10,329 research outputs found

    Zinc as a potential therapy for Burkittā€™s lymphoma

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    Burkitts lymphoma (BL) is a form of non-Hodgkin lymphoma (NHL) that arises from germinal center B cells. BL is characterized by translocations of the C-MYC oncogene to immunoglobulin light and heavy chain loci resulting in its constitutive deregulated expression. BL shows a rapid and aggressive growth pattern. There are three different forms of BL; sporadic BL (sBL), immunodeficiency-associated BL and endemic BL (eBL) which accounts for ~50% of all paediatric cancers in Sub-Saharan Africa. Due to financial restrictions, treatment and supportive care options are limited resulting in poorer outcomes in low - middle income countries (LMICs). Thus, there is a need to develop new affordable effective low toxicity treatments for eBL. Prior to this study, a panel of BL cell lines were tested against an in-house custom drug repurposing library developed in our lab (FMC Library) that contains ~100 approved and commonly used drug. This screen identified the nutritional supplement zinc acetate as an effective anti-BL candidate. Dose response studies showed that all BL cell lines tested had little/no response to zinc at 50 Ī¼M whereas 100 Ī¼M zinc killed all BL cell lines. In contrast, 100 Ī¼M zinc acetate induced no killing against a panel of non-BL cell lines including acute myeloid leukaemia (AML) which is a non BL cell tumour, diffuse large B cell lymphoma (DLBCL) which represent a B cell lymphoma that arise from germinal centre B cells and BV infected lymphoblastoid cell lines (LCL) as a control cells. The latter were used as karyotypically normal B cell controls. Cell death in BL cells was associated with positive flow cytometry staining for propidium iodide and annexin V and activation of caspase 3 and 9 (western blotting) indicating cell death by apoptosis. The proto-oncogene C-MYC is mutated or deregulated in >50% of cancers. In BL, deregulated expression occurs as a consequence of translocation of C-MYC on chromosome 8q24 to either the immunoglobulin heavy chain enhancer region on 14q32 (85% of cases) or the immunoglobulin kappa light chain or lambda loci on 2p12 or 22q11, respectively (15% of cases). Thus, the effect of zinc on C-MYC protein levels were studied. Western blot analysis showed that 100 Ī¼M zinc was able to reduce C-MYC protein levels rapidly and sustainably in BL cell lines whereas no change in C-MYC protein levels was observed in non-BL cell lines. Zinc-induced reduction of C-MYC protein levels was time-dependent, reducing by approximately 20% after 6 hours with little/no protein detectable after 24 hours. C-MYC protein levels were not reduced following treatment with 50 Ī¼M zinc. Quantitative real time PCR (qRT-PCR) also showed a rapid reduction in C-MYC mRNA levels in BL cell lines after 6 hours exposure to 100 Ī¼M but not upon exposure to 50Ī¼M. Again, no reduction in C-MYC mRNA levels was seen in non-BL cell lines. Translocations of other genes to the immunoglobulin loci occur in other forms of NHL. The DLBCL cell line SU-DHL-4 has a t(14;18) translocation resulting in deregulated expression of the protooncogene BCL2. Western blotting showed no decrease in BCL-2 protein levels in SU-DHL-4 in response to either 100 Ī¼M or 50 Ī¼M zinc acetate after 6 or 24 hours indicating a selectivity of zinc action against C-MYC protein in BL cells. To further investigate the role of altered C-MYC expression in zinc-mediated killing of BL cells, the eBL cell lines Raji and Namalwa were stably transfected with C-MYC using a piggyBac transposon system that allows gene expression under a constitutively active promoter. However, overexpression of C-MYC from an alternative promoter did not rescue BL cells from killing by 100Ī¼M zinc. Although western blotting showed that C-MYC protein levels were protected after 6 hours, protein reduction and loss of viability was again observed after 24 hours indicating that loss of C-MYC is important in zinc-mediated killing of BL cells. In a second approach to rescue C-MYC expression, the proteasome inhibitor Bortezomib was used to inhibit C-MYC protein degradation via the ubiquitin-proteasome system (UPS). Whilst increases were observed in overall ubiquitinated proteins indicating bortezomib was working, western blotting and flow cytometry showed no rescue of C-MYC protein levels. Furthermore, bortezomib did not rescue cells from zinc-mediated killing after 24 hours. In conclusion, findings from this study have identified that 100 mM zinc is effective at killing BL cell lines selectively, and that this killing is associated with activation of apoptotic markers. Treatment with zinc resulted in a rapid and sustained reduction in C-MYC mRNA and protein levels that could not be rescued through constitutive overexpression or the use of proteasome inhibitors. Given that zinc deficiency is common in sub-Saharan Africa and that zinc supplementation is safely used to treat diarrhoeal episodes in children, the studies proposed here indicate that zinc may safely be used as an adjunctive therapy to target C-MYC in BL

