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sPYY3-36 in a restraint cage. PYY peptide effects on food intake and FPO were monitoredsimultaneously in fasted or non-fasted mice. Gastric emptying was determined 2 h after PYYpeptides injected IP in fasted/re-fed mice. In the distal colon, Y2 receptor expression wasassessed by RT-PCR in the mucosa or layers of submucosa and muscle, and location inwhole mounts of longitudinal muscle/myenteric plexus by immunohistochemistry. Results:PYY3-36, PYY, and NPY (8 nmol/kg) inhibited the stimulated 1-h FPO in response to noveltystress by 89%, 58% and 52% respectively compared with saline; lower doses (0.8, 2.5 nmol/kg) had no effect. Inhibition induced by PYY3-36, PYY and NPY reached 94%, 92% and57% respectively within 15 min. PYY and PYY3-36, but not Y1 agonists, prevented the 1-h restraint-induced FPO and colonic contractions, and abolished 5-HTP (10 mg/kg)-inducedFPO and diarrhea. BIIE-0246 (5 mg/kg) blocked PYY and PYY3-36 inhibitory actions onthe colonic responses to novelty stress and 5-HTP. PYY3-36 (25 nmol/kg) suppressedbethanechol (5 mg/kg, IP)-stimulated FPO and diarrhea. PYY3-36 inhibitory action on FPOstimulated by novel environment was still observed in VIP knockout mice. PYY and PYY3-36, but not Y1 agonist, reduced the 2-h gastric emptying by 56% and 48% respectively.PYY3-36 inhibitory effects on food intake and FPO were correlated both in fasted mice inlight phase and non-fasted mice in dark phase. Y2 mRNA was expressed in both mucosaand muscle layers and Y2-like immunoreactivity was detected in the colonic myentericplexus. Conclusions: PYY and PYY3-36 potently blocked colonic contractions, fecal outputand diarrhea stimulated by stress, 5-HT or cholinergic agonist. PYY inhibitory action ismediated through Y2 receptors present in the colon. These data suggest that Y2 receptorsmay play a role in the development of constipation.

M1239

Alterations in Synaptic Transmission in the Enteric Nervous System andCorrelation to Motility Defects in CB1 Receptor-Deficient MiceIan M. Hons, Catherine M. Keenan, Martin Storr, Beat Lutz, Keith A. Sharkey

The endocannabinoid (EC) system has been shown to be important in regulating the plasticityof central nervous system synapses. However, the role of ECs on peripheral neurons hasnot been extensively investigated. The enteric nervous system (ENS) is a self-containedintegrative network possessing intrinsic reflexes and rhythmic network activity located inthe wall of the gut. The ENS possesses extensive synaptic connectivity, and additionally,these synapses have been shown to be highly plastic in pathological situations. The CB1receptor is localized in the ENS. Using CB1 receptor-deficient mice, we sought to study therole of ECs in the ENS, and investigated the functional consequences of inactivation of theCB1 receptor gene. Female CB1-/- mice on a C57BL/6N background were bred in Calgary.Comparisons were made between CB1-/- mice (KO) and littermate controls (CB1+/+, WT).The distal ileum was removed and maintained in oxygenated Krebs solution containingnicardipine and scopolamine. The myenteric plexus was dissected from a segment of ileum,and S and AH type neurons were examined by intracellular voltage recordings. Passive andactive electrical properties were evaluated as well as synaptic events evoked by focal stimula-tion of adjacent ganglia. Motility was assessed in WT and KO mice gavaged with Evans blue(5% in 5% gum arabic). 15 min after the gavage, animals were sacrificed and the distancetraveled by the dye front was measured and expressed as a percentage of the length of theentire small intestine. Neurons where assigned to 2 groups using electrophysiological andmorphological criteria: Dogiel type I S neurons which receive fast excitatory post-synapticpotentials (EPSPs), and AH neurons which posses a characteristic action potential shape,prolonged after-hyperpolarization, and Dogiel type II morphology. Recordings of the basalelectrical activity from neurons of KO animals displayed a higher number of neurons receivingspontaneous EPSPs in S type neurons when compared to WT controls (1/6 WT, 6/6 KO,P < 0.05). Measurements of upper GI transit indicated an increase in transit in KO animals(70.3 ± 3.27% WT, 92.1 ± 2.5% KO, P < 0.01). These results are consistent with ECsplaying a role in dampening synaptic activity in the ENS. In addition, they indicate thatnormal gut function requires a basal level of EC production to control activity in enteric neuralnetworks. When disrupted, the ENS becomes spontaneously active, leading to abnormal gutfunction (i.e. rapid transit). Our data indicate that CB1 receptors and ECs are involved insynaptic communication in the ENS and that this system contributes to normal gut function.

