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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.
171

Immunomodulatory role of P28GST, a recombinant enzyme from the schistosome helminth parasite in the prevention of experimental colitis / Rôle immunomodulateur de la P28GST, une enzyme recombinant du parasite helminthe Schistosome dans la prévention de la colite expérimentale

El Nady, Mohamed 17 December 2012 (has links)
Les maladies inflammatoires chroniques de l’intestin font partie des pathologies immunitaires. Leur pathogenèse est directement liée à une réponse immune exagérée dirigée contre des bactéries commensales normalement présentes dans l’intestin, chez des individus génétiquement prédisposés. Parmi les facteurs favorisants, on trouve l’amélioration du niveau d’hygiène ainsi qu’une diminution des infections parasitaires. Des études épidémiologiques ont suggéré une relation entre la prévalence des infections par les helminthes et l’incidence des maladies inflammatoires chroniques de l’intestin dans les pays en développement. Ces infections parasitaires induisant une réponse immune de type Th2, il est donc proposé qu’elles participent la régulation des maladies inflammatoires médiées par une réponse immune de type Th1, comme la maladie de Crohn.Notre équipe s’est intéressée à l’effet immuno-modulateur d’une protéine du Schistosome, la P28GST (Glutathion S-transferase) dont les propriétés immunogénétiques pro-Th2 ont été démontrées précédemment dans des modèles expérimentaux et chez l’homme. Au cours de notre travail, nous avons montré que l’immunisation avec la P28GST était capable de diminuer de manière façon significative la colite expérimentale dans deux modèles animaux. L’immunisation avec cette enzyme parasitaire, produite sous forme recombinante, a réduit les scores cliniques et histologiques obtenus après induction de colite expérimentale par injection de l’haptène TNBS chez des rats Sprague Dawley rats ainsi que chez des souris C57Bl/6. Cet effet est associé à une diminution des marqueurs de l’inflammation (Myéloperoxidase) et de lexpression de l’ARN messager codant pour des cytokines pro-inflammatoires (IL-1β, IL-17 et TNF) dans le colon des animaux. Nous détectons une modulation de la réponse immune caractérisée par une diminution du profil Th1 mesuré par la présence d’ARN messager codant pour l’IFNγ vers un profil de type Th2, associé à une augmentation de l’ARN messager codant pour l’IL-4, l’IL-5 et l’IL-13. L’augmentation du rapport ARN messager Arg1/iNOS2 ainsi que la détection de cellules Arginase positives par immuno-histo chimie dans le colon des animaux immunisés suggèrent la présence de macrophages alternatifs (AAM), dont on connait le rôle anti-inflammatoire et l’association à une réponse de type Th2. Des résultats similaires ont été obtenus dans un autre modèle expérimental, chez la souris.Nous avons comparé l’effet de cette protéine du Schistosome avec l’effet de l’infection par des larves du parasite grâce à deux modèles d’infection : soit une infection au long cours (associé avec une réponse immune de type Th2), soit une infection récente (avec une réponse immune de type Th1). Nos résultats montrent que l’immunisation par une seule protéine de schistosome, la P28GST, réduit l’inflammation intestinale aussi bien que l’infection au long cours, tandis que les animaux récemment infectés n’étaient pas protégés de la colite. En conclusion, notre étude présente les premières évidences que l’immunisation avec une protéine recombinante de Schistosome pourrait réduire de manière préventive la colite expérimentale induite par l’injection d’une haptène dans deux modèles de rongeurs. Si les mécanismes d’action précis doivent encore être élucidés, nos travaux suggèrent que l’effet anti-inflammatoire de la P28 GST puisse avoir des applications dans la prévention de l’inflammation intestinale permettant d’envisager une utilisation chez l’homme, notamment dans la prévention des rechutes de la maladie de Crohn. / Inflammatory bowel diseases are considered part of immune-mediated inflammatory disorders. Their pathogenesis was linked to an inappropriate exaggerated immune response to commensal bacteria normally present in the bowel, in genetically predisposed individuals. Increase of the level of hygiene and decrease exposure to helminthic infections was suggested as predisposing factors to IBD. Epidemiologic data have given a clue on the relation of prevalence of helminthic infections and the incidence of inflammatory bowel diseases in developing countries. The Th2 polarized T cell response driven by helminthic infection has been linked to the attenuation of Th1 driven inflammatory responses, preventing some Th1 mediated autoimmune diseases in their host, including Crohn’s disease.Our work focused on the immuno-modulatory effect of a Schistosome protein – P28GST (a Glutathion S-transferase). Its immuno-genetique, pro-Th2, characters have been previously demonstrated in experimental models as well as clinical trials. We showed that immunization with P28GST was able to significantly reduce experimentally induced colitis in two animal models.Immunisation with this recombinant parasitic enzyme reduced clinical and histological scores of the TNBS induced colitis in both Sprague Dawley rats as well as in C57Bl/6 mice. This effect was associated with a decrease in the expression of inflammatory markers (Myeloperoxidase) as well as mRNA expression of pro-inflammatory cytokines (IL-1β, IL-17 and TNF) in the colon of sacrificed animals. We detected a shift of the immune response characterized with decrease of Th1 immune response assessed by the mRNA expression of IFNγ towards a less pathological Th2 immune response assessed by the mRNA expression of IL-4, IL-5 and IL-13. An increase in the ratio of mRNA expression of Arg1/iNOS2, as well as the immuno-histochemical detection of Arginase positive cells in the colon of the sacrificed animals suggested the presence of alternatively activated macrophages (AAMs) characterized by their anti-inflammatory effect and their association with the Th2 immune response. Similar results have been obtained in another animal model, the C57Bl/6 mice.We have also compared the effect of a single recombinant Schistosome protein to two models of infection with living schistosome parasites, either with long standing infection (associated with a Th2-type response) or with a recent onset exposure (a Th1-type response). Our results showed that immunisation with a single Schistosome protein, the P28GST; give similar results to established infection in term of reduction of intestinal inflammation, whereas recently infected rats were not protected against colitis.In conclusion, this study provides the first evidence that immunization with a recombinant protein from the Schistosome helminth parasite prevents hapten-induced colitis in two models of rodents. Although further studies are needed to illustrate the exact mechanisms of action implicated in the immuno-modulatory effect, P28GST is a promising molecule exerting a potent anti-inflammatory role in the prevention of colitis. The potential effect of this helminthic enzyme is actually taken in consideration in the prevention of Crohn’s disease relapses in humans.
172

