Lymphatic vessels in the colonic mucosa in ulcerative colitis

In the normal colonic mucosa, lymphatics are found only in a narrow band associated with the muscularis mucosae and are absent from the rest of the mucosa. This study examined whether this arrangement of lymphatics is also valid in ulcerative colitis. Histological sections of colon from 15 long-standing cases were investigated with antibodies against CD 34 (negative for lymphatics; positive for blood vessel endothelium) and, in selected cases, podoplanin (positive for lymphatic endothelium; negative for blood vessel endothelium). Whereas inflammation of the mucosa was not associated with changes in lymphatics, an increase in intramucosal lymphatics was seen when the pathological changes included widening of the muscularis mucosae or penetration of the mucosa by muscle fibers, filiform changes in the mucosa, and hyperplasia of the mucosa-associated lymphoid tissue (MALT). In specimens with epithelial dysplasia, an association between the dysplastic epithelium and ectatic and quantitatively increased lymphatics was observed. With superimposed carcinoma, no relationship between the malignant tumor and lymphatics was identifiable. Nevertheless, pre-existing lymphatics in the muscularis mucosae were involved in lymphatic tumor spread. The immunohistochemical findings demonstrated that lymphatics occurred in all areas of the mucosa in ulcerative colitis (or, in effect, at sites which were not normally found under physiological conditions) and in regions that favored lymphatic tumor dissemination. Whether these lymphatics were actually involved in metastasis remains to be defined.     

Bacterial invasion into the colonic mucosa in ulcerative colitis

Abstract This study investigated interactions between mucosal lesions and bacterial invasion in ulcerative colitis using the acridine-orange staining method. In all 16 cases of ulcerative colitis, the mucosa was found to be invaded by small rods and cocci. In five of 10 controls, bacteria were seen only adhering to the mucosa and no bacteria were detected in the five remaining cases. It is suggested that the presence of bacteria in the colonic mucosa may be a factor responsible for the persistence or aggravation of ulcerative colitis.     

Tissue-type plasminogen activator of colonic mucosa in ulcerative colitis

Microvascular endothelial alterations are thought to be a crucial step for development of hemorrhagic changes in various pathological states. In this study, we determined the activity and amount of tissue-type plasminogen activator (t-PA) in the biopsy specimens from sigmoid colon of patients with ulcerative colitis to evaluate endothelial alterations and vascular changes of permeability. The results of this investigation revealed that mucosal amount of t-PA in the active stage of ulcerative colitis was two- to threefold higher than in healthy controls, while t-PA levels in plasma samples showed no remarkable differences among the groups. Increased t-PA activity appeared to correlate well to the degree of inflammation of colonic mucosa, and t-PA amount was still increased in the inactive stage. The present study indicates that t-PA determination in colonic biopsy specimens may be useful for the evaluation of clinical activity of ulcerative colitis in terms of the mucosal microvascular endothelial changes.This work was supported by the grant from the Japanese Ministry of Education No. 63440033 and by the grant from Keio University, School of Medicine.     

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 ± 0.36 kb 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. (Received May 6, 1997; accepted Sept. 26, 1997)     

Urocortin 1 in colonic mucosa in patients with ulcerative colitis

Ulcerative colitis (UC) is characterized by a long-standing chronic inflammation of the bowel with intermittent periods of exacerbation and remission. Its acute exacerbation appears to be related to various stresses. Urocortin 1 (Ucn1) may play important roles in integrated local responses to stress. We therefore examined local production of Ucn1 in patients with UC by immunohistochemistry and mRNA in situ hybridization. Ucn1 immunoreactivity was predominantly detected in lamina propria plasma cells and enterochromaffin cells. In UC patients without glucocorticoid treatment, Ucn1-positive cells and plasma cells increased in proportion to the severity of inflammation (P < 0.0001). Ucn1-positive cells significantly increased in UC patients with advanced inflammatory grades, compared with a control group (P < 0.0001) and nonspecific colitis group (P < 0.0001). In glucocorticoid-treated patients, Ucn1-positive cells were significantly lower in number, compared with the nonglucocorticoid-treated group. Ucn1 mRNA was expressed in lamina propria plasma cells, and both corticotropin-releasing factor(1) and corticotropin-releasing factor(2(a)) mRNAs were also partially coexpressed in these cells and macrophages. The present study showed that Ucn1-positive cells were correlated with the severity of inflammation in colonic mucosa with UC, and glucocorticoid treatment decreased these cells. Ucn1 therefore may act as a possible local immune-inflammatory mediator in UC.     

