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PubMed1985

Scanning electron microscopic appearance of chronic ulcerative colitis with and without dysplasia.

This study was conducted to determine whether scanning electron microscopy of colonic mucosal biopsy specimens can help to detect dysplasia in patients with chronic ulcerative colitis. In the first phase of the study, using light microscopy as the standard for the diagnosis, the scanning electron microscopic appearance of specimens from patients with chronic ulcerative colitis and control patients was examined. Descriptive criteria were established to identify normal, atrophic, and dysplastic colonic mucosa. In the second phase, quantitative techniques were used to develop more objective criteria for the diagnosis of dysplasia in ulcerative colitis. Twenty-one coded colonic specimens from 11 patients were sequentially examined by scanning electron microscopy and by light microscopy. The three morphometric analyses performed on the surface epithelial cells were number of cells per unit area, number of microvilli per unit area, and percentage of microvilli with a normal width. The cell count and percentage of microvilli with a normal width were significantly reduced in the seven specimens with colonic dysplasia as compared with non-dysplastic tissues. Scanning electron microscopy may serve as an adjunct to light microscopy in the diagnosis of colonic dysplasia.

Atrophy↗
PubMed2004

Macroscopic, microscopic and biochemical characterisation of spontaneous colitis in a transgenic mouse, deficient in the multiple drug resistance 1a gene.

1 A novel animal model of spontaneous colonic inflammation, the multiple drug-resistant (mdr1) a(-/-) mouse, was identified by Panwala and colleagues in 1998. The aim of our study was to further characterise this model, specifically by measuring cytokines that have been implicated in inflammatory bowel disease (IBD) (IL-8 and IFN-gamma) in the colon/rectum of mdr1a(-/-) mice, and by determining the sensitivity of these, together with the macroscopic, microscopic and disease signs of colitis, to dexamethasone (0.05, 0.3 and 2 mg kg(-1) subcutaneously (s.c.) daily for 7 days). 2 All mdr1a(-/-) mice had microscopic evidence of inflammation in the caecum and colon/rectum, while control mice with the same genetic background did not. Significant increases in colon/rectum and caecal weights and also in cytokine levels (both IFN-gamma and IL-8) in homogenised colon/rectum were observed in mdr1a(-/-) mice compared to mdr1a(+/+) mice. 3 Dexamethasone reduced the increases in tissue weights and also microscopic grading of colitis severity, but had no effect on IFN-gamma or IL-8. 4 This study supports the similarity of the gastrointestinal inflammation present in mdr1a(-/-) mice to that of human IBD, in particular Crohn's disease. This has been demonstrated at the macroscopic and microscopic levels, and was supported further by elevations in colonic levels of IFN-gamma and IL-8 and the disease signs observed. The incidence of colitis was much higher than previously reported, with all mice having microscopic evidence of colitis. The limited variance between animals in the parameters measured suggests that this model is reproducible.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1979

Light and electron microscopic studies of antibiotic associated colitis in the hamster.

Lincomycin and its analogue, clindamycin, are capable of producing mild to severe colonic mucosal injury in humans (antibiotic associated colitis). Patients with the disorder may have severe diarrhoea, pseudomembranous plaques, confluent pseudomembranes, and/or a frank, diffuse haemorrhagic colitis. The present study was designed to assess the Golden Syrian hamster as an animal model for antibiotic associated colitis and to describe lesions seen in the animal model by light, transmission electron, and scanning electron microscopy. A colitis was produced in Golden Syrian hamsters by oral or parenteral administration of lincomycin, clindamycin, or N-demethyl clindamycin. Animals were killed at intervals and microscopic studies made of sequential morphological changes in the ileum, caecum, and colon. The microscopic lesions in the early stages of the disorder were abnormalities within the brush border, cellular oedema, and hyperaemia. Changes in the intracellular organelles were observed in more severely damaged epithelial cells. Epithelial hyperplasia resulted in the piling up of cells on the mucosal surfaces. In specimens with the most severe damage, complete loss of epithelium from the mucosal surface was observed. Pseudomembranous plaques were occasionally seen. Comparison of the clinical, gross, and histological features of the animal disease with the human disorder suggest that, although minor differences are present, the hamster model is suitable for experimental studies of antibiotic associated colitis.