The Role of Dysfunctional Na+/H+ Exchange in the Development of Dysbiosis and Subsequent Colitis

Harrison, Christy Anne, Harrison, Christy Anne January 2017 (has links)
The last half-century has seen a dramatic and alarming rise in the incidence of autoimmune disease in industrialized nations too rapid to be accounted for by genetics alone. Among those, Inflammatory Bowel Disease (IBD) has risen from a western disease affecting industrialized populations to an emerging global threat affecting diverse populations around the world. IBD is a complex disease that combines genetic susceptibility and environmental exposure, but one aspect appears to be clear: the involvement of the gut microbiome. Current thought holds that IBD is an autoimmune attack on commensal microbiota, causing extensive collateral damage to the host intestinal tissues in the process. However, it has remained unclear in the field whether the changes observed in the IBD microbiome are causative in nature or whether the microbiome is responding to already-underway inflammatory processes within the host. This dissertation investigates one host factor in particular with regard to the microbiome and the development of inflammation: sodium-hydrogen exchange at the brush border, mediated by sodium hydrogen exchanger 3 (NHE3). NHE3 is inhibited during active IBD, but its loss in knockout animals is also enough to promote spontaneous colitis in a microbiome-dependent fashion. This dissertation investigates the specific contribution of the microbiome in NHE3 knockout animals to determine whether loss of NHE3 may be mediating the onset of colitis through pro-inflammatory changes in the microbiome. Our results suggest that the microbiome fostered in an NHE3-deficient environment may accelerate the onset and severity of experimental colitis, though likely in concert with additional host factors.
173

Conséquences physiopathologiques de la dysbiose associée aux maladies inflammatoires chroniques de l'intestin. / Impact of Inflammatory bowel disease associated dysbiosis in the intestinal ecosystem

