• Head imaging and craniometry: A historical note on a base line error

      Lewis, Stephen J.; Chester College of Higher Education (College of Radiographers, 1995-07)
      This journal article discusses the work of Lysholm, Reid, and von Ihering in standarding patient positioning during radiological examination of the skull.
    • Health benefits of Tai Chi exercise: Improved balance and blood pressure in middle-aged women

      Thornton, Everard W.; Sykes, Kevin; Tang, Wai K.; University of Liverpool ; University College Chester ; University College Chester (Oxford University Press, 2004-03)
      Tai Chi has been widely practiced as a Chinese martial art that focuses on slow sequential movements, providing a smooth, continuous and low intensity activity. It has been promoted to improve balance and strength and to reduce falls in the elderly, especially those 'at risk'. The potential benefits in healthy younger age cohorts and for wider aspects of health have received less attention. The present study documented prospective changes in balance and vascular responses for a community sample of middle-aged women. Seventeen relatively sedentary but healthy normotensive women aged 33-55 years were recruited into a three times per week, 12-week Tai Chi exercise programme. A further 17 sedentary subjects matched for age and body size were recruited as a control group. Dynamic balance measured by the Functional Reach Test was significantly improved following Tai Chi, with significant decreases in both mean systolic (9.71 mmHg) and diastolic (7.53 mmHg) blood pressure. The data confirm that Tai Chi exercise can be a good choice of exercise for middle-aged adults, with potential benefits for ageing as well as the aged.
    • Health-related effects and improving extractability of cereal arabinoxylans

      Fadel, Abdulmannan; Mahmoud, Ayman M.; Ashworth, Jason J.; Li, Weili; Ng, Yu L.; Plunkett, Andrew; Manchester Metropolitan University; Beni-Suef University; Charité-University Medicine; University of Chester (Elsevier, 11/11/2017)
      Arabinoxylans (AXs) are major dietary fibers. They are composed of backbone chains of -(1–4)- linked xylose residues to which -l-arabinose are linked in the second and/or third carbon positions. Recently, AXs have attracted a great deal of attention because of their biological activities such as their immunomodulatory potential. Extraction of AXs has some difficulties; therefore, various methods have beenusedto increase the extractability ofAXs withvaryingdegrees of success, suchas alkaline, enzymatic, mechanical extraction. However, some of these treatments have been reported to be either expensive, such as enzymatic treatments, or produce hazardous wastes and are non-environmentally friendly, such as alkaline treatments. On the other hand, mechanical assisted extraction, especially extrusion cooking, is an innovative pre-treatment that has been used to increase the solubility of AXs. The aim of the current review article is to point out the health-related effects and to discuss the current research on the extraction methods of AXs.
    • Heart rate and perceived muscle pain responses to a functional walking test in McArdle disease

      Buckley, John P.; Quinlivan, Ros M.; Sim, Julius; Eston, Roger G.; Short, Deborah S. (Routledge, 14/04/2014)
      The aim of this study was to assess a 12-min self-paced walking test in patients with McArdle disease. Twenty patients (44.7 ±11 years; 11 female) performed the walking test where walking speed, distance walked, heart rate (HR) and perceived muscle pain (Borg CR10 scale) were measured. Median (interquartile range) distance walked was 890 m (470–935). From 1 to 6 min, median walking speed decreased (from 75.0 to 71.4 m∙min–1) while muscle pain and %HR reserve increased (from 0.3 to 3.0 and 37% to 48%, respectively). From 7 to 12 min, walking speed increased to 74.2 m∙min–1, muscle pain decreased to 1.6 and %HR reserve remained between 45% and 48%. To make relative comparisons, HR and muscle pain were divided by walking speed and expressed as ratios. These ratios rose significantly between 1 and 6 min (HR:walking speed P = .001 and pain:walking speed P < .001) and similarly decreased between 6 and 11 min (P = .002 and P = .001, respectively). Peak ratios of HR:walking speed and pain:walking speed were inversely correlated to distance walked: rs (HR) = −.82 (P < .0001) and rs (pain) = −.55 (P = .012). Largest peak ratios were found in patients who walked < 650 m. A 12-min walking test can be used to assess exercise capacity and detect the second wind in McArdle disease.
    • Heat shock proteins form part of a danger signal cascade in response to lipopolysaccharide and GroEL

