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PubMed2006

Endoscopic mucosal resection for flat neoplasia in chronic ulcerative colitis: can we change the endoscopic management paradigm?

BACKGROUND: The potential of endoscopic mucosal resection (EMR) for treating flat dysplastic lesions in chronic ulcerative colitis (CUC) has not been addressed so far. Historically, such lesions were referred for colectomy. Furthermore, there are only limited data to support endoscopic resection of exophytic adenoma-like mass (ALM) lesions in colitis. AIMS: To evaluate the safety and clinical outcomes of patients with colitis undergoing EMR for Paris class 0-II and class I ALM compared with sporadic controls. Secondary aims were to re-evaluate the prevalence, anatomical "mapping" and histopathological characteristics of both Paris class 0-II and class I lesions in the context of CUC. METHODS: Prospective clinical, pathological and outcome data of patients with colitis-associated Paris class 0-II and Paris class I ALM treated with EMR (primary end points being colorectal cancer development, resection efficacy, metachronous lesion rates and post-resection recurrence rates) were compared with those of sporadic controls. RESULTS: 204 lesions were diagnosed in 169 patients during the study period: 167 (82%) diagnosed at "entry" colonoscopy, and 36 (18%) diagnosed at follow-up. 170 ALMs, 18 dysplasia-associated lesion masses (DALMs) and 16 cancers were diagnosed. A total of 4316 colonoscopies were performed throughout the study period (median per patient: 6; range: 1-8). The median follow-up period for the complete cohort was 4.1 years (range: 3.6-5.21). 1675 controls were included from our prospective database of patients without CUC who had undergone EMR for sporadic Paris class 0-II and snare polypectomy of Paris type I lesions from 1998 onwards, and were considered to be at moderate to high lifetime risk of colorectal cancer. 3792 colonoscopies were performed throughout the study period in this group (median per patient: 4; range: 1-7). The median follow-up period was 4.8 years (range: 2.9-5.2). No statistically significant differences were observed between the CUC study group and controls with respect to age, sex, median number of colonoscopies per patient, median follow-up duration, post-resection complications, median lesional diameter or interval cancer rates. However, there was a significant between-group difference regarding the prevalence of Paris class 0-II lesions in the CUC group (82/155 (61%)) compared with controls (285/801 (35%); chi(2) = 31.13; p<0.001). Furthermore, recurrence rates of lateral spreading tumours were higher in the colitis cohort (1/7 (14%)) than among controls (0/10 (0%); p = 0.048 (95% CI 11.64% to 40.21%)). CONCLUSIONS: Flat DALM, similarly to Paris class I ALM, can be managed safely by EMR in CUC. A change in management paradigm to include EMR for the resection of flat dysplastic lesions in selected cases is proposed.

Adenoma↗
PubMed1981

Disodium cromoglycate in the treatment of ulcerative colitis and Crohn's disease.

A controlled clinical study on disodium cromoglycate (DSCG) at a dose of 800 mg per day versus placebo was carried out in 141 patients with ulcerative colitis and 25 patients with Crohn's disease. Those of the ulcerative colitis patients who had been on sulphasalazine treatment continued that treatment during the trial (101 patients). Forty patients were intolerant of sulphasalazine. No patient received steroids during the last month before the study. Patients with Crohn's disease had their possible sulphasalazine treatment stopped before the trial. No beneficial effect of DSCG as compared with placebo was found, as the DSCG and the placebo group showed the same number of relapses in patients with a clinically inactive ulcerative colitis at the start of the trial and the same number of patients improving, deteriorating, and maintaining steady state in patients with clinically active ulcerative colitis at the start of the trial. There was no difference between relapse rate in DSCG and placebo groups in patients with Crohn's disease. No correlation between the eosinophil count in rectal mucosa and the outcome of the attack of ulcerative colitis could be demonstrated.

Clinical Trials as Topic↗
PubMed1982

Comparison of the composition of faecal fluid in Crohn's disease and ulcerative colitis.

