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J C Schang

Publications and source records attributed to J C Schang.

18 recordsLinked to original sources

[Relationship between intestinal motility and absorption. Electromyographic study in the dog. (author's transl)].

The effects of different food components on intestinal motility were studied by means of an electromyographic technique. The electrical activity of the small intestine in the fasted state consists of a cyclic recurring phenomenon - the myoelectric complex - which is inhibited by feeding. The duration of inhibition of the myoelectric complex was shown to depend on the nature of the food components (glucose, peptides or lipids) as well as on the caloric load. In the opposite, the intensity of the intestinal motility was seen to depend only on the nature of the food components, and not on the caloric load. Thus, the duration of inhibition of themyoelectric complex can be considered as a consistent and objective parameter, which reflects the duration of the fed state.

Animals

[Study on the effects of bromopride on intestinal peristalsis (author's transl)].

The effect of 4-amino-5-bromo-N-[2-(diethylamino)-ethyl]-2-methoxy benzamide (bromopride, Viaben) on the intestinal motility was studied in dogs. Highly sensitive transducers were implanted on the intestinal serosa, allowing to measure both electrical and mechanical impulses at the same point from the small intestine. These studies were performed in 5 dogs to which bromopride was administered in i.v. or i.m. doses of 10, 20 and 30 mg. The results of the studies were as follows: 1. Bromopride causes an increase in both the number and amplitude of the spikes; at the same time there is a significant increase in the number and amplitude of the intestinal contractions. 2. The average duration of the cycle of the myoelectric complex does not change. This indicates that bromopride has no effect on the normal cycle of motoric activity in the intestine. 3. Bromopride seems more effective in the fasted state than in the post-prandial phase. 4. The effect of i.v. infection is greater than that of i.m. injection and begins earlier.

Action Potentials

Specific effects of different food components on intestinal motility. Electromyographic study in dogs.

Interdigestive intestinal myoelectric activity is characterized by repetitive aborally migrating complexes which are inhibited by feeding. The aim of the present work was to study the effects of different food components on the duration of inhibition of the myoelectric complex and on the number of spike potentials during this period. 4 dogs were prepared for chronic recordings with electrodes implanted on the jejunum and an alimentary cannula placed into the duodenum. Glucose, peptides and lipids were given into the cannula at doses of 7.5 and 15 kcal/kg. The results indicated that the inhibition of the myoelectric complex was longer for lipids than for glucose and even longer than for peptides. When the caloric load was increased, the duration of inhibition was also increased. As concerns the spike potentials, their number was increased after administration of glucose and of peptides, whereas it was decreased after lipids. Lastly, the increase of the caloric load did not change the number of spike potentials significantly. These results indicated that the duration of inhibition of the myoelectric complex depended on both the nature and the caloric load of the food components, whereas the number of spike potentials was determined only by the composition of food.

Action Potentials

[Applications of electromyography in the study of changes in intestinal motility following surgery on the small intestine].

Changes in the intestinal motility were studied in dogs after different surgical operations performed on the small bowel. Electrodes were implanted on the intestine and the electrical activity of the bowel was recorded after transection of the bowel and after jejunoileal shunt. The results showed that the transection of the bowel provoked a slowing of the propagation of the intestinal contractions. This phenomenon was particularly important at the level of the ileum. The jejunoileal shunt was followed by a strong increase of the level of the motor activity, probably related with an increase of the intraluminal content at the level of the ileum. These results gave an explanation for the slowing of the intestinal transit which is observed after some operations which involve a transection of the small bowel.

Animals

[Intestinal motility after intraduodenal and intrajejunal feeding].

Post-prandial intestinal motility, analysed through two electromyographic parameters, duration of inhibition of myoelectric complex (DIMC) and percentage of spike potentials (PSP), was studied after ingestion of glucids, proteins and lipids. Post-prandial intestinal motility depends on both chemical nature and caloric load of nutriments: DICM depends on those two factors but PSP only depends on nature of nutriments. Post-prandial intestinal motility also depends on route of administration of nutriments. Intra-jejunal administration versus intra-duodenal administration increases DIMC observed for glucids and proteins, diminishes DIMC observed for lipids and diminishes PSP observed for glucids and proteins. These results indicate a specificity of intestinal post-prandial motility with characteristics of nutriments. Intestinal digestion and absorption of nutriments, just as hormonal secretion in response to intestinal passage of nutriments could explain such a specificity.

Action Potentials

Intestinal changes after jejuno-ileal shunt in obesity: a report of 2 cases.

Two cases of end-to-end and end-to-side jejuno-ileal bypass for the treatment of obesity are reported in which both patients underwent reoperation 17 and 23 months later respectively. Macroscopic examination and measurements of length of the various segments of the small intestine have been performed twice in each patient: at the time of the bypass and at the second surgical procedure. In one patient a histological study of both the excluded and functioning small intestine was carried out at the time of each surgical procedure. The functioning intestine had increased in size while the excluded segment had become narrowed. The height of the villi had increased slightly in the functioning ileum and more so in the functioning jejunum compared with the preoperative measurements. In contrast, the height of the villi was moderately reduced in both the bypassed jejunal and ileal segments. These findings confirm the results of experimental studies in animals.

