Neil Chadborn

PTEN couples Sema3A signalling to growth cone collapse

Distinct changes in glycogen synthase kinase-3 (GSK-3) signalling can regulate neuronal morphogenesis including the determination and maintenance of axonal identity, and are required for neurotrophin-mediated axon elongation. In addition, we have previously shown a dependency on GSK-3 activation in the semaphorin 3A (Sema3A)-mediated growth-cone-collapse response of sensory neurons. Regulation of GSK-3 activity involves the intermediate signalling lipid phosphatidylinositol 3,4,5-trisphosphate, which can be modulated by phosphatidylinositol 3-kinase (PI3K) and the tumour suppressor PTEN. We report here the involvement of PTEN in the Sema3A-mediated growth cone collapse. Sema3A suppresses PI3K signalling concomitant with the activation of GSK-3, which depends on the phosphatase activity of PTEN. PTEN is highly enriched in the axonal compartment and the central domain of sensory growth cones during axonal extension, where it colocalises with microtubules. Following exposure to Sema3A, PTEN accumulates rapidly at the growth cone membrane suggesting a mechanism by which PTEN couples Sema3A signalling to growth cone collapse. These findings demonstrate a dependency on PTEN to regulate GSK-3 signalling in response to Sema3A and highlight the importance of subcellular distributions of PTEN to control growth cone behaviour.

Ligand-Dependent Conformational Equilibria of Serum Albumin Revealed by Tryptophan Fluorescence Quenching

Ligand-dependent structural changes in serum albumin are suggested to underlie its role in physiological solute transport and receptor-mediated cellular selection. Evidence of ligand-induced (oleic acid) structural changes in serum albumin are shown in both time-resolved and steady-state fluorescence quenching and anisotropy measurements of tryptophan 214 (Trp214). These studies were augmented with column chromatography separations. It was found that both the steady-state and time-resolved Stern-Volmer collisional quenching studies of Trp214 with acrylamide pointed to the existence of an oleate-dependent structural transformation. The bimolecular quenching rate constant of defatted human serum albumin, 1.96 x 10(9) M-1 s-1, decreased to 0.94 x 10(9) M-1 s-1 after incubation with oleic acid (9:1). Furthermore, Stern-Volmer quenching studies following fractionation of the structural forms by hydrophobic interaction chromatography were in accordance with this interpretation. Time-resolved fluorescence anisotropy measurements of the Trp214 residue yielded information of motion within the protein together with the whole protein molecule. Characteristic changes in these motions were observed after the binding of oleate to albumin. The addition of oleate was accompanied by an increase in the rotational diffusion time of the albumin molecule from approximately 22 to 33.6 ns. Within the body of the protein, however, the rotational diffusion time for Trp214 exhibited a slight decrease from 191 to 182 ps and was accompanied by a decrease in the extent of the angular motion of Trp214, indicating a transition after oleate binding to a more spatially restricted but less viscous environment.

Changes in iron-regulatory gene expression occur in human cell culture models of Parkinson's disease.

BACKGROUND Neuronal iron accumulation is thought to be relevant to the pathogenesis of Parkinsons disease (PD), although the mechanism remains elusive. We hypothesized that neuronal iron uptake may be stimulated by functional mitochondrial iron deficiency. OBJECTIVE To determine firstly whether the mitochondrial toxin, 1-methyl-4-phenylpyridinium iodide (MPP(+)), results in upregulation of iron-import proteins and transporters of iron into the mitochondria, and secondly whether similar changes in expression are induced by toxins with different mechanisms of action. METHODS We used quantitative PCR and Western blotting to investigate expression of the iron importers, divalent metal transporter, transferrin receptor 1 and 2 (TfR1 and TfR2) and mitoferrin-2 and the iron exporter ferroportin in differentiated SH-SY5Y cells exposed to three different toxins relevant to PD, MPP(+), paraquat (a free radical generator) and lactacystin (an inhibitor of the ubiquitin-proteasome system (UPS)). RESULTS MPP(+) resulted in increased mRNA and protein levels of genes involved in cellular iron import and transport into the mitochondria. Similar changes occurred following exposure to paraquat, another inducer of oxidative stress. Lactacystin also resulted in increased TfR1 mRNA levels, although the other changes were not found. CONCLUSION Our results support the hypothesis of a functional mitochondrial iron deficit driving neuronal iron uptake but also suggest that differences exist in neuronal iron handling induced by different toxins.

