Randomised controlled trial of mesalazine in IBS.

OBJECTIVE: Low-grade intestinal inflammation plays a role in the pathophysiology of IBS. In this trial, we aimed at evaluating the efficacy and safety of mesalazine in patients with IBS. DESIGN: We conducted a phase 3, multicentre, tertiary setting, randomised, double-blind, placebo-controlled trial in patients with Rome III confirmed IBS. Patients were randomly assigned to either mesalazine, 800 mg, or placebo, three times daily for 12 weeks, and were followed for additional 12 weeks. The primary efficacy endpoint was satisfactory relief of abdominal pain/discomfort for at least half of the weeks of the treatment period. The key secondary endpoint was satisfactory relief of overall IBS symptoms. Supportive analyses were also performed classifying as responders patients with a percentage of affirmative answers of at least 75% or >75% of time. RESULTS: A total of 185 patients with IBS were enrolled from 21 centres. For the primary endpoint, the responder patients were 68.6% in the mesalazine group versus 67.4% in the placebo group (p=0.870; 95% CI -12.8 to 15.1). In explorative analyses, with the 75% rule or >75% rule, the percentage of responders was greater in the mesalazine group with a difference over placebo of 11.6% (p=0.115; 95% CI -2.7% to 26.0%) and 5.9% (p=0.404; 95% CI -7.8% to 19.4%), respectively, although these differences were not significant. For the key secondary endpoint, overall symptoms improved in the mesalazine group and reached a significant difference of 15.1% versus placebo (p=0.032; 95% CI 1.5% to 28.7%) with the >75% rule. CONCLUSIONS: Mesalazine treatment was not superior than placebo on the study primary endpoint. However, a subgroup of patients with IBS showed a sustained therapy response and benefits from a mesalazine therapy. TRIAL REGISTRATION NUMBER: ClincialTrials.gov number, NCT00626288.

Salmonella gastroenteritis during childhood is a risk factor for irritable bowel syndrome in adulthood.

BACKGROUND & AIMS: Acute infectious gastroenteritis increases the risk for irritable bowel syndrome (IBS) and functional dyspepsia (FD). Children are particularly vulnerable to gastroenteritis because of the immaturity of their intestinal barrier, enteric nervous system, and immune response to pathogens. We investigated whether acute gastroenteritis in early life increases the risk of IBS and FD throughout adulthood. METHODS: In 1994, we identified and monitored a single culture-proven foodborne Salmonella enteritidis outbreak that involved 1811 patients (mostly pediatric) in Bologna, Italy. Clinical data were collected and a prospective, controlled, cohort study was designed. Long-term effects were assessed by mailing a questionnaire to 757 subjects 16 years after the outbreak (when all of the children were adults). We randomly selected a cohort of 250 adults exposed to Salmonella as children, all 127 individuals exposed as adults, and a cohort of nonexposed participants matched for number, age, sex, and area of residence (controls). RESULTS: Among 198 exposed participants, 64 reported FD (32.3%), compared with 51 of 188 controls (27.1%; P = .268). Among 204 exposed participants, 75 reported having IBS (36.8%) compared with 44 of 189 controls (23.3%; P = .004). The odds ratio for IBS among people exposed to the Salmonella was 1.92 (95% confidence interval: 1.23-2.98). The prevalence of IBS was higher in individuals exposed Salmonella as children than in controls (35.3% vs 20.5%; P = .008), but not in individuals exposed as adults, compared with controls. After multivariate logistic regression, post-infectious IBS was independently associated with anxiety and FD. CONCLUSIONS: Based on data collected from a single culture-proven foodborne Salmonella enteritidis outbreak in 1994, Salmonella-induced gastroenteritis during childhood (but not adulthood) is a risk factor for IBS.

Enteroendocrine profile of α-transducin immunoreactive cells in the gastrointestinal tract of the European sea bass (Dicentrarchus labrax).

