Gastroenterology - Articles in Press

Increased Seroprevalence of HBV DNA with Mutations in the S Gene among Individuals > 18 Years of Age after Complete Vaccination - Accepted Manuscript

2012-05-14

Abstract: Background & Aims: Despite the success of a universal vaccination program against hepatitis B virus (HBV) in Taiwan, a small but substantial proportion of individuals remain infected by mutant viruses that escape the vaccine. We investigated the sero-epidemiology and genotypic characteristic of HBV for long time periods after neonatal vaccination. Methods: We measured hepatitis B surface antigen (HBsAg), hepatitis B core antigen (anti-HBc), and levels of antibodies to HBsAg (anti-HBs) in 1214 serum samples collected throughout Taiwan from individuals 0.6–87.8 years old in 2007. HBV-DNA was detected using PCR and sequence analysis in vaccine recipients who tested positive for anti-HBc and/or HBsAg. Results: The overall seroprevalence of HBsAg and anti-HBc were significantly lower among individuals born after the initiation of the nationwide vaccination program (P<.001). However, we observed increasing seroprevalence of anti-HBc and isolated anti-HBs when subjects were grouped by age: at 10–14, 14–18, to 18–21 years old, values were 0.4%, 1.9%, and 8.1% (P=.0135) and 43.7%, 55.4%, and 59.6% (P=.0093), respectively, X2 test for trend. A large increase was observed in the percentage of patients who tested positive for HBV-DNA at 18–21 years of age (3.0% vs 0.2%; P=.002 for all eligible subjects and 5.7% vs 0.3%; P<.001 for subjected vaccinated with ≥ 3 doses). Five of 8 completely vaccinated individuals who were seropositive for HBV-DNA carried variants with mutations in the S gene. Conclusions: Universal vaccination effectively controls HBV infection in children and adolescents. However, after adolescence, there is a significant increase in the seroprevalence of anti-HBs, anti-HBc and HBV-DNA, indicating that new preventative strategies are needed for adults.

MicroRNAs in Pathogenesis, Diagnosis, and Treatment of Gastroesophageal Cancers - Accepted Manuscript

Jee Hoon Song, Stephen J. Meltzer — 2012-05-14

Abstract: The incidence of gastroesophageal cancers is increasing each year, but despite much research, their molecular mechanisms are incompletely understood. microRNAs (miRNAs) are noncoding RNAs that have been associated with gastroesophageal carcinogenesis. We review the involvement of miRNAs in gastric and esophageal cancers and their mechanisms of regulation, effects on gene expression, and biological functions. Many miRNAs are dysregulated in gastroesophageal cancer cells via alterations in transcription, epigenetic features, or copy number of the genes that encode them. Each type of gastroesophageal tumor has a unique gene expression profile. miRNAs contribute to gastroesophageal carcinogenesis by altering expression of oncogenes and tumor suppressors to affect cell proliferation, apoptosis, and motility and invasion. A number of miRNAs, including circulating miRNAs, have been associated with tumor type or stage, or patient survival, and might be developed as diagnostic or prognostic markers. Greater understanding of the roles of miRNAs in gastroesophageal carcinogenesis could provide insights into the mechanisms of tumor development and identify therapeutic targets.

Risk of Melanoma and Non-Melanoma Skin Cancer among Patients with Inflammatory Bowel Disease - Accepted Manuscript

2012-05-14

Abstract: Background & Aims: Patients with inflammatory bowel disease (IBD) are at risk for certain malignancies. We aimed to determine the risk of melanoma and non-melanoma skin cancer (NMSC) in patients with IBD and how medications affect these risks. Methods: We performed retrospective cohort and nested case-control studies using administrative data from LifeLink™ Health Plan Claims Database from 1997 to 2009. The cohort comprised108,518 patients with IBD, were each matched to 4 individuals without IBD. Melanoma and NMSC risks were evaluated by incidence rate ratio (IRR) and by adjusted Cox proportional hazard ratio (HR) modeling. In nested case-control studies, patients with melanoma or NMSC were matched to 4 patients with IBD without melanoma or NMSC. Conditional logistic regression was used to determine associations between medications and both skin cancers. Results: In the cohort, IBD was associated with an increased incidence of melanoma (IRR, 1.29; 95% confidence interval [CI], 1.09–1.53). Risk was greatest among individuals with Crohn’s disease (IRR, 1.45; 95% CI, 1.13–1.85; adjusted HR, 1.28; 95% CI, 1.00–1.64). The incidence of NMSC also increased among patients with IBD (IRR, 1.46; 95% CI, 1.40–1.53), and was greatest among those with CD (IRR, 1.64; 95%, CI 1.54–1.74). In the nested case-control studies, therapy with biologics increased the risk for melanoma (odds ratio [OR], 1.88; 95% CI, 1.08–3.29). Patients that had used thiopurines had increased risk for NMSC (OR, 1.85; 95% CI, 1.66–2.05). Conclusions: Immunosuppression increases the risk of melanoma and NMSC among patients with IBD. Melanoma risk is increased by biologic use and NMSC risk is increased by thiopurines. Patients with IBD should be counseled and monitored for skin cancer.

Association between Colorectal Cancer Susceptibility Loci and Survival Time Following Diagnosis with Colorectal Cancer - Accepted Manuscript

2012-05-10

Abstract: Genome-wide association studies have identified 16 germline single nucleotide polymorphisms (SNPs) that are associated with colorectal cancer (CRC) incidence. We examined the relationship between these SNPs and survival of 2611 individuals with CRC, enrolled in 5 cohort studies. We used Cox regression analysis to associate SNPs with overall and CRC-specific survival times. The minor allele in rs4939827 (SMAD7) was associated with reduced overall survival (hazard-ratio [HR], 1.16; 95% confidence interval [CI], 1.06–1.27; P=.002] and disease-specific survival (HR, 1.17; 95% CI, 1.05–1.30; P=.005). Other SNPs were not significantly associated with survival. Common germline variations might be prognostic factors for patients with CRC. A variant in SMAD7 could affect progression of CRC.

Hepatocytes that Express Variants of Cyclophilin A are Resistant to HCV Infection and Replication - Accepted Manuscript

2012-05-10

Abstract: Background & Aims: The hepatitis C virus (HCV) uses several host factors to infect and replicate in human hepatocytes. Cyclophilin A (CypA) is required for viral replication and CypA inhibitors are in development. We investigated the effects of non-synonymous single nucleotide polymorphisms (SNPs) in the region of peptidyl-prolyl isomerase A (PPIA) that encodes CypA on HCV infection and replication of human hepatocytes. Methods: We used a combination of virologic, biochemical, and genetic approaches to investigate the effects of PPIA variants on HCV replication in cultured Huh-7.5 cells. We reduced levels of CypA in these cells using a small hairpin (sh)RNAs. Results: Using shRNAs, we showed that CypA was required for replication of HCV in Huh-7.5 cells, and identified 3 SNPs in PPIA that protected cells from HCV entry or replication. Levels of HCV RNA were reduced 3–4 log in cells homozygous for the variant alleles; release of new particles was also reduced but viral entry was not affected. The effects of the variant alleles were recessive and stronger for preventing replication of full-length HCV genomes than subgenomes. CypA inhibitors prevented replication of residual HCV in hepatocytes. The variants appeared to destabilize the CypA protein; the single amino acid changes led to rapid degradation of the protein. Conclusion: We identified variants in PPIA that destabilize its product, CypA, and prevent HCV infection and replication. These findings indicate mechanisms by which some cells might be resistant to HCV infection and that CypA is a good therapeutic target.

