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Impact des facteurs micro-environnementaux de l'hôte sur la colonisation instestinale des Escherichia Coli adhérents et invasifs. / Impact of microenvironmental host factors on the gut colonization of adherent-invasive Escherichia coliGibold-Lyonne, Lucie 28 September 2016 (has links)
La maladie de Crohn (MC) est une affection inflammatoire chronique du tube digestif dont l’étiologie est multifactorielle. Les lésions intestinales des patients atteints de MC sont anormalement colonisées par des souches pathogènes d’Escherichia coli appartenant au pathovar AIEC pour «Adherent-Invasive Escherichia coli ». Ces souches sont capables d’adhérer et d’envahir les cellules épithéliales intestinales, et ont la capacité de survivre et de se multiplier en macrophages en induisant une synthèse intense de cytokines pro-inflammatoires. Les AIEC pourraient ainsi être impliquées dans l’induction et/ou l’entretien de l’état inflammatoire de la muqueuse intestinale.L’objectif de ce travail est d’identifier les déterminants bactériens des AIEC qui vont intervenir dans les étapes précoces de l’implantation des AIEC au niveau intestinal et de définir quel est le rôle des facteurs micro-environnementaux de l’hôte dans cette implantation.Nous montrons que l’AIEC LF82 possède une activité mucinolytique qui est portée par le gène vat-AIEC et qui favorise la traversée du mucus et la colonisation intestinale. Nous avons retrouvé ce gène chez 42% des souches AIEC isolées de patients atteints de MC, et chez 97% des souches AIEC appartenant au phylogroupe B2. Par ailleurs, nous avons montré que les sels biliaires augmentent l’expression de cette mucinase.Nous avons ensuite étudié l’influence des sels biliaires sur l’expression globale des gènes de la souche LF82. Les sels biliaires modifient profondément le métabolisme de la souche, induisant une diminution globale des voies de biosynthèse (protéines, lipides) et une augmentation des voies de dégradation (alcools, acides carboxyliques, polyamines, …). L’étude du catabolisme de l’éthanolamine et du propanediol indique que les AIEC pourraient se servir de ces substrats pour s’implanter au sein de la flore iléale. De plus, les analyses transcriptomiques révèlent que les sels biliaires augmentent l’expression de gènes codant des facteurs de virulence comme l’invasine IbeA, les systèmes de sécrétion de type VI et la yersiniabactine. Nous montrons également qu’ils favorisent la formation de biofilm chez les souches AIEC.Ces données indiquent que les sels biliaires constituent un signal permettant à la souche AIEC LF82 de mettre en place différentes voies métaboliques et déterminants bactériens nécessaires à son implantation au niveau intestinal.Mots-clé : Escherichia coli, maladie de Crohn, mucines, serine protéase, mucinase, AIEC, / The etiology of Crohn's disease (CD) involves disorders in host genetic factors and intestinal microbiota. Ileal mucosa of CD patients is often abnormally colonized by adherent-invasive Escherichia coli (AIEC). These strains isolated from the intestinal mucosa of CD patients are able to adhere to intestinal epithelial cells (IECs). This adhesion to IECs promotes the invasion of cells by the bacteria. Furthermore, the invasive ability of AIEC strains allows bacteria to translocate across the human intestinal epithelium, move into the deep tissues and activate immune cells continuously upon arrival. Thus AIEC could be involved in the inflammatory state of the intestinal mucous membrane. The aim of this study was to identify components of AIEC virulence, which might favor their implantation in the gut of CD patients and to define the role of several chemical factors from the ileal environment. Here, we reported a protease called Vat-AIEC from AIEC which favors the penetration of AIEC through the mucus layer and enhances gut colonization. The screening of E. coli strains isolated from CD patients revealed a preferential vat-AIEC association with AIEC strains belonging to the B2 phylogroup. Besides, Vat-AIEC transcription was increased with bile salts from the ileum environment. Then a global RNA sequencing (RNA-seq) of E. coli LF82 has been used to observe the impact of bile salts on the expression of bacterial genes. The results demonstrate the explosive effect of bile salts with a dysregulation of about 40% of the genome, with a global upregulation of genes involved in degradation and downregulation of those implicated in several biosynthesis. Our results show that LF82 use ethanolamine as a nitrogen source and propane diol as a carbon source, which can favor their colonization in the gut compared to the other bacteria. We also studied virulence genes expression in the presence of bile salts. They increase the expression of several virulence factors like the IbeA invasion, the type 6 secretion systems and the yersiniabactin. Furthermore, we noticed an increased expression of genes implicated in biofilm formation. These results improve the understanding of the global regulatory network in the presence of bile salts and thus of AIEC implantation in the human gut of CD patients.
