Altered intestinal tight junctions' expression in patients with liver cirrhosis: a pathogenetic mechanism of intestinal hyperpermeability.

BACKGROUND: Increased intestinal permeability in cirrhosis exerts a pivotal role in the pathogenesis of spontaneous bacterial peritonitis and other complications of cirrhosis through promotion of systemic endotoxemia. This study was designed to investigate whether the expression of tight junction (TJ) proteins, which regulate gut paracellular permeability, is altered in the intestinal mucosa of patients with liver cirrhosis and study its potential association with the stage of liver disease and the development of systemic endotoxemia. DESIGN: Twenty-four patients with cirrhosis at a decompensated (n = 12, group A) or compensated condition (n = 12, group B) and 12 healthy controls (group C) were subjected to duodenal biopsy. The expression of the TJ proteins occludin and claudin-1 in the intestinal epithelium was evaluated by immunohistochemistry. Plasma endotoxin concentrations were also determined. RESULTS: Patients with cirrhosis presented significantly higher serum endotoxin concentrations as compared to healthy controls (P < 0·001), whilst endotoxemia was higher in decompensated disease (P < 0·05 vs. compensated cirrhosis). Patients with decompensated and compensated cirrhosis presented significantly reduced expression of occludin and claudin-1 as compared to controls (P < 0·01, respectively). These alterations were significantly more pronounced in decompensated patients as compared to compensated (P < 0·05). Regarding occludin, in patients with cirrhosis, a specific pattern of expression in the intestinal epithelium was observed, with a gradually increasing loss of expression from crypt to tip of the villi. Occludin and claudin-1 expression were inversely correlated with Child-Pugh score (P < 0·001), the grade of oesophageal varices (P < 0·01) and endotoxin concentrations (P < 0·001). CONCLUSIONS: This study demonstrates for the first time that human liver cirrhosis induces significant alterations in enterocytes' TJs. These changes might represent an important cellular mechanism for intestinal barrier dysfunction and hyperpermeability in patients with liver cirrhosis.

Intestinal epithelial cell proliferation, apoptosis and expression of tight junction proteins in patients with obstructive jaundice.

BACKGROUND: Intestinal hyperpermeability has been repeatedly confirmed in patients with obstructive jaundice and is considered a pivotal factor in the development of septic and renal complications in these patients. However, little is known on the mechanism(s) leading to this phenomenon. This study was undertaken to investigate the cellular and subcellular intestinal alterations in patients with obstructive jaundice. DESIGN: Sixteen patients with obstructive jaundice of malignant (n = 8, group A) or benign (n = 8, group B) aetiology, without concomitant cholangitis, and eight healthy controls (group C) were subjected to duodenal biopsy distal to the ampulla of Vater. Specimens were examined histologically and the apoptotic activity in the cryptal epithelium was recorded. Epithelial proliferation was evaluated by immunohistochemical expression of Ki67 antigen. The expression of the tight junction (TJ) proteins occludin, claudin-1, claudin-4 and claudin-7 in the intestinal epithelium was also evaluated by immunohistochemistry. RESULTS: Patients with malignant or benign obstructive jaundice presented significantly decreased intestinal epithelial cell proliferation rates compared with controls (P < 0·05), whereas no differences were detected in apoptotic activity. In a semiquantitative analysis of TJ protein expression, occludin, claudin-1 and -7 were significantly decreased (P < 0·001), whereas claudin-4 was significantly increased (P < 0·01) in jaundiced patients and their distribution was altered. No differences were detected between patients with malignant or benign obstructive jaundice for all intestinal barrier parameters studied. CONCLUSION: Decreased enterocyte proliferation and altered TJ protein expression might represent important mechanisms for intestinal barrier dysfunction and hyperpermeability in patients with extrahepatic cholestasis. The potential pharmacological modulation of these factors may lead to better control of intestinal permeability in the jaundiced patient with improved clinical outcome.

Changes in indications for upper gastrointestinal tract endoscopy and endoscopic findings during the last fifteen years in south-western Greece.

