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Effect of glucocorticoids on rectal transport in normal subjects and patients with ulcerative colitis.

The acute effects of single pharmacological doses of glucocorticoid hormones on net electrolyte and water transport and electrical potential difference (pd) in the rectum was studied in control subjects and in patients with either active or inactive ulcerative colitis, using a dialysis technique. Compared with 17 control subjects, nine patients with active ulcerative colitis exhibited marked decreases in net sodium absorption and rectal pd, while these transport parameters were normal in six patients with inactive ulcerative colitis. Intravenous administration of hydrocortisone hemisuccinate (100 mg) resulted five hours later in significant and quantitatively similar increases in net sodium and water absorption and pd in nine control subjects, seven patients with active ulcerative colitis, and six patients with inactive ulcerative colitis. Intravenous administration of methylprednisolone phosphate (40 mg) to eight control subjects produced increases in net sodium and water absorption and pd five hours later, which did not differ significantly from those produced by hydrocortisone; methylprednisolone induced similar changes in two patients with active ulcerative colitis. These results indicate that single pharmacological doses of glucocorticoids stimulate acute increases in rectal sodium and water absorption in control subjects and in patients with acute ulcerative colitis. The ability of systemically administered glucocorticoids to reduce diarrhoea in ulcerative colitis may therefore be related to direct effects on distal colonic sodium and water transport, as well as to their better known anti-inflammatory action.

Acute Disease↗

Colorectal cancer in ulcerative colitis: a cohort study of primary referrals from three centres.

A retrospective cohort of 823 patients with ulcerative colitis who resided at the time of diagnosis in one of three defined geographical areas (West Midlands region, Oxford region, England and Stockholm County, Sweden) was assembled. The patients were first seen at named hospitals in these areas and the diagnosis of ulcerative colitis established within five years of onset of symptoms between 1945-1965. All patients were 15 years of age or more at onset of disease and were followed for a minimum of 17 years and a maximum of 38 years. Ninety seven per cent completeness of follow up was achieved. Examining the colorectal cancer risk in the series relative to the risk in the general population by standardised morbidity ratios, there was an eight fold increased risk of cancer in the series as a whole. Dividing the series by extent of colitis, extensive colitis patients showed a 19 fold increase in risk. A four fold increased risk was shown in the remainder of the series (left sided colitis, proctitis and extent unknown). Life table analyses in extensive colitis gave cumulative risks of 7.2% (CI 3.6-10.8) at 20 years from onset of disease and 16.5% (CI 9.0-24.0) at 30 years from onset. No significant effect of age at onset, sex or referral centre could be detected. Examination of the data by interval from onset to cancer and by actual age at development of cancer suggests that patients who develop colorectal cancer will do so in a distribution around 50 years of age independent of duration of disease in adult onset ulcerative colitis (greater than 15 years at onset of disease). An inverse relationship was shown between age at onset of disease and interval from onset of disease to cancer. Further age specific rates for cancer increased up to 50 years and decreased thereafter. These results suggest that extensive colitis patients have a genetic predisposition to colorectal cancer and that longstanding inflammation is not of primary importance in the initiation/promotion of cancer in this disease.

Actuarial Analysis↗

Mucosal enzyme activity for butyrate oxidation; no defect in patients with ulcerative colitis.