In vertebrates, chemosensitivity of nutrients occurs through the activation of taste receptors coupled with G-protein subunits, including α-transducin (G(αtran)) and α-gustducin (G(αgust)). This study was aimed at characterising the cells expressing G(αtran) immunoreactivity throughout the mucosa of the sea bass gastrointestinal tract. G(αtran) immunoreactive cells were mainly found in the stomach, and a lower number of immunopositive cells were detected in the intestine. Some G(αtran) immunoreactive cells in the stomach contained G(αgust) immunoreactivity. Gastric G(αtran) immunoreactive cells co-expressed ghrelin, obestatin and 5-hydroxytryptamine immunoreactivity. In contrast, G(αtran) immunopositive cells did not contain somatostatin, gastrin/cholecystokinin, glucagon-like peptide-1, substance P or calcitonin gene-related peptide immunoreactivity in any investigated segments of the sea bass gastrointestinal tract. Specificity of G(αtran) and G(αgust) antisera was determined by Western blot analysis, which identified two bands at the theoretical molecular weight of ~45 and ~40 kDa, respectively, in sea bass gut tissue as well as in positive tissue, and by immunoblocking with the respective peptide, which prevented immunostaining. The results of the present study provide a molecular and morphological basis for a role of taste-related molecules in chemosensing in the sea bass gastrointestinal tract.

Contrast-enhanced ultrasound in the differential diagnosis of exocrine versus neuroendocrine pancreatic tumors.

OBJECTIVES: Contrast-enhanced ultrasound (CEUS) has been developed to better characterize the microvasculature of solid masses in several organs, including the pancreas. In this study, we assessed CEUS accuracy in differentiating exocrine from endocrine pancreatic tumors. METHODS: A total of 127 patients with single, undetermined pancreatic masses were prospectively examined with transabdominal ultrasound and CEUS, before surgical resection or percutaneous biopsy. RESULTS: Exocrine and endocrine pancreatic tumors showed different intralesional vascularization patterns: 98.9% (90/91) of exocrine tumors were hypoenhancing, whereas 95.8 % (23/24) of endocrine tumors had a hypervascular supply. A hypoenhancing pattern, indicative of ductal adenocarcinoma, had a significant (P < 0.001) diagnostic accuracy of 91.3% with a sensitivity of 96.8%, a specificity of 85.3%, a positive predictive value and a negative predictive value of 94.7% and 90.6%, respectively. The hyperenhancing pattern, indicative of endocrine tumors, had a significant (P = 0.031) diagnostic accuracy of 73.8% with a sensitivity of 83.3%, a specificity of 60.0%, a positive predictive value and negative predictive value of 83.3% and 60.0%, respectively. CONCLUSIONS: Contrast-enhanced ultrasound has a valuable diagnostic accuracy in differentiating exocrine from endocrine pancreatic tumors, which is a fundamental step to address appropriate histological evaluation, therapeutic approach, and follow-up.

Expression and regulation of α-transducin in the pig gastrointestinal tract.

Taste signalling molecules are found in the gastrointestinal (GI) tract suggesting that they participate to chemosensing. We tested whether fasting and refeeding affect the expression of the taste signalling molecule, α-transducin (Gαtran ), throughout the pig GI tract and the peptide content of Gαtran cells. The highest density of Gαtran -immunoreactive (IR) cells was in the pylorus, followed by the cardiac mucosa, duodenum, rectum, descending colon, jejunum, caecum, ascending colon and ileum. Most Gαtran -IR cells contained chromogranin A. In the stomach, many Gαtran -IR cells contained ghrelin, whereas in the upper small intestine many were gastrin/cholecystokinin-IR and a few somatostatin-IR. Gαtran -IR and Gαgust -IR colocalized in some cells. Fasting (24 h) resulted in a significant decrease in Gαtran -IR cells in the cardiac mucosa (29.3 ± 0.8 versus 64.8 ± 1.3, P < 0.05), pylorus (98.8 ± 1.7 versus 190.8 ± 1.9, P < 0.0 l), caecum (8 ± 0.01 versus 15.5 ± 0.5, P < 0.01), descending colon (17.8 ± 0.3 versus 23 ± 0.6, P < 0.05) and rectum (15.3 ± 0.3 versus 27.5 ± 0.7, P < 0.05). Refeeding restored the control level of Gαtran -IR cells in the cardiac mucosa. In contrast, in the duodenum and jejunum, Gαtran -IR cells were significantly reduced after refeeding, whereas Gαtran -IR cells density in the ileum was not changed by fasting/refeeding. These findings provide further support to the concept that taste receptors contribute to luminal chemosensing in the GI tract and suggest they are involved in modulation of food intake and GI function induced by feeding and fasting.

