Colonoscopy in management of colonic strictures.
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A total of 160 strictures were examined in 154 patients with the fibreoptic colonoscope. When it was possible to make a pre-examination diagnosis colonoscopy proved it wrong in 52% of cases. Unnecessary laparotomy was probably avoided in over half this series. All strictures of the large bowel should be examined colonoscopially whenever possible before considering surgery. (+info)
Review of harmful gastrointestinal effects of carrageenan in animal experiments.
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In this article I review the association between exposure to carrageenan and the occurrence of colonic ulcerations and gastrointestinal neoplasms in animal models. Although the International Agency for Research on Cancer in 1982 identified sufficient evidence for the carcinogenicity of degraded carrageenan in animals to regard it as posing a carcinogenic risk to humans, carrageenan is still used widely as a thickener, stabilizer, and texturizer in a variety of processed foods prevalent in the Western diet. I reviewed experimental data pertaining to carrageenan's effects with particular attention to the occurrence of ulcerations and neoplasms in association with exposure to carrageenan. In addition, I reviewed from established sources mechanisms for production of degraded carrageenan from undegraded or native carrageenan and data with regard to carrageenan intake. Review of these data demonstrated that exposure to undegraded as well as to degraded carrageenan was associated with the occurrence of intestinal ulcerations and neoplasms. This association may be attributed to contamination of undegraded carrageenan by components of low molecular weight, spontaneous metabolism of undegraded carrageenan by acid hydrolysis under conditions of normal digestion, or the interactions with intestinal bacteria. Although in 1972, the U.S. Food and Drug Administration considered restricting dietary carrageenan to an average molecular weight > 100,000, this resolution did not prevail, and no subsequent regulation has restricted use. Because of the acknowledged carcinogenic properties of degraded carrageenan in animal models and the cancer-promoting effects of undegraded carrageenan in experimental models, the widespread use of carrageenan in the Western diet should be reconsidered. (+info)
Feasibility of iodine-125 labeled anti-human hemoglobin antibody in the detection of bleeding sites from the large bowel-A preliminary study.
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A monoclonal anti-human hemoglobin antibody that cross-reacts with mouse hemoglobin was labeled with Iodine-125 through the Chloramine-T method. The labeled antibody was used in an attempt to recognize bleeding sites from the large bowel in a mouse model, through a non-invasive enema-like study. In vitro experiments after double column chromatography of the labeled antibody and 10% trichloroacetic acid conjugation revealed that about 80% of the radioactivity was incorporated into protein. Inhibition assay containing cold (non-radiolabeled) antibody showed that Iodine-125 radiolabeled antibody preserved its immunoreactivity. Autoradiographs exquisitely demonstrated accumulation of isotope in the corresponding intestinal bleeding areas. These findings suggest that this method can be useful for scintigraphic localization of bleeding sites in the large bowel. (+info)
Florid vascular proliferation of the colon related to intussusception and mucosal prolapse: potential diagnostic confusion with angiosarcoma.
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With the exception of angiodysplasia, vascular abnormalities of the intestines are unusual. We describe a florid benign vascular proliferation of the colon in five adult patients, three of whom presented with idiopathic intussusception. In all cases, the proliferation was sufficiently exuberant to raise the possibility of angiosarcoma as a diagnostic consideration. The group included 2 males and 3 females with a median age of 43 years. Two patients were HIV positive. Four patients presented with a colonic mass; other symptoms at presentation included abdominal pain, diarrhea, bleeding, and bowel obstruction. In all cases, a florid lobular proliferation of small vascular channels lined by plump endothelial cells extended from the submucosa through the entire thickness of the bowel wall. The endothelial cells showed minimal nuclear atypia, and mitotic figures were infrequent. The overlying mucosa showed ulceration with ischemic-type changes, and had features of mucosal prolapse. A possible underlying arteriovenous malformation was identified in two cases. All patients were alive and well at last follow-up (interval, 6 months to 5 years). The presence of intussusception or mucosal prolapse in all of the cases suggests repeated mechanical forces applied to the bowel wall as a possible etiologic factor. The role of HIV infection in the pathogenesis of these lesions remains to be determined. (+info)
Overt colon ischemia after endovascular aneurysm repair: the importance of microembolization as an etiology.
