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Colon Samples (colon + sample)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Inflammatory bowel disease in the setting of autoimmune pancreatitis,

INFLAMMATORY BOWEL DISEASES, Issue 9 2009
Karthik Ravi MD
Abstract Background: Despite scattered case reports, the prevalence of inflammatory bowel disease (IBD) in patients with autoimmune pancreatitis (AIP) is unknown. We sought to better characterize the putative association between the conditions. Methods: Medical records of 71 patients meeting accepted criteria for AIP were reviewed to identify those with endoscopic and histological evidence of IBD. Colon samples in patients with both AIP and IBD were immunostained to identify IgG4-positive cells. Results: Four patients with AIP (5.6%) had a diagnosis of IBD: 3 had ulcerative colitis (UC) and 1 had Crohn's disease (CD). The diagnosis of IBD preceded or was simultaneous to that of AIP. Two AIP-UC patients treated for AIP with prednisone had a recurrence of AIP, and 1 required 6-mercaptopurine for long-term corticosteroid-sparing treatment. Two AIP-IBD patients underwent Whipple resections, and 1 had recurrent AIP. All 3 patients with UC presented with pancolitis, and 2 required colectomy. Colon samples from 1 patient with UC and 1 patient with CD were available for review. Increased numbers of IgG4-positive cells (10 per high-power field) were noted on the colon sample from the patient with UC. Conclusions: Almost 6% of patients with proven AIP had a diagnosis of IBD, compared to a prevalence of ,0.4%,0.5% in the general population, potentially implying a 12,15-fold increase in risk. Patients with both AIP and IBD may have increased extent and severity of IBD. The finding of IgG4-positive cells on colon biopsy suggests that IBD may represent an extrapancreatic manifestation of AIP. (Inflamm Bowel Dis 2009) [source]

Desulfotomaculum genus- and subgenus-specific 16S rRNA hybridization probes for environmental studies

ENVIRONMENTAL MICROBIOLOGY, Issue 2 2000
Krassimira R. Hristova
Based on comparative analysis of 16S rRNA sequences and the recently established phylogeny of the genus Desulfotomaculum, a set of phylogenetically nested hybridization probes was developed and characterized. A genus-specific probe targets all known Desulfotomaculum species (with the exception of Desulfotomaculum acetoxidans,), and five specific probes target subclusters within the Desulfotomaculum genus. The dissociation temperature of each probe was determined experimentally. Probe specificities were verified through hybridizations with pure culture rRNA isolated from a wide variety of target and non-target organisms and through an evaluation of probe ,nesting' using samples obtained from four different environments. Fixation and hybridization conditions for fluorescence in situ hybridizations were also optimized. The probes were used in quantitative membrane hybridizations to determine the abundance of Desulfotomaculum species in thermophilic anaerobic digesters, in soil, in human faeces and in pig colon samples. Desulfotomaculum rRNA accounted for 0.3,2.1% of the total rRNA in the digesters, 2.6,6.6% in soil, 1.5,3.3% in human faeces and 2.5,6.2% in pig colon samples. [source]

Differential stress-induced alterations of colonic corticotropin-releasing factor receptors in the Wistar Kyoto rat

NEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2010
D. O'malley
Abstract Background, A growing body of data implicates increased life stresses with the initiation, persistence and severity of symptoms associated with functional gut disorders such as irritable bowel syndrome (IBS). Activation of central and peripheral corticotropin-releasing factor (CRF) receptors is key to stress-induced changes in gastrointestinal (GI) function. Methods, This study utilised immunofluorescent and Western blotting techniques to investigate colonic expression of CRF receptors in stress-sensitive Wistar Kyoto (WKY) and control Sprague Dawley (SD) rats. Key Results, No intra-strain differences were observed in the numbers of colonic CRFR1 and CRFR2 positive cells. Protein expression of functional CRFR1 was found to be comparable in control proximal and distal colon samples. Sham levels of CRFR1 were also similar in the proximal colon but significantly higher in WKY distal colons (SD: 0.38 ± 0.14, WKY: 2.06 ± 0.52, P < 0.01). Control levels of functional CRFR2 were similar between strains but sham WKYs samples had increased CRFR2 in both the proximal (SD: 0.88 ± 0.21, WKY: 1.8 ± 0.18, P < 0.001) and distal (SD: 0.18 ± 0.08, WKY: 0.94 ± 0.32, P < 0.05) regions. Exposure to open field (OF) and colorectal distension (CRD) stressors induced decreased protein expression of CRFR1 in SD proximal colons, an effect that was blunted in WKYs. CRD stimulated decreased expression of CRFR2 in WKY rats alone. Distally, CRFR1 is decreased in WKY rats following CRD but not OF stress without any apparent changes in SD rats. Conclusions & Inferences, This study demonstrates that psychological and physical stressors alter colonic CRF receptor expression and further support a role for local colonic CRF signalling in stress-induced changes in GI function. [source]

Distribution of serotonin receptors and interacting proteins in the human sigmoid colon

NEUROGASTROENTEROLOGY & MOTILITY, Issue 5 2009
N. Chetty
Abstract, This study aimed to examine the distribution of 5-HT receptors in the human colon. 5-HT induces desensitization of the circular muscle and as this is facilitated by G-protein coupled receptor kinases (GRKs) and other proteins, we also examined their distribution. Human sigmoid colon samples were dissected into three separate layers (mucosa, taeniae coli and intertaenial strips) and RNA was amplified by RT-PCR. The 5-HT2B receptor and all 5-HT7 receptor splice variants were expressed in all tissues. 5-HT4 a,b,c and n splice variants were also expressed in all tissues and 5-HT4d, 5-HT4g and 5-HT4i were only detected in some samples. The 5-HT2A receptor was seen predominantly in the intertaenial strips of the colon. Only one transcript of the serotonin transporter (SERT) was detected in the muscle layers. Variation was seen in GRK expression with GRK2 and 3 predominantly expressed in the mucosa, while GRK5 and 6 were found more commonly in the taeniae coli. PDZ (named after postsynaptic density protein, Drosophila disc large tumour suppressor and tight junction protein ZO-1) domain containing proteins, which may be involved in 5-HT receptor trafficking, were also detected throughout the sigmoid colon. The 5-HT3A subunit was expressed in all tissues, whereas the 5-HT3E subunit was mainly found in the mucosa layer while the 5-HT3B subunit was more common in the muscle layers. Receptor interacting chaperone (RIC-3), which is involved in transporting 5-HT3 receptor subunits, is expressed less in mucosa compared to muscle layers. In conclusion, these results show that there is variation in distribution of 5-HT receptors and interacting proteins within the sigmoid colon that may contribute to colonic function. [source]