We determined the ionic composition of faecal fluid from 13 patients with Crohn's disease limited to the colon, 10 with diffuse ulcerative colitis, and eight with ulcerative proctitis. The Crohn's and colitis groups had similar proportions of colon surface involved radiographically and similar 24 hour faecal weights. However, Crohn's patients' faecal fluid had arithmetically lower mean sodium and statistically lower mean chloride (34.8 mmol/l +/- 16.2 SD vs. 53.1 mmol/l +/- 23.1 SD) and higher potassium (49.2 mmol/l +/- 20.2 SD vs. 33.0 mmol/l +/- 13.8 SD) concentrations (p less than 0.05 for each) and much higher osmolality (487.1 mOsmol/kg +/- 87.1 SD vs. 341.1 mOsmol/kg +/- 88.9 SD, p less than 0.001). Separation of these patients using the faecal osmotic gap agreed with the clinical classification in 86% of cases. The diarrhoea of proctitis patients had a nearly normal ionic composition which was clearly distinguishable from that of diffuse colitis. These results suggest differences in the composition and perhaps the pathogenesis of the diarrhoea of Crohn's and ulcerative colitis. The composition of fluid may prove a useful, non-invasive method for classifying patients with inflammatory bowel disease and, in ulcerative colitis, determining the extent of the inflammatory process.

Chlorides↗
PubMed1982

Overwhelming pneumococcal septicaemia in a patient with ulcerative colitis and splenic atrophy.

This report describes a young woman with ulcerative colitis who developed rapidly fatal pneumococcal septicaemia. Necropsy revealed splenic atrophy. This case supports the hypothesis that splenic atrophy might contribute to the morbidity of ulcerative colitis. The occurrence of splenic atrophy in ulcerative colitis is now well established. Splenic atrophy from other causes has been associated with severe bacterial infections, often pneumococcal. It has been suggested that splenic atrophy is most severe when ulcerative colitis is active and may contribute to postoperative morbidity. This case documents overwhelming septicaemia in a patient with splenic atrophy whose colitis was in remission.

Adult↗
PubMed1985

Campylobacter colitis: histological immunohistochemical and ultrastructural findings.

The colonic biopsy specimens of 22 patients with colitis and positive stool cultures for Campylobacter jejuni were studied in order to obtain histological and immunohistochemical criteria to differentiate Campylobacter colitis from chronic inflammatory bowel disease. In addition we tried to identify Campylobacter inclusions by means of immunohistochemistry and electron microscopy as evidence for invasion of the colonic mucosa. The results show that the majority of patients with Campylobacter colitis have the histological picture of acute infectious colitis with increased numbers of IgA and IgM containing plasma cells in the colonic mucosa in contrast with patients with active chronic inflammatory bowel disease who show increases of IgA and IgG (ulcerative colitis) or IgA-, IgM and IgG containing plasma cells (M Crohn) in their colonic biopsies. The results of immunohistochemical stainings with Campylobacter antiserum show invasion of Campylobacter in the colonic mucosa. These findings were confirmed ultrastructurally.

Campylobacter Infections↗
PubMed1987

Local IgA subclass alterations in ulcerative colitis and Crohn's disease of the colon.

The subclass distribution of IgA producing cells was determined by paired immunofluorescence staining in colonic specimens from 10 patients with ulcerative colitis and eight with Crohn's disease. Compared with normal colonic mucosa, the percentage of IgA1 immunocytes showed a striking increase in both disorders. The proportion of mucosal IgA1 cells was significantly higher (p less than 0.05) in ulcerative colitis (median, 71.2%) than in Crohn colitis (median, 56.9%). Within each category of specimens no significant differences were noted between luminal and basal mucosal zones. The submucosal proportion of IgA1 cells was, however, significantly higher than the mucosal one in both ulcerative colitis (median, 89.1%; p less than 0.002) and Crohn colitis (median, 91.8%; p less than 0.005). The mucosal shift towards IgA1 production paralleled the magnitude of the submucosal IgA1 cell proportion in individual tissue samples. Taken together with the previously reported dramatic increase of local IgG production (particularly observed in the submucosa and basal parts of the mucosa), our findings indicated that there is an influx and/or proliferation of B cells representing systemic secondary immunity in the lesions of both diseases.

Adult↗
PubMed1988

Ulcerative colitis specific cytotoxic IgG-autoantibodies against colonic epithelial cancer cells.

