PubMed Health⌕ Search

Biomedical subjects

G Devroede

Publications and source records attributed to G Devroede.

108 records · Page 6Linked to original sources
PubMed1972

Excitatory effects of adrenaline upon isolated preparations of human colon.

The effect of beta-adrenergic blockade with oxprenolol upon adrenaline-induced relaxation of strips of human sigmoid colon was investigated. Following blockade of beta-adrenoceptors with oxprenolol, adrenaline evoked dose-dependent contractions of both longitudinal and circular muscle strips. Storage of the tissues for periods up to 24 hours at 4 degrees C did not modify the responses to adrenaline. Furthermore, the contractions induced by adrenaline following oxprenolol were significantly diminished by the addition of phentolamine, an alpha-adrenoceptor blocking agent. Our results would suggest that oxprenolol has the property of unmasking or revealing alpha receptors responsible for the excitatory effects of adrenaline upon isolated strips of human colon.

Colon↗
PubMedDate not supplied

Changes in the rectal mucosa induced by hypertonic enemas.

The aspect of the rectal mucosa after administration of hypertonic enemas is occasionally confused with the macroscopic appearance of quiescent ulcerative colitis. Criteria for a diagnosis of enema reaction were derived from a retrospective series and tested prospectively on 11 healthy volunteers. Photographs and biopsies were obtained before and after administration of a sodium phosphate hypertonic enema. Three observers evaluated blindly the "before" and "after" macroscopic and microscopic pictures, graded the features, and made an overall diagnosis. In random studies, two observers mistakenly classified a macroscopic picture, but all correct histologic diagnoses of "before" and "after" biopsies. In decreasing order of discriminating power, the following features of an enema reaction were found to be useful: separation and mucous depletion of the glands (no observer variation), increase in mucosal fragility in 91 per cent of cases (82--100 per cent), edema of the lamina propria in 88 per cent (73--100 per cent), straightening of the basal membrane in 82 per cent (73--91 per cent) and an increase in extruded mucus in 70 per cent (18--100 per cent). In 39 per cent of cases (36--45 per cent), erythrocytes appeared focally in the lamina propria. The effects of hypertonic enemas can be recognized on biopsy.

Adult↗
PubMedDate not supplied

Segmental colonic transit time.

Mean segmental transit time of radiopaque markers through the right colon, left colon and rectosigmoid areas of adults and children has been calculated form their distribution on consecutive plain films of the abdomen. Overall mean transit does not differ significantly in the large bowel between adults and children. However, there are regional differences within the colon in relation to age. Mean transit time in the right colon is 13.8 hours in adults and 7.7 in children (p less than 0.01). Corresponding values in the left colon are 14.1 and 8.7 hours (p less than 0.02) and, in the rectum, 11 and 12.4 hours (p = NS). The percentage of the mean total large bowel transit time spent in the right colon, left colon and rectosigmoid area are respectively for adults and children 33 +/- 4 and 28 +/- 3 per cent (p = NS); 39 +/- 4 and 32 +/- 4 per cent (p = NS); and 28 +/- 4 and 41 +/- 4 per cent (p less than 0.05), indicating a relative stagnation in the rectosigmoid area of children. These physiologic differences may have implications in diseased states.

Adolescent↗
PubMedDate not supplied

[Constipation caused by colonic inertia and distal obstruction: electromyographic study].

Colonic motility was evaluated in 15 patients with chronic constipation and 12 healthy subjects by both measuring the transit time of 20 radiopaque markers and recording the colonic myoelectric signals by means of a silastic tube equipped with 4 ring contact electrodes. The tube was introduced by flexible sigmoidoscopy so as the electrodes be located at 50, 40, 30 and 20 cm from the anal verge. Constipation resulted from colonic inertia in 7 patients, the markers being delayed over the whole length of the colon. In the 8 other patients, constipation was due to distal obstruction, the markers accumulating electively in the rectum. The myoelectric tracings showed in the control subjects, on one hand rhythmical stationary spike potentials that occurred at only one electrode site at a mean rate of 10 per minute; on the other hand sporadic (non-rhythmic) spike potentials that were either propagating over the colonic segment (sporadic propagating potentials) or not (sporadic non-propagating potentials). In the constipated patients, the following changes were observed: 1) the number of sporadic propagating potentials was significantly decreased in colonic inertia (2.5 +/- 1.3 bursts of spikes per hour) compared to the controls (8.5 +/- 1.1 bursts/h) or distal obstruction (7.9 +/- 1.3 bursts/h); 2) sporadic propagating potentials usually moved aborally; however, 19.8 +/- 0.9 p. 100 moved orally in colonic obstruction, while 4.6 +/- 0.2 p. 100 in the controls and 4.7 +/- 0.1 p. 100 in colonic inertia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