Effect of baclofen on the acid pocket at the gastroesophageal junction.

Previous studies established that a pocket of highly acidic gastric juice is present postprandially at the gastroesophageal junction in man. The GABA-B agonist baclofen inhibits postprandial reflux events through its effects on the lower esophageal sphincter (LES). The aim of the current study was to investigate whether baclofen would affect the location and the extent of the postprandial acid pocket in healthy volunteers. Twelve healthy volunteers underwent acid pocket studies on two different occasions, at least 1 week apart. LES position was determined preprandially with pull-through manometry. Dual pH electrode and manometry probe stepwise pull-through (1 cm/minute, LES-10 to +5 cm) was performed at 30-minute intervals for 150 minutes, with administration of placebo or baclofen 40 mg after the first and ingestion of a liquid meal after the second pull-through. After placebo, a significant drop in intragastric gastric pH was present at the gastroesophageal junction after the meal, reflecting the acid pocket, and this was associated with a drop in LES pressure. Baclofen did not affect the presence of the acid pocket, but prevented the postprandial drop in LES pressure, and the extent of the acid pocket above the upper margin of the manometrically located LES was significantly decreased by baclofen (1.6 ± 0.7 vs. 0.3 ± 0.4 cm at 60 minutes, 2.2 ± 0.6 vs. 0.2 ± 0.6 at 90 minutes, and 1.5 ± 0.5 vs. 0.7 ± 0.7 cm at 120 minutes, all P < 0.05). Baclofen does not alter the intragastric acid pocket, but limits its extension into the distal esophagus, probably through an increase in postprandial LES pressure.

A double-blind sham-controlled study of the effect of radiofrequency energy on symptoms and distensibility of the gastro-esophageal junction in GERD.

OBJECTIVES: Several studies have reported symptom relief in gastro-esophageal reflux disease (GERD) patients treated with radiofrequency delivery (Stretta procedure) at the gastro-esophageal junction (GEJ), but the mechanism underlying this improvement is unclear. The objective of this study was to test the hypothesis that Stretta alters GEJ resistance. METHODS: We conducted a double-blind randomized cross-over study of Stretta and sham treatment. Consecutive GERD patients were included in the study. The study was conducted in a tertiary care center. Patients underwent two upper gastrointestinal endoscopies with 3 months interval, during which active or sham Stretta treatment was performed in a randomized double-blind manner. Symptom assessment, endoscopy, manometry, 24-h esophageal pH monitoring, and a distensibility test of the GEJ were done before the start of the study and after 3 months. RESULTS: Barostat distensibility test of the GEJ before and after administration of sildenafil was the main outcome measure. In all, 22 GERD patients (17 females, mean age 47±12 years) participated in the study; 11 in each group. Initial sham treatment did not affect any of the parameters studied. Three months after initial Stretta procedure, no changes were observed in esophageal acid exposure and lower esophageal sphincter (LES) pressure. In contrast, symptom score was significantly improved and GEJ compliance was significantly decreased. Administration of sildenafil, an esophageal smooth muscle relaxant, normalized GEJ compliance again to pre-Stretta level, arguing against GEJ fibrosis as the underlying mechanism. CONCLUSIONS: The limitation of this study was reflux evaluation did not include impedance monitoring. In this sham-controlled study, Stretta improved GERD symptoms and decreased GEJ compliance. Decreased GEJ compliance, which reflects altered LES neuromuscular function, may contribute to symptomatic benefit by decreasing refluxate volume.

Patients with esophageal motility disorders show distinct patterns based on axial force measurements.

BACKGROUND: Using manometry, the classification of motility-related disorders in the esophagus is vague and overlapping. We present a new method, which combines manometry and axial force measurements in a single catheter. AIM: The aim was to examine the manometric and axial force recordings during swallows. METHODS: Recordings from 20 patients suffering from diffuse esophageal spasms (DES) (8), achalasia (5) and other diseases including gastro-oesophageal reflux (7) were compared to recordings made in ten healthy subjects. The probe was capable of measuring axial force 6.5-cm proximal to the lower esophageal sphincter (LES) and pressures 8-, 10- and 12-cm proximal to the LES. After insertion, five dry and five wet swallows were made. Swallows were repeated with 0, 2, 4 and 6 ml of water in a bag mounted distal to the axial force recording site. Each contraction was analysed for duration and amplitude, and was categorised according to its configuration. RESULTS: The number of failed contractions measured with axial force was lower for the achalasia (P < 0.001) and DES groups (P < 0.001) compared to the healthy volunteers. The number of multi-peaked contractions was unchanged for the achalasia and DES groups while it increased for the group of healthy volunteers. On several occasions a negative traction force was encountered though the manometric pattern appeared normal. CONCLUSIONS: Measurements of axial force generated by primary peristalsis provide additional information about esophageal neuromuscular function in different diseases that is not demonstrable with manometry alone.

