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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.
121

Mitochondrial damage-associated molecular patterns (DAMPs) in inflammatory bowel disease

Boyapati, Ray Kiran January 2018 (has links)
Background The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) are chronic relapsing inflammatory disorders which have a rising incidence and cause significant morbidity. There are currently several treatment options with many more in the drug pipeline, but there are a lack of accurate biomarkers for decisions on treatment choice, assessment of disease activity and prognostication. There is a growing interest and desire for personalised or 'precision' medicine in IBD where novel biomarkers may help individualise IBD care in terms of diagnosis, choice of therapy, monitoring of response and detection of relapse. One class of functionally active biomarkers which have yet to be thoroughly investigated in IBD is damage-associated molecular patterns (DAMPs) including mitochondrial DNA (mtDNA). It has been recently shown that gut mitochondrial dysfunction can result in loss of epithelial barrier function and the development of colitis. Mitochondrial DAMPs have recently been described as elevated in several inflammatory diseases. Hypothesis The primary hypothesis of this thesis is that circulating levels of mtDNA is elevated in IBD. Secondary hypotheses are: (a) levels of other mitochondrial DAMPs are elevated in IBD, (b) circulating mtDNA can be used as a novel biomarker in IBD and (c) mtDNA is released locally at sites of inflammation in IBD. Methods Plasma and serum were collected prospectively from recruited IBD patients and non-IBD controls. Faeces and colonic tissue were collected from a subset of these patients. mtDNA in serum, plasma and faeces was measured using qPCR (amplifying COXIII/ND2 genes). Mass spectrometry was used to detect mitochondrial formylated peptides in the plasma of a subset of patients. IBD tissue was assessed for (a) mitochondrial damage using transmission electron microscopy (TEM) and (b) TLR9 expression, the target for mtDNA. Results 97 patients with IBD (67 UC and 30 CD), and 40 non-IBD controls were recruited. Plasma mtDNA levels were increased in UC and CD (both p < 0.0001) compared to non-IBD controls; with significant correlations with blood (CRP, albumin, white cell count), clinical and endoscopic markers of severity; and disease activity. In active UC, we detected significantly higher circulating mitochondrial formylated peptides and faecal mtDNA levels (vs. non-IBD controls [p < 0.01 and < 0.0001 respectively]) with demonstrable TEM evidence of intestinal mucosal mitochondrial damage. In active IBD, TLR9+ lamina propria inflammatory cells were significantly higher in UC/CD compared to controls (both p < 0.05). Conclusions Taken together, the findings suggest mtDNA is released during active inflammation in inflammatory bowel disease and is a potential novel mechanistic biomarker.
122

The comparative efficacy of biologics in patients with Crohn´s disease and Ulcerative Colitis

Khalaf, Elan Adel January 2019 (has links)
Introduction The fundamental concept for modern inflammatory bowel disease (IBD) treatment algorithm is an early induction of mucosal healing and its maintenance. Biological therapies are becoming mainstays of IBD therapy. It is however still unclear if there is a difference between Crohn’s disease (CD) and Ulcerative Colitis (UC) in time from diagnosis to stable maintenance treatment when biological treatment is introduced. Aim To investigate the comparative efficacy of biological agents in CD and UC by studying the time course when biological treatment is introduced. Methods Retrospective study of patients suffering from IBD at Falu Hospital, receiving a new start with biologics between 2015-01-01 and 2016-12-31. Remission rate after 3 months of induction therapy was analyzed. Subsequently, when 6 months passed without active disease, it was considered a stable remission. Results Through database extraction 58 patients were identified. A total of 52 % patients fulfilled the criteria for remission. Of patients with CD 49 % got in remission, whereof 33 % had treatment with infliximab, 48 % adalimumab and 19 % vedolizumab. Of patients with UC 60 % got in remission, whereof 33 % had treatment with infliximab and 67 % with adalimumab. Log rank test showed no significant difference in efficacy of biologics in patients suffering from CD or UC in time from diagnosis respective after initiation with biologics to stable maintenance treatment. ConclusionsIn this study patients with CD and UC responded equally to biological treatment.
123

