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S1250 Twenty-Four Hour Pan-Colonic Manometry in Patients with Severe Slow Transit Constipation Demonstrates Diminished Propagating Pressure Wave Activity in the Transverse Colon

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S1250 Twenty-Four Hour Pan-Colonic Manometry in Patients with Severe Slow Transit Constipation Demonstrates Diminished Propagating Pressure Wave Activity in the Transverse Colon
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        A      G      A      A      b    s     t    r    a    c     t    s S1250Twenty-Four Hour Pan-Colonic Manometry in Patients with Severe SlowTransit Constipation Demonstrates Diminished Propagating Pressure WaveActivity in the Transverse Colon Philip G. Dinning, Natalia Zarate, Linda M. Hunt, Sergio E. Fuentealba, Michal M.Szczesniak, Sahar Mohammed, Sean L. Preston, Nicholas J. Lutton, David Z. Lubowski, SMark Scott, Ian J. CookBackground: 24h pan-colonic manometry, with closely spaced recording sites, has not beenachieved in patients with slow transit constipation (STC). Thus, while a reduced frequencyof high amplitude propagating sequences (HAPS) is commonly reported in STC, character-istics of propagating sequence (PS) activity throughout the colon are unknown. Aim: Toestablished the first detailed map of PS activity throughout the entire colon of patients withSTC. Hypotheses: The derangements in motor patterns underpinning STC are mulitfactorial,but the amplitude, timing, extent of propagation and spatio-temporal patterning of PSs willbetter define the disorder than altered HAPS frequency alone. Methods: In 12 patients withscintigraphically confirmed STC and 9 healthy controls, a 5m long silicone catheter with16 recording sites spanning the colon at 7.5cm intervals was positioned colonoscopicallywith the tip clipped to the cecum. Water-perfused manometry was recorded for 24h. Results: As previously described, patients demonstrated a significant decrease in the frequency (3±5vs. 20±8 /24h; P<0.001) and amplitude (81±19 vs. 142±24mmHg; P<0.001) of HAPScompared to controls. In addition, although the overall total colonic frequency and velocityof both antegrade and retrograde PSs did not differ between the two groups, the frequencyof antegrade PSs srcinating in the transverse colon was significantly reduced in patients(STC, 16±9 vs. 30±16 PS/24hr; P=0.05). In addition, PSs srcinating in the ascending colonextended a significantly shorter distance than those recorded in controls (21±5 vs. 38±10cm; P<0.00001). Taken together, these factors account for a significant reduction in thefrequency of propagated pressure waves (PPW) in the transverse colon of STC patients(82±41 vs. 141±63 PPW/24hr; P=0.03). Throughout all regions of the colon, the amplitudeof antegrade PSs was significantly reduced in patients (32±6 vs. 68±15mmHg; P<0.001).Finally, a 1000 KCal meal induced no significant changes in PS characteristics in patients.In comparing the delta values (postprandial - basal) between patients and controls, onlyHAPS frequency differed significantly (delta: -0.07±0.7 v 3.3±2.8 /2hr; P=0.01). Conclusion:Patients with STC demonstrate the ability to generate a normal daily frequency of antegradePSs. However these PSs extend only short distances around the colon and are of significantlyreduced amplitude. There is also a marked reduction in propagated activity through thetransverse colon and this may represent a target region for future research. Supported byNHMRC Australia. S1251Estrogen Inhibits Colonic Contractility via a Non-Nuclear Mediated ProteinKinase-Dependent Mechanism  Aisling Hogan, Rory Kennelly, Danielle Collins, Alan W. Baird, Des WinterIntroduction: Classical effects of estrogen (E2) involve activation of target genes after bindingnuclear receptors. Estrogenic effects too rapid for DNA transcription (non-genomic) are nowknown to occur. Aims & Background: Effects of E2 on colonic motility are unknowndespitetheincreasedprevalenceofgastrointestinalsymptomsinpregnantandpremenopausalwomen. The objective was to explore this effect. Method: Histologically normal humancolon was obtained from the proximal resection margin of colorectal carcinoma specimens.Circular smooth muscle strips were microdissected and suspended under 1g of