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Background: Patients with eosinophilic esophagitis (EoE) present with mechanical type dysphagia. Barium esophagrams occasionally demonstrate focal strictures or multiple concentric rings. Diffuse narrowing has also been reported but may be difficult to recognize because of lack of normative data., Aim: The aim of this study is to assess esophageal diameters at multiple sites in healthy controls in comparison with EoE patients., Methods: A standardized barium swallow was performed in 22 healthy male volunteers without esophageal symptoms and compared with 10 untreated EoE patients. A radiopaque ruler attached at the subject's back was used to measure maximal esophageal diameter at three esophageal sites by a blinded observer. Peak intraepithelial eosinophil counts and Mayo Dysphagia Questionnaire scores were correlated to esophageal diameters in EoE patients., Results: Two of 10 EoE patients had areas of focal narrowing on barium Xray. Esophageal diameters were significantly less at all three esophageal sites in EoE patients compared with controls. Using a total esophageal diameter score (i.e., sum of the three diameters) to establish the 95th percentile for minimal diameter in controls, four of 10 EoE patients fell below the normal range. There was no significant correlation between esophageal diameters, peak eosinophil counts and any of the Mayo Dysphagia Questionnaire severity scores., Conclusion: Patients with EoE have a diffusely narrow esophagus in comparison to healthy controls, and this abnormality may not be appreciated without using appropriate normative data.

Inflammation causes proliferation of intestinal smooth muscle cells (ISMC), contributing to a thickened intestinal wall and to stricture formation in Crohn's disease. Proliferation of ISMC in vitro and in vivo caused decreased expression of marker proteins, but the underlying cause is unclear. Since epigenetic change is important in other systems, we used immunocytochemistry, immunoblotting, and quantitative PCR to examine epigenetic modification in cell lines from rat colon at low passage or after extended growth to evaluate phenotype. Exposure to the histone deacetylase (HDAC) inhibitor trichostatin A or the DNA methyltransferase inhibitor 5-azacytidine reversed the characteristic loss of phenotypic markers among high-passage cell lines of ISMC. Expression of smooth muscle actin and smooth muscle protein 22, as well as functional expression of the neurotrophin glial cell line-derived neurotrophic factor, was markedly increased. Increased expression of muscarinic receptor 3 and myosin light chain kinase was correlated with an upregulated response to cholinergic stimulation. In human ISMC (hISMC) lines from the terminal ileum, phenotype was similarly affected by extended proliferation. However, in hISMC from resected Crohn's strictures, we observed a significantly reduced contractile phenotype compared with patient-matched intrinsic controls that was associated with increased patient-specific expression of DNA methyltransferase 1, HDAC2, and HDAC5. Therefore, protracted growth causes epigenetic alterations that account for an altered phenotype of ISMC. A similar process may promote stricture formation in Crohn's disease, where the potential for halting progression, or even reversal, of disease through control of phenotypic modulation may become a novel treatment option.

Arginase-1 (Arg1) converts arginine to urea and ornithine in the distal step of the urea cycle in liver. We previously generated a tamoxifen-inducible Arg1 deficient mouse model (Arg1-Cre) that disrupts Arg1 expression throughout the whole body and leads to lethality ≈ 2 weeks after gene disruption. Here, we evaluate if liver-selective Arg1 loss is sufficient to recapitulate the phenotype observed in global Arg1 knockout mice, as well as to gauge the effectiveness of gene delivery or hepatocyte transplantation to rescue the phenotype. Liver-selective Arg1 deletion was induced by using an adeno-associated viral (AAV)-thyroxine binding globulin (TBG) promoter-Cre recombinase vector administered to Arg1 "floxed" mice; Arg1 fl/fl ). An AAV vector expressing an Arg1-enhanced green fluorescent protein (Arg1-eGFP) transgene was used for gene delivery, while intrasplenic injection of wild-type (WT) C57BL/6 hepatocytes after partial hepatectomy was used for cell delivery to "rescue" tamoxifen-treated Arg1-Cre mice. The results indicate that liver-selective loss of Arg1 (> 90% deficient) leads to a phenotype resembling the whole body knockout of Arg1 with lethality ≈ 3 weeks after Cre-induced gene disruption. Delivery of Arg1-eGFP AAV rescues more than half of Arg1 global knockout male mice (survival > 4 months) but a significant proportion still succumb to the enzyme deficiency even though liver expression and enzyme activity of the fusion protein reach levels observed in WT animals. Significant Arg1 enzyme activity from engrafted WT hepatocytes into knockout livers can be achieved but not sufficient for rescuing the lethal phenotype. This raises a conundrum relating to liver-specific expression of Arg1. On the one hand, loss of expression in this organ appears to be both necessary and sufficient to explain the lethal phenotype of the genetic disorder in mice. On the other hand, gene and cell-directed therapies suggest that rescue of extra-hepatic Arg1 expression may also be necessary for disease correction. Further studies are needed in order to illuminate the detailed mechanisms for pathogenesis of Arg1-deficiency.