Clinical approach to diarrhea.

Diarrhea is defined as reduced stool consistency, increased water content and number of evacuations per day. A wide array of causes and pathophysiological mechanisms underlie acute and chronic forms of diarrhea. This review focuses on the major clinical aspects which should aid clinicians to diagnose chronic diarrhea. Clinical history, physical examination and stool evaluation and the predominant stool characteristic, i.e., bloody, watery, and fatty diarrhea, may narrow the differential diagnosis. Although mainly involved in acute diarrhea, many different infectious agents, including bacteria, viruses and protozoa, can be identified in chronic bloody/inflammatory diarrhea by appropriate microbiological tests and colonoscopic biopsy analysis. Osmotic diarrhea can be the result of malabsorption or maldigestion, with a subsequent passage of fat in the stool leading to steatorrhea. Secretory diarrhea is due to an increase of fluid secretion in the small bowel lumen, a mechanism often identified in gastroenteropancreatic neuroendocrine tumors. The evaluation of the fecal osmotic gap may help to characterize whether a chronic diarrhea is osmotic or secretory. Fatty diarrhea (steatorrhea) occurs if fecal fat output exceeds the absorptive/digestive capacity of the intestine. Steatorrhea results from malabsorption or maldigestion states and tests should differentiate between these two conditions. Individualized diagnostic work ups tailored on pathophysiological and clinical features are expected to reduce costs for patients with chronic diarrhea.

Mucosal permeability and immune activation as potential therapeutic targets of probiotics in irritable bowel syndrome.

There is increasingly convincing evidence supporting the participation of the gut microenvironment in the pathophysiology of irritable bowel syndrome (IBS). Studies particularly suggest an interplay between luminal factors (eg, foods and bacteria residing in the intestine), the epithelial barrier, and the mucosal immune system. Decreased expression and structural rearrangement of tight junction proteins in the small bowel and colon leading to increased intestinal permeability have been observed, particularly in postinfectious IBS and in IBS with diarrhea. These abnormalities are thought to contribute to the outflow of antigens through the leaky epithelium, causing overstimulation of the mucosal immune system. Accordingly, subsets of patients with IBS show higher numbers and an increased activation of mucosal immunocytes, particularly mast cells. Immune factors, released by these cells, including proteases, histamine, and prostanoids, participate in the perpetuation of the permeability dysfunction and contribute to the activation of abnormal neural responses involved in abdominal pain perception and changes in bowel habits. All these mechanisms represent new targets for therapeutic approaches in IBS. Probiotics are an attractive therapeutic option in IBS given their recognized safety and by virtue of positive biological effects they can exert on the host. Of importance for the IBS pathophysiology is that preclinical studies have shown that selective probiotic strains exhibit potentially useful properties including anti-inflammatory effects, improvement of mucosal barrier homeostasis, beneficial effects on intestinal microbiota, and a reduction of visceral hypersensitivity. The effect of probiotics on IBS is positive in most randomized, controlled studies, although the gain over the placebo is small. Identifying tailored probiotic approaches for subgroups of IBS patients represents a challenge for the future.

Does colorectal endometriosis alter intestinal functions? A prospective manometric and questionnaire-based study.

