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Biomedical subjects

G Vantrappen

Publications and source records attributed to G Vantrappen.

At least 181 records · Page 10Linked to original sources
PubMed1986

24-hour recording of esophageal pressure and pH in patients with noncardiac chest pain.

Sixty patients with anginalike chest pain of noncardiac origin were studied to determine the diagnostic value of 24-h ambulatory esophageal pH and pressure monitoring. The results of these 24-h studies were compared with those obtained by established methods, including x-rays, endoscopy with biopsy, conventional esophageal manometry, and acid perfusion test. Esophageal origin of the chest pain was considered to be likely if the familiar pain sensation was reproduced by the acid perfusion test, or if the pain occurred during an episode of gastroesophageal reflux, severe motor disorders, or both. When the results of established methods were combined and interpreted according to predetermined criteria, esophageal origin of the pain was shown to be likely in 27% of the patients. The 24-h recordings, alone, showed the esophagus to be the likely cause of the pain in 35% of the patients. Combination of all conventional examinations and of 24-h recordings made esophageal origin of the pain likely in 48% of the patients.

Adult↗
PubMed1986

Motilin receptors in rabbit stomach and small intestine.

Motilin receptors in rabbit antral and duodenal smooth muscle tissue were characterized by direct binding technique using 125I-labeled porcine motilin as a tracer ligand. Binding at 30 degrees C was maximal at 90 min, was saturable and partially reversible. Displacement studies with natural porcine motilin, synthetic leucine-motilin or norleucine-motilin indicated a dissociation constant (Kd) of 1.1 +/- 0.3 nM and a maximal binding capacity (Bmax) of 42 +/- 10 fmol/mg protein. Binding was unaffected by glucagon, pancreatic polypeptide and somatostatin, but substance P interfered via an unknown mechanism. By density gradient centrifugation motilin receptors were shown to be present in plasma membranes. Binding could only be demonstrated in preparations from antrum and upper duodenum. These observations provide evidence for a localized target region for motilin in the gastrointestinal tract, and for a direct interaction of motilin with gastrointestinal smooth muscle tissue.

Animals↗
PubMed1986

Comparison of the biological activity of canine and porcine motilin in rabbit.

The biological activity of porcine and canine motilin was studied in rabbits by establishing dose-response curves of both peptides using two different methods. The dissociation constant, obtained from the displacement of iodinated porcine motilin by canine motilin was 0.6 +/- 0.3 nM, versus 1.2 +/- 0.4 nM for porcine motilin. For the 13-norleucine and 13-leucine analogues of porcine motilin a value of 0.8 +/- 0.3 nM was obtained. Both motilins were almost equipotent in stimulating the in vitro contractile response of longitudinal smooth muscle strips: half-maximal effect was achieved at a concentration of 1.0 +/- 0.1 nM for canine versus 1.3 +/- 0.2 nM for the 13-norleucine analogue of porcine motilin. We conclude that porcine and canine motilin have a comparable bioactivity in the rabbit, although canine motilin is slightly more effective. The motilin receptor is probably specific for the N-terminal portion which is identical in both molecules.

Acetylcholine↗
PubMed1986

The benefits of endoscopy in upper gastrointestinal bleeding.

Management of the patient with upper gastrointestinal bleeding is a continuing challenge to the gastroenterologist and the surgeon. Endoscopy early in the course of bleeding benefits the patient only when diagnostic accuracy is combined with definitive hemostatic therapy. Effective methods are now available for endoscopic hemostasis of bleeding ulcers and bleeding varices. However, an improvement in the outcome of gastrointestinal bleeding is not easily achieved, since age and the incidence of severe underlying disease in patients with upper G.I. hemorrhage have been steadily increasing over the years.

Endoscopy↗
PubMed1986

Crohn's disease of the esophagus.

Crohn's disease only rarely affects the esophagus, usually producing strictures and fistulas. Superficial lesions such as erosive esophagitis are infrequent. Histological proof of esophageal Crohn's disease is only exceptionally obtained with endoscopic biopsies. In a 4-year period we have followed 500 patients with Crohn's disease. Esophageal involvement was recognized in nine patients, usually because of painful dysphagia. Esophagoscopy revealed large aphthoid lesions. The clinical picture was characterized by: (a) involvement of multiple segments of the gastrointestinal tract, (b) extraintestinal manifestations, and (c) critical illness of the patients. Esophageal lesions and symptoms disappeared quickly with therapy. Routine histology of esophagoscopic biopsies revealed granulomas in only two patients, but additional sections showed granulomas in another five.