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Resultado do tratamento da doença de Crohn com anti-fator de necrose tumoral alfa / Outcomes in the treatment of Crohn´s disease with anti tumor necrososis factor-alphaMalheiros, Anna Paula Rocha 19 August 2008 (has links)
A doença de Crohn é uma inflamação crônica do trato gastrointestinal. O tratamento convencional é muitas vezes desapontador. Apesar da variedade de drogas disponíveis para o tratamento da doença inflamatória intestinal, tais como: salicilatos e seus derivados, corticosteróides, antibióticos e imunossupressores, nenhuma destas mostrou ser totalmente eficaz ou definitiva para o tratamento da doença e seus surtos de exacerbação. Pesquisas têm sido desenvolvidas com o objetivo de apresentar drogas mais efetivas. Dentre estas, destacam-se as drogas biológicas. O infliximabe é um anticorpo monoclonal quimérico anti-fator de necrose tumoral alfa e está indicado na doença de Crohn refratária e fistulizante. O objetivo deste estudo visa avaliar prospectivamente os resultados e efeitos colaterais precoces e tardios do uso do anti-TNF alfa no tratamento de 60 doentes com doença de Crohn, no período de julho de 1999 a dezembro de 2005. Os doentes foram tratados com anti-TNF alfa (infliximabe), na dose de 5mg/kg de peso, aplicado por via endovenosa em intervalos de dois meses. A avaliação foi realizada por protocolo clínico que classificava os quesitos: estado geral, sintomas intestinais e doença perianal em melhor, inalterado e pior, e pelo índice de atividade da doença de Cronh. Os doentes tratados com anti-TNF alfa apresentaram mediana de duração da doença de sete anos, variando de um a 28 anos entre a data do início dos sintomas e a data de início da pesquisa. 34 doentes (56,7%) já haviam sido submetidos a uma ou mais operações abdominais e 38 (63,3%) a operações orificiais. O software utilizado para a realização dos cálculos foi o SPSS® 9.0 for Windows, sendo estatisticamente significantes os testes com p<0,05. Foram aplicadas 225 doses de anti-TNF alfa, em média, 3,7 doses por paciente num período de aproximadamente cinco anos, variando de uma a 14 doses. No tratamento inicial 76% dos pacientes responderam a droga. As principais indicações para o emprego do anti-TNF alfa foram a presença de doença perianal em 36 casos (60%) e a intratabilidade clínica em 24 casos (40%). Observou-se que após a primeira dose da medicação, os doentes com mais de dez anos de doença e submetidos à operação abdominal tiveram resultado satisfatório semelhantemente aqueles doentes com menos de cinco anos de doença e não operados com p<0,05. O índice de atividade da doença de Crohn foi em média de 189,7 antes do início do tratamento e na primeira aplicação diminuiu em média para 135,4, e progressivamente ao longo das aplicações (115, 102, 109 e 88,4 até a quinta dose), sendo o resultado estatisticamente significativo. Houve efeito colateral em 40 aplicações (17,8%), sendo os efeitos principais: eritema cutâneo, dispnéia e dor abdominal. O tratamento com anti-fator de necrose tumoral alfa, obedecidas as indicações precisas, associou-se a baixo índice de efeitos colaterais graves tendo apresentado bons resultados na resolução da doença de Crohn perianal, na melhora da sintomatologia intestinal e no estado geral dos pacientes / Crohn´s disease is a chronic inflammatory disorder of the gastrointestinal tract. Conventional treatment is many times disappointing. Besides the great number of available medications to treat inflammatory bowel diseases, such as salicilates and derivatives, corticosteroids, antibiotics and immunosuppressive agents, none of them proved to be totally efficient or the ultimate treatment for inflammatory diseases and their exacerbation. Researches have been carried out to find more effective therapeutic drugs. Among these therapeutics, biologic treatments have been in evidence. Infliximab is a chimeric IgG1 monoclonal antibody against tumor necrosis factor-alpha, and is indicated for refractory luminal and fistulizing Crohns disease. The aim of this study is to prospectively evaluate the outcome, early and late adverse events, in 60 patients diagnosed with Crohn´s disease and treated with infliximab between July 1999 and December 2005. All patients were treated with anti-TNF-alpha (infliximab), 5mg/kg/dose, intravenously, each two months. Patients were clinically evaluated using a protocol that classified the evolution of the health status, intestinal symptoms and perianal disease, as better, worse or unchanged, during the treatment. Crohn´s disease activity index was also evaluated. Patients treated with anti-TNF-alpha presented a median disease duration of seven (range 1-28) years, between the beginning of the disease symptoms and the beginning of the research protocol. Thirty-four patients (56.7%) have been submitted to one or more abdominal surgeries before, and 38 (63.3%) to anal-rectum surgeries. All statistics tests were performed with computer software Statistical Package for the Social Sciences (SPSS® 9.0) for WindowsTM, and p values of less than 0.05 were considered statistically significant. Totals of 225 anti-TNF-alpha doses were administered. The mean doses administered per patient, in a period of approximately five years, were 3.7 (range 1-14) doses. After the initial treatment, 76% of the patients achieved a response. The most frequent indications for anti-TNF-alpha was perianal disease, occurring in 36 patients (60%), and clinical failure to the conventional treatment, happening in 24 patients (40%). After the first dose of anti-TNF-alpha, patients with more than 10 years of treatment and previously submitted to abdominal surgery presented a satisfactory outcome, similar to those with less than 5 years of disease and not submitted to surgery, p<0.05. Crohn´s disease activity index showed a mean index of 189.7 before treatment, that decreased to 135.4 after the first dose, and progressively decreased with the subsequent doses (means: 115, 102, 109 and 88.4, until the fifth dose, p<0.05). Adverse events were reported in 40 administrations (17,8%) from the total. The most prevalent adverse events were: rash, dyspnoea and abdominal pain. The treatment with anti-TNF-alpha, following precise indications, was associated with a low incidence of severe adverse events and presented good outcomes in the resolution of perianal Crohn´s disease, improving intestinal symptomatology and patients´ health status
