• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 109
  • 73
  • 35
  • 25
  • 18
  • 13
  • 9
  • 8
  • 4
  • 2
  • 1
  • Tagged with
  • 383
  • 383
  • 383
  • 120
  • 92
  • 65
  • 58
  • 49
  • 42
  • 42
  • 38
  • 37
  • 36
  • 27
  • 26
  • 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.
331

Investigating traditional and emerging cardiovascular disease risk factors in paediatric populations with chronic inflammatory disease

Pickard, Vanessa January 2017 (has links)
For most children, occult vascular damage is minimal and has a slow rate of progression likely due to the existence of healthy lifestyles and the prevalence of preventative behaviours. However, there is evidence to suggest a marked increase in the prevalence of traditional and emerging cardiovascular risk factors in children with chronic inflammatory conditions due to the common aetiology pathways of inflammation and atherosclerosis. In the current cross-sectional study, a comprehensive vascular assessment was conducted on 21 children with various chronic inflammatory conditions including juvenile idiopathic arthritis (JIA), cystic fibrosis (CF), type I diabetes mellitus (T1DM) and inflammatory bowel disease (IBD) (CIC, 12.7 ± 2.3 years) compared to 9 healthy, age and sex- matched controls (CON, 13.1 ± 1.8 years). B-mode ultrasound images were used to assess carotid artery intima media thickness (cIMT) as well as local arterial stiffness through measurement of compliance and distensibility with the use of concurrent applanation tonometry. Whole-body arterial stiffness was measured by assessing pulse wave velocity (PWV) between the carotid and dorsalis pedis arteries. A brachial flow mediated dilation (FMD) test was implemented to assess endothelial function of the brachial artery. Twelve hour-fasted blood samples were collected and analyzed for blood lipids and an acute inflammatory marker, C-reactive protein (CRP). There were no group differences in cIMT (p=0.18), distensibility (p=0.40), compliance (p=0.88), whole body PWV (p=0.74) or LDL- cholesterol (p=0.99). The CIC group demonstrated significantly lower FMD when iii compared to CON (p=0.01). There were no group differences in inflammatory levels, as indicated by concentration of CRP (p=0.63). Sub-analyses revealed similar cIMT, distensibility, compliance, PWV and LDL levels between children with JIA (n=11, 12.6 ± 2.9 years), CON (n=9, 13.1 ± 1.8 years) and the other inflammatory conditions (INFL, n=10, 12.4 ± 1.7 years). Both JIA and INFL reported lower FMD when compared to CON (p=0.04). INFL had lower BMI compared to JIA and CON (p=0.02). The primary findings from this study suggest that arterial structure is similar between children with a CIC and their healthy peers; however, arterial function, as indicated by FMD (%), was reduced in the CIC group. This finding is essential in that it helps to identify an area for targeted intervention and/or prevention of future CV events as endothelial dysfunction is known to be an early event in the pathophysiology of atherosclerosis. / Thesis / Master of Science (MSc)
332

Livet med inflammatorisk tarmsjukdom : En litteraturöversikt / Life with inflammatory bowel disease : A literature review

Rahmani, Armin, Sundström, Maximilian January 2024 (has links)
Bakgrund: Inflammatorisk tarmsjukdom innefattar både ulcerös kolit och Crohns sjukdom, vilka är kroniska inflammatoriska tarmsjukdomar. De båda sjukdomarna löper i skov med plötsliga försämringsperioder och långa perioder utan besvär. Det är viktigt att sjuksköterskan vidtar specifika omvårdnadsåtgärder samt förhåller sig personcentrerat där värden som värdighet bevaras för att stödja personen. Syfte: Att beskriva personers erfarenheter av att leva med inflammatorisk tarmsjukdom. Metod: Till metod valdes en litteraturöversikt och de databaser som användes var PubMed samt Cinahl Complete. Inklusionskriterier var vetenskapliga originalartiklar, genomgått peer-review, engelskt språk samt publicerade från år 2014 till 2024. Genom ett systematiskt urval arbetades tio artiklar fram, varav nio med kvalitativ design och en med mixad metod. Resultat: I litteraturöversiktens resultat framkom det att personer med inflammatorisk tarmsjukdom hade erfarenheten av att sjukdomen påverkade deras dagliga liv, både i det sociala livet och yrkeskarriären. Personer med inflammatorisk tarmsjukdom hade även erfarenheter att sjukdomen påverkade det emotionella välbefinnandet. Det lyftes även fram hur personer hanterade sjukdomen, vilka strategier som användes och stödets betydelse beskrevs. Slutsats: Litteraturöversikten visade att personer med inflammatorisk tarmsjukdom möter utmaningar inom många områden i livet. På grund av de anpassningar som individen måste genomgå är det viktigt att sjuksköterskan bidrar med stöd för att möjliggöra effektiv sjukdomshantering. Roys adaptionsteori kan ge sjuksköterskan en bättre förståelse för personernas anpassningsförmåga och kompensera med stöd för att hälsa och livskvalité ska upprätthållas. / Background: Inflammatory bowel disease encompasses both ulcerative colitis and Crohn's Disease, which are chronic inflammatory bowel diseases. Both diseases are characterized by periods of flare-ups with sudden exacerbations and long periods of remission. It is important for nurses to implement specific nursing interventions and to maintain a person-centered approach where values like dignity are preserved to support the person. Aim: To describe people's experiences of living with inflammatory bowel disease. Method: The chosen method was a literature review, with PubMed and CINAHL Complete as the selected databases. Inclusion criteria were scientific original articles that had undergone peer review, were in English, and were published from 2014 onwards. Through a systematic selection process, ten articles were identified, of which nine had a qualitative design and one used mixed methods. Results: In the results of the literature review, it was found that individuals with inflammatory bowel disease experienced the impact of the disease on their daily lives, including their social life and professional careers. They also reported that the disease affected their emotional well-being. Additionally, the review highlighted how individuals managed the disease, the strategies they used, and the significance of support. Conclusion: The literature review showed that individuals with inflammatory bowel disease face challenges in many areas of life. Due to the adaptations that the individual must undergo, it is important for nurses to provide support to enable effective disease management. Roy`s adaption theory can provide the nurse with a better understanding of individual`s adaptability and compensate with support to maintain health and quality of life.
333

