Diseased Colonic Mucosa Research Articles

Oral intake of titanium dioxide nanoparticles affect the course and prognosis of ulcerative colitis in mice: involvement of the ROS-TXNIP-NLRP3 inflammasome pathway

BackgroundTitanium dioxide (TiO2), no matter in nanoscale or micron sizes, has been widely used in food industry as additives for decades. Given the potential impact of TiO2 on the gastrointestinal epithelial and parenchymal cells, including goblet cells, the public consumers may suffer the risk of diseases caused by its widespread dissemination in food products. We therefore set out to investigate the impact of TiO2 NPs on the course and prognosis of ulcerative colitis by oral gavaging TiO2 NPs at the doses levels of 0, 30, 100, and 300 mg/kg during the induction (7 days, from day 1 to day 7) and recovery (10 days, from day 8 to day 17) phases of colitis in mice.ResultsThe ulcerative colitis (UC) disease model was established by administrating of 2.5% dextran sulfate sodium (DSS) solution. Our results show that TiO2 NPs significantly enhanced the severity of DSS-induced colitis, decreased the body weight, increased the disease activity index (DAI) and colonic mucosa damage index (CMDI) scores, shortened the colonic length, increased the inflammatory infiltration in the colon. The most significant changes occurred in the low dose (30 mg/kg) group of TiO2 NPs exposure during the development phase of UC and the high dose (300 mg/kg) group of TiO2 NPs during UC self-healing phase. Increased reactive oxygen species (ROS) level and upregulation of anti-oxidant enzymes including total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX) and catalase (CAT), demonstrate that the TiO2 NP exposure has triggered oxidative stress in mice. Moreover, the upregulation of caspase-1 mRNA and increased expression of thioredoxin interacting protein (TXNIP) further demonstrate the involvement of the ROS-TXNIP-NLR family pyrin domain containing 3 (NLRP3) inflammasome pathway in aggravating the development of UC.ConclusionOral intake of TiO2 NPs could affect the course of acute colitis in exacerbating the development of UC, prolonging the UC course and inhibiting UC recovery.Graphical

The beneficial effects of Fomitopsis pinicola chloroform extract on a dextran sulfate sodium-induced ulcerative colitis mice model.

As an intestinal non-specific inflammatory lesion, ulcerative colitis (UC) affects the health of many individuals. This study examined the possible beneficial effects of the chloroform extract of Fomitopsis pinicola (Swartz.: Fr) Karst (FPKc) on UC. The mice were given free access to drink with 4% dextran sulfate sodium (DSS) for 1 week to establish acute UC model. Next, 35 mg of FPKc or sulfasalazine (SASP) was given to the mice via gavage for 3 weeks. The disease activity index (DAI) and colonic mucosa damage index (CMDI) scores were calculated. The colon tissues of the mice were collected to measure the length and perform hematoxylin and eosin staining. The thymus and spleen indexes were determined. Interleukin (IL)-6, IL-8, tumor necrosis factor-α, aminotransferase (AST) and alanine aminotransferase (ALT) levels in the serum were determined. FPKc or SASP treatment alleviated hematochezia and weight loss, ameliorated DAI and CMDI scores, and improved the crypt structure and length of the colon tissues. Relative to the UC model group, the spleen index in the FPKc group was reduced, which was accompanied by decreases of the IL-6 and IL-8 levels in the serum. FPKc also lowered the AST and ALT levels in the serum of the UC mice. FPKc protected the mice from DSS-induced UC injury. It may be that FPKc activates immune regulation and downregulates the expression of pro-inflammatory cytokines.

Advances of Heat Shock Family in Ulcerative Colitis.

