Introduction: Cerebrovascular events are a major cause of mortality, disability and healthcare resource use. Despite this, there is a lack of reliable information on their costs and outcomes, particularly related to transient ischaemic attacks (TIA) and minor stroke. Such information is vital to inform decisions about local and national service provision, and to provide reliable estimates for use in cost-effectiveness analyses. Aims This thesis estimates the costs and outcomes of stroke and TIA using data from a population-based study undertaken in a population of over 91,000 individuals in Oxfordshire (the Oxford Vascular Study – OXVASC). In addition, the thesis aims to estimate the short-term cost-effectiveness of two secondary stroke prevention programmes evaluated in a study nested within OXVASC. Methods: Using multiple methods of case ascertainment, 1,282 patients were identified as having suffered a stroke or TIA, of which 1,199 (723 stroke and 476 TIA) patients consented to the study. Follow-up of patients took place at 1, 6, 12 and 24 months, with data collected on patients’ disability, medication usage, living arrangements, and quality of life. Healthcare resource use information was derived from hospital and primary care records, and priced using published unit costs. Findings: Stroke patients had higher case-fatality rates than TIA patients (15% vs. 1%; p<0.001), with 5-year life expectancy being one year longer for TIA patients. For stroke and TIA survivors, the risk of disability remained higher, at around 30% at each of the four follow-ups, than at baseline (17%; p<0.001 for all follow-ups). After standardising for age and gender, average quality of life for stroke and TIA patients combined was significantly lower than English population norms (p<0.001 for all follow-ups). However, when quality of life was compared to population norms by event type, quality of life differences between TIA patients and English population norms no longer remained statistically significant. Important predictors of quality of life included event severity, baseline disability and recurrent vascular events. Total costs were considerably higher 1-year after the initial stroke or TIA than for the year preceding it and, except for day cases, increases were observed for all resource-use categories. Five years after the index event, stroke patients incurred costs of £16,923 (95% CI: 15,149 to 18,858) per patient, significantly higher than those incurred by TIA patients, at £13,904 (95% CI: 11,488 to 16,657; p=0.019). In multivariate analyses, event severity was found to be a significant predictor of inpatient care resource use and costs, as were the presence of recurrent vascular events, especially stroke and coronary events. For non-hospitalised patients, results showed that urgent outpatient specialist assessment and treatment reduced the 90-day risk of fatal or disabling stroke (0.4% vs. 5%, p<0.001) compared with less urgent assessment and treatment. In terms of resource usage, patients who were assessed and treated urgently had lower recurrent stroke hospitalisation (2% vs. 8%; p=0.001), and reduced overall number of days in hospital (average reduction of 4 days; p=0.017). These reductions in hospital resource usage generated savings of £643 per patient assessed and treated urgently in an outpatient clinic (p=0.028). Conclusion: Despite the impact of stroke on death, disability and healthcare resource use, there is a lack of reliable information on costs and outcomes, especially for TIA and minor stroke. Through the use of a population-based study, the gold-standard study design when assessing the incidence and outcomes of TIA and stroke, this thesis provides healthcare decision makers and researchers with a wealth of data on the resource use patterns, costs and outcomes of TIA and stroke patients, and their main predictors.

