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Transmural Inflammation (transmural + inflammation)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Diagnostic difficulties in inflammatory bowel disease pathology

HISTOPATHOLOGY, Issue 2 2006
R K Yantiss
This review summarizes some of the common diagnostic problems encountered by pathologists when evaluating patients with chronic colitis and in whom inflammatory bowel disease (IBD) is either suspected or within the differential diagnosis. Both ulcerative colitis (UC) and Crohn's disease (CD) show characteristic, but non-specific, pathological features that may overlap and result in a diagnosis of ,indeterminate colitis' (IC). However, other reasons why pathologists may entertain a diagnosis of IC include failure to recognize or accept certain ,hardcore' histological features as indicative of CD, an attempt to classify cases of chronic colitis based on mucosal biopsy material or in the absence of adequate clinical and radiographic information, and the presence of other disease processes that mask, or mimic, IBD. In addition, some cases of UC may show unusual CD-like features, such as discontinuous or patchy disease, ileal inflammation, extracolonic inflammation, granulomatous inflammation in response to ruptured crypts, aphthous ulcers, or transmural inflammation. Furthermore, other forms of colitis, such as microscopic colitis, diverticulitis and diversion colitis may, on occasion, also show IBD-like changes. The clinical and pathological features that aid in the distinction between these entities, and others, are covered in detail in this review. [source]

Induction of colonic transmural inflammation by bacteroides fragilis.

INFLAMMATORY BOWEL DISEASES, Issue 2 2005
Implication of Matrix Metalloproteinases
Abstract Background: Commensal bacteria are implicated in the pathophysiology of intestinal inflammation, but the precise pathogenetic mechanisms are not known. We hypothesized that Bacteroides fragilis -produced metalloproteinases (MMPs) are responsible for bacterial migration through the intestinal wall and transmural inflammation. Aim: To investigate the role of bacterial-MMP activity in an experimental model of colitis induced by the intramural injection of bacteria. Methods: Suspensions of viable B. fragilis or Escherichia coli were injected into the colonic wall, and the effect of the MMP inhibitor (phenantroline) on histologic lesion scores was tested. MMP activity in bacterial suspensions was measured by azocoll assay. Results: The inoculation with B. fragilis induced chronic inflammatory lesions that were preferentially located in the subserosa, whereas inoculation with E. coli induced acute-type inflammatory reactions, evenly distributed in both the submucosa and subserosa. Treatment with phenantroline significantly decreased subserosal lesion scores in rats inoculated with B. fragilis, but not in rats inoculated with E. coli. Bacterial suspensions of B. fragilis showed MMP activity, but E. coli suspensions did not. Sonication of B. fragilis reduced MMP activity and virulence to induce serosal lesions. Conclusion: Our data suggest that bacterial MMPs may be implicated in the serosal migration of B. fragilis and in the induction of transmural inflammation. [source]

Medical therapy for Crohn's disease strictures

INFLAMMATORY BOWEL DISEASES, Issue 1 2004
Gert Van Assche MD
Abstract Intestinal fibrostenosis is a frequent and debilitating complication of Crohn's disease (CD), not only resulting in small bowel obstruction, but eventually in repeated bowel resection and short bowel syndrome. Over one third of patients with CD have a clear stenosing disease phenotype, often in the absence of luminal inflammatory symptoms. Intestinal fibrosis is a consequence of chronic transmural inflammation in CD. As in other organs and tissues, phenotypic transformation and activation of resident mesenchymal cells, such as fibroblasts and smooth muscle cells, underlie fibrogenesis in the gut. The molecular mechanisms and growth factors involved in this process have not been identified. However, it is clear that inflammatory mediators may have effects on mesenchymal cells in the submucosa and the muscle layers that are profoundly different from their action on leukocytes or epithelial cells. Transforming growth factor-beta (TGF-,), for instance, has profound anti-inflammatory activity in the mucosa and probably serves to keep physiologic inflammation at bay, but at the same time it appears to be driving the process of fibrosis in the deeper layers of the gut. Tumor necrosis factor, on the other hand, has antifibrotic bioactivity and pharmacologic inhibition of this cytokine carries a theoretical risk of enhanced stricture formation. Endoscopic management of intestinal strictures with balloon dilation is an accepted strategy to prevent or postpone repeated surgery, but careful patient selection is of paramount importance to ensure favorable long-term outcomes. Specific medical therapy aimed at preventing or reversing intestinal fibrosis is not yet available, but candidate molecules are emerging from research in the liver and in other organs. [source]

Tissue reaction of the rabbit urinary bladder to tension-free vaginal tape and porcine small intestinal submucosa

BJU INTERNATIONAL, Issue 6 2002
D.M. Rabah
Objectives ,To compare the histological tissue reactions of urinary bladder in close contact with polypropylene mesh tension-free vaginal tape (TVT) or porcine small intestinal submucosal (SIS) grafts, as the commercial availability of various materials has considerably simplified sling procedures for treating urinary incontinence, but erosion and infection after using artificial sling materials remain an important concern. Materials and methods ,Thirty female New Zealand rabbits were randomized to three groups, i.e. group A (TVT, 12 animals), group B (SIS, 12) and group C (surgical control, six). Through a laparotomy under anaesthesia and an aseptic technique, the bladder was approached at its dome, where a 0.5 × 1 cm piece of TVT or SIS was fixed in direct contact with the bladder wall. The control group underwent only bladder manipulation with no material applied. Half the animals in each group were killed after 6 weeks and the other half after 12 weeks. The urinary bladder was harvested and examined histologically. Results ,The grafts in both groups were characterized by dense foreign-body type reactions and were mostly attached loosely to the bladder wall by a thin layer of fibrovascular tissue. More importantly, the bladder wall reactions showed no inflammation in all 12 animals in group A (TVT) but three of them had various grades of fibrosis. There was severe transmural inflammation in one animal in group B (SIS); one rabbit had grade I and two had grade II fibrosis. The controls, as expected, showed no bladder wall reactions. Conclusion ,In this descriptive analysis of reaction types elicited on the urinary bladder by these grafts, both materials appeared to be safe. Although TVT elicited fewer and less severe adverse reactions, no statistical conclusions can be drawn. The clinical significance of these findings should emerge from long-term clinical data when they become available. [source]

Incomplete cellular depopulation may explain the high failure rate of bovine ureteric grafts

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 5 2008
J. I. Spark
Background: The aim was to assess the results of a decellularized bovine ureter graft (SynerGraft®) for complex venous access. Methods: Bovine ureter conduits were implanted in patients with a failed fistula or access graft in whom native vessels were unsuitable as conduits. Graft histories were obtained from all patients who had undergone this procedure at one institution. Failed grafts were explanted and subjected to histological examination. A sample of fresh bovine ureter was immunostained for galactose (,1 , 3) galactose (,-Gal). Results: Nine patients with a median age of 46 (range 25,70) years underwent complex venous access surgery between August 2004 and November 2006 using a SynerGraft®. Graft types included loop superficial femoral artery to stump of long saphenous vein (four patients), loop brachial artery to vein (two), brachial artery to axillary vein (two) and left axillary artery to innominate vein (one). Three grafts developed aneurysmal dilatation and two thrombosed. Histological assessment of the explanted bovine ureters revealed acute and chronic transmural inflammation. Immunostaining of fresh bovine ureter suggested residual cells and the xenoantigen ,-Gal. Conclusion: Graft failure with aneurysmal dilatation and thrombosis in complex arteriovenous conduits using bovine ureter may be due to residual xenoantigens. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]