• Oesophageal stenting: Status quo and future challenges.

      Kaltsidis, Harry; Mansoor, Wasat; Park, Jung-Hoon; Song, Ho-Young; Edwards, Derek W.; Laasch, Hans-Ulrich (2018-06-11)
      Oesophageal stents are widely used for palliating dysphagia from malignant obstruction. They are also used with increasing frequency in the treatment of oesophageal perforation, as well as benign strictures from a variety of causes. Improved oncological treatments have led to prolonged survival of patients treated with palliative intent; as a consequence, stents need to function and last longer in order to avoid repeat procedures. There is also increasing need for meticulous procedure planning, careful selection of the device most appropriate for the individual patient and planned follow-up. Furthermore, as more patients are cured, there will be more issues with resultant long-term side-effects, such as recalcitrant strictures due to radiotherapy or anastomotic scarring, which will have to be addressed. Stent design needs to keep up with the progress of cancer treatment, in order to offer patients the best possible long-term result. This review article attempts to illustrate the changing realities in oesophageal stenting, differences in current stent designs and behaviour, as well as the pressing need to refine and modify devices in order to meet the new challenges.
    • Office workers’ experiences of attempts to reduce sitting-time: An exploratory, mixed- methods uncontrolled intervention pilot study

      Dewitt, Stephen; Hall, Jennifer; Smith, Lee; Buckley, John P.; Biddle, Stuart J. H.; Mansfield, Louise; Gardner, Benjamin; University of Chester (BMC Springer Nature, 2019-06-25)
      Background: Office workers typically sit for most of the workday, which has been linked to physical and mental ill- health and premature death. This mixed-methods study sought to identify barriers and facilitators to reducing sitting and increasing standing among office workers who received an intervention prototype (the ‘ReSiT [Reducing Sitting Time] Study’). The intervention comprised a sit-stand workstation and tailored advice to enhance motivation, capability and opportunity to displace sitting with standing. Methods: Twenty-nine UK university office workers (aged ≥18y, working ≥3 days per week, most time spent at a seated desk) participated in a 13-week uncontrolled study. They were initially monitored for one-week. In a subsequent face-to-face consultation, participants received sitting time feedback from a prior one-week monitoring period, and selected from a set of tailored sitting-reduction techniques. Quantitative data comprising sitting, standing and stepping time, which were objectively monitored for 7 consecutive days across three post- intervention timepoints, were descriptively analysed. Qualitative data, from semi-structured interviews conducted at 1, 6 and 12-weeks post-intervention, were thematically analysed. Results: Compared to baseline, mean sitting time decreased at weeks 1, 6 and 12 by 49.7mins, 118.2mins, and 109.7mins respectively. Despite prior concerns about colleagues’ reactions to standing, many reported encouragement from others, and standing could be equally conducive to social interaction or creating private, personal space. Some perceived less cognitively-demanding tasks to be more conducive to standing, though some found standing offered a valued break from challenging tasks. Participants prioritised workload over sitting reduction and were more likely to stand after rather than during work task completion. Temporary context changes, such as holidays, threatened to derail newfound routines. Conclusions: Our findings emphasise the importance of understanding workers’ mental representations of their work, and the social functions of sitting and standing in the workplace. Workplace intervention developers should incorporate a pre-intervention sitting time monitoring period, encourage workers to identify personally meaningful tasks and cues for standing, and build organisational support for sitting-reduction. We will use these insights to refine our intervention for self-administered delivery. Trial registration: ISRCTN29395780 (registered 21 November 2016). Keywords: Sedentary behaviour, Workplace, Qualitative, Occupational health
    • Oxygen Costs of the Incremental Shuttle Walk Test in Cardiac Rehabilitation Participants: An Historical and Contemporary Analysis

