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Biomedical subjects

K Geboes

Publications and source records attributed to K Geboes.

At least 19 recordsLinked to original sources
PubMed1992

Influence of rhein anthrone and rhein on small intestine transit rate in rats: evidence of prostaglandin mediation.

The present study was undertaken to investigate the role of prostaglandins in the shortening of transit time observed after intraduodenal administration of rhein anthrone and rhein. After intraduodenal administration of rhein anthrone (0.5-10 mg/rat), a dose-dependent acceleration of small intestinal transit was observed. The effect for rhein (1-10 mg/rat) was far less pronounced. In the same test conditions, analysis of small intestinal tissue revealed a significant increase of prostaglandin E2 (PGE2), reaching its maximum value 30 min after administration of rhein anthrone. The increase in PGE2 found 30 min after administration of rhein was not significant. The effects provoked by rhein anthrone could be largely prevented by pretreatment of the animals with indomethacin (1-3 mg rat) or cortisol (10 mg/rat). It is concluded that prostaglandins play an important role in the acceleration of the transit provoked in rats by rhein anthrone.

Animals↗
PubMed1992

The effect of rhein and rhein anthrone on intestinal fluid transport and on large intestine transit in germ-free rats.

The effect of rhein and rhein anthrone on the transit and the transport of water and electrolytes in the large intestine was investigated in germ-free rats. After intracaecal administration, neither of the two compounds was found to accelerate the transit of a colour marker through the large intestine. Both drugs reduced the net absorption of sodium and chloride in the colon and enhanced net potassium secretion. Net water absorption was decreased by rhein and even reversed into net secretion by rhein anthrone. Our results show that the secretagogue activity of the compounds is not sufficient to induce laxation in germ-free rats. Furthermore rhein and rhein anthrone had no laxative properties under our experimental conditions.

Animals↗
PubMed1992

Major histocompatibility class II expression on the small intestinal nervous system in Crohn's disease.

Widespread alterations of the gut autonomic nervous system have been described in Crohn's disease. Immunohistochemistry shows that these alterations are associated with the expression of major histocompatibility (MHC) class II antigens (HLA-DR) on enteroglial cells in the ganglia of the submucous and myenteric plexuses and on the enteroglial sheaths of the nerve extensions. Neuronal cell bodies and extensions do not express MHC class II antigens. The class II expression is associated with the presence of UCHL1-positive T lymphocytes. MHC class II expression can also be found on endothelial cells and vascular smooth muscle cells but not on smooth muscle cells of the muscularis mucosae or propria. The intensity of MHC class II expression on the glial cells of the enteric nervous plexus and on endothelial cells correlates well with the intensity of class II expression on epithelial cells.

Adolescent↗
PubMed1992

Rifabutin and ethambutol do not help recurrent Crohn's disease in the neoterminal ileum.

We tested the efficacy of rifabutin and ethambutol in combination in healing severe recurrent Crohn's disease in the neoterminal ileum. Sixteen patients who had undergone an ileal resection with partial colectomy and ileocolonic anastomosis and who had severe recurrent lesions in the neoterminal ileum at baseline ileocolonoscopy were included in the study. The patients received rifabutin in a dose of 5 mg/kg together with ethambutol, 20 mg/kg. Ten patients were treated for 6 months; six patients dropped out because of adverse events. As no effect was observed after 6 months, five patients completed a 12-month therapy course. Follow-up ileocolonoscopy was performed at 3, 6, and 12 months. In none of the 10 patients who completed the 6-month trial and in none of the five patients who completed 12 months of therapy was endoscopic improvement of the lesions observed. In four patients the disease was clinically progressive, and two patients underwent a reresection after 6 and 8 months, respectively. This study shows that long-term therapy with rifabutin and ethambutol does not heal Crohn's disease in the neoterminal ileum and does not prevent recurrence of symptoms and complications.

Adult↗
PubMed1992

Whipple's disease: a histological, immunocytochemical and electronmicroscopic study of the immune response in the small intestinal mucosa.

Whipple's disease is a multisystem disorder with protean manifestations and with poorly understood aetiopathogenesis. It is unclear how the immune system reacts, whether it functions normally or not, whether it protects the organism or is defeated in one way or another by the 'Whipple bacillus'. The purpose of our study was to assess humoral and cellular immunity at the level of the intestinal mucosa. This histochemical, immunocytochemical and electronmicroscopic study, based on 16 cases, has shown that the changes in components of the mucosal immune system in Whipple's disease are quite different from normal. The phagocytic capacity of the macrophages, assessed microscopically, is abnormal, the number of intra-epithelial lymphocytes is increased, the CD 4/CD 8 cell ratio is decreased and the IgM positive cells in the lamina propria outnumber the IgA positive cells. These changes may be inter-dependent.