Animals↗
PubMed2006

Autoimmune hepatitis in association with lymphocytic colitis.

Autoimmune hepatitis is a rare, chronic inflammatory disorder which has been associated with a number of other auto-immune conditions. However, there are no reports in the medical literature of an association with microscopic (lymphocytic) colitis. We report the case of a 53-year-old woman with several autoimmune conditions, including lymphocytic colitis, who presented with an acute hepatitis. On the basis of the clinical features, serology, and histopathology, we diagnosed autoimmune hepatitis. To our knowledge, this is the first report of autoimmune hepatitis in association with lymphocytic colitis, and lends support to the theory of an autoimmune etiology for lymphocytic colitis.

Biopsy↗
PubMed2003

Gross versus microscopic pancolitis and the occurrence of neoplasia in ulcerative colitis.

OBJECTIVE: The gross extent of ulcerative colitis (UC) is a recognized risk factor for the development of colitis-related dysplasia and colorectal cancer (CRC). The risk of neoplasia associated with the microscopic extent of colitis is unknown. The aim of this study was to describe the gross and microscopic extent of colitis in patients with UC-related dysplasia/CRC. METHODS: All patients who underwent colectomy at our institution between 1992-2001 with colitis-related dysplasia/CRC were identified. Histological sections from each colectomy specimen were reviewed for the microscopic extent of colitis and the location of all lesions with dysplasia/CRC. RESULTS: Thirty-six patients with colitis-related dysplasia/CRC were identified of whom 30 had slides available for review. Gross pancolitis was identified in 19 patients, though microscopic pancolitis was evident in all 30 patients. Among the 11 patients with only distal gross colitis, 4/15 neoplastic lesions were proximal to the area of gross involvement. CONCLUSIONS: UC-related neoplasia can occur in areas of the colon not grossly involved with colitis, though it did not occur in any patients without microscopic pancolitis. To devise rational cancer surveillance guidelines, further studies are needed to determine the risk of colitis-related neoplasia in patients with microscopic pancolitis but limited gross disease.

Adolescent↗
PubMed2001

CD4 T cells monospecific to ovalbumin produced by Escherichia coli can induce colitis upon transfer to BALB/c and SCID mice.

Although some animal models suggest an involvement of CD4 T cells reactive to luminal microbial antigen(s) for the pathogenesis of inflammatory bowel diseases (IBD), direct linkage between microflora-driven clonal expansion of CD4 T cells and the development of colitis has not been well studied. Here, BALB/c and SCID mice were given CD4 T cells purified from Rag-2(-/-) mice crossed to transgenic mice expressing TCR specific to ovalbumin (OVA) then administered with antibiotic-resistant Escherichia coli producing OVA (ECOVA) or LacZ (ECLacZ) via the rectum. The ECOVA-inoculated BALB/c and SCID mice developed a subacute colitis with microscopic features of distortion of crypt architecture, loss of goblet cells, and focal infiltration by mononuclear cells in the lamina propria (LP) and submucosa. Expanding OVA-specific CD4 T cells were detected in colonic follicles of mice with ECOVA. Early in colitis, OVA-specific CD4 T cells producing IFN-gamma predominate in the LP of the colon, which was followed by an emergence of OVA-specific CD4 T cells producing IL-4 and IL-10 at a later time point. Co-transfer of an IL-10-secreting OVA-specific CD4 T cell line prevented colitis. Thus, an expansion of CD4 T cells monospecific to OVA, an antigen non-cross-reactive to colonic tissue, can mediate both induction and inhibition of the colitis which was associated with hyperplasia of lymph follicles.

