Two updates on oesophagogastric junction adenocarcinoma from the fifth WHO classification: Alteration of definition and emphasis on HER2 test.

INTRODUCTION: The incidence of oesophagogastric junction adenocarcinoma has increased rapidly but remains controversial over the last decades. There are two crucial updates of the fifth World Health Organization (WHO) classification, including the alteration of its definition and the emphasis on the human epidermal growth factor receptor 2 (HER2) test. METHODS: A total of 566 clinicopathological samples from patients who were diagnosed with gastric adenocarcinoma were retrospectively analyzed. We comprehensively compared the clinicopathological features of oesophagogastric junction adenocarcinoma between the fourth (V4.0) and fifth (V5.0) WHO versions. The clinicalpathological features among oesophagogastric junction, proximal and distal gastric tumors with fourth and fifth edition were also compared, respectively. Also, we discuss the correlation of HER2-expression with clinicopathological features according to the V5.0. RESULTS: The results showed that the difference was mainly between oesophagogastric junction and distal adenocarcinoma in V4.0, while some were found between proximal and distal adenocarcinoma in V5.0. Tumors invading the oesophagus more than 3cm were still mainly oesophagogastric junction tumors. The expression of HER2 in oesophagogastric junction and proximal gastric adenocarcinoma was still higher than that in gastric body and distal sites. CONCLUSIONS: The clinicopathological parameters of the oesophagogastric junction tumors changed to some extent in the updated WHO version. The proximal gastric tumors tended to be more invasive, more than those located in oesophagogastric junction. But the latter with oesophageal invasion required additional management. The HER2-expression of oesophagogastric junction adenocarcinoma is the highest. The classification of V5.0 is reasonable and worth recommendation.

The expressions and prognostic implications of Twist and E-cadherin in adenocarcinomas of the gastroesophageal junction and proximal gastric carcinoma.

Twist and E-cadherin are crucial for the development of different types of cancer; however, their clinical significance in adenocarcinoma of the gastroesophageal junction (AGE) remains unknown. Here, we investigated the correlation between the expression of Twist and E-cadherin and their impact on the clinical outcomes and prognosis of patients with AGE and proximal gastric carcinoma (PGC).Using immunohistochemistry, we determined the expression of Twist and E-cadherin in the tissue samples of patients with AGE and PGC. The correlation of the expression of Twist and E-cadherin with the clinicopathological factors was assessed by using the chi-square test, Fisher exact test, and non-parametric Mann-Whitney U test. The Kaplan-Meier method along with the log-rank test and Cox proportional-hazards model were used to evaluate the correlation of Twist and E-cadherin expression with the overall survival (OS) of patients.Overall, 94 patients with AGE (n = 45, 47.87%) or PGC (n = 49, 52.13%) who underwent primary tumor resection were included in this study. The median follow-up period was 40.5 months. We observed a significant difference in the smoking status (P < .001) and differentiation grade (P = .004) between patients with AGE and PGC. There was a significant association of a high Twist expression with T stage (only in PGC, P = .008), lymph node metastasis (AGE, P = .075; PGC, P = .051), and advanced pathological stages (AGE, P = .019; PGC, P = .006). A low E-cadherin expression showed similar results; however, it was not significantly associated with the advanced pathological stages of AGE (P = .372). A low E-cadherin expression was significantly associated with a low differentiation grade of AGE (P = .002). In addition, a significant inverse relationship was observed between Twist and E-cadherin expression. The Kaplan-Meier survival analysis and Cox regression analysis revealed that a high Twist expression and low E-cadherin expression were independent prognostic factors for short OS of patients with AGE or PGC.A high Twist expression or low E-cadherin expression was associated with unfavorable clinicopathological factors and independently predicted short OS of patients with AGE or PGC.

24-hour multi-pH recording of the postprandial acid pocket and the nocturnal acid distribution at the esophagogastric junction in healthy volunteers.

