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The objective of this work is to develop and evaluate experimental approaches with different analytical techniques to measure the permeability, diffusivity, and solubility of water in model coatings. These properties are of primary relevance in studies of coatings for corrosion protection. For water permeation measurements, setups were designed and prepared to facilitate measurements by microcalorimetry, gravimetry, and thermogravimetric analysis. For sorption measurements, films were prepared in various thicknesses to allow a proper analysis with Fourier-transform infrared spectroscopy in transmission mode and gravimetry. Both methods are successful in following water uptake kinetic curves, being complementary in film thickness ranges that can be analyzed. The validity of the permeabilities calculated from permeation measurements is compared to results from group contribution methods and reported values in the literature. Diffusivities were determined using data from the transient region in sorption and permeation measurements, as well as from the steady-state permeation rate and equilibrium solubility in permeation and sorption measurements, respectively. [ABSTRACT FROM AUTHOR]

Summary: Background: Fibrotic stricture is a common complication of Crohn's disease (CD) affecting approximately half of all patients. No specific anti‐fibrotic therapies are available; however, several therapies are currently under evaluation. Drug development for the indication of stricturing CD is hampered by a lack of standardised definitions, diagnostic modalities, clinical trial eligibility criteria, endpoints and treatment targets in stricturing CD. Aim: To standardise definitions, diagnosis and treatment targets for anti‐fibrotic stricture therapies in Chron's disease. Methods: An interdisciplinary expert panel consisting of 15 gastroenterologists and radiologists was assembled. Using modified RAND/University of California Los Angeles appropriateness methodology, 109 candidate items derived from systematic review and expert opinion focusing on small intestinal strictures were anonymously rated as inappropriate, uncertain or appropriate. Survey results were discussed as a group before a second and third round of voting. Results: Fibrotic strictures are defined by the combination of luminal narrowing, wall thickening and pre‐stenotic dilation. Definitions of anastomotic (at site of prior intestinal resection with anastomosis) and naïve small bowel strictures were similar; however, there was uncertainty regarding wall thickness in anastomotic strictures. Magnetic resonance imaging is considered the optimal technique to define fibrotic strictures and assess response to therapy. Symptomatic strictures are defined by abdominal distension, cramping, dietary restrictions, nausea, vomiting, abdominal pain and post‐prandial abdominal pain. Need for intervention (endoscopic balloon dilation or surgery) within 24‐48 weeks is considered the appropriate endpoint in pharmacological trials. Conclusions: Consensus criteria for diagnosis and response to therapy in stricturing Crohn's disease should inform both clinical practice and trial design. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Surgery for ileal pouch–anal anastomosis (IPAA) has evolved over time, especially since the introduction of laparoscopy. The aim of this retrospective study was to report the impact of surgical evolution on outcome over a period of 25 years. Method: All patients who had IPAA surgery for ulcerative colitis from 1990 to 2015 at the University Hospitals of Leuven were included. Patients were divided into three period arms (period A 1990–1999; period B 2000–2009; period C 2010–2015). The main outcome measure was anastomotic leakage. Results: A total of 335 patients (58.8% male) with a median age of 39 years (interquartile range 32–49 years) at surgery were included. Median follow‐up was 5 years (interquartile range 2–10 years). Overall anastomotic leakage (grades A–C) was 14.9%. A significant decrease in leakage rate was observed over time (from 21.4% in period A to 12.1% in period B to 10.0% in period C; P = 0.04). The defunctioning ileostomy rate at the time of pouch construction decreased from 91.7% (period A) to 40.3% (period B) to 11.1% (period C) (P < 0.001). We observed an increase in the use of laparoscopy (23.9% in period A vs 72.6% in period B, vs 84.4% in period C; P = 0.001) and a shift to a modified two‐stage procedure (4.1% in period A, vs 66.7% in period C; P < 0.0001). In a monocentric study with some of the data retrieved retrospectively it was not possible to account for the impact of preoperative nutritional status (weight loss, serum albumin level) or disease burden. Other outcome factors were not measured, for example sexual function and fecundity. Conclusion: A higher rate of laparoscopic IPAA surgery, together with a shift towards modified two‐stage procedures, was associated with a lower leakage rate despite a reduction in the use of defunctioning ileostomy. [ABSTRACT FROM AUTHOR]

Summary: Background: The presence of antibodies towards infliximab (ATI) is associated with lower infliximab (IFX) trough concentrations and loss of response. IFX treatment intensification is effective for restoring response in most, but not all patients with Crohn's disease (CD). Aim: To compare outcome, pharmacokinetics and immunogenicity of treatment intensification strategies in patients with CD who lost clinical response to IFX. Methods: A retrospective cohort study was conducted, including 103 patients with CD who lost clinical response during IFX maintenance therapy and therefore received a double dose IFX (10 mg/kg) and/or a next infusion after a shortened interval. IFX and ATI concentrations were measured in consecutive trough samples, just before (T0) and after (T+1) treatment intensification. Results: Clinical response (physicians' global assessment) and biological response and remission (CRP) were restored in 63%, 42% and 24% of patients (evaluated at T+1). Treatment intensification increased IFX trough concentrations from 1.2 μg/mL [0.3‐3.6] at T0 to 3.6 μg/mL [0.5‐10.2] at T+1 (P < .0001). Using a drug tolerant assay, ATI were detected in the T0 sample of 47% of patients. ATI negatively impacted the achieved IFX trough concentration (Spearman r −0.57, P < .0001) and the probability of clinical response (P = 0.034) at T+1. When ATI were quantifiable but <282 ng/mL eq. at T0, combined interval shortening and dose doubling was more effective for restoring therapeutic IFX trough concentrations (≥3 μg/mL at T+1) than dose doubling alone, which in turn was more effective than interval shortening alone (P < .001). Conclusion: Antibodies towards infliximab can guide clinical decision‐making on treatment intensification. [ABSTRACT FROM AUTHOR]

