Showing papers in "Gut in 2000"

The Vienna classification of gastrointestinal epithelial neoplasia

Abstract: Background—Use of the conventional Western and Japanese classification systems of gastrointestinal epithelial neoplasia results in large diVerences among pathologists in the diagnosis of oesophageal, gastric, and colorectal neoplastic lesions. Aim—To develop common worldwide terminology for gastrointestinal epithelial neoplasia. Methods—Thirty one pathologists from 12 countries reviewed 35 gastric, 20 colorectal, and 21 oesophageal biopsy and resection specimens. The extent of diagnostic agreement between those with Western and Japanese viewpoints was assessed by kappa statistics. The pathologists met in Vienna to discuss the results and to develop a new consensus terminology. Results—The large diVerences between the conventional Western and Japanese diagnoses were confirmed (percentage of specimens for which there was agreement and kappa values: 37% and 0.16 for gastric; 45% and 0.27 for colorectal; and 14% and 0.01 for oesophageal lesions). There was much better agreement among pathologists (71% and 0.55 for gastric; 65% and 0.47 for colorectal; and 62% and 0.31 for oesophageal lesions) when the original assessments of the specimens were regrouped into the categories of the proposed Vienna classification of gastrointestinal epithelial neoplasia: (1) negative for neoplasia/dysplasia, (2) indefinite for neoplasia/dysplasia, (3) non-invasive low grade neoplasia (low grade adenoma/ dysplasia), (4) non-invasive high grade neoplasia (high grade adenoma/ dysplasia, non-invasive carcinoma and suspicion of invasive carcinoma), and (5) invasive neoplasia (intramucosal carcinoma, submucosal carcinoma or beyond). Conclusion—The diVerences between Western and Japanese pathologists in the diagnostic classification of gastrointestinal epithelial neoplastic lesions can be resolved largely by adopting the proposed terminology, which is based on cytological and architectural severity and invasion status. (Gut 2000;47:251‐255)

Butyrate inhibits inflammatory responses through NFκB inhibition: implications for Crohn's disease

Abstract: BACKGROUND/AIM Proinflammatory cytokines are key factors in the pathogenesis of Crohn9s disease (CD). Activation of nuclear factor kappa B (NFκB), which is involved in their gene transcription, is increased in the intestinal mucosa of CD patients. As butyrate enemas may be beneficial in treating colonic inflammation, we investigated if butyrate promotes this effect by acting on proinflammatory cytokine expression. METHODS Intestinal biopsy specimens, isolated lamina propria cells (LPMC), and peripheral blood mononuclear cells (PBMC) were cultured with or without butyrate for assessment of secretion of tumour necrosis factor (TNF) and mRNA levels. NFκB p65 activation was determined by immunofluorescence and gene reporter experiments. Levels of NFκB inhibitory protein (IκBα) were analysed by western blotting. The in vivo efficacy of butyrate was assessed in rats with trinitrobenzene sulphonic acid (TNBS) induced colitis. RESULTS Butyrate decreased TNF production and proinflammatory cytokine mRNA expression by intestinal biopsies and LPMC from CD patients. Butyrate abolished lipopolysaccharide (LPS) induced expression of cytokines by PBMC and transmigration of NFκB from the cytoplasm to the nucleus. LPS induced NFκB transcriptional activity was decreased by butyrate while IκBα levels were stable. Butyrate treatment also improved TNBS induced colitis. CONCLUSIONS Butyrate decreases proinflammatory cytokine expression via inhibition of NFκB activation and IκBα degradation. These anti-inflammatory properties provide a rationale for assessing butyrate in the treatment of CD.

Increased rectal mucosal enteroendocrine cells, T lymphocytes, and increased gut permeability following acute Campylobacter enteritis and in post-dysenteric irritable bowel syndrome

Abstract: BACKGROUND AND AIMS Post-dysenteric irritable bowel syndrome (PD-IBS) develops in up to 25% of patients following Campylobacter enteritis. Our aim was to define the pathological basis of this subgroup of IBS. METHODS Twenty one patients (group 1) underwent serial rectal biopsy and gut permeability testing following acute Campylobacter enteritis as did 10 PD-IBS patients (group 2) and 12 asymptomatic controls. RESULTS In group 1, enteroendocrine cell (EC) numbers were markedly increased initially and at six and 12 weeks (p r =0.6, p=0.01). At one year, seven subjects (five with persistent loose stools) had rectal biopsies which showed significantly elevated EC, CD3, and IEL counts. In group 2, EC and IEL counts were significantly increased compared with controls (p CONCLUSION Increased EC, T lymphocytes, and gut permeability are acute changes following Campylobacter enteritis which can persist for more than a year and may contribute to PD-IBS.

A reproducible grading scale for histological assessment of inflammation in ulcerative colitis

Abstract: BACKGROUND Evaluation of histological activity in ulcerative colitis needs to be reproducible but has rarely been tested. This could be useful both clinically and in clinical trials. AIM To develop reproducible criteria which are valid in the assessment of acute inflammation (activity) and chronicity, and to evaluate these features in an interobserver variability study. METHODS A six grade classification system for inflammation was developed which could also be fine tuned within each grade. The grades were: 0, structural change only; 1, chronic inflammation; 2, lamina propria neutrophils; 3, neutrophils in epithelium; 4, crypt destruction; and 5, erosions or ulcers. Ninety nine haematoxylin-eosin sections from endoscopically inflamed and non-inflamed mucosa from patients with distal ulcerative colitis were assessed in two separate readings by three pathologists independently and without knowledge of the clinical status. Interobserver agreement was compared pairwise using kappa statistics. RESULTS Initially, kappa values between the observers were 0.20, 0.42, and 0.26, which are too low to be of value. Following development of a semiquantitative pictorial scale for each criterion, kappa values improved to 0.62, 0.70, and 0.59. For activity defined by neutrophils between epithelial cells, kappa values were 0.903, 1.000, and 0.907. Complete agreement was reached in 64% of samples of endoscopically normal and in 66% of endoscopically inflamed tissue. Neutrophils in epithelium correlated with the presence of crypt destruction and ulceration. CONCLUSION A histological activity system was developed for ulcerative colitis that showed good reproducibility and modest agreement with the endoscopic grading system which it complemented. It has potential value both clinically and in clinical trials.

