Biomedical subjects

Jozef Janssens

Publications and source records attributed to Jozef Janssens.

8 recordsLinked to original sources

PubMed2003

Influence of duodenal acidification on the sensorimotor function of the proximal stomach in humans.

Decreased acid clearance and increased exposure to acid of the duodenum have been reported in a subset of functional dyspepsia patients. However, the mechanism by which increased duodenal acid exposure may affect symptoms is unclear. The aim of the present study was to investigate the effects of duodenal acidification on proximal gastric tone and mechanosensitivity in humans. An infusion tube with a pH electrode attached was positioned in the second part of the duodenum, and a barostat bag was located in the gastric fundus. In 12 healthy subjects, fundic tone and sensitivity to distensions were assessed before and during duodenal infusion of 0.1 N hydrochloric acid or saline in a randomized, double-blind design. In 10 healthy subjects, meal-induced accommodation was measured during duodenal infusion of acid or saline. Acid infusion in the duodenum significantly increased fundic compliance and decreased fasting fundic tone. This was accompanied by a significant decrease in the pressures and the corresponding wall tensions at the thresholds for discomfort. During infusion of acid, significantly higher perception and symptom scores were obtained for the same distending pressures. The meal-induced fundic relaxation was significantly smaller during acid infusion compared with saline infusion. In conclusion, duodenal acidification induces proximal gastric relaxation, increases sensitivity to gastric distension, and inhibits gastric accommodation to a meal. Through these mechanisms, increased duodenal acid exposure may be involved in the pathogenesis of dyspeptic symptoms.

Acids↗

PubMed2003

Acid infusion enhances duodenal mechanosensitivity in healthy subjects.

Duodenal acid has been suggested to be of importance for dyspeptic symptoms. We investigated the effects of acid on duodenal mechanosensitivity and antroduodenal motility in 10 healthy subjects before and during duodenal infusion of acid (0.1 N HCl) or water by using a combined barostat-manometry assembly. During acid infusion, increased sensitivity to balloon distension was seen, with reduced perception (P = 0.04) and discomfort thresholds (P = 0.06) and higher intensity of discomfort (P = 0.02) compared with water. Higher balloon volumes were seen during acid infusion, indicating decreased tone (P = 0.05). Large volume waves were more prevalent during acid than water infusion (P = 0.009). The acid infusion suppressed antral contractions (P = 0.04) and increased the number of contractions in the proximal duodenum (P = 0.02) compared with before the infusion. In conclusion, duodenal acid enhances mechanical sensitivity in the duodenum, affects gastroduodenal motor function, and might be of importance for dyspeptic symptoms.

Adult↗

PubMed2003

Dietary restrictions during ambulatory monitoring of duodenogastroesophageal reflux.

To avoid food impaction artifacts during ambulatory bile reflux monitoring (Bilitec), some groups have allowed only a liquid diet, while others omitted the meal and postprandial periods from the analysis. Our aim was to study whether Bilitec monitoring requires the use of a liquid diet. In 40 healthy subjects and 211 consecutive patients evaluated for suspected gastroesophageal reflux disease, we performed ambulatory 24-hr esophageal pH and Bilitec monitoring. The subjects were randomized to either solid or liquid meals during the procedure. All patients underwent an upper gastrointestinal endoscopy. In healthy subjects, liquid and solid diets were followed by similar acid exposure of the distal esophagus. During bile reflux monitoring, major meal artifacts occurred in 19% of the patients using solid meals, but in none of the patients using liquid meals. With liquid meals, but not with solid meals, a progressive increase in duodenoesophageal reflux occurred with increasing severity of endoscopic lesions. With liquid meals, but not with solid meals, the prevalence of pathological exposure to duodenoesophageal reflux increased with increasing severity of endoscopic lesions. With liquid meals, the results of pH monitoring and bile reflux monitoring correlated better than with solid meals. Thus, ambulatory Bilitec monitoring requires the use of liquid meals, as the use of solid meals is associated with too many meal artifacts and a poorer correlation with acid reflux and severity of endoscopic lesions.

Adolescent↗

PubMed2003

Heterogeneity of symptom pattern, psychosocial factors, and pathophysiological mechanisms in severe functional dyspepsia.

BACKGROUND & AIMS: Categorization of functional dyspepsia into subgroups is based on expert opinion according to (dominant) symptoms or on underlying pathophysiological mechanisms. We used an evidence-based approach to the determination of subtypes of functional dyspepsia. METHODS: Consecutive functional dyspepsia patients were recruited from a tertiary referral center. The following were performed: (1) exploratory (EFA) and confirmatory factor analysis (CFA) of symptom patterns in a large group of patients with functional dyspepsia; (2) external validation of these factors by the determination of their association pattern with physio- and psychopathological mechanisms, and with health-related quality of life and sickness behavior; and (3) cluster analysis of their distribution in this population. RESULTS: Both EFA and CFA do not support the existence of functional dyspepsia as a homogeneous (unidimensional) condition. A 4-factor model is found to be valid, with differential distribution within the patient population according to cluster analysis. Factor 1 is characterized by nausea, vomiting, early satiety, and weight loss and factor 2 by postprandial fullness and bloating. Both factor 1 and 2 are associated with delayed emptying, but only factor 1 is associated with younger age, female sex, and sickness behavior. Factor 3 is characterized by pain symptoms and associated with gastric hypersensitivity and several psychosocial dimensions including medically unexplained symptoms and health-related quality of life dimensions. Factor 4, characterized by belching, is also associated with hypersensitivity, but is unrelated to psychosocial dimensions. CONCLUSIONS: In a tertiary care population, functional dyspepsia is a heterogeneous condition characterized by 4 major dimensions differentially associated with psychopathological and physiopathological mechanisms.