Background Adalimumab is used to treat moderate to severe Crohn's disease ( CD) and ulcerative colitis ( UC) when conventional therapies fail. Aim To update long-term adalimumab safety from CD and UC trials; the previous report was CD only, 3160 patients/3402 patient-years ( PYs). Methods Treatment-emergent adverse events ( AEs; first dose to 70 days after last dose/December 31, 2015) in adults in phase 2/3 and 3/3b trials and open-label extensions were coded using Medical Dictionary for Regulatory Activities (Med DRA-v18.1). Rates were assessed as events/100 (E/100 PYs). Results The database (16 trials; CD, N = 3606; UC, N = 1739) represented 4145 and 3397 PYs of exposure, respectively. For CD, incidences of any AEs with adalimumab were 60.8%-65.1%, depending on dose, and 71.5% with placebo; for UC, the incidences were 53.5%-54.8% and 56.1%, respectively. Rates of any AEs ( CD, 605 E/100 PYs; UC, 361 E/100 PYs), serious AEs ( CD, 36.1 E/100 PYs; UC, 18.9 E/100 PYs), and malignancies ( CD, 1.2 E/100 PYs; UC, 1.0 E/100 PYs) were similar between current and prior analyses. Apparent rate of opportunistic infections was lowered to 0.3 and 0.2 E/100 PYs for CD and UC, respectively, by recent Med DRA changes excluding oral candidiasis and tuberculosis. Standardised incidence ratios for malignancies were similar to the general population ( CD, 1.45 [95% CI, 0.90-2.22]; UC, 1.36 [95% CI, 0.84-2.07]). Demyelinating disorders were uncommon ( CD, 0.1 E/100 PYs; UC, <0.1 E/100 PYs). Conclusions Patients with moderately to severely active Crohn's disease or ulcerative colitis continued to experience acceptable safety with adalimumab, without new safety signals. [ABSTRACT FROM AUTHOR]

Background Despite improvements in medical therapy, the majority of patients with Crohn's disease still require surgery. The aim of this study was to report safety, and clinical and surgical recurrence rates, including predictors of recurrence, after ileocaecal resection for Crohn's disease. Methods This was a cohort analysis of consecutive patients undergoing a first ileocaecal resection for Crohn's disease between 1998 and 2013 at one of two specialist centres. Anastomotic leak rate and associated risk factors were assessed. Kaplan-Meier estimates were used to describe long-term clinical and surgical recurrence. Univariable and multivariable regression analyses were performed to identify risk factors for both endpoints. Results In total, 538 patients underwent primary ileocaecal resection (40·0 per cent male; median age at surgery 31 (i.q.r. 24-42) years). Median follow-up was 6 (2-9) years. Fifteen of 507 patients (3·0 per cent) developed an anastomotic leak. An ASA fitness grade of III (odds ratio ( OR) 4·34, 95 per cent c.i. 1·12 to 16·77; P = 0·033), preoperative antitumour necrosis factor therapy ( OR 3·30, 1·09 to 9·99; P = 0·035) and length of resected bowel specimen ( OR 1·06, 1·03 to 1·09; P < 0·001) were significant risk factors for anastomotic leak. Rates of clinical recurrence were 17·6, 45·4 and 55·0 per cent after 1, 5 and 10 years respectively. Corresponding rates of requirement for further surgery were 0·6, 6·5 and 19·1 per cent. Smoking (hazard ratio ( HR) 1·67, 95 per cent c.i. 1·14 to 2·43; P = 0·008) and a positive microscopic resection margin ( HR 2·16, 1·46 to 3·21; P < 0·001) were independent risk factors for clinical recurrence. Microscopic resection margin positivity was also a risk factor for further surgery ( HR 2·99, 1·36 to 6·54; P = 0·006). Conclusion Ileocaecal resection achieved durable medium-term remission, but smoking and resection margin positivity were risk factors for recurrence. [ABSTRACT FROM AUTHOR]

Background Data on dose de-escalation in patients with Crohn's disease (CD) are limited. Aim To evaluate outcomes of dose de-escalation from adalimumab (ADM) every other week (EOW) to every three weeks (ETW). Methods We selected patients with CD receiving maintenance therapy with ADM 40 mg ETW with serum levels (SL) available before and after dose de-escalation. Sex- and age-matched controls continuing ADM 40 mg EOW were identified. Patient reported outcome, C-reactive protein (CRP) and serum albumin were collected. Results Out of 898 patients, we identified 40 (11 male, median 37 years) who de-escalated to ADM 40 mg ETW for ADM-related adverse events (AE, n = 1), ADM SL >7 μg/mL ( n = 8), or both ( n = 31). Compared to controls, ADM SL dropped significantly within 4 months, without associated clinical or biochemical changes. In 53% of patients, dose de-escalation was associated with disappearance of AE (8/16 skin manifestation, 3/6 arthralgia, 5/7 frequent infectious episodes). During a median follow-up of 24 months, 65% of patients maintained clinical response, but 35% needed dose escalation back to ADM 40 mg EOW because of clinical relapse ( n = 8), ADM SL <4 μg/mL ( n = 2), or both ( n = 4). CRP <3.5 mg/L at dose de-escalation was independently associated with dose escalation-free survival [odds ratio 6.28 (95% CI 1.83-21.59), P = 0.004]. We could not define a minimal ADM SL to consider or maintain dose de-escalation. Conclusions Overall, 65% of patients who de-escalated to adalimumab 40 mg every 3 weeks remained in clinical remission for a median of 24 months. In 53% of patients, adalimumab-related adverse events disappeared after dose de-escalation. Regardless of adalimumab SL, disease remission should be assessed objectively prior to dose de-escalation. [ABSTRACT FROM AUTHOR]

Background The long-term efficacy of infliximab in patients with Crohn's disease is suboptimal. Aim To study prognostic factors for real-life long-term effcacy of infliximab in Crohn's disease. Methods All consecutive Crohn's disease patients treated with infliximab at a tertiary centre were retrospectively analysed. Only patients who received scheduled infliximab maintenance treatment were considered. Patient- and disease-related factors were used to identify independent predictors of infliximab failure-free survival using Cox proportional hazards regression. Results Of 1031 patients with Crohn's disease, 261 were eligible for inclusion. Median time on infliximab was 2.4 [ IQR 1.4-4.7] years, and 65 (24.9%) patients experienced infliximab failure. Estimated 5-year infliximab failure-free survival was 65.9% (95% CI 58.3-73.5). Multivariate Cox regression identified disease duration ≥1 year ( HR 2.5 (95% CI 1.2-5.2), P = 0.02), L1 disease location [ HR 2.0 (1.1-3.5), P = 0.02], prior anti- TNF use [ HR 2.3 (1.1-4.8), P = 0.03], haemoglobin <13.5 g/dL [ HR 2.3 (1.2-4.4), P = 0.02], not using therapeutic drug monitoring [ HR 8.0 (4.1-15.6), P = 1 × 10−9], and first dose optimisation within first year [ HR 3.7 (2.1-6.6), P = 5 × 10−6] as independent predictors of infliximab failure-free survival. Stratifying patients into risk groups resulted in estimated 3-year infliximab failure-free survival rates ranging from 95.3% (94.2-96.4) to 26.3% (8.6-44.0) depending on the number of risk factors ( P = 8 × 10−13). Conclusions This study identified several easy to obtain predictors of infliximab failure in patients with Crohn's disease, and these are in line with previous reports. Those with a high-risk profile for infliximab failure in whom infliximab initiation is considered, should be treated as early as possible making use of therapeutic drug monitoring. [ABSTRACT FROM AUTHOR]