tension inorgan baths containing oxygenated Kreb's solution at 37C. After an equilibration period,tissues were exposed to 17B estradiol (n=8) or bovine serum albumin (BSA)-conjugatedestrogen (n=8) (too large to cross cell membrane). Fulvestrant, an E2 receptor antagonistwas added to some baths (n=8) with 17B estradiol. Other tissue strips were exposed toCalphostin C (Protein kinase inhibitor) or Cycloheximide (protein synthesis inhibitor). Thecholinergic agonist carbachol was used. Contractile activity was recorded isometrically.Institutional research board approval was granted. Results: Estrogen inhibited carbachol-induced contractility (mean difference 19.6%; n=8; p<0.0001; CI 95%). In keeping with anon-genomic, rapid onset steroid action, the effect was within minutes and reversible. Itwas observed in both 17-B estradiol and BSA-conjugated estrogen and was unaltered bycycloheximide(proteinsynthesisinhibitor).Therapid,non-genomiccellmembranereceptor-mediated,smoothmuscleeffectswereinhibitedbyfulvestrant,suggestingreceptormediation.Estrogen decreases contractility in human colonic smooth muscle in a non-genomic mechan-ism involving cell-membrane coupling. S1252Profiling the Adherent Mucosal and Luminal Microbiota in Diarrhea-Predominant Irritable Bowel Patients Ian M. Carroll, Young-Hyo Chang, R. Balfour Sartor, Yehuda . Ringel A role for an altered intestinal microbiota in the pathophysiology of irritable bowel syndrome(IBS) has been suggested. However, the structure of the mucosal-adherent microbiota andthe luminal microbiota in IBS patients has not yet been determined. Aim: To characterizethe mucosal-adherent and luminal gut microbiota in patents with diarrhea-predominant IBS  A-222 AGA Abstracts (D-IBS) and controls. Methods: We analyzed fecal and colonic mucosal samples from 10patients that met the Rome III criteria for D-IBS and 10 healthy controls. To avoid anyeffects of bowel preparation on the intestinal microbiota, all mucosal samples were collectedduring an un-prepped flexible sigmoidoscopy. Fecal and colonic biopsy samples were ana-lyzed using two different methods: conventional culture techniques and quantitative poly-merase chain reaction (qPCR). Samples were analyzed to enumerate specific bacteria of interestincludingtotalaerobes,totalanaerobes,Lactobacillusspp.,Bacteroidesspp.,Clostrid-ium spp., Bifidobacterium spp., and  Escherichia coli . Bacterial 16S rDNA sequences werequantified from fecal or biopsy DNA by qPCR and viable levels of bacterial species weredetermined using selective and non-selective media on fresh fecal or biopsy samples. Results:Culture ofbacteria demonstrateda significant decreasein the totalnumber ofaerobic bacteriain fecal samples from patients with D-IBS compared to controls (1.37 × 10 7 vs. 8.37 × 10 8 CFU/g feces, respectively; P < 0.05). This phenomenon was not found in biopsy samples.qPCR analysis demonstrated a significant increase in Lactobacillus and Bifidobacteria spp.in fecal samples from D-IBS patients compared to controls (Lactobacillus spp.: 2.4 × 10 4 vs. 1.5 × 10 4 16S copies/  µ g fecal DNA, respectively; P < 0.05. Bifidobacteria spp.: 1.09 ×10 7 vs. 3.8 × 10 6 16S copies/  µ g fecal DNA, respectively; P < 0.01). An increase in Bifidobac-teria spp. was observed in mucosal biopsies from D-IBS patients when compared to controls(2.56 × 10 6 vs. 1.06 × 10 6 16S copies/  µ g biopsy DNA, respectively). However, no notabledifference in Lactobacillus spp. in mucosal biopsies was observed. A decrease in the levelsof   E. coli  was observed in D-IBS patients when compared to healthy controls in both stool(2.1 × 10 6 vs. 2.6 × 10 6 16S copies/  µ g fecal DNA, respectively) and biopsy samples (1.16× 10 6 vs. 1.4 × 10 8 16S copies/  µ g biopsy DNA, respectively). Conclusions: We demonstratequantitative microbiological differences in the adherent and luminal intestinal microbiotabetween patients with D-IBS and healthy controls. The decreased number of   E. coli  observedin both fecal and mucosal samples in the D-IBS group requires further investigation. S1253MicroRNA-29a Regulates Intestinal Membrane Permeability in Patients withIrritable Bowel Syndrome QiQi Zhou, Carlo M. Croce, Wiley W. Souba, G Nicholas VerneBackground: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder in whichthe molecular