OBJECTIVE: To objectively evaluate using anorectal manometry whether endometriotic nodules influence intestinal function and to reveal subjective intestinal dysfunctions in patients with rectosigmoid deep infiltrating endometriosis. DESIGN: Prospective study. SETTING: Tertiary care university hospital. PATIENT(S): Patients (n = 25) with a preoperative diagnosis of rectosigmoid endometriosis. INTERVENTION(S): Patients underwent anorectal manometry; after that, they filled a questionnaire about defecatory functions and ranked their pain symptoms. MAIN OUTCOME MEASURE(S): The parameters studied were resting pressure, maximum squeezing pressure, pushing, rectoanal inhibitory reflex, and rectal sensibility. We analyzed the responses to the defecatory function questionnaire and the scored the endometriosis pain symptoms using a Visual Analogue Scale. RESULT(S): No alterations of the rectoanal inhibitory reflex were found. Hypertone of the internal anal sphincter was found in 20 of 25 patients. Almost half of the patients had an increase of the threshold of desire to defecate, and 7 patients had a reduction of the anal sphincter squeeze pressure. According to the responses to the defecatory function questionnaire, incomplete evacuation was the most common symptom. CONCLUSION(S): We did not find marked motility or sensitive dysfunctions at the anorectal manometry, whereas subjectively patients reported some defecatory disorders. We revealed the presence of hypertone of the internal anal sphincter in most of the patients. CLINICAL TRIAL REGISTRATION NUMBER: 74/2010/O/Sper.

Sigmoid compliance and visceral perception in spinal cord injury patients.

Intestinal motor and sensory dysfunctions in traumatic complete or incomplete spinal cord injury (SCI) are frequent and result in altered mechanisms of defecation. The aim of this study is to investigate sigmoid compliance and perception in chronic SCI patients. Sigmoid responses to fixed-tension distentions were assessed using a tensostat in six patients (six men, 42 ± 4 years) with chronic complete transection of the spinal cord (high-SCI; five tetraplegic C5-C7 and one paraplegic T4-T6) and impaired evacuation (i.e. constipation). A group of 10 healthy individuals (six men, 25 ± 1 years) served as controls. SCI patients had higher sigmoid compliance at the highest distention level than the controls (10.3 ± 2.4 vs. 5.1 ± 0.8 ml/mmHg; P<0.05). Perception scores at first sensation were higher in SCI patients (2.3 ± 0.7 vs. 1.1 ± 0.1; P<0.05), but were not different at the highest distention levels (3.7 ± 0.8 vs. 3 ± 1; NS). The most commonly reported sensation by patients was distention/bloating and was referred less commonly to the hypogastrium compared with distention/bloating in controls. An increased sigmoid compliance can be detected in constipated SCI patients. The preservation of some degree of visceral sensations, although abnormally referred, could imply the occurrence of sensory input remodeling at the spinal level.

The immune system in irritable bowel syndrome.

The potential relevance of systemic and gastrointestinal immune activation in the pathophysiology and symptom generation in the irritable bowel syndrome (IBS) is supported by a number of observations. Infectious gastroenteritis is the strongest risk factor for the development of IBS and increased rates of IBS-like symptoms have been detected in patients with inflammatory bowel disease in remission or in celiac disease patients on a gluten free diet. The number of T cells and mast cells in the small and large intestine of patients with IBS is increased in a large proportion of patients with IBS over healthy controls. Mediators released by immune cells and likely from other non-immune competent cells impact on the function of enteric and sensory afferent nerves as well as on epithelial tight junctions controlling mucosal barrier of recipient animals, isolated human gut tissues or cell culture systems. Antibodies against microbiota antigens (bacterial flagellin), and increased levels of cytokines have been detected systemically in the peripheral blood advocating the existence of abnormal host-microbial interactions and systemic immune responses. Nonetheless, there is wide overlap of data obtained in healthy controls; in addition, the subsets of patients showing immune activation have yet to be clearly identified. Gender, age, geographic differences, genetic predisposition, diet and differences in the intestinal microbiota likely play a role and further research has to be done to clarify their relevance as potential mechanisms in the described immune system dysregulation. Immune activation has stimulated interest for the potential identification of biomarkers useful for clinical and research purposes and the development of novel therapeutic approaches.

Cystic dystrophy of the duodenal wall is not always associated with chronic pancreatitis.