Background The detrimental effect of smoking on development and progression of Crohn's disease ( CD) is generally accepted. Aim To evaluate the awareness of smoking risks in a Belgian inflammatory bowel disease ( IBD) population. Methods In the out-patient clinic of a tertiary referral centre, 625 consecutive patients with CD, 238 patients with ulcerative colitis ( UC) and 289 non- IBD controls, filled out a simple questionnaire. This questionnaire included data on smoking behaviour and awareness of smoking-related health effects, including effects on IBD. Results At diagnosis, more CD patients were active smokers compared to UC (40% vs. 17%, P < 0.001). Remarkably, smoking cessation rates after diagnosis were similar for CD and UC (both 56%, P = 0.997). The great majority recognised a detrimental influence of smoking on general health (98-99%), lung cancer (95-97%), myocardial infarction (89-92%) and stroke (78-87%). Although CD patients more frequently acknowledged risks of smoking on their disease, only 37% were aware of a link with CD development, 30% of increased surgical rates and 27% of increased post-operative CD recurrence. Active smokers more frequently denied an increased risk of surgery and higher post-operative CD recurrence. Intriguingly, within the active smokers with CD, those not willing to quit smoking most often denied a potential bad influence of smoking. Taking into account disease duration, previous surgery, education level, working status and nicotine dependence, we were unable to define specific subgroups of patients requiring extra education. Conclusion Although patients with Crohn's disease were better informed on the detrimental effects of smoking, the awareness rate was still low. [ABSTRACT FROM AUTHOR]

Background The general increased life expectancy is reflected in the age of patients with inflammatory bowel disease ( IBD). The knowledge about efficacy and safety of anti-tumour necrosis factor ( TNF) therapy in elderly is scarce and conflicting. Aim To assess the efficacy and safety of anti- TNF therapy in elderly patients taking into account eventual comorbidity. Methods Observational and retrospective single-centred study where 66 IBD patients initiating anti- TNF treatment at age ≥65 years (cases: ≥65 anti- TNF) were compared with 112 IBD patients initiating anti- TNF <65 years (controls <65 anti- TNF) and 61 anti- TNF naïve IBD patients treated with immunosuppressants ( IMS) and/or corticosteroids ( CS) ≥65 years (controls ≥65 IMS/ CS). Controls were matched to cases for IBD type, follow-up, disease duration and anti- TNF type. Comorbidity was assessed by using the Charlson Comorbidity Index ( CCI). Both efficacy and safety of treatment were adjusted for comorbidity. Results The short-term clinical response to anti- TNF at 10 weeks was significantly lower in cases: ≥65 anti- TNF (68% vs. 89%; P < 0.001), whereas at ≥6 months, differences were not significant (79.5% vs. 82.8%; P = 0.639). The risk for any severe adverse events was higher in cases: ≥65 anti- TNF than in controls <65 anti- TNF ( RR = 4.7; P < 0.001) or controls ≥65 IMS/ CS ( RR = 3.09; P = 0.0008). Age older than 65 and CCI > 0 were independent risk factors for malignancy and mortality regardless of the medication. Conclusion Elderly patients treated with anti- TNF have a lower rate of short-term clinical response and a higher rate of severe adverse events than the younger patients under the same treatment. [ABSTRACT FROM AUTHOR]

Background Data for adalimumab in ulcerative colitis after prior use of infliximab are scarce. Aims To study adalimumab response rates and predictors of response in ulcerative colitis, including drug concentrations. Methods In this single centre cohort study 73 UC patients, previously exposed to infliximab, were assessed for response to adalimumab at weeks 12 and 52. Serum samples prior to week 12 were available and included in multivariate analysis to predict response. Results Overall clinical response at week 12 and 52 were 75% and 52%, respectively. Adalimumab was continued without need for dose escalation throughout year 1 in 16 patients, 22 needed dose escalation and 35 discontinued treatment within 1 year. Prior response to infliximab and early serum concentrations correlated with response. Receiver operator characteristic curve analysis yielded optimal adalimumab concentrations of 4.58 μg/mL for week 12 and 7.0 μg/mL for week 52. Independent predictors for response at week 12 were primary response to infliximab [odds ratio (OR) 8.33; 95% confidence interval (CI) 1.8-33.3; P = 0.006] and an adalimumab concentration ≥4.58 μg/mL at week 4 (OR 4.85; 95% CI 1.3-18.6; P = 0.009). Positive predictors for week 52 response were primary response to infliximab (OR 5.2; 95% CI 1.14-23.8; P = 0.034) and adalimumab concentration at week 4 of ≥7 μg/mL (OR 3.56; 95% CI 1.17-10.79; P = 0.025). Conclusion Prior response to infliximab and high early adalimumab serum concentrations predict week 12 and year 1 responses to adalimumab in ulcerative colitis. [ABSTRACT FROM AUTHOR]

Background Patients with moderately to severely active ulcerative colitis occasionally do not respond to or lose initial response to maintenance dosing of anti- TNF therapy. Aim To report the efficacy of escalation from every other week ( EOW) to weekly adalimumab dosing in patients from the clinical trial ULTRA 2 ( NCT00408629), by week 8 response (i.e. response after adalimumab induction therapy). Methods Week 52 remission, response, and mucosal healing rates were assessed in ULTRA 2 adalimumab-randomised patients who escalated to weekly dosing. Patients were stratified by week 8 response per partial Mayo score. Kaplan-Meier and logistic regression analyses estimated time to weekly dosing and defined predictors of escalation to weekly dosing, respectively. Adverse events were reported for patients receiving open-label adalimumab. Results The rate of escalation to weekly dosing was 16.3% (20/123) for week 8 responders and 38.4% (48/125) for week 8 nonresponders. Week 52 remission, response and mucosal healing rates with weekly dosing were 20%, 45%, and 45% for week 8 responders and 2.1%, 25% and 29.2% for nonresponders, respectively ( NRI). The median time to weekly dosing was 288 days for week 8 nonresponders and not estimable for responders. Prior anti- TNF use was a significant predictor of escalation to weekly dosing. Treatment-emergent adverse event rates were similar for patients receiving open-label EOW or weekly adalimumab. Conclusions Escalation to weekly adalimumab dosing demonstrated clinical benefits for patients who lost response to therapy and may be beneficial for patients not initially responding to induction therapy. No new safety risks were identified with weekly dosing. [ABSTRACT FROM AUTHOR]