Effect of buspirone, a 5-HT1A receptor agonist, on esophageal motility in healthy volunteers.

There are limited data concerning the effects of 5-HT(1A) receptor activation on esophageal motility. Sumatriptan, a 5-HT(1A) receptor agonist, was recently reported to enhance esophageal peristalsis after intravenous administration. Buspirone, an orally available 5-HT(1A) receptor agonist, was shown to modulate gastroduodenal motor function. Our aim was to evaluate the effect of buspirone on esophageal motility of healthy volunteers. On two separate visits, 20 healthy volunteers aged 21-29 years (nine women) underwent esophageal manometry before and 10, 30, and 60 minutes after the administration of buspirone 20-mg or placebo capsule, according to a double-blind crossover design. At each time point, we compared buspirone and placebo effects on: resting pressure of the lower esophageal sphincter (LES); residual pressure and duration of LES relaxation; amplitude, duration, and onset velocity of esophageal body contractions, during 10 swallows of 5 mL of water. Significant analysis of variance differences (P < 0.05) are presented as mean ± standard deviation. Buspirone significantly increased mean distal esophageal wave amplitude (151 vs. 87 mmHg, P < 0.05) and duration (6.1 vs. 4.2 seconds, P < 0.05). Similarly, buspirone significantly increased mean LES resting pressure (26 vs. 21 mmHg, P < 0.05) and mean residual LES pressure (7.9 vs. 2 mmHg, P < 0.05), whereas reduced mean LES relaxation duration (7.2 vs. 8.0 seconds, P < 0.05) and mean distal onset velocity (7.6 vs. 14.7 cm/second, P < 0.05). Buspirone enhances esophageal peristalsis and LES function in healthy volunteers. Further study is warranted on the effects of buspirone on esophageal function and symptoms in patients with ineffective esophageal motility.

Bile acids aspiration reduces survival in lung transplant recipients with BOS despite azithromycin.

Azithromycin (AZM) improved bronchiolitis obliterans syndrome (BOS) and reduced aspiration in lung transplant (LTx) recipients. We hypothesize that AZM could improve graft and overall survival more efficiently in LTx patients with BOS who have bile acid (BA) aspiration by protecting against the aspiration-induced progression of BOS. The goal was to compare FEV(1) (% baseline), BOS progression and overall survival in LTx recipients treated with AZM for BOS, both with versus without BA aspiration. Therefore, LTx recipients treated with AZM for BOS were recruited and broncho-alveolar lavage (BAL) samples were analyzed for the presence of BA and neutrophilia before the start of AZM treatment. Short-term effect of AZM on FEV(1) and BAL neutrophilia was assessed, progression of BOS and survival were followed-up for 3 years and results were compared between patients with/without BA aspiration. 19/37 LTx patients had BA in BAL. BA aspiration predisposed to a significantly worse outcome, in terms of decline in FEV(1) , progression of BOS ≥ 1 and survival. AZM does not seem to protect against the long-term allograft dysfunction caused by gastroesophageal reflux (GER) and aspiration and an additional treatment targeting aspiration may be indicated in those LTx patients.

Characteristics of gastroesophageal reflux and potential risk of gastric content aspiration in children with cystic fibrosis.

