Unaffected Mucosa Research Articles

Coeliac disease is associated with impaired expression of acyl-CoA-synthetase 5

Coeliac disease and other disorders of the small intestine are associated with disturbances in mucosal architecture. The most severe injury to tissue architecture is villus atrophy. In coeliac disease, molecules reflecting the state of the villus architecture are not well characterized at present. Expression of acyl-CoA-synthetase 5 (ACS5) was studied in unaffected human small/large intestinal tissue and in coeliac disease using several methods including molecular techniques, as well as an in situ approach using a novel established monoclonal antibody directed against human ACS5. Strong expression, synthesis, and enzymatic activity of ACS5 were found in normal small intestinal mucosa compared with unaffected colon mucosa. In normal small intestine, ACS5 preferentially located to the epithelium covering villi. In coeliac disease, expression of ACS5 was regularly associated with differentiation of villi. Thus, ACS5 was found in the villus epithelium of the small intestine with coeliac disease of Marsh grades I, II, IIIa, or IIIb respectively. In Marsh grade IIIc coeliac disease lesions, strong expression of ACS5 was detectable neither in the surface epithelium nor in the epithelium lining hyperplastic crypts. These data suggest that ACS5 is a very suitable marker molecule for the detection of villus atrophy in the small intestine.

P0700 PROSPECTIVE EVALUATION OF ORAL CROHNS DISEASE IN CHILDREN

Introduction: Previous reports indicate that oral lesions occur in 6 to 20% of patients with Crohn’s disease (CD). A recent retrospective study at our centre revealed a significantly higher incidence of disease specific oral lesions (48%) in patients undergoing formal evaluation by a paediatric dental surgeon. The aim of this study was to prospectively document the proportion of children with oral lesions at initial evaluation for suspected inflammatory bowel disease. Methods: Data were collected between Jan 1999 and Dec2001. All children suspected of having IBD were included in the study. Systematic dental examinations were carried out on the day of endoscopy and findings documented. Information regarding age, sex, presenting symptoms, oral symptoms, family history, medications, findings on clinical examination, routine laboratory results and barium follow-through studies were recorded. All children underwent upper gastrointestinal endoscopy and colonoscopy. Biopsy specimens were taken from grossly affected tissue and unaffected gastric and colonic mucosa. Oral biopsies were taken as appropriate. Results: Forty-eight of 49 patients with CD were examined by the dentist. Findings consistent with oral CD were found in 20 patients (41.7%). Non-specific changes were found in 8(16.7%) patients, while 20(41.7%) patients had a normal oral examination. Six patients with oral CD were on medications at the time of evaluation. Patients with oral CD were more likely to complain of oral symptoms, 14 /20(70%) versus 9/28 (32.1%) of patients without oral CD (p=0.013). Oral findings included mucogingivitis (12), tags (4), deep ulceration (4), cobblestoning (3), lip swelling (3) and pyostomatitis vegetans (1). Non-caseating granulomas were found in each of the eight oral biopsies that were performed. Two patients with granulomas in oral biopsies had no granulomas in biopsies from elsewhere in the GI tract. There was no difference in the systemic symptoms or laboratory markers in patients with or without oral CD. When comparing disease location between patients with and without oral CD five patients were excluded as they had H. Pylori infection (n=43). Children with oral CD were more likely to have perianal disease 10/20 (50%) compared to 4/23 (17.4%) (p =0.023), but other sites of disease were similarly affected in both groups. In seven patients (36.84%) with oral CD was the mouth found to be abnormal by the gastroenterologist. Only in 25(58.1%) of patients did the consultants findings correlate with those of the dentist. Conclusion: Children with CD commonly have oral CD findings even in the absence of symptoms. These oral changes provide important diagnostic information. Expert dental evaluation is necessary in order to accurately identify these oral lesions.

