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Denison R, Piazza E, Silver M. Predictive context biases perceptual selection during binocular rivalry. J Vis 2011. [DOI: 10.1167/11.11.312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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52
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Bressler D, Silver M. Manipulating contrast of multistable stimuli dissociates selection and maintenance of perceptual dominance in binocular rivalry. J Vis 2011. [DOI: 10.1167/11.11.319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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53
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Piazza E, Silver M. The time course of hemispheric asymmetries in perceptual selection of spatial frequency information. J Vis 2011. [DOI: 10.1167/11.11.307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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54
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Silver M, Kosovicheva A, Landau A. ERP correlates of orientation-specific surround suppression. J Vis 2011. [DOI: 10.1167/11.11.1168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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55
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Prinzmetal W, Rokem A, Silver M. What Stimulus Attributes are Enhanced by Attention? J Vis 2011. [DOI: 10.1167/11.11.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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56
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Jeong JY, Silver M, Parnes A, Nikiforow S, Berliner N, Vanasse GJ. Resveratrol ameliorates TNFα-mediated suppression of erythropoiesis in human CD34(+) cells via modulation of NF-κB signalling. Br J Haematol 2011; 155:93-101. [PMID: 21762122 DOI: 10.1111/j.1365-2141.2011.08800.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Overexpression of pro-inflammatory cytokines, including tumour necrosis factor alpha (TNFα), has been implicated in the pathogenesis of anaemia of inflammation. TNFα suppresses erythroid colony formation via both direct and indirect effects on haematopoietic progenitors, often involving activation of nuclear factor (NF)-κB signalling resulting in downregulation of transcription factors critical for erythropoiesis. There is a dearth of effective and safe therapies for many patients with inflammatory anaemia. Resveratrol is a flavanol found in red wine grapes that possesses potent anti-inflammatory properties, but studies of its impact on human erythropoiesis have proven contradictory. We investigated whether resveratrol ameliorates TNFα-mediated suppression of erythropoiesis in human CD34(+) haematopoietic progenitors. We found that resveratrol partially reverses the erythroid suppressive effects of TNFα, leading to significant recovery in burst forming unit-erythroid colony formation in human CD34(+) cells. CD34(+) cells pre-incubated with resveratrol for 72 h in the presence of TNFα inhibited NF-κB activation via decreased NF-κB nuclear localization without altering total NF-κB protein levels and independent of IκB degradation. Resveratrol also significantly restored the baseline expression of erythroid transcription factors NFE2 and the GATA1/GATA2 ratio in CD34(+) cells treated with TNFα. In conclusion, resveratrol may inhibit TNFα-mediated NF-κB activation and promote erythropoiesis in primary human CD34(+) cells.
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Hankey W, Silver M, Sun BSH, Zibello T, Berliner N, Khanna-Gupta A. Differential effects of sumoylation on the activities of CCAAT enhancer binding protein alpha (C/EBPα) p42 versus p30 may contribute in part, to aberrant C/EBPα activity in acute leukemias. Hematol Rep 2011; 3:e5. [PMID: 22184527 PMCID: PMC3238474 DOI: 10.4081/hr.2011.e5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/13/2011] [Accepted: 05/13/2011] [Indexed: 01/19/2023] Open
Abstract
In this study, we have examined the role of post-translational modification of the myeloid master regulator C/EBPα by small ubiquitin-related modifier (SUMO). We have used transient transfection analysis, oligonucleotide pulldown assays and chromatin immuno-precititation in all-trans retinoic acid (ATRA)-inducible promyelocytic cell lines MPRO and NB4. We demonstrate that sumoylated wild-type p42-C/EBPα is associated with negative regulation of the myeloid specific lactoferrin (LF) gene in early myeloid cells and that a reduction in p42-C/EBPα sumoylation coincides with expression of the LF gene in maturing myeloid cells. In the acute promyelocytic leukemia cell line NB4 however, sumoylated p42 remains persistently bound to the LF promoter following ATRA-induction. This correlates with lack of lactoferrin expression in these cells. Changes in sumoylation status of C/EBPα thus appear to contribute to a switch that regulates transcriptional activity of this master regulator during normal neutrophil development. We also demonstrate that sumoylation of the AML associated dominant negative p30-C/EBPα isoform does not alter transactivation activity of the LF promoter. This may be because the p30 C/EBPα isoform binds to the LF promoter much less efficiently than its full length counterpart. Our data suggest that the activity of p42-C/EBPα in the developing neutrophil is more sensitive to changes in sumoylation than the p30 isoform. This difference may contribute to the leukemogenic potential of p30-C/EBPα.
