA cleaned seed layer into the epi-layer. RTA for the SPC seed layer can effectively eliminate the intragrain defects in the seed layer and improve structural quality of both of the seed layer and the epi-layer. Consequently, epitaxial grown poly-Si solar cell on the RTA treated seed layer shows better solar cell efficiency, V{sub oc} and J{sub sc} than the one on the seed layer without RTA treatment.

  14. PLC-dependent intracellular Ca2+ release was associated with C6-ceramide-induced inhibition of Na+ current in rat granule cells.

    Science.gov (United States)

    Liu, Zheng; Fei, Xiao-Wei; Fang, Yan-Jia; Shi, Wen-Jie; Zhang, Yu-Qiu; Mei, Yan-Ai

    2008-09-01

    In this report, the effects of C(6)-ceramide on the voltage-gated inward Na(+) currents (I(Na)), two types of main K(+) current [outward rectifier delayed K(+) current (I(K)) and outward transient K(+) current (I(A))], and cell death in cultured rat cerebellar granule cells were investigated. At concentrations of 0.01-100 microM, ceramide produced a dose-dependent and reversible inhibition of I(Na) without alteration of the steady-state activation and inactivation properties. Treatment with C(2)-ceramide caused a similar inhibitory effect on I(Na). However, dihydro-C(6)-ceramide failed to modulate I(Na). The effect of C(6)-ceramide on I(Na) was abolished by intracellular infusion of the Ca(2+)-chelating agent, 1,2-bis (2-aminophenoxy) ethane-N, N, N9, N9-tetraacetic acid, but was mimicked by application of caffeine. Blocking the release of Ca(2+) from the sarcoplasmic reticulum with ryanodine receptor blocker induced a gradual increase in I(Na) amplitude and eliminated the effect of ceramide on I(Na). In contrast, the blocker of the inositol 1,4,5-trisphosphate-sensitive Ca(2+) receptor did not affect the action of C(6)-ceramide. Intracellular application of GTPgammaS also induced a gradual decrease in I(Na) amplitude, while GDPbetaS eliminated the effect of C(6)-ceramide on I(Na). Furthermore, the C(6)-ceramide effect on I(Na) was abolished after application of the phospholipase C (PLC) blockers and was greatly reduced by the calmodulin inhibitors. Fluorescence staining showed that C(6)-ceramide decreased cell viability and blocking I(Na) by tetrodotoxin did not mimic the effect of C(6)-ceramide, and inhibiting intracellular Ca(2+) release by dantrolene could not decrease the C(6)-ceramide-induced cell death. We therefore suggest that increased PLC-dependent Ca(2+) release through the ryanodine-sensitive Ca(2+) receptor may be responsible for the C(6)-ceramide-induced inhibition of I(Na), which does not seem to be associated with C(6)-ceramide-induced granule

  15. Characterization of cytoskeletal and junctional proteins expressed by cells cultured from human arachnoid granulation tissue

    Directory of Open Access Journals (Sweden)

    Mehta Bhavya C

    2005-10-01

    Full Text Available Abstract Background The arachnoid granulations (AGs are projections of the arachnoid membrane into the dural venous sinuses. They function, along with the extracranial lymphatics, to circulate the cerebrospinal fluid (CSF to the systemic venous circulation. Disruption of normal CSF dynamics may result in increased intracranial pressures causing many problems including headaches and visual loss, as in idiopathic intracranial hypertension and hydrocephalus. To study the role of AGs in CSF egress, we have grown cells from human AG tissue in vitro and have characterized their expression of those cytoskeletal and junctional proteins that may function in the regulation of CSF outflow. Methods Human AG tissue was obtained at autopsy, and explanted to cell culture dishes coated with fibronectin. Typically, cells migrated from the explanted tissue after 7–10 days in vitro. Second or third passage cells were seeded onto fibronectin-coated coverslips at confluent densities and grown to confluency for 7–10 days. Arachnoidal cells were tested using immunocytochemical methods for the expression of several common cytoskeletal and junctional proteins. Second and third passage cultures were also labeled with the common endothelial markers CD-31 or VE-cadherin (CD144 and their expression was quantified using flow cytometry analysis. Results Confluent cultures of arachnoidal cells expressed the intermediate filament protein vimentin. Cytokeratin intermediate filaments were expressed variably in a subpopulation of cells. The cultures also expressed the junctional proteins connexin43, desmoplakin 1 and 2, E-cadherin, and zonula occludens-1. Flow cytometry analysis indicated that second and third passage cultures failed to express the endothelial cell markers CD31 or VE-cadherin in significant quantities, thereby showing that these cultures did not consist of endothelial cells from the venous sinus wall. Conclusion To our knowledge, this is the first report of

  16. NEDDylation promotes stress granule assembly.

    Science.gov (United States)

    Jayabalan, Aravinth Kumar; Sanchez, Anthony; Park, Ra Young; Yoon, Sang Pil; Kang, Gum-Yong; Baek, Je-Hyun; Anderson, Paul; Kee, Younghoon; Ohn, Takbum

    2016-07-06

    Stress granules (SGs) harbour translationally stalled messenger ribonucleoproteins and play important roles in regulating gene expression and cell fate. Here we show that neddylation promotes SG assembly in response to arsenite-induced oxidative stress. Inhibition or depletion of key components of the neddylation machinery concomitantly inhibits stress-induced polysome disassembly and SG assembly. Affinity purification and subsequent mass-spectrometric analysis of Nedd8-conjugated proteins from translationally stalled ribosomal fractions identified ribosomal proteins, translation factors and RNA-binding proteins (RBPs), including SRSF3, a previously known SG regulator. We show that SRSF3 is selectively neddylated at Lys85 in response to arsenite. A non-neddylatable SRSF3 (K85R) mutant do not prevent arsenite-induced polysome disassembly, but fails to support the SG assembly, suggesting that the neddylation pathway plays an important role in SG assembly.

  17. An optimized multilayer structure of CdS layer for CdTe solar cells application

    International Nuclear Information System (INIS)

    Han Junfeng; Liao Cheng; Jiang Tao; Spanheimer, C.; Haindl, G.; Fu, Ganhua; Krishnakumar, V.; Zhao Kui; Klein, A.; Jaegermann, W.

    2011-01-01

    Research highlights: → Two different methods to prepare CdS films for CdTe solar cells. → A new multilayer structure of window layer for the CdTe solar cell. → Thinner CdS window layer for the solar cell than the standard CdS layer. → Higher performance of solar cells based on the new multilayer structure. - Abstract: CdS layers grown by 'dry' (close space sublimation) and 'wet' (chemical bath deposition) methods are deposited and analyzed. CdS prepared with close space sublimation (CSS) has better crystal quality, electrical and optical properties than that prepared with chemical bath deposition (CBD). The performance of CdTe solar cell based on the CSS CdS layer has higher efficiency than that based on CBD CdS layer. However, the CSS CdS suffers from the pinholes. And consequently it is necessary to prepare a 150 nm thin film for CdTe/CdS solar cell. To improve the performance of CdS/CdTe solar cells, a thin multilayer structure of CdS layer (∼80 nm) is applied, which is composed of a bottom layer (CSS CdS) and a top layer (CBD CdS). That bi-layer film can allow more photons to pass through it and significantly improve the short circuit current of the CdS/CdTe solar cells.

  18. Characterization of two novel nuclear BTB/POZ domain zinc finger isoforms. Association with differentiation of hippocampal neurons, cerebellar granule cells, and macroglia

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Kjaerulff, Karen M; Pedersen, Hans C

    2002-01-01

    BTB/POZ (broad complex tramtrack bric-a-brac/poxvirus and zinc finger) zinc finger factors are a class of nuclear DNA-binding proteins involved in development, chromatin remodeling, and cancer. However, BTB/POZ domain zinc finger factors linked to development of the mammalian cerebral cortex......, cerebellum, and macroglia have not been described previously. We report here the isolation and characterization of two novel nuclear BTB/POZ domain zinc finger isoforms, designated HOF(L) and HOF(S), that are specifically expressed in early hippocampal neurons, cerebellar granule cells, and gliogenic...

  19. A vertically integrated dynamic RAM-cell: Buried bit line memory cell with floating transfer layer

    NARCIS (Netherlands)

    Mouthaan, A.J.; Vertregt, Maarten

    1986-01-01

    A charge injection device has been realized in which charge can be injected on to an MOS-capacitor from a buried layer via an isolated transfer layer. The cell is positioned vertically between word and bit line. LOCOS (local oxidation) is used to isolate the cells and (deep) ion implantation to

  20. GRANULATION TRIALS OF WASTE THE DUST SILICON CARBIDE FOR UTILIZATION IN METALLURGY

    Directory of Open Access Journals (Sweden)

    Gabriel Borowski

    2016-09-01

    Full Text Available The article presents the results of laboratory granulation tests of dust silicon carbide and the results of research on the selection of the binder and the properties of the granules obtained. The research material was a waste of the silicon carbide powder with a high fragmentation, mixed with a cement or an organic modified starch specimen. Six tests were performed in a disc granulator with 100 cm in diameter. In each series of trial specified: the type and share of the binder, the diameter of the granules, tenderness, type of structure and mechanical properties. Good granules of silicon carbide obtained with the addition of cement binder with 4% of the mass fraction and at least 24 hours of seasoning. The binder should be added twice by powdering, first in a stirred granulator, and again after manufacture. It was found that the resulting granules may be used as a replacement of ferrosilicon in the process of steelmaking.

  1. Fetuin-A/albumin-mineral complexes resembling serum calcium granules and putative nanobacteria: demonstration of a dual inhibition-seeding concept.

    Directory of Open Access Journals (Sweden)

    Cheng-Yeu Wu

    2009-11-01

    Full Text Available Serum-derived granulations and purported nanobacteria (NB are pleomorphic apatite structures shown to resemble calcium granules widely distributed in nature. They appear to be assembled through a dual inhibitory-seeding mechanism involving proteinaceous factors, as determined by protease (trypsin and chymotrypsin and heat inactivation studies. When inoculated into cell culture medium, the purified proteins fetuin-A and albumin fail to induce mineralization, but they will readily combine with exogenously added calcium and phosphate, even in submillimolar amounts, to form complexes that will undergo morphological transitions from nanoparticles to spindles, films, and aggregates. As a mineralization inhibitor, fetuin-A is much more potent than albumin, and it will only seed particles at higher mineral-to-protein concentrations. Both proteins display a bell-shaped, dose-dependent relationship, indicative of the same dual inhibitory-seeding mechanism seen with whole serum. As ascertained by both seeding experiments and gel electrophoresis, fetuin-A is not only more dominant but it appears to compete avidly for nanoparticle binding at the expense of albumin. The nanoparticles formed in the presence of fetuin-A are smaller than their albumin counterparts, and they have a greater tendency to display a multi-layered ring morphology. In comparison, the particles seeded by albumin appear mostly incomplete, with single walls. Chemically, spectroscopically, and morphologically, the protein-mineral particles resemble closely serum granules and NB. These particles are thus seen to undergo an amorphous to crystalline transformation, the kinetics and completeness of which depend on the protein-to-mineral ratios, with low ratios favoring faster conversion to crystals. Our results point to a dual inhibitory-seeding, de-repression model for the assembly of particles in supersaturated solutions like serum. The presence of proteins and other inhibitory factors tend

  2. Proximate analysis of Sweet Potato Toasted Granules | Meludu ...

    African Journals Online (AJOL)

    Sweet potato is an important root crop in the food system of many African countries. The yield, nutrition and economic potential of sweet potato have been identified as very high. In this study, sweet potato was processed and toasted into granules. The proximate analysis performed on the toasted granules showed protein, ...

  3. Characterization and use of crystalline bacterial cell surface layers

    Science.gov (United States)

    Sleytr, Uwe B.; Sára, Margit; Pum, Dietmar; Schuster, Bernhard

    2001-10-01

    Crystalline bacterial cell surface layers (S-layers) are one of the most common outermost cell envelope components of prokaryotic organisms (archaea and bacteria). S-layers are monomolecular arrays composed of a single protein or glycoprotein species and represent the simplest biological membranes developed during evolution. S-layers as the most abundant of prokaryotic cellular proteins are appealing model systems for studying the structure, synthesis, genetics, assembly and function of proteinaceous supramolecular structures. The wealth of information existing on the general principle of S-layers have revealed a broad application potential. The most relevant features exploited in applied S-layer research are: (i) pores passing through S-layers show identical size and morphology and are in the range of ultrafiltration membranes; (ii) functional groups on the surface and in the pores are aligned in well-defined positions and orientations and accessible for chemical modifications and binding functional molecules in very precise fashion; (iii) isolated S-layer subunits from a variety of organisms are capable of recrystallizing as closed monolayers onto solid supports (e.g., metals, polymers, silicon wafers) at the air-water interface, on lipid films or onto the surface of liposomes; (iv) functional domains can be incorporated in S-layer proteins by genetic engineering. Thus, S-layer technologies particularly provide new approaches for biotechnology, biomimetics, molecular nanotechnology, nanopatterning of surfaces and formation of ordered arrays of metal clusters or nanoparticles as required for nanoelectronics.