BACKGROUND: Butyrate is an important energy source for the colon and its metabolism has been reported to be defective in ulcerative colitis. One mechanism for defective butyrate metabolism in patients with ulcerative colitis could be an enzyme deficiency in the beta-oxidation pathway of butyrate. AIMS: This study was undertaken to measure the activity of each enzyme involved in the beta-oxidation pathway of butyrate in colonic epithelium. PATIENTS: Patients with ulcerative colitis (n = 33), Crohn's colitis (n = 10), and control subjects with colorectal cancer or diverticular disease (n = 73) were studied. METHODS: Analysis was carried out using fluorometric and spectrophotometric techniques on homogenised epithelial biopsy specimens. RESULTS: Significantly increased butyryl CoA dehydrogenase activity was found in mucosa from patients with ulcerative colitis (33.2 (28.3, 38.1) mumol/g wet weight/min:mean (95% CI)) compared with activity in mucosa from control patients (24.3 (20.9, 27.7) mumol/g wet weight/min:mean (95% CI)) p < 0.02. No significant increase in activity of the enzymes butyryl-CoA synthetase, crotonase or hydroxybutyryl-CoA dehydrogenase was found in patients with ulcerative colitis. In contrast the mucosal thiolase activity was significantly lower in those patients with quiescent colitis (3.21 (2.61, 3.81) mumol/g wet weight/min:mean (95% CI)) when compared with control mucosa (5.69 (5.09, 6.29) mumol/g wet weight/min:mean (95% CI)) p < 0.001. However, mucosal thiolase activity increases with the age of the donor patient and differences in the age range of the patient groups probably account for this finding. CONCLUSIONS: This study shows no substantial deficiency of enzyme activity in the beta-oxidation pathway of butyrate in the mucosa of patients with ulcerative colitis in histological remission.

Adolescent↗

High Fas ligand expression on lymphocytes in lesions of ulcerative colitis.

BACKGROUND: The pathogenesis of ulcerative colitis is unclear, but cytotoxic T lymphocytes infiltrating the mucosa have been implicated in mucosal damage. The Fas ligand (FasL), expressed on cytotoxic T lymphocytes, induces apoptosis in cells expressing Fas. AIM: To analyse FasL expression in affected colonic mucosa to ascertain Fas-FasL interaction in ulcerative colitis. METHODS: FasL mRNA was quantified in colonic mucosal specimens from healthy subjects and patients with ulcerative colitis or Crohn's disease, using the competitive reverse transcription polymerase chain reaction. FasL mRNA localisation was determined by in situ hybridisation. Expression of Fas in colonic mucosa was analysed immunohistochemically. Phenotypes of lamina propria lymphocytes that expressed FasL were analysed by flow cytometry. RESULTS: FasL mRNA was strongly expressed in active ulcerative colitis lesions, but not in those associated with active Crohn's disease or active proctitis-type ulcerative colitis. In situ hybridisation showed that FasL mRNA expression occurred in mononuclear cells infiltrating lesions. Fas was expressed in epithelial cells in ulcerative colitis and Crohn's disease, and in normal subjects. Cytometry showed that FasL was expressed in CD3 lymphocytes infiltrating the lamina propria in active lesions. CONCLUSIONS: FasL is expressed in CD3 lymphocytes infiltrating into ulcerative colitis but not Crohn's disease lesions, suggesting that Fas-FasL induced apoptosis participates in the mucosal damage of ulcerative colitis.

Acute Disease↗

The contribution of sulphate reducing bacteria and 5-aminosalicylic acid to faecal sulphide in patients with ulcerative colitis.

BACKGROUND: Butyrate oxidation within the colonocyte is selectively inhibited by hydrogen sulphide, reproducing the metabolic lesion observed in active ulcerative colitis. AIMS: To study generation of hydrogen sulphide by sulphate reducing bacteria (SRB) and the effects of 5-aminosalicylic acid (5-ASA) in patients with ulcerative colitis in order to identify a role of this noxious agent in pathogenesis. PATIENTS: Fresh faeces were obtained from 37 patients with ulcerative colitis (23 with active disease) and 16 healthy controls. METHODS: SRB were enumerated from fresh faecal slurries and measurements made of sulphate reducing activity, and sulphate and hydrogen sulphide concentrations. The effect of 5-ASA on hydrogen sulphide production was studied in vitro. RESULTS: All controls and patients with active ulcerative colitis carried SRB and total viable counts were significantly related to the clinical severity grade. SRB were of two distinct types: rapidly growing strains (desulfovibrios) which showed high sulphate reduction rates, present in 30% of patients with ulcerative colitis and 44% of controls; and slow growing strains which had little activity. In vitro, 5-ASA inhibited sulphide production in a dose dependent manner; in patients with ulcerative colitis not on these drugs faecal sulphide was significantly higher than in controls (0.55 versus 0.25 mM, p=0.027). CONCLUSIONS: Counts and carriage rates of SRB in faeces of patients with ulcerative colitis are not significantly different from those in controls. SRB metabolism is not uniform between strains and alternative sources of hydrogen sulphide production exist in the colonic lumen which may be similarly inhibited by 5-ASA. The evidence for hydrogen sulphide as a metabolic toxin in ulcerative colitis remains circumstantial.