Background Tumour necrosis factor ( TNF)-antagonists have an established role in the treatment of inflammatory bowel diseases ( IBDs), however, subtherapeutic drug levels and the formation of anti-drug antibodies ( ADAs) may decrease their efficacy. Aim The evidence supporting the use of therapeutic drug monitoring ( TDM) based clinical algorithms for infliximab ( IFX) and their role in clinical practice will be discussed. Methods The literature was reviewed to identify relevant articles on the measurement of IFX levels and antibodies-to-infliximab. Results Treatment algorithms for IBD have evolved from episodic monotherapy used in patients refractory to all other treatments, to long-term combination therapy initiated early in the disease course. Improved remission rates have been observed with this paradigm shift, nevertheless many patients ultimately lose response to therapy. Although empiric dose optimization or switching agents constitute the current standard of care for secondary failure, these interventions have not been applied in an evidence-based manner and are probably not cost-effective. Multiple TDM-based algorithms have been developed to identify patients that may benefit from measurement of IFX and ADA levels to guide adjustments to therapy. Conclusions Therapeutic drug monitoring offers a rational approach to the management of secondary failure to IFX. This concept has gained momentum based on evidence from case series, cohort studies and post-hoc analyses of randomised controlled trials. [ABSTRACT FROM AUTHOR]

Background Patients with moderately-to-severely active ulcerative colitis ( UC) are unlikely to continue anti- TNF therapy in the absence of early therapeutic response. Aim To assess week 52 efficacy, safety and benefit/risk balance of adalimumab treatment in patients with moderately-to-severely active UC failing conventional therapy who achieved clinical response at week 8 in the 52-week ULTRA 2 trial. Methods Patients randomised to adalimumab (160/80 mg, week 0/2; 40 mg, every other week thereafter) in ULTRA 2 who achieved clinical response at week 8 per partial Mayo score (Mayo score without endoscopy subscore) were assessed for week 52 clinical remission, clinical response, mucosal healing, steroid-free remission and steroid discontinuation rates, overall and by prior anti- TNF use. Benefit/risk balance for the overall ITT population (regardless of week 8 responder status) was assessed using 'net efficacy adjusted for risk' ( NEAR) odds ratios. Safety was assessed using adverse event rates. Results Of 248 adalimumab-treated patients, 123 (49.6%) achieved clinical response at week 8. Of these, 30.9%, 49.6%, and 43.1% achieved clinical remission, clinical response, and mucosal healing, respectively, at week 52. Of the week 8 responders using corticosteroids at baseline ( N = 90), 21.1% achieved steroid-free remission and 37.8% were steroid-free at week 52. NEAR odds ratios indicated a positive benefit/risk balance for achievement of week 8 and week 52 response or remission without serious adverse events or serious infections. No safety concerns were identified. Conclusions Adalimumab treatment was associated with a positive benefit/risk balance in the overall population of patients with moderately-to-severely active ulcerative colitis in ULTRA 2; early response was predictive of a positive outcome at 1 year (NCT00408629). [ABSTRACT FROM AUTHOR]

Aim Diarrhoea with urgency is a debilitating long-term complication of ileal pouch anal anastomosis (IPAA) after a proctocolectomy. Somatostatin analogues are used to control diarrhoea and high-output ostomies. Hence, we designed a prospective, double-blind, crossover trial to explore the efficacy and tolerability of octreotide to reduce diarrhoea in adult patients with IPAA. Method Patients were randomized to octreotide subcutaneously (SC), 500 μg three times daily (t.i.d.), or matching placebo SC for 7 days. Responders (a reduction in stool frequency of three or more stools per 24-h period and with a reduction in stool frequency of at least 30% after 7 days of treatment compared with baseline; the primary end-point) remained in the same group and nonresponders could cross over to the alternative treatment for 7 days. Open-label octeotide LAR 30 mg was offered to all responders on day 14. Flexible pouchoscopy with biopsies was performed at baseline in all patients and was repeated on days 7 and 14 in patients with pouchitis. Results Fifteen patients (11 men, median age 52 years), all with ulcerative colitis, were randomized. Three patients were withdrawn for side effects during the blinded phase. Response was achieved by two of 12 and two of 11 patients treated with octreotide or placebo, respectively (including crossover, P = 0.9). The median stool frequency remained stable in both groups [Δoctreotide: 0 (IQR, −4 to 0), Δplacebo: −1 (IQR, −1 to 1), P = 0.45]. Octreotide had no effect on the modified pouch disease activity index (mPDAI), and pouchitis persisted in five of six subjects with pouchitis at onset. One subject received open-label octreotide LAR. Conclusion Octreotide has no clear beneficial effect on the stool pattern or on pouchitis severity in patients with high stool frequency after IPAA. [ABSTRACT FROM AUTHOR]

While some probiotic strains might have adjuvant effects in the therapy for inflammatory bowel diseases (IBD), these effects remain controversial and cannot be generalized. In this study, a dltD mutant of the model probiotic Lactobacillus rhamnosus GG (LGG), having a drastic modification in its lipoteichoic acid (LTA) molecules, was analysed for its effects in an experimental colitis model. Dextran sulphate sodium (DSS) was used to induce either moderate to severe or mild chronic colitis in mice. Mice received either phosphate-buffered saline (PBS), LGG wild-type or the dltD mutant via the drinking water. Macroscopic parameters, histological abnormalities, cytokine and Toll-like receptor (TLR) expression were analysed to assess disease activity. LGG wild-type did not show efficacy in the different experimental colitis set-ups. This wild-type strain even seemed to exacerbate the severity of colitic parameters in the moderate to severe colitis model compared to untreated mice. In contrast, mice treated with the dltD mutant showed an improvement of some colitic parameters compared to LGG wild-type-treated mice in both experimental models. In addition, treatment with the dltD mutant correlated with a significant down-regulation of Toll-like receptor-2 expression and of downstream proinflammatory cytokine expression in the colitic mice. These results show that molecular cell surface characteristics of probiotics are crucial when probiotics are considered for use as supporting therapy in IBD. [ABSTRACT FROM AUTHOR]

Background Endoscopic dilatation of Crohn's diseaserelated strictures is an alternative to surgical resection in selected patients. The influence of disease activity and concomitant medical therapy on long-term outcomes is largely unknown. Aim and methods To study the long-term safety and efficacy of stricture dilatation in a single centre cohort. Results Between 1995 and 2006, 237 dilatations where performed in 138 patients (mean age 50.6613.4, 56% female) for a clinically obstructive stricture (<5 cm, 84% anastomotic). Immediate success of a first dilatation was 97% with a 5% serious complication rate. After a median follow-up of 5.8 years (IQR 3.0e8.4), recurrent obstructive symptoms led to a new dilatation in 46% or surgery in 24%. Niether elevated levels of C-reactive protein nor endoscopic disease activity predicted the need for new intervention. None of the concomitant therapies influenced the outcome. Conclusion This largest series ever reported confirms that long term efficacy of endoscopic dilatation of Crohn's disease outweighs the complication risk. Neither active disease at the time of dilatation nor medical therapy afterwards predict recurrent dilatation or surgery. [ABSTRACT FROM AUTHOR]

