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Biomedical subjects

M Samsom

Publications and source records attributed to M Samsom.

At least 73 records · Page 4Linked to original sources
PubMed1999

Clinical relevance of antroduodenal manometry.

OBJECTIVE: To evaluate the outcome of antroduodenal manometry studies and their effect on the clinical treatment of patients. DESIGN: A retrospective review of clinical antroduodenal manometric studies performed between September 1990 and March 1997 (n = 109). SETTING: Tertiary referral centre. MAIN OUTCOME MEASURES: The predominant symptom, the indication for the study, the outcome and the clinical impact were scored. A positive impact was defined as an outcome that resulted in an alteration of the management of the patient (medication, surgery, feeding), established a new diagnosis, or resulted in new investigations or in referral to another specialist. RESULTS: Full records were obtained from 91 studies in 85 patients (mean age 43 years). Nausea and vomiting were the most predominant symptoms (37.4%). In 49.5% of the cases, the test was performed due to suspicion of a generalized motor disorder. A normal outcome was found in 37 studies. Non-specific motor abnormalities were reported in 72% of the studies with an abnormal outcome. Pseudo-obstruction was diagnosed in 20%. The manometric studies resulted in a new therapy in 12.6%, a new diagnosis in 14.9%, and referral to another specialist in 8%. A positive clinical impact was found in 28.7% of the patients. CONCLUSION: Antroduodenal manometry can be a helpful diagnostic technique in a specialized centre. More research is needed to gain insight into the significance of the large number of non-specific abnormalities that are often found.

Adolescent↗
PubMed1999

Effect of coffee on gastro-oesophageal reflux in patients with reflux disease and healthy controls.

BACKGROUND: Many patients with gastro-oesophageal reflux disease (GORD) report that coffee aggravates their symptoms and doctors tend to discourage its use in GORD. OBJECTIVE: To assess the effect of coffee ingestion on gastro-oesophageal acid reflux. DESIGN: A randomized, controlled, crossover study. PARTICIPANTS: Seven GORD patients and eight healthy subjects. METHODS: After 1 day of coffee abstinence, participants underwent 24-h oesophageal pH and manometric monitoring. At well-defined times, they ingested either 280 ml of regular paper-filtered coffee or 280 ml of warm water. Coffee or water was drunk 1 h after breakfast, during lunch, 1 h after dinner and after an overnight fast Reflux and oesophageal motility parameters were assessed for the first hour after each coffee or water intake. RESULTS: Coffee had no effect on postprandial acid reflux time or number of reflux episodes, either in GORD patients or in healthy subjects. Coffee increased the percentage acid reflux time only when ingested in the fasting period in the GORD patients (median 2.6, range 0-19.3 versus median 0, range 0-8.3; P = 0.028), but not in the healthy subjects. No effect of coffee on postprandial lower oesophageal sphincter pressure (LOSP), patterns of LOSP associated with reflux episodes or oesophageal contractions was found. CONCLUSION: Coffee has no important effect on gastro-oesophageal acid reflux in GORD patients, and no effect at all in healthy subjects.

Adult↗
PubMed1999

Physiological changes in blood glucose do not affect gastric compliance and perception in normal subjects.

Marked hyperglycemia (blood glucose approximately 14 mmol/l) slows gastric emptying and affects the perception of sensations arising from the gut. Elevation of blood glucose within the physiological range also slows gastric emptying. This study aimed to determine whether physiological changes in blood glucose affect proximal gastric compliance and/or the perception of gastric distension in the fasting state. Paired studies were conducted in 10 fasting healthy volunteers. On a single day, isovolumetric and isobaric distensions of the proximal stomach were performed using an electronic barostat while the blood glucose concentration was maintained at 4 and 9 mmol/l in random order. Sensations were quantified using visual analog scales. The blood glucose concentration had no effect on the pressure-volume relationship during either isovolumetric or isobaric distensions or the perception of gastric distension. At both blood glucose concentrations, the perceptions of fullness, nausea, bloating, and abdominal discomfort, but not hunger or desire to eat, were related to intrabag volume (P </= 0.002) and pressure (P </= 0.01). We conclude that, in the fasted state, elevations of blood glucose within the physiological range do not affect proximal gastric compliance or the perception of gastric distension.

Adult↗
PubMed1999

Development of a test to measure gastric accommodation in humans.