Effect of butyrate enemas on the colonic mucosa in distal ulcerative colitis.

Short-chain fatty acid irrigation has been shown to ameliorate inflammation in diversion colitis. In this study the effect of butyrate enemas was tested in 10 patients with distal ulcerative colitis who had been unresponsive to or intolerant of standard therapy for 8 weeks. They were treated for 2 weeks with sodium butyrate (100 mmol/L) and 2 weeks with placebo in random order (single-blind trial). Before and after treatment, clinical symptoms were noted and the degree of inflammation was graded endoscopically and histologically. Rectal proliferation was assessed by autoradiography. After butyrate irrigation, stool frequency (n/day) decreased from 4.7 +/- 0.5 to 2.1 +/- 0.4 (P less than 0.01) and discharge of blood ceased in 9 of 10 patients. The endoscopic score fell from 6.5 +/- 0.4 to 3.8 +/- 0.8 (P less than 0.01). The histological degree of inflammation decreased from 2.4 +/- 0.3 to 1.5 +/- 0.3 (P less than 0.02). Overall crypt proliferation was unchanged, but the upper crypt-labeling index fell from 0.086 +/- 0.019 to 0.032 +/- 0.003 (P less than 0.03). On placebo, all of these parameters were unchanged. These data support the view that butyrate deficiency may play a role in the pathogenesis of distal ulcerative colitis and that butyrate irrigation ameliorates this condition.     

Squamous-cell metaplasia with severe dysplasia of the colonic mucosa in ulcerative colitis

Squamous-cell metaplasia in the colonic mucosa alone in ulcerative colitis has not been reported before. A case is presented where such changes were found in relation to strictures in the transverse and sigmoid colon in a male, aged 41, with a 27-year history of ulcerative colitis.     

Protein kinase C activity of colonic mucosa in ulcerative colitis.

Protein kinase C (PKC) activity was measured in the inflamed colonic mucosa of 24 patients with ulcerative colitis and in the normal colonic mucosa of 10 patients with other benign diseases. The particulate fraction activity in ulcerative colitis mucosa was significantly increased compared with that of normal mucosa (320 +/- 47 versus 200 +/- 30 pmol/min/mg protein; p less than 0.05). Inflamed ulcerative colitis mucosa also showed significantly increased total PKC activity in the particulate fractions compared with normal mucosa (147 +/- 26 versus 37 +/- 8 pmol/min/mg tissue; p less than 0.05). Mucosal samples from ulcerative colitis patients were divided into 12 with mild and 12 with severe inflammation by histologic examination. The particulate PKC activity of severely inflamed mucosa was significantly lower than that of mildly inflamed mucosa (p less than 0.05). These results indicate that colonic inflammation in ulcerative colitis may be associated with altered cellular PKC activity.     

Glycoprotein composition of colonic mucosa. Specific alterations in ulcerative colitis

A micromethod has been developed to permit determination of human colonic mucin glycoprotein heterogeneity in biopsy specimens of colonic mucosa. Sialic acid, galactose, and galactosamine residues of oligosaccharide side chains from colonic glycoproteins were radiolabeled by combined metaperiodate and galactose oxidase treatment followed by sodium borotritide reduction. Mucin glycoproteins were separated from nonmucin components by mini-Sepharose 4B column chromatography. Subsequent chromatography of labeled mucin of normal controls (n = 15) on diethylaminoethyl-cellulose demonstrated at least six labeled mucin species. Labeled mucin species I-VI were found to cochromatograph with corresponding unlabeled mucin species prepared from large surgical specimens. An identical mucin profile was observed in normal biopsy specimens from rectum (n = 5), sigmoid (n = 10), transverse (n = 5), and ascending colon (n = 4). However, mucin profiles from sigmoid mucosa of patients with ulcerative colitis (n = 14) demonstrated a selective decrease in mucin species IV, which was also present in specimens from uninvolved proximal colon (n = 7). This finding persisted in patients who had a subsequent biopsy at times of clinical and histologic remission (n = 8). In addition, colonic mucin from samples of ulcerative colitis patients in remission had a relative decrease in mucin fraction III and an increase in fraction V when compared to patients with active disease. Normal mucin profiles were found in a variety of colonic disease controls including Crohn's (n = 9), ischemic (n = 4), infectious (n = 8), and radiation (n = 3) colitis. These observations indicate the presence of a relatively uniform mucin profile throughout the normal colon and substantiate the association of specific alterations in colonic mucin with ulcerative colitis.     

