The incidence and mortality from cardiovascular disease (CVD) in patients with chronic kidney disease (CKD) far exceeds that seen in the general population. Whilst a number of risk factors and associations have been identified in patients with CKD that may contribute to the increased risk of CVD, our understanding of the underlying pathophysiology remains poor. It has previously been reported that uraemic animals sustain larger myocardial infarcts and that this ‘reduced ischaemia tolerance’ may in part explain the excess mortality from CVD seen in CKD patients. The aim of this work was to establish an in vivo model of uraemic myocardial infarction in order to further explore the pathophysiology of uraemic CVD with particular focus on ameliorating myocardial ischaemia-reperfusion injury using ischaemic and pharmacological preconditioning. An increase in myocardial infarct size was demonstrated in the sub-total nephrectomy model of chronic uraemia, confirming previous reports in the literature. However, infarct size was not found to be increased in adenine diet induced renal failure. In addition, it was demonstrated for the first time, that the techniques of ischaemic preconditioning (IPC) and remote ischaemic preconditioning (RIPC) are both efficacious and not attenuated by chronic uraemia induced by sub-total nephrectomy or adenine diet (IPC only). Investigations were undertaken using an agent (a HIF stabiliser, FG4497) to induce pharmacological preconditioning in both animals with renal insufficiency and those without. These studies demonstrate that stabilisation of hypoxia inducible factor (HIF) may be a promising strategy to induce pharmacological preconditioning. It is hoped that this work may lay the foundations for future investigations to determine why sub-totally nephrectomised rats have larger infarcts whilst those with adenine induced renal failure, with a substantially greater degree of renal dysfunction, do not. Moreover, it is hoped that; by demonstrating that uraemia 3 does not prevent or attenuate the myocardial protection afforded by ischaemic preconditioning, the recruitment of patients with CKD will be encouraged to clinical trials of both ischaemic preconditioning and other therapies to limit myocardial infarction.

Cardiovascular disease is the leading cause of death in patients with underlying chronic kidney disease (CKD). Up to one third of patients presenting with an acute coronary syndrome have CKD stage 3-5. Outcomes following acute myocardial infarction in patients with underlying CKD remain poor. CKD patients are routinely excluded from clinical trials in novel cardioprotective strategies resulting in a paucity of prospective data on which to base guidelines for clinical practice. The aims of this work were to: • Establish and characterise two models of chronic uraemia in rodents: the subtotal nephrectomy model and the adenine diet model. • Determine the effects of underlying chronic uraemia on myocardial ischaemia tolerance. • Examine pharmacological cardioprotective strategies in the context of underlying uraemia using a PARP inhibitor • Investigate the cardioprotective effects of ischaemic conditioning in the context of uraemia. Ischaemic preconditioning and postconditioning protocols were used in both uraemic and non-uraemic animals in a model of acute myocardial infarction. • Preliminary work, using standard molecular biological techniques, was carried out in order to confirm the putative survival pathways responsible for the effect of preconditioning. • Investigate the effect of combining early and late remote ischaemic preconditioning to identify whether summation of these strategies could provide additional tissue protection in a model of acute kidney injury. The results demonstrate that both models develop a uraemic phenotype. Subtotal nephrectomy animals exhibit reduced ischaemia tolerance. PARP inhibition as a pharmacological post conditioning agent was shown to be ineffective at conferring tissue protection, whereas both ischaemic preconditioning and postconditioning were effective cytoprotective strategies in both non-uraemic and uraemic animals. Furthermore, additional benefit was seen when early and late remote preconditioning were summated in a rodent model of acute kidney injury. This work provides a basis for future clinical trials in cardioprotection in the context of underlying CKD.