  4. Layer-by-layer assembled cell instructive nanocoatings containing platelet lysate.

    Science.gov (United States)

    Oliveira, Sara M; Santo, Vítor E; Gomes, Manuela E; Reis, Rui L; Mano, João F

    2015-04-01

    Great efforts have been made to introduce growth factors (GFs) onto 2D/3D constructs in order to control cell behavior. Platelet lysate (PL) presents itself as a cost-effective source of multiple GFs and other proteins. The instruction given by a construct-PL combination will depend on how its instructive cues are presented to the cells. The content, stability and conformation of the GFs affect their instruction. Strategies for a controlled incorporation of PL are needed. Herein, PL was incorporated into nanocoatings by layer-by-layer assembling with polysaccharides presenting different sulfation degrees (SD) and charges. Heparin and several marine polysaccharides were tested to evaluate their PL and GF incorporation capability. The consequent effects of those multilayers on human adipose derived stem cells (hASCs) were assessed in short-term cultures. Both nature of the polysaccharide and SD were important properties that influenced the adsorption of PL, vascular endothelial growth factor (VEGF), fibroblast growth factor b (FGFb) and platelet derived growth factor (PDGF). The sulfated polysaccharides-PL multilayers showed to be efficient in the promotion of morphological changes, serum-free adhesion and proliferation of high passage hASCs (P > 5). These biomimetic multilayers promise to be versatile platforms to fabricate instructive devices allowing a tunable incorporation of PL. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A low-density culture method of cerebellar granule neurons with paracrine support applicable for the study of neuronal morphogenesis.

    Science.gov (United States)

    Kubota, Kenta; Seno, Takeshi; Konishi, Yoshiyuki

    2013-11-20

    Cerebellar granule neuronal cultures have been used to study the molecular mechanisms underlying neuronal functions, including neuronal morphogenesis. However, a limitation of this system is the difficulty to analyze isolated neurons because these are required to be maintained at a high density. Therefore, in the present study, we aimed to develop a simple and cost-effective method for culturing low-density cerebellar granule neurons. Cerebellar granule cells at two different densities (low- and high-density) were co-cultivated in order for the low-density culture to be supported by the paracrine signals from the high-density culture. This method enabled morphology analysis of isolated cerebellar granule neurons without astrocytic feeder cultures or supplements such as B27. Using this method, we investigated the function of a polarity factor. Studies using hippocampal neurons suggested that glycogen synthase kinase-3 (GSK-3) is an essential regulator of neuronal polarity, and inhibition of GSK-3 results in the formation of multiple axons. Pharmacological inhibitors for GSK-3 (6-bromoindirubin-3'-oxime and lithium chloride) did not cause the formation of multiple axons of cerebellar granule neurons but significantly reduced their length. Consistent results were obtained by introducing kinase-dead form of GSK-3 beta (K85A). These results indicated that GSK-3 is not directly involved in the control of neuronal polarity in cerebellar granule neurons. Overall, this study provides a simple method for culturing low-density cerebellar granule neurons and insights in to the neuronal-type dependent function of GSK-3 in neuronal morphogenesis. © 2013 Elsevier B.V. All rights reserved.

  6. Substrate and p-layer effects on polymorphous silicon solar cells

    Directory of Open Access Journals (Sweden)

    Abolmasov S.N.

    2014-07-01

    Full Text Available The influence of textured transparent conducting oxide (TCO substrate and p-layer on the performance of single-junction hydrogenated polymorphous silicon (pm-Si:H solar cells has been addressed. Comparative studies were performed using p-i-n devices with identical i/n-layers and back reflectors fabricated on textured Asahi U-type fluorine-doped SnO2, low-pressure chemical vapor deposited (LPCVD boron-doped ZnO and sputtered/etched aluminum-doped ZnO substrates. The p-layers were hydrogenated amorphous silicon carbon and microcrystalline silicon oxide. As expected, the type of TCO and p-layer both have a great influence on the initial conversion efficiency of the solar cells. However they have no effect on the defect density of the pm-Si:H absorber layer.

  7. Occurance of aldehyde-fuchsin and performic acid-victoria blue positive granules in the ovarian pedicle of Dysdercus koenigii F. (Pyrrhocridae: Heteroptera).

    Science.gov (United States)

    Srivastava, R C; Srivastava, B P

    1976-10-15

    A cycle of activity of aldehyde-fuchsin and performic acid-Victoria blue positive granules was observed in the ovarian pedicle of Dysdercus koenigii during the first ovipositional cycle. The quantitative variation of these granules in the pedicle can also be correlated directly with the increase or decrease of the neurosecretory material in the A-type cells of the pars intercerebralis medialis region of the protocerebrum of the brian.

  8. In vitro binding of puroindolines to wheat starch granules

    DEFF Research Database (Denmark)

    Sørensen, Helle Aagaard; Darlington, H.F.; Shewry, P.R.

    2001-01-01

    Puroindoline (pin) preparations made from flours of hard and soft wheats contained a mixture of pin-a, 0.19/0.53 alpha -amylase inhibitor, and purothionins. Starch granule preparations from the same cultivars were treated with proteinase to remove surface proteins and incubated with solutions...... of the pin preparations. Binding of pin-a and purothionins but not the 0.19/0.53 inhibitor was observed with no apparent differences between the behavior of the pin preparations or starch granule preparations from hard or soft types. No binding was observed when several other proteins (bovine serum albumin......, total albumins, a commercial preparation of wheat alpha -amylase inhibitors, and barley beta -amylase) were incubated with the starch granules under the same conditions, indicating that in vitro binding can be used to study specific starch granule and protein interactions....

  9. A review of monitoring methods for pharmaceutical wet granulation.

    Science.gov (United States)

    Hansuld, E M; Briens, L

    2014-09-10

    High-shear wet granulation is commonly used in the pharmaceutical industry to improve powder properties for downstream processes such as tabletting. Granule growth, however, is difficult to predict because the process is sensitive to raw material properties and operating conditions. Development of process analytical technologies is encouraged by regulatory bodies to improve process understanding and monitor quality online. The primary technologies investigated for high-shear wet granulation monitoring include power consumption, near-infrared spectroscopy, Raman spectroscopy, capacitance measurements, microwave measurements, imaging, focused beam reflectance measurements, spatial filter velocimetry, stress and vibration measurements, as well as acoustic emissions. This review summarizes relevant research related to each of these technologies and discusses the challenges associated with each approach as a possible process analytical technology tool for high-shear wet granulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Efficient small-molecule organic solar cells incorporating a doped buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Dei-Wei [Department of aviation and Communication Electronics, Air Force Institute of Technology, Kaohsiung 820, Taiwan (China); Chen, Kan-Lin [Department of Electronic Engineering, Fortune Institute of Technology, Kaohsiung 831, Taiwan (China); Huang, Chien-Jung, E-mail: chien@nuk.edu.tw [Department of Applied Physics, National University of Kaohsiung, Nanzih, Kaohsiung 811, Taiwan (China); Tsao, Yao-Jen [Department of Applied Physics, National University of Kaohsiung, Nanzih, Kaohsiung 811, Taiwan (China); Chen, Wen-Ray; Meen, Teen-Hang [Department of Electronic Engineering, National Formosa University, Hu-Wei, Yunlin 632, Taiwan (China)

    2013-06-01

    Small-molecule organic solar cells (OSCs) with an optimized structure of indium tin oxide/poly (3,4-ethylenedioxythioxythiophene):poly(styrenesulfonate)/copper phthalocyanine (CuPc) (10 nm)/CuPc: fullerene (C{sub 60}) mixed (20 nm)/C{sub 60} (20 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen) (5 nm)/Ag were fabricated. In this study, the cesium carbonate-doped BPhen (Cs{sub 2}CO{sub 3}:BPhen) was adopted as the buffer layer to enhance the efficiency of the OSCs. The photovoltaic parameters of the OSCs, such as the short-circuit current density and fill factor, depend on the doping concentration of Cs{sub 2}CO{sub 3} in the BPhen layer. The cell with a Cs{sub 2}CO{sub 3}:BPhen (1:4) cathode buffer layer exhibits a power conversion efficiency (PCE) of 3.51%, compared to 3.37% for the device with the pristine BPhen layer. The enhancement of PCE was attributed to the energy-level alignment between the C{sub 60} layer and the Cs{sub 2}CO{sub 3}:BPhen layer. In addition, the characterization measured using atomic force microscopy shows that the Cs{sub 2}CO{sub 3}:BPhen layers have smoother surfaces. - Highlight: • Cs2CO3-doped 4,7-diphenyl-1,10-phenanthroline (BPhen) cathode buffer layer. • Cs2CO3:BPhen layer with different ratios affects organic solar cells performance. • Cell with 1:4 (Cs2CO3:BPhen) ratio shows 3.51% power conversion efficiency.

  11. On-line monitoring of fluid bed granulation by photometric imaging.

    Science.gov (United States)

    Soppela, Ira; Antikainen, Osmo; Sandler, Niklas; Yliruusi, Jouko

    2014-11-01

    This paper introduces and discusses a photometric surface imaging approach for on-line monitoring of fluid bed granulation. Five granule batches consisting of paracetamol and varying amounts of lactose and microcrystalline cellulose were manufactured with an instrumented fluid bed granulator. Photometric images and NIR spectra were continuously captured on-line and particle size information was extracted from them. Also key process parameters were recorded. The images provided direct real-time information on the growth, attrition and packing behaviour of the batches. Moreover, decreasing image brightness in the drying phase was found to indicate granule drying. The changes observed in the image data were also linked to the moisture and temperature profiles of the processes. Combined with complementary process analytical tools, photometric imaging opens up possibilities for improved real-time evaluation fluid bed granulation. Furthermore, images can give valuable insight into the behaviour of excipients or formulations during product development. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Isolated secretion granules from parotid glands of chronically stimulated rats possess an alkaline internal pH and inward-directed H+ pump activity

    International Nuclear Information System (INIS)

    Arvan, P.; Castle, J.D.

    1986-01-01

    Secretion granules have been isolated from the parotid glands of rats that have been chronically stimulated with the β-adrenergic agonist, isoproterenol. These granules are of interest because they package a quantitatively different set of secretory proteins in comparison with granules from the normal gland. Polypeptides enriched in proline, glycine, and glutamine, which are known to have pI's >10, replace α-amylase (pI's = 6.8) as the principal content species. The internal pH of granules from the treated rats changes from 7.8 in a potassium sulfate medium to 6.9 in a choline chloride medium. The increased pH over that of normal parotid granules (∼6.8) appears to protect the change in composition of the secretory contents. Whereas normal mature parotide granules have practically negligible levels of H + pumping ATPase activity, the isolated granules from isoproterenol-treated rats undergo a time-dependent internal acidification that requires the presence of ATP and is abolished by an H + ionophore. Additionally, an inside-positive granule transmembrane potential develops after ATP addition that depends upon ATP hydrolysis. Two independent methods have been used that exclude the possibility that contaminating organelles are the source of the H + -ATPase activity. Together these data provide clear evidence for the presence of an H + pump in the membranes of parotid granules from chronically stimulated rats. However, despite the presence of H + -pump activity, fluorescence microscopy with the weak base, acridine orange, reveals that the intragranular pH in live cells is greater than that of the cytoplasm

  13. A microfluidic galvanic cell on a single layer of paper

    Science.gov (United States)

    Purohit, Krutarth H.; Emrani, Saina; Rodriguez, Sandra; Liaw, Shi-Shen; Pham, Linda; Galvan, Vicente; Domalaon, Kryls; Gomez, Frank A.; Haan, John L.

    2016-06-01

    Paper microfluidics is used to produce single layer galvanic and hybrid cells to produce energy that could power paper-based analytical sensors. When two aqueous streams are absorbed onto paper to establish co-laminar flow, the streams stay in contact with each other with limited mixing. The interface at which mixing occurs acts as a charge-transfer region, eliminating the need for a salt bridge. We designed a Cusbnd Zn galvanic cell that powers an LED when two are placed in series. We also used more powerful redox couples (formate and silver, formate and permanganate) to produce higher power density (18 and 3.1 mW mg-1 Pd). These power densities are greater than previously reported paper microfluidic fuel cells using formate or methanol. The single layer design is much more simplified than previous reports of multi-layer galvanic cells on paper.

  14. Flexible bactericidal graphene oxide-chitosan layers for stem cell proliferation

    Science.gov (United States)

    Mazaheri, M.; Akhavan, O.; Simchi, A.

    2014-05-01

    Graphene oxide (GO)-chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ˜1 μm and thickness of ˜1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ˜80% and 45%, respectively. Similar to the chitosan layer, the GO-chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured on the chitosan and GO(1.5 wt%)-chitosan composite layers was found nearly the same, while it significantly decreased by increasing the GO content to 3 and 6 wt%. Our results indicated that although a high concentration of GO in the chitosan layer (here, 6 wt%) could decelerate the proliferation of the hMSCs on the flexible layer, a low concentration of GO (i.e., 1.5 wt%) not only resulted in biocompatibility but also kept the mechanical flexibility of the self-sterilized layers for high proliferation of hMSCs.

