The Egyptian Cardiothoracic Surgeon (ECTS - E-Journal)
Not a member yet
46902 research outputs found
Sort by
Reactive Transport of Chemicals in Unsaturated Soils: Numerical Model Development and Verification
No full textIL-1alpha induces angiogenesis in brain endothelial cells in vitro: implications for brain angiogenesis after acute injury
No full textInflammation is a major contributor to neuronal injury and is associated with poor outcome after acute brain injury such as stroke. The pro-inflammatory cytokine interleukin (IL)-1 is a critical regulator of cerebrovascular inflammation after ischemic injury, mainly through action of both of its isoforms, IL-1α and IL-1β, at the brain endothelium. In contrast, the differential action of these ligands on endothelial activation and post-stroke angiogenesis is largely unknown. Here, we demonstrate that IL-1α is chronically elevated in the brain after experimental stroke suggesting that it is present during post-stroke angiogenic periods. Furthermore, we demonstrate that IL-1α is a potent mediator of endothelial activation and inducer of angiogenic markers in endothelial cells in vitro. Using brain endothelial cell lines, we found that IL-1α was significantly more potent than IL-1β at inducing endothelial cell activation, as measured by expression of the pro-angiogenic chemokine CXCL-1. IL-1α also induced strong expression of the angiogenic mediator IL-6 in a concentration-dependent manner. Furthermore, IL-1α induced significant proliferation and migration of endothelial cells, and promoted formation of tube-like structures that are established key hallmarks of angiogenesis in vitro. Finally, all of those responses were blocked by the IL-1 receptor antagonist (IL-1RA). In conclusion, our data highlights a potential new role for IL-1 in brain repair mechanisms and identifies IL-1α as a potential new therapy to promote post-stroke angiogenesis. Inflammation is a major contributor to neuronal injury and is associated with poor outcome after neurotrauma. We demonstrate that cytokine IL-1α is chronically elevated in the brain after experimental stroke suggesting that it is present chronically post-stroke. We demonstrate that IL-1α is a potent mediator of endothelial activation and inducer of angiogenic markers in endothelial cells. Our data highlights a new role for IL-1 in brain repair mechanisms and identifies IL-1α as a potential therapy to promote post-stroke angiogenesis.</p
Diversity between mammalian tolloid proteinases: Oligomerisation and non-catalytic domains influence activity and specificity
No full textThe mammalian tolloid family of metalloproteinases is essential for tissue patterning and extracellular matrix assembly. The four members of the family: bone morphogenetic protein-1 (BMP-1), mammalian tolloid (mTLD), tolloid-like (TLL)-1 and TLL-2 differ in their substrate specificity and activity levels, despite sharing similar domain organization. We have previously described a model of substrate exclusion by dimerisation to explain differences in the activities of monomeric BMP-1 and dimers of mTLD and TLL-1. Here we show that TLL-2, the least active member of the tolloid family, is predominantly monomeric in solution, therefore it appears unlikely that substrate exclusion via dimerisation is a mechanism for regulating TLL-2 activity. X-ray scattering and electron microscopy structural and biophysical analyses reveal an elongated shape for the monomer and flexibility in the absence of calcium. Furthermore, we show that TLL-2 can cleave chordin in vitro, similar to other mammalian tolloids, but truncated forms of TLL-2 mimicking BMP-1 are unable to cleave chordin. However, both the N- and C-terminal non-catalytic domains from all mammalian tolloids bind chordin with high affinity. The mechanisms underlying substrate specificity and activity in the tolloid family are complex with variation between family members and depend on both multimerisation and substrate interaction
The microstructure of a graphene-reinforced tennis racquet
No full textThe microstructure of a graphene-reinforced tennis racquet has been analysed using a combination of optical microscopy and Raman spectroscopy. It is shown that the main structural components in the racquet frame are high-strength carbon fibres in an epoxy resin matrix. It is also found that graphene-based nanoparticles are used to reinforce resin-rich regions in the shaft of the racquet at the discontinuity in the fibre tows, where the handle is joined to the racquet head. From a detailed analysis of the relative positions and intensities of the Raman G and 2D bands, it is demonstrated that the nanoparticles employed in the racquet are most probably graphite nanoplatelets which have been added to improve the mechanical properties of the resin-rich regions. The nomenclature used for describing graphene-based materials is also discussed in the context of this present study
Book Review: Clive Barnett, Paul Cloke, Nick Clarke, Alice Malpass Globalizing Responsibility: The Political Rationalities of Ethical Consumption
No full textTough choices: School behaviour management and institutional context
No full textIn the light of recent disciplinary reform in U.S. and U.K. schools academic attention has increasingly focused on school punishment. Drawing on interviews with school staff in alternative and mainstream schools in the U.S. and the U.K., we highlight differences in understandings and practices of school discipline. We argue that, in both countries, there is a mismatch between mainstream schools and alternative schools regarding approaches to punishment, techniques employed to manage student behaviour, and supports given to students. We raise questions about the impact of these mismatches on children’s experiences and the potential for school disciplinary reform to achieve lasting results
From Lone Wolves to Relational Reindeer:Sustainability of Anthropological Myths and Methods in Contemporary Northern Communities
No full textThis chapter examines how a new methodological approach, peer observation of research, was used as part of a comparative, ethnographic study of social resilience in Alaska and Siberia. The approach evolved through the collaboration of two researchers working in two different regions of the Arctic. Breaking from what has become a standard auto-ethnographic or self-reflexive enterprise in anthropology, our study aimed to document the collaborative ethnographic interaction from multiple perspectives and positions. We present two fieldwork episodes demonstrating the process and potential utility of a peer observation method for social researchers working in collaboration with indigenous communities and people in the Arctic. Peer observation of research reveals: (1) the ways in which our methods and models of collaborative research are relational and negotiated within an indigenous community and cultural context and (2) the degree to which kinship and association influences our ethnographic outcomes in a fieldwork setting leading to productive points of orientation and disorientation.<br/