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Biomedical subjects

G Vantrappen

Publications and source records attributed to G Vantrappen.

At least 163 records · Page 9Linked to original sources

Local nerve blockade by tetrodotoxin induces ectopic phase 3 of the migrating myoelectric complex in dogs.

The effect on the migrating myoelectric complex (MMC) of local nerve blockade in the jejunum was studied in five unanesthetized dogs. A silastic catheter was implanted in a terminal branch of a jejunal artery, perfusing a 5- to 10-cm segment, 45 cm below the ligament of Treitz. Small-bowel motor activity was studied electromyographically with implanted electrodes. Three different doses of tetrodotoxin (166, 333, 500 ng/kg/h) were administered intra-arterially for 5 h. During the 333- and 500-ng but not during the 166-ng/kg/h perfusions ectopic activity fronts started just below the perfused segment. At this time no phase-3 activity was observed in the proximal bowel. In addition to ectopic fronts normal MMCs were observed during the perfusions. These observations show that local nerve blockade induces phase-3 activity, probably by inhibiting an inhibitory nerve action.

Animals↗

Interdigestive motility and motilin in hypophysectomized patients.

Basal fluctuations of motilin and their correlation to intestinal motor activity were studied in five hypophysectomized (anterior lobe resection) patients. A cyclic pattern of motor activity identical to the one described in normal volunteers was observed. The mean interval between two activity fronts (AF) was 115 min, which is not significantly different from the normal length. Motilin levels were within the normal range, and fluctuations correlated with the occurrence of an AF. The mean difference between motilin levels 15 min before the AF and at the time of the start of the AF was +15 pM (P less than 0.05). For the levels 15 min after the AF the mean difference was -9 pM (P less than 0.05). These values correlate well with those reported by us in normal volunteers, in whom the mean differences were +11 pM and -14 pM, respectively. It is concluded that the adenohypophysis is not involved in the regulation of motilin levels or in the regulation of interdigestive motility in man.

Digestion↗

13CO2 breath test using naturally 13C-enriched lactose for detection of lactase deficiency in patients with gastrointestinal symptoms.

A 13CO2 breath test using naturally enriched 13C-lactose as a substrate was performed in 47 patients with chronic abdominal pain or chronic diarrhea, taken from a population with a low prevalence of primary acquired lactase deficiency. The cumulative 13CO2 excretion 4 hours after 13C-lactose intake was compared with the H2 breath excretion and with jejunal lactase activity. A physiologically significant relation was found between the cumulative 13CO2 excretion (at 4 hours) and lactase activity, 14.5% 13CO2 excretion being the best cutoff point for discrimination between patients with low and normal lactase activity. The 13CO2 breath test was found to be more sensitive (0.84 versus 0.68) and more specific (0.96 versus 0.89) than the H2 breath test in detecting low jejunal lactase activity. Concordant results of both breath tests performed simultaneously give a reliable picture of the lactose absorption status of the patient. Discordance in results of 13CO2 and H2 lactose breath tests, if not explained by history, indicates in which patients a jejunal biopsy should be performed. If lactase activity and morphology of the biopsy are normal, other causes of discordance must be investigated.

Abdomen↗

The irritable oesophagus--a frequent cause of angina-like pain.

33 patients with angina-like chest pain of oesophageal origin were investigated. In 8 (24%) the pain proved to be related to oesophageal motor disorders unaccompanied by gastro-oesophageal reflux; in 12 (36%) acid reflux contributed to chest pain; but in the remaining 13 (40%) identical chest pain episodes were due to various mechanisms including reflux without motor disorders, motor disorders without reflux, motor disorders without reflux but with positive acid-perfusion test, and acid reflux without motility disorders but with positive edrophonium-stimulation test. These data strongly suggest that the mechanism of pain in these patients is related to irritability of the oesophagus.

Adult↗

Effects of partial ileocolectomy and Crohn's disease on biliary lipid secretion.