Viscous Topical is More Effective than Nebulized Steroid Therapy for Patients with Eosinophilic Esophagitis - Accepted Manuscript

2012-05-07

Abstract: We performed a randomized trial to compare nebulized and viscous topical steroid treatments for eosinophilic esophagitis (EoE). Subjects with incident EoE (n=25) received budesonide 1 mg twice daily—either nebulized and then swallowed (NEB) or as an oral viscous slurry (OVB)—for 8 weeks. Baseline eosinophil counts for the NEB and OVB groups were 101 and 83 (P=.62). Post-treatment counts were 89 and 11 (P=.02). The mucosal medication contact time, measured by scintigraphy, was higher for the OVB group than the NEB group (P<.005) and was inversely correlated with eosinophil count (R= –0.67; P=.001). OVB was more effective than NEB in reducing numbers of esophageal eosinophils in patients with EoE. OVB provided a significantly higher level of esophageal exposure to the therapeutic agent, which correlated with lower eosinophil counts.

Prevention of Esophageal Stricture After Endoscopic Submucosal Dissection Using Tissue-Engineered Cell Sheets - Accepted Manuscript

2012-05-07

Abstract: Background & Aims: The use of esophageal endoscopic submucosal dissection (ESD) to remove superficial esophageal neoplasms is gradually becoming more common in Japan. However, large-scale esophageal ESD often requires subsequent multiple balloon dilations to prevent postoperative esophageal stricture. We investigated the safety and efficacy of endoscopic transplantation of tissue-engineered autologous oral mucosal epithelial cell sheets in preventing formation of strictures after ESD. Methods: We performed an open-label, single-arm, single-institute study. We collected specimens of oral mucosal tissue from 9 patients with superficial esophageal neoplasms. Epithelial cell sheets were fabricated ex vivo by culturing isolated cells for 16 days on temperature-responsive cell culture surfaces. After a reduction in temperature, these sheets were endoscopically transplanted directly to the ulcer surfaces of patients that had just undergone ESD. All patients were monitored by endoscopy once a week until epithelialization was complete. Results: Autologous cell sheets were successfully transplanted to ulcer surfaces using an endoscope. Complete re-epithelialization occurred within a median time of 3.5 weeks. No patients experienced dysphagia, stricture, or other complications following the procedure, except for 1 patient who had a full circumferential ulceration that expanded to the esophagogastric junction. Conclusions: Sutureless, endoscopic transplantation of carrier-free cell sheets composed of autologous oral mucosal epithelial cells safely and effectively promotes re-epithelialization of the esophagus after ESD. Patients in this study did not experience any serious complications. This procedure might be used to prevent stricture formation following ESD and improve patients’ quality of life. Further study will be needed to show that stricture formation can be prevented.

Development of Sub-Squamous High-Grade Dysplasia and Adenocarcinoma after Successful Radiofrequency Ablation of Barrett’s Esophagus - Accepted Manuscript

2012-05-07

Abstract: Patients with Barrett's esophagus are frequently treated with radiofrequency ablation (RFA). Those that undergo this procedure have a low risk for developing sub-squamous intestinal metaplasia, and none have been reported to develop sub-squamous dysplasia or cancer. We report the development of sub-squamous neoplasia in 3 patients that were treated with RFA for Barrett’s esophagus (2 developed adenocarcinoma and 1 developed high-grade dysplasia). The identification of these cases indicate the need for continued surveillance following RFA, even after complete eradication of intestinal metaplasia, and caution for widespread use of ablation, especially in patients with low-risk Barrett’s esophagus.

Safety and Efficacy of Adalimumab for Moderate to Severe Crohn's Disease in Children - Accepted Manuscript

2012-05-04

Abstract: Background & Aims: The IMAgINE 1 study (NCT00409682) evaluated safety and efficacy of adalimumab double-blind maintenance dosing regimens following open-label induction for pediatric patients with moderate to severe Crohn’s disease (CD). Methods: We studied 192 patients with Pediatric Crohn’s Disease Activity Index (PCDAI) scores >30 for whom conventional treatment was unsuccessful. Patients received open-label induction therapy with subcutaneous adalimumab at weeks 0 and 2 (160mg and 80mg, or 80mg and 40mg, for body weight [BW] ≥40 kg or <40kg). At week 4, 188 patients were assigned to groups based on achievement of clinical response (defined as PCDAI decrease ≤15 points from baseline, 155/188 [82.4%]) and prior exposure to infliximab (82/188, 43.6%). Groups were given double-blind maintenance therapy with adalimumab at high (40 mg or 20 mg for BW ≥40 kg or <40 kg; n=93) or low doses (20 mg or 10 mg for BW ≥40 kg or <40 kg; n=95), every other week for 48 weeks. Clinical remission (PCDAI ≤10) at week 26 (the primary endpoint) was compared between groups using the Cochran-Mantel-Haenszel test, adjusting for strata, with non-responder imputation. Adverse events were monitored to evaluate safety. Results: 152/188 patients (80.9%) completed all 26 weeks of the study. At week 26, 63 patients (33.5%) were in clinical remission, with no significant difference between high- and low-dose groups (36/93, 38.7% vs 27/95, 28.4%; P=.075). No new safety signals were detected. Conclusion: Adalimumab induced and maintained clinical remission of children with CD, with a safety profile comparable to of adult patients with CD. More children that received high than low dose were in remission at week 26, but the difference between dose groups was not statistically significant.

Selective Ablation of Peptide YY Cells in Adult Mice Reveals Their Role in β-Cell Survival - Accepted Manuscript

2012-05-04

Abstract: Background & Aims: In the pancreas, the peptide (P)YY is expressed by a subpopulation of non-β cells in the islets of Langerhans. We investigated the function of these cells in the pancreas of adult mice. Methods: We generated mice in which administration of diphtheria toxin (DT) led to specific ablation of PYY-expressing cells. We investigated the effects of loss of PYY cells on glucose homeostasis. Results: Loss of PYY cells in adult mice resulted in severe hyperglycaemia, which was associated with significant loss of pancreatic insulin and disruption of islet morphology. In vitro administration of DT to isolated islets significantly reduced numbers of PYY-expressing cells and levels of insulin. Administration of either PP (a strong agonist of the receptor Y4) or PYY3-36 (a selective agonist of the receptor Y2) did not restore loss of pancreatic insulin following DT administration. However, a long-acting PYY analogue reduced the loss of insulin, and administration of this analogue reduced the hyperglycaemia and insulin loss induced by streptozotocin in mice. Conclusion: PYY appears to regulate β-cell function and survival via the receptor Y1/2. These findings might be developed to treat and prevent loss of β cells in patients with diabetes mellitus.