      Buckley, John P.; Cardoso, Fernando M. F.; Birkett, Stefan T.; Sandercock, Gavin R. H.; University Centre Shrewsbury (Springer, 2016-04-07)
      Background The incremental shuttle walk test (ISWT) is a standardised assessment for cardiac rehabilitation. Three studies have reported oxygen costs (VO2)/metabolic equivalents (METs) of the ISWT. In spite of classic rep- resentations from these studies graphically showing curvilinear VO2 responses to incremented walking speeds, linear regression techniques (also used by the American College of Sports Medicine [ACSM]) have been used to estimate VO2. Purpose The two main aims of this study were to (i) re- solve currently reported discrepancies in the ISWT VO2- walking speed relationship, and (ii) derive an appropriate VO2 versus walking speed regression equation. Methods VO2 was measured continuously during an ISWT in 32 coronary heart disease [cardiac] rehabilitation (CHD-CR) participants and 30 age-matched controls. Results Both CHD-CR and control group VO2 responses were curvilinear in nature. For CHD-CR VO2 = 4.4- e0.23 9 walkingspeed (km/h). The integrated area under the curve (iAUC) VO2 across nine ISWT stages was greater in the CHD-CR group versus the control group (p \ 0.001): & John P. Buckley j.buckley@chester.ac.uk 1 (±86) ml􏰀kg-1􏰀min-1􏰀km􏰀h-1; con- trol = 316 (±52) ml􏰀kg-1􏰀min-1􏰀km􏰀h-1. Conclusions CHD-CR group vs. control VO2 was up to 30 % greater at higher ISWT stages. The curvilinear nature of VO2 responses during the ISWT concur with classic studies reported over 100 years. VO2 estimates for walking using linear regression models (including the ACSM) clearly underestimate values in healthy and CHD-CR par- ticipants, and this study provides a resolution to this when the ISWT is used for CHD-CR populations.
    • Palliative opioid use, palliative sedation and euthanasia: reaffirming the distinction.

      Schofield, Guy; Baker, Idris; Bullock, Rachel; Clare, Hannah; Clark, Paul; Willis, Derek; Gannon, Craig; George, Rob (2019-06-20)
      We read with interest the extended essay published from Riisfeldt and are encouraged by an empirical ethics article which attempts to ground theory and its claims in the real world. However, such attempts also have real-world consequences. We are concerned to read the paper's conclusion that clinical evidence weakens the distinction between euthanasia and normal palliative care prescribing. This is important. Globally, the most significant barrier to adequate symptom control in people with life-limiting illness is poor access to opioid analgesia. Opiophobia makes clinicians reluctant to prescribe and their patients reluctant to take opioids that might provide significant improvements in quality of life. We argue that the evidence base for the safety of opioid prescribing is broader than that presented, restricting the search to palliative care literature produces significant bias as safety experience and literature for opioids and sedatives exists in many fields. This is not acknowledged in the synthesis presented. By considering additional evidence, we reject the need for agnosticism and reaffirm that palliative opioid prescribing is safe. Second, palliative sedation in a clinical context is a poorly defined concept covering multiple interventions and treatment intentions. We detail these and show that continuous deep palliative sedation (CDPS) is a specific practice that remains controversial globally and is not considered routine practice. Rejecting agnosticism towards opioids and excluding CDPS from the definition of routine care allows the rejection of Riisfeldt's headline conclusion. On these grounds, we reaffirm the important distinction between palliative care prescribing and euthanasia in practice. [Abstract copyright: © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.]
    • Patients’ Perspectives of Oral and Injectable Type 2 Diabetes Medicines, Their Body Weight and Medicine-Taking Behavior in the UK: A Systematic Review and Meta-Ethnography

      Psarou, Aikaterini; Cooper, Helen; Wilding, John P. H. (Springer Healthcare, 2018-08-17)
      AbstractThe aim of this review is to identify peoples’ perspectives of their glucose-lowering and anti-obesity drugs in relation to diabetes and weight control and to explore how these views affect medication adherence. Theoretical perspectives associated with medicine-taking behavior are also explored. The systematic review was based on a meta-ethnography of qualitative studies identified through a search of 12 medical and social science databases and subsequent citation searches. The quality of all studies was assessed. Sixteen studies were included with data from 360 UK individuals. No relevant studies were identified which focused on anti-obesity and non-insulin injectable drugs. The review revealed that the patients’ perspectives and emotional state were influenced by starting and/or changing to a new glucose-lowering medicine. These were also influenced by prior medication experience, disease perceptions and interactions with clinicians. Despite reports of positive experiences with and positive perceptions of medicines, and of participation in strategies to regain life control, medication non-adherence was common. Accepting glucose-lowering medicines impacted on the individual’s perception of lifestyle changes, and it was notable that weight loss was not perceived as a strategy to support diabetes management. Synthesis revealed that more than one theory is required to explain medicine-taking behavior. New insights into the underlying factors of poor adherence and the specific practical issues identified in this review can help in the development of patient-centered interventions.Funding: Diabetes UK.
    • Prescribing in mental health practice - the balancing act