Epidemiologie chronisch entzündlicher Darmerkrankungen bei Kindern und Jugendlichen in Sachsen auf Basis des Sächsischen Kinder-CED-Registers im 15-Jahreszeitraum 2000 – 2014

Kern, Ivana 03 June 2024 (has links)
Die vorliegende wissenschaftliche Arbeit widmet sich epidemiologischen Frage-stellungen zu CED bei Kindern und Jugendlichen am Anfang des 21. Jahrhunderts in Deutschland. Konkrete Aufgabenstellungen bestanden in der Vervollständigung, Validierung, Aufbereitung, Auswertung und Publikation der über 15 Jahre (2000-2014) erhobenen Daten des Sächsischen Kinder-CED-Registers mit dem Ziel, die hypothetische Zunahme der CED in Sachsen zu untersuchen, zu dokumentieren und quantifizieren. Im Fokus der Auswertung stehen vor allem die Inzidenz, Prävalenz und die bisherigen und zukünftigen Trends von CED bei Kindern und Jugendlichen bis zum 15. Lebensjahr in einem der neuen Bundesländer Deutschlands.:Abkürzungsverzeichnis V Abbildungsverzeichnis VII Tabellenverzeichnis VIII Zusammenfassung 1 Abstract 4 1 Einführung in die Thematik 7 1.1 Wissenschaftliche Ausgangssituation 7 1.2 Hintergrund für die Registergründung in Sachsen 8 1.3 Aufgabenstellung 9 2 Theoretisch wissenschaftlicher Ansatz der eigenen Arbeiten 10 2.1 Material und Methoden 10 2.1.1 Sächsisches Kinder-CED-Register 10 2.1.2 Finanzielle Förderung 11 2.1.3 Zweite Datenquelle und Registervollständigkeit 12 2.1.4 Population unter Risiko 12 2.1.5 Merkmale der Patientenkohorte 13 2.2 Statistische Auswertungen 13 3 Wesentliche wissenschaftliche Ergebnisse 15 3.1 Inzidenzraten und Prävalenz 15 3.2 Analyse von Inzidenztrends 18 3.3 Analyse des Alterstrends bei Manifestation 20 3.4 Diagnostische Latenz 21 3.5 Prognostizierte Inzidenztrends 23 4 Diskussion 26 4.1 Langzeitentwicklung der Anzahl von CED-Patienten 26 4.2 Internationale und nationale Einordnung der Ergebnisse 27 4.3 Stärken und Limitationen 32 4.3.1 Stärken der Arbeit 32 4.3.2 Limitationen der Arbeit 32 5 Schlussfolgerungen und Ausblick 33 Literatur IX Danksagung XVIII Anlage 1: Erklärungen zur Eröffnung des Promotionsverfahrens XIX Anlage 2: Erklärung über die Einhaltung gesetzlicher Bestimmungen XXI Anlage 3: Kern et al. (2021) XXII Anlage 4: Kern et al. (2022) XLI Anlage 5: Einwilligungserklärung der Eltern LXI Anlage 6: Erstmeldebogen LXII Anlage 7: Dokumentationsbogen LXIII Anlage 8: Eigenanteil LXIV
334

Aberrant response of human myeloid dendritic cells to microbial stimuli in patients with inflammatory bowel disease

Thomas, Saskia 06 July 2011 (has links)
In zahlreichen Studien konnte an Mausmodellen gezeigt werden, dass dendritische Zellen eine wichtige Rolle im Rahmen der mukosalen Immunabwehr spielen. Eine unkontrollierte Aktivierung immunologischer Effektorzellen durch antigenpräsentierende Zellen ist die Folge, welche die Antigene der luminalen Flora folglich falsch erkennen und damit zu einer Schädigung des Gewebes führen. In der Arbeit wurden humane CD1c+CD11c+CD14-CD19- myeloide dendritische Zellen (mDCs) aus dem peripheren Blut und der intestinalen Mukosa von CED Patienten sowie von gesunden Probanden phänotypisch und funktionell näher charakterisiert. mDCs von Patienten reagieren auf LPS im Gegensatz zu DCs von Gesunden mit der Ausbildung eines aktivierten Phänotyps und der Sekretion pro-inflammatorischer Zytokine. Die Daten lassen vermuten, dass ihre tolerogene Rolle gestört ist und die Zellen so möglicherweise aktiv zum Entzündungsgeschehen durch eine Fehlreaktion auf die kommensale Flora beitragen. Es konnte gezeigt werden, dass zirkulierende mDCs von Erkrankten mehr LPS aufnehmen. Des Weiteren ist die Häufigkeit von mukosalen und aktivierten mDCs bei CED Patienten signifikant erhöht. Die vermehrte Häufigkeit von aktivierten mDCs in der entzündeten Mukosa ist ein Hinweis auf intestinales „homing“, also ein Wiedereinwandern der gereiften Lymphozyten in die Darmwand. Es ist bekannt, dass die Hefe Saccharomyces boulardii (Sb) eine Wirksamkeit bei entzündlichen sowie infektiösen Erkrankungen des Gastrointestinaltraktes hat. Kulturexperimente von mDCs mit Zellkulturüberständen von Sb (SbS) und LPS zeigten eine deutliche Reduzierung in der Expression von CD40 und CD80 sowie des Reifemarkers CD197. SbS reduzierte die Sekretion von TNF- und IL-6. Während es die Sekretion von IL-10 bei gesunden Probanden erhöhte, konnte bei CED Patienten eine leichte Abnahme verzeichnet werden. SbS vermindert die Proliferation von naïven T-Zellen in einer gemischten Lymphozytenreaktion mit gesunden mDCs signifikant. / Various animal studies have provided insights that mucosal dendritic cells play a key role in this process. However, the specific function of certain dendritic cells in IBD is still unknown. Primary CD1c+CD11c+CD14-CD19- myeloid blood (mDCs) and mucosal DCs from IBD patients and healthy controls were compared. More mDCs from IBD patients exhibited an activated phenotype shown by expression of co-stimulatory molecules. mDCs from patients secrete higher levels of pro- and anti-inflammatory cytokines. Circulating mDCs from IBD patients take up more LPS and the frequency of mucosal mDCs and the number of activated, i.e. CD40 and CD80 expressing mucosal mDCs, is significantly greater in CED. The increased frequency of activated mDCs in the inflamed mucosa suggests intestinal homing of mDCs in acute stages of IBD. Further, the data suggests an aberrant LPS response of mDCs in patients suffering from IBD which results in an inflammatory phenotype. The most widely accepted hypothesis for the cause of IBD is a disturbed interaction of the host immune system with commensal microflora and other luminal antigens. The well controlled balance of the intestinal immune system is disturbed and luminal antigens like LPS gain access to the underlying mucosal tissue via the leaky barrier. It was investigated whether the yeast preparation Saccharomyces boulardii (Sb) modulates dendritic cell function which has shown efficacy in inflammatory and infectious disorders of the gastrointestinal tract. Culture experiments of mDCs in the presence of Sb culture supernatant (SbS) significantly reduced the expression of CD40 and CD80 as well as the DC maturation marker CD197 (CCR7) induced by the prototypical microbial antigen LPS. SbS reduced secretion of TNF- and IL-6, while the secretion of anti-inflammatory IL-10 increased. IBD patients showed also a reduction in their secretion level of IL-10. SbS inhibited proliferation of naïve T cells in a mixed lymphocyte reaction with healthy mDCs.
335