<b>Background:</b> Comparative assessments of the vascular and upper gastrointestinal risks of different regimens of non-steroidal anti-inflammatory drugs (NSAIDs) are required. <b>Methods:</b> Meta-analyses were conducted, using individual participant data where possible, of placebo-controlled trials of a selective cyclo-oxygenase [COX]-2 inhibitor ('coxib') or traditional NSAID, or randomised trials of a coxib versus traditional NSAIDs. A prespecified subdivision of traditional NSAID regimens of those with antiplatelet activity (mainly naproxen) and those without (mainly diclofenac) was made. Primary outcomes were major vascular events (MVEs; nonfatal myocardial infarction, nonfatal stroke or vascular death) and upper gastrointestinal complications (UGICs; perforation, obstruction or bleed). <b>Findings:</b> Searches identified 788 trials: 200 comparisons of a coxib vs placebo (88,604 participants, mean follow-up 0.60 years), 206 comparisons of a traditional NSAID vs placebo (43,482 participants, 0.46 years) and 149 comparisons of a coxib vs traditional NSAID (137,466 participants, mean follow-up 0.95 years). Compared to placebo, allocation to a coxib increased the risk of MVEs (rate ratio 1.38, 95&percnt; CI 1.14-1.66), vascular mortality (1.58, 1.11-2.24) and UGICs (1.81, 1.17-2.81). Overall, in the population studied, coxibs were associated with three additional major vascular events (one fatal) and two (rarely fatal) upper gastrointestinal complications per 1000 person-years exposure. There was no evidence of heterogeneity by duration of follow-up, coxib type, dose (other than for celecoxib), or patient characteristics, for the primary outcomes. The risk of MVEs for traditional NSAIDs without antiplatelet activity (mostly diclofenac 75mg bd or ibuprofen 800mg tds) were comparable to coxibs (1.40, 1.15-1.72); but the risk of UGICs (1.98, 1.39-2.84) was significantly greater. For traditional NSAIDs with antiplatelet activity (mostly naproxen 500mg bd) there were no significant excess of MVEs (0.84, 0.66-1.08), but UGICs were substantially increased (4.06, 2.85-5.78). Both coxibs and traditional NSAIDs increased risk of hospitalisation for heart failure by about two-fold. <b>Interpretation:</b> The vascular and upper gastrointestinal risks of coxibs and high-dose tNSAID regimens can be predicted, allowing the choice of analgesia to be tailored for particular patients.

In Western Europe the incidence of tick-borne encephalitis (TBE) has increased over the last 30 years, coupled with changes in distribution. Modifications in the TBE enzootic cycle, through a combination of changes in temperature, vertebrate abundance and habitat suitability may have increased the risk of TBE in recent years. In Switzerland, analysis using satellite-derived climate data demonstrated that the environment of areas with TBE since the 1980s and areas that recently became endemic for TBE have become more similar between 2001 and 2009. This was coupled with an increase in April, May and June temperature, which could have affected the tick population and/or human exposure to ticks. Deer and boar abundance also changed in some cantons. In Germany, spatio-temporal modelling demonstrated the importance of temperature, vertebrate abundance and unemployment in the incidence and distribution of TBE between 2001 and 2009. Changes in TBE reporting, April, May and June temperature, vertebrate abundance and pesticide use may have contributed to increases in TBE in 1992 and 2001. Human exposure patterns, however, appear to be as important as the enzootic cycle in shaping the incidence of TBE, not only in determining the overall trend but also in interacting with the weekly, seasonal and yearly patterns of tick hazard to give the observed incidence. In Switzerland, in weeks with warm, sunny weather, human exposure to ticks is promoted and short-term increases in tick bites are seen. Human outdoor activity also shifts the seasonal pattern of tick bites, when compared with tick questing. There was no apparent increase in time spent in outdoor activities between the 1990s and 2000s in Italy, Germany and Austria, but survey data demonstrated that walking and hiking were already popular activities across Europe by the 1990s. The popularity of mushroom and berry foraging as a source of income in Latvia, Lithuania and Poland, coupled with the expense of vaccination, provide an inverse link between economic wellbeing and TBE risk. Correspondingly, in 2009, the economic recession was associated with an increase with TBE in these three countries.