Background Adalimumab (ADA) and certolizumab pegol (CZP) have demonstrated efficacy in Crohn’s disease (CD) patients previously treated with infliximab (IFX). Aim To assess the efficacy and tolerability of a third anti-TNF in CD after failure of and/or intolerance to two different anti-TNF antibodies. Methods Crohn’s disease patients who received ADA or CZP after loss of response and/or intolerance to two anti-TNF agent were included in this retrospective study. Data were collected using a standardized questionnaire. Clinical response, duration, safety and reasons for discontinuation were assessed. Results Sixty-seven patients treated with CZP ( n = 40) or ADA ( n = 27) were included. A clinical response was observed in 41 (61%) at week 6 and 34 patients (51%) at week 20. The probability of remaining under treatment at 3 months, 6 months and 9 months was 68%, 60% and 45%, respectively. At the end of follow-up, the third anti-TNF had been stopped in 36 patients for intolerance ( n = 13), or failure ( n = 23). Two deaths were observed. Conclusions The treatment with a third anti-TNF (CZP or ADA) agent of CD patients, who have experienced loss of response and/or intolerance to two anti-TNF antibodies, has favourable short-term and long-term efficacy. It is an option to be considered in patients with no other therapeutic options. [ABSTRACT FROM AUTHOR]

The article discusses a study which examines the outcome of surgery for symptomatic Crohn's rectovaginal fistula (RVF) and the effect of therapy with antibody against tumour necrosis factor (TNF) on healing. The study shows that most patients achieve fistula closure but require more than one operation. It notes that 81 per cent of 52 patients achieve fistula closure and 56 per cent attain primary surgical success rate while 57 per cent achieve secondary surgical success rate.

Background and aims: This study evaluates the long-term safety of infliximab in patients with inflammatory bowel disease (IBD) treated with the drug over a 14-year period. Methods: The medical records of 734 patients with IBD treated with infliximab and 666 control patients not treated with infliximab were reviewed for adverse events. The time of onset and outcome, severity and concomitant medication were recorded. Results: Patients and controls were followed up for serious adverse events for a median time of 58 months (IQR 33-88) and 144 months (IQR 83-163), respectively. 112 severe adverse events occurred in 93 patients (13%) treated with infliximab and 157 occurred in 126 (19%) control patients (OR 1.33 (95% CI 0.56 to 3.00, p = 0.45). There was no difference between the two groups in mortality, malignancies and infection rate. Tuberculosis was diagnosed in two patients receiving infliximab who had negative skin tests at baseline whereas none of 16 patients with positive skin tests who received prophylaxis developed tuberculosis. Concomitant treatment with steroids was the only independent risk factor for infections in patients treated with infliximab (OR 2.69 (95% CI 1.18 to 6.12), p = 0.018). The most commonly observed systemic side effects were skin eruptions including psoriasiform eruptions in 150 patients (20%). Conclusions: Long-term infliximab treatment had a good overall safety profile in the patient cohort studied. [ABSTRACT FROM AUTHOR]

Background and aims: This observational study assessed the long-term clinical benefit of infliximab (IFX) in 614 consecutive patients with Crohn's disease (CD) from a single centre during a median follow-up of 55 months (interquartile range (IQR) 27-83). Methods: The primary analysis looked at the proportion of patients with initial response to IFX who had sustained clinical benefit at the end of follow-up. The long-term effects of IFX on the course of CD as reflected by the rate of surgery and hospitalisations and need for corticosteroids were also analysed. Results: 10.9% of patients were primary non-responders to IFX. Sustained benefit was observed in 347 of the 547 patients (63.4%) receiving long-term treatment. In 68.3% of these, treatment with IFX was ongoing and in 31.7% IFX was stopped, with the patient being in remission. Seventy patients (12.8%) had to stop IFX due to side effects and 118 (21.6%) due to loss of response. Although the yearly drop-out rates of IFX in patients with episodic (10.7%) and scheduled treatment (7.1%) were similar, the need for hospitalisations and surgery decreased less in the episodic than in the scheduled group. Steroid discontinuation also occurred in a higher proportion of patients in the scheduled group than in the episodic group. Conclusions: In this large real-life cohort of patients with CD, long-term treatment with IFX was very efficacious to maintain improvement during a median follow-up of almost 5 years and changed disease outcome by decreasing the rate of hospitalisations and surgery. [ABSTRACT FROM AUTHOR]

A newly developed hyphenated technique is presented combining an existing rheometer and differential scanning calorimeter into a single experimental setup. Through the development of a fixation accessory for differential scanning calorimeter (DSC) crucibles and a novel rotor, the simultaneous measurement is performed inside the well-controlled thermal environment of a Tzero™ DSC cell. Hence, the evolution of thermal and flow properties of a material can be simultaneously measured using steady or oscillatory shear measurements and regular or modulated temperature DSC measurements. Along with the construction of a prototype, a validation of the design was performed. The technique offers interesting opportunities for the investigation of flow-induced transitions, for instance, crystallization or phase separation, and provides an asset for high-throughput screening of materials. The potential of the novel technique is demonstrated by two case studies: the chemorheology during the cure of a thermosetting epoxy-amine system and the flow-induced crystallization of syndiotactic polypropylene. [ABSTRACT FROM AUTHOR]

Background The natural course of Crohn's disease is characterized by flare-ups altered with periods of remission. The majority of Crohn's disease patients need surgery within 10 years of diagnosis. Major advances in treatment options over the past years have made our treatment goals more ambitious and modification of the natural course has become the ultimate endpoint. Aim To review the evidence of existing therapies for Crohn's disease for changing the natural history. Methods A Medline search was undertaken by using ‘natural history’, ‘Crohn's disease’, ‘therapy’ (corticosteroids, azathioprine, methotrexate, infliximab and enteral feeding), ‘surgery’, ‘hospitalizations’ and ‘mucosal healing’. Results Corticosteroids do not alter the disease course and maintenance therapy with corticosteroids should be avoided given their side effects. The immunomodulators azathioprine and methotrexate heal the mucosa but their onset of action is slow. Infliximab therapy introduces rapid mucosal healing and is associated with decreased hospitalizations and surgical interventions. Despite the fact that immunomodulators and infliximab are effective in maintaining clinical and endoscopic remission, there is little hard evidence at present that these therapies alter the natural history of the disease. The main reason being the fact that these therapies have so far been used only in refractory patients and that early initiation in the right patient is crucial in order to change the disease course. Conclusion Prospective studies should validate predictors of complicated disease and randomized studies in high-risk groups should be performed to answer if early introduction of immunomodulators or biological therapies slows down disease progression and alters natural history. [ABSTRACT FROM AUTHOR]