      Green, Ben; University of Chester (SAGE, 2013-01-15)
      This book chapter aims to discuss the potential impact of psychiatric pharmacology on the physical health of people with mental health problems; discuss the potential impact of medical prescibing on those with mental health problems; and reflect on the role of the mental health practitioner in medication management.
    • Pro-Inflammatory Priming of Umbilical Cord Mesenchymal Stromal Cells Alters the Protein Cargo of Their Extracellular Vesicles

      Hyland, Mairead; Mennan, Claire; Wilson, Emma; Clayton, Aled; Kehoe, Oksana; School of Medicine, Keele University, School of Pharmacy and Bioengineering at the RJAH Orthopaedic Hospital, Chester Medical School, School of Medicine, Cardiff
      Umbilical cord mesenchymal stromal cells (UCMSCs) have shown an ability to modulate the immune system through the secretion of paracrine mediators, such as extracellular vesicles (EVs). However, the culture conditions that UCMSCs are grown in can alter their secretome and thereby affect their immunomodulatory potential. UCMSCs are commonly cultured at 21% O2 in vitro, but recent research is exploring their growth at lower oxygen conditions to emulate circulating oxygen levels in vivo. Additionally, a pro-inflammatory culture environment is known to enhance UCMSC anti-inflammatory potential. Therefore, this paper examined EVs from UCMSCs grown in normal oxygen (21% O2), low oxygen (5% O2) and pro-inflammatory conditions to see the impact of culture conditions on the EV profile. EVs were isolated from UCMSC conditioned media and characterised based on size, morphology and surface marker expression. EV protein cargo was analysed using a proximity-based extension assay. Results showed that EVs had a similar size and morphology. Differences were found in EV protein cargo, with pro-inflammatory primed EVs showing an increase in proteins associated with chemotaxis and angiogenesis. This showed that the UCMSC culture environment could alter the EV protein profile and might have downstream implications for their functions in immunomodulation.
    • Promoting patient utilization of outpatient cardiac rehabilitation: A joint International Council and Canadian Association of Cardiovascular Prevention and Rehabilitation position statement

      Santiago de Araújo Pio, Carolina; Varnfield, Marlien; Sarrafzadegan, Nizal; Beckie, Theresa M.; Babu, Abraham S.; Baidya, Sumana; Buckley, John P.; Chen, Ssu-Yuan; Gagliardi, Anna; Heine, Martin; et al. (Elsevier, 2019-07-04)
      Background: Cardiac Rehabilitation (CR) is a recommendation in international clinical practice guidelines given its’ benefits, however use is suboptimal. The purpose of this position statement was to translate evidence on interventions that increase CR enrolment and adherence into implementable recommendations. Methods: The writing panel was constituted by representatives of societies internationally concerned with preventive cardiology, and included disciplines that would be implementing the recommendations. Patient partners served, as well as policy-makers. The statement was developed in accordance with AGREE II, among other guideline checklists. Recommendations were based on our update of the Cochrane review on interventions to promote patient utilization of CR. These were circulated to panel members, who were asked to rate each on a 7-point Likert scale in terms of scientific acceptability, actionability, and feasibility of assessment. A web call was convened to achieve consensus and confirm strength of the recommendations (based on GRADE). The draft underwent external review and public comment. Results: The 3 drafted recommendations were that to increase enrolment, healthcare providers, particularly nurses (strong), should promote CR to patients face-to-face (strong), and that to increase adherence part of CR could be delivered remotely (weak). Ratings for the 3 recommendations were 5.95±0.69 (mean ± standard deviation), 5.33±1.12 and 5.64±1.08, respectively. Conclusions: Interventions can significantly increase utilization of CR, and hence should be widely applied. We call upon cardiac care institutions to implement these strategies to augment CR utilization, and to ensure CR programs are adequately resourced to serve enrolling patients and support them to complete programs.
    • The protein phosphatase 4 - PEA15 axis regulates the survival of breast cancer cells