The effects of interruption of the enterohepatic circulation of bile acids on biliary lipid secretion have only been studied experimentally, and quantitative data in patients are lacking. Therefore, biliary lipid secretion during steady-state meal perfusion of the duodenum was studied in six patients with partial ileocolectomy, five patients with Crohn's disease, and five normal subjects. Bile acid outputs in the resection patients were significantly lower than in normal controls, (6.87 +/- 2.10 mmol/6 hr and 13.5 +/- 2.16, respectively; P less than 0.001) and were also decreased in two of the five Crohn's disease patients. Bile acid outputs in patients with resection progressively decreased in the course of the perfusion study; phospholipid and cholesterol secretion did not decrease to the same extent, and cholesterol saturation gradually increased. Bile of these patients, therefore, was frequently supersaturated due to uncoupling of bile acid secretion and outputs of the other biliary lipids. Bile acid outputs, although decreased, did not reach very low values, which shows that the enterohepatic circulation was not totally interrupted. Chenodeoxycholic acid was the main bile acid component of bile in patients with ileocolonic resection. Deoxycholic acid was absent from bile of four resected patients and two Crohn's patients. Two patients with active Crohn's disease had low bile acid outputs despite only moderate fecal bile acid losses. Therefore, decreased outputs may be caused by decreased bile acid pool not compensated for by increased bile acid synthesis in severely ill patients.

Adult↗

Migrating action potential complexes in a patient with secretory diarrhea.

A 70-year-old woman with secretory diarrhea was studied with a novel technique of recording small intestinal myoelectrical activity which allowed us to obtain long, uninterrupted records of slow waves and spikes at eight or more different intestinal levels simultaneously. Typical migrating action potential complexes (MAPCs) were observed, consisting of spike bursts that extended over more than one slow wave and migrated distally at the same propagation velocity as the slow waves. This motility pattern occurred frequently during the period the patient presented with secretory diarrhea and disappeared with the disappearance of the diarrhea. It was observed only once in a series of 10 normal control subjects. This is the first report on MAPC activity in man and on the association of this myoelectrical pattern with secretory diarrhea in man.

Action Potentials↗

Influence of metenkephalin analogue on motor activity of the gastrointestinal tract.

The effect of the metenkephalin analogue Hoe 825 on esophageal motility, fundic accommodation to distention, and migrating myoelectric complex was studied in 17 healthy volunteers. The metenkephalin analogue (40 micrograms i.v.) significantly increased the duration, amplitude, and propagation velocity of the postdeglutitive esophageal peristaltic contraction waves. It had no effect on the basal lower esophageal sphincter pressure but significantly decreased the completeness of the sphincteric relaxation from 85% +/- 5% on placebo to 70% +/- 7% (p less than 0.01). The metenkephalin analogue (40 micrograms i.v.) significantly decreased the fundic accommodation to distention. In doses ranging from 20 to 60 micrograms i.v. it induced a premature phase III of the migrating motor complex that started ectopically in the duodenum (without a gastric component) and migrated distally at a significantly higher velocity than a spontaneous phase III. It is hypothesized that the metenkephalin analogue induces these effects via an inhibition of the inhibitory nervous system.

Adult↗

Angina-like chest pain of oesophageal origin.

Angina-like chest pain of non-cardiac origin is a major diagnostic and therapeutic problem. The oesophagus is frequently suspected to be the cause of the chest pain in these patients. However, a positive statement for the oesophageal origin of the pain can only be made when during manometry or pH-monitoring the familiar pain attack appears to be accompanied by reflux, severe motor disorders or a combination of both. Due to the intermittent nature of the pain this is only rarely the case during short-listing conventional examinations. Provocation tests have been used to induce the familiar chest pain. The Bernstein acid perfusion test and the edrophonium test yield the best results. Prolonged (24-hour) ambulatory recording of intra-oesophageal pressure and pH to increase the chances of recording chest pain concomitantly with an episode of reflux and/or motor disorders appears to be the most sensitive and also the most physiological test. It is the only test that provides reliable information on the underlying mechanism of the pain, especially in patients with the syndrome of irritable oesophagus, thus contributing in establishing the appropriate therapy for these patients.