BACKGROUND: During the past years, major advances in the management of upper gastrointestinal diseases have been achieved. The aim of this study was to determine if changes in indications for upper gastrointestinal endoscopy and endoscopic findings have occurred during the last 15 years in our area. METHODS: Indications for upper gastrointestinal tract endoscopy and endoscopy findings of patients who underwent upper endoscopy in years 1990, 1995, 2000, and 2005 in our department were compared. RESULTS: Over the 15-year period, the number of diagnostic endoscopies performed in our department in years 1990, 1995, 2000, and 2005 increased (953, 1245, 2350, and 2528, respectively). Acute upper gastrointestinal bleeding had become less frequent (40%, 42.8%, 19.7%, 14.3%, P<0.001), but dyspepsia (24.4%, 33.6%, 54.3%, 51.3%, P=0.002) and reflux (1.8%, 1.3%, 5.1%, 10.8%, P=0.005) more frequent indications for upper endoscopy. The endoscopic findings of duodenal ulcer (39.1%, 22.5%, 20.5%, 9.3%, P<0.001), gastric ulcer (15.9%, 8.3%, 5.7%, 4.6%, P=0.036) as well as erosive gastroduodenitis (35.6%, 22.2%, 15.3%, 4.7%, P<0.001) decreased, whereas that of reflux esophagitis (3.1%, 10.1%, 12%, 16%, P=0.034) increased. Moreover, the percentage of patients with negative endoscopy or minimal endoscopic findings (eg, nonerosive gastritis) increased (12.8%, 33.7%, 54.1%, 64.4%, P<0.001). CONCLUSIONS: In south-western Greece, dyspepsia and reflux as an indication for upper endoscopy have been increasing, whereas acute upper gastrointestinal bleeding has been decreasing. The finding of peptic ulcers at the upper gastrointestinal tract endoscopy has become significantly less frequent, while the percentage of patients with negative results of endoscopy seems to have been increasing rapidly.

Acute upper gastrointestinal bleeding in octogenarians: clinical outcome and factors related to mortality.

AIM: To evaluate the aetiology, clinical outcome and factors related to mortality of acute upper gastrointestinal bleeding (AUGIB) in octogenarians. METHODS: We reviewed the records of all patients over 65 years old who were hospitalised with AUGIB in two hospitals from January 2006 to December of 2006. Patients were divided into two groups: Group A (65-80 years old) and Group B (>80 years old). RESULTS: Four hundred and sixteen patients over 65 years of age were hospitalized because of AUGIB. Group A included 269 patients and Group B 147 patients. Co-morbidity was more common in octogenarians (P=0.04). The main cause of bleeding was peptic ulcer in both groups. Rebleeding and emergency surgery were uncommon in octogenarians and not different from those in younger patients. In-hospital complications were more common in octogenarians (P=0.05) and more patients died in the group of octogenarians compared to the younger age group (P=0.02). Inability to perform endoscopic examination (P=0.002), presence of high risk for rebleeding stigmata (P=0.004), urea on admission (P=0.036), rebleeding (P=0.004) and presence of severe co-morbidity (P<0.0001) were related to mortality. In multivariate analysis, only the presence of severe co-morbidity was independently related to mortality (P=0.032). CONCLUSION: While rebleeding and emergency surgery rates are relatively low in octogenarians with AUGIB, the presence of severe co-morbidity is the main factor of adverse outcome.

Pleiotropic effects of bombesin and neurotensin on intestinal mucosa: not just trefoil peptides.

Bombesin and neurotensin are neuropeptides which exert a wide spectrum of biological actions on gastrointestinal tissues influencing intestinal growth and adaptation, intestinal motility, blood flow, secretion, nutrient absorption and immune response. Based mainly on their well-established potent enterotrophic effect, numerous experimental studies investigated their potential positive effect on the atrophic or injured intestinal mucosa. These peptides proved to be effective mucosa-healing factors, but the potential molecular and cellular mechanisms for this action remained unresolved. In a recently published study (World J Gastroenterol 2008; 14(8): 1222-1230), it was shown that their protective effect on the intestine in experimentally induced inflammatory bowel disease was related to anti-inflammatory, antioxidant and antiapoptotic actions. These results are in close agreement with our previous studies on jaundiced and hepatectomized rats that showed a regulatory effect of bombesin and neurotensin on critical cellular processes such as enterocyte' proliferation and death, oxidative stress and redox equilibrium, tight junctions' formation and function, and inflammatory response. The pleiotropic effects of bombesin and neurotensin on diverse types of intestinal injury may justify their consideration for clinical trials.

Twenty-four hour prophylaxis with increased dosage of octreotide reduces the incidence of post-ERCP pancreatitis.