Background: An uncontrolled pilot study demonstrated that daclizumab, a humanised monoclonal antibody to the interleukin 2 receptor (CD25), might be effective for the treatment of active ulcerative colitis. Methods: A randomised, double blind, placebo controlled trial was conducted to evaluate the efficacy of daclizumab induction therapy in patients with active ulcerative colitis. A total of 159 patients with moderate ulcerative colitis were randomised to receive induction therapy with daclizumab 1 mg/kg intravenously at weeks 0 and 4, or 2 mg/kg intravenously at weeks 0, 2, 4, and 6, or placebo. The primary end point was induction of remission at week 8. Remission was defined as a Mayo score of 0 on both endoscopy and rectal bleeding components and a score of 0 or 1 on stool frequency and physician's global assessment components. Response was defined as a decrease from baseline in the Mayo score of at least 3 points. Results: Two per cent of patients receiving daclizumab 1 mg/kg (p = 0.11 v placebo) and 7% of patients receiving 2 mg/kg (p=0.73) were in remission at week 8, compared with 10% of those who received placebo. Response occurred at week 8 in 25% of patients receiving daclizumab 1 mg/kg (p=0.04) and in 33% of patients receiving 2 mg/kg (p=0.30) versus 44% of those receiving placebo. Daclizumab was well tolerated. The most frequently reported adverse events in daclizumab treated patients compared with placebo treated patients were nasopharyngitis (14.6%) and pyrexia (10.7%). Conclusion: Patients with moderate ulcerative colitis who are treated with daclizumab are not more likely to be in remission or response at eight weeks than patients treated with placebo. [ABSTRACT FROM AUTHOR]

Introduction: Interferon γ is a potent proinflammatory cytokine implicated in the inflammation of Crohn's disease (CD). We evaluated the safety and efficacy of fontolizumab, a humanised anti-interferon γ antibody, in patients with moderate to severe CD. Methods: A total of 133 patients with Crohn's disease activity index (CDAI) scores between 250 and 450, inclusive, were randomised to receive placebo or fontolizumab 4 or 10 mg/kg. Forty two patients received one dose and 91 patients received two doses on days 0 and 28. Investigators and patients were unaware of assignment. Study end points were safety, clinical response (decrease in CDAI of 100 points or more), and remission (CDAI ⩽ 150). Results: There was no statistically significant difference in the primary end point of the study (clinical response) between the fontolizumab and placebo groups alter a single dose at day 28. However, patients receiving two doses of fontolizumab demonstrated doubling in response rate at day 56 compared with placebo: 32% (9/28) versus 69% (22/32, p=0.02) and 67% (21/31, p=0.03) for the placebo, and 4 and 10 mg/kg fontolizumab groups, respectively. Stratification according to elevated baseline C reactive protein levels resulted in a decreased placebo response and pronounced differences in clinical benefit. Two grade 3 adverse events were reported and were considered to be related to CD. One death (during sleep) and one serious adverse event (an elective hospitalisation) occurred, both considered unrelated. Conclusion: Treating active CD with fontolizumab was well tolerated and resulted in increased rates of clinical response and remission compared with placebo. [ABSTRACT FROM AUTHOR]

Introduction: This study was designed to evaluate the safety of fontolizumab, a humanised anti-interferon y antibody, in patients with moderate to severe Crohn's disease (CD). Patients and methods: Forty five patients with a CD activity index (CDAI) of 250-450 were randomised in a double blind, placebo controlled, dose escalating fashion to receive single doses of fontolizumab (0.1, 1.0, and 4.0 mg/kg) or placebo. By day 29, patients with clinical response were re-randomised to receive three additional doses of one half their initial fontolizumab dose or placebo at four weekly intervals. Primary objectives were safety and tolerability. Secondary outcomes included assessments of immunogenicity, clinical activity, and potential pharmacodynamic surrogates. Results: Treatment was generally well tolerated. There were slightly more reports of chills, flu-like syndrome, asthenia, nausea, and vomiting in the 1.0 mg and 4.0 mg/kg fontolizumab cohorts. Two serious adverse events rated as worsening of CD occurred under fontolizumab. Antibodies to fontolizumab were confirmed in one patient. No differences in clinical activity parameters were noted between any of the active treatment groups and placebo, with the placebo group having a particularly favourable outcome (60% response and 40% remission). By day 29, a more enhanced decrease in median Crohn's disease endoscopic index of severity (p=0.02) and serum C reactive protein (p<0.001) was observed in the 4.0 mg/kg (n = 14) fontolizumab cohort compared with placebo (n = 10). Pharmacodynamic effects were observed by immunohistochemistry. Conclusions: Fontolizumab was well tolerated with minimal immunogenicity at doses of up to 4.0 mg/kg in patients with CD. A biological activity of fontolizumab is suggested. [ABSTRACT FROM AUTHOR]

Laboratory markers have been investigated in inflammatory bowel disease (IBD) for diagnostic and differential diagnostic purposes, for assessment of disease activity and risk of complications, for prediction of relapse, and for monitoring the effect of therapy. The introduction of biological therapies in IBD has renewed interest in inflammatory markers (especially C reactive protein (CRP)), given their potential to select responders to these treatments. Of all the laboratory markers, CRP is the most studied and has been shown to have the best overall performance. CRP is an objective marker of inflammation and correlates well with disease activity in Crohn's disease (CD). Increased CRP levels are associated with better response rates and normal CRP levels predict high placebo response rates in clinical trials with biologicals. However, despite the advantages of CRP over other markers, it is still far from ideal. Furthermore, CRP correlates less well with disease activity in patients with ulcerative colitis (UC) as compared with CD. Other laboratory markers, including erythrocyte sedimentation rate (ESR), leucocyte and platelet count, albumin, and α1 acid glycoprotein (orosomucoid), have been studied either less extensively in IBD or have proven to be less useful than CRP. Faecal markers seem promising and may be more specific in detecting gut inflammation in patients with established IBD. Promising results have been reported with the use of faecal calprotectin in CD as well as in UC. Recent data however suggest that the performance of the faecal calprotectin test is superior for UC than for CD. Taken together, laboratory markers are useful and should be part of the global management of our IBD patients. They are however not magic and until more data become available, the use of CRP and other laboratory markers should be seen as an additive tool to clinical observation and physical examination rather than a replacement. [ABSTRACT FROM AUTHOR]