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Avaliação do estresse oxidativo em modelo experimental da doença de Crohn submetido ao tratamento de oxigênio hiperbárico / Evaluation of oxidative stress in experimental model of Chron\'s disease under hyperbaric oxygen treatmentFernanda Serafim Nakutis 12 August 2015 (has links)
Introdução: O conhecimento da fisiopatogênese da Doença Inflamatória Intestinal (DII) tem evoluído nas últimas décadas. No entanto, apesar das terapias terem evoluído, 2/3 dos casos ainda necessitam de drogas alternativas e terapias de suporte. A busca constante de tratamentos alternativos e modalidades mais eficazes tem gerado algumas abordagens promissoras, tais como a utilização do oxigênio hiperbárico (HBO). O uso dessa terapia cresceu rapidamente nos anos 90 mostrando bons resultados e poucos efeitos colaterais sendo, posteriormente \"esquecida\" ante a eficácia apresentada pelo uso das terapias biológicas. Objetivos: Os objetivos deste trabalho foram avaliar os efeitos do tratamento com HBO em camundongos com colite induzida quimicamente pelo ácido 2,4,6 trinitro benzeno sulfônico 2,5% (TNBS), sobre a avaliação dos animais, a análise histológica, o perfil inflamatório através das citocinas IL-4, IL-10, IL-12, IL-13, IL-17, fator de necrose tumoral alfa (TNFalfa) e Interferon y e da atividade das enzimas antioxidantes superóxido dismutase (SOD), glutationa peroxidase (GPx) e glutationa redutase (GR) em intestino de camundongos. Metodologia: Camundongos machos foram divididos em 6 grupos. No grupo 1, a colite foi induzida por TNBS 2,5% + Etanol 35%, sendo chamado de grupo TNBS; o grupo 2 também recebeu TNBS 2,5% + Etanol 35% seguido do tratamento com o HBO, sendo chamado de grupo TNBS+HBO; o grupo 3 recebeu apenas o veículo etanólico a 35%, sendo chamado de grupo ÁLCOOL; o grupo 4 também recebeu o veículo etanólico a 35% associado ao HBO, sendo chamado de grupo ÁLCOOL+HBO; o grupo 5 recebeu apenas solução salina (NaCl 0,9%), sendo chamado de grupo SALINA; e o grupo 6 recebeu a solução salina associado ao HBO, sendo chamado de grupo SALINA+HBO. Durante o tratamento os animais foram avaliados diariamente. O tratamento com HBO foi realizado por 4 dias e, ao final, as amostras da porção final do intestino foram retiradas e armazenadas para análise histológica, enzimas antioxidantes e citocinas. Resultados: A avaliação mostrou que o HBO promoveu uma melhora significativa no quadro clínico desses animais. A aplicação do ácido 2,4,6 trinitro benzeno sulfônico nos animais do grupo TNBS resultou na perda de 12,71% do peso corpóreo dos animais após 24 horas e, ao final do período experimental uma perda de peso total de 14,63%. Por outro lado, os animais que também receberam 2,4,6 trinitro benzeno sulfônico associado ao tratamento com o HBO (TNBS+HBO) tiveram uma perda de apenas 7,52% nas primeiras 24 horas, apresentando uma recuperação de 5,58% de seu peso no final do período experimental. A avaliação do quadro histológico mostrou uma melhora significativa entre o grupo TNBS+HBO quando comparado com o grupo TNBS. O tratamento com HBO aumentou a atividade das enzimas antioxidantes SOD e GPx em todos os grupos, sendo somente significativo entre os grupos TNBS vs TNBS+HBO, não sendo observado diferença da GR entre os grupos. Com relação ao perfil inflamatório foi observado que o tratamento com o HBO promoveu a diminuição das citocinas pró-inflamatórias INFy, IL-12, IL-17 e TNF? e o aumento das citocinas anti-inflamatórias IL-4 e IL-10, e não houve alteração da IL-13. Em modelo experimental, esses dados representam, o potencial efeito anti-inflamatório e o do aumento das defesas antioxidantes enzimáticas promovido pelo HBO / Introduction: The Knowledge about the physiopathogenesis of inflammatory bowel disease (IBD) has evolved over the last decades. However, although therapies have improved, 2/3 of the cases still need alternative drugs and support therapy. The constant search for alternative treatments and more effective modalities has brought to light some promising strategies, as the use of hyperbaric oxygen (HBO). The use of such therapy surged rapidly in the 90´s showing good results and few side effects being, later on, \"forgotten\" due to the efficacy shown by the use of biological therapies. Objective: This study aimed to evaluate the effects of HBO treatment in mice with chemically induced colitis, using 2,4,6 trinitrobenzene sulfonic acid 2,5% (TNBS) over the evaluation of the animals, histological analysis, inflammatory profile through cytokines IL-4, IL-10, IL-12, IL-13, IL-17, TNF- alfa and interferon y, and also the activity of the antioxidant enzymes superoxide dismutase (SOD), gluthatione peroxidase (GPx) and gluthatione reductase (GR) in intestine of mice. Methodology: Male mice were