Rajca, Sylvie 29 May 2015 (has links)
Ces dernières années, l'implication du microbiote intestinal dans la physiopathogénie des maladies inflammatoires chroniques de l'intestin (MICI) a été mise en évidence. Le but de nos travaux est de déterminer l'impact de la dysbiose sur l'écosystème intestinal au cours des MICI. Ces trois études nous ont permis de confirmer le rôle central de la dysbiose associée aux MICI : d'une part comme outil potentiellement prédictif de rechute, précédant une inflammation locale ou systémique, d'autre part comme acteur dans l'apparition d'un déséquilibre de l'écosystème intestinal. Ce déséquilibre est marqué par l'altération de l'activité enzymatique du microbiote modifiant le pool d'acides biliaires dans la lumière intestinale et pouvant affecter les effets anti-inflammatoires de certains acides biliaires sur les cellules épithéliales intestinales participant ainsi à une inflammation chronique au cours des MICI. Par ailleurs, cette dysbiose est possiblement entretenue par un déficit en défensine hBD1 et HD5, perpétuant une inflammation chronique intestinale.Ces résultats renforcent le rôle proéminent du microbiote dans l'évolution des MICI et suggèrent que la restauration de la normobiose au cours de la maladie devrait être un nouveau but dans la prise en charge de ces patients. / In recent years, the involvement of intestinal microbiota in the pathogenesis of inflammatory bowel disease (IBD) has been established. The aim of our study was to determine the impact of dysbiosis in intestinal ecosystem of IBD patients.These three studies allowed us to confirm the fundamental role of IBD-associated dysbiosis. First, IBD-associated dysbiosis has been identified as a potential predictive tool of relapse, before local or systemic inflammation. Second, IBD-associated dysbiosis has been involved as an actor in the emergence of an imbalance of intestinal ecosystem. This imbalance was characterised by an alteration of microbiota enzymatic activity leading to modifications in the luminal bile acid pool composition and may affect the anti-inflammatory effects of some bile acids on gut epithelial cells and could participate in the chronic inflammation loop of IBD. Moreover, a deficiency in the antimicrobial defense systems of defensins may be an explanation for the break of the antibacterial barrier function in inflammatory bowel diseases maintaining dysbiosis.These results reinforce the prominent role of the microbiota in the development of IBD and suggest that restoring normobiosis could be a new goal for optimal IBD management.
174

The association between environmental exposures during childhood and the subsequent development of crohn's disease in the Western Cape