Safety of Band Ligator Use in the Small Bowel and Colon

In the August 2003 Gastrointestinal Endoscopy(58(2); 274-279), Junquera et al. noted in a case series that endoscopic band ligation for bleeding small bowel vascular lesions was safe and efficacious. There have been several other published case reports of band ligators used for bleeding lesions, usually Dieulafoy's, in the stomach, proximal small bowel and colon. In addition, this method has been used for post-polypectomy bleeding stalks. There has never been a critical look at the anatomic consequences of banding in the thinner sections of bowel. The purpose of this study is to define the anatomic and histologic consequences of applying band ligator devices to the small and large bowel. Fresh surgical specimens, both large and small bowel, that were excised because of neoplastic lesions were transported to our endoscopy unit where one end of the intact bowel was sutured shut. A standard upper endoscope was passed via the open end and the bowel closed tightly with rubber band ties. The bowel was then insufflated and band ligators were applied to unaffected mucosa using standard technique. Photo documentation from the inside and outside the bowel was obtained. Some of the band polyps were cut above the band and some below the band in the fresh state. Some were fixed in formalin and examined microscopically. Histologic sectioning occurred at the level of the bands. The results were striking in that there were large holes (1 cm) in the fresh ileum specimen. There was gross serosal entrapment manifested by visible puckers on the outer surfaces of the specimens, especially in the small bowel and right colon. The left colon, anatomically thicker, was less affected. The histologic evaluation revealed inclusion by the band ligator of the muscularis propria and serosa on the small bowel, the muscularis propria in the right colon, and the submucosa in the left colon. Based on these findings, we conclude that band ligator devices are not safe in the small bowel and right colon but probably are safe in the thicker left colon.

Human papillomavirus-positive tonsillar carcinomas: a different tumor entity?

Human papillomavirus (HPV) infections are thought to be one of the causal factors in the development of head and neck squamous cell carcinomas (HNSCC), particularly in tumors arising from the Waldeyer's tonsillar ring. We screened 98 carefully stratified HNSCC and different control tissues for the presence of HPV DNA by nested polymerase chain reaction (PCR) specific for genital- and Epidermodysplasia verruciformis (EV)-associated HPVs and by HPV16-specific single step PCR. Typing was performed by direct sequencing and/or sequencing of cloned amplimers. On average HNSCC showed rather low HPV DNA prevalences; 18% of the oral cavity cancers, 8% of nasopharyngeal cancers, 25% of hypopharyngeal cancers and 7% of laryngeal cancers were HPV DNA positive. In contrast, HPV sequences could be detected in 45% of the oropharyngeal cancers, particularly tonsillar carcinomas (58%). Tonsillar carcinomas were significantly more likely to be HPV positive than tumors from any other site ( P<0.001). All tonsillar cancers contained oncogenic HPV types, predominantly HPV16 (13 of 14; 93%). Unaffected tonsils were available from two of these patients, but both tested negative for HPV DNA. Furthermore, no HPV DNA could be found in tonsillar biopsy specimens from control groups. Localization and load of HPV DNA was determined in HPV16-positive tonsillar carcinomas, their metastases and in unaffected mucosa using laser-assisted microdissection and subsequent real time fluorescence PCR. We demonstrated that the HPV genome is located in the cancer cells, whereas the infection of normal mucosa is a rare event. Quantification of HPV16 DNA in samples of seven patients yielded viral loads from 6 to 153 HPV DNA copies per beta-globin gene copy and the load values in both locations were roughly comparable. These loads are comparable with data shown for other HPV-associated lesions. Statistical evaluation of data related to clinicopathological parameters showed a significant correlation of the HPV positivity of tonsillar carcinomas with tumor grading ( P=0.008) and alcohol consumption ( P=0.029). Taken together our findings show a preferential association of HPV DNA with tonsillar carcinomas. Furthermore our results argue for HPV-positive tonsillar carcinomas representing a separate tumor entity, which is less dependent on conventional HNSCC risk factors.

The increased expression of an array of C-X-C and C-C chemokines in the colonic mucosa of patients with ulcerative colitis: regulation by corticosteroids

