Bile reflux gastritis and Barrett's oesophagus: further evidence of a role for duodenogastro-oesophageal reflux?

Duodenogastric reflux in health and disease: insights from a computational fluid dynamics model of the stomach

The stomach is responsible for physically and chemically processing the ingested meal before controlled emptying into the duodenum through the pyloric sphincter. An incompetent pylorus allows reflux from the duodenum back into the stomach, and if the amount of reflux is large enough, it could alter the low-pH environment of the stomach and erode the mucosal lining of the lumen. In some cases, the regurgitated contents can also reach the esophagus, leading to additional complications. In this work, "StomachSim", an in silico model of the fluid dynamics of the stomach, is used to study the mechanism of duodenogastric reflux. The effects of variations in food properties and motility disorders on reflux are investigated. The simulations show that the primary driver of reflux is the relaxation of the antrum after a stomach contraction terminates near the pylorus. The region of the stomach walls exposed to the regurgitated contents depends significantly on the density of the stomach contents. For stomach contents of higher viscosity, the increased pressure required to maintain gastric emptying reduces the amount of duodenogastric reflux. Concomitant stomach motility disorders that weaken the relaxation of the walls also affect the amount of reflux. The study illustrates the utility of in silico models in analyzing the factors at play in gastrointestinal diseases.NEW & NOTEWORTHY An in silico model of the stomach is presented to study the phenomenon of duodenogastric reflux. We use the model to investigate the role of pyloric incompetence, food properties, and gastroparesis on reflux. This first-ever in silico study of duodenogastric reflux provides new insights into the mechanisms and factors implicated in this reflux and the sequelae of conditions that result from the exposure of the stomach lumen to bile.

Comparative Study of Pyloromyotomy and H-M Pyloroplasty in Proximal Gastrectomy for Adenocarcinoma of Esophageal-Gastric Junction

INTRODUCTION

The incidence of adenocarcinoma of esophageal-gastric junction (AEJ) has been increasing in recent years. Esophagogastrostomy after proximal gastrectomy (PG-EG) is the most commonly used surgical method for this disease which causes a constant spasm of the pyloric sphincter by cutting the vagus nerve around the esophagus, so H-M pyloroplasty (Heineke-Mikulicz pyloroplasty) is often operated after PG-EG to prevent delayed gastric emptying. However, H-M pyloroplasty destroys anti-reflux structure of pylorus and leads to serious bile reflux. The present study was designed to compare pyloromyotomy and H-M pyloroplasty in proximal subtotal gastrectomy through clinical studies and animal experiments.

METHODS

We retrospectively evaluated the outcomes of 73 AEJ patients (39 underwent PG-EG with an H-M pyloroplasty and 34 underwent PG-EG with a pyloromyotomy) between January 2016 and August 2020, and perioperative variables were compared. In the animal experiment, 48 rats were randomly divided into four groups (n = 12): vagotomy group (V group), H-M pyloroplasty group (HM group), pyloromyotomy group (PM group), and control group (O group). Gastric emptying and bile reflux were evaluated in each group.

RESULTS

In the retrospective clinic study, pyloromyotomy and H-M pyloroplasty could all prevent delayed gastric emptying effectively, and the incidence of bile reflux found by electronic gastroscopy in the PM group was significantly lower than that in the HM group (HM, 14/39; PM, 4/34; P = 0.028). In the animal experiment, there was no significant between-group difference of gastric emptying rate (%) in the HM group and PM group (HM, 70.6 ± 16; PM, 72.3 ± 12; P = 0.68) while the gastric emptying rate (%) was significantly lower in the V group than in the HM, PM, and control group (P values were 0.037, 0.021, and 0.001 respectively). The gastric mucosa bile acid concentration was significantly higher in the HM group than other group (P values were all less than 0.001).

CONCLUSIONS

The pyloromyotomy could prevent delayed gastric emptying effectively after PG-EG for types II and III AEJ and reduce bile reflux compared to Heineke-Mikulicz pyloroplasty.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

Features of therapeutic correction of GERD: focus on cytoprotection (with a clinical case)

Тo date, the possible links of the pathogenesis of this disease have been well studied and described, which predetermine certain approaches to the treatment of various variants of gastroesophageal reflux disease (GERD). Effective drug therapy for GERD includes proton pump inhibitors (PPI). However, PPI monotherapy is not always effective. One approach is to increase the PPI dose. At the same time, combination therapy with the addition of drugs that affect the protective properties of the esophageal mucosa seems to be more rational. It is known that in the development of GERD, the violation of cytoprotection of the esophageal mucosa is one of the key links in pathogenesis. Consequently, the issue of combination therapy of PPIs with drugs that increase the protective properties of the mucous barrier along with acid suppression becomes relevant. An example of such an approach is the  appointment of  rebamipide, the  action of  which is to regulate the  synthesis of  prostaglandins through COX-2  mediated mechanisms, influence on endothelial growth factor, increase the expression of tight intercellular contact proteins in epithelial cells of the mucous membrane, reduce the level of interleukin-8 and free oxygen radicals, directed to protect the mucous membrane of  the  gastrointestinal tract and restore its natural barrier properties. The  effectiveness of  the  combination of  PPI and rebamipide contributes to a greater regression of complaints in patients with GERD and a lower frequency of disease relapses than with PPI monotherapy. This article provides a review of the literature on the features of GERD therapy, primarily with an emphasis on the correction of the cytoprotective properties of the esophageal mucosa, including against the background of the use of nonsteroidal anti-inflammatory drugs (NSAID), and a clinical case analysis with a discussion of rational pharmacological correction.

Gastroesophageal Reflux Disease and Foregut Dysmotility in Children with Intestinal Failure

Gastrointestinal dysmotility is a common problem in a subgroup of children with intestinal failure (IF), including short bowel syndrome (SBS) and pediatric intestinal pseudo-obstruction (PIPO). It contributes significantly to the increased morbidity and decreased quality of life in this patient population. Impaired gastrointestinal (GI) motility in IF arises from either loss of GI function due to the primary disorder (e.g., neuropathic or myopathic disorder in the PIPO syndrome) and/or a critical reduction in gut mass. Abnormalities of the anatomy, enteric hormone secretion and neural supply in IF can result in rapid transit, ineffective antegrade peristalsis, delayed gastric emptying or gastroesophageal reflux. Understanding the underlying pathophysiologic mechanism(s) of the enteric dysmotility in IF helps us to plan an appropriate diagnostic workup and apply individually tailored nutritional and pharmacological management, which might ultimately lead to an overall improvement in the quality of life and increase in enteral tolerance. In this review, we have focused on the pathogenesis of GI dysmotility in children with IF, as well as the management and treatment options.

Intestinal metaplasia around the gastroesophageal junction is frequently associated with antral reactive gastropathy: implications for carcinoma at the gastroesophageal junction

Increasing evidence suggests that bile reflux (BR) plays a major role in mucosal injury, leading to adenocarcinoma of the proximal stomach and distal esophagus. However, gastric BR is difficult to diagnose and investigate. Reactive gastropathy (RG), in the absence of nonsteroidal anti-inflammatory drugs (NSAIDs) and other known causes, likely represents bile-mediated injury to the gastric mucosa. The goal of this study is to explore the association between antral RG and gastroesophageal junction (GEJ) mucosal inflammation and intestinal metaplasia (IM). The pathology database was searched for patients who had gastric biopsies with a diagnosis of antral RG and concurrent gastric cardia/GEJ/distal esophagus biopsies from 2013 to 2015. Age- and sex-matched patients with normal gastric antral biopsies served as controls. Biopsies from the GEJ region were evaluated for histological changes, including inflammation, antral and pancreatic metaplasia, RG, the type of gastric glands, proton pump inhibitor (PPI) changes, and IM. Detailed clinical history and medication use (including PPIs and NSAIDs) were recorded. IM in the GEJ region was more frequent in patients with antral RG than in controls (33.0% vs. 5.2%, 95% confidence interval [18.3-37.3%]). In addition, inflammation, other mucosal changes around the GEJ (RG and foveolar hyperplasia), antral IM, and PPI-associated mucosal changes were also more frequently seen in patients with antral RG. Our results show that antral RG is associated with mucosal injury and IM around GEJ, suggesting a role of BR. Further studies are needed to study duodenogastric-esophageal BR and its role in development of proximal gastric and distal esophageal adenocarcinoma.