Adult↗

Development of antigen induced colitis in SCID mice reconstituted with spleen derived memory type CD4(+) CD45RB(+) T cells.

BACKGROUND AND AIMS: Enteric bacterial and/or food antigens may be crucial in the development of colitis but little is known of the exact mechanism of antigen specific reactions in this condition. The aim of this study was to determine whether systemically primed antigen specific CD4(+) T cells containing both CD45RB(high) and CD45RB(low) populations participate as a pathogenic subset that in turn leads to inflammatory reactions selectively in the large intestine. METHODS: SCID mice were reconstituted with splenic CD4(+) CD45RB(+) T cells or CD4(+) CD45RB(low) T cells isolated from donor mice systemically primed with ovalbumin (OVA) plus CFA. The reconstituted mice were then fed OVA for several weeks. RESULTS: Reconstitution of SCID mice with OVA primed splenic CD4(+) T cells, containing populations of CD45RB(high) and CD45RB(low), resulted in the development of colitis by 4-5 weeks following repeated administration of oral OVA. Histopathological study revealed thickened wall, inflammatory cell infiltration, crypt elongation, and loss of goblet cells in the large intestine. The CD4(+) CD45RB(low) population of cells extracted from the affected large intestine secreted high levels of interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) at the protein and mRNA levels. Administration of neutralising antibodies to TNF-alpha, but not to IFN-gamma, prevented the development of colitis. Furthermore, adoptive transfer with OVA primed splenic CD4(+) CD45RB(low) T cells evoked severe colitis. CONCLUSIONS: These results demonstrate that systemically primed activated/memory CD4(+) CD45RB(low) T cells can mediate the development of specific antigen induced colitis in SCID mice, and also that TNF-alpha is critical in the induction of this type of colitis. Our results contrast with those from studies in some colitis models in which CD45RB(low) T cells appeared to prevent colitis through secretion of immunosuppressive cytokines.

Adoptive Transfer↗

Incidence and prevalence of ulcerative colitis in Punjab, North India.

INTRODUCTION: Ulcerative colitis occurs worldwide. It is considered common in most of Europe and North America and uncommon in most of the developing Asian countries. The incidence/prevalence of ulcerative colitis varies not only according to geographical region but also with race and ethnicity. There are no reported data from India on the incidence of the disease and its prevalence. MATERIAL AND METHODS: A house to house survey was conducted by questionnaire, formulated to enquire about symptoms that are suggestive of ulcerative colitis. Those with prolonged diarrhoea with or without rectal bleeding were considered as suspected cases. These suspected cases were subjected to video sigmoidoscopy/colonoscopy and rectal biopsy. In addition, patients already diagnosed and receiving treatment for ulcerative colitis, encountered during the survey, were reviewed. Resurvey of the same areas was conducted after a one year interval to detect new cases. Using direct methods, standardised rates were calculated using world standard population weights 22, 18, 16, 12, 12, 9, 7, 3, and 1 for each 10 year age group. Standardised rates were also obtained separately for males, females, and combined populations, using the Punjab state 1991 population census data. Rates were also estimated according to UK 2000 population data. Ninety five per cent confidence intervals (95% CI) of prevalence and incidence rates of ulcerative colitis were estimated under the assumption that the distribution of cases followed a Poisson probability model. RESULTS: A total population of 51 910 were screened from January to March 1999. We identified 147 suspected cases and of these 23 were finally established as ulcerative colitis cases, giving a crude prevalence rate of 44.3 per 100 000 inhabitants (95% CI 29.4-66.6). A second visit to the same areas after one year identified 10 suspected cases in a population of 49 834. Of these, three were confirmed as "definite" ulcerative colitis giving a crude incidence rate of 6.02 cases per 100 000 inhabitants (95% CI 1.2-17.6). CONCLUSIONS: This is the first population based study from India reporting on the incidence and prevalence of ulcerative colitis. The disease frequency is not much less than that reported from Europe and North America.

