Periodontal disease is a common and painful condition in the horse. Although awareness of the condition is growing amongst the veterinary profession and horse owners, the presence of the disease is often overlooked and treatment can be difficult. Despite this, there have been few recent studies of the aetiopathogenesis of the condition. Certain species of bacteria may act as periodontal pathogens, stimulating a destructive inflammatory response in periodontal tissues and this has been well recognised as being important to the aetiopathogenesis of the disease in man. However few equine studies on this aspect of the disease have been carried out. The main aims of this study were: - 1) to identify the bacteria associated with a healthy oral cavity and periodontitis in horses using culture dependent and independent methods; 2) to assess the differences in bacterial populations between the healthy and periodontitis groups and identify putative pathogens; 3) to quantify the expression patterns of TLRs 2, 4 and 9, the pro-inflammatory cytokines IL-1β and TNFα, anti-inflammatory cytokine IL-10 and Th1/Th2/Th17 cytokines IL-4, IL-6/ IL-12, IFNɣ/ IL-17, within gingival tissue from each sample group; 4) to use matched data to establish if associations exist between the presence and quantity of bacterial species present and TLR expression and 5) to determine activation of TLRs 2, 4 and 9 by putative pathogens using specific in- vitro TLR assays. Swabs were taken from the gingival sulcus of 42 orally healthy horses and plaque samples were taken from the periodontal pockets of 61 horses with periodontal disease. The location and grade of the lesion was noted and an equine dental chart completed for each case. Bacteria were identified using high throughput 16S rRNA gene sequencing, QPCR, whole genome sequencing and conventional culture followed by 16S gene sequencing. Gingival biopsies were taken from 13 orally healthy horses and 20 horses with periodontitis and gene expression of TLR 2, TLR 4, TLR 9, IL-1β, IL-4, IL-6, IL-10, IL-12, IL-17, TNFα and IFNɣ was measured. THP-1X Blue, MyD88 THP-1X Blue, HEK hTLR 2 Blue and HEK hTLR 4 Blue human cell lines were co-cultured with putative periodontal pathogens and their response measured via level of secreted embryonic alkaline phosphatase. Clinical, microbiological and immunological data underwent cross-matching analysis. Microbial populations showed 89% dissimilarly between oral health and periodontitis with a less diverse population present in diseased equine periodontal pockets. The most discriminative bacteria between health and disease identified at genus level were Fusobacteria and Acinetobacter in health and Pseudomonas and Prevotella in periodontitis. The most abundant genera were Gemella (36.5%), Pseudomonas (14%) and Acinetobacter (8%) in orally healthy samples and Pseudomonas (25%), Prevotella (14%) and Acinetobacter (9.4%) in periodontitis samples. Whole genome sequencing revealed the presence of 75 species of Prevotella in the equine oral cavity and a significantly higher number of reads corresponding to Prevotella bivia, Prevotella dentalis, Prevotella denticola, Prevotella intermedia, Prevotella melaninogenica, Prevotella nigrescens were noted in diseased samples. Significant increases in expression of TLR 4 mRNA, TLR 9 mRNA and, in particular TLR 2, mRNA were noted in diseased equine gingival tissue in addition to increased pro-inflammatory and anti-inflammatory cytokine mRNA expression. Presence of P. intermedia was significantly positively correlated with expression of TLR 2 in equine periodontitis. In addition, the presence of Aggregatibacter actinomycetemcomitans was positively associated with disease severity and expression of TLR 4 mRNA in the horse. Co-culture of periodontal pathogens with human cell lines revealed that the innate immune response to the presence of these bacteria is mainly mediated through TLR 2 activation. The use of both culture dependent and culture independent methods to investigate the equine oral microbiome has provided significant breadth and depth of information on the microbiology of equine periodontal disease. Microbial populations are significantly different as expected and bacteria belonging to the Prevotella genus have been strongly implicated in the aetiopathogenesis of the condition. The innate immune response produced in periodontally diseased equine gingival tissue has been characterised for the first time in the horse.