M1240

The Roles of Serotonin 5-HT2C and 3 Receptors in Anorexia and DelayedGastric Emptying in Cisplatin-Treated RatsKoji Yakabi, Susumu Kurosawa, Tomohisa Hattori, Yuzurihara Mitsutoshi, Shino Ohno

Background/Aim: It has been indicated that the acute gastrointestinal tract disorders causedby anticancer drugs involve serotonin secreted from the enterochromaffin cells. Moreover,cerebral serotonin contributes to regulate feeding behavior and energy balance. Mutatedserotonin 5-HT2C receptor display leptin-independent hyperphagia that leads to a late onsetof obesity (Nature 374, 1995). In order to clarify the mechanisms of cisplatin-inducedanorexia, we aimed to investigate the regulation of several 5-HT receptors expression betweenfasting condition and anorexia induced by anticancer drugs. Methods: Exp.1: Anorexia wasinduced in S.D. rats by consecutive (1, 2, 4 mg/kg, i.p.) injection of cisplatin for 4 days.The stomach and hypothalamus were collected to determine 5-HT receptor gene expressionby RT-PCR. Exp.2: In order to investigate the function of 5-HT receptor in cisplatin-treatedrats, 5-HT2C receptor antagonist (SB242084HCl at 10, 30 nmol/rat icv) or 5-HT3 receptorantagonists (granisetoron at doses of 0.1 and 0.5 mg/kg, s.c. or ondansetron at dose of 1mg/kg, s.c.) was administered to rats 6hr after cisplatin treatment, and the 24hrs food intakeand solid gastric emptying were determined. Results: The food intake in cicplatin-treatedrats was markedly decreased, compared with saline-treated rats. Moreover, serotonin 5-HT2C receptor gene expression in cisplatin-treated rats was increased in hypothalamus, andit was unchanged in stomach. Serotonin 5-HT3 receptor gene expression in cisplatin-treatedrats was significantly increased in stomach, while it was not increased in hypothalamus.Administration of SB242084HCl was significantly inhibited the decrease in 16hr food intakein cisplatin-treated rats, whereas it in 5-HT3 receptor antagonist-treated group wasunchanged. Granisetron at dose of 0.1 mg/kg and 0.5 mg/kg, and ondansetron inhibitedthe decrease in solid gastric emptying in cisplatin-treated rats. Conclusion: The results

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indicate that an increase in 5-HT2C receptor in hypothalamus and an increase in 5-HT3receptor in stomach are involved in anorexic effect of cisplatin.

M1241

Contractile and Secretory Responses of Luminal Short-Chain Fatty Acids andthe Expression of These Receptors, GPR41 and GPR43, in the Human Smalland Large IntestinesShin-ichiro Karaki, Hideaki Tazoe, Izumi Kaji, Yasuko Otomo, Takaji Yajima, AtsukazuKuwahara

