Skeletal muscle comprises about half of the body weight in mammals and its diverse roles in metabolism and innate immune functions makes cultured muscle as a useful tool in biomedical research. In this thesis, some of the major technical obstacles in porcine primary muscle cell cultures such as inadequate differentiation of myoblasts into myotubes and the premature detachment of the formed myotubes have been overcome with the achievement of high differentiation and myotube fusion rate of over 85% along with prolonged maintenance of myotubes in excess of 70 days. Myosin heavy chain (MyHC) expression profile of differentiated myotubes recapitulated adult muscle fibres and displayed phenotypic plasticity of gene expression in response to different media. Growth factor ractopamine (Ract) treatment (1h and 6h) of myotubes followed with subsequent bioinformatics analysis of a stable isotope labelling by amino acids in cell culture (SILAC) based proteomics study suggested differential expression of proteins associated with anti-viral innate immune response and increased protein accretion. Porcine muscle cells were infected with influenza A viruses to evaluate their immune function. Porcine muscle cells expressed influenza virus sialic acid α-2,3 and α-2,6 receptors and were fully permissive to influenza virus infection. Myoblasts produced more virus particles than myotubes. Muscle cells expressed the pro-inflammatory genes tumor necrosis factor alpha (TNF-α) and antiviral gene Mx-1 and the infected cells had elevated caspase 3/7 activity to indicate apoptosis. However, myotubes pre-treated with Ract appeared to confer no reduction in influenza virus output. Evidence presented herein suggests that the functional myotubes developed by this work can be used as a tool to study the molecular mechanisms of growth and innate immune pathways in muscle.

Abdominal pain (colic) in the horse is one of the most common emergency problems in the horse, but there are major gaps in the current evidence. Five original studies were undertaken to build evidence on the primary assessment of abdominal pain in the horse. The first study was a systematic review of risk factors for abdominal pain. This identified 83 publications on risk factors for colic; 47 met inclusion criteria and were reviewed and categorised. Twenty four studies were evaluated using the JBI-Mastari critical appraisal tool. Evidence from the ten publications with least susceptibility to bias was collated. There was consensus of evidence for increasing age, recent change in diet and previous history of abdominal pain are risk factors for colic. This evidence should inform veterinary practitioner’s clinical decision making and approach to disease prevention. The second study was a systematic review of diagnostic tests for abdominal pain. This identified 190 publications; 46 publications met inclusion criteria and were reviewed and categorised. Thirty studies were evaluated using the QUADAS critical appraisal tool. None of the studies used a suitable methodology to assess the value of a diagnostic test to differentiate critical cases. The outcomes of this systematic review were a description of the current evidence and recommendations for future research using appropriate study designs. Both systematic reviews highlighted a lack of evidence from primary practice. The third study was a prospective survey of the primary assessment of horses with abdominal pain by veterinary practitioners. Data was collected from 1016 cases, including clinical history, presenting signs, diagnostic and treatment approaches and case outcome. Cases were categorised as critical or non-critical. Multivariate logistic regression was used to identify clinical features associated with critical cases. Five variables remained in the final model: pain, heart rate, capillary refill time, pulse character and gastrointestinal borborygmi. These should be considered essential components of the initial assessment and triage of horses presenting with colic. The fourth study was an online survey of veterinary practitioner’s opinions of diagnostic tests for colic. Responses from 228 participants were analysed. The most frequently used tests were ‘response to analgesia’, ‘rectal examination’ and ‘nasogastric intubation’, but there was a wide variation in practitioners’ approaches. The main reasons for not using tests were that practitioners considered they were not required, or had concerns around personal safety, lack of facilities or financial constraints. The final phase was two multi-disciplinary workshops to review current evidence and generate recommendations. Fifty participants attended the first workshop and generated 84 statements on the recognition of colic. Forty one participants attended the second workshop and generated 160 statements on the assessment of horses with colic. These statements form the first phase of a multi-disciplinary Delphi process to develop best practice guidelines on the recognition and primary assessment of horses with abdominal pain. This research makes significant contributions to the current evidence on abdominal pain in the horse. It has consolidated existing information, made recommendations for future research, and worked with practitioners to address evidence gaps, and involved different stakeholders in deciding how this evidence should be applied.

Abstract not available.

To examine which component(s) of soy proteins are diabetogenic, studies were designed to look at diabetes-related soy protein fractions. In a study of diabetes-prone and control BB (BioBreeding) rats, sera from BBc (non-diabetes-prone), BBdp (diabetes-prone), BBd-U (diabetic untreated) and BBd-T (diabetic insulin-treated) rats at different risk of developing diabetes were tested against the proteins extracted from different soy protein sources. A diabetes-related protein designated S10 was identified and reactivity against two protective bands designated S6 and S13 was associated with less risk of developing diabetes. Two separate cross sectional and prospective (blood samples collected at 45 d, 70 d and 149 d or at diagnosis) studies were carried out. Western blotting results in both studies confirmed that high S10 reactivity in the pre-diabetic period was associated with diabetes. Overall Western blot analyses showed interestingly that two soy protein-fractions, S6 and S13, were related to resistance and reactivity against these two fractions may be protective and the S10 soy protein fraction appears to be highly diabetes-related and associated with diabetes. In studies using human serum, two sets of blood samples from newly diagnosed diabetic children showed the same association for the S10 soy protein fraction. Early oral dosing with soybean meal delayed the onset of diabetes and protected some of the animals from developing the disease. Pre-absorption studies showed there was an overall reduction in reactivity to soy antigens using pre-absorbed sera. This indicated some cross reactivity between food antigens and RIN cell proteins. (Abstract shortened by UMI.)

Accounting for much of the landscape of southern England, chalk stream environments hold significant cultural, economic and ecological value. However, attempts to retain this value are often hindered by the remnants of historic management practices that have occurred across several millennia, as well as contemporary demands upon chalk stream amenity, including water abstraction, recreational use and fisheries management. One land-use that is believed to have a detrimental effect upon chalk streams, but which has been inadequately researched, is cattle grazing. Within this thesis the effects of cattle grazing in English chalk streams are assessed using a range of techniques. Terrestrial laser-scanning is employed to show that cattle can cause small, local changes in river bank topography. Direct and remote observations are used to link cattle behaviour to landscape utilisation, and a staticially significant correlation between air temperature and in-stream cattle activity is identified. Laboratory faecal analysis is conducted to establish the nutrient loading due to cattle, with results showing that cattle faeces contain signfiicant concentrations of phosphate. In-stream water turbidity monitoring is combined with remotely sensed cattle behaviour data to demonstrate that in-stream cattle activity has a minimal effect upon suspended sediment concentrations in an English chalk stream. A study using the diffuse fine sediment risk model, SCIMAP, highlights the hydrologically disconnected nature of English chalk streams, with model outputs concluding that topography, rather than land-use (cattle grazing), is the key control on diffuse fine sediment risk in English chalk streams. Combined, these individual findings provide a detailed, inter-disciplinary assessment that concludes the effects of cattle grazing in English chalk streams are different to those recorded in research from other environments, with physio-chemical effects (i.e. nutrient loading) being of greater significance than geomorphological agency (i.e. river bank destabilisation). This overarching conclusion has implications for the management of cattle grazing in English chalk streams, and these are discussed.

No description available.

No description available.

No description available.

No description available.

No description available.