Serum antibodies cytotoxic to the colon cancer cell line RPMI 4788 were studied in 42 patients with ulcerative colitis, 61 patients with Crohn's disease, 27 patients with other inflammatory diseases (disease-controls) and 22 healthy controls. Cytotoxicity of antibodies towards RPMI 4788 was studied by means of a chromium release assay using peripheral blood mononuclear leucocytes of healthy subjects as effector cells. Using a four hour antibody dependent cell mediated cytotoxicity assay sera from 29% of ulcerative colitis patients contained antibodies cytotoxic for the target, while only 3% of the Crohn's patients and 6% of the disease controls and non of the healthy controls were positive. When an 18 hour assay was applied, however, not only 40% of ulcerative colitis patients, but also 14% of Crohn's patients and 21% of disease controls were found positive. The reactive antibody in the four hour assay was mainly of the IgG class, which points at a classical antibody dependent cell mediated cytotoxicity mechanism. In the 18 hour cytotoxic assay IgG and particularly IgM antibodies were found to be reactive. This suggests that in the latter case other cellular cytotoxic mechanism might be involved. There was a significant inverse correlation between the appearance of the ulcerative colitis restricted IgG-anticolon epithelial cell antibodies (four hour assay) and the disease activity (p less than 0.01). Absorption studies showed that the reactive antigen is not specific for ulcerative colitis colonic tissue, but is similarly found in Crohn's bowel tissue, and to a lower extent in normal bowel, liver and kidney. The reactive antigen, however, could not be detected in brain and lymphoblastoid cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1988

Diminished neutrophil function in Crohn's disease and ulcerative colitis identified by decreased oxidative metabolism and low superoxide dismutase content.

Features of the neutrophil oxidative metabolism and enzyme activity in peripheral blood neutrophils were studied in 43 patients with Crohn's disease, 13 with ulcerative colitis and 33 healthy controls. The production of superoxide anion (O2-.) by phorbol-myristate-acetate stimulated neutrophils from patients with Crohn's disease and ulcerative colitis was significantly diminished compared with controls mean (SE) = 47.1 (3.6) and 38.0 (3.8) v 67.4 (7.5) nmol/10(7) cells/min, p less than or equal to 0.02, respectively, while the production of hydrogen peroxide was normal. The neutrophil content of superoxide dismutase (SOD), a cytoprotective enzyme, was also markedly diminished in Crohn's disease mean (SE) = 7.11 (0.23) ng SOD/micrograms DNA, p less than 0.05, and ulcerative colitis mean (SE) = 5.74 (0.42) compared with controls 7.84 (0.27), p less than 0.001. In contrast, the concentration of neutrophil elastase, a neutral protease, was found to be normal when compared with neutrophils from controls. The neutrophil O2-. production and the SOD concentrations were significantly and negatively correlated with the disease activity in Crohn's disease and ulcerative colitis. The results indicate diminished neutrophil function in peripheral blood of patients with Crohn's disease and ulcerative colitis as illustrated by a diminished oxidative system, which correlates with the disease activity.

Adolescent↗
PubMed1988

Ulcerative colitis and Crohn's disease in an unselected population of monozygotic and dizygotic twins. A study of heritability and the influence of smoking.

By running the Swedish twin registry containing about 25,000 pairs of twins of the same sex together with the central national diagnosis register of hospital inpatients, 80 twin pairs suffering from inflammatory bowel disease were found. In the ulcerative colitis group one of 16 monozygotic pairs was concordant for the disease, but all the other 20 pairs (dizygotic or unknown zygosity) were discordant. In the Crohn's disease group eight of 18 monozygotic pairs and one of 26 dizygotic pairs were concordant. The proband concordance rate among monozygotic twins was 6.3% for ulcerative colitis and 58.3% for Crohn's disease. The calculated heritability of liability based on monozygotic pairs was 0.53 and 1.0 respectively. Thus heredity as an aetiological factor is stronger in Crohn's disease than in ulcerative colitis. Monozygotic twins with Crohn's disease were more likely to be smokers than monozygotic twins with ulcerative colitis. Smoking did not explain the discordance of twin pairs with either ulcerative colitis, or Crohn's disease. The combination of identical heredity and similar smoking habit is not sufficient to cause disease.

Adolescent↗
PubMed1992

Surface epithelium related activation of complement differs in Crohn's disease and ulcerative colitis.