Background and aim: Short-chain fatty acids (SCFAs) are luminal fermented products fromsome kinds of dietary fibers especially in large intestine. In animal experiments, luminalSCFAs are reported to induce a variety of physiological effects on intestinal functionsincluding smooth muscle contraction and epithelial secretion. However, there is little evidenceof the effects of SCFAs in the human intestine. Therefore, the aim of present study tried toshow the physiological effects of SCFAs in the human small and large intestines, andexamined the expression of the SCFA receptors, GPR41 and GPR43, possibly mediating theresponses. Methods: Human terminal ileum and colon were used in nonpathological regionof surgical specimens obtained from the patients of large intestinal cancer following informedconsent. Smooth muscle strips with mucosa and without mucosa were tied to an isometricforce transducer and suspended in a tissue bath in order to record the smooth musclecontractile activity. To record transepithelial ion transport, mucosa-submucosal preparationswere mounted on Ussing flux chamber and short-circuit current (Isc) were measured. ForRT-PCR and Western blot analysis for GPR41 and GPR43, total RNA and protein wereextracted from the tissues, respectively. Moreover, tissues were fixed in Zamboni's fixative,and 10 µm-thin cryostat sections were made for immunohistochemistry of GPR41 andGPR43. Results: In terminal ileum, propionate-induced transient contractions were observedin circular muscle strip with mucosa, but not without mucosa. This is the first to showthe SCFA-induced contractile response in the human small intestine. In Ussing chamberexperiments, propionate evoked negative Isc probably by K+ secretion in large intestine, butrarely evoked positive Isc by Cl- secretion as previously reported in rat distal colon. Moreover,mRNA and proteins of both SCFA receptors, GPR41 and GPR43, were detected in the humanintestinal mucosa. In immunohistochemistry, these receptors were observed to localize onepithelial cells especially enteroendocrine cells containing peptide YY. Conclusion: The presentstudy first shows the physiological effects of SCFAs and the SCFA receptor expressions inthe human intestine. However, there is no direct evidence that GPR41 and/or GPR43mediate(s) these physiological effects of SCFAs yet. Therefore, further study is necessary toperform in order to reveal whether these receptors really involve with the effects of SCFAsin the human intestine.

M1242

Pharmacological Characterization of Murine Lower Esophageal Sphincter(LES) RelaxationScott Carmichael, John Sauvé, David V. Miller, Yong Zhang, William G. Paterson

AIM: Because of the availability of genetic knockouts, the mouse has been increasinglyutilized as a model for studying GI motility. To date there is limited data available on thephysiology of the LES motor function in normal or mutant mice. METHODS: We character-ized pharmacologically the putative cholinergic, nitrergic and purinergic innervation of theLES circular smooth muscle from CD-1 mice using isometric tension recording from isolatedLES rings. The magnitude of LES relaxation (LESR) was expressed as a percent of maximalLESR induced by 1 µM isoproterenol. Preliminary experiments were also conducted in W/Wv mutant mice, which lack intramuscular interstitial cells of Cajal (ICCs). RESULTS: Ringsof LES muscle from CD-1 mice developed spontaneous tone shortly after suspension in thetissue bath. Electrical field stimulation of intrinsic nerves (100V, 10 Hz, 0.5 ms pulseduration, 5 sec) evoked a reproducible LESR (45.4 ± 6.8 %; n=30) followed by a post-relaxation contraction. This relaxation was abolished by application of the nitric oxidesynthase antagonist N(G)-nitro-L-arginine methyl ester (L-NAME; 100µM). In the presence ofL-NAME, cumulative application of atropine (3 µM) restored LESR to a level not significantlydifferent than control (55.8 ± 8.4%). Furthermore, atropine virtually abolished the post-relaxation contraction. Subsequent application of apamin (300 nM), a small conductanceCa2+-activated K+ channel blocker, significantly attenuated the LESR to 20.4 ± 4.2% (p<0.05)suggesting a purinergic component to LESR. Application of the neurokin-2 receptor antagon-ist MEN-10376 (3 µM) or Substance P tachyphylaxis had no consistent effects on the post-relaxation contraction. LES rings from W/Wv mutant mice developed significantly lessspontaneous tone and weaker KCl-induced contraction than strips from control mice. Whentone was restored by pre-application of carbachol in LES rings from W/Wv mutant mice,electrical field stimulation induced relaxation that was abolished by L-NAME. CONCLU-SIONS: These experiments indicate that in the mouse LES both nitrergic and purinergicinhibitory neurotransmission is present. Acetylcholine appears to be the major excitatoryneurotransmitter. In ICC deficient mice, LES muscle contractility is impaired, but nitrergicrelaxation is intact, suggesting that ICCs are not required for nitrergic neurotransmission.(Supported by CIHR)

