The role of apoptosis in the development of AGM hematopoietic stem cells revealed by Bcl-2 overexpression

Apoptosis is an essential process in embryonic tissue remodeling and adult tissue homeostasis. Within the adult hematopoietic system, it allows for tight regulation of hematopoietic cell subsets. Previously, it was shown that B-cell leukemia 2 (Bcl-2) overexpression in the adult increases the viability and activity of hematopoietic cells under normal and/or stressful conditions. However, a role for apoptosis in the embryonic hematopoietic system has not yet been established. Since the first hematopoietic stem cells (HSCs) are generated within the aortagonad-mesonephros (AGM; an actively remodeling tissue) region beginning at embryonic day 10.5, we examined this tissue for expression of apoptosis-related genes and ongoing apoptosis. Here, we show expression of several proapoptotic and antiapoptotic genes in the AGM. We also generated transgenic mice overexpressing Bcl-2 under the control of the transcriptional regulatory elements of the HSC marker stem cell antigen-1 (Sca-1), to test for the role of cell survival in the regulation of AGM HSCs. We provide evidence for increased numbers and viability of Sca-1(+) cells in the AGM and subdissected midgestation aortas, the site where HSCs are localized. Most important, our in vivo transplantation data show that Bcl-2 overexpression increases AGM and fetal liver HSC activity, strongly suggesting that apoptosis plays a role in HSC development

Postprandial incorporation of EPA and DHA from transgenic Camelina sativa oil into blood lipids is equivalent to that from fish oil in healthy humans

Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are important components of cell membranes. Since humans have limited ability for EPA and DHA synthesis, these must be obtained from the diet, primarily from oily fish. Dietary EPA and DHA intakes are constrained by the size of fish stocks and by food choice. Seed oil from transgenic plants that synthesise EPA and DHA represents a potential alternative source of these fatty acids, but this has not been tested in humans. We hypothesised that incorporation of EPA and DHA into blood lipids from transgenic Camelina sativa seed oil (CSO) is equivalent to that from fish oil. Healthy men and women (18 to 30 years or 50 to 65 years) consumed 450 mg EPA plus DHA from either CSO or commercial blended fish oil (BFO) in test meals in a double blind, postprandial cross-over trial. There were no significant differences between test oils or sexes in EPA and DHA incorporation into plasma triacylglycerol, phosphatidylcholine or non-esterified fatty acids over 8 hours. There were no significant differences between test oils, age groups or sexes in postprandial VLDL, LDL or HDL sizes or concentrations. There were no significant differences between test oils in postprandial plasma TNFα, interleukin 6 or 10, or soluble intercellular cell adhesion molecule-1 concentrations in younger participants. These findings show that incorporation into blood lipids of EPA and DHA consumed as CSO was equivalent to BFO and that such transgenic plant oils are a suitable dietary source of EPA and DHA in humans

Research from therapeutic radiographers : an audit of research capacity within the UK

Research from Allied Health Professionals (AHPs) is anecdotally known to lag behind that of other professions. The developing research landscape within other therapies and internationally led us to question how UK practice in therapeutic radiography was developing. The aim of the survey was to audit research capacity across therapy radiography in the UK. Method: An electronic survey was sent to Radiotherapy Service Managers (RSM) and research leads in each of the radiotherapy centres in the UK. An adapted version of the 'Auditing Research Capacity' tool (ARC © tool) was used as the basis of the questionnaire. Results: A total of 45 RSM responded to the survey (67% response rate) and 30 Research radiographers (RR) (45% response rate). A total of 51 RR were in post equating to 40.3 whole time equivalents and averaging 1 RR per centre. Variation was evident in the commitment to the development of a research culture identified by practices such as linking research to the business planning cycle, inclusion of research in recruitment and advertising materials, or having a nominated therapeutic radiographer lead on research for the department. Over a third of responding centres did not have a research strategy and training for RRs was limited; specifically in areas such as writing funding bids, writing for publication and the research and governance process. Conclusion: A number of short and long-term strategies are proposed that should enhance a positive research culture and improve research capacity for therapeutic radiography led research. These include utilisation of the existing infrastructure provided by the National Institute for Health Research, a lead or co-ordinator for research activity with a remit to motivate others. Development of links and networks, and the development of a research strategy linked to wider Trust research priorities. The research strategy should include mentoring or developing appropriate research skills for those engaged in research (including higher degree qualifications). RSMs should also encourage peer-reviewed publications, and conference presentations from all staff to ensure research results are disseminated to the wider profession

Cell shape analysis of random tessellations based on Minkowski tensors

To which degree are shape indices of individual cells of a tessellation characteristic for the stochastic process that generates them? Within the context of stochastic geometry and the physics of disordered materials, this corresponds to the question of relationships between different stochastic models. In the context of image analysis of synthetic and biological materials, this question is central to the problem of inferring information about formation processes from spatial measurements of resulting random structures. We address this question by a theory-based simulation study of shape indices derived from Minkowski tensors for a variety of tessellation models. We focus on the relationship between two indices: an isoperimetric ratio of the empirical averages of cell volume and area and the cell elongation quantified by eigenvalue ratios of interfacial Minkowski tensors. Simulation data for these quantities, as well as for distributions thereof and for correlations of cell shape and volume, are presented for Voronoi mosaics of the Poisson point process, determinantal and permanental point processes, and Gibbs hard-core and random sequential absorption processes as well as for Laguerre tessellations of polydisperse spheres and STIT- and Poisson hyperplane tessellations. These data are complemented by mechanically stable crystalline sphere and disordered ellipsoid packings and area-minimising foam models. We find that shape indices of individual cells are not sufficient to unambiguously identify the generating process even amongst this limited set of processes. However, we identify significant differences of the shape indices between many of these tessellation models. Given a realization of a tessellation, these shape indices can narrow the choice of possible generating processes, providing a powerful tool which can be further strengthened by density-resolved volume-shape correlations.Comment: Chapter of the forthcoming book "Tensor Valuations and their Applications in Stochastic Geometry and Imaging" in Lecture Notes in Mathematics edited by Markus Kiderlen and Eva B. Vedel Jense