Sabe, Victor T. January 2015 (has links)
Magister Scientiae (Medical Bioscience) - MSc(MBS) / Background: A subtype of inflammatory bowel disease, Crohn’s disease is thought to represent a complex interaction between environmental factors, a defective immune system, the gastrointestinal microbiome and genetic susceptibility. Aim: The focus of this study was to investigate the association between environmental exposures during childhood and the subsequent development of Crohn’s disease, thus the two primary aims were to: 1) conduct a systematic review of the literature evaluating environmental risk factors during childhood, defined by studies either as, age intervals (e.g., 0-5, 6-10 and 11-18 years), or more 'broadly' as 0-18 years; and 2) investigate the association between childhood environmental exposures during three age intervals (0-5, 6-10 and 11-18 years), as well as frequency of childhood infections and the future development of Crohn's disease based on a score analysis, using a subset of previously collected data from a completed doctoral thesis involving a case control study design in study population, in the Western Cape, South Africa. The aim included a primary analysis of the latter dataset for childhood infections. Design: For the first aim of the study, a systematic search was conducted during March 2015 in electronic databases, such as EMBASE, EBSCOhost (Medline), Ovid, Scopus and World Cat, PubMed and Biomed Central, to identify epidemiological studies that examined the association between childhood environmental exposures and the subsequent development of Crohn's disease. Studies evaluating childhood exposure either by age intervals, or more broadly, from birth until 18 years were included. The environmental exposures evaluated in the review were; farm animal contact, place of upbringing, sibship size, household pets, primary water source and hot water availability. Of the 181 identified articles, 16 were included in the final systematic review. The second aim of the study involved a post hoc analysis of a subset of findings from the completed doctoral research by Abigail Basson with regard to the multiple logistic regression analysis evaluating environmental risk factor exposure during three age intervals; 0-5 years, 6-10 years and 11-18 years. In the present research, two different methodological approaches were undertaken. Briefly, exposure variables, of similar nature, were combined into subgroups and assigned weighting scores. The two 'subgroup models' were designated as: Group A and Group B. Based on these premises, a score analysis was performed, and the difference in scores, between case and control groups, was compared. In addition, multiple logistic regression models were conducted on a subset of original data from the aforementioned completed doctoral study to assess the association between the frequency of childhood infections between 0-20 years and risk of Crohn’s disease development. Following this, a score analysis was again performed. Results: Sixteen studies were included in the systematic review. Of the five studies that investigated the association between place of upbringing during the age interval 0-5 years and the subsequent development of Crohn's disease, three found no significant association; however of the three studies evaluating place of upbringing during the age intervals 6-10 and 11-18 years, only one study identified a significant association. Three studies investigated exposure to farm animals during the age interval 0-5 years, of which, two identified a significant association. Of the latter three studies, two investigated farm animal contact during the age intervals 6-10 and 11-18 years, but only one reported a significant association during these age intervals. Notably, this was the study which had failed to identify an association during the 0-5 year age interval. Both studies which broadly evaluated farm animal exposure during 'childhood' reported that not having contact with animals significantly increased the risk of developing Crohn's disease. Of the five studies that investigated exposure to pets during the age interval 0-5 years, only one identified a significant risk association, namely with exposure to cats. Of the three which investigated pet exposure during the age intervals 6-10 years and 11-18 years, one identified a significant association, for both age intervals. Five studies investigated pet exposure during 'childhood'; one found that having a pet significantly increased the risk of developing Crohn's disease, two reported that not having a pet significantly increased risk in developing Crohn's disease, whereas the remaining studies found no significant association. Only one study evaluated primary water source during the three age intervals; during the age interval 0-5 years and 11-18 years, having piped tap or bottled water was significantly associated with CD development. Of the four studies investigating primary water source during ‘childhood’, only one reported a significant association between primary water source and the development of Crohn's disease. The availability of hot water during the age interval 0-5 years was significantly associated with Crohn's disease development in one of the three relevant studies. Two studies investigated hot water availability during 6-10 and 11-18 years, however both failed to identify a significant association. When broadly evaluated, hot water availability during 'childhood' was significantly associated with Crohn's disease risk, in two of the three relevant studies. None of the studies which investigated sibship size and the risk of future Crohn's disease development during defined age intervals reported a significant association. Only two of the seven studies that evaluated sibship size during childhood reported a significant association. Results of the score analysis revealed a significant difference during all three age intervals between the case and control groups with Group A and Group B, with cases having significantly lower exposure scores (approximately 30% and 40% lower, respectively), when compared with that of controls. On multiple logistic regression analysis, subjects who never had tooth decay/cavity (OR = 1.78; 95% CI, 1.05-3.04), periodontitis (OR = 1.95; 95% CI, 1.10, 3.48), diarrhoea (OR = 2.71; 95% CI, 1.62-4.62), gastritis (OR = 2.13; 95% CI, 1.30-3.35), or mouth ulcers (OR = 2.02; 95% CI, 1.12-3.70), at least once per year or more, were at an increased risk for later development of Crohn's disease, when compared to those who were exposed to these infections at least once per year or more. There was a significant difference in exposure scores between the case and control groups (OR = 0.88; 95% CI, 0.82-0.94), thus indicating that cases had 12% less exposure to childhood infections from birth until the age of 20 years, when compared to the controls. Conclusion: The systematic review of the literature provides evidence in support of the hygiene hypothesis, in that delayed exposure to immunostimulatory microbes through the environmental exposures increases the risk for future CD development, in genetically susceptible individuals. In addition, the literature supports that the childhood environment plays an important role in the aetiology of Crohn's disease. However, the lack of consistent findings between studies, particularly those which have broadly defined ‘childhood’ implies that timing of exposure plays a crucial role in this ever evolving paradigm. Results from the score analysis provide insight into the 'compound' effects from multiple environmental exposures in the aetiology of Crohn's disease. While the present research was unable to provide any explanation for the underlying mechanism of disease pathogenesis, overall, the findings have important implications for future IBD-related studies as they demonstrate the importance of accounting for environment as a 'whole' when conducting epidemiological studies, as opposed to focusing on individual environmental factors, as well as that it is imperative to investigate environmental exposures within the context of defined age intervals.
175

The development of a model of follow up care for adult patients with inflammatory bowel disease

