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Biomedical subjects

G Vantrappen

Publications and source records attributed to G Vantrappen.

At least 55 records · Page 3Linked to original sources
PubMed1994

Combined carbon-13-glycine/carbon-14-octanoic acid breath test to monitor gastric emptying rates of liquids and solids.

UNLABELLED: The aim of the present study was to develop a dual-carbon-labeled breath test for simultaneously measuring gastric emptying rates of liquids and solids with significantly less radiation burden to the patient than the radioscintigraphic technique. METHODS: A test meal was used in which the liquid phase was labeled with two markers, i.e., 3.7 MBq of 111In-DTPA and 100 mg of 13C-glycine; the solid phase also was dually labeled with 110 MBq of 99mTc-albumin colloid and 74 kBq of 14C-octanoic acid. Simultaneous radioscintigraphic and breath-test measurements were performed in 27 subjects, 10 normal controls and 17 patients with dyspeptic symptoms. Mathematic analysis of the excretion rate of labeled CO2 allowed the definition of four parameters, i.e., the gastric emptying coefficient, the gastric half-emptying time, the peak excretion time and the lag phase. RESULTS: There was a good to excellent correlation between the gastric emptying coefficient and the scintigraphic half-emptying time (r = 0.74 for liquids and r = 0.88 for solids), between the half-emptying time determined by breath test and the scintigraphic half-emptying time (r = 0.91 for liquids and r = 0.92 for solids), between the peak excretion time and the scintigraphic half-emptying time (r = 0.91 for liquids and r = 0.96 for solids) and between the lag phase of solid emptying determined by both techniques (r = 0.89). CONCLUSION: The dual carbon-labeled breath test is a valid, minimally invasive technique to measure the gastric emptying rate of both liquids and solids.

Adult↗
PubMed1993

Purification and amino acid sequence of motilin from cat small intestine.

Motilin was isolated from cat small intestine by a series of chromatographic steps. Using a radioreceptor assay, based upon binding of iodinated porcine motilin to rabbit antral smooth muscle membranes, it was shown that cat duodenal mucosa contains about 495 ng/g tissue, the jejunal mucosa 161 ng/g tissue and the ileal mucosa 95 ng/g tissue motilin. The duodenal mucosa was extracted with 6% acetic acid and concentrated on a cation exchange Whatman CM-52 gel. After lyophilization the material was further purified by gel filtration (Sephadex G-50), followed by reverse phase (C18), cation exchange HPLC (Mono S) and three runs on a reverse phase HPLC (Nucleosil 300-5C18) column. The UV absorbance and the radioreceptor assay were used to monitor the purification. After Mono S chromatography two forms of motilin were detected. The major peak corresponded to a 22 amino acid peptide, which differed only from canine motilin at position 12, where Lys is replaced by Arg. The smaller peak probably corresponds to a deamidated form of this peptide. The sequence homology between cat and porcine/human motilin or cat and rabbit motilin is 81.8% and 72.7%, respectively. The conservation of the first six amino acids in all five species studied is striking, confirming that the biological activity of the peptide resides in the N-terminal part.

Amino Acid Sequence↗
PubMed1993

Measurement of gastric emptying rate of solids by means of a carbon-labeled octanoic acid breath test.

BACKGROUND: The aim of the present study was to develop a breath test for measuring gastric emptying rate of solids that would induce less radiation exposure than radioscintigraphy and would be applicable to field testing. METHODS: A test meal was used in which [14C]-octanoic acid was mixed with egg yolk and prepared as a scrambled egg. The test meal was labeled with a second marker, 99mTc-albumin colloid, and simultaneous radioscintigraphic and breath test measurements were performed in 36 subjects, 16 normal controls, and 20 patients with dyspeptic symptoms. Mathematical analysis of the excretion rate of labeled CO2 resulted in the definition of three parameters, i.e., gastric emptying coefficient, gastric half-emptying time, and lag phase. RESULTS: There was an excellent correlation between the gastric emptying coefficient and the scintigraphic half-emptying time (r = -0.88); between the half-emptying time determined by the breath test and the scintigraphic half-emptying time (r = 0.89); and between the lag phases determined by scintigraphy and those determined by breath test (r = 0.92). 14C can be replaced by 13C for labeling the octanoic acid used in the breath test. CONCLUSIONS: It is concluded that the octanoic acid breath test is a reliable noninvasive test to measure gastric emptying rate of solids.