Bovine mastitis, inflammation of the mammary gland, is one of the most costly and prevalent diseases in the dairy industry. It is commonly caused by bacteria, and Streptococcus uberis is one of the most prevalent causative agents. With advancements in omics technologies, the analysis of system-wide changes in the expression of proteins and metabolites in milk has become possible, and such analyses have broadened the knowledge of molecular changes in bovine mastitis. The work presented in this thesis aims to understand the dynamics of molecular changes in bovine mastitis caused by Streptococcus uberis through system-wide profiling and integrated analysis of milk proteins and metabolites. To this end, archived milk samples collected at specific intervals during the course of an experimentally induced model of Streptococcus uberis mastitis were used. Label-free quantitative proteomics and untargeted metabolomics data were generated from the archived milk samples obtained from six cows at six time-points (0, 36, 42, 57, 81 & 312 hours post-challenge). A total of 570 bovine proteins and 690 putative metabolites were quantified. Hierarchical cluster analysis and principal component analysis showed clustering of samples by the stage of infection, with similarities between pre-infection and resolution stages (0 and 312 hours post-challenge), early infection stages (36 and 42 hours post-challenge) and late infection stages (57 and 81 hours post-challenge). The proteomics and metabolomics data were analysed at both individual omics-layer level and combined inter-layer-level. At individual omics layer-level, the temporal changes identified include changes in the expression of proteins in acute-phase response signalling, FXR/RXR activation, complement system, IL-6 and IL-10 pathways, and changes in the expression of metabolites related to amino acid, carbohydrate, lipid and nucleotide metabolisms. The combined inter-layer-level analyses revealed functional relevance of proteins and metabolites enriched in the co-expression modules. For example, possible immunomodulatory role of bile acids via the FXR/RXR activation pathways could be inferred. Similarly, the actin-binding proteins could be linked to endocytic trafficking of signalling receptors. Overall, the work presented in this thesis provides deeper understanding of molecular changes in mastitis. On a secondary note, it also serves as a case study in the use of integrative polyomics analysis methods in the investigation of host-pathogen interactions.

No description available.

Lymphoma is the most common haematopoietic malignancy of dogs, but little is known about its aetiology and pathogenesis. Canine lymphoma is composed of a clinically heterogeneous group of tumours, as in human non-Hodgkin lymphoma (hNHL), which shares many similarities with the canine disease. In humans, lymphoma is classified into many different subtypes, each with its own clinicopathological characteristics, prognosis, and in many cases, treatment regime. In dogs, diagnosis is often rudimentary, and many cases are not routinely or robustly subtyped. This has hampered efforts to develop accurate prognostic indicators and novel therapies, as heterogeneous groups of cases are analysed. More accurate classification of canine lymphomas is required before real progress can be made. In the work described in this thesis, molecular techniques were used to develop diagnostic tests to aid diagnosis of canine lymphoma, with a view to improving disease classification, and gaining a greater understanding of disease pathogenesis. The diagnosis of canine lymphoma can be assisted by PCR for antigen receptor rearrangements (PARR), which can determine clonality and tumour cell lineage. Diagnostic samples from suspected lymphoma patients were screened with multiple published PARR primers to establish a panel of assays for routine use. Primer coverage was assessed, and modifications to both primer sequences and primer combinations made where necessary. The optimised PARR assay was robust, highly sensitive and specific, comparable with published studies and provided useful diagnostic information unavailable from other tests. In humans, the Epstein-Barr virus (EBV) is associated with several lymphoma subtypes. Recently, it has been suggested that EBV or an EBV-like virus is circulating in dogs. Serological and molecular techniques were used to investigate whether EBV, or a novel herpesvirus, is associated with canine lymphoma. In an assay designed to detect antibodies to EBV viral capsid antigens, 41% of dogs were positive. Dogs with cancers, including lymphoma, were more frequently positive than controls, but no particular association with B-cell lymphoma was noted. EBV-specific RNA and DNA sequences were not detected in lymphoma tissue by in situ hybridisation or PCR and herpesvirus genomes were not detected using multiple degenerate PCR assays with the ability to detect novel herpesviruses. No evidence that herpesviruses are directly involved in common types of canine lymphoma was found, although the presence of an EBV-like virus in the canine population cannot be excluded. Gene expression profiling has been used to subtype human diffuse large B-cell lymphoma, and to provide insight into pathogenesis. Next-generation sequencing was used to generate transcriptome data from a panel of canine B- and T-cell lymphomas. Gene expression analysis showed clear clustering of B-cell and T-cell types, and suggested that differentiation within the B-cell group was possible. Pathway analysis demonstrated up-regulation of genes in pathways appropriate to the tumour type. Sequence data were also explored to identify variants in important genes and pathways which may have functional consequences. Many affected genes were identified, and comparison with hNHL suggested that common driver mutations are present. By identifying novel targets, such studies may pave the way for development of new therapies to benefit both man and dog.