Administration, Rectal↗
PubMed2004

The emergence of Clostridium difficile as a pathogen of food animals.

Clostridium difficile causes pseudomembranous colitis in humans, usually after disruption of the bowel flora by antibiotic therapy. Factors mediating the frank disease include the dose and toxigenicity of the colonizing strain, its ability to adhere to colonic epithelium, the concurrent presence of organisms that affect multiplication and toxin production or activity, and the susceptibility of the host. Toxins A (an enterotoxin) and B (a cytotoxin) play the major role in pathogenesis and the detection of toxins in gut contents is the gold standard for diagnosis. Disease in horses takes the form of often-fatal foal hemorrhagic enteritis. Nosocomial, antibiotic-associated, disease is increasingly common in adult horses. Enteric clinical signs are reported in ostriches, companion animals and recently calves. Clostridium difficile colitis is now a common diagnosis in neonatal pigs in the USA and elsewhere. Clinical features include onset at 1-5 days of age, sometimes with dyspnea, mild abdominal distension and scrotal edema, and commonly with yellow, pasty diarrhea. There is mesocolonic edema grossly, with microscopic diffuse colitis, mucosal edema, crypt distension, epithelial necrosis and superficial mucosal erosion. Neutrophil infiltration of the lamina propria is common, and fibrin and numerous rod-shaped bacteria are observed on the surface. About two-thirds of litters and one-third of piglets will be affected (based upon positive toxin tests), although this appears to vary with the season. The case fatality rate is probably low if considering only direct effects of C. difficile infection. The significance of toxin-positive non-diarrheic pigs and the nature of the interaction of toxins A and B with enterocytes are unknown. Given the widespread occurrence of the disease, there is substantial effort to develop immunoprophylactic products.

Animals↗
PubMed2005

Irritable bowel syndrome and inflammatory bowel disease: interrelated diseases?

In the past inflammatory bowel disease (IBD), celiac disease and irritable bowel syndrome (IBS) were regarded as completely separate disorders. Now, with the description of inflammation, albeit low-grade, in IBS, and of symptom overlap between IBS and celiac disease, this contention has come under question. Is there true overlap between these disorders? Despite the limitations of available data one cannot but be struck by some areas of apparent convergence: IBD and celiac disease in remission, lymphocytic colitis and microscopic inflammation in IBS, in general, and, especially, in the post-infectious IBS category. The convergence between latent celiac disease and sub-clinical IBD, on the one hand, and IBS, on the other, appears, based on available evidence, to be somewhat spurious and may largely relate to misdiagnosis, a phenomenon which may also explain the apparent evolution of IBS into IBD in some studies. Similarities between IBS and lymphocytic colitis are more striking and less readily dismissed; as for IBS, well documented instances of progression of lymphocytic colitis to full-blown IBD are infrequent, suggesting a true separation between this disorder and classical IBD. Do IBS and lymphocytic colitis represent different responses to similar triggers? Will some of the 'inflamed' IBS subgroup be reclassified as part of the spectrum of lymphocytic colitis in the future? Will inflammation emerge as a common underlying factor in the pathogenesis of IBS? The answer to these and many questions must await further study of this fascinating area.

Environment↗
PubMed1985

[Secondary reconstruction of intestinal continuity following colectomy for ulcerative colitis].

In 37 patients with a clinically and microscopically confirmed ulcerative colitis the rectum was retained after subtotal (n = 29) or left-sided (n = 8) colectomy. In the following 1.6 years in 25 of the 37 patients the rectal stump was removed; in 9 of these cases a straight ileoanal anastomosis was constructed; after 4 years in 4 of the 8 surviving patients the anastomosis has been removed for various reasons. In 12 of 37 patients the rectum was preserved over 10.8 years only in 4 of these cases with rapidly decreasing protectitis the construction of an ileo-rectal anastomosis was possible.

Adult↗
PubMed1986

Differential diagnosis of Crohn's disease of the colon from ulcerative colitis: ultrastructure study with the scanning electron microscope.