Cystic dystrophy of the duodenal wall is a rare form of the disease which was described in 1970 by French authors who reported the presence of focal pancreatic disease localized in an area comprising the C-loop of the duodenum and the head of the pancreas. German authors have defined this area as a "groove". We report our recent experience on cystic dystrophy of the paraduodenal space and systematically review the data in the literature regarding the alterations of this space. A MEDLINE search of papers published between 1966 and 2010 was carried out and 59 papers were considered for the present study; there were 19 cohort studies and 40 case reports. The majority of patients having groove pancreatitis were middle aged. Mean age was significantly higher in patients having groove carcinoma. The diagnosis of cystic dystrophy of the duodenal wall can now be assessed by multidetector computer tomography, magnetic resonance imaging and endoscopic ultrasonography. These latter two techniques may also add more information on the involvement of the remaining pancreatic gland not involved by the duodenal malformation and they may help in differentiating "groove pancreatitis" from "groove adenocarcinoma". In conclusion, chronic pancreatitis involving the entire pancreatic gland was present in half of the patients with cystic dystrophy of the duodenal wall and, in the majority of them, the pancreatitis had calcifications.

Chronic intestinal pseudo-obstruction: clinical features, diagnosis, and therapy.

CIPO is the very "tip of the iceberg" of functional gastrointestinal disorders, being a rare and frequently misdiagnosed condition characterized by an overall poor outcome. Diagnosis should be based on clinical features, natural history and radiologic findings. There is no cure for CIPO and management strategies include a wide array of nutritional, pharmacologic, and surgical options which are directed to minimize malnutrition, promote gut motility and reduce complications of stasis (ie, bacterial overgrowth). Pain may become so severe to necessitate major analgesic drugs. Underlying causes of secondary CIPO should be thoroughly investigated and, if detected, treated accordingly. Surgery should be indicated only in a highly selected, well characterized subset of patients, while isolated intestinal or multivisceral transplantation is a rescue therapy only in those patients with intestinal failure unsuitable for or unable to continue with TPN/HPN. Future perspectives in CIPO will be directed toward an accurate genomic/proteomic phenotying of these rare, challenging patients. Unveiling causative mechanisms of neuro-ICC-muscular abnormalities will pave the way for targeted therapeutic options for patients with CIPO.

Therapeutic management and clinical outcome of autoimmune pancreatitis.

BACKGROUND: Autoimmune pancreatitis, in comparison to other benign chronic pancreatic diseases, is characterized by the possibility of curing the illness with immunosuppressant drugs. The open question is whether to differentiate autoimmune pancreatitis as a primary or secondary disease based on the presence or absence of other autoimmune diseases or whether to consider autoimmune pancreatitis a clinical and pathological systemic entity, called IgG4-related sclerosing disease, since this aspect is also very important from a therapeutic point of view. METHODS: In this paper, we reviewed the conventional therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality. We also reviewed some aspects which are important for the correct management of autoimmune pancreatitis, such as the surgical approach, the outcome of surgically treated autoimmune pancreatitis patients, whether medical treatment is always necessary, and, finally, when medical treatment should be initiated. CONCLUSIONS: Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open such as the dosage of steroids in the acute phase and the duration of steroid therapy; finally, it should be assessed if other immunosuppressive non-steroidal drugs may become the first-line therapy in patients with AIP without jaundice and without atrophic pancreas.

Mechanisms underlying visceral hypersensitivity in irritable bowel syndrome.

Visceral hypersensitivity is currently considered a key pathophysiological mechanism involved in pain perception in large subgroups of patients with functional gastrointestinal disorders, including irritable bowel syndrome (IBS). In IBS, visceral hypersensitivity has been described in 20%-90% of patients. The contribution of the central nervous system and psychological factors to visceral hypersensitivity in patients with IBS may be significant, although still debated. Peripheral factors have gained increasing attention following the recognition that infectious enteritis may trigger the development of persistent IBS symptoms, and the identification of mucosal immune, neural, endocrine, microbiological, and intestinal permeability abnormalities. Growing evidence suggests that these factors play an important role in pain transmission from the periphery to the brain via sensory nerve pathways in large subsets of patients with IBS. In this review, we will report on recent data on mechanisms involved in visceral hypersensitivity in IBS, with particular attention paid to peripheral mechanisms.

Is the pancreas affected in patients with septic shock?--a prospective study.