      Mohammed, Hiba N.; Pickard, Mark R.; Mourtada-Maarabouni, Mirna; Keele University; University of Chester (Elsevier, 2016-06-15)
      BACKGROUND: The control of breast cell survival is of critical importance for preventing breast cancer initiation and progression. The activity of many proteins which regulate cell survival is controlled by reversible phosphorylation, so that the relevant kinases and phosphatases play crucial roles in determining cell fate. Several protein kinases act as oncoproteins in breast cancer and changes in their activities contribute to the process of transformation. Through counteracting the activity of oncogenic kinases, the protein phosphatases are also likely to be important players in breast cancer development, but this class of molecules is relatively poorly understood. Here we have investigated the role of the serine/threonine protein phosphatase 4 in the control of cell survival of breast cancer cells. METHODS: The breast cancer cell lines, MCF7 and MDA-MB-231, were transfected with expression vectors encoding the catalytic subunit of protein phosphatase 4 (PP4c) or with PP4c siRNAs. Culture viability, apoptosis, cell migration and cell cycle were assessed. The involvement of phosphoprotein enriched in astrocytes 15kDa (PEA15) in PP4c action was investigated by immunoblotting approaches and by siRNA-mediated silencing of PEA15. RESULTS: In this study we showed that PP4c over-expression inhibited cell proliferation, enhanced spontaneous apoptosis and decreased the migratory and colony forming abilities of breast cancer cells. Moreover, PP4c down-regulation produced complementary effects. PP4c is demonstrated to regulate the phosphorylation of PEA15, and PEA15 itself regulates the apoptosis of breast cancer cells. The inhibitory effects of PP4c on breast cancer cell survival and growth were lost in PEA15 knockdown cells, confirming that PP4c action is mediated, at least in part, through the de-phosphorylation of apoptosis regulator PEA15. CONCLUSION: Our work shows that PP4 regulates breast cancer cell survival and identifies a novel PP4c-PEA15 signalling axis in the control of breast cancer cell survival. The dysfunction of this axis may be important in the development and progression of breast cancer.
    • Psychiatric responses to traumatic events

      Mason-Whitehead, Elizabeth; Green, Ben (University of Chester, 2015-01)
      The main aims and objectives of this Ph.D. by publication are: • To analyse, explore and contextualise the psychiatric response to trauma and aetiological issues • To analyse and explore the management of Post-Traumatic Stress Disorder (PTSD) • To critically analyse the wider historical, legal and political management of mental disorder. Five peer-reviewed publications from recent years are presented on the theme of psychiatric responses to traumatic events. Two papers focus on the aetiology, (where the Oxford definition of aetiology is the ‘cause, set of causes, or manner of causation of a condition’), of PTSD and therefore consider the injuries that cause PTSD and also potential vulnerability factors (Green & Griffiths, 2013). These papers contain a mixture of quantitative and qualitative methods – examining characteristics such as psychological conceptions of risk in relation to illness duration within a case series for instance and a comparative statistical analysis of birth order in differing samples. Two papers consider modern aspects of the treatment of PTSD – including pharmacological and psychotherapeutic and difficulties and use a methodology of a structured review of the literature including analysis of the evidence base for trauma-focused Cognitive Behavioural Therapy (CBT) including Numbers Needed to Treat (NNT) (Green 2013, Green 2014). A final paper looks at admissions trends for PTSD and a range of other mental disorders and uses a statistical analysis of national data looking for emerging trends against a historical and political background of changes in the management of mental disorder (Green & Griffiths, 2014). These recent papers are set in context against older papers from a career which has spanned epidemiological research into risk factors for depression over six years, writings about psychopharmacology, and planned future research into birth order and domestic violence, and an editorial for the British Journal of General Practice (Green & Gowans, 2014) seeking to promote future epidemiological research into unmet mental health needs in the community. The papers can be viewed as being within the context of a continuum of research interests and publications (represented diagrammatically below in Figure One). In the narrative text I refer to this earlier work and also explain my plans for progress in terms of future research and publications, thus setting the work in this Ph.D. by publication in context within a continuing pattern of interests.
    • PWE-055 Stigma in inflammatory bowel disease: building resilience

      Dibley, Lesley; Norton, C.; Mason-Whitehead, Elizabeth; Kings College; University of Chester (BMJ Publishing Group, 2015-06-01)
      qualitative study aimed to: a) understand the experience of stigma in people with IBD and whether stigma derives from the bowel disorder diagnosis or from related FI; b) understand how stigma affects social, personal and emotional wellbeing, and how people with IBD manage these issues. Using purposive stratified sampling, 40 members of a UK IBD charity were recruited. Participants self-identified as having FI or not, and feeling stigmatised or not.
    • Quantifying the impact of tissue metabolism on solute transport in feto-placental microvascular networks

