59 research outputs found

    Transplantation tolerance: lessons from experimental rodent models

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    Immunological tolerance or functional unresponsiveness to a transplant is arguably the only approach that is likely to provide long-term graft survival without the problems associated with life-long global immunosuppression. Over the past 50 years, rodent models have become an invaluable tool for elucidating the mechanisms of tolerance to alloantigens. Importantly, rodent models can be adapted to ensure that they reflect more accurately the immune status of human transplant recipients. More recently, the development of genetically modified mice has enabled specific insights into the cellular and molecular mechanisms that play a key role in both the induction and maintenance of tolerance to be obtained and more complex questions to be addressed. This review highlights strategies designed to induce alloantigen specific immunological unresponsiveness leading to transplantation tolerance that have been developed through the use of experimental models

    Characterisation of a murine model of the late asthmatic response

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    Background: The incidence of asthma is increasing at an alarming rate. While the current available therapies are effective, there are associated side effects and they fail to adequately control symptoms in all patient subsets. In the search to understand disease pathogenesis and find effective therapies hypotheses are often tested in animal models before progressing into clinical studies. However, current dogma is that animal model data is often not predictive of clinical outcome. One possible reason for this is the end points measured such as antigen-challenge induced late asthmatic response (LAR) is often used in early clinical development, but seldom in animal model systems. As the mouse is typically selected as preferred species for pre-clinical models, we wanted to characterise and probe the validity of a murine model exhibiting an allergen induced LAR. Methods: C57BL/6 mice were sensitised with antigen and subsequently topically challenged with the same antigen. The role of AlumTM adjuvant, glucocorticoid, long acting muscarinic receptor antagonist (LAMA), TRPA1, CD4+ and CD8+ T cells, B cells, Mast cells and IgE were determined in the LAR using genetically modified mice and a range of pharmacological tools. Results: Our data showed that unlike other features of asthma (e.g. cellular inflammation, elevated IgE levels and airway hyper-reactivity (AHR) the LAR required AlumTMadjuvant. Furthermore, the LAR appeared to be sensitive to glucocorticoid and required CD4+ T cells. Unlike in other species studied, the LAR was not sensitive to LAMA treatment nor required the TRPA1 ion channel, suggesting that airway sensory nerves are not involved in the LAR in this species. Furthermore, the data suggested that CD8+ T cells and the mast cell—B-cell - IgE axis appear to be protective in this murine model. Conclusion: Together we can conclude that this model does feature steroid sensitive, CD4+ T cell dependent, allergen induced LAR. However, collectively our data questions the validity of using the murine pre-clinical model of LAR in the assessment of future asthma therapies

    Insulin-like growth factor-I induces the phosphorylation and nuclear exclusion of forkhead transcription factors in human neuroblastoma cells

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    Akt-mediated phosphorylation of forkhead transcription factors is linked to growth factor-stimulated cell survival. We investigated whether the survival activity of insulin-like growth factor-I (IGF-I) in SH-SY5Y human neuroblastoma (NBL) cells is associated with phosphorylation and/or localization changes in forkhead proteins. IGF-I induced phosphorylation of Erks (p42/p44), FKHR (FOXO1a) (Ser 253), FKHRL1 (FOXO3a) (Ser 256), and Akt (Ser 473). PI3-K inhibitor, LY294002, reduced IGF-I-stimulated phosphorylation of FKHR, FKHRL1, and Akt, but did not affect Erk phosphorylation. Using a GFP-FKHR construct, FKHR imported into the nucleus during growth factor withdrawal-induced apoptosis. In addition, IGF-I rescue from serum withdrawal-induced apoptosis is associated with a rapid export of GFP-FKHR into the cytoplasm. Leptomycin B, an inhibitor of Crm1-mediated nuclear export, decreased the level of FKHRL1 phosphorylation in the presence of IGF-I in vector and FKHR overexpressing cells, but had no effect on the phosphorylation status of FKHR. In addition, leptomycin B prevented IGF-I stimulated nuclear export of GFP-FKHR. These studies show IGF-I phosphorylation of FKHR and FKHRL1 via a PI3-K-dependent pathway in NBL cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44353/1/10495_2005_Article_429.pd

    Retrospective examination of the healthcare 'journey' of chronic orofacial pain patients referred to oral and maxillofacial surgery

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    Objective To gain a deeper understanding of the clinical journey taken by orofacial pain patients from initial presentation in primary care to treatment by oral and maxillofacial surgery.Design Retrospective audit.Sample and methods Data were collected from 101 consecutive patients suffering from chronic orofacial pain, attending oral and maxillofacial surgery clinics between 2009 and 2010. Once the patients were identified, information was drawn from their hospital records and referral letters, and a predesigned proforma was completed by a single examiner (EVB). Basic descriptive statistics and non-parametric inferential statistical techniques (Krushal-Wallis) were used to analyse the data.Data and discussion Six definitive orofacial pain conditions were represented in the data set, 75% of which were temporomandibular disorders (TMD). Individuals within our study were treated in nine different hospital settings and were referred to 15 distinct specialties. The mean number of consultations received by the patients in our study across all care settings is seven (SD 5). The mean number of specialities that the subjects were assessed by was three (SD 1). The sample set had a total of 341 treatment attempts to manage their chronic orofacial pain conditions, of which only 83 (24%) of all the treatments attempted yielded a successful outcome.Conclusion Improved education and remuneration for primary care practitioners as well as clear care pathways for patients with chronic orofacial pain should be established to reduce multiple re-referrals and improve efficiency of care. The creation of specialist regional centres for chronic orofacial pain may be considered to manage severe cases and drive evidence-based practice
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