BACKGROUND: Postprandial stationary pH monitoring studies have identified the acid pocket. To what extent a similar pool of acid is present in the fasting state or at night remains however unclear. METHODS: The study was performed in 9 HV without a hiatal hernia. A pH-impedance-pressure catheter was positioned at the Z-line. First, the presence of the acid pocket was monitored under stationary conditions during 2 hours after ingestion of a standardized meal. Thereafter, the equipment was connected to an ambulatory monitoring device for 24-hour recording. RESULTS: Under stationary conditions, a postprandial acid pocket was present in 7 of the 9 HV, from 9 ± 7 minutes after meal onwards during 47 ± 8 minutes. During ambulatory 24-hour monitoring, postprandial acid pockets emerged significantly later, but no differences in duration or position were detected. During nighttime, an acid pool was detected with its proximal border at the level of the cardia, which at later, time points gradually moved to a more distal position. This led to a gradual decrease in nocturnal acid exposure from proximal to distal, a phenomenon that was preceded by a bust of gastric contractions. Nocturnal reflux originated from the cardiac region, and was more acidic in the early compared with late nocturnal period. CONCLUSION: The acid pocket is present in the postprandial period under both stationary and ambulatory conditions. Of interest, at night, a pool of acid can be demonstrated which is periodically shifted more distally. This pool of acid represents the reservoir from which nocturnal reflux originates.

Impact of Specimen Type and Specimen Number on HER2 Status in Gastroesophageal Junction and Gastric Adenocarcinoma.

OBJECTIVES: Human epidermal growth factor receptor 2 (HER2) is expressed in some gastric and gastroesophageal junction adenocarcinomas. There were two goals: assess the impact of specimen type on HER2 status and evaluate HER2 concordance with multiple specimens. METHODS: All cases were evaluated by immunohistochemistry (IHC) for HER2 and interpreted using established criteria. Fluorescence in situ hybridization (FISH) was performed on a subset. RESULTS: Of 460 specimens, 83.9% were IHC negative, 5.4% were equivocal, and 10.7% were IHC positive. Of those with FISH testing, 78.5% were FISH negative, and 21.5% were FISH positive. IHC-FISH concordance for biopsy specimens, resections, and metastases was 82%, 84%, and 86%, respectively. With one vs two vs three or more specimens, the HER2-positive rate increased from 10.5% to 18.1% to 24.1%, respectively. CONCLUSIONS: HER2 testing may be performed on biopsy specimens with a relatively high concordance rate with resection specimens, and if multiple samples are analyzed from a single patient, the HER2-positive rate increases over twofold.

Tumor Platinum Concentrations and Pathological Responses Following Cisplatin-Containing Chemotherapy in Gastric Cancer Patients.

PURPOSE: There is a wide range in tumor response following preoperative chemotherapy in locally advanced gastric or gastroesophageal junction cancers. We investigated the relationship between tumor platinum levels and pathological responses in these patients. METHODS: Tumor and adjacent normal tissues were retrieved. Pathological responses were assessed per standard criteria. Tissue platinum concentrations were determined with high-performance liquid chromatography mass spectrometry. Platinum distribution in tissue components was evaluated with imaging mass cytometry. Collagen content was evaluated using trichrome staining. RESULTS: Surgical specimens from 10 patients were available. Surgery was performed at a median time of 49 days (range: 28-72) after the last cycle of chemotherapy. The mean platinum level in tumor tissue in patients with any response was significantly higher than in those with no response (893 ± 460 vs. 38.8 ± 8.8 pg, P = 0.007), so was the collagen content (37.4 ± 6.8 vs. 11.5 ± 8.6%, P < 0.05). Platinum preferentially bound to collagen. CONCLUSIONS: Platinum was detectable in surgical specimens up to 72 days after preoperative chemotherapy. Higher tumor platinum concentration correlated with improved pathological response. Collagen binding potentially explained the high interpatient variability in tumor platinum concentrations.

Overexpression of EGFR as an Independent Prognostic Factor in Adenocarcinoma of the Esophagogastric Junction.

BACKGROUND: Adenocarcinoma of the esophagogastric junction (AEG) has increased in Western and Eastern countries, and its prognosis remains poor. We tested whether epidermal growth factor receptor (EGFR), that is overexpressed in various tumors, acts as a cancer-promoting gene through overexpression in AEG. MATERIALS AND METHODS: We analyzed 104 primary AEG tumors which were curatively resected in our hospital between 2000 and 2010. RESULTS: Overexpression of EGFR protein was detected in 47% primary AEG tumor samples, and significantly associated with venous and lymphatic invasion, tumor depth and lymph node metastasis. The high-expression group had a significantly poorer prognosis than the low expression group for overall and disease-free survival. EGFR positivity was independently associated with a worse outcome in the multivariate analysis (p=0.0397, hazard ratio(HR)=2.048). CONCLUSION: EGFR plays a pivotal role in AEG through its overexpression, which highlights its usefulness as a prognosticator and potential therapeutic target in AEG.

