Commotio retinae describes retinal opacification following trauma and affected 16% of British soldiers suffering major trauma. The macula was affected in 55% of soldiers and 31% of civilian cases, permanently reducing vision to less than 6/9 in 26% of cases, associated with photoreceptor degeneration. In an experimental rat model, commotio retinae was more readily induced by high velocity ballistic injury (20m/s) than low velocity weight drop (2-7m/s). In rats, after experimentally induced commotio retinae, photoreceptors died by a combination of necrosis (central to the impact site) and apoptosis (peripheral to it), demonstrated by morphological changes on electron micrographs and TUNEL staining. Photoreceptor death after commotio retinae was associated with reduced ERG a-wave amplitude. Apoptosis occurred through the intrinsic pathway, mediated by caspase 9 but not involving any of the classical executioner caspases (3, 6 and 7). Inhibition of caspase 9 reduced photoreceptor death and improved retinal function, assessed by a-wave amplitude. Clinical studies suggested a protective effect of female gender after commotio retinae, but progesterone treatment increased photoreceptor death after ballistic injury in the experimental model.

Glucocorticoids (GC) are regulators of permissive and adaptive physiology. GC excess can lead to metabolic complications including type 2 diabetes and metabolic syndrome. Levels are regulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which reactivates GC. 11β-HSD1 activity is deregulated in a range metabolic disorders in which GC levels are normal. I hypothesise that 11β-HSD1 is a critical regulator of adipose tissue sensitivity to GC excess, and that through 11β-HSD1 depletion adipose tissue will be desensitised to GCs and resist metabolic deregulation. Using 11β-HSD1 KO mice in a model of GC excess we demonstrate that 11β-HSD1 mediates the adverse metabolic effects of GC excess on a global scale. I further investigated brown adipose tissue (BAT) with GC excess. I demonstrate that 11β-HSD1 regulates BAT activity and mitochondrial function, possibly suppressing BATs thermogenic potential. I extended my studies to examine the potential for white adipose tissue (WAT) to assume markers of thermogneic and mitochondrial function in the context of 11βHSD1 and GC excess. The data suggest 11β-HSD1 may suppress the potential of WAT to assume a ‘BAT-like’ profile. These data show 11β-HSD1 loss of function confers a protective phenotype with GC excess and demonstrates it’s role in mediating the metabolic phenotype associated with GCs. These data support the idea that GCs can influence BAT and WAT thermogenic potential and may increase knowledge of metabolic dysregulation in humans suffering form GC excess. This therefore highlights 11β-HSD1 as an exciting potential target for the treatment for the metabolic disease associated with GC excess.

Analysis of the amino-acid co-substitution patterns has long promised the prediction of protein structure but has failed to deliver. One possible reason is that most methods presume that co-substitution is indicative of residue-residue contact, yet the extent to which this conjecture is true is unproven. Here, a method is developed to investigate the relationship between specific co-substitution types and their propensity to occur at different physical separations in a protein structure. Amino-acids are typically segregated into two types; hydrophilic residues, predominantly found on the protein surface, and the hydrophobic residues in the protein interior. Thus, the propensity of a given amino-acid substitution occurring at the surface must differ from that in the interior of the protein, the implications of this for co-substitution has never previously been considered. To allow a definition of surface and buried residues, the cross-over point demarcating the surface residues from the protein interior was calculated here, using a Half Sphere Exposure with a radius of 13 A, as 20 HSEu, above which value a residue can be considered buried, and below which it can be considered to be on the surface.