Preeclampsia is one of the leading causes of maternal and fetal mortality and morbidity. Furthermore, women who have had preeclampsia have an increased risk of cardiovascular events over the next 10-15 years. Indeed, preeclampsia is associated with a four-fold increase in the risk of hypertension and double the risk of fatal and non fatal ischaemic heart disease and stroke. In addition, offspring born to preeclampsia are more likely to have higher blood pressure from childhood and stroke in later life. The risk to mother and offspring is greatest when preeclampsia is diagnosed at an earlier gestation, suggesting a more severe form of preeclampsia. As the long term cardiovascular risk to both mother and child is known from delivery, the main interest of my research was to identify key phenotypic variations in mothers and children during the years between the episode of preeclampsia and emergence of established cardiovascular disease, which might explain the link between the two conditions. This information could then be used to devise ways to identify subjects at greatest risk of later cardiovascular disease and to establish intermediate endpoints for future preventative interventions. Therefore, in a case control study, women diagnosed with preeclampsia between 1998 and 2003 and their offspring were recruited and underwent comprehensive cardiovascular and metabolic phenotyping. Furthermore, young adults born preterm to hypertensive pregnancy were also investigated in their twenties. The research demonstrates that early-onset preeclampsia, diagnosed before 34 weeks gestation, is associated with blood pressure patterns in mothers 6-13 years after pregnancy that are distinct from those seen following later-onset disease. Furthermore, there is evidence of distinct differences in cardiac, vascular and metabolic profiles in these individuals with women having evidence of increased arterial stiffness, changes in cardiac function and reduced capillary density. Preterm offspring of hypertensive pregnancies similarly have higher blood pressure than seen in those born following late-onset disease and, in young adult life, have reduced endothelial function and changes in cardiac size proportional to this dysfunction. This research demonstrates adverse cardiac and vascular remodelling after preeclampsia in mothers and offspring that are evident before the development of clinical cardiovascular disease. The identified differences in cardiac and vascular function may be useful as surrogate endpoints in future preventive trials.

One approach that has demonstrated success in the field of molecular imaging utilizes microparticles of iron oxide (MPIO) conjugated to specific antibodies and/or peptides to provide contrast effects on MRI in relation to the molecular expression of a specified target. The experimental aims of this thesis were 1) to investigate the ability of VCAM-1 and P-selectin targeted MPIO to detect the expression of VCAM-1 and P-selectin on the activated endothelium in-vitro and in-vivo in mouse models of renal and cerebral ischemia reperfusion injury, and 2) develop a novel contrast agent for imaging αvβ3-integrin expression in angiogenesis using RGD peptide conjugated MPIO (RGD-MPIO) in-vitro. MPIO (1.0 µm) were conjugated to monoclonal antibodies against VCAM-1 (VCAM-MPIO) or P-selectin (PSEL-MPIO). In vitro, MPIO bound in a dose-dependent manner to tumor necrosis factor (TNF)-alpha stimulated sEND-1 endothelial cells when conjugated to VCAM-1 (R² = 0.88, P<0.01) and P-selectin antibodies (R² = 0.93, P<0.01), reflecting molecular VCAM-1 and P-selectin mRNA and protein expression. Mice subjected to unilateral, transient (30 minutes) renal ischemia and subsequent reperfusion received intravenous VCAM-MPIO and PSEL-MPIO (4.5 mg iron/kg body weight). In ischemic kidneys, MR related contrast effects of VCAM-MPIO were 4-fold higher than unclamped kidneys (P<0.01) and 1.5-fold higher than clamped kidneys of PSEL-MPIO injected mice (P<0.05). VCAM-MPIO binding was less evident in IRI kidneys pre-treated with VCAM-1 antibody (P<0.001). VCAM-1 mRNA expression and VCAM-MPIO contrast volume were highly correlated (R² = 0.901, P<0.01), indicating that quantification of contrast volume reflected renal VCAM-1 transcription. In mice subjected to cerebral ischemia, contrast volume was 11-fold greater in animals injected with VCAM-MPIO versus control IgG-MPIO (P<0.05). Finally, S-nitroso-N-acetylpenicillamine (SNAP) stimulated HUVEC-C cells, which express αvβ3-integrin, showed 44-fold greater RGD-MPIO binding than unstimulated cells (P<0.001) and 4-fold greater RGD-MPIO binding than SNAP stimulated cells blocked with soluble RGD peptide (P<0.001) in-vitro. This thesis demonstrated that targeted MPIO exhibited contrast effects that defined and quantified the molecular expression of specific targets through the use of high-resolution MRI in in-vitro and in-vivo models of vascular inflammation.