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OBJECTIVE: The purpose of this study was to analyze the incidence, severity, and etiologic factors of the development of colon ischemia after endovascular aortoiliac aneurysm repair (EVAR). METHODS: During the last 9 years we performed 278 elective EVARs using a variety of grafts. To facilitate these repairs, one hypogastric artery (HA) was coil embolized in 109 patients and both HAs were coil embolized in 13 patients. The preprocedural status of the inferior mesenteric, hypogastric, and iliac arteries as well as anatomical characteristics of the abdominal aortic aneurysm were determined arteriographically and by computerized tomographic scans. Postoperative colon ischemia was documented by colonoscopy or operative findings. RESULTS: Colon ischemia occurred in eight patients (2.9%). Three patients with colon ischemia died and had evidence of widespread (cutaneous, renal, small bowel, and/or lower extremity) microembolization. One of these three had a colectomy and microscopic emboli were present. One other patient who required a colectomy also had pathologic evidence of colonic microembolization but survived. Four other patients with colon ischemia were treated conservatively and survived. In one patient, previous colectomy with interruption of mesenteric collaterals may have been a contributory cause of colon ischemia. Of the eight patients with colon ischemia, only one had unilateral HA occlusion, and none had bilateral HA occlusion. The other 121 patients with unilateral and bilateral HA occlusion had no evidence of colon ischemia. CONCLUSIONS: Colon ischemia occurs after EVAR with an incidence approximating that of open repair. Colon ischemia was unrelated to HA interruption. Embolization appears to be a major cause of colon ischemia, although inadequate mesenteric collateral circulation may also play an etiologic role. Mortality with colon ischemia accompanied by widespread embolization was high, whereas colon ischemia without it was often mild and amenable to nonoperative management. (+info)
Diagnosis and current management of gastrojejunocolic fistula.
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Gastrojejunocolic fistula is a late complication of gastroenterostomy and is associated with inadequate gastric resection and incomplete vagotomy. In the past, attempted primary repair had high mortality and staged operations were normally performed. We present two cases of gastrojejunocolic fistula and discuss the modern management of this condition. In both cases, improved nutritional support allowed successful one-stage surgical repair to be performed. (+info)
Intimin type influences the site of human intestinal mucosal colonisation by enterohaemorrhagic Escherichia coli O157:H7.
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BACKGROUND: Enterohaemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli epithelial cell adhesion is characterised by intimate attachment, and attaching and effacing (A/E) lesion formation. This event is mediated in part by intimin binding to another bacterial protein, Tir (translocated intimin receptor), which is exported by the bacteria and integrated into the host cell plasma membrane. Importantly, EPEC (O127:H6) and EHEC (O157:H7) express antigenically distinct intimin types known as intimin alpha and gamma, respectively. EHEC (O157:H7) colonises human intestinal explants although adhesion is restricted to the follicle associated epithelium of Peyer's patches. This phenotype is also observed with EPEC O127:H6 engineered to express EHEC intimin gamma. AIMS: To investigate the influence of intimin on colonisation of human intestine by E coli O157:H7, and intimin types on tissue tropism in humans. METHODS: Human intestinal in vitro organ culture with wild type and mutant strains of O157:H7 were employed. RESULTS: Introducing a deletion mutation in the eae gene encoding intimin gamma in EHEC (O157:H7) caused the strain (ICC170) to fail to colonise human intestinal explants. However, colonisation of Peyer's patches and A/E lesion formation were restored with intimin gamma expression from a plasmid (ICC170 (pICC55)). In contrast, complementing the mutation with intimin alpha resulted in a strain (ICC170 (pCVD438)) capable of colonising and producing A/E lesions on both Peyer's patch and other small intestinal explants. CONCLUSION: Intimin is necessary for human intestinal mucosal colonisation by E coli O157:H7. Intimin type influences the site of colonisation in a Tir type independent mechanism; intimin gamma appears to restrict colonisation to human follicle associated epithelium. (+info)
Management of gastrointestinal haemorrhage.
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A variety of endoscopic haemostatic techniques have enabled major advances in the management of not only bleeding peptic ulcers and bleeding varices, but also in a variety of bleeding lesions in the small intestine and in the colon. Indeed, the development and widespread implementation of endoscopic haemostasis has been one of the most important developments in clinical gastroenterology in the past two decades. An increasingly ageing cohort of patients with multiple co-morbidity are being treated and therefore improving the outcome of gastrointestinal bleeding continues to pose major challenges. (+info)