      Nye, Gareth; Erlich, Alexander; Brownbill, Paul; Chernyavsky, Igor; Jenson, Oliver; University of Manchester (Royal Society, 2019-08-16)
      The primary exchange units in the human placenta are terminal villi, in which fetal capillary networks are surrounded by a thin layer of villous tissue, separating fetal from maternal blood. To understand how the complex spatial structure of villi influences their function, we use an image-based theoretical model to study the effect of tissue metabolism on the transport of solutes from maternal blood into the fetal circulation. For solute that is taken up under first-order kinetics, we show that the transition between flow-limited and diffusion-limited transport depends on two new dimensionless parameters defined in terms of key geometric quantities, with strong solute uptake promoting flow-limited transport conditions. We present a simple algebraic approximation for solute uptake rate as a function of flow conditions, metabolic rate and villous geometry. For oxygen, accounting for nonlinear kinetics using physiological parameter values, our model predicts that villous metabolism does not significantly impact oxygen transfer to fetal blood, although the partitioning of fluxes between the villous tissue and the capillary network depends strongly on the flow regime
    • Reciprocal regulation of GAS5 lncRNA levels and mTOR inhibitor action in prostate cancer cells.

      Yacqub-Usman, Kiren; Pickard, Mark R.; Williams, Gwyn T.; Keele University (Wiley, 2015-02-03)
      BACKGROUND: New therapies are required for castrate-resistant prostate cancer (CRPC), and growth-arrest specific 5 (GAS5) lncRNA, which riborepresses androgen receptor action, may offer novel opportunities in this regard. This lncRNA promotes the apoptosis of prostate cancer cells and its levels decline as prostate cancer cells acquire castrate-resistance, so that enhancing GAS5 expression may improve the effectiveness of chemotherapies. Since GAS5 is a member of the 5' terminal oligopyrimidine gene family, we have examined mTOR inhibition as a strategy to increase GAS5 expression. Furthermore, we have determined if GAS5 itself mediates the action of mTOR inhibitors, as demonstrated for other chemotherapeutic agents in prostate cancer cells. METHODS: The effects of mTOR inhibitors on GAS5 lncRNA levels and cell growth were determined in a range of prostate cancer cell lines. Transfection of cells with GAS5 siRNAs and plasmid constructs was performed to determine the involvement of GAS5 lncRNA in mTOR inhibitor action. RESULTS: First generation mTORC1, combined mTORC1/mTORC2 and dual PI3K/mTOR inhibitors all increased cellular GAS5 levels and inhibited culture growth in androgen-dependent (LNCaP) and androgen-sensitive (22Rv1) cell lines, but not in androgen-independent (PC-3 and DU 145) cell lines. The latter exhibited low endogenous GAS5 expression, and GAS5 silencing in LNCaP and 22Rv1 cells decreased the sensitivity to mTOR inhibitors, whereas transfection of GAS5 lncRNA sensitized PC-3 and DU 145 cells to these agents. CONCLUSION: mTOR inhibition enhances GAS5 transcript levels in certain prostate cancer cell lines. This selectivity is likely to be related to endogenous GAS5 expression levels, since GAS5 lncRNA is itself required for mTOR inhibitor action in prostate cancer cells.
    • Regulation of apoptosis by long non-coding RNA GAS5 in breast cancer cells: implications for chemotherapy.

      Pickard, Mark R.; Williams, Gwyn T.; Keele University, United Kingdom (2014-05-01)
      The putative tumour suppressor and apoptosis-promoting gene, growth arrest-specific 5 (GAS5), encodes long ncRNA (lncRNA) and snoRNAs. Its expression is down-regulated in breast cancer, which adversely impacts patient prognosis. In this preclinical study, the consequences of decreased GAS5 expression for breast cancer cell survival following treatment with chemotherapeutic agents are addressed. In addition, functional responses of triple-negative breast cancer cells to GAS5 lncRNA are examined, and mTOR inhibition as a strategy to enhance cellular GAS5 levels is investigated. Breast cancer cell lines were transfected with either siRNA to GAS5 or with a plasmid encoding GAS5 lncRNA and the effects on breast cancer cell survival were determined. Cellular responses to mTOR inhibitors were evaluated by assaying culture growth and GAS5 transcript levels. GAS5 silencing attenuated cell responses to apoptotic stimuli, including classical chemotherapeutic agents; the extent of cell death was directly proportional to cellular GAS5 levels. Imatinib action in contrast, was independent of GAS5. GAS5 lncRNA promoted the apoptosis of triple-negative and oestrogen receptor-positive cells but only dual PI3K/mTOR inhibition was able to enhance GAS5 levels in all cell types. Reduced GAS5 expression attenuates apoptosis induction by classical chemotherapeutic agents in breast cancer cells, providing an explanation for the relationship between GAS5 expression and breast cancer patient prognosis. Clinically, this relationship may be circumvented by the use of GAS5-independent drugs such as imatinib, or by restoration of GAS5 expression. The latter may be achieved by the use of a dual PI3K/mTOR inhibitor, to improve apoptotic responses to conventional chemotherapies.
    • The regulation of osteoprotegerin and dickkopf-1 production in osteoblastic cells