Adult↗
PubMed1993

5-hydroxytryptamine-3 receptors are involved in the initiation of gastric phase-3 motor activity in humans.

BACKGROUND: 5-hydroxytryptamine-3 (5-HT3) receptor antagonists inhibit gastric phase-3 motor activity in the dog. This study examined the role of 5-HT3 receptors in the generation of gastric phase 3 of the migrating motor complex in humans. METHODS: Interdigestive motor activity was recorded manometrically in 16 subjects before and after administration of ondansetron, a selective 5-HT3 receptor antagonist. Plasma motilin values were also assayed in 7 individuals. The incidence of gastric activity fronts before and after ondansetron was compared with a control group that had not received ondansetron. The ability of erythromycin to induce a gastric activity front in the presence of ondansetron was also evaluated in 7 subjects. RESULTS: The incidence of gastric activity fronts was 69% before ondansetron vs. 19% after ondansetron. In contrast, in the control group there was no significant change in the incidence of gastric activity fronts over time. Activity fronts preceding ondansetron were associated with motilin peaks while activity fronts after ondansetron were not. Despite the previous administration of ondansetron, erythromycin induced gastric activity fronts in 89% of cases. CONCLUSIONS: Selective antagonism of 5-HT3 receptors suppresses the gastric component of phase-3 motor activity and simultaneously suppresses plasma motilin peaks. The results suggest that the suppression of gastric activity fronts is achieved via the suppression of plasma motilin peaks because in the presence of ondansetron a motilin agonist like erythromycin restores the gastric phase 3.

Adult↗
PubMed1993

Metabolism of erythritol in humans: comparison with glucose and lactitol.

The metabolism of erythritol was assessed in six normal volunteers by measuring the amount of 13CO2 excretion and H2 excretion in breath, and erythritol in urine after intake of 25 g 13C-labelled erythritol. The results were compared with the same variables obtained after intake of 25 g 13C-labelled glucose and 13C-labelled lactitol. In addition, the H2 production by faecal flora supplemented with small amounts of erythritol, glucose and lactitol was measured in vitro, as an index of bacterial metabolism of non-absorbed substrate. In contrast to the results obtained after intake of glucose and lactitol, no increase in breath 13CO2 and H2 was observed after intake of erythritol, and erythritol was nearly completely recovered in urine. The in vitro experiments showed that no H2 was formed by faecal flora from erythritol as compared with glucose and lactitol. It is concluded that erythritol is a substrate that is readily absorbed, and undergoes no metabolism by the host. If part of it escapes absorption, it is not metabolized by faecal flora.

Adult↗
PubMed1993

Proctitis and rectal stenosis induced by nonsteroidal antiinflammatory suppositories.

Anorectal ulceration eventually leading to rectal stenosis was observed in 10 patients who abused analgetic suppositories containing acetylsalicylic acid, acetaminophen, and codeine. Most patients were middle-aged women with a neurotic or psychiatric background. Perianal skin lesions were present in half of the patients. The endoscopic aspect of the sharply demarcated distal rectal lesions with squamous and transitional epithelium (anoderm) ascending from the anal canal was rather typical, but the appearances on biopsy were nonspecific. Possible pathophysiological mechanisms include mucosal prostaglandin depletion secondary to blockade of cyclooxygenase and shift to lipoxygenase products in the arachidonic acid cascade. Treatment options include drug cessation, topical steroids, and endoscopic dilation. Supporting psychological therapy often is necessary.

Acetaminophen↗
PubMed1993

Endoscopic injection therapy to prevent rebleeding from peptic ulcers with a protruding vessel: a controlled comparative trial.