  15. FMRP Associates with Cytoplasmic Granules at the Onset of Meiosis in the Human Oocyte.

    Directory of Open Access Journals (Sweden)

    Roseanne Rosario

    Full Text Available Germ cell development and primordial follicle formation during fetal life is critical in establishing the pool of oocytes that subsequently determines the reproductive lifespan of women. Fragile X-associated primary ovarian insufficiency (FXPOI is caused by inheritance of the FMR1 premutation allele and approximately 20% of women with the premutation allele develop ovarian dysfunction and premature ovarian insufficiency. However, the underlying disease mechanism remains obscure, and a potential role of FMRP in human ovarian development has not been explored. We have characterised the expression of FMR1 and FMRP in the human fetal ovary at the time of germ cell entry into meiosis through to primordial follicle formation. FMRP expression is exclusively in germ cells in the human fetal ovary. Increased FMRP expression in germ cells coincides with the loss of pluripotency-associated protein expression, and entry into meiosis is associated with FMRP granulation. In addition, we have uncovered FMRP association with components of P-bodies and stress granules, suggesting it may have a role in mRNA metabolism at the time of onset of meiosis. Therefore, this data support the hypothesis that FMRP plays a role regulating mRNAs during pivotal maturational processes in fetal germ cells, and ovarian dysfunction resulting from FMR1 premutation may have its origins during these stages of oocyte development.

  16. [Pharmacological availability of erythromycin granules for children's use].

    Science.gov (United States)

    Korenev, S V; Garsheva, G B; Nesterova, L Ia; Grakovskaia, L K; Tentsova, A I

    1990-08-01

    Pharmaceutical availability of erythromycin granules with polymeric coating of different composition+ was studied. With an account of the ++anatomo-physiological features of a child organism and the properties of the antibiotic, acetylphthalyl cellulose in combination with hydroxypropyl methylcellulose or methyl cellulose was used as a film forming agent. The coated granules were estimated by such parameters as the time of disintegration and the rate of dissolution in various media. The results of the study showed that coating of the erythromycin granules with the film composed of acetylphthalyl cellulose and hydroxypropyl methylcellulose in the ratio of 8 to 2 provided the required protection of the antibiotic in acid media and high pharmaceutical availability of the drug.

  17. Jinlida granule inhibits palmitic acid induced-intracellular lipid accumulation and enhances autophagy in NIT-1 pancreatic β cells through AMPK activation.

    Science.gov (United States)

    Wang, Dingkun; Tian, Min; Qi, Yuan; Chen, Guang; Xu, Lijun; Zou, Xin; Wang, Kaifu; Dong, Hui; Lu, Fuer

    2015-02-23

    Jinlida granule (JLDG), composed of seventeen Chinese medical herbs, is a widely used Chinese herbal prescription for treating diabetes mellitus. However, the mechanism underlying this effect remains unclear. To determine the main components in JLDG and to explore the effect of JLDG on autophagy and lipid accumulation in NIT-1 pancreatic β cells exposed to politic acid (PA) through AMP activated protein kinase (AMPK) signaling pathway. JLDG was prepared and the main components contained in the granules were identified by ultra performance liquid chromatography (UPLC) fingerprint. Intracellular lipid accumulation in NIT-1 cells was induced by culturing with medium containing PA. Intracellular lipid droplets were observed by Oil Red O staining and triglyceride (TG) content was measured by colorimetric assay. The formation of autophagosomes was observed under transmission electron microscope. The expression of AMPK and phospho-AMPK (pAMPK) proteins as well as its downstream fatty acid metabolism-related proteins (fatty acid synthase, FAS; acetyl-coA carboxylase, ACC; carnitine acyltransferase 1, CPT-1) and autophagy-related genes (mammal target of rapamycin, mTOR; tuberous sclerosis complex 1, TSC1; microtubule-associated protein 1 light chain 3, LC3-II) were determined by Western blot. The expression of sterol regulating element binding protein 1c (SREBP-1c) mRNA was examined by real time PCR (RT-PCR). Our data showed that JLDG could significantly reduce PA-induced intracellular lipid accumulation in NIT-1 pancreatic β cells. This effect was associated with increased protein expression of pAMPK and AMPK in NIT-1 cells. Treatment with JLDG also decreased the expression of AMPK downstream lipogenic genes (SREBP-1c mRNA, FAS and ACC proteins) whereas increased the expression of fatty acid oxidation gene (CPT-1 protein). Additionally, JLDG-treated cells displayed a markedly increase in the number of autophagosomes which was accompanied by the down-regulation of m

  18. Plasticity of hippocampal stem/progenitor cells to enhance neurogenesis in response to kainate-induced injury is lost by middle age

    OpenAIRE

    Hattiangady, Bharathi; Rao, Muddanna S.; Shetty, Ashok K.

    2008-01-01

    A remarkable up-regulation of neurogenesis through increased proliferation of neural stem/progenitor cells (NSCs) is a well-known plasticity displayed by the young dentate gyrus (DG) following brain injury. To ascertain whether this plasticity is preserved during aging, we quantified DG neurogenesis in the young adult, middle-aged and aged F344 rats after kainic acid induced hippocampal injury. Measurement of new cells that are added to the dentate granule cell layer (GCL) between post-injury...

  19. Artificial Intelligence Tools for Scaling Up of High Shear Wet Granulation Process.

    Science.gov (United States)

    Landin, Mariana

    2017-01-01

    The results presented in this article demonstrate the potential of artificial intelligence tools for predicting the endpoint of the granulation process in high-speed mixer granulators of different scales from 25L to 600L. The combination of neurofuzzy logic and gene expression programing technologies allowed the modeling of the impeller power as a function of operation conditions and wet granule properties, establishing the critical variables that affect the response and obtaining a unique experimental polynomial equation (transparent model) of high predictability (R 2 > 86.78%) for all size equipment. Gene expression programing allowed the modeling of the granulation process for granulators of similar and dissimilar geometries and can be improved by implementing additional characteristics of the process, as composition variables or operation parameters (e.g., batch size, chopper speed). The principles and the methodology proposed here can be applied to understand and control manufacturing process, using any other granulation equipment, including continuous granulation processes. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. Correlation between microbial community and granule conductivity in anaerobic bioreactors for brewery wastewater treatment

    DEFF Research Database (Denmark)

    Shrestha, Pravin; Malvankar, Nikhil S.; Werner, Jeffrey

    2014-01-01

    Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical conducti......Prior investigation of an upflow anaerobic sludge blanket (UASB) reactor treating brewery wastes suggested that direct interspecies electron transfer (DIET) significantly contributed to interspecies electron transfer to methanogens. To investigate DIET in granules further, the electrical...... conductivity and bacterial community composition of granules in fourteen samples from four different UASB reactors treating brewery wastes were investigated. All of the UASB granules were electrically conductive whereas control granules from ANAMMOX (ANaerobic AMMonium OXidation) reactors and microbial...... granules from an aerobic bioreactor designed for phosphate removal were not. There was a moderate correlation (r = 0.67) between the abundance of Geobacter species in the UASB granules and granule conductivity, suggesting that Geobacter contributed to granule conductivity. These results, coupled...

  1. Cellular interaction of a layer-by-layer based drug delivery system depending on material properties and cell types.

    Science.gov (United States)

    Brueckner, Mandy; Jankuhn, Steffen; Jülke, Eva-Maria; Reibetanz, Uta

    2018-01-01

    Drug delivery systems (DDS) and their interaction with cells are a controversial topic in the development of therapeutic concepts and approaches. On one hand, DDS are very useful for protected and targeted transport of defined dosages of active agents. On the other hand, their physicochemical properties such as material, size, shape, charge, or stiffness have a huge impact on cellular uptake and intracellular processing. Additionally, even identical DDS can undergo a completely diverse interaction with different cell types. However, quite often in in vitro DDS/cell interaction experiments, those aspects are not considered and DDS and cells are randomly chosen. Hence, our investigations provide an insight into layer-by-layer designed microcarriers with modifications of only some of the most important parameters (surface charge, stiffness, and applied microcarrier/cell ratio) and their influence on cellular uptake and viability. We also considered the interaction of these differently equipped DDS with several cell types and investigated professional phagocytes (neutrophil granulocytes; macrophages) as well as non-professional phagocytes (epithelial cells) under comparable conditions. We found that even small modifications such as layer-by-layer (LbL)-microcarriers with positive or negative surface charge, or LbL-microcarriers with solid core or as hollow capsules but equipped with the same surface properties, show significant differences in interaction and viability, and several cell types react very differently to the offered DDS. As a consequence, the properties of the DDS have to be carefully chosen with respect to the addressed cell type with the aim to efficiently transport a desired agent.

  2. Partial nitrification using aerobic granules in continuous-flow reactor: rapid startup.

    Science.gov (United States)

    Wan, Chunli; Sun, Supu; Lee, Duu-Jong; Liu, Xiang; Wang, Li; Yang, Xue; Pan, Xiangliang

    2013-08-01

    This study applied a novel strategy to rapid startup of partial nitrification in continuous-flow reactor using aerobic granules. Mature aerobic granules were first cultivated in a sequencing batch reactor at high chemical oxygen demand in 16 days. The strains including the Pseudoxanthomonas mexicana strain were enriched in cultivated granules to enhance their structural stability. Then the cultivated granules were incubated in a continuous-flow reactor with influent chemical oxygen deamnad being stepped decreased from 1,500 ± 100 (0-19 days) to 750 ± 50 (20-30 days), and then to 350 ± 50 mg l(-1) (31-50 days); while in the final stage 350 mg l(-1) bicarbonate was also supplied. Using this strategy the ammonia-oxidizing bacterium, Nitrosomonas europaea, was enriched in the incubated granules to achieve partial nitrification efficiency of 85-90% since 36 days and onwards. The partial nitrification granules were successfully harvested after 52 days, a period much shorter than those reported in literature. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Efficient organic photovoltaic cells on a single layer graphene transparent conductive electrode using MoOx as an interfacial layer.

    Science.gov (United States)

    Du, J H; Jin, H; Zhang, Z K; Zhang, D D; Jia, S; Ma, L P; Ren, W C; Cheng, H M; Burn, P L

    2017-01-07

    The large surface roughness, low work function and high cost of transparent electrodes using multilayer graphene films can limit their application in organic photovoltaic (OPV) cells. Here, we develop single layer graphene (SLG) films as transparent anodes for OPV cells that contain light-absorbing layers comprised of the evaporable molecular organic semiconductor materials, zinc phthalocyanine (ZnPc)/fullerene (C60), as well as a molybdenum oxide (MoO x ) interfacial layer. In addition to an increase in the optical transmittance, the SLG anodes had a significant decrease in surface roughness compared to two and four layer graphene (TLG and FLG) anodes fabricated by multiple transfer and stacking of SLGs. Importantly, the introduction of a MoO x interfacial layer not only reduced the energy barrier between the graphene anode and the active layer, but also decreased the resistance of the SLG by nearly ten times. The OPV cells with the structure of polyethylene terephthalate/SLG/MoO x /CuI/ZnPc/C60/bathocuproine/Al were flexible, and had a power conversion efficiency of up to 0.84%, which was only 17.6% lower than the devices with an equivalent structure but prepared on commercial indium tin oxide anodes. Furthermore, the devices with the SLG anode were 50% and 86.7% higher in efficiency than the cells with the TLG and FLG anodes. These results show the potential of SLG electrodes for flexible and wearable OPV cells as well as other organic optoelectronic devices.

  4. Osseous drill holes to promote granulation tissue: Radiologic appearance

    International Nuclear Information System (INIS)

    Resnik, C.S.; Reiner, B.I.; Diaconis, J.N.; Goldberg, N.H.

    1991-01-01

    Skin grafting following extensive soft-tissue loss is often delayed until adequate granulation tissue can be generated. Surgical drill holes into the marrow cavity promote development of granulation tissue. This article illustrates the radiology appearance of these drill holes in four patients. (orig.)

  5. The transformation from anammox granules to deammonification granules in micro-aerobic system by facilitating indigenous ammonia oxidizing bacteria.

    Science.gov (United States)

    Wang, Xiaolong; Gao, Dawen

    2018-02-01

    Granular deammonification process is a good way to retain aerobic and anaerobic ammonia oxidizing bacteria (AOB and anammox bacteria) and exhaust flocculent nitrite oxidizing bacteria (NOB). In this study, to facilitate indigenous AOB growth on anammox granules, by stepwise reducing influent nitrite, anammox granules were effectively transformed into deammonification granules in a micro-aerobic EGSB in 100 days. Total nitrogen removal efficiency of 90% and nitrogen removal rate of 2.3 g N/L/d were reached at stable deammonification stage. High influent FA and limited oxygen supply contributed suppression for Nitrospira-like NOB. In transition stages, Proteobacteria and Chloroflexi were always dominated. Anammox abundance decreased, while AOB abundance grew fast. Anammox bacteria and AOB were dominated by Brocadia fulgida and Nitrosomonas europaea, respectively. Denitrification activity and bacteria existed although without influent organic. The final AOB abundance was about 4.55-13.8 times more than anammox bacteria abundance, with almost equal potential activities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Mechanical behaviour of PEM fuel cell catalyst layers during regular cell operation

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2010-01-01

    Damage mechanisms in a proton exchange membrane fuel cell are accelerated by mechanical stresses arising during fuel cell assembly (bolt assembling), and the stresses arise during fuel cell running, because it consists of the materials with different thermal expansion and swelling coefficients. Therefore, in order to acquire a complete understanding of the mechanical behaviour of the catalyst layers during regular cell operation, mechanical response under steady-state hygro-thermal stresses s...