      McCarthy, Helen S. (University of ChesterCharles Salt Centre, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Trust in Oswestry, 2011-06)
      Bone is a highly specialised living tissue and has both mechanical and metabolical functions. Remodelling of the bone ensures a healthy bone mass and is regulated by a trio of secreted proteins, namely receptor-activator of NFKB (RANK), receptor-activator of NFKB ligand (RANKL) and osteoprotegerin (OPG). OPG, a major regulator of osteoclastogenesis, bone resorption and vascular calcification, is produced by various cell types including mesenchymally derived cells, particularly osteoblastic cells. Wnt signalling also plays a role in maintaining healthy bone mass. Dickkopf- 1 (DKK-1) is a soluble inhibitor of Wnt signalling and its excessive expression contributes to bone loss in rheumatoid arthritis and multiple myeloma. Recently, NDKK-1 has been demonstrated to be over-produced in osteoblasts of patients with Paget's disease of bone (PDB). The osteoblastic cell lines MG63 and Saos-2 were subjected to a series of different growth factors, hormones and cytokines to investigate the production of OPG, DKK-1 and the expression of various Wnt proteins. These results demonstrate that during standard culture conditions, both OPG and DKK-1 production in osteoblastic cells depend on a factor present in serum. Serum deprivation resulted in the up-regulation of Wnt4 and Wnt11, while down-regulating the expression of Wnt7b. Serum-induced OPG and DKK-1 production and Wnt expression was found to be regulated via a number of different signalling pathways. OPG production and expression was stimulated by platelet-derived growth factor-AB (PDGF-AB) not only in MG63 and Saos-2 osteosarcoma cells, but also a mouse pre-osteoblastic cell line (MC3T3-E1) and human bone marrow stromal cells (BMSC). PDGF-AB was shown to act through the PDGF receptor, PKC, PI3K, ERK and P38 and not via NFKB or JNK. PDGF isoforms AA, BB and AB demonstrated a similar stimulation of OPG production. The importance of PDGF in fracture healing suggests a role for OPG production in countering bone resorption during the early phase of this process. BIO, an inhibitor of canonical Wnt signalling resulted in the down-regulation of DKK-1 and the up-regulation of WntSa. Phorbol ester (PE), a known stimulator of PKC resulted in the up-regualtion of DKK-1, Wnt4, WntTa and Wnt16. The effects of PE were inhibited by bisindolymaleamide but not staurosporine. DKK-1 production, but not expression, was observed to be stimulated by calcium along with an up-regulation of WntTb and a down-regulation of WntWa and Wnt11. Incubation of pre-stimulated cells with Triton-X demonstrated the ability of calcium to increase DKK-1 secretion. DKK-1 was shown to be significantly elevated in the serum of PDB patients compared to healthy controls and did not correlate with ALP levels. Immunohistochemistry demonstrated that DKK-1 production is increased in both osteoblasts and fibrotic cells within the marrow cavity in PDB patients compared to fracture callus. B-catenin was found to be localised to intercellular membranes of plump osteoblasts, demonstrating its alternate role as a cell adhesion protein. DKK-1 therefore may be a useful biomarker of PDB and that Dkk-1 may play a central role in the aetiology of PDB. In summary, the results presented in this thesis have investigated the ways in which OPG and DKK-1 production in osteoblastic cells can be modulated with various effectors and the effect of Wnt signalling. These results may therefore be beneficial to increase the understanding of bone biology, improve fracture repair and generate further research into the role DKK-1 and the osteoblast in the aetiology of PDB to enable improved treatments to be developed.
    • Regulation of the cell cycle and cell death by protein phosphatase 4 in breast cancer cell lines

