Morphometric studies in rectal biopsy specimens from patients with ulcerative colitis: effect of oral 5 amino salicylic acid and rectal prednisolone treatment

Germinated barley foodstuff ameliorates inflammation in mice with colitis through modulation of mucosal immune system

OBJECTIVE

Germinated barley foodstuff (GBF) is a prebiotic product made from malt which contains glutamine-rich protein and hemicellulose-rich fiber. Although GBF has been observed to attenuate colonic mucosal inflammation and bowel movements in ulcerative colitis, both experimentally and clinically, the details of the immune response remain elusive. The aim of this study was to investigate the effects of GBF on the colonic epithelium immune response in a CD45RB(high) T cell chronic colitis model.

MATERIAL AND METHODS

Colitis was induced by transferring CD4+ CD45RB(high) T cells to severe combined immunodeficiency (SCID) mice (control n=8, GBF n=8) and the effects of GBF on the colitis were evaluated. The evaluation included measurement of body-weight, occult blood tests, histological examination, mucosal cytokine reverse transcription-polymerase chain reaction (RT-PCR) analysis (interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta)) as well as IL-6 measurements.

RESULTS

Seven weeks after transferring the above cells, body-weight loss and occult blood were significantly reduced in the mice that had been fed with GBF. In these mice, there were also significant reductions in IFN-gamma mRNA expressions and IL-6 in the colonic mucosa, as compared with the control group. GBF also significantly attenuated, mucosal damage and mucin positive goblet cell depletion. Conversely, TGF-beta expression significantly increased in the GBF group, compared with the control group.

CONCLUSIONS

In this preliminary study using an experimental model in which colitis was induced by transferring CD4+ CD45RB(high) T cells to SCID mice, GBF reduced inflammation by modulating the colonic microflora.

[Ulcerative colitis with segmental involvement]

INTRODUCTION

Ulcerative colitis is a chronic inflammatory disease affecting areas of the colon or the full length. From the endoscopic point of view, ulcerative colitis presents lesions that stretch continuously from the rectum to variable colon segments, a characteristic that is of great value when distinguishing it from Crohn's disease. Continuous involvement, without healthy patches, justifies ending endoscopic exploration once the distal end of the lesion has been reached.

OBJECTIVE

To retrospectively study the frequency of segmental lesions in the colonoscopies performed in patients with ulcerative colitis.

METHODS

Diagnosis of ulcerative colitis and proctitis was established by clinical, endoscopic, histologic, analytical, and radiological criteria. The indication and number of endoscopies was made on the basis of the clinical criteria of diagnosis, acute episodes, refractoriness or dysplasia screening. The extent of the examination also depended on clinical criteria: the severity of the episode, tolerance to colonoscopy or the degree of cleansing.

RESULTS

A total of 155 coloscopies were performed. In 113 colonoscopies (73%) the distal end of the lesion was reached and in 70 (45%) the cecum was reached. Of the 80 patients, 27 (33%) presented ulcerative proctitis at diagnosis. Nine of the 80 patients (11.3%) biopsies were performed in healthy colonic patches, which confirmed histological normality. Six of the 9 patients were receiving no treatment. In all patients except two, the cecum was reached in one or more of the colonoscopies. The distribution of the segmental lesions varied but these were mainly found in the periappendicular region and in the cecum in 6 of the 7 patients in whom the cecum was reached. Of the 80 patients, endoscopic evidence of rectal sparing was found in 5 (6.3%); of these, 4 were receiving systemic or topical treatment. Histological analysis confirmed the absence of inflammatory lesions in these patients. The only patient who was not receiving treatment presented microscopic lesions compatible with ulcerative colitis.

CONCLUSIONS

Endoscopic segmental lesions in ulcerative colitis were present in 11.3% of patients. Segmental lesions were most frequently found in the cecum and periappendicular region. Endoscopic and histologic evidence of rectal sparing may be the result of systemic or topical treatment.

Histopathological and morphometric analyses of late rectal injury after irradiation

The aim of the present study was to assess and quantify changes in the structural components of the rectal wall after irradiation with varying single doses of x-rays. A total of 70 CDF1/Bom male mice were irradiated at a selective 1.5 cm of the distal rectum with varying single doses of 0-30 Gy. At 32 weeks postirradiation the mice were sacrificed and the rectum was removed. Sampling of the specimens was based on unbiased stereological principles using systematic random sampling. Vertical tissue sections were used to estimate mucosal surface area density and to measure the thickness and volume fraction of the different intestinal wall layers. The surface area density decreased with increasing dose (p<0.02) due to pronounced injury of the crypts and mucosal morphology. The thickness and the volume fraction of the submucosa were significantly increased in the 20, 25 and 30 Gy treatment groups (p<0.0001 and p<0.0001), whereas the thicknesses of the mucosa, the lamina muscularis propria and the serosa did not change after irradiation. It is concluded that irradiation causes histopathological changes in the rectal mucosa and submucosa, and changes in the thickness of the submucosal intestinal layer. These changes were found to be dose-dependent.