  7. UV radiation hardness of silicon inversion layer solar cells

    International Nuclear Information System (INIS)

    Hezel, R.

    1990-01-01

    For full utilization of the high spectral response of inversion layer solar cells in the very-short-wavelength range of the solar spectrum sufficient ultraviolet-radiation hardness is required. In addition to the charge-induced passivation achieved by cesium incorporation into the silicon nitride AR coating, in this paper the following means for further drastic reduction of UV light-induced effects in inversion layer solar cells without encapsulation are introduced and interpretations are given: increasing the nitride deposition temperature, silicon surface oxidation at low temperatures, and texture etching and using higher substrate resistivities. High UV radiation tolerance and improvement of the cell efficiency could be obtained simultaneously

  8. Efficiency limit of solar cells with index-near-zero photon management layers

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, A.P.

    2017-05-15

    As single-junction solar cells saturate in efficiency, the topic of photon management has generated interest in the long running quest to exceed the Shockley-Queisser efficiency limit. While a mirror applied to the backside of a solar cell has proven its benefit as a photon management layer in record setting devices that fall within the Shockley-Queisser limit, it has been proposed that a new type of photon management layer – a transparent index-near-zero (INZ) material – applied to the top surface of a solar cell will allow it to finally exceed the Shockley-Queisser limit. INZ layers – and their influence on solar cell current density, open circuit voltage, and power conversion efficiency – are analyzed. By considering the principle of detailed balance, Snell's law, and the role that entropy plays, it is shown that INZ layers do not allow a solar cell to exceed the Shockley-Queisser efficiency limit. At best, a solar cell with an INZ layer would have the same Shockley-Queisser limiting efficiency as a conventional solar cell tracked under a direct solar spectrum (direct beam radiation only), yet would suffer diminished efficiency under a global solar spectrum (direct beam plus diffuse light) due to the presence of an external critical acceptance angle.

  9. Efficiency limit of solar cells with index-near-zero photon management layers

    International Nuclear Information System (INIS)

    Kirk, A.P.

    2017-01-01

    As single-junction solar cells saturate in efficiency, the topic of photon management has generated interest in the long running quest to exceed the Shockley-Queisser efficiency limit. While a mirror applied to the backside of a solar cell has proven its benefit as a photon management layer in record setting devices that fall within the Shockley-Queisser limit, it has been proposed that a new type of photon management layer – a transparent index-near-zero (INZ) material – applied to the top surface of a solar cell will allow it to finally exceed the Shockley-Queisser limit. INZ layers – and their influence on solar cell current density, open circuit voltage, and power conversion efficiency – are analyzed. By considering the principle of detailed balance, Snell's law, and the role that entropy plays, it is shown that INZ layers do not allow a solar cell to exceed the Shockley-Queisser efficiency limit. At best, a solar cell with an INZ layer would have the same Shockley-Queisser limiting efficiency as a conventional solar cell tracked under a direct solar spectrum (direct beam radiation only), yet would suffer diminished efficiency under a global solar spectrum (direct beam plus diffuse light) due to the presence of an external critical acceptance angle.

  10. Efficiency limit of solar cells with index-near-zero photon management layers

    Science.gov (United States)

    Kirk, A. P.

    2017-05-01

    As single-junction solar cells saturate in efficiency, the topic of photon management has generated interest in the long running quest to exceed the Shockley-Queisser efficiency limit. While a mirror applied to the backside of a solar cell has proven its benefit as a photon management layer in record setting devices that fall within the Shockley-Queisser limit, it has been proposed that a new type of photon management layer - a transparent index-near-zero (INZ) material - applied to the top surface of a solar cell will allow it to finally exceed the Shockley-Queisser limit. INZ layers - and their influence on solar cell current density, open circuit voltage, and power conversion efficiency - are analyzed. By considering the principle of detailed balance, Snell's law, and the role that entropy plays, it is shown that INZ layers do not allow a solar cell to exceed the Shockley-Queisser efficiency limit. At best, a solar cell with an INZ layer would have the same Shockley-Queisser limiting efficiency as a conventional solar cell tracked under a direct solar spectrum (direct beam radiation only), yet would suffer diminished efficiency under a global solar spectrum (direct beam plus diffuse light) due to the presence of an external critical acceptance angle.

  11. Atomic layer deposition for photovoltaics: applications and prospects for solar cell manufacturing

    International Nuclear Information System (INIS)

    Van Delft, J A; Garcia-Alonso, D; Kessels, W M M

    2012-01-01

    Atomic layer deposition (ALD) is a vapour-phase deposition technique capable of depositing high quality, uniform and conformal thin films at relatively low temperatures. These outstanding properties can be employed to face processing challenges for various types of next-generation solar cells; hence, ALD for photovoltaics (PV) has attracted great interest in academic and industrial research in recent years. In this review, the recent progress of ALD layers applied to various solar cell concepts and their future prospects are discussed. Crystalline silicon (c-Si), copper indium gallium selenide (CIGS) and dye-sensitized solar cells (DSSCs) benefit from the application of ALD surface passivation layers, buffer layers and barrier layers, respectively. ALD films are also excellent moisture permeation barriers that have been successfully used to encapsulate flexible CIGS and organic photovoltaic (OPV) cells. Furthermore, some emerging applications of the ALD method in solar cell research are reviewed. The potential of ALD for solar cells manufacturing is discussed, and the current status of high-throughput ALD equipment development is presented. ALD is on the verge of being introduced in the PV industry and it is expected that it will be part of the standard solar cell manufacturing equipment in the near future. (paper)

  12. Creep of granulated loose-fill insulation

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    This report presents a proposal for a standardised method for creep tests and the necessary theoretical framework that can be used to describe creep of a granulated loose-fill material. Furthermore results from a round robin test are shown. The round robin test was carried out in collaboration...... with SP-Building Physics in Sweden and VTT Building Technology in Finland. For the round robin test a cellulosic fibre insulation material was used. The proposed standardised method for creep tests and theories are limited to cases when the granulated loose-fill material is exposed to a constant...

  13. Modified Back Contact Interface of CZTSe Thin Film Solar Cells: Elimination of Double Layer Distribution in Absorber Layer.

    Science.gov (United States)

    Zhang, Zhaojing; Yao, Liyong; Zhang, Yi; Ao, Jianping; Bi, Jinlian; Gao, Shoushuai; Gao, Qing; Jeng, Ming-Jer; Sun, Guozhong; Zhou, Zhiqiang; He, Qing; Sun, Yun

    2018-02-01

    Double layer distribution exists in Cu 2 SnZnSe 4 (CZTSe) thin films prepared by selenizing the metallic precursors, which will degrade the back contact of Mo substrate to absorber layer and thus suppressing the performance of solar cell. In this work, the double-layer distribution of CZTSe film is eliminated entirely and the formation of MoSe 2 interfacial layer is inhibited successfully. CZTSe film is prepared by selenizing the precursor deposited by electrodeposition method under Se and SnSe x mixed atmosphere. It is found that the insufficient reaction between ZnSe and Cu-Sn-Se phases in the bottom of the film is the reason why the double layer distribution of CZTSe film is formed. By increasing Sn content in the metallic precursor, thus making up the loss of Sn because of the decomposition of CZTSe and facilitate the diffusion of liquid Cu 2 Se, the double layer distribution is eliminated entirely. The crystallization of the formed thin film is dense and the grains go through the entire film without voids. And there is no obvious MoSe 2 layer formed between CZTSe and Mo. As a consequence, the series resistance of the solar cell reduces significantly to 0.14 Ω cm 2 and a CZTSe solar cell with efficiency of 7.2% is fabricated.

  14. The Effect of Wetting on The Course of The Drum Granulation

    Directory of Open Access Journals (Sweden)

    Błaszczyk Michał

    2017-06-01

    Full Text Available This paper presents the results of experimental drum granulation of silica flour with the use of wetting liquids with different values of surface tension. Additionally, different liquid jet breakup and different residual moisture of the bed were applied in the tests. The process was conducted periodically in two stages: wetting and proper granulation, during which no liquid was supplied to the bed. The condition of the granulated material after the period of wetting (particle size distribution and moisture of separate fractions and a change in the particle size distribution during the further conduct of the process (granulation kinetics were determined.

  15. Consolidating nanoparticles in micron-sized granules using spray drying

    International Nuclear Information System (INIS)

    Lindeloev, J S; Wahlberg, M

    2011-01-01

    Suspensions of nanoparticles (SiO 2 , SiC, TiO2, CNT, Nanoclay and Hydroxyapatite) were spray dried to produce dry granulated products. The nanoparticles were consolidated in granules making them more convenient and safer to use in further processing compared to handling of nanopowders.

  16. Recombination barrier layers in solid-state quantum dot-sensitized solar cells

    KAUST Repository

    Roelofs, Katherine E.

    2012-06-01

    By replacing the dye in the dye-sensitized solar cell design with semiconductor quantum dots as the light-absorbing material, solid-state quantum dot-sensitized solar cells (ss-QDSSCs) were fabricated. Cadmium sulfide quantum dots (QDs) were grown in situ by successive ion layer adsorption and reaction (SILAR). Aluminum oxide recombination barrier layers were deposited by atomic layer deposition (ALD) at the TiO2/hole-conductor interface. For low numbers of ALD cycles, the Al2O3 barrier layer increased open circuit voltage, causing an increase in device efficiency. For thicker Al2O3 barrier layers, photocurrent decreased substantially, leading to a decrease in device efficiency. © 2012 IEEE.

  17. MICROMORPHOLOGICAL STUDIES OF STARCH GRANULES IN SELECTED PROCESSED INDIGENOUS FLOUR OF SOUTH WESTERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Adeniyi A. JAYEOLA

    2013-06-01

    Full Text Available Starch granules of yam stem tubers, plantain fruits and cassava root tubers were studied using the light microscope and then compared. Yam and plantain, both monocotyledons, had morphologically similar granules between locations, being mostly oval in shape while the granules of cassava, a dicot, were predominantly globular but varied between locations. Differences in processing methods between locations might be responsible for the observed variation in cassava granules. There is a suggestion that starch granule morphology might follow lineages in a broad sense. The unique micromorphology of cassava starch granule could make it easily detectable when adulterated, substituted or contaminated with yam or plantain granules and this could provide a cost effective clue in forensic determination.

  18. Sr, Mg cosubstituted HA porous macro-granules: potentialities as resorbable bone filler with antiosteoporotic functions.

    Science.gov (United States)

    Landi, Elena; Uggeri, Jacopo; Medri, Valentina; Guizzardi, Stefano

    2013-09-01

    Porous macro-granules of nanostructured apatite with Ca ions partially cosubstituted with Mg and Sr ions in different ratios (SrMgHAs), were synthesized at 37°C and compared with Mg and/or Sr free apatites (MgHAs and HA). Strontium improved the Mg substitution extent in the apatite and the chemical-physical and thermal stability of the resulting cosubstituted apatite. Porous macro-granules of 400-600 micron with selected composition were tested for the ionic release in synthetic body fluid and the data were related with the results of preliminary cell investigation in vitro. As compared to the corresponding Sr-free granulate, the SrMgHA could be exploited to prolong the beneficial Mg release during the bone regeneration process. In addition the contemporary in situ supply of Sr, an antiosteoporotic and anticarie ion, could influence the quality of new hard tissues. The ionic multirelease created a more favorable environment for human osteoblasts, demonstrated by a proliferative effect for each dose tested in the range 0.1-10 mg/mL. Copyright © 2013 Wiley Periodicals, Inc.

  19. Linking macroscopic with microscopic neuroanatomy using synthetic neuronal populations.

    Science.gov (United States)

    Schneider, Calvin J; Cuntz, Hermann; Soltesz, Ivan

    2014-10-01

    Dendritic morphology has been shown to have a dramatic impact on neuronal function. However, population features such as the inherent variability in dendritic morphology between cells belonging to the same neuronal type are often overlooked when studying computation in neural networks. While detailed models for morphology and electrophysiology exist for many types of single neurons, the role of detailed single cell morphology in the population has not been studied quantitatively or computationally. Here we use the structural context of the neural tissue in which dendritic trees exist to drive their generation in silico. We synthesize the entire population of dentate gyrus granule cells, the most numerous cell type in the hippocampus, by growing their dendritic trees within their characteristic dendritic fields bounded by the realistic structural context of (1) the granule cell layer that contains all somata and (2) the molecular layer that contains the dendritic forest. This process enables branching statistics to be linked to larger scale neuroanatomical features. We find large differences in dendritic total length and individual path length measures as a function of location in the dentate gyrus and of somatic depth in the granule cell layer. We also predict the number of unique granule cell dendrites invading a given volume in the molecular layer. This work enables the complete population-level study of morphological properties and provides a framework to develop complex and realistic neural network models.

  20. Azurophil granule proteins constitute the major mycobactericidal proteins in human neutrophils and enhance the killing of mycobacteria in macrophages.

    Directory of Open Access Journals (Sweden)

    Prajna Jena

    Full Text Available Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule proteins (AZP were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane resulting in killing of mycobacteria. Exogenous addition of AZP to murine macrophage RAW 264.7, THP-1 and peripheral blood monocyte-derived macrophages significantly reduced the intracellular survival of mycobacteria without exhibiting cytotoxic activity on macrophages. Immunofluorescence studies showed that macrophages actively endocytose neutrophil granular proteins. Treatment with AZP resulted in increase in co-localization of BCG containing phagosomes with lysosomes but not in increase of autophagy. These data demonstrate that neutrophil azurophil proteins may play an important role in controlling intracellular survival of mycobacteria in macrophages.