Ulcerative Colitis (UC) is a non-specific and chronic inflammatory disease of colonic mucosa whose exact etiology and mechanisms remain unclear. The incidence rate of UC is increasing year by year worldwide. What followed is that the medical costs are also rising rapidly. Therefore, it is urgent to understand the pathogenesis and find promising therapeutic targets for UC. Intestinal mucosal homeostasis is essential for normal bowel function, and its imbalance may be an important pathogenesis of UC. Endogenous homeostatic regulators play roles in repairing intestinal mucosa injury after stress. Heat shock family proteins are essential endogenous homeostasis factors. They can inhibit inflammation, regulate intestinal epithelial cells’ survival and death, and promote mucosal healing. Thus, they play important roles in sustaining intestinal mucosal homeostasis and protecting against UC progression. However, the heat shock family may promote UC carcinogenesis. Here, we summarize the advances in the research of the functions of the heat shock family in UC. And this review is an attempt to light on the etiopathogenesis of UC, highlighting the endogenous protective mechanisms, hoping to provide a novel therapeutic target for UC treatment.

Mesalazine preparations for the treatment of ulcerative colitis: Are all created equal?

Oral mesalazine (also known as mesalamine) is a 5-aminosalicylic acid compound used in the treatment of mild to moderate ulcerative colitis, with high rates of efficacy in induction and maintenance of remission. The therapeutic effect of mesalazine occurs topically at the site of diseased colonic mucosa. A myriad of oral mesalazine preparations have been formulated with various drug delivery methods to minimize systemic absorption and maximise drug availability at the inflamed colonic epithelium. It remains unclear whether different oral mesalazine formulations are bioequivalent. This review aims to evaluate the differences between mesalazine formulations based on the currently available literature and explore factors which may influence the selection of one agent above another.

PTU-062 Crohn’s Disease-associated Escherichia Coli Can Tolerate Low Nutrient, Low Ph And High Chemical Stress Environments Encountered Within The Phagolysosome Of Mucosal Macrophages

IntroductionMucosa-associated adherent, invasive E.coli (AIEC), found in increased number in Crohn disease (CD) ileal and colonic mucosa, can replicate within host mucosal macrophages.1,2 Other pathogens, known to survive within macrophages...

DISTINGUISHING BETWEEN HYPERPLASTIC AND ADENOMATOUS POLYPS AND NORMAL COLONIC MUCOSA BY USING MULTIPHOTON LASER SCANNING MICROSCOPY

Precisely distinguishing between hyperplastic and adenomatous polyps and normal human colonic mucosa at the cellular level is of great medical significance. In this work, multiphoton laser scanning microscopy (MPLSM) was used to obtain the high-contrast images and the morphological characteristics from normal colonic mucosa, hyperplastic polyps and tubular adenoma. By integrating the length and area measurement tools and computing tool, we quantified the difference of crypt morphology and the alteration of nuclei in normal and diseased human colonic mucosa. Our results demonstrated that the morphology of crypts had an obvious tendency to cystic dilatation or elongated in hyperplastic polyps and tubular adenoma. The content and number of mucin droplets of the scattered goblet cells had a piecemeal reduction in hyperplastic polyps and a large decrease in tubular adenoma. The nuclei of epithelial cells might be elongated and pseudostratified, but overt dysplasia was absent in hyperplastic polyps. Nevertheless, the nuclei showed enlarged, crowded, stratified and a rod-like structure, with loss of polarity in tubular adenoma. These results suggest that MPLSM has the capacity to distinguish between hyperplastic and adenomatous polyps and normal human colonic mucosa at the cellular level.

REG gene expression in inflamed and healthy colon mucosa explored by in situ hybridisation