    Discovery of selective saccharide receptors via Dynamic Combinatorial Chemistry

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    The diagnosis of various diseases and pathological conditions can be accomplished by screening and detecting glycans in cells. Certain glycans serve as excellent biomarkers, being related to cell malfunctioning, while other structurally similar glycans perform completely different functions and are naturally present in healthy cells. Despite the theoretical feasibility of using glycans as biomarkers for early disease detection, our current inability to discriminate between them limits their use. One promising approach to distinguishing between glycans is targeting their dissimilarities in saccharide chains. However, designing selective receptors for saccharides is challenging due to the complexity of these molecules. Their vast diversity, the fact that they exist in many interconvertible forms, their lack of recognisable functional groups, or the fact that they are normally heavily solvated in aqueous environments have made the design of receptors for saccharides a challenge that has kept the scientific community busy for the last 35 years. Although there have been ground-breaking discoveries in the field, improvements are needed to enhance our disease detection and risk stratification tools. To address this challenge, we employed a technique known as Dynamic Combinatorial Chemistry (DCC). DCC enables the self-formation and self-selection of the best possible receptor for a given target from a pool or library of potentially good ligands. DCC has been effective for creating receptors for biomolecules such as DNA, RNA, and proteins, but its use for discovering sugar receptors is less explored. In this work, we filled this gap by implementing DCC for screening common saccharides (glucose, galactose, mannose, and fructose) using small, simple, and inexpensive building blocks. Our results indicated that molecule 2DD, which consists of a benzene ring with 2 units of amino acid aspartic acid derivatives connected in positions 1 and 3, is the best receptor in a library of very similar structures for the saccharides glucose, galactose, and mannose. For fructose, molecule 1P, a benzene ring linked to just one unit of the amino acid phenylaldehyde, was appointed as the best receptor. The differential behaviour of fructose can provide insight into the relatively unknown processes behind molecular recognition of sugars. Molecules 2DD and 1P, as well as some other library members as negative controls, were then synthesised for further testing and DCC results were then validated by Isothermal Titration Calorimetry (ITC) and NMR techniques, proving the effectiveness of DCC as a molecular recognition tool for the creation of receptors for saccharides. Moreover, molecule 1P was found to have a high binding constant (Ka_{a} = 1762 Māˆ’1^{-1}) and selectivity (50-100 times over other sugars) for fructose, which is surprisingly good considering the simplicity of the receptor. A much more challenging approach was attempted by employing short peptides as scaffolds in DCC experiments. The benefits of using peptides are numerous but can be summarised in three bullet points: customisability, flexibility, and easiness in their synthesis. Unfortunately, we encountered many difficulties for the complete functionalisation of the peptides within the Dynamic Combinatorial Library (DCL) and this approach did not yield the desired results before the research project came to an end. However, we believe in its potential and the knowledge that we gained on the topic helped to stablish the foundations on which new research will be carried out in the near future within the research group. In summary, this thesis reports the development of a rapid methodology for the discovery of selective receptors for monosaccharides, employing a library of simple and inexpensive starting building blocks. While this was a proof-of-concept study, it can be scalable to larger library sizes and to target more complex biomolecules, becoming a useful tool that could accelerate the discovery of new molecules with biomedical applications

