Microscopic colitis: a concise review.

Microscopic colitis is an increasingly common cause of chronic watery diarrhoea, and often a causes of abdominal pain of unknown origins. The increase of interest for this clinical entity is due to a misdiagnosis of any symptoms that have been frequently attributed to diarrhea-predominant irritable bowel syndrome, often for many years before diagnosis. Presumably, most estimates of incidence and prevalence understate the true frequency of microscopic colitis for this reason. The aim of this paper is to evaluate the importance of microscopic colitis as cause of chronic non bloody diarrhoea, on the basis of literature review. These kind of colitis are characterized by normal colonic mucosa at endoscopy or barium enema but with increased inflammation in colonic biopsies. Microscopic colitis consists of two main subtypes, collagenous colitis and lymphocytic colitis, distinguished by the presence of absence of a thickened subepithelial collagen band. Several models of pathogenesis has been proposed but no convincing mechanism has been identified, although is difficult to characterize this clinical entity as an independent phenomenon or a simple manifestation or related factors active to induce microscopic changing in the colonic mucosa. A rational approach to therapy does not exist and was conduct with several types of drugs after the exclusion of other causes, commonly characterized by this symptoms and the definitive histological assessment in the biopsies specimens. In the majority of cases this condition tends to follow a self-limited course but potentially can assume the characteristics of relapsing course with the necessity to a chronic therapy. Several long-term follow-up studies excluded a possible progression to neoplastic malignancies of microscopic colitis.

Optimisation of isolation of richly pure and homogeneous primary human colonic smooth muscle cells.

BACKGROUND: Inherent properties of gastrointestinal smooth muscle can be assessed using isolated cell suspensions. Currently available isolation techniques, based on short 2-h enzymatic digestion, however, present the disadvantage of low cellular yield with brief viability. These features are an important limiting factor especially in studies in humans in which tissue may not be available daily and mixing of samples is not recommended. AIMS: To optimise the isolation procedure of cells from human colon to obtain a richly pure primary smooth muscle cell preparation. METHODS: Slices of circular muscle layer, obtained from surgical specimens of human colon, were incubated overnight in Dulbecco's modified eagle's medium supplemented with antibiotics, foetal bovine serum, an ATP-regenerating system and collagenase. On the following day, digested muscle strips were suspended in HEPES buffer, and spontaneously dissociated smooth muscle cells were harvested and used either immediately or maintained in suspension for up to 72 h. Cell yield, purity, viability, contractile responses, associated intracellular calcium signals and RNA and protein extraction were evaluated and compared to cell suspensions obtained with the current short digestion protocol. RESULTS AND CONCLUSION: The overnight isolation protocol offers the advantage of obtaining a pure, homogeneous, long-life viable cell suspension that maintains a fully differentiated smooth muscle phenotype unchanged for at least 72 h and that allows multiple functional/biochemical studies and efficient RNA extraction from a single human specimen.

Efficacy of gluten-free diet alone on recovery from iron deficiency anemia in adult celiac patients.

OBJECTIVE: Iron deficiency anemia has been reported as the most frequent extraintestinal symptom in adult celiac disease. Prospective studies on the effect of gluten-free diet on recovery from iron deficiency anemia are lacking. The aim of this study was to verify in adult patients with celiac disease the efficacy of and the time course of recovery from iron deficiency anemia by a gluten-free diet alone. METHODS: We studied 190 consecutive adult patients with iron deficiency anemia, screened for celiac disease by duodenal biopsies. New diagnosed celiac patients were invited to follow a gluten-free diet alone without iron supplementation. After 6 months of diet, duodenal biopsies were performed and hematological tests were repeated at 6, 12, and 24 months. RESULTS: Celiac disease was diagnosed in 26 (24 women, 2 men; 13.7%) adult patients. After 6 months of gluten-free diet 14 of 18 (77.8%) female patients recovered from anemia, but only 5 of 18 (27.8%) reversed from iron deficiency. At 12-month control all but one patient (94.4%) recovered from anemia and 9 patients (50%) from iron deficiency. After 24 months of diet, only the patient who did not recover from anemia at 12-month control was still anemic, whereas 10 patients (55.5%) reversed from iron deficiency. A significant inverse correlation (r = -0.7141, p = 0.0003) between increase of Hb concentrations and decrease of individual histological scores of duodenitis was observed. CONCLUSIONS: A screening for celiac disease should be carried out in adult patients with iron deficiency anemia. Recovery from anemia occurs between 6 and 12 months on a gluten-free diet alone as a consequence of normalization of histological alterations of the intestinal mucosa.