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J Dent

Publications and source records attributed to J Dent.

At least 127 records · Page 7Linked to original sources

The effect of duodenal distension upon antro-pyloric motility and liquid gastric emptying in pigs.

BACKGROUND: This study has investigated first the role of the antrum and pylorus in the retardation of gastric emptying during distension of the duodenum, and second whether ascending duodenal intramural nerves contribute to control of both antro-pyloric motility and liquid gastric emptying in response to distension of the duodenum. METHODS: Studies were performed on 18 pigs. In six the duodenum was transected 1-2 cm distal to the pylorus, to interrupt intramural nerves, in six the pylorus was excised and a further six pigs without any transection or resection acted as controls. Motility of the antrum, pylorus and duodenum was recorded by a sleeve/side hole manometric catheter. Gastric emptying was measured by drainage of the duodenum through a cannula. RESULTS: In control animals distension of the duodenum inhibited antro-pyloric pressure waves (APPW), from 1.52 waves/min at minimum distension to 0.25/min at maximum distension (P=0.0007), stimulated isolated pyloric pressure waves (IPPW), from 0.56/min to 1.80/min (P=0.034) and slowed emptying of a 1000 mL load of 5% dextrose over 30 min from 788 mL to 251 mL (P=0.0001). Duodenum transected animals did not show the duodenal distension-induced stimulations of IPPW (maximum distension: 0.93/min), but both the distension-induced inhibition of APPW (maximum distension: 0.85/min) and slowing of emptying (maximum distension: 52 mL emptied) were unaltered. Similarly in pylorus-excised animals, duodenal distension inhibited APPW (maximum distension: 0.47/min) and slowed liquid emptying (maximum distension: 267 mL), effects which did not differ from control animals. Retardation of gastric emptying by duodenal distension may be due in part to inhibition of antral contractions. CONCLUSIONS: Under the conditions of this experiment, increased pyloric resistance to flow does not play a major role in the slowing of emptying by duodenal distension, but the stimulation of the pylorus by duodenal distension depends on duodenal intramural neural pathways. Duodenal distension-induced feedback control of emptying is mediated primarily via pathways other than ascending intraduodenal nerves.

Animals↗

Relation between oesophageal acid exposure and healing of oesophagitis with omeprazole in patients with severe reflux oesophagitis.

BACKGROUND/AIMS: Reducing oesophageal acid exposure by suppressing acid secretion with omeprazole is highly effective in healing reflux oesophagitis. Some patients with severe oesophagitis, fail to heal and whether this results from inadequate acid suppression or other factors is unclear. The aim of this study, was to investigate the relation between oesophageal acid exposure and healing in patients with severe reflux oesophagitis treated with omeprazole. METHODS: Sixty one patients with grade 3 or 4 ulcerative oesophagitis were treated for eight weeks with omeprazole 20 mg every morning. Those patients unhealed at eight weeks were treated with 40 mg every morning for a further eight weeks. Endoscopy and 24 hour oesophageal pH monitoring were performed before treatment and at the end of each treatment phase while receiving treatment. RESULTS: Thirty per cent of patients failed to heal with the 20 mg dose. Unhealed patients had greater total 24 hour oesophageal acid exposure before treatment, and while receiving treatment also had greater acid exposure and a smaller reduction in acid exposure than did patients who healed. Forty seven per cent of the unhealed patients also failed to heal with the 40 mg dose. These patients had similar levels of acid exposure before treatment to those who healed, but had greater acid exposure while receiving treatment, particularly at night when supine. CONCLUSIONS: Patients with severe ulcerative oesophagitis who are refractory to omeprazole have greater oesophageal acid exposure while receiving treatment than responding patients. This is due to a reduced responsiveness to acid suppression, and is likely to be an important factor underlying the failure of the oesophagitis to heal.

Adult↗

Influence of surgery on deglutitive upper oesophageal sphincter mechanics in Zenker's diverticulum.