Human papillomavirus type 16 (HPVI6) is a causative agent of cervical cancer. The HPV16 viral transcription/replication factor E2 is essential for the viral life cycle. The function of E2 is dependenton the interaction with cellular partner proteins. The amino- terminal domain of E2 is an acidic protein-protein interaction domain essential for all of the functions of E2. A yeast-2-hybrid screen using the amino-terminal domain of HPV16 E2 as bait identified multiple possible partner proteins for E2 function (Boner & Morgan 2002) including the DNA replication/repair protein TopBPl. E2 molecules from HPVI6 and HPV18 interact with multiple proteins involved in the cellular response to DNA damage (e.g. p53, BRCAl, PARP and TopBPl). The role of TopBPl in E2 function and the functional response of E2 to DNA damage stimuli were investigated. Overexpression of TopBPl enhances the transcription and replication activation functions of E2. Overexpression of an amino-terminal truncation mutant of TopBPl has no effect on the transcription/replication functions of E2. During this study a novel method for the detection of E1/E2 DNA replication function by real-time PCR was developed. The UVB irradiation of cells resulted in the significant reduction of both E2 transactivation function and E2 protein amount. These results demonstrated that E2 function is altered by cellular DNA damage response proteins and signaling pathways. In many HPV induced cancers the HPV genome is either present integrated into the cellular chromosomes or is maintained episomally with large DNA deletions/rearrangements. Therefore HPV genome stability is a significant risk factor for the development of HPV induced cancer. Thus the fidelity of DNA replication activated by the HPV 16 E1/E2 replication factors was investigated on undamaged and UVC damaged templates in a variety of genetic backgrounds. On undamaged DNA templates there were a significant amount of mutations due to DNA deletions/rearrangements and the frequency of mutation increased when the template was damaged. This increase on damaged templates was marked in cells with defects in key DNA replication or repair proteins. These results highlight the instability of HPV16 genome replication. The interaction of E2 with DNA damage response proteins and the reduction of E2 function in response to DNA damage may be an evolutionary response by the virus to ensure genetic integrity and host cell viability.

The historical development, uses, pharmacology, chemistry and metabolism of phanothiazine and the phenothiazine tranquillisers are reviewed along with the analytical techniques which have been used for their detection and determination. The metabolism and excretion by the horse of promazine chlorpromazine, acepramazine and propionylpromazine, tranquillisers commonly used in equine practice, have been examined qualitatively and quantitatively. Methods of collection, storage and analysis of horse urine have been developed, and the use of mass spectroscopy in combination with gas liquid chromatography for the detection of phenothiazine derivatives in biological fluids has been examined. Qualitative results have shown that many biotransformations of such derivatives take place in the horse. 30 metabolites of promazine were detected in addition to the parent drug, 20 of chlorpromazine and 11 and 6 respectively from acepromazine and propion ylpromazine. Hydroxylation followed by conjugation, prademinantly with glucoronic acid and to a smaller extent with sulphuric acid, is the major route of metabolism of promazine and chlorpromazine. Acapromazine and propionylpromezine, on the other hand, are not conjugated to a great extent. Instead they lose the side chain ketone grouping attached to the nucleus at the 2-position and are excreted in the sulphoxide form. Quantitative results have shown that excretion is irregular and prolonged, in some cases lasting for a week after administration. The percentage of dose detected as urinary metabolites res low, being approximately 19% for chlorpromazine, 10% for promazine and 3% for acepromazine. Conjugated metabolites were excreted predominantly as sulphide derivatives, whereas the unconjugated fraction were predominantly in the sulphoxide form. The applicability of the techniques used for the detection of phenothiazine derivatives, after administration in small doses just sufficient to produce an effect, has also been examined.

