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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metabolomic profiling in inflammatory bowel disease

Hildebrand, Diane Rosemary January 2017 (has links)
Introduction Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder that encompasses two major subtypes; Crohn’s Disease (CD) and Ulcerative Colitis (UC). Our knowledge regarding disease pathogesis is rapidly increasing. However, these disease entities provide challenges in diagnosis, monitoring of disease activity and assessing individual response to treatment, because there is a lack of validated clinical biomarkers. Metabolomics involves the study of numerous analytes that have very diverse physical and chemical properties and occur in a wide concentration range. Early evidence suggests there is potential for metabolomic profiling to be used in the differentiation of CD and UC. However, knowledge is limited regarding the metabolic changes seen in relation to disease activity or to medical or surgical treatments. Aims A metabolomics approach was taken to determine whether metabolomic profiles could distinguish between patients with CD or UC and healthy controls. We also aimed to define the relationship between metabolomic profile and disease activity, and to determine the effect of medical (anti-TNFa agents) and surgical treatment on the metabolome. Methods A metabolomics approach was undertaken. Serum and urine sample sets were collected from a total of 41 patients with ulcerative colitis, 43 patients with Crohn’s disease, and 62 healthy controls (HC). In order to allow a comparison of metablomic profile and disease activity, 4 sample sets were taken from the same patient at 3 monthly intervals over the period of one year. Those patients undergoing either surgical or biological treatment had sample sets taken pre and post intervention. Metabolomic analysis using gas chromatography time of flight mass spectrometry (GC-ToF-MS) and ultra-high performance liquid chromatography Fourier Transform mass spectrometry (UHPLC-FTMS) was carried out on both serum and urine. Results Serum and urine GC-ToF-MS and UHPLC-FTMS metabolomic analyses show differentiation between UC, CD and healthy controls, most significantly in urine analyses. No significant differentiation was seen in pre- and post-surgical patients, or pre- and post-biological therapy patients. It was possible to differentiate surgical patients from healthy controls, especially in the urine analyses. Metabolite identification revealed consistently more dietary variation in the healthy controls than in the IBD patients. Significant differences (p < 0.05) were seen between healthy controls and IBD patients in classes of metabolites relating to the citric acid cycle and the uronic acid pathway, as well as amino acids, fatty acids and cholesterols. The behaviour or location of disease, or the disease activity score did not appear to influence the metabolome in either serum or urine analyses using GC-ToF-MS and UHPLC-FTMS. Conclusion Metabolomic profiling of urine and serum in IBD may provide a novel methodology aiding both clinical diagnosis through biomarker development, and advancing knowledge of disease pathogenesis.
2

Metabolomic profiling in inflammatory bowel disease

Johnston, Colette January 2014 (has links)
Introduction: Inflammatory bowel disease is a common, complex relapsing disorder characterised by immune dysregulation, altered intestinal permeability and microbial insult. Limited knowledge is available regarding the metabolic changes observed during progression of the disease, and limited biomarkers of disease available that have been validated and shown to be of sound clinical value. Aim of Study: A two stage metabolomics approach was adopted to determine if metabolic signature profiles, could distinguish inflammatory bowel disease Crohn’s disease (CD) patients from ulcerative colitis (UC) patients and from healthy controls. Methods: A serum metabolomics approach was undertaken to define metabolic changes associated with UC and CD. Serum samples from a discovery study of 30 UC, 30 CD and 29 ethnically, age and gender matched controls were analysed by ultra-performance liquid chromatography mass spectrometry. A subsequent validation study was preformed using 28UC, 31CD, and 29 gender matched controls were also analysed using UPLC-MS.ResultsClasses of metabolites, identified as biologically interesting and at significantly different levels (p<0.05) in comparisons of control and CD and UC cohorts included: steroids and steroid derivatives, phosphocholine, Vitamin D metabolites, fatty acids and conjugates, glycerolipids, isoprenoids, amino acids, and phosphosphingolipids. There were fewer discriminatory metabolites differentiating the CD and UC cohorts. Conclusion: Serum Metabolomic profiling may represent a novel technology which could be used to distinguish individuals with CD from those with UC and healthy controls.
3

Vitamin D in Normal Breast Tissue Correlates to Early Breast Carcinogenesis

Lan, Shang-Lun January 2016 (has links)
No description available.

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