IgG1 and activated complement are colocalised on the colonic epithelial brush border in active ulcerative colitis. To investigate whether such deposition is specific for ulcerative colitis, we examined ethanol fixed mucosal specimens from 18 patients with Crohn's colitis and 14 with terminal ileitis by indirect two colour immunofluorescence staining. Monoclonal antibodies to the IgG subclasses and to neoepitopes of activated complement C3b and the terminal complement complex were used in combination with rabbit antiserum to C1q, C4c or cytokeratin. Granular deposition of C3b and terminal complement complex were observed at the luminal face of the surface epithelium in 10 of 18 patients with Crohn's colitis. Specimens from eight of 14 patients with ileal involvement were intensely stained for activated complement (primarily C3b) within the surface mucus layer. No epithelial IgG, C1q or C4c deposition was observed. The results suggest that early and late phase complement activation takes place at the luminal face of the epithelium in Crohn's disease. The absence of colocalised IgG and complement components involved in the classical activation pathway (C1q and C4c), however, suggest that other immunopathological mechanisms (the alternative pathway?) are primarily involved in Crohn's disease in contrast with ulcerative colitis.

Adolescent↗
PubMed1993

Adsorbents as antiendotoxin agents in experimental colitis.

The intestinal mucosa protects the body from a large reservoir of intraluminal pathogenic bacteria and endotoxins. This mucosal barrier is disrupted by the inflammation and ulceration of inflammatory bowel disease and may permit the absorption of toxic bacterial products. Systemic endotoxaemia has been demonstrated in ulcerative colitis and Crohn's disease and correlates with the extent and activity of disease. In this study the efficacy of absorbents as antiendotoxin agents in a hapten induced rat model of colitis is investigated. Induction of colitis was associated with systemic endotoxaemia. Enteral administration of terra fullonica and kaolin, but not of charcoal, significantly reduced systemic endotoxaemia (terra fullonica 4.2 (1.40) pg/ml; kaolin 5.29 (1.86) pg/ml; charcoal 32.7 (16.6) pg/ml; water 39.8 (12.6) pg/ml). Data expressed as mean (SE). With increasing severity of colitis, there was a decreasing ability of adsorbent therapy (terra fullonica) to control systemic endotoxaemia. Enteral administration of adsorbents controls gut derived systemic endotoxaemia in experimental colitis in animals and may be a useful antiendotoxin treatment in patients with inflammatory bowel disease.

Adsorption↗
PubMed1994

Butyrate oxidation is impaired in the colonic mucosa of sufferers of quiescent ulcerative colitis.

The short chain fatty acids, acetate, propionate, and butyrate are produced by colonic bacterial fermentation of non-starch polysaccharides. Butyrate is the major fuel source for the colonic epithelium and there is evidence to suggest that its oxidation is impaired in ulcerative colitis. Triplicate biopsy specimens were taken at colonoscopy from five regions of the large bowel in 15 sufferers of ulcerative colitis. These patients all had mild or quiescent colitis as assessed by clinical condition, mucosal endoscopic and histological appearance. The rate of oxidation of glucose, glutamine, and butyrate through to carbon dioxide was compared with that in biopsy specimens from 28 patients who had no mucosal abnormality. Butyrate (272 (199-368)) was the preferred fuel source for the colitic mucosa followed by glutamine (33 (24-62)) then glucose (7.2 (5.3-15)) pmol/micrograms/hour; medians and 95% confidence intervals, p < 0.01. There was no regional difference in the rate of utilisation of these metabolites. In the group with colitis the rate of butyrate oxidation to carbon dioxide was significantly impaired compared with that in normal mucosa decreasing from 472 (351-637) pmol/micrograms/hour to 272 (199-368) pmol/micrograms/hour; median and 95% confidence intervals, p = 0.016. The rate of glucose and glutamine utilisation were not significantly different between normal and colitic mucosa. These data confirm that in quiescent ulcerative colitis there is an impairment of butyrate oxidation.

Adult↗
PubMed1994

Increased group II phospholipase A2 in colonic mucosa of patients with Crohn's disease and ulcerative colitis.

The immunochemical protein content of group II phospholipase A2 (PLA2) and PLA2 enzymatic activity were measured for colonic mucosal biopsy samples obtained from patients with either Crohn's disease of the colon or ulcerative colitis, and control patients without inflammatory bowel disease. Immunoreactive group II PLA2 (IR-PLA2 II) content and PLA2 activity in actively inflamed colonic mucosa of Crohn's disease patients were significantly higher than those in inactively inflamed mucosa of Crohn's disease patients and the colonic mucosa of controls. IR-PLA2 II content and PLA2 activity in severely inflamed mucosa of ulcerative colitis patients were significantly higher than those in the colonic mucosa of the controls. Mucosal PLA2 enzymatic activity was closely correlated with mucosal IR-PLA2 II content in patients with Crohn's disease and ulcerative colitis. These results suggest that an increase in PLA2 enzymatic activity in inflamed colonic mucosa of Crohn's disease and ulcerative colitis was mainly attributed to increased protein content of group II PLA2, and that an increase in mucosal group II PLA2 may be involved in the pathogenesis of intestinal inflammation of Crohn's disease and ulcerative colitis.

