64,456 research outputs found
The role of gangliosides in fenretinide-induced apoptosis of neuroblastoma
No full textFenretinide is thought to induce apoptosis via increases in ceramide levels but the mechanisms of ceramide generation and the link between ceramide and subsequent apoptosis in neuroblastoma cells is unclear. In SH-SY5Y neuroblastoma cells, evidence suggests that acid sphingomyelinase activity is essential for the induction of ceramide and apoptosis in response to fenretinide. Downstream of ceramide, apoptosis in response to fenretinide is mediated by increased glucosylceramide synthase activity resulting in increased levels of gangliosides GD3 and GD2 via GD3 synthase. GD3 is a key signalling intermediate leading to apoptosis via the activation of 12-Lipoxygenase, and the parallel induction of GD2 suggests that fenretinide might enhance the response of neuroblastoma to therapy with anti-GD2 antibodies
Performance Anxiety: An exploration of spectacle, spectatorship and moral panic in the twenty-first century
Get PDFIn the last decade there has been an explosion of new technologies that enable discourse, power and truth formations to be produced, contested and dispersed. As communication and information technologies continue to evolve, so too do the ways in which individuals construct identities and form communities. The notion of a moral panic is utilised to describe those critical moments in time and space when social norms are perceived to be under threat. I suggest that the complex interplay of spectacle, spectatorship and moral panic involved in such instances can be both conceptualised and interrogated as performance. This dissertation draws upon two distinct performance paradigms – one theoretical and the other practical – to inform a critical reading of three significant ‘social events’ of the last decade: the drug-trafficking trial of Australian woman Schapelle Corby in Indonesia in 2005, the end-of-life legal case focused on American woman Terri Schiavo, which culminated in 2005, and the race relations associated with the ‘Redfern riots’ which occurred in Sydney in 2004. Informed by a range of theoretical positions from Michel Foucault, Zygmunt Bauman, Giorgio Agamben, Judith Butler, Baz Kershaw, and Michael Hardt and Antonio Negri, this dissertation fleshes out contemporary understandings of mediatised spectacle and spectatorship, with the aim of revealing the ways in which they contribute to creating and sustaining moral panic. A critical finding of the dissertation is that through both subjectification and objectification processes the central players and the spectators become indivisible from the spectacle itself, thus maintaining the interweaving cycle of spectator, spectacle and moral panic. By exploring the ways in which people interpret and respond to social phenomena, the possibilities for performance and social theory can be extended
Octahedral cation ordering in olivine at high temperature. II: an in situ neutron powder diffraction study on synthetic MgFeSiO4 (Fa50)
No full textThe partitioning of Fe and Mg between the M1 and M2 octahedral sites of olivine has been investigated by in situ time-of-flight neutron powder diffraction. The degree of M-cation order was determined from direct measurements of site occupancies in a synthetic sample of Fo50Fa50 heated to 1250 °C at the Fe-FeO oxygen buffer. Fe shows slight preference for M1 at temperatures below about 600 °C, progressively disordering on heating to this temperature. Above 630 °C, the temperature at which site preferences cross over (Tcr), Fe preferentially occupies M2, becoming progressively more ordered into M2 on increasing temperature. The cation-ordering behaviour is discussed in relation to the temperature dependence of the M1 and M2 site geometries, and it is suggested that vibrational entropy, crystal field effects and changes in bond characteristics play a part in the cross-over of partitioning behaviour. The temperature dependence of site ordering is modelled using a Landau expansion of the free energy of ordering of the type ΔG = -hQ + gTQ + 2-a (T- Tc)Q2 + 4-b Q4, with a/h = 0.00406 K-1, b/h = 2.3, Tc = 572 K and g/h = 0.00106 K-1. These results suggest that the high-temperature ordering behaviour across the forsterite-fayalite join will have a bearing on the activity-composition relations of this important rock-forming mineral, and indicate that Fe-Mg olivine solid solutions become less ideal as temperature increases
Molecular mechanisms of fenretinide-induced apoptosis of neuroblastoma