BACKGROUND/AIMS: To evaluate the role of upper oesophageal sphincter (UOS) compliance in dysphagia, the functional consequences of surgery were evaluated in eight patients with pharyngeal diverticula. The study examined the hypotheses that hypopharyngeal intrabolus pressure is an indicator of UOS compliance and that UOS opening and intrabolus pressure are normalised by surgery. METHODS: In eight patients and nine healthy controls, we measured the timing of swallow events, UOS relaxation, maximal UOS dimensions, intrabolus pressure, and trans-sphincteric bolus flow rates by simultaneous videoradiography and pharyngeal manometry. RESULTS: Bolus flow rates were not changed by surgery. Surgery significantly increased UOS opening (p = 0.0001) and reduced hypopharyngeal intrabolus pressure (p = 0.0001). The slope of the relation between sphincter area and intrabolus pressure was steeper in patients than controls and was normalised by surgery. Surgery had minor effects on basal UOS tone and timing of swallow events. CONCLUSIONS: Upper oesophageal sphincter compliance is poor in Zenker's diverticulum and is normalised by surgery. Hypopharyngeal intrabolus pressure, which correlates with resistance to trans-sphincteric bolus flow, is a useful indicator of UOS compliance. Intrabolus pressure may be a predictor of outcome after myotomy in pharyngeal dysphagia. Cricopharyngeal myotomy is a mandatory component of surgery for Zenker's diverticulum.

Aged↗

Hyperglycemia affects proximal gastric motor and sensory function during small intestinal triglyceride infusion.

Hyperglycemia slows gastric emptying in normal individuals and patients with diabetes mellitus and may affect both somatic and visceral sensation. The effects of hyperglycemia on proximal gastric motility and sensation during intraduodenal infusion of a triglyceride emulsion were evaluated using a barostat in six normal subjects during euglycemia and hyperglycemia (approximately 15 mmol/l). Isobaric distension induced greater bag volumes during hyperglycemia compared with euglycemia at 3 (452 +/- 26 vs. 343 +/- 12 ml, P < 0.05) and 4 mmHg (600 +/- 55 vs. 497 +/- 50 ml, P < 0.05) above basal pressure. During isovolumetric distension, intrabag pressure was less during hyperglycemia at 500 (2.5 +/- 0.3 vs. 3.5 +/- 0.5 mmHg above basal pressure, P < 0.05) and 600 ml (3.0 +/- 0.4 vs. 4.5 +/- 0.5 mmHg above basal pressure, P < 0.05). Perception of nausea (P < 0.05) and fullness (P < 0.05) was increased during hyperglycemia compared with euglycemia. We conclude that hyperglycemia 1) reduces proximal gastric tone during intraduodenal triglyceride infusion, an effect that may contribute to delayed gastric emptying, and 2) increases the intensity of nausea and fullness during intraduodenal triglyceride infusion and proximal gastric distension, indicative of an effect on visceral sensation.

Adult↗

Mechanics of pulsatile transpyloric flow in the pig.

1. In eight conscious pigs equipped with gastric and duodenal cannulae, the relationship of transpyloric flow to gastro-duodenal motor events was evaluated during gastric emptying of 1000 ml of saline. Rates of liquid gastric emptying were correlated with pressures at the antrum, pylorus and duodenum, recorded by a sleeve sensor and multiple perfused side-holes. Transpyloric flow was recorded concurrently by continuous collection and weighing of the duodenal effluent. 2. In three pigs the above measurements were repeated during concurrent videofluoroscopy of gastric emptying after adding 100 ml of liquid barium to the gastric instillate. 3. The mean volume of saline emptied in 30 min was 627 +/- 51.2 ml. Pulsatile flow accounted for 71% of total emptying. Pulses had a mean flow rate of 3.9 +/- 0.44 ml s-1. Most flow pulses (59%) occurred during the first 5 min of emptying. 4. Distinctive, low-amplitude (4.8 +/- 0.33 mmHg), relatively long-lasting (15.8 +/- 0.46 s) antral pressure waves were associated with 58% of flow pulses. In all antral pressure recording points, the first and longest duration component of these pressure waves had an identical timing, amplitude and waveform consistent with pressurization of the entire antrum-gastric cavity. 5. Videofluoroscopy and concurrent manometry showed that these antral common cavity pressure waves were associated with non-lumen-occlusive contractions of the gastric wall, initially observed at the corpus which propagated down to the pylorus; 93% of these contractions became lumen occlusive in the terminal antrum and pylorus when pressure waves of a unique pattern for each recording point were recorded at this level. 6. The onset of 68% of the flow pulses which accounted for 62% of pulsatile emptying occurred in the interval (mean 7.9 +/- 0.65 s) between the onset of the common cavity wave and the onset of localized, lumen-occlusive distal antral-pyloric pressure waves. 7. These findings indicate that in the pig, pulsatile emptying of non-nutrient liquids into the duodenum occurs predominantly during the non-lumen-occlusive stage of a propagated gastric contraction, which is recognisable as a common cavity pressure wave. This is a previously inadequately recognized pattern of gastric pumping.