This thesis describes the impact of service delivery initiatives (SDIs) on patients’ waiting times within radiology departments. A systematic review of the literature (71 studies included) found the following broad type of SIDs: extended scope practice, quality management, productivity-enhancing technologies, outsourcing, pay-for-performance and multiple interventions. Ninety-six percent of the studies used either the pre- and post-intervention without control or the post-intervention only designs; but these designs are fundamentally weak and prone to bias. Furthermore, this thesis also described a case-study for the evaluation of the impact on patients’ waiting times of a 320-slice computed tomography (CT) scanner, speech recognition reporting and extended-working-hours within the Birmingham Heartlands Hospital (Heart of England NHS Foundation Trust), Birmingham. The evaluation combined the interrupted time series (ITS) design and qualitative interviews with healthcare professionals in a mixed methods approach. The mixed methods approach leverages the strengths of the quantitative and qualitative methods, so that the triangulation of the findings of one research method might be strengthened when supported by the findings of the other research method. The thesis used a distinctive implementation of ITS segmented regression which accounts for the changing trends of patients waiting times – an approach referred to as ITS ‘segmented spline’ regression.

The flaws of current methods of assessing disease severity in patients with COPD and emphysema are increasingly recognised, and new methods of assessing disease activity are urgently required. Although many potential biomarkers have been suggested to fulfil this role, few have been effectively validated, and furthermore any biomarker should be based on our current understanding of the pathophysiology the disease process. This is poorly understood, however it is apparent that neutrophil proteases (particularly neutrophil elastase (NE) and proteinase 3 (Pr3)) may represent a final common pathway leading to tissue destruction. The current thesis describes the development and validation of a new marker of NE activity (Aα-Val360), and the identification of a marker of Pr3 activity, as potential biomarkers of COPD and emphysema disease activity. Methods Following in vitro validation, the performance of Aα-Val360 was assessed in a series of patient populations. Mass spectrometry was used to identify a specific marker of Pr3 activity. Results and Conclusion Aα-Val360 demonstrated acceptable in vitro and in vivo variability; related to physiological, radiological and patient reported outcomes in subjects with (or at risk of developing) COPD and emphysema (both with and without A1AT deficiency); increased during acute exacerbations; decreased in response to treatment; and partly related to disease progression in some populations. Also, a Pr3 specific cleavage product was identified which could be used to develop a new specific assay of Pr3 activity. These potential biomarkers of disease activity may be important in the assessment of patients with COPD and emphysema (or who are at risk of developing these conditions), particularly in early phase clinical trials.

Background: Decisions on which tests to use should be informed by evidence that they do more good than harm. Test-treatment RCTs are recommended as the ‘gold–standard’ approach, but have attracted criticism that question whether they are fit for purpose. Confronting this question, the thesis investigates four key challenges by finding and analysing all identifiable test-treatment RCTs (2004–2007). Methods: Capture–recapture analysis estimated the total population of trials; descriptive analysis characterised the diagnostic questions evaluated by RCT; reviews of reporting and methodological quality investigated how informative and valid trials are; analytic induction was used to develop a theoretical framework linking tests to health outcomes, from which a tool was designed. Results: Published trials were poor quality, and found to be highly complex studies that will be challenging to evaluate reliably: interventions are difficult to capture and translate into protocols; several methods traditionally used to eliminate bias are more difficult to implement; test-treatment strategies impact on patient health in numerous and highly complicated ways. Conclusion: Test-treatment trials have the potential to be very useful instruments, and though highly challenging they could be both reliable and informative. However, it must be acknowledged that trials will not be suited to all comparisons.

Parkinson's disease (PD) motor and non-motor symptoms progress relentlessly leading to frequent hospitalisations and an increase in the economic and societal burden of the disease. A major challenge in assessing treatments which can potentially reduce neurodegeneration, is the lack of tools that can be used to identify individuals with early PD with high sensitivity and specificity. There were several facets to this thesis, which were aimed at addressing these issues. Firstly a retrospective analysis of PD hospital admissions was conducted to provide background data on hospitalisation and clinical coding accuracy. A systematic review of literature for interventions to reduce hospital admissions was performed. Effect of treatments for PD motor symptoms on hospitalisation was also evaluated. Lastly, screening of potential lanthanide and 19 Fluorine based MRI probes for future use as diagnostic tools in PD was conducted. Results of these studies highlight significant underreporting ofPD hospitalisation which has a negative effect on PD resource allocation. A lack of robust evidence for measures which reduce PD admissions was demonstrated. Although the initial attempts to develop a novel MRI sensitive tool for use in PD were negative, the study refined a protocol that has potential for use in screening future probes.