OBJECTIVE: To better understand the extent to which chemokines participate in the mucosal inflammatory response in patients with ulcerative colitis (UC), we assessed the expression of an array of chemokines in the colonic mucosa of UC patients and evaluated the effect of corticosteroids on their expression. METHODS: Colonic mucosal biopsy specimens were obtained from 15 patients with UC and 12 normal controls. Messenger RNA levels for 10 chemokines were quantitated by reverse transcription polymerase chain reaction using synthetic standard RNAs. The biopsy specimens were also cultured in the presence or absence of tumor necrosis factor α (TNFα) and/or dexamethasone, and secreted chemokines in culture supernatants were assayed by ELISA. RESULTS: The messenger RNA expression of C-X-C (interleukin 8, growth-related α [GROα], GROβ, GROγ, epithelial cell-derived neutrophil activator 78, and interferon-γ-inducible protein 10) and C-C (monocyte chemotactic protein 1, macrophage inflammatory protein 1β, and RANTES [regulated on activation, normal T-cell expressed and secreted]) but not C (lymphotactin) chemokines was significantly higher in the affected mucosa of UC patients than in the unaffected mucosa of UC patients or in the normal mucosa of normal controls. The degree of increased expression was more prominent in the C-X-C than in the C-C chemokines. Further, the secretion of interleukin 8, GROα, epithelial cell-derived neutrophil activator 78, and monocyte chemotactic protein 1 was higher in UC patients than in normal controls, induced significantly by TNFα, and downregulated by dexamethasone. Secretions of macrophage inflammatory protein 1β and RANTES also showed a trend toward an increase in UC, induction by TNFα, and downregulation by dexamethasone, but it did not reach statistical significance. CONCLUSIONS: The increased expression of a variety of chemokines in UC and their downregulation by dexamethasone suggest that chemokines may play an important role in the immunopathogenesis of UC.

Changes in physico-chemical properties of human large intestine tumour cells membrane.

Tumour cells produce and excrete to blood many substances which are present in the cell itself in trace amounts only. Our work has been aimed at the determination of changes in electric charge and in phospholipid composition of large intestine normal mucosa and colorectal cancer cells. Surface charge density of tumour unaffected mucosa and of tissue sections from tumours, was measured by electrophoresis. The measurements were carried out at various pH of solution. Membrane isoelectric point was determined by measuring its electric charge in function of pH as well as total positive charge at low pH and total negative charge at high pH. Qualitative and quantitative composition of phospholipids in the membrane was determined by HPLC. Four phospholipid classes were identified: PI, PS, PE and PC and their surface concentrations were determined. The electric charge calculated from phospholipid concentrations is by three orders of magnitude higher than that determined electrophoretically. It indicates that the groups present in the membrane surface are involved in equilibria in which the charge is neutralized. The electric charge calculated from phospholipid concentrations is by three orders of magnitude higher than that determined electrophoretically. It indicates that the groups present in the membrane surface are involved in equilibria in which the charge is neutralized. Tumour changes provoke an increase in surface charge density of large intestine membrane, whereas the content of individual phospholipids increased or decreased depending on a patient.

Transforming Growth Factor-α and Epidermal Growth Factor Receptor in Colonic Mucosa in Active and Inactive Inflammatory Bowel Disease

Transforming growth factor-α (TGF-α) is overexpressed in colonic carcinomas and promotes mucosal wound healing. It may be implicated in chronic inflammatory bowel disease (IBD). We analyzed the expression of TGF-α and its receptor, epidermal growth factor receptor (EGF-r), in the colonic mucosa of patients with Crohn's disease (CD) or ulcerative colitis (UC), in active or inactive stages, as compared with controls. Proteins and mRNA were detected in biopsies from the right and left colon and in surgical colonic specimens. Immunoblot analysis revealed TGF-α protein as a 29 k Da band. This band was normally expressed in uninvolved colonic mucosa of patients with CD or UC whether in active or inactive stages, but decreased or absent in involved mucosa of active IBD, even when TGF-α mRNA and EGF-r protein were detected. In the unaffected mucosa of CD, the intensity of TGF-α immunoreactivity was similar to that of controls in the right colon but stronger (P 0.05) in the left colon. There was no TGF-α overexpression in dysplastic regions. In conclusion, in active IBD disease, the decreased TGF-α protein amount seems not only related to epithelial cell loss but reflects a down-regulation at least at the protein level. We speculate that TGF-α does not play a role within the active stage but may be implicated later in the repair process.