      Davies, Emma L.; Bacelar, Maria M. F. V. G.; Marshall, Michael J.; Johnson, E.; Wardle, T. D.; Andrew, Sarah M.; Williams, John H. H.; University of Chester ; University of Chester ; Charles Salt Centre, The Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry ; Spinal Studies, The Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry ; Countess of Chester Hospital ; University of Chester ; University of Chester (Wiley, 2006-04)
      An increasing number of cell types, including peripheral blood mononuclear cells (PBMCs), have been demonstrated to release heat shock proteins (Hsps). This paper investigates further the hypothesis that Hsps are danger signals. PBMCs and Jurkat cells released Hsp70 (0·22 and 0·7 ng/106 cells, respectively) into medium over 24 h at 37°C. Release of Hsp70 was stimulated 10-fold by GroEL (P < 0·001) and more than threefold by lipopolysaccharide (LPS) (P < 0·001). Although Hsp60 could be detected in the medium of cells cultured at 37°C for 24 h, the low rates of release were due probably to cell damage. Significant release of Hsp60 was observed when Jurkat cells were exposed to GroEL (2·88 ng/106 cells) or LPS (1·40 ng/106 cells). The data are consistent with the hypothesis that Hsp70 and Hsp60 are part of a danger signalling cascade in response to bacterial infection.
    • Heat shock proteins: Interactions with bone and immune cells

      Williams, John H. H.; Davies, Emma L. (University of Liverpool (Chester College of Higher Education), 2004-09)
      Heat shock proteins (Hsps) are increasingly being seen as having roles other than those of intracellular molecular chaperones, particularly with regard to their potential to act as cytokines, and to stimulate the innate immune system. Hsps have also been found to promote bone resorption and osteoclast formation in vitro, although the mechanism has not been previously identified. The overall aims of this thesis were to determine whether Hsps could stimulate bone resorption by affecting the RANKL/OPG pathway, and to address the hypothesis that Hsps can act as a danger signal to the innate immune system. In order for Hsps to affect either the RANKL/OPG system of bone resorption or act as danger signals they would need to be actively released from cells, ideally in a controlled manner following exposure to the source of stress. Hsp60 and Hsp70 were found to be released from a range of immune cells including the cell lines Jurkat and U937, and also PBMCs, T-cells and B-cells. This release was not due to cell damage. The release of Hsp60 and Hsp70 were downregulated by inhibitors of protein secretion, in particular Hsp70 release was reduced by compounds that inhibited lysosomal pathways and Hsp60 release by classical secretion inhibitors. Hsp60, Hsp70, GroEL and LPS all affected the RANKL/OPG system of bone regulation; OPG production and release was down-regulated in the MG63 and GCT osteoblast-like cell lines following treatment with Hsp60, Hsp70 and LPS, and RANKL expression was upregulated following treatment with Hsp60, Hsp70, GroEL and LPS. This effect on the RANKL/OPG system was found to translate into an effect on osteoclast formation when conditioned media from treated osteoblasts was added to osteoclast precursors in the presence of M-CSF. A range of different factors that affected Hsp release were identified; PHA activation of PBMCs was found to upregulate Hsp60 release from PBMCs. GroEL and LPS caused an upregulation in Hsp70 release from PBMCs and GCT osteoblast like cells, and Hsp70 was found to stimulate Hsp60 release from PBMCs and GCT cells. These responses of Hsp release were used to form a theory of a cascade-like danger signal that may occur when cells are exposed to bacterial infection and which would result in activation of antigen presenting cells via previously identified receptors for Hsps such as CD14/TLR4 or by unidentified pathways. The elevated release of Hsps in response to GroEL and LPS was also identified as a mechanism that could stimulate bone loss during infection or autoimmuniry by affecting the RANKL/OPG system. hi conclusion, Hsp60 and Hsp70 can be released from immune cells under normal conditions, and from both immune and osteoblast-like cells following stimulation with LPS and other Hsps. The observed release responses provide a mechanism through which Hsps can act as danger signals to the innate immune system, and also as promoters of bone resorption via the RANKL/OPG system.
    • Helpers influence on territory use and maintenance in Alpine marmot groups