Postprandial symptoms of bloating, distension, early satiety, and nausea are associated with impaired postprandial gastric accommodation, which is detectable by means of an intragastric, barostatically controlled balloon in the proximal stomach and by ultrasound in the distal stomach. Our aim was to develop a noninvasive method to measure the entire gastric accommodation reflex. In 10 healthy volunteers, we used single photon emission computed tomography (SPECT) to measure fasting and postprandial gastric volumes. This method involved intravenous injection of (99m)Tc pertechnetate and gastric reconstruction of tomographic images with Analyze software. SPECT-Analyze imaging detects the postprandial gastric accommodation reflex in vivo. Mean fasting gastric volume was 182 +/- 11 (SE) ml and mean postprandial volume was 690 +/- 32 ml (P < 0.001). Both proximal and distal segments of stomach showed a two- to almost fourfold difference in volumes postprandially. Intraobserver coefficients of variation in estimated fasting and postprandial volumes were 9 and 8%; interobserver variations were 13 and 12%, respectively. SPECT-Analyze noninvasively measures postprandial gastric (total, proximal, and distal) accommodation in humans. This method appears promising to compare the accommodation response in health and disease and to perform mechanistic studies of the accommodation response.

Adolescent↗
PubMed1999

Hyperglycemia attenuates the gastrokinetic effect of erythromycin and affects the perception of postprandial hunger in normal subjects.

OBJECTIVE: The major aims of this study were to determine in normal subjects whether the effects of erythromycin on gastric emptying, postprandial hunger, and fullness are modified by the blood glucose concentration. RESEARCH DESIGN AND METHODS: A total of 10 normal subjects (aged 20-39 years) underwent concurrent measurements of gastric emptying, blood glucose, hunger, and fullness on four separate occasions: twice during euglycemia (approximately 4 mmol/l) and twice during hyperglycemia (approximately 15 mmol/l). Either erythromycin (3 mg/kg) or saline (0.9%) was administered intravenously immediately before ingestion of a radioisotopically labeled solid meal. RESULTS: Gastric emptying was slower (P < 0.0001) during hyperglycemia when compared with euglycemia after both erythromycin and saline administration. During hyperglycemia, erythromycin reduced the lag phase (77.8 +/- 12.6 vs. 20.3 +/- 7.3 min; P < 0.05) but had no effect on the postlag emptying rate (0.32 +/- 0.077% per min vs. 0.24% per min). Hunger decreased (P < 0.001) and fullness increased (P < 0.001) after the meal. Postprandial hunger was less during hyperglycemia after saline infusion (P < 0.05) but not after erythromycin. Hunger was greater after erythromycin during both hyperglycemia and euglycemia (P < 0.05). CONCLUSIONS: At a blood glucose concentration of approximately 15 mmol/l, 1) gastric emptying of a solid meal is slower, when compared with euglycemia, even after administration of erythromycin; 2) the effect of erythromycin on gastric emptying of a solid meal is attenuated; and 3) the perception of postprandial hunger is reduced.

Adult↗
PubMed1999

24-h recording of intragastric pH: technical aspects and clinical relevance.

BACKGROUND: Information about gastric acid secretion and gastric acidity can be obtained using several techniques but, presently, continuous intragastric pH recording is probably the one applied most frequently. This paper aims to review the technical aspects and some important applications of intragastric pH monitoring in research and clinical practice. METHODS: Literature review. RESULTS: Most studies on intragastric pH are performed with either glass or antimony electrodes. Optimal measurement of 24-h intragastric pH requires accurate calibration of the pH measuring system, exact positioning of the pH electrodes, and a sufficient sample rate. Depending on the aim of the study the results of intragastric pH monitoring are expressed either as median H+ activity or as median pH values. Gastric acidity shows a circadian rhythm, modified by buffering meals and nocturnal duodenogastric reflux. In health, age, gender and smoking habits are known to influence gastric acidity. In duodenal ulcer disease an increased gastric acidity is found and in patients with gastric ulcer gastric acidity is decreased. In GERD, no relation between reflux oesophagitis and gastric acidity is found. Helicobacter pylori affects intragastric pH most pronounced during acid inhibitory therapy, both in DU patients and in healthy subjects. In the absence of H. pylori the effect of proton-pump inhibitors on intragastric pH is much less than in the presence of the microorganism, whereas the effect of ranitidine on intragastric pH is barely affected by the H. pylori status. CONCLUSIONS: Despite some limitations, intragastric pH monitoring provides important information about gastric acidity.

Circadian Rhythm↗
PubMed1998

Genomic organization and promoter characterization of human CXCR4 gene.

