Diabetes is currently a wide spread global disease. As a result of the side effects of the current therapies, herbal plants may present alternative source of drugs for management of the disease. Mucuna pruriens is a plant that is traditionally used for diabetes and anaemia. There are experimental reports of the hypoglycaemic effect of the alcoholic extracts but the anti-diabetic effects of the aqueous extract has not been investigated. Therefore, the aim of this project was to investigate the potential anti-diabetic mechanisms of the aqueous extract of Mucuna pruriens leaves. The leaf extract was prepared by decoction. The potential mechanisms of anti-diabetic effect of this extract was evaluated as follows: Antioxidant activity of the aqueous Mucuna pruriens leaf extract was investigated in reduced β-nicotinamide adenine dinucleotide (NADH)/phenazine methosulphate (PMS), and Xanthine /Xanthine oxidase superoxide generating systems. In addition, the effect of aqueous Mucuna pruriens leaf extract against oxidative stress was measured as cytoprotective effect of the extract against paraquat induced oxidant injury in NRK-52E renal cells. Cytoprotective effect was measured as cell viability and cell death using 3-(4,5-Dimethylthiazol-2-Yl)-2,5 Diphenyltetrazolium Bromide (MTT) and Lactose dehydrogenase (LDH) assays respectively. Finally the effect of aqueous Mucuna pruriens leaf extract on glucose uptake was evaluated in NRK-52E renal cells and 3T3-L1 adipocytes. The results revealed that aqueous Mucuna pruriens leaf extract had significant superoxide scavenging activity which increased from 21.35% to 99.8% in xanthine/xanthine oxidase and 36.15% to 62.4% in NADH/PMS superoxide generating systems at p < 0.05. However, aqueous Mucuna pruriens leaf extract did not protect against paraquat induced oxidative stress. Data from glucose uptake experiments showed that 1mg/ml of aqueous Mucuna pruriens leaf extract inhibited glucose uptake in NRK-52E renal by 35.5% compared to control at p < 0.05. This effect was comparable to 1mM Phloridzin (a non- selective inhibitor of sodium glucose transporters). Finally, 50 and 100μg/ml of both aqueous Mucuna pruriens leaf extract and its acid hydrolysed fractions prepared with liquid-liquid partitioning in diethyl ether, stimulated glucose uptake in 3T3-L1 adipocytes. Specifically, 50 and 100μg/ml aqueous Mucuna pruriens leaf extract stimulated glucose uptake be 57.06 and 86.24% respectively compared to negative control at p < 0.05. Increase in glucose uptake was also observed in cells treated with diethyl ether acid hydrolysed fractions. Taken together, the results show that aqueous the Mucuna pruriens leaf extract used in this study may exert anti-diabetic effects via antioxidant and glucose uptake modulatory mechanisms.