OBJECTIVES: Increased gastroesophageal reflux (GER) is common in children with cystic fibrosis (CF). We studied the occurrence of acid, weakly acidic (WA), and weakly alkaline (WALK) reflux in children with CF and evaluated a possible surrogate marker for risk of gastric content aspiration. PATIENTS AND METHODS: Twenty-four children with CF underwent impedance-pH monitoring for detection of acid (pH < 4), WA (pH 4-7), and WALK-GER (pH > or = 7). In 11 children, cough was objectively recorded with esophageal manometry and the symptom association probability was calculated to determine the reflux-cough relation. Presence of bile acids (BA) was measured in the saliva of 65 patients with CF and 23 healthy children, respectively. RESULTS: Sixteen of the 24 children had increased GER (esophageal acid exposure). The majority of reflux events were acidic in nature. WA reflux was less common and WALK reflux was rare. The sequence reflux-cough was found in 8 of the 11 children and 1 of 11 children had a positive symptom association probability for reflux-cough. The sequence cough-reflux was found in only 3 of the 11 children. Only a small fraction of the total esophageal acid and volume exposure was secondary to cough. Twenty-three of the 65 children with CF had BA in saliva compared with none of the healthy controls. CONCLUSIONS: Although WA-GER is uncommon, acid GER is prevalent in children with CF. It is a primary phenomenon and is not secondary to cough. One third of the children with CF have BA in saliva, which may indicate an increased risk for aspiration. However, the impact of salivary BA and potential aspiration on CF pulmonary disease needs further investigation.

The spectrum of motor function abnormalities in gastroesophageal reflux disease and Barrett's esophagus.

Barrett's esophagus has traditionally been regarded as the most severe end of the spectrum of gastroesophageal reflux disease and is of great clinical importance in view of the association with esophageal adenocarcinoma. Studies have documented high levels of esophageal acid exposure in Barrett's esophagus. Various pathogenetic mechanisms underlie this phenomenon. These include abnormalities in esophageal peristalsis, defective lower esophageal sphincter pressures, gastric dysmotility and bile reflux. Whilst these factors provide evidence for an acquired cause of Barrett's esophagus, an underlying genetic predisposition cannot be ruled out. Although the past decade has brought about many new discoveries in the pathogenesis of Barrett's esophagus, it has also added further controversy to this complex disorder. A detailed analysis of the gastrointestinal motor abnormalities occurring in Barrett's esophagus follows, with a review of the currently available literature and an update on this condition that continues to be of interest to the gastroenterologist.

Azithromycin reduces gastroesophageal reflux and aspiration in lung transplant recipients.

Azithromycin (AZI) is a macrolide antibiotic that improves lung function in lung transplant recipients (LTx). Gastroesophageal reflux (GER) has been implicated in the pathogenesis of chronic rejection after LTx. Macrolide antibiotics may affect GER by modifying esophageal and gastric motility. The purpose of this study was to evaluate the effect of AZI on GER and gastric aspiration after LTx. Acid and weakly acidic GER was measured with 24-h pH-impedance monitoring in 47 LTx patients (12 patients "on" AZI). Gastric aspiration was assessed in a separate group of 30 LTx patients before and after AZI by measurements of pepsin and bile acid in bronchoalveolar lavage fluid (BALF). Patients "on" AZI had a significant lower total number of reflux events [41 (30-61) vs. 22.5 (7-37.5)], number of acid reflux events [24 (16-41) vs. 8 (4-18)], esophageal acid exposure [2.9% (0.7-7.3) vs. 0.2% (0.1-2.0)], bolus exposure [0.73% (0.5-1.4) vs. 0.21% (0.12-0.92)], and proximal extent of reflux [14 (9-24) vs. 5 (2-7)]. AZI reduced the concentration of bile acids in BALF without affecting levels of pepsin. LTx patients "on" AZI have less GER and bile acids aspiration. This effect might be due to enhanced esophageal motility and accelerated gastric emptying.

Gastro-oesophageal reflux and aspiration of gastric contents in adult patients with cystic fibrosis.