The regenerating islet-derived (REG) gene family encodes a group of proteins highly expressed in several human pathologies, many of which are associated with epithelial inflammation. All human family members, namely REG1A, REG1B, REG3A and REG4, are closely related in genomic sequence and all are part of the c-type lectin superfamily. REGs are highly expressed during inflammatory bowel disease (IBD)-related colonic inflammation and the in vivo expression pattern of REG1A and REG4 has been localised by using immunohistochemistry. However, the function of the encoded proteins is largely unknown and the cellular localisation of REG expression during colonic inflammation has not been described. Therefore, we have used in situ hybridisation to demonstrate the cellular localisation of REG expression in healthy and diseased colonic mucosa. Samples drawn from an IBD cohort including both inflamed and un-inflamed colonic mucosa are described, as are samples from non-IBD inflammation and healthy controls. Immunohistochemistry against known cell-type markers on serial sections has localised the expression of REGs to metaplastic Paneth cells (REG1A, REG1B and REG3A) and enteroendocrine cells (REG4), with a marked expansion of expression during inflammation. The group of REGs can, based on gene expression patterns, be divided into at least two groups; REG1A, REG1B and REG3A with their expression focused in the crypt base spreading from Paneth cells and REG4 being more highly expressed towards the luminal face. This exploration of expression pattern forms provides the background for further exploration of REG function in the intestine.Electronic supplementary materialThe online version of this article (doi:10.1007/s00441-013-1592-z) contains supplementary material, which is available to authorized users.

Investigation of Genome Instability in Exfoliated Colonic Epithelial Cells and in Mitogen-Stimulated Lymphocytes of Patients with Ulcerative Colitis

Objective: The present study aimed to evaluate the micronucleus (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in the mitogen-stimulated lymphocytes of patients with ulcerative colitis (UC). In addition, we assessed MN frequency in exfoliated colonic epithelial cells obtained from both the diseased and healthy colonic mucosa of patients. Design: The study was conducted in 22 newly diagnosed patients with UC and in 22 healthy controls. MN, NPB and NBUD values scored in binucleated (BN) cells were obtained from the mitogen-stimulated lymphocytes of patients and control subjects. In addition, the MN values in exfoliated epithelial cells obtained from the diseased and healthy colonic mucosa of patients were evaluated. Results: We found significantly higher MN, NPB and NBUD frequencies in the BN cells of patients with UC than in those of the control subjects (1.61 ± 0.75 vs. 0.89 ± 0.29, 3.93 ± 1.91 vs. 1.39 ± 1.10, and 1.55 ± 0.89 vs. 0.64 ± 0.48, p = 0.001). Also, a statistically significant difference was found between MN frequencies obtained from the diseased and healthy colonic mucosa of patients (1.07 ± 0.46 vs. 0.59 ± 0.21, p = 0.001). No significant relationship was found between age and MN frequency in patients with UC (r = 0.076, p = 0.735). Conclusion: Increased MN, NPB and NBUD frequencies observed in both the lymphocytes and exfoliated colonic epithelial cells obtained from patients with UC may reflect genomic instability.

Mitochondrial electron transport chain complex dysfunction in the colonic mucosa in ulcerative colitis

Ulcerative colitis (UC) is characterized by an energy deficiency state of the colonic epithelium. This study evaluated mitochondrial electron transport chain (ETC) complex activity in normal and disease mucosa in patients with UC. Alterations in ETC complexes were also investigated in experimental colitis in mice. Biopsies were obtained from macroscopically normal and diseased colonic mucosa of 43 patients with UC and 35 controls undergoing screening colonoscopy and ETC complex activity was assayed biochemically. ETC complex activities were also assayed in colonic epithelial cells isolated from Swiss albino mice with dextran sodium sulfate (DSS)-induced colitis at various stages of induction of colitis. Mucosal nitrite levels and protein carbonyl content were determined. The activity of Complex II was significantly decreased in colonic biopsies from UC patients compared with controls, while activities of other mitochondrial complex were normal. Complex II activity was equally decreased in diseased and normal mucosa in UC; the degree of reduction did not correlate with clinical, endoscopic, or histological grading of disease activity. In DSS-fed mice, a reduction in activity of Complex IV and Complex II was observed. Activity of other complex was not affected. Administration of aminoguanidine, an inducible nitric oxide synthase (iNOS) inhibitor, attenuated all parameters of colitis as well as the reductions in Complex IV and Complex II activity. Reduction in Complex II activity appears to be a specific change in UC, present in quiescent and active disease. Mitochondrial complex dysfunction occurs in DSS colitis in mice and appears to be mediated by nitric oxide.

