Home About us Contact
|
Home About us Contact | ||
|
|
||
Colonic Mucosal Biopsies (colonic + mucosal_biopsy)
Selected AbstractsAnti tumour necrosis-, therapy increases the number of FOXP3+ regulatory T cells in children affected by Crohn's diseaseIMMUNOLOGY, Issue 2 2008Ida Ricciardelli Summary Crohn's disease (CD) is a chronic inflammatory disease of the gastrointestinal tract. Its pathogenesis is not completely understood, though the prevailing model is that the intestinal flora drives a strong intestinal T helper 1 (Th1)/Th17 type immune response and inflammation in the genetically susceptible host. This leads to overly aggressive T-cell responses to normal bacteria causing tissue damage. Intestinal homeostasis and maintenance of tolerance to harmless antigens in the intestine has been shown to be maintained by CD4+ CD25+ T regulatory cells (Treg) in animal models of inflammatory bowel diseases. Here we investigated whether Infliximab, a chimeric monoclonal antibody directed against tumour necrosis factor (TNF)-, shown to be highly effective in the treatment of CD, has any effect on mucosal CD4+ CD25+ (FOXP3+) Tregs. Colonic mucosal biopsies from children with active Crohn's disease treated in vivo with Infliximab and controls were analysed to determine FOXP3 expression by immunofluorescence and reverse transcription,polymerase chain reaction. We observed that FOXP3+ T cells were significantly reduced in mucosa of CD patients with active disease compared with controls and restored to normal following Infliximab treatment. The frequency of FOXP3+ cells and mRNA expression was significantly increased in CD mucosa from patients treated in vivo with Infliximab compared with CD patients treated with conventional therapies. In conclusion, we show that Infliximab treatment does not solely neutralize soluble TNF-,, but also affects activation and possibly expansion of mucosal regulatory T cells. We suggest that anti TNF-, immunotherapy can also restore mucosal homeostasis in Crohn's disease. [source] Halophilic archaea in the human intestinal mucosaENVIRONMENTAL MICROBIOLOGY, Issue 9 2010Andrew P. A. Oxley Summary The human gastrointestinal tract microbiota, despite its key roles in health and disease, remains a diverse, variable and poorly understood entity. Current surveys reveal a multitude of undefined bacterial taxa and a low diversity of methanogenic archaea. In an analysis of the microbiota in colonic mucosal biopsies from patients with inflammatory bowel disease we found 16S rDNA sequences representing a phylogenetically rich diversity of halophilic archaea from the Halobacteriaceae (haloarchaea), including novel phylotypes. As the human colon is not considered a salty environment and haloarchaea are described as extreme halophiles, we evaluated and further discarded the possibility that these sequences originated from pre-colonoscopy saline lavage solutions. Furthermore, aerobic enrichment cultures prepared from a patient biopsy at low salinity (2.5% NaCl) yielded haloarchaeal sequence types. Microscopic observation after fluorescence in situ hybridization provided evidence of the presence of viable archaeal cells in these cultures. These results prove the survival of haloarchaea in the digestive system and suggest that they may be members of the mucosal microbiota, even if present in low numbers in comparison with methanogenic archaea. Investigation of a potential physiological basis of this association may lead to new insights into gastrointestinal health and disease. [source] Quantification of mitochondrial DNA mutation loadAGING CELL, Issue 5 2009Laura C. Greaves Summary Mitochondrial DNA (mtDNA) mutations are an important cause of genetic disease and have been proposed to play a role in the ageing process. Quantification of total mtDNA mutation load in ageing tissues is difficult as mutational events are rare in a background of wild-type molecules, and detection of individual mutated molecules is beyond the sensitivity of most sequencing based techniques. The methods currently most commonly used to document the incidence of mtDNA point mutations in ageing include post-PCR cloning, single-molecule PCR and the random mutation capture assay. The mtDNA mutation load obtained by these different techniques varies by orders of magnitude, but direct comparison of the three techniques on the same ageing human tissue has not been performed. We assess the procedures and practicalities involved in each of these three assays and discuss the results obtained by investigation of mutation loads in colonic mucosal biopsies from ten human subjects. [source] Alcohol Stimulates Activation of Snail, Epidermal Growth Factor Receptor Signaling, and Biomarkers of Epithelial,Mesenchymal Transition in Colon and Breast Cancer CellsALCOHOLISM, Issue 1 2010Christopher B. Forsyth Background:, Alcohol consumption is associated with the risk of progressive cancers including colon and breast cancer. The mechanisms for the alcohol-induced aggressive behavior of these epithelial cancer cells have not been fully identified. Epithelial,mesenchymal transition (EMT) is a developmental program recently shown to play a role in cancer progression and metastases. We hypothesized that alcohol might promote cancer progression by inducing EMT in cancer cells and tested this hypothesis by assessing alcohol-stimulated changes in phenotypic markers of EMT as well as the EMT transcription factor Snail and its related cell signaling. Methods:, Colon and breast cancer cell lines and a normal intestinal epithelial cell line were tested as well as colonic mucosal biopsy samples from alcoholic subjects. Cells were treated with alcohol and assessed for EMT-related changes using immunofluorescent microscopy, western blotting, reporter assays, RT-PCR, and knockdown of Snail with siRNA. Results:, We show alcohol upregulated the signature EMT phenotypic marker vimentin as well as matrix metalloprotease (MMP)-2, MMP-7, and MMP-9 and cell