BACKGROUND: Acute pancreatitis is a common complication of ERCP, occurring in up to 10% of cases. Chemoprevention of post-ERCP pancreatitis remains a debated issue. OBJECTIVE: This study evaluated whether increased dosage of octreotide, a potent inhibitor of pancreatic secretion, could reduce the incidence of post-ERCP pancreatitis. DESIGN: In a randomized, double-blind, placebo controlled trial, the effect of 500 microg octreotide, given 3 times daily subcutaneously starting 24 hours before the ERCP procedure, was compared with that of placebo in patients who underwent diagnostic and/or therapeutic ERCP. PATIENTS: A total of 202 patients were included in the trial. The 2 groups were similar in regards to age, sex, indications for treatment, underlying diseases, and types of therapeutic procedures. Patients were clinically evaluated, and serum amylase levels were determined before ERCP and at 6 to 8 hours thereafter. Standardized criteria were used to diagnose and to grade the severity of post-ERCP pancreatitis. RESULTS: The medication was discontinued because of an allergic reaction in 1 patient in the octreotide group. The incidence of post-ERCP pancreatitis was significantly lower in the octreotide group compared with the placebo group (2/10 [2%] vs 9/101 [8.9%], P = .03). All cases of acute pancreatitis were mild, except 2 (1 moderate and 1 severe) in the placebo group. CONCLUSIONS: The results of this trial support the use of 24-hour prophylaxis with high dose of octreotide in the prevention of post-ERCP pancreatitis.

Experimental obstructive jaundice alters claudin-4 expression in intestinal mucosa: effect of bombesin and neurotensin.

AIM: To investigate the influence of experimental obstructive jaundice and exogenous bombesin (BBS) and neurotensin (NT) administration on the expression of the tight junction (TJ)-protein claudin-4 in intestinal epithelium of rats. METHODS: Forty male Wistar rats were randomly divided into five groups: I = controls, II = sham operated, III = bile duct ligation (BDL), IV = BDL+BBS (30 microg/kg per d), V = BDL+NT (300 microg/kg per d). At the end of the experiment on d 10, endotoxin was measured in portal and aortic blood. Tissue sections of the terminal ileum were examined histologically and immunohistochemically for evaluation of claudin-4 expression in intestinal epithelium. RESULTS: Obstructive jaundice led to intestinal barrier failure demonstrated by significant portal and aortic endotoxemia. Claudin-4 expression was significantly increased in the upper third of the villi in jaundiced rats and an upregulation of its lateral distribution was noted. Administration of BBS or NT restored claudin-4 expression to the control state and significantly reduced portal and aortic endotoxemia. CONCLUSION: Experimental obstructive jaundice increases claudin-4 expression in intestinal epithelium, which may be a key factor contributing to the disruption of the mucosal barrier. Gut regulatory peptides BBS and NT can prevent this alteration and reduce portal and systemic endotoxemia.

Effect of oral glutamine administration on bacterial tanslocation, endotoxemia, liver and ileal morphology, and apoptosis in rats with obstructive jaundice.

Postoperative complications in patients with obstructive jaundice remain increased when associated with endotoxemia and the inflammatory response due to gut barrier failure. Administration of glutamine has been proposed to maintain the integrity of the gut mucosa and thus reduce bacterial translocation (BT), but the effects of this pretreatment on apoptosis and histologic morphology of various organs affected by BT in obstructive jaundice have not been studied. We therefore studied the effects of oral glutamine supplementation on endotoxemia, BT, liver and terminal ileal morphology, and apoptosis in an experimental model of obstructive jaundice. A total of 60 male Wistar rats were randomly divided into four groups of 15 each: I, controls; II, sham-operated; III, bile duct ligation (BDL); IV, BDL + glutamine (4.5 g/kg/day in drinking water). Ileal samples for histology, DNA and protein content, liver biopsies, mesenteric lymph nodes (MLNs) for culture, and portal and systemic blood samples for endotoxin measurements were obtained 10 days later. Compared to the controls, a significant increase in contaminated MLN and liver samples and increased endotoxemia were noted in group III (p < 0.01) but were significantly reduced in group IV (p < 0.05). Group IV also had a significantly higher number of mitoses per crypt (M/c) (p < 0.05), less apoptotic body counts (ABCs) (p < 0.05), and a higher DNA content than did group III (p < 0.05). Liver biopsies from group III displayed typical changes of large duct obstruction that significantly improved after glutamine treatment, with decreased ductular proliferation. We concluded that supplementation of oral glutamine in the presence of obstructive jaundice ameliorates BT, endotoxemia, and apoptosis and improves the ileal and liver histology.

Acute upper gastrointestinal bleeding in operated stomach: outcome of 105 cases.