Duodenogastric biliary reflux assessed by scintigraphic scan in patients with reflux symptoms after sleeve gastrectomy: preliminary results

BACKGROUND

Bile reflux is a factor in the appearance of severe esophagitis and Barrett's esophagus, which have been reported after sleeve gastrectomy (SG). Incompetent lower esophageal sphincter and increased gastroesophageal acid reflux have been demonstrated after this operation. Some reports have shown bile content in the antrum during endoscopic control, but no investigations objectively confirm the presence of duodenogastric bile reflux in these patients.

OBJECTIVES

To evaluate the presence of duodenogastric bile reflux (DGR) after SG in patients presenting reflux symptoms.

SETTING

University hospital.

METHODS

Prospective study of 22 patients presenting reflux symptoms who underwent SG for morbid obesity and who received endoscopic evaluation and scintigraphic study to confirm esophagitis and duodenogastric bile reflux.

RESULTS

Erosive esophagitis was observed in 11 patients and Barrett's esophagus in 2 patients. Seven patients (31.8%) presented positive DGR. Among them, 3 had type B and C esophagitis. The other 4 patients did not present esophagitis in spite of reflux symptoms.

CONCLUSION

DGR may be present in patients with gastroesophageal reflux after SG. This line of investigation requires further studies to confirm this hypothesis.

Motion sensing superpixels (MOSES) is a systematic computational framework to quantify and discover cellular motion phenotypes

Correct cell/cell interactions and motion dynamics are fundamental in tissue homeostasis, and defects in these cellular processes cause diseases. Therefore, there is strong interest in identifying factors, including drug candidates that affect cell/cell interactions and motion dynamics. However, existing quantitative tools for systematically interrogating complex motion phenotypes in timelapse datasets are limited. We present Motion Sensing Superpixels (MOSES), a computational framework that measures and characterises biological motion with a unique superpixel 'mesh' formulation. Using published datasets, MOSES demonstrates single-cell tracking capability and more advanced population quantification than Particle Image Velocimetry approaches. From > 190 co-culture videos, MOSES motion-mapped the interactions between human esophageal squamous epithelial and columnar cells mimicking the esophageal squamous-columnar junction, a site where Barrett's esophagus and esophageal adenocarcinoma often arise clinically. MOSES is a powerful tool that will facilitate unbiased, systematic analysis of cellular dynamics from high-content time-lapse imaging screens with little prior knowledge and few assumptions.

Adenocarcinoma of oesophagus involving gastro-oesophageal junction following mini-gastric bypass/one anastomosis gastric bypass

Mini-gastric bypass/one anastomosis gastric bypass (MGB/OAGB) is an emerging weight loss surgical procedure. There are serious concerns not only regarding the symptomatic biliary reflux into the stomach and the oesophagus but also the increased risk of malignancy after MGB/OAGB. A 54-year-old male, with a body mass index (BMI) of 46.1 kg/m², underwent Robotic MGB at another centre on 22^nd June 2016. His pre-operative upper gastrointestinal endoscopy was not done. He lost 58 kg within 18 months after the surgery and attained a BMI of 25.1 kg/m². However, 2-year post-MGB, the patient had rapid weight loss of 19 kg with a decrease in BMI to 18.3 kg/m² within a span of 2 months. He also developed progressive dysphagia and had recurrent episodes of non-bilious vomiting. His endoscopy showed eccentric ulcerated growth in lower oesophagus extending up to the gastro-oesophageal junction and biopsy reported adenocarcinoma of oesophagus. MGB/OAGB has a potential for bile reflux with increased chances of malignancy. Surveillance by endoscopy at regular intervals for all patients who have undergone MGB/OAGB might help in early detection of Barrett's oesophagus or carcinoma of oesophagus or stomach.

Response to TNF-α Is Increasing Along with the Progression in Barrett's Esophagus

BACKGROUND AND AIMS

Barrett's esophagus, a metaplasia resulting from a long-standing reflux disease, and its progression to esophageal adenocarcinoma (EAC) are characterized by activation of pro-inflammatory pathways, induced by cytokines.

METHODS

An in vitro cell culture system representing the sequence of squamous epithelium (EPC1 and EPC2), Barrett's metaplasia (CP-A), dysplasia (CP-B) to EAC (OE33 and OE19) was used to investigate TNF-α-mediated induction of interleukin-8 (IL-8).

RESULTS

IL-6 and IL-8 expressions are increasing with the progression of Barrett's esophagus, with the highest expression of both cytokines in the dysplastic cell line CP-B. IL-8 expression in EAC cells was approx. 4.4-fold (OE33) and eightfold (OE19) higher in EAC cells than in squamous epithelium cells (EPC1 and EPC2). The pro-inflammatory cytokine TNF-α increased IL-8 expression in a time-, concentration-, and stage-specific manner. Furthermore, TNF-α changed the EMT marker profile in OE33 cells by decreasing the epithelial marker E-cadherin and increasing the mesenchymal marker vimentin. The anti-inflammatory compound curcumin was able to repress proliferation and to activate apoptosis in both EAC cell lines.

CONCLUSION

The increased basal expression levels of IL-8 with the progression of Barrett's esophagus constrain NFκB activation and its contribution in the manifestation of Barrett's esophagus. An anti-inflammatory compound, such as curcumin, could create an anti-inflammatory microenvironment and thus potentially support an increase chemosensitivity in EAC cells.

Cholecystectomy and duodenogastric reflux: interacting effects over the gastric mucosa

AIMS

To evaluate association between duodenogastric reflux and early gastric mucosal changes before and after the cholecystectomy procedure.

MATERIALS AND METHODS

Patients were evaluated with preoperative and postoperative endoscopy and endoscopic biopsy. Demographic and clinical characteristics, histological parameters, presence of duodenogastric reflux, and Updated Sydney scores were noted.

RESULTS

A total of fifty patients who obeyed the follow-up were enrolled into the study. Median age of the patients was 43 years (range 25-84). Male-female ratio was 0.51 (17/33). Duodenogastric reflux % and Updated Sydney scores before and after cholecystectomy were 24 (48%) versus 39 (78%) and 2.38 ± 2.21 versus 3.46 ± 3.05, respectively (p = 0.001, p < 0.000). Mucosal inflammation degree showed significant increase in 15 (30%) patients, decrease in 7 (14%) patients and equality in 28 (56%) patients (p = 0.037). Neutrophil activation degree was significantly higher in 21 (42%) patients, lower in 5 (10%) patients after the surgery (p = 0.005). Postoperative glandular atrophy degree was also higher in 13 (26%) patients and equal in 37 (74%) patients (p = 0.001). Pre- and postoperative degree of intestinal metaplasia and H. pylori density did not any show significant difference (p = 0.157, p = 0.248, respectively).There were significant positive correlation between postoperative H. pylori infection and mucosal activity, inflammation, atrophy and intestinal metaplasia.

CONCLUSION

Cholecystectomy is a potent inducer of pathologic duodenogastric reflux. Early onset of duodenogastric reflux and underlying H. pylori gastritis cause early gastric mucosal injury following cholecystectomy procedure by interacting collectively.