Kemp, Karen January 2013 (has links)
Introduction: Inflammatory bowel disease (IBD), Crohn’s Disease and ulcerative colitis, are long term conditions which follow a relapsing and remitting pattern. The rising incidence of IBD in adults and children has implications for the lifelong burden of disease and the provision of specialist services. Patients are predominantly managed by secondary care and follow a traditional, scheduled follow-up cycle, which is unsustainable and unsatisfactory. Patients with IBD should have access to specialist care which is delivered according to their values and needs. However few studies have examined patients’ views of follow-up care. There is also concern in the UK that services for patients with long term conditions are not orgnised to promote independence with silo working in primary and secondary care.These may be brought together formally through the development of models of care. Utilization of current out-patient spaces to regularly review stable patients is inappropriate and is challenged by commissioners. The question remains as to what models of follow-up are we able to offer patients which are acceptable and what is the role of the general practitioner (GP) and primary care within this. The aim of this study was to develop an integrated, acceptable, model of follow-up care for patients with IBD.Methods The study follows the development phase of the MRC Framework for complex interventions. A best evidence synthesis was undertaken to identify the follow-up care models in IBD. A meta-synthesis of the health and social care needs of patients with IBD was conducted to explore the impact of living with IBD. Qualitative interviews with 24 IBD patients (18 patients had CD, and 6 UC, age range 27-72 years, disease duration range 2 – 40yr) and 20 GPs purposively selected from across NW England were carried out. Patients were asked about their experience, values and preference of follow-up care. The GPs were questioned about their current and potential role in IBD. Analysis was undertaken using Framework Analysis. The best evidence synthesis, meta-synthesis and interviews were synthesised by an expert panel, Consultant Gastroenterologist, patient, GP, IBD Nurse, to develop the model of follow-up care.Results There were similarities and commonalities between the patient and general practitioner interviews. Patients did not want to be seen when well, GPs wanted more involvement in care and there is scope for an IBD outreach nurse at the interface of primary/secondary care. Discharging quiescent patients into enhanced GP care, to ensure equitable treatment, was acceptable to all, as was the concept of ‘virtual’ clinics. Patients would initiate self referral within the ‘virtual’ arm whilst patients under GP care would be referred back into secondary care as a rapid referral < 7days and not using a new patient tariff. Complex IBD patients would remain under secondary care. A stratified model of follow-up care was developed.Conclusion This study provides an acceptable integrated model of follow-up for patients with IBD. It takes into account the growing incidence of IBD and UK policy to reduce inappropriate follow-up. It emphasises role of self management, the integration of primary and secondary care, placing the patient closer to home whilst allowing secondary care to concentrate on complex patient management.
176

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.
177

Estudo do potencial imunomodulador de Dehidroepiandrosterona (DHEA) na inflamação intestinal experimental / Study of the immunomodulatory potential of Dehydroepiandrosterone (DHEA) in experimental intestinal inflammation

