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Biomedical subjects

M Dapoigny

Publications and source records attributed to M Dapoigny.

18 recordsLinked to original sources
PubMed1992

Vagal influence on colonic motor activity in conscious nonhuman primates.

We investigated the role of the vagi in modulation of colonic motor activity in the fasted and fed states and determined the extent of vagal influence on colon motility in conscious monkeys. Monkeys were implanted with force transducers on the colon. A vagal cooling chamber was implanted supradiaphragmatically, and a vagal stimulating electrode was implanted just distal to the chamber. One week was allowed for recovery. After an overnight fast, control recordings were made for 1 h, and then the monkeys were either fed or remained fasting, with or without adrenergic blockade (propranolol and phentolamine). Then while recordings continued the vagi were cooled to their predetermined denervation temperature for 1 h. In a second set of experiments, adrenergic blockers were injected, and the vagi were stimulated during vagal cooling with or without atropine administration. In both the fasted and fed states, the contractile frequency was decreased during vagal cooling, with or without adrenergic blockade. With adrenergic blockade, however, the frequency of colon contractions was greater during cooling than during cooling without such blockade. Inhibition of colonic contractions during cooling decreased in magnitude from the proximal to the distal colon. Vagal efferent stimulation increased contractile frequency at all sites, but after atropine it decreased contractile frequency. We conclude that the vagi have either a direct or indirect influence on fasting and fed colonic motor activity throughout the colon, and that a nonadrenergic, noncholinergic inhibitory pathway is under vagal control.

Animals↗
PubMed1991

Effects of physical exercise on colonic motor activity.

We investigated the effect of physical exercise on colonic motor activity in the fasted and fed states in six conscious dogs. Each dog was implanted with nine strain gauge transducers: three on the proximal, three on the middle, and three on the distal colon. The dogs ran for 1 h on a treadmill at 5 km/h (slope 5%). In the fasted state, the dogs exercised during the 5th h of recording after an overnight fast, and in the fed state during the 1st, 3rd, and 5th postprandial hour. In the fasted state, exercise significantly decreased the frequency of colonic migrating motor complexes (MMCs) but had no effect on the total or the mean duration of contractile states in the proximal, middle, and distal colon. Postprandially, exercise disrupted colonic MMCs and replaced them with nonmigrating motor complexes in all three periods of exercise (1st, 3rd, and 6th h). Exercise also increased the total duration per hour of contractile activity throughout the colon during the 1st and 3rd h and only in the distal colon during the 6th h after the meal. The dogs never defecated during rest in the fasted or the fed state. Shortly after the start of exercise in the fasted and fed states, giant migrating contractions (GMCs) occurred, and they were followed by defecation. In approximately 40% of the experiments, another GMC originated in the proximal colon, approximately 10 min after the first defecation, and migrated caudad up to the middle colon. These GMCs were not associated with defecation but caused mass movements.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Validation of an ultrasonographic method of gastric emptying measurement in men].

Our purpose was to validate an ultrasonographic technique based on the assessment of the gastric antrum. Sixteen patients presenting with various functional disorders were studied by ultrasound on two occasions. Ten healthy volunteers were simultaneously studied by scinti- and ultrasonic scans. After an overnight fast, the healthy subjects ingested a 2,000 kJ test meal containing 150 microCi of 111In DTPA in 250 ml orange juice and 3 mCi of 99m Tc sulfur colloid in chicken liver. Using an ultrasound scanner fitted with a 3.5 MHz transducer, the area of the gastric antrum section was always measured in the same plane. Ultrasonographic measurement of gastric emptying rate was feasible in all of the 10 healthy subjects and in 14 of 16 selected patients. The ultrasonographic method was reproducible, and repeated t 1/2 measurements in 14 patients correlated well (95.3 +/- 27.9 vs 99.2 +/- 20.6 min; r = 0.70, P less than 0.001). The t 1/2 measurement was 39.4 +/- 7.7 min with the ultrasonographic method, and correlated well with 36.4 +/- 4.3 min for the t 1/2 measurement of the liquid phase with the scintigraphic method. We conclude that the ultrasonic method was reproducible and could be used for assessment of gastric emptying rate when repeated measurements are necessary, especially in pharmacologic studies.

Adult↗
PubMed1990

[Epidemiology of the irritable bowel syndrome].