    Milton's Hellenism

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    This thesis investigates the Hellenism of the English poet John Milton from his student writings at Cambridge through to Paradise Lost. It explores Miltonā€™s engagement with classical, Hellenistic, Byzantine, and Early Modern Greek texts and it considers Miltonā€™s reading of Greek scholarship and interactions with Greek scholars and Hellenic scholarship. Chapter 1, ā€˜Miltonā€™s Cambridge Greekā€™, consists of two sections: ā€˜Protestant Hellenism at Miltonā€™s Cambridge: A Case Study of James Duportā€™s Greek Paraphrase of the Book of Job, Threnothriambos (1637)ā€™ and ā€˜Greek and the ā€œLady of Christā€™s Collegeā€: Latinā€“Greek Code-Switching in Milton ā€˜Prolusion VIā€™ā€™. Chapter 2, ā€˜Milton Among the Hellenists in England and Italyā€™ considers the role that Greek played in Miltonā€™s correspondence and poetic exchanges with Charles Diodati and Lucas Holstenius; it also considers the nature of Miltonā€™s own Hellenic research at libraries in Rome and Florence during his travels in Italy from 1638ā€“39. Chapter 3 considers the political and polemical roles that Greek texts played for Milton from the mid-1640s to 1660 and consists of three sections: ā€˜Marshallā€™s Ignorant Hand: Miltonā€™s Greek Epigram and the 1645 Poems Frontispiece and the First Edition of Langbaineā€™s Longinus (1636)ā€™; ā€˜O Soul of Sir John Cheek: Milton and the Legacy of Sixteenth-Century Greek Humanismā€™; and ā€˜John Milton, Leonard Philaras, and Early Modern Advocacy for Greeceā€™s Liberation from the Ottoman Empireā€™. The final, fourth chapter explores the influence of Greek textsā€”ranging from the Homeric epics and the fragmentary Epic Cycle through to Byzantine and Early Modern Greek textsā€”upon Miltonā€™s design of Books 1 and 2 of Paradise Lost

    Understanding the experience of ā€˜brain fogā€™ in coeliac disease: an interpretative phenomenological analysis

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    This thesis is submitted by Emily May Ahmed in partial fulfilment of the degree of Doctor of Clinical Psychology at the University of Birmingham. The thesis is comprised of three chapters. The first chapter is a meta-analysis which aims to provide a current prevalence estimate of depression in adults with coeliac disease, including evaluation of risk of bias factors. Additionally, it includes a brief secondary analysis, within the appendix, describing prevalence and relative risk estimates for other mental health disorders associated with coeliac disease. The second chapter is a qualitative empirical study which uses interpretative phenomenological analysis (IPA) methodology to explore the complex lived experiences of one of the lesser-known symptoms associated with coeliac disease ā€“ ā€˜brain fogā€™, in seven participants. Both the meta-analysis and empirical studies have clear clinical implications for the cognitive and psychological support that individuals with coeliac disease should be offered during and after diagnosis. Finally, the third chapter is comprised of two press release documents, which provides an accessible summary of the main findings of both the meta-analysis and the empirical research study

    Investigating the role of complement in the pathogenesis of pre-eclampsia in previously healthy pregnant women, and in high-risk groups.

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    Pre-eclampsia (PE) is a leading cause of obstetric morbidity and mortality. Certain groups of women, including those with chronic kidney disease (CKD) and those of sub-Saharan African (SSA) ethnicity, are at particularly high risk. There remains no definitive treatment other than expedited delivery of baby and placenta. Previous studies suggest a role for complement dysregulation in the pathogenesis of PE, but results are often conflicting, and it remains unclear whether changes in circulating complement concentrations reflect a general heightened inflammatory state in PE or are directly associated with placental complement-mediated injury. This thesis tested the hypothesis that PE is associated with excessive complement activation within placental tissue, with concurrent complement activation within the maternal and fetal circulation, and that groups with a high prevalence of PE, and of PE with severe features (women with CKD and women of SSA ethnicity) would exhibit a greater degree of systemic complement activation. Three arms of research were conducted, and I report: ā€¢ In a cohort of previously healthy women, PE was associated with significant placental complement deposition, associated with concurrent changes in maternal and fetal circulating complement markers (reduced maternal properdin and C4, and elevated maternal and fetal Ba). Placental C4d deposition was strongly correlated with maternal properdin and C4, suggesting that those patients with the most excessive changes in circulating markers of complement activation also have the greatest extent of placental complement-mediated damage. ā€¢ There was no evidence of excessive complement activation in the maternal circulation in superimposed PE in a cohort of women with CKD. However, raised Ba levels were associated with adverse pregnancy outcomes in women with CKD. ā€¢ There was no evidence of excessive complement activation in PE in a Ghanaian cohort of women of SSA ethnicity when compared to healthy pregnant controls. However, pregnant women of SSA ethnicity did have significantly elevated levels of C5b-9, serum free light chains, and immunoglobulin G, when compared to the UK-recruited cohorts; suggestive of a baseline elevated inflammatory state. The results suggest that inhibition of complement activation is a potential therapeutic target for certain groups of women with PE. However, PE is a heterogenous syndrome and additional pathophysiological mechanisms may contribute to the development of disease in women with CKD and women of SSA ethnicity