Adolescent↗
PubMed1995

Increased faecal mucin sulphatase activity in ulcerative colitis: a potential target for treatment.

Colonic mucin is heavily sulphated and it has been shown that enzymatic desulphation by faecal bacterial sulphatases greatly increases its susceptibility to degradation by faecal glycosidases. A possible role for faecal mucin sulphatase in the pathogenesis of inflammatory bowel disease has therefore been explored. Faecal mucin sulphatase activity assayed using 35S mucin as substrate was increased in ulcerative colitis (median 80.2 units/g pellet weight (range 6.9-1063; 95% confidence intervals (CI): 45.2 to 293.8, n = 22) compared with 11.3 units/g (range 3.0-53.5; 95% CI: 8.7 to 29.8, n = 17) in healthy controls (p < 0.01), where one unit released 1000 dpm free sulphate/hour from 35S mucin (1680 dpm/microgram). Patients with active ulcerative colitis had higher sulphatase activity (median 146; 95% CI: 98 to 253 units/g, n = 10) than those with inactive ulcerative colitis (median 42.2; CI: 22.5 to 81.6 units/g, n = 12) (p < 0.05). Longitudinal studies in patients with ulcerative colitis show fluctuations of faecal mucin sulphatase activity corresponding to clinical disease activity in six of seven patients. Faecal mucin sulphatase activity was not significantly increased in Crohn's disease (median 36.6, range 5.7-106.6; 95% CI: 22.9 to 65.3 units/g, n = 14). The bismuth salts, bismuth subcitrate and bismuth subsalicylate were found to inhibit faecal mucin sulphatase activity at concentrations achievable therapeutically. The increased faecal mucin sulphatase activity in ulcerative colitis could be the result of greater intraluminal substrate (mucin) availability leading to bacterial enzyme induction, but would probably result in more rapid degradation of secreted mucin and represents a potential target for treatment.

Adult↗
PubMed1995

Colonic epithelium is diffusely abnormal in ulcerative colitis and colorectal cancer.

The hypothesis that the colonic epithelium is diffusely abnormal in ulcerative colitis was examined by comparing disease related responses in expression of markers of differentiation by colonic crypt cells to culture with and without butyrate. Cells were isolated from patients with normal colon (15), cancer (24), ulcerative colitis (19), or Crohn's disease (16). Alkaline phosphatase activities were measured in cell homogenates and the rate of glycoprotein synthesis assessed at the end of 24 hours of culture and expressed relative to the rate of protein synthesis as the G:P ratio. Alkaline phosphatase activities, but not G:P ratios, differed across the groups before and after 24 hour culture (p < 0.05), activities being lowest in the cancer group and highest in inflammatory bowel disease groups. Butyrate (1 mM) suppressed alkaline phosphatase activities in the cancer group by mean (SEM) of 17 (4) (p = 0.006) compared with no change in the other groups. Butyrate suppressed G:P ratios only in the cancer (6 (3)%, p = 0.03) and ulcerative colitis groups (5 (3)%, p = 0.04) and the changes in both were different (p < 0.05) from those in normal cells (increase of 10 (7)%). Changes in ulcerative colitis were different from those in Crohn's disease (p = 0.029). Responses were independent of the presence or absence of mucosal inflammation. These data confirm the diffuse nature of epithelial abnormalities in colorectal cancer. In ulcerative colitis, a different pattern of abnormality occurs, supporting the notion that the epithelium is also diffusely abnormal independent of mucosal inflammation.

Adult↗
PubMed1997

Prophylactic effect of dietary glutamine supplementation on interleukin 8 and tumour necrosis factor alpha production in trinitrobenzene sulphonic acid induced colitis.