Quality of Life and Coping with Ulcerative colitis and Crohn's disease

Larsson, Kjerstin January 2007 (has links)
<p>The aim of this thesis was to investigate health-related quality of life (HRQoL) and coping strategies for individuals with ulcerative colitis (UC) or Crohn’s disease (CD), and to study the effect of a group-based patient information on anxiety/depression and HRQoL. HRQoL and anxiety/depression were investigated (n=492) (Study I). In Study II, anxiety/depression, HRQoL, satisfaction with information and evaluation of the patient information were studied (n=49). Coping with disease activity was investigated in 166 patients reporting current exacerbation (Study III). Fifteen patients were interviewed about disease-related stress, how this is managed and the need of support from the health care (Study IV). Patients with UC reported better HRQoL and less anxiety/depression than did patients with CD during both remission and exacerbation. Satisfaction with information had increased at follow-up 6 months after patient information. The information and the possibility to discuss with lecturers and group members were valued as most important. No change was found in anxiety/depression or HRQoL at follow-up. Both problem-focused and emotion-focused strategies were employed to cope with disease activity, with no difference between patients with UC or CD. The urgent need of toilet availability and stress associated to social situations were the major disease-related stressors. This stress was managed by finding out the location of toilets, bringing toilet paper and extra underwear and emptying bowel before an activity. The patients wanted information and possibilities to talk to experienced staff and to other patients about how to live with the disease. This thesis shows that HRQoL for some patients with UC, and primarily for patients with CD, is impaired. Thus medical staff should be observant of the psychosocial well-being of patients with CD and also of patients with relapse. Methods to identify and support patients with anxiety/depression and poor HRQoL need to be developed. Interventions should target the patient’s specific problems and at appropriate times.</p>
124

Quality of Life and Coping with Ulcerative colitis and Crohn's disease

Larsson, Kjerstin January 2007 (has links)
The aim of this thesis was to investigate health-related quality of life (HRQoL) and coping strategies for individuals with ulcerative colitis (UC) or Crohn’s disease (CD), and to study the effect of a group-based patient information on anxiety/depression and HRQoL. HRQoL and anxiety/depression were investigated (n=492) (Study I). In Study II, anxiety/depression, HRQoL, satisfaction with information and evaluation of the patient information were studied (n=49). Coping with disease activity was investigated in 166 patients reporting current exacerbation (Study III). Fifteen patients were interviewed about disease-related stress, how this is managed and the need of support from the health care (Study IV). Patients with UC reported better HRQoL and less anxiety/depression than did patients with CD during both remission and exacerbation. Satisfaction with information had increased at follow-up 6 months after patient information. The information and the possibility to discuss with lecturers and group members were valued as most important. No change was found in anxiety/depression or HRQoL at follow-up. Both problem-focused and emotion-focused strategies were employed to cope with disease activity, with no difference between patients with UC or CD. The urgent need of toilet availability and stress associated to social situations were the major disease-related stressors. This stress was managed by finding out the location of toilets, bringing toilet paper and extra underwear and emptying bowel before an activity. The patients wanted information and possibilities to talk to experienced staff and to other patients about how to live with the disease. This thesis shows that HRQoL for some patients with UC, and primarily for patients with CD, is impaired. Thus medical staff should be observant of the psychosocial well-being of patients with CD and also of patients with relapse. Methods to identify and support patients with anxiety/depression and poor HRQoL need to be developed. Interventions should target the patient’s specific problems and at appropriate times.
125

Ulcerative colitis : colorectal cancer risk and surveillance in an unselected population