      Pasquaretta, Cristian; Busia, Laura; Ferrari, Caterina; Bogliani, Giuseppe; Reale, Denis; von Hardenberg, Achaz; University of Pavia, Universiteé du Quebec a Montreal, Gran Paradiso National Park (22/04/2015)
      In social mammals, territory size and shape vary according to the number and strength of neighbour individuals competing for resources. Two main theories have been proposed to explain this variability: the Group Augmentation (GA) and the realized Resource Holding Potential (rRHP) hypotheses. The first states that the outcome of the interactions among groups depends on the total number of individuals in the group while the second states that only the number of animals directly involved in intergroup competition determines this outcome. We collected data on space use of individually tagged Alpine marmots ( Marmota marmota), a cooperative breeding species that overlaps part of its territory with neighbouring groups. In accordance with the rRHP hypothesis, we found that groups having higher proportion of helpers, rather than higher total number of individuals, had lower percentage of the territory overlapping with neighbouring groups and a larger area available for individual exclusive use.
    • Hen Harrier Circus cyaneus nest sites on the Isle of Mull are associated with habitat mosaics and constrained by topography

      Geary, Matthew; Haworth, Paul F.; Fielding, Alan H.; University of Chester; Haworth Conservation Ltd. (Taylor & Francis, 07/02/2018)
      Capsule: Hen Harrier on the Isle of Mull, UK, are associated with habitat mosaics consisting of moorland, scrub and forestry but avoid grazed land, suggesting that forested habitats could be managed sympathetically for Hen Harrier in the future should the current UK population increase. Aims: To use distribution modelling to investigate nesting habitat associations using a long term dataset for Hen Harrier on Mull. Methods: We develop area-interaction models using a LASSO penalty to explore the distribution of 102 Hen Harrier nest sites in relation to habitat and topography. Our model is then successfully validated in tests using data for 70 nest sites from subsequent years. Results: Our model is effective in predicting suitable areas for Hen Harrier nest sites and indicates that Hen Harriers on Mull are found in habitat mosaics below 200 m asl. Hen Harrier nest intensity is positively associated with increasing proportions of moorland and scrub, open canopy forestry and closed canopy forestry. Nest intensity is negatively associated with increasing proportions of grazed land. Conclusion: Hen Harrier avoid grazed areas but are relatively tolerant of other habitat combinations. These findings are supported by previous observations of Hen Harrier habitat use and have implications for the recovery of some Hen Harrier SPA populations and future forest management. Open canopy forest and forest mosaics could potentially be incorporated into landscape-scale conservation plans for Hen Harriers using the population in Mull as an example.
    • High CIP2A levels correlate with an antiapoptotic phenotype that can be overcome by targeting BCL-XL in chronic myeloid leukemia. Leukemia

      Lucas, Claire; Milani, Mateus; Butterworth, Michael; Carmell, Natasha; Scott, Laura; Clark, Richard; Cohen, Gerald; Varadarajan, Shankar; University of Liverpool (Nature, 29/02/2016)
      Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a predictive biomarker of disease progression in many malignancies, including imatinib-treated chronic myeloid leukemia (CML). Although high CIP2A levels correlate with disease progression in CML, the underlying molecular mechanisms remain elusive. In a screen of diagnostic chronic phase samples from patients with high and low CIP2A protein levels, high CIP2A levels correlate with an antiapoptotic phenotype, characterized by downregulation of proapoptotic BCL-2 family members, including BIM, PUMA and HRK, and upregulation of the antiapoptotic protein BCL-XL. These results suggest that the poor prognosis of patients with high CIP2A levels is due to an antiapoptotic phenotype. Disrupting this antiapoptotic phenotype by inhibition of BCL-XL via RNA interference or A-1331852, a novel, potent and BCL-XL-selective inhibitor, resulted in extensive apoptosis either alone or in combination with imatinib, dasatinib or nilotinib, both in cell lines and in primary CD34(+) cells from patients with high levels of CIP2A. These results demonstrate that BCL-XL is the major antiapoptotic survival protein and may be a novel therapeutic target in CML.
    • High drug related mortality rates following prison release: Assessing the acceptance likelihood of a naltrexone injection and related concerns