Adolescent↗
PubMed1986

Somatostatin induces ectopic activity fronts via a local intestinal mechanism during fed state or pentagastrin.

The effect of local intra-arterial infusions of somatostatin on small bowel motility in the postprandial period and during an intravenous pentagastrin infusion was studied in five dogs. A Silastic catheter was implanted in a small branch of the superior mesenteric artery perfusing a 5-to 10-cm jejunal segment located 30-40 cm distally to Treitz. Small bowel myoelectric activity was recorded by means of a series of bipolar electrodes implanted subserosally along the small intestine. Experiments were started 2 wk after surgery and were performed in conscious animals. Intra-arterial infusion of somatostatin induced activity fronts in the fed state and during intravenous pentagastrin infusion in a dose-dependent manner. These activity fronts always started at or just below the perfused segment, migrated distally over the remaining small bowel, and were superimposed on the fed pattern. We conclude that local administration of somatostatin is able to initiate normally migrating ectopic activity fronts, despite the presence of neural and hormonal factors that control the fed state. Local release of somatostatin might be involved in the initiation of spontaneously occurring activity fronts.

Animals↗
PubMed1986

An adaptive on-line method for the extraction of the complete fetal electrocardiogram from cutaneous multilead recordings.

The detection of a fetal electrocardiogram (FECG) is described to be a so-called inverse problem. A geometric interpretation of such a problem is presented. It can be solved by determining the weights to be used in one or more weighted sums of measurement signals. A novel method is presented to determine these weights. Theoretical and experimental evidence is given that this method has the following attractive properties. Application of the method results in one or more FECG signals, free of maternal ECG (MECG) which are at the same time maximal with respect to noise. It is shown that one FECG signal does not always suffice to describe the observed electrical heart activity in a set of cutaneous electrodes, equivalently to the adult ECG (see figure 7). It is explained and experimentally verified that the application of three thoracic signals is useful to guarantee the suppression of the MECG. The positions of the abdominal electrodes then determine the obtained FECG to noise ratio, and will have no influence on the degree of MECG suppression (see figure 6). It is expected that a total of about eight measurement signals are sufficient in most cases. The method is simple to apply by medical personnel, and after a transient of about 1 s the signals with the mentioned properties are obtained (see figure 5). Further on, the weights are allowed to change in order to adapt automatically to sudden changes in the measurement signal properties (see figure 6). These may occur e. g. due to fetal movement. Application of the method requires no human interpretation or decision in order to obtain the claimed properties.

Electrocardiography↗
PubMed1986

[Treatment of primary motility disorders of the esophagus].

All treatment modalities of achalasia aim at reducing the resistance at the cardia sufficiently to allow easy aboral flow, but insufficiently to favour gastroesophageal reflux. This can be achieved either by powerful dilatation or by cardiomyotomy. Early and late results, morbidity and mortality rates and late complications of these different treatment modalities are discussed. The personal experience of the authors with progressive pneumatic dilatations in a series of 700 patients is described.

Dilatation↗
PubMed1985

Expression of MHC Class II antigens by oesophageal epithelium in herpes simplex oesophagitis.

An immunoperoxidase technique with monoclonal antibodies for the identification of lymphocyte subsets and MHC Class II antigens was applied to oesophageal biopsies from two patients with herpetic oesophagitis. Oesophageal epithelial cells were found to express the MHC Class II antigen. The inflammatory infiltrate of the lamina propria was composed of both B lymphocytes and T lymphocytes.

Antigens↗
PubMed1985

Long term results of treatment of vascular malformations of the gastrointestinal tract by neodymium Yag laser photocoagulation.

The effect of Yag laser photocoagulation on the course of bleeding of gastrointestinal vascular malformations was studied in 59 patients, with a total of 482 lesions. The lesions were located in the upper gastrointestinal tract alone in 25 patients, in the lower tract alone in 31 patients and in both the lower and the upper gastrointestinal tract in three patients. In the month before laser therapy the number of bleeding episodes averaged 1.09 +/- 0.6 (SD) per patient (n = 57) and the transfusion requirements 2.4 +/- 2.6 red blood cells units per patient, while in the month after treatment the bleeding incidence averaged 0.16 +/- 0.5 and the transfusion requirements 0.21 +/- 0.8 (both p less than 0.001). Long term results were analysed considering for each patient an equally long pretreatment and follow up period. After a mean follow up period of 11.5 months (1-48 months), 17 of the 57 patients available for follow up rebled. The reduction of the bleeding rate was statistically significant at one, six, 12, and 18 months of follow up, while transfusion rate was significantly decreased at one, six, and 12 months. The results were disappointing in patients with Osler-Weber-Rendu (n = 4) and in patients with angiomas associated with Von Willebrand's disease (n = 3), who all rebled. In angiodysplasia the treatment was successful in 82% of the 49 patients. The more numerous the lesions, the less effective the reduction in bleeding rate by laser treatment was. Histological studies showed that the haemostatic effect of Yag laser photocoagulation was obtained by destruction of the lesion. Rebleeding was due to lesions missed at the first treatment, incompletely treated lesions and recurrence of new lesions. In two patients a free caecal perforation necessitated a right hemicolectomy. In both patients numerous or very large lesions had been treated in the caecum.

Adolescent↗
PubMed1985

Medical management of reflux esophagitis.

Esophageal reflux should be treated only if symptoms are severe enough for patients to seek therapy or if esophagitis results. One study found that the number of reflux episodes lasting more than 5 min was the best indicator of esophagitis. Factors such as efficiency of the antireflux barrier, esophageal clearing, and aggressive power of refluxed material impact on the pathogenesis of reflux esophagitis. Therapy should be aimed at these factors and depends on severity of disease. Dietary measures, postural measures, and drug therapy can be used to alleviate symptoms and/or improve healing of esophageal lesions, with surgery recommended only in rare cases. Antacids, Gaviscon, and motor-stimulating drugs (metoclopramide, domperidone, bethanechol) may be sufficient to treat pathologic reflux without esophagitis. Once erosive or ulcerative lesions have developed, more rigorous medical treatment including H2 receptor blockers is mandatory.

Antacids↗
PubMed1984

Different meals produce different digestive motility patterns.

The purpose of these experiments was to characterize the pattern of digestive myoelectric activity produced by four different test meals in dogs. A new approach for the analysis of the myoelectric activity of the small intestine was used. In contrast with methods dividing the tracings into present time periods, the present method respected the "motor entities," hence the continuity, of the tracing. Two types of motor entities occurred: "activity units" which are groups of consecutive slow waves with spiking, and "rest units," which are groups of consecutive slow waves without spiking. The frequency of occurrence and frequency of alternation of the various activity and rest units occurring during digestion was calculated. Digestive myoelectrical activity was characterized by the frequent occurrence and alternation of short activity and rest units. Three different patterns of digestive activity could be discriminated, ie, a fat, a protein and carbohydrate, and a canned food pattern.

Animals↗
PubMed1984

Intestinal motility after infusion of arachis oil into duodenum and ileum of dogs.

Arachis oil and a mixture of arachis oil with bile and pancreatic enzymes were infused into the duodenum and ileum of dogs via surgically positioned catheters in order to study the mechanism of disruption of the migrating complex by intraluminally infused triglycerides, the importance of cholecystokinin and neurotensin in this event, and the pattern of digestive myoelectrical activity during fat digestion. When infused into the duodenum both arachis oil and the oil-bile-pancreatic enzyme mixture disrupted the migrating myoelectric complex (MMC). When infused into the ileum, only the oil-bile-pancreatic enzyme mixture disrupted the MMC. The duration of the disruption lasted as long as when the same amount of oil was administered orally. Triglyceride-induced digestive activity was characterized by the frequent alternation of short periods of spiking activity and short periods of quiescence. It is concluded that the triglyceride-induced disruption of the MMC-pattern is not caused by the triglyceride itself but by some emulsion or digestion product. We further suggest that the disruption is hormonally mediated and due to fat-stimulated neurotensin, rather than cholecystokinin (CCK), release.

Administration, Oral↗
PubMed1984

The value of ileoscopy with biopsy in the diagnosis of intestinal Crohn's disease.

Studies to determine the diagnostic value of ileoscopy and biopsy are not available. In an attempt to clarify the role of this technique in the diagnosis of intestinal Crohn's disease, 110 patients with a radiological diagnosis of inflammatory disease of the terminal ileum were examined in a prospective study. Suspicion of Crohn's disease was rejected in 28 patients. In 18 patients the terminal ileum was normal, while 10 patients had lymphoid nodular hyperplasia. Endoscopic lesions with a predictive value of 0.96 were found in 25 of 48 patients with the final diagnosis of Crohn's disease. Diagnostic granulomas were only found in 4 patients, but lesions consistent with Crohn's disease were present in the pathology sections of 17 patients. It was concluded that ileoscopy with biopsy is a valuable tool in the diagnosis of inflammatory ileal disease and can provide useful information about the nature and extent of the inflammation.

Adolescent↗