Adolescent↗

Colonic bicarbonate output as a test of disease activity in ulcerative colitis.

No available test objectively measures impairment of function of the inflamed colonic mucosa in ulcerative colitis. To study function we assessed rectal bicarbonate output by rectal dialysis in the presence of water and bacterial fatty acid (n-butyrate) in 21 controls, 18 patients with acute ulcerative colitis, 12 patients with ulcerative colitis in remission, and 12 patients with other forms of colitis. In acute ulcerative colitis, compared with controls, bicarbonate output and pH was reduced (p less than 0.001); stimulated bicarbonate output with bacterial fatty acid (incremental bicarbonate output) was reduced by 80% in acute ulcerative colitis (p less than 0.01). Results indicate that bicarbonate output is a useful and selective test of mucosal function in acute ulcerative colitis. A diminished incremental bicarbonate output with n-butyrate supports the view of inadequate oxidation of bacterial fatty acids in vivo by the mucosa in ulcerative colitis. Whether the test will prove to be an index of prognosis or will aid choice between medical or surgical therapy requires further study.

Acute Disease↗

What is the origin of ulcerative colitis? Still more questions than answers.

Despite more than a century of existence as a clinical entity, the true origin of ulcerative colitis still remains elusive. Several factors probably contribute to the development of this condition. Recently discovered technologies have clarified the role of bacterial species, which may account for intestinal dysbiosis, as a factor triggering ulcerative colitis. Genetic susceptibility together with abnormal innate immunoreactivity probably comprise the essential prerequisites for the initiation and perpetuation of ulcerative colitis. Although the genetic background has been more clearly recognised in patients with Crohn's disease than in those with ulcerative colitis, some candidate loci associated with ulcerative colitis have also been intensively studied. Additionally, environmental factors may interfere with inherent predispositions to ulcerative colitis, and either suppress or reinforce them. Whatever the origin, the search for the aetiology of ulcerative colitis must have the same goal: the improvement of treatment and the quality of life in patients with ulcerative colitis.

Appendicitis↗

Inosine reduces inflammation and improves survival in a murine model of colitis.

Inosine, a naturally occurring purine formed from the breakdown of adenosine, has recently been shown to exert powerful anti-inflammatory effects both in vivo and in vitro. This study evaluated inosine as a potential therapy for colitis. Colitis was induced in mice by the administration of dextran sulfate sodium (DSS). Oral treatment with inosine was begun either before the onset of colitis or as a posttreatment once colitis was established. Evaluation of colon damage and inflammation was determined grossly (body wt, rectal bleeding), histologically, and biochemically (colon levels of MPO, MDA, and cytokines). DSS-induced colitis significantly increased inflammatory cell infiltration into the colon. DSS-induced colitis also increased colon levels of lipid peroxidation, cytokines, and chemokines. Inosine protected the colon from DSS-induced inflammatory cell infiltration and lipid peroxidation. Inosine also partially reduced these parameters in an experimental model of established colitis. Thus inosine treatment may be a potential therapy in colitis.

Animals↗

Inhibitory effect of experimental colitis on fluid absorption in rat jejunum: role of the enteric nervous system, VIP, and nitric oxide.