Yesterday and today of Barrett's esophagus: Historical evolution and research hotspots

It has been more than 60 years since the concept of Barrett's esophagus (BE) was put forward, and over these a few decades, we have made great progress in the diagnosis and treatment of BE. BE does not cause clinical symptoms, but it attracts wide attention, because it is an important precursor lesion of esophageal adenocarcinoma. The purpose of this article is to review the process of the recognition of BE and the current research hotspots as well as to discuss the current status of esophageal adenocarcinoma screening in BE patients. We aim to provide clinicians with an overview of the ins and outs of the disease, which will help them improve the diagnosis and treatment of BE in clinical practice and provide patients with beneficial treatment.

Proton pump inhibitors and helicobacter pylori-associated pathogenesis

The fact that long-term use of proton pump inhibitors (PPIs) aggravates corpus atrophic gastritis in patients with Helicobacter pylori infection has been proven clinically and experimentally. Corpus atrophic gastritis is a known risk factor for gastric cancer. Therefore, gastric neoplasia might be associated with the long-term use of PPIs. One of the causes of worsening corpus atrophic gastritis, leading to the development of adenocarcinoma, might be bacterial overgrowth under conditions of hypochlorhydria. The production of potentially carcinogenic N-nitrosocompounds by nitrosating organisms under conditions of hypochlorhydria might be associated with carcinogenesis. Interactions between bile acids, pH, and H. pylori might also contribute to carcinogenicity, especially in patients with gastro-esophageal reflux disease (GERD). The concentration of soluble bile acids, which have bactericidal or chemorepellent properties toward H. pylori, in gastric contents is considerably higher in patients undergoing continuous PPI therapy than in healthy individuals with normal acid production. Under these circumstances, H. pylori might colonize the stomach body rather than the pyloric antrum. Hypergastrinemia induced by PPI administration might promote the development of gastric cancer. Because the main cause of corpus atrophic gastritis is H. pylori infection, and not PPI administration, H. pylori infection should be eradicated before starting long-term PPI therapy.

Uncut Roux-en-Y Reconstruction after Laparoscopic Distal Gastrectomy Can Be a Favorable Method in Terms of Gastritis, Bile Reflux, and Gastric Residue

Purpose

Laparoscopic distal gastrectomy (LDG) is a well-established procedure for the treatment of early gastric cancer. Several reconstruction methods can be adopted after LDG according to tumor characteristics and surgeon preference. This study aimed to compare the remnant gastric functions after different reconstructions.

Materials and Methods

In total, 221 patients who underwent LDG between March 2005 and October 2013 were reviewed retrospectively. The patients were classified into four groups based on the reconstructive procedure: Billroth I (BI) anastomosis, Billroth II (BII) with Braun anastomosis, Roux-en-Y (RY) reconstruction, or uncut RY reconstruction. Patient demographics, surgical outcomes, and postoperative endoscopic findings were reviewed and compared among groups.

Results

Endoscopic evaluations at 11.8±3.8 months postoperatively showed less frequent gastritis and bile reflux in the remnant stomach in the RY group compared to the BI and BII groups. There was no significant difference in the gastric residue among the BI, BII, and RY groups. The incidence of gastritis and bile reflux in the uncut RY group was similar to that in the RY group, while residual gastric content in the uncut RY group was significantly smaller and less frequently observed than that in the RY group (5.8% versus 35.3%, P=0.010).

Conclusions

RY and uncut RY reconstructions are equally superior to BI and BII with Braun anastomoses in terms of gastritis and bile reflux in the remnant stomach. Furthermore, uncut RY reconstruction showed improved stasis compared to conventional RY gastrojejunostomy. Uncut RY reconstruction can be a favorable reconstructive procedure after LDG.

Potential mechanism of corpus-predominant gastritis after PPI therapy in Helicobacter pylori-positive patients with GERD

The long-term use of proton pump inhibitors (PPIs) exacerbates corpus atrophic gastritis in patients with Helicobacter pylori (H. pylori) infection. To identify a potential mechanism for this change, we discuss interactions between pH, bile acids, and H. pylori. Duodenogastric reflux, which includes bile, occurs in healthy individuals, and bile reflux is increased in patients with gastroesophageal reflux disease (GERD). Diluted human plasma and bile acids have been found to be significant chemoattractants and chemorepellents, respectively, for the bacillus H. pylori. Although only taurine conjugates, with a pKa of 1.8-1.9, are soluble in an acidic environment, glycine conjugates, with a pKa of 4.3-5.2, as well as taurine-conjugated bile acids are soluble in the presence of PPI therapy. Thus, the soluble bile acid concentrations in the gastric contents of patients with GERD after continuous PPI therapy are considerably higher than that in those with intact acid production. In the distal stomach, the high concentration of soluble bile acids is likely to act as a bactericide or chemorepellent for H. pylori. In contrast, the mucous layer in the proximal stomach has an optimal bile concentration that forms chemotactic gradients with plasma components required to direct H. pylori to the epithelial surface. H. pylori may then colonize in the stomach body rather than in the pyloric antrum, which may explain the occurrence of corpus-predominant gastritis after PPI therapy in H. pylori-positive patients with GERD.

Epigenetic regulation of hepatocellular carcinoma in non-alcoholic fatty liver disease

Emerging evidence that epigenetics converts alterations in nutrient and metabolism into heritable pattern of gene expression has profound implications in understanding human physiology and diseases. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome including obesity and diabetes which elevate the risk of hepatocellular carcinoma (HCC) especially in male. This review focuses on the molecular connections between metabolic dysfunction and aberrant epigenetic alterations in the development of HCC in NAFLD. The metabolites derived from excessive insulin, glucose and lipid may perturb epigenetic gene regulation through DNA methylation, histone modifications, and RNA interference, leading to activation of pro-inflammatory signaling and deregulation of metabolic pathways. The interplay and crosstalk of chromatin-modifying enzymes, microRNAs, signaling pathways and the downstream transcription factors result in epigenomic reprogramming that drives hepatocellular transformation. The interactions between sex hormone pathways and the epigenetic machineries that influence chromatin states in NAFLD provide potential molecular mechanisms of gender disparity in HCC. A deeper understanding of these connections and comprehensive molecular catalog of hepatocarcinogenesis may shed light in the identification of druggable epigenetic targets for the prevention and treatment of HCC in obese or diabetic patients.

Columnar metaplasia in a surgical mouse model of gastro-esophageal reflux disease is not derived from bone marrow-derived cell

The incidence of esophageal adenocarcinoma has increased in the last 25 years. Columnar metaplasia in Barrett's mucosa is assumed to be a precancerous lesion for esophageal adenocarcinoma. However, the induction process of Barrett's mucosa is still unknown. To analyze the induction of esophageal columnar metaplasia, we established a mouse gastro-esophageal reflux disease (GERD) model with associated development of columnar metaplasia in the esophagus. C57BL/6 mice received side-to-side anastomosis of the esophagogastric junction with the jejunum, and mice were killed 10, 20, and 40 weeks after operation. To analyze the contribution of bone marrow-derived cells to columnar metaplasia in this surgical GERD model, some mice were transplanted with GFP-marked bone marrow after the operation. Seventy-three percent of the mice (16/22) showed thickened mucosa in esophagus and 41% of mice (9/22) developed columnar metaplasia 40 weeks after the operation with a mortality rate of 4%. Bone marrow-derived cells were not detected in columnar metaplastic epithelia. However, scattered epithelial cells in the thickened squamous epithelia in regions of esophagitis did show bone marrow derivation. The results demonstrate that reflux induced by esophago-jejunostomy in mice leads to the development of columnar metaplasia in the esophagus. However, bone marrow-derived cells do not contribute directly to columnar metaplasia in this mouse model.

Intra-operative change of gastric pH during laparotomic cholecystectomy under general anaesthesia: A prospective case-control study

Background:

Gastric decompression by suctioning often shows greenish/greenish-yellow-coloured gastric aspirates following cholecystectomy under general anaesthesia (GA). Possible intraoperative regurgitation of duodenal contents into stomach because of surgical manipulation may be the reason for such alteration in colour of the gastric secretions.