Animals↗

Role of antral intramural neural pathways in control of gastric emptying in the pig.

1. The role of antral intramural pathways in the control of antropyloric motility and gastric emptying was evaluated in five conscious pigs equipped with chronic gastric and duodenal cannulae. Neural pathways were divided by transection and re-anastomosis of the antrum 2 cm proximal to the pylorus. Concurrent measurements of gastric emptying, transpyloric flow and antropyloric motility were performed before and 6 weeks after surgery. 2. Antral transection retarded gastric emptying, only 36% of 1000 ml saline being emptied in 30 min compared with 62% before transection. Transection did not alter the number of transpyloric flow pulses (22.0 +/- 4.0 cf. 24.4 +/- 3.2 pre-transection), but reduced (P < 0.01) the volume of flow pulses substantially (8.6 +/- 0.4 cf. 18.7 +/- 1.5 ml pre-transection). 3. Antral transection was associated with a reduction in the rate of distal antral pressure waves (P < 0.05), but no alteration in the rate of phasic low level pressurization of the entire gastric content by gastric contractions (gastric common cavity pressure waves). However, transection was associated with a significant (P < 0.05) shortening of the interval between the onset of gastric common cavity pressure waves, and the onset of lumen-occlusive pyloric pressure waves generated by the same contraction sequence (3.2 +/- 0.3 cf. 7.9 +/- 0.6 s). 4. Transection did not alter the inhibition of antral pressure waves, stimulation of localized pyloric pressure waves, and retardation of gastric emptying produced by infusion of 25% dextrose into the duodenum. 5. These studies suggest that antral intramural nerves regulate the emptying of liquids from the stomach by modulating the timing of pyloric closure in relation to phasic gastric antral and corpus contractions. 6. Distal antral intramural neural pathways do not appear to play a major role in the suppression of antral motor activity produced by duodenal glucoreceptors.

Animals↗

Effect of cisapride on myoelectrical and motor responses of antropyloroduodenal region during intraduodenal lipid and antral tachygastria in conscious dog.

The myoelectrical and motor response of the antropyloroduodenal region to intraduodenal nutrient stimulation or antral tachygastria represent useful models for, respectively, physiological and pathophysiological gastric stasis to test the efficacy of prokinetic drugs. We evaluated the effects of an intravenous bolus of cisapride (0.63 mg/kg) on the myoelectrical and motor response of the antropyloroduodenal region to an intraduodenal triglyceride emulsion (10% Intralipid, 0.5 ml/min) or antral tachygastria in conscious dogs. Intraduodenal lipid suppressed antral motility (P < 0.05, compared to intraduodenal saline) and stimulated phasic pyloric contractions (P < 0.01, compared to intraduodenal saline), a motor pattern known to be associated with delayed gastric emptying. During intraduodenal lipid stimulation cisapride virtually abolished all isolated pyloric motor events (P < 0.05) and stimulated antral and duodenal motility (P < 0.05 for both) and antropyloroduodenal coordination (65% versus 15%; P < 0.05). Antral tachygastria was associated with a higher number of isolated pyloric motor events in the fasted state [0.8 (0.7-1.1) per minute versus 0.2 (0-0.3) per minute; P < 0.05], but not during intraduodenal lipid stimulation [1.1 (0.9-1.7) per minute versus 1.2 (1.0-1.9) per minute; NS]. Cisapride decreased the number and duration of spontaneous episodes of antral tachygastria during intraduodenal saline and lipid infusion (P < 0.05 for both) and abolished the tachygastria-associated motor patterns. Cisapride induced a 20% decrease in the antral slow-wave frequency during intraduodenal saline and lipid, irrespective of gastric pacemaker rhythm. We conclude that: (1) cisapride overcomes feedback from small intestinal lipid receptors on myoelectrical and motor activities of the antropyloroduodenal region and decreases antral slow-wave frequency, and (2) cisapride inhibits antral tachygastria and tachygastria-associated motor patterns. These effects may contribute to the effective gastrokinetic properties of cisapride in physiological and certain forms of pathophysiological gastric stasis.

Animals↗

Optimizing acid suppression for treatment of acid-related diseases.