Guidelines for the management of iron deficiency anaemia

Abstract: Background Iron deficiency anaemia (IDA) occurs in 2–5% of adult men and postmenopausal women in the developed world and is a common cause of referral to gastroenterologists. Gastrointestinal (GI) blood loss from colonic cancer or gastric cancer, and malabsorption in coeliac disease are the most important causes that need to be sought. Defining iron deficiency anaemia The lower limit of the normal range for the laboratory performing the test should be used to define anaemia (B). Any level of anaemia should be investigated in the presence of iron deficiency (B). The lower the haemoglobin the more likely there is to be serious underlying pathology and the more urgent is the need for investigation (B). Red cell indices provide a sensitive indication of iron deficiency in the absence of chronic disease or haemoglobinopathy (A). Haemoglobin electrophoresis is recommended when microcytosis and hypochromia are present in patients of appropriate ethnic background to prevent unnecessary GI investigation (C). Serum ferritin is the most powerful test for iron deficiency (A). Investigations Upper and lower GI investigations should be considered in all postmenopausal female and all male patients where IDA has been confirmed unless there is a history of significant overt non-GI blood loss (A). All patients should be screened for coeliac disease (B). If oesophagogastroduodenoscopy (OGD) is performed as the initial GI investigation, only the presence of advanced gastric cancer or coeliac disease should deter lower GI investigation (B). In patients aged >50 or with marked anaemia or a significant family history of colorectal carcinoma, lower GI investigation should still be considered even if coeliac disease is found (B). Colonoscopy has advantages over CT colography for investigation of the lower GI tract in IDA, but either is acceptable (B). Either is preferable to barium enema, which is useful if they are not available. Further direct visualisation of the small bowel is not necessary unless there are symptoms suggestive of small bowel disease, or if the haemoglobin cannot be restored or maintained with iron therapy (B). In patients with recurrent IDA and normal OGD and colonoscopy results, Helicobacter pylori should be eradicated if present. (C). Faecal occult blood testing is of no benefit in the investigation of IDA (B). All premenopausal women with IDA should be screened for coeliac disease, but other upper and lower GI investigation should be reserved for those aged 50 years or older, those with symptoms suggesting gastrointestinal disease, and those with a strong family history of colorectal cancer (B). Upper and lower GI investigation of IDA in post-gastrectomy patients is recommended in those over 50 years of age (B). In patients with iron deficiency without anaemia, endoscopic investigation rarely detects malignancy. Such investigation should be considered in patients aged >50 after discussing the risk and potential benefit with them (C). Only postmenopausal women and men aged >50 years should have GI investigation of iron deficiency without anaemia (C). Rectal examination is seldom contributory, and, in the absence of symptoms such as rectal bleeding and tenesmus, may be postponed until colonoscopy. Urine testing for blood is important in the examination of patients with IDA (B). Management All patients should have iron supplementation both to correct anaemia and replenish body stores (B). Parenteral iron can be used when oral preparations are not tolerated (C). Blood transfusions should be reserved for patients with or at risk of cardiovascular instability due to the degree of their anaemia (C).

UK guidelines on the management of variceal haemorrhage in cirrhotic patients

Abstract: These updated guidelines on the management of variceal haemorrhage have been commissioned by the Clinical Services and Standards Committee (CSSC) of the British Society of Gastroenterology (BSG) under the auspices of the liver section of the BSG. The original guidelines which this document supersedes were written in 2000 and have undergone extensive revision by 13 members of the Guidelines Development Group (GDG). The GDG comprises elected members of the BSG liver section, representation from British Association for the Study of the Liver (BASL) and Liver QuEST, a nursing representative and a patient representative. The quality of evidence and grading of recommendations was appraised using the AGREE II tool.The nature of variceal haemorrhage in cirrhotic patients with its complex range of complications makes rigid guidelines inappropriate. These guidelines deal specifically with the management of varices in patients with cirrhosis under the following subheadings: (1) primary prophylaxis; (2) acute variceal haemorrhage; (3) secondary prophylaxis of variceal haemorrhage; and (4) gastric varices. They are not designed to deal with (1) the management of the underlying liver disease; (2) the management of variceal haemorrhage in children; or (3) variceal haemorrhage from other aetiological conditions.

The neurobiology of stress and gastrointestinal disease

Abstract: The role of stress in the modulation of the most common gastrointestinal disorders has traditionally been considered a domain of psychology, and has frequently been lumped together with the role of psychiatric comorbidity. Among clinicians, the term “stress” is generally taken as synonymous with psychological (“exteroceptive”) stress. Based on the deeply ingrained Cartesian view in medicine and gastroenterology, stress and psychological factors have been considered fundamentally separate and unrelated to the “real” biological changes underlying organic disease. However, recent breakthroughs in the understanding of the neurobiology of the organism's response to acute and chronic stress, and the evolving understanding of elaborate brain-gut interactions and their modulation in health and disease, are beginning to require a reassessment of chronic stress in the pathophysiology and management not only of functional but also of “organic” gastrointestinal disorders. Certain stressful life events have been associated with the onset or symptom exacerbation in some of the most common chronic disorders of the digestive system, including functional gastrointestinal disorders (FGD), inflammatory bowel disease (IBD), gastro-oesophageal reflux disease (GORD), and peptic ulcer disease (PUD). Even though methodological differences in reported studies which do and do not support such an association remain to be resolved, the association of sustained stressful life events preceding symptom exacerbation is based on several well designed surveys in patients with FGD,1-4with post-infectious irritable bowel syndrome (IBS),4 and with IBD.5-8 In addition, acute life threatening stress episodes in adult life (rape, post-traumatic stress syndrome) are an important risk factor in the development of functional gastrointestinal disorders.9 Finally, early life stress in the form of abuse plays a major role in the susceptibility of individuals to develop functional as well as IBD10-14 later in life. Thus, depending on the type of stressor, the lag time between the stressful event …

Lamivudine and alpha interferon combination treatment of patients with chronic hepatitis B infection: a randomised trial