Effets préventifs et thérapeutiques des polyphénols dans un modèle in vitro et in vivo de maladie inflammatoire de l’intestin : caractérisation des polyphénols de la pelure de pomme et de la canneberge par spectrométrie de masse

Denis, Marie-Claude 08 1900 (has links)
La muqueuse intestinale est exposée à des agents oxydants provenant de l’ingestion d’aliments modifiés, de cellules immuno-inflammatoires et de la flore intestinale. Une diète élevée en fruits et légumes peut diminuer le stress oxydant (SOx) ainsi que l’inflammation via plusieurs mécanismes. Ces effets bénéfiques peuvent être attribuables à leur contenu élevé en polyphénols. La première étude de mon doctorat consistait à tester l’hypothèse que les polyphénols extraits de pelures de pomme (DAPP) pouvaient diminuer le stress oxydant et l'inflammation impliqués dans les maladies inflammatoires de l'intestin (MII). Nous avons caractérisé les polyphénols des DAPP par spectrométrie de masse (LC-MS) et examiné leur potentiel antioxydant et anti-inflammatoire au niveau des cellules intestinales. L’identification des structures chimiques des polyphénols a été effectuée par LC-MS. Le SOx a été induit par l’ajout du complexe fer/ascorbate (Fe/Asc, 200 µM/2 mM) et l’inflammation par la lipopolysaccharide (LPS, 200µg/mL) à des cellules intestinales Caco-2/15 pré-incubées avec les DAPP (250 µg/mL). L’effet du SOx est déterminé par le dosage du malondialdéhyde (MDA), de la composition des acides gras polyinsaturés et de l’activité des enzymes antioxydantes endogènes (SOD et GPx). L’impact des DAPP sur l’inflammation a été testé par l’analyse de l’expression des marqueurs inflammatoires: cyclooxygénase-2 (COX-2), le facteur de nécrose tumorale alpha (TNF-a et l’interleukine-6 (IL-6) et les facteurs de transcription NF-KB, Nrf-2 et PGC1α par immunobuvardage. Nos données ont montré que les flavonols et les flavan-3-ols constituent les composés polyphénoliques majoritaires des DAPP. L’ajout de Fer2+/Asc a provoqué une augmentation de la peroxidation lipidique comparativement aux cellules contrôles, un appauvrissement des acides gras polyinsaturés n-3 et n-6, et une modulation des enzymes antioxydantes, se traduisant par une augmentation de l’activité de la SOD et une diminution de la GPx. En contrepartie, les DAPP ont exhibé leur potentiel à corriger la plupart des perturbations, y compris l’expression protéique anormalement élevée du COX-2 et la production de la prostaglandine E2 (PGE2), ainsi que l’inflammation telle que réflétée par les facteurs NF-κB, TNF-α et IL-6. Par ailleurs, les mécanismes sous-jacents à ces changements bénéfiques des DAPP ont fait intervenir les facteurs de transcription antioxydants (Nrf-2, PGC1α). Vraisemblablement, cette première étude a permis de démontrer la capacité des DAPP à amoindrir le SOx et à réduire l’inflammation, deux processus étroitement impliqués dans les MII. Dans la deuxième étape de mon doctorat, nous avons voulu comparer les résultats de DAPP à ceux des polyphénols dérivant de la canneberge qui est considérée par la communauté scientifique comme le fruit ayant le plus fort potentiel antioxydant. À cette fin, nous avons caractérisé l’effet des composés polyphénoliques de la canneberge (CPC) sur le SOx, la défense antioxydante et l’inflammation au niveau intestinal tout en définissant leur métabolisme intraluminal. Les différents CPC ont été séparés selon leur poids moléculaire par chromatographie et leurs structures chimiques ont été identifiées par LC-MS. Suite à une pré-incubation des cellules Caco-2/15 avec les extraits CPC (250 µg/mL), le Fe/Asc et la LPS ont été administrés comme inducteurs du SOx et de l’inflammation, respectivement. La caractérisation globale des CPC a révélé que les acides phénoliques composaient majoritairement l’extrait de canneberge de petit poids moléculaire (LC) alors que les flavonoïdes et les procyanidines dimériques/trimériques représentaient l’extrait de poids moléculaire moyen (MC) tout en laissant les procyanidines oligo et polymériques à l’extrait de haut poids moléculaire (HC). Les CPC ont permis de restaurer la plupart des perturbations engendrées dans les Caco-2/15 par le Fe/Asc et le LPS. Les CPC exhibaient le potentiel d’abaisser les niveaux de MDA, de corriger la composition des acides gras polyinsaturés n-3 et n-6, d’augmenter l’activité des enzymes antioxydantes (SOD, GPx et CAT) et d’élever l’expression de Nrf2 et PGC1α. En outre, les CPC pouvaient aussi réduire les niveaux élevés des protéines inflammatoires COX-2, TNF-α et IL-6 ainsi que la production des PGE2 par un mécanisme impliquant le NF-κB. Au niveau mitochondrial, les procyanidines oligomériques ont réussi à corriger les dysfonctions reliées à la production d’énergie (ATP), l’apoptose (Bcl-2, Cyt C et AIF) et le statut des facteurs de transcription mitochondriaux (mtTFA, mtTFB1, mtTFB2). Dans le but de bien comprendre les mécanismes d’action des CPC, nous avons défini par LC-MS les composés polyphénoliques qui ont été transportés ou absorbés par l’entérocyte. Nos analyses soulignent le transport (i) des acides cinnamiques et benzoïques (LC); (ii) la quercétine glycosylée et conjuguée et les procyanidines dimériques de type A (MC); et (iii) l’épicatéchine et les procyanidines oligomériques (HC). Les processus de métabolisation (méthylation, glucuronidation et sulfatation) au niveau de l’entérocyte ont probablement permis le transport de ces CPC surtout sous leur forme conjuguée. Les procyanidines oligomériques ayant un degré de polymérisation supérieur à 2 (HC) ont semblé adhérer aux cellules Caco-2/15. L’épicatéchine suivi par les procyanidines dimériques de type A ont été trouvés majoritaires au niveau des mitochondries. Même si nous ignorons encore l’action biologique de chaque composé polyphénolique, nous pouvons suggérer que leurs effets combinatoires exercent des fonctions antioxydantes, anti-inflammatoires et mitochondriales dans le modèle intestinal Caco-2/15. Dans une troisième étape, nous avons procédé à l’évaluation des aspects préventifs et thérapeutique des DAPP tout en sondant les mécanismes sous-jacents dans une étude préclinique. À cette fin, nous avons exploité le modèle de souris avec colite expérimentale provoquée par le Dextran Sulfate de Sodium (DSS). L’induction de l’inflammation intestinale chez la souris C57BL6 a été effectuée par l’administration orale de DSS à 2.5% pendant 10 jours. Des doses physiologiques et supra-physiologiques de DAPP (200 et 400 mg/kg/j, respectivement) ont été administrées par gavage pendant 10 jours pré- et post-DSS. L’inflammation par le DSS a provoqué une perte de poids, un raccourcissement du côlon, le décollement dystrophique de l’épithélium, l’exulcération et les infiltrations de cellules mono et polynucléaires au niveau du côlon. De plus, le DSS a induit une augmentation de la peroxidation lipidique, une régulation à la baisse des enzymes antioxydantes, une expression protéique à la hausse de la myéloperoxidase (MPO), du COX-2 et de la production des PGE2. Par ailleurs, les DAPP ont permis de corriger ou du