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Biomedical subjects

A J Smout

Publications and source records attributed to A J Smout.

At least 73 records · Page 4Linked to original sources
PubMed1998

Gastric myoelectrical and antroduodenal motor activity in patients with achalasia.

Achalasia is a primary motor disorder of the oesophagus, in which the myenteric plexus is involved. However, abnormalities in other parts of the digestive tract have also been described in achalasia. Whether gastric myoelectrical and duodenal motor activity in these patients is also affected is unknown. Therefore, interdigestive and postprandial gastric myoelectrical and antroduodenal motor activity were studied in 11 patients with achalasia, using electrogastrography (EGG) and stationary antroduodenal manometry. Electrogastrographically, no differences were found in the gastric frequency, incidence of dysrhythmias and postprandial/fasting power ratio. In the interdigestive state a lower propagation velocity of phase III episodes was found in the achalasia patients, but other parameters were unaltered. Postprandially, no differences were found in the number of pressure waves, in the amplitude of pressure waves or in antroduodenal coordination. We conclude that gastric myoelectrical activity and antral motor activity in patients with achalasia is normal, suggesting an intact extrinsic and intrinsic neural innervation of the distal stomach. Although postprandial duodenal motility is normal, a lower propagation velocity of phase III suggests involvement of the small intestine in achalasia.

Adult↗
PubMed1998

Is the sensitivity to gastric acid inhibition Helicobacter pylori status-dependent?

BACKGROUND: Recent studies using 24-h intragastric pH monitoring suggest that treatment with a proton-pump inhibitor is less effective in Helicobacter pylori-negative than in H. pylori-positive subjects. AIM: To survey and discuss the available information on the interaction between H. pylori status and the sensitivity to inhibition of gastric acid secretion. METHODS: Literature review. RESULTS: Upon cure of the infection in H. pylori-positive subjects (healthy controls and duodenal ulcer patients), the effect of omeprazole on gastric pH decreases significantly. The findings indicate that H. pylori or H. pylori-related gastritis augments the sensitivity to proton-pump inhibitors. Preliminary information suggests that the sensitivity to H2-receptor antagonists might be less dependent on H. pylori status. The mechanisms through which H. pylori or the H. pylori-associated gastritis leads to increased sensitivity to acid inhibition have not been fully elucidated. It has been hypothesized that the gastritis associated with H. pylori infection plays a role, since the mucosal inflammatory infiltrate can release acid inhibitory cytokines. Another possible mechanism involves the production of acid neutralizing substances by H. pylori, in particular ammonia. Ammonia might also interfere with the activity of the H+/K+-ATPase pump. Finally, H. pylori has been shown to produce fatty acids that inhibit the proton pump. CONCLUSIONS: An interaction exists between H. pylori status and sensitivity to acid inhibition. This interaction has important clinical implications. In H. pylori-negative patients, current dosing with a proton-pump inhibitor may result in insufficient acid control for optimal treatment of gastro-oesophageal reflux disease (GORD). In future studies on treatment and the natural course of GORD, H. pylori status must be taken into account.

Enzyme Inhibitors↗
PubMed1998

Responses to gastric distension in functional dyspepsia.

BACKGROUND: Studies have shown that an altered visceral perception threshold plays a role in the pathogenesis of upper gastrointestinal tract symptoms in dyspeptic patients. However, it is not clear whether the compliance and adaptive relaxation of the proximal stomach contribute to the symptoms. AIMS: To investigate whether abnormal relaxation or adaptation of the proximal stomach during the interdigestive state and the postprandial phase could explain the symptoms of functional dyspepsia. SUBJECTS: Twelve volunteers and 12 patients with dysmotility-like functional dyspepsia were included in the study. METHODS: An electronic barostat was used to investigate adaptation to distension of the proximal stomach and accommodation in response to a liquid meal. Dyspeptic symptoms during distension and accommodation were assessed. RESULTS: When the subjects were in the fasting state, the pressure-volume curve showed slightly higher compliance in the dyspeptic patients (p < 0.05). Patients not only had a higher score for nausea, bloating, and pain but also the increase in nausea and pain scores with intragastric pressure was higher than in volunteers (p < 0.05). The increase in intragastric bag volume in response to a meal was significantly lower in patients (p < 0.05). Both bloating and pain significantly increased in the patients (p < 0.05), but not in the healthy volunteers. CONCLUSIONS: Patients with functional dyspepsia show slightly higher compliance to mechanical distension. Their visceral perception of mechanical stress is enhanced. In contrast with the balloon distension, relaxation after a meal was less. Therefore the postprandial symptoms cannot be explained fully by greater global tension in the stomach wall, as assessed by the barostat technique. Visceral hypersensitivity plays a major role in the pathogenesis of the symptoms.