Aim:

We conducted this study to determine whether there were any pH changes of gastric secretions during laparotomic cholecystectomy operation to confirm our hypothesis of regurgitation of duodenal contents into the stomach.

Settings and Designs:

Prospective observational controlled study in the Department of Anaesthesiology and Critical Care in a tertiary care university teaching hospital.

Methods:

Fifty adult ASA I and II patients scheduled for open cholecystectomy operation under GA were included in the study group and another 50 non-abdominal surgical patients without any gall bladder disease were taken as controls. Three to five milliliters of gastric secretions were aspirated just after intubation and also before reversal of residual neuromuscular blockade for analysis of pH.

Statistical Analysis:

Analysis of variance test and Chi-square test with Fisher's exact correction were used for statistical analysis. Differences were significant when the P value was <0.05.

Results:

Post-operative values of pH in the study group were significantly higher than their pre-operative values (2.40±1.10 vs. 4.04±1.6, P≤0.001). Forty-nine patients (98%) in the study group had altered coloured post-operative gastric aspirations, while no patient in the control group had such changes (P<0.001).

Conclusions:

A significant change in gastric pH takes place during laparotomic cholecystectomy due to reflux of duodenal content into the stomach.

Reactive gastropathy is associated with inflammatory conditions throughout the gastrointestinal tract

BACKGROUND

The epidemiology of reactive gastropathy and its relationship with other conditions of the gastrointestinal tract associated with NSAID use have not been evaluated.

AIMS

To test the hypothesis that if reactive gastropathy shares common aetiological factors with these conditions, the analysis of a large cohort would unveil associations.

METHODS

We queried a national pathology database for subjects with a diagnosis of reactive gastropathy; controls were patients with normal gastric biopsies. We also extracted diagnoses of H. pylori infection, intestinal metaplasia, duodenal lymphocytosis, duodenitis, ileitis, microscopic colitis and focal colitis.

RESULTS

Of 504 011 patients with gastric biopsies, 69 101 had oesophageal, 166 134 duodenal, 13 010 ileal and 83 334 colonic biopsies. Reactive gastropathy was diagnosed in 15.6% of patients, H. pylori infection in 10.3% and normal gastric mucosa in 16.3%. Reactive gastropathy was evenly distributed across the US and increased from 2.0% in the first decade of life to >20% in octogenarians. Compared with controls, reactive gastropathy was significantly associated with Barrett's mucosa (OR 1.21 95% CI 1.16-129); duodenitis (OR 1.36; 95% CI 1.28-1.44); duodenal intraepithelial lymphocytosis (OR 1.25; 95% CI 1.13-1.39); active ileitis (OR 1.88; 95% CI 1.47-2.40); focal active colitis (OR 1.57; 95% CI 1.33-1.86); and collagenous colitis (OR 1.50; 95% CI 1.12-2.03).

CONCLUSIONS

Reactive gastropathy, a common histopathological feature of the stomach, shows an age-dependent rise and is associated with changes of the digestive tract believed to be caused by NSAID use or duodenogastric reflux. However, a large fraction of reactive gastropathy remains unexplained; its frequent occurrence merits further efforts at elucidating its aetiology.

Ablation of Barrett's oesophagus: towards improved outcomes for oesophageal cancer?

Barrett's oesophagus is the major risk factor for the development of oesophageal adenocarcinoma. The management of Barrett's oesophagus entails treating reflux symptoms with acid-suppressing medication or surgery (fundoplication). However, neither form of anti-reflux therapy produces predictable regression, or prevents cancer development. Patients with Barrett's oesophagus usually undergo endoscopic surveillance, which aims to identify dysplastic changes or cancer at its earliest stage, when treatment outcomes should be better. Alternative endoscopic interventions are now available and are suggested for the treatment of early cancer and prevention of progression of Barrett's oesophagus to cancer. Such treatments could minimize the risks associated with oesophagectomy. The current status of these interventions is reviewed. Various endoscopic interventions have been described, but with long-term outcomes uncertain, they remain somewhat controversial. Radiofrequency ablation of dysplastic Barrett's oesophagus might reduce the risk of cancer progression, although cancer development has been reported after this treatment. Endoscopic mucosal resection (EMR) allows a 1.5-2 cm diameter piece of oesophageal mucosa to be removed. This provides better pathology for diagnosis and staging, and if the lesion is confined to the mucosa and fully excised, EMR can be curative. The combination of EMR and radiofrequency ablation has been used for multifocal lesions, but long-term outcomes are unknown. The new endoscopic interventions for Barrett's oesophagus and early oesophageal cancer have the potential to improve clinical outcomes, although evidence that confirms superiority over oesphagectomy is limited. Longer-term outcome data and data from larger cohorts are required to confirm the appropriateness of these procedures.

The histological and immunohistochemical aspects of bile reflux in patients with gastroesophageal reflux disease

Introduction. The pathogenesis of GERD is strongly related with mixed acid and bile reflux. Benign and malignant esophageal and gastric lesions have been associated with synergetic activity between those parameters. Bile reflux causes reactive gastropathy evaluated with Bile Reflux Index (BRI). The aim was to investigate if the sequence: bile reflux-intestinal metaplasia-GERD-esophagitis, is associated with apoptotic/oncogenetic disturbances. Materials/Methods. Fifteen asymptomatic subjects and 53 GERD patients underwent gastroscopy with biopsies. The specimens examined histologically and immunohistochemically for p53, Ki-67, Bax, and Bcl-2. Results. Elevated BRI score detected in 47% (25/53) of patients with GERD and in 13% (2/15) of controls (P = 0.02). Severe esophageal lesions were significantly more common in BRI (+) patients (14/25) compared to BRI (-) ones (P = 0.0049). Immunohistochemical analysis did not show associations between BRI score and biomarker expression. Conclusions. Bile reflux gastropathy is associated with GERD severity, but not with oncogene expression or apoptotic discrepancies of the upper GI mucosa.

MicroRNA-196a & microRNA-101 expression in Barrett's oesophagus in patients with medically and surgically treated gastro-oesophageal reflux

BACKGROUND

Proton pump inhibitor (PPI) medication and surgical fundoplication are used for the control of gastro-oesophageal reflux in patients with Barrett's oesophagus, but differ in their effectiveness for both acid and bile reflux. This might impact on the inflammatory processes that are associated with progression of Barrett's oesophagus to cancer, and this may be evident in the gene expression profile and microRNA expression pattern in Barrett's oesophagus mucosa. We hypothesised that two miRNAs with inflammatory and oncogenic roles, miR-101 and miR-196a, are differentially expressed in Barrett's oesophagus epithelium in patients with reflux treated medically vs. surgically.

FINDINGS

Mucosal tissue was obtained at endoscopy from patients with Barrett's oesophagus whose reflux was controlled by proton pump inhibitor (PPI) therapy (n = 20) or by fundoplication (n = 19). RNA was extracted and the expression of miR-101 and miR-196a was measured using real-time reverse transcription - polymerase chain reaction. There were no significant differences in miR-101 and miR-196a expression in Barrett's oesophagus epithelium in patients treated by PPI vs. fundoplication (p = 0.768 and 0.211 respectively). Secondary analysis showed a correlation between miR-196a expression and Barrett's oesophagus segment length (p = 0.014).

CONCLUSION

The method of reflux treatment did not influence the expression of miR-101 and miR-196a in Barrett's oesophagus. This data does not provide support to the hypothesis that surgical treatment of reflux better prevents cancer development in Barrett's oesophagus. The association between miR-196a expression and Barrett's oesophagus length is consistent with a tumour promoting role for miR-196a in Barrett's oesophagus.