Salmonella typhimurium is a major cause of diarrhea and causes significant morbidity and mortality worldwide, and perturbations of the gut microbiota are known to increase susceptibility to enteric infections. The purpose of this study was to investigate whether a Microbial Ecosystem Therapeutic (MET-1) consisting of 33 bacterial strains, isolated from human stool and previously used to cure patients with recurrent Clostridium difficile infection, could also protect against S. typhimurium disease. C57BL/6 mice were pretreated with streptomycin prior to receiving MET-1 or control, then gavaged with S. typhimurium. Weight loss, serum cytokine levels, and S. typhimurium splenic translocation were measured. NF-κB nuclear staining, neutrophil accumulation, and localization of tight junction proteins (claudin-1, ZO-1) were visualized by immunofluorescence. Infected mice receiving MET-1 lost less weight, had reduced serum cytokines, reduced NF-κB nuclear staining, and decreased neutrophil infiltration in the cecum. MET-1 also preserved cecum tight junction protein expression, and reduced S. typhimurium translocation to the spleen. Notably, MET-1 did not decrease CFUs of Salmonella in the intestine. MET-1 may attenuate systemic infection by preserving tight junctions, thereby inhibiting S. typhimurium from gaining access to the systemic circulation. We conclude that MET-1 may be protective against enteric infections besides C. difficile infection.

Professional antigen-presenting cells (APCs) play a crucial role in initiating immune responses. Under pathological conditions, epithelial cells at mucosal surfaces act as nonprofessional APCs, thereby regulating immune responses at the site of exposure. Epithelial cells in the esophagus may contribute to the pathogenesis of eosinophilic esophagitis (EoE) by presenting antigens on the major histocompatibility complex (MHC) class II. Our goal was to demonstrate the ability of esophageal epithelial cells to process and present antigens on the MHC class II system and to investigate the contribution of epithelial cell antigen presentation to EoE. Immunohistochemistry detected HLA-DR, CD80, and CD86 expression and enzyme-linked immunosorbent assay detected interferon-γ (IFNγ) in esophageal biopsies. Antigen presentation was studied using the human esophageal epithelial cell line HET-1A by reverse transcriptase-PCR, flow cytometry, and confocal microscopy. T helper cell lymphocyte proliferation was assessed by flow cytometry and IL-2 secretion. IFNγ and MHC class II were increased in mucosa of patients with EoE. IFNγ increased mRNA of HLA-DP, HLA-DQ, HLA-DR, and CIITA in HET-1A cells. HET-1A engulfed cell debris and processed ovalbumin. HET-1A cells expressed HLA-DR after IFNγ treatment. HET-1A stimulated T helper cell activation. In this study, we demonstrated the ability of esophageal epithelial cells to act as nonprofessional APCs in the presence of IFNγ. Esophageal epithelial cell antigen presentation may contribute to the pathophysiology of eosinophilic esophagitis., (Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Background/objective: Liver biopsy has been the gold standard for grading and staging chronic hepatitis C virus (HCV)- mediated liver injury. Traditionally, this has been performed by trained practitioners using a nonimage-guided percutaneous technique at the bedside. Recent literature suggests an expanding role for radiologists in obtaining biopsies using an ultrasound (US)-guided technique. The present study was undertaken study to determine if the two techniques produced liver biopsy specimens of similar quality and hypothesized that at our institution, non-US-guided percutaneous liver biopsies for HCV would be of higher quality than US-guided specimens., Methods: Liver biopsies from 100 patients with chronic HCV infection (50 consecutive US-guided and 50 consecutive non-US-guided), were retrospectively identified using a hospital histopathology database. All original biopsy slides were coded and prospectively reanalyzed by a single hepatopathologist who was blinded to the technique used in obtaining the biopsy. Additionally, all liver biopsies for chronic HCV infection completed at the centre from 1998 to 2007 were identified and the technique used was recorded. Biopsy quality was determined primarily by the number of complete portal tracts (CPTs) identifiable in the slides. The total length of specimen and the degree of fragmentation were secondary outcome measures., Results: There was a slight difference observed between the US-guided and non-US-guided groups in mean age (46.3 years versus 42.5 years, respectively; P=0.018) but no differences in sex, presence of cirrhosis, bilirubin, creatinine, international normalized ratio, and grade or stage of disease. Biopsies obtained using the US-guided technique produced higher quality specimens than the non-US-guided technique based on our primary outcome of number of CPTs in the biopsy (11.8 versus 7.4; P<0.001). US-guided specimens also were longer (24.4 mm versus 19.7 mm; P=0.001), had less fragmentation (P=0.016), and a higher overall histopathological quality assessment (P=0.026) than the non-US-guided biopsies. However, there was no significant difference between the two groups in the ability to grade and stage the disease (96% US-guided versus 90% in non-US-guided (P=0.20). Over a 10-year period, 763 biopsies for chronic HCV infection were identified with an obvious trend toward the increased use of US-guided technique observed at 2% in 1998 to 85% in 2007., Conclusions: US-guided liver biopsies for chronic HCV are the most common method of obtaining specimens at the Kingston General Hospital, Kingston, Ontario, and are of higher quality than non-US-guided specimens. However, there is no significant difference in the two techniques in the ability to grade and stage chronic HCV.

