Multi-parametric metabolic assessment of cells under stress conditions

Glycolysis, glutaminolysis, the Krebs cycle and oxidative phosphorylation are the main metabolic pathways. Exposing cells to key metabolic substrates (glucose, glutamine and pyruvate); investigation of the contribution of substrates in stress conditions such as uncoupling and hypoxia was conducted. Glycolysis, O2 consumption, O2 and ATP levels and hypoxia inducible factor (HIF) signalling in PC12 cells were investigated. Upon uncoupling with FCCP mitochondria were depolarised similarly in all cases, but a strong increase in respiration was only seen in the cells fed on glutamine with either glucose or pyruvate. Inhibition of glutaminolysis reversed the glutamine dependant effect. Differential regulation of the respiratory response to FCCP by metabolic environment suggests mitochondrial uncoupling has a potential for substrate-specific inhibition of cell function. At reduced O2 availability (4 % and 0 % O2), cell bioenergetics and local oxygenation varied depending on the substrate composition. Results indicate that both supply and utilisation of key metabolic substrates can affect the pattern of HIF-1/2α accumulation by differentially regulating iO2¬, ATP levels and Akt/Erk/AMPK pathways. Inhibition of key metabolic pathways can modulate HIF regulatory pathways, metabolic responses and survival of cancer cells in hypoxia. Hypoxia leads to transcriptional activation, by HIF, of pyruvate dehydrogenase (PDH) kinase which phosphorylates and inhibits PDH, a mitochondrial enzyme that converts pyruvate into acetyl-CoA. The levels of PDH (total and phosphorylated), PDH kinase and HIF-1α were analysed in HCT116 and HCT116 SCO2-/- (deficient in complex IV of the respiratory chain) grown under 20.9 % and 3 % O2. Data indicate that regulation of PDH can occur in a manner independent of the HIF-1/PDH kinase 1 axis, mitochondrial respiration and the demand for acetyl-CoA. Collectively these results can be applied to many diseases; reduced nutrient supply and O2 during ischemia/stroke, hypoglycaemia in diabetes mellitus and cancer associated changes in uncoupling protein expression levels.

The use of PET-CT in the assessment of patients with colorectal carcinoma.

Colorectal cancer is the third most commonly diagnosed cancer, accounting for 53,219 deaths in 2007 and an estimated 146,970 new cases in the USA during 2009. The combination of FDG PET and CT has proven to be of great benefit for the assessment of colorectal cancer. This is most evident in the detection of occult metastases, particularly intra- or extrahepatic sites of disease, that would preclude a curative procedure or in the detection of local recurrence. FDG PET is generally not used for the diagnosis of colorectal cancer although there are circumstances where PET-CT may make the initial diagnosis, particularly with its more widespread use. In addition, precancerous adenomatous polyps can also be detected incidentally on whole-body images performed for other indications; sensitivity increases with increasing polyp size. False-negative FDG PET findings have been reported with mucinous adenocarcinoma, and false-positive findings have been reported due to inflammatory conditions such as diverticulitis, colitis, and postoperative scarring. Therefore, detailed evaluation of the CT component of a PET/CT exam, including assessment of the entire colon, is essential.

Assessment in primary education in Ireland

This doctoral study examines assessment in primary education in the Republic of Ireland. The nature and purpose of assessment offer an insight into the values which are prioritised by an education system. In 2011, in the Republic of Ireland, the Department of Education and Skills (DES) published a strategy aiming to improve standards of literacy and numeracy. The document, entitled, Literacy and numeracy for learning and life: the national strategy to improve literacy and numeracy for children and young people 2011-2020, contains improvement targets as measured by standardised tests. It also mandates the increased use of standardised tests in primary education, and directs that aggregated scores should be reported to both Boards of Management and the DES. The study is framed by the theoretical perspectives of Michel Foucault and Pierre Bourdieu. Both of these commentators examine social policy and practice in an effort to provide insight into the history and operation of social institutions. This study is especially influenced by Foucault’s archaeology and genealogy of knowledge, and his notion of governmentality. It is also particularly cognisant of Bourdieu’s thoughts on habitus, doxa and capital. The study contains reviews of literature in the areas of assessment, assessment policy, and assessment policy in Ireland. These reviews highlight current debate in each of these areas while also grounding this debate in an historical context. The dissertation contains four empirical sections. 1) It analyses policy documents prepared in the development of the published strategy as well as investigating the strategy itself. In so doing it is aware of the burgeoning influence of pan-national bodies on policy development. 2) A number of high profile policy makers were interviewed as part of the study and their views are interpreted in light of the findings of the literature reviews. 3) The perspective of teachers was sought through a questionnaire survey. This gathered data on these teachers’ views on the purpose of assessment as well as their actual practice. 4) Finally, children were also included as participants in this study. They were interviewed in focus groups and encouraged to contribute drawings as well on their views of assessment in primary school. Literacy and numeracy for learning and life is seen as a seminal document in Irish education. This study is significant in its analysis of original data from high profile policy makers, including two Ministers for Education and Skills. It is also significant in its inclusion of the perspectives of primary school pupils. Finally, the study considers the nature and role of assessment in a holistic manner by including the views of policy makers, teachers and pupils. The study notes that policy development in Ireland underwent a change in the preparation of Literacy and numeracy for learning and life and that international influences, while present, are also mediated to suit the local context. It also highlights a lack of clarity in the definition of assessment in primary education and argues that there is a lack of balance in the approaches that are prioritised. The study demonstrates that teachers are impacted by the strategy but that they also change it by focusing on their own concerns while using assessment tools. The children provide compelling evidence of the impact of assessment on the learner. The study shows how assessment tools (and school subjects) are valued with differing levels of importance by a variety of stakeholders.