divided into 6 groups, in group 1, colitis was induced by TNBS 2,5%+ Ethanol 35%, named as TNBS, group 2 also received TNBS 2,5%+ Ethanol 35% + HBO, named as TNBS+HBO, group 3 received only Ethanol 35%, named as ALCOHOL, group 4 received Ethanol 35% associated with HBO, named as ALCOHOL+HBO, group 5 received Saline (NaCl 0,9%), named as SALINE and group 6 received Saline combined with HBO, named as SALINE+HBO. During the treatment the animals were evaluated daily. The treatment with HBO was performed for 4 days and at the end, the samples of the final portion of the bowel were removed and stored for histological, antioxidant enzymes and cytokines analysis. Results: This study has shown that the HBO promoted a significant improve on these animals clinical status. The group which received TNBS showed a 12,71% body weight loss after 24 hours, and by the end of the experimental period the average weight loss was 14,63%. On the other hand, the animals treated with HBO showed only 7,52% weight loss during the first 24 hours, having recovered the weight lost in 5,58% by the end of the experimental period. The histological evaluation of the TNBS+HBO group presented a significant improvement when compared with TNBS group. The treatment with HBO increased the activity of the antioxidant enzymes SOD and GPx in all groups, being only significant among the groups TNBS vs TNBS+HBO, difference in the activity of GR was not observed among the groups. Regarding the inflammatory profile, it was observed that the treatment with HBO promoted the decrease of pro-inflammatory cytokines INFy, IL-12, IL-17 and TNFalfa, as well as the increase of anti-inflammatory cytokines IL-4 and IL-10, while IL-13 was not affected. These data represents, in experimental model, the potential anti-inflammatory effect and the increase of the enzymatic antioxidant defenses promoted by the HBO
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Contribuição da atenção farmacêutica ao tratamento de pacientes com doenças inflamatórias intestinais / The contribution of pharmaceutical care to the treatment of patients with inflammatory bowel diseases.Nathalie de Lourdes Souza Dewulf 21 July 2010 (has links)
As doenças inflamatórias intestinais (DII) - doença de Crohn e retocolite ulcerativa, são condições crônicas que, na maioria dos casos, exigem controle com terapia medicamentosa. A atenção farmacêutica (AF), definida como a provisão responsável do tratamento farmacológico, com o propósito de alcançar resultados concretos que melhorem a qualidade de vida do paciente, constitui nova forma de cuidado ao paciente, que necessita ser mais extensivamente avaliada. Este estudo teve o objetivo de avaliar a contribuição da atenção farmacêutica ao tratamento clínico de pacientes com DII em acompanhamento ambulatorial em hospital terciário. Ao longo de um ano, foi avaliado um grupo que recebeu a atenção farmacêutica (GAF; N=18) e um grupo controle (GC; N=17) não submetido aos procedimentos da AF. Os resultados da contribuição da AF foram avaliados pela comparação de diferentes variáveis entre os grupos, que foram obtidas na primeira entrevista - T(0), aos seis - T(6) e 12 - T(12) meses do estudo. Quanto aos aspectos clínicos, houve redução significativa dos índices de atividade clínica de T(6) para T(12) no GAF (mediana; variação: 2,20; 0,99 3,77 versus 1,90; 0,99 3,77; p=0,02), o que não ocorreu no GC (1,69; 0,99 3,77 versus 1,69; 0,99 3,48). No GAF, houve aumento significativo do percentual de pacientes mais aderentes ao tratamento medicamentoso (27,8% versus 72,2%; p<0,05), quando da avaliação por meio do teste de Morisky, mas não foram observadas diferenças (72,2% versus 88,9%) na adesão avaliada pelo cotejo entre medicamentos utilizados e prescrições registradas. Em ambas as formas de avaliação da adesão, tanto pelo teste de Morisky (41,2% versus 41,2%), quanto pelo confronto das medicações utilizadas e prescrições registradas (88,2% versus 82,4%), não foram observadas alterações no GC. Houve aumento significativo dos índices de conhecimento do paciente sobre o tratamento no GAF entre T(0) e T(12) (mediana; variação: 80%; 40% 100% versus 100%; 100% 100%; p0,0001), o que não ocorreu no GC (80%; 0 100% versus 80%; 60% 100%). No que se refere à qualidade de vida, avaliada pelo instrumento SF36, houve diferenças estatisticamente significativas nos dois grupos apenas no domínio de saúde mental. No GAF, houve elevação dos escores deste domínio entre T(0) e T(12) (54,0 versus 66,0; p=0,04), o que, também ocorreu no GC (60,0 versus 68,0; p=0,01). Porém, no GAF, esta mudança ocorreu mais precocemente, de T(0) para T(6) (54,0 versus 66,0; p<0,01). A AF possibilitou a identificação, em média, de 3,8 problemas relacionados ao medicamento por paciente, que em sua maioria foram resolvidos, com intervenções predominantemente focadas em orientações aos pacientes. Os pacientes do GAF, ao término do estudo, apresentaram alto grau de satisfação com a AF. Os resultados obtidos permitem concluir que a introdução de um programa de atenção farmacêutica a pacientes ambulatoriais com DII seguidos em hospital terciário trouxe contribuição positiva, proporcionando benefícios mensuráveis aos pacientes. / Inflammatory bowel diseases (IBD) Crohns disease and ulcerative colitis are chronic conditions which are usually controlled with drug therapy. Pharmaceutical care (PC), defined as the responsible provision of drug therapy for the purpose of achieving definite outcomes that improve patients quality of life, is a new patient care modality, which needs to be more extensively evaluated. This study aimed at assessing the contribution