Effect of Substance P on Histamine Secretion from Gut Mucosa in Inflammatory Bowel Disease

Background: Mast cell hyperplasia in the gut is a feature of inflammatory bowel disease (IBD), but the role of mast cells in this disease is still unclear. Since mast cell-nerve interactions might have some impact on intestinal inflammation, the present study investigated whether the neuropeptide substance P causes histamine secretion from human gut mucosal mast cells. Methods: Four hundred and eighteen colorectal endoscopic samples from 20 patients with IBD and 10 controls were studied. Colorectal biopsy samples were cultured in an oxygenated medium for spontaneous histamine release or were stimulated with substance P, anti-human immunoglobulin E, and a combination of substance P and anti-human immunoglobulin E. Histamine release was measured using a highly sensitive and specific radioimmunoassay. Results: Substance P failed to induce mast cell activation in histologically normal mucosa from controls. In contrast, mucosal specimens taken from inflamed IBD tissue or from uninvolved Crohn disease tissue showed a considerably enhanced rate of histamine secretion towards substance P, alone or in combination with anti-IgE. Unaffected mucosa with ulcerative colitis appeared insensitive towards substance P. Conclusions: The neuropeptide substance P was shown to preferentially enhance mucosal mast cell mediator secretion in active IBD. Thus, it appears likely that mast cell-nerve interactions are involved in as yet uninvestigated neurovegetative histamine-releasing processes of the gut in IBD.

A quantitative immunohistochemical evaluation of inflammatory cells at the affected and unaffected sites of inflammatory bowel disease.

Levels of T lymphocytes, histiocytes and mast cells have been reported to be increased in the affected mucosa of Crohn's disease (CD) and ulcerative colitis (UC), but the colorectal distribution of these cells is not fully understood. We hypothesized that differences in cell densities between CD and UC would be characteristic, not only in the affected, but also in the unaffected mucosa. The aims of the present study were to clarify whether there were any differences in cell densities in CD, UC and infectious colitis (IC) in the affected mucosa and between CD and UC in the unaffected mucosa. Using mouse monoclonal antibodies recognizing memory T cells (OPD4), cytotoxic/suppressor T cells (C8/144B), histiocytes (PG-M1) and mast cells (AA1), we evaluated mucosal cell densities in biopsy specimens from both endoscopically affected and unaffected sites of CD (n = 12) and UC (n = 15) and from affected sites of IC (n = 10). Ten normal controls were also examined. At affected sites, all cells were significantly more abundant in UC than in the other conditions, except that the density of PG-M1+ in CD was similar to that seen in UC. Although the densities of OPD4+ and C8/144B+ cells at unaffected sites were slightly higher in both CD and UC and in UC, respectively, there was no significant difference in cell densities between CD and UC. The ratio of OPD4+ cell density at affected sites to that at unaffected sites was appreciably higher in UC than in CD. The results suggest that a common feature of UC and CD is an increase in PG-M1+ cells at the affected mucosa but that the other inflammatory cells studied are more abundant, particularly in UC, and that the difference between UC and CD is conspicuous when comparing the OPD4+ cell density of the affected mucosa with that of the unaffected mucosa.

Telomere shortening in the colonic mucosa of patients with ulcerative colitis.

Telomere length in human somatic cells gradually decreases with the number of cell divisions and is regarded as a marker of somatic cell turnover. Mucosal cells of the affected colon show rapid turnover in individuals with active ulcerative colitis (UC). Telomere length was determined by Southern blot analysis of terminal restriction fragments (TRFs) from the colonic mucosa of 17 patients with UC in remission, two of whom showed dysplasia, and 17 control subjects without colitis. For each individual, mean TRF length was compared between rectal mucosa and unaffected cecal mucosa. The mean TRF length of the rectal mucosa was significantly less than that of cecal mucosa in UC patients (7.87 +/- 0.36kb versus 8.77 +/- 0.21 kb; P = 0.0015, Wilcoxon signed rank test), whereas no significant difference was detected in the control subjects. The extent of telomere shortening was 10.6 +/- 3.35% in UC patients, compared with 0.8 +/- 0.64% in noncolitis controls (P = 0.0024, Mann-Whitney U-test). Four UC patients, two of whom had dysplasia, showed telomere shortening of more than 20% in the rectal mucosa. These observations suggest that telomere shortening in the colonic mucosa of individuals with UC may represent the history of mucosal inflammation during disease of long duration, and that it may contribute to aneuploidy in UC.