Efficacy of Treatment for Patients with Achalasia Depends on the Distensibility of the Esophagogastric Junction - Accepted Manuscript

W.O. Rohof, D.P. Hirsch, B.F. Kessing, G.E. Boeckxstaens — 2012-05-04

Abstract: Background & Aims: Many patients with persistent dysphagia and regurgitation after therapy have low or no lower esophageal sphincter (LES) pressure. Distensibility of the esophagogastric junction (EGJ) largely determines esophageal emptying. We investigated whether assessment of the distensibility of the EGJ is a better and more integrated parameter than LES pressure for determining efficacy of treatment for patients with achalasia. Methods: We measured distensibility of the EGJ using an endo functional luminal imaging probe (EndoFLIP) in 15 healthy volunteers (controls; 8 male, 40±4.1 y) and 30 patients with achalasia (16 male, age 51±3.1 y). Patients were also assessed by esophageal manometry and a timed barium esophagogram. Symptom scores were assessed using the Eckardt score, with a score below 4 indicating treatment success. The effect of initial and additional treatment on distensibility and symptoms were evaluated in 7 and 5 patients respectively. Results: EGJ distensibility was significantly reduced in untreated patients with achalasia, compared with controls (0.7±0.9 mm2/mmHg vs 6.3±0.7 mm2/mmHg; P 3 (1.6 ± 0.3 vs 4.4 ± 0.5 mm2/mmHg; P=.001). Even when LES pressure was low, EGJ distensibility could be reduced, which was associated with impaired emptying and recurrent symptoms. Conclusions: EGJ distensibility is impaired in patients with achalasia, and in contrast to LES pressure, is associated with esophageal emptying and clinical response. Assessment of EGJ distensibility by EndoFLIP is a better parameter than LES pressure for evaluating efficacy of treatment for achalasia.

A Submucosal Tumor in the Cecum - Uncorrected Proof

Chung-Chieh Cheng, Jin-Tung Liang — 2012-04-30

Question: A 52-year-old woman underwent a screening colonoscopy. A 3-cm, submucosal tumor with a smooth and intact surface was found in the cecum. A thickened cecal wall also could be seen close to the tumor (). Abdominal computed tomography disclosed a 6.8 × 2.7 cm, well-defined, hypodense extraluminal tumor (), causing compression to the cecum, with a tail extending to the ileocecal junction part ().

Bleeding After Glue Injection in Gastric Varices - Uncorrected Proof

Malay Sharma, Amit Goyal — 2012-04-30

Question: A 50-year-old man presented with massive hematemesis and hemodynamic instability requiring multiple units of blood transfusion. He had hepatitis C-related decompensated cirrhosis for which he was awaiting liver transplantation. He had an episode of massive upper gastrointestinal bleed from large fundal varices requiring 3 mL of N-butyl-2-cyanoacrylate glue injection 6 months previously. A check endoscopy 4 months after glue injection showed an ulcerated area at the site of extrusion of glue injection. After the extrusion of the glue caste, he had 2 episodes of gastrointestinal bleeding and in both the episodes no source of bleeding could be identified on endoscopy. He was managed by blood transfusions and β-blockers. During the current episode, he was hospitalized and an upper gastrointestinal endoscopy revealed a bleeding point from the base of the ulcer from where the glue had extruded (). Endoscopic ultrasonography was performed ().

Iron Deficiency After Non–Small Cell Lung Cancer - Uncorrected Proof

Stijn J.B. Van Weyenberg, Nicole C. Van Grieken, Jan Hein T.M. Van Waesberghe — 2012-04-30

Question: A 57-year-old woman was referred for analysis of iron-deficiency anemia. Five months earlier she had underwent right lower lobectomy for stage 1a non–small cell lung cancer. She did not experience melena or rectal blood loss, nor were there any other abdominal symptoms. Except for a thoracotomy scar, physical examination was unremarkable. Her laboratory studies showed an hemoglobin of 10.8 g/dL. Mean corpuscular volume was 71 fL and serum ferritin was 11 ng/mL. Esophagogastroduodenoscopy showed no abnormalities, whereas ileocolonoscopy revealed mild diverticulosis of the sigmoid, without signs of inflammation. To investigate a possible bleeding cause in the small intestine, video capsule endoscopy was performed. The complete small intestine was visualized, but no abnormalities were found.

An Unusual Ileum Tumor in a Young Woman - Uncorrected Proof

Biyan Lu, Huanliang Liu, Weibiao Ye — 2012-04-30

Question: A 29-year-old woman was referred to our hospital because of progressive abdominal pain accompanied by nausea, vomiting and body weight loss for 6 months. She reported no changes in bowel habits and no anorexia, jaundice, melena, or hematochezia. The patient did not have a significant past medical history. Physical examination revealed a large mass in the right lower abdomen. The mass was fixed and ill-defined. Laboratory tests were not remarkable apart from hemoglobin (85 g/L) and C-reactive protein (15 mg/dL). Intravenous contrast-enhanced computed tomography showed an ill-defined, multilocular, low-density mass measuring 13 × 8 × 7 cm in the pelvis and lower abdomen ().

An Extremely Rare Small Bowel Lesion Associated With Refractory Ascites - Uncorrected Proof

Sophocles Lanitis, Christos Kontovounisios, Constantine Karaliotas — 2012-04-30

Question: An 81-year-old man presented with a 6-month history of a 20-kg weight loss associated with increased abdominal distention. He complained about crampy abdominal pain, anorexia, constipation, and bilateral lower limb edema. He had an otherwise unremarkable medical history. Clinically, he had abdominal distention, normal temperature, and no lymphadenopathy. An extensive workup was performed. Laboratory blood results revealed normocytic anemia and hypoalbuminemia, with normal liver and renal function tests. Hepatitis virus panel and tumor markers were within normal ranges. Upper and lower gastrointestinal endoscopy revealed only uncomplicated sigmoid diverticular disease. Computed tomography of the abdomen revealed the presence of severe ascites, thickening of the terminal ileum, and distension of the rest of the small bowel. There was no obvious lymphadenopathy or other pathology from the visceral organs (). A diagnostic paracentesis of the ascites showed low serum ascites albumin gradient. The fluid was sent for cytology, full biochemistry, and microbiology. The Gram stain and cytopathology did not reveal any abnormality. The patient had also a negative test for tuberculosis.

An Unusual Cause of Recurrent Diarrhea With Small Intestinal “Polyposis” - Uncorrected Proof

Malay Sharma, Amit Goyal, Ruth Shifa Ecka — 2012-04-30

Question: A 27-year-old man presented with recurrent episodes of watery diarrhea for the last 4 years. He has been studying in China for education for last 4 years and was back home in India for a short holiday. He was relatively asymptomatic at the time of his consultation as far as the gastrointestinal symptoms were concerned. He had lost 11 kg in last 2 years and on examination had low body mass index (15.23 kg/m2). Laboratory investigations showed: hemoglobin, 15.0 gm%; total leukocyte count, 7800; polymorphs, 69%; lymphocytes, 28%; eosinophils, 3%; serum albumin, 3.4 g/dL (normal, 3.5–5.0); globulin 2.6, g/dL (normal, 2.8–4.5); vitamin B12, 184 pg/mL (normal, 211–911); serum immunoglobulin (Ig)A tTG, 1.72 U/mL (normal, <15); and normal stool routine examination. HIV-1 and -2 serology was nonreactive. Thyroid, renal, liver, and pulmonary function tests and chest x-ray were normal.