Lindberg, Jan January 2007 (has links)
Ulcerative colitis is a chronic inflammatory disease that mainly affects the colon and rectum. Onset of disease is most common between the ages of 15-35 years. There is an observed increased risk of colorectal cancer associated with the disease. The risk is often described to be 2% after 10 years, 8% after 20 years and 18% after 30 years disease. Since 1977, all known patients with ulcerative colitis in the catchment area of Örnsköldsvik Hospital have been invited to attend a colonoscopic surveillance programme. At endpoint of the studies included in this thesis there were 214 patients that had attended the surveillance programme. The aims of these studies have been to evaluate the efficiency of the surveillance programme, analyse the impact of findings of DNA aneuploidy, and determine the outcome for patients that underwent limited resections instead of complete proctocolectomy. Further, we have studied the long-term outcome for patients who had an early onset of disease and analysed the expression of cytokeratin 7 and 20 in respect to findings of dysplasia, DNA aneuploidy and colorectal cancer. At the end of the studies the prevalence for ulcerative colitis was 261/100 000 and the incidence rate was 7.6/100 000/year. During the period 1977-2005, four patients died of ulcerative colitis. Nine colorectal cancers were diagnosed in eight patients, one of whom died of the cancer. Fifty-two patients had findings of dysplasia and five of these patients developed colorectal cancer. In the subgroup of patients studied (N= 147) for DNA aneuploidy, 20 were found to have specimens with DNA aneuploidy on at least one occasion. The sensitivity of aneuploidy for development of dysplasia (LGD or higher) was found to be 0.50 and the specificity 0.94. The investigation of the outcome for the patients that underwent limited resections of the colon or rectum showed that none of the patients under surveillance died of colorectal cancer or metachronous cancer in their remaining colon or rectum. A separate study concerning early onset of ulcerative colitis revealed no particular increased risk of colorectal cancer in this cohort but a fairly high incidence of primary sclerosing cholangitis was seen. In the analyses of cytokeratins it was found that 7 out of 10 patients with low-grade dysplasia and 3 of 6 with high-grade dysplasia were positive for CK7. Our results indicate a possible relationship between the expression of CK7 and CK20 and neoplastic development of colorectal mucosa in patients with ulcerative colitis. The studies on which this thesis is based, were performed on a relatively small number of patients, however the time of observation was long and, most importantly, the patients were from a well defined catchment area. We conclude that the surveillance programme has been efficient in minimising the risk of lethal colorectal cancer. Analysing DNA ploidy helps to target the patients that need more attention but the method cannot stand alone. Our study on cytokeratins points to a relationship between dysplasia and CK7 but the results are preliminary and further studies needs to be done. We have shown that it is safe to do a limited colorectal resection in respect to lethal colorectal cancer. Early onset of ulcerative colitis as a risk factor for colorectal cancer was not found in the group we have studied, which could be due to effective surveillance and/or medication. A fairly high operation rate in this group may also have contributed. The most important variable in the beneficial outcome regarding lethal colorectal cancer in these studies is, in our opinion, the outstanding compliance of the patients to the colonoscopic surveillance programme.
126

The neuronal and non-neuronal substance P, VIP and cholinergic systems in the colon in ulcerative colitis

Jönsson, Maria January 2009 (has links)
Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease. Neuropeptides, especially vasoactive intestinal peptide (VIP) and substance P (SP), have long been considered to play key roles in UC. Among other effects, these neuropeptides have trophic and growth-modulating as well as wound-healing effects. Furthermore, whilst VIP has anti-inflammatory properties, SP has pro-inflammatory effects. It is generally assumed that the main source of SP and VIP in the intestine is the tissue innervation. It is not known whether or not they are produced in the epithelial layer. The details concerning the expressions of their receptors in UC are also, to a great extent, unclear. Apart from the occurrence of peptidergic systems in the intestine, there are also neuronal as well as non-neuronal cholinergic systems. The pattern concerning the latter is unknown with respect to UC. The studies in this thesis aimed to investigate the expression of SP and VIP and their major receptors (NK-1R and VPAC1) in UC colon, compared to non-UC colon. The main emphasis was devoted to the epithelium. A second aim was to examine for levels of these neuropeptides in blood plasma in UC. Another aim was to examine for the non-neuronal cholinergic system in UC, thus, to investigate whether there is acetylcholine production outside nerves in the UC colon. Methods used in the thesis were immunohistochemistry, in situ hybridization, enzyme immunosorbent assay, and in vitro receptor autoradiography. For the first time, mRNA for VIP and SP has here been found in the colonic epithelium. That was especially noted in UC mucosa showing a rather normal morphology, and in non-UC mucosa. Marked derangement of the mucosa was found to lead to a distinct decrease in VIP binding, and also a decrease in the expression level of VIP receptor VPAC1 in the epithelium. In general, there was an upregulation of the SP receptor NK-1R in the epithelium when the mucosa was deranged. The plasma levels of SP and VIP were higher for UC patients compared to healthy controls. There were marked correlations between the levels of the peptides in plasma, their levels in the mucosa and the degree of mucosal derangement/inflammation. A pronounced nonneuronal cholinergic system was found in both UC and non-UC colon. Certain changes occurred in this system in response to inflammation/derangement in UC. The present study shows unexpectedly that expressions for VIP and SP are not only related to the nerve structures and the inflammatory cells. The downregulation of VPAC1 expression, and the tendencies of upregulation of NK-1R expression levels when there is marked tissue derangement, may be a drawback for the intestinal function. The study also shows that there is a marked release of neuropeptides to the bloodstream in parallel with a marked derangement of the mucosa in UC. The cholinergic effects in the UC colon appear not only to be associated with nerverelated effects, but also effects of acetylcholine produced in local non-neuronal cells. The thesis shows that local productions for not only acetylcholine, but also SP and VIP, occur to a larger extent than previously considered.
127

Study of the protective effects of polysaccharides from Angelica sinensis on ulcerative colitis in rats

Wong, Kai-chung., 黃啟宗. January 2006 (has links)
published_or_final_version / Medical Sciences / Master / Master of Medical Sciences
128