Abstract: BACKGROUND, AIM, AND METHODS—Alpha interferon is the generally approved therapy for HBe antigen positive patients with chronic hepatitis B, but its efficacy is limited. Lamivudine is a new oral nucleoside analogue which potently inhibits hepatitis B virus (HBV) DNA replication. To investigate the possibility of an additive effect of interferon-lamivudine combination therapy compared with interferon or lamivudine monotherapy, we conducted a randomised controlled trial in 230 predominantly Caucasian patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis B. Previously untreated patients were randomised to receive: combination therapy of lamivudine 100 mg daily with alpha interferon 10 million units three times weekly for 16 weeks after pretreatment with lamivudine for eight weeks (n=75); alpha interferon 10 million units three times weekly for 16 weeks (n=69); or lamivudine 100 mg daily for 52 weeks (n=82). The primary efficacy end point was the HBeAg seroconversion rate at week 52 (loss of HBeAg, development of antibodies to HBeAg and undetectable HBV DNA). RESULTS—The HBeAg seroconversion rate at week 52 was 29% for the combination therapy, 19% for interferon monotherapy, and 18% for lamivudine monotherapy (p=0.12 and p=0.10, respectively, for comparison of the combination therapy with interferon or lamivudine monotherapy). The HBeAg seroconversion rates at week 52 for the combination therapy and lamivudine monotherapy were significantly different in the per protocol analysis (36% (20/56) v 19% (13/70), respectively; p=0.02). The effect of combining lamivudine and interferon appeared to be most useful in patients with moderately elevated alanine aminotransferase levels at baseline. Adverse events with the combination therapy were similar to interferon monotherapy; patients receiving lamivudine monotherapy had significantly fewer adverse events. CONCLUSIONS—HBeAg seroconversion rates at one year were similar for lamivudine monotherapy (52 weeks) and standard alpha interferon therapy (16 weeks). The combination of lamivudine and interferon appeared to increase the HBeAg seroconversion rate, particularly in patients with moderately elevated baseline aminotransferase levels. The potential benefit of combining lamivudine and interferon should be investigated further in studies with different regimens of combination therapy. Keywords: chronic hepatitis B; hepatitis B virus; nucleoside analogue; lamivudine; alpha interferon; combination therapy; HBeAg seroconversion

Ulcerative colitis in Olmsted County, Minnesota, 1940-1993: incidence, prevalence, and survival.

Abstract: BACKGROUND There is significant geographic variation in the reported incidence of ulcerative colitis. AIMS To update the incidence and prevalence of ulcerative colitis in Olmsted County, Minnesota, examine temporal trends, and determine overall survival. PATIENTS All Olmsted County residents diagnosed with ulcerative colitis between 1940 and 1993 (incidence cases), and all residents with ulcerative colitis alive on 1 January 1991 (prevalence cases). METHODS Incidence and prevalence rates were adjusted using 1990 US census figures for whites. The effects of age, sex, and calendar year on incidence rates were evaluated using Poisson regression. Survival from diagnosis was compared with that expected for US north-central whites. RESULTS Between 1940 and 1993, 278 incidence cases were identified, for an adjusted incidence rate of 7.6 cases per 100 000 person years (95% confidence interval (CI), 6.7 to 8.5). On 1 January 1991, there were 218 residents with definite or probable ulcerative colitis, for an adjusted prevalence rate of 229 cases per 100 000 (95% CI, 198 to 260). Increased incidence rates were associated with later calendar years (p 0.2). CONCLUSIONS The overall incidence rate of ulcerative colitis in Olmsted County increased until the 1970s, and remained stable thereafter. Incidence rates among men and urban residents were significantly higher. The prevalence rate in Rochester in 1991 was 19% higher than that in 1980. Overall survival was similar to that of the general population.

Irritable bowel syndrome in general practice: prevalence, characteristics, and referral

Abstract: BACKGROUND AND AIMS Little is known about the prevalence, symptoms, diagnosis, attitude, and referral to specialists of patients with irritable bowel syndrome (IBS) in general practice. This study aimed to determine these characteristics. METHODS 3111 patients attending 36 general practitioners (GPs) at six varied locations in and near Bristol, UK, were screened to identify those with a gastrointestinal problem. These patients (n=255) and their doctors were given questionnaires. Six months later the case notes were examined to reach criteria based diagnoses of functional bowel disorders. RESULTS Of 255 patients with a gastrointestinal complaint, 30% were judged to have IBS and 14% other functional disorders. Compared with 100 patients with an “organic” diagnoses, those with IBS were more often women and more often judged by their GP to be polysymptomatic and to have unexplained symptoms. The majority of patients with IBS (58%) were diagnosed as such by the GP; 22% had other functional diagnoses. Conversely, among 54 patients diagnosed as having IBS by the GPs, the criteria based diagnosis was indeed functional in 91%; only one patient had organic disease (proctitis). More patients with IBS than those with organic disease feared cancer. In most some fear remained after the visit to the doctor. On logistic regression analysis, predictors of referral to a specialist (29% referred) were denial of a role for stress, multiple tests, and frequent bowel movements. CONCLUSIONS Half the patients with gut complaints seen by GPs have functional disorders. These are usually recognised, and few patients are referred. In IBS, cancer fears often remain, suggesting unconfident diagnosis or inadequate explanation.

A simple method for assessing intestinal inflammation in Crohn's disease

Abstract: BACKGROUND AND AIMS—Assessing the presence and degree of intestinal inflammation objectively, simply, and reliably is a significant problem in gastroenterology. We assessed faecal excretion of calprotectin, a stable neutrophil specific marker, as an index of intestinal inflammation and its potential use as a screening test to discriminate between patients with Crohn's disease and those with irritable bowel syndrome. METHODS—The validity of faecal calprotectin as a marker of intestinal inflammation was assessed in 22 patients with Crohn's disease (35 studies) by comparing faecal excretions and concentrations using four day faecal excretion of 111indium white cells. A cross sectional study assessed the sensitivity of faecal calprotectin concentration for the detection of established Crohn's disease (n=116). A prospective study assessed the value of faecal calprotectin in discriminating between patients with Crohn's disease and irritable bowel syndrome in 220 patients referred to a gastroenterology clinic. RESULTS—Four day faecal excretion of 111indium (median 8.7%; 95% confidence interval (CI) 7-17%; normal <1.0%) correlated significantly (p<0.0001) with daily (median ranged from 39 to 47 mg; normal <3 mg; r=0.76-0.82) and four day faecal calprotectin excretion (median 101 mg; 95% CI 45-168 mg; normal <11 mg; r=0.80) and single stool calprotectin concentrations (median 118 mg/l; 95% CI 36-175 mg/l; normal <10 mg/l; r=0.70) in patients with Crohn's disease. The cross sectional study showed a sensitivity of 96% for calprotectin in discriminating between normal subjects (2 mg/l; 95% CI 2-3 mg/l) and those with Crohn's disease (91 mg/l; 95% CI 59-105 mg/l). With a cut off point of 30 mg/l faecal calprotectin has 100% sensitivity and 97% specificity in discriminating between active Crohn's disease and irritable bowel syndrome. CONCLUSION—The calprotectin method may be a useful adjuvant for discriminating between patients with Crohn's disease and irritable bowel syndrome. Keywords: inflammatory bowel disease; Crohn's disease; intestinal inflammation; irritable bowel syndrome