Patterns of PD-L1 expression and CD8 T cell infiltration in gastric adenocarcinomas and associated immune stroma.

OBJECTIVE: Recent data supports a significant role for immune checkpoint inhibitors in the treatment of solid tumours. Here, we evaluate gastric and gastro-oesophageal junction (G/GEJ) adenocarcinomas for their expression of programmed death-ligand 1 (PD-L1), infiltration by CD8+ T cells and the relationship of both factors to patient survival. DESIGN: Thirty-four resections of primary invasive G/GEJ were stained by immunohistochemistry for PD-L1 and CD8 and by DNA in situ hybridisation for Epstein-Barr virus (EBV). CD8+ T cell densities both within tumours and at the tumour-stromal interface were analysed using whole slide digital imaging. Patient survival was evaluated according to PD-L1 status and CD8 density. RESULTS: 12% of resections showed tumour cell membranous PD-L1 expression and 44% showed expression within the immune stroma. Two cases (6%) were EBV positive, with one showing membranous PD-L1 positivity. Increasing CD8+ densities both within tumours and immune stroma was associated with increasing percentage of tumour (p=0.027) and stromal (p=0.005) PD-L1 expression. Both tumour and immune stromal PD-L1 expression and high intratumoral or stromal CD8+ T cell density (>500/mm2) were associated with worse progression-free survival (PFS) and overall survival (OS). CONCLUSIONS: PD-L1 is expressed on both tumour cells and in the immune stroma across all stages and histologies of G/GEJ. Surprisingly, we demonstrate that increasing CD8 infiltration is correlated with impaired PFS and OS. Patients with higher CD8+ T cell densities also have higher PD-L1 expression, indicating an adaptive immune resistance mechanism may be occurring. Further characterisation of the G/GEJ immune microenvironment may highlight targets for immune-based therapy.

Barrett's Esophagus: A Comprehensive and Contemporary Review for Pathologists.

This review provides a summary of our current understanding of, and the controversies surrounding, the diagnosis, pathogenesis, histopathology, and molecular biology of Barrett's esophagus (BE) and associated neoplasia. BE is defined as columnar metaplasia of the esophagus. There is worldwide controversy regarding the diagnostic criteria of BE, mainly with regard to the requirement to histologically identify goblet cells in biopsies. Patients with BE are at increased risk for adenocarcinoma, which develops in a metaplasia-dysplasia-carcinoma sequence. Surveillance of patients with BE relies heavily on the presence and grade of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating dysplasia, particularly with regard to the more recently recognized unconventional variants. Identification of non-morphology-based biomarkers may help risk stratification of BE patients, and this is a subject of ongoing research. Because of recent achievements in endoscopic therapy, there has been a major shift in the treatment of BE patients with dysplasia or intramucosal cancer away from esophagectomy and toward endoscopic mucosal resection and ablation. The pathologic issues related to treatment and its complications are also discussed in this review article.

Characteristics of cardiac epithelium at the esophagogastric junction of a pediatric population with gastroesophageal reflux.

Cardiac mucosa (CM) of the adult, regardless its location, shares phenotypic characteristics with Barrett's epithelium, namely villin expression and a Barrett's pattern of cytokeratins 7 and 20 expression. As far as we know, the phenotypic profile of CM in children has not been studied. The objective was to evaluate the phenotypic profile of cardiac mucosa from the esophagogastric junction of children with reflux symptoms. Biopsies routinely performed at the esophagogastric junction of children submitted to upper-gastrointestinal endoscopy for complaints suggestive of reflux were retrieved from the archive and used for the purposes of this study. Biopsies were assessed for the presence of squamous epithelium, cardiac and oxyntic mucosa and intestinal metaplasia. Samples displaying both squamous and columnar epithelia were immunohistochemically evaluated for the presence of villin and sucrase-isomaltae and for the expression of cytokeratins 7 and 20. From the 42 biopsies samples retrieved, 30 had simultaneously squamous and columnar epithelia. Cardiac mucosa was present in 86.7% of the cases, and intestinal metaplasia was observed only in one (3.3%). Villin expression in cardiac mucosa was observed in 96% of the cases and a cytokeratins 7 and 20 Barrett's pattern in 73%. Sucrase-isomaltase and MUC2 were only expressed in the case with intestinal metaplasia. Cardiac mucosa was high prevalent in biopsies from the esophagogastric junction of children with reflux. As in adults, cardiac mucosa in children has an immunoprofile similar to Barrett's esophagus. For the first time, it was shown that pediatric cardiac mucosa frequently expresses villin.