Prokaryotic toxin-antitoxin (TA) systems (also known as addiction modules), are ubiquitous genetic modules first discovered due to their role in stabilising vertical transmission of plasmids. Generally they are two-gene systems encoding a stable toxin (Tx) and an unstable antitoxin (ATx). Loss of the TA module leads to rapid ATx degradation and depletion, leaving the Tx free to interact with cellular targets and inhibit growth. For plasmid encoded TA systems, this leads to the death of plasmid free daughter cells, ensuring plasmid maintenance in a population, and gives rise to the term "addiction module". More recently, the expansion in microbial genome data has highlighted the prevalence and diversity of TA systems, and demonstrated that they are common features of many bacterial chromosomes. In addition, metagenomic surveys have pointed to the enrichment of some TA families in particular microbial ecosystems; a prime example from surveys of the human gut microbiome and RelBE TA family. Collectively, these observations indicate a wider role for TA modules in bacterial function, with numerous roles for TA systems now hypothesised. These include: i) Stabilisation of TA associated chromosomal DNA during vertical transmission; ii) Formation of "persister" cells resistant to environmental stresses, and; iii) Population level resistance to bacteriophage attack. Additionally, some Tx components have shown activity in eukaryotic cells, raising the potential for a role in prokaryote-eukaryote interaction. Here we undertook a systematic study of Type II TA systems, to provide a comprehensive assessment of their distribution and relative abundance, to confirm activity of prevalent TA systems, and to understand putative roles these may play in gut associated bacteria and the gut microbiome. A comparative genomic and metagenomic analysis of 3919 bacterial chromosomes, 4580 plasmids, 711 bacteriophage genomes, and 781 metagenomes encompassing 16 distinct habitats was conducted using all known Type II TA systems present in the Toxin Antitoxin Database (~10,100 TA genes ~1:1 Tx:ATx). Of the 817 Type II TA system homologues found in human gut datasets, 686 were observed to have significantly higher relative abundance in the human gut microbiome over other microbial ecosystems. In parallel to these in silico findings, PCR and qPCR surveys of microbiomes from 65 stool samples obtained from healthy volunteers, as well as those with polyps or colorectal cancer, were undertaken. This demonstrated a higher ATx presence than Tx or complete module, however no differences in Tx copy number between health groups was seen. To confirm the activity of the most abundant TA system homologues identified in sequence surveys, ORFs were amplified from gut metagenomic DNA, and individual Tx or ATx cloned under the control of inducible promoters. Induction of Tx expression under normal growth conditions resulted in bacterial growth inhibition, while live dead staining showed entry into a viable but non-cultivatable state, commensurate with TA function. Experiments simulating environmental stresses encountered during colonisation of the GI tract (starvation, low pH, bile), indicated that expression of these TA systems could increase cell survival when carbon or nitrogen availability was limited (starvation). Since antibiotics are also commonly encountered by gut associated-bacteria (both as residents of the GI tract and during colonisation of other body sties) a role for gut associated TA systems in facilitating survival during antibiotic exposure was also explored. This revealed an increased number of cells surviving two hours post-treatment with β-lactams when Tx genes were expressed, and in keeping with an impact on cell growth. To test the hypothesis that TA systems may stabilize associated regions of DNA, the composition of gene neighbourhoods surrounding TA systems were also explored. ORFs surrounding TA system homologues identified in metagenomic and genomic datasets were identified using the Metagene annotator, and ORF functions predicted based on searches of the Clusters of Orthlogous Groups (COG) database. This revealed significant increases in ORFs with functions related to replication/recombination/repair and those with unknown functions. It also identified a decrease in the proportion of ORFs encoding functions such as carbohydrate and lipid transport and metabolism in regions surrounding TA systems, suggesting involvement with stabilization of mobile elements. Finally, we explored the potential for gut associated TA systems to modulate phage-microbe, and host-microbe interactions. In the case of phage-host interactions, TA systems have previously been shown to function as mediators of phage resistance at the population level, by directing cells towards a dormant state which prevents phage replication, and permits a sub-set of cells to survive phage attack. Our findings indicated the potential for gut associated TA systems to provide some degree of protection during particular host-phage interactions, but specific modules did not provide universal protection against phage. In the case of host-microbe interaction, some Type II TA system Tx components have been shown to be functional in cultured eukaryotic cells, promoting apoptosis when introduced and expressed in these cell types. However, no studies to date have examined the potential for bacterially expressed TA systems to influence eukaryotic cell health in co-culture models. To investigate this, we assessed the impact of bacterial TA system expression on the health of the intestinal epithelial cell line Caco-2 in co-culture systems specifically focusing on cell apoptosis and necrosis whilst in the presence of Escherichia coli expressing p22-RelBE.