Adult↗
PubMed1998

Effects of long-term oral L-arginine on esophageal motility and gallbladder dynamics in healthy humans.

Inhibitory nitrergic neurons are known to play a role in the regulation of motility patterns of the distal esophagus, the lower esophageal sphincter (LES), and the gallbladder. Our study aim was to investigate the effects of "long-term" (i.e., prolonged) oral intake of L-arginine (L-Arg), the endogenous source for nitric oxide (NO) synthesis, on postprandial LES pressure (LESP), esophageal motility, gastroesophageal reflux, and gallbladder motility. L-Arg (30 g/day) or glycine (placebo; 13 g/day; isosmolar) was given orally to 10 healthy male volunteers for 8 days, according to a randomized, crossover design. Twenty-four-hour urinary nitrite/nitrate excretion was measured to indicate NO synthesis. Basal early postprandial LESP was lower after L-Arg ingestion (2.2 kPa) than after glycine ingestion (2.7 kPa) (P < 0.05). L-Arg abolished the physiological late postprandial rise in LESP. Transient LES relaxations were longer lasting after L-Arg ingestion (P < 0.02). Esophageal motility and reflux were not affected (not significant). Fasting and residual gallbladder volumes were greater after L-Arg ingestion (P < 0.05). Urinary nitrite/nitrate excretion was higher after L-Arg intake (P < 0.05). In conclusion, long-term oral L-Arg suppresses late postprandial LESP increase, prolongs transient LES relaxations, and increases fasting and residual gallbladder volumes. These effects may be mediated by increased NO synthesis.

Adult↗
PubMed1997

Effects of a new motilide, ABT-229, on gastric emptying and postprandial antroduodenal motility in healthy volunteers.

BACKGROUND: ABT-229 is a recently developed derivative of erythromycin, devoid of antibiotic activity. We studied the effect of ABT-229 on gastric emptying and postprandial antroduodenal motility in healthy volunteers. METHODS: Placebo, 4 and 16 mg ABT-229 were given as a single oral dose to nine healthy volunteers, in a randomized, 3-period crossover design. A solid meal (250 kcal) was given twice, 45 min after drug ingestion and 4 h later. Gastric emptying of each meal was studied using the 13C-octanoic breath test. Antroduodenal motility was recorded during the total 9-h period. RESULTS: After the first meal, both the 4 and 16 mg doses increased the gastric emptying rate to a similar extent. ABT-229 stimulated the contractile motility of the antrum dose-dependently. The half-emptying time and the lag-phase of gastric emptying correlated with the number of pressure waves that were propagated over the antrum and the mean amplitude of antral pressure waves. After the second meal no significant effects of ABT-229 were found. CONCLUSIONS: A single dose of the new motilin agonist ABT-229 strongly increases the gastric emptying rate in healthy volunteers by increasing the strength and length of propagation of antral pressure waves. ABT-229 has the potential to become a new prokinetic drug.

Administration, Oral↗
PubMed1997

The roles of excessive gastro-oesophageal reflux, disordered oesophageal motility and decreased mucosal sensitivity in the pathogenesis of Barrett's oesophagus.

Barrett's oesophagus is often considered an end stage of gastro-oesophageal reflux disease. In its pathogenesis increased oesophageal acid exposure, disturbed oesophageal motility and decreased oesophageal mucosal sensitivity are thought to be of importance. In this review the role of each of these factors will be discussed and an update of the recent literature will be given.

Animals↗
PubMed1997

Gastrointestinal motor mechanisms in hyperglycaemia induced delayed gastric emptying in type I diabetes mellitus.