CD10 immunohistochemistry stains enteric mucosa, but negative staining is unreliable in the setting of active enteritis

Ileal pouch–anal anastomosis is the definitive therapy for ulcerative colitis that is refractory to medical treatment or that has developed neoplasia. Patients with this procedure are routinely followed using directed endoscopic biopsies to monitor for dysplasia in the rectal cuff, residual/recurrent ulcerative colitis, and nonspecific acute inflammation of the ileal pouch (pouchitis), which have different clinical management and outcomes. Thus, accurate localization of mucosal biopsies is crucial to a definitive histological diagnosis, but is complicated by overlapping clinical presentations of pouchitis and ulcerative colitis, post-surgical and inflammatory changes to the mucosa, and altered endoscopic anatomy, resulting in difficulty determining whether a mucosal biopsy is ileal or rectal in origin for both the endoscopist and the pathologist. We explored the utility of CD10 immunohistochemistry to aid diagnosis in this clinical setting by highlighting the enteric mucosa, based on previous studies showing its utility in brush border staining and in the diagnosis of microvillous inclusion disease. We found uniformly positive CD10 immunostaining in normal enteric mucosa, but variable loss of expression in the setting of active enteritis. Specifically, CD10 staining was lost in up to 10% of the mucosa in 1/12 ileostomies and 4/13 enteric anastomoses, in 10–80% of the mucosa in 9/10 cases of Crohn's ileitis, in 10–60% of the mucosa in 7/16 ileal pouches, and in 20–90% of the mucosa in 6/8 cases of backwash ileitis, usually in the presence of active inflammation. There was no CD10 expression by normal or diseased colonic mucosa. Therefore, while CD10 immunostaining identifies normal enteric mucosa with 100% specificity, negative staining does not definitively exclude small intestinal mucosa in the setting of active enteritis, a common condition in ileal pouch mucosa.

Peroxisome proliferator‐activated receptor γ 2 mutation may cause a subset of ulcerative colitis

Previous studies suggest the homeostasis between acquisition of tolerance to the indigenous microflora and protective immune responses appears to be disrupted in inflammatory bowel disease (IBD). Some experimental studies indicate peroxisome proliferator-activated receptor γ (PPARγ) has been implicated as a regulator of intestinal inflammatory responses. In addition, the toll-like receptor (TLR)-4 can regulate expression of PPARγ in colonic epithelial cells. We attempted to demonstrate whether the functional imbalance between TLRs and PPARγ could lead to the onset and some polymorphisms of those genes could contribute to susceptibility to IBD. RT-PCR analysis were performed to detect TLR4 and PPARγ mRNA associated with those of P65 of NFκB, TNFα, MyD88, NOD2/CARD15, TLR-2,5,9, in the diseased colonic mucosa in ulcerative colitis (UC; n = 13) and Crohn's disease (CD; n = 7) compared with normal controls (n = 18). Consequently, we genotyped UC (n = 29) and CD (n = 10) compared with normal controls (n = 134) for the prevalence of suspicious mutations. In a subset of UC patients who were revealed to carry PPARγ Pro12Ala mutation later, impaired expression of normal PPARγ mRNA was noted in the diseased mucosa accompanied with upregulations of MyD88 TLR-4, 5, 9, P65 and TNFα in mRNA levels. The prevalence of PPARγ Pro12Ala mutation was more frequently found in UC patients compared with CD patients and normal controls (P < 0.05). These findings suggested that imbalances between TLRs and PPARγ in response to luminal bacteria could lead to colonic inflammation in some UC patients. Alternative explanations will be needed for the onset of the rest of UC and CD.