Impairment of small intestinal absorption has been described in patients with ulcerative colitis and in animal models of experimental colitis. The pathophysiology of this dysfunction has not been elucidated. The aim of this study was to investigate the effect of chemical colitis on jejunal fluid absorption and determine the role of the enteric nervous system and some putative neurotransmitters. In a rat model of iodoacetamide-induced colitis, jejunal net fluid absorption was evaluated by the in vivo single-pass perfusion technique. The effects of 1) tetrodotoxin (TTX), 2) benzylalkonium chloride (BAC), 3) capsaicin, 4) vasoactive intestinal polypeptide (VIP) antagonism, 5) nitric oxide (NO) synthase (NOS) inhibition, and 6) 5-hydroxytryptamine type 3 and 4 (5-HT(3) and 5-HT(4)) receptor antagonism on the changes in fluid movement were investigated. A significant decrease in jejunal net fluid absorption was found 2 and 4 days after colitis induction: 26 (SD 14) and 28 (SD 19) microl x min(-1) x g dry intestinal wt(-1), respectively [P < 0.0002 compared with sham rats at 61 (SD 6.5) microl x min(-1) x g dry intestinal wt(-1)]. No histological changes were evident in jejunal sections. TTX and BAC reversed this decrease in fluid absorption: 54 (SD 13) and 44 (SD 14) microl x min(-1) x g dry intestinal wt(-1) (P = 0.0005 and P = 0.019, respectively, compared with colitis). Ablation of capsaicin-sensitive primary afferent fibers had a partial effect: 45 (SD 5) microl x min(-1) x g dry intestinal wt(-1) (P = 0.001 and P = 0.003 compared with colitis and sham, respectively). Constitutive and neuronal NOS inhibition and VIP antagonism returned jejunal net fluid absorption to normal values: 66 (SD 19), 61 (SD 5), and 56 (SD 14) microl x min(-1) x g dry intestinal wt(-1), respectively. 5-HT(3) and 5-HT(4) receptor antagonism had no effect. Chemical colitis is associated with a significant decrease in jejunal net fluid absorption. This decrease is neurally mediated and involves VIP- and NO-related mechanisms.

Animals↗

Hypersensitive prostaglandin and thromboxane response to hormones in rabbit colitis.

Inflammation of the colon is associated with increased production of prostaglandins (PG) and thromboxanes (Tx), and these eicosanoids may contribute to the inflammatory, secretory, and motility dysfunctions in colitis. To evaluate the potential role of peptide hormones in the enhanced eicosanoid release, colitis was established in rabbits by a delayed-type hypersensitivity reaction to dinitrochlorobenzene and by an immune-complex-mediated reaction. PG and Tx were identified in the venous effluent of isolated perfused colons by radiochromatography after [14C]arachidonic acid prelabeling, as well as by bioassay, and then quantitated by immunoassay. The two colitis models were morphologically similar. Basal release of PGE2, PGI2, and TxA2 was two- to threefold greater from colitis tissue than from control tissue. Bradykinin (BK) and angiotensin II (ANG II) increased release of 14C-labeled eicosanoids, whereas several gastrointestinal hormones had no effect. In control colons, BK and ANG II increased PGE2 and PGI2 release (by about 2-fold) but did not alter TxA2. In contrast, BK and ANG II markedly exaggerated the release of eicosanoids in colitis. BK increased TxA2 release with 10-ng bolus injections in colitis, but there was no response with up to 10-micrograms bolus injections in control colons. The BK-induced Tx release in colitis was associated with an increase in vascular resistance (measured as perfusion pressure). Infusion of the selective Tx inhibitors dazoxiben and OKY-046 reduced TxB2 release by 96% and blunted the transient rise in perfusion pressure (from 17 +/- 5 to 5 +/- 2 mmHg). Since BK and possibly ANG II are increased at sites of inflammation, the hypersensitive eicosanoid response to these peptides may augment the eicosanoid-mediated manifestations of colitis.

Animals↗

An orally active inhibitor of leukotriene synthesis accelerates healing in a rat model of colitis.

Leukotrienes (LTs) have been implicated as mediators of the inflammation and ulceration associated with ulcerative colitis and Crohn's disease. In the present study, the effects of a novel, orally active inhibitor of LT synthesis (MK-886) were examined in a rat model of chronic colitis. Colitis was induced by intracolonic administration of trinitrobenzenesulfonic acid. Colonic LTB4 synthesis was measured after incubation of tissue samples in vitro and by in vivo equilibrium dialysis. A single dose of MK-886 (10 mg/kg) significantly inhibited colonic LTB4 synthesis for greater than 24 h. Daily treatment with this dose significantly reduced colonic damage, as assessed macroscopically and histologically, when the treatment was performed 2 h before induction of colitis and daily thereafter for 1 wk, but not when treatment was performed during the second week after induction of colitis. A less marked beneficial effect of MK-886 was observed when the pretreatment dose was excluded, suggesting a role for LTs in the early events of the inflammatory process. Inhibition of LT synthesis during the first 24 h after induction of colitis did not alter the extent of infiltration of neutrophils into the colon, as measured by tissue myeloperoxidase activity. Daily treatment with sulfasalazine (100 mg/kg po) either during the first or second week after induction of colitis did not significantly affect the rates of healing. At the dose used, sulfasalazine only produced a transient inhibition of colonic LTB4 synthesis. This study therefore demonstrates that a specific, orally active inhibitor of LT synthesis can significantly accelerate healing in this animal model of colitis when the treatment is performed during the early phase of the inflammatory response.

