Biomedical subjects

C Cherbut

Publications and source records attributed to C Cherbut.

46 records · Page 3Linked to original sources

PubMed1992

Short-chain fatty acids do not alter jejunal motility in man.

Short-chain fatty acids (SCFAs) alter ileal and colonic motility, but their effects on duodenojejunal motility are unknown. Simultaneous jejunal manometric recordings and hydrogen breath tests after lactulose were performed in eight healthy subjects during continuous duodenal infusion of either saline or SCFAs. These experiments were conducted in the fasting state and postprandially. The effects of various boluses of SCFAs on duodenojejunal motility were also determined in six subjects. During the fasting period, the number and characteristics of migrating motor complex, prolonged propagated contractions, discrete clustered contractions, motility index, and orocecal transit time were similar during saline and SCFAs. Similarly, the motility index and the duration of the postprandial period were not different between SCFAs and saline after the meal. The motility index was significantly increased after each of the 100-ml boluses (saline or SCFAs), but was not altered after the 12.5-ml boluses, suggesting a volume-related effect. Thus, SCFAs do not seem to affect proximal small bowel motility in healthy humans.

Adult↗

PubMed1991

Alterations of intestinal microflora by antibiotics. Effects on fecal excretion, transit time, and colonic motility in rats.

The effects of intragastric antibiotics in rats were examined on fecal microflora and excretion and through transit time and cecocolonic myoelectric activity. A solution of nonabsorbable antibiotics infused into the stomach for 20 days had a dramatic effect on the quantity, composition, and bacterial content of rat feces. Both the dry weight and the water content of feces were increased. The amount of short-chain fatty acids in the feces was dramatically lowered. However, neither total nor cecocolonic transit time of solids was affected. The cyclic organization of cecocolonic myoelectric activity was altered by antibiotic treatment, and the motility index, ie, the quantity of myoelectric activity recorded on the colon, progressively increased. An infusion of short-chain fatty acids modified this motor pattern but did not restore activity to a level comparable to that of control animals. In conclusion, intragastric antibiotics dramatically reduced intestinal microflora and increased fecal excretion of dry matter and water but did not affect the transit time of solid gut contents, although they did influence cecocolonic motility.

Animals↗

PubMed1990

Action of guar gums on the viscosity of digestive contents and on the gastrointestinal motor function in pigs.

The apparent viscosity of three test meals containing 6% of different guar gums was measured in the gastric, duodenal and jejunal contents and related with the gastrointestinal myoelectric activity and transit time in pigs. The motility index (mV/min) and the spike burst frequency (number of spike bursts/min) were closely related to the digesta viscosity: they were significantly increased by most viscous contents in stomach and small intestine. This effect was associated with an increase in the orocecal transit time of liquids and solids.

Animals↗

PubMed1989

[Digital storage and semi-automatic analysis of esophageal pressure signals. Evaluation of a commercialized system (PC Polygraft, Synectics)].

The aim of this work was to evaluate a new commercially available pressure recording system (PC Polygraf, Synectics) and to compare this system with a classical method using perfused catheters. The PC Polygraf uses microtransducers and allows direct digitized storage and semi-automatic analysis of data. In the first part of this study, manometric assessment was conducted using only perfused catheters. The transducers were connected to both an analog recorder and to a PC Polygraf. Using the two methods of analysis, contraction amplitudes were strongly correlated (r = 0.99; p less than 0.0001) whereas durations were significantly but loosely correlated (r = 0.51; p less than 0.001). Resting LES pressure was significantly correlated (r = 0.87; p less than 0.05). In the second part of this study, simultaneous recordings of esophageal pressure were conducted in 7 patients, by placing side by side the two tubes (microtransducers and perfused catheters) with the sideholes at the same level. The characteristics of the waves were determined both by visual analysis of analog tracing and by semi-automatic analysis of digitized recording with adequate program. Mean amplitude was lower with the microtransducers than with the perfused catheters (60 vs 68 cm H2O; p less than 0.05), but the duration of waves was not significantly different when using both systems. Values obtained for each of these parameters using both methods were significantly correlated (amplitude: r = 0.74; duration: r = 0.51). The localization and the measure of the basal tone of sphincter were found to be difficult when using microtransducers. These results show that PC Polygraf allows a satisfactory analysis of esophageal pressure signals. However, only perfused catheters offer an excellent reliability for complete studies of both sphincter and peristaltism.

Adult↗

PubMed1989

[Are intraluminal electrodes reliable for recording myoelectric activity of the small intestine?].

In humans except for the postoperative state, electromyographic activity of the small bowel can only be recorded with intraluminal electrodes. The aim of this study was to validate the use of intraluminal electrodes in pigs by comparing the signal recorded from such electrodes to those recorded with surgically implanted electrodes. A polyethylene probe equipped with bipolar ring-shaped electrodes was placed in the lumen of the proximal jejunum of 6 pigs, at the same level as intramuscular implanted electrodes. The signals were recorded in conscious pigs fed normally. By comparison to the myoelectric activity recorded from the intramuscular implanted electrodes, the intraluminal electrodes provided reliable spike burst detection (sensitivity 85 p. 100; positive predictive value 91 p. 100) in the fasted and fed state, and good identification of migrating myoelectric complexes. Spectral analysis showed the same frequency patterns for signals obtained with both types of electrodes. In conclusion, intraluminal ring-shaped electrodes allow reliable detection of small bowel myoelectric activity and may represent a useful tool for motility studies in man.