M1248

Bacterial and Fungal Colonization of Endoscopic Intragastric Balloons Insertedin Patients with Morbid ObesityJohn A. Karagiannis, Nicoletta G. Mathou, Konstantia D. Paraskeva, Georgios K.Anagnostopoulos, Konstantinos Zografos, Nausika Kontostergiou, StamatinaKonstantinou, Zoi Roussou

INTRODUCTION Endoscopic intragastric balloon insertion consists an acceptable methodfor, at least short-term, weight loss in morbid obese patients. Upon removal of the balloonit was noticed in several patients that it looked macroscopically abnormal with a patternreminiscent of fungal colonization. AIM OF THE STUDY Aim of the study was to visually

inspect and culture every endoscopic intragastric balloon removed from patients with morbidobesity. PATIENTS - METHODS During the last eighteen months fourteen consecutiveballoons were removed from 14 patients (4 male, 10 female, age range 35-56 years). Theballons (BIB, INAMED, USA) were supplied sealed and sterile (according to specifications)and were inserted endoscopically with the standard technique. They were removed eitherafter the planned 6 months period (10 patients, 71.5%) or prematurely (4 patients, 28.5%,with the balloon in situ for at least 4 weeks) if balloon intolerance occurred (in one onpatient demand after unplanned pregnancy). Upon removal all balloons were inserted insterile plastic bags and were sent for culture. Patients demographics, use of PPI's or prokinet-ics, body weight and BMI before and after removal were also recorded. None of the patientshad known history of any disease predisposing to impaired immunocompetence. RESULTSOn removal 8 (57%) balloons looked macroscopically abnormal with a fungal colonizationpattern (white-yellow surface islets) while 6 (43%) looked normal. On culture, 8 (57%)were positive for fungi (4 candida albicans, 4 candida crusei with 1/4 fluconazole resistant),9 (64%) were positive for cocci while 3 (21.5%) were sterile. In these positive for cocci,pathogenic strains were isolated in 5 (55.5%) (3 Staph. Aureus and 2 Enteroc. Faecium)while in 4 (44.5%) commensial strains were isolated (2 Staph. Epidermis, 2 Strept. Mitis).Six balloons (43%) were positive for both fungi and cocci. Regarding balloon colonization,no significant differences were noticed between patients demographics, PPI's use, prematureballoon removal, BMI or differences in weight loss at the time of removal. All patients withpositive cultures were followed-up for 6 months after balloon removal without any clinicallysignificant symptoms related to balloon colonization. CONCLUSION There is a rather highincidence of bacterial and/or fungal colonization of endoscopic intragastric balloons insertedfor morbid obesity but without any evidence of clinical significance in immune competentpatients. However, its use in immunocompromized patients should be taken into account.

M1249

Peroral Endoscopic Anastomotic Reduction Improves Intractable DumpingSyndrome in Roux-en-Y Gastric Bypass PatientsGloria Fernandez-Esparrach, David B. Lautz, Christopher C. Thompson