An immunohistochemical study of histiocytic ulcerative colitis in boxer dogs

Histiocytic ulcerative colitis (HUC) is an inflammatory bowel disease (IBD) that occurs predominantly in dogs of the boxer breed. The lesions are characterized by mucosal ulceration and mixed inflammatory cell infiltrate that includes the presence of periodic acid-Schiff (PAS)-positive macrophages. However, the phenotype of the inflammatory cells has not been characterized further. In the present study, immunohistochemistry and computer-aided morphometric analysis were used to define populations of leucocyte subsets in the colon of 14 boxer dogs with HUC. Biopsies from six of these dogs included both lesional and non-lesional regions. Colonic tissue from 11 dogs of various breeds without evidence of gastrointestinal disease served as controls. In HUC lesions there were significantly more IgG(+), IgG3(+), IgG4(+)plasma cells, CD3(+)T cells, MHC class II(+)cells, L1(+)cells and PAS(+)cells in the lamina propria than in both control colon and non-lesional colonic regions of affected dogs. In the epithelial compartment, goblet cells were significantly decreased in HUC lesions compared to both control and non-lesional HUC colon, and intensity of enterocyte MHC class II expression was significantly increased. These observations are similar to those documented in human IBD, especially ulcerative colitis, and suggest an important role for the mucosal immune system in the pathogenesis of canine HUC.

Diagnostic difficulty arising from rectal recovery in ulcerative colitis

AIMS

To ascertain whether the dogma that a normal rectal biopsy precludes a diagnosis of ulcerative colitis is correct.

METHODS

Rectal biopsy specimens from a prospective group of 24 asymptomatic patients, with an established diagnosis of ulcerative colitis, were examined in a blinded study alongside 10 normal rectal biopsy specimens from an age and sex matched patient cohort without ulcerative colitis. Each biopsy specimen was assessed by three pathologists and ascribed to one of four categories: normal; borderline abnormality (one or more minor nonspecific abnormalities which, when combined, did not fulfil the minimal acceptable criteria for a diagnosis of ulcerative colitis); minimal features of chronic ulcerative colitis; and unequivocal ulcerative colitis.

RESULTS

Two patients with ulcerative colitis had normal biopsy specimens; nine specimens were categorised as borderline abnormality, one as showing the minimal changes of chronic ulcerative colitis, and 12 as having the typical changes of chronic ulcerative colitis. Thus, 11 (46%) of the 24 patients had a rectal biopsy specimen that was devoid of the acceptable attributes on which a diagnosis is established, despite a confident previous diagnosis. Ten of these 11 cases had disease limited to the rectum. Review of all previous histological biopsy specimens (n = 164) and clinical data, including drug treatment, failed to identify any attributes that might be prognostic markers for future rectal mucosal healing.

CONCLUSIONS

A normal rectal biopsy specimen, though uncommon, may occur in longstanding colitis. Moreover, in 46% of these asymptomatic but established cases the degree of healing may preclude a diagnosis of ulcerative colitis without comprehensive clinical and radiological details. Pathologists need to be aware of this minimal end of the spectrum of disease.

A morphometric study of histological variations during cellular differentiation of normal human colorectal epithelium

Quantifiable variations existing in the colorectal crypt during cellular differentiation were detected by using simple computer-aided morphometric techniques applied to routinely prepared H&E stained and semithin toluidine blue stained sections of normal colonic mucosa. Generally, most of the morphometric parameters including nuclear volume, nuclear volume weighted mean volume, cytoplasmic volume, cellular volume, nuclear axial ratio (a/b), mean nuclear diameter, nuclear shape factor (NSF) and nuclear maximum angle (Agmax) showed an increasing trend between basal and surface segments. Conversely, the nuclear-cytoplasmic (N/C) ratio, NSF and nuclear circularity index (NCI) decreased between these segments. Epithelial cells in the basal segment had the highest N/C ratio and the lowest cell volume due to their low volumes of cytoplasm. However, substantial increases of cytoplasmic volume occurred in the intermediate segment, thereby expanding the cell volume to 136% of that of the basal segment cell. Data for a/b, NSF, NCI and Agmax suggest that the epithelial nuclei were more ellipsoidal in shape and were aligned more perpendicular to the basement membrane as they reached the surface epithelium. Numerical densities for epithelial cell nuclei were highest in the basal segment, indicating more nuclear profiles at this region per unit area or volume. This also suggested that the basal segment was the active proliferating zone. Such observations agree with previously reported cell kinetic and autoradiographic studies.

Is topical therapy necessary in acute distal colitis? Double-blind comparison of high-dose oral mesalazine versus steroid enemas in the treatment of active distal ulcerative colitis

Thirty-seven patients suffering an attack of acute distal ulcerative colitis of mild or moderate severity were randomized in a double-blind, double-dummy fashion to receive either 800 mg oral mesalazine four times daily (18 patients) or steroid enemas twice daily (19 patients) for 4 weeks. Both treatments were well tolerated with no adverse effects. Three patients in each group were withdrawn because of clinical deterioration but both treatments produced significant clinical improvement with decreases in stool frequency and scores for urgency, bleeding and tenesmus. There were no significant differences between the treatments although there was a slight trend in favour of the enemas for reduction in rectal bleeding. Activity of the colitis as graded at sigmoidoscopy also decreased significantly with both treatments and there were corresponding improvements in histological parameters of inflammatory activity assessed with the aid of a computerized morphometric system. Little correlation was seen between clinical, sigmoidoscopic and histological changes.