moins d’alléger la plupart de ces anomalies en situation préventive ou thérapeutique, en plus d’abaisser l’expression protéique de NF-κB et des cytokines inflammatoires (TNF-a et l’IL-6) tout en stimulant les facteurs de transcription antioxydants (Nrf-2, PGC1α). Conséquemment, les polyphénols des DAPP ont exhibé leur puissant pouvoir antioxydant et anti-inflammatoire au niveau intestinal dans un modèle in vivo. Leurs actions sont associées à la régulation des voies de signalisation cellulaire et des changements dans la composition du microbiote. Ces trois projets de recherche permettent d’envisager l’évaluation des effets préventifs et thérapeutiques des DAPP cliniquement chez les patients avec des désordres inflammatoires de l’intestin. / The intestinal mucosa is exposed to oxidizing agents from the ingestion of modified foods, immuno-inflammatory cells and intestinal flora. Diet high in fruits and vegetables may reduce oxidative stress and inflammation via several mechanisms. These beneficial effects may be due to their high polyphenol content. The first aims for my PhD was to define the nature of polyphenols extracted from dried apple peels (DAPP) and to determine their antioxidant and anti-inflammatory potential in the intestine. Caco-2/15 cells were used to study the role of DAPP preventive actions against oxidative stress (OxS) and inflammation induced by iron-ascorbate (Fe/Asc) and lipopolysaccharide (LPS), respectively. The combination of HPLC with fluorescence detection, HPLC-ESI-MS TOF and UPLC-ESI-MS/MS QQQ allowed us to characterize the phenolic compounds present in the DAPP (phenolic acids, flavonols glycosides, flavan-3-ols, procyanidins). The addition of Fe/Asc to Caco-2/15 cells induced OxS as demonstrated by the rise in malondialdehyde, depletion of n-3 polyunsaturated fatty acids, and alterations in the activity of endogenous antioxidants (SOD, GPx, G-Red). However, preincubation with DAPP prevented Fe/Asc-mediated lipid peroxidation and counteracted LPS-mediated inflammation as evidenced by the down-regulation of cytokines (TNF-α and IL-6), and prostaglandin E2. The mechanisms of action triggered by DAPP induced also a down-regulation of cyclooxygenase-2 and nuclear factor-kB, respectively. These actions were accompanied by the induction of Nrf2 (orchestrating cellular antioxidant defenses and maintaining redox homeostasis), and PGC-1α (the “master controller” of mitochondrial biogenesis). Our findings provide evidence of the capacity of DAPP to reduce OxS and inflammation, two pivotal processes involved in inflammatory bowel diseases. The cranberry fruit has been reported to have high antioxidant effectiveness that is potentially linked to its richness in diversified polyphenolic content. Therefore, the second objective was to compare the results for apple to those for the cranberry. More specifically, the aim of this study was to determine the role of cranberry polyphenolic fractions in oxidative stress, inflammation and mitochondrial functions using intestinal Caco-2/15 cells. The second aim of this work was to determine the polyphenolic species that were responsible for the observed biological activity. The combination of HPLC and UPLC-TDQ techniques allowed us to characterize the profile of low, medium and high molecular weight polyphenolic compounds in cranberry extracts. The medium molecular weight fraction was enriched with flavonoids and procyanidin dimers whereas procyanidin oligomers (degree of polymerization > 4) were the dominant class of polyphenols in the high molecular weight fraction. Pre-incubation of Caco-2/15 cells with these cranberry extracts prevented Fer/Asc-mediated lipid peroxidation and counteracted LPS-mediated inflammation as evidenced by the decrease in pro-inflammatory cytokines (TNF-α and IL-6), cyclooxygenase-2 and prostaglandin E2. Cranberry polyphenols fractions limited both NF-B activation and Nrf2 down-regulation. Consistently, cranberry procyanidins alleviated oxidative stress-dependent mitochondrial dysfunctions as showed by the rise in ATP production and the up-regulation of Bcl-2, as well as the decline of protein expression of cytochrome C and apoptotic inducing factor. These mitochondrial effects were associated with a significant stimulation of PGC1α, a central inducing factor of mitochondrial biogenesis and transcriptional co-activator of numerous downstream mediators. Finally, cranberry procyanidins forestalled the effect of Fer/Asc on the protein expression of mitochondrial transcription factors (mtTFA, mtTFB1, mtTFB2). The analysis of different pathways, including absorption and transport of polyphenol species revealed which species in the three cranberry fractions have been responsible for the antioxidant activity observed. Especially, the identification of flavan-3-ols and A-type procyanidins in mitochondria suggested that these polyphenol species were responsible for the antioxidant activity in this organelle. Our findings provide evidence for the capacity of cranberry polyphenols to reduce intestinal oxidative stress and inflammation while improving mitochondrial dysfunction. Subsequently, we evaluated the preventive and therapeutic aspects of DAPP polyphenols on intestinal inflammation while elucidating the underlying mechanisms and clinical benefits. Induction of intestinal inflammation in the C57BL6 mice was performed by oral administration of the inflammatory agent DSS (Dextran Sodium Sulfate, 2.5% for 10 days). Physiological and supraphysiological doses of DAPP (200 and 400 mg/ kg/day, respectively) were administered by gavage for 10 days pre- and during-DSS. DSS caused weight loss, shortening of the colon, dystrophic detachment of the epithelium, erosion and infiltration of mono- and polymorphonuclear cells in the colon. Additionally, the DSS induced an increase in lipid peroxidation, a down-regulation of antioxidant enzymes, a rise in MPO and COX-2 expression, and PGE2 production. However, the DAPP corrected or at least alleviated most of these abnormalities in preventive and therapeutic situations, in addition to lowering protein expression of NF-kB and inflammatory cytokines (TNF-a and IL-6) while stimulating antioxidant transcription factors (Nrf2, PGC1α). The supraphysiological dose of DAPP in therapeutic situation has corrected mitochondrial dysfunction, as evidenced by the raised ADP/ATP ratio, reduced apoptosis (Cyt C and AIF) and the DNA repair enzyme (OGG1) that eliminated DNA damage, caused by oxidative stress, thereby preventing the initiation of the ROS vicious cycle. The relative abundance of colitogenic bacteria was slightly decreased in DAPP-treated mice compared to DSS-induced colitis group. Conclusions: Polyphenols of DAPP exhibit a powerful anti-oxidant and anti-inflammatory power in the intestine. Their actions are associated with the regulation of cellular signaling pathways and changes in microbiota composition. Therefore, preventive and therapeutic effects of DAPP may be clinically feasible in individuals with intestinal disorders such as colonic cancer.
336