Vanessa Beatriz Freitas Alves 30 March 2016 (has links)
As Doenças inflamatórias intestinais (DII) são multifatoriais e sua etiologia envolve susceptibilidade genética, fatores ambientais, disbiose e ativação exacerbada do sistema imunológico no intestino. Essas doenças também tem sido relacionadas a baixos níveis de dehidroepiandrosterona (DHEA), um hormônio precursor de diversos esteroides e relacionado à modulação das respostas imunes. Porém, os mecanismos precisos que relacionam as ações deste hormônio com a proteção ou susceptibilidade à doença de Crohn ou colite ulcerativa ainda não são totalmente conhecidos. Sendo assim, este projeto buscou entender o papel imunomodulador do DHEA exógeno in vitro e in vivo durante a inflamação intestinal experimental induzida por dextran sulfato de sódio (DSS) em camundongos C57BL/6. Inicialmente, in vitro, DHEA inibiu a proliferação de células do baço de forma dose dependente nas concentrações de 5?M, 50?M ou 100?M, com diminuição da produção de IFN-?. Este hormônio não foi tóxico para células de linhagem mieloide, embora tenha causado necrose em leucócitos nas doses mais elevada (50 ?M e 100?M), o que pode ter influenciado a diminuição das citocinas in vitro. Nos ensaios in vivo, os camundongos tratados com DHEA (40 mg/Kg) foram avaliados na fase de indução da doença (dia 6) e durante o reparo tecidual, quando os animais expostos ao DSS e ao DHEA por 9 dias foram mantidos na ausência destas drogas até o dia 15. Houve diminuição do escore pós-morte, melhora no peso e nos sinais clínicos da inflamação intestinal, com redução de monócitos no sangue periférico com 6 dias e aumento de neutrófilos circulantes na fase de reparo tecidual (15 dias). Ainda, a suplementação com DHEA levou à redução da celularidade da lâmina própria (LP) e ao restabelecimento do comprimento normal do intestino. O uso deste hormônio também diminuiu a expressão do RNAm de IL-6 e TGF-?, enquanto aumentou a expressão de IL-13 no colón dos animais durante a fase de indução da doença, o que provavelmente ajudou na atenuação da inflamação intestinal. Além disso, houve acúmulo de linfócitos CD4+ e CD8+ no baço e diminuição apenas de linfócitos CD4+ nos linfonodos mesentéricos (LNM), indicando retenção das células CD4+ no baço após uso do DHEA. O tratamento foi também capaz de aumentar a frequência de células CD4 produtoras de IL-4 e diminuir CD4+IFN-?+ no baço, além de reduzir a frequência de CD4+IL-17+ nos LNM, sugerindo efeito do DHEA no balanço das respostas Th1/Th2/Th17 relacionadas à colite. Em adição, as células de baço dos animais tratados com DHEA e expostos ao DSS se tornaram hiporresponsivas, como visto pela diminuição da proliferação após re-estímulos in vitro. Finalmente, DHEA foi capaz de atuar no metabolismo dos camundongos tratados, levando à diminuição de colesterol total e da fração LDL no soro durante a fase de indução da doença, sem gerar quaisquer disfunções hepáticas. Com isso, podemos concluir que o DHEA atua por meio do balanço das respostas imunes exacerbadas, minimizando os danos locais e sistêmicos causados pela inflamação intestinal induzida por DSS. / Inflammatory bowel diseases (IBD) are multifactorial diseases whose etiology involves genetic susceptibility, environmental factors, dysbiosis and exacerbated activation of the immune system in the gut. These diseases have also been associated to lower levels of dehydroepiandrosterone (DHEA), a precursor of various steroid hormones, related to modulation of immune responses. However, the precise mechanisms that link the actions of this hormone with protection or susceptibility to Crohn\'s disease or ulcerative colitis are still not fully understood. Thus, this project aimed to understand the immunomodulatory role of exogenous DHEA in vitro and in vivo in experimental intestinal inflammation induced by dextran sodium sulfate (DSS) in C57BL/6 mice. Initially, in vitro, DHEA inhibited the proliferation of spleen cells in a dose dependent way on the concentrations of 5?M, 50?M and 100?M, with decreased production of IFN-?. This hormone was not toxic to myeloid lineage cells, although it caused necrosis of leukocytes at the highest doses (50?M and 100?M), which may have influenced the decrease of the cytokines in vitro. Mice treated with DHEA (40 mg / kg) were evaluated at the induction phase of the disease (day 6) and during tissue repair, when animals exposed to DSS and DHEA for 9 days were maintained in the absence these drugs until the day 15. There was decrease of postmortem score, improved weight and clinical signs of intestinal inflammation, besides reduced peripheral blood monocytes on day 6, together with an increase in circulating neutrophils in tissue repair phase (15 days). Supplementation with DHEA also led to a reduction in cellularity of the lamina propria (LP) and to the restoration of normal length of the gut. The use of this hormone also decreased the expression of of IL-6 and TGF-? mRNA, while IL-13 was augmented in the colon of mice during the induction phase of the disease, a fact probably related to attenuation of intestinal inflammation. Furthermore, there was accumulation of CD4+ and CD8+ cells in the spleen along with decreased CD4+ leukocytes in mesenteric lymph nodes (MLN), indicating retention of CD4+ cells in the spleen after use of DHEA. The treatment was also able to increase the frequency of CD4+ cells producing IL-4 and decrease CD4+IFN-?+ in spleen, with reduced frequency of CD4+IL-17+ in the MLN, suggesting a role for DHEA on the balance of Th1/Th2/Th17 responses related colitis. In addition, splenocytes of mice treated with DHEA and exposed to DSS became hiporresponsives as seen by decreased proliferation after re-stimulation in vitro. Finally, DHEA was able to act on the metabolism of treated mice, leading to decreased total cholesterol and LDL cholesterol in serum during the induction phase of the disease, without generating any liver dysfunction. Thus, we concluded that DHEA acts by balancing the exacerbated immune responses, minimizing local and systemic damages caused by intestinal inflammation induced by DSS.
178