Transcript dosage effect in familial adenomatous polyposis: Model offered by two kindreds with exon 9 APC gene mutations

Analysis of genotype-phenotype correlations in familial adenomatous polyposis (FAP) patients demonstrated that the phenotypic heterogeneity of FAP is partly related to the mutation site. We investigated the molecular basis for the difference in severity of colorectal disease observed comparing FAP patients from two kindreds with neighbouring germline mutations in exon 9 of the APC gene. Patients from one kindred presented with a attenuated form of FAP, characterized by a low number of colorectal adenomas (up to 22). In FAP patients from this kindred, the APC gene mutation was localized at codon 367, in the portion of exon 9 that is alternately spliced. This is expected to result in the splicing-out of the mutation site in a fraction of mRNA molecules and in the residual production of wild-type transcripts from the mutant APC allele. Patients from the other kindred manifested a FAP phenotype characterized by hundreds of colorectal adenomas (320 to >500). In these patients, the APC gene mutation abolished the donor site of exon 9a, used in both alternately spliced isoforms of the exon. The analysis of the relative levels of mutant and wild-type transcripts in unaffected colonic mucosa demonstrated that the mutant allele was not expressed. The model offered by our FAP patients with neighbouring exon 9 APC mutations supports the view that in addition to the mutation site, the type of mutation and transcript dosage effects contribute to the heterogeneity of disease phenotypes. Hum Mutat 11:197–201, 1998. © 1998 Wiley-Liss, Inc.

Universal Skew of T Cell Receptor (TCR) Vβ Usage for Crohn's Disease (CrD)

It would be of clear interest and importance to identify T cell populations which correlate with the initiation of some T cell-mediated diseases; however, it is difficult to observe the initial response of T cells in these diseases because of modification due to immunosuppressive treatment. We investigated T cell receptor (TCR) Vβ usage in both affected and unaffected mucosa from 16 patients with active Crohn's disease (CrD), undergoing nutritional therapy without any immunomodulatory medications. Semiquantitative reverse transcriptase-polymerase chain reaction showed increased expression of Vβ12 and 13 in the entire mucosa of CrD but not in the controls. This was confirmed by introducing a random cloning method. Such skewing was observed primarily in CD4+lamina propria lymphocytes. DNA sequence analysis demonstrated a striking clonal expansion of Vβ12 T cells, but the dominant clones were not identical in the patients. These findings suggest the importance of superantigen as well as specific T cell response in the pathogenesis of CrD.

Colonic retinoblastoma protein and proliferation in cancer and non-cancer patients.

Both suppressor oncogene and proliferative activity are believed to indicate colon cancer risk. The retinoblastoma (Rb) gene is a suppressor oncogene affecting cell differentiation. Retinoblastoma gene inactivation is associated with tumour development. However, the relation of the Rb protein to cell proliferation and colon tumour formation is unknown. Retinoblastoma protein quantity was correlated with proliferative activity in flat, unaffected mucosa specimens from 36 cancer patients, 21 non-cancer control subjects and in 29 tumour tissue samples from cancer patients. Nuclear Rb protein was measured by using automated CAS-200 image analysis of monoclonal antibody labelled frozen sections from fresh, surgically removed tissue. All colon cells within 15 whole crypts were imaged. Proliferative activity was also measured by using analysis with Ki-67 monoclonal antibody. Retinoblastoma protein content correlated directly with proliferative activity in flat mucosa of non-cancer control subjects (r = 0.63; P < 0.001; n = 21). A significant correlation was also found in flat mucosa specimens of non-metastatic (Duke's stages A and B) cancer patients (r = 0.52; P < 0.01; n = 22). However, Rb protein did not correlate with proliferation in flat mucosa from metastatic (Duke's stages C and D) cancer patients (r = 0.03; NS; n = 14) or in cancer tissue (r = 0.068; NS; n = 29). Mucosal Rb protein in the colon normally increases as proliferation increases. Dissociation between Rb protein and colon proliferation may occur in flat mucosa in patients with a higher risk of metastatic tumour growth. Future studies comparing Rb protein quantity and proliferative activity may help identify high-risk colon cancer patients.