Mucosal biopsies from patients with Crohn's disease and with ulcerative colitis were studied by scanning electron microscopy. Important abnormalities of the mucosal surface were found in both diseases. For Crohn's disease, the characteristic abnormality was loss of the regularity of the polygonal units, but with preservation of the mucosal integrity and of the normal mucosal design. For ulcerative colitis, the abnormalities were disorganization of the cells, signs of sloughing, and superficial erosions. Patients with Crohn's disease always had a significantly increased number of muciparous cells, while those with ulcerative colitis had obvious signs of decreased mucus production. The lesions of ulcerative colitis could be seen under the scanning electron microscope in mucosal areas that appeared normal endoscopically. We feel therefore that scanning electron microscopy of biopsy specimens from patients with inflammatory bowel diseases can be of great help in differential diagnosis.

Colitis, Ulcerative↗
PubMed1998

[Obstructive colitis: analysis of 7 patients].

The term "obstructive colitis" is defined by the presence of ulcero-inflammatory lesions in a colonic area proximal to a potentially obstructive lesion. Seven cases retrospectively identified during a 5-year period are here reported. They illustrate the clinico-pathological spectrum of this entity. Most patients were women, with a mean age of 66 years and with history of chronic underlying disease (diabetes mellitus and arterial hypertension). Abdominal distension and pain, as well as acute constipation were the main clinical symptoms. An adenocarcinoma predominantly located at the rectosigmoidal region accounted for the obstructive nature in 100% of cases. Macroscopically the colitis area was moderately dilated and there were single or confluent ulcers in the luminal surface. Characteristically, there was always a transitional preserved area between the obstruction and the colitis area. Microscopically, the mucosa was totally replaced by a granulation tissue with a relevant inflammatory infiltrate involving up to the muscularis propria. The cytometric study revealed and increase in the cell cycle (S-phase) and proliferation index, at the level of the obstructive lesion, with marked aneuploidy in cases with advanced neoplastic invasion. The role of mural hypoperfusion with localized ischemia in the pathogenesis is discussed. The similarities with other colonic inflammatory diseases are emphasized.

Aged↗
PubMed1994

Endoscopic features of chronic inflammatory bowel disease in childhood.

Flexible endoscopy, performed after oral bowel preparation and under moderate intravenous sedation, proves to be well tolerated, safe and highly effective in the diagnosis and management of children with IBD. At St Bartholomew's Hospital it is performed as the investigation of first choice, on the basis that it supplies colour documentation, histopathological and (where relevant) bacteriological evidence, which achieves certain confirmation or exclusion in almost every case and in the shortest possible time. Biopsies must always be taken, as mucosa of normal appearance can show either microscopic ulcerative colitis or Crohn's disease. When there are the characteristic 'aphthoid' ulcers, visual diagnosis of Crohn's disease is reasonably certain, particularly in early-stage disease, although amoebic and other infective causes of colitis can give misleadingly similar appearances. The endoscopist can usually inspect (and almost always biopsy) the terminal ileum, and can expect many children to show the prominent 'nodular lymphoid hyperplasia' which is essentially a normal finding-though sometimes misdiagnosed radiologically as being Crohn's deformity. However, it is important that radiological assessment by barium follow-through complements colonoscopy in view of the not infrequent cases of intestinal Crohn's disease in children where the proximal small intestine is involved, even if the colon and terminal ileum are spared.

Child↗
PubMed2005

Expression of inducible nitric oxide synthase and effects of L-arginine on colonic nitric oxide production and fluid transport in patients with "minimal colitis".

