Inflamed Colonic Mucosa Of Patients Research Articles

Olfactomedin 4 Is Not a Precise Marker for Human Intestinal Stem Cells, But Is Involved in Intestinal Carcinogenesis

Olfactomedin 4 Is Not a Precise Marker for Human Intestinal Stem Cells, But Is Involved in Intestinal Carcinogenesis

Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease.

To investigate intestinal alkaline phosphatase (iAP) in the intestinal mucosa of children with inflammatory bowel disease (IBD). Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtained both from inflamed and non-inflamed areas. The iAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localization of iAP and Toll-like receptor (TLR) 4 was investigated by immunofluorescent staining. The iAP protein level in the inflamed mucosa of children with Crohn's disease (CD) and ulcerative colitis (UC) was significantly decreased when compared with controls (both P < 0.05). Similarly, we found a significantly decreased level of iAP protein in the inflamed mucosa in CD compared with non-inflamed mucosa in CD (P < 0.05). In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD (P < 0.05). iAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls. iAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significantly different from that in non-inflamed colonic mucosa with CD. Expression of iAP mRNA in patients with non-inflamed mucosa and in controls were similar. Co-localization of iAP with TLR4 showed intense staining with a dotted-like pattern. iAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. However, the fluorescent signal of TLR4 was more pronounced in the colon compared with the terminal ileum in all groups studied. Lower than normal iAP protein levels in inflamed mucosa of IBD patients may indicate a role for iAP in inflammatory lesions in IBD. Based on our results, administration of exogenous iAP enzyme to patients with the active form of IBD may be a therapeutic option.

Impaired Peripheral Dopaminergic System in Patients with Ulcerative Colitis

Ulcerative colitis (UC) is the chronic inflammatory disease unknown etiology. Little is known on the role of dopaminergic system in the pathogenesis of UC, despite the evidence that dopaminergic hypoactivity may result in excessive inflammation. We demonstrated a diminished risk for UC in patients with schizophrenia (hyper‐dopaminergic system) (Tolstanova G. et al. Gastroenterology 2010;138 (5):S‐264). In this study we tested the hypothesize that patients with chronic UC is characterized by the disturbance of peripheral dopaminergic system.MethodsColonic biopsy samples from 7 patients with chronic UC with recurrence stage and 7 ‐ from healthy colon were included in the study. Expressions and localization of D2, D3 dopamine receptors, DAT (responsible for dopamine re‐uptake) and tyrosine hydroxylase (TH, rate‐limiting enzyme of dopamine synthesize) were investigated with immunohistochemistry.ResultsProfound expression of DАТ, D2R, D3R and ТН was found in apical membrane of colonocytes and basal membrane of Goblet cells of healthy colonic mucosa. Inflamed colonic mucosa of patients with UC was characterized by 25% decrease in levels of D2R and D3R; 75% decrease levels of TH, mostly in colonocytes. Levels and localization of DAT was not significantly changed. ConclusionRecurrence of chronic UC is associated with the downregulation of dopamine synthesize, D2R and D3R expression in colonic mucosa. Restitution of dopaminergic system may be new molecular targets for the UC therapy. Study was supported by the grant 01BF‐03601 MES of Ukraine.

No association between the SOCS-1 -1478CA/del polymorphism and ulcerative colitis in Turkish subjects.

Suppressor of cytokine signaling (SOCS)-1 is an essential regulator of many cytokine signaling pathways, including those upregulated in the inflamed colonic mucosa of patients with ulcerative colitis. We sought to investigate whether the functional SOCS-1 -1478CA>del polymorphism is associated with UC susceptibility and its disease phenotype in a Turkish clinical sample. A total of 104 subjects were enrolled in a case-control study (52 UC cases and 52 controls). The SOCS-1 -1478CA>del polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The odds ratio of the del allele for UC relative to the CA allele was not significant (OR = 1.04, 95 % CI 0.59-1.82, P = 0.88). These results did not change after adjustment for age and sex in multivariable regression analysis (OR = 1.07, 95 % CI 0.42-1.69, P = 0.73). When the SOCS-1 -1478CA>del polymorphism was analyzed among UC patients according to continuous disease and non-continuous disease, the del allele was not associated with disease recurrence (OR = 1.56, 95 % CI 0.78-4.56, P = 0.83). Furthermore, when we divided UC patients into two groups according to a previous history of colectomy, we found no significant effect of the del allele (OR = 1.94, 95 % CI 0.55-5.61, P = 0.91). Taken together, these findings suggest that SOCS-1 -1478CA>del polymorphism does not contribute to UC susceptibility and its disease phenotype in Turkish subjects.