BACKGROUND: It is well established that glutamine supplemented elemental diets result in less severe intestinal damage in experimental colitis. However, few studies have examined the mode of action of glutamine in reducing intestinal damage. AIMS: To examine the effects of glutamine supplemented elemental diets on the potent inflammatory cytokines interleukin 8 (IL-8) and tumour necrosis factor alpha (TNF-alpha) in trinitrobenzene sulphonic acid (TNBS) induced colitis which presents with both acute and chronic features of ulcerative colitis. METHODS: Sprague-Dawley rats were randomised into three dietary groups and fed 20% casein (controls), or 20% casein supplemented with either 2% glutamine (2% Gln) or 4% glutamine (4% Gln). After two weeks they received intracolonic TNBS to induce colitis. RESULTS: Both Gln groups of rats gained more weight than the control group (p < 0.05) which had progressive weight loss. Colon weight, macroscopic, and microscopic damage scores for the Gln groups were lower than in the control group (p < 0.05). IL-8 and TNF-alpha concentrations in inflamed colonic tissues were lower in the Gln groups than in the control group (p < 0.05), and correlated well with disease severity. Bacterial translocation was lower both in incidence (p < 0.05) and in the number of colony forming units (p < 0.05) for the Gln groups, than in the control group. With respect to all indices studied, the 4% Gln group performed better than did the 2% Gln group. CONCLUSION: Prophylactic glutamine supplementation modulates the inflammatory activities of IL-8 and TNF-alpha in TNBS induced colitis.

Analysis of Variance↗
PubMed1997

Is there an excess risk for colorectal cancer in patients with ulcerative colitis and concomitant primary sclerosing cholangitis? A population based study.

BACKGROUND: Patients with ulcerative colitis have an increased risk of colorectal cancer. Duration, age, and extent of the disease at diagnosis are the only established risk factors. Patients with ulcerative colitis and concomitant primary sclerosing cholangitis (PSC) have been reported to have a higher frequency of colonic DNA aneuploidy and/or dysplasia than expected, findings indicating an increased risk of colorectal cancer compared with other patients with ulcerative colitis. METHODS: A population based cohort consisting of 125 patients with a verified diagnosis of PSC was followed up by linkage to the Swedish Cancer Registry for the occurrence of colorectal cancer. RESULTS: There were 12 colorectal cancers. Six cancers were diagnosed prior to the diagnosis of PSC. Among the 104 patients with an intact colon at the time of the diagnosis of PSC there was a cumulative risk for colorectal cancer of 16% after 10 years. Among the 58 patients with a diagnosis of ulcerative colitis and colorectal cancer prior to the diagnosis of PSC, there were five colorectal cancers corresponding to a cumulative risk of 25% after 10 years. CONCLUSIONS: Patients with ulcerative colitis and concomitant PSC seem to constitute a subgroup with a high risk for colorectal cancer.

Actuarial Analysis↗
PubMed1998

Hyperbaric oxygen: a novel modality to ameliorate experimental colitis.

BACKGROUND: Hyperbaric oxygen (HBO) has been suggested to be beneficial in inflammatory bowel disease but the mechanisms responsible for its therapeutic effects have not been elucidated. AIM: To assess the effect of HBO treatment on colonic damage in two models of experimental colitis, and to examine whether this effect is mediated by modulation of NO synthesis. METHODS: Colitis was induced by either flushing the colon with 2 ml 5% acetic acid or intracolonic administration of 30 mg trinitrobenzenesulphonic acid (TNB) dissolved in 0.25 ml 50% ethanol. Rats were exposed to HBO (100% oxygen at 2.4 atmosphere absolute) for one hour twice on the day of colitis induction and once daily thereafter. Control rats were treated only with acetic acid or TNB. Rats were killed 24 hours after acetic acid administration or one and seven days after TNB treatment. The colon was isolated, washed, and weighed, the lesion area was measured, and mucosal scrapings were processed for determination of myeloperoxidase (MPO) and NO synthase (NOS) activities, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) generation. RESULTS: In control rats exposed for seven days to HBO, colonic NOS activity was significantly decreased by 61%, compared with its activity in untreated rats (2.93 (0.17) nmol/g/min). HBO significantly reduced by 51 and 62% the extent of injury induced by acetic acid and TNB respectively. The protection provided by HBO was accompanied by a significant decrease in colonic weight, PGE2 generation, MPO, and NOS activities. In acetic acid colitis, LTB4 generation was also significantly decreased. CONCLUSIONS: (1) HBO effectively decreases colitis induced by acetic acid and TNB. (2) The decreased NOS activity induced by HBO suggests that reduction in NO generation may be among the mechanisms responsible for the anti-inflammatory effect of HBO. (3) HBO may be considered in the treatment of patients with refractory inflammatory bowel disease.

Acetic Acid↗