BACKGROUND: Hyperamylasemia can be observed anecdotally during the course of severe sepsis or septic shock. This study aimed to investigate the possibility of pancreatic involvement in patients with septic shock using serum pancreatic enzyme determinations and imaging techniques in 21 consecutive patients with septic shock and 21 healthy subjects as controls. METHODS: The serum activity of pancreatic amylase and lipase was assayed initially in all subjects and 24 and 48 hours after the initial observation in the 21 patients with septic shock. All patients also underwent radiological examination to detect pancreatic abnormalities. RESULTS: The serum activity of pancreatic amylase was significantly higher in the 21 patients with septic shock than in the 21 control subjects during the study period, while the serum activity of lipase was similar to that of the control subjects. Amylase and lipase serum activity did not significantly changed throughout the study period in the 21 patients with septic shock. None of the patients with pancreatic hyperenzymemia had clinical signs or morphological alterations compatible with acute pancreatitis. CONCLUSION: The presence of pancreatic hyperenzymemia in septic shock patients is not a biochemical manifestation of acute pancreatic damage, and the management of these patients should be dependent on the clinical situation and not merely the biochemical results.

Plasma concentrations of angiogenetic factors and angiogenetic inhibitors in patients with ductal pancreatic neoplasms. A pilot study.

BACKGROUND: The aim of the study was to evaluate the circulating concentrations of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2 (VEGFR-2), vascular endothelial growth factor-D (VEGF-D) and endostatin in patients with intraductal papillary mucinous neoplasm (IPMN), and in those with ductal adenocarcinomas. METHODS: Sixty patients (32 males, 28 females, mean age 69.3±11.3 years) were enrolled: 31 (51.7%) had IPMNs and 29 (48.3%) had histologically confirmed pancreatic adenocarcinomas. Thirty blood donors were also studied as controls. In all study subjects, the concentrations of VEGF, VEGF-D, VEGFR-2, and endostatin were determined using enzyme-linked immunosorbent assays. RESULTS: Serum concentrations of VEGF, VEGF-D, and VEGFR-2 were significantly higher in patients with pancreatic ductal adenocarcinoma and those with IPMNs compared with healthy subjects, while endostatin was significantly higher only in patients with pancreatic ductal adenocarcinoma compared with healthy subjects. Within the group of patients, VEGFR-2 was significantly higher in patients with ductal adenocarcinoma compared to those with IPMNs. The sensitivity and the specificity of VEGFR-2 in differentiating patients with ductal adenocarcinomas from those with IPMN at a cut-off range of 4003-4034 pg/mL was 86.2% and 54.8%, respectively. CONCLUSIONS: IPMNs have serum VEGFR-2 concentrations different from those in patients with ductal adenocarcinomas. However, serum VEGFR-2 cannot be routinely utilized to differentiate IPMNs from pancreatic ductal adenocarcinomas.

Tyrosine kinase inhibitors, pancreatic hyperenzymemia and acute pancreatitis: a review.

The advent of new drugs can rapidly increase the number of substances causing acute pancreatitis. This is the case of tyrosine kinase inhibitors; these drugs are currently used for chronic myeloid leukemia, gastrointestinal stromal tumors, unresectable hepatocellular carcinomas and advanced renal cell carcinomas that and they have been reported to cause acute pancreatitis or asymptomatic elevations of serum pancreatic enzymes. Of the classes of drugs capable of inducing acute pancreatitis, we aimed to evaluate, in which class tyrosine kinase inhibitors can be allocated. A search was carried out using the MEDLINE database in order to select the data existing in the literature on pyrimidines and acute pancreatitis or serum lipase/amylase elevation covering the period from January 1966 to January 2010; thirteen papers were found and utilized for this review. Based on the data in the literature, we found that tyrosine kinase inhibitors may often cause an increase in pancreatic enzymes in plasma and patients treated with these drugs, especially those who are treated with sorafenib, might be at risk of developing acute pancreatitis. Whether acute pancreatitis due to tyrosine kinase inhibitors is associated only with sorafenib or may also be caused by other drugs of the same class remains an open question. Recent patents on tyrosine kinase inhibitors and acute pancreatitis are pointed out in this review.