The pathogenesis of Barrett's metaplasia and the progression to esophageal adenocarcinoma

The most important risk factor for the development of Barrett's esophagus is the reflux of both gastric and duodenal contents into the esophagus. The reason why Barrett's metaplasia develops only in a minority of patients suffering from gastroesophageal reflux disease remains unknown.The exact mechanism behind the transition of normal squamous epithelium into specialized columnar epithelium is also unclear. It is likely that stem cells are involved in this metaplastic change, as they are the only permanent residents of the epithelium. Several tumorigenic steps that lead to the underlying genetic instability, which is indispensable in the progression from columnar metaplasia to esophageal adenocarcinoma have been described. This review outlines the process of pathogenesis of Barrett's metaplasia and its progression to esophageal adenocarcinoma.

Nitric oxide-mediated invasion in Barrett's high-grade dysplasia and adenocarcinoma

Nitric oxide (NO) has been shown to induce double strand DNA breaks in Barrett's oesophagus (BO) and in other cancers has a role in invasion. The specific aims of this study were to investigate whether NO can induce invasion in cells representative of different stages of Barrett's progression and to determine possible underlying mechanisms. Physiological concentrations of NO that mimic luminal production of NO from dietary sources enhanced invasion in cell lines from high-grade dysplasia (GihTERT) and oesophageal adenocarcinoma (FLO) but not a non-dysplastic Barrett's cell line (QhTERT). Real-time reverse transcription-polymerase chain reaction revealed that NO induced expression of matrix metalloproteinase (MMP)-1, -3, -7, -9 and -10 and tissue inhibitor of metalloproteinase (TIMP)-1, -2 and -3 in these cell lines. Furthermore, ex vivo treatment of Barrett's biopsy samples with NO induced increases in MMP-1 and TIMP-1 expression, suggesting that NO enhances invasion through deregulating MMP and TIMP expression in epithelial cells. In keeping with these findings, microarray analysis and immunohistochemistry performed on biopsy samples showed enhanced expression of MMP-1, -3, -7 and -10 and TIMP-1 in the progression from non-dysplastic BO to adenocarcinoma, although this could not be directly attributed to the effect of NO. Thus, NO may play a role in Barrett's carcinogenesis through deregulating MMP and TIMP expression to enhance invasive potential.

Gastric surgery is not a risk factor for erosive esophagitis or Barrett's esophagus

OBJECTIVE

The role of gastric acid reflux is difficult to separate from that of pancreatic-biliary reflux in the pathogenesis of erosive esophagitis (EE) and Barrett's esophagus (BE). Gastric surgery patients provide a good model for both significant pancreatic-biliary reflux and marked gastric acid inhibition. We assessed the risk of EE and BE after distal gastrectomy in a case-controlled study.

MATERIAL AND METHODS

One hundred and sixty patients (121 men, 39 women; median age 68 years; range 32-86 years) with distal gastrectomies (Billroth-I) and 160 sex- and age-matched controls with intact stomachs were enrolled. The presence of EE and BE were diagnosed based on the Los Angeles Classification and the Prague C & M Criteria, respectively. A conditional logistic regression model with adjustments for potential confounding factors was used to assess the associations.

RESULTS

According to the multivariate analyses, patients with distal gastrectomies tended to have inverse associations with the risks of EE and BE, and the inverse association with the risk of BE reached a significant level.

CONCLUSIONS

Distal gastrectomy is not a risk factor for the development of EE and BE. This lack of a positive association between distal gastrectomy and EE and BE may suggest that pancreatic-biliary reflux with a limited amount of acid is not sufficient to damage the esophageal mucosa.

Acid and bile salt up-regulate BMP4 expression in human esophageal epithelium cells

OBJECTIVE

Barrett's esophagus (BE) with an intestinal-type epithelium is thought to be a precancerous lesion of adenocarcinoma of the esophagus. The pathophysiology of Barrett's metaplasia is poorly understood. Previous studies suggest that differentiation of multipotent cells to columnar epithelium may be one of the possible mechanisms. Bone morphogenetic protein 4 (BMP4), a factor determining the fate of cells, is up-regulated in BE and esophagitis mucosa when compared with normal squamous or non-goblet cell-containing cardiac epithelium. The aim of this study was to demonstrate that BMP4 is a molecular mediator that links etiological agents of BE to the phenotypic changes in human esophagus epithelium cells (HEECs).

MATERIAL AND METHODS

Primary cultured HEECs were used to investigate the effect of acid and bile salt on BMP4 expression and to examine the biological effects of BMP4 on HEECs.

RESULTS

Acid and bile salt increased the expression of BMP4. In addition, recombinant human BMP4 induced villin expression in HEECs, as did chronic acid exposure, which can be effectively inhibited by Noggin, a specific antagonist of BMP4. Results from a Western blot assay suggest that BMP4 induces activation of smad1 and promotes protein expression of ID2 and CDX2.

CONCLUSION

BMP4 may play an important role in the development of BE.

Gallstones increase the prevalence of Barrett's esophagus

PURPOSE

Bile and acid exposures are thought to be major risk factors for Barrett's esophagus in Western countries. The association of gallstones with Barrett's esophagus has not been fully evaluated. The present study was designed as a case-control study for determining the possible factors associated with endoscopically suspected esophageal metaplasia (ESEM), defined as an endoscopic finding suggestive of Barrett's esophagus, in Japanese patients.

METHODS

A total of 528 patients with ESEM were allocated to the case group, while 528 age- and gender-matched patients without ESEM were allocated to the control group. Findings on esophagogastroduodenoscopy and clinical background factors were compared using a multivariate logistic regression model.

RESULTS

The presence of gallstones and hiatus hernia and the severity of gastric mucosal atrophy were independently associated with the presence of ESEM [odds ratio (OR) 1.67, 95% confidence interval (CI) 1.03-2.69; OR 2.75, 95% CI 1.75-4.33; OR 1.25, 95% CI 1.01-5.6, respectively]. Compared with subjects with neither gastric corpus atrophy nor gallstones, although subjects with gallstones alone were not associated with the presence of ESEM (OR 1.59, 95% CI 0.87-2.92), having both gastric corpus atrophy and gallstones was strongly associated with the presence of ESEM (OR 2.94, 95% CI 1.40-6.17).

CONCLUSIONS

The presence of gallstones was independently associated with the presence of ESEM in the Japanese outpatient population, suggesting a causal association of distal esophageal bile exposure with the development of ESEM. Further studies are needed to confirm our findings in cases with histologically confirmed Barrett's esophagus.

Bile acids induce cdx2 expression through the farnesoid x receptor in gastric epithelial cells

Clinical and experimental studies showed that the reflux of bile into the stomach contributes to the induction of intestinal metaplasia of the stomach and gastric carcinogenesis. Caudal-type homeobox 2 (Cdx2) plays a key role in the exhibition of intestinal phenotypes by regulating the expression of intestine-specific genes such as goblet-specific gene mucin 2 (MUC2). We investigated the involvement of the farnesoid X receptor (FXR), a nuclear receptor for bile acids, in the chenodeoxycholic acid (CDCA)-induced expression of Cdx2 and MUC2 in normal rat gastric epithelial cells (RGM-1 cells). RGM-1 cells were treated with CDCA or GW4064, an FXR agonist, in the presence or absence of guggulsterone, an FXR antagonist. CDCA induced dose-dependent expression of Cdx2 and MUC2 at both the mRNA and protein levels. The maximum stimulation of Cdx2 and MUC2 mRNA induced by CDCA was observed at 3 h and by 6 h, respectively. GW4064 also induced expression of these molecules. The effects of CDCA and GW4064 on expression of Cdx2 and MUC2 were abolished by guggulsterone. These findings suggest that bile acids may induce gastric intestinal metaplasia and carcinogenesis through the FXR.