No full textSynthetic retinoids such as fenretinide [N-(4-hydroxyphenyl)retinamide] induce apoptosis of neuroblastoma cells, act synergistically with chemotherapeutic drugs, and may provide opportunities for novel approaches to neuroblastoma therapy. Fenretinide-induced cell death of neuroblastoma cells is caspase dependent and results in the release of cytochrome c from mitochondria independently of changes in permeability transition. This is mediated by a signaling pathway characterized by the generation of reactive oxygen species (ROS) via 12-lipoxygenase (12-LOX), and an oxidative-stress-dependent induction of the transcription factor, GADD153 and the BCL2-related protein BAK. Upstream events of fenretinide-induced signaling involve increased levels of ceramide as a result of increased sphingomyelinase activity, and the subsequent metabolism of ceramide to gangliosides via glucosylceramide synthase and GD3 synthase. These gangliosides may be involved in the regulation of 12-LOX leading to oxidative stress and apoptosis via the induction of GADD153 and BAK. The targeting of sphingomyelinases or downstream effectors such as 12-LOX or GADD153 may present novel approaches for the development of more effective and selective drugs for neuroblastoma therapy
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
Bak: A Downstream Mediator of Fenretinide-Induced Apoptosis of SH-SY5Y Neuroblastoma Cells
No full textUnlike 13-cis-retinoic acid, the synthetic retinoid fenretinide [N-(4-
hydroxyphenyl)retinamide] induces apoptosis of neuroblastoma cells by
mechanisms involving retinoic acid receptors and oxidative stress. After
screening a cDNA array for apoptosis-related genes, the Bcl2-related
protein Bak was identified as a fenretinide-inducible gene in SH-SY5Y
neuroblastoma cells, and this was confirmed by Western blotting and flow
cytometry. Although fenretinide acts synergistically in vitro with chemotherapeutic
drugs, these drugs did not induce Bak expression. Retinoic
acid receptor antagonists did not block the induction of Bak by fenretinide.
Conversely, Bak induction was blocked by the antioxidant vitamin C.
Overexpression of Bak increased apoptosis in both the presence and
absence of fenretinide, whereas expression of antisense Bak inhibited
fenretinide-induced apoptosis. Bak expression was also induced in cells
overexpressing the stress-induced transcription factor GADD153, but Bak
expression was inhibited in cells expressing an antisense GADD153 construct.
These results suggest that Bak is a downstream mediator of an
oxidative stress pathway leading to apoptosis of SH-SY5Y neuroblastoma
cells in response to fenretinid
Bak: a downstream mediator of fenretinide-induced apoptosis of SH-SY5Y neuroblastoma cells.
No full textUnlike 13-cis-retinoic acid, the synthetic retinoid fenretinide [N-(4-hydroxyphenyl)retinamide] induces apoptosis of neuroblastoma cells by mechanisms involving retinoic acid receptors and oxidative stress. After screening a cDNA array for apoptosis-related genes, the Bcl2-related protein Bak was identified as a fenretinide-inducible gene in SH-SY5Y neuroblastoma cells, and this was confirmed by Western blotting and flow cytometry. Although fenretinide acts synergistically in vitro with chemotherapeutic drugs, these drugs did not induce Bak expression. Retinoic acid receptor antagonists did not block the induction of Bak by fenretinide. Conversely, Bak induction was blocked by the antioxidant vitamin C. Overexpression of Bak increased apoptosis in both the presence and absence of fenretinide, whereas expression of antisense Bak inhibited fenretinide-induced apoptosis. Bak expression was also induced in cells overexpressing the stress-induced transcription factor GADD153, but Bak expression was inhibited in cells expressing an antisense GADD153 construct. These results suggest that Bak is a downstream mediator of an oxidative stress pathway leading to apoptosis of SH-SY5Y neuroblastoma cells in response to fenretinide
Bak: a downstream mediator of fenretinide-induced apoptosis of SH-SY5Y neuroblastoma cells
No full textUnlike 13-cis-retinoic acid, the synthetic retinoid fenretinide [N-(4-hydroxyphenyl)retinamide] induces apoptosis of neuroblastoma cells by mechanisms involving retinoic acid receptors and oxidative stress. After screening a cDNA array for apoptosis-related genes, the Bcl2-related protein Bak was identified as a fenretinide-inducible gene in SH-SY5Y neuroblastoma cells, and this was confirmed by Western blotting and flow cytometry. Although fenretinide acts synergistically in vitro with chemotherapeutic drugs, these drugs did not induce Bak expression. Retinoic acid receptor antagonists did not block the induction of Bak by fenretinide. Conversely, Bak induction was blocked by the antioxidant vitamin C. Overexpression of Bak increased apoptosis in both the presence and absence of fenretinide, whereas expression of antisense Bak inhibited fenretinide-induced apoptosis. Bak expression was also induced in cells overexpressing the stress-induced transcription factor GADD153, but Bak expression was inhibited in cells expressing an antisense GADD153 construct. These results suggest that Bak is a downstream mediator of an oxidative stress pathway leading to apoptosis of SH-SY5Y neuroblastoma cells in response to fenretinide
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
Get PDFThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
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