Based on recent epidemiologic studies of functional intestinal disorders, we have attempted to answer the following two questions: a) what is the prevalence of functional intestinal disorder in the Western world, b) are there epidemiologic variations in the different modes of symptomatic presentation of functional intestinal disorders? The overall prevalence of functional intestinal disorders in the Western world ranges between 17 and 23 percent according to the country considered, and is between 14 and 18 percent for the irritable bowel syndrome and 4 to 8 percent for painless constipation. The "irritable intestine" group is characterized by a sex ratio of close to one, a median age near 40, a strong influence of stress on symptoms, and the frequency of complaints such as nausea, vomiting, migraine, and pyrosis. The syndrome is seen in active subjects, who believe that they are "sick", and as such, seek medical advice often. Anxiety and depression are frequently encountered. Patients are often athletes, smokers, and have diarrhea. On the other hand, "painless constipation" is characterized by a high prevalence of women and age over 50. Often these subjects do not have any active professional activity. Stress-related and extradigestive symptoms are rare. They do not consider themselves "sick" and do not seek medical advice very often. Conversely, they use laxatives frequently. Individualization of epidemiologically different groups suggests that the pathophysiology may differ between the two groups and perhaps that there are specific therapeutic and diagnostic approaches accordingly.

Age Factors↗
PubMed1989

Effects of buprenorphine on motor activity of the sphincter of Oddi in man.

Buprenorphine, (Temgesic), a N-cyclopropylmethyl derivative of oripavine, is both an agonist and antagonist of morphine. Its effect on the motility of the sphincter of Oddi (SO) in humans have been investigated by endoscopic manometry (EM). Buprenorphine leads to a significant decrease in the amplitude of SO contraction waves without altering other parameters. Thus, it has no morphine-like effect on SO motility, but it does act like a partial antagonist of morphine in reducing the amplitude of SO contraction waves.

Adult↗
PubMed1989

[Interobserver and intercenter agreement of gastro-esophageal endoscopic signs in cirrhosis. Results of a prospective multicenter study].

Because of the diagnostic and prognostic value of gastroesophageal endoscopic signs in cirrhosis, we studied their interobserver and intercenter agreement. Fifty cirrhotic patients without previous digestive bleeding were included in this study. The gastroesophageal endoscopic examinations of these patients, recorded on video tape, were independently viewed by 12 observers belonging to different hospitals. Agreement was evaluated by the kappa index (k), the values of which were given with p less than 0.001. Agreement was good for the presence (k = 0.40) or the size (k = 0.51) of esophageal varices as well as for red signs on the mucosa overlying esophageal varices, but it was poor for the color (k = 0.10) or the extent (k = 0.20) of esophageal varices. Agreement was poor for all gastric signs: fundic varices (k = 0.35), red spots (k = 0.28), associated lesions (k = 0.27), mosaic pattern (k = 0.27), gastropathy (k = 0.11). The mean diameter of esophageal varices, evaluated without any scale, varied from 3.5 +/- 1.4 to 7.5 +/- 4.0 mm between the 12 observers (p less than 0.001). Agreement was maximum for the more developed grade of a sign and minimum for the intermediate grade. The value of kappa indexes in this intercenter study was compared to that obtained in a previous study from one institution: interobserver agreement was significantly better within one center than between different centers. In conclusion, intercenter agreement is good for the size of esophageal varices and the presence of red signs, and poor for all the other signs. The millemetric measurement of esophageal varices diameter, without any scale, appears to be unreliable.(ABSTRACT TRUNCATED AT 250 WORDS)

Esophageal and Gastric Varices↗
PubMed1988

Myoelectric spiking activity of right colon, left colon, and rectosigmoid of healthy humans.

The tip of an intraluminal probe was positioned in the cecum, and before and after a standard meal (greater than 800 kcal), the rapid myoelectrical activity of the right, the left, and the rectosigmoid colon in six healthy subjects was recorded. In each colonic site, we recorded two different patterns of spike bursts: Short spike bursts and long spike bursts, as previously described. We observed no difference in either the duration or the amplitude of the two kinds of spike bursts among the three different parts of the colon. Before the meal, the number of long spike bursts was lower in the right than in the left colon (P less than 0.01) and than in the rectosigmoid (P less than 0.01). After the meal, a significant activity increase in long spike bursts lasted 20 min in the right colon (P less than 0.001), 100 min in the left colon, and in the rectosigmoid (P less than 0.001-P less than 0.05). This activity was always significantly less intense in the right colon than in the two other sites (P less than 0.001-P less than 0.01) and was less marked in the left colon than in the rectosigmoid (P 0.01-P less than 0.05). The short spike burst activity remained unchanged. These results provide evidence for the heterogeneity of motility in the different parts of the colon, with a relative hypomotility of the right colon compared to the left colon and the rectosigmoid in the healthy human.