Master of Science / Biomedical Sciences / Daniel U. Thomson / Two studies were conducted to evaluate two animal welfare issues in the beef industry today. The welfare of animals has become a major discussion among consumers and producers. The objective of these studies was to evaluate if certain production practices are beneficial to the wellbeing of the animals in a production setting. The first study evaluated if castration and implementation of growth promotion technologies of physically mature male beef cattle, which failed the breed soundness exam (BSE), improved carcass quality compared to male beef cattle left intact. Sixteen month old Angus bulls (n = 24; 606 + 11.4 kg) were stratified by weight and randomly assigned to 2 treatments: intact control (BULL) and castrated with growth promotion technology (STR) to evaluate performance and carcass quality. Cattle assigned to STR treatment were implanted with 120 mg trenbolone acetate (TBA) and 24 mg estradiol on d 0, and were fed ractopamine hydrochloride (300 mg/d) the final 28 d prior to slaughter. Cattle were fed a dry-rolled corn-based finishing diet (1.41 Mcal/kg NEg) for 62 d (final wt = 697 +/- 24.3 kg) then harvested at a commercial abattoir. Carcass characteristics were recorded and longissimus muscle samples were obtained. There were no differences between treatments for quality grade, yield grade, HCW, back fat thickness, or dressing percent. Steak tenderness values based on Warner Bratzler shear force (WBSF), and sensory panel evaluation showed no difference between BULL and STR steaks in myofibrillar tenderness, juiciness, beef flavor intensity, connective tissue, overall tenderness, and off flavor intensity. Cattle within the BULL treatment tended to have improved average daily gain (ADG) and feed efficiency, with no difference in carcass characteristics, WBSF, or sensory panel measurements compared to STR administered growth promotion technology. The second study evaluated if cohorts with horns within a pen lot of cattle caused an increase in carcass bruising, and to determine if horn tipping and dehorning is necessary. Carcasses from (n = 4,287) feedlot cattle were observed at one commercial beef packing plant in southwest Kansas to investigate the relationship between the presence and size of horns in cattle and the prevalence, anatomical location, and severity of bruising of carcasses. Horn measurements taken were the length of the longest horn from base to tip and the tip-to-tip distance between the tips of both horns. Bruises were evaluated by location and severity. Bruise severity was scored at 3 levels: minor: ≤ 5 cm, moderate: 5 to 15 cm, and severe: > 15 cm. Within pen lots of cattle, the percentage of cattle with horns ranged from 0 to 26%. There were 4,287 carcasses evaluated and 2,295 had one or more bruises for a total, overall bruise prevalence of 53.5%. Of the total number of bruises, 25.6% were severe, 35.6% were moderate, and 38.8% were minor. The majority of bruises (61.8%) occurred on the dorsal mid-line with similar rates of bruising occurring on the left (18.6%) and right (19.5%) sides. There was no relationship found between the prevalence of horns and prevalence of bruising in a pen lot of cattle (P = 0.90). These two studies conclude that feeding of bulls that fail the BSE could eliminate an animal welfare concern while removing the cost and management of growth promotion technology administration. Additionally to that there may be other factors causing carcass bruising at other than cohorts with horns.

A variety of inflammatory markers, coupled with changes in a number of haematological and biochemical parameters have classically been used to diagnose, monitor, and prognosticate disease in horses. Unfortunately these traditional markers respond fairly slowly to the presence of disease and inflammation and have wide normal ranges (Allen and Cold 1988; Pepys et al., 1989). Serum amyloid A (SAA), and haptoglobin are acute phase proteins common to humans, cattle, sheep, mice, and several other species, including the horse. In several of these species, plasma concentration of SAA has been shown to increase 1000-fold following tissue injury, cellular necrosis, inflammation, and infection and decline rapidly in the recovery phase. In the studies presented here the concentration of serum amyloid A (SAA), haptoglobin and fibrinogen and other indices of health were measured in a number of different groups of horses, including; normal horses, those subjected to operative surgery, horses with surgical colic, racehorses in training, some of which had evidence of gastric ulceration, and foals with respiratory disease. Acute phase protein concentration was modeled with the outcome and with other commonly measured indices of health relevant to the disease states of interest. The study indicates that there is an association between acute and chronic inflammation and between the present of disease both overt and latent and suggests that the concentration of a number of acute phase proteins could be used to aid decision making when planning diagnostic or treatment interventions in horses.

M.Tech. (Homeopathy) / Please refer to full text to view abstract

No description available.