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Rokem A, Silver M. Cholinergic enhancement augments the magnitude and specificity of perceptual learning in the human visual system: a pharmacological fMRI study. J Vis 2010. [DOI: 10.1167/10.7.1101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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59
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Silver M, Maddock R, Rokem A, Yoon J. Gamma-aminobutyric acid concentration is reduced in visual cortex in schizophrenia and correlates with orientation-specific surround suppression. J Vis 2010. [DOI: 10.1167/10.7.908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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60
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Silver M, Bullock D, Grossberg S, Histed M, Miller E. A neural model of how rank-selective spatial working memory and the supplementary eye fields control sequences of saccadic eye movements. J Vis 2010. [DOI: 10.1167/10.7.552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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61
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Denison R, Hillenbrand S, Silver M. Separate contributions of magno- and parvocellular streams to perceptual selection during binocular rivalry. J Vis 2010. [DOI: 10.1167/10.7.355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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62
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Landau A, Kosovicheva A, Silver M. Interactions of sustained spatial attention and surround suppression: an SSVEP study. J Vis 2010. [DOI: 10.1167/10.7.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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63
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Prinzmetal W, Rokem A, Landau A, Wallace D, Silver M, D'Esposito M. The D2 dopamine receptor agonist bromocriptine enhances voluntary but not involuntary spatial attention in humans. J Vis 2010. [DOI: 10.1167/10.7.155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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64
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Dispirito AA, Silver M, Voss L, Tuovinen OH. Flagella and pili of iron-oxidizing thiobacilli isolated from a uranium mine in northern ontario, Canada. Appl Environ Microbiol 2010; 43:1196-200. [PMID: 16346016 PMCID: PMC244205 DOI: 10.1128/aem.43.5.1196-1200.1982] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Five strains of Thiobacillus ferrooxidans, which included three recent isolates from a uranium mine, possessed flagella. Three of the strains had several pili per cell. The dimensions, fine structure, and orientation of the flagella were different. Both polar and peritrichous flagella were observed, indicating strain-dependent ultrastructural variation in acidophilic thiobacilli. Neither flagella nor pili were detected in eight other strains of T. ferrooxidans and two strains of Thiobacillus acidophilus by electron microscopy, although all of the cultures contained motile cells.
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Silver M. Distribution of iron-oxidizing bacteria in the nordic uranium tailings deposit, elliot lake, ontario, Canada. Appl Environ Microbiol 2010; 53:846-52. [PMID: 16347328 PMCID: PMC203767 DOI: 10.1128/aem.53.4.846-852.1987] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Iron-oxidizing bacteria are present within the top 2 m (but not always at the surface) and near the water table-capillary fringe of the vegetated Nordic uranium deposit, Elliot Lake, Ontario, Canada. They are distributed uniformly in the top 0.5 m of unvegetated tailings. The locations of these bacteria correlate with zones of pyrite oxidation as delineated in previous studies by the formation of soluble iron and sulfate. Heterotrophic bacteria are also present in the tailings, with greatest concentrations at the surface and near the water table-capillary fringe. Sulfate-reducing bacteria were detected in the soil and peat at the base of the tailings. The results of this study suggest that the establishment of vegetation directly upon the tailings surface does not arrest bacterial pyrite oxidation.