Short Circuit Currents of Normal and Crohn's Diseased Human Colonic Mucosa

Aims: Inflammatory Bowel Disease (IBD) is a condition of unknown aetiology that causes chronic gut dysfunction and comprises two pathologically different forms, Crohn's Disease (CD) and Ulcerative Colitis (UC). Both conditions are characterised by a marked disturbance in the equilibrium between absorptive and secretory electrolyte transport in inflamed colonic mucosa but the underlying mechanisms are not known.

Expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in ulcerative colitis

To examine the expression of metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the colonic mucosa of patients with ulcerative colitis (UC). Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were used to study the expression of MMP-1 and TIMP-1 at both mRNA and protein levels in patients with UC and controls. The relationship between MMP-1 mRNA, TIMP-1 mRNA, MMP-1 mRNA/TIMP-1 mRNA ratio and the severity of clinical symptoms of the patients with UC were also analyzed. The expression of MMP-1 mRNA and TIMP-1 mRNA in the ulcerated and inflamed colonic mucosa was significantly higher than that in the non-inflamed colonic mucosa (P < 0.001), but there was no statistically significant difference in the non-inflamed colonic mucosa of UC patients and normal controls (P > 0.05). The mRNA expression of MMP-1 and TIMP-1 in ulcerated colonic mucosa of UC patients was increased by 80-fold and 2.2-fold, respectively when compared with the normal controls. In the inflamed colonic mucosa, the increase was 30-fold and 1.6-fold, respectively. Immunohistochemical analysis showed that among the ulcerated, inflamed, and non-inflamed colonic mucosae of UC patients and the normal controls, the positive rate of MMP-1 expression was 87%, 87%, 40% and 35% respectively, and the positive rate of TIMP-1 expression was 89%, 89%, 80% and 75%, respectively. Furthermore, the expression of MMP-1 mRNA, TIMP-1 mRNA and the MMP-1 mRNA/ TIMP-1 mRNA ratio were correlated with the severity of clinical symptoms (P <0.05). Excessive expression of MMP-1 in the diseased colonic mucosa causes excessive hydrolysis of the extracellular matrix (ECM) and ulceration in UC patients. MMP-1 mRNA, TIMP-1 mRNA and MMP-1 mRNA/TIMP-1 mRNA ratio can be used as biomarkers to judge the severity of clinical symptoms in patients with UC. Exogenous TIMP-1 or MMP-1 inhibitor therapy is a novel treatment for patients with UC.

In vivo Histology of Normal and Diseased Human Colonic Mucosa Using a Fluorescence Confocal Endomicroscope

In vivo Histology of Normal and Diseased Human Colonic Mucosa Using a Fluorescence Confocal Endomicroscope

Distribution of activated complement, C3b, and its degraded fragments, iC3b/C3dg, in the colonic mucosa of ulcerative colitis (UC).

The third component of complement (C3) is central to both the classical and alternative pathways in complement activation. In this study, involvement of C3 activation in the mucosal injury of UC was investigated. We examined the distribution of activated (C3b) and degraded fragments (iC3b/C3dg) of C3, terminal complement complex (TCC), and complement regulatory proteins in normal and diseased colonic mucosa including UC and other types of colitis using immunohistochemical techniques at the level of light and electron microscopy. While C3b and iC3b/C3dg staining was negligible in the normal mucosa, iC3b/C3dg and, to a lesser extent, C3b were deposited in UC mucosa along the epithelial basement membrane. The deposition was enhanced in relation to the severity of mucosal inflammation (C3b, P less than 0.05; iC3b/C3dg, P less than 0.01). Epithelial deposition of TCC was not observed in most UC mucosa. Immunoelectron microscopy showed that C3b and iC3b/C3dg were distributed mainly along the epithelial basement membrane and the underlying connective tissue in a granular, studded manner, and weakly present along the basolateral surface of epithelial cells. These C3 fragments were also deposited in inflammatory control mucosa such as ischaemic and infectious colitis. Our findings suggest that deposition of the C3 fragments occurs in inflamed colonic mucosa of diverse etiologies, including UC, but to define a role of the deposition in the development of mucosal injury in UC awaits direct study.