Vitamine D et prévention du cancer colorectal associé à la colite ulcéreuse : modèles murins

Elimrani, Ihsan 03 1900 (has links)
Les patients atteints de maladies inflammatoires de l'intestin (MII) ont un risque accru de développer un cancer colorectal dû aux lésions épithéliales secondaires à l’inflammation chronique. La vitamine D (vD) régule NOD2, gène impliqué dans la réponse inflammatoire et dans la susceptibilité aux MII, et induit son expression dans les monocytes et dans l’épithélium intestinal. Dans ce projet, nous avons d’abord induit le cancer colorectal associé à la colite ulcéreuse (CAC) en administrant un traitement combiné d’azoxyméthane (AOM) et de dextran de sulfate de sodium (DSS) aux souris C57BL/6J. Par la suite, nous avons étudié l'effet d’une carence en vD3 sur le développement du CAC et évalué la capacité préventive d’une supplémentation en vD3 sur la tumorigenèse, et vérifié si cet effet est médié par NOD2, en utilisant les souris Nod2-/-. Les C57BL/6J et les Nod2-/-, ayant reçu une diète déficiente en vD3, étaient moins résistantes au CAC par rapport aux souris supplémentées. Le pourcentage de perte de poids, l’indice d’activation de la maladie (DAI), le taux de mortalité et le poids relatif du côlon (mg/cm) chez les souris déficientes en vD3 étaient plus élevés en comparaison avec celles supplémentées en vD3. Une augmentation du score d'inflammation et de la multiplicité tumorale corrélait avec une expression accentuée de l’Il6 dans les colonocytes des souris déficientes en vD3. La vD3 régulait l’expression génétique de Cyp24, Vdr et de gènes pro-inflammatoires chez les C57BL/6, comme chez les Nod2-/-. En conclusion, la supplémentation en vD3 peut prévenir le développement du CAC indépendamment de NOD2. / Patients with inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer due to continuing epithelial cell injury from the chronic inflammatory process. Vitamin D (vD) regulates NOD2, a gene involved in the inflammatory response and in IBD susceptibility, and induces its expression in monocytes and intestinal epithelial cells. In this project, we first established an azoxymethane (AOM)/dextran sodium sulfate (DSS) murine model of colitis-associated colorectal cancer (CAC) using C57Bl/6J. We then investigated the effect of vD3 deficiency on CAC development, and evaluated the ability of vD3 supplementation to prevent tumorigenesis. Lastly, we assessed whether the preventive benefits of vD3 on colon carcinogenesis are mediated via NOD2 using Nod2 knockout mice (Nod2-/-). vD3 deficient C57Bl/6J and Nod2-/- mice displayed increased severity of AOM/DSS-induced CAC compared to mice given vD3 supplemented diets. In vD3 deficient mice, body weight loss, Disease Activity Index (DAI), mortality rate and the colon weight/length ratio were higher compared to vD3-supplemented mice. An increased inflammation score was observed in the mucosa of vD3 deficient mice along with augmentation in the expression level of IL-6. Higher tumour multiplicity was also observed in vD3 deficient groups compared to vD3-supplemented groups. In both C57Bl/6J and Nod2-/- mice, vD3 regulated Cyp24, Vdr and pro-inflammatory genes. In conclusion, vD3 supplementation can prevent CAC independently of NOD2.
337

Vliv bakteriálních komponent v protekci a terapii střevních zánětů / The effects of bacterial lysates on the gut barrier function and microbiota composition