Non-pathogenic bacteria elicit a differential cytokine response by intestinal epithelial cell/leucocyte co-cultures

Abstract: Background and aim—Intestinal epithelial cells (IEC) are thought to participate in the mucosal defence against bacteria and in the regulation of mucosal tissue homeostasis. Reactivity of IEC to bacterial signals may depend on interactions with immunocompetent cells. To address the question of whether non-pathogenic bacteria modify the immune response of the intestinal epithelium, we co-cultivated enterocyte-like CaCO-2 cells with human blood leucocytes in separate compartments of transwell cultures. Methods—CaCO-2/PBMC co-cultures were stimulated with non-pathogenic bacteria and enteropathogenic Escherichia coli. Expression of tumour necrosis factor alpha (TNF-AE), interleukin (IL)-1‚, IL-8, monocyte chemoattracting protein 1 (MCP-1), and IL-10 was studied by enzyme linked immunosorbent assays (cytokine secretion) and by semiquantitative reverse transcription-polymerase chain reaction. Results—Challenge of CaCO-2 cells with non-pathogenic E coli and Lactobacillus sakei induced expression of IL-8, MCP-1, IL-1‚, and TNF-AE mRNA in the presence of underlying leucocytes. Leucocyte sensitised CaCO-2 cells produced TNF-AE and IL-1‚ whereas IL-10 was exclusively secreted by human peripheral blood mononuclear cells. CaCO-2 cells alone remained hyporesponsive to the bacterial challenge. Lactobacillus johnsonii, an intestinal isolate, showed reduced potential to induce proinflammatory cytokines but increased transforming growth factor beta mR˝A in leucocyte sensitised CaCO-2 cells. TNF-AE was identified as one of the early mediators involved in cellular cross talk. In the presence of leucocytes, discriminative activation of CaCO-2 cells was observed between enteropathogenic E coli and non-pathogenic bacteria. Conclusion—The diVerential recognition of non-pathogenic bacteria by CaCO-2 cells required the presence of underlying leucocytes. These results strengthen the hypothesis that bacterial signalling at the mucosal surface is dependent on a network of cellular interactions. (Gut 2000;47:79‐87)

Influence of hepatitis delta virus infection on morbidity and mortality in compensated cirrhosis type B

Abstract: BACKGROUND—The effect of hepatitis delta virus (HDV) infection on the clinical course of cirrhosis type B is poorly defined. AIMS—To investigate the impact of HDV status on morbidity and mortality in cirrhosis type B. PATIENTS/METHODS—Retrospective cohort study of 200 Western European patients with compensated cirrhosis type B followed for a median period of 6.6 years. RESULTS—At diagnosis, 20% of patients had antibodies to HDV (anti-HDV); median age was lower in anti-HDV positive cirrhotics (34 v 48 years respectively). Kaplan-Meier five year probability of hepatocellular carcinoma (HCC) was 6, 10, and 9% in anti-HDV positive/HBeAg negative, anti-HDV negative/HBeAg negative, and anti-HDV negative/HBeAg positive cirrhotics respectively; the corresponding figures for decompensation were 22, 16, and 19% and for survival they were 92, 89, and 83% respectively. Cox regression analysis identified age, albumin concentration, γ-globulin concentration, and HDV status as significant independent prognostic variables. After adjustment for clinical and serological differences at baseline, the risk (95% confidence interval) for HCC, decompensation, and mortality was increased by a factor of 3.2 (1.0 to 10), 2.2 (0.8 to 5.7), and 2.0 (0.7 to 5.7) respectively in anti-HDV positive relative to HDV negative cirrhotic patients. The adjusted estimated five year risk for HCC was 13, 4, and 2% for anti-HDV positive/HBeAg negative, anti-HDV negative/HBeAg negative, and anti-HDV negative/HBeAg positive cirrhotics respectively; the corresponding figures for decompensation were 18, 8, and 14% and for survival 90, 95, and 93% respectively. CONCLUSIONS—HDV infection increases the risk for HCC threefold and for mortality twofold in patients with cirrhosis type B. Keywords: delta hepatitis; prognosis; hepatocellular carcinoma; decompensation; survival

Long term outcome after transjugular intrahepatic portosystemic stent-shunt in non-transplant cirrhotics with hepatorenal syndrome: a phase II study

Abstract: BACKGROUND Recent small studies on hepatorenal syndrome (HRS) indicate some clinical benefit after transjugular intrahepatic portosystemic stent-shunt (TIPS) but sufficient long term data are lacking. AIM We studied prospectively feasibility, safety, and long term survival after TIPS in 41 non-transplantable cirrhotics with HRS (phase II study). PATIENTS AND METHODS HRS was diagnosed using current criteria (severe (type I) HRS, n=21; moderate (type II) HRS, n=20). Thirty one patients (14 type I, 17 type II) received TIPS (8–10 mm) while advanced liver failure excluded shunting in 10. During follow up (median 24 months) we analysed renal function and survival (Kaplan-Meier). RESULTS TIPS markedly reduced the portal pressure gradient (21 (5) to 13 (4) mm Hg (mean (SD)); p CONCLUSIONS TIPS provides long term renal function and probably survival benefits in the majority of non-transplantable cirrhotics with HRS. These data warrant controlled trials evaluating TIPS in the management of HRS.

Guidelines for osteoporosis in coeliac disease and inflammatory bowel disease

Abstract: Osteoporotic fractures are a major public health problem. It has been estimated that in the USA the remaining lifetime fracture risk at the age of 50 years is 40% for white women and 13% for white men,1 the major fracture sites being spine, forearm and hip. This results in considerable morbidity and mortality and rising costs, including acute hospital care and long term care in the home or nursing home. The estimated total annual cost of osteoporotic fractures in England and Wales is £742 million ($464 million).2These costs are likely to increase as the population ages. ### 2.1 BONE MINERAL DENSITY Osteoporosis can be reliably detected by measurement of bone mineral density (BMD), which can be expressed as the number of SDs above or below either the mean BMD for young adults (T score) or the mean BMD for age matched controls (Z score). A BMD more than 2.5 SD below the mean for a young adult is generally taken to indicate osteoporosis.3 Stratification for fracture risk is possible using BMD. The risk increases roughly twofold for each SD decline in BMD below the population mean.4 5 This compares with a 1.5-fold increase in the risk of death from coronary artery disease with each SD increase in cholesterol concentrations or diastolic pressure. ### 2.2 RISK FACTORS FOR FRACTURE It is important to recognise that osteoporosis is but one of a number of factors predisposing to fracture, just as a raised cholesterol and diastolic pressure are each just one of many factors predisposing to coronary artery disease. Awareness of surroundings, mobility, and eyesight collectively contribute to a tendency to fall and all are likely to be important.6 Furthermore, bone strength is largely related to trabecular structure, certainly in the proximal femur, whereas BMD is a composite measurement of both cortical and trabecular bone.7 Although the …

Bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity

Abstract: BACKGROUND AND AIMS The gastrointestinal microflora exerts a barrier effect against enteropathogens. The aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria. METHODS Antibacterial activity was examined in vitro against a wide range of Gram negative and Gram positive pathogens. Inhibition of Salmonella typhimurium SL1334 cell association and cell invasion was investigated in vitro using Caco-2 cells. Colonisation of the gastrointestinal tract in vivo by bifidobacteria was examined in axenic C3/He/Oujco mice. Antimicrobial activity was examined in vivo in axenic C3/He/Oujco mice infected by the lethal S typhimurium C5 strain. RESULTS Fourteen human bifidobacterium strains isolated from infant stools were examined for antimicrobial activity. Two strains (CA1 and F9) expressed antagonistic activity against pathogens in vitro, inhibited cell entry, and killed intracellular S typhimurium SL1344 in Caco-2 cells. An antibacterial component(s) produced by CA1 and F9 was found to be a lipophilic molecule(s) with a molecular weight of less than 3500. In the axenic C3/He/Oujco mice, CA1 and F9 strains colonised the intestinal tract and protected mice against S typhimurium C5 lethal infection. CONCLUSION Several bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity, suggesting that they could participate in the “barrier effect” produced by the indigenous microflora.

Mucins and mucosal protection in the gastrointestinal tract: new prospects for mucins in the pathology of gastrointestinal disease

Abstract: The luminal surface of the gastrointestinal tract is covered by a viscoelastic mucous gel layer that acts as a protective barrier against the harsh luminal environment. The structural characteristics of this barrier are primary indicators of its physiological function and changes to its composition have long been identified in gastrointestinal pathologies. During the past decade significant improvements in analytical techniques coupled with detailed knowledge of the genes coding for the mucin proteins have provided exciting new insights into the role of the mucous layer and its relevance to gastrointestinal disease. The high molecular weight mucins are responsible for the viscoelastic properties of the mucous barrier. They are widely expressed in epithelial tissues and are characterised by variable number tandem repeat peptide sequences rich in serine, threonine, and proline which carry large numbers of O -linked oligosaccharide chains.1 2 At present, 12 genes have been described, shown in table 1.1 3 Secreted and membrane associated forms have been found based on their function as extracellular viscous secretions or viscoelastic polymer gels or location as membrane anchored molecules in the glycocalyx.3 4 Two clusters have been reported, the secretory mucin genes MUC2, MUC5AC, MUC5B, and MUC6 on chromosome 11p15.5, and MUC3, MUC11, and MUC12 on chromosome 7q22.3 View this table: Table 1 Mucin genes and their location in the human gastrointestinal tract Histochemical techniques for mucin detection rely on the ability to detect carbohydrate or negative charge and were widely used for classification of changes in disease.5 6 The use of lectins and anticarbohydrate antibodies has greatly improved the specific detection of mucins histochemically and biochemically.5 6 A group of mucin oligosaccharide antigens, including Tn, sialyl-Tn, T, Lewisx and Lewisy, sialyl and sulpho-Lewisx and -Lewisa, and the blood group ABH antigens, have been identified …

Hepatitis C virus related cirrhosis: time to occurrence of hepatocellular carcinoma and death

Abstract: BACKGROUND—In patients with hepatitis C virus (HCV) infection and cirrhosis, long term outcome and the incidence of hepatocellular carcinoma (HCC) are still debated. DESIGN—From January 1987 to January 1997, 416 patients (240 male, median age 57 years) with uncomplicated Child-Pugh A HCV related cirrhosis were followed in two Paris area centres from diagnosis of cirrhosis until death or reference date (1 June 1998). The analysis used a three state disability model generalising the Cox model. RESULTS—Of the 416 patients, 60 developed HCC with a five year rate of 13.4% (95% confidence interval (CI) 9.0-17.8%) and 83 died (including 34 with HCC), with a five year death rate of 15.3% (95% CI 12.6-18.0%). By multivariable analysis, time to HCC relied on age (hazard ratio (HR) 1.05 per year; p=0.0005), male sex (HR 2.13; p=0.01), oesophageal varices (HR 2.36; p= 0.008), decreased platelet count (HR 0.99; p=0.03), and bilirubin level (HR 1.01; p=0.003), while death after HCC was mainly related to tobacco consumption (HR 1.04; p=0.0006). In contrast, death free of HCC was dependent on age (HR 1.04; p=0.01), oesophageal varices (HR 2.75; p=0.001), low platelet count (HR 0.99; p=0.006), and albumin level (HR 0.90; p=0.0001). CONCLUSION—The incidence of HCC and mortality should be higher in these patients than previously stated, and prognostic factors of HCC and death are closely related age and symptoms of portal hypertension. Keywords: hepatitis C; cirrhosis; hepatocellular carcinoma; survival

Inflammatory mediators in human acute pancreatitis: clinical and pathophysiological implications

Abstract: Background—The time course and relationship between circulating and local cytokine concentrations, pancreatic inflammation, and organ dysfunction in acute pancreatitis are largely unknown. Patients and methods—In a prospective clinical study, we measured the proinflammatory cytokines interleukin (IL)1‚, IL-6 and IL-8, the anti-inflammatory cytokine IL-10, interleukin 1‚ receptor antagonist (IL-1RA), and the soluble IL-2 receptor (sIL-2R), and correlated our findings with organ and systemic complications in acute pancreatitis. In 51 patients with acute pancreatitis admitted within 72 hours after the onset of symptoms, these parameters were measured daily for seven days. In addition, 33 aspirates from ascites and the lesser sac were measured. Results—Sixteen patients had mild acute pancreatitis (AP) and 35 severe AP (Atlanta classification); 18 patients developed systemic complications requiring treatment. All mediators were increased in AP. sIL-2R, IL-10, and IL-6 were significantly elevated in patients with distant organ failure. An imbalance in IL-1‚/ IL-1RA was found in severe AP and pulmonary failure. Peak serum sIL-2R predicted lethal outcome and IL-1RA was an early marker of severity. IL-6 was the best prognostic parameter for pulmonary failure. Conclusion—Our results suggest that local mediator release, with a probable IL-1‚-IL-1RA imbalance in severe cases, is followed by the systemic appearance of pro- and anti-inflammatory mediators. The pattern of local and systemic mediators in complicated AP suggests a role for systemic lymphocyte activation (triggered by local release of mediators) in distant organ complications in severe AP. (Gut 2000;47:546‐552)