mechanism(s) underlying the pathophysiology is poorly understood; however,increased intestinal permeability in IBS patients has been reported. Glutamine supplementa-tion has been shown to decrease membrane permeability and improve gastrointestinalfunction. The objective of this study was to evaluate the expression of glutamine synthetaseand its complementary miRNA in the blood and gut tissues of IBS patients with increasedintestinal membrane permeability. Methods: We evaluated 19 diarrhea-predominant IBSpatients and 10 controls for intestinal membrane permeability using the lactulose/mannitolmethod. MicroRNA microarray analysis was performed in blood microvessicles and guttissue. Glutamine synthetase was evaluated in the gut tissues of patients.  In Vitro  experimentswere also conducted with cell culture to further confirm the relationship between miR-29aand glutamine synthetase expression. Results: A total of 8/19 IBS patients had increasedintestinal membrane permeability and decreased glutamine synthetase expression comparedto IBS patients with normal membrane permeability and controls. Also, increased expressionof miR-29a was present in blood microvesicles, small bowel and colon tissues of the IBSpatients with increased membrane permeability. Increased intestinal permeability was regu-lated by miR-29a which has a complementary site in the 3'-UTRs of GLUL (glutaminesynthetase) gene. Conclusions: Increased miR-29a expression lead to decreased glutaminesynthetase levels and resulting increased membrane permeability. Thus, miR-29a mediatesintestinal membrane permeability in IBS patients through glutamine dependent signalingpathways. This information may lead to new therapeutic approaches for the treatment of patients with IBS. S1254The Effect of Reported Early Childhood Abuse On Sleep and Indices of Autonomic Nervous System Balance in Women with Irritable Bowel Syndrome Monica Jarrett, Margaret W. Baker, Anne Poppe, Robert L. Burr, Kevin C. Cain, MargaretHeitkemperPurpose: Early childhood traumatic experiences including emotional, physical, and sexualabuse may contribute to the pathophysiology of irritable bowel syndrome (IBS) as well assleep disturbances. Whether these childhood experiences are associated with markers of physiological arousal including measures of autonomic nervous system function remain tobe determined. Methods: Women with IBS and healthy control women were recruited fromthe community. Using the Childhood Trauma Questionnaire 61 women (IBS, n=30 [meanage 30]; controls, n=31 [mean age 31]) were interviewed regarding childhood emotional,physical and sexual abuse. The Pittsburgh Sleep Quality Index was used to assess subjectivesleep quality. First void urine samples were collected across 5 days and cortisol, catecholam-ine, and creatinine levels measured. In addition, all women underwent three nights of polysomnography and heart rate monitoring for heart rate variability in a university sleeplaboratory. Results: As compared to control women, more women in the IBS group reporteda history of emotional, physical, and sexual abuse (IBS, n=10,8,7 respectively; Controls n=3, 2,2 respectively). Women with IBS who also reported a history of abuse history weremore likely to report constipation symptoms (straining, hard stools). Within the IBS group,those women who reported childhood emotional and/or physical abuse reported poorersleep quality, and exhibited prolonged sleep latency, less heart rate variability, and decreasedepinephrine/norepinephrine ratio as compared to those who denied a history of emotionaland/or physical abuse. Within the IBS group, women who reported a history of sexual abusealso reported poorer sleep quality, showed increased time spent in stage 1 and 2 sleep, anddecreased slow wave sleep but no differences in heart rate variability indices as comparedto IBS women without this history. There were no significant differences in urine cortisollevels between IBS women with a history of abuse (any type) as compared to those without.Conclusion:WomenwithIBSwhoreportahistoryofabuse,inparticularchildhoodemotionaland physical abuse, exhibit a different pattern of nighttime autonomic balance and poorsleep quality as compared to those IBS women without this history.
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