      Murphy, Philip N.; Mohammed, Faizal; Wareing, Michelle; Cotton, Angela; McNeil, John; Irving, Paula; Jones, Steven; Sharples, Louisa; Monk, Rebecca; Elton, Peter; et al. (Elsevier, 04/07/2018)
      Background and aims. High drug related mortality amongst former prisoners in the 4 weeks following release is an internationally recognised problem. Naltrexone injections at release could diminish this by blockading opioid receptors, but naltrexone is not licenced for injection for treating opiate misuse in the United Kingdom and some other countries. This study examined the likelihood of accepting a naltrexone injection at release, and the relationship of this likelihood to other relevant variables. Method. Sixty-one male prisoners with a history of heroin use, who were approaching release from two prisons in the north-west of England, provided likelihood ratings for accepting a naltrexone injection if it were to have been available. Additional data was gathered regarding demographic and drug use histories, and also from psychometric instruments relevant to drug misuse and treatment preparedness. Results. Maximum likelihood ratings for accepting a naltrexone injection were recorded by 55.7% of the sample with only 9.8% indicating no likelihood of accepting an injection. Likelihood ratings were positively related to serving a current sentence for an acquisitive offence compared to drug related or violence offences, and negatively related to peak methadone dosages during the current sentence. Conclusions. Although naltrexone injections were not available to participants in this study, the findings suggest that the potential uptake for this intervention is sufficient to warrant a clinical trial with this population of British prisoners, with a view to potential changes to its current licencing status
    • Higher risk of gastrointestinal parasite infection at lower elevation suggests possible constraints in the distributional niche of Alpine marmots

      Zanet, Stefania; Miglio, Giacomo; Ferrari, Caterina; Bassano, Bruno; Ferroglio, Ezio; von Hardenberg, Achaz; Università di Torino; Gran Paradiso National Park; University of Chester (Public Library of Science, 01/08/2017)
      Alpine marmots Marmota marmota occupy a narrow altitudinal niche within high elevation alpine environments. For animals living at such high elevations where resources are limited, parasitism represents a potential major cost in life history. Using occupancy models, we tested if marmots living at higher elevation have a reduced risk of being infected with gastrointestinal helminths, possibly compensating the lower availability of resources (shorter feeding season, longer snow cover and lower temperature) than marmots inhabiting lower elevations. Detection probability of eggs and oncospheres of two gastro-intestinal helminthic parasites, Ascaris laevis and Ctenotaenia marmotae, sampled in marmot feces, was used as a proxy of parasite abundance. As predicted, the models showed a negative relationship between elevation and parasite detectability (i.e. abundance) for both species, while there appeared to be a negative effect of solar radiance only for C. marmotae. Site-occupancy models are used here for the first time to model the constrains of gastrointestinal parasitism on a wild species and the relationship existing between endoparasites and environmental factors in a population of free-living animals. The results of this study suggest the future use of site-occupancy models as a viable tool to account for parasite imperfect detection in ecoparasitological studies, and give useful insights to further investigate the hypothesis of the contribution of parasite infection in constraining the altitudinal niche of Alpine marmots.
    • Higher satiety ratings following yogurt consumption relative to fruit drink or dairy fruit drink

      Tsuchiya, Ami; Almiron-Roig, Eva; Lluch, Anne; Guyonnet, Denis; Drewnowski, Adam; University of Washington ; University of Washington ; Danone Research Centre, France ; Danone Research Centre, France ; University of Washington (Elsevier, 2006-04)
      This article compares the satiating power of semisolid and liquid yogurts with fruit beverages and dairy fruit drinks using 32 volunteers.
    • The historical problems of travel for women undertaking geological fieldwork