      Mohammed, Hiba N.; Pickard, Mark R.; Williams, Gwyn T.; Mourtada-Maarabouni, Mirna; Keele University, United Kingdom (NCRI Cancer Conference 2014 Abstracts, 2014)
      Background At the molecular level, cell death is often regulated by the level of phosphorylation of particular proteins, i.e. by the balance of between opposing kinase and phosphatase activities on those proteins. Protein phosphatase 4 (PP4) is a PP2A-related serine/threonine phosphatase. PP2A has already been implicated in the control of cell proliferation, cell cycle and tumorigenesis. Using a functional expression cloning strategy, we have previously identified the catalytic subunit of PP4 (PP4c) as an important gene influencing the regulation of both apoptosis and cell proliferation in human leukaemic cell lines and in normal lymphocytes. The aims of this study were to examine the effects of PP4c overexpression and silencing on the cell death and survival of breast cancer cell lines. Method MCF7 and MDA-MB-231 cells were transfected with pcDNA3.1 encoding PP4c (pcDNA3-PP4c) or siRNAs to different PP4c sequences. Cells transfected with scrambled siRNA or empty vector were considered as controls. Culture viability, apoptosis and cell cycle were assessed post transfection. Results In MCF7 and metastatic MDA-MB-231 cells, PP4c over-expression exerted an inhibitory effect on cell proliferation, enhanced spontaneous apoptosis and decreased their colony forming ability. Conversely, siRNA mediated silencing of PP4 enhanced the proliferation and survival of MCF7 and MDA-MB-231 cells, affected cell cycle kinetics by enhancing the proportion of cells in S and G2/M phases, increased the colony forming ability and stimulated the anchorage independent growth. Conclusion PP4c promotes cell death and inhibits proliferation in breast cells, suggestive of a role of PP4c as tumour suppressor gene. Down regulation of PP4c expression increases cell survival, proliferation and anchorage independent growth of breast cancer cells, indicating a potential link between the PP4c expression levels, tumorigenesis and metastasis.
    • The ReSiT study (reducing sitting time): rationale and protocol for an exploratory pilot study of an intervention to reduce sitting time among office workers

      Gardner, Benjamin; Dewitt, Stephen; Smith, Lee; Biddle, Stuart J. H.; Mansfield, Louise; Buckley, John P.; University Centre Shrewsbury (BMC, 2017-11-28)
      Background: Desk-based workers engage in long periods of uninterrupted sitting time, which has been associated with morbidity and premature mortality. Previous workplace intervention trials have demonstrated the potential of providing sit-stand workstations, and of administering motivational behaviour change techniques, for reducing sitting time. Yet, few studies have combined these approaches or explored the acceptability of discrete sitting-reduction behaviour change strategies. This paper describes the rationale for a sitting-reduction intervention that combines sit-stand workstations with motivational techniques, and procedures for a pilot study to explore the acceptability of core intervention components among university office workers. Methods: The intervention is based on a theory and evidence-based analysis of why office workers sit, and how best to reduce sitting time. It seeks to enhance motivation and capability, as well as identify opportunities, required to reduce sitting time. Thirty office workers will participate in the pilot study. They will complete an initial awareness-raising monitoring and feedback task and subsequently receive a sit-stand workstation for a 12-week period. They will also select from a ‘menu’ of behaviour change techniques tailored to self-declared barriers to sitting reduction, effectively co-producing and personally tailoring their intervention. Interviews at 1, 6, and 12 weeks post-intervention will explore intervention acceptability. Discussion: To our knowledge, this will be the first study to explore direct feedback from office workers on the acceptability of discrete tailored sitting-reduction intervention components that they have received. Participants’ choice of and reflections on intervention techniques will aid identification of strategies suitable for inclusion in the next iteration of the intervention, which will be delivered in a self-administered format to minimise resource burden.
    • Retroviral insertional mutagenesis implicates E3 ubiquitin ligase RNF168 in the control of cell proliferation and survival

      Kizilors, Aytug; Pickard, Mark R.; Schulte, Cathleen E.; Yacqub-Usman, Kiren; McCarthy, Nicola J.; Gan, Shu-Uin; Darling, David; Gäken, Joop; Williams, Gwyn T.; Farzaneh, Farzin; et al. (Portland Press, 2017-08-14)
      The E3 ubiquitin ligase RNF168 is a ring finger protein that has previously been identified to play an important regulatory role in the repair of double-strand DNA breaks. In the present study, an unbiased forward genetics functional screen in mouse granulocyte/ macrophage progenitor cell line FDCP1 has identified E3 ubiquitin ligase RNF168 as a key regulator of cell survival and proliferation. Our data indicate that RNF168 is an important component of the mechanisms controlling cell fate, not only in human and mouse haematopoietic growth factor-dependent cells, but also in the human breast epithelial cell line MCF-7. These observations therefore suggest that RNF168 provides a connection to key pathways controlling cell fate, potentially through interaction with PML nuclear bodies and/or epigenetic control of gene expression. Our study is the first to demonstrate a critical role for RNF168 in the in the mechanisms regulating cell proliferation and survival, in addition to its well-established role in DNA repair.
    • The role of MAPK signalling pathways in leukemic cell death