Up-regulation and Pre-activation of TRAF3 and TRAF5 in Inflammatory Bowel Disease

Objective: TRAF3 and TRAF5 share a common ancestral gene, and interact as essential components of signaling pathways in immunity. TRAF3 and TRAF5 are overexpressed in the colon of rat/mouse models with colitis. However, the expressions of TRAF3 and TRAF5 in patients with inflammatory bowel disease have not been elucidated. The aim of the present study is to explore the potential roles of TRAF3 and TRAF5 in patients with inflammatory bowel disease.Methods: Plasma levels of TRAF3 and TRAF5 proteins were detected by Enzyme-linked Immunosorbent Assay (ELISA). Colonic expression of TRAF3 and TRAF5 proteins was detected by western blot analysis. Quantitative Real-time PCR (qRT-PCR) was applied for gene expression. Inflamed intestinal mucosa and non-inflamed intestinal mucosa in patients with inflammatory bowel disease and normal mucosa was analyzed from healthy controls.Results: The plasma levels of TRAF3 and TRAF5 were significantly higher both in patients with Crohn's disease and ulcerative colitis than in healthy controls. Only soluble TRAF5 showed a weak correlation with endoscopic disease activity index (Baron score) in patients with ulcerative colitis (spearman's r=0.358, P=0.022). Gene expressions of TRAF3 and TRAF5 in peripheral blood mononuclear cells were significantly higher both in patients with Crohn's disease and ulcerative colitis than in healthy controls (all P<0.0001). Gene and protein expressions of TRAF3 and TRAF5 were significantly higher in inflamed colonic mucosa of patients with Crohn's disease and ulcerative colitis than in non-inflamed colonic mucosa and normal mucosa of healthy controls (all P<0.0001). Furthermore, gene and protein expressions of TRAF3 and TRAF5 were also significantly higher in non-inflamed colonic mucosa of patients with Crohn's disease and ulcerative colitis than in normal mucosa of healthy controls.Conclusions: TRAF3 and TRAF5 are overexpressed in inflammatory bowel disease. Although the endoscopic appearance can be normal, TRAF3 and TRAF5 pre-activation can be detected in non-inflamed colonic segments.

P046 Differential expression of microRNAs in inflamed colonic mucosa of patients with ulcerative colitis

Conclusions: IFX acts locally at mucosa level, as shown by the decrease in inflammatory infiltrate and cytokines contents. The effect of IFX is partially dependent on direct effect on epithelial cells. IFX seems to ameliorate epithelial cell healing by blocking the detrimental capacity of TNF-a pre-treated fibroblast on intestinal epithelial cells. More data are necessary to unravel molecular pathways of these observations, in order also to clarify mechanisms of loss of responses to it as well as new targets for potential new therapies.

Increased expression of microRNA in the inflamed colonic mucosa of patients with active ulcerative colitis

MicroRNA (miRNA) are endogenous, approximately 22-nucleotide non-coding RNA that suppress gene expression at post-transcriptional levels by binding to the 3'-untranslated region of specific mRNA targets through base-pairing. It has been recently reported that miRNA have critical functions in key biological processes such as cell proliferation and cell death in various cancer cells. However, the relationship between intestinal inflammation and miRNA expression remains unclear. In the present study, we used microarray technology to identify miRNA induced in the colonic mucosa of patients with active ulcerative colitis (UC). Two colonic biopsy specimens from patients with active stage (>Matts grade 2) of UC under colonoscopy and two colonic biopsy specimens from healthy volunteers were obtained for gene expression profiles. Total RNA was extracted, and miRNA expression profiles were investigated using miRNA Microarray. Subsequently, to confirm the result of the Microarray investigation, we checked the expression of several selected miRNA using real-time polymerase chain reaction (PCR) in 12 colonic biopsy specimens from patients with active UC under colonoscopy and 12 specimens from the healthy volunteers. In the microarray study, the expression of several miRNA was upregulated in the colonic mucosa of patients with active UC. Furthermore, two miRNA (miR-21, miR-155) were selected in the study using real-time PCR. Upregulated miRNA may be responsible for the development of intestinal inflammation in UC.