Acute gastrointestinal hemorrhage from a gastroaortic fistula in the gastric fundoplication pouch is a rare complication of Nissen fundoplication. The present case reports a gastroaortic fistula secondary to gastric ulceration associated with prior Nissen fundoplication and nonsteroidal anti-inflammatory drug use. A 55-year-old man presented with massive hematemesis and died of exsanguination during emergency laparotomy. Recognition of factors that predispose a patient to gastric ulceration after fundoplication, including nonsteroidal anti-inflammatory drug use, is critical to arouse the high index of suspicion required to diagnose and manage this life-threatening complication.

Background and Study Aims: Surveillance for mucosal dysplasia in patients with chronic ulcerative colitis requires numerous biopsies (often over 40). The aim of the present study was to determine if two biopsies could be obtained with jumbo forceps before removing them from the instrument (double biopsy technique), as opposed to one biopsy per pass, without sacrificing the histological quality of the biopsy material., Methods: Twelve patients with chronic ulcerative colitis underwent colonoscopy, and four-quadrant biopsies were obtained at 10 cm intervals. For biopsies at each interval, two quadrants were obtained using the double biopsy technique and the other two quadrants were obtained individually. Two pathologists blinded to the biopsy technique examined each biopsy for technical and diagnostic qualities. The primary outcome was the histological adequacy in the evaluation of dysplasia., Results: A total of 468 biopsies were obtained. A higher proportion of double-biopsy specimens were inadequate for dysplasia assessment compared with single-biopsy specimens (OR=2.78, 95% CI 1.37 to 5.59; P=0.005). In the double biopsy technique group, 14 samples were deemed inadequate due to actual tissue specimen loss, compared with eight samples in the single biopsy technique. However, when analysis was repeated using only the retrieved specimens, the double biopsy technique continued to be at higher risk of obtaining inadequate specimens (OR=14.5, 95% CI 2.1 to 98.7; P=0.006)., Conclusions: The results of the present study suggest that the double biopsy technique is vulnerable to specimen loss and reduced histological quality, and the adoption of this technique as an equivalent method for tissue sampling may be premature.

Increasing numbers of intestinal adenocarcinomas in patients with Crohn's disease have been reported, but the strength of this association still needs to be elucidated. Adenocarcinoma has also been documented in different types of fistulous tracts associated with Crohn's disease. The first case of well-differentiated mucinous adenocarcinoma involving only enterocutaneous fistulae is reported in a patient with long-standing Crohn's disease complicated by persistent abdominal wall fistulous tracts. The malignant lesion arose from neoplastic transformation of columnar epithelium lining portions of the fistulae occurring as a result of either re-epithelialization of these inflammatory tracts or mural implantation of mucosal tissue secondary to prior ulceration. The patient has remained disease-free eight years after surgical resection of the tumour. Even though intestinal carcinoma is not as strongly associated with Crohn's disease as with ulcerative colitis, intestinal carcinoma should be considered in the setting of long-standing disease, previous intestinal exclusion surgeries and complications such as enterocutaneous or other types of fistulous tracts. The prognosis of such patients may be excellent with early diagnosis and treatment.