Differential expression of matrix metalloproteinases and their tissue inhibitors in colon mucosa of patients with inflammatory bowel disease

Abstract: BACKGROUND/AIMS—Alterations in synthesis and breakdown of extracellular matrix components are known to play a crucial role in tissue remodelling during inflammation and wound healing. Degradation of collagens is highly regulated by a cascade of matrix metalloproteinases (MMPs). The current study was therefore designed to determine gene expression patterns of MMPs and their tissue inhibitors (TIMPs) in single endoscopic biopsies of patients with inflammatory bowel disease (IBD). PATIENTS/METHODS—mRNA expression was measured by quantitative competitive polymerase chain reaction (PCR) in biopsies from patients with ulcerative colitis (n=21) and Crohn's disease (n=21). Protein expression was analysed by western blotting and immunohistochemistry. RESULTS—MMP-2, MMP-14, and TIMP-1 mRNAs were marginally increased in inflamed, but 9-12-fold increased in ulcerated colonic mucosa in IBD whereas TIMP-2 mRNA expression remained unchanged. MMP-1 and MMP-3 mRNA expression correlated well with the histological degree of acute inflammation, resulting in more than 15-fold increased MMP-1 and MMP-3 mRNA levels in inflamed versus normal colon samples from patients with ulcerative colitis and Crohn's disease. CONCLUSION—Profound overexpression of MMP-1 and MMP-3 mRNA transcripts suggests an important role for these enzymes in the process of tissue remodelling and destruction in inflammatory bowel disease. Keywords: matrix metalloproteinases; polymerase chain reaction; extracellular matrix; Crohn's disease; ulcerative colitis.

Value of endoscopic ultrasound guided fine needle aspiration biopsy in the diagnosis of solid pancreatic masses

Abstract: Aim—To assess the feasibility and diagnostic accuracy of endoscopic ultrasound guided fine needle biopsy (EUS-FNAB) in patients with solid pancreatic masses. Methods—Ninety nine consecutive patients with pancreatic masses were studied. Histological findings obtained by EUS-FNAB were compared with the final diagnosis assessed by surgery, biopsy of other tumour site or at postmortem examination, or by using a combination of clinical course, imaging features, and tumour markers. Results—EUS-FNAB was feasible in 90 patients (adenocarcinomas, n = 59; neuroendocrine tumours, n = 15; various neoplasms, n = 6; pancreatitis, n = 10), and analysable material was obtained in 73. Tumour size (> or < 25 mm in diameter) did not influence the ability to obtain informative biopsy samples. Diagnostic accuracy was 74.4% (adenocarcinomas, 81.4%; neuroendocrine tumours, 46.7%; other lesions, 75%; p<0.02). Overall, the diagnostic yield in all 99 patients was 68%. Successful biopsies were performed in six patients with portal hypertension. Minor complications (moderate bleeding or pain) occurred in 5% of cases. Conclusions—EUS-FNAB is a useful and safe method for the investigation of pancreatic masses, with a high feasibility rate even when lesions are small. Overall diagnostic accuracy of EUS-FNAB seems to depend on the tumour type. (Gut 2000;46:244‐249)

Chemotherapy for cancer causes apoptosis that precedes hypoplasia in crypts of the small intestine in humans

Abstract: BACKGROUND AND AIMS—The mechanism of gastrointestinal damage (mucositis) induced by cancer chemotherapy remains uncertain. The aims of this study were to define the time course and mechanism of small intestinal damage following chemotherapy in humans. METHODS—Patients receiving chemotherapy underwent upper gastrointestinal endoscopy (a maximum of two per patient) with duodenal biopsy prior to chemotherapy and again at 1, 3, 5, and 16 days after chemotherapy. Tissue was taken for morphometry, disaccharidase assays, electron microscopy, and for assessment of apoptosis using the Tdt mediated dUTP-biotin nick end labelling (TUNEL) method. Villus area, crypt length, and mitotic index were measured by a microdissection technique. RESULTS—Apoptosis increased sevenfold in intestinal crypts at one day, and villus area, crypt length, mitotic count per crypt, and enterocyte height decreased at three days after chemotherapy. Disaccharidase activities remained unchanged. Electron microscopy showed increased open tight junctions of enterocytes at day 3, consistent with more immature cells. All indices improved by 16 days. CONCLUSION—Small intestinal mucositis is associated with apoptosis in crypts that precedes hypoplastic villous atrophy and loss of enterocyte height. Keywords: chemotherapy; mucositis; small intestine

Mucin secretion is modulated by luminal factors in the isolated vascularly perfused rat colon

Abstract: BACKGROUND—Mucins play an important protective role in the colonic mucosa. Luminal factors modulating colonic mucus release have been not fully identified. AIM—To determine the effect of some dietary compounds on mucus discharge in rat colon. METHODS—An isolated vascularly perfused rat colon model was used. Mucus secretion was induced by a variety of luminal factors administered as a bolus of 1 ml for 30 minutes in the colonic loop. Mucin release was evaluated using a sandwich enzyme linked immunosorbent assay supported by histological analysis. RESULTS—The three dietary fibres tested in this study (pectin, gum arabic, and cellulose) did not provoke mucus secretion. Luminal administration of sodium alginate (an algal polysaccharide used as a food additive) or ulvan (a sulphated algal polymer) induced a dose dependent increase in mucin discharge over the concentration range 1-25 mg/l (p<0.05 for 25 mg/l alginate and p<0.05 for 10 and 25 mg/l ulvan). Glucuronic acid and galacturonic acid, which are major constituents of a variety of fibres, produced significant mucin secretion (p<0.05). Hydrogen sulphide and mercaptoacetate, two sulphides produced in the colonic lumen by microbial fermentation of sulphated polysaccharides, did not modify mucin secretion. Among the short chain fatty acids, acetate (5-100 mM) induced a dose dependent release of mucus (p<0.05 for 100 mM acetate). Interestingly, butyrate at a concentration of 5 mM produced colonic mucin secretion (p<0.05), but increasing its concentration to 100 mM provoked a gradual decrease in mucus discharge. Propionate (5-100 mM) did not induce mucin release. Several dietary phenolic compounds (quercetin, epicatechin, resveratrol) did not provoke mucus discharge. CONCLUSIONS—Two algal polysaccharides (alginate and ulvan), two uronic acids (glucuronic acid and galacturonic acid), and the short chain fatty acids acetate and butyrate induce mucin secretion in rat colon. Taken together, these data suggest that some food constituents and their fermentation products may regulate the secretory function of colonic goblet cells. Keywords: mucin secretion; colon; dietary fibres; algal fibres; short chain fatty acids; sulphides