Background: Dumping syndrome (DS) is a well described outcome of Roux-en-Y gastricbypass (RYGB). Although it can benefit some patients, a subset will develop intractable DS(IDS) characterized by symptomatic episodes with most meals. We describe the first seriesof patients treated endoscopically for IDS. Aim: To investigate the efficacy of endoscopicgastrojejunal anastomotic reduction to induce delayed pouch emptying in RYGB patientswith IDS. Methods: RYGB patients referred for IDS with a dilated (>2 cm) gastrojejunalanastomosis (GJA) by screening endoscopy were considered for participation. All procedureswere performed by a single endoscopist following the same technique. Following the denud-ing of mucosa at the GJA, endoscopic sutures were placed surrounding the rim of theanastomosis using the Bard EndoCinch suturing system. The sutures were then secured toform tissue plications, reducing the size of the GJA. Fibrin glue was then applied to thesutured areas. Final GJA apertures were measured and the pouch carefully inspected. Allpatients were followed for evidence of symptomatic relief and complications. Results: SixRYGB patients with IDS and dilated GJA underwent endoscopic anastomotic reductionbetween July 2005 and July 2007. IDS symptoms reported pre-procedure included: immedi-ate post-prandial nausea and severe diarrhea in all patients, as well as, diaphoresis (n=1),palpitations (n=1), and hypoglycemia (n=1). Five patients reported symptoms severe enoughto significantly limit daily activity. The average pre-procedure BMI was 34.5+7.1, with amean pouch length of 5+1 cm and mean anastomotic diameter of 23+4.5 mm. All procedureswere performed without immediate complications. After reduction, the average GJA diameterwas 8+0.4 mm (p<0.05). One patient reported hematemesis 2 days post-procedure and wasfound to have a nonbleeding ulcer with clot, and was treated with a hemostatic clip. Noother complications were reported. In all cases, IDS symptoms resolved completely andimmediately following the procedure. All patients reported persistent resolution of symptomsat median follow-up of 636 days. All patients also reported weight loss following procedurewith subsequent regain in 5 patients. The final mean BMI was 33+6 at the time of follow-up. Conclusions: This initial series implies that endoscopic anastomotic reduction can be usedto symptomatically treat post-RYGB IDS with minimal morbidity and significant resolution ofsymptoms.

M1250

Improvement of Serum C-Reactive Protein Level in Obese Chinese PatientsUndergoing Endoscopic or Laparoscopic Bariatric ProceduresEnders K. Ng, Bonnie Y. Tsung, Candice C. Lam, Man Yee Yung, Wilfred L. Mui

Background: C-reactive protein (CRP) is an inflammatory-response peptide, which is alsoa valuable serum marker indicating the cardiovascular risk of obese patients. Bioentericintragastric balloon (BIB) and bariatric surgery, such as laparoscopic sleeve gastrectomy(LSG) or laparoscopic gastric banding (LGB), are now commonly employed interventionsfor weight reduction in Asia. The aims of this study were to determine the risk factors forincreased CRP and the efficacy of various anti-obesity operations in lowering CRP in a groupof Chinese obese patients. Methods: All patients undergoing weight reduction proceduresin our unit between 2004 and 2007 were considered eligible. They were followed up byphysicians on a regular basis with body weight, BMI, eating habit, anthropometric parametersand blood tests recorded by dedicated dietitians and research nurses. Results: 90 patients(49 BIB, 25 LGB and 16 LSG) with complete sets of blood results and demographic datawere included. There was a female predominance (68.9%) with a mean age of 37.6(SD =9.4)years. The median (inter-quartile range) baseline BMI and CRP were 38.4(27.4 to 68.4)kg/m2 and 4.9(<0.99 to 33.4)mg/l, respectively. Multivariate linear regression analysis identifiedthat a higher baseline BMI, increased fasting blood glucose and a male gender were signific-antly related to an elevation in serum CRP, whereas age, lipid profiles and waist to hip ratiowere not of any predictive value. After a mean treatment period of 9.7(S.D.=5.7) months,both median BMI and serum CRP level were significantly reduced in all three treatmentgroups (Wilcoxon Signed Ranks Test). LSG resulted in a significantly more %loss in excessivebody weight(EBW) than BIB or LGB (Table 1). Stepwise multivariate linear regression revealedthat %lost in CRP was independently correlated to %loss of EBW(p = 0.01), treatment

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period (p = 0.026) and %loss in the waist to hip ratio (p = 0.047). Among them, % EBWloss accounted for the largest portion (28.4%) of CRP changes. Conclusions: For Chinese,a male diabetic patients with a high BMI is prone to have an increased CRP level. Reductionin the EBW, regardless of the mode of therapy, is the single most important factor toameliorate such a high CRP status.Outcomes of different weight reduction procedures for 90 Chinese obese patients