    Dinuclear Lanthanide(III) complexes for light emitting surfaces and plasmonic nanomaterials

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    Lanthanide(III) luminescence is extremely valuable for the development of optical devices. The long luminescence lifetimes, high photostability and narrow and characteristic emission peaks of lanthanides(III) are accompanied by low molar absorption coefficients, demanding sensitisation from light harvesting units via the antenna effect. In addition to careful ligand design, nanostructured plasmonic materials can enhance lanthanide(III) luminescence and overcome some of the most common limitations of luminescent materials and particularly near infrared (NIR) emission, such as poor signal to noise ratios and low quantum yields and brightness. Here, we present novel surface active bis Ī²-diketonatelanthanide(III) complexes for the fabrication of visible and NIR emitting materials. The incorporation of thioacetate units in the ligand scaffold enables the complexes to be anchored on metallic substrates. The characteristic visible and NIR luminescence is retained upon coating on gold (Au) surfaces, and the preparation of a handheld sensing device is demonstrated as a response of the Eu(III) surfaces to F- coordination. Incorporation of the complexes to plasmonic substrates is determined to be an excellent approach for the enhancement of both visible and NIR luminescence. Plasmonic Au (pGold) surfaces, in particular, lead to exceptional resolution and intensity of NIR Nd(III) and Yb(III) emission, driving the progress of lanthanide(III) NIR light to advanced applications. Finally, the complexes are anchored on Au nanoparticles (AuNPs), producing highly emissive H2O dispersed nanomaterials. An alternative approach for the preparation of surface active bis Ī²-diketonates is demonstrated by coordination of functionalised 1,10-phenanthroline units, also optimising the luminescent output of both the complex in solution and on AuNPs

    Appropriate residential site environments for the elderly in Baan Pong Nuea sub-district municipality of Hang Dong district in Chiang Mai province

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    Old age is a critical stage of life, in which a personā€™s physical environment of the residential site plays an important role. However, although the most important characteristics of a suitable environment for the elderly is well described, the perceptions of older people within residential site environmental settings and their features have yet to be studied in-depth in Asian countries within rural settings. As critical points of at least two inter-related gaps, this study addresses these gaps by widening the focus on residential sites in a rural Asian context, with a mixed-methodology based on the extent of Person-Environment (Pā€“E) fit. Thus, the principal research aims of this project are to understand how older adults perceive, utilise and relate to their residential site environments in a rural context as evaluated by older residents themselves in a case study of a village in northern Thailand. This study considers three research questions concerning the residential site environments in the rural Asian context - their concepts as the main considerations of the characteristics, the contribution to the outdoor usages and satisfaction, and the perceptions and evaluations among older people. The evidence presented in the study suggests that residential sitesā€™ environmental characteristics are essential to creating appropriate relationships between elders and their environments in a rural context and affect eldersā€™ perception, outdoor usage, and environmental satisfaction. This study contributes to the developed line of analysis of the residential site environments for ageing in a rural Asian context to broaden what has been set in that existing body of knowledge relating to living environments for older people. This research could lead to residential and rural development policy interventions and has implications for practice. The findings from this study allow elders or related organisations to promote, apply and create the appropriate and desirable residential environments in confronting an ageing society