The changes in the control of breathing in man at high altitude have been studied at 5,800 m (19,000 ft). The differences between 1owlanders and Sherpas were compared at 4,880 m (16,000 ft.). Ventilatory response to C0\(_2\), hypoxia and exercise were studied, and acid-base status of the blood and CSF measured. Acclimatization to altitude is characterized by a shift of the C0\(_2\) response curve to the left and an increase in its slope. The hypoxic sensitivity appears unchanged. On moderate exercise there results a progressive increase in ventilatory equivalent with increasing altitude. At maximum work rate ventilation increases more rapidly due to falling Sao\(_2\). Sherpas show no significant difference in response to C0\(_2\) but a remarkable lack of response to hypoxia. The C0\(_2\) response showed little change in slope with change of P0 \(_2\) and on exercise acutely changing PO\(_2\)had little effect on ventilation. Sherpas ventilate less on exercise and have higher maximum 0\(_2\) intakes per kg than lowlanders. The arterial pH of highlanders is normal whereas in lowlanders it remains slightly elevated after k-6 weeks at altitude. CSF pH of highlanders is about 0.04 units more acid than lowlanders at the same altitude, indicating a greater central contribution to respiratory drive and a reduced peripheral component. The role of anaerobic cerebral metabolism in respiratory acclimatization is discussed.

Neutrophils constitute the main immune defense against microbial invasion. When activated, they migrate towards the site of infection where they eliminate any foreign material in an effort to prevent wide-spread tissue damage and ultimately resolve infection. Previous work on neutrophil function in the elderly has highlighted a number of neutrophil effector functions, including phagocytosis, superoxide production and migration that exhibit decreased efficiency suggesting the potential for reduced pathogen clearance in older adults. This thesis reveals a migratory phenotype distinctive of neutrophils isolated from healthy elderly donors (> 60 years) and characterized by a maintained speed of migration (chemokinesis) but with significantly reduced directional migration (chemotaxis) and overall migratory accuracy in response to a range of chemoattractants. This migratory phenotype was shown to be associated with a constitutive basal activation of PI3Kinase in neutrophils isolated from older donors and appears to be a causative factor as treatment of neutrophils with inhibitors selective for PI3Kinase-γ and –δ, was able to restore migratory dynamics. The ‘old-migratory’ phenotype was amenable to correction by pre-incubation with 1nM Simvastatin in vitro and a two-week prescription of 80mg/day Simvastatin in vivo in healthy older adults. The ability of simvastatin to modulate migratory dynamics potentially provides a safe, cost effective intervention to reduce morbidity and mortality from infections in the elderly population.

The aim of this thesis was to explore three factors that are easily available and contribute important information for women before commencing in-vitro fertilisation (IVF) treatment: ethnicity, body-mass index (BMI) and thyroid disease. Results of the systematic review, cohort study and meta-analysis investigating ethnicity and IVF outcome showed South Asian and Black women have lower adjusted live-birth (LB) rates, after fresh cycle treatment, compared with White women. The relationship between BMI and IVF outcome was explored in a prediction model estimating chances of LB following first cycle. The model found BMI has reduced effect on IVF outcome when adjusting for other confounders such as age. The prevalence of thyroid dysfunction and thyroid peroxidase antibodies (TPOAb) was examined across the UK in >7000 women of reproductive age, and a cohort study investigating the effect of subclinical hypothyroidism (SCH) on IVF outcome was also performed. The prevalence of overt thyroid disease was 0.38% and subclinical disease 3.45%. Using an upper limit cut off for thyroid-stimulating hormone of 2.5mU/L the prevalence of SCH was 19.64%. The overall prevalence of TPOAb was 9.11%; this was 7.98% in euthyroid women. Finally, there were no significant differences in LB between euthyroid women and women with SCH.