  1. Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride.

    Science.gov (United States)

    Timgren, Anna; Rayner, Marilyn; Dejmek, Petr; Marku, Diana; Sjöö, Malin

    2013-03-01

    Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous phase, both with and without salt in a phosphate buffer, was also studied. Quinoa, which had the smallest granule size, had the best capacity to stabilize oil drops, especially when the granules had been hydrophobically modified by heat treatment or by OSA. The average drop diameter (d 32) in these emulsions varied from 270 to 50 μm, where decreasing drop size and less aggregation was promoted by high starch concentration and absence of salt in the system. Of all the starch varieties studied, quinoa had the best overall emulsifying capacity, and OSA modified quinoa starch in particular. Although the size of the drops was relatively large, the drops themselves were in many instances extremely stable. In the cases where the system could stabilize droplets, even when they were so large that they were visible to the naked eye, they remained stable and the measured droplet sizes after 2 years of storage were essentially unchanged from the initial droplet size. This somewhat surprising result has been attributed to the thickness of the adsorbed starch layer providing steric stabilization. The starch particle-stabilized Pickering emulsion systems studied in this work has potential practical application such as being suitable for encapsulation of ingredients in food and pharmaceutical products.

  2. Superlattice doped layers for amorphous silicon photovoltaic cells

    Science.gov (United States)

    Arya, Rajeewa R.

    1988-01-12

    Superlattice doped layers for amorphous silicon photovoltaic cells comprise a plurality of first and second lattices of amorphous silicon alternatingly formed on one another. Each of the first lattices has a first optical bandgap and each of the second lattices has a second optical bandgap different from the first optical bandgap. A method of fabricating the superlattice doped layers also is disclosed.

  3. Preparation of porcelain tile granulates by more environmentally sustainable processes

    Energy Technology Data Exchange (ETDEWEB)

    Gil, C.; Silvestre, D.; Piquer, J.; Garcia-Ten, J.; Quereda, E.; Vicente, M. J.

    2012-07-01

    This study examines the feasibility of manufacturing glazed porcelain tiles with a more environmentally friendly manufacturing process, by reducing water and thermal energy consumption. The process studied in this paper is dry milling in a pendulum mill, with subsequent granulation (in order to obtain a press powder with similar flow ability to that of spray dried powders). The different morphology of the new granulate with respect to the standard spray-dried granulate modifies the microstructure of the green compacts and thus, their behaviour and fired tile properties. In order to obtain porcelain tiles with the required properties (water absorption, mechanical strength,) changes have been made in the raw materials mixture and in the processing variables. Finally, porcelain tiles measuring 50x50 cm have been manufactured at industrial scale with the new granulate using a conventional firing cycle, obtaining quality levels identical to those provided by the spray-dried granulate. These results open the possibility of preparing porcelain tile body compositions through a manufacturing process alternative to the standard one, more environmentally friendly and with lower costs. (Author)

  4. Magnetoelectric effect in two-layered self-biased composites Tb{sub 0.12}Dy{sub 0.2}Fe{sub 0.68}/epoxy - PbZr{sub 0.53}Ti{sub 0.47}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kalgin, A.V.; Gridnev, S.A.; Popov, I.I. [Voronezh State Technical University, Voronezh (Russian Federation)

    2017-03-15

    Direct magnetoelectric (ME) effect in two-layered Tb{sub 0.12}Dy{sub 0.2}Fe{sub 0.68}/Epoxy - PbZr{sub 0.53}Ti{sub 0.47}O{sub 3} composites containing magnetostrictive layers of the epoxy with distributed in it Tb{sub 0.12}Dy{sub 0.2}Fe{sub 0.68} granules and piezoelectric layers of the PbZr{sub 0.53}Ti{sub 0.47}O{sub 3} ceramics was studied. It was found, that the gradient distribution of Tb{sub 0.12}Dy{sub 0.2}Fe{sub 0.68} granules in magnetostrictive layers induces the internal (self-biased) magnetic field. This field leads to the increase in ME responses in composites with the gradient distribution of Tb{sub 0.12}Dy{sub 0.2}Fe{sub 0.68} granules in magnetostrictive layers as compared with ME responses in composites with the random distribution of Tb{sub 0.12}Dy{sub 0.2}Fe{sub 0.68} granules in magnetostrictive layers, which does not induce the internal magnetic field. We revealed the possibility of controlling and determining values of the internal magnetic field in composites and conditions for obtaining optimal ME responses. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Repulsion forces of superplasticizers on ground granulated blast furnace slag in alkaline media, from AFM measurements to rheological properties

    OpenAIRE

    Palacios, M.; Bowen, P.; Kappl, M.; Butt, H. J.; Stuer, M.; Pecharromán, C.; Aschauer, U.; Puertas, F.

    2012-01-01

    The electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these superplasticizers the slag suspensions had negative zeta potentials, ranging from -3 to -10 mV. For the first time the adsorbed layer thicknesses for superplasticizers on slag using colloidal probe atomi...

  6. Characterization of muscarinic receptor subtypes in primary cultures of cerebellar granule cells using specific muscarinic receptor antagonists

    International Nuclear Information System (INIS)

    McLeskey, S.W.

    1989-01-01

    In cerebellar granule cell cultures, two muscarinic receptor mediated responses were observed: inhibition of adenylate cyclase (M-AC) and stimulation of phosphoinositide hydrolysis (M-PI). These responses were antagonized by three purported specific muscarinic antagonists: pirenzipine and (-)QNX (specific for M-PI) and methoctramine (specific for M-AC). However, the specificity for the three antagonists in blocking these responses is not comparable to the specificity observed in binding studies on these cells or to that quoted in the literature. Two peaks of molecular sizes were found in these cells corresponding to the two molecular sizes of muscarinic receptive proteins reported in the literature. Muscarinic receptive proteins were alkylated with 3 H-propylbenzilylcholine mustard followed by sodium dodecylsulfate polyacrylamide gel electrophoresis. Pirenzipine and (-)QNX were able to block alkylation of the high molecular size peak, which corresponds to the receptive protein m 3 reported in the literature. Methoctramine was able to block alkylation of a portion of the lower molecular size peak, possibly corresponding to the m 2 and/or m 4 receptive proteins reported in the literature. Studies attempting to show the presence of receptor reserve for either of the two biochemical responses present in these cells by alkylation of the receptive protein with nonradiolabeled propylbenzilylcholine mustard (PBCM) were confounded by specificity of this agent for the lower molecular weight peak of muscarinic receptive protein. Thus the muscarinic receptive proteins coupled to M-AC were alkylated preferentially over the ones coupled to M-PI

  7. Pigment granule translocation in red ovarian chromatophores from the palaemonid shrimp Macrobrachium olfersi (Weigmann, 1836): functional roles for the cytoskeleton and its molecular motors.

    Science.gov (United States)

    Milograna, Sarah Ribeiro; Ribeiro, Márcia Regina; Baqui, Munira Muhammad Abdel; McNamara, John Campbell

    2014-12-01

    The binding of red pigment concentrating hormone (RPCH) to membrane receptors in crustacean chromatophores triggers Ca²⁺/cGMP signaling cascades that activate cytoskeletal motors, driving pigment granule translocation. We investigate the distributions of microfilaments and microtubules and their associated molecular motors, myosin and dynein, by confocal and transmission electron microscopy, evaluating a functional role for the cytoskeleton in pigment translocation using inhibitors of polymer turnover and motor activity in vitro. Microtubules occupy the chromatophore cell extensions whether the pigment granules are aggregated or dispersed. The inhibition of microtubule turnover by taxol induces pigment aggregation and inhibits re-dispersion. Phalloidin-FITC actin labeling, together with tannic acid fixation and ultrastructural analysis, reveals that microfilaments form networks associated with the pigment granules. Actin polymerization induced by jasplaquinolide strongly inhibits RPCH-induced aggregation, causes spontaneous pigment dispersion, and inhibits pigment re-dispersion. Inhibition of actin polymerization by latrunculin-A completely impedes pigment aggregation and re-dispersion. Confocal immunocytochemistry shows that non-muscle myosin II (NMMII) co-localizes mainly with pigment granules while blebbistatin inhibition of NMMII strongly reduces the RPCH response, also inducing spontaneous pigment dispersion. Myosin II and dynein also co-localize with the pigment granules. Inhibition of dynein ATPase by erythro-9-(2-hydroxy-3-nonyl) adenine induces aggregation, inhibits RPCH-triggered aggregation, and inhibits re-dispersion. Granule aggregation and dispersion depend mainly on microfilament integrity although microtubules may be involved. Both cytoskeletal polymers are functional only when subunit turnover is active. Myosin and dynein may be the molecular motors that drive pigment aggregation. These mechanisms of granule translocation in crustacean

  8. Photoautotrophic Polyhydroxybutyrate Granule Formation Is Regulated by Cyanobacterial Phasin PhaP in Synechocystis sp. Strain PCC 6803

    Science.gov (United States)

    Hauf, Waldemar; Watzer, Björn; Roos, Nora; Klotz, Alexander

    2015-01-01

    Cyanobacteria are photoautotrophic microorganisms which fix atmospheric carbon dioxide via the Calvin-Benson cycle to produce carbon backbones for primary metabolism. Fixed carbon can also be stored as intracellular glycogen, and in some cyanobacterial species like Synechocystis sp. strain PCC 6803, polyhydroxybutyrate (PHB) accumulates when major nutrients like phosphorus or nitrogen are absent. So far only three enzymes which participate in PHB metabolism have been identified in this organism, namely, PhaA, PhaB, and the heterodimeric PHB synthase PhaEC. In this work, we describe the cyanobacterial PHA surface-coating protein (phasin), which we term PhaP, encoded by ssl2501. Translational fusion of Ssl2501 with enhanced green fluorescent protein (eGFP) showed a clear colocalization to PHB granules. A deletion of ssl2501 reduced the number of PHB granules per cell, whereas the mean PHB granule size increased as expected for a typical phasin. Although deletion of ssl2501 had almost no effect on the amount of PHB, the biosynthetic activity of PHB synthase was negatively affected. Secondary-structure prediction and circular dichroism (CD) spectroscopy of PhaP revealed that the protein consists of two α-helices, both of them associating with PHB granules. Purified PhaP forms oligomeric structures in solution, and both α-helices of PhaP contribute to oligomerization. Together, these results support the idea that Ssl2501 encodes a cyanobacterial phasin, PhaP, which regulates the surface-to-volume ratio of PHB granules. PMID:25911471

  9. Granulated Silica Method for the Fiber Preform Production

    Directory of Open Access Journals (Sweden)

    Sönke Pilz

    2017-07-01

    Full Text Available During the past few years, we have studied the granulated silica method as a versatile and cost effective way of fiber preform production and the sol-gel method. Until now, we have used the sol-gel technology together with an iterative re-melting and milling step in order to produce rare earth or transition metal doped granular material for the granulated silica method. Here, we present that the iterative re-melting (laser-assisted and milling step is no longer needed to reach a high homogeneity. The sol-gel method also offers a high degree of compositional flexibility with respect to dopants; it further facilitates achieving high concentrations, even in cases when several dopants are used. We employed optical active doped sol-gel derived granulate for the fiber core, whereas pure or index-raised granulated silica has been employed for the cladding. Based on the powder-in-tube technique, where silica glass tubes are appropriately filled with these granular materials, fibers has been directly drawn (“fiber rapid prototyping”, or eventually after an additional optional quality enhancing vitrification step. The powder-in-tube technique is also ideally suited for the preparation of microstructured optical fibers.

  10. Granular activated carbon as nucleating agent for aerobic sludge granulation: Effect of GAC size on velocity field differences (GAC versus flocs) and aggregation behavior.

    Science.gov (United States)

    Zhou, Jia-Heng; Zhao, Hang; Hu, Miao; Yu, Hai-Tian; Xu, Xiang-Yang; Vidonish, Julia; Alvarez, Pedro J J; Zhu, Liang

    2015-12-01

    Initial cell aggregation plays an important role in the formation of aerobic granules. In this study, three parallel aerobic granular sludge reactors treating low-strength wastewater were established using granular activated carbon (GAC) of different sizes as the nucleating agent. A novel visual quantitative evaluation method was used to discern how GAC size affects velocity field differences (GAC versus flocs) and aggregation behavior during sludge granulation. Results showed that sludge granulation was significantly enhanced by addition of 0.2mm GAC. However, there was no obvious improvement in granulation in reactor amended with 0.6mm GAC. Hydraulic analysis revealed that increase of GAC size enhanced the velocity field difference between flocs and GAC, which decreased the lifecycle and fraction of flocs-GAC aggregates. Overall, based on analysis of aggregation behavior, GAC of suitable sizes (0.2mm) can serve as the nucleating agent to accelerate flocs-GAC coaggregation and formation of aerobic granules. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Giant arachnoid granulation in a patient with benign intracranial hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Kiroglu, Yilmaz; Yaqci, Baki; Cirak, Bayram; Karabulut, Nevzat [Pamukkale University, Department of Radiology, School of Medicine, Denizli (Turkey)

    2008-10-15

    We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms. (orig.)