Study of the protective mechanisms of cigarette smoke and nicotine on experimental ulcerative colitis in rats

沈毅峰, Sham, Ngai-fung. January 2001 (has links)
published_or_final_version / Pharmacology / Master / Master of Philosophy
129

Development, Evaluation and Application of a Pediatric Ulcerative Colitis Index (PUCAI)

Turner, Dan 01 August 2008 (has links)
This thesis uses the methods of sychometrics and clinimetrics to develop and evaluate a Pediatric Ulcerative Colitis Activity Index (PUCAI). The initial phases of item generation and reduction were performed previously. This thesis comprises five main studies. Study one: the weighting and formatting of an initial draft PUCAI using a cohort of 157 children with ulcerative colitis, enrolled prospectively in five pediatric IBD centers. Study two: the validation of the final draft on a separate prospective cohort of 48 children undergoing complete colonoscopy. The PUCAI was highly correlated with physician global assessment (PGA) (r=0.91), Mayo score (r=0.95) and colonoscopic appearance (r=0.77). The PUCAI was able to differentiate the different categories of disease activity, and cutoff points were defined. Study three: Assessment of the responsiveness of the PUCAI. The index demonstrated excellent responsiveness on 75 children seen twice during the study period (effect size=1.9, standardized response mean=2.2, responsiveness statistics=2.6, correlation with PGA of change=0.84, and area under the ROC curve=0.97 95%CI 0.93- 0.99). Study four was aimed at evaluating the predictive validity of the PUCAI, on a retrospective cohort of 99 children with severe ulcerative colitis admitted for intravenous corticosteroid therapy. The PUCAI, calculated on the third and fifth day of therapy was highly predictive of therapy failure at discharge and one year post discharge (area under the ROC curve 0.84 (95%CI 0.76-0.92). Study five: a methodological study evaluating the preferred way to determine the minimal clinically important difference (MCID) of health-related outcome measures. This study was conducted using the PUCAI and three other well established instruments. It was concluded that the MCID should be determined primarily by the anchor-based approach using the ROC curve method on the entire cohort, supplemented by calculating the minimal detectable difference beyond statistical error using the standard error of measurement. Small, moderate and large MCID values could be presented based on the degree of expected relevant change. Together, these studies have contributed to the rigorous development and thorough evaluation of a novel, non-invasive tool for assessing disease activity in pediatric ulcerative colitis clinical studies and practice.
130

Development, Evaluation and Application of a Pediatric Ulcerative Colitis Index (PUCAI)

Turner, Dan 01 August 2008 (has links)
This thesis uses the methods of sychometrics and clinimetrics to develop and evaluate a Pediatric Ulcerative Colitis Activity Index (PUCAI). The initial phases of item generation and reduction were performed previously. This thesis comprises five main studies. Study one: the weighting and formatting of an initial draft PUCAI using a cohort of 157 children with ulcerative colitis, enrolled prospectively in five pediatric IBD centers. Study two: the validation of the final draft on a separate prospective cohort of 48 children undergoing complete colonoscopy. The PUCAI was highly correlated with physician global assessment (PGA) (r=0.91), Mayo score (r=0.95) and colonoscopic appearance (r=0.77). The PUCAI was able to differentiate the different categories of disease activity, and cutoff points were defined. Study three: Assessment of the responsiveness of the PUCAI. The index demonstrated excellent responsiveness on 75 children seen twice during the study period (effect size=1.9, standardized response mean=2.2, responsiveness statistics=2.6, correlation with PGA of change=0.84, and area under the ROC curve=0.97 95%CI 0.93- 0.99). Study four was aimed at evaluating the predictive validity of the PUCAI, on a retrospective cohort of 99 children with severe ulcerative colitis admitted for intravenous corticosteroid therapy. The PUCAI, calculated on the third and fifth day of therapy was highly predictive of therapy failure at discharge and one year post discharge (area under the ROC curve 0.84 (95%CI 0.76-0.92). Study five: a methodological study evaluating the preferred way to determine the minimal clinically important difference (MCID) of health-related outcome measures. This study was conducted using the PUCAI and three other well established instruments. It was concluded that the MCID should be determined primarily by the anchor-based approach using the ROC curve method on the entire cohort, supplemented by calculating the minimal detectable difference beyond statistical error using the standard error of measurement. Small, moderate and large MCID values could be presented based on the degree of expected relevant change. Together, these studies have contributed to the rigorous development and thorough evaluation of a novel, non-invasive tool for assessing disease activity in pediatric ulcerative colitis clinical studies and practice.

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