Inhaled drug delivery is ideal for treatment of asthma and chronic obstructive pulmonary disease (COPD) as it allows a local action of the medication at the disease site. Biodegradable polymeric nanoparticles which might allow extended/sustained release of inhaled drugs are synthesized using various methods however; these do not permit high encapsulation efficiency for hydrophilic drugs. The aim of the project was to test the hypothesis that it was possible to develop an efficient method for the co-encapsulation of a hydrophilic and lipophilic drug (theophylline and budesonide respectively) into nanoparticles. In order to improve the loading efficiency of both hydrophilic and hydrophobic drugs, a modified double emulsification solvent diffusion (DESD) method was developed and both co-encapsulated and mono-encapsulated nanoparticles (containing either drug) were synthesized. Improved loading efficiency, studied using high performance liquid chromatography (HPLC), for both drugs was obtained. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) showed that particles were in the sub-micron range (150-400 nm). Measurement of zeta potential showed that the particles had a negative surface charge and additionally Fourier-transform infra-red (FT-IR) spectroscopy confirmed that this was due to the polymer and no drug was adsorbed on the external surface of the nanoparticles. Resemblance of nanoparticles thermograms, obtained using differential scanning calorimetry (DSC), to those of the polymer alone suggested successful encapsulation of the drugs. Stability studies of the drug encapsulated nanoparticles conducted at different temperatures indicated that storage conditions of 2-8°C over a period of 6 months showed minimal changes in the particle size, zeta potential and morphological characteristics of the nanoparticles. Storage (of the nanoparticles) at 40°C over the course of 6 months resulted in larger variations on the particle size and zeta potential but also loss of morphological features of the nanoparticles, suggestive of changes in the polymer state at this temperature. Franz diffusion cells were used to study the release of drugs from the nanoparticles over 24 hours at room temperature and at 37oC. The results showed that release of theophylline and budesonide from nanoparticles was biphasic and sustained compared to release of drug from solutions containing an equivalent concentration of drug. The effect of the nanoparticles on the viability of airway epithelial cells was studied using a human bronchial epithelial cell line (16HBE14o-) using a 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The nanoparticles had no significant effect ii on cell viability except at the highest concentration of the suspension studied (5 mg/mL) (P < 0.05). The permeability of 16HBE14o- cells, cultured at an air-liquid interface, to theophylline and budesonide applied in solution and as mono-encapsulated and co-encapsulated nanoparticles was studied. The nanoparticles and drug solutions did not affect the tight junctions of the cells and similar to the results obtained in the Franz diffusion cells, both drugs crossed the cells more slowly when applied as nanoparticles in comparison to the solutions. To study deposition of the nanoparticles; nebulized suspensions of the nanoparticles in de-ionized water and dry powder formulations using different grades of lactose were compared. The prepared formulations were studied using a multi-stage liquid impinger (MSLI). The results indicated that drug deposition was greatest in stages 1 and 2 of the MSLI where particle size was greater than 6.8μm from the dry powder formulations in contrast to deposition throughout the five stages of the MSLI from the nebulized suspension. Morphological assessment of the dry powder formulations using SEM showed nanoparticles adhered to the lactose but also included nanoparticles in the absence of lactose and vice versa. In conclusion, theophylline and budesonide nanoparticles were successfully formulated using PLA by application of the DESD method. Nanoparticles possessed desired physicochemical properties including submicron size range and negatively charged surface; however a higher loading efficiency of the hydrophobic drug was obtained despite modifications to the DESD method. Low toxicity of the nanoparticles to human bronchial epithelial cells and sustained release over a period of 24 hours was achieved. Nanoparticles were delivered successfully in the target site at a desired particle size range when formulated as nebulized suspensions.

The aim of the study was to describe how patient understanding and attitude to the effects of rheumatoid arthritis on the foot, and the services available to help limit this, influences self reporting of foot problems. Referral to podiatry was occurring at a stage in the disease process too late to instigate certain preventative interventions. Preliminary fieldwork highlighted that the responsibility for the instigation of this locally lay with the patient. Literature supports the inclusion of podiatry within the multidisciplinary rheumatology team and early foot assessment with regular monitoring. There was a gap in the literature relating to the effectiveness of patient self-reporting in terms of foot health and the implications of relying on this approach.