of pharmaceutical care to the clinical treatment of outpatients with IBD assisted at a reference hospital. During one year, a group receiving pharmaceutical care (PCG; N=18) and a control group (CG; N=17), which did not undergo PC procedures, were evaluated. Results of PC contribution were assessed by comparing the two groups regarding different variables obtained in the first interview at - T(0), at six - T(6) and 12 - T(12) months of study. Regarding the clinical aspects, there was a significant decrease of clinical activity indexes from T(6) to T(12) in the PCG (median; range: 2.20; 0.99 3.77 versus 1.90; 0.99 3.77; p=0.22), but not in the CG (1.69; 0.99 3.77 versus 1.69; 0.99 3.48). In the PCG, there was a significant increase in the percentage of patients who were more compliant to drug treatment (27.8 % versus 72.2 %; p<0.05) as assessed using the Morisky scale; however, no differences in compliance rates were observed (72.2 % versus 88.9 %) by comparing drugs taken with registered prescriptions. In the CG, no differences were observed in none of the compliance assessment methods, neither by the Morisky scale (41.2% versus 41.2%), nor by comparing drugs taken with registered prescriptions (88.2% versus 81.2%). There was a significant increase in the values of an index for patients knowledge about the treatment in the PCG between T(0) and T(12) (median; range: 80%; 40 100 versus 100%; 100 100; p0,0001), but not in the CG (80%; 0 100 versus 80%; 60 100). With respect to quality of life, assessed by the SF36 scale, there were statistically significant differences in both groups only in the mental health domain. There was an increase in scores for this domain between T(0) and T(12) in both PCG (54.0 versus 66.0; p=0,04), and CG (60.0 versus 68.0; p=0,01). However, PCG had this increasing scores earlier, between T(0) and T(12) (54.0 versus 74.0; p<0,01). PC enabled the identification of a number of drug-related problems per patient (mean = 3.8), which were mostly solved by interventions predominantly focused on patient orientation. At the end of the study, patients in the PC group showed a high degree of satisfaction with the intervention. The achieved results allow concluding that the implementation of a pharmaceutical care program to outpatients with IBD followed at a tertiary hospital gave a positive contribution, providing measurable benefits to patients.
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Stratégies thérapeutiques visant à limiter les E.coli Adhérents-Invasifs du tractus digestif dans le cadre de la Maladie de Crohn. / Prophylactic and therapeutic strategies to limit Adherent-Invasive Escherichia coli (AIEC) in the digestive tract in the context of Chron's diseaseSivignon, Adeline 30 June 2015 (has links)
La maladie de Crohn (MC) est une maladie inflammatoire chronique du tube digestif caractérisée par un état d’hyperactivation du système immunitaire intestinal. Les données cliniques et expérimentales montrent que l’étiologie de la MC serait une réponse immunitaire aberrante à des facteurs environnementaux et/ou infectieux chez un hôte génétiquement prédisposé. Les patients atteints de MC présentent une perméabilité intestinale anormalement élevée pouvant expliquer la stimulation du système immunitaire intestinal par les bactéries et antigènes du microbiote. La muqueuse iléale des patients atteints de MC est anormalement colonisée par des souches de Escherichia coli ayant la propriété d’adhérer et d’envahir les cellules épithéliales intestinales, de survivre et de se multiplier dans les macrophages en entraînant la sécrétion de TNF-α (Tumor Necrosis Factor-alpha). Un pathovar de E. coli associé à la MC et dénommé AIEC pour « Adherent-Invasive E. coli » a été défini. Les souches AIEC adhérent via l’adhésine FimH des pili de type 1 aux résidus mannose de la glycoprotéine CEACAM6, anormalement exprimée au niveau de l’épithélium iléal des patients atteints de MC. Au cours de la maladie, l’inflammation intestinale peut être contrôlée par les traitements médicamenteux ou la chirurgie sans pour autant obtenir de rémission complète et définitive.Le but du travail était d’analyser les conséquences de l’infection par des bactéries AIEC in vivo dans un modèle murin reproduisant l’interaction AIEC/CEACAM6 et de proposer des stratégies pour éliminer ces bactéries de l’intestin. Nous avons montré que les AIEC avaient la capacité d’altérer la fonction de barrière de l’épithélium intestinal chez des souris transgéniques CEABAC10 exprimant CEACAM6. Cette altération est associée à une forte induction de l’expression de la protéine de jonction Claudine-2, comme observée chez les patients atteints de MC. Nous avons ensuite démontré que la levure S. cerevisiae CNCM I-3856 et des produits de levures étaient capables de maintenir l’intégrité de la barrière intestinale des souris en prévenant la colonisation du tractus digestif par les bactéries AIEC. Dans une deuxième partie, nous nous sommes intéressés au développement de nouvelles molécules antagonistes de l’adhésine FimH. Les thiazolylaminomannosides ont montré un puissant effet inhibiteur de l’adhésion des bactéries AIEC à des cellules épithéliales intestinales. Les heptyl-mannosides sont également de puissants inhibiteurs de l’adhésion des AIEC et leur présentation en multivalence sur des corps polymériques ou des cyclodextrines potentialisent l’effet anti-adhésif. De manière intéressante, certains heptyl-mannosides diminuent fortement la colonisation de l’intestin par les bactéries AIEC et préviennent la colite chez des souris CEABAC10. Toutefois, la multivalence n’apporte pas d’efficacité