Seventy five patients with severely bleeding peptic ulcer were included in a controlled comparative trial to assess the efficacy and safety of endoscopic injection therapy in preventing rebleeding from peptic ulcers that presented at endoscopy with a protruding vessel. Twenty five patients were treated with injection of epinephrine followed by polidocanol, 25 were treated with injection of absolute alcohol, and 25 with sham injection. Rebleeding occurred in 44% of patients in the sham group, 40% of those treated with epinephrine and polidocanol, and in 20% of those treated with absolute ethanol. The difference in the haemostasis rate between the control and ethanol treated subjects nearly reached significance (p = 0.07). A second therapy session resulted in haemostasis rates of 68% in the epinephrine-polidocanol group and of 88% in the absolute ethanol group. These rates after two treatments as well as the emergency surgery rates (32% in the epinephrine-polidocanol group and 8% in the absolute ethanol group; p = 0.07) were not significantly different. In eight of the 11 patients with rebleeding in the sham treatment group, definitive haemostasis was achieved by elective injection therapy. Overall transfusion requirements were mean (SD) 6.0 (0.7) units in the sham group, 6.0 (0.9) in the epinephrine-polidocanol group, and 3.9 (0.5) in the absolute ethanol group. Only the difference between ethanol and sham was significant (p = 0.02). This study shows that injection with absolute ethanol reduces rebleeding in these patients and significantly lowers transfusion requirements. Absolute ethanol was superior to epinephrine-polidocanol, which was not significantly better than sham therapy.

Adult↗
PubMed1993

Bursts of non-deglutitive simultaneous contractions may be a normal oesophageal motility pattern.

The frequency and characteristics of non-deglutitive motor activity of the human oesophagus and its relation to motility patterns in the antrum and upper small intestine were studied in 25 fasted healthy subjects. Motility of the oesophagus, antrum, and upper small intestine was recorded by means of a manometric perfused catheter system. The most striking non-deglutitive motility pattern consisted of repetitive bursts of non-sequential pressure peaks occurring in the smooth muscle portion of the oesophagus. The mean number of pressure peaks per burst was 2.7 (SD 2) waves with a mean amplitude of 19.5 (SD 9.9) mm Hg and a duration of 3.09 (SD 0.22) seconds. The highest amplitude was 80 mm Hg and the longest burst consisted of 13 repetitive waves. The bursts were recorded up to a distance of 15-20 cm above the lower oesophageal sphincter. Ninety five per cent of the bursts occurred during a 15 minute period before the onset of phase 3 of the migrating motor complex in the antral or upper small intestinal area, or during the lower oesophageal sphincter component of the migrating motor complex. In conclusion, spontaneous bursts of non-sequential pressure peaks occurred in the smooth muscle part of the human oesophagus in relation to phase 3 of the migrating motor complex. They represent the oesophageal body component of phase 3 of the migrating motor complex and are not a sign of oesophageal motor abnormalities.

Adult↗
PubMed1993

The use of the startle reflex measurement in patients with various types of fixation of the ossicular chain.

The results of startle and acoustic stapedius reflex measurements can be used to subclassify various types of fixation of the ossicular chain. Reflex measurements were performed on a group of subjects with normal hearing and on a group of patients with surgically verified ossicular chain fixation. In 97% of the subjects with normal hearing (n = 30), reproducible impedance changes were observed as part of a startle reaction and four different reaction patterns could be distinguished. In a subgroup of subjects with normal hearing who had a relatively, statistically significant, high acoustic reflex threshold, a characteristic response was found which was most probably caused by contraction of the tensor tympani muscle only. The same response was detected in 77% of the patients (n = 22) with otosclerosis. In the remaining 23%, no middle ear impedance changes occurred as part of a startle reaction. In five out of six patients with fixation of the malleus, no response was observed. Although the startle reflex measurement is a valuable tool for distinguishing between stapes fixation and multiple ossicular chain fixations, the results are not conclusive.

Acoustic Impedance Tests↗
PubMed1993

Solubilization and characterization of motilin-receptor complexes from rabbit antral smooth muscle tissue.

In the present study, the motilin receptor was characterized by enzymatic digestion studies and by solubilization of the motilin-receptor complex from prelabeled membranes using the anionic detergent cholic acid. Motilin binding was significantly decreased by preincubation of membranes of rabbit antral tissue with trypsin, phospholipase A2, C, D, dithiothreitol and 2-mercaptoethanol but not by neuraminidase and beta-galactosidase. Treatment of prelabeled membranes with 1% cholic acid resulted in solubilization of 24 +/- 5% of the proteins and 65 +/- 3% of the radioactivity. The latter was for 77 +/- 4% due to the presence of the motilin-receptor complex as estimated with PEG-precipitation. Upon gel-filtration on Superose 6 the complex partially dissociated but 43 +/- 3% eluted with macromolecular components in the void volume. This peak was not detected when membranes were first incubated with unlabeled motilin. Further disaggregation was accomplished by the addition of 0.5 M NaCl to the elution buffer. The chromatographic profile then showed a peak of about 370 kDa and a second one of 100 kDa. The latter value probably reflects the molecular mass of a single 125I-motilin-receptor-complex.