OBJECTIVE: Some patients with idiopathic, chronic diarrhoea have minimal, non-specific colonic inflammation. As nitric oxide (NO) acts as a secretagogue in the colon, we studied the expression of inducible NO synthase (iNOS) in mucosal biopsies and the effects of NOS stimulation on colonic transfer of fluid and output of NO in patients with "minimal colitis". MATERIAL AND METHODS: Twelve patients with idiopathic, chronic diarrhoea and "minimal colitis" and 6 healthy volunteers were included in the study. Expression of iNOS in colonic mucosal biopsies was quantified by Western blot analysis and localized by immunohistochemistry. The effects of topical L-arginine or placebo on colonic net fluid transfer and nitrite/nitrate (NOx) output were assessed during "steady state" perfusion of the whole colon. Concentrations of NOx were measured by Griess' assay. RESULTS: The expression of iNOS was increased 10-fold (p<0.01) in patients with "minimal colitis" compared with that in healthy volunteers and localized to the colonic epithelium. Colonic absorption of fluid was impaired (mean (SEM) 1.5 (0.2) versus 3.0 (0.2) ml/min, p<0.001) and the output of NOx was increased (47 (4) nmol/min versus <37 nmol/min, p<0.05) in patients with "minimal colitis" compared with that in healthy volunteers. Luminal L-arginine (20 mM) reduced colonic absorption of fluid in both groups (95% confidence intervals (CIs) 21-50% in patients with "minimal colitis" versus 4-18% in healthy volunteers), but an increase in NOx output was detectable only in the group of patients (8-106%). In time control experiments, colonic net transfer rates of fluid and outputs of NOx were unaffected by placebo. CONCLUSIONS: In patients with idiopathic, chronic diarrhoea and histopathological evidence of "minimal colitis", colonic absorption of fluid is impaired, while epithelial expression of iNOS and mucosal production of NO is enhanced. It could be speculated that NO in excess contributes to the diarrhoea observed in "minimal colitis".

Adult↗
PubMed1983

The pathology of experimental Corynebacterium equi infection in foals following intrabronchial challenge.

Six foals were inoculated intrabronchially with a suspension of Corynebacterium equi. Six weeks before this challenge, three foals were vaccinated with a C. equi bacterin. Three foals were unvaccinated controls. All foals developed a severe bronchopneumonia in the inoculated lung, indicating that vaccination was not protective. Three foals (two vaccinated, one control) were killed eight to nine days after infection. One control died on day 9 with lesions of disseminated intravascular coagulation. The remaining two foals (one vaccinated, one control) were killed on day 17. C. equi was cultured in large numbers from affected lung and bronchial lymph nodes, and in smaller numbers from unaffected lung, spleen, and liver in all foals. In the 8- to 9-day-old lung lesions, the alveoli were filled with macrophages, neutrophils, and multinucleate giant cells and most contained numerous C. equi. The few foci of alveolar necrosis were associated with groups of bacteria-laden macrophages undergoing degeneration. In the lesions of 17-day duration, there was extensive parenchymal destruction with little fibrous tissue reaction. Lesions common to both groups included hyperplastic bronchiolitis, pulmonary edema, and perivascular lymphocytic cuffs and a pyogranulomatous lymphadenitis in bronchial nodes. One vaccinated foal had a microscopic pyogranulomatous colitis. The lesions in the experimentally infected foals are compared with those in naturally infected foals and discussed in terms of likely pathogenetic mechanisms involved in C. equi pneumonia in foals.

Animals↗
PubMed2004

Septic arthritis of the knee by Salmonella montevideo.

We describe a case of salmonella septic arthritis of the knee in a middle-aged woman with the following predisposing conditions: long-term corticosteroids and microscopic collagenous colitis. The patient presented with enteritis caused by the same strain 3 months before the arthritis. The first series of cultures were negative and the possibility of a chronic carriage of the disease was not suspected initially. The patient was treated with antibiotics and arthroscopic washouts; the corticosteroid treatment was maintained. There was a progressive clinical and microbiological improvement and the patient was discharged 3 weeks later. Salmonella montevideo is a rare form of salmonella and is known to be associated with tropical fishes, reptiles and imported species.

Arthritis, Infectious↗