      Burek, Cynthia V.; Kolbl-Ebert, Martina; University of Chester ; Jura-Museum, Willibaldsburg (The Geological Society of London, 2007)
      From unsuitable clothes to a lack of chaperones, from sexual harrassment to lack of proper funding, throughout history women geologists have encountered difficulties travelling to their field location or wotking in the field, whether these locations were close by or abroad. From Etheldred Benett to the present day problems are often sociological and political as well as logistical. Most early women geologists were able to avoid many difficulties because they were protected through working locally where their high social standing was known and respected or because they worked in a team with husband, father, or brother. However the problem developed virulence in the second half of the nineteenth century when women started to appear as students and professionally trained geologists. The single travelling women geologist had to face desciminating attitudes, ranging from pity to disregard and even to sexual harrassment. Benevolent society also had its problems with these women when, for example, professors needed their wives as chaperones to take women students on field trips.
    • Homocysteine and cognitive decline in healthy elderly

      McCaddon, Andrew; Hudson, Peter R.; Davies, Gareth K.; Hughes, Alan; Williams, John H. H.; Wilkinson, Clare; University of Wales College of Medicine ; Wrexham Maelor Hospital ; Wrexham Maelor Hospital ; Royal Alexandra Hospital, Paisley ; Chester College ; University of Wales College of Medicine (Karger, 2001-09)
      Serum homocysteine is increased, and correlates inversely with cognitive scores, in Alzheimer's disease (AD), vascular dementia and "age-associated memory impairment". Elevated levels might signal accelerated cognitive decline, although this remains to be established. We therefore repeated Mini-Mental State Examinations, together with additional ADAS-Cog assessments, in 32 healthy elderly individuals to determine whether prior homocysteine levels predicted cognitive changes over a 5-year period.
    • The Hormone Response Element Mimic Sequence of GAS5 LncRNA is Sufficient to Induce Apoptosis in Breast Cancer Cell Lines

      Pickard, Mark R.; Williams, Gwyn T.; Keele University, United Kingdom (2015)
      Growth arrest-specific 5 (GAS5) encodes snoRNAs and lncRNA. The latter promotes apoptosis, but its expression is down-regulated in breast cancer. The mTOR and nonsense-mediated decay pathways together regulate GAS5 transcript levels but rapalogues fail to enhance GAS5 levels in triple-negative breast cancer cells, so that mTOR inhibitor-independent induction of GAS5 may be more productive in enhancing apoptotic responses to therapies in breast cancer. Notably, GAS5 lncRNA acts by riborepression of glucocorticoid/related receptors; a stem-loop sequence constitutes the GAS5 hormone response element mimic (HREM). The aim of this study was to determine if the GAS5 HREM sequence alone is sufficient to promote the apoptosis of breast cancer cells. Cells were nucleofected with a DNA oligonucleotide corresponding to the GAS5 lncRNA HREM; controls received oligonucleotides either with scrambled GAS5 sequence or with stem complementarity present but lacking the GAS5 HRE consensus. Cells were irradiated with ultraviolet-C (UV-C) light at 20 h post-transfection to induce apoptosis. The basal apoptotic rate almost doubled in MCF7 and MDA-MB-231 cells transfected with the HREM oligonucleotide compared with controls. This effect was apparent at 20 h post¬-transfection, and a corresponding decrease was observed in culture viability; clonogenic activity was also impaired. The HREM sequence also enhanced UV-C-induced apoptosis in an additive manner in both cell lines. Endogenous GAS5 lncRNA expression was unaffected by transfection of the HREM sequence. Thus the GAS5 lncRNA HREM is sufficient to induce apoptosis in breast cancer cells, including TNBC cells and this may serve as the basis for the development of novel oligonucleotide cancer therapies. Funded by the Breast Cancer Campaign.
    • The hormone response element mimic sequence of GAS5 lncRNA is sufficient to induce apoptosis in breast cancer cell lines – towards oligonucleotide therapies?