Severity of Acute Pancreatitis: Impact of Local and Systemic Complications - Uncorrected Proof

Maxim S. Petrov, David C. Whitcomb, John A. Windsor — 2012-04-30

We read with interest a recent report by van Santvoort et al on a large cohort of patients with acute pancreatitis who were considered for enrolment in 2 interventional studies. The cohort represents a mix of patients who received conventional management or an experimental intervention, which had a significant impact on the mortality and morbidity of at least a quarter of the patients in the combined cohort. The paper makes an important contribution to the evidence in support of a more conservative and less invasive approach to the treatment of necrotizing pancreatitis. Beyond that, the authors have attempted to answer several important questions related to the impact of local and systemic factors on the severity of acute pancreatitis. It is this latter aspect that requires further discussion if future studies will take us forward.

Covering the Cover - Uncorrected Proof

Anson W. Lowe, Richard H. Moseley — 2012-04-30

Eosinophilic esophagitis in adults commonly presents as dysphagia, food impaction, chest pain, reflux symptoms, or abdominal pain. The most common presentation is dysphagia to solid foods. It may also present as chest pain or reflux symptoms that are refractory to antacid therapy. In patients presenting with consistent symptoms, endoscopy establishes the diagnosis, which grossly may include linear furrowing, strictures, stacked circular rings, or whitish papules that represent eosinophilic microabscesses. Histologic confirmation requires at least 15 eosinophils per high power field (400×).

A Cholecystohepatic Shunt Pathway: Does the Gallbladder Protect the Liver? - Uncorrected Proof

James L. Boyer, Carol J. Soroka — 2012-04-30

See “Defects in gallbladder emptying and bile acid homeostasis in mice with cystic fibrosis transmembrane conductance regulator deficiencies,” by Debray D, Raintrau D, Barbu V, et al, on page 000.

Self-Renewal of Tumor-Initiating Cells: What's New About Hepatocellular Carcinoma? - Uncorrected Proof

Anna Alisi, Georges Baffet, Irset, Inserm — 2012-04-30

See “p28GANK prevents degradation of Oct4 and promotes expansion of tumor-initiating cells in hepatocarcinogenesis” by Qian Y-W, Chen Y, Yang W, et al, on page 00.

Presentation of the Julius M. Friedenwald Medal to Emmet B. Keeffe, MD - Uncorrected Proof

David Lieberman — 2012-04-30

A memoriam for Dr. Keeffe was published in the November issues of American Journal of Gastroenterology, Gastroenterology, Gastrointestinal Endoscopy, Hepatology, and Liver Transplantation. See Ahmed and Esquivel. Gastroenterology 2011;1537–1538.

Reply - Uncorrected Proof

2012-04-30

We thank Dr Petrov and colleagues for their interest in our paper and welcome further discussion on the impact of local and systemic factors on the severity of acute pancreatitis.

Basiliximab Does Not Increase Efficacy of Corticosteroids in Patients with Steroid-Refractory Ulcerative Colitis - Accepted Manuscript

2012-04-30

Abstract: Background & Aims:: Basiliximab is a chimeric monoclonal antibody that binds CD25 and thereby inhibits interleukin (IL)-2mediated proliferation of lymphocytes. IL-2 might contribute to the resistance of T cells to steroids. We investigated the efficacy and safety of basiliximab as a steroid-sensitizing agent in patients with steroid-refractory ulcerative colitis (UC). Methods:: We studied 149 patients with moderate to severe UC (Mayo score ≥6 and endoscopic subscore ≥2) despite treatment for at least 14 days with oral prednisone (4050 mg/d). Subjects were randomly assigned to groups that were given 20 mg (n=46) or 40 mg (n=52) basiliximab or placebo (n=51) at weeks 0, 2, and 4. All subjects received 30 mg/d prednisone through week 2; the dose was reduced by 5 mg each week to 20 mg/d, which was maintained until week 8. At week 8, we compared the rates of clinical remission (Mayo score ≤2, no subscore>1) for patients given basiliximab with the rate for patients given placebo. Results:: Twenty-eight percent of patients given placebo, 29% of those given the 40 mg dose of basiliximab, and 26% of those given the 20 mg dose achieved clinical remission ( P =1.00 vs placebo for each dose). Basiliximab was generally well tolerated. Six subjects that received basiliximab had serious adverse events (6.1%), compared with 2 that received placebo (3.9%; P =.72). In subjects given basiliximab, incomplete saturation of CD25 (<50%) on peripheral T cells was associated with the presence of anti-basiliximab antibodies (odds ratio, 21; 95% confidence interval, 2.4184). Conclusions:: Basiliximab does not increase the effect of steroids in the induction of remission in outpatients with steroid-resistant moderate to severe UC.

Loss of Interleukin-10 Signaling and Infantile Inflammatory Bowel Disease - Implications for Diagnosis and Therapy - Accepted Manuscript

2012-04-30

Abstract: Background & Aims: Homozygous loss of function mutations in interleukin-10 ( IL10) and interleukin-10 receptors ( IL10R) cause severe infantile (very early onset) inflammatory bowel disease (IBD). Allogeneic hematopoietic stem cell transplantation (HSCT) was reported to induce sustained remission in 1 patient with IL-10R deficiency. We investigated heterogeneity among patients with very early onset IBD, its mechanisms, and the use of allogeneic HSCT to treat this disorder. Methods: We analyzed 66 patients with early onset IBD (< 5 years of age) for mutations in the genes encoding IL-10, IL-10R1, and IL-10R2. IL-10R deficiency was confirmed by functional assays on patients’ peripheral blood mononuclear cells (immunoblot and ELISA analyses). We assessed the therapeutic effects of standardized allogeneic HSCT. Results: Using a candidate gene sequencing approach, we identified 16 patients with IL-10 or IL-10R deficiency: 3 patients had mutations in IL-10, 5 had mutations in IL-10R1, and 8 had mutations in IL-10R2. Refractory colitis became manifest in all patients within the first 3 months of life and was associated with perianal disease (16/16 patients). Extraintestinal symptoms included folliculitis (11/16) and arthritis (4/16). Allogeneic HSCT was performed in 5 patients and induced sustained clinical remission with a median follow-up time of 2 years. In vitro experiments confirmed reconstitution of IL-10R–mediated signaling in all patients that received the transplant. Conclusions: We identified loss of function mutations in IL-10 and IL-10R in patients with very early onset IBD. These findings indicate that infantile IBD patients with perianal disease should be screened for IL-10 and IL-10R deficiency and that allogeneic HSCT can induce remission in those with IL-10R deficiency.