Expression of bile acid transporting proteins in Barrett's esophagus and esophageal adenocarcinoma

OBJECTIVES

Barrett's esophagus (BE) is a metaplastic lesion characterized by replacement of the normal squamous epithelium by columnar intestinal epithelium containing goblet cells. It is speculated that this process is an adaptation to protect cells from components of refluxate, such as gastric acid and bile acids. In contrast to the normal squamous epithelium, enterocytes of the distal ileum are adapted to transport bile acids from the intestinal lumen. Several bile acid transporters are utilized for effective removal of bile acids, including the apical sodium-dependent bile acid transporter (ASBT), the ileal bile acid-binding protein (IBABP), and the multidrug-resistant protein 3 (MRP3). We hypothesized that one of the possible functions of newly arising metaplastic epithelium, in the esophagus, is to transport bile acids. Our major goal was to evaluate the expression of bile acid transporters in normal squamous epithelium, BE with different grades of dysplasia, and esophageal adenocarcinoma (EAC).

METHODS

A total of 101 patients were included in this study. Immunohistochemistry (IHC) and reverse transcriptase (RT)-PCR were used to detect the expression of these transporters at the mRNA and protein levels.

RESULTS

Our immunohistochemical studies showed that all three bile acid transporters are expressed in BE glands, but not in squamous epithelium. ASBT was found in the apical border in BE biopsies. The highest frequency of ASBT expression was in patients with nondysplastic BE (9 of 15, 60%), and a progressive loss of ASBT was observed through the stages of dysplasia. ASBT was not detected in EAC (0 of 15). IBABP staining was observed in the cytoplasm of BE epithelial surface cells. Expression of IBABP was found in 100% of nondysplastic BE (14 of 14), in 93% of low-grade dysplasia (LGD, 15 of 16), in 73% of high-grade dysplasia (HGD, 10 of 14), and in 33% of EAC (5 of 15). MRP3 was expressed in the basolateral membrane in 93% of nondysplastic BE (13 of 14), in 60% of LGD (10 of 16), and in 86% of HGD (11 of 13). Only weak MRP3 staining was detected in EAC biopsies (5 of 15, 33%). In addition, RT-PCR studies showed increased expression of mRNA coding for ASBT (6.1x), IBABP (9.1x), and MRP3 (2.4x) in BE (N=13) compared with normal squamous epithelium (N=15). Significantly increased mRNA levels of IBABP (10.1x) and MRP3 (2.5x) were also detected in EAC (N=21) compared with normal squamous epithelium.

CONCLUSIONS

We found that bile acid transporters expression is increased in BE tissue at the mRNA and protein levels and that expression of bile acid transporter proteins decreased with progression to cancer.

Surgical therapy for gastroesophageal reflux disease: indications, evaluation, and procedures

Gastroesophageal reflux is a very common condition, and surgery remains a reasonable options in select patients. Successful surgical care for GERD depends on proper patient selection, workup and operative technique. This manuscript reviews surgical care for GERD.

Role of bile reflux and Helicobacter pylori infection on inflammation of gastric remnant after distal gastrectomy

OBJECTIVE

The influence of the main pathogenic factors on remnant gastritis is still to be evaluated. The aim of this study was to investigate the role of bile reflux and Helicobacter pylori infection on endoscopic inflammation and histological changes of gastric remnant after distal gastrectomy.

METHODS

A total of 281 patients with a more than 1-year history of distal gastrectomy were retrospectively involved after excluding those with tumors and ulcers on endoscopy. The severity of endoscopic remnant gastritis and bile reflux were recorded during the endoscopy. The histological changes including chronic inflammation, activity, atrophy, intestinal metaplasia and H. pylori were evaluated independently.

RESULTS

An endoscopic inflammation of remnant gastric mucosae was found in 81.1% (228/281) of the patients. The prevalence of H. pylori infection and bile reflux in patients with endoscopic remnant gastritis was more common than in those without gastritis (21.5%vs 0%, 88.6%vs 24.5%, P < 0.0001). The score of histological chronic inflammation was significantly higher in patients with bile reflux than in those without obvious bile reflux (1.65 vs 1.45, P = 0.02). Chronic inflammation (1.82 vs 1.57), activity (0.78 vs 0.34), atrophy (0.67 vs 0.41) and intestinal metaplasia (0.67 vs 0.27) in H. pylori-positive patients were all significantly more severe than in H. pylori-negative patients.

CONCLUSION

Bile reflux and H. pylori infection exacerbates the severity of endoscopic remnant gastritis and chronic histological inflammation.

Esophageal adenocarcinoma in "mice and men": back to basics!

Adenocarcinoma related to Barrett's esophagus (BE) is increasing in the West faster than any other cancer. There are many potential chemopreventive agents as well as predictive biomarkers of cancer progression, but what is required is a robust high-throughput model in which to test hypotheses preclinically. The pathophysiology of metaplasia and cancer has been studied in 10 animal species. Though they have considerable genetic divergence, anatomical dissimilarity, and experimental flaws, they have provided some data to test in the clinic, especially relating to activation of common genetic pathways, role of hypergastrinemia, and duodenogastric reflux in cancer progression. In this regard, the human postesophagectomy model, which has a 30% recurrence of BE within 3 yr and a 5% recurrence of adenocarcinoma over 10 yr, is now being utilized to understand how human metaplasia occurs. Furthermore, improved clinical trial designs mean that more sophisticated questions can be addressed in man.

Effect of Roux-en-Y surgery and medical intervention on Barrett's-type changes: an in vivo model

In animal models, mixed acid and bile reflux into lower esophagus induces histological changes comparable to Barrett's metaplasia (BM) and neoplasia. The aim of this study was to compare the effects of Roux-en-Y (REY) surgery and medical therapy on BM in animals before the development of neoplasia. Vagus preserving esophagojejunostomy operation was performed on Sprague-Dawley rats to achieve gastroduodenal reflux (GDR) into the esophagus in 30 animals. After 3 months, changes were reversed in 10 animals (Group REY) by REY operation, 10 animals (Group proton pump inhibitor [PPI]) were given PPI during the postoperative period, and 10 animals (Group GDR) did not have further intervention. At 4 months, histological examination of the lower esophagus was performed by an experienced pathologist. Physiological parameters were also analyzed in all animals preoperatively and at 4 months postoperatively. The length of columnar mucosa, degree of acute inflammation, degree of metaplasia, and composite BM score were significantly reduced by REY surgery compared with medical therapy and with control (columnar mucosa in cm [mean +/- standard error of the mean] Group REY 0.44 +/- 0.06, Group PPI 0.92 +/- 0.08, P < 0.001/Group GDR 1.17 +/- 0.31, P < 0.03). There was no neoplasia seen in any specimen. At 4 months, postoperatively controls Group REY surgery showed significantly more normalization of physiological parameters to preoperative levels than Group PPI (P < 0.05). REY surgery is potentially more beneficial than medical therapy in reversing the histological and biochemical changes of Barrett's esophagus due to GDR.

Phenotypic differences between esophageal and gastric intestinal metaplasia

Intestinal metaplasia is a cancer precursor in the esophagus and the stomach. Marked differences exist between the carcinogenic processes in the two locations in terms of natural history and clinical significance. We investigated biopsies from 52 patients with Barrett's esophagus and from 50 patients with gastric intestinal metaplasia in an attempt to throw light on their pathogenic processes. Morphologic characteristics, presence of Helicobacter pylori (H. pylori), and markers of differentiation, inflammation, and proliferation were evaluated by histochemical and immunohistochemical techniques. The area covered by incomplete type of intestinal metaplasia and the proportion of sulfomucins were significantly higher in the esophagus than in the stomach. Immunoreactivity with MUC1, MUC2, MUC5AC, Das-1, cytokeratins 7 and 20, inducible nitric oxide synthase and cyclooxygenase-2 antibodies was also significantly greater in Barrett's esophagus than in gastric intestinal metaplasia. In gastric intestinal metaplasia, the presence of MUC1, MUC5AC, Das-1 and cytokeratin 7 was restricted to areas with the incomplete type of metaplasia. Cell proliferation (Ki-67) was significantly higher in Barrett's esophagus than in gastric intestinal metaplasia. H. pylori was absent in all of the patients with Barrett's esophagus, while it was present in 70% of the patients with gastric intestinal metaplasia. Our observations made clear that Barrett's esophagus shares some phenotypic characteristics with gastric intestinal metaplasia, leading us to suggest that both could arise in response to injuries with eventual carcinogenic potential. However, the progression to more advanced lesions could be modulated by the nature of the carcinogenic insult.