All values are expressed in median with inter-quartile range in parenthesis

M1251

Predictive Factors for Body Weight Control and Quality of Life in ObesePatients Treated with Endoscopic Bioenteric Intragastric BalloonEnders K. Ng, Bonnie Y. Tsung, Candice C. Lam, Man Yee Yung, Frances K. Cheung,Philip W. Chiu, Wilfred L. Mui

Background: Endoscopic placement of bioenteric intragastric balloon (BIB) is being advocatedas a non-invasive treatment option for obesity. However, its efficacy on weight control andquality of life have not been clearly defined. Methods: All patients undergoing endoscopicBIB placement between 2004 and 2007 in our unit were studied. Their baseline demographics,body weight, body mass index (BMI), fasting blood glucose, lipid profile and blood pressurewere measured. Quality of life (QoL) of these patients before and 6 months after BIB treatmentwas assessed with the standardized questionaire SF36 containing 8 domains of physical andemotional components. Percentage change in excess body weight (EBW: defined as actualbody weight - ideal body weight) by BIB therapy was analysed against the abovementionedvariables using regression model on an intention to treat basis. Results: A total of 160 obesepatients (45 men and 115 women) with a mean age (S.D.) of 38.2 (9.5) years had BIBtreatment during the 4 years period. 146 patients were able to complete the 6 months oftreatment but 14 patients had BIB removed prematurely due to intolerance. Multivariatelinear regression analysis revealed that a lower baseline BMI (R=0.5; p<0.001) and an olderage (R=0.53; p<0.001)were significantly associated with a better % loss in EBW. Quality oflife before the treatment, however, had no impact on the success or failure of the BIB therapy.Paired comparison on the baseline QoL with end of therapy QoL showed that all domainsexcept that for mental health in SF36 had improved significantly, and the improvementcorrelated well with %loss in EBW. Conclusions: Endoscopic BIB therapy is an effectivetreatment only for patients with mild obesity. Its efficacy is less obvious in the youngerpatient. Remarkable improvement in QoL is observed with successful weight control byBIB, but it does not translate to a better mental health in the patients.

M1252

Use of Pharmacotherapy for Long-Term Maintenance of Weight Loss FollowingExplantation of Intragastric BalloonEvzen Machytka, Pavel Klvana, Lada Hanuskova, Igor Janik

Introduction: The intragastric balloon (BIB) is an effective and safe method for treatingobesity at least from the short-term perspective of a few months, although the subsequentdevelopment in patients with regard to long-term maintenance of weight loss is currentlyuncertain. Most of the patients have previously undergone a few unsuccessful attempts toreduce their weight, including pharmacotherapy. Sibutramin is the most frequently usedmedication in pharmacotherapy for obesity, its major advantage being the long-term successin maintenance of weight loss confirmed by numerous studies. Objective: Use of pharmaco-therapy with Sibutramin following the B.I.B. explantation for long-term maintenance ofweight loss Methodology: A group of 25 patients with a history of failed therapy usingSibutramin. A six-month course of 10mg Sibutramin immediately after the BIB explantation.Comparison against a control group of 25 patients treated exclusively with BIB withoutthe subsequent pharmacotherapy. Results: The average weight loss following the B.I.B.explantation was 16.49+12,97 kg. Further weight loss on average by 2.36+1,97 kg wasdetected in patients treated with Sibutramin after 6 months and after further 6 months ofmonitoring the body weight only increased by 1.76+1,48 kg on average compared to theweight following explantation. The body weight in patients treated exclusively with B.I.B.increased on average by 5.21+2,83 kg 6 months after explantation and by 6.78+4,12 kgafter 1 year. The difference is statistically significant.p<0,001 Conclusion: Patients with ahistory of failed pharmacotherapy using Sibutramin whose weight has been successfullyreduced using the intragastric balloon method may benefit from the use of Sibutraminfollowing the BIB explantation and achieve long-term maintenance of weight loss. Thecombination of endoscopic and pharmacological therapy may become a suitable alternativefor treating obesity.

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