supplémentaire dans ce contexte. En conclusion, deux stratégies anti-adhésives ont été étudiées : les levures et les mannosides. Elles pourraient être proposées aux patients atteints de MC fortement colonisés par les AIEC afin d’éliminer ces bactéries du tractus digestif pour espérer diminuer l’inflammation. Les perspectives à ce travail seront la mise au point de techniques de détection simples et rapides des personnes colonisées ou susceptibles d’être colonisées par ces souches de E. coli pour cibler la population à traiter par les probiotiques levures et les molécules anti-adhésives. / Crohn’s disease (CD) is an inflammatory bowel disease (IBD) with a multifactorial etiology, resulting from an exacerbated inflammatory response to intestinal microbes and/or microbial components in genetically susceptible hosts. CD patients present an increased intestinal permeability which can favor the overstimulation of the intestinal immune system by bacteria or antigens from microbiota. Ileal mucosa from CD patients is abnormally colonized by Escherichia coli strains sharing the ability to adhere to and to invade intestinal epithelial cells, to survive and to replicate within macrophages, inducing high secretion of TNF-α (Tumor Necrosis Factor-). These strains associated with CD are grouped in a pathovar of E. coli named AIEC for « Adherent-Invasive E. coli ». AIEC bacteria adhere via the adhesin FimH localized at the tip of the type 1 pili, to mannose residues exposed on the glycoprotein CEACAM6 abnormally expressed at the ileal mucosa of CD patients. Currently, intestinal inflammation can be controlled with drugs or intestinal surgery but total remission cannot be yet achieved. The aim of the present work was to investigate consequences of AIEC infection in a murine model mimicking the AIEC/CEACAM6 interaction and to test different strategies to eradicate these bacteria from the gut. We showed that AIEC bacteria altered barrier function of the intestinal epithelium in transgenic CEABAC10 mice expressing human CEACAM6. The overexpression of the pore-forming tight junction protein claudin-2 was correlated with the increase intestinal permeability, as observed in CD patients. We demonstrated that the yeast strain S. cerevisiae CNCM I-3856, as well as some yeast products, were able to prevent increase of intestinal permeability in decreasing AIEC gut colonization. In a second part, we investigated another strategy targeting AIEC bacteria using antagonists to FimH adhesin. Thiazolylaminomannosides molecules exerted a strong inhibitory effect on the ability of AIEC bacteria to adhere to intestinal epithelial cells. Heptyl-mannosides (HM) also shared high inhibitory properties in vitro and their efficacy can be potentiated when HM are harbored in multiple copies on polymeric or cyclodextrin cores. Interestingly, some HM molecules strongly decreased AIEC gut colonization and the signs of colitis in vivo, in AIEC LF82-infected CEABAC10 mice. In that context, multivalency did not improve inhibitors efficacy.To conclude, two different strategies were studied: probiotic yeasts and anti-adhesive mannosides. These treatments should be proposed in CD patients highly colonized by AIEC bacteria in order to eliminate these bacteria from the gut and to decrease intestinal inflammation. Future works will focus on the development of quick and easy detection methods to determine people colonized or susceptible to be colonized by AIEC bacteria to treat this subpopulation of CD patients.
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Clinical and Experimental Studies on Inflammatory Bowel Disease with special emphasis on Collagenous ColitisWagner, Michael January 2010 (has links)
This thesis describes studies in patients with inflammatory bowel disease (IBD) and collagenous colitis (CC). We investigated mucosal eosinophil and neutrophil granulocytes and T-cells involved in the inflammatory processes and aimed at determining whether these processes are reflected in the faecal (F) contents of specific proteins secreted by cells in the intestinal mucosa. Thus, we measured eosinophil cationic protein (ECP) and eosinophil protein X (EPX) and the neutrophil derived myeloperoxidase (MPO) and calprotectin (C); and in addition, chromogranin A (CgA), Chromogranin B (CgB) and secretoneurin (SN), derived from EEC cells and cells in the enteric nervous system. We found that a normalised FC level can serve as a surrogate marker for successful treatment in patients with IBD, but persistently high FC levels need further evaluation (study I). Furthermore, FC and F-MPO appear to relate better than F-EPX to treatment outcome in IBD. We evaluated F-ECP, F-EPX, F-MPO and FC as markers of disease activity and treatment outcome in patients with CC (study III) and concluded that F-ECP was the best discriminator of detecting active CC. Normalised F-ECP and F-EPX could serve as markers of successful treatment. We showed that the inflammation in CC is characterised by activated eosinophils, but that there is no neutrophil activity (study II). T-cells have a lower grade of activity in active CC than in control subjects. During budesonide treatment the normal activation of eosinophils and T-cells is restored, with concomitant clinical remission. The findings in studies II and III indicate that the eosinophils have an essential role in the pathophysiology of CC. Markedly higher values of F-CgA, F-CgB and F-SN were found in patients with CC than in those with IBD and controls (study IV) indicating a crucial role for the intestinal neuro-endocrine system in the pathogenesis of collagenous colitis.