Zákostelská, Zuzana January 2012 (has links)
Dynamic molecular interactions between the microbiota and the intestinal mucosa play an important role in the establishment and maintenance of mucosal homeostasis. Aberrant host- microbiota interaction could lead to many diseases such as inflammatory bowel disease. The aim of our study was to evaluate the commensal and probiotic bacteria activities and their ability to induce pathological or exert beneficial effects. The most important trigger for immune system development is an exposure to microbial components. Here, we show that there is a time window at about three weeks of age, which enables the artificial colonization of germ free mice by a single oral dose of cecal content. The delayed colonization by either inoculation or co-housing causes permanent changes in immune system reactivity, which may downgrade the results of experiments performed on first generation of colonized animals. In this thesis we report that even non-living commensal bacteria such as Parabacteroides distasonis (mPd) or well known probiotics such as L. casei DN-114 001 (Lc) possess anti-inflammatory effects in experimental model of colitis. The mechanisms that this effect is achieved by the lysate of L. casei DN-114 001 comprise: a) improvement in the gut barrier function, b) correction of the dysbiosis, and c) modulation of the...
338

Hochauflösende Magnetresonanztomographie entzündlicher Darmerkrankungen am Kaninchenmodell

Bleckmann, Tim 20 June 2003 (has links)
Chronisch entzündliche Darmerkrankung (CED) bereiten in der Diagnostik durch das meist jüngere Patientenalter, die Tendenz zu Rezidiven im Erkrankungsverlauf, welche häufig den Einsatz diagnostischer Mittel erfordert, und die extraintestinalen Pathologien, die endoskopisch nicht zugänglich sind, Probleme. Durch die bisherigen etablierten Untersuchungsmethoden sind in diesen speziellen Fragestellungen CED nicht immer befriedigend darstellbar. Daher wäre die Einführung der Magnetresonanztomographie (MRT) als Diagnostikalternative von Vorteil. Experimentell soll überprüft werden, wie valide die MRT den pathologischen Befund abbilden kann, ferner die Möglichkeiten einer rechnergestützten, nach festgelegten Algorithmen durchgeführten Auswertung. An einem Kaninchenmodell werden durch Irritantienapplikation chronisch entzündliche Darmerkrankungen simuliert, die resezierten Darmabschnitte mit Wandpathologien im MRT durch eine Mikrospule vermessen und in der Pathologie mikroskopisch untersucht. Am MRT werden die Darmschnitte durch einen konventionellen Editor und einen DICOM-Editor rechnergestützt semiautomatisch ausgewertet. Die transmurale Darmwanddickenmessung zeigt eine gute Korrelation zwischen den maximalen Dickenmessungen der Pathologie und dem konventionellen Editor (rho = 0,850) bzw. der Pathologie und dem DICOM-Editor (r = 0,843). In der Varianzanalyse der nach den Befunden "Normalbefund", "akute Entzündung" und "chronische Entzündung" aufgeschlüsselten maximalen Darmwanddickenbefunde können signifikante Unterschiede zwischen den Gruppen "Normalbefund" und "chronische Entzündung" sowie "akute Entzündung" und "chronische Entzündung" festgestellt werden (jeweils p < 0,01). Dabei enthält die Gruppe der chronischen Entzündungen durchschnittlich die höchsten Darmwanddicken. In einer Analyse der transmuralen Profile liegen die Maxima überwiegend in der dem Lumen zugewandten Seite. Das Kaninchenmodell kann zur Simulation chronisch entzündlicher Darmerkrankungen genutzt werden und ist ausreichend stabil. Höhere Auflösung, kürzere Meßzeiten sowie kostengünstigere MRTs und die Nutzung rechnergestützter Auswertung erweitern die Einsatzmöglichkeiten der bei Problemfällen in der Diagnostik der CED. / Several problems exist in the diagnosis of chronic inflammatory bowel diseases (CIBD). Most patients are young, the diseases have a tendency to recur, which requires repeat diagnostic evaluation, and they may have extraintestinal pathologies, which can not reached by endoscopy. The capabilities of magnetic resonance imaging (MRI) shall be tested by an experiment. CIBD are simulated in a rabbit model by application of an irritating solution. The resected bowel walls with pathologies are measured by using a MRI micro coil system and examined by a pathologist. Bowel sections are evaluated by the conventional editor of the MRI scanner and semiautomatic by fixed algorithms with a DICOM-Editor. The measurement of the bowel thickness shows a good correlation between the maximum thickness of the pathology and the maximum thickness of the conventional editor (rho = 0,850), and , pathology and DICOM-editor (r = 0,843), respectively. In the analysis of variance the measured thickness differed significantly between "normal findings", "acute inflammation" and "chronic inflammation". It differed between the groups "normal findings" and "chronic inflammation" as well as between "acute inflammation" and "chronic inflammation" (each p < 0.01). On average, the group of chronic inflammation contains the highest bowel thickness. In an analysis of the location of signal intensity maximum, the greatest signal was found on the luminal side of the bowel wall. The rabbit model can be used to simulate chronic inflammatory bowel diseases. It is sufficiently reproducible. Higher resolution, shorter measurement periods and more cost-effective MRIs as well as semiautomatic computerized evaluation by fixed algorithms will increase the use of MRI in the case of chronic inflammatory bowel diseases.
339

Diferença de frequência dos anticorpos anticitoplasma de neutrófilos (ANCAs) na colangite esclerosante primária com ou sem doença inflamatória intestinal, nos subtipos de hepatite autoimune e na colangite biliar primária / Difference of frequency on antineutrophil cytoplasmic antibodies (ANCA) in primary sclerosing cholangitis with or without IBD, subtypes of autoimmune hepatitis and primary biliary cholangitis