Lymphangiogenesis and prognostic significance of vascular endothelial growth factor C in gastro-oesophageal junction adenocarcinoma.

Vascular endothelial growth factor C (VEGF-C) is a crucial regulator of the development of lymphatic vessels and is involved in the lymph node metastasis of cancer. The levels of VEGF-C expression and lymphatic vessel density (LVD) in 128 gastro-oesophageal junction adenocarcinoma (GEJA) tissues were examined by immunohistochemistry and analysed for their association with clinicopathological features and disease-free survival. We found that 75.0% of tumour samples displayed strong immunoreactivity to VEGF-C. The levels of VEGF-C expression in the tumour tissues were associated with the stages of the clinical tumours and the lymph node metastasis status, but not with the age, gender and the size and type of tumours in the cohort. Similarly, LVD, as evaluated by anti-D2-40 staining, was also associated with the clinical stages of GEJA. The values of LVD were positively correlated with the levels of VEGF-C expression in these samples (r = 0.3760, P = 0.0001). High levels of VEGF-C expression and high values of LVD were associated with shorter periods of disease-free survival (DFS) in patients with GEJA (P < 0.001). In addition, GEJA at N1 and N2 stages, at T4 stage, chemotherapy after surgery, high levels of VEGF-C expression and lower marginal resection were independent factors for the prognosis of DFS in patients with GEJA. Our data indicate that VEGF-C may promote the lymphangiogenesis and lymphatic metastasis of GEJA and that VEGF-C may be a valuable biomarker for the diagnosis of lymphatic metastasis and a prognostic factor of the survival of patients with GEJA.

Signet-ring cell melanoma of the gastroesophageal junction: a case report and literature review.

We report the first case, to our knowledge, of a possible primary, signet-ring cell melanoma of the gastroesophageal junction. The mass was initially diagnosed as an invasive, poorly differentiated carcinoma; however, on further review and immunohistochemical workup, the diagnosis of signet-ring cell melanoma was made. The lesion consisted of oval to round epithelioid cells undermining the gastric mucosa and infiltrating the muscularis mucosae. Tumor cells demonstrated abundant cytoplasm and eccentrically located nuclei, many with signet-ring cell morphology. The tumor cells were negative for mucin and pancytokeratin, strongly positive for S100 protein and Melan-A, and focally but strongly positive for human melanoma black-45. Diagnostic imaging failed to prove another site of melanoma, and no history of melanoma or cutaneous lesion was reported by the patient. Therefore, it was determined this was likely a primary lesion. We review the literature and previously reported cases of this rare histologic variant of melanoma.

[Role of the pathologist in the processing of adenocarcinoma of the stomach, oesophagogastric junction and lower third of the oesophagus]. / Place du pathologiste dans la prise en charge des adénocarcinomes de l'estomac, de la jonction œsogastrique et du tiers inférieur de l'œsophage après traitement néo-adjuvant.

Adenocarcinoma of the stomach, oesophagogastric junction and lower oesophagus remains a major global public health issue. Recently, the introduction of neoadjuvant chemotherapy in the treatment of these cancers has changed the pathological processing of the surgical resection specimens of these patients. The neoadjuvant treatment induces histological changes of the tumour called "tumour response". This tumour response needs to be evaluated, even if at present, there is no adaptation of the adjuvant chemotherapy to the histological tumour response. Several grading systems have been proposed for the different tumour sites (lower oesophagus, oesophagogastric junction and stomach). We will discuss first the macroscopic processing of the surgical resection specimens and then the different ways of assessing the histological response to chemotherapy. A standardized assessment of the histological tumour response is a necessary prerequisite for future studies looking at the adaptation of chemotherapy depending on the histological tumour response.