Expression of catalytic proteasome subunits in the gut of patients with Crohn’s disease

Background and purposeActivation of the transcription factor NF-κB by proteasomes and subsequent nuclear translocation of cytoplasmatic complexes play a crucial role in the intestinal inflammation. Proteasomes have a pivotal function in NF-κB activation by mediating degradation of inhibitory IκB proteins and processing of NF-κB precursor proteins. This study aims to analyze the expression of the human proteasome subunits in colonic tissue of patients with Crohn’s disease.Materials and methodsThirteen patients with Crohn’s disease and 12 control patients were studied. The expression of immunoproteasomes and constitutive proteasomes was examined by Western blot analysis, immunoflourescence and quantitative real-time PCR. For real-time PCR, AK2C was used as housekeeping gene.ResultsThe results indicate the influence of the intestinal inflammation on the expression of the proteasomes in Crohn’s disease. Proteasomes from inflamed intestine of patients with Crohn’s disease showed significantly increased expression of immunosubunits on both protein and mRNA levels. Especially, the replacement of the constitutive proteasome subunit β1 by inducible immunosubunit β1i was observed in patients with active Crohn’s disease. In contrast, relatively low abundance of immunoproteasomes was found in control tissue.ConclusionsOur data demonstrate that in contrast to normal colonic tissue, the expression of immunoproteasomes was evidently increased in the inflamed colonic mucosa of patients with Crohn’s disease. Thus, the chronic intestinal inflammation process in Crohn’s disease leads to significant alterations of proteasome subsets.

Usefulness of quantitative real-time PCR assay for early detection of cytomegalovirus infection in patients with ulcerative colitis refractory to immunosuppressive therapies

Studies suggest that cytomegalovirus (CMV) infection exacerbates ulcerative colitis (UC) refractory to immunosuppressive therapies. Early and accurate diagnosis of CMV infection is important for the treatment of UC. We evaluated the usefulness of quantitative real-time polymerase chain reaction (PCR) for detecting CMV infection in inflamed colonic mucosa of patients with UC refractory to immunosuppressive therapies. From 2003 to 2006, 30 patients (mean age: 41 +/- 18 years; 14 men, 16 women) with UC refractory to immunosuppressive therapies were enrolled in the study. We evaluated CMV infection by CMV antigenemia, histologic examination, and quantitative real-time PCR for CMV using colonic mucosa and investigated the clinical outcomes of antiviral therapy. CMV-DNA was detected only in the inflamed colonic mucosa in 17 (56.7%) of 30 patients. Of the 17 CMV-DNA-positive patients, 4 were positive for CMV antigenemia or inclusion bodies on histologic examination; of the 13 CMV-DNA-negative patients none was positive for CMV antigenemia or inclusion bodies. Of the 17 CMV-DNA-positive patients, 12 (70.6%) were treated with ganciclovir for 2 weeks and 10 patients went into remission. Two other patients required colectomy after antiviral therapy. In contrast, of the 13 CMV-DNA-negative patients 12 (92.3%) achieved remission after intensifying their immunosuppressive therapies. Quantitative real-time PCR assay for detecting CMV-DNA is useful for early, accurate diagnosis of CMV infection in patients with UC refractory to immunosuppressive therapies, enabling prompt and appropriate treatment.

Decreased expression of thioredoxin interacting protein mRNA in inflamed colonic mucosa in patients with ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease associated with intestinal inflammation and tissue damage. It is assumed that the oxidative stress that accompanies chronic inflammation contributes to the development of colorectal cancer (CRC). Thioredoxin interacting protein (TXNIP), whose expression is induced by various types of stress including oxidative stress and is downregulated in various types of human cancer including colorectal cancer, is a negative regulator of thioredoxin, which is an important regulator of redox balance. However, TXNIP expression in clinical specimens of UC remains unclear. Herein, using TaqMan RT-PCR assay, we demonstrated that TXNIP expression in UC and CRC colonic mucosa specimens was significantly lower than that in normal tissues (p=0.0007 and p<0.0001, respectively). In addition, in situ hybridization study showed that inflammatory cells expressing the TXNIP transcript were abundant in lymphoid follicles, the lamina propria and submucosa in the colonic mucosa of UC patients, but not in epithelial cells on the flat surface, whereas the TXNIP transcript was abundant in normal mucosa. Our results suggest that downregulation of TXNIP may be partly involved in the pathogenesis of UC, including inflammation and colitis-associated colon carcinogenesis.