Microsatellite instability in early gastric cancer

Microsatellite replication errors (RERs), consisting in random tumour-associated allele contractions or expansions, represent a frequent genetic alteration in gastric cancer and appear to be associated with important clinicopathologic parameters. To verify the role of microsatellite instability in the initial phases of gastric carcinogenesis, we analysed the status of II microsatellites in paired microdissected samples of tumour and unaffected mucosa from 30 cases of early gastric carcinoma. Fifteen tumours (50%) demonstrated RERs: these included 7 cases with RERs at one locus and 8 cases with RERs at 2 or more loci. Cases with 2 or more RERs were more frequent among intramucosal tumours, compared to tumours with submucosal spread (43% vs. 12%) and among tumours staged T1NOMx, compared to tumours staged T1N1Mx (35% vs. 0%). RER-positive microsatellite typings were statistically more frequent among tumours with intramucosal extension, lower stage (T1NOMx) and excavated growth pattern (macroscopic type III), compared to tumours with submucosal extension, higher stage (T1N1Mx) and elevated, flat or depressed growth patterns (macroscopic types IIa-IIb-IIc respectively). The above findings indicate that microsatellite instability occurs early in the progression of sporadic gastric cancer and tends to be associated with good prognostic indicators.

Phenotypic analysis of intestinal non-inflamed mucosa in Crohnʼs disease

The objective of this study was to examine mononuclear cell subpopulations and evidence of cellular activation in unaffected jejunal mucosa in Crohn's disease. A cross-sectional study was performed in patients with Crohn's disease from the ambulatory unity of the University Hospital, UFRJ. Mucosal samples from 20 patients with Crohn's colitis or ileitis were obtained by peroral jejunal biopsy. Patients with jejunal involvement or pregnant women were excluded from the study. Specimens were analysed histologically and by indirect immunoperoxidase method using anti-monoclonal antibodies to CD2, CD4, CD8, CD25, CD45RO, RFDR1, RFD1 and RFD7 by two 'blind' observers. Seven patients with non-inflammatory bowel disorders and two healthy volunteers were studied as controls. Lamina propria CD2-positive (CD2+) cells were reduced in Crohn's disease (P < 0.004) whether clinically active (P < 0.02) or clinically inactive (P < 0.008). CD4+ and CD8+ cells were also reduced in Crohn's disease (P < 0.003), whereas the CD4:CD8 ratio did not differ from that in controls. CD25+, CD45RO+ and HLA-DR+ cells were not significantly increased in patients with Crohn's disease. RFD7+ cells were decreased in Crohn's disease (P < 0.02), whereas RFD1+ cells were not significantly different from the control group. No evidence of cellular activation was found in the unaffected mucosa of Crohn's disease. The reduction in T-cell and macrophage-like cell numbers may result from cell migration to inflamed areas. It is also possible that this finding represents a primary defect which may have a role in the pathogenesis of Crohn's disease.

Unaffected intestinal mucosa of Crohn's disease (CD) produces increased levels of interleukin (IL) 1 β and tumor necrosis factor α (TNF): [formula omitted]1,3,4 Ch. Wittersheim 1, S. Dumont 4, Ch Muller 4, L. Thiry 2, R. Baumann 1, P. Poindron 4, B. Duclos 1,3. Depts of Gastroenterology 1 and Surgery 2 Hopital de Hautepierre and INSERM U 381 3 Strasbourg;

Unaffected intestinal mucosa of Crohn's disease (CD) produces increased levels of interleukin (IL) 1 β and tumor necrosis factor α (TNF): [formula omitted]1,3,4 Ch. Wittersheim 1, S. Dumont 4, Ch Muller 4, L. Thiry 2, R. Baumann 1, P. Poindron 4, B. Duclos 1,3. Depts of Gastroenterology 1 and Surgery 2 Hopital de Hautepierre and INSERM U 381 3 Strasbourg;

Abnormal leukotriene C4 released by unaffected jejunal mucosa in patients with inactive Crohn's disease.

The mucosal release of inflammatory mediators is enhanced in active inflammatory bowel disease. This study examines whether leukotriene C4 production occurs in apparently unaffected segments of the gut. The intraluminal release of leukotriene C4 was determined by jejunal perfusion in seven healthy controls, in nine patients with chronic ulcerative colitis, and in 13 patients with Crohn's disease (six with ileal disease, and seven with only colonic). All patients were in clinical remission and none of them had evidence of jejunal involvement. Mild intraluminal irritation with a 2.5 mmol/l deoxycholic acid solution was induced to stimulate local inflammatory mechanisms. The release of DNA (a marker of mucosal desquamation) and prostaglandin E2 (PGE2) was simultaneously measured. Jejunal release of DNA was higher in Crohn's disease patients than in ulcerative colitis or healthy controls. Basal release of PGE2 was similar in the three groups of patients. Basal release of leukotriene C4 was considerably enhanced, however, in Crohn's disease patients compared with healthy controls. In ulcerative colitis patients, basal leukotriene C4 release was non-significantly different from controls. Bile acid perfusion stimulated PGE2, leukotriene C4, and DNA release in all groups studied, but leukotriene C4 release was significantly higher in Crohn's disease patients. It is concluded that in inactive Crohn's disease there is an enhanced intraluminal release of leukotriene C4 in apparently unaffected segments of proximal small bowel, which may reflect fundamental changes in the function of the gut mucosal barrier.