BACKGROUND: Hyperglycaemia delays gastric emptying, both in healthy controls and in patients with diabetes mellitus. The effect of hyperglycaemia on antroduodenal motility in diabetes has not yet been studied. AIM: To investigate the gastrointestinal motor mechanisms involved in the hyperglycaemia induced retardation of gastric emptying in patients with type I diabetes mellitus and autonomic neuropathy. In eight diabetic patients antroduodenal manometry was performed simultaneously with scintigraphic measurement of emptying of a mixed solid-liquid meal, during euglycaemia (5-8 mmol/l glucose) and hyperglycaemia (16-19 mmol/l glucose), on separate days, in random order. RESULTS: Hyperglycaemia decreased the cumulative antral motility index from 38.3 (range 24.2-47.6) to 30.8 (range 17.3-38.1) (p = 0.025) and reduced the number of antral pressure waves propagated over > or = 4.5 cm (p = 0.04). Duodenal phase III-like activity was seen irrespective of the glycaemic state (in three patients during euglycaemia and in four patients during hyperglycaemia). Hyperglycaemia significantly affected gastric emptying of the solid meal: it prolonged the lag phase from 20.0 minutes to 28.5 minutes (P = 0.02), increased the 50% emptying time from 73.5 minutes to 104.5 minutes (p = 0.03), and increased the percentage of isotope remaining in the stomach after 120 minutes from 33.5% to 46.5% (p = 0.02). The cumulative antral motility index was correlated with the 50% emptying time (r = 0.75, p = 0.02) during euglycaemia, but not during hyperglycaemia (r = 0.28, P = 0.31). Liquid emptying was not influenced by the blood glucose concentration. CONCLUSIONS: Hyperglycaemia reduces postprandial antral contractile activity and its organisation in patients with type I diabetes and autonomic neuropathy. These changes in antroduodenal motility are likely to constitute the mechanism through which gastric emptying of solids is delayed during high blood glucose concentrations in these diabetic patients.

Adult↗
PubMed1997

Effects of oral erythromycin on fasting and postprandial antroduodenal motility in patients with type I diabetes, measured with an ambulatory manometric technique.

OBJECTIVE: The aim of this double-blind crossover study was to evaluate the effects of oral erythromycin (250 mg t.i.d.) on fasting and postprandial gastrointestinal motility and gastrointestinal symptoms in patients with type I diabetes. RESEARCH DESIGN AND METHODS: Antroduodenal motility was recorded with an ambulatory manometric technique for a 20-h period, including a high-caloric high-fat dinner and a low-caloric low-fat breakfast and a long fasting period, after 2 weeks erythromycin and placebo treatment in 12 patients with type I diabetes. During the manometric study, plasma glucose concentrations were assessed by frequent self-testing. Gastrointestinal symptoms were scored daily to assess the severity of the symptoms (range 0-3). RESULTS: Oral erythromycin decreased the migrating motor complex cycle length from 118.9 +/- 46.0 to 86.2 +/- 25.3 min (P = 0.03) by shortening phase II from 68.7 +/- 23.5 to 48.5 +/- 19.4 min (P < 0.05). The total number of duodenal phase III increased from 48 to 62 (P = 0.075). However, the degree of antral participation to duodenal phase III did not increase. Erythromycin significantly decreased the duration of the postprandial period after dinner (from 417.0 +/- 137.9 to 348.8 +/- 93.8 min, P = 0.04). During this shorter postprandial period, the number of antral contractions (P < 0.01) and the antral motility index increased (P < 0.03), and early phase III activity at the level of the duodenum was abolished. In diabetic patients with antral hypomotility, after dinner, the mean symptom score improved significantly, from 2.07 +/- 0.86 to 1.52 +/- 0.63 (P = 0.018). CONCLUSIONS: This ambulatory antroduodenal manometric study showed that oral erythromycin (250 mg t.i.d.) improves both fasting and postprandial antroduodenal motor activity after a high-caloric meal in patients with type I diabetes. Furthermore, in diabetic subjects with postprandial antral hypomotility, erythromycin reduces dyspeptic symptoms.

Administration, Oral↗
PubMed1996

Source modeling of esophageal evoked potentials.

Evoked potentials can be recorded from the scalp after stimulation of the esophagus by balloon distension. The purpose of this study was to estimate the number and localization of sources contributing to the esophageal evoked potential (EEP). The EEP was recorded from 32 scalp electrodes in 5 healthy subjects. Spatio-temporal dipole modeling was performed in the time interval from 185 msec to 525 msec after stimulation (mean values). The EEP was best explained by the combined activity of 1 dipole located relatively high in the midline and 2 lateral dipoles. Given the anatomical projection of esophageal sensory fibers and the location of these dipoles the sources were probably located in the cingulate gyri and insular cortex. There was no evidence that sources in the lower brain-stem contributed to the scalp recorded EEP.