Immunostimulatory Oligonucleotides Inhibit Colonic Proinflammatory Cytokine Production in Ulcerative Colitis

We previously showed that Toll-like receptor-9 (TLR-9) ligands ameliorate experimental colitis. In this study, we evaluated the effect of TLR-9 ligands on the generation of proinflammatory cytokines by human colonic mucosa. Colonoscopic biopsies were obtained from patients with active ulcerative colitis (UC) and from normal subjects. The tissue was organ cultured for 24 hours in the presence or absence of different types of immunostimulatory (ISS) (CpG)-oligonucleotides (ODNs). Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels in the medium were determined by enzyme-linked immunosorbent assay. In active UC, hTNF-alpha and hIL-lbeta generation by inflamed colonic mucosa is 7- and 3-fold higher, respectively, than their generation by normal mucosa. Class B CpG ODNs inhibited colonic TNF-alpha and IL-1beta generation by 50%, whereas class A or C ODNs had a partial or no effect, respectively. A novel class of ODNs that is based on multiple TCG repeats was as effective as class B ODNs. This inhibition resulted from the transcriptional suppression of IL-1beta that occurred within the first 2 hours after ISS-ODN incubation. The addition of chloroquine abolished the inhibitory effects of ISS-ODNs on colonic TNF-alpha and IL-1beta generation. Only certain classes of ISS-ODNs inhibit the enhanced TNF-alpha and IL-1beta generated ex vivo by inflamed colonic mucosa of patients with UC. The effect of ISS-ODNs is mediated by triggering of TLR-9. These results suggest a potential therapeutic value for ISS-ODNs in UC.

Analysis of intestinal haem-oxygenase-1 (HO-1) in clinical and experimental colitis.

Haem-oxygenase-1 (HO-1) has been shown to exert anti-inflammatory, anti-apoptotic and anti-proliferative effects. We investigated HO-1 expression in patients with inflammatory bowel disease (IBD) and could demonstrate a scattered expression of HO-1 in the intestinal epithelium of severely inflamed colonic mucosa of patients with IBD compared to control specimens such as diverticulitis, suggesting dysregulated expression in IBD. To further analyse potential mechanisms of HO-1 induction in the intestine we employed an in vitro epithelial cell apoptosis model and an experimental colitis model. In vitro induction of HO-1 by the HO-1 inducer cobalt protoporphyrin (CoPP) resulted in a dose-dependent down-regulation of caspase-3 activation in HT-29 cells, indicating an anti-apoptotic function of HO-1 in the intestine. In vivo, preventive HO-1 induction by CoPP in acute dextran sodium sulphate (DSS)-induced colitis led to a significant down-regulation of colonic inflammation (P < 0.01) with a concomitant reduction in interferon (IFN)-gamma - but unaffected interleukin (IL)-10-secretion by isolated mesenteric lymph nodes (P < 0.01). Additionally, TUNEL staining of colonic sections demonstrated fewer apoptotic epithelial cells in the colon of CoPP treated animals. No beneficial effects were observed if HO-1 was induced by CoPP after the onset of acute colitis or in chronic DSS-induced colitis. In conclusion, the data suggest a protective role of HO-1 if it is induced before the onset of inflammation. However, as shown by the lack of effects in established acute or in chronic colitis, the induction of HO-1 may not be a promising approach for the treatment of IBD.

Cytokine profile in colonic mucosa of ulcerative colitis correlates with disease activity and response to granulocytapheresis

OBJECTIVE: The aim of this study was to clarify the correlation between cytokine profile in colonic mucosa with disease activity and response to granulocytapheresis (GCAP) in patients with ulcerative colitis (UC), using a reliable, reproducible quantitative method. METHODS: Colonoscopic biopsies of inflamed colonic mucosa (16 patients, 21 cases) and uninflamed colonic mucosa (25 patients, 33 cases) were obtained from UC patients. Messenger (m)RNA was extracted and subjected to real-time polymerase chain reaction for quantitative measurement of interleukin (IL)-12, interferon-γ, tumor necrosis factor-α, IL-4, IL-8, and IL-18 mRNAs. In seven patients with high disease activity despite prednisolone (PSL) treatment (≥20 mg/day), one course of GCAP was conducted, and pre- and post-GCAP cytokine profiles were determined. RESULTS: In inflamed colonic mucosa of UC patients, three cytokine profiles were observed: 1) high expression of interferon-γ, tumor necrosis factor-α, and IL-4 mRNAs but low expression of IL-8 mRNA; 2) high expression of IL-8 mRNA and low expression of others; and 3) low expression of all cytokines examined. Inflamed colonic mucosa of patients with high disease activity showed the second pattern. Inflamed colonic mucosa of patients who were not treated with PSL and who had low disease activity showed the first pattern, whereas those on high-dose PSL exhibited the second pattern. IL-8 mRNA was significantly higher in inflamed UC samples than in uninflamed samples. GCAP was effective in five of seven PSL-resistant patients (71.4%). IL-8 was the only cytokine that correlated with effectiveness of GCAP. Compared with GCAP nonresponders, responders had significantly higher IL-8 mRNA before GCAP and showed marked reduction of IL-8 mRNA after GCAP. CONCLUSIONS: IL-8 mRNA was significantly increased in inflamed mucosa of UC. Patients with high IL-8 mRNA expression in colonic mucosa despite PSL treatment were responsive to GCAP. Therefore, quantitative measurement of mucosal IL-8 mRNA may be useful in predicting the response to GCAP.