Expression of the antiapoptosis gene,Survivin, predicts death from recurrent colorectal carcinoma

Abstract: BACKGROUND/AIMS—Inhibition of programmed cell death (apoptosis) is associated with increased tumour aggressiveness, and expression of Survivin, an antiapoptosis gene, in colorectal carcinomas may provide important prognostic information. PATIENTS/METHODS—Expression of Survivin messenger RNA was evaluated by reverse transcription-polymerase chain reaction in 144 colorectal carcinomas and 86 adjacent histologically normal mucosa samples from patients for whom long term follow up data were available. RESULTS—Survivin transcripts were detected in a significantly greater proportion of carcinomas (63.5%) than normal mucosa samples (29.1%; p<0.001). The prevalence of Survivin expression was independent of advancing pathological stage. Death due to recurrent cancer following curative resection was predicted independently by tumour expression of Survivin (hazard ratio (HR) 2.60; 95% confidence interval (95% CI) 1.17-5.75) and lymph node metastases (HR 2.38; 95% CI 1.21-4.70). On stage wise analysis, the predictive value of Survivin expression was limited to patients with stage II colorectal carcinomas; those with Survivin negative tumours had a five year survival rate of 94.4% compared with 44.8% for patients with Survivin positive tumours (p=0.004, log rank test). CONCLUSION—In patients with stage II colorectal carcinomas, Survivin expression provides prognostic information that may have important therapeutic implications. Keywords: colorectal neoplasia; messenger RNA; polymerase chain reaction; prognosis; survival

Leptin secretion and leptin receptor in the human stomach

Abstract: BACKGROUND AND AIM The circulating peptide leptin produced by fat cells acts on central receptors to control food intake and body weight homeostasis. Contrary to initial reports, leptin expression has also been detected in the human placenta, muscles, and recently, in rat gastric chief cells. Here we investigate the possible presence of leptin and leptin receptor in the human stomach. METHODS Leptin and leptin receptor expression were assessed by immunohistochemistry, reverse transcriptase-polymerase chain reaction (RT-PCR), and western blot analysis on biopsy samples from 24 normal individuals. Fourteen (10 healthy volunteers and four patients with non-ulcer dyspepsia and normal gastric mucosa histology) were analysed for gastric secretions. Plasma and fundic mucosa leptin content was determined by radioimmunoassay. RESULTS In fundic biopsies from normal individuals, immunoreactive leptin cells were found in the lower half of the fundic glands. mRNA encoding ob protein was detected in the corpus of the human stomach. The amount of fundic leptin was 10.4 (3.7) ng leptin/g mucosa, as determined by radioimmunoassay. Intravenous infusions of pentagastrin or secretin caused an increase in circulating leptin levels and leptin release into the gastric juice. The leptin receptor was present in the basolateral membranes of fundic and antral gastric cells. mRNA encoding Ob-RL was detected in both the corpus and antrum, consistent with a protein of ∼120 kDa detected by immunoblotting. CONCLUSION These data provide the first evidence of the presence of leptin and leptin receptor proteins in the human stomach and suggest that gastric epithelial cells may be direct targets for leptin. Therefore, we conclude that leptin may have a physiological role in the human stomach, although much work is required to establish this.

Anatomy and physiology of the enteric nervous system.

Abstract: The enteric nervous system (ENS) is a quasi autonomous part of the nervous system and includes a number of neural circuits that control motor functions, local blood flow, mucosal transport and secretions, and modulates immune and endocrine functions. Although these functions operate in concert and are functionally interlinked, it is useful to consider the neural circuits involved in each separately.1 This short summary will concentrate mainly on the neural circuits involved in motor control.2 The enteric neural circuits are composed of enteric neurones arranged in networks of enteric ganglia connected by interganglionic strands. Most enteric neurones involved in motor functions are located in the myenteric plexus with some primary afferent neurones located in the submucous plexus. As in all nervous systems involved in sensory-motor control, the ENS comprises primary afferent neurones, sensitive to chemical and mechanical stimuli, interneurones and motorneurones that act on the different effector cells including smooth muscle, pacemaker cells, blood vessels, mucosal glands, and epithelia, and the distributed system of intestinal cells involved in immune responses and endocrine and paracrine functions. The digestive tract is unique among internal organs because it is exposed to a large variety of physicochemical stimuli from the external world in the form of ingested food. As a consequence, the intestine has developed a rich repertoire of coordinated movements of its muscular apparatus to ensure the appropriate mixing and propulsion of contents during digestion, absorption, and excretion. The oro-aboral transit of the intestinal contents can be regarded as a form of adaptive locomotion that occurs over a wide range of spatial and temporal domains.3 The movements of the intestine are the result of interaction of the neural apparatus and the muscular apparatus.4 The muscular apparatus is organised in muscle layers made up of large collections of smooth muscle cells …

Marker antibody expression stratifies Crohn's disease into immunologically homogeneous subgroups with distinct clinical characteristics.

Abstract: BACKGROUND Perinuclear antineutrophil cytoplasmic antibodies (pANCA) have been detected in a clinically distinct Crohn9s disease subpopulation. Antibodies to Saccharomyces cerevisiae (ASCA) have been demonstrated in the majority of patients with Crohn9s disease. AIMS To examine the relationship between selective marker antibody expression in Crohn9s disease and disease onset, location, and clinical behaviour patterns. METHODS Sera from 156 consecutive patients with established Crohn9s disease were evaluated in a blinded fashion for the presence of ASCA and ANCA. Clinical profiles were generated by investigators blinded to immune marker status. RESULTS Using multiple regression analyses, higher ASCA levels were shown to be independently associated with early age of disease onset as well as both fibrostenosing and internal penetrating disease behaviours. Higher ANCA levels were associated with later age of onset and ulcerative colitis-like behaviour. Substratification of the Crohn9s disease population using selective ANCA and ASCA expression (high levels of a single marker antibody): (1) distinguished homogeneous subgroups that manifested similar disease location and behaviours; and (2) identified patients with more aggressive small bowel disease. CONCLUSIONS The findings suggest that by taking into account the magnitude of the host immune response, Crohn9s disease can now be stratified on an immunological basis into more homogeneous clinically distinct subgroups, characterised by greater uniformity among anatomical distribution of disease and disease behaviour.