CXCR4 is the receptor for the CXC chemokine SDF1 that has essential functions on embryo organogenesis, immunological functions and T lymphocyte trafficking. Recently, CXCR4 has drawn unexpected attention as it was recently identified as a co-factor required for entry of lymphotropic HIV isolates in CD4+ T lymphocytes. CXCR4 is the only SDF1 receptor identified so far. This suggests that CXCR4 expression is critical for the biological effects of SDF1. To investigate the mechanisms controlling both the constitutive and induced expression of CXCR4 receptors we have isolated and characterized the promoter region and determined the genomic structure of the human gene. The CXCR4 gene contains two exons separated by an intronic sequence. A 2.6 kb 5'-flanking region located upstream the CXCR4 open reading frame contains a TATA box and the transcription start site characteristic of a functional promoter. This region also contains putative consensus binding sequences for different transcription factors, some of them associated with the hemopoiesis and lymphocyte development.

Base Sequence↗
PubMed1998

[Causes of spread and return of scabies in health care institutes; literature analysis of 44 epidemics].

OBJECTIVE: To determine the risk factors that contribute to the transmission and return of scabies in health care institutions. DESIGN: Literature analysis. SETTING: Public Health Care Service Midden-Kennemerland. Heemskerk, the Netherlands. METHODS: Search of Medline over the years 1976-1996 yielded 34 reports of 44 outbreaks. The contents were qualitatively examined on factors possibly contributing to the transmission and return of scabies in health care institutions. RESULTS: Six such factors that contribute to the transmission and return of scabies in health care institutions were found: (a) among residents in health care institutions a considerable number are, once infested, at risk of developing crusted scabies, (b) many people are exposed through close contact, (c) the generally long diagnostic delay, (d) insufficient survey of the epidemiological problem, (e) treatment failures and (f) incomplete post-intervention monitoring.

Disease Outbreaks↗
PubMed1998

Proximal gastric motor activity in response to a liquid meal in type I diabetes mellitus with autonomic neuropathy.

Disordered gastric emptying occurs in 30-50% of patients with diabetes mellitus. Although the rate of gastric emptying is dependent on the integration of motor activity in different regions of the stomach, there is limited information about the function of the proximal stomach in diabetes mellitus. In the present study the response of the proximal stomach to a liquid meal was examined in eight diabetic patients with autonomic neuropathy and gastrointestinal symptoms and in 10 healthy volunteers, using an intragastric bag connected to an electronic barostat. Postprandial relaxation of the proximal stomach was measured as an increase of intragastric bag volume at a constant pressure level of 1 mm Hg above the intraabdominal pressure. During the experiment the blood glucose levels were maintained within the euglycemic range. Before ingestion of the meal the intragastric bag volume was larger in the diabetic patients than in the healthy volunteers, 234.4 +/- 29.1 ml vs 155.3 +/- 15.3 ml (P = 0.06). The maximum volume was not different in diabetics compared to the healthy controls (386.3 +/- 45.2 ml versus 399.0 +/- 35.2 ml). However, the maximum volume increase was significantly less in diabetics (143.7 +/- 38.6 ml) compared to the controls (231.4 +/- 30.5 ml, P < 0.04). Bloating was inversely correlated with the volume changes, which suggests that impaired relaxation of the proximal stomach may play a role in the genesis of this sensation. In conclusion, this study shows a lower fasting fundal tone and a decrease in volume change of the gastric fundus after a nutrient drink in patients with autonomic neuropathy due to type I diabetes mellitus. These abnormalities may play a role in the abnormal distribution of food, disordered liquid gastric emptying, and in the genesis of the sensation of bloating observed in these patients.

Autonomic Nervous System Diseases↗
PubMed1998

Effect of meal temperature on the frequency of gastric myoelectrical activity.

It was hypothesized that the transient post-prandial decrease of the dominant frequency in the electrogastrogram (EGG) is related to the temperature of the meal. In a randomized three-period cross-over design. EGG recordings were made in 10 healthy volunteers. A liquid meal (36 kcal, 300 mL) was ingested at either 4, 37 or 55 degrees C. The changes in the dominant EGG frequency that occurred in the first 25 min postprandial were calculated using running spectrum analysis. After the meal a transient shift in frequency was seen, which was significantly greater after the cold meal than after the other meals (P < 0.001), with a greater decrease in the dominant frequency (4 degrees C: -0.75 [-0.92(-)-0.68], 37 degrees C: -0.34 [-0.51(-)-0.18], 55 degrees C: -0.30 [-0.45(-)-0.12] cpm; P = 0.020) and a longer duration (4 degrees C: 16 [13-19], 37 degrees C: 12 [6-14], 55 degrees C: 5 [3-8] min; P = 0.014). No differences were found between the 37 degrees C and 55 degrees C meals, the power ratios or the number of dysrhythmias. The magnitude of the postprandial shift in frequency of gastric myoelectrical activity depends on the temperature of the meal. Meal temperature should be taken into account in studies on postprandial gastric motility.

Adult↗
PubMed1998

A novel portable perfused manometric system for recording of small intestinal motility.