migration in colon and breast cancer cells,all characteristics of EMT. Alcohol also stimulated nuclear localization of Snail phosphorylated at Ser246, transcription from a Snail reporter plasmid, and Snail mRNA expression by RT-PCR. Snail siRNA knockdown prevented alcohol-stimulated vimentin expression. In vivo, Snail expression was significantly elevated in colonic mucosal biopsies from alcoholics. Also, we found alcohol stimulated activation of epidermal growth factor receptor (EGFR) signaling and an EGFR inhibitor blocked alcohol-induced cell migration and Snail mRNA expression. Conclusions:, Collectively, our data support a novel mechanism for alcohol promoting cancer progression through stimulating the EMT program in cancer cells via an EGFR-Snail mediated pathway. This study reveals new pathways for alcohol-mediated promotion of cancer that could be targeted for therapy or prevention of alcohol-related cancers. [source] Cyclooxygenase-2 immunoreactivity in collagenous colitisAPMIS, Issue 7 2009SIGNE WILDT Collagenous colitis (CC) is an inflammatory bowel disease of unknown aetiology and pathogenesis. In ulcerative colitis and Crohn's disease, prostaglandins may be involved in the pathogenesis of inflammation, and increased expression of cyclo-oxygenase-2 (COX-2) has been detected. The purpose of this study was to examine the presence and cellular localization of COX-2 in colonic mucosa of patients with CC. Using immunohistochemistry, immunoflouresence and Western blot analysis, COX-2 expression was evaluated in colonic mucosal biopsies from 10 patients with active untreated CC, and compared with samples from eight normal controls, and samples from eight patients with ulcerative colitis or Crohn's disease. Specimens from patients with CC expressed COX-2 protein in increased amounts compared with controls, but similar to patients with ulcerative colitis and Crohn's disease. COX-2 expression was localized to the mononuclear cells of the lamina propria. COX-2 expression was most evident in macrophages. Co-localization of COX-2 and macrophages was increased in number in comparison with controls. In conclusion COX-2 is expressed in increased amounts primarily in the macrophage subpopulation of the inflammatory infiltrate of lamina propria in CC. Increased recruitment of macrophages, increased expression of COX-2 and increased prostaglandin synthesis may be involved in the pathogenesis of CC. [source] Successful granulocyte-colony stimulating factor treatment of Crohn's disease is associated with the appearance of circulating interleukin-10-producing T cells and increased lamina propria plasmacytoid dendritic cellsCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2009P. J. Mannon Summary Granulocyte-colony stimulating factor (G-CSF) has proved to be a successful therapy for some patients with Crohn's disease. Given the known ability of G-CSF to exert anti-T helper 1 effects and to induce interleukin (IL)-10-secreting regulatory T cells, we studied whether clinical benefit from G-CSF therapy in active Crohn's disease was associated with decreased inflammatory cytokine production and/or increased regulatory responses. Crohn's patients were treated with G-CSF (5 µg/kg/day subcutaneously) for 4 weeks and changes in cell phenotype, cytokine production and dendritic cell subsets were measured in the peripheral blood and colonic mucosal biopsies using flow cytometry, enzyme-linked immunosorbent assay and immunocytochemistry. Crohn's patients who achieved a clinical response or remission based on the decrease in the Crohn's disease activity index differed from non-responding patients in several important ways: at the end of treatment, responding patients had significantly more CD4+ memory T cells producing IL-10 in the peripheral blood; they also had a greatly enhanced CD123+ plasmacytoid dendritic cell infiltration of the lamina propria. Interferon-, production capacity was not changed significantly except in non-responders, where it increased. These data show that clinical benefit from G-CSF treatment in Crohn's disease is accompanied by significant induction of IL-10 secreting T cells as well as increases in plasmacytoid dendritic cells in the lamina propria of the inflamed gut mucosa. [source] Routine colonic mucosal biopsy and ileoscopy increases diagnostic yield in patients undergoing colonoscopy for diarrheaJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2002IAN F YUSOFF Abstract Background and Aims: In patients undergoing colonoscopy for diarrhea, when the examination is normal, the role of routine mucosal biopsy remains controversial, particularly in the open-access setting. It is uncertain whether routine ileoscopy adds anything to colonoscopy alone. We aimed to assess the yield of mucosal biopsy and ileoscopy in patients with diarrhea. Methods: We retrospectively reviewed all colonoscopies performed for diarrhea over a 9-year period in a tertiary referral center with an open-access service. We then selected cases where the examination was normal and biopsies were performed. The histopathology reports of these selected cases were then reviewed. Results There were 1131 cases identified. The mucosal examination was normal in 465 cases (41%); 362 of these had colonic biopsies performed. Histology was normal in 316 cases (87%) and was non-specific in 28 cases (8%). Significant histopathology was present in 18 cases (5%) with a significantly higher prevalence of microscopic colitis in patients above 60 years old. Ileoscopy was performed in 508 cases and was abnormal in 26 cases (5%). The abnormality on ileoscopy was the sole abnormality in 13 cases (3%). Conclusions Routine colonic mucosal biopsy and ileoscopy each identify significant additional pathology in 5% of cases when investigating patients with diarrhea, and are recommended as routine practice in this setting. We found ileal biopsy unhelpful when ileoscopy was normal. © 2002 Blackwell Science Asia Pty Ltd [source] | |||||||||||||