Endosonographic features predictive of benign and malignant gastrointestinal stromal cell tumours

Abstract: BACKGROUND/AIM Some endoscopic ultrasonographic (EUS) features have been reported to be suggestive of malignancy in gastrointestinal stromal cell tumours (SCTs). The aim of this study was to assess the predictive value of these features for malignancy. METHODS A total of 56 histologically proven cases of SCT studied by EUS between 1989 and 1996 were reviewed. There were 42 gastric tumours, 12 oesophageal tumours, and two rectal tumours. The tumours were divided into two groups: ( a ) benign SCT, comprising benign leiomyoma (n = 34); ( b ) malignant or borderline SCT (n = 22), comprising leiomyosarcoma (n = 9), leiomyoblastoma (n = 9), and leiomyoma of uncertain malignant potential (n = 4). The main EUS features recorded were tumour size, ulceration, echo pattern, cystic spaces, extraluminal margins, and lymph nodes with a malignant pattern. The two groups were compared by univariate and multivariate analysis. RESULTS Irregular extraluminal margins, cystic spaces, and lymph nodes with a malignant pattern were most predictive of malignant or borderline SCT. Pairwise combinations of the three features had a specificity and positive predictive value of 100% for malignant or borderline SCT, but a sensitivity of only 23%. The presence of at least one of these three criteria had 91% sensitivity, 88% specificity, and 83% predictive positive value. In multivariate analysis, cystic spaces and irregular margins were the only two features independently predictive of malignant potential. The features most predictive of benign SCTs were regular margins, tumour size ⩽30 mm, and a homogeneous echo pattern. When the three features were combined, histology confirmed a benign SCT in all cases. CONCLUSIONS The combined presence of two out of three EUS features (irregular extraluminal margins, cystic spaces, and lymph nodes with a malignant pattern) had a positive predictive value of 100% for malignant or borderline gastrointestinal SCT. Tumours less than 30 mm in diameter with regular margins and a homogeneous echo pattern are usually benign.

Prospective study of liver dysfunction in pregnancy in Southwest Wales

Abstract: Background: Liver dysfunction in pregnancy has serious consequences. Its frequency and characteristics have not been systematically documented in Britain. We have prospectively determined incidence, causes, and outcome of liver dysfunction in pregnancy in an obstetric unit in Southwest Wales, UK. Methods: A central laboratory identified all abnormal liver tests (bilirubin >25 μmol/l, aspartate transaminase >40 U/l, or γ glutamyl transpeptidase >35 U/l) from patients in antenatal clinics and wards of an obstetric unit serving a population of 250 000. Patients with abnormal liver tests were assessed and followed through after pregnancy. Medical advice was provided to obstetric teams. Findings: There were 4377 deliveries during the 15 month study. A total of 142 patients had abnormal liver tests. There were 206 contributing diagnoses, the great majority being pregnancy specific. Among the most important were pre-eclampsia (68), HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome (30), obstetric cholestasis (23), hyperemesis gravidarum (11), acute fatty liver of pregnancy (five), and hepatic infarct (one). Sepsis, postoperative factors, and placental pathology (51) were not uncommonly responsible but incidental or pre-existing hepatobiliary disease was infrequent (17). Sixty five patients were delivered early by induction or caesarean section because of liver dysfunction. Despite substantial liver related morbidity, there were no maternal deaths and only two intrauterine deaths. Conclusions: Liver dysfunction was seen in 3% of deliveries during a 15 month prospective study and was usually directly related to pregnancy with spontaneous recovery in the puerperium. Incidence of the most serious conditions, acute fatty liver of pregnancy and HELLP syndrome, was much greater than previously reported. Profound effects on maternal and infant health were observed but close medical and obstetric collaboration ensured low mortality.

Butyrate and trichostatin A effects on the proliferation/differentiation of human intestinal epithelial cells: induction of cyclin D3 and p21 expression

Abstract: BACKGROUND—Sodium butyrate, a product of colonic bacterial fermentation, is able to inhibit cell proliferation and to stimulate cell differentiation of colonic epithelial cell lines. It has been proposed that these cellular effects could be linked to its ability to cause hyperacetylation of histone through the inhibition of histone deacetylase. AIM—To analyse the molecular mechanisms of butyrate action on cell proliferation/differentiation and to compare them with those of trichostatin A, a well known inhibitor of histone deacetylase. METHODS—HT-29 cells were grown in the absence or presence of butyrate or trichostatin A. Cell proliferation and cell cycle distribution were studied after DNA staining by crystal violet and propidium iodide respectively. Cell cycle regulatory proteins were studied by western blot and reverse transcription-polymerase chain reaction. Cell differentiation was followed by measuring brush border enzyme activities. Histone acetylation was studied by acid/urea/Triton acrylamide gel electrophoresis. RESULTS—Butyrate blocked cells mainly in the G1 phase of the cell cycle, whereas trichostatin A was inhibitory in both G1 and G2 phases. Butyrate inhibited the mRNA expression of cyclin D1 without affecting its protein expression and stimulated the protein expression of cyclin D3 without affecting its mRNA expression. Trichostatin A showed similar effects on cyclin D1 and D3. Butyrate and trichostatin A stimulated p21 expression both at the mRNA and protein levels, whereas their effects on the expression of cyclin dependent kinases were slightly different. Moreover, butyrate strongly stimulated the activity of alkaline phosphatase and dipeptidyl peptidase IV, whereas trichostatin A had no effect. Finally, a six hour exposure to butyrate or trichostatin A induced histone H4 hyperacetylation. At 15 and 24 hours, histone H4 remained hyperacetylated in the presence of butyrate, whereas it returned to control levels in the presence of trichostatin A. CONCLUSIONS—The data may explain how butyrate acts on cell proliferation/differentiation, and they show that trichostatin A does not reproduce every effect of butyrate, mainly because of its shorter half life. Keywords: butyrate; cyclin D; p21; trichostatin A; colonic epithelial cells; histone acetylation