Chronic lymphocytic leukaemia (CLL) is the most common adult leukaemia, and despite recent introduction of targeted therapies, remains incurable. An important hallmark of CLL is severe immune deficiency, including the failure to mount effective anti-tumour immune responses. This can partly be explained by insufficient antigen presentation, but also by the existence of complex CLL-induced T-cell defects. Based on the cancer immuno-editing hypothesis that the immune system not only protects a host against tumour formation but can also be compromised to actively provide a pro-tumour microenvironment, modulating cancer-induced T-cell defects could restore the full anti-tumour response and result in more durable clinical responses. The immune checkpoint molecules PD-1 (expressed on activated immune effector cells) and PD-L1 (expressed on antigen-presenting and microenvironmental cells including tumour cells) have emerged as important mediators of T-cell suppression. Several studies suggest that PD-L1/PD-1 inhibitory signalling in CLL might be overcome by the immune modulatory drug lenalidomide. Furthermore, directly targeting PDL-1/PD-1 interactions produces significant responses in solid cancers. However, similar studies are notably absent in CLL, and the effect of PDL-1/PD-1 blockade on restoring cancer-induced immune dysfunction is not understood. Transgenic Eμ-TCL1 mice have been extensively validated as an adequate preclinical model of aggressive human CLL, and our group showed their suitability to mirror T-cell defects observed in human CLL. Using the Eμ-TCL1 model, this dissertation project substantially extends our previous characterization of CLL-induced T-cell dysfunction and evaluates the functional impact of PD-L1/PD-1 inhibitory signalling both in parallel with disease development and in different microenvironments. The findings to be described here demonstrate that developing CLL is associated with specific T-cell subset alterations, phenotypic changes, and functional defects that are very similar in peripheral blood and secondary lymphoid organs. In addition to PD-L1, PD-L2 is identified as a potential mediator of inhibitory signalling in CLL. CD8+ T cells in leukaemic mice are characterised as a functionally heterogeneous population, in which subsets of cells are able to exert effector functions despite PD-1 expression. In vivo lenalidomide treatment repairs selected phenotypic alterations and immune synapse formation, and a PD-L1 IgG blocking antibody effectively controls disease and reverses global T-cell defects even in cells expressing PD-1. In sum, this work provides a strong rationale to explore PD-L1/PD-1 targeting in CLL clinical trials, potentially in combination with novel agents.

No description available.

Alzheimer’s disease (AD) is the commonest form of dementia and is characterised with neuropathological hallmarks such as aggregated amyloid plaques and hyper-phosphorylated tau protein. One type of AD is autosomal dominant AD (ADAD) which is caused by highly penetrant variants in one of three genes (APP, PSEN1 and PSEN2), other cases of AD are described as sporadic and can have a late onset of disease symptoms (> 65 years of age) or early onset (≤ 65 years or age). Late-onset Alzheimer’s disease (LOAD) is estimated to be 70% heritable and is common. Conversely sporadic early-onset Alzheimer’s disease (sEOAD) is estimated to 90% heritable but is relatively rare. The difference in prevalence between the two types of AD has resulted in genome wide association studies focusing on LOAD with sEOAD receiving little attention. Here we use an Illumina human exome genotyping chip customised with neurodegenerative markers (NeuroX) to genotype the coding region of sEOAD samples in a hope to elucidate the genetic aetiology of sEOAD. Sanger sequencing exons 16 and 17 of APP was conducted in a sEOAD cohort (n=451) to screen for variants known to cause ADAD; 9% (n=4) of the cohort were heterozygous for known causative variants and where subsequently removed from the sEOAD NeuroX genotyping data before analyses. Screening also highlighted an intronic 6bp deletion downstream of exon 17 in APP with a non-significant increased minor allele frequency (MAF) in sEOAD, however it did not appear to influence splicing of exon 17. Screening the sEOAD cohort for other variants known to cause neurodegenerative disease was conducted using the NeuroX genotyping data (n=408) which identified two samples with variants in PARK2, these variants are thought to contribute susceptibility to Parkinson’s disease (PD) suggesting these variants might elicit risk for multiple diseases. A further study with increased power would ascertain if the 6bp deletion and PARK2 variants are associated with sEOAD. Statistical analyses of the sEOAD NeuroX genotypes highlighted many variants, genes and pathways that could be contributing to susceptibility to disease; however no tests reached significance after adjusting for multiple testing. The genes most associated (PDZK1, DCLK3, SLC33A1 and BLOC1S2) appear to be biologically relevant and would be ideal candidates for further study. Additionally, just under half of the variants that are significant associated with LOAD were genotyped on the NeuroX and two of these were significantly associated with sEOAD after correcting for multiple testing (rs3851179 and rs3764650). The genotypes of all the variants highlighted would need to be verified before their functionalities were investigated further.