      Pickard, Mark R.; Williams, Gwyn T.; Keele University, United Kingdom (NCRI Cancer Conference 2014 Abstracts, 2014)
      Background Growth arrest-specific 5 (GAS5), a non-protein coding gene, encodes snoRNAs and lncRNA; transcript levels are controlled by the mTOR and nonsense-mediated decay pathways. GAS5 lncRNA promotes the apoptosis of breast cells, including triple-negative breast cancer (TNBC) cells, but its expression is down-regulated in breast cancer. Rapalogues enhance GAS5 levels in oestrogen receptor-positive breast cancer cells but not in TNBC cells, so that mTOR inhibitor-independent induction of GAS5 may be more productive in enhancing apoptotic responses to therapies. Notably, GAS5 lncRNA acts by riborepression of glucocorticoid/related receptors; a stem-loop sequence constitutes the GAS5 hormone response element mimic (HREM). The aim of this study was to determine if the GAS5 HREM sequence alone is sufficient to promote the apoptosis of breast cancer cells. Method Cells were nucleofected with a DNA oligonucleotide corresponding to the GAS5 lncRNA HREM; controls received oligonucleotides either with scrambled GAS5 sequence or retaining stem-loop structure but lacking the GAS5 HRE consensus; mock-transfected cells were also studied. Cells were irradiated with ultraviolet-C (UV-C) light at 20 h post-transfection to induce apoptosis. Culture viability and apoptosis were assessed and cellular GAS5 levels were determined by RT-qPCR. Results The basal apoptotic rate almost doubled in MCF7 and MDA-MB-231 cells transfected with the HREM oligonucleotide compared with controls. This effect was apparent at 20 h post­-transfection, and a corresponding decrease was observed in culture viability. The HREM sequence also enhanced UV-C-induced apoptosis in an additive manner in both cell lines. Endogenous GAS5 lncRNA expression was unaffected by transfection of the HREM sequence. Conclusion The GAS5 lncRNA HREM is sufficient to induce apoptosis in breast cancer cells, including TNBC cells. This study serves as an exemplar of how emerging knowledge of biologically important lncRNAs may be exploited towards the development of novel oncotherapeutic agents.
    • The hormone response element mimic sequence of GAS5 lncRNA is sufficient to induce apoptosis in breast cancer cells.

      Pickard, Mark R.; Williams, Gwyn T.; Keele University (Impact Journals, 03/02/2016)
      Growth arrest-specific 5 (GAS5) lncRNA promotes apoptosis, and its expression is down-regulated in breast cancer. GAS5 lncRNA is a decoy of glucocorticoid/related receptors; a stem-loop sequence constitutes the GAS5 hormone response element mimic (HREM), which is essential for the regulation of breast cancer cell apoptosis. This preclinical study aimed to determine if the GAS5 HREM sequence alone promotes the apoptosis of breast cancer cells. Nucleofection of hormone-sensitive and -insensitive breast cancer cell lines with a GAS5 HREM DNA oligonucleotide increased both basal and ultraviolet-C-induced apoptosis, and decreased culture viability and clonogenic growth, similar to GAS5 lncRNA. The HREM oligonucleotide demonstrated similar sequence specificity to the native HREM for its functional activity and had no effect on endogenous GAS5 lncRNA levels. Certain chemically modified HREM oligonucleotides, notably DNA and RNA phosphorothioates, retained pro-apoptotic. activity. Crucially the HREM oligonucleotide could overcome apoptosis resistance secondary to deficient endogenous GAS5 lncRNA levels. Thus, the GAS5 lncRNA HREM sequence alone is sufficient to induce apoptosis in breast cancer cells, including triple-negative breast cancer cells. These findings further suggest that emerging knowledge of structure/function relationships in the field of lncRNA biology can be exploited for the development of entirely novel, oligonucleotide mimic-based, cancer therapies.
    • Hsp70 release from peripheral blood mononuclear cells