Administration, Oral↗

Beneficial effects of local or systemic lidocaine in experimental colitis.

Neuropeptides liberated from enteric neurons have been suggested to contribute to the inflammatory process in colitis. Based in part on this evidence, lidocaine enemas have recently been suggested as a treatment for ulcerative colitis, but their effects have yet to be fully characterized. We have assessed the effects of lidocaine on the development and maintenance of colitis induced by trinitrobenzenesulfonic acid (TNBS) in rats. In the initial experiments, rats were given lidocaine [5-100 mg/kg intrarectally] 30 min before TNBS administration, and the severity of colitis was assessed 6-24 h later. In subsequent experiments, rats received lidocaine intrarectally or subcutaneously 30 min before TNBS administration and once daily for 7 days. The severity of colitis was assessed by blind macroscopic scoring, measurement of myeloperoxidase activity, and histological evaluation. Lidocaine dose dependently reduced the severity of colitis and the infiltration of granulocytes at 24 h and 7 days post-TNBS. At the latter time point, lidocaine was also found to improve the histological appearance of the tissue and significantly reduce mucosal mast cell hyperplasia. Beneficial effects were also evident when intrarectal lidocaine treatment was initiated after induction of colitis or when lidocaine was given subcutaneously. Granulocyte infiltration into the colon could also be attenuated by a substance P receptor antagonist. These results suggest that lidocaine can exert anti-inflammatory effects in colitis, perhaps by virtue of its effects on intrinsic and/or extrinsic nerves.

Administration, Rectal↗

Experimental colitis increases blood-brain barrier permeability in rabbits.

Extraintestinal manifestations of inflammatory bowel disease are numerous. This study examined the effects of two models of acute colitis on cerebral blood flow (CBF) and permeability of the blood-brain barrier in rabbits. CBF (measured with radiolabeled microspheres), or the extraction ratio or permeability-surface area (PS) product of the blood-brain barrier to fluorescein and FITC-dextran, was measured 48 h after colitis induction with acetic acid (HAc) or trinitrobenzene sulfonic acid (TNBS). PS product for fluorescein increased (P < 0.05) in TNBS colitis (1.33 x 10(-5) +/- 0.52 x 10(-5) ml/s and 0.48 x 10(-5) +/- 0.13 x 10(-5) ml/s (mean +/- SE) for treated (n = 14) and untreated (n = 10) animals, respectively. PS product for the larger FITC-dextran was not different in TNBS colitis (0.24 x 10(-5) +/- 0.09 x 10(-5) ml/s, n = 7) compared with untreated controls (0.19 x 10(-5) +/- 0.04 x 10(-5) ml/s, n = 8). PS product for fluorescein increased (P < 0.01) in HAc colitis compared with vehicle (2.66 x 10(-5) +/- 1.46 x 10(-5) ml/s and 0.33 x 10(-5) +/- 0.05 x 10(-5) ml/s, respectively; n = 6 in each group). The extraction of fluorescein from the blood to the brain increased by 75% during TNBS colitis when compared with vehicle (P < 0.05). CBF and cerebrovascular resistance did not change from the untreated control after TNBS colitis. Our data suggest that, irrespective of induction method, acute colitis increases the permeability of the blood-brain barrier to small molecules without changing CBF.

Acetic Acid↗

Prevalence of celiac disease in collagenous and lymphocytic colitis.