Novel Genetic Mutations Specific for Intraductal Papillary Neoplasm of the Pancreas - Uncorrected Proof

Yuzo Kodama, Tsutomu Chiba — 2012-04-27

Wu J, Matthaei H, Maitra A, et al. Recurrent GNAS mutations define an unexpected pathway for pancreatic cyst development. Sci Transl Med 2011;3:92ra66. Recent technological advances and the widespread use of abdominal imaging have resulted in a marked increase in the number of patients with pancreatic cysts (Am J Roentgenol 2008;191:802–807). Clinical, pathologic, and molecular studies have shown that intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are potential precursor lesions of invasive pancreatic ductal adenocarcinomas (PDAs), whereas serous cyst adenomas (SCAs) and other cysts, including retention cysts or congenital cysts, have minimal malignant potential (Nat Rev Gastroenterol Hepatol 2011;8:141–150). Indeed, molecular alterations that characterize PDAs, such as mutations in KRAS or TP53, are also detected in IPMNs and MCNs, supporting their nature as precancerous lesions (Nat Rev Gastroenterol Hepatol 2011;8:141–150). It is well recognized that PDAs derived from IPMNs are less aggressive and show a far better prognosis than PDAs that develop without any cystic precursors (Gastroenterology 2010;139:708–713). Thus, distinguishing pancreatic cysts with malignant potential from those without, or determining whether PDAs are derived from cystic precursors or not, is of great clinical importance. However, no specific marker is clinically available to predict the malignant tendency of pancreatic cysts. Therefore, to establish new diagnostic modalities and improve the understanding of the molecular pathogenesis of pancreatic cysts, especially those with malignant potential, it is critical to identify the genetic characteristics of pancreatic cystic neoplasms.

Uncorrected Proof

••• ••• — 2012-04-27

Uncorrected Proof

2012-04-27

Can Dietary Fish Intake Prevent Liver Cancer? - Uncorrected Proof

Neal D. Freedman, Jorge A. Marrero, Keith S. Henley — 2012-04-27

See “Consumption of n-3 fatty acids and fish reduces risk of hepatocellular carcinoma,” by Sawada N, Inoue M, Iwasaki M, et al, on page 000.

Treatment of Eosinophilic Esophagitis: Diet, Drugs, or Dilation? - Uncorrected Proof

Alex Straumann — 2012-04-27

See “Elimination diet effectively treats eosinophilic esophagitis in adults; food reintroduction identifies causative factors,” by Gonsalves N, Ynag GY, Doerfler B, et al, on page 000.

An Unusual Diaphragmatic Hernia - Uncorrected Proof

Hideo Ohtsuka, Kazuhiro Imamura, Kensuke Adachi — 2012-04-26

Question: A previously healthy 39-year-old man presented to our hospital with a 1-week history of epigastric pain, nausea, and vomiting. He had no concomitant medical condition. His past medical history was unremarkable. He had no previous surgery or thoracoabdominal trauma history. The routine work-up on admission was normal. An immediate chest radiograph demonstrated the air–fluid level that projected above the diaphragm, to the far left of the midline (). The upper gastrointestinal (GI) series showed the esophagogastric junction was in the normal position (). The contour and orientation of the stomach by upper GI series and endoscopy suggested a mesenteroaxial gastric volvulus with herniation of gastric body into the thorax (). Subsequent computed tomography of the chest and abdomen showed a diaphragmatic hernia containing the transverse colon as well as a significant portion of the posterior gastric fundus (). He elected to undergo a laparoscopic operation. The intraoperative finding is shown in Figure E (1, lower esophagus; 2, left paraesophageal space; 3, intervening muscle band; 4, left diaphragmatic crus; 5, left lower lobe through the defect).

An Unusual Cause of Lower Gastrointestinal Bleeding in Crohn's Disease - Uncorrected Proof

Jana G. Hashash, Steve Abo, Miguel Regueiro — 2012-04-26

Question: A 62-year-old woman with an 8-year history of fistulizing ileocolonic Crohn's disease (CD) presented to our institution with profuse bleeding from a perianal fistula. The patient has been maintained on oral 5-aminosalicylic acid (5-ASA) since diagnosis and 6-mercaptopurine (6MP) 100 mg/d for the previous 8 months. The patient complained of sudden-onset bleeding from her perianal fistula. Her blood pressure was 105/60 mmHg and pulse rate 102, bpm. Her perianal examination was significant for pyoderma gangrenosum on the skin of her buttock () and a large perianal fistula with active bleeding. Digital rectal examination was significant for a nodular and hard rectal mucosa with a palpable stricture above the dentate line. Blood work was significant for a hemoglobin of 9.6 g/dL (baseline, 11 g/dL) and a white blood cell count of 3.6/L. The remainder of her laboratory work was within normal limits.

Upper GI Bleeding in a Post–Liver Transplant Patient - Uncorrected Proof

Anoop Prabhu, Narasimham L. Dasika, Pratima Sharma — 2012-04-26

Question: A 45-year-old man presented to the emergency room with large-volume hematochezia and subsequent hematemesis. His medical history is notable for alpha-1 antitrypsin deficiency with eventual liver failure. He underwent orthotopic liver transplantation 9 months prior, which was complicated by ischemic cholangiopathy with recurrent cholangitis and need for serial percutaneous cholangiogram tube exchanges. He underwent retransplantation 2 months before presentation, this time with a relatively uncomplicated postoperative course. The patient was not on aspirin or any nonsteroidal anti-inflammatory drugs. On this presentation, he was afebrile but hemodynamically unstable with a blood pressure of 82/60 mmHg and a heart rate of 110 bpm. Nasogastric lavage returned bright red blood with clot. Laboratory values were as follows: White blood cell count, 8,300/μL (neutrophils, 82%); hemoglobin, 8.2 g/dL; platelet count, 192,000/mm3; blood urea nitrogen, 24 mg/dL; creatinine, 1.0 mg/dL; prothrombin time, 12.4 seconds; and International Normalized Ratio, 1.2. Between admission and intervention, the patient required a total transfusion of 12 U of packed red blood cells for hemodynamic support.

A Man With Colon Cancer and Tonsil Swelling - Uncorrected Proof

Frédéric Lemay, Pascale Cervera, Aimery de Gramont — 2012-04-26

Question: A 43-year-old man was evaluated for left tonsil swelling. He had been diagnosed 1 year earlier with a left-sided colon cancer revealed by altered bowel habits. At diagnosis, the preoperative evaluation did not show distant metastasis. The patient underwent left hemicolectomy, which showed a 4-cm, moderately differentiated adenocarcinoma invading the omentum (T4a). Thirty regional lymph nodes were positive for tumor extension (N2b). There was no microsatellite instability, and no KRAS mutations were found. The tumor was classified as stage IIIc disease based on the American Joint Committee on Cancer classification.

The Process of Applying for Gastroenterology Fellowship - Uncorrected Proof

Arthur J. DeCross, Deborah D. Proctor — 2012-04-26

In the United States, with rare exception, the credentials required for the allopathic clinical practice of gastroenterology (GI) include the successful completion of a GI fellowship training program (GI fellowship) accredited by the Accreditation Council for Graduate Medical Education (ACGME). The successful completion of an ACGME accredited GI fellowship is also required for GI specialist certification by the American Board of Internal Medicine. Increasingly, both board certification and accredited fellowship training are required to receive and maintain privileges as a practicing gastroenterologist at a health care facility, and to be paneled as a GI specialist provider by third-party insurers. The ACGME is currently reviewing and revising program requirements to mandate that all GI fellows in ACGME-accredited GI fellowships must be graduates of an ACGME-accredited internal medicine residency; these trainees may have gone to either allopathic or osteopathic American medical schools or to international medical schools.