Adult↗
PubMed1996

Objective determination of pH thresholds in the analysis of 24 h ambulatory oesophageal pH monitoring.

In 24 h oesophageal pH monitoring, pH 4 is widely but arbitrarily used as the threshold between reflux and non-reflux pH values. The aim of the study was to define pH thresholds objectively, based on Gaussian curve fitting of pH frequency distributions. Single-channel 24 h oesophageal pH monitoring was performed in 26 healthy volunteers and 26 patients with pathological gastro-oesophageal reflux, and five-channel pH-metry was performed in 14 healthy volunteers and 14 patients. The calculated pH thresholds varied between healthy volunteers from 5 center dot 0 to 6 center dot 4 in the upright position and from 4 center dot 5 to 5 center dot 7 in the supine position, but were constant between different oesophageal recording sites. In 15 and nine patients (single-channel and five-channel pH-metry respectively), pH thresholds could not be determined at the distal oesophageal sites. However, the calculated pH thresholds in the proximal oesophagus were in the same range as in the control subjects. The authors conclude that the use of the conventional threshold of pH 4 leads to underestimation of the extent of gastrooesophageal reflux, but are reluctant to advocate the use of higher thresholds in clinical practice.

Adult↗
PubMed1996

Small intestinal motor abnormalities in patients with functional dyspepsia demonstrated by ambulatory manometry.

AIMS/METHODS: In 30 patients with functional dyspepsia and in 20 healthy volunteers, ambulatory duodenojejunal manometry was performed to examine the interdigestive and postprandial small intestinal motility patterns in relation to symptoms. RESULTS: In the fasting state, the number of migrating motor complex cycles mean (SEM) was significantly lower in patients, especially in patients with dysmotility-like dyspepsia, than in control subjects (3.8 (0.4), 2.6 (0.5), and 5.3 (0.7) cycles, respectively; p < 0.05), due to a longer duration of phase II. Non-propagated and retrogradely propagated phase III activity was more prevalent in patients than in control subjects (48% v 15%; p = 0.020). During phase II and after dinner no differences were found in contraction incidence, mean amplitude or motility index. However, 1 1/2 hours after completing breakfast the motility index was higher in patients at all three recording levels (p < 0.05). Burst activity was more prevalent in patients than in control subjects (22% v 6% of the subjects; p = 0.003). In 41% of the patients the symptom index was > 75%. CONCLUSIONS: These results suggest that small intestinal motor abnormalities, especially during fasting, participate in the pathogenesis of symptoms in patients with functional dyspepsia. Ambulatory manometry of the small intestine is a valuable tool to demonstrate these abnormalities in outpatients pursuing their daily activities.

Adult↗
PubMed1996

Prevalence of esophageal disorders in patients with chest pain newly referred to the cardiologist.

STUDY OBJECTIVE: The prevalence of esophageal disorders (dysmotility and/or gastroesophageal reflux) in patients with chest pain newly referred to a cardiologic clinic is unknown. The aims of our study were to investigate the prevalence of esophageal abnormalities in these patients and to assess the value of medical history in predicting the origin of the patient's chest pain. DESIGN: We evaluated 28 consecutive patients who were newly referred to the cardiologist because of angina-like chest pain. Patients with evidence of severe myocardial ischemia were excluded. Cardiologic evaluation included medical history, physical examination, ECG, and exercise testing; further cardiologic workup was carried out only when considered necessary. Gastroenterologic evaluation consisted of medical history, esophageal manometry, endoscopy, and 24-h ambulatory monitoring of esophageal pH and pressure. MEASUREMENTS AND RESULTS: In five patients a diagnosis of ischemic coronary artery disease was made. In only two of these five patients, the cardiologic history strongly suggested a cardiac origin of the pain. Twelve patients had a pathologic 24-h pH profile, four of whom also had reflux esophagitis. Ten patients had symptomatic reflux. In only three of these ten patients, the history was judged to be indicative of an esophageal origin of the chest pain. No motility disorders were found. CONCLUSIONS: Thirty-six percent of the patients with chest pain newly referred to a cardiologic out-patient clinic have symptomatic gastroesophageal reflux. Neither cardiologic nor gastroenterologic history data have a high predictive value with respect to the origin of the chest pain.