Gastric acid is of central importance in the pathogenesis of duodenal ulcer, gastric ulcer, and gastroesophageal reflux disease. Pharmacological reduction of acid secretion is, therefore, the mainstay of current treatment, but the optimal degree of acid suppression remains incompletely understood. This paper considers the ideal ways of assessing and reporting the pharmacological effectiveness of acid-inhibiting drugs and relating such data to clinical efficacy. Twenty-four-hour intragastric pH measurements are widely used for this purpose, although this technique cannot measure secretion quantitatively. Data on suppression of 24-hr intragastric acidity for groups of subjects have been successfully correlated with healing rates for duodenal ulcer, gastric ulcer, and gastroesophageal reflux disease. Three primary determinants of healing have been derived from antisecretory data. These are the degree of suppression of acidity, the duration of suppression of acidity, and the duration of treatment. The order of importance of these determinants varies depending on the disease. Data on 24-hr intragastric acidity should be accompanied whenever possible by data on 24-hr plasma gastrin levels, as the relationship between suppression of acidity and a rise in gastrin varies widely between individuals. It is not possible to predict the plasma gastrin level from the intragastric pH or any other measurement of intragastric acidity. Comparative data sets in groups of subjects may provide useful information. Proton pump inhibitors produce a greater and longer-lasting degree of suppression of acidity than conventional doses of H2-receptor antagonists. For this reason, they are more effective in healing duodenal ulcer and gastric ulcer. However, in view of the importance of duration of treatment, healing rates with the H2-receptor antagonists approach those obtained with proton pump inhibitors if treatment is continued for a longer time. In gastroesophageal reflux disease in particular, although the optimal degree of acid suppression is not yet defined, the consistently superior performance of proton pump inhibitors demonstrates that increased suppression of acidity is clinically beneficial.

Duodenal Ulcer↗

Mechanisms of gastroesophageal reflux in ambulant healthy human subjects.

BACKGROUND/AIMS: Investigation of the motor events underlying gastroesophageal reflux has largely been confined to resting, recumbent subjects. The motor events associated with reflux during physical activity remain unknown. The aim of this study was to investigate the patterns of lower esophageal sphincter (LES) function underlying reflux in healthy subjects and the effect of exercise and physical activity on reflux mechanisms. METHODS: LES pressure was recorded with a perfused sleeve sensor in 10 healthy subjects; intraluminal transducers recorded pressure in the stomach, esophagus, and pharynx, and pH was recorded 5 cm above the LES. Signals were stored in a portable data-logger. Recordings were made for 24 hours, including moderate physical activity, periods of rest and sleep, standardized meals, and standardized exercise. RESULTS: Most reflux episodes (81 of 123; 66%) occurred in the 3 hours after food intake; only 2 episodes occurred during exercise. LES pressure was < or = 3 cm H2O in 79% of reflux episodes. Transient LES relaxation was the mechanism of reflux in 82% of episodes, irrespective of activity or body position, whereas swallow-related LES relaxations accounted for 13% and persistently absent LES pressure accounted for 1%. Straining occurred in only 20% of episodes. CONCLUSIONS: In ambulant healthy subjects, accurate continuous recording of LES function is possible, reflux usually occurs during transient LES relaxations, and straining is not a major factor in the induction of reflux.

Acids↗

Effect of atropine on the frequency of reflux and transient lower esophageal sphincter relaxation in normal subjects.

BACKGROUND & AIMS: Low basal lower esophageal sphincter (LES) pressure is believed to be an important mechanism of reflux. The effects of atropine on the frequency and mechanisms of gastroesophageal reflux under the experimental conditions of a low basal LES pressure in 13 normal subjects were studied. METHODS: LES pressure, esophageal pressures, esophageal pH, and crural diaphragm electromyogram were recorded simultaneously in the postprandial period for 30 minutes before and two 30-minute periods after the injection of atropine. RESULTS: Atropine reduced the basal LES pressure from 16.4 +/- 3 to 8.7 +/- 2 mm Hg. The frequencies of reflux in the control and two postatropine periods were 3.5 +/- 0.5, 0.4 +/- 0.2, and 0.8 +/- 0.3, respectively (P < 0.05). The frequencies of transient LES relaxations decreased from 3.5 +/- 0.5 in the control to 0.4 +/- 0.2 and 1.5 +/- 0.4 in the two postatropine periods (P < 0.05). Transient LES relaxation and associated inhibition of the crural diaphragm was the major mechanism of reflux under conditions of low LES pressure induced by atropine. CONCLUSIONS: Atropine-induced low LES pressure does not predispose to reflux in normal healthy subjects. Atropine reduces the frequency of reflux by its inhibitory effect on the frequency of transient LES relaxation.

Adolescent↗

Esophageal body and lower esophageal sphincter function in healthy premature infants.