  12. Giant arachnoid granulation in a patient with benign intracranial hypertension

    International Nuclear Information System (INIS)

    Kiroglu, Yilmaz; Yaqci, Baki; Cirak, Bayram; Karabulut, Nevzat

    2008-01-01

    We report magnetic resonance (MR), computed tomography (CT) and angiographic imaging of an unusual giant arachnoid granulation in the superior sagittal sinus in a man with headache and vertigo. Intrasinus pressure measurements revealed a significant pressure gradient across the lesion. MR imaging is useful to identify giant arachnoid granulation and dural sinus thrombosis, whereas dural sinus pressure measurement in certain cases of giant arachnoid granulations can be used to evaluate the lesion as the cause of the patient's symptoms. (orig.)

  13. Enhanced Performance of Nanowire-Based All-TiO2 Solar Cells using Subnanometer-Thick Atomic Layer Deposited ZnO Embedded Layer

    International Nuclear Information System (INIS)

    Ghobadi, Amir; Yavuz, Halil I.; Ulusoy, T. Gamze; Icli, K. Cagatay; Ozenbas, Macit; Okyay, Ali K.

    2015-01-01

    In this paper, the effect of angstrom-thick atomic layer deposited (ALD) ZnO embedded layer on photovoltaic (PV) performance of Nanowire-Based All-TiO 2 solar cells has been systematically investigated. Our results indicate that by varying the thickness of ZnO layer the efficiency of the solar cell can be significantly changed. It is shown that the efficiency has its maximum for optimal thickness of 1 ALD cycle in which this ultrathin ZnO layer improves device performance through passivation of surface traps without hampering injection efficiency of photogenerated electrons. The mechanisms contributing to this unprecedented change in PV performance of the cell have been scrutinized and discussed

  14. TABLETING PROPERTIES OF EXPERIMENTAL AND COMMERCIALLY AVAILABLE LACTOSE GRANULATIONS FOR DIRECT COMPRESSION

    NARCIS (Netherlands)

    BOLHUIS, GK; ZUURMAN, K

    1995-01-01

    Lactose granulations (125-250 mu m) were prepared from two different alpha-lactose monohydrate powders and one roller dried beta-lactose powder respectively, by wet granulation with only water as a binder. As an effect of the granulation process, the flow properties improved, but the compactibility

  15. Metatranscriptomics reveals the molecular mechanism of large granule formation in granular anammox reactor

    KAUST Repository

    Bagchi, Samik

    2016-06-20

    Granules enriched with anammox bacteria are essential in enhancing the treatment of ammonia-rich wastewater, but little is known about how anammox bacteria grow and multiply inside granules. Here, we combined metatranscriptomics, quantitative PCR and 16S rRNA gene sequencing to study the changes in community composition, metabolic gene content and gene expression in a granular anammox reactor with the objective of understanding the molecular mechanism of anammox growth and multiplication that led to formation of large granules. Size distribution analysis revealed the spatial distribution of granules in which large granules having higher abundance of anammox bacteria (genus Brocadia) dominated the bottom biomass. Metatranscriptomics analysis detected all the essential transcripts for anammox metabolism. During the later stage of reactor operation, higher expression of ammonia and nitrite transport proteins and key metabolic enzymes mainly in the bottom large granules facilitated anammox bacteria activity. The high activity resulted in higher growth and multiplication of anammox bacteria and expanded the size of the granules. This conceptual model for large granule formation proposed here may assist in the future design of anammox processes for mainstream wastewater treatment.

  16. RNA Recognition and Stress Granule Formation by TIA Proteins

    Science.gov (United States)

    Waris, Saboora; Wilce, Matthew Charles James; Wilce, Jacqueline Anne

    2014-01-01

    Stress granule (SG) formation is a primary mechanism through which gene expression is rapidly modulated when the eukaryotic cell undergoes cellular stresses (including heat, oxidative, viral infection, starvation). In particular, the sequestration of specifically targeted translationally stalled mRNAs into SGs limits the expression of a subset of genes, but allows the expression of heatshock proteins that have a protective effect in the cell. The importance of SGs is seen in several disease states in which SG function is disrupted. Fundamental to SG formation are the T cell restricted intracellular antigen (TIA) proteins (TIA-1 and TIA-1 related protein (TIAR)), that both directly bind to target RNA and self-associate to seed the formation of SGs. Here a summary is provided of the current understanding of the way in which TIA proteins target specific mRNA, and how TIA self-association is triggered under conditions of cellular stress. PMID:25522169

  17. Diversity, Localization, and Physiological Properties of Filamentous Microbes Belonging to Chloroflexi Subphylum I in Mesophilic and Thermophilic Methanogenic Sludge Granules

    Science.gov (United States)

    Yamada, Takeshi; Sekiguchi, Yuji; Imachi, Hiroyuki; Kamagata, Yoichi; Ohashi, Akiyoshi; Harada, Hideki

    2005-01-01

    We previously reported that the thermophilic filamentous anaerobe Anaerolinea thermophila, which is the first cultured representative of subphylum I of the bacterial phylum Chloroflexi, not only was one of the predominant constituents of thermophilic sludge granules but also was a causative agent of filamentous sludge bulking in a thermophilic (55°C) upflow anaerobic sludge blanket (UASB) reactor in which high-strength organic wastewater was treated (Y. Sekiguchi, H. Takahashi, Y. Kamagata, A. Ohashi, and H. Harada, Appl. Environ. Microbiol. 67:5740-5749, 2001). To further elucidate the ecology and function of Anaerolinea-type filamentous microbes in UASB sludge granules, we surveyed the diversity, distribution, and physiological properties of Chloroflexi subphylum I microbes residing in UASB granules. Five different types of mesophilic and thermophilic UASB sludge were used to analyze the Chloroflexi subphylum I populations. 16S rRNA gene cloning-based analyses using a 16S rRNA gene-targeted Chloroflexi-specific PCR primer set revealed that all clonal sequences were affiliated with the Chloroflexi subphylum I group and that a number of different phylotypes were present in each clone library, suggesting the ubiquity and vast genetic diversity of these populations in UASB sludge granules. Subsequent fluorescence in situ hybridization (FISH) of the three different types of mesophilic sludge granules using a Chloroflexi-specific probe suggested that all probe-reactive cells had a filamentous morphology and were widely distributed within the sludge granules. The FISH observations also indicated that the Chloroflexi subphylum I bacteria were not always the predominant populations within mesophilic sludge granules, in contrast to thermophilic sludge granules. We isolated two mesophilic strains and one thermophilic strain belonging to the Chloroflexi subphylum I group. The physiological properties of these isolates suggested that these populations may contribute to the

  18. Sludge granulation during anaerobic treatment of pre-hydrolysed ...

    African Journals Online (AJOL)

    An upflow anaerobic sludge bed (UASB) digester was operated at different hydraulic retention times (HRT) ranging from 26.7 h to 2.2 h, while the organic load rate (OLR) ranged from 0.9 to 7.3 kgCOD/m3·d. Sludge granulation was observed after day 150 of operation, at an HRT of 3.4 h, when small granules of less than 2 ...

  19. Stem cell engineered bone with calcium-phosphate coated porous titanium scaffold or silicon hydroxyapatite granules for revision total joint arthroplasty.

    Science.gov (United States)

    García-Gareta, Elena; Hua, Jia; Rayan, Faizal; Blunn, Gordon W

    2014-06-01

    Aseptic loosening in total joint replacements (TJRs) is mainly caused by osteolysis which leads to a reduction of the bone stock necessary for implant fixation in revision TJRs. Our aim was to develop bone tissue-engineered constructs based on scaffolds of clinical relevance in revision TJRs to reconstitute the bone stock at revision operations by using a perfusion bioreactor system (PBRS). The hypothesis was that a PBRS will enhance mesenchymal stem cells (MSCs) proliferation and osteogenic differentiation and will provide an even distribution of MSCs throughout the scaffolds when compared to static cultures. A PBRS was designed and implemented. Scaffolds, silicon substituted hydroxyapatite granules and calcium-phosphate coated porous TiAl6V4 cylinders, were seeded with MSCs and cultured either in static conditions or in the PBRS at 0.75 mL/min. Statistically significant increased cell proliferation and alkaline phosphatase activity was found in samples cultured in the PBRS. Histology revealed a more even cell distribution in the perfused constructs. SEM showed that cells arranged in sheets. Long cytoplasmic processes attached the cells to the scaffolds. We conclude that a novel tissue engineering approach to address the issue of poor bone stock at revision operations is feasible by using a PBRS.

  20. Influence of layer-by-layer assembled electrospun poly (L-lactic acid) nanofiber mats on the bioactivity of endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Keke; Zhang, Xiazhi; Yang, Wufeng; Liu, Xiaoyan; Jiao, Yanpeng, E-mail: tjiaoyp@jnu.edu.cn; Zhou, Changren

    2016-12-30

    Highlights: • Layer-by-layer assembled PLLA nanofiber mats were successfully prepared. • The modified PLLA nanofiber mats enhanced the adhesion, proliferation of endothelial cells. • The modified PLLA nanofiber mats had inhibited the inflammatory response to some extent. - Abstract: Electrospun poly(L-lactic acid) (PLLA) nanofiber mats were successfully modified by deposition of multilayers with chitosan (CS), heparin (Hep) and graphene oxide (GO) through electrostatic layer-by-layer (LBL) self-assembly method. In this study, the surface properties of PLLA nanofiber mats before and after modification were investigated via scanning electron microscope (SEM), atomic force microscopy (AFM), attenuated total reflectance fourier transformation infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. In addition, the cytocompatibility of the modified PLLA nanofiber mats were investigated by testing endothelial cells compatibility, including cell attachment, cell proliferation and cell cycle. The results revealed that the surfaces of modified PLLA nanofiber mats become much rougher, stifiness and the hydrophilicity of the LBL modified PLLA nanofiber mats were improved compared to original PLLA one. Moreover, the modified PLLA nanofiber mats had promoted the endothelial cells viability attachment significantly. Besides, we studied the PLLA nanofiber mats on the expression of necrosis factor (TNF-α), interleukine-1β (IL-1β), monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) in endothelial cells. The results showed that modified PLLA nanofiber mats had inhibited the inflammatory response to some extent.

  1. Metatranscriptomics reveals the molecular mechanism of large granule formation in granular anammox reactor

    KAUST Repository

    Bagchi, Samik; Lamendella, Regina; Strutt, Steven; Van Loosdrecht, Mark C. M.; Saikaly, Pascal

    2016-01-01

    to formation of large granules. Size distribution analysis revealed the spatial distribution of granules in which large granules having higher abundance of anammox bacteria (genus Brocadia) dominated the bottom biomass. Metatranscriptomics analysis detected all

  2. YKL-40, a mammalian member of the chitinase family, is a matrix protein of specific granules in human neutrophils

    DEFF Research Database (Denmark)

    Volck, B; Price, P A; Johansen, J S

    1998-01-01

    YKL-40, also called human cartilage glycoprotein-39 (HC gp-39), is a member of family 18 glycosyl hydrolases. YKL-40 is secreted by chondrocytes, synovial cells, and macrophages, and recently it has been reported that YKL-40 has a role as an autoantigen in rheumatoid arthritis (RA). The function...... of patients with RA, and the cells are assumed to play a role in joint destruction in that disorder. Therefore, we examined whether neutrophils are a source of YKL-40. YKL-40 was found to colocalize and comobilize with lactoferrin (the most abundant protein of specific granules) but not with gelatinase...... YKL-40 at the myelocyte-metamyelocyte stage, the stage of maturation at which other specific granule proteins are formed. Assuming that YKL-40 has a role as an autoantigen in RA by inducing T cell-mediated autoimmune response, YKL-40 released from neutrophils in the inflamed joint could be essential...

  3. Microbial granulation for lactic acid production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which...... increased, reaching 67 g L-fermenter−1h−1 at HRT 0.17 h. The size of LA-producing granules and hydrophobicity gradually increased with decrease in HRT, reaching 6.0 mm and 60%, respectively. These biogranules were also found to have high settling velocities and low porosities, ranging 2.69-4.73 cm s−1 and 0...

  4. Mechanistic modelling of the drying behaviour of single pharmaceutical granules

    DEFF Research Database (Denmark)

    Thérèse F.C. Mortier, Séverine; Beer, Thomas De; Gernaey, Krist

    2012-01-01

    The trend to move towards continuous production processes in pharmaceutical applications enhances the necessity to develop mechanistic models to understand and control these processes. This work focuses on the drying behaviour of a single wet granule before tabletting, using a six...... phase (submodel 2), the water inside the granule evaporates. The second submodel contains an empirical power coefficient, b. A sensitivity analysis was performed to study the influence of parameters on the moisture content of single pharmaceutical granules, which clearly points towards the importance...

  5. Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin.