Animals↗
PubMed1992

Irritable esophagus.

An esophageal origin of noncardiac chest pain is generally accepted if prolonged pH and pressure recordings show that the pain episodes correlate in time with acid reflux, esophageal motor abnormalities, or a combination of both, or if provocative testing (acid perfusion, edrophonium, balloon distention) is positive. Many patients with noncardiac chest pain of esophageal origin are said to have an irritable esophagus. Irritable esophagus has been defined in two ways. Some researchers suggest it is actually a lowered esophageal pain threshold, based on the finding that such patients feel chest pain at lower balloon volumes than controls during intraesophageal balloon distention; they are said to be hypersensitive to balloon distention. Hypersensitivity to an esophageal stimulus is generally found in patients with noncardiac chest pain of esophageal origin, and hypersensitivity to a single stimulus is one criterion for a diagnosis. Our group defines irritable esophagus as a condition in which several different stimuli result in the same type of chest pain. Accordingly, we have grouped patients with esophageal chest pain into three categories: (a) patients with an acid-sensitive esophagus, in whom spontaneous pain episodes can be related to acid reflux (with or without accompanying motor disorders), and/or the acid perfusion test is positive; (b) patients with a mechano-sensitive esophagus, in whom the spontaneous pain episodes can be related to motility disturbances (without reflux), and/or the edrophonium test or balloon distention test is positive; (c) patients with an irritable esophagus, in whom some spontaneous pain episodes are related to reflux, while others are related to abnormal motility (without reflux). The last group includes patients whose spontaneous chest pain is related to reflux, with a positive motility tests; whose pain is related to abnormal motility, with a positive reflux test; and patients with positive tests for both reflux and abnormal motility. Seven studies examined a total of 281 noncardiac chest pain patients using prolonged pH and pressure recordings and provocative tests. An acid-sensitive, a mechano-sensitive, or an irritable esophagus was found in 20%, 14%, and 24% of patients, respectively.

Chest Pain↗
PubMed1992

Critique of the session on diagnostic testing.

During the session on diagnostic testing, various diagnostic tests used to identify the cause of chest pain were discussed. This critique of diagnostic assessments of the complex etiology of chest pain is presented as a contribution toward further investigation and clarification of this difficult clinical syndrome. The first step in the evaluation process is to exclude coronary artery disease. Patients with angina and normal coronary artery flow may have atypical disease, such as microvascular angina or syndrome X. The precise relationship between these disorders and esophageal disease or gastroesophageal reflux, as well as their possible involvement in chest pain of undetermined origin, requires further definition. A limitation of esophageal provocation tests is that they may identify the esophagus as the source of pain without determining the specific esophageal disorder that causes the pain. Problems associated with 24-hour pH and pressure monitoring include (a) poor correlation between reflux episodes and heartburn symptoms, (b) the lack of a good functioning swallowing signal, and (c) the huge amount of data that must be analyzed, along with shortcomings in computer-aided analysis. Nevertheless, the various available diagnostic tests can provide important information to the clinician.

Angina Pectoris↗
PubMed1992

High-frequency diaphragmatic flutter: symptoms and treatment by carbamazepine.

Classic diaphragmatic flutter, a rare disorder associated with dyspnoea, thoracic or abdominal wall pain, and epigastric pulsations, is caused by involuntary contractions of the diaphragm with a frequency of 0.5-8.0 Hz. We have seen three patients with diaphragmatic flutter of higher frequency not associated with respiratory disease. The patients presented with longstanding oesophageal belching, hiccups, and retching, respectively. The diagnosis was established by the presence on electromyography of the diaphragm and scalene and parasternal intercostal muscles of repetitive discharges of 9-15 Hz. Spirographic tracings, especially those of volume or flow vs time, showed similar high-frequency oscillations superimposed on tidal respiratory movements. Treatment with carbamazepine 200-400 mg three times daily led to disappearance or great improvement of flutter and clinical symptoms in all three patients. The phenomenon was not seen in other patients with chronic hiccups or oesophageal belching or in patients without these symptoms who had undergone electromyography or spirography for other reasons. Thus, high-frequency diaphragmatic flutter seems to be a new disease entity. The response to carbamazepine, which suggests that the flutter causes the symptoms, requires further study.

Adult↗