Overutilization of Endoscopic Surveillance in Nondysplastic Barrett's: Too Much of a Good Thing? - Uncorrected Proof

David A. Klibansky, Stuart R. Gordon, Timothy B. Gardner — 2012-04-25

Crockett SD, Lipkus IM, Bright ST, et al. Overutilization of endoscopic surveillance in nondysplastic Barrett's esophagus: a multicenter study. Gastrointest Endosc 2012;75:23–31.

Eradicating Helicobacter Pylori in Functional Dyspepsia - Uncorrected Proof

Alexander C. Ford — 2012-04-25

Mazzoleni LE, Sander GB, de Magalhaes Francesconi CF, et al. Helicobacter pylori eradication in functional dyspepsia. HEROES trial. Arch Intern Med 2011;171:1929–1936. Dyspepsia is common in the community, with a population prevalence as high as 40% (Br Med J 1989;298:30–32). Most individuals have no structural explanation for their symptoms (Clin Gastroenterol Hepatol 2010;8:830–837), and therefore are labeled as having functional dyspepsia. This condition is a chronic, relapsing and remitting disorder, and the pathogenesis is not fully understood. Higher rates of Helicobacter pylori infection have been reported in patients with functional dyspepsia, compared with healthy controls (Gastroenterology 1988;94:33–40). In a pooled analysis of nonrandomized studies of eradication therapy in H pylori-positive functional dyspepsia patients, rates of symptom improvement appeared higher in those achieving successful eradication (Aliment Pharmacol Ther 1996;10:843–850). As a result, eradication of H pylori has been advocated as a treatment for individuals with functional dyspepsia infected with the bacterium.

Gender-Specific Differences in Colorectal Neoplasia and Potential Implications for Screening Policy: Is It Time to Discriminate Based on Gender? - Uncorrected Proof

Sameer D. Saini — 2012-04-25

Ferlitsch M, Reinhart K, Pramhas S, et al. Sex-specific prevalence of adenomas, advanced adenomas, and colorectal cancer in individuals undergoing screening colonoscopy. JAMA 2011;306:1352–1358.

Cellular Origin of Barrett's Esophagus: Controversy and Therapeutic Implications - Uncorrected Proof

Wa Xian, Khek Yu Ho, Christopher P. Crum, Frank McKeon — 2012-04-25

Esophageal adenocarcinoma is on the rise in the West and yet its marginal survival rate has not changed in 30 years. Preemptive approaches, including radiofrequency ablation (RFA), and photodynamic therapy (PDT) for Barrett's esophagus and dysplasia are achieving dramatic initial results. Although the long-term efficacy of these nonspecific ablative therapies is awaiting longitudinal studies, reports of recurrences are increasing. More targeted therapies, particularly directed at the stem cells of Barrett's esophagus, demand knowing the origin of this intestinal metaplasia (IM). The prevailing concept holds that Barrett's esophagus arises from the “transcommitment” of esophageal stem cells to produce an intestine-like epithelium. Given the remarkable frequency with which Barrett's esophagus appears in Western populations, empirical data for such a transcommitment phenomenon have been surprisingly limited. An alternative explanation derives from the discovery of a discrete population of residual embryonic cells (RECs) existing at the gastroesophageal junction in normal individuals that expands and colonizes regions of the esophagus denuded by chronic reflux. These RECs form IM within days of esophageal injury, suggesting a novel mechanism of tumorigenesis. A corollary of this work is that the Barrett's stem cell is distinct from that of the squamous epithelium and, once identified, will form the basis of new strategies for addressing Barrett's and its related neoplasia.

Within You, Without You: Is Gastroenterology Ready to Embrace the “Exposome”? - Uncorrected Proof

Bruce E. Sands — 2012-04-25

It was the twins who compelled me to consider the limitations of genetics. My 29-year-old patient had experienced 3 years of intermittent diarrhea that did not much trouble him, but the eventual onset of right lower quadrant abdominal pain and weight loss prompted an imaging study suggesting ileal Crohn's disease (CD), confirmed by colonoscopy and biopsy. The family history elicited no inflammatory bowel disease (IBD), but raised a single probing question from the patient: What was the likelihood that his twin brother, now residing 2500 miles away in Boise, Idaho, would also develop CD?

Circulating Microparticles as Disease-Specific Biomarkers of Severity of Inflammation in Patients with Hepatitis C or Nonalcoholic Steatohepatitis - Accepted Manuscript

2012-04-25

Abstract: Background & Aims: Microparticles released into the bloodstream upon activation or apoptosis of CD4+ and CD8+ T cells correlate with inflammation, determined by histologic analysis, in patients with chronic hepatitis C (CHC). Patients with nonalcoholic fatter liver (NAFL) or nonalcoholic steatohepatitis (NASH) can be differentiated from those with CHC based on activation of distinct sets of immune cells in the liver. Methods: We compared profiles of circulating microparticles from patients with NAFL and NASH (n=67) to those with CHC (n=42), compared with healthy individuals (controls) using flow cytometry; the profiles were correlated with inflammation grade and fibrosis stage, based on histologic analyses. We assessed the ability of the profiles determine the severity of inflammation and fibrosis, based on serologic and histologic analyses. Results: Patients with CHC had increased levels of microparticles from CD4+ and CD8+ T cells; the levels correlated with disease severity, based on histologic analysis and levels of alanine aminotransferase (ALT). Patients with NAFL or NASH had significant increases in numbers of microparticles from invariant natural killer T (iNKT) cells and macrophages/monocytes (CD14+), which mediate pathogenesis of NASH. Microparticles from CD14+ and iNKT cells correlated with levels of ALT and severity of NASH (based on histology). Levels of microparticles could differentiate between patients with NAFL or NASH and those with CHC, or either group of patients and controls (area under the receiver operating characteristic curves ranging from 0.56 to 0.99). Conclusions: Quantification of immune cell microparticles from serum samples can be used to assess the extent and characteristics of hepatic inflammation in patients with chronic liver disease.

Consensus Statements for Management of Barrett’s Dysplasia and Early-Stage Esophageal Adenocarcinoma, Based on a Delphi Process - Accepted Manuscript

2012-04-25

Abstract: Background & Aims: Esophageal adenocarcinoma (EA) is increasingly common among patients with Barrett’s esophagus (BE). We aimed to provide consensus recommendations based on the medical literature that clinicians could use to manage patients with BE and low-grade dysplasia, high-grade dysplasia (HGD), or early-stage EA. Methods: We performed an international, multi-disciplinary, systematic, evidence-based review of different management strategies for patients with BE and dysplasia or early-stage EA. We used a Delphi process to develop consensus statements. The results of literature searches were screened using a unique, interactive, web-based data-sifting platform; we used 11,904 papers to inform the choice of statements selected. An a priori threshold of 80% agreement was used to establish consensus for each statement. Results: Eighty-one of the 91 statements achieved consensus despite generally low quality of evidence, including 8 clinical statements: 1. specimens from endoscopic resection are better than biopsies for staging lesions, 2. it is important to carefully map the size of the dysplastic areas, 3. patients that receive ablative or surgical therapy require endoscopic follow-up, 4. high-resolution endoscopy is necessary for accurate diagnosis, 5. endoscopic therapy for HGD is preferred to surveillance, 6. endoscopic therapy for HGD is preferred to surgery, 7. the combination of endoscopic resection and radiofrequency ablation is the most effective therapy, and 8. following endoscopic removal of lesions from patients with HGD, all areas of BE should be ablated. Conclusions: We developed a data-sifting platform and used the Delphi process to create evidence-based consensus statements for the management of patients with BE and early-stage EA. This approach identified important clinical features of the diseases and areas for future studies.