BACKGROUND: Gastro-oesophageal reflux (GOR) is increased in cystic fibrosis (CF), but its prevalence, characteristics, association with gastric aspiration and respiratory impact are not well characterised. We investigated acid and weakly acidic reflux, aspiration and respiratory symptoms/function in adult CF patients. METHODS: Thirty-three CF patients [19 men; 29 (18-55) years, [10 post-lung transplant (LTx)] underwent impedance-pH monitoring for detection of acid (pH<4) and weakly acid GOR (pH 4-7). In 16 patients cough was objectively recorded with oesophageal manometry, and the symptom association probability (SAP) was calculated. Saliva and bronchoalveolar lavage fluid (BALF) were tested for bile acids. RESULTS: Twenty-eight patients had increased GOR (21 acid, 5 weakly acidic and 2 acid+weakly acidic) and 10 had a positive SAP for reflux cough. GOR parameters were similar in non-LTx and post-LTx CF patients. The sequence reflux cough was significantly more common than cough reflux. Sixteen of 38 patients had bile acids in saliva and 6/10 in BALF and this was almost exclusively observed in patients with genotype DF508/DF508. Only 12/28 with increased GOR and 9/22 with bile acids in saliva/BALF had typical reflux symptoms. There was a positive correlation (r = 0.53, p = 0.03) between oesophageal acid exposure and cough. SAP-positive patients with for reflux cough had a lower lung function than SAP-negative patients. CONCLUSION: Increased GOR is prevalent in CF and not secondary to cough. Acid GOR is common, but weakly acidic GOR may also occur. CF patients have a high risk of aspiration and reflux seems to be associated with more cough and poorer lung function. Outcome studies with intense anti-reflux therapy are needed to confirm the deleterious role of reflux in CF progression.

Short exposure of oesophageal mucosa to bile acids, both in acidic and weakly acidic conditions, can impair mucosal integrity and provoke dilated intercellular spaces.

BACKGROUND: Severe duodeno-gastro-oesophageal reflux (DGOR) is a risk factor for oesophagitis and Barrett's oesophagus. Patients with non-erosive reflux disease (NERD) have a slight increase in DGOR. Patients with gastro-oesophageal reflux disease (GORD), who are taking proton pump inhibitors (PPIs), still have reflux but of weakly acidic pH and persistence of bile. In these two groups of patients, heartburn might be due to increased oesophageal mucosal permeability and dilated intercellular spaces (DIS). We aimed to assess whether experimental short exposure of the oesophageal mucosa to bile acids, in low concentrations (at acidic, weakly acidic and neutral conditions) can increase mucosal permeability and provoke DIS. METHODS: Rabbit oesophageal mucosa was studied in diffusion and Ussing chambers. We assessed the effects of different solutions containing bile acids, applied to the mucosal side, on transepithelial electrical resistance (R(T)) and permeability to fluorescein. The diameter of intercellular spaces was assessed by using transmission electron microscopy. RESULTS: Incubation of oesophageal mucosa with acidic solutions (pH 2.0) containing a range of bile acids (0.5-5 mmol/l) markedly decreased R(T) and increased mucosal permeability. Weakly acidic solutions (pH 5.0), and to some extent neutral solutions (pH 7.4), containing some bile acids also decreased R(T) and increased permeability, although the effects were much less marked and in some combinations no effect was seen. Exposure to bile acids provoked DIS in acid and weakly acidic conditions but not in neutral (pH 7.4) solutions. CONCLUSIONS: Experimental short exposure of the oesophageal mucosa to solutions with a bile acid concentration and acidity similar to that observed in the gastric contents of patients with NERD or ERD, and who are taking PPIs, may impair oesophageal mucosal integrity and even induce dilated intercellular spaces. Such a situation could, theoretically, underlie the occurrence and/or persistence of symptoms in these patients.

Gastro-oesophageal reflux and gastric aspiration in lung transplant patients with or without chronic rejection.

Acid gastro-oesophageal reflux (GOR) and gastric aspiration have been labelled as risk factors for chronic rejection bronchiolitis obliterans syndrome (BOS) after lung transplantation (LTx). The present study aimed to further characterise GOR (both acid and nonacid) and the degree of gastric aspiration in LTx recipients both with and without BOS. Impedance-pH recordings were used for GOR detection. Pepsin and bile acid levels were measured in bronchoalveolar lavage fluid (BALF). A total of 48% of patients had increased GOR, of which 27% had exclusively increased nonacid reflux. Cystic fibrosis patients had the highest prevalence of GOR. Pepsin was found in BALF of all patients and bile acids in BALF of 50% of the patients. Patients with BOS had neither increased GOR nor elevated pepsin in BALF. However, 70% of the patients with BOS had bile in BALF compared with 31% of stable patients. Proton pump inhibitor (PPI) treatment reduced acid reflux but did not affect nonacid reflux. Moreover, pepsin and bile levels in BALF were not reduced by PPI. One-half of the lung transplant patients had increased reflux, and nonacid reflux was common. Gastric aspiration occurred in most lung transplant patients. Pepsin was a more general marker and bile acids a more specific marker that might be associated with bronchiolitis obliterans syndrome. Proton pump inhibitor treatment did not prevent nonacid reflux and gastric aspiration.

Improved diagnosis of gastro-oesophageal reflux in patients with unexplained chronic cough.

BACKGROUND: Symptoms, oesophageal pHmetry and proton pump inhibitor treatment are used for diagnosing gastro-oesophageal reflux-related cough. Weakly acidic reflux is now increasingly associated with reflux symptoms such as regurgitation or chest pain. AIM: To study the association between weakly acidic reflux and cough in a selected, large group of patients with unexplained chronic cough. METHODS: A total of 100 patients with chronic cough (77 'off' and 23 'on' a proton pump inhibitor) were studied using impedance-pHmetry for reflux detection and manometry for objective cough monitoring. Symptom Association Probability (SAP) Analysis characterized the reflux-cough association. RESULTS: Acid reflux could be a potential mechanism for cough in 45 patients (with either heartburn, high acid exposure or +SAP for acid reflux). Weakly acidic reflux could be a potential mechanism for cough in 24 patients (with either increased oesophageal volume exposure, increased number of weakly acidic reflux or +SAP for weakly acidic reflux). Reflux could not be identified as a potential mechanism for cough in 31 patients. CONCLUSION: A positive association between cough and weakly acidic reflux was found in a significant subgroup of patients with unexplained chronic cough. Impedance-pH-manometry identified patients in whom cough can be related to reflux that would have been disregarded using the standard diagnostic criteria for acid reflux.

Relevance of mild ineffective oesophageal motility (IOM) and potential pharmacological reversibility of severe IOM in patients with gastro-oesophageal reflux disease.

BACKGROUND: Several studies showed high prevalence of ineffective oesophageal motility (IOM) in gastro-oesophageal reflux disease (GERD) and suggested an important role for ineffective oesophageal motility in increased acid exposure. However, impedance-manometric studies proposed that only severe ineffective oesophageal motility might affect oesophageal clearance. OBJECTIVES: (i) To re-assess the relevance of mild IOM in GERD and (ii) to test the reversibility of IOM. METHODS: Oesophageal motility, clearance and acid exposure were assessed in 191 GERD patients: 99 without IOM; 58 with mild IOM (30-80% ineffective contractions) and 34 with severe IOM (>80% ineffective contractions). In 30 patients with oesophagitis, the potential reversibility of IOM was evaluated with edrophonium intravenously. RESULTS: Patients with mild IOM had identical oesophageal clearance and acid exposure in comparison with those without IOM. Patients with severe IOM had a higher probability of prolonged supine clearance and acid exposure [odds ratio: 2.88 (1.16-7.17); 2.48 (0.99-6.17)]. This effect was independent of the presence of hiatal hernia and male sex. Severe IOM could be transiently reverted in 55% of patients. CONCLUSIONS: Mild IOM does not affect oesophageal clearance. Only severe IOM is associated with prolonged clearance and acid exposure, particularly in supine periods. The edrophonium test might be useful to predict severe IOM response to prokinetic medications.

Randomized clinical trial: effect of the 5-HT4 receptor agonist revexepride on reflux parameters in patients with persistent reflux symptoms despite PPI treatment.

BACKGROUND: Approximately, 20-30% of patients with gastro-esophageal reflux disease (GERD) experience persistent symptoms despite treatment with proton pump inhibitors (PPIs). These patients may have underlying dysmotility; therefore, targeting gastric motor dysfunction in addition to acid inhibition may represent a new therapeutic avenue. The aim of this study was to assess the pharmacodynamic effect of the prokinetic agent revexepride (a 5-HT4 receptor agonist) in patients with GERD who have persistent symptoms despite treatment with a PPI. METHODS: This was a phase II, exploratory, multicenter, randomized, placebo-controlled, double-blind, parallel-group study in patients with GERD who experienced persistent symptoms while taking a stable dose of PPIs (ClinicalTrials.gov identifier: NCT01370863). Patients were randomized to either revexepride (0.5 mg, three times daily) or matching placebo for 4 weeks. Reflux events and associated characteristics were assessed by pH/impedance monitoring and disease symptoms were assessed using electronic diaries and questionnaires. KEY RESULTS: In total, 67 patients were enrolled in the study. There were no significant differences between study arms in the number, the mean proximal extent or the bolus clearance times of liquid-containing reflux events. Changes from baseline in the number of heartburn, regurgitation, and other symptom events were minimal for each treatment group and no clear trends were observed. CONCLUSIONS & INFERENCES: No clear differences were seen in reflux parameters between the placebo and revexepride groups.

Comparison of various methods for monitoring hybridoma cell proliferation.

The design of a strategy for the control of large scale cultures of hybridoma cells requires the use of convenient indicators to monitor properly the evolution of the biomass. In order to select appropriate indicators, we have measured in parallel, in bulk cultures of mouse hybridoma cells, the evolution of several metabolic parameters together with those of cell density and viability. We observed that flow cytometry analysis gives an early indication of the proliferative capacity of the cell population. Determination of metabolic rates (i.e. glucose, glutamine, amino acid, consumption, lactic acid or ammonium production) adequately indicates the current metabolic status of the cells. Indeed, a sharp decrease in these metabolic rates occurs rapidly following nutrient deficiency. Finally, measurements of lactate dehydrogenase (LDH) and DNA fragments released into the culture supernatants accurately reflect the kinetics of cell death.

Structure of an extracellular polysaccharide produced by Lactobacillus rhamnosus strain C83.

The extracellular polysaccharide produced by Lactobacillus rhamnosus strain C83 was found to be composed of D-glucose and D-galactose in a molar ratio of 2:3. The primary structure of the polysaccharide was shown by sugar analysis, methylation analysis, FABMS, partial acid hydrolysis and nuclear magnetic resonance (NMR) spectroscopy to consist of a pentasaccharide repeating unit having the following structure: -->3)-alpha-D-Glcp-(1-->2)-beta-D-Galf-(1-->6)-alpha-D-Galp-(1-->6 )-alpha-D -Glcp-(1-->3)-beta-D-Galf-(1-->

Review article: the pathophysiology, differential diagnosis and management of rumination syndrome.

BACKGROUND: Rumination syndrome, characterised by the effortless, often repetitive, regurgitation of recently ingested food into the mouth, was originally described in children and in the developmentally disabled. It is now well-recognised that rumination syndrome occurs in patients of all ages and cognitive abilities. AIM: To review a scholarly review on our current understanding of the rumination syndrome. METHODS: The review was conducted on the basis of a medline search to identify relevant publications pertaining to the pathophysiology, clinical diagnosis and management of rumination syndrome. RESULTS: The Rome III consensus established diagnostic criteria for rumination syndrome in adults, children and infants. A typical history can be highly suggestive but oesophageal (high resolution) manometry/impedance with ingestion of a meal may help to distinguish rumination syndrome from other belching/regurgitation disorders. The pathophysiology is incompletely understood, but involves a rise in intra-gastric pressure, generated by a voluntary, but often unintentional, contraction of the abdominal wall musculature, at a time of low pressure in the lower oesophageal sphincter, causing retrograde movement of gastric contents into the oesophagus. To date, controlled trials in the treatment rumination syndrome are lacking. The mainstay of treatment for rumination syndrome is explanation and behavioural treatment which consists of habit reversal techniques that compete with the urge to regurgitate. Chewing gum, prokinetics, baclofen and even antireflux surgery have been proposed as adjunctive therapies, but high quality studies are generally lacking. CONCLUSIONS: Rumination is an under-recognised condition with incompletely understood pathophysiology. Behavioural therapy seems effective, but controlled treatment trials are lacking.

Increasing body weight enhances prevalence and proximal extent of reflux in GERD patients 'on' and 'off' PPI therapy.