BACKGROUND & AIMS: Gastroesophageal reflux is a common problem in premature infants. The aim of this study was to use a novel manometric technique to measure esophageal body and lower esophageal sphincter pressures in premature infants. METHODS: Micromanometric feeding assemblies (OD, < or = 2 mm) incorporating 4-9 manometric channels were used in 49 studies of 27 premature neonates. Esophageal body motility was recorded at three sites for 20 minutes after feeding. Twenty attempts (one per minute) were made to stimulate swallowing via facial stimulation (Santmyer reflex). In 32 studies lower esophageal sphincter pressures were recorded (sleeve) for 15 minutes before and after feeding. RESULTS: Peristaltic motor patterns were less common than non-peristaltic motor patterns (26.6% vs. 73.4%; P < 0.0001) that comprised 31.1% synchronous, 34.6% incomplete, and 6.3% retrograde pressure waves. Reflex swallowing was elicited more frequently in neonates older than 34 weeks postconceptional age than in younger infants (33.4% vs. 20.4%; P < 0.05). Mean lower esophageal sphincter pressure was 20.5 +/- 1.7 mm Hg before and 13.7 +/- 1.3 mm Hg after feeding (P < 0.0005). CONCLUSIONS: Premature infants show nonperistaltic esophageal motility that may contribute to poor clearance of refluxed material. In contrast, the lower esophageal sphincter mechanisms seem well developed.

Deglutition↗

Catatonic syndrome following recovery from neuroleptic malignant syndrome.

In June 1992, a 51-year-old Caucasian man with a mild learning disability was prescribed chlorpromazine and thioridazine for sleeplessness and agitation. He developed neuroleptic malignant syndrome (NMS) which was treated successfully with intravenous diazepam. Without further exposure to neuroleptics, the patient became acutely unwell with signs of catatonic syndrome in March 1993 and responded to oral diazepam. When the dose of diazepam was reduced in August 1993, the catatonic syndrome recurred and responded to an increase in his oral diazepam. In the past, the patient had been admitted to hospital in 1983 and 1986 with severe extrapyramidal symptoms and parkinsonism following prescription of neuroleptics for agitation. This case provides evidence that patients with a predisposition to catatonic syndrome may be at increased risk of developing NMS, and therefore, should not be treated with neuroleptics.

Anti-Anxiety Agents↗

Postural changes in proximal gastric volume and pressure measured using a gastric barostat.

A barostat was used to examine the effect of changes in posture on the volume and pressure in a bag positioned in the proximal stomach of 14 normal volunteers. Volumes in the supine position were compared with those in the standing, left lateral and right lateral positions at a constant pressure 2 mmHg above basal intragastric pressure. A separate series of measurements was then used to evaluate the effects of the same postural changes on pressure within the bag whilst its volume was kept constant. Changing from the supine to the left lateral position decreased bag volume by 62% when pressure was controlled; pressure increased by 60% when volume was controlled. In contrast, movement from the supine to the right lateral position resulted in a 68% increase in bag volume and a 31% fall in pressure. Moving from supine to standing had inconsistent effects on bag volume and pressure. There was a negative correlation between the magnitudes of the changes in pressure and volume (r2 = 0.557). The observed effects of posture probably result from changes in the compression of the stomach by abdominal viscera and indicate that subject position must be specified and maintained constant in studies of proximal gastric motor function using a barostat.

Adult↗

Effect of drink temperature on antropyloroduodenal motility and gastric electrical activity in humans.

There is little information on the motor mechanisms underlying the effects of meal temperature on gastric emptying. The effects on antropyloric pressures and the surface electrogastrogram of ingesting drinks at 4 degrees C, 37 degrees C, and 50 degrees C (350 ml normal saline and 50 ml low calorie (7 kj) orange cordial) given in randomised order were measured over 60 minutes in 12 normal volunteers (10 men and 2 women, aged 18-55 years). The warm and cold drinks suppressed antral pressure waves (p < 0.05), altered the organisation of antropyloric pressure waves (p < 0.05), stimulated isolated pyloric pressure waves (p < 0.05), and increased electrogastrogram frequency (p < 0.05) when compared with the 37 degrees C drink. These changes were greatest in the first 30 minutes after ingestion and greater (p < 0.05) with the 4 degrees C drink. Temperature has major effects on postprandial antropyloroduodenal motility in normal subjects. Both cold and warm drinks stimulate a pattern of motility associated with retardation of transpyloric flow.