Peptides have attracted increasing attention as therapeutics in recent years, at least partially as a consequence of the widespread acceptance of protein therapeutics; but also as possible solutions to problems such as short half-life and delivery of molecules, and as therapeutics in their own right. The current work presents three projects that involve applications of peptides in a therapeutic environment. The first project studies the use of ER retaining peptides and CPPs (Cell penetrating peptides) in enhancing the effective concentration of DNJ (1-deoxynojirimycin), an α-glucosidase inhibitor, in cells. DNJ constructs with ER retaining peptides (6-[N-(1-deoxynojirimycino)]-hexanoyl-KDEL and 6-[N-(1-deoxynojirimycino)]-hexanoyl-KKAA) and CPPs (6-[N-(1-deoxynojirimycino)]-hexanoyl-TAT and 6-[N-(1-deoxynojirimycino)]-hexanoyl-MAP) were synthesised and analysed for their inhibitory activity against α-glucosidase I and II in vitro. The constructs were then analysed in a cell-based assay to determine their inhibitory activity on α¬-glucosidase-mediated hydrolysis of N-linked oligosaccharides. FITC-labelled ER retaining peptides were also synthesised to determine the internalisation and trafficking of the constructs by FACS and IF-microscopy. While none of the DNJ-constructs showed higher cellular inhibition than NB-DNJ (N-butyl DNJ; Miglustat), the CPP construct 6-[N-(1-deoxynojirimycino)]-hexanoyl-TAT showed comparable activity and the ER retaining construct 6-[N-(1-deoxynojirimycino)]-hexanoyl-KDEL showed a small but significant increase in activity following long-term administration. The second project focuses on beauveriolides, a cyclic depsipeptide family shown to have activity as ACAT inhibitors and thus a possible treatment for Alzheimer’s disease by the decrease in the production of Amyloid β (Aβ). A published total synthetic method was improved by the use of a cross-metathesis to reduce the total synthesis by 5 steps and increase its flexibility to allow the production of analogues. The synthesised beauveriolide III was used in attempts to develop an IF-FACS-based assay to measure the intracellular concentrations of Aβ. However, the location of γ-secretase in the used cell-line meant that levels of intracellular Aβ were not sufficient to track any decrease caused by ACAT inhibition. The third project involves the design of a cyclic peptide that could block the binding site for the influenza virus in the host cell. The cyclic peptide (cGSGRGYGRGWGVGA) was developed from a comparative study of four different sialic acid-binding proteins and synthesised by solution cyclisation of the linear peptide synthesised by traditional solid phase peptide synthesis (SPPS). An in silico study showed that the cyclic peptide allowed overlap with the binding site of Hemagglutinin. A 1H NMR titration determined the dissociation constant of the cyclic peptide to sialic acid. The KD corresponded to a low binding affinity, however the observed binding seemed to be specific and caused by a single bound conformation.

<b>Background</b>: Evidence-based policy making (EBPM) has become an article of faith. While critiques have begun to emerge, they are predominately based on theory or opinion. This thesis uses the 2008 case study of tobacco control policy making for Indigenous Australians to analyse empirically the concept of EBPM. <b>Research questions</b>: (1) How, if at all, did the Government use evidence in Indigenous tobacco control policy making? (2) What were the facilitators of and barriers to the use of evidence? (3) Does the case study augment or challenge the apparent inviolability of EBPM? <b>Methods</b>: Data were collected through: (1) a review of primary documents largely obtained under the Freedom of Information Act 1982; and (2) interviews with senior politicians, senior bureaucrats, government advisors, Indigenous health advocates and academics. <b>Results</b>: Historically, Indigenous smoking was not problematised because Indigenous people faced other urgent health/social problems and smoking was considered a coping mechanism. High prevalence data acquired salience in 2007/08 in the context of a campaign to reduce disparities between Indigenous and non-Indigenous health outcomes. Ensuing policy proposals were based on recommendations from literature reviews, but evidence contained in those reviews was weak; notwithstanding this, the proposals were adopted. Historical experiences led policy makers to give special weight to proposals supported by Indigenous stakeholders. Moreover, the perceived urgency of the problem was cited to justify a trial-and-evaluate approach. <b>Conclusion</b>: While the policies were not based on quality evidence, their formulation/adoption was neither irrational nor reckless. Rather, the process was a justifiable response to a pressing problem affecting a population for which barriers existed to data collection, and historical experiences meant that evidence was not the only determinant of policy success. The thesis proposes a more nuanced appraoch to conceptualising EBPM wherein evidence is neither a necessary nor a sufficient condition for policy. The approach recognises that rigorous evidence is always desirable but that, where circumstances affect the ability of such research being conducted, consideration must be given to acting on the basis of other knowledge (e.g. expert opinion, small-scale studies). Such an approach is justifiable where: (1) inaction is likely to lead to new/continued harm; and (2) there is little/no prospect of the intervention causing additional harm. Under this approach, non-evidentiary considerations (e.g. community acceptability) must be taken into account.