A novel dietary-related model of esophagitis and Barrett's esophagus, a premalignant lesion

Barrett's esophagus (BE) is a premalignant lesion in which columnar epithelium (containing goblet cells) replaces esophageal squamous cells. Previous evidence suggested that hydrophobic bile acids and zinc deficiency each play a role in BE development. We fed wild-type C57BL/6 mice a zinc-deficient diet containing the hydrophobic bile acid, deoxycholic acid for various times up to 152 days. All mice fed this diet developed esophagitis by 69 days on the diet and 63% of the mice on this diet for 88 to 152 days also developed a BE-like lesion. Esophageal tissues showed thickened mucosa, increased proliferation, and increased expression of markers associated with oxidative and nitrosative stress. The newly formed BE-like lesions expressed Mucin-2, a marker of columnar differentiation. They also showed translocation of the p65 subunit of nuclear factor-kappaB and beta -catenin to the nucleus and typical histological changes associated with BE lesions. This mouse model of esophagitis and BE is expected to contribute to a deeper understanding of BE pathogenesis and to strategies for prevention of BE progression to cancer.

Bile reflux index after therapeutic biliary procedures

Background

Therapeutic biliary procedures disrupt the function of the sphincter of Oddi. Patients are potential "bile refluxers". The aim of this study was to assess how these procedures affect the histology-based bile reflux index (BRI), which can be used to reflect duodenogastric reflux (DGR).

Methods

Gastric antrum and corpus biopsies were collected from 131 subjects (56 men, 75 women; mean age, 55.9 ± 15.6 years). Group 1 (Biliary group-BG; n = 66) had undergone endoscopic sphincterotomy, endoscopic stenting, or choledochoduodenostomy for benign pathology; Group 2 (n = 20) had undergone cholecystectomy alone; and Group 3 (n = 6) Billroth II gastroenterostomy. Group 4 (no cholecystectomy; n = 39) had upper endoscopy with normal findings and served as controls. BRI > 14 indicated DGR (BRI [+]). To eliminate confounding effects of Helicobacter pylori (Hp) infection, comparisons were made according to Hp colonization.

Results

Fifty-nine subjects (45%) were Hp (+). The frequencies of BRI (+) status in antrum and corpus specimens from Hp (-) BG patients were 74.3% and 71.4%, respectively (85.7% for both antrum and corpus for choledochoduodenostomy). Corresponding results were 60% and 60% for Group 2, 100% (only corpus) for Group 3, and 57.1% and 38.1% for controls (BG, Group 2, and Group 3 vs controls – p > 0.05 antrum, p < 0.05 corpus). Fifty-four BG patients had previously undergone cholecystectomy. Excluding those, the rates of BRI (+) in Hp (-) BG patients were 75% antrum and 62.5% corpus (p > 0.05 for both vs. Group 2).

Conclusion

Patients who had undergone biliary procedures showed similar bile-related histological changes in both corpus and antrum biopsies, but the changes seen in controls were more prominent in the antrum than corpus. Therapeutic biliary procedures increase the rate of BRI (+) especially in the case of choledochoduodenostomy. Therapeutic biliary procedures without cholecystectomy also increase the rate of BRI (+) similar to that observed in patients with cholecystectomy.

Bile acids and Barrett's oesophagus: a sine qua non or coincidence?

BACKGROUND

Barrett's oesophagus (BO), a premalignant condition associated with the development of oesophageal adenocarcinoma (OAC), is thought to be a consequence of chronic duodeno-gastro-oesophageal reflux. Of the refluxates, bile acids, either alone or in combination with acid, are probably the most important.

METHODS

Analysis of the literature on the role played by bile acids in inducing BO and/or progression to OAC.

RESULTS

Combined pH and Bilitec 2000 (as a measure of bile reflux) monitoring and oesophageal aspiration studies in humans suggest a combined role for bile acids, particularly taurine conjugated bile acids, in causing oesophageal mucosal injury. Evidence from animal models has demonstrated that duodenal juice alone is also able to induce BO and/or OAC. Likewise, ex vivo studies with biopsies from BO patients show that increased proliferation and cyclo-oxygenase-2 expression are present after a pulsed exposure to acid or conjugated bile acids, but not if acid and bile acids are combined. Proton-pump inhibitors (PPIs) have been shown to decrease the biliary component of the refluxate. There is some evidence that PPIs are able to reduce neoplastic progression in BO. On the other hand, chronic PPIs can also stimulate bacterial overgrowth, which can result in increased production of secondary bile acids, particularly deoxycholic acid, in the stomach. Deoxycholic acid has been demonstrated to have a tumour-promoting capacity.

CONCLUSIONS

It is unknown what factors of the refluxate (acid and/or bile) induce BO and/or promote carcinogenesis, but there is evidence that secondary bile acids play a role. A better understanding of the molecular steps involved in the induction of BO, and the role of bile acids herein, may identify targets at which preventive therapies can be directed.

Esophageal acid exposure at pH < or = 2 is more common in Barrett's esophagus patients and is associated with oxidative stress

Barrett's esophagus (BE) patients demonstrate a higher distal esophageal acid exposure profile than other gastroesophageal reflux disease patients. Cellular oxidative stress has been proposed to contribute to the development of BE and esophageal adenocarcinoma. However, a relationship between low esophageal pH and oxidative stress has yet to be elucidated. The aim of this study was to determine the duration of low pH exposure in the esophagus of BE patients compared to those with erosive esophagitis (EE) and to test if brief exposure to low pH leads to the induction of reactive oxygen species (ROS). Seventy-three patients with BE or EE were evaluated by 24-hour esophageal pH monitoring and the percentage of time during which there was exposure to pH < or = 4 and pH < or = 2 was recorded. In vitro, Seg-1 and Het-1A cells were evaluated after brief exposure to pH4 or pH2 by flow cytometry and fluorescent microscopy for the production of ROS. BE patients demonstrated a significantly higher exposure to low pH values (pH < or = 2) than EE patients. The mean percent total time, duration and mean number of reflux episodes at pH < or = 2 were 2.8 +/- 0.53%, 28.8 +/- 3.6 seconds and 79 +/- 11.4 episodes in BE patients, whereas in EE patients they were significantly less, 1.16 +/- 0.3%, 15.6 +/- 1.2 seconds and 48.3 +/- 8.8 episodes, respectively (P < 0.05). In vitro experiments indicate that esophageal cells, when exposed to pH 2, produce ROS. In vitro studies using brief pH 2 exposure are biologically relevant to the clinical situation. Our studies indicate that such exposure induces oxidative stress. This stress may cause DNA damage, mutations and progression to cancer.

Histopathologic evaluation of an animal model for Barrett's esophagus and adenocarcinoma of the distal esophagus

INTRODUCTION

Barrett's esophagus and adenocarcinoma of the esophagus are related to long-standing duodeno-gastroesophageal reflux. The development of an animal model in which Barrett's esophagus and/or carcinoma is induced by duodeno-(gastro-)esophageal reflux could provide better understanding of the pathogenesis of the metaplasia-dysplasia-carcinoma sequence and would create the possibility of investigating new treatment strategies for this aggressive disease.