Crescente, Juliana Goldbaum 24 January 2017 (has links)
Introdução: Os anticorpos anticitoplasma de neutrófilos (ANCA) são classificados em três padrões observados na imunofluorescência indireta (IFI) utilizando neutrófilos humanos fixados em etanol e formaldeído como substrato. O c-ANCA apresenta forte associação com a enzima neutrofílica proteinase 3 (PR3), enquanto o p-ANCA está fortemente associado à mieloperoxidase (MPO). Na hepatite autoimune (HAI), colangite esclerosante primária (CEP) e doença inflamatória intestinal (DII) é observado outro padrão de IFI classificado como p-ANCA atípico que não apresenta reatividade contra as enzimas PR3 e MPO. Objetivo: Determinação da frequência dos diferentes padrões de ANCAs na CEP com ou sem DII concomitante (CEP/DII+, CEP/DII-), em três subtipos de hepatite autoimune (HAI-1 com anticorpo antimúsculo liso padrão tubular; HAI-2 com anticorpo antimicrossoma de fígado e rim tipo 1; HAI antiantígeno hepático solúvel/fígado e pâncreas, na colangite biliar primária (CBP) e em controles saudáveis. O anticorpo antinúcleo poderia estar presente em todos os subtipos. Os resultados dos ANCAs foram comparados com os do ELISA para verificação de concordância entre os padrões e as reatividades antigênicas. Metodologia: Foram estudados 249 pacientes (42 CEP/DII+; 33 CEP/DII-; 31 HAI-1; 30 HAI-2; 31 HAI-3; 52 CBP; 30 indivíduos saudáveis). As amostras de soro desses pacientes foram processadas pelos ensaios comerciais INOVA: ANCA Etanol, Quanta LiteTM MPO ELISA, Quanta LiteTMPR3 ELISA, Quanta LiteTM FAN HEp-2; e em lâminas com neutrófilos humanos fixados em etanol preparadas in house. Para as análises estatistícas foram utilizados os testes de Fisher com correção de Holm, os testes kappa e de McNemar. Resultados: O p-ANCA esteve presente em 4 (1,6%), o c-ANCA em 3 (1,2%), o p-ANCA atípico em 62 (24,9%), o c-ANCA atípico em dois (0,8%) e o padrão inconclusivo em 14 (5,6%) de 249 amostras testadas. O p-ANCA atípico foi mais frequentemente detectado na CEP/DII+ (52,4%; IC 95% = 37,7-66,6) em relação à CEP/DII- (21,2; IC 95% = 10,4-38,0), p=0,005. Não houve diferença significante na frequência do p-ANCA atípico na CEP/DII- em relação a CBP (15,38%, IC 95% = 7,83-27,89), p=0,501. O p-ANCA atípico foi significantemente mais positivo na HAI-1 (45,2%, IC 95% = 29,15-62,24, p < 0,001) e HAI-3 (32,3%, IC = 18,46-49,97, p=0,012) em comparação a HAI-2 (3,3%, IC 95% = 0-18,09). Não foi detectada diferença entre a HAI-1 e a HAI-3 (p=0,434). Ao considerarmos todos os padrões conjuntamente, persistiram as mesmas diferenças significantes entre a CEP/DII+ versus CEP/ DII- (p=0,037) e entre a HAI-2 versus HAI-1 (p=0,011) e versus HAI-3 (p=0,024). A reatividade do anti-PR3 foi encontrada em 25 das 249 amostras, sendo mais frequente na CEP/DII+ (31,0% IC 95%: 22,94 - 50,88) do que na CEP/ DII- (12,1%, IC 95%: 4,52-29,46, p = 0,025). Anticorpos anti-MPO foram identificados em oito de 249 amostras (3,2%). Das 25 amostras positivas para o anti-PR3 apenas uma apresentou c-ANCA; outras duas amostras positivas para o c-ANCA foram negativas para o anti-PR3. As oito amostras positivas para o anti-MPO não apresentaram reatividade para o p-ANCA e as quatro que tinham esse padrão não foram reativas para o anti-MPO. Entre as 62 amostras reativas para o p-ANCA atípico 49 não apresentaram reatividade para o anti-PR3 e anti-MPO. Das treze amostras positivas para o p-ANCA atípico e que exibiram reatividade ao ELISA, doze apresentaram positividade para o anti-PR3 e uma para o anti-MPO e para o anti-PR3. Conclusões: 1) Do ponto de vista de reatividade dos ANCAs e do anti-PR3 a CEP/DII+ teve comportamento diferente da CEP/ CEP/ DII - que que que que teve comportamento semelhante ao da CBP, o que pode sugerir que a maior frequência do p-ANCA atípico e do anti-PR3 esteja mais associada à DII do que à CEP; 2) Quanto à reatividade dos ANCAs, pacientes com HAI-1 e HAI-3 tiveram características semelhante entre si e diferente do da HAI-2; 3) Não houve concordância entre os resultados da IFI para os padrões c-ANCA e p-ANCA clássicos e os do ELISA anti-PR3 e anti-MPO; 4) A melhor concordância de leitura dos padrões do ANCA foi para o p-ANCA atípico, porque a maioria dos soros com esse padrão não teve reatividade nem para o anti-PR3 nem para o anti-MPO por ELISA; 5) Para doenças do aparelho digestivo (DII, CEP e HAI) é difícil relacionar os padrões do ANCA obtidos na imunofluorescência indireta com a reatividade observada nos ELISAs comerciais / Background: The antineutrophil cytoplasmic antibodies (ANCA) has 3 main subtypes according to the pattern observed by indirect immunofluorescence (IIF) on ethanol and formalin fixed human neutrophils. The cANCA has a strong association to a neutrophil enzyme proteinase 3 (PR3), while the classical pANCA has a strong association to myeloperoxidase (MPO), catepsin G, elastase, lactoferrin, lysozyme. Autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD), shows another pattern called atypical pANCA that does not react to the enzymes PR3 and MPO. Aims: Determine the frequency of different types of ANCA in PSC, with or without association to IBD (PSC/IBD+, PSC/IBD-); 3 AIH subtypes (AIH type 1, with antismooth muscle antibody (ASMA) with the tubular pattern and with or without antinuclear antibody (ANA); AIH type 2, with anti-LKM1 antibody; AIH anti-Soluble liver antigen/liver pancreas antigen (anti-SLA/LP), with or without ANA associated); primary biliary cholangites (CBP) and healthy controls. Methods: we studied 249 patients (42 PSC/IBD+; 33 PSC/IBD-; 31 AIH-1; 30 AIH-2; 31 HAI antiSLA/LP; 52 CBP; 30 healthy controls). The serum sample of these patients were processed with the INOVAÒ commercial kits: ANCA Etanol, Quanta LiteTM MPO ELISA, Quanta LiteTM PR3 ELISA, Quanta LiteTM FAN HEp-2; and human neutrophil slides ethanol fixed in house. Statistical analysis were performed using the Fisher Test, with Holm correction when nedeed, McNemar and Kappa Test. Results: The classical pANCA were present in 1.9% (IC 95%: 0 - 11.07) CBP patients and 7.1% (IC 95%: 1.77 - 19.7) of PSC/IBD+ patients. There were no statistical significance between groups. The atypical pANCA were identified in 62 out of 249 samples (24.9%). It were more frequently detected in PSC/IBD+ (52.4%, IC 95%: 37.72-66.6) then in PSC/IBD- (21.2%, IC 95%: 10.38 - 38.05), p = 0.005. The Fisher test did not show statistical significance between PSC/IBD+ and CBP for atypical pANCA reactivity (21.2%, IC 95%: 10.38-38.05 versus 15.4%, IC 95%: 7.74 - 27.79), p = 0.56. However, there was statistical significance for atypical pANCA between AIH subtypes, p < 0,001. Among AIH subtypes, the atypical pANCA were more frequent in AIH-1 than in AIH-2 (45.2%, IC 95%: 29.15 - 62.24 versus 3.3%, IC 95%: 0 - 18.09, p < 0.001) and more frequent in AIH-3 than in AIH-2 (32.3%, IC 95%: 18.46-49.97 versus.3.3%, IC 95%: 0 - 18.09, p = 0.012). There were no statistical diference between AIH-1 e a AIH-3 (p = 0.434).None of the 30 healthy controls showed the atypical pANCA pattern. The classical cANCA were present in just 3 of 249 patient samples (1.2%), 1 CBP, 1 PSC/IBD+ and 1 AIH-1. The atypical cANCA is rarely described in the literature. We identified just 2 samples with the atypical cANCA of 249 samples (0.8%), one PSC/IBD+ patient and another AIH-2 patient. 14 out of 249 samples (5.6%), showed a positive fluorescence on ethanol fixed slides, even though we couldn\'t define a ANCA pattern because of the ANA interference. However, the Fisher test did not show a statistical significance between the studied groups (among AIH subtypes, p= 0.207 and PSC/IBD+ versus PSC/IBD-, p = 0.945). Antibodies against proteinase-3, that is considered the classical cANCA target, we detected 25 out of 249 samples (10.0%). The anti-PR3 were more frequent in PSC/IBD+ (31.0%, IC 95%: 22.94-50.88) than in PSC/IBD- (12.1%, IC 95%:4.52-29.46), p = 0,025. Antibodies against antimyeloperoxidase, one of the target antigens of the classical pANCA, were identified in 8 out of 249 samples (3.2%). The overall ELISA results, adding the anti-PR3 and anti-MPO, show that this autoantibodies were more frequent in PSC among the other groups, mainly PSC/IBD+ (p= 0.002). It is worth mentioning that PSC/IBD+ 2 patients showed simultaneously anti-PR3 and anti-MPO reactivity. If we consider atypical pANCA as atypical pANCA by IIF and negative ELISA (anti-MPO and anti-PR3), 49 out of 249 samples (19.7%), The Fisher test showed a difference statistical significance in atypical pANCA IIF+/ELISA- between PSC/IBD+ (35.7%, IC 95%: 22.94 - 50.88) and PSC/IBD- (12.1%, IC 95%:4.21 - 27.93), p = 0,018. The Fisher test did not show significant difference between PSC/IBD- and CBP (13.5%, IC 95%: 6.37 - 25.58), p = 1. The same test showed statistical significance reactivity of ANCA IIF+/ELISA- among AIH subtypes (p=0,001), been more frequent in AIH-1 then in AIH-2 (p = 0.001) and among AIH-3 versus AIH-2 (p = 0.025). There was no statistical difference among AIH-1 versus AIH-3, p = 0,426. Conclusion:SC/IBD+ had a different serological pattern compared with PSC/IBD-, since atypical p-ANCA and anti-PR3 antibodies were significantly more frequent in the former. According to the ANCA profile, PSC/IBD- had a similar behavior to PBC which may suggest that atypical p-ANCA and anti-PR3 antibodies are more associated with IBD than with PSC. Patients with ASMA AIH and with anti-SLA/LP had higher frequency of atypical p-ANCA than anti-LKM1 AIH; There was no concordance between the results of indirect immunofluorescence and those of ELISA. Then, the results of ANCA by immunofluorescence are completely observer-dependent
340