Adult↗
PubMed1988

[The role of total colonic electromyography in children in case of chronic constipation. Preliminary study].

Since December 1987, the chirurgical pediatric team in Clermond-Ferrand performs total colonic electromyography in children. This examination is integrated into a diagnostic and therapeutic protocol for chronic constipation. We used an intraluminal probe supporting 10 groups of 3 ring electrodes. Inside the probe a lead pellet was placed opposite each electrode. The probe was inserted through the colon by colonoscopy into a starving child. The recording starts 24 hours later and is registered for 3 hours before and 3 hours after a meal. The aim of this work is to report the preliminary results of 6 electromyography in constipated children.

Adolescent↗
PubMed1988

[Colonic response to the meal of the right colon, the left colon, the rectosigmoid and the rectosigmoidal junction in digestive functional disorders].

The aim of this work was to answer the two following questions: 1) is there any difference between the right colonic, the left colonic, and the rectosigmoid motility? 2) does the rectosigmoid junction (radiological and endoscopic entity) exhibit a specific motility pattern? Colonic motility was assessed by electromyography. We used an intraluminal probe supporting 15 groups of 3 ring electrodes. Inside the probe a lead pellet was placed opposite each electrode. The probe was inserted through the colon by colonoscopy. A visual analysis of the signal was performed and we distinguished: Long Spike Bursts (LSB) activity (propagating in oral or aboral direction or not propagating) from Short Spike Bursts (SSB) activity as previously described. Twenty patients suffering from the irritable bowel syndrome included in a subgroup defined as abdominal pain, were studied, and two groups were defined as follows: the tip of the probe was positioned in the caecum in 9: group "Right colon" patients. An electrode was specifically located on the rectosigmoid junction in 15: group "Junction" patients. In the "Right colon" group, the postprandial increase of LSB activity in the rectosigmoid lasted longer than in the right and left colons. During the postprandial period, the right colon exhibited a lower LSB activity than the rectosigmoid (p less than 0.01). After the meal LSB activity propagating in aboral direction was increased in the right colon while it was inhibited in the rectosigmoid. LSB activity propagating in the oral direction was increased both in the right colon and rectosigmoid after the meal. In the "Junction" group, we observed a specific myoelectrical activity at the rectosigmoid junction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Stimulation of colonic peristalsis by vasopressin: electromyographic study in normal subjects and patients with chronic idiopathic constipation.

The effects of vasopressin on colonic motility were investigated in 6 healthy subjects and 10 patients with chronic idiopathic constipation. Recordings of the colonic myoelectric spiking activity were performed by means of 50-cm long silastic tube, equipped with four bipolar ring electrodes fixed at 10-cm intervals, which was introduced by flexible colonoscopy into the left colon. Tracing were obtained for 1 h in the fasting state and for another hour after an intramuscular injection of a pharmacological dose of vasopressin (0.3 U/kg). The different types of spike bursts generated by the colonic smooth muscle were compared before and after vasopressin injection. In both controls and patients, the tracing showed (i) rhythmic stationary spike bursts (RSB) that were seen at only one electrode site; and (ii) sporadic bursts that were either propagating over all four electrodes (SPB) or nonpropagating (SNPB). Injection of vasopressin in controls was followed for 30 min by a significant increase in the number of propagating bursts from 2.7 +/- 0.6 (mean +/- SEM) to 5.2 +/- 1.4 bursts (p less than 0.05); RSB and SNPB were not altered by vasopressin. In the constipated patients, the number of propagating bursts during the control period was significantly lower (0.8 +/- 0.2 bursts/30 min) than in the volunteers (p less than 0.05). After vasopressin, there was a significant increase to 3.6 +/- 0.8 bursts/30 min (p less than 0.001); RSB and SNPB also did not show significant alteration after vasopressin. Finally, 4 out of the 10 patients passed stools during the recording session.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Epidemiology of intestinal functional disorders in an apparently healthy population].