    Science.gov (United States)

    Johnson, Adam S; García, Dana M

    2007-12-19

    Inside bluegill (Lepomis macrochirus) retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog) is one example. Previous research indicates that the carbachol-receptor interaction activates a Gq-mediated pathway which is commonly linked to Ca2+ mobilization. The purpose of the present study was to test for involvement of calcium and to probe calcium-dependent mediators to reveal their role in carbachol-mediated dispersion. Carbachol-induced pigment granule dispersion was blocked by the calcium chelator BAPTA. In contrast, the calcium channel antagonist verapamil, and incubation in Ca2+-free medium failed to block carbachol-induced dispersion. The calcineurin inhibitor cypermethrin blocked carbachol-induced dispersion; whereas, two protein kinase C inhibitors (staurosporine and bisindolylmaleimide II) failed to block carbachol-induced dispersion, and the protein kinase C activator phorbol 12-myristate 13-acetate failed to elicit dispersion. A rise in intracellular calcium is necessary for carbachol-induced dispersion; however, the Ca2+ requirement is not dependent on extracellular sources, implying that intracellular stores are sufficient to enable pigment granule dispersion to occur. Calcineurin is a likely Ca2+-dependent mediator involved in the signal cascade. Although the pathway leads to the generation of diacylglycerol and calcium (both required for the activation of certain PKC isoforms), our evidence does not support a significant role for PKC.

  6. Lemongrass Oil Granules AS Aedes Aegypti Larvicide

    OpenAIRE

    Mulyani, Sri

    2014-01-01

    One way to prevent the spread of Haemorrhage Dengue Fever is the use of abate. The use of abate as larvicides often complained causing an unpleasant smell, and can cause resistance. Lemongrass oil is reported to have activity as larvicides, and this study aims to make granules of lemongrass oil preparation, as well as determining the value of LC50, LC90 against larvae of Ae. aegypti instar III. The granules of lemongrass oil preparation are made with lactose filler and binder CMC-Na. Larvicid...

  7. Molecular composition of IMP1 ribonucleoprotein granules

    DEFF Research Database (Denmark)

    Jønson, Lars; Vikesaa, Jonas; Krogh, Anders

    2007-01-01

    Localized mRNAs are transported to sites of local protein synthesis in large ribonucleoprotein (RNP) granules, but their molecular composition is incompletely understood. Insulin-like growth factor II mRNA-binding protein (IMP) zip code-binding proteins participate in mRNA localization, and in mo......Localized mRNAs are transported to sites of local protein synthesis in large ribonucleoprotein (RNP) granules, but their molecular composition is incompletely understood. Insulin-like growth factor II mRNA-binding protein (IMP) zip code-binding proteins participate in mRNA localization...

  8. File list: Unc.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  9. File list: His.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.05.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  10. File list: His.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.50.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  11. File list: His.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.10.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  12. File list: Unc.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.20.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  13. File list: Unc.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Neu.10.AllAg.Cerebellar_granule_neurons mm9 Unclassified Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Unc.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  14. File list: His.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.Neu.20.AllAg.Cerebellar_granule_neurons mm9 Histone Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/His.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  15. Organic solar cells with graded absorber layers processed from nanoparticle dispersions.

    Science.gov (United States)

    Gärtner, Stefan; Reich, Stefan; Bruns, Michael; Czolk, Jens; Colsmann, Alexander

    2016-03-28

    The fabrication of organic solar cells with advanced multi-layer architectures from solution is often limited by the choice of solvents since most organic semiconductors dissolve in the same aromatic agents. In this work, we investigate multi-pass deposition of organic semiconductors from eco-friendly ethanol dispersion. Once applied, the nanoparticles are insoluble in the deposition agent, allowing for the application of further nanoparticulate layers and hence for building poly(3-hexylthiophene-2,5-diyl):indene-C60 bisadduct absorber layers with vertically graded polymer and conversely graded fullerene concentration. Upon thermal annealing, we observe some degrees of polymer/fullerene interdiffusion by means of X-ray photoelectron spectroscopy and Kelvin probe force microscopy. Replacing the common bulk-heterojunction by such a graded photo-active layer yields an enhanced fill factor of the solar cell due to an improved charge carrier extraction, and consequently an overall power conversion efficiency beyond 4%. Wet processing of such advanced device architectures paves the way for a versatile, eco-friendly and industrially feasible future fabrication of organic solar cells with advanced multi-layer architectures.

  16. File list: Pol.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.50.AllAg.Cerebellar_granule_neurons mm9 RNA polymerase Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  17. File list: Pol.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.20.AllAg.Cerebellar_granule_neurons mm9 RNA polymerase Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  18. File list: Pol.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Neu.10.AllAg.Cerebellar_granule_neurons mm9 RNA polymerase Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  19. Exocytosis and endocytosis in juxtaglomerular cells

    DEFF Research Database (Denmark)

    Friis, U G; Jensen, B L; Hansen, Pernille B. Lærkegaard

    2000-01-01

    fusion events between secretory granules and cell membrane and measurement of intermittent secretion of renin from single afferent arterioles, with a renin content of each secretion episode that corresponds to the renin content of one secretory granule. More recently it has been demonstrated...... that the afferent arterioles lose a large number of renin granules after acute stimulation without changing the average granular volume. Current electrophysiological techniques have now permitted direct measurements of cell membrane capacitance in juxtaglomerular (JG) cells as a measure of net addition (exocytosis...... and endocytosis are regulated processes in the JG-cells and both may be important for the long-term control of renin secretion at the single cell level....

  20. Evaluation of white matter hyperintensities and retinal fiber layer, ganglion cell layer, inner-plexiform layer, and choroidal layer in migraine patients.

    Science.gov (United States)

    Tak, Ali Zeynel Abidin; Sengul, Yıldızhan; Bilak, Şemsettin

    2018-03-01

    The aim of our study is to assess retinal nerve fiber layer (RNFL), the ganglion cell layer (GCL), inner-plexiform layer (IPL), and choroidal layer in migraine patients with white matter lesion (WML) or without WML, using spectral domain optical coherence tomography (OCT). To our study, 77 migraine patients who are diagnosed with migraine in accordance to the International Classification of Headache Disorders (ICHD)-3 beta and 43 healthy control are included. In accordance to cranial MRI, migraine patients are divided into two groups as those who have white matter lesions (39 patients), and those who do not have a lesion (38 patients). OCT was performed for participants. The average age of participants was comparable. The RNFL average thickness parameter in the migraine group was significantly lower than in the control group (p layer measuring scales. The proofs showing that affected retinal nerve fiber layer are increased in migraine patients. However, it is not known whether this may affect other layers of retina, or whether there is a correlation between affected retinal structures and white matter lesions. In our study, we found thinner RNFL in migraine patients when we compared with controls but IPL, GCL, and choroid layer values were similar between each patient groups and controls. Also, all parameters were similar between patients with WML and without WML. Studies in this regard are required.

  1. Conductive polymer layers to limit transfer of fuel reactants to catalysts of fuel cells to reduce reactant crossover

    Science.gov (United States)

    Stanis, Ronald J.; Lambert, Timothy N.

    2016-12-06

    An apparatus of an aspect includes a fuel cell catalyst layer. The fuel cell catalyst layer is operable to catalyze a reaction involving a fuel reactant. A fuel cell gas diffusion layer is coupled with the fuel cell catalyst layer. The fuel cell gas diffusion layer includes a porous electrically conductive material. The porous electrically conductive material is operable to allow the fuel reactant to transfer through the fuel cell gas diffusion layer to reach the fuel cell catalyst layer. The porous electrically conductive material is also operable to conduct electrons associated with the reaction through the fuel cell gas diffusion layer. An electrically conductive polymer material is coupled with the fuel cell gas diffusion layer. The electrically conductive polymer material is operable to limit transfer of the fuel reactant to the fuel cell catalyst layer.

  2. Stimulation by ATP of proinsulin to insulin conversion in isolated rat pancreatic islet secretory granules. Association with the ATP-dependent proton pump

    International Nuclear Information System (INIS)

    Rhodes, C.J.; Lucas, C.A.; Mutkoski, R.L.; Orci, L.; Halban, P.A.

    1987-01-01

    Isolated rat pancreatic islets were pulse-labeled for 5 min with [ 3 H]leucine then chased for 25 min, during which time endogenously labeled [ 3 H]proinsulin becomes predominantly compartmented in immature secretory granules. The islets were then homogenized in isotonic sucrose (pH 7.4) and a beta-granule preparation obtained by differential centrifugation and discontinuous sucrose gradient ultracentrifugation. This preparation was enriched 8-fold in beta-granules. Aside from contamination with mitochondria and a limited number of lysosomes, the beta-granule preparation was essentially free of any other organelles involved in proinsulin synthesis and packaging (i.e. microsomal elements and, more particularly, Golgi complex). Conversion of endogenously labeled [ 3 H]proinsulin was followed in this beta-granule fraction for up to 2 h at 37 degrees C in a buffer (pH 7.3) that mimicked the cationic constituents of B-cell cytosol, during which time 92% of the beta-granules remained intact. Proinsulin conversion was analyzed by high performance liquid chromatography. The rate of proinsulin conversion to insulin was stimulated by 2.2 +/- 0.1-fold (n = 6) (at a 60-min incubation) in the presence of ATP (2 mM) and an ATP regenerating system compared to beta-granule preparations incubated without ATP. This ATP stimulation was abolished in the presence of beta-granule proton pump ATPase inhibitors (tributyltin, 2.5 microM, or 1,3-dicyclohexylcarbodiimide, 50 microM). Inhibitors of mitochondrial proton pump ATPases had no effect on the ATP stimulation of proinsulin conversion. When granules were incubated in a more acidic buffer, proinsulin conversion was increased relative to that at pH 7.3. At pH 5.5, ATP no longer stimulated conversion, and tributyltin and 1,3-dicyclohexylcarbodiimide had no effect

  3. Electrophysiological characterization of granule cells in the dentate gyrus immediately after birth

    Directory of Open Access Journals (Sweden)

    Andrea ePedroni

    2014-02-01

    Full Text Available Granule cells (GCs in the dentate gyrus are generated mainly postnatally. Between embryonic day 10 and 14, neural precursors migrate from the primary dentate matrix to the dentate gyrus where they differentiate into neurons. Neurogenesis reaches a peak at the end of the first postnatal week and it is completed at the end of the first postnatal month. This process continues at a reduced rate throughout life. Interestingly, immediately after birth, GCs exhibit a clear GABAergic phenotype. Only later they integrate the classical glutamatergic trisynaptic hippocampal circuit. Here, whole patch clamp recordings, in current clamp mode, were performed from immature GCs, intracellularly loaded with biocytin (in hippocampal slices from P0-P3 old rats in order to compare their morphological characteristics with their electrophysiological properties. The vast majority of GCs were very immature with small somata, few dendritic branches terminating with small varicosities and growth cones. In spite of their immaturity their axons reached often the CA3 area. Immature GCs generated, upon membrane depolarization, either rudimentary sodium spikes or more clear overshooting action potentials that fired repetitively. They exhibited also low threshold calcium spikes. In addition, most spiking neurons showed spontaneous synchronized network activity, reminiscent of giant depolarizing potentials (GDPs generated in the hippocampus by the synergistic action of glutamate and GABA, both depolarizing and excitatory. This early synchronized activity, absent during adult neurogenesis, may play a crucial role in the refinement of local neuronal circuits within the developing dentate gyrus.

  4. Plasma-assisted atomic layer deposition of TiO2 compact layers for flexible mesostructured perovskite solar cells

    NARCIS (Netherlands)

    Zardetto, V.; Di Giacomo, F.; Lucarelli, G.; Kessels, W.M.M.; Brown, T.M.; Creatore, M.

    2017-01-01

    In mesostructured perovskite solar cell devices, charge recombination processes at the interface between the transparent conductive oxide, perovskite and hole transport layer are suppressed by depositing an efficient compact TiO2 blocking layer. In this contribution we investigate the role of the

  5. The converse magnetoelectric coupling in asymmetric granule/matrix composite film with Ni/PZT component

    Science.gov (United States)

    Chen, Bo; Su, Ning-Ning; Cui, Wen-Li; Yan, Shi-Nong

    2018-04-01

    In this work, a type of asymmetric granule/matrix composite film is designed, where the Ni granule is dispersed in PZT matrix, meanwhile the top and bottom electrode is constituted by Au and SRO respectively. Predicted through the electrostatic screening model and mean field approximation, considerable electrostatic charge is induced on Ni granule surface by ferroelectric PZT polarization. Predicted through the spin splitting model and spherical shell approximation, both the magnetization and magnetic anisotropy of Ni granule are modulated by ferroelectric PZT polarization. As the volume fraction of Ni granule is increased, the electric modulation of magnetization and magnetic anisotropy is reduced and enhanced respectively. As the dimension of granule/matrix composite is varied, such modulation is retained. Due to the large area-volume ratio of nano-granule, this work benefits to realize the converse magnetoelectric coupling in nanoscale.

  6. File list: Oth.Neu.50.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.50.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.50.AllAg.Cerebellar_granule_neurons.bed ...

  7. File list: Oth.Neu.20.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.20.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.20.AllAg.Cerebellar_granule_neurons.bed ...

  8. File list: Oth.Neu.10.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.10.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.10.AllAg.Cerebellar_granule_neurons.bed ...

  9. File list: Oth.Neu.05.AllAg.Cerebellar_granule_neurons [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Neu.05.AllAg.Cerebellar_granule_neurons mm9 TFs and others Neural Cerebellar granule neurons... http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Neu.05.AllAg.Cerebellar_granule_neurons.bed ...