      Hunter-Lavin, Claire; Davies, Emma L.; Bacelar, Maria M. F. V. G.; Marshall, Michael J.; Andrew, Sarah M.; Williams, John H. H.; University of Chester ; University of Chester ; University of Chester ; The Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry ; University College Chester ; University College Chester (Elsevier, 12/11/2004)
      There are an increasing number of studies reporting the presence of Hsps in human serum. We have investigated the release of Hsp70 into blood and culture medium from peripheral blood mononuclear cells (PBMCs), and whether this release is due to cell damage or active secretion from the cells. Intact Hsp70 was released from cells within whole blood and from purified PBMCs under normal culture conditions. Hsp70 release was rapid (0.1 ng/106 cells/h) over the first 2 h of culture and continued at a reduced rate up to 24 h (<0.025 ng/106 cells/h). Using viable cell counts and lactate dehydrogenase release we were able to confirm that the release of Hsp70 was not due to cellular damage. Hsp70 release was inhibited by monensin, methyl-β-cyclodextrin, and methylamine, but not by brefeldin A. These data suggest that Hsp70 is released from cells via a non-classical pathway, possibly involving lysosomal lipid rafts.
    • Hsp72 modulation of inflammatory immune responses

      Williams, John H. H.; Ireland, H. Elyse (University of Liverpool (University of Chester), 2009-03)
      The body initiates an immune response to danger signals. The Danger model of the immune system postulates that danger signals are produced by exogenous molecules from foreign invaders, such as bacteria, and endogenous molecules released from damaged or injured cells. The response involves antigen recognition leading to up-regulation of cytokines and cell surface markers, followed by the recruitment of antigen presenting cells and T-helper cells which determine how the immune system responds. Endogenous danger signals include Hsp72 and HMGB-1. This thesis describes the development of specific antibodies and ELISAs for use in the quantification and detection of intra-cellular Hsp72 from cell extracts, and released Hsp72 from cell cultures which enabled the confirmation of physiological levels of Hsp72 from model systems. The ability of endogenous Hsp72 to stimulate an immune response was demonstrated and this response was not solely due to LPS contamination of recombinant protein preparations. Hsp72 was able to augment the response to LPS. In the presence of another endogenous danger signal, HMGB-1, relative amounts of Hsp72 were shown to augment a pro-inflammatory response whilst being able to maintain an anti-inflammatory response demonstrating Hsp72 has the ability to modulate the immune response. Hsp72 was also shown to be able to stimulate an immune response by binding to cell surface receptors, which could be blocked by specific peptides corresponding to known receptors. These include some receptors not utilised by LPS. The proportion of these different danger signals has consequences for the progression and outcome of an immune response and this may well be modulated by imposition of a supplemental or future stress at different points. In the most severe case, this can lead to death through sepsis following trauma.
    • Hsp72 translocation and secretion in in vivo and in vitro models

      Williams, John H. H.; Andrew, Sarah M.; Leoni, Francesca (University of Liverpool (Chester College of Higher Education), 2009-03)
      Evidence suggesting that Hsp72 is actively participating in cellular signalling as well interacting with immune system dynamics has been increasing. This is true in healthy, stressed and diseased cells but to different degrees. Modulation of the plasma membrane association and secretion in the extracellular environment by different types of stressors is the key event that leads to different degrees of immune system activation. Hence a better understanding of the mechanisms of Hsp72 secretion and association with plasma membrane is crucial. This thesis investigated the tissue source and mechanism of Hsp72 surface presentation to plasma membrane structures and release in relation with different cellular and physiological stressors. In vivo models confirmed that different tissue types determine specific Hsp72 responses following the same stress and increase serum Hsp72 dependant on intensity and duration of the stress. Diseases models confirm that Hsp72 responses in specific cell populations is related to disease progression, while in vitro models clearly showed that there are multiple mechanisms of secretion and surface presentation, dependent on the nature of the stressor as well as the intensity and duration. This observations clearly change the view of extracellular Hsp72 as a danger signal and lead to a revision of the original danger model. It also suggests that manipulation of Hsp72 translocation through the different pathways involved may prove effective therapeutically.