    Acute Sarcopenia: the last remaining acute organ insufficiency

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    Introduction: Acute sarcopenia is defined by incident sarcopenia (muscle insufficiency defined by low muscle strength with low muscle quantity or quality) within six months, normally following a stressor event. It is under-considered in clinical practice, but has potential to lead to reduced quality of life and adverse outcomes from hospitalisation itself. Methods: I undertook two prospective studies, including (Study 1) hospitalised patients aged 70 years and older, and (Study 2) healthy volunteers aged 18-35. Study 1 involved serial assessments of muscle quantity, quality, and physical function in elective colorectal surgery, emergency abdominal surgery, and general medical (infective diagnosis) patients. Study 2 assessed the variability of muscle quantity and quality measurements performed with Bioelectrical Impedance Analysis (BIA) and ultrasound with position and exercise. In addition, a systematic review was performed to synthesise evidence for interventions to ameliorate negative changes in muscle quantity and function in hospitalised older adults. Results: Eighty-one participants were recruited (mean age 79, 38.3% female) to Study 1. Serial assessments of muscle quantity, quality, and function were shown to be feasible and acceptable to participants. Variability in trajectories of muscle parameters was demonstrated, with some participants experiencing declines, and others experiencing improvements or recovery across timepoints. Baseline nutritional status and step count were shown to interact in determination of recovery of muscle quantity. Penalised regression models revealed that prescription of steroids was positively associated with sarcopenia at 7 days, and the presence of delirium was negatively associated with change in BATT to 7 days. Forty-four participants (mean age 26, 52% female) were recruited to Study 2. Ultrasound measurements were shown to increase from the reclined to sitting position and after exercise, demonstrating the importance of ensuring protocol standardisation. Interventions identified within the systematic review included physical activity interventions (27 studies), nutritional interventions (11 studies), testosterone (1 study), GH (2 studies), nandrolone (1 study), erythropoietin (1 study), and Neuromuscular Electrical Stimulation (3 studies). Evidence for effectiveness/efficacy was limited. Conclusions: Acute sarcopenia research in complex heterogeneous populations of older adults is acceptable and feasible to patients. Targeting interventions to patients most at risk (e.g. those on treatments with steroids) should be considered in future trials. Pragmatic multi-arm trials including physical activity, nutritional, and pharmaceutical agents (e.g. GH) are encouraged

    Exploring the impact of integrated COPD care in general practice

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    Integrated care is an umbrella term used to describe collaboration across differing healthcare sectors. Integrated care interventions directed towards patients with Chronic Obstructive Pulmonary Disease (COPD) in primary care have been shown to improve patient outcomes, such as quality of life. However, the utilisation of integrated care interventions to improve guideline adherence and reduce the prevalence of COPD misdiagnosis in primary care has not been explored previously. The mixed methods systematic review demonstrated that misdiagnosis of COPD does occur in primary care and is predominantly due to difficulties utilising spirometry and differentiating COPD from asthma. Integrated care interventions utilising specialist led spirometry were shown to be able to identify misdiagnosed patients and were perceived to be able to reduce the prevalence of COPD misdiagnosis in primary care. The impact of integrating COPD specialists into GP practices was evaluated through a pragmatic cluster randomised controlled trial (INTEGR COPD). The integration of COPD specialists led to significant improvements in the delivery of guideline adherent care, which was shown to correlate with improvements in quality of life. Integrating COPD specialists into GP practice also led to misdiagnosed patients being identified and having their diagnosis and treatment corrected. The integration of COPD specialists into GP practices was found to be acceptable to patients and healthcare professionals. The reluctance to challenge historic diagnoses was thought to be the underlying cause of patients remaining misdiagnosed in primary, within this cohort. Specialist involvement was deemed to have a positive impact in reducing the extent of COPD misdiagnosis in primary care. The findings from this thesis suggest that integrated COPD care has a positive impact on the delivery of optimal patient care as well as the prevalence of COPD misdiagnosis in GP practices

    Diagnosing brain tumours through functional imaging and machine learning

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    Non-invasive in vivo functional imaging plays a key role in the clinical management of brain tumours. Magnetic resonance spectroscopy estimates the metabolite profiles of brain tissues. Diffusion weighted imaging shows the water diffusion map of the whole brain. Such imaging biomarkers facilitate the precise classification of brain tumours. Prior to classification, this the- sis optimised image and spectroscopy preprocessing and feature selection. Magnetic resonance spectroscopy was processed through adaptive wavelet noise suppression. Imaging features were selected based on the diagnostic ability across all tumour types. Additionally, imaging features of the minority class were oversampled through semi-synthetic wavelets oversampling. Combining these techniques, the cross validated classification accuracy for ependymomas, medulloblastomas and pilocytic astrocytomas was dramatically improved to be 100%. The findings from this thesis enhanced the role of magnetic resonance spectroscopy in clinical neuroscience
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