James Thomas
Institute of Education
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Publication
Featured researches published by James Thomas.
Hepatology | 2011
James Thomas; Caroline Pope; Davina Wojtacha; Andrew Robson; Timothy T. Gordon-Walker; Stephen N. Hartland; Marielle Van Deemter; David A. Hume; John P. Iredale; Stuart J. Forbes
Clinical studies of bone marrow (BM) cell therapy for liver cirrhosis are under way but the mechanisms of benefit remain undefined. Cells of the monocyte‐macrophage lineage have key roles in the development and resolution of liver fibrosis. Therefore, we tested the therapeutic effects of these cells on murine liver fibrosis. Advanced liver fibrosis was induced in female mice by chronic administration of carbon tetrachloride. Unmanipulated, syngeneic macrophages, their specific BM precursors, or unfractionated BM cells were delivered during liver injury. Mediators of inflammation, fibrosis, and regeneration were measured. Donor cells were tracked by sex‐mismatch and green fluorescent protein expression. BM‐derived macrophage (BMM) delivery resulted in early chemokine up‐regulation with hepatic recruitment of endogenous macrophages and neutrophils. These cells delivered matrix metalloproteinases‐13 and ‐9, respectively, into the hepatic scar. The effector cell infiltrate was accompanied by increased levels of the antiinflammatory cytokine interleukin 10. A reduction in hepatic myofibroblasts was followed by reduced fibrosis detected 4 weeks after macrophage infusion. Serum albumin levels were elevated at this time. Up‐ regulation of the liver progenitor cell mitogen tumor necrosis factor‐like weak inducer of apoptosis (TWEAK) preceded expansion of the progenitor cell compartment. Increased expression of colony stimulating factor‐1, insulin‐like growth factor‐1, and vascular endothelial growth factor also followed BMM delivery. In contrast to the effects of differentiated macrophages, liver fibrosis was not significantly altered by the application of macrophage precursors and was exacerbated by whole BM. Conclusion: Macrophage cell therapy improves clinically relevant parameters in experimental chronic liver injury. Paracrine signaling to endogenous cells amplifies the effect. The benefits from this single, defined cell type suggest clinical potential. (HEPATOLOGY 2011;)
Proceedings of the National Academy of Sciences of the United States of America | 2013
Tom Bird; Wei-Yu Lu; Luke Boulter; Sabrina Gordon-Keylock; Rachel A. Ridgway; Michael Williams; Jessica Taube; James Thomas; Davina Wojtacha; Adriana Gambardella; Owen J. Sansom; John P. Iredale; Stuart J. Forbes
Tissue progenitor cells are an attractive target for regenerative therapy. In various organs, bone marrow cell (BMC) therapy has shown promising preliminary results, but to date no definite mechanism has been demonstrated to account for the observed benefit in organ regeneration. Tissue injury and regeneration is invariably accompanied by macrophage infiltration, but their influence upon the progenitor cells is incompletely understood, and direct signaling pathways may be obscured by the multiple roles of macrophages during organ injury. We therefore examined a model without injury; a single i.v. injection of unfractionated BMCs in healthy mice. This induced ductular reactions (DRs) in healthy mice. We demonstrate that macrophages within the unfractionated BMCs are responsible for the production of DRs, engrafting in the recipient liver and localizing to the DRs. Engrafted macrophages produce the cytokine TWEAK (TNF-like weak inducer of apoptosis) in situ. We go on to show that recombinant TWEAK activates DRs and that BMC mediated DRs are TWEAK dependent. DRs are accompanied by liver growth, occur in the absence of liver tissue injury and hepatic progenitor cells can be isolated from the livers of mice with DRs. Overall these results reveal a hitherto undescribed mechanism linking macrophage infiltration to DRs in the liver and highlight a rationale for macrophage derived cell therapy in regenerative medicine.