Direct measurement of local raised subplasmalemmal calcium concentrations in growth cones advancing on an N-cadherin substrate

We have used the membrane‐localized calcium probe fura‐piperazine‐C12H25 (FFP‐18) to examine cytosolic calcium concentrations in a volume close to the plasmalemma. Although promotion of axon outgrowth by cell adhesion molecules requires extracellular calcium and is correlated with an opening of plasmalemmal channels, conventional indicators cannot detect a change in the calcium concentration in such stimulated growth cones. We have examined calcium signalling in chick retinal ganglion cell growth cones extending along stripes of N‐cadherin. Subplasmalemmal calcium concentrations, reported by FFP‐18, were significantly higher in these growth cones than in neighbouring growth cones on either fibronectin or polylysine. In contrast, the bulk cytosolic calcium concentration throughout the growth cone, as measured by Fura‐2, was identical in growth cones on and off the N‐cadherin stripes. Our results suggest that guidance cues can use extremely local calcium signals to control pathfinding decisions.

Using comprehensive geriatric assessment for quality improvements in healthcare of older people in UK care homes: protocol for realist review within Proactive Healthcare of Older People in Care Homes (PEACH) study

Introduction Care home residents are relatively high users of healthcare resources and may have complex needs. Comprehensive geriatric assessment (CGA) may benefit care home residents and improve efficiency of care delivery. This is an approach to care in which there is a thorough multidisciplinary assessment (physical and mental health, functioning and physical and social environments) and a care plan based on this assessment, usually delivered by a multidisciplinary team. The CGA process is known to improve outcomes for community-dwelling older people and those in receipt of hospital care, but less is known about its efficacy in care home residents. Methods and analysis Realist review was selected as the most appropriate method to explore the complex nature of the care home setting and multidisciplinary delivery of care. The aim of the realist review is to identify and characterise a programme theory that underpins the CGA intervention. The realist review will extract data from research articles which describe the causal mechanisms through which the practice of CGA generates outcomes. The focus of the intervention is care homes, and the outcomes of interest are health-related quality of life and satisfaction with services; for both residents and staff. Further outcomes may include appropriate use of National Health Service services and resources of older care home residents. The review will proceed through three stages: (1) identifying the candidate programme theories that underpin CGA through interviews with key stakeholders, systematic search of the peer-reviewed and non-peer-reviewed evidence, (2) identifying the evidence relevant to CGA in UK care homes and refining the programme theories through refining and iterating the systematic search, lateral searches and seeking further information from study authors and (3) analysis and synthesis of evidence, involving the testing of the programme theories. Ethics and dissemination The PEACH project was identified as service development following submission to the UK Health Research Authority and subsequent review by the University of Nottingham Research Ethics Committee. The study protocols have been reviewed as part of good governance by the Nottinghamshire Healthcare Foundation Trust. We aim to publish this realist review in a peer-reviewed journal with international readership. We will disseminate findings to public and stakeholders using knowledge mobilisation techniques. Stakeholders will include the Quality Improvement Collaboratives within PEACH study. National networks, such as British Society of Gerontology and National Care Association will be approached for wider dissemination. Trial registration number The realist review has been registered on International Prospective Register of Systematic Reviews (PROSPERO 2017: CRD42017062601).

Cycling- Exercise or trying to stop pollution: Methods to explore children's agency in health and climate change

The media have framed obesity and climate change as problems the next generation will inherit. The two issues have overlapping causative factors and temporalities, and share pre-emptive approaches, focusing on children. The aim of our study was to develop an approach to explore childrens perceptions of the interconnectedness of health and climate that avoids creating anxiety or apathy. Drawing on research with 10- and 11-year-old children living in urban areas, we reflect on our development of methods devised to engage children to talk about issues linking climate change and health, specifically their opportunities to participate in activities such as cycling or walking to school. Children were variously given photographic prompts, asked to draw and write about their thoughts and feelings, draw maps of their route to school, and create posters. We found that these methods enabled children to actively engage with climate change issues, evidencing individual and collective agency both in group work and their understandings of the possibilities of their own present and future role in low carbon healthy lifestyles.