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Epidemiologie chronisch entzündlicher Darmerkrankungen bei Kindern und Jugendlichen in Sachsen sowie jungen Erwachsenen in LeipzigZurek, Marlen 13 June 2013 (has links) (PDF)
Hintergrund: Angaben zu Inzidenz und Prävalenz von chronisch entzündlichen Darmerkrankungen (CED) bei Kindern und Jugendlichen in Deutschland fehlen bisher, die Daten des im Jahr 2000 gegründeten Sächsischen CED-Registers für Kinder und Jugendliche wurden bisher nicht veröffentlicht. Bei internen Diskussionen der Registerdaten zeigte sich stets eine nicht erklärbare abfallende altersspezifische Inzidenz der CED ab dem 15. Lebensjahr. Es wurde vermutet, dass einige ältere Jugendliche ausschließlich von Erwachsenengastroenterologen betreut wurden und bei einigen Adoleszenten eine längere diagnostische Latenz zur Diagnosestellung nach dem 18. Lebensjahr führte.
Patienten und Methoden: Zur Prüfung der Thesen wurden alle gastroenterologisch tätigen Internisten in Leipzig aufgesucht und Patienten eingeschlossen, bei denen bis zum 26. Lebensjahr in den Jahren 2005-2009 eine CED endoskopisch neu diagnostiziert wurde. Die Auswertung des Sächsischen CED-Registers erfolgte hinsichtlich Inzidenz, Prävalenz, Geschlechterverteilung und diagnostischer Latenz im Zehnjahreszeitraum 2000-2009.
Ergebnisse: Es wurden tatsächlich einige Jugendliche vor dem 18. Lebensjahr ausschließlich von Internisten betreut und nicht an das Register gemeldet. Die korrigierte Inzidenz von CED bei Patienten bis zum 18. Lebensjahr in Leipzig lag um 37 % höher als im Register angegeben. Nach dem 15. Lebensjahr wurde – ebenfalls in Abweichung zu den Registerdaten – ein kontinuierlicher Anstieg der altersspezifischen Inzidenz bis zum 18. Lebensjahr registriert. Es zeigte sich eine Tendenz zur längeren diagnostischen Latenz bei Adoleszenten, die sich jedoch nicht statistisch sichern ließ. Bis zum 15. Lebensjahr wurden nahezu alle Patienten im CED-Register erfasst.
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Sjukdomsrelaterad oro hos personer med Crohns sjukdom- en intervjustudie / Disease-related worries in persons with Crohn´s disease - an interview studyWåhlin, Monica January 2015 (has links)
Bakgrund: En kronisk oförutsägbar sjukdom som Crohns sjukdom framkallar fysisk, psykologisk och social stress. Sjukdomen påverkar vardagen, försämrar livskvalitet och skapar oro. För att bedriva personcentrerad vård krävs insikt i hur denna oro upplevs. Syfte: Syftet med studien var att belysa sjukdomsrelaterad oro hos personer med Crohns sjukdom. Metod: Åtta kvinnor och fyra män mellan 30 och 64 år som skattat sin sjukdomsrelaterade oro som hög eller mycket hög identifierades. Intervjuer genomfördes och analyserades med kvalitativ innehållsanalys. Resultat: Analysen genererade tre kategorier: (1) Oro för sjukdomen i sig, (2) känslor runt oron, (3) samt hantering av oron. Sjukdomens oförutsägbarhet samt nedsatt funktion till följd av trötthet och bristande kontroll över tarmfunktionen var de mest framträdande orsakerna till oro. Oron skapade känslor av stress, skuld och besvikelse. Deltagarna uttryckte önskemål att få prata om och synliggöra oron men hade också funnit egna sätt att hantera denna. Slutsats: Det finns ett kvarstående behov av att ventilera och få förståelse för sjukdomsrelaterad oro, även efter många års sjukdom. Personer med Crohns sjukdom måste få prata om sin oro, vara en aktiv partner i vården och tillsammans med vårdgivaren finna sätt att hantera oron så att denna kan lindras. / Background: A chronic, unpredictable disease as Crohn's disease provides physical, psychological and social stress. The disease affects everyday life, impairs quality of life and create worries. To conduct person-centered care requires insight into how this worry is experienced. Objective: To explore disease-related worries in persons with Crohn´s disease. Method: Eight women and four men between 30 and 64 who estimated their disease-related worries high or very high were identified. Interviews were conducted and analyzed with content analysis. Results: The analysis generated three categories: (1) Worries about the disease itself, (2) feelings around the worries, (3) management of the worries. The unpredictable course of the disease and the impaired function due to fatigue and lack of control of bowel function were the most prominent causes of worries. The worries created feelings of stress, guilt and disappointment. The participants expressed the wish to talk about and make the worries visible but had also found their own ways to handle it. Conclusion: There is a persistent need to vent and get an understanding of disease-related worries, even after many years of disease. Persons with Crohn's disease need to talk about their worries, be an active partner in healthcare and together with the health-care providers find ways to handle the worries so it can be relieved.