4-1BB ligand (4-1BBL) expressed on antigen-presenting cells interacts with 4-1BB on activated T cells (especially CD8+ cells) and co-stimulates the latter to secrete cytokines and to proliferate. The role of 4-1BB−4-1BBL interaction was studied here in a model of colitis based on naive CD4+ T cell transfer to SCID mice, a disease model in which CD8 cells do not take part. We found that CD4+ T cells from 4-1BB-deficient mice, after transfer in SCID mice, proliferated more rapidly compared to wild-type CD4+ T cells. Mice reconstituted with naive CD4+ T cells from 4-1BB-deficient mice developed colitis, however, with a mixed Th1/Th2 response, in contrast to the Th1-type response in mice reconstituted with wild-type naive CD4+ T cells. Importantly, this altered cytokine response did not temper colitis severity. Although it has been reported previously that 4-1BB co-stimulation may contribute to regulatory T cell functioning, we found that CD4+CD25+ regulatory T cells from 4-1BB-deficient mice were perfectly able to prevent naive CD4+ T cell-induced colitis. In conclusion, our data provide evidence that 4-1BB−4-1BBL interaction modulates the effector CD4+ T cell-driven immune response and cytokine production in experimental colitis without affecting regulatory T cell function. [ABSTRACT FROM AUTHOR]

Major depressive disorder is the most common psychiatric diagnosis in Crohn's disease. In other chronic diseases, evidence suggests that depression influences the course of the disease. Strong evidence of such a mediating role of major depressive disorder in Crohn's disease has never been found. To assess the relationship between major depressive disorder and outcome of treatment of luminal Crohn's disease with infliximab. In this prospective study, 100 consecutive unselected patients underwent assessment of psychosocial, demographical disease-related biological and clinical parameters at baseline and at 4 weeks after infliximab. Major depressive disorder was diagnosed using the Patient Health Questionnaire. Subsequently, the patients were followed up clinically until the next flare or during 9 months. The Crohn's disease responded in 75% of the patients, and remission was achieved in 60%. The presence of major depressive disorder at baseline predicted a lower remission rate (OR = 0.166, 95% CI = 0.049–0.567, P = 0.004). At follow-up, 88% of the patients needed retreatment. At univariate regression analysis, major depressive disorder significantly decreased time to retreatment ( P = 0.001). Multivariate Cox regression confirmed major depressive disorder as an independent determinant of active disease both at baseline and at re-evaluation (hazard ratio = 2.271, 95% CI: 1.36–3.79, P = 0.002). Major depressive disorder is a risk factor for failure to achieve remission with infliximab and for earlier retreatment in patients with active luminal Crohn's disease. Assessment and management of major depressive disorder should be part of the clinical approach to patients with Crohn's disease. [ABSTRACT FROM AUTHOR]

Introduction: Crohn's disease is a chronic inflammatory disorder of the gut. It is assumed that a defective interaction between the bacterial flora of the gut and the innate immune system plays a key role in the pathogenesis of the disease. This may lead to specific histological lesions. The epithelioid granuloma is particularly interesting in this regard as it is also observed in several bacterial infections of the gut. Aims and methods: We hypothesised that genetic or environmental factors with a known influence on inflammation or immunity would lead to an increased prevalence of granulomas. Therefore, surgical specimens from 161 patients were evaluated for the presence of granulomas. Patients were genotyped for the three single nucleotide polymorphisms in caspase recruitment domain 15 (CARD15)/NOD2 associated with CD and for Asp299Gly in Toll-like receptor 4 (TLR4). Results: The overall prevalence of granulomas was 68.9%. We did not find a significant correlation between granulomas and TLR4 or CAROl 5 variants. The frequency of granulomas increased with more distal disease (63% small bowel, 72% right colon, 88% left colon, 90% rectum; p =0.01). Granulomas were more frequent in younger patients (odds ratio 0.95 (95% confidence interval 0.92-0.98) p =0.007). Conclusion: In this study of 161 well documented CD patients, we found no significant association between CARD 15 and TLR4 variants and granulomas. This finding seems to refute our initial hypothesis. However, it may be that additional factors are needed for granuloma development. Granulomas may develop only when specific bacterial components are present. Therefore, future research on granuloma pathogenesis should be orientated towards detection and identification of bacterial components in these lesions. [ABSTRACT FROM AUTHOR]

: By temporarily suppressing the immune response, the anti-tumour necrosis factor agent, infliximab, may increase the risk of peri-operative complications. : To test this hypothesis for intestinal resection in a cohort of 313 Crohn's disease patients treated with infliximab. Forty received one or more infusions prior to intestinal resection (31/40 within 12 weeks). : The post-operative events of these patients were compared with those of a control group (infliximab naive) of 39 patients adjusted for age, gender and surgical procedure. Early (10 days) and late (3 months) major or minor complications were identified. : The incidence of early minor (15.0% vs. 12.8%) and major (12.5% vs. 7.7%) and late minor (2.5% vs. 5.1%) and major (17.5% vs. 12.8%) complications and the mean hospital stay after surgery (10.3 ± 4.0 days vs. 9.9 ± 5.5 days) were similar in both groups. A trend towards an increased early infection rate was found in infliximab pre-treated patients (6 vs. 1; P = 0.10), but more patients in this group received corticosteroids and/or immunosuppressives (29 vs. 16 patients; P < 0.05). : The use of infliximab before intestinal resection does not prolong the hospital stay and does not increase the rate of post-operative complications. [ABSTRACT FROM AUTHOR]

An imbalance of immunoregulatory factors and/or cells contributes to uncontrolled mucosal T cell activation and inflammation in Crohn's disease (CD). Bioactive interleukin (IL)-18 has been shown to be produced by macrophages in CD lesions. We report here that T cells freshly isolated from inflamed tissue of CD patients (and not T cells from control intestinal tissue) were responsive to IL-18. In the presence of IL-18, these T cells produced more interferon (IFN)- γ and less IL-10. To analyse further the role of IL-18 in this disease, an acute and a chronic model of murine colitis were used. IL-18 mRNA was significantly enhanced in trinitrobenzene sulphonic acid (TNBS) induced colitis, and treatment with IL-18 binding protein (IL-18BPa), which neutralizes IL-18 bioactivity, significantly reduced the severity of colitis. However, IL-18BPa did not affect the course of chronic colitis in CD45RBhighCD4+ T cell reconstituted SCID mice. Production of IFN- γ in lamina propria mononuclear cell cultures from IL-18BPa-treated SCID mice was decreased, but at the same time fewer lamina propria CD4+ T cells harvested from IL-18BPa-treated mice compared to non-treated mice were in apoptosis. We conclude that IL-18 clearly has a modulatory role in the inflammatory cascade of CD and experimental colitis by affecting IFN- γ and IL-10 production, and apoptosis. In view of the divergent effects of IL-18 neutralization in the two different murine colitis models, it is unlikely that IL-18 is at the top of this cascade. [ABSTRACT FROM AUTHOR]