  10. Pluripotency Factors in Embryonic Stem Cells Regulate Differentiation into Germ Layers

    OpenAIRE

    Thomson, Matt; Liu, Siyuan John; Zou, Ling-Nan; Smith, Zack; Meissner, Alexander; Ramanathan, Sharad

    2011-01-01

    Cell fate decisions are fundamental for development, but we do not know how transcriptional networks reorganize during the transition from a pluripotent to a differentiated cell state. Here, we asked how mouse embryonic stem cells (ESCs) leave the pluripotent state and choose between germ layer fates. By analyzing the dynamics of the transcriptional circuit that maintains pluripotency, we found that Oct4 and Sox2, proteins that maintain ESC identity, also orchestrate germ layer fate selection...

  11. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Qiang, E-mail: kongqiang0531@hotmail.com [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China); Ngo, Huu Hao [School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Shu, Li [School of Engineering, Faculty of Science, Engineering and Built Environment, Deakin University, Geelong, Victoria 3216 (Australia); Fu, Rong-shu; Jiang, Chun-hui [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China); Miao, Ming-sheng, E-mail: mingshengmiao@163.com [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China)

    2014-08-30

    Highlights: • Zero-valent iron (ZVI) was used firstly to enhance the aerobic granulation. • ZVI significantly decreased the start-up time of the aerobic granulation. • ZVI had the function of enhancing organic material diversity identified by 3-D EEM. • ZVI could enhance the diversity of microbial community. - Abstract: This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe{sup 2+} dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation.

  12. Ultraviolet and gamma-radiation effect on the zymotic characteristics of turnip moth's granules

    Energy Technology Data Exchange (ETDEWEB)

    Khakimova, M A

    1975-01-01

    Virus granules of the winter cutworm (Agrotis segetum Schiff) were used as agents for biological control of this pest of field and vegetable crops. The authors first studied the effect of uv and gamma radiation on granules of the cutworm. A purified suspension of winter moth granules, 0.5 mg of granules per mm/sup 3/, was irradiated with a BUV-15 lamp at a distance of 9 cm from the radiation source. The dose rate was 6.6x10/sup 3/ ergs/cm/sup 2/.sec. The results showed that a uv dose of 71.1x10/sup 6/ ergs/cm/sup 2/ decreased the virulence of the granules by a factor of 3 compared to the original suspension (larval mortality of 27.5%) and a dose of 95x10/sup 6/ ergs/cm/sup 2/ completely inactivated the granules. With gamma radiation (/sup 60/Co or /sup 137/Cs) the inactivating dose was only 21.6x10/sup 5/ rads. The work indicated that cutworm granules are very resistant to uv and gamma radiation.

  13. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

    International Nuclear Information System (INIS)

    Kong, Qiang; Ngo, Huu Hao; Shu, Li; Fu, Rong-shu; Jiang, Chun-hui; Miao, Ming-sheng

    2014-01-01

    Highlights: • Zero-valent iron (ZVI) was used firstly to enhance the aerobic granulation. • ZVI significantly decreased the start-up time of the aerobic granulation. • ZVI had the function of enhancing organic material diversity identified by 3-D EEM. • ZVI could enhance the diversity of microbial community. - Abstract: This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe 2+ dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation

  14. Se interlayer in CIGS absorption layer for solar cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung-Kyu; Sim, Jae-Kwan [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of); Kissinger, N.J. Suthan [Department of General Studies, Physics Group, Jubail University College, Royal Commission for Jubail, Jubail 10074 (Saudi Arabia); Song, Il-Seok; Kim, Jin-Soo; Baek, Byung-Joon [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of); Lee, Cheul-Ro, E-mail: crlee7@jbnu.ac.kr [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of)

    2015-06-05

    Highlights: • Se interlayer is deposited between the CuGa and CuIn/In/Mo/STS stacked layer. • Both CIG precursor layers were selenized at 500 °C for 1 h. • SIMS depth profile shows that Ga distribution is uniform by Se interlayer. • The efficiency was improved for the CIGS solar cell by Se interlayer. - Abstract: A CIGS absorber layer with high gallium contents in the space-charge region can reduce the carrier recombination and improve the open circuit voltage V{sub oc}. Therefore, controlling Ga grading on top of CIGS thin film solar cells is the main objective of this experiment. To reduce Selenium (Se) vacancy, it is important that the diffusion of Ga elements into Se vacancy between Mo back contact and CIGS absorption layer would be controlled. In order to reduce Se vacancy and confirm Ga inter-diffusion, two CIGS solar cells were fabricated by converting CIG precursor with and without Se interlayer. The copper-indium metallic precursors were fabricated corresponding to the sequence CuIn/In/Mo/STS on stainless steel (STS) substrates by sequential direct current magnetron sputtering while Se layer was evaporated by rapid thermal annealing (RTA) system to obtain a Se/CuIn/In/Mo/STS stack. CuGa precursor layer was also fabricated on the Se/CuIn/In/Mo/STS stack. Finally, both CuGa/Se/CuIn/In/Mo/STS and CuGa/CuIn/In/Mo/STS stacks were selenized at 500 °C for 1 h. It was clearly observed from the secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) that there was a change between the fabricated CIGS absorption layers and the amount of Ga elements. Furthermore, the Ga elements gradually decreased from the top to the bottom layer of the CIGS absorption layer. We also discussed the effect of Se interlayer in the CIGS absorption layer and its influence on the solar cell’s performance.

  15. Se interlayer in CIGS absorption layer for solar cell devices

    International Nuclear Information System (INIS)

    Lee, Seung-Kyu; Sim, Jae-Kwan; Kissinger, N.J. Suthan; Song, Il-Seok; Kim, Jin-Soo; Baek, Byung-Joon; Lee, Cheul-Ro

    2015-01-01

    Highlights: • Se interlayer is deposited between the CuGa and CuIn/In/Mo/STS stacked layer. • Both CIG precursor layers were selenized at 500 °C for 1 h. • SIMS depth profile shows that Ga distribution is uniform by Se interlayer. • The efficiency was improved for the CIGS solar cell by Se interlayer. - Abstract: A CIGS absorber layer with high gallium contents in the space-charge region can reduce the carrier recombination and improve the open circuit voltage V oc . Therefore, controlling Ga grading on top of CIGS thin film solar cells is the main objective of this experiment. To reduce Selenium (Se) vacancy, it is important that the diffusion of Ga elements into Se vacancy between Mo back contact and CIGS absorption layer would be controlled. In order to reduce Se vacancy and confirm Ga inter-diffusion, two CIGS solar cells were fabricated by converting CIG precursor with and without Se interlayer. The copper-indium metallic precursors were fabricated corresponding to the sequence CuIn/In/Mo/STS on stainless steel (STS) substrates by sequential direct current magnetron sputtering while Se layer was evaporated by rapid thermal annealing (RTA) system to obtain a Se/CuIn/In/Mo/STS stack. CuGa precursor layer was also fabricated on the Se/CuIn/In/Mo/STS stack. Finally, both CuGa/Se/CuIn/In/Mo/STS and CuGa/CuIn/In/Mo/STS stacks were selenized at 500 °C for 1 h. It was clearly observed from the secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) that there was a change between the fabricated CIGS absorption layers and the amount of Ga elements. Furthermore, the Ga elements gradually decreased from the top to the bottom layer of the CIGS absorption layer. We also discussed the effect of Se interlayer in the CIGS absorption layer and its influence on the solar cell’s performance

  16. Method of producing granulated ceramic nuclear fuels

    International Nuclear Information System (INIS)

    Wilkinson, W.L.

    1976-01-01

    For the production of granulated ceramic nuclear fuels with a grain size spectrum as narrow as possible it is proposed to suspend the nuclear fuel powder in a non-aqueous solvent with small content of hydrogen (e.g. chloridized hydrocarbons) while adding a binding agent and then dry it by means of rays. As binding agent polybutyl methane acrylate in dibutyl phthalate is proposed. The method is described by the example of UO 2 -powder in trichloroethylene. The dry granulated material is produced in one working step. (UWI) [de

  17. Rice starch granule amylolysis--differentiating effects of particle size, morphology, thermal properties and crystalline polymorph.

    Science.gov (United States)

    Dhital, Sushil; Butardo, Vito M; Jobling, Stephen A; Gidley, Michael J

    2015-01-22

    The underlying mechanism of amylolysis of rice starch granules was investigated using isolated starch granules from wild-type, as well as SBEIIb mutant and down-regulated lines. Fused granule agglomerates isolated from mutant and transgenic lines were hydrolysed at similar rates by amylases, and had similar crystalline patterns and thermal properties as individual granules. Surface pores, a feature previously only reported for A-polymorphic starch granules, were also observed in B- and C-polymorphic rice starch granules. Although the microscopic patterns of hydrolysis among granules with different crystalline polymorphs were qualitatively similar, the extent and the rate of amylolysis were different, suggesting that B-type crystalline polymorphs are intrinsically more resistant to enzymatic hydrolysis than A-type in rice starch granules. It is proposed that the slightly longer branch lengths of amylopectin which leads to the formation of more stable B-type double helical structures compared to their A-type counterparts is the major parameter, with other factors such as granule size, surface pores and interior channels having secondary roles, in determining the rate of enzymatic hydrolysis of rice starch granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Enhanced Charge Collection with Passivation Layers in Perovskite Solar Cells.

    Science.gov (United States)

    Lee, Yong Hui; Luo, Jingshan; Son, Min-Kyu; Gao, Peng; Cho, Kyung Taek; Seo, Jiyoun; Zakeeruddin, Shaik M; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

    2016-05-01

    The Al2 O3 passivation layer is beneficial for mesoporous TiO2 -based perovskite solar cells when it is deposited selectively on the compact TiO2 surface. Such a passivation layer suppressing surface recombination can be formed by thermal decomposition of the perovskite layer during post-annealing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Angiogenic effect of the aqueous extract of Cynodon dactylon on human umbilical vein endothelial cells and granulation tissue in rat.

    Science.gov (United States)

    Soraya, Hamid; Moloudizargari, Milad; Aghajanshakeri, Shahin; Javaherypour, Soheil; Mokarizadeh, Aram; Hamedeyazdan, Sanaz; Esmaeli Gouvarchin Ghaleh, Hadi; Mikaili, Peyman; Garjani, Alireza

    2015-01-29

    Cynodon dactylon, a valuable medicinal plant, is widely used in Iranian folk medicine for the treatment of various cardiovascular diseases such as heart failure and atherosclerosis. Moreover, its anti-diabetic, anti-cancer and anti-microbial properties have been also reported. Concerning the critical role of angiogenesis in the incidence and progression of tumors and also its protective role in cardiovascular diseases, we investigated the effects of the aqueous extract prepared from the rhizomes of C. dactylon on vascular endothelial growth factor (VEGF) expressions in Human Umbilical Vein Endothelial Cells (HUVECs) and also on angiogenesis in carrageenan induced air-pouch model in rats. In the air-pouch model, carrageenan was injected into an air-pouch on the back of the rats and following an IV injection of carmine red dye on day 6, granulation tissue was processed for the assessment of the dye content. Furthermore, in an in vitro study, angiogenic property of the extract was assessed through its effect on VEGF expression in HUVECs. Oral administration of 400 mg/kg/day of the extract significantly increased angiogenesis (p<0.05) and markedly decreased neutrophil (p<0.05) and total leukocyte infiltration (p<0.001) into the granulation tissues. Moreover, the extract increased the expression of total VEGF in HUVECs at a concentration of (100 μl/ml). The present study showed that the aqueous extract of C. dactylon promotes angiogenesis probably through stimulating VEGF expression.

  20. Surface-Layer (S-Layer) Proteins Sap and EA1 Govern the Binding of the S-Layer-Associated Protein BslO at the Cell Septa of Bacillus anthracis

    Science.gov (United States)

    Kern, Valerie J.; Kern, Justin W.; Theriot, Julie A.; Schneewind, Olaf

    2012-01-01

    The Gram-positive pathogen Bacillus anthracis contains 24 genes whose products harbor the structurally conserved surface-layer (S-layer) homology (SLH) domain. Proteins endowed with the SLH domain associate with the secondary cell wall polysaccharide (SCWP) following secretion. Two such proteins, Sap and EA1, have the unique ability to self-assemble into a paracrystalline layer on the surface of bacilli and form S layers. Other SLH domain proteins can also be found within the S layer and have been designated Bacillus S-layer-associated protein (BSLs). While both S-layer proteins and BSLs bind the same SCWP, their deposition on the cell surface is not random. For example, BslO is targeted to septal peptidoglycan zones, where it catalyzes the separation of daughter cells. Here we show that an insertional lesion in the sap structural gene results in elongated chains of bacilli, as observed with a bslO mutant. The chain length of the sap mutant can be reduced by the addition of purified BslO in the culture medium. This complementation in trans can be explained by an increased deposition of BslO onto the surface of sap mutant bacilli that extends beyond chain septa. Using fluorescence microscopy, we observed that the Sap S layer does not overlap the EA1 S layer and slowly yields to the EA1 S layer in a growth-phase-dependent manner. Although present all over bacilli, Sap S-layer patches are not observed at septa. Thus, we propose that the dynamic Sap/EA1 S-layer coverage of the envelope restricts the deposition of BslO to the SCWP at septal rings. PMID:22609927