Food Antigen Sensitivity in Coeliac Disease Assessed by the Mucosal Patch Technique

Kristjánsson, Guðjón January 2005 (has links)
<p>A diagnosis of coeliac disease (CD) in adults relies on the presence of a structurally abnormal intestinal mucosa, followed by a clear clinical remission on a gluten-free diet. There is a clear need for a rapid, simple, safe and sensitive method to determine the type and intensity of inflammation in the gut mucosa in clinical practice. The overall aims of our studies were to develop and evaluate a new technique, “the mucosal patch technique”, to characterize rectal local inflammatory process after rectal food challenge in patients with CD<b>. In study 1</b> we evaluated the potential of the new technique. The technique was well tolerated and easily applied. Pronounced neutrophil and eosinophil involvement in ulcerative colitis (UC) was demonstrated. With the high sensitivity of the technique, low-degree mucosal neutrophil activation could also be quantified in patients with collagen colitis,UC in clinical remission and in patients with irritable bowel syndrome. <b>In study 2 and 3</b> the aim was to elucidate the dynamics of the rectal inflammatory response and nitric oxide (NO) production after rectal gluten challenge. We found a pronounced neutrophil activation in coeliac patients after rectal gluten challenge. This activation was apparent 4 hours after challenge and remains for at least 48 hours. A more modest eosinophil activation started 1-2 hours later and remained at least for 48 hours. The biphasic pattern of neutrophil and eosinonphil activation after challenge suggests a biphasic inflammatory reaction. The activation of neutrophils and eosinophils precedes a pronounced enhancement of mucosal NO production. Some of our coeliac patients displayed signs of an inflammatory reaction after rectal corn gluten challenge. <b>In study 4</b> the aim was to investigate the local inflammatory reaction to gluten and cow’s milk protein in CD patients in remission. The findings indicate that not only gluten sensitivity but also cow’s milk (CM) protein sensitivity is common in CD. The data support the hypothesis that CM sensitivity may contribute to persistent symptoms in coeliac patients on gluten-free diet.</p>

Page generated in 0.1407 seconds