The development of solid-state catheters with miniature pressure transducers and portable dataloggers with a large memory capacity has allowed recording of gastrointestinal motility in ambulant subjects. Developments in silicone rubber extrusion technology made it possible to build a perfused manometric system, using a perfused manometric assembly requiring a low volume of perfusate. In the present study the feasibility of recording and automated analysis of small intestinal motility using a perfused multiple lumen manometric system was evaluated in seven healthy volunteers. Pressures were recorded from 12 sideholes arranged in four clusters spaced at 10-cm intervals from the catheter tip. Each channel was perfused at 0.15 mL min-1 with degassed water by a portable, low-compliance, perfusion pump. The 12 sidehole recording channels were connected to external transducers mounted on a belt. Pressure data were stored in two dataloggers. Motility was recorded in the sitting (30 min), and supine (30 min) position, during walking (30 min) and postprandially (90 min). Using purpose-built software baseline variations were corrected for and manometric variables (number of pressure waves, mean amplitude and motility index) calculated. Bench testing of the manometric assembly showed a median baseline pressure offset of 4.2 kPa (range 3.7-10.1) and upon occlusion a rise rate of 27.8 kPa sec-1 (range 19.7-30.8). Changes in body position affected baseline pressures so that compared to the supine position changes in baseline pressure varied between 1.5 +/- 0.7 kPa and 1.9 +/- 0.6 kPa during sitting (P < 0.02), and between 1.7 +/- 0.7 kPa and 1.5 +/- 0.9 kPa during walking (P < 0.03). Manometric recordings obtained during the fasting period showed an increase in small intestinal motor activity during walking. In the postprandial period no differences in motility variables were observed within one cluster and in time. Recording of small intestinal motility with a multiple-channel silicone rubber manometric assembly with a portable perfusion system is a feasible technique which is relatively inexpensive. Computer-assisted data processing allows for adequate elimination of artefacts and automated numerical analysis.

Adult↗
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

Gastrointestinal motility and gastric tube feeding in mechanically ventilated patients.

OBJECTIVE: To determine the fasted and fed gastrointestinal motility characteristics that are possibly responsible for gastric retention in mechanically ventilated patients. DESIGN: Prospective, case series. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: Seven patients who required mechanical ventilation for thoracic or combined thoracic-neurologic injuries and nine healthy volunteers. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Antroduodenal manometry was performed during fasting and gastric feeding with a polymeric diet in patients during mechanical ventilation, weaning, and after detubation. Gastric retention volumes were determined during gastric tube feeding. Motility data were compared with recordings from nine healthy volunteers. During the fasting state, under sedation and morphine, the migrating motor complex in patients was significantly (p < .001) shortened: median 32.0 vs. 101.0 mins in healthy volunteers. During gastric tube feeding, the motility pattern did not convert to a normal postprandial pattern until morphine was discontinued. An interdigestive or mixed interdigestive-postprandial pattern was seen during gastric tube feeding in most patients during morphine administration. Most (94%) of the activity fronts during gastric feeding started in the duodenum. Gastric retention percentages during gastric tube feeding were negatively correlated (r2=.44; p < .01) with antral motor activity. CONCLUSIONS: These data suggest that morphine administration affects antroduodenal motility in mechanically ventilated patients. The gastrointestinal motor pattern involved in impaired gastric emptying in morphine-treated patients is characterized by antral hypomotility and persisting duodenal activity fronts during continuous intragastric feeding. The observed motility patterns suggest that early administration of enteral feeding might be more effective into the duodenum or jejunum than into the stomach of mechanically ventilated patients.

Adult↗
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 intraduodenal glucose infusion on gastric myoelectrical activity and antropyloroduodenal motility.

Intraduodenal nutrient infusions cause an inhibition of antral motility and an increase in pyloric motility. The involvement of gastric myoelectrical activity in this intestinogastric feedback was studied. Electrogastrography and antropyloroduodenal manometry were performed in 10 healthy volunteers. The effects of 20-mininfusions of 25% glucose (4 kcal/min) and saline were compared. Intraduodenal glucose infusions caused a decrease in the power of the dominant frequency in the electrogastrogram (P = 0.028), but the frequency itself remained unchanged. The total number of dysrhythmias increased (P = 0.035). An inhibition of antral motor activity (P = 0.001), an increase in the number of isolated pyloric pressure waves (P = 0.027), and an increase in basal pyloric tone (P = 0.001) were simultaneously recorded. The change in power during glucose infusion correlated positively with the change in the antral motility index (rs = 0.50, P = 0.001). It is concluded that inhibition of gastric myoelectrical activity is one of the mechanisms underlying an inhibition of motor activity in the gastric antrum.

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

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↗