      Williams, John; Ireland, Elyse; Cordingley, Michelle (University of Chester, 2018-09-18)
      Mitogen-activated protein kinase (MAPK) signalling pathways are important signalling pathways involved in mediating various cellular processes including both cell survival and cell death. The c-Jun N-terminal kinase (JNK) pathway, the p38 pathway and the extracellular signal-regulated kinase (ERK1/2) pathway are three well-studied conventional MAPK signalling pathways. Previous research has shown these MAPK signalling pathways play an important role in the development and progression of leukaemia and in the response of leukemic cells to therapy. Whilst it appears to be well established that the constitutive activation of ERK mediates leukemic cell survival, the roles of the JNK and p38 signalling pathways in leukemogenesis, in particular the role in acute myeloid leukaemia (AML), are less well understood. This thesis investigates the role of the JNK, p38 and ERK signalling pathways in leukemic death. MAPK signalling pathways were targeted in the U937 monocytic cell line using small molecule MAPK inhibitors in combination with various cell stressors: UV light, chemotherapeutic agents (doxorubicin and vincristine) and heat treatment. The effects on cell death were examined using plate-based assays, flow cytometry and fluorescence microscopy. Preliminary investigations were also performed in peripheral blood mononuclear cells (PBMCs) from healthy individuals to allow a comparison to non-leukemic cells. Results show inhibition of ERK signalling in U937 cells induced cell death and ERK signalling had little effect on UV-induced and heat treatment-induced cell death. JNK signalling and p38 signalling provided protection against UVinduced cell death in both U937 cells and in PBMCs from healthy individuals. JNK and p38 signalling mediated cell survival in response to heat treatment to a certain extent. JNK signalling was required for the induction of cell death induced by doxorubicin whereas p38 signalling provided a level of protection against doxorubicin-induced cell death. U937 cells were found to be more sensitive to vincristine treatment than PBMCs from healthy individuals and the activation of JNK and p38 signalling was essential for vincristine-induced cell death in U937 cells. Taken together, the results presented in this thesis demonstrate that the roles of the JNK, p38 and ERK signalling pathways in leukemic cell death are stimuli-specific. This highlights the importance of understanding the involvement of particular pathways in the response to specific chemotherapeutic agents, in order to provide effective leukaemia therapy. Therapeutic inhibition of MAPK signalling pathways to increase the sensitivity of leukemic cells to chemotherapy could be beneficial when MAPKs are involved in providing protection against chemotherapy-induced cell death. For chemotherapies which require MAPK activation for cell death, failure to activate MAPKs may provide a mechanism for chemoresistance. Therapeutic methods to enhance activation of the pathways provide a possible approach to increase the susceptibility of leukemic cells to death.
    • Second generation tyrosine kinase inhibitors prevent disease progression in high-risk (high CIP2A) chronic myeloid leukaemia patients.

      Lucas, Claire; Harris, Robert; Holcroft, Alison; Scott, Laura; Carmell, Natasha; McDonald, Elizabeth; Polydoros, Fotis; Clark, Richard (Nature, 2015-03-13)
      High cancerous inhibitor of PP2A (CIP2A) protein levels at diagnosis of chronic myeloid leukaemia (CML) are predictive of disease progression in imatinib-treated patients. It is not known whether this is true in patients treated with second generation tyrosine kinase inhibitors (2G TKI) from diagnosis, and whether 2G TKIs modulate the CIP2A pathway. Here, we show that patients with high diagnostic CIP2A levels who receive a 2G TKI do not progress, unlike those treated with imatinib (P=<0.0001). 2G TKIs induce more potent suppression of CIP2A and c-Myc than imatinib. The transcription factor E2F1 is elevated in high CIP2A patients and following 1 month of in vivo treatment 2G TKIs suppress E2F1 and reduce CIP2A; these effects are not seen with imatinib. Silencing of CIP2A, c-Myc or E2F1 in K562 cells or CML CD34+ cells reactivates PP2A leading to BCR-ABL suppression. CIP2A increases proliferation and this is only reduced by 2G TKIs. Patients with high CIP2A levels should be offered 2G TKI treatment in preference to imatinib. 2G TKIs disrupt the CIP2A/c-Myc/E2F1 positive feedback loop, leading to lower disease progression risk. The data supports the view that CIP2A inhibits PP2Ac, stabilising E2F1, creating a CIP2A/c-Myc/E2F1 positive feedback loop, which imatinib cannot overcome.