Determination of pH turning point with pH mapping of the gastroesophageal junction: an alternative technique to orientate esophageal pH monitoring.

Manometric location of the lower esophageal sphincter (LES) has been mandatory before esophageal pH monitoring, despite costs and discomfort related with esophageal manometry. The aims of the study were: (i) to map the pH of the gastroesophageal junction (GEJ) to determine a pH turning point (PTP) and its relation with LES; and (ii) to test the feasibility of this technique to orientate esophageal pH monitoring. We studied 310 adult patients who underwent esophageal manometry and pH monitoring off acid-suppressive therapy. GEJ pH mapping was carried out by step-pulling the pH sensor from 5 cm below to 5 cm above LES, and a PTP was determined when pH changed from below to above 4, in centimeters from the nostril. Thirty-six patients referred only for pH monitoring were studied with pH sensor placed at 5 cm above the PTP. Out of 310 patients, a PTP was found in 293 (94.5%): inside LES in 86.3%, into the stomach in 8.2% and in the esophageal body in 5.5% of patients. The median distance between PTP and place where pH sensor monitored reflux was 8 cm. Among 36 patients who performed pH monitoring without LES manometry, there was no gastric monitoring during reflux testing. In adult patients investigated off acid suppressive therapy, GEJ pH mapping with reflux monitoring 5 cm above the PTP can be an alternative technique to perform esophageal pH monitoring when LES manometry is not available. Additional studies are needed before the widespread use of GEJ pH mapping in the clinical practice.

Transsphincteric pH profile at the gastroesophageal junction.

BACKGROUND & AIMS: Esophageal acid exposure conventionally is measured 5 cm above the lower esophageal sphincter (LES). The aim of this study was to compare pH profiles at sites within the LES, the distal esophagus, and the proximal stomach. METHODS: Ten normal subjects underwent esophageal manometry followed by 24-hour esophagogastric pH monitoring using an 8-channel pH probe recording at 5 and 1.5 cm above and at 0, 1.5, 3.0, 4.5, 6.0, and 9.5 cm below the proximal LES border. During pH recording, a 4-hour gastric emptying test with an egg sandwich meal was performed. RESULTS: The LES was 3.2 +/- 0.4 cm in length. There was a progressive increase in acid exposure from the esophageal to the gastric pH sensors. pH was less than 4 for 3.4% +/- 1.6%, 12.7% +/- 8.5%, 26.5% +/- 10.2%, 48.1% +/- 11.3%, 66.5% +/- 9.9%, 80.8% +/- 5.6%, 89.2% +/- 3.0%, and 96.7% +/- 1.1% of the total time for pH probes at 5 and 1.5 cm above and 0, 1.5, 3, 4.5, 6.0, and 9.5 cm below the proximal LES border, respectively. Percentage acid exposures correlated significantly with the position of the probe (r = -0.95; P < .01). Intrasphincteric acidity increased postprandially. Gastric emptying was correlated inversely with the intragastric hydrogen ion concentration (r = -0.82). CONCLUSIONS: The percentage of recording time that pH was less than 4 was significantly higher in the intrasphincteric area and 1.5 cm above the proximal LES compared with the traditional site 5 cm above the proximal manometric LES border. High acid exposure in the intrasphincteric region might explain the susceptibility of the distal esophagus to erosions, strictures, and Barrett's esophagus.

"Seedling" mesenchymal tumors (gastrointestinal stromal tumors and leiomyomas) are common incidental tumors of the esophagogastric junction.

Gastrointestinal stromal tumors (GISTs) are the most common nonepithelial neoplasm of the gastrointestinal tract and show a predilection for the stomach. Most are detected because of symptoms, but some are incidental findings at autopsy or surgery for other reasons. Incidental GISTs tend to be smaller at diagnosis, but even small (<1 cm) GISTs have been shown to harbor activating KIT mutations at rates similar to advanced GISTs. However, the prevalence and characteristics of small GISTs in surgical resections of the esophagogastric junction (EGJ) remains unclear. We studied 150 esophagogastric resections for esophageal or EGJ carcinomas (100 with preoperative chemoradiation and 50 untreated cases) that had been extensively embedded for histologic examination (mean 30 sections/case). Number, size, morphology, and location of all GISTs and leiomyomas were recorded. All potential GISTs were evaluated with CD117 and CD34 immunohistochemistry, and a subset (35) leiomyomas with smooth muscle actin, desmin, and CD117. We found 18 incidental GISTs in 15 of 150 (10%) patients; 3 patients harbored 2 separate lesions. Prevalence of GIST was identical in treated (10 of 100) and untreated (5 of 50) cases. All (100%) showed positivity for both CD117 and CD34 and all were of spindle cell morphology. Lesions ranged from 0.2 to 3.0 mm in size (mean 1.3 mm). Eight (44%) were based in the outer muscularis propria, 7 (39%) in inner muscularis, and 3 (17%) between the muscle layers. The lesions tended to cluster near the EGJ, with 8 (44%) on the gastric side, 9 (50%) on the esophageal side, and 1 (6%) undetermined owing to overlying ulceration. Leiomyomas were even more common than GIST, occurring in 47% of patients (44% of treated and 52% of untreated, P=0.39), with a mean of 3 leiomyomas per patient (range 1 to 13) and mean size of 1.7 mm (range 0.2 to 12 mm). Unlike colorectal leiomyomas, most (91%) EGJ leiomyomas were located in the inner muscularis propria and only rarely (1%) in muscularis mucosa. These results suggest that GIST and leiomyoma are common incidental "seedling" lesions of the EGJ, found in 10% and 47% of patients undergoing surgery for esophageal carcinoma. The common occurrence of microscopic GISTs compared with the rarity of clinically manifest and malignant esophagogastric GISTs suggests that additional genetic or epigenetic alterations must happen for neoplastic progression.

Fe-S cluster proteins are intracellular targets for nitric oxide generated luminally at the gastro-oesophageal junction.

In human, high concentrations of nitric oxide are generated at the gastro-oesophageal junction through entero-salivary recirculation of dietary nitrate. Nitric oxide is known to have a high affinity for Fe-S cluster proteins. The aim of this study is to investigate whether nitric oxide arising from the lumen diffuses into the adjacent tissue where it can interact with Fe-S proteins both in a rat animal model and human. An electron paramagnetic resonance detectable complex, dinitrosyl dithiolato iron complex (DNIC), was used as a biomarker for the interaction between Fe-S proteins and nitric oxide. The generation of the complex was evaluated in resected gastric tissue of nitrite-administered rat or biopsy specimens from human after nitrate ingestion. The activity of aconitase, one of the Fe-S cluster proteins, was also determined. The signal of the complex was observed at the rat gastro-oesophageal junction where luminal generation of nitric oxide from nitrite was maximal, and the intensity increased in a dose- and time-dependent manner. The appearance of the complex was accompanied by a significant inhibition of the aconitase activity at that site. The complex appeared in biopsy specimens from the gastro-oesophageal junction in three of five men after nitrate ingestion. Since DNIC is considered to be a decomposition product when Fe-S cluster proteins interact with nitric oxide, the appearance of the signal provides direct evidence that nitric oxide arising from the lumen can destroy such proteins. DNIC formation may represent the cellular mechanism responsible for the high prevalence of disease at the gastro-oesophageal junction.

Cdx-2 expression in squamous and metaplastic columnar epithelia of the esophagus.

The molecular pathogenesis of Barrett's esophagus is poorly understood. Evidence suggests that at a phenotypic level, the metaplastic process begins with the transformation of squamous epithelium in the distal esophagus to cardiac mucosa, which subsequently becomes intestinalized. The homeobox gene Cdx-2 has been shown to be an important transcriptional regulator of embryonic differentiation and maintenance of adult intestinal type epithelium. We hypothesized that Cdx-2 gene expression levels increase with the phenotypic transformation of normal squamous mucosa to the intestinalized columnar mucosa of Barrett's esophagus. Endoscopic biopsies were obtained at the gastroesophageal junction in patients with symptoms of gastroesophageal reflux disease and classified according to histology: normal squamous mucosa (n = 62), cardiac mucosa (n = 19), oxynto-cardiac mucosa (n = 14), and intestinal metaplasia (n = 15). Duodenal biopsies (n = 26) served as the columnar control. After laser capture microdissection and RNA isolation, gene expression levels of Cdx-2 were measured in each tