Biomedical subjects

J Janssens

Publications and source records attributed to J Janssens.

At least 19 recordsLinked to original sources

PubMed2003

Differential effects of baclofen on lower oesophageal sphincter pressure and proximal gastric motility in humans.

BACKGROUND: The gamma-aminobutyric acid receptor type B agonist, baclofen, inhibits transient lower oesophageal sphincter relaxations by influencing a vagal pathway. Although post-prandial proximal gastric function, which is vagally mediated, is important in the occurrence of transient lower oesophageal sphincter relaxations, the effects of baclofen on post-prandial proximal gastric motility in humans remains undetermined. AIM: To determine the effects of baclofen on post-prandial lower oesophageal sphincter function and proximal gastric motility in healthy subjects. METHODS: In 11 healthy volunteers, a barostat bag and an oesophageal manometric catheter with a sleeve were simultaneously positioned; 40 mg of oral baclofen or placebo was then given in a randomized, double-blind manner. Subsequently, the intragastric bag volume, oesophageal and lower oesophageal sphincter pressure and oesophageal pH were recorded during the 90 min before and 120 min after a meal. RESULTS: During the post-prandial period, unlike the fasting period, baclofen decreased the rate of transient lower oesophageal sphincter relaxations and increased the basal lower oesophageal sphincter pressure compared with placebo. However, the meal-induced decrease in the tone and phasic contractility of the fundus was not affected by baclofen. CONCLUSION: The gamma-aminobutyric acid receptor type B agonist, baclofen, has a potent effect on post-prandial lower oesophageal sphincter motility without altering post-prandial proximal gastric motility, suggesting differential effects of baclofen on different signals of gastrointestinal vagal afferents.

Adult↗

PubMed2003

Influence of the selective serotonin re-uptake inhibitor, paroxetine, on gastric sensorimotor function in humans.

BACKGROUND: The role of 5-hydroxytryptamine in the control of gastric fundus tone in humans is still unknown. Selective 5-hydroxytryptamine re-uptake inhibitors act both centrally and peripherally to enhance the availability of physiologically released 5-hydroxytryptamine. AIM: To study the influence of a selective 5-hydroxytryptamine re-uptake inhibitor, paroxetine, on gastric fundus tone, on the perception to gastric distension and on gastric accommodation to a meal. METHODS: Sixteen healthy volunteers underwent a gastric barostat study on two occasions, after pre-treatment with placebo or paroxetine, 20 mg/day. Graded isobaric and isovolumetric distensions were performed and perception was scored by a questionnaire. Subsequently, the amplitude of the gastric accommodation to a mixed liquid meal was also measured. RESULTS: Pre-treatment with paroxetine did not alter the thresholds for perception and discomfort during isobaric (4.7 +/- 2.3 vs. 4.0 +/- 2.0 mmHg and 13.3 +/- 3.1 vs. 12.7 +/- 2.3 mmHg above the minimum intragastric distending pressure, N.S.) and isovolumetric (307 +/- 90 vs. 417 +/- 114 mL and 772 +/- 74 vs. 750 +/- 76 mL, N.S.) distensions. Paroxetine significantly enhanced the amplitude of the meal-induced fundus relaxation (136 +/- 51 vs. 255 +/- 43 mL, P < 0.05). CONCLUSIONS: Pre-treatment with paroxetine enhances gastric accommodation to a meal. These data suggest that the release of 5-hydroxytryptamine, probably at the level of the enteric nervous system, is involved in the control of the accommodation reflex in humans, and that paroxetine may be beneficial to patients with impaired post-prandial fundus relaxation.

Adult↗

PubMed2003

Electrical stimulation reveals complex neuronal input and activation patterns in single myenteric guinea pig ganglia.

The myenteric plexus plays a key role in the control of gastrointestinal motility. We used confocal calcium imaging to study responses to electrical train stimulation (ETS) of interganglionic fiber tracts in entire myenteric ganglia of the guinea pig small intestine. ETS induced calcium transients in a subset of neurons: 52.2% responded to oral ETS, 65.4% to aboral ETS, and 71.7% to simultaneous oral and aboral ETS. A total of 41.3% of the neurons displayed convergence of oral and aboral ETS-induced responses. Responses could be reversibly blocked with TTX (10(-)6 M), demonstrating involvement of neuronal conduction, and by removal of extracellular calcium. omega-Conotoxin (5 x 10(-7) M) blocked the majority of responses and reduced the amplitude of residual responses by 45%, indicating the involvement of N-type calcium channels. Staining for calbindin and calretinin did not reveal different response patterns in these immunohistochemically identified neurons. We conclude that, at least for ETS close to a ganglion, confocal calcium imaging reveals complex oral and aboral input to individual myenteric neurons rather than a polarization in spread of activity.

Animals↗

PubMed2003

Validation of a new method of measuring esophageal acid exposure: comparison with 24-hour pH monitoring.

Recently, we developed a disposable acid exposure sensor whose in vitro response to acid below pH 4 is linearly determined by the duration of exposure and the degree of acidity. The aim of the present study was to compare the SR to simultaneous esophageal pH and duodenogastroesophageal reflux (DGER) monitoring (Bilitec) in patients investigated for presumed gastroesophageal reflux disease (GERD). Twenty-six patients (16 men, mean age 46 +/- 2 years) with symptoms suggestive of GERD underwent 24-hr ambulatory pH monitoring and SR monitoring at 5 cm proximal to the LES. DGER monitoring was performed in 21 patients. Exposure of the esophagus to acid and to DGER were analyzed. These data were compared to SR. A significant correlation was found between the exposure of the distal esophagus to acid and SR (R = 0.85; P < 0.0001). Similarly, the area below a cutoff pH 4 was significantly correlated to SR (r = 0.81; P < 0.0001). SR was not correlated to DGER (r = 0.16; NS). At a cutoff of 50, the sensitivity and specificity of SR to predict esophageal acid exposure > 5% of time were 91% and 93%, respectively conclusion, the response of the acid exposure sensor is strongly correlated with the results of simultaneous esophageal pH monitoring. The sensor seems able to reliably predict pathological esophageal acid exposure. These findings warrant larger studies of the clinical potential of the acid exposure sensor in the diagnosis and quantification of GERD.

Bile Reflux↗

PubMed2003

Effect of the GABA(B) agonist baclofen in patients with symptoms and duodeno-gastro-oesophageal reflux refractory to proton pump inhibitors.

BACKGROUND AND AIMS: A subset of patients with gastro-oesophageal reflux disease (GORD) with refractory symptoms during therapy with proton pump inhibitors (PPIs), have persistent non-acid duodeno-gastro-oesophageal reflux (duodenal reflux). The aim of the present study was to investigate the effect of the GABA(B) receptor agonist baclofen, which was shown to inhibit the occurrence of transient lower oesophageal sphincter relaxations (TLOSRs) in patients with persistent non-acid duodenal reflux during PPI therapy. METHODS: Patients were eligible for the study if they had persistent reflux symptoms, normal pH monitoring, and pathological Bilitec monitoring during PPI treatment. Upper gastrointestinal endoscopy and reflux symptom score were performed at the beginning of the study. Baclofen 5 mg three times daily was associated with treatment, and was increased by 5 mg every fourth day until a maintenance dose of 20 mg three times daily was reached. A reflux symptom questionnaire, ambulatory pH monitoring, and Bilitec monitoring were repeated four days later while PPI and baclofen were continued. All data are given as mean (SEM) or median (interquartile range) and were compared using the Student's t test or the Mann-Whitney U test. RESULTS: Sixteen patients (11 women, mean age 46 (3) years) with persistent heartburn or regurgitation for at least three months, in spite of PPI therapy, were included in the study. Erosive oesophagitis was present in seven patients (five with grade 1, two with grade 2). Under PPI therapy alone, all patients had normal acid exposure (0.3 (0.05; 2.2)% of the time) but pathological duodenal reflux exposure (13.8 (11.8; 15.5)% of the time). After addition of baclofen 20 mg three times daily, acid exposure was similar (0.4 (0.15; 2.3)% of the time; NS) but duodenal reflux had significantly decreased (6.1 (0.8; 10.3)% of the time; p<0.05). The number of duodenal reflux episodes and the number of longlasting duodenal reflux episodes (>5 minutes) was decreased, respectively, from 23 (14.5; 34) to 12 (5; 21) (p = 0.06) and from 5 (3; 8) to 2 (0.5;4.5) (p<0.05). The cumulative severity score for 14 reflux symptoms decreased from 10.3 (1.7) to 5.8 (1.3) (p<0.01). Four patients reported mild side effects of nausea or drowsiness. CONCLUSIONS: The GABA(B) receptor agonist baclofen improves duodenal reflux and associated reflux symptoms that persist during PPI therapy.

Adult↗

PubMed2003

Relevance of ineffective oesophageal motility during oesophageal acid clearance.

BACKGROUND: Oesophageal clearance of acid reflux consists of an initial volume clearance followed by neutralisation of the acidified mucosa by swallowed saliva (chemical clearance). Ineffective oesophageal motility (IOM), a frequent finding in patients with gastro-oesophageal reflux disease (GORD), has been claimed to underlie prolonged acid clearance by affecting oesophageal emptying and saliva transport. Intraluminal impedance allows non-radiological monitoring of movement of oesophageal liquids. AIMS: To evaluate the relevance of IOM during oesophageal volume and chemical clearance using combined pH impedance measurements. SUBJECTS: Impedance was validated with fluoroscopy to study volume clearance in three healthy subjects. Acid clearance tests were performed in 10 healthy subjects in the upright and supine positions, before and after oesophageal peristaltic disruption with sildenafil 50 mg. METHODS: After instillation of an acid bolus, simultaneous manometry, pH, and impedance were used to study oesophageal motility, chemical clearance, and volume clearance, respectively. RESULTS: Impedance allowed assessment of volume clearance accurately, showing a strong correlation with fluoroscopy (r(2)=0.89). Sildenafil provoked a graded impairment in oesophageal motility in healthy subjects without affecting saliva secretion. In the upright position, volume clearance was slightly prolonged only with severe IOM (>80% abnormal peristaltic sequences). In the supine position, severe IOM significantly prolonged chemical and volume clearance. Moderate IOM (30-80% abnormal peristalsis) had no effect. With normal peristalsis and moderate IOM, clearance times were similar in the upright and supine positions. Severe IOM however had a greater impact on clearance in the supine than in the upright position. CONCLUSION: Ineffective oesophageal motility has little effect on oesophageal clearance during upright acid reflux. With supine reflux, only severe IOM is associated with prolonged oesophageal clearance.

Acids↗

PubMed2003

Assessment of meal induced gastric accommodation by a satiety drinking test in health and in severe functional dyspepsia.

AIMS: Impaired gastric accommodation is a major pathophysiological mechanism in functional dyspepsia. The aim of the present work was to assess a satiety drinking test in the evaluation of accommodation in health and dyspepsia. METHODS: Twenty five controls and 37 severely dyspeptic patients seen at a tertiary care centre completed a dyspepsia questionnaire, and gastric emptying and gastric barostat studies. The amount of liquid meal ingested at maximum satiety during a slow satiety drinking test was determined. In controls, we studied the influence of caloric density and of pharmacological agents that influence accommodation. RESULTS: In patients, satiety scores were higher and maximum satiety occurred at lower calories (542 (50) v 1508 (53) kcal; p<0.0001). Six patients had required nutritional support, but excluding these did not alter the correlations. With increasing severity of early satiety, less calories were ingested at maximum satiety. In multivariate analysis, the amount of calories was significantly correlated to accommodation but not to gastric emptying or sensitivity. Sensitivity and specificity of the satiety test in predicting impaired accommodation reached 92% and 86%, respectively. At different caloric densities, ingested volume rather than caloric load determined maximum satiety. Pharmacological agents (sumatriptan, cisapride, erythromycin) affected the satiety test according to their effect on accommodation. CONCLUSION: A slow caloric drinking test can be used to evaluate accommodation and early satiety. It provides a non-invasive method of predicting impaired accommodation and quantifying pharmacological influences on accommodation.

Adult↗

PubMed2002

Calcium signalling and removal mechanisms in myenteric neurones.

To characterize further the Ca2+ signalling mechanisms of myenteric neurones, we studied the effect of thapsigargin, a blocker of the Ca2+-store ATPase, and the mechanisms involved in restoring the intracellular Ca2+ concentration ([Ca2+]i) after activation. Thapsigargin (5 x 10(-6) mol L(-1)) induced an oscillatory [Ca2+]i response in 86.6% of the neurones (n=276), which was blocked by the removal of extracellular Ca2+ and by omega-conotoxin MVIIA (5 x 10(-7) mol L(-1)). The IP3-blocker, 2-aminoethyl-diphenyl-borate (75 x 10(-6) mol L(-1)), blocked or reduced the responses in 74.5% of the neurones. The oscillatory responses induced by the depletion of Ca2+ stores suggest that myenteric neurones might recruite N-type Ca2+ channels as a refill mechanism. Thapsigargin pretreatment increased the amplitude, the upstroke and duration of the K+-induced [Ca2+]i responses. Mitochondrial blockers (rotenone and antimycin/oligomycin) also prolonged the responses, but without affecting the amplitude. Furthermore, it was found that for high [Ca2+]i, the thapsigargin-sensitive Ca2+ uptake was crucial, while mitochondrial blockade affected the Ca2+ uptake over a wide range of concentrations. The Ca2+-sequestering components might also have been compensating for each other, as most drugs only delayed and not inhibited Ca2+ removal.

Animals↗

PubMed2002

Electrical behaviour of interleukin-1 beta (IL-1 beta) and prostaglandin-E2 (PGE2) on colonic myenteric neurones.

Abstract Intracellular recordings were used to examine the effects on electrical and synaptic behaviour of interleukin (IL)-1beta and prostaglandin E2(PGE2) on myenteric neurones of the guinea-pig colon. Application of IL-1beta and PGE2resulted in a concentration-dependent slow depolarization with enhanced spike discharge in, respectively, 45% (21/47) and 83% (33/41) of the impaled colonic neurones. Administration of IL-1beta in three neurones (6%) elicited a hyperpolarization. Responses remained during tetrodotoxin application, indicative of a direct effect of both substances on the impaled neurones. The effects of IL-1beta remained in the presence of indomethacine, a prostaglandin synthase inhibitor. Responses were seen in both nitric oxide synthase- and choline acetyl transferase-immunoreactive neurones. IL-1beta evoked a 26% reduction of the fast excitatory postsynaptic potential. These results indicate that the application of IL-1beta and PGE2evoke direct excitatory actions on a subset of myenteric neurones. For IL-1beta, direct inhibition and presynaptic inhibition of the fast excitatory postsynaptic potential has also been found. In the distal colon, responses to IL-1beta are not mediated through PGE2pathways.

Animals↗

PubMed2002

Role of nitric oxide in the gastric accommodation reflex and in meal induced satiety in humans.

AIMS: In humans, impaired gastric accommodation is associated with early satiety and weight loss. In animals, accommodation involves activation of gastric nitrergic neurones. Our aim was to study involvement of nitric oxide in gastric accommodation and in meal induced satiety in humans. METHODS: The effect of N(G)-monomethyl-L-arginine (L-NMMA) 4 mg/kg/h and 8 mg/kg/h on gastric compliance, on sensitivity to distension, and on gastric accommodation was studied with a barostat in double blind, randomised, placebo controlled studies. The effect of L-NMMA 8 mg/kg/h on meal induced satiety was studied using a drinking test. RESULTS: L-NMMA had no significant effect on fasting compliance and sensitivity. Ingestion of a meal induced a relaxation of 274 (15) ml which was significantly smaller after L-NMMA 4 mg/kg/h (132 (45) ml; p=0.03) or L-NMMA 8 mg/kg/h (82 (72) ml; p=0.03). L-NMMA 8 mg/kg/h significantly decreased the amount of food ingested at maximum satiety from 1058 (67) to 892 (73) kcal (p<0.01). CONCLUSION: In humans, fasting gastric tone and sensitivity to distension are not influenced by nitric oxide synthase inhibition, but the gastric accommodation reflex involves activation of nitrergic neurones. Inhibition of nitric oxide synthase impairs accommodation and enhances meal induced satiety.

Adaptation, Physiological↗

PubMed2001

Effect of intranasal sumatriptan on gastric tone and sensitivity to distension.

Sumatriptan is able to improve symptoms of early satiety in dyspeptic patients by relaxing the gastric fundus. The aim of this study was to verify the efficacy of intranasal administration of sumatriptan on gastric sensory motor function, in order to provide a new pharmacotherapeutic approach to functional dyspepsia. Thirteen healthy subjects were investigated twice on separate days. A gastric barostat was used to study the effect of placebo and sumatriptan, 20 mg intranasally, on basal fundic tone. In addition, stepwise isobaric distensions were performed and perception was measured before and after administration of drugs. Placebo had no effect on gastric tone and on perception. Sumatriptan caused a small, but short-lasting gastric relaxation and had no significant effect on sensitivity to distension and gastric compliance. Unlike the subcutaneous formulation, the intranasal administration of sumatriptan had no effect on gastric sensory motor functions, and this probably reflects a low biovailability of intranasally administered sumatriptan.

Administration, Intranasal↗

PubMed2001

Contractile effects and intracellular Ca2+ signalling induced by motilin and erythromycin in the circular smooth muscle of human colon.

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 micromol 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.

Acetylcholine↗

PubMed2001

Effect of sildenafil, a phosphodiesterase-5 inhibitor, on oesophageal peristalsis and lower oesophageal sphincter function in cats.

The propagation of oesophageal peristaltic contractions and lower oesophageal sphincter (LOS) relaxation depends on neural release of nitric oxide (NO) which acts to increase intracellular cGMP. Sildenafil, a phosphodiesterase-5 inhibitor that increases cGMP, reduces basal LOS pressure in patients with achalasia. We investigated the effect of sildenafil on the propagation of oesophageal contractions and LOS relaxation in the cat. Oesophageal manometry was performed in five cats under light sedation. Peristaltic contractions were monitored at 1, 2, 3, 4 and 8 cm proximal to the LOS, at the LOS using a Dent sleeve, and at 3 cm distal to the upper oesophageal sphincter. Swallow-induced oesophageal contractions and LOS relaxation were recorded during 30 min before and 30 min after intravenous administration of sildenafil. Sildenafil reduced the amplitude of oesophageal contractions only in the smooth muscle oesophagus. The latency from swallow to distal oesophageal contractions was significantly delayed. LOS pressure was significantly reduced but the relaxation nadir was not modified by sildenafil. Sildenafil has profound effects on oesophageal motility: it modifies propagation and amplitude of oesophageal contractions and reduces LOS pressure. Slowing down the propagation of contractions in the transitional zone between the striated and smooth muscle can be a useful tool in patients with segmental aperistalsis or intermittent simultaneous contractions, while the effect on the LOS can benefit patients with achalasia.

Animals↗

PubMed2001

Free cytosolic Ca2+ recordings from myenteric neurones in multilayer intestinal preparations.

The ability to simultaneously monitor different myenteric neurones in a multilayer preparation may enhance our understanding of the enteric nervous system. Longitudinal muscle myenteric plexus preparations were mounted in recording chambers with a coverslip base and loaded with Indo-1-AM. cytosolic Ca2+ concentration ([Ca2+]i); changes were recorded at room temperature with a confocal microscope. In addition to mechanical (pressure-ring) and pharmacological (nifedipine) reduction of muscle contractions, purpose-designed software was developed to reposition regions of interest and avoid artefacts. Confocal scanning permitted optical selection of single cell layers. High K+ depolarization, used to distinguish between excitable and nonexcitable cells, caused a synchronous [Ca2+]i rise in 84.3% of the ganglion cells. Acetylcholine, substance P and serotonin (all at 10(-5) mol L(-1)) induced transient [Ca2+]i changes in subpopulations of myenteric neurones (45.1%, 42.9 and 21.9%, respectively). In addition to immediate responses to agonists, delayed [Ca2+]i changes were also recorded, suggesting the presence of both directly activated and synaptically driven neurones. Functionally identified neurones and other cells in close apposition to the ganglia (interstitial cells of Cajal) could also be studied. This study demonstrates the potential of optical Ca2+ recordings to monitor spread of activity in myenteric neurones and to study their interaction with non-neuronal targets.

Acetylcholine↗

PubMed2001

Acid, nonacid, and gas reflux in patients with gastroesophageal reflux disease during ambulatory 24-hour pH-impedance recordings.

BACKGROUND & AIMS: Gastroesophageal reflux can be acid, nonacid, pure liquid, or a mixture of gas and liquid. We investigated the prevalence of acid and nonacid reflux and the air-liquid composition of the refluxate in ambulant healthy subjects and patients with reflux disease (GERD). METHODS: Twenty-four-hour ambulatory recordings were performed in 30 patients with symptomatic GERD and erosive esophagitis and in 28 controls. Esophageal pH and impedance were used to identify acid reflux (pH drop below 4.0), minor acid reflux (pH drop above 4.0), nonacid reflux (pH drop less than 1 unit + liquid reflux in impedance), and gas reflux. RESULTS: The total rate of gastroesophageal reflux episodes was similar in patients and controls. Patients with GERD had a higher proportion (45% vs. 33%) and rate of acid reflux than controls (21.5 [9-35]/24 h vs. 13 [6.5-21]/24 h; P < 0.05). One third of reflux events was nonacid in both groups. Mixed reflux of gas and liquid was the most frequent pattern with gas preceding liquid in 50%-80% of cases. Pure liquid reflux was more often acid in patients with GERD than controls (45% vs. 32%; P < 0.05). CONCLUSIONS: Reflux of gastric contents was similarly frequent in patients with GERD and controls. Although there was no difference in the overall number of reflux episodes, more acidic reflux occurred in symptomatic patients with GERD, suggesting differences in gastric acid secretion or distribution.

Adult↗

PubMed2001

Symptoms associated with hypersensitivity to gastric distention in functional dyspepsia.

BACKGROUND & AIMS: Hypersensitivity to gastric distention has been reported in functional dyspepsia, but its characteristics and relevance to symptoms remain unclear. The aim of this study was to define hypersensitivity to gastric distention and its association to specific symptoms in functional dyspepsia. METHODS: We used a gastric barostat to study sensitivity to gastric distention in 80 healthy subjects and in 160 functional dyspepsia patients. Demographic characteristics, gastric emptying, Helicobacter pylori status, gastric accommodation, and a dyspepsia symptom score were obtained from all patients and the relationship with visceral sensitivity was assessed using univariate and multivariate analysis. RESULTS: The increase of intra-balloon pressure over intra-abdominal pressure needed to induce discomfort or pain is the most appropriate expression of sensitivity to gastric distention because it yields a meaningful lower range of normal and it is independent from age and body mass index. Hypersensitivity to gastric distention was found in 34% of the patients, who did not differ from the other patients in demographic and other pathophysiological characteristics. Hypersensitivity to distention was associated with a higher prevalence of postprandial pain, belching, and weight loss. CONCLUSIONS: Hypersensitivity to gastric distention is present in a subset of functional dyspepsia patients. It is associated with symptoms of postprandial epigastric pain, belching, and weight loss.

Abdominal Pain↗

PubMed2001

Reproducibility of gastric barostat studies in healthy controls and in dyspeptic patients.

OBJECTIVES: Gastric barostat studies are increasingly being performed, but their reproducibility and the most suitable study protocol have not been determined. The aim of this study was to verify the reproducibility of gastric sensitivity and accommodation testing in healthy and in dyspeptic subjects, and to compare stepwise and double random staircase distensions. METHODS: A total of 13 dyspeptic patients and 25 healthy control subjects underwent two successive studies. Sensory thresholds were assessed on a same-day/different-days protocol, using a stepwise (11/14 healthy subjects and 11/13 patients) or a double random staircase inflation (11/21 healthy subjects). In 10 healthy subjects, both methods were compared. Gastric accommodation was measured on different days in 13 patients and nine healthy subjects. Data (mean +/- SEM) were compared using the paired t test, and individual variability was expressed as the percent coefficient of variation. RESULTS: In healthy subjects, the thresholds for first perception and for discomfort were highly reproducible (p > 0.05) and the pressure thresholds showed a lower degree of variability than the volumes. Pressure thresholds quantified by stepwise showed lower variability than double random staircase inflation. In the patients, the sensory thresholds were unchanged between the sessions on the same and on different days (p > 0.05). Gastric accommodation also showed excellent reproducibility for both dyspeptic patients and healthy control subjects (p > 0.05). CONCLUSIONS: Both in dyspeptic patients and in healthy control subjects, gastric sensitivity and accommodation quantified by isobaric distensions show excellent reproducibility. Pressure and volume thresholds both are well reproducible, but the former shows less variability. Finally, the simplest stepwise protocol is better than the double random staircase to assess the gastric sensitivity to distension.

Adult↗

PubMed2001

Composition of the postprandial refluxate in patients with gastroesophageal reflux disease.

OBJECTIVE: It is not known whether the characteristics of the postprandial refluxate in patients with gastroesophageal reflux disease (GERD) differ from those observed in normal subjects. The aim of this study was to characterize the postprandial refluxate in adult patients with GERD using combined intraluminal electrical impedance and pH measurements. METHODS: Postprandial gastroesophageal reflux was assessed in 16 patients with GERD and 15 controls. pH and intraluminal electrical impedance were used to identify acid and nonacid reflux of liquid, mixed (liquid + gas) or gas. RESULTS: Transient lower esophageal sphincter relaxations (TLESRs) and reflux of gastric contents were equally frequent in both groups. However, patients with GERD had more acid reflux [8 (4.7-10.5)/h vs 3.5 (2.6-6)/h, p < 0.05], and normal subjects had more nonacid reflux [5 (4.3-6.7)/h is 3 (1-3.5)/h, p < 0.05]. Gas reflux was less frequent in GERD than in controls (51% vs 68%; p < 0.05). Pure liquid reflux, however, was more frequent (40% vs 26%, p < 0.05) and twice as likely to be acid in GERD. During TLESRs, liquid acid reflux was more frequent in GERD than in controls. CONCLUSIONS: TLESRs and reflux of gastric contents are similarly frequent in patients with GERD and controls. However, patients with GERD have more acid reflux and less nonacid reflux. Differences in the air-liquid composition of the refluxate may contribute to the higher rate of acid reflux observed in these patients.

Acids↗