Neisseria meningitidis causes 500,000 cases of meningitis and septicaemia annually worldwide, with a mortality rate of approximately 10%. Most disease in developed countries is caused by serogroup B infection, against which there is no universal vaccine. Opa proteins are major meningococcal outer membrane proteins, and a limited number of Opa variants have been associated with hyperinvasive serogroup B meningococci, suggesting their use as a potential novel vaccine. Immunisation of mice with recombinant Opa elicited high levels of meningococcal-specific serum bactericidal antibody (SBA), demonstrating proof in principle of this approach. Opa proteins mediate bacterial adherence to host cells and modulate human cellular immunity, and there are conflicting data regarding their effects on CD4⁺ T cells. opa genes from N. meningitidis strain H44/76 were cloned into the plasmid vector pBluescript, disrupted using antibiotic resistance cassettes and transformed into H44/76 to sequentially disrupt the four opa genes. This produced a unique panel of 15 isogenic Opa-deficient strains, including an Opa-negative strain, which enabled investigation of the immunomodulatory role of surface-expressed Opa proteins. There was no consistent effect of Opa expressed on the surface of OMVs and inactivated bacteria on CD4⁺ T cells, with significant heterogeneity of responses between individuals. The rate of Opa phase variation was between 10^-3 and 10^-4, and increased 180-fold following transformation of bacteria with unrelated DNA. These data support further investigation of Opa as a potential meningococcal vaccine component, and highlight the importance of host and bacterial factors in the development of OMV vaccines.

This study used the Health Belief Model to examine the predictors of AIDS preventive behavior. The independent variables were the variables of individual perception, modifying factors (psychological variables), and likelihood variables. The respondents, the Taiwanese students of the University of North Texas, were influenced both by Chinese sexuality and Western values in their AIDS-risk behavior. The results revealed that 90% of the respondents were misinformed on the availability of AIDS vaccine. In addition, a majority of the students were either abstaining from sex or practicing monogamy. Using Pearson's correlation coefficient and multiple regression analysis, this study found that the psychological variables rather than cognitive variables significantly influenced the respondents' AIDS preventive behavior. Finally, suggestions were made for future research on AIDS, and for AIDS preventive behavior campaigns.

The aim of this thesis was to develop yoga as a complex intervention in health care for the improvement of health-related quality of life (HRQoL) in adult cancer. As the Indian tradition of practising yoga increases in popularity worldwide, populations in the West are beginning to see yoga as an opportunity to prevent and treat health conditions. The Medical Research Council’s framework has provided a methodology to address a paucity of coherent evidence for the myriad of unsupported health claims made by yoga enthusiasts. The thesis structure included a step-by-step approach to investigate biomedical theories of how yoga might work to improve health, to synthesise evidence of yoga interventions, to model their process and outcomes, and to test evaluation procedures in the context of a randomised controlled trial (RCT). The results of a bibliometric analysis indicated an overall increase in the publication rate of yoga research in health care, and in 2005 this research began to focus on cancer. A component analysis, semi-structured patient interviews (n=10) and oncologist surveys (n=29) were successively designed, implemented and analysed to advance a model of yoga intervention specific to adult cancer. The cumulative results were applied to design three yoga interventions randomly allocated to men and women receiving treatment for cancer (n=15). Outcomes of the feasibility study demonstrated that yoga intervention is appropriate for adult patients and can be administered safely in a clinical setting. In its conclusion, this thesis produces evidence-based support for the optimisation of yoga intervention in the context of a large-scale RCT for HRQoL in adult cancer, and it provides recommendations to improve research methodology and reporting of complex interventions in health care.