Adult↗
PubMed1996

Abnormalities of antroduodenal motility in type I diabetes.

OBJECTIVE: In the present study, a recently developed manometric technique was used to study antroduodenal motility in ambulant type I diabetic subjects. RESEARCH DESIGN AND METHODS: In 12 patients with type I diabetes, antroduodenal manometry was performed for 20 h during the fasting period and the postprandial period after a standardized dinner and breakfast. All patients had evidence of cardiac autonomic neuropathy and complained of dyspeptic symptoms. During the manometric study, the blood glucose levels were frequently monitored and kept close to euglycemia in the diabetic patients. The results were compared with 12 healthy control subjects. RESULTS: The migrating motor complex cycles observed in the diabetic subjects were longer than in the control subjects, 118.9 +/- 46.0 vs. 87.0 +/- 21.6 min (P < 0.05). This increase was attributable to a prolonged phase II, 78.0 +/- 35.5 vs. 37.7 +/- 18.5 min (P < 0.05). In the diabetic subjects, antral phase III was seen significantly less than in the control subjects, 16.7 vs. 43.3% (P < 0.005). In 50% of the diabetic patients, total absence of antral phase III was observed-this phenomenon was not seen in the healthy control subjects. After dinner, the antral motility index was less in diabetic subjects compared with the healthy volunteers, indicating antral hypomotility (P < 0.01). Six diabetic patients showed abnormal duodenal activity such as early recurrence of phase III and bursts after dinner. No significant differences in antral motility index or in duodenal motility patterns were observed after breakfast. Six diabetic patients complained of dyspeptic symptoms after dinner, whereas none had dyspeptic symptoms after breakfast. In 67% of the patients, nausea was reported after an early phase III or a burst. CONCLUSIONS: This study shows that prolonged ambulatory antroduodenal manometry is a feasible technique in patients. Recording multiple migrating motor complexes showed that interdigestive motor abnormalities of the stomach and duodenum are common in diabetic patients. Furthermore, it shows the occurrence of antral hypomotility and abnormal duodenal motility patterns after a high-calorie meal, with dyspeptic symptoms in diabetic patients being related to the composition of the meal.

Adult↗
PubMed1996

Gastro-oesophageal reflux disease in The Netherlands. Results of a multicentre pH study.

Information on the relationships between gastro-oesophageal reflux (GOR), reflux symptoms, hiatal hernia (HH) and oesophagitis, and the response to antisecretory treatment is lacking. In a multicentre study endoscopy, ambulatory 24-h pH monitoring and symptom assessment were carried out in 142 patients with symptomatic reflux disease before and during treatment with ranitidine. Using a randomized, double-blind design, patients took ranitidine 150 mg bid or 300 mg bid. Macroscopic oesophagitis (grade I or II) was found in 85 patients; the remaining 57 patients had normal oesophageal mucosa. A significant correlation was found between the presence of an HH and the presence of oesophagitis. Symptom scores were similar in patients with and without oesophagitis, and in patients with and without HH. Patients with oesophagitis had significantly greater oesophageal acid exposure during the night, and in the total 24-h period, but not during the day. Likewise, patients with HH had greater acid exposure during the night (p < 0.008). Both doses of ranitidine significantly decreased oesophageal acid exposure and the effect was independent of baseline acid exposure. Reflux symptoms cannot be used to differentiate between presence or absence of oesophagitis and/or HH. Reflux patients without oesophagitis have less night-time reflux. Ranitidine dose-dependently decreases oesophageal acid exposure, and the effect is independent of baseline reflux.

Chi-Square Distribution↗
PubMed1996

Low-amplitude distal esophageal spasm as a cause of severe dysphagia for solid food.

This case report presents a patient with progressive dysphagia, accompanied by weight loss, in the absence of organic disease. Esophageal motility studies initially failed to reveal a diagnosis. At simultaneous manometry and fluoroscopy, with bread/barium boluses, the diagnosis of esophageal spasm in a relatively weak esophagus was made. All conservative treatment modalities failed. Thoracoscopic myotomy resulted in partial field of symptoms. Finally, an esophagectomy was performed because of sever dysphagia accompanied by persisting weight loss.

Chronic Disease↗