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Rimkunas V, Crosby K, Kelly M, Silver M, Hincman K, Polakiewicz R, Li D, Zhou X, Haack H. Frequencies of ALK and ROS in NSCLC FFPE tumor samples utilizing a highly specific immunohistochemistry-based assay and FISH analysis. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.10536] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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67
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Bressler D, Silver M. The effects of spatial attention and population receptive field size estimation on fMRI topographic mapping signals. J Vis 2010. [DOI: 10.1167/8.6.803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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68
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Rokem A, Sanghvi S, Silver M. Motion adaptation bandwidth anisotropies in the human visual system. J Vis 2010. [DOI: 10.1167/7.15.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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69
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Lauritzen T, Shenhav A, D'Esposito M, Silver M. fMRI coherency analysis reveals feedforward progression of visual responses in human early visual cortex. J Vis 2010. [DOI: 10.1167/7.15.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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70
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Landau A, Prinzmetal W, Robertson L, Silver M. Neural mechanisms of voluntary and involuntary attention. J Vis 2010. [DOI: 10.1167/9.8.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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71
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Bressler D, Silver M. Attention improves response reliability by decreasing noise: Reduction in the amplitude of fluctuations of fMRI signal at non-stimulus frequencies using periodic retinotopic mapping stimuli. J Vis 2010. [DOI: 10.1167/9.8.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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72
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Rokem A, Garg D, Landau A, Prinzmetal W, Silver M. Effects of cholinergic enhancement on voluntary and involuntary visuospatial attention in humans. J Vis 2010. [DOI: 10.1167/9.8.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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73
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Rokem A, Sanghvi S, Silver M. A model of V1-to-MT connectivity accounts for motion perception anisotropies in the human visual system. J Vis 2010. [DOI: 10.1167/8.6.1030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Fowden AL, Ralph MM, Silver M. Nutritional regulation of uteroplacental prostaglandin production and metabolism in pregnant ewes and mares during late gestation. EXPERIMENTAL AND CLINICAL ENDOCRINOLOGY 2009; 102:212-21. [PMID: 7995343 DOI: 10.1055/s-0029-1211285] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Prostaglandins (PGs) are produced by a variety of uteroplacental tissues during pregnancy and are released into the fetal fluid sacs and both the uterine and umbilical circulations. Uterine PG output increases towards term and is enhanced by maternal undernutrition in pregnant ewes and mares. In both species, withdrawal of food but not water for 30-48 h increases uterine venous PG levels and the uterine venous arterial concentration differences in PGE and 13, 14, dihydro-15-keto-prostaglandin F2 alpha (PGFM), the stable metabolite of PGF2 alpha. The increments in uterine V-A concentration differences in PGE and PGFM increase towards term and are associated with raised plasma PG levels in the fetal circulation. The PG changes observed during fasting are closely related to the fall in plasma glucose and the rise in plasma FFA in peripheral plasma. When normal metabolite levels are restored either by refeeding or glucose infusion, there is a rapid fall in PG levels with a narrowing of the uterine V-A concentration differences in the ewe and mare. When the data from all the animals are combined, there is an inverse correlation between uterine glucose uptake and PGFM output in both the pregnant ewe and mare. The availability of glucose and FFA to the gravid uterus therefore has an important role in controlling uteroplacental PG production and metabolism in late gestation although the specific steps in biochemical pathways regulated by these metabolites remain unclear. In the ewe, fasting increases uterine contractility and leads to early delivery of viable lambs in animals close to term (> 95% gestation), whereas in the mare it causes premature delivery of non-viable foals in most animals in late gestation (> 80% gestation). Nutritionally induced changes in uteroplacental PG production and metabolism therefore have important consequences for the outcome of pregnancy and may have a pivotal role in the induction of labour both before and at normal term.
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Silver M. Placental progestagens in the sheep and horse and the changes leading to parturition. EXPERIMENTAL AND CLINICAL ENDOCRINOLOGY 2009; 102:203-11. [PMID: 7995342 DOI: 10.1055/s-0029-1211284] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Placental progestagen production and metabolism during pregnancy, the changes which precede parturition and the extent of fetal involvement in the latter processes are compared in the sheep and the horse. Neither species requires the presence of a corpus luteum for maintenance of the latter part of pregnancy, but the mechanisms involved in placental progesterone/progestagen production are very different in the two species. In sheep the primary product is progesterone (P4), levels of which are high in the maternal but not the fetal circulations. By contrast, in the mare P4 is not detectable in maternal blood after 200 days gestation although it is present in the placenta and fetal circulation. A range of P4 metabolites (primarily 5 alpha-pregnanes) are produced by the equine placenta, while in the fetus pregnenolone and its metabolites are the predominant progestagens. In sheep the prepartum endocrine cascade in which the rise in fetal cortisol stimulates enzyme changes in the placenta so that P4 declines and estrogens and prostaglandins eventually rise, is fairly well established compared with the events preceding delivery in the mare. In the latter species there is a gradual rise in progestagens for 10-20 days before term, at a time when the fetal adrenal is relatively quiescent and unresponsive to ACTH i.e. fetal cortisol levels are low. In the last 24-48 h before delivery maternal progestagens fall, just after fetal plasma cortisol concentrations begin to escalate. The ways in which maternal and fetal prepartum endocrine changes may be interrelated and the possibility of a fetal trigger to parturition in the mare are discussed.
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