British Journal of Cancer | 2007
D A Montgomery; K Krupa; Wilma Jack; G R Kerr; Ian Kunkler; James Thomas; J M Dixon
The guidelines for follow-up of breast cancer patients concentrate on the first 3–5 years, with either reduced frequency of visits or discharge after this. They also recommend mammography, but no evidence exists to inform frequency. We analyse treatable relapses in our unit from 1312 patients with early stage breast cancer treated by breast conserving surgery (BCS) and postoperative radiotherapy between 1991 and 1998 to assess appropriateness of the guidelines. A total of 110 treatable relapses were analysed. Treatable relapse developed at 1–1.5% per year throughout follow-up. Forty-eight relapses were in ipsilateral breast, 25 ipsilateral axilla, 35 contralateral breast, 2 both breasts simultaneously. Thirty-seven relapses (33.5%) were symptomatic, 56 (51%) mammographically detected, 15 (13.5%) clinically detected, 2 (2%) diagnosed incidentally. Mammography detected 5.37 relapses per 1000 mammograms. Patients with symptomatic or mammographically detected ipsilateral breast relapse had significantly longer survival from original diagnosis (P=0.0002) and from recurrence (P=0.0014) compared with clinically detected. Treatable relapse occurs at a constant rate for at least 10 years. Clinical examination detects a minority (13.5%). Relapse diagnosed clinically is associated with poorer outcome. Long-term follow-up based on regular mammography is warranted for all patients treated by BCS.
Liver International | 2011
Bianca G. Couto; Regina Coeli dos Santos Goldenberg; Lea Mirian Barbosa da Fonseca; James Thomas; Bianca Gutfilen; Célia Maria Coelho Resende; Feliciano Silva de Azevedo; Daniel Mercante; André L. Moreira Torres; Henrique Sérgio Moraes Coelho; Angelo Maiolino; Alessandra L. dos Anjos Alves; Juliana Dias; Maria Cláudia R. Moreira; Ana Luisa Sampaio; Maria Auxiliadora Jeunon Sousa; Tais Hanae Kasai-Brunswick; Sergio Augusto Lopes de Souza; Antonio C. Campos-de-Carvalho; Guilherme F. M. Rezende
Background: Bone marrow‐derived cell therapy has been investigated in patients with severe liver disease.
Histopathology | 2007
James Thomas; H S Julian; R Green; David Cameron; Michael Dixon
Aims:u2002 Neoadjuvant systemic therapy of large and locally advanced breast cancers may, through shrinkage, enable breast conservation surgery. Letrozole, an aromatase inhibitor, is used frequently in the treatment of oestrogen receptor‐positive breast cancer. The aim was to examine the response patterns in a letrozole‐treated group compared with a chemotherapy‐treated group.
Evidence & Policy: A Journal of Research, Debate and Practice | 2015
Jenny Caird; Katy Sutcliffe; Irene Kwan; Kelly Dickson; James Thomas
When swift, accurate appraisal of evidence is required to inform policy concerning broad research questions, and budgetary constraints limit the employment of large research teams, researchers face a significant challenge which is sometimes met by reviewing existing systematic reviews. In this paper we highlight the challenges inherent in the reviews of reviews (RoR) method in order to advance understanding of this important tool for policy makers. Drawing on our experiences, we present, where possible, potential solutions to these challenges to demonstrate that RoRs, despite their limitations, can be useful for mediating policy-relevant evidence at speed.
BMJ Open | 2015
Andrew King; Darren Barton; H A Beard; Nwe Ni Than; Joanna Moore; Chris Corbett; James Thomas; Kathy Guo; Indra Neil Guha; D Hollyman; Deborah D. Stocken; Christina Yap; Richard Fox; Shareen Forbes; Philip N. Newsome
Introduction Liver disease mortality and morbidity are rapidly rising and liver transplantation is limited by organ availability. Small scale human studies have shown that stem cell therapy is safe and feasible and has suggested clinical benefit. No published studies have yet examined the effect of stem cell therapy in a randomised controlled trial and evaluated the effect of repeated therapy. Methods and analysis Patients with liver cirrhosis will be randomised to one of three trial groups: group 1: Control group, Standard conservative management; group 2 treatment: granulocyte colony-stimulating factor (G-CSF; lenograstim) 15u2005µg/kg body weight daily on days 1–5; group 3 treatment: G-CSF 15u2005µg/kg body weight daily on days 1–5 followed by leukapheresis, isolation and aliquoting of CD133+ cells. Patients will receive an infusion of freshly isolated CD133+ cells immediately and frozen doses at days 30 and 60 via peripheral vein (0.2×106 cells/kg for each of the three doses). Primary objective is to demonstrate an improvement in the severity of liver disease over 3u2005months using either G-CSF alone or G-CSF followed by repeated infusions of haematopoietic stem cells compared with standard conservative management. The trial is powered to answer two hypotheses of each treatment compared to control but not powered to detect smaller expected differences between the two treatment groups. As such, the overall α=0.05 for the trial is split equally between the two hypotheses. Conventionally, to detect a relevant standardised effect size of 0.8 point reduction in Model for End-stage Liver Disease score using two-sided α=0.05(overall α=0.1 split equally between the two hypotheses) and 80% power requires 27 participants to be randomised per group (81 participants in total). Ethics and dissemination The trial is registered at Current Controlled Trials on 18 November 2009 (ISRCTN number 91288089, EuDRACT number 2009-010335-41). The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.