Declining Risk of Colorectal Cancer in Patients with Inflammatory Bowel Disease Over 30 Years - Accepted Manuscript

2012-04-20

Abstract: Background & Aims: The risk for colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD) could have changed over time, with changes in treatment options. We studied CRC risk in a nationwide cohort of 47,374 Danish patients with IBD over a 30-year period. Methods: We determined relative risk (RR) values using Poisson regression-derived incidence rate ratios of CRC from 1 year after IBD diagnosis, adjusted for age, sex, and calendar time. We compared incidence of CRC among patients with IBD vs. individuals without IBD. Results: During 178 million person-years of follow-up, 268 patients with ulcerative colitis (UC) and 70 with Crohn’s disease (CD) developed CRC. The overall risk of CRC among patients with UC was comparable to that of the general population (RR, 1.07; 95% confidence interval [CI], 0.95–1.21). However, patients diagnosed with UC in childhood or as adolescents, those with long duration of disease, and those with concomitant primary sclerosing cholangitis were at increased risk. For patients with UC, the overall RR for CRC decreased from 1.34 (95% CI, 1.13–1.58) in 1979-1988 to 0.57 (95% CI, 0.41–0.80) in 1999-2008. Among patients with CD, the overall RR for CRC was 0.85 (95% CI, 0.67–1.07), which did not change over time. Conclusion: A diagnosis of UC or CD no longer seems to increase patients’ risk of CRC, although subgroups of patients with UC remain at increased risk. The declining risk for CRC from 1979 to 2008 might result from improved therapies for patients with IBD.

Intestinal Microbes Affect Phenotypes and Functions of Invariant Natural Killer T cells in Mice - Accepted Manuscript

2012-04-20

Abstract: Background & Aims: Invariant natural killer T (iNKT) cells undergo canonical, Vα14–Jα18 rearrangement of the T-cell receptor (TCR) in mice; this form of the TCR recognizes glycolipids presented by CD1d. iNKT cells mediate many different immune reactions. Their constitutive activated and memory phenotype and rapid initiation of effector functions after stimulation indicate previous antigen-specific stimulation. However, little is known about this process. We investigated whether symbiotic microbes can determine the activated phenotype and function of iNKT cells. Methods: We analyzed the numbers, phenotypes, and functions of iNKT cells in germ-free mice, germ-free mice reconstituted with specified bacteria, and mice housed in specific pathogen-free (SPF) environments. Results: SPF mice, obtained from different vendors, have different intestinal microbiota. iNKT cells isolated from these mice differed in TCR Vβ7 frequency and cytokine response to antigen, which depended on the environment. iNKT cells isolated from germ-free mice had a less mature phenotype and were hypo-responsive to activation with the antigen α-galactosylceramide. Intra-gastric exposure of germ-free mice to Sphingomonas bacteria, which carry iNKT cell antigens, fully established phenotypic maturity of iNKT cells. In contrast, reconstitution with Escherichia coli, which lack specific antigens for iNKT cells, did not affect the phenotype of iNKT cells. The effects of intestinal microbes on iNKT cell responsiveness did not require toll-like receptor signals, which can activate iNKT cells independently of TCR stimulation. Conclusions: Intestinal microbes can affect iNKT cell phenotypes and functions in mice.

Persistance of HCV in Quiescent Hepatic Cells during an Interferon-Induced Antiviral Response - Accepted Manuscript

2012-04-20

Abstract: Background & Aims: Hepatitis C virus (HCV) is a common cause of chronic liver disease. Many patients do not clear the viral infection; little is known about the mechanisms of HCV persistence or the frequent failure of interferon (IFN) to eliminate it. Better culture systems are needed to study viral replication in quiescent liver cells. Methods: We used human hepatoma (Huh7.5 cells) and those that had undergone proliferation arrest and differentiation (Huh7.5dif) to study the persistence of HCV infection following exposure of the cells to IFN-α and to compare the anti-viral effects of IFN-α and -λ. We validated these results with primary human hepatocytes and Huh7 cells that expressed an IFN-inducible fluorophore. Results: Following infection of Huh7.5dif cells, HCV replicated persistently and released infectious particles. Long-term exposure of the cells to IFN-α reduced HCV replication ~1000-fold, but did not eliminate the virus; viral replication rebounded after withdrawal of IFN, as it does in patients with chronic HCV infection. HCV replicated at higher levels, but not exclusively, in cells that had a low level of response to IFN-α. Following incubation of cells with equipotent concentrations of IFN-α or -λ, Huh7.5dif cells expressed a wider pattern of IFN-stimulated genes than undifferentiated Huh7.5 cells or primary human hepatocytes, indicating that the antiviral response depends on the cells’ differentiation status. Conclusions: We developed a cell culture system using hepatoma cells to study persistent HCV infection during the type I or type III IFN-induced antiviral response. The level and range of the antiviral responses were associated with differentiation of the cells. We propose that HCV exploits the stochastic nature of the response of hepatocytes to IFN to sustain persistence.

Efficacy of Neoadjuvant Chemoradiation, Followed by Liver Transplantation, for Perihilar Cholangiocarcinoma at 12 US Centers - Uncorrected Proof

2012-04-16

Background & Aims: Excellent single-center outcomes of neoadjuvant chemoradiation and liver transplantation for unresectable perihilar cholangiocarcinoma caused the United Network of Organ Sharing to offer a standardized model of end-stage liver disease (MELD) exception for this disease. We analyzed data from multiple centers to determine the effectiveness of this treatment and the appropriateness of the MELD exception. Methods: We collected and analyzed data from 12 large-volume transplant centers in the United States. These centers met the inclusion criteria of treating 3 or more patients with perihilar cholangiocarcinoma using neoadjuvant therapy, followed by liver transplantation, from 1993 to 2010 (n = 287 total patients). Center-specific protocols and medical charts were reviewed on-site. Results: The patients completed external radiation (99%), brachytherapy (75%), radiosensitizing therapy (98%), and/or maintenance chemotherapy (65%). Seventy-one patients dropped out before liver transplantation (rate, 11.5% in 3 months). Intent-to-treat survival rates were 68% and 53%, 2 and 5 years after therapy, respectively; post-transplant, recurrence-free survival rates were 78% and 65%, respectively. Patients outside the United Network of Organ Sharing criteria (those with tumor mass >3 cm, transperitoneal tumor biopsy, or metastatic disease) or with a prior malignancy had significantly shorter survival times (P < .001). There were no differences in outcomes among patients based on differences in surgical staging or brachytherapy. Although most patients came from 1 center (n = 193), the other 11 centers had similar survival times after therapy. Conclusions: Patients with perihilar cholangiocarcinoma who were treated with neoadjuvant therapy followed up by liver transplantation at 12 US centers had a 65% rate of recurrence-free survival after 5 years, showing this therapy to be highly effective. An 11.5% drop-out rate after 3.5 months of therapy indicates the appropriateness of the MELD exception. Rigorous selection is important for the continued success of this treatment.