The characteristics and the prevalence of functional bowel disorders in the general French population are unknown. Based on an epidemiological inquiry in a random population of 1,200 persons who were not seeking care, residents in our country we established: the prevalence of symptoms suggestive of functional bowel disorders; the epidemiological differences between symptomatic subgroups which included abdominal pain with or without bowel dysfunction, diarrhea and constipation. The amount of cases and the prevalence in each subgroup were: abdominal pain, 165, 13.8 p. 100, painless constipation, 75, 6.3 p. 100, diarrhea, 10, 0.8 p. 100. As a whole, functional bowel disorders occurred in 20 p. 100 of our population. The "irritable bowel syndrome" group defined as abdominal pain and/or diarrhea differ from normal subjects by the following higher frequency of age under 50, subjects in active duty, antecedents of diverticulosis, influence of stress on symptoms, nausea, vomiting, migraines, pyrosis and number of visits to a doctor. However neither the sex-ratio nor professional occupation were relevant. The constipation group differed from normal because of the higher frequency of female sex, antecedents of hiatus hernia, use of laxatives but not because of age nor by the number of associated symptoms. In conclusion, functional bowel disorders occurred in 20 p. 100 of our population; two subgroups were clearly different from an epidemiological point of view, the irritable bowel syndrome (13 p. 100) and constipation (7 p. 100); therefore these two groups deserve a specific physiopathological, psychological and therapeutic approach.

Abdomen↗
PubMed1985

[Colonic myoelectric activity during fasting and postprandial periods in healthy subjects and colonopathic patients].

The purpose of this prospective study was to assess colonic myoelectric activity during fasting and after a test meal in patients with the Irritable Bowel Syndrome (IBS) and in control subjects. Colonic electromyographic activity was recorded using an intraluminal probe in 14 patients and in 8 controls. Only rapid electrical activity [i. e. Short Spike Bursts (SSB) and Long Spike Bursts (LSB)] was taken into account. In control subjects the test meal provoked a significant increase in LSB from 46.7 +/- 16.3 to 88.6 +/- 20.3 (p less than 0.001) but not in SSB. In IBS patients rapid myoelectrical activity was not significantly modified by food intake (47.2 +/- 10.3 vs. 62.2 +/- 10.9; NS). The increase of postprandial LSB activity was found to be significantly higher in controls than in IBS patients (41.8 +/- 7.6 vs. 12.9 +/- 8.4; p less than 0.05). These results showed that colonic myoelectrical activity in IBS patients is different from that of controls; such a difference could be useful in classifying IBS patients.

Colon↗
PubMedDate not supplied

Specific receptors for 1,25-dihydroxyvitamin D3 (1,25-DR) and human colorectal carcinogenesis.

Because it is a common prerequisite for steroid responsiveness in target tissue, we investigated the presence of specific 1,25-DR in spontaneous human colorectal adenocarcinomas (ADC) and adjacent normal-appearing mucosa (NAM) from 23 operative specimens (12 male and 11 female patients). 1,25-DR was determined in cytosol by a DCC assay technique. 1,25-DR was present in 21 of 23 NAM and in only 4 of 23 HCRA. All positive ADC were well differentiated. Receptor content expressed in femtomoles/mg of protein (mean +/- SEM) was respectively 63.9 +/- 7.6 for right colon NAM and 51.3 +/- 12.9 for left colon or rectum NAM. When we compared all NAM specimens, receptor content was 56.7 +/- 8.0 femtomoles/mg of protein. No difference in 1,25-DR NAM level was observed between right colon and left colon or rectum. In adenocarcinoma the mean content was 66.5 +/- 14 fmoles/mg of protein. Scatchard analysis showed a single class of specific high-affinity saturable 1,25-DR with a dissociation constant (Kd) of 0.97 +/- 0.57 and 1.03 +/- 0.39 chi 10(-10) M in NAM and ADC respectively. These preliminary data represent the first demonstration of 1,25-DR throughout the entire human colon and indicate that the receptivity for this hormone is often lost during malignant transformation of the human colorectal mucosa. In addition, 1,25-DR could be a marker of differentiation in ADC. These preliminary results provide evidence supporting the addition of Vitamin D to the roster of developmental cancer chemopreventative agents.

Adenocarcinoma↗