Kvinnors upplevelser av att leva med inflammatorisk tarmsjukdom : En litteraturstudie / Women's experience of living with inflammatory bowel disease : A literature review

Lindgren, Ida, Olsson, Isabella January 2021 (has links)
Bakgrund: Inflammatorisk tarmsjukdom räknas som en folksjukdom i Sverige. Tillstånden drabbar oftast personer i ett tidigt skede av livet och symtomen kommer i skov. Patientens vardagliga liv kan påverkas markant efter insjuknande och behandling går ut på att minska risken för nya skov och förhindra en försämring av patientens livskvalitet. Stödjande faktorer är viktigt för patienterna samt att skapa strategier för att hantera sjukdomens påverkan på dagligt liv. Syfte: Syftet med litteraturstudien var att beskriva kvinnors upplevelser av att leva med IBD. Metod: En litteraturstudie med en kvalitativ design baserad på 12 vetenskapliga artiklar utfördes. Litteratursökningen gjordes i databaserna CINAHL, PubMed och Psycinfo. De utvalda studierna kvalitetsgranskades och analyserades med innehållsanalys. Resultat: Smärta och fatigue var de två fysiologiska konsekvenser av inflammatorisk tarmsjukdom som framförallt beskrevs påverka dagligt liv. Kvinnorna kände sig ofta begränsade av sina symtom och i sin kost vilket påverkade både aktivitetsnivån, arbetslivet och socialt samliv. Begränsningarna orsakade emotionella konsekvenser och support och stöd var viktigt. Kvinnorna beskrev att de var i större behov av information gällande sin sjukdom men att det behovet inte alltid kunde tillgodoses av vårdpersonal. Konklusion: Med den ökad förståelse för sjukdomens yttrande i vardagligt liv kan sjuksköterskan genom ett helhetsperspektiv tillämpa en personcentrerad vård utifrån patientens behov och vara uppmärksam på outtalade behov som kan behövas lyftas fram i vården av patienten. / Background: Inflammatory bowel disease is considered an endemic disease in Sweden. The conditions usually affect people at an early stage of life and the symptoms come inflare-ups. The patient's daily life can be significantly affected by their illness and treatment aims to reduce the risk of new relapses and prevent a deterioration in the patient's quality of life. Supporting factors are important for patients and to create strategies for managing the impact the disease has on daily life. Aim: The aim of the literature study was to describe women's experiences of living with IBD. Method: A literature study with a qualitative design based on 12 scientific articles was conducted. The literature search was performed in the databases CINAHL, PubMed and Psycinfo. The chosen studies were quality reviewed and a content analysis was conducted. Results: Pain and fatigue were the two physiological consequences of inflammatory bowel disease that were primarily described to affect daily life. The women often felt limited by their symptoms and in their diet, which affected both the level of activity, working life and social cohabitation. The limitations caused emotional consequences and support was important. The women emphasized that they were in greater need of information regarding their illness, but that this need could not always be met by healthcare staff. Conclusion: With the increased understanding of the disease's manifestation in everyday life, the nurse can, through a holistic perspective, apply a person-centered care based on the patient's needs and be aware of unspoken needs that may need to be highlighted inthe care of the patient.
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Serial fecal ASCA measurements in the evaluation of children with Crohn's disease