Ileoneorectal anastomosis: early clinical results of a restorative procedure for ulcerative colitis and familial adenomatous polyposis without formation of an ileoanal pouch.

To evaluate a new surgical procedure, ileoneorectal anastomosis (INRA), in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Surgical treatment in UC and FAP aims to resect diseased colonic mucosa and restore oroanal continuity. The ileopouch anal anastomosis achieves this but has a 15% to 35% complication rate, a 10% failure rate, and an unpredictable functional outcome. An alternative surgical technique, INRA, has been developed in which the rectal mucosa is replaced by a vascularized ileal mucosa graft. Eleven patients underwent an INRA procedure with a temporary diverting ileostomy. Clinical history, repeat endoscopy, histologic examination, and rectal compliance measurements were carried out before and after surgery. The INRA procedure was technically successful in all patients. Endoscopy showed ingrowth of ileal mucosa in the neorectum, with 100% coverage after 6 weeks. No patient had pelvic sepsis, neorectal-anal or -vaginal fistula, autonomic nerve damage, or fecal incontinence. Neorectal function improved with time. The median 24-hour defecation frequency decreased from 15 (range 9 to 25) to 7 (range 4 to 10) at 11 months follow-up, and the median maximum tolerated volume increased to 157 (range 130 to 225) ml. Anal manometry and electrosensitivity were not affected by the surgery. Histologic biopsy samples after 1 year showed a normal small intestinal mucous membrane, without inflammation or fibrosis. The combination of a low complication rate and good neorectal function at 1 year is a substantial improvement that justifies extension of the clinical application in patients with UC and FAP.

Selective COX-2 inhibitors and human inflammatory bowel disease.

Much recent effort has been made to produce selective inhibitors of cyclo-oxygenase-2 (COX-2) in the belief that these will lack the gastrointestinal damaging effects of traditional non-steroidal anti-inflammatory drugs (NSAIDs). Inflammatory bowel disease is associated with increased local production of prostanoids. These prostanoids, particularly PGE2 and PGI2, may well be protective as inflammatory bowel disease is aggravated by NSAID use. To examine the effects of a traditional NSAID and a highly selective COX-2 inhibitor on the production of these prostanoids in human inflammatory bowel disease. Colonic mucosal biopsies were obtained from patients undergoing routine colonoscopy and biopsy for diagnostic or surveillance purposes. Biopsies were incubated in culture medium containing 10% foetal calf serum and antibiotics, plus test drugs or vehicle for 24 h, after which time the medium was removed and the content of PGE2, PGI2 (measured as 6 keto-PGF1alpha) and thromboxane (Tx) A2 (measured as TxB2) determined. Biopsies obtained from diseased colonic mucosa produced significantly more PGE2, PGI2 and thromboxane A2 than did controls (for example, PGE2: ulcerative colitis, 4.17+/-1.06; Crohn's disease, 3.97+/-1.66; control, 0.12 +/-0.13 ng/mL, n = 8-12). These increases were inhibited to a similar extent by either a highly selective COX-2 inhibitor (L-745,337) or a traditional non-selective NSAID (indomethacin). Until selective COX-2 inhibitors have been assessed adequately in human inflammatory bowel disease, these compounds should not be assumed to be safe for the gastrointestinal tract in inflammatory bowel disease.

Expression of alpha5 (CD49e) and alpha6 (CD49f) integrin subunits on T cells in the circulation and the lamina propria of normal and inflammatory bowel disease colonic mucosa.