AIM: To compare the causes and clinical outcome of patients with acute upper gastrointestinal bleeding (AUGB) and a history of gastric surgery to those with AUGB but without a history of gastric surgery in the past. METHODS: The causes and clinical outcome were compared between 105 patients with AUGB and a history of gastric surgery, and 608 patients with AUGB but without a history of gastric surgery. RESULTS: Patients who underwent gastric surgery in the past were older (mean age: 68.1+/-11.7 years vs 62.8+/-17.8 years, P = 0.001), and the most common cause of bleeding was marginal ulcer in 63 patients (60%). No identifiable source of bleeding could be found in 22 patients (20.9%) compared to 42/608 (6.9%) in patients without a history of gastric surgery (P = 0.003). Endoscopic hemostasis was permanently successful in 26 out of 35 patients (74.3%) with peptic ulcers and active bleeding or non-bleeding visible vessel. Nine patients (8.6%) were operated due to continuing or recurrent bleeding, compared to 23/608 (3.8%) in the group of patients without gastric surgery in the past (P = 0.028). Especially in peptic ulcer bleeding patients, emergency surgery was more common in the group of patients with gastric surgery in the past (9/73 (12.3%) vs 19/360 (5.3%), P = 0.025). Moreover surgically treated patients in the past required more blood transfusion (3.3+/-4.0 vs 1.5+/-1.7, P = 0.0001) and longer hospitalization time (8.6+/-4.0 vs 6.9+/-4.9 d, P = 0.001) than patients without a history of gastric surgery. Mortality was not different between the two groups (4/105 (3.8%) vs 19/608 (3.1%)). CONCLUSION: Upper gastrointestinal bleeding seems to be more severe in surgically treated patients than in non-operated patients.

Acute upper gastrointestinal bleeding in patients on long-term oral anticoagulation therapy: endoscopic findings, clinical management and outcome.

AIM: Acute gastrointestinal bleeding is a severe complication in patients receiving long-term oral anticoagulant therapy. The purpose of this study was to describe the causes and clinical outcome of these patients. METHODS: From January 1999 to October 2003, 111 patients with acute upper gastrointestinal bleeding (AUGIB) were hospitalized while on oral anticoagulants. The causes and clinical outcome of these patients were compared with those of 604 patients hospitalized during 2000-2001 with AUGIB who were not taking warfarin. RESULTS: The most common cause of bleeding was peptic ulcer in 51 patients (45%) receiving anticoagulants compared to 359/604 (59.4%) patients not receiving warfarin (P < 0.05). No identifiable source of bleeding could be found in 33 patients (29.7%) compared to 31/604 (5.1%) patients not receiving anticoagulants (P = 0.0001). The majority of patients with concurrent use of non-steroidal anti-inflammatory drugs (NSAIDs) (26/35, 74.3%) had a peptic ulcer as a cause of bleeding while 32/76 (40.8%) patients not taking a great dose of NSAIDs had a negative upper and lower gastrointestinal endoscopy. Endoscopic hemostasis was applied and no complication was reported. Six patients (5.4%) were operated due to continuing or recurrent hemorrhage, compared to 23/604 (3.8%) patients not receiving anticoagulants. Four patients died, the overall mortality was 3.6% in patients with AUGIB due to anticoagulants, which was not different from that in patients not receiving anticoagulant therapy. CONCLUSION: Patients with AUGIB while on long-term anticoagulant therapy had a clinical outcome, which is not different from that of patients not taking anticoagulants. Early endoscopy is important for the management of these patients and endoscopic hemostasis can be safely applied.

Effect of bombesin and neurotensin on gut barrier function in partially hepatectomized rats.