Both collagenous and lymphocytic colitis have been described in patients with celiac disease, suggesting an association between the conditions. Over the past few years, the availability, sensitivity and specificity of serological markers for celiac disease have improved - the most recent advancement being the description of tissue transglutaminase as the major antigen for endomysium antibody. A quantitative ELISA was used to measure titres of immunoglobulin A (IgA) antibody to tissue transglutaminase (tTG) along with an immunofluorescent technique for IgA endomysium antibody (EmA) in 15 patients with lymphocytic colitis and eight with collagenous colitis to determine whether celiac disease latency could be detected. One patient with lymphocytic colitis demonstrated both elevated titres of tTG antibody and positive EmA, and small bowel biopsy confirmed celiac disease. One patient with collagenous colitis had a slightly elevated titre of tTG antibody with a negative EmA, and results of a small bowel biopsy were normal. Three other patients with lymphocytic colitis were already treated for previously diagnosed celiac disease. The prevalence of celiac disease occurring in lymphocytic colitis was found to be 27%, but no cases of celiac disease in association with collagenous colitis were found.

Adult↗

Lower gastrointestinal bleeding and ischemic colitis.

OBJECTIVE: To compare the incidence and clinical characteristics of lower gastrointestinal (LGI) bleeding due to ischemic colitis with those with LGI bleeding of other causes. METHODS: A chart review was performed of patients admitted with LGI bleeding to Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, between July 1, 1997 and January 31, 2000. RESULTS: Of 124 patients with LGI bleeding, 24 cases were due to ischemic colitis, 62 to diverticulosis, 11 to inflammatory bowel disease (IBD) and 27 to all other causes ('others'). The average ages of patients in each group were 66.5, 76.5, 40.5 and 77.5 years, respectively. Patients with ischemic colitis were statistically younger than those with diverticular bleeding and 'others'. Patients with IBD were younger than those in the other three groups. The only statistical difference for vascular disease risks was hypertension, because of its absence from the IBD group. Three patients with ischemic colitis underwent blood transfusions, while 23 with diverticulosis, 15 'others' and none with IBD received blood. Three patients with ischemic colitis and one patient from the 'others' group died. More women (75) than men (49) had LGI bleeding - in total and within each subgroup. Of women with LGI bleeding, many more with ischemic colitis (44.4%) than with diverticulosis (3.0%), IBD (0%) or 'others' (5.6%) were taking estrogen. CONCLUSIONS: Ischemic colitis was the second most common cause of LGI bleeding. LGI bleeding from all causes was more common in women than in men. Many more women in the ischemic colitis group than in the other groups were using estrogen therapy.

Adult↗

Preferential migration of CD62L cells into the appendix in mice with experimental chronic colitis.

BACKGROUND: Clinical and experimental studies suggest that appendectomy can protect against development of ulcerative colitis and Crohn's disease. However, how T cells in the appendix affect the development of colitis has not been clarified. AIM: To investigate the in vivo migration and activation of colitis-inducing CD62L+ cells during development of chronic colitis. METHODS: CD62L+CD4+ cells were fluorescently labeled and transferred to severe combined immunodeficient (SCID) mice to induce colitis. In vivo migration of T cells into the mucosa of the appendix and colon was quantified by in vivo microscopy after 7 weeks. In a second experiment, unlabeled CD62L+CD4+ cells were transferred, reisolated after 7 weeks, and adhesion molecule (integrin alpha4beta7) and costimulatory molecule (CD154) expression was analyzed. RESULTS: Six to eight weeks after CD62L+CD4+ cell transfer, SCID mice developed chronic colitis. In vivo microscopic analysis demonstrated a preferential migration of fluorescence-labeled CD62L+CD4+ cells into the mucosa of the appendix versus the colon. Re-isolation of lamina propria cells from mice with colitis confirmed that CD62L+CD4+ cell migration was significantly enhanced in the appendix, compared to the colon (3.5-fold). Furthermore, a higher proportion of CD62L+CD4+ cells re-isolated from the appendix expressed integrin alpha4beta7 and CD154 than from the colon. CONCLUSION: This study demonstrates the preferential migration of CD62L+CD4+ cells into the appendix as compared to the colon. This migration pattern correlated with upregulation of integrin alpha4beta7 and CD154 (CD40 ligand) on T cells. Our results suggest an important role of the appendix in the pathogenesis of colitis.

Adoptive Transfer↗