Mojdehbakhsh, Rachel 08 April 2016 (has links)
BACKGROUND: Pediatric patients with Inflammatory Bowel Disease (IBD) undergo costly and invasive investigations to diagnose and treat their chronic disease. To that end, it is important for researchers and physicians to continue to work to find novel tools to improve diagnosis and treatment processes. One of the main challenges is differentiating between the two main forms of IBD, Crohn disease (CD) and ulcerative colitis (UC). Physicians currently rely on a combination of endoscopic evaluations, mucosal biopsies, radiology studies, and biochemical testing to assess for the presence and extent of inflammation in the gastrointestinal (GI) tract. Serologic biomarkers can be useful to some extent, but changes in these markers do not typically reflect disease specific to the GI tract, or the state of inflammation related to a patient's IBD. In contrast, fecal biomarkers have the unique potential to provide specific information about inflammation in the GI tract. While serum antibody levels have been well studied for use in the diagnosis of patients with IBD, fecal antibody levels and anti-saccharomyces cerevisiae antibody (ASCA) in particular, have not been extensively evaluated. In this study, we will assess the dynamic range of fecal ASCA levels in acute and convalescent fecal samples collected from children and adolescents with CD and UC. METHODS: We recruited pediatric patients from inpatient and ambulatory settings at the Gastroenterology Program at Boston Children's Hospital. Patients had a diagnosis of either CD or UC. We collected baseline stool samples during a point of active disease, and follow-up samples three to six months later during a point of inactive disease. Samples were analyzed for fecal ASCA as well as lactoferrin (FLA), another marker of inflammation that can be measured in the stool. RESULTS: In patients with CD, fecal ASCA levels were significantly higher during active disease than during inactive disease. Additionally, fecal ASCA levels were higher in patients with CD than in patients with UC, regardless of disease activity. When compared to FLA, ASCA was shown to differentiate between CD and UC, with greater changes in the level of fecal ASCA (active - inactive) correlating with a diagnosis of CD. In patients with CD, FLA levels were significantly higher in the context of active disease than in inactive disease. However, FLA did not differentiate between CD and UC. CONCLUSIONS: Our results suggest that fecal ASCA may be a new marker of inflammation in the GI tract. Unlike FLA, changes in fecal ASCA levels appear more dynamic in patients with CD. Future studies are required to further demonstrate both how changes in fecal ASCA may help physicians distinguish between different forms of IBD as well as how measurement of fecal ASCA may help assess disease activity and response to therapy in patients with CD.
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Vitamin D prescribing habits and clinical outcome in pediatric patients with inflammatory bowel disease

Yang, Timothy 13 July 2017 (has links)
INTRODUCTION: The inflammation observed in patients with IBD can negatively impact the intake or absorption of vitamin D. This can increase the risk of disease relapse, impact patients’ quality of life, and increase the risk of IBD related surgeries. In addition to the traditional observation that vitamin D deficiency may be a comorbid manifestation of IBD, there is now growing evidence pointing to serum vitamin D levels as a pathogenic factor contributing to the initiation and propagation of mucosal inflammation in patients with IBD. It is well-established that variation in clinical practice leads to less optimal outcomes in any clinical setting. The relative scarcity of clinical and translational studies is even more pronounced in the pediatric population. OBJECTIVES: The primary objective of this study is to quantify the prevalence of clinician assessment of vitamin D levels in pediatric patients with IBD. We will also look at this behavior in subpopulations and compare their vitamin D status. It is secondary for this study to also describe variations in physician practices with respect to the testing and treatment of vitamin D deficiency at a single tertiary care IBD Center. METHODS: We conducted a retrospective cohort study on consecutive patients with UC, CD, and ID, that were followed in the ambulatory program in the Center for Inflammatory Bowel Disease at Boston Children’s Hospital from 1/1/2014 to 12/31/2014. We identified 498 patients and collected their demographic information, serologic testing, and physician prescribing behavior. RESULTS: Out of the entire population, 64% of the patients were vitamin D deficient (vitamin D level below 32 ng/ml). 24% of the patients received vitamin D supplementation. Vitamin D deficiency was less prevalent in patients with UC than those with CD, with an OR of 0.64 (95% CI 0.43-0.94). Out of the ones receiving supplementation, 37% of them were deficient. In terms of physician practice trends, 62% of the patients were not formally prescribed supplementation. 14.5% of those who were prescribed supplementation were receiving 50,000 IU weekly, and the rest receiving 400 – 2,000 IU daily. Patients with vitamin D levels below 20 ng/ml were more likely to receive the high dose vitamin D prescription (OR 11.5) than those with levels between 20 and 30 ng/ml (OR 5.7). CONCLUSIONS: Our study suggests that despite high prevalence of vitamin D deficiency in pediatric patients with IBD, there is a lack of consensus with respect to the assessment of vitamin D levels and consistency in prescribing vitamin D supplementation. With the potential role that vitamin D plays in IBD pathology and suggestions of the therapeutic effects of vitamin D supplementation, further studies are needed to explore this area.

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