AIM: To investigate the effect of regulatory peptides bombesin (BBS) and neurotensin (NT) on intestinal barrier function in partially hepatectomized rats. METHODS: Ninety male Wistar rats were randomly divided into five groups: I (n=0): controls, II (n= 20): sham operated, III (n=20): partial hepatectomy 70% (PHx), IV (n=20): PHx+BBS (30 microg/kg/d), V (n=20): PHx+NT (300 microg/kg/d). Groups IV and V were treated for 8 days before PHx and 48 h post surgery. At the end of the experiment, on day 10, intestinal barrier function was assessed by measuring endotoxin concentrations in portal and aortic blood. Tissue sections of the terminal ileum were examined histologically and villus density, mucosal thickness, mitotic activity and apoptosis in crypts were assessed. In addition, ileal mucosa was analyzed for DNA and protein content and microbiological analysis was performed in cecal contents. To estimate intestinal oxidative stress, lipid peroxidation was determined on tissue homogenates from terminal ileum. RESULTS: BBS or NT administration significantly reduced portal and systemic endotoxemia observed 48 h after partial hepatectomy. In hepatectomized rats (group III), a trend towards induction of mucosal atrophy was observed, demonstrated by the reduction of villus density, mucosal thickness, protein content and significant reduction of DNA, while these alterations were reversed by regulatory peptides administration. This trophic effect of BBS and NT was accompanied by induction of mitoses above control levels and a significant reduction of apoptosis in intestinal crypts. Intestinal lipid peroxidation was found significantly lower in PHx group and regulatory peptides exerted an antioxidant action, further decreasing this parameter of oxidative stress. The bacterial population of E. coli and aerobic Gram (+) cocci was increased in cecal content of hepatectomized rats, while this parameter was not affected by the administration of BBS or NT. CONCLUSION: Gut regulatory peptides BBS and NT improve intestinal barrier function and reduce endotoxemia in experimental partial hepatectomy. This effect is, at least in part, mediated by their trophic, anti-apoptotic, mitogenic, and antioxidant effect on the intestinal epithelium. This observation might be of potential value in patients undergoing liver resection.

The effect of octreotide as an adjunct treatment in active nonvariceal upper gastrointestinal bleeding.

GOALS: The aim of this study was to determine the effect ofoctreotide on active or recent gastrointestinal bleeding from benign peptic ulcers. STUDY: This is a prospective, randomized study including 110 patients with gastric or duodenal peptic ulcers presenting with active spurting or oozing bleeding or nonbleeding visible vessel. All patients were subjected to endoscopic hemostasis by injection of noradrenaline, and they were then randomized to either receive octreotide (55 patients) or placebo (55 patients). The groups did not differ with respect to age, sex, use of nonsteroidal antiinflammatory drugs, previous history of ulcer or bleeding, Helicobacter pylori infection, site, and severity of bleeding. RESULTS: The rebleeding rate was 36% in placebo and 32% in octreotide group, which does not present a statistically significant difference. Surgical intervention was required for 18 patients (32.7%) in the placebo group and for 16 patients (29%) in the octreotide group. The mortality rate was 2 patients (3.6%) in the placebo and 4 patients (7.2%) in the octreotide group. All the above presented no statistical difference. In addition, there was no statistically significant difference between the 2 groups with respect to the number of blood units transfused and hospital stay. CONCLUSIONS: The use of octreotide as an adjunct treatment in patients with acutely bleeding benign peptic ulcer or/and visible vessel did not seem to offer significant benefits regarding their outcome.

Changes in aetiology and clinical outcome of acute upper gastrointestinal bleeding during the last 15 years.

OBJECTIVES: The diagnostic and therapeutic approaches to patients with acute upper gastrointestinal bleeding have been improved during the last decades. The aim of this study was to compare the aetiology and clinical outcome of acute upper gastrointestinal bleeding (AUGIB) between two distinct periods during the last 15 years. METHODS: The causes of AUGIB and clinical outcome of 668 patients hospitalised with the problem in 1986-1987 were compared to 636 patients with AUGIB in 2000-2001. Patients were admitted to our hospital or they bled while they were inpatients for other reasons. No patient was excluded because of age or concurrent diseases. Endoscopic haemostasis with adrenaline injection for bleeding peptic ulcers was performed in the second period while no endoscopic method of haemostasis was performed in the first period. RESULTS: We observed an increase in the age of patients (56.5 +/- 16.9 vs 62.9 +/- 17.5 years, P < 0.0001) and the percentage of patients who received non-steroidal anti-inflammatory drugs (NSAIDs) before bleeding (from 44% to 63.5%, P < 0.0001). An increase in the diagnosis rate of gastric ulcer (12% vs 19.2%, P = 0.005) and varices (13.2% vs 3.3%, P < 0.001) with a simultaneous decrease in that of erosive gastroduodenitis (18.4% vs 7.2%, P < 0.0001) and duodenal ulcer (48.7% vs 33.3%, P < 0.0001) as a cause of bleeding was also observed. In peptic ulcer bleeding, emergency surgical haemostasis was reduced from 14% to 5.3%, P < 0.001. Overall mortality was also reduced from 5.2% to 3.1% and in peptic ulcer bleeding patients from 3.3% to 2.4%, respectively, but the differences are not statistically significant. CONCLUSION: The aetiology of AUGIB has changed during the last 15 years probably due to the better therapeutic approach to chronic duodenal ulcers and increasing use of NSAIDs in the elderly. Emergency surgical haemostasis has been reduced but the reduction of mortality was not significant.