Animals↗

PubMed1986

Effect of diet on intestinal xylose absorption in dogs.

The absorption of xylose at different levels of the intestine was compared in five dogs receiving diets containing either wheat bran, polyethylene particles (PE), or horse-bean hulls. The absorption was determined by serial collection of the interstitial fluid (ISF) in different parts of the small intestine and colon, and blood concentration after the administration of D-xylose as a solution (0.5 g/kg body weight) into the duodenal bulb. Xylose was mostly absorbed from the duodenum, and its concentration in the duodenal ISF and in plasma was reduced on a diet containing fiber, irrespective of the nature of fiber. In contrast, a negative linear relation between the mean retention time of digesta in the small intestine and the amount of xylose absorbed by duodenum was evidenced (r = -0.843). The results indicate that changes in transit linked to the presence of fiber in a diet are a major operative factor in the rate of carbohydrate absorption. They suggest that the absorption can be affected by a relatively minor change in the intestinal transit of digesta.

Animals↗

PubMed1986

Relationships between electromyographic ileal and colonic motility patterns in cats during fasting and feeding.

The relationship between ileal and colonic electromyographic motility patterns were investigated in six awake cats chronically fitted with subserosal electrodes implanted in the smooth muscles of the ileum and colon. Smooth muscle electrical activity (electromyogram) was recorded in both fed and fasted conditions under a 12-12 hours dark-light schedule. It consisted of electrical long spike bursts having two different patterns for each condition. Short sequences of three to five long spike bursts were propagated either aborally or orally from any part of the colon; they were most frequent during the interdigestive or fasting period and no relationship was observed between these long spike bursts and the electrical activity of the ileum. During the digestive or feeding period, the colonic activity was organized in long sequences of 10-15 long spike bursts, termed migrating spike bursts, which started near the caecal junction and propagated aborally to the distal colon. These migrating spike bursts were correlated with the ileal motility. This relationship demonstrated between ileum and colon after feeding is dependent upon the amount of food intake.

Animals↗

PubMed1985

The effect of indigestible particles on digestive transit time and colonic motility in dogs and pigs.

The myoelectric activity of the colon was examined in three dogs and three pigs when they were given a basal diet or a basal diet plus indigestible particles (IP), 2 mm in diameter, at 100 g/kg dry matter. The mean retention time was determined using coloured discs as a marker added to the daily meal. Colonic electromyograms of dogs and pigs given IP revealed a 30% reduction in the number of long spike bursts (LSB) when compared with controls. The other components, propulsive migrating spike bursts (MSB) or non-propulsive short spike bursts (SSB), were unchanged. Mean retention time was decreased from 28.6 h to 17.6 h in dogs and from 129 h to 94.2 h in pigs. These changes developed progressively during 3-4 d in both species, suggesting that the reduction in motor activity was an adaptation to the changes in bulk contents. From the decreased motility of the colon linked to the reduction of LSB and paralleled by an increased transit time, it was concluded that one of the functions of the LSB is to impede the passage of digesta.

Adaptation, Physiological↗

PubMed1984

[Changes in electromyogram of the colon related to ingestion of undigestible particles in dogs].

The relationship between undigestible particle intake and myoelectric activity of the colon was examined in three dogs fed with a low-fiber diet alone or with polyethylene particles containing 10 p. 100 and 45 p. 100 of dry matter. When compared to controls colonic electromyograms of dogs fed on polyethylene revealed a 40 p. 100 reduction in long spike bursts (LSBs). The sequences of LSBs propagated over long distances, or MSBs (migrating spike bursts) were unchanged and only the myoelectric activity corresponding to LSBs propagated for very short distances was abolished by polyethylene diets. Concurrently, the percentage of water excreted in the feces was increased. Undigestible and inert particles were thus able to modify the colonic motor profile and to increase the fecal excretion of water. Such effects were similar to those observed with dietary fibers. It is suggested that dietary fiber effects on fecal excretion and colonic motility are partially induced by their mechanical action on the intestinal wall. In addition, the absence of LSBs propagated in both directions and for short distances on the canine proximal and transverse colons seems to be a limiting factor in the movements of water absorption.

Animals↗

PubMedDate not supplied

Does the route of feeding modify gastric emptying in rats?

BACKGROUND: It has been shown that the pattern of previous nutrient intake can influence gastric emptying. However, the effect of the absence of enteral stimulation in the setting of a normal energy supply on gastric emptying has not been examined. The aim of this study was to determine whether the absence of enteral stimulation during total parenteral nutrition (TPN) could modify gastric emptying in rats. METHODS: Two experiments were performed. First, gastric emptying of a peptone meal was compared between rats receiving TPN, oral liquid diet (same solution as TPN), or regular diet (control group) for 10 days. In the second experiment, gastric emptying of two test meals (40% peptone and 25% glucose) was studied before and after rats received TPN or intragastric nutrition (same solution as TPN) for 10 to 12 days. RESULTS: In experiment 1, gastric emptying of 40% peptone in the TPN and liquid diet groups was slower than that in the control group. This difference was significant between the TPN group and the control group (p < .01) but not between the liquid diet and control groups (p = .076). Gastric emptying of this meal in the TPN and liquid diet groups was similar. In experiment 2, no difference in gastric emptying of 40% peptone or 25% glucose was found between rats receiving TPN and those receiving intragastric nutrition for 10 to 12 days. CONCLUSIONS: The composition of diet not the route of feeding is important in the modification of gastric emptying by the pattern of previous nutrient intake.

Animals↗