MATERIALS AND METHODS

Two rat models were analyzed. In the first experiment, 44 male Sprague Dawley rats underwent end-to-side esophagojejunostomy with gastric resection, to ensure duodenoesophageal reflux without gastric acid. In the second experiment a side-to-side esophago-gastrojejunostomy was performed in 30 rats, ensuring duodeno-gastroesophageal reflux. In both experiments animals were not exposed to any exogenous carcinogens during the experiment. Sequential morphological changes (i.e., esophagitis, intestinal metaplasia, dysplasia, and carcinoma) were studied after 4, 6, and 12 months. To analyze histopathologic characteristics, evaluation of the hematoxylin and eosin specimens was combined with immunohistochemical stainings for high-iron diamine-alcian blue, alcian blue/periodic acid-Schiff, the proliferation marker PCNA, and mutations in the tumor suppressor gene p53.

RESULTS

In the first experiment, only 11 animals survived the postoperative period. These animals had to be sacrificed at a median of 11 weeks due to persistent weight loss and failure to thrive. Severe ulcerative esophagitis was seen in all animals, with a 2-mm segment of metaplastic epithelium found at the anastomosis. In four animals a large, well-differentiated, mucinous tumor without malignant characteristics was observed. In the second experiment, eight animals died postoperatively. Twelve animals were sacrificed according to protocol at 4 or 6 months. In these animals, extensive esophagitis with squamous cell hyperplasia was found. In addition, a short (2 mm) segment of metaplastic epithelium was observed, without dysplasia. The remaining animals survived 1 year. After 1 year, 9 of the 10 animals had developed a glandular metaplastic segment (median length, 10 mm), which was histologically and immunohistologically characteristic for the specialized columnar epithelium of Barrett's esophagus without signs of dysplasia. Finally, in seven animals a mucinous tumor with cytologic characteristics of a well-differentiated mucinous adenocarcinoma was found without infiltrative growth. These tumors were always found at the site of the anastomosis, originated in the submucosa, and did not reach either the luminal surface or the muscular layer. The mucinous lesions were not positive for p53, and PCNA was only slightly increased. Although they showed cytological characteristics of malignancy, histopathologic evaluation was more suggestive of a reactive mucous producing lesion fitting the diagnosis "esophagitis cystica profunda."

CONCLUSION

This study demonstrates the development of a long Barrett's segment in an animal duodeno-gastroesophageal reflux model. Although mucinous tumors resembling adenocarcinomas develop around the anastomosis, these are probably not reflux induced and are more likely to be reactive lesions. However, the true nature of these tumors remains to be elucidated.

Oxidative damage in an experimentally induced gastric and gastroduodenal reflux model

The exact pathophysiologic mechanisms of esophageal cell damage and carcinogenesis by gastroesophageal reflux are not clearly understood. The aim of this study was to evaluate the damage to the esophageal epithelium that occurs after acid reflex and mixed acid and bile reflux by assessing histopathology, reactive oxygen species, and DNA damage. Eighty 10-week-old male Sprague-Dawley rats were divided into two groups, an acid reflux group and a mixed (acid/bile) reflux group. Acid reflux was achieved by esophagogastroplasty in which mixed reflux was encouraged via esophagoduodenal anastomosis. Each group contained a control subgroup that underwent sham laparotomy alone. The rats were killed 3, 6, 9, and 12 months after surgery. Malondialdehyde, protein carbonyl content, and DNA damage were determined in lymphocytes. Histopathologic analysis was performed according to the histologic activity index. Inflammation, ulcer, and regeneration in both reflux groups were significantly increased in the esophagus at 3, 6, 9, and 12 months compared with the control group. Mucosal damage was greater in the mixed reflux group compared with the gastric reflux group. Malondialdehyde and carbonyl content in the serum, and DNA damage in lymphocytes, were significantly increased in both reflux groups. At 9 and 12 months, oxidative damage was increased in the mixed reflux group compared with the acid reflux group. Oxygen-derived free radicals seem to be one of the important mediators in the evaluation and generation of reflux esophagitis. The impact of oxygen free radicals, as demonstrated in this study, can be evaluated by assessing the damage that they incur to lipid membranes, serum proteins, and circulating lymphocyte DNA. Serum malondialdehyde and carbonyl content as well as lymphocyte DNA damage were significantly increased in the setting of acid and mixed acid/bile reflux in these rodent models. Further, these serum and lymphocytic changes were associated with esophageal ulceration, inflammation, and regeneration. Evaluation of such markers as serum malondialdehyde and carbonyl content as well as evaluation of lymphocyte DNA might prove to be useful investigations in patients with precancerous and cancerous conditions in addition to conventional methods of diagnosis. Further studies, both animal and human are warranted.

Risk factors, DNA damage, and disease progression in Barrett's esophagus

Esophageal adenocarcinoma develops on a background of Barrett's esophagus. A number of risk factors have been linked to both conditions, including gastroesophageal reflux and smoking. However, the molecular mechanisms by which these factors influence disease progression remain unclear. One possibility is that risk factors generate promutagenic DNA damage in the esophagus. The comet assay was used to measure DNA damage in esophageal (Barrett's and squamous) and gastric mucosa of Barrett's patients with (n = 24) or without (n = 50) associated adenocarcinoma or high-grade dysplasia in comparison with control patients (squamous mucosa) without Barrett's esophagus (n = 64). Patients completed a questionnaire detailing exposure to some of the known risk factors for Barrett's esophagus and adenocarcinoma. In Barrett's esophagus patients, DNA damage was higher in Barrett's mucosa compared with normal esophageal and gastric mucosa (P < 0.001). In addition, the highest quartile of DNA damage in Barrett's mucosa was associated with an increased risk (odds ratio, 9.4; 95% confidence interval, 1.1-83.4; P = 0.044) of developing adenocarcinoma or high-grade dysplasia compared with DNA damage levels in the lowest quartile. Smoking was associated with higher DNA damage in squamous epithelium in all patient groups (P < 0.01) and in Barrett's mucosa (P < 0.05) in Barrett's esophagus patients only. In controls only, current reflux was associated with higher DNA damage, whereas anti-inflammatory drug use resulted in lower levels. Collectively, these data imply a genotoxic insult to the premalignant Barrett's mucosa that may explain the genetic instability in this tissue and the progression to adenocarcinoma. There is an indication for a role for smoking in inducing DNA damage in esophageal mucosa but an understanding of the role of reflux requires further investigation.

Influence of bile reflux and Helicobacter pylori infection on gastritis in the remnant gastric mucosa after distal gastrectomy

BACKGROUND

Two main pathogenic factors, bile reflux and Helicobacter pylori infection, have been identified in the remnant stomach, but it is still unclear which factor is important in the pathogenesis of gastritis in the remnant stomach after distal gastrectomy.

METHODS

In 184 patients who had had distal gastrectomy performed using the Billroth-I procedure (B-I; n-106), Billroth-II procedure (B-II; n-36), and jejunal interposition (J-I; n-42) we examined the severity of remnant gastritis endoscopically and carried out examinations for H. pylori infection and histological examination.

RESULTS

The endoscopic severity of remnant gastritis was grade 1 or more in 101 of the 106 B-I patients (95.3%) and in all 36 B-II patients (100%). But, of the 42 J-I patients, the grade was 0 in 33 (78.6%). The endoscopic severity of remnant gastritis was significantly milder for J-I than for B-I (P < 0.001) and B-II (P < 0.001). H. pylori infection was confirmed in 59 of the 106 B-I patients (55.6%), 21 of the 36 B-II patients (58.3%), and 32 of the 42 J-I patients (76.1%). The rate of H. pylori infection was higher for J-I patients than for B-I (P < 0.05), but not for B-II patients (P = 0.1495). The severity of chronic and active inflammatory cellular infiltration tended to be inverse proportional relation with the endoscopic severity of the remnant gastritis. Furthermore, the histological inflammation and activity scores of H. pylori-positive patients were higher than those of H. pylori-negative patients, without regard to the endoscopic grade of gastritis.

CONCLUSIONS

Reconstruction techniques play an important role in the prevention of bile reflux, and we found that endoscopically more severe remnant gastritis was associated with a lower rate of H. pylori infection and with a lower degree of inflammatory cellular infiltration.