Adult↗
PubMed1992

The innervation of the lymphoid tissue at the ileocolonic transition: an enzyme and immunohistochemical study.

Using enzyme and immunohistochemical methods on whole-mount preparations and cryostat sections, a morphologic and semiquantitative study was performed of the nervous tissue in the appendix and the ileum (areas with and without Peyer's patches) of the rabbit. The plexus submucous externus (Meissner) consists of a network of small ganglia, vaguely associated with the vascular submucosal plexus. From the nerve cell bodies, cell processes occasionally penetrate the lymphoid follicles at the junction between the mucosa and the submucosa while other extensions form a dense plexus in the lamina propria of the mucosa. No nerve fibers are present in the dome of the follicles. The plexus submucous internus (Henle), consisting of large cell bodies and large processes, closely follows the blood vessels. The numeration of the nerve fibers of the submucosal plexus endorses the histological finding that the appendix is a richly innervated lymphoid organ. In addition, the plexus myentericus (Auerbach) of the appendix is a network of small meshes, while in the ileum, in the area of Peyer's patches, the same plexus is composed of a network with large meshes. These differences point to a higher density of innervation in the appendix. Yet a specialized anatomic distribution of the innervation of lymphoepithelial structures cannot be demonstrated.

Animals↗
PubMed1992

Granulomatous gastritis and Whipple's disease.

Granulomatous gastritis is an uncommon morphological diagnosis. An etiopathogenetic diagnosis can be reached only by combining the morphological examination with clinical and laboratory investigations. The diagnosis of Whipple's disease in our patient was based upon a classical clinical picture and upon the likewise classical morphological appearance of the small intestinal mucosal biopsy. To our knowledge, this case report is the first to describe granulomatous gastritis in a patient with Whipple's disease.

Gastritis↗
PubMed1992

Zenker's diverticulum: is a myotomy of the cricopharyngeus useful? How long should it be?

In a series of 100 consecutive patients surgically treated for Zenker's diverticulum (ZD) biopsy specimens were taken at the level of the cricopharyngeal muscle in 62 patients and also at the level of the striated muscle wall of the cervical esophagus in 10 patients. Contractility, pathological enzymo- and immunohistochemical characteristics were studied in comparison with a group of 15 controls. Obvious pathological findings were noted in 95% of the ZD specimens as compared with the control specimens. These pathological changes, although somewhat less pronounced, were also documented in the biopsy specimens taken at the level of the striated cervical muscle wall. The findings were judged important enough to justify a long extramucosal myotomy of the cricopharyngeal muscle and cervical esophagus as an essential step in the treatment of ZD. The treatment of choice in this series was a diverticulopexy and a four to five centimeter long extramucosal myotomy, starting from the cricopharyngeal muscle and extending downwards into the striated muscle wall of the cervical esophagus. Excellent or very good results were obtained in 96% of the patients with respect to diverticulum-related symptoms.

Adult↗
PubMed1991

Conventional X-ray examination in esophageal cancer: an opinion.

Double contrast is the best radiological technique for the detection of small esophageal cancer. Gastrografin is indicated when a blind mediastinal fistula is suspected; in cases of choking or suspicion of a fistula with the airways, a low osmotic hydrosoluble Iodium compound must be used. Conventional radiology and endoscopy are complementary techniques for the detection of esophageal cancer, as some lesions may be missed or misinterpreted by both. The need for endoscopic biopsy being incontestable for diagnostic confirmation and characterization, radiology presents some advantages over classic esophagoscopy for preoperative and the general pretherapeutic staging of esophageal carcinoma: assessment of topographical relation with the surrounding organs is possible and with the upper esophageal sphincter is easier; appreciation of tumoral extension along the longitudinal axis (tumor length, gastric invasion) remains mostly possible even in cases of severe stenosis; tumoral extension along the transverse axis (kinking, fistula) may be evaluated; detection of a second tumor or concomitant pathology distally from a stenosing tumor is mostly possible; moreover radiology is important before starting radiotherapy; and finally, previous radiology may reduce the (small) risk of endoscopic perforation. Radiology is indispensable or indicated in the posttherapeutic follow-up of esophageal carcinoma, as well after surgery as after endoscopic interventions, radiotherapy or chemotherapy.

Diatrizoate Meglumine↗
PubMed1991

Inflammatory disorders of the esophagus.