Adolescent↗

Evaluation of antral motility in humans using manometry and scintigraphy.

Recent studies suggest that scintigraphy can be used to evaluate non-invasively antral motility in humans, although scintigraphic techniques have not yet been compared with more conventional measurements of intraluminal pressures by manometry. Simultaneous scintigraphic and manometric measurements of antral motility were performed in nine healthy volunteers. After intubation with a sleeve/sidehole catheter which incorporated five pressure sideholes located at 1.5 cm intervals spanning the antrum, each subject ingested 100 g minced beef labelled with 100 MBq 99mTc-chicken liver and 150 ml water. Between 40-43, 60-63, 80-83, and 100-103 minutes after meal ingestion, radioisotopic data were acquired in two second frames. Time-activity curves showing antral 'contractions' resulting from wall motion were derived by drawing small regions of interest over the antrum to coincide with the position of the antral manometric sideholes. Scintigraphic contraction rates approximated 3/minute, whereas antral pressure waves that occluded the lumen were less frequent (p < 0.01 for all), particularly in the proximal antrum. The amplitude of wall motion, evaluated scintigraphically, and the amplitude of pressure waves were both inversely related to the distance from the pylorus (r > -0.32, p < 0.05) and antral volume r > -0.29 (p < 0.05). There were significant relationships between the amplitude of contractions assessed scintigraphically and the number of lumen-occlusive antral pressure waves in the distal antrum (r -0.48, p < 0.05) but not in the more proximal antral regions. It is concluded that scintigraphy can detect antral wall motion with greater sensitivity than manometry, particularly in the proximal antrum. As manometry gives information on the amplitude as well as the temporal and spatial organisation of those contractions which result in lumen occlusion, the combination of scintigraphic and manometric techniques in the evaluation of antral motility shows considerable promise.

Adult↗

Influence of normal aging on oral-pharyngeal and upper esophageal sphincter function during swallowing.

The influence of aging on oral-pharyngeal swallowing was assessed by simultaneous manometry and videoradiography in 14 nondysphagic elderly individuals (mean age 76 yr) and 11 healthy, young controls (mean age 21 yr). Sphincter opening was diminished significantly in the elderly (P = 0.0001), but trans-sphincteric bolus flow rates were preserved. The increased impedance to trans-sphincteric bolus flow from reduced sphincter opening in the aged was reflected in a significant increase in hypopharyngeal intrabolus pressure (P = 0.003). Oral transit time was significantly prolonged in the aged (P = 0.01). The timing of upper esophageal sphincter (UES) manometric relaxation and of opening was significantly delayed in the aged (P = 0.0001), and this delay was comparable in magnitude to the prolongation in oral transit. Coordination of UES relaxation and opening with midpharyngeal contraction was not significantly affected by age. Deglutitive hyolaryngeal motion was not affected by age but was delayed by a duration equivalent to the prolongation in oral transit. We conclude that normal aging prolongs the oral-pharyngeal swallow that impairs UES opening but does not influence pharyngo-sphincteric coordination.

Adolescent↗

Relationship between surface electrogastrography and antropyloric pressures.

The cutaneous electrogastrogram (EGG) and intraluminal antropyloroduodenal pressures were recorded in 12 healthy volunteers for 30-min periods during phase II of the interdigestive motor complex, during intraduodenal infusion of 10% triglyceride, and after intravenous erythromycin (3 mg/kg). During phase II, the frequency of the EGG was relatively constant in each individual, with a median frequency of 0.046 Hz [2.8 counts per minute (cpm)]. EGG frequency was greater (P < 0.05) than the median rate of antral pressure waves (1.8 cpm). The suppression of antral pressure waves (P < 0.05) and stimulation of isolated pyloric pressure waves (IPPWs) (P < 0.05) produced by triglyceride infusion were not associated with changes in EGG frequency compared with phase II. The frequency of the EGG and the rate of IPPWs were comparable. After erythromycin, EGG frequency was 0.03 Hz (1.8 cpm), less than during both phase II and triglyceride infusion (P < 0.05) and almost identical to the rate of antral pressure waves. Pressure waves were nearly always associated with an EGG signal. In contrast, the temporal relationship between the EGG signal and pressure waves was variable. During triglyceride infusion (r = 0.83, P < 0.001) and after erythromycin (r = 0.83, P < 0.001) there was a close (approximately 1:1) relationship between the rate of pressure waves and EGG frequency. However, there was no significant relationship (r = 0.32, not significant) between the number of pressure waves and EGG frequency frequency during pase II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