BACKGROUND: Increased body weight is associated with higher intragastric pressure. Proximal extent of reflux is a determinant of symptoms in patients with gastro-esophageal reflux disease (GERD). We aimed to investigate the association between body mass index (BMI) and abdominal circumference on the incidence and proximal extent of reflux. METHODS: A total of 95 patients [37 men, age 51(16-82) years] with typical and/or atypical GERD symptoms underwent 24 h impedance-pH monitoring. Forty-nine patients were studied 'off' and 46 'on' proton pump inhibitors (PPI) treatment. Reflux was classified as acid (pH < 4) or weakly acidic (pH 4-7). Proximal extent was defined as the number of reflux events reaching ≥15 cm above the lower esophageal sphincter. Body mass index and abdominal circumference (cm) were assessed. KEY RESULTS: In patients 'off' PPI, there was a correlation between BMI and esophageal acid exposure (ρ = 0.53, P < 0.001), volume exposure (ρ = 0.48, P < 0.001), total number of reflux events (ρ = 0.47, P < 0.001) and number of acid reflux events (ρ = 0.49, P < 0.001). In patients 'on' PPI there was a correlation between BMI and esophageal acid exposure (ρ = 0.32, P = 0.03), volume exposure (ρ = 0.46, P < 0.01) and total number of reflux events (ρ = 0.33, P = 0.03). Similar correlations were found between abdominal circumference and reflux. A correlation between BMI and proximal extent of reflux was present in patients 'off' PPI (ρ = 0.32, P = 0.03). In patients 'on' PPI, we found a correlation between abdominal circumference and proximal extent (ρ = 0.31, P = 0.03). CONCLUSIONS & INFERENCES: Body mass index and abdominal circumference may contribute to GER and its proximal extent, in patients 'on and 'off' PPI. Further studies investigating the role of weight reduction in the control of GERD symptoms are warranted.

The effects of itopride on oesophageal motility and lower oesophageal sphincter function in man.

BACKGROUND: Itopride is a new prokinetic agent that combines antidopaminergic and cholinesterase inhibitory actions. Previous studies suggested that itopride improves heartburn in functional dyspepsia, and decreases oesophageal acid exposure in gastro-oesophageal reflux disease. It remains unclear whether this effect is due to effects of itopride on the lower oesophageal sphincter (LES). AIMS: To study the effects of itopride on fasting and postprandial LES function in healthy subjects. METHODS: Twelve healthy volunteers (five men; 32.6 ± 2.0 years) underwent three oesophageal sleeve manometry studies after 3 days premedication with itopride 50 mg, itopride 100 mg or placebo t.d.s. Drug was administered after 30 min and a standardized meal was administered after 90 min, with measurements continuing to 120 min postprandially. Throughout the study, 10 wet swallows were administered at 30-min intervals, and gastrointestinal symptoms were scored on 100 mm visual analogue scales at 15-min intervals. RESULTS: Lower oesophageal sphincter resting pressures, swallow-induced relaxations and the amplitude or duration of peristaltic contractions were not altered by both doses of itopride, at all time points. Itopride pre-treatment inhibited the meal-induced rise of transient LES relaxations (TLESRs). CONCLUSIONS: Itopride inhibits TLESRs without significantly affecting oesophageal peristaltic function or LES pressure. These observations support further studies with itopride in gastro-oesophageal reflux disease.

Modulation of the postprandial acid and bile pockets at the gastro-oesophageal junction by drugs that affect gastric motility.

BACKGROUND: Previous studies have established the presence of a postprandial acid pocket at the gastro-oesophageal junction. AIMS: To investigate whether altering gastric motility would affect the location and the extent of postprandial acid pockets in healthy volunteers and also to study the presence of bile in this pocket. METHODS: A total of 16 healthy volunteers underwent pH and Bilitec probe stepwise pull-through to measure regional differences in pH and bile absorbance before and 10, 30 and 50 min after a liquid meal. At the start of the meal, saline, erythromycin or sumatriptan was administered. RESULTS: After saline, ingestion of a meal induced an acid pocket, with a mean pH drop of 2.26 (compared to 0.25 before the meal, P < 0.05) and a nadir pH of 2.71. The acid pocket persisted 30 and 50 min postprandially (pH drops 1.59 and 1.68 and nadir pH 3.17 and 2.52 respectively). Compared with saline, erythromycin significantly suppressed the pH drop and nadir pH (on average 0.66 and 3.4 at 10 min; comparable patterns at 30 and 50 min). After sumatriptan a significantly lower nadir pH was observed at 30 and 50 min (respectively 2.02 and 1.74, P < 0.05 compared with saline). A postprandial bile pocket was noted in 50% of pull-throughs after saline, compared to 78% after erythromycin and 31% after sumatriptan. CONCLUSIONS: The presence of a bile pocket in a subset of the subjects confirms the heterogeneity of postprandial intragastric contents. Erythromycin disrupts the acid pocket but increases the presence of bile, while sumatriptan has opposite effects.