The aim was to elucidate the social construction of chronic pain as a cause of work absence in the UK, focusing on negotiation of sickness certification and return to work, in the context of recent policies to tackle rising sick-listing rates, including a national educational programme about the health benefits of work, and introduction of the ‘fit note’. Following a literature review, two qualitative studies were conducted from a symbolic interactionist perspective. The first comprised semi-structured interviews with doctors and chronic pain patients, leading to a second study in which employers and employees with chronic pain were interviewed. Interviews were transcribed verbatim and analysed according to constructivist grounded theory principles. The first study revealed tensions in the doctor-patient relationship as the process of sickness certification was negotiated. The indeterminacy of chronic pain rendered the biomedical approach to diagnosis and assessment of capability for work problematic, while a shift to the psychosocial model could generate feelings of invalidation in patients. A wide range of moral and socio-cultural factors was invoked by doctors and patients to contest sick-listing decisions. The second study identified difficulties that can emerge when chronic pain patients return to work. Employees discussed how managers failed to understand their problems or make sustained adaptations; employers reported difficulty reconciling the needs of employees with organisational imperatives and argued that employees and doctors colluded in sanctioning low resilience. All stakeholder groups supported the fit note’s focus on capacity not incapacity, but were skeptical about whether it would surmount the tensions and difficulties that arise in sickness certification and return to work for chronic pain patients. Struggles for meaning and construction of identities are difficult for policy to address, but deeper understanding of the processes behind them and rich accounts of stakeholders’ views, may nudge the system towards more appropriate responses.

Dental caries is a multifactorial, bacterial, chronic infection that affects millions of people in the world and has become a public health problem. Also referred to as tooth decay, this disease is one of the most common disorders throughout the world, second only to the common cold. Dental caries is the most common chronic childhood disease in the United States and is 5 to 7 times more common than asthma. According to the World Oral Health Report in 2003, dental caries affect 60-80% of school children and a vast majority of adults. Dental caries is a chronic bacterial infection of the hard tissue of the tooth that is characterized by alternating phases of demineralization and remineralization. Dental decay can lead to significant pain and dysfunction that can interfere with basic functions such as eating, sleeping, and speaking. If left untreated, dental caries can result in cavities forming and eventually tooth loss. Although the prevalence and severity of dental caries has decreased over the years, this disease can be better controlled with proper fluoride exposure. Fluoride therapy has become the cornerstone strategy in the prevention of dental caries development and progression. With fluoride being available in various forms, fluoride exposure and/or treatment has greatly increased and has led to decreased incidences of dental caries. Fluoride has the ability to control the initiation and progression of carious lesions, mainly through the promotion of remineralization and the reduction in tooth enamel demineralization. Whether administered systemically or topically, the use of fluoride has proven to be effective in reducing the prevalence of dental caries. The aim of this review is to compare the topical methods of fluoride therapy with systemic applications. The goal is to evaluate the various forms of fluoride treatments based on cost effectiveness, safety, concentration and dosage of fluoride, ease of application, and accessibility to the community. This review will also identify the populations that are most susceptible to dental caries. The purpose of this review is to examine the benefits and risks of the various options of fluoride treatments in order to determine which would be the most the effective, safe, and efficient means of preventing dental caries in high risk populations. Based on the literature review, it was determined that the populations with the greatest risk for dental caries comprised of young children who were from lower socioeconomic backgrounds and elderly adults over the age of 65. After comparing the various forms of fluoride therapies, it was found that systemic fluoride treatments, mainly water fluoridation, would be the most effective in preventing dental caries in high caries risk populations.

Every year an estimated 42 million people worldwide suffer a mild traumatic brain injury (MTBI) or concussion, with approximately 3.6 million sports related concussions occurring yearly in the United States alone (Bailes, 2015, Azad et al., 2015). An MTBI is an acute brain injury resulting from mechanical energy to the head from external forces (Bailes 2015). Symptoms of an MTBI include visual disturbances, dizziness, nausea and vomiting, light sensitivity, loss of balance, and a general feeling of fatigue (Bailes 2015). MTBI’s are first diagnosed through changes in ImPACT baseline scores as well as Vestibular Ocular Motor Screening (Mucha et al., 2014). Repetitive MTBI and/or repetitive sub-concussive head trauma have been tentatively linked to increased risk for a variety of neurodegenerative diseases including chronic traumatic encephalopathy (CTE) (Gardner et al., 2015). The major limitation of the link between MTBI and CTE is that CTE can only be diagnosed post-mortem (Azad et al., 2015). Due to that limitation, the prevalence of CTE is unknown and the amount of MTBI or sub-concussive trauma exposure necessary to produce CTE is unclear (Gardner et al., 2015). Newer methods of research including SNTF immunostaining and L-COSY are being further developed and studied to better diagnose MTBI and its link to CTE by exploring changes in brain protein formation and brain neurochemistry (Johnson et al., 2015, Lin et al., 2015). Through research development and case studies on professional American football players and boxers, a link between MTBI, particularly repetitive MTBI and CTE has been formed (Maroon et al., 2014).