Summary Background : Monoclonal antibodies to the pro-inflammatory cytokine tumour necrosis factor-α have shown efficacy in treating Crohn's disease, but can be immunogenic. Soluble tumour necrosis factor-binding proteins are being studied as potential alternative anti-tumour necrosis factor agents in Crohn's disease. Aim : To investigate the safety and efficacy of onercept, a recombinant form of the natural human soluble p55 tumour necrosis factor receptor, in the treatment of patients with active Crohn's disease. Methods : In a pilot study, 12 patients with active Crohn's disease were randomized to receive onercept at either 11.7 or 50 mg three times weekly for 2 weeks. Patients were followed up for 6 months after the end of treatment. Results : The Crohn's disease activity index decreased rapidly during treatment in both groups. Seven responses (Crohn's disease activity index decrease of 100 points) were observed over the first 6 weeks of the study, including five remissions (Crohn's disease activity index decrease of 150 points). Improvement was sustained for 2–4 months after stopping treatment. Treatment was well tolerated. No patients developed antibodies to onercept. Conclusions : Neutralizing the activity of tumour necrosis factor-α with its soluble p55 receptor may be valuable in the treatment of patients with Crohn's disease. Larger placebo-controlled trials are indicated. [ABSTRACT FROM AUTHOR]

The cloning of quantum variables with continuous spectra is investigated. We define a Gaussian 1-to-2 cloning machine that copies equally well two conjugate variables such as position and momentum or the two quadrature components of a light mode. The resulting cloning fidelity for coherent states, namely F = 2/3, is shown to be optimal. An asymmetric version of this Gaussian cloner is then used to assess the security of a continuous-variable quantum key distribution scheme that allows two remote parties to share a Gaussian key. The information versus disturbance tradeoff underlying this continuous quantum cryptographic scheme is then analyzed for the optimal individual attack. Methods to convert the resulting Gaussian keys into secret key bits are also studied. Finally, the extension of the Gaussian cloner to optimal N-to- M continuous cloners is discussed, and it is shown how to implement these cloners for light modes using a phase-insensitive optical amplifier and beam splitters. In addition, a phase-conjugate input cloner is defined, yielding M clones and M' anticlones from N replicas of a coherent state and N' replicas of its phase-conjugate (with M' - M = N' - N). This novel kind of cloners is shown to outperform the standard N-to- M cloners in some cases. [ABSTRACT FROM AUTHOR]

Background: Anti-TNFα therapy with infliximab is effective for Crohn’s disease. Infliximab neutralizes the biological activities of TNFα, a cytokine involved in host-defence against certain infections. Aim: To evaluate the effects of infliximab on the gut and peripheral immune system functions. Methods: Biopsies and blood samples from three clinical trials of infliximab in Crohn’s disease were analysed. Pharmacokinetics, changes in leucocyte counts and T cell subsets, T cell function, and cytokine profiles of lamina propria mononuclear cells (LPMC) and peripheral blood mononuclear cells (PBMC) were analysed. Results: Infliximab has a serum half-life of 9.5 days and is still detectable in serum 8 weeks after infusion. Leucocyte counts showed consistent changes from baseline toward normal values after therapy. Monocytes and lymphocytes were modestly increased, while neutrophils were decreased 4 weeks after treatment. Lymphocyte subsets and T cell proliferative responses were not altered after therapy. The proportion of PBMCs capable of producing IFNγ and TNFα did not change, while Th1 cytokine production by stimulated LPMC was decreased after infliximab therapy. Conclusion: The clinical efficacy of infliximab is based on local anti-inflammatory and immunomodulatory effects in the bowel mucosa, without generalized suppression of systemic immune functions in Crohn’s disease patients. [ABSTRACT FROM AUTHOR]

Motilin has excitatory effects on the colon of the rabbit and the dog, but little is known of its effect on the human colon. The aim of this study was to investigate the effects induced by motilin and erythromycin A (EMA) on muscle strips and on single cells from primary cultures from human colon. Isotonic contraction was recorded in circular muscle strips from macroscopically normal resection specimens of patients operated on for colonic neoplasm. Agonist-induced intracellular Ca2+ ([Ca2+]i) signalling was studied in primary cultures of colonic smooth-muscle cells using the ratiometric Ca2+ indicator Indo 1, on a laser-scanning confocal epifluorescence microscope. In circular muscle strips, norleucine13-porcine motilin ([Nle13]-pm)and EMA induced tonic contractions with an EC50 of 92 ± 21 nmol L-1 and 31 ± 16 μmol L-1, respectively. The maximal contraction was 21 ± 4% (motilin) and 33 ± 12% (EMA) of the response to 10-4 mol L-1 acetylcholine (ACh). The motilin antagonist OHM-11526 (10-5.5 mol L-1) abolished the effects of both [Nle13]-pm and EMA. Neither tetrodotoxin (10-5.5 mol L-1), L-nitro-D-arginine methyl ester (L-NAME) (10-3.5 mol L-1) nor guanethidine (10-5 mol L-1) interfered with the effects of [Nle13]-pm or EMA. [Nle13]-pm (10-11-10-6 mol L-1) induced rises of [Ca2+]i in cultured colonic myocytes. At 10-6 mol L-1, 94% of the cells responded, and half of the cells responded at 1.4 nmol L-1 [Nle13]-pm. 81% (35/43) and 95% (75/79) responded to EMA (10-6 mol L-1) and acetylcholine (ACh, 10-4 mol L-1), respectively. The motilin antagonist GM-109 inhibited motilin- and EMA-induced [Ca2+]i rises. In the absence of extracellular Ca2+, only 13% (7/52) of the cells responded to [Nle13]-pm (10-6 mol L-1) vs. 90% (47/52) to ACh (10-4 mol L-1). Motilin and EMA have direct excitatory effects on circular smooth muscle from the human colon and these effects are mediated via a smooth-muscle motilin receptor. These findings suggest that motilin may regulate colonic motility and that motilides may have therapeutic potential for the treatment of colonic hypomotility. [ABSTRACT FROM AUTHOR]

Trinitrobenzenesulphonic acid (TNBS)-induced colitis decreases the contractile response of the rabbit colon to motilin, and inflammation may increase plasma motilin levels. We studied whether the decreased contractility could be due to a down-regulation of motilin receptors, caused by increased plasma motilin levels. As this would affect all tissues, uninflamed sites were studied as well. Colitis was induced by different doses (100–150 mg kg-1) of TNBS. In the colon, the TNBS dose-dependent decrease of the contractile response towards motilin was reflected in a decrease in motilin receptor density. In contrast, in the antrum, receptors were upregulated by 150 mg kg-1 TNBS, while central motilin receptors in the cerebellum were not affected. Plasma motilin levels were not influenced by inflammation, although the motilin content and mRNA expression in the duodenal and jejunal mucosa, but not in the colon, was significantly increased. The opposite was true for interleukin-1β and interleukin receptor antagonist mRNA expression. We conclude that the decreased motilin contractility in rabbit colitis is due to a downregulation of motilin receptors in the colon, but this is not caused by chronic hormonal stimulation. [ABSTRACT FROM AUTHOR]