Angina Pectoris↗

Neodymium-YAG laser photocoagulation versus multipolar electrocoagulation for the treatment of severely bleeding ulcers: a randomized comparison.

A randomized trial comparing the efficacy of BICAP electrocoagulation and YAG laser photocoagulation was carried out in 100 patients presenting at endoscopy with peptic ulcer and a spurting or oozing vessel or a nonbleeding vessel. Fifty patients were enrolled in each treatment group. All lesions were pretreated with injection of epinephrine 1:10,000. Subsequently, 1-sec pulses of 80 watt YAG laser power were applied to the vessel or 1- to 2-sec pulses of electrocoagulation of 25 watt BICAP at a setting of 10. The 10 F BICAP probe was always used. Definitive hemostasis after one treatment amounted to 72% in both the laser and in the BICAP group. After two sessions the cumulative success rate was 88% in the laser group and 86% in the BICAP group. Emergency surgery and mortality were also comparable. One perforation occurred in each treatment group and both patients were operated upon without complications. It is concluded that both YAG laser and BICAP are highly and equally effective in the treatment of severe bleeding from peptic ulcers. This study stresses the importance of repeated treatment sessions in order to obtain optimal results.

Adult↗

Prevention of duodenal ulcer recurrence by pirenzepine 50 mg twice daily.

Eighty-four patients with healed duodenal ulcers were treated for 1 year with pirenzepine, 50 mg twice daily, or placebo in this double-blind, randomized, multicenter trial. Clinical follow-up and endoscopy were performed before and after 3, 6, and 12 months of treatment. Endoscopy was also carried out whenever symptoms compatible with ulcer recurrence were present for more than 2 days. Both groups were well matched for age, sex, duration of peptic ulcer disease, and smoking habits. There were 21 drop-outs due to lack of compliance. Therefore, 32 patients treated with pirenzepine and 31 with placebo were included in the analysis. Expressed in cumulative percentage of recurrence, with pirenzepine, 28% of the patients had a relapse at 3 months, 41% at 6 months, and 53% at 12 months; with placebo, the recurrence rates were 58% at 3 months, 68% at 6 months, and 71% at 12 months. The mean success time at 1 year is also longer for pirenzepine (7.38 months) than for placebo (5.52 months). These differences are significantly in favor of pirenzepine (p less than 0.05). Both treatments were well tolerated. Dry mouth was more frequently observed with pirenzepine (14 versus 5 patients). We conclude that pirenzepine, 50 mg twice daily, significantly reduces the relapse rate of duodenal ulcers during a 1-year maintenance treatment.

Adult↗

In man, only activity fronts that originate in the stomach correlate with motilin peaks.

We have tested the hypothesis that the imperfect correlation between the occurrence of plasma motilin peaks and the migrating motor complex (MMC) is related to the site of origin of the MMC. Gastric and small-intestinal motor activity was recorded manometrically in 16 normal subjects after an overnight fast. Blood samples were taken every 10 min and assayed for motilin. Fifty MMCs were recorded: 29 (58%) originated in the antrum and 21 (42%) in the small intestine. For gastric MMCs a motilin peak (45 +/- 5 pM) was found 10 min before the occurrence of the MMC in the duodenum. For intestinal MMCs no peak could be demonstrated. On an individual basis 27 of the 29 gastric activity fronts were associated with a motilin peak, versus 5 out of 21 intestinal MMCs. It is concluded that in man only gastric activity fronts are associated with plasma motilin peaks. Apparently, motilin is only involved in the regulation of the MMCs originating from the stomach.

Adult↗

The cellular composition of granulomas in mesenteric lymph nodes from patients with Crohn's disease.