Cytokine profile in colonic mucosa of ulcerative colitis correlates with disease activity and response to granulocytapheresis.

The aim of this study was to clarify the correlation between cytokine profile in colonic mucosa with disease activity and response to granulocytapheresis (GCAP) in patients with ulcerative colitis (UC), using a reliable, reproducible quantitative method. Colonoscopic biopsies of inflamed colonic mucosa (16 patients, 21 cases) and uninflamed colonic mucosa (25 patients, 33 cases) were obtained from UC patients. Messenger (m)RNA was extracted and subjected to realtime polymerase chain reaction for quantitative measurement of interleukin (IL)-12, interferon-gamma, tumor necrosis factor-alpha, IL-4, IL-8, and IL-18 mRNAs. In seven patients with high disease activity despite prednisolone (PSL) treatment (> or = 20 mg/day), one course of GCAP was conducted, and pre- and post-GCAP cytokine profiles were determined. In inflamed colonic mucosa of UC patients, three cytokine profiles were observed: 1) high expression of interferon-gamma, tumor necrosis factor-alpha, and IL-4 mRNAs but low expression of IL-8 mRNA; 2) high expression of IL-8 mRNA and low expression of others; and 3) low expression of all cytokines examined. Inflamed colonic mucosa of patients with high disease activity showed the second pattern. Inflamed colonic mucosa of patients who were not treated with PSL and who had low disease activity showed the first pattern, whereas those on high-dose PSL exhibited the second pattern. IL-8 mRNA was significantly higher in inflamed UC samples than in uninflamed samples. GCAP was effective in five of seven PSL-resistant patients (71.4%). IL-8 was the only cytokine that correlated with effectiveness of GCAP. Compared with GCAP nonresponders, responders had significantly higher IL-8 mRNA before GCAP and showed marked reduction of IL-8 mRNA after GCAP. IL-8 mRNA was significantly increased in inflamed mucosa of UC. Patients with high IL-8 mRNA expression in colonic mucosa despite PSL treatment were responsive to GCAP. Therefore, quantitative measurement of mucosal IL-8 mRNA may be useful in predicting the response to GCAP.

Orally administered glutathione peroxidase-mimetic (BXT-51072) is a potent anti-oxidant: Protection against oxidation & nitration of inflamed colonic mucosa in patients with ulcerative colitis [UC

Orally administered glutathione peroxidase-mimetic (BXT-51072) is a potent anti-oxidant: Protection against oxidation & nitration of inflamed colonic mucosa in patients with ulcerative colitis [UC

Evaluation of the Role of Neutrophils in the Pathogenesis of Acetic Acid-Induced Colitis in Mice

Background: Neutrophils are thought to play a role in the pathogenesis of inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease, since prominent neutrophil infiltration has been observed in the inflamed colonic mucosa of patients with IBD. However, the role of neutrophils in the pathogenesis of IBD and experimental colitis remains equivocal. The aim of the present study is to clarify the possible role of neutrophils in the progression of acetic acid-induced colitis in mice. Methods: Using neutropenic mice treated with cyclophosphamide or with an LTB4 receptor antagonist, ONO-4057, the relationship between the severity of macroscopic colonic damage, the extent of myeloperoxidase (MPO) activities in the colonic tissues, and the number of neutrophils in the blood were examined after induction of colitis in mice. Results: Changes of MPO activity in the colonic tissues paralleled well with the severity of the mucosal damage. In spite of a significant reduction in the number of neutrophils in the blood in cyclophosphamide-treated mice, neither the severity of mucosal damage in the colon nor the increase in MPO activities in the colonic tissues was affected 24 h after induction of colitis. Treatment with ONO-4057 significantly suppressed both the severity of mucosal damage in the colon and MPO activities in the colonic tissues in acetic acid-induced colitis in mice. Conclusions: The present results, obtained using treatment with cyclophosphamide and ONO-4057, show that the severity or the progression of acetic acid-induced colitis in mice was not influenced by a reduction of circulating neutrophils to about 25% of base line.