miR-375 Inhibits Autophagy and Reduces Viability of Hepatocellular Carcinoma Cells Under Hypoxic Conditions - Uncorrected Proof

2012-04-16

Background & Aims: Tumor cells survive hypoxic conditions by inducing autophagy. We investigated the roles of microRNAs (miRNAs) in regulating autophagy of hepatocellular carcinoma (HCC) cells under hypoxic conditions. Methods: We used gain- and loss-of-function methods to evaluate the effect of miRNAs on autophagy in human HCC cell lines (Huh7 and Hep3B) under hypoxic conditions. Autophagy was quantified by immunoblot, immunofluoresence, and transmission electron microscopy analyses, and after incubation of cells with bafilomycin A1. We used a luciferase reporter assay to confirm associations between miRNAs and their targets. We analyzed growth of HCC xenograft tumors in nude mice. Results: miR-375 was down-regulated in HCC cells and tissues; it inhibited autophagy under hypoxic conditions by suppressing the conversion of LC3I to LC3II and thereby autophagic flux. The ability of miR-375 to inhibit autophagy was independent of its ability to regulate 3′-phosphoinositide-dependent protein kinase-1–AKT–mammalian target of rapamycin signaling, but instead involved suppression of ATG7, an autophagy-associated gene. miR-375 bound directly to a predicted site in the 3′ untranslated region of ATG7. Up-regulating miR-375 or down-regulating ATG7 inhibited mitochondrial autophagy of HCC cells, reduced the elimination of damaged mitochondria under hypoxia, increased release of mitochondrial apoptotic proteins, and reduced viability of HCC cells. In mice, xenograft tumors that expressed miR-375 had fewer autophagic cells, larger areas of necrosis, and grew more slowly than tumors from HCC cells that expressed lower levels of miR-375. Conclusions: miR-375 inhibits autophagy by reducing expression of ATG7 and impairs viability of HCC cells under hypoxic conditions in culture and in mice. miRNAs that inhibit autophagy of cancer cells might be developed as therapeutics.

Abatacept for Crohn’s Disease and Ulcerative Colitis - Accepted Manuscript

2012-04-16

Abstract: Background: The efficacy of abatacept, a selective costimulation modulator, in Crohn’s disease (CD) and ulcerative colitis (UC) is unknown. Methods: Four placebo-controlled trials evaluated the efficacy and safety of abatacept as induction (IP) and maintenance (MP) therapy in adults with active, moderate-to-severe CD (CD-IP; CD-MP) and UC (UC-IP1; UC-MP). In CD-IP and UC-IP1, 451 patients with CD and 490 with UC were randomized to abatacept 30, 10, or 3 mg/kg (according to body weight) or placebo and dosed at Weeks 0, 2, 4 and 8. In MP, 90 patients with CD and 131 with UC who responded to abatacept at Week 12 in the induction trials were randomized to abatacept 10 mg/kg or placebo every 4 weeks through Week 52. Results: In CD-IP, 17.2, 10.2 and 15.5% of patients receiving abatacept 30, 10 and 3 mg/kg achieved a clinical response at Weeks 8 and 12, versus 14.4% receiving placebo (P=0.611, P=0.311 and P=0.812, respectively). In UC-IP1, 21.4, 19.0 and 20.3% of patients receiving abatacept 30, 10, and 3 mg/kg achieved a clinical response at Week 12, versus 29.5% receiving placebo (P=0.124, P=0.043 and P=0.158, respectively). In CD-MP, 23.8 versus 11.1% of abatacept versus placebo patients were in remission at Week 52. In UC-MP, 12.5 versus 14.1% of patients receiving abatacept versus placebo were in remission at Week 52. Safety was generally comparable between groups. Conclusions: The studies demonstrated that abatacept is not efficacious for the treatment of moderate-to-severe CD or UC.

Identification of Pancreatic Cancer Stem Cells and Selective Toxicity of Chemotherapeutic Agents - Accepted Manuscript

2012-04-16

Abstract: Background & Aims: Identification and purification of cancer stem cells (CSCs) could lead to new therapeutic targets, but their heterogeneous expansion is an obstacle to their study. We investigated whether it is possible to monitor pancreatic CSCs in real time, based on their intrinsic low level of proteasome activity. Methods: We engineered human pancreatic adenocarcinoma cells (PANC1, MIAPaCa2, BxPC3, and KLM1) to express a green fluorescent molecule fused to the degron of ornithine decarboxylase (Gdeg) from a retroviral vector; the fluorescent Gdeg accumulates in CSCs due to low activity of the 26S proteasome. Cells with high and low levels of fluorescence (Gdeg high and Gdeglow) were isolated by flow cytometry; tumor growth was analyzed in immunocompromised mice. We performed a screen for agents that were specifically toxic to pancreatic CSCs, in a synthetic lethal manner. Results: Gdeghigh, but not Gdeglow cells, formed spheres and underwent asymmetric division—features of CSCs. Injection of as few as 10 Gdeghigh cells led to tumor formation in mice. Gemcitabine was toxic to cultured Gdeglow, whereas Gdeghigh cells were resistant. We observed that quercetin was toxic to Gdeghigh cells in culture and in pre-established tumors grown from these cells in mice. Nuclear accumulation of β-catenin was detected in Gdeghigh, but not Gdeglow cells, and lost after exposure to quercetin. Conclusion: We used a fluorescence marker system for level of proteasome activity to identify pancreatic cancer cells with features of cancer stem cells. We identified quercetin as a compound that is specifically toxic to the pancreatic CSCs.

Induced MIST1 Expression Promotes Remodeling Of Mouse Pancreatic Acinar Cells - Accepted Manuscript

2012-04-16

Abstract: Background & Aims: Early embryogenesis involves cell fate decisions that define the body axes and establish pools of progenitor cells. Development does not stop once lineages are specified; cells continue to undergo specific maturation events, and changes in gene expression patterns lead to their unique physiological functions. Secretory pancreatic acinar cells mature post-natally to synthesize large amounts of protein, polarize, and communicate with other cells. The transcription factor MIST1 is expressed by only secretory cells and regulates maturation events. Mist1-deficient acinar cells in mice do not establish apical-basal polarity, properly position zymogen granules, or communicate with adjacent cells, disrupting pancreatic function. We investigated whether Mist1 directly induces and maintains the mature phenotype of acinar cells. Methods: We analyzed the effects of Cre-mediated expression ofMist1in adultMist1deficient ( Mist1 KO) mice. Pancreatic tissues were collected and analyzed by light and electron microscopy, immunohistochemistry, real-time PCR analysis, and chromatin immunoprecipitation. Primary acini were isolated from mice and analyzed in amylase secretion assays. Results: Induced expression ofMist1in adultMist1 KO mice restored wild-type gene expression patterns in acinar cells. The acinar cells changed phenotypes, establishing apical-basal polarity, increasing the size of zymogen granules, reorganizing the cytoskeletal network, communicating intercellularly (by synthesizing gap junctions), and undergoing exocytosis. Conclusions: The exocrine pancreas of adult mice can be remodeled by re-expression of the transcription factor MIST1. MIST1 regulates acinar cell maturation and might be used to repair damaged pancreata in patients with pancreatic disorders.