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Le locus 1q32 : susceptibilité aux maladies inflammatoires de l’intestin et rôles biologiques de C1orf106 et KIF21BDavid, Geneviève 04 1900 (has links)
La maladie de Crohn (MC) et la colite ulcéreuse (CU) sont des maladies inflammatoires de l’intestin (MII) caractérisées par une inflammation chronique du tube digestif. Ces maladies à traits complexes sont le résultat d’un dérèglement du système immunitaire. Les études d’association pangénomique ont identifié au total 99
loci de susceptibilité aux MII. La région 1q32 du chromosome 1 a été identifiée comme locus de susceptibilité à la MC, la CU et la sclérose en plaque. La région autour du marqueur génétique (rs11584383) contient quatre gènes : Chromosome 1 open reading frame 106 (C1orf106), Kinesin family member 21B (KIF21B), Calcium channel, voltage-dependant, L type, alpha 1S subunit (CACNA1S) et Chromosome 1
open reading frame 81 (C1orf81). L’objectif de l’étude est de mettre ces quatres gènes dans un contexte biologique et de déterminer leur rôle potentiel dans les MII.
Par réaction de polymérisation en chaîne quantitatif (qPCR), nous avons déterminé le profil d’expression de ces gènes dans des tissus murins et des lignées cellulaires
humaines. KIF21B et C1orf106 sont exprimés dans les tissus gastrointestinal et immunitaire. Par la suite, nous avons testé l’implication de KIF21B et C1orf106 dans
les voies biologiques connues pour leur rôle dans les MII comme l’activité NF-kB et le stress du réticulum endoplasmique (RE). Nos résultats montrent que la
surexpression de KIF21B dans les cellules HEK293T diminue l’activité de NF-kB et la surexpression de C1orf106 augmente le stress du RE et l’activité de la voie Wnt. Globalement, ces résultats suggèrent que KIF21B et C1orf106, dans la région 1q32, sont des gènes candidats prometteurs puisqu’ils interviennent dans des voies
biologiques connues des maladies inflammatoire de l’intestin. / Crohn’s disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) characterized by chronic inflammation along the gastrointestinal tract.
These complex diseases appear to be the result of an immune system dysregulation. Genome-wide association studies have identified 99 loci that contribute to IBD
susceptibility. Region 1q32 of chromosome 1 has been identified as a CD, UC and multiple sclerosis susceptibility locus and the region around this marker (rs11584383)
contains four genes: Chromosome 1 open reading frame 106 (C1orf106), Kinesin family member 21B (KIF21B), Calcium channel, voltage-dependant, L type, alpha 1S
subunit (CACNA1S) and Chromosome 1 open reading frame 81 (C1orf81). The goal of the present study is to place these genes in a biological context and to determine
their possible involvement in IBD. By using quantitative PCR (qPCR), we determined the expression profile of these genes in murine tissues and human cell lines and we observed that KIF21B and C1orf106 were expressed in immune as well as gastrointestinal tissues. Next, we tested the involvement of KIF21B and C1orf106
in biological pathways previously implicated in IBD, more specifically NF-kB activity and endoplasmic reticulum (ER) stress. We found that overexpression of KIF21B in HEK293T cells decreased the activity of NF-kB whereas C1orf106 overexpression increased ER stress and Wnt activity. Taken together, these results suggest that KIF21B and C1orf106 are good candidate causal genes in the 1q32 region.
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Caractérisation de facteurs bactériens essentiels à la virulence des souches de Escherichia coli associées à la maladie de CrohnChassaing, Benoit 09 December 2011 (has links) (PDF)
La maladie de Crohn (MC) est une affection inflammatoire chronique du tube digestif dont l'étiologie est multifactorielle. Les lésions iléales des patients atteints de MC sont anormalement colonisées par des souches pathogènes de Escherichia coli appartenant au pathovar AIEC pour " Adherent-Invasive E. coli ". Ces souches sont capables d'adhérer et d'envahir les cellules épithéliales intestinales, et ont la capacité de survivre et de se multiplier fortement en macrophages en induisant une synthèse intense de TNF-α. L'objectif de ce travail s'inscrit dans la compréhension des mécanismes permettant aux bactéries AIEC de coloniser la muqueuse intestinale et d'induire les stades précoces de la pathologie. Une précédente étude menée au laboratoire avait permis de mettre en évidence l'importance de l'activation de la voie de régulation dépendante du facteur bactérien sigma alternatif RpoE (ou σE) dans le processus d'adhésion et d'invasion des cellules épithéliales intestinales par la souche AIEC de référence LF82 via l'expression des pili de type 1 et des flagelles. En continuité de ces travaux, nous montrons que l'activation de la voie de signalisation dépendante du facteur σE est également primordiale pour la capacité des souches AIEC à former des biofilms, et une analyse bioinformatique ayant pour but d'identifier les gènes régulés par σE a montré que l'opéron waaWVL, impliqué dans la biosynthèse du lipopolysaccharide, est primordial pour la formation de biofilm par les souches AIEC. De plus, nous avons mis en évidence que les long polar fimbriae (LPF) sont impliqués dans le ciblage de l'épithélium associé aux plaques de Peyer par les bactéries AIEC, et ceci en leur permettant de cibler spécifiquement les cellules M. L'inactivation du gène Nod2, gène de susceptibilité à la MC, conduit à une augmentation du nombre de plaques de Peyer ainsi que des cellules M à leur surface, indiquant que les bactéries AIEC pourraient tirer avantage d'une susceptibilité génétique pour cibler les plaques de Peyer.
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