Human colorectal tumour infiltrating lymphocytes express activation markers and the CD45RO molecule, showing a primed population of lymphocytes in the tumour area.

This study investigated the phenotype of freshly isolated human tumour infiltrating lymphocytes (TIL) from 14 patients with colorectal tumours, and compared them with lymphocytes derived from the lamina propria of the unaffected mucosa and with lymphocytes derived from peripheral blood of the same patients. It was found that TIL expressed the activation markers CD25 and HLA-DR to a higher extent than the peripheral blood lymphocytes (p = 0.01), and that both lamina propria lymphocytes and TIL preferentially expressed the CD45RO + phenotype, associated with memory cells, in contrast with peripheral blood lymphocytes [corrected]. Both lamina propria lymphocytes and TIL contained few natural killer (NK) cells (CD3-CD56+) compared with peripheral blood lymphocytes (p = 0.001), and this was reflected in the cytotoxicity assays. After 1 to 2 weeks in culture with interleukin-2 100 U/ml, lymphocytes from all three compartments had a high cytolytic activity against all targets tested, consistent with the lymphokine activated killer cell phenomenon. No increase in the number of NK cells was noted after culture, but 20-30% of the T cells now coexpressed the CD56 molecule. This was most prominent in the CD8+ subset, but lymphokine activated killer cell activity was found in both CD4+ and CD8+ subsets. Possible tumour escape mechanisms are discussed.

Collagenase and stromelysin in recurrent aphthous ulcers (RAU)

Six patients with recurrent aphthous ulcers were studied for the presence of matrix metalloproteinases (MMP) 1, 3, and 8 in the lesions and in the clinically unaffected control mucosa obtained from the opposite side. MMP-type specific antisera were applied in the avidin-biotin-peroxidase complex staining method. Neutrophil-type collagenase (MMP-8) was found intracellularly in the connective tissue under the necrotized epithelium, and also laterally to the ulcer in association with the basement membrane. Fibroblast-type collagenase (MMP-1) and stromelysin (MMP-3) were found in the epithelial cells adjacent to the ulcerous lesion. They were found also in the endothelium of capillary blood vessels and postcapillary venules and also in some macrophage- and fibroblast-like mononuclear cells in the lamina propria laterally to the ulcer. A small number of MMP-1 and MMP-3 positive cells were noted in the control biopsies obtained from the clinically uninvolved control mucosa. These findings suggest regional differences in the distribution of the two main collagenases, implying distinct roles in tissue destruction and remodeling.

Eosinophils in nasal polyps and nasal mucosa: An immunohistochemical study

Immunohistochemical staining was performed at the time of endoscopic sinus surgery (ESS), after 6 months, and after 1 year on nasal polyps and biopsy specimens of the macroscopically unaffected mucosa of the middle and inferior turbinate bones of 46 patients with nasal polyps. During the follow-up period the patients were treated with topical corticosteroids. At time of ESS significantly more BMK13 + and EGI + (pan eosinophil markers) and EG2 + (activation marker) eosinophils were found in the polyps than in the macroscopically unaffected mucosa of the middle and inferior turbinate bones of the patients. In the middle and inferior turbinate bones of 10 healthy subjects no EG2+ (activated) eosinophils were detected, whereas low-to-moderate numbers of BMK13 + and EGl + eosinophils were seen in these specimens. This emphasizes that eosinophils play a role in the pathogenesis of nasal polyps. Compared with numbers at ESS, after 6 months and 1 year of follow-up, lower numbers of BMK13 +, EGl +, and especially of EG2 + eosinophils were found in recurrences of polyps and in the macroscopically unaffected mucosa of the middle and inferior turbinate bones of the patients. The decrease in number of EG2+ (activated) eosinophils is an indication of a reduced local inflammatory reaction, and could be an important factor in postponement of recurrences of nasal polyps.