The immunohistochemical findings in granulomatous lymphadenitis in patients with Crohn's disease are presented and compared with conventional light microscopic findings. The cellular composition of the granulomas in mesenteric lymph nodes was examined with a broad panel of monoclonal and polyclonal antibodies directed to B-cells, T-cells, monocytes/macrophages, dendritic reticulum cells, HLA-DR antigens and the transferrin receptor. The centre of the granulomas contains OKIa+, OKM1+, OKT9+, DRC-, To5- epithelioid cells and giant cells and OKT3+ lymphocytes. In general, the majority of the small lymphocytes within the granulomas expresses the OKT3+, OKT4+ Leu 3a+ phenotype which points toward T-helper cells. Fewer OKT3+ OKT8+ T suppressor/cytotoxic cells are observed. At the periphery of the granulomas a lymphocytic corona composed of BA1+, B1+ B lymphocytes may be present. From these findings it can be concluded that the granulomas in mesenteric lymph nodes from patients with Crohn's disease are composed of centrally located T-lymphocytes and of epithelioid cells which are of monocyte/macrophage origin and have the characteristics of antigen-presenting cells.

Adolescent↗

Gastrointestinal motility disorders.

A classification of gastrointestinal motility disorders is offered based upon the type of disorder in transit (delay or acceleration), and the region of the gastrointestinal tract affected. Specific abnormalities of myoelectrical patterns are identified when possible and related to disturbances in transit in the stomach and small bowel.

Animals↗

Biliary lipid composition in patients with nonoperated Crohn's disease.

Lipid composition of fasting duodenal bile was studied in 56 patients with nonoperated Crohn's disease, 21 normals matched for age and sex, 13 patients with cholesterol cholelithiasis, and 9 patients with ileal resections. Crohn's patients had a significantly higher mean saturation index, calculated according to Thomas (0.84 +/- 0.51) when compared to normal (0.63 +/- 0.25). Patients with ileocolonic Crohn's disease and patients with severe bile acid malabsorption, particularly, showed an increased incidence of cholesterol saturated bile. Saturation in patients with nonoperated Crohn's disease was not increased to the levels found in patients with ileal resection or cholesterol gallstones. Bile acid composition of gallbladder bile was characterized by a significant decrease of the deoxycholate fractions in patients with Crohn's ileocolitis and colitis as well as in ileal resected patients. These qualitative changes of bile acid composition may influence cholesterol solubility. It is concluded that patients with nonoperated Crohn's disease may have an increased risk of developing cholesterol gallstones.

Adult↗

Pancreatic secretion in man with subclinical vitamin D deficiency.

The effects of subclinical vitamin D deficiency and vitamin D supplementation on oral glucose tolerance and secretion of pancreatic hormones were studied in 10 diphenylhydantoin-treated epileptic patients and 15 geriatric patients. Their mean serum concentrations of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 decreased markedly, but returned to normal within 2 weeks of oral supplementation with 25-hydroxyvitamin D3. The serum concentration of ionized calcium was within the normal range before treatment, and remained unchanged. Serum parathyroid hormone was increased during vitamin D deficiency, but decreased significantly (p less than 0.05) afterwards. In vitamin D-deficient epileptic and geriatric patients, the 2- and 3-h insulin levels after glucose ingestion were increased when compared with control values, and glucagon secretion was not suppressed by glucose. Oral glucose tolerance of both groups of patients did not change after 25-hydroxyvitamin D3 supplementation. Insulin secretion remained unchanged in geriatric patients, but was reduced to normal values in epileptic patients. Glucagon suppressibility by glucose was partly restored after vitamin D supplementation in epileptic patients but not in geriatric patients. In contrast to that observed in severely vitamin D-deficient rats or rabbits, correction of subclinical vitamin D deficiency failed to enhance insulin secretion or to improve glucose tolerance in man.

Age Factors↗