Enhanced colonic nitric oxide generation and nitric oxide synthase activity in ulcerative colitis and Crohn's disease.

Recent studies have suggested that nitric oxide (NO.), the product of nitric oxide synthase in inflammatory cells, may play a part in tissue injury and inflammation through its oxidative metabolism. In this study the colonic generation of oxides of nitrogen (NOx) and nitric oxide synthase activity was determined in ulcerative colitis and Crohn's disease. Colonic biopsy specimens were obtained from inflammatory bowel disease patients and from normal controls. Mucosal explants were cultured in vitro for 24 hours and NOx generation was determined. Nitric oxide synthase activity was monitored by the conversion of [3H]-L-arginine to citrulline. Median NOx generation by inflamed colonic mucosa of patients with active ulcerative colitis and Crohn's colitis was 4.2- and 8.1-fold respectively higher than that by normal human colonic mucosa. In ulcerative colitis and Crohn's colitis nitric oxide synthase activity was 10.0- and 3.8-fold respectively higher than in normal subjects. Colonic NOx generation is significantly decreased by methylprednisolone and ketotifen. The decrease in NOx generation by cultured colonic mucosa induced by methylprednisolone suggests that NO synthase activity is induced during the culture and the steroid effect may contribute to its therapeutic effect. Enhanced colonic NOx generation by stimulated nitric oxide synthase activity in ulcerative colitis and Crohn's disease may contribute to tissue injury.

Increased production of luminol enhanced chemiluminescence by the inflamed colonic mucosa in patients with ulcerative colitis.

Reactive oxygen species have been implicated as mediators of inflammation in ulcerative colitis. Chemiluminescence is a reliable means of estimating reactive oxygen species in biological media. Increased reactive oxygen species values in the inflamed colonic mucosa in rats were seen by chemiluminescence. The aims of the study were to find out if chemiluminescence is raised in the colonic mucosa of patients with ulcerative colitis and correlates with disease activity, and to elucidate the sources of the chemiluminescence. It was found that reactive oxygen species, as measured by the chemiluminescence technique, are raised in inflamed colonic mucosa and correlates with symptom score, sigmoidoscopic score, disease activity, and activity of the neutrophil enzyme myeloperoxidase. Chemiluminescence was inhibited by a myeloperoxidase inhibitor (azide) and an H2O2 scavenger (catalase) but not by allopurinol, an inhibitor of the enzyme xanthine oxidase. Chemiluminescence was also inhibited by indomethacin, but this did not seem to be related to inhibition of cyclo-oxygenase. These findings suggest that a likely cellular source of reactive oxygen species in the inflamed colon of patients with ulcerative colitis is the neutrophil and that myeloperoxidase conversion of H2O2 to hypochlorous acid, contributes to the chemiluminescence signal and possibly, to the tissue injury. Neither cyclo-oxygenase nor lipoxygenase seem to play a part as sources for the chemiluminescence.

5-Aminosalicylic acid is a potent inhibitor of interleukin 1 beta production in organ culture of colonic biopsy specimens from patients with inflammatory bowel disease.

Interleukin 1 beta in biopsy specimens from inflamed colonic mucosa of patients with active inflammatory bowel disease was studied. Compared with normal colonic mucosal biopsy specimens, a significantly greater amount of interleukin 1 beta was present in rectal mucosa before (median (range) 4.3 (2.0-11.8) v 119.2 (30.1-286.8) pg/mg; p less than 0.01) and produced during organ culture (39.1 (9.4-106.8) v 97.6 (28.2-991.6) pg/mg; p less than 0.01). Values of interleukin 1 beta after culture correlated with concentrations of thromboxane B2. Organ culture of inflamed biopsy specimens in the presence of 5 aminosalicylic acid and dexamethasone reduced the amount of interleukin 1 beta detected. At the doses studied, 5 aminosalicylic acid also reduced the amount of leukotriene B4 detected after culture.