Esophagitis is a very common disorder. The etiology cna be highly variable and is not always clear from the biopsy. The main microscopic inflammatory lesions are located in the epithelium. They consist of an increase in inflammatory cells, either polymorphs or mononuclear cells, or both. They are associated with architectural mucosal changes. It is often difficult or impossible to distinguish reflux esophagitis from drug-induced or viral esophagitis. Yet some microscopic patterns are characteristic and provide information on the etiology of the lesions.

Biopsy↗
PubMed1990

Expression of MHC class II antigens and immunoglobulin M by the corneal epithelial cells in herpetic keratitis.

The corneal buttons obtained from 4 patients with active epithelial and stromal herpetic keratitis were studied with routine microscopy and immunohistochemistry. We used an immunoperoxidase technique with monoclonal antibodies directed against Langerhans cells, lymphocyte subsets, MHC products and immunoglobulins A, G, M and D. The epithelium and stroma contained an inflammatory infiltrate composed of polymorpho-nuclear leukocytes, dendritic cells, B-lymphocytes and T-lymphocytes (helper/inducer and suppressor/cytotoxic subsets). The epithelial cells of all the corneal buttons expressed MHC class II antigens. IgM was bound to the membrane of the epithelial cells in 3 specimens. HSV antigenic material was localized in the epithelial cells and in the stromal keratocytes by a direct immunofluorescence technique. Our data suggest that cell-mediated as well as antibody-mediated immune responses are involved, with a possible role for an autoimmune mechanism in the pathogenesis of this condition.

Adult↗
PubMed1990

The immunopathology of Schistosoma mansoni granulomas in human colonic schistosomiasis.

The immunopathology of Schistosoma mansoni infection was studied in colonic biopsies obtained from 14 patients with established schistosomiasis. The characteristic lesions of this parasitic infection are mainly induced by the presence of living eggs in the tissue. Different types of lesions can be present simultaneously. The earliest lesions contain T-lymphocytes as well as accessory cells around living eggs. They transform into granulomas composed of eosinophils, T-lymphocytes, a few B-lymphocytes and large mononuclear cells expressing major histocompatibility (MHC) class II antigens. These cells are also Mac 387 positive. This means that they are monocytes/macrophages freshly recruited from the blood. In other, probably older, granulomas, MHC class II positive cells tend to disappear and the centrally located multinucleated giant cells are negative for antibodies directed against MHC class II antigens. It appears thus that the composition of the granulomas in schistosomiasis is variable. The lesions may have characteristics of cell-mediated immunity and/or of a foreign-body reaction. Contrary to what is often seen in Crohn's disease or intestinal tuberculosis no major hyperplasia of the lymphoid tissue is observed in the colon in association with S. mansoni infection.

Adolescent↗
PubMed1990

Predictability of the postoperative course of Crohn's disease.

Eighty-nine patients who had been treated by ileal resection for Crohn's disease between 1979 and 1984 were included in a prospective cohort follow up to study the natural course of early postoperative lesions. Recurrent lesions were observed endoscopically in the neoterminal ileum within 1 year of surgery in 73% of the patients, although only 20% of the patients had symptoms. Three years after surgery, the endoscopic recurrence rate had increased to 85% and symptomatic recurrence occurred in 34%. The ultimate course of the disease was best predicted by the severity of the early postoperative lesions, as observed at ileoscopy. Clinical parameters that influenced outcome were preoperative disease activity, the indication for surgery, and the number of surgical resections. When patients were stratified for preoperative disease activity, the severity of lesions found at endoscopy remained a strong predictive factor for symptomatic recurrence. In 22 other patients submitted to "curative" ileal resection and ileocolonic anastomosis, the segment to be used as neoterminal ileum was carefully examined during surgery, and two large biopsies were taken before making the anastomosis. An ileoscopy was performed 6 months after surgery. Although all patients had a macroscopically normal neoterminal ileum and 19 had entirely normal biopsies at the time of surgery, 21 patients were found at ileoscopy to have developed ileitis involving a 15-cm segment (range, 4-30 cm), and 20 had unequivocal microscopic lesions on biopsies. These studies suggest that early lesions in the neoterminal ileum after Crohn's resection do not originate from microscopic inflammation present in this bowel segment at the time of surgery. The early postoperative lesions in the neoterminal ileum seem to be a suitable model to study the pathogenesis of Crohn's disease and also to evaluate new therapeutic modalities, either to prevent development of these early lesions or to treat progressive recurrence.

Actuarial Analysis↗