“Our biggest killer”: multimodal discourse representations of dementia in the British press

ABSTRACT A recent (2016) Office for National Statistics report stated that dementia is now “the leading cause of death” in England and Wales. Ever fixated with the syndrome (an unfailingly newsworthy topic), the British press was quick to respond to the bulletin, consistently headlining that dementia was the nation’s “biggest killer,” while (re)formulating other aspects of the report in distorting and emotive metaphorical terms. In this paper we examine how the media, through use of a recurring set of linguistic and visual semiotic tropes, portrayed dementia as an agentive entity, a “killer,” which remorselessly attacks its “victims.” Such a broadly loaded and sensationalist representation, we argue, not only construed dementia as a direful and pernicious disease, but also, crucially, obscured the personal and social contexts in which the syndrome is understood and experienced (not least by people with dementia themselves). This intensely lurid type of representation not only fails to address the ageist misinformation and common misunderstandings that all too commonly surround dementia, but is also likely to exacerbate the stress and depression frequently experienced by people with dementia and their families.

A systematic mapping review of outdoor activities and mobility in care homes

Background: Cancer is considered as chronic condition, especially in the older people. Prevalence of cancer is especially high in the Nordic countries and Mediterranean countries. People with cance ...Background: To measure the attitudes towards older people and perceptions of working with older people of undergraduate health and social care students in 5 European countries. Questionnaires are one of the most widely used data collection methods. The use of questionnaires constructed and validated in a setting to other setting is an essential aspect in international studies, which have as main objective to compare and deduce similarities and differences within different contexts. There are three main aspects in validation, the linguistic, the cultural and statistic validation,all these three aspects are essential during theprocess. Materials: Two questionnaires were used: Attitudes towards Older People Scale (Kogan1966) and Students’ Perception of Working with Older People Scale (Nolan et al, 2006). Methods: Five Countries were involved in the study namely Ireland, Finland, Germany, Latvia, and Italy. Back translation methodology was used in order to translate questionnaire (Linguistic and cultural validation) while a Cronbach was calculate to assess internal validity (statistic validation). Results: Students (n = 955) completed the two questionnaires. Students’ Perception of Working with Older People Scale, shows a 0.81 a Cronbach for all sample, for Ireland 0.84, Germany, 0.79, Italy 0.79, Finland 0.84 and Latvia 0.59, Attitudes towards Older People Scale shows a 0.83 a Cronbach for all sample,for Ireland 0.85, Germany, 0.83, Italy 0.62, Finland 0.86 and Latvia 0.74. Respondents were generally positive towards older people with few differences between countries. Those with least experience with older people displayed more negative attitudes. Significant relationships were found between positive 50

Qualitative study investigating the commissioning process for older people's services provided by third sector organisations: SOPRANO study protocol

Introduction The commissioning of third sector services for older people may influence the quality, availability and coordination of services for older people. The SOPRANO study aims to understand the relationships between and processes of commissioning bodies and third sector organisations providing health and social care services for older people. Methods and analysis This qualitative study will be based in the East Midlands region of England. An initial scoping survey of commissioners will give an overview of services to maintain the health and well-being of older people in the community that are commissioned. Following this, semistructured interviews will be conducted with 4 sample groups: health and social care commissioners, service provider managers, service provider case workers and older service users. A sample size of 10–15 participants in each of the 4 groups is expected to be sufficient to reach data saturation, resulting in a final expected sample size of 40–60 participants. Informed consent will be gained from all participants, and those unable to provide informed consent will be excluded. The interview data will be analysed by 2 researchers using framework content analysis. Ethics and dissemination Approval for the study has been gained from the University of Nottingham School of Medicine ethical review board, and the relevant approvals have been gained from the National Health Service (NHS) research and development departments for interviewing NHS staff. Early engagement with a wide range of stakeholders will ensure that the research findings are extensively disseminated to relevant stakeholders (including commissioners and third sector providers) in an accessible format using the extensive communication networks available to the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care CLAHRCs (applied health research organisations covering all of England). The study will also be disseminated through academic routes such as conference presentations and journal papers.