Journal of Clinical Nursing | 2017
Catherine Houghton; Kathy Murphy; Ben Meehan; James Thomas; Dawn Brooker; Dympna Casey
AIMS AND OBJECTIVESnTo explore the experiences and perceptions of healthcare staff caring for people with dementia in the acute setting. This article focuses on the methodological process of conducting framework synthesis using nvivo for each stage of the review: screening, data extraction, synthesis and critical appraisal.nnnBACKGROUNDnQualitative evidence synthesis brings together many research findings in a meaningful way that can be used to guide practice and policy development. For this purpose, synthesis must be conducted in a comprehensive and rigorous way. There has been previous discussion on how using nvivo can assist in enhancing and illustrate the rigorous processes involved.nnnDESIGNnQualitative framework synthesis.nnnMETHODSnTwelve documents, or research reports, based on nine studies, were included for synthesis.nnnCONCLUSIONnThe benefits of using nvivo are outlined in terms of facilitating teams of researchers to systematically and rigorously synthesise findings. nvivo functions were used to conduct a sensitivity analysis. Some valuable lessons were learned, and these are presented to assist and guide researchers who wish to use similar methods in future.nnnRELEVANCE TO CLINICAL PRACTICEnUltimately, good qualitative evidence synthesis will provide practitioners and policymakers with significant information that will guide decision-making on many aspects of clinical practice. The example provided explored how people with dementia are cared for acute settings.
Journal of Clinical Epidemiology | 2017
Jane Noyes; Andrew Booth; Kate Flemming; Ruth Garside; Angela Harden; Simon Lewin; Tomas Pantoja; Karin Hannes; Margaret Cargo; James Thomas
The Cochrane Qualitative and Implementation Methods Group develops and publishes guidance on the synthesis of qualitative and mixed-method implementation evidence. Choice of appropriate methodologies, methods, and tools is essential when developing a rigorous protocol and conducting the synthesis. Cochrane authors who conduct qualitative evidence syntheses have thus far used a small number of relatively simple methods to address similarly written questions. Cochrane has invested in methodological work to develop new tools and to encourage the production of exemplar reviews to show the value of more innovative methods that address a wider range of questions. In this paper, in the series, we report updated guidance on the selection of tools to assess methodological limitations in qualitative studies and methods to extract and synthesize qualitative evidence. We recommend application of Grades of Recommendation, Assessment, Development, and Evaluation-Confidence in the Evidence from Qualitative Reviews to assess confidence in qualitative synthesized findings. This guidance aims to support review authors to undertake a qualitative evidence synthesis that is intended to be integrated subsequently with the findings of one or more Cochrane reviews of the effects of similar interventions. The review of intervention effects may be undertaken concurrently with or separate to the qualitative evidence synthesis. We encourage further development through reflection and formal testing.
Gut | 2009
James Thomas; Stuart J. Forbes
A virtually unlimited supply of hepatocytes for transplantation, bio-artificial livers and drug testing would be highly desirable. If stem cell biology is to fulfil its potential and deliver this dream, then certain requirements must be met. Stem cell-derived “hepatocytes” should be readily available from an ethically acceptable source, tolerate cryopreservation allowing “off the shelf” use, demonstrate adequate metabolic and synthetic activity and, if transplanted should functionally integrate with non-parenchymal cells in the liver. Most importantly, cell transplantation must be safe. Derivation from an autologous source, thereby overcoming immunological barriers would further increase the applicability of this potential therapy.nnThere is a growing number of potential starting cell populations from which one may potentially derive hepatocyte-like cells (for a comprehensive review, see Oertel and Shafritz1). Broadly speaking the starting cell populations may be developmentally “primitive” such as the embryonic stem cells or be more differentiated such as foetal hepatocytes. Generally, the more primitive the starting cell population, then the greater is the potential to expand in culture the numbers of cells available for use. The challenge with such cells is to accurately control their differentiation into mature cells types such as hepatocytes and control their subsequent proliferation so that unwanted tumours do not form. Embryonic stem cells have an almost unlimited capacity for proliferation and have the ability to form all cell types – so-called pluripotentiality. However, the current use of embryonic stem cell derived tissues for transplantation is hampered by the potential of these cells to form tumours. Induced pluripotent stem cells have been an extremely exciting innovation from the Yamanaka laboratory.2 By over-expressing certain transcription factors …