Complex Regional Pain Syndrome (CRPS) is a chronic neuropathic pain condition associated with significant alterations in the somatosensory and motor cortex brain regions. Cognitive-affective alterations have recently been recognized in patients suffering with CRPS, however, relatively little neuroimaging research has been done to examine these dimensions. Moreover, many children and adolescents suffer from CRPS, but very little is known about the impact of this condition on brain states in the pediatric population. The aim of this paper is to assess the structural brain differences between children with CRPS and healthy controls and to examine to what degree fear level influences such differences. This study is part of a larger investigation that integrates functional and structural brain differences to evaluate fear-related brain circuitry in patients with CRPS. Thirty-seven patients with CRPS were age and gender matched with 35 healthy controls. The two groups underwent structural magnetic resonance imaging (MRI) scans as well as completed the Fear of Pain Questionnaire, child report (FOPQ). To examine gray matter differences, voxel-based morphometry (VBM) and cortical thickness (CT) analysis was completed. Patients with CRPS in this study had an average age of 13.2 (SD=2.7) and were predominantly female (73%). Of the 35 patients who completed FOPQ, 49% reported clinically significant pain-related fear. Compared with healthy controls, CRPS patients had significantly less in gray matter (GM) volume in pain- and fear-related brain regions, including the dorsolateral prefrontal gyrus, motor and somatosensory cortex, anterior and posterior cingulate cortex, nucleus accumbens, putamen, amygdala, and hippocampus. Furthermore, gray matter decreases in regions such as anterior midcingulate cortex, nucleus accumbens, and putamen were associated with elevated pain-related fear in patients. Differences in gray matter volume in fear-circuitry areas could potentially be one mechanism by which abnormal fear learning and extinction develops in youth suffering with CRPS. Further research examining brain changes post-treatment is needed to determine if treatments that target improving pain and fear levels are associated with concomitant normalization of brain structures.

Several successful pathogens evade host defenses resulting in the establishment of persistent and chronic infections. One such pathogen, Porphyromonas gingivalis, induces chronic low-grade inflammation associated with local inflammatory oral bone loss and systemic inflammation manifested as atherosclerosis. The pathogenic mechanisms contributing to P. gingivalis evasion of host immunity and chronic inflammation are not well defined. P. gingivalis evades host immunity at Toll-like receptor (TLR)-4 through expression of an atypical lipopolysaccharide (LPS) that contains lipid A species that exhibit TLR4 agonist or antagonist activity or fail to activate TLR4. By utilizing a series of P. gingivalis lipid A mutants we demonstrated that expression of antagonist lipid A structures resulted in weak induction of proinflammatory mediators. Moreover, expression of antagonist lipid A failed to activate the inflammasome, which correlated with increased bacterial survival in macrophages. Oral infection of atherosclerotic prone apolipoprotein E (ApoE) deficient mice with the antagonist lipid A strain resulted in vascular inflammation characterized by macrophage accumulation and atherosclerosis progression. In contrast, a P. gingivalis strain expressing exclusively agonist lipid A augmented levels of proinflammatory mediators and activated the inflammasome in a caspase-11 dependent manner, resulting in host cell lysis and decreased bacterial survival. ApoE deficient mice infected with the agonist lipid A strain exhibited diminished vascular inflammation. Notably, the ability of P. gingivalis to induce local inflammatory oral bone loss was independent of lipid A expression, indicative of distinct mechanisms for induction of local versus systemic inflammation by this pathogen. We next investigated the role of TLRs and lipid A on bacterial trafficking by the autophagic pathway. Originally characterized as a cell autonomous pathway for recycling damaged organelles and proteins, autophagy is now recognized to play a critical role in innate defense and release of the proinflammatory cytokine interleukin (IL)-1β. We demonstrated that P. gingivalis suppresses the autophagic pathway in macrophages for pathogen survival and intercepts autophagy-mediated IL-1β release. P. gingivalis-mediated suppression of autophagy was independent of lipid A expression but partially dependent on TLR2 signaling. Collectively, our results indicate that P. gingivalis evasion of innate immunity plays a role in chronic inflammation.