In the UK, there are now more people over state pensionable age than there are children. With the UK Government‟s plans to raise state pension age in line with increasing longevity, many older people may need further paid employment into what would formerly be termed their retirement years. The concept of retirement is becoming an unknown entity that brings challenges and uncertainty. It is a UK Government priority to address the need for cost-effective, innovative initiatives to promote health and well-being of older people, preparing them effectively for their retirement years. Occupational therapists are ideally placed to collaborate with such individuals to attain optimal levels of health, functioning and life satisfaction through meaningful occupation.

The expanding field of stroke medicine lacks foundation if it fails to embrace the infrastructure of experiential evidence, instrumental in shaping future services by identification of need. Potential seriousness of fleeting illness, like transient ischaemic attack (TIA) a precursor for stroke with devastating health and social consequences may be underestimated. Lack of awareness leads to under-reporting and not accessing timely medical attention and the latter could obviate serious consequences of long-term disability. Informed choice and opportunity to avert these circumstances by lifestyle changes needs to be available to all to take responsibility for health. The literature gap of lived experience of illness needs narrowing, particularly transient illnesses like TIA that comes under the umbrella of stroke yet is a discrete illness of very short duration and nonetheless alarming. Health and social care lifetime costs of stroke are immense. Implications for evidence-based clinical practice concern influencing lifestyle changes, a role that physiotherapists could take to help avert disastrous costly outcomes consequent upon modifiable risks. This lead to a research question of: What is the lived experience of a TIA? The intention of this study was to position the research within current UK National Health Service (NHS) policy considering the historical and philosophical background and psychosocial theories of health and illness. A tension exists between increasing public awareness of health matters and improved health against unhealthy behaviours of sedentary lifestyles and poor diets leading to lifestyle diseases with budgetary implications. Multiple behaviour theories affect lifestyle change. One trigger is evidence-based information with sufficient impact to awaken a response to take responsibility for health. Influences are education, knowledge, patient-centred care, partnership, choice, empowerment, consumerism and professional roles and identity. Studies of other transient illnesses were considered.

Back pain is a common and costly disorder affecting 80% of the population, with 80-90% of the symptoms reported to have no pathological cause and it is suggested that this non-specific low back pain can be improved by the adoption of proper posture and body mechanics during normal daily life.

This thesis explores perceptions of nursing held by a range of stakeholders at the beginning of the 21st century. Using a constructivist methodology, this study locates nursing within the current context of healthcare, acknowledging the historical and socio-political influences which have contributed to shaping nursing’s identity and nursing work. The use of a case study approach as the mode for constructivist inquiry draws on an understanding of this approach as a ‘depth examination of an instance’ (Lincoln and Guba, 1985 p.360). This recognises the contemporary and time bound nature of the study, located in a time of modernisation and change within both nursing and the wider National Health Service.

Mechanisms of cochlea excitation and amplification were investigated experimentally across a range of mammalian species. Distortion product otoacoustic emissions (DPOAEs) are used to clinically assess hearing. DPOAEs recorded from the ears of human subjects in the presence of a low frequency, high level tone were compared with similar recordings made from guinea pigs. Both guinea pig and human data were found to originate from a common cochlear nonlinearity; the Boltzmann model of DPOAE generation at the output of a spatially localised single-saturating non-linearity. Accordingly, the guinea pig cochlea can be used as a human model system for the study of DPOAE generation.

Novel steroidal oestrogens, that incorporate some of the structural motifs of non-steroidal antioestrogens, were synthesised and tested for their actions on the BK channel. These novel compounds were first checked for purity and structure using, where appropriate, 1H NMR, 13C NMR, IR spectroscopy, mass spectroscopy, thin layer chromatography, melting point analysis, elemental analysis and X-ray crystallography. Using Oestrone as the starting compound, the following five novel compounds were synthesised; DME-Oestrone, Quat-DME-Oestrone, DME-Oestradiol, Quat-DME-Oestradiol and Oestrone-Oxime. Two of the derivatives, Quat-DME-Oestrone and Quat-DME-Oestradiol, incorporated a quaternary ammonium side-chain making them membrane impermeable.