Abdominal Pain↗

PubMed2003

Symptoms associated with impaired gastric emptying of solids and liquids in functional dyspepsia.

OBJECTIVE: The relationship between functional dyspepsia and delayed gastric emptying of solids or liquids is still unclear. The aim of the present study was to investigate in dyspeptic patients the prevalence of delayed gastric emptying for solids or for liquids and to investigate the relationship to the dyspepsia symptom pattern. METHODS: In 392 and 330 patients with functional dyspepsia, the solid and liquid gastric emptying, respectively, was measured using breath tests, and the severity of eight dyspeptic symptoms was scored. RESULTS: Gastric emptying of solids and liquids were delayed in 23% and 35% of the patients. Multivariate analysis showed that the presence of vomiting and postprandial fullness was associated with delayed solid emptying (OR 2.65, 95% CI = 1.62-4.35 and OR 3.08, 95% CI = 1.28-9.16, respectively). Postprandial fullness was also associated with the risk of delayed liquid emptying when symptom was present (OR 3.5, 95% CI = 1.57-8.68), relevant or severe (OR 2.504, 95% CI = 1.41-4.65), and severe (OR 2.214, 95% CI = 1.34-3.67). Severe early satiety was associated with the risk of delayed liquid emptying (OR 1.902, 95% CI = 1.90-3.30). CONCLUSIONS: A subset of dyspeptic patients has delayed gastric emptying of solids or of liquids. Delayed gastric emptying of solids was constantly associated with postprandial fullness and with vomiting. Delayed emptying for liquids was also associated with postprandial fullness and with severe early satiety.

Adolescent↗

PubMed2002

Functional Heartburn.

Functional heartburn is defined as the presence of a retrosternal burning sensation in the absence of pathologic gastroesophageal reflux. The underlying pathophysiology seems to be heterogeneous. In a subset of patients, esophageal hypersensitivity to physiologic esophageal acid exposure is involved, and this is likely to respond to intensive antireflux treatment. Antireflux surgery was not studied systematically in these patients and should be considered only in exceptional cases. In the remaining patients, non-acid reflux, esophageal mechanosensitivity, and psychological factors may be involved. Treatment options in these patients are limited owing to a lack of studies. Emerging therapies include selective serotonin reuptake inhibitors and relaxation therapy.

Journal Article↗

PubMed2002

Clinical and pathophysiological characteristics of acute-onset functional dyspepsia.

BACKGROUND & AIMS: Functional bowel disorders may follow acute intestinal infection. In animals, postinflammatory dysmotility is associated with nitrergic dysfunction. The aim of this study was to identify and characterize patients with presumed postinfectious dyspepsia (PD) compared with unspecified-onset dyspepsia (UD). METHODS: A total of 400 consecutive dyspeptic patients filled out a questionnaire to assess whether their symptoms were of postinfectious origin. They underwent testing for Helicobacter pylori infection as well as gastric emptying and gastric barostat studies. Pharmacological studies of nitrergic gastric function were performed in controls, in patients with presumed PD, and in patients with UD using sumatriptan, an activator of nitrergic neurons, and amylnitrite, a nitric oxide donor. RESULTS: Presumed PD was present in 17% of the patients and associated with more prevalent early satiety, weight loss, nausea, and vomiting compared with UD. Both groups did not differ in H. pylori infection, gastric emptying, or gastric sensitivity. Impaired accommodation was significantly more prevalent in patients with presumed PD (67% vs. 30%; P < 0.05). Sumatriptan relaxed the stomach in controls and patients with UD but not in patients with presumed PD, whereas amyl nitrite relaxed the stomach in all subjects. CONCLUSIONS: A subset of dyspeptic patients has a history suggestive of postinfectious dyspepsia. These patients have a high prevalence of impaired accommodation attributable to a dysfunction at the level of gastric nitrergic neurons.

Adolescent↗

PubMed2002

Gastric electrical stimulation in intractable symptomatic gastroparesis.

BACKGROUND: The treatment of gastroparesis remains unsatisfactory despite prokinetic and anti-emetic drugs. Gastric electrical stimulation has been proposed as a therapeutic option. We have assessed the effect of gastric electrical stimulation on symptoms, medical treatment, body weight and gastric emptying in patients with intractable symptomatic gastroparesis in a non-placebo-controlled study. METHODS: In this multicenter study, 38 highly symptomatic patients with drug-refractory gastroparesis were enrolled. Patients first received temporary electrical stimulation using percutaneous electrodes. The 33 responders to temporary stimulation then underwent surgical implantation of a permanent stimulator. Severity of vomiting and nausea was assessed before and after stimulation. Patients were reassessed 3, 6, and 12 months after permanent implantation. RESULTS: With stimulation, 35/38 patients (97%) experienced >80% reduction in vomiting and nausea. This effect persisted throughout the observation period (2.9-15.6 months, 341 patient-months). Gastric emptying did not initially change, but improved in most patients at 12 months. At 1 year, the average weight gain was 5.5% and 9/14 patients initially receiving enteral or parenteral nutrition were able to discontinue it. CONCLUSION: Electrical stimulation of the stomach has an immediate and potent anti-emetic effect. It offers a safe and effective alternative for patients with intractable symptomatic gastroparesis.

Adolescent↗