Intestinal lamina propria T cells are believed to be derived, via the systemic circulation, from gut-associated lymphoid tissue. After migration into the lamina propria, T cells are capable of luminally directed migration following the loss of surface epithelial cells. For adhesion and migration within the extracellular matrix, T cells are likely to utilize the integrin family of adhesion molecules. The aim of this study was to quantitatively and qualitatively investigate the expression of alpha5 and alpha6 integrin subunits on the surface of human T cells that: (a) migrated out of the lamina propria, (b) remained resident within the matrix and (c) were present in the circulation. In both subpopulations of CD4 and CD8-positive T cells, from both normal and inflamed (inflammatory bowel disease) colonic mucosa, there were significantly fewer alpha5 and alpha6-positive cells than in the peripheral blood. In addition, there were significantly fewer alpha6 integrin molecules on the surface of CD4 and CD8-positive lamina propria T-cell subpopulations, compared with those in the circulation. Our studies suggest that, following migration into the lamina propria, there is down-regulation of alpha5 and alpha6 integrin-subunit expression on the surface of T cells. Molecules other than members of very late activation antigen-5 (VLA-5) (alpha5beta1) and VLA-6 (alpha6beta1) families of adhesion molecules are likely to be important in interactions with extracellular components in the lamina propria of normal and inflamed human colonic mucosa.

Antineutrophil cytoplasmic antibodies in T-cell receptor alpha-deficient mice with chronic colitis

BACKGROUND & AIMS: Antineutrophil cytoplasmic antibodies (ANCAs) have been detected in approximately 60% of sera from patients with ulcerative colitis. The aim of this study was to examine the presence of ANCAs and distribution of ANCA-producing B cells in the lymphoid tissue of T-cell receptor alpha-deficient (TCR-alpha-/-) mice that develop chronic colitis resembling human ulcerative colitis. METHODS: Sera from 87 TCR-alpha-/- mice were tested for the presence of ANCAs by enzyme-linked immunosorbent assay against a human neutrophil extract and selected antigens and by immunofluorescence study using human neutrophils. Enzyme-linked immunospot assay was used for detecting ANCA-producing cells from spleen, mesenteric lymph node (MLN), or colon. RESULTS: Approximately 70% of sera from TCR-alpha-/- mice showed reactivity against human neutrophil extracts by enzyme-linked immunosorbent assay. Sixty percent of ANCA-positive sera showed a perinuclear reaction pattern. By enzyme-linked immunospot, ANCA-producing cells were detected in MLN and colon and less often in the spleen of TCR-alpha-/- mice with chronic colitis. The predominant immunoglobulin isotype of these autoantibodies was immunoglobulin A in the colon but not in the MLN and spleen. CONCLUSIONS: TCR-alpha-/- mice produce ANCAs. The ANCA (immunoglobulin A isotype)-producing B cells exist primarily in the diseased colonic mucosa of TCR-alpha-/- mice. (Gastroenterology 1997 Dec;113(6):1828-35)

Treatment of colonic bleeding in Klippel-Trenaunay syndrome with combined partial colectomy and endoscopic laser

Klippel-Trenaunay syndrome can be associated with significant lower gastrointestinal bleeding from diffuse cavernous hemangiomata of the colon. Distal colectomy is curative but the formation of a colostomy is undesirable in patients who already have a poor self-image due to the other manifestations of Klippel-Trenaunay syndrome such as multiple cutaneous hemangiomata, severe varicose veins, and prominent limb hypertrophy. Endoscopic laser ablation alone is often not feasible in these patients because of the extensive and often circumferential nature of the colonic hemangiomata. This report describes successful treatment of gastrointestinal hemorrhage due to colonic hemangiomata by a novel combination of partial colonic resection and endoscopic laser therapy. Case 1 demonstrates that endoscopic laser ablation of the diseased colonic mucosa, while not feasible with the extensive involvement of the left colon, was very effective when combined with partial colectomy at curing the bleeding while maintaining anal sphincter function. In case 2 the disease was more limited and more easily amenable to endoscopic laser ablation. Combined surgical and laser endoscopic therapy is recommended in treating the colonic hemangiomata associated with Klippel-Trenaunay syndrome.