Adult

[Study of intestinal motility. Contribution of electromyography].

The longitudinal and circular deformations of the intestinal wall have been studied simultaneously with the intestinal electrical activity. Tracings were obtained for several weeks by means of a compact device which was implanted on the jejunum in 6 dogs and 4 rabbits. The results showed that the transverse movements of the intestine corresponded to the muscular activity of the circular layer. The longitudinal movements were observed permanently in the rabbit. In the dog they could correspond to a contraction or a relaxation movement. In the two cases, no electrical activity was related to the longitudinal mechanical activity of the intestine.

Animals

[Gastro-intestinal electromyography: interest in the study of mechansims of regulation of intestinal motility (author's transl)].

Investigations we carried out in man and animals in order to study the relationships between the electrical and the mechanical activities of the intestine, and to precise the role of BER in the regulation of intestinal motility. In the dog, an intestinal movements transducer allowed to establish that spiking activities were concomitant with circular contractions, and that these two phenomena were rhythmed by the slow waves. Under basal conditions, the longitudinal movements occurred independently; under stimulation longitudinal movements occurred independently; under stimulation longitudinal relaxations were observed to correspond to circular contractions. In man, the post-laparotomy paralytic ileus provoked abnormalities in the BER which seemed to be related to a disturbance of the coordination of the motility, resulting in the absence of intraluminal propulsion. Administration of coherin, a postpituitary extract, was followed by a regularization of the BER and by a decrease of paralytic ileus duration. This confirms the important role of the BER in the myogenic regulation of the intestinal motility.

Animals

Simultaneous recording of circular and longitudinal muscle contractions of the canine jejunum.

A method has been developed for monitoring the mechanical activities of individual longitudinal and circular muscles in a 5 millimeters long segment of intact intestine in the anesthetized dog. The longitudinal contractions were recorded by means of a new movement transducer. The circular contractions were recorded simultaneously using a water-filled intraluminal balloon. A precise separation of longitudinal and circular motor activities was obtained with this method. The two muscle layers manifested motor activity most of the time, but their contractions were out of phase. Phase locking was observed only during short periods of time. The contractions were then sequential, the circular one being first.

Animals

Effects of some drugs on electrical activity of the gut in the postoperative period.

Myoelectrical activity of the gut has been studied in the postoperative period on 54 patients who underwent cholecystectomy. They have been divided into one control group and four other groups which were treated with pentagastrin, cholecystokinin, prostigmine or coherin (a posterior pituitary extract). In all patients, bursts of spikes were recorded during the early postoperative period. However, the slow waves were strongly disturbed at this time. Pentagastrin, CCK-PZ and prostigmine had no effect on the slow waves, while they increased the frequency of the spikes. These substances did not reduce the duration of the 'physiological' ileus. On the contrary, coherin was found to improve the regularity of the slow waves and to reduce the duration of the 'physiological' ileus.

Cholecystectomy

The effects of transections on the basic electrical rhythm in the canine jejunum.

The basic electrical rhythm (BER) was studied in situ in the jejunum in 14 anaesthetized mongrel dogs by the mean six monopolar electrodes. The BER frequency was measured in the intact intestine and after proximal and distal transections of the gut 5 cm apart from the electrodes. No significant differences were found between the BER frequencies recorded by each electrode, demonstrating the existence of a frequency plateau which remained after each transection. In the intact intestine the frequency in the plateau was 13.2 +/- 0.3 cpm2. After the proximal transection, this frequency dropped to 12.0 +/- 0.4 cpm (p less than 0.05) and, after the distal transection, it dropped to 10.9 +/- 0.4 cpm (p less than 0.005). This last frequency change shows the influence of the distal intestine on the electrical behaviour of the jejunum.

Action Potentials

Gastrointestinal myoelectrical activity during the postoperative period in man.

Myoelectrical activity of the gastrointestinal tract has been studied in the postoperative period of 13 patients who underwent cholecystectomy. The recordings have been performed by means of extracellular electrodes which were implanted at the levels of stomach, jejunum, ileum and colon during the surgical procedure. The records showed that fast activity is always persistent while the basic electrical rhythm is greatly disorganized during the immediate postoperative period. Such a characteristic pattern of the electrical activity suggested that the lack of peristaltic and propulsive movements, always noted during this period, is not correlated with a disappearance of gastrointestinal contractions, but only with a disturbance in their coordination.

Action Potentials

[Renal preservation: comparative effectiveness of 2 simple perfusion technics].

The authors compare the efficacy of two perfusates, Collins' solution and Perfudex, for conservation of kidneys for short periods by perfusion and hypothermic immersion. 22 dog kidneys, removed by lombotomy, were preserved for 24 hours with one or other of these solutions and then re-implanted into their host. Radio-isotopic renography, the uptake of Hg 197 Cl3 and a hippuran renogram, used to assess the function of the transplants, suggested the functional superiority of kidneys preserved with Collins solutions. Histological controls carried out beyond the 10 th post-operative week, confirmed these results. The correlations observed between these various findings also assessed the reliability of radio-isotope examinations in the exploration of renal function.

Animals