Bactericidal/permeability-increasing protein in colonic mucosa in ulcerative colitis.

BACKGROUND/AIMS: Increased mucosal concentration of bactericidal/permeability-increasing protein (BPI) has been shown in inflammatory bowel diseases. The purpose of the present study was to investigate the relationship between the mucosal concentration of BPI and the grade of mucosal inflammation in ulcerative colitis. METHODOLOGY: Samples of colonic mucosa from 12 patients with ulcerative colitis and from 8 control patients were studied. The concentration of BPI in tissue extracts was measured by a time-resolved fluoroimmunoassay. The concentration of BPI was compared between samples with histological inflammatory changes of different severity. BPI was localized in tissue sections by immunohistochemistry. RESULTS: The concentration of BPI was higher (p < 0.001) in samples of colonic mucosa from patients with ulcerative colitis (median: 3.2 micrograms/g, range: 0.3-22.6 micrograms/g) than in control samples (0.4 microgram/g, 0.1-0.6 microgram/g,). Moreover, the concentration of BPI was higher (p = 0.015) in samples with severe inflammation (2.5 mu/g, 0.3-22.6 micrograms/g) than in those with mild inflammation (0.5 mu/g, 0.3-2.5 micrograms/g). The concentration of BPI in mucosal samples correlated well with the degree of histological inflammation (Spearman R = 0.70, p = 0.01). BPI was localized in polymorphonuclear leukocytes in the mucosa and stroma of the colonic wall. CONCLUSIONS: The concentration of BPI is increased in the colonic mucosa of patients with ulcerative colitis. The increase in the concentration of BPI in colonic mucosa seems to be closely associated with the inflammatory activity of ulcerative colitis.     

Ectopic colonic mucosa in ulcerative colitis and in Crohn's disease of the colon

Colectomy specimens from 62 patients (22 with ulcerative colitis, 20 with Crohn's disease of the colon, and 20 with invasive adenocarcinoma [without inflammatory bowel disease]) were reviewed for the presence of ectopic colonic mucosa. One or more foci of ectopic colonic mucosa were found in 16 of the 22 specimens (72 per cent) with ulcerative colitis and in 11 of the 20 specimens (55 per cent) with Crohn's disease of the colon. None of the 20 specimens having adenocarcinoma (without chronic inflammatory bowel disease) had ectopic colonic epithelium. The presence of ectopic colonic mucosa was found to be dependent on the age of the patients (more frequent among younger patients) and on the number of sections per specimen. One adenocarcinoma in a case of long-standing ulcerative colitis had apparently originated in ectopic colonic mucosa. This study was supported by grants from the Karolinska Institute.     

Induction of experimental ulcerative colitis by Fusobacterium varium isolated from colonic mucosa of patients with ulcerative colitis

BACKGROUND: Bacteria are implicated in certain forms of model chronic colitis but the identity and role of bacteria in human ulcerative colitis (UC) are uncertain. AIMS: To isolate pathogenic bacteria from inflamed mucosa of patients with UC, to examine whether the bacteria have a toxin to Vero cells, and to determine whether the toxin induces UC-like lesions in animals. METHODS: Bacteria were isolated from UC patients and supernatants from cultures were filtered and tested for cytotoxicity to Vero cells. Bacterial cells producing the cytotoxic supernatants were examined by polymerase chain reaction for verotoxin genes. Culture supernatants of cytotoxic strains were examined by high performance liquid chromatography for organic acid concentrations. Mice were given enemas containing organic acid at the mean concentration in the supernatants of cytotoxic strains to ascertain whether colonic lesions appear in UC. RESULTS: Only supernatants from cultures of Fusobacterium varium killed Vero cells. Bacterial cells lacked verotoxin genes. Bacterial culture supernatants contained high concentrations of n-butyric acid and the mean concentration (32 mmol/l) was cytotoxic to Vero cells. Twenty four hours after mice were given enemas containing either butyric acid or F varium culture supernatants, colonic ulcers with crypt abscesses, inflammatory cell infiltration, and apoptotic changes were observed. CONCLUSIONS: Butyric acid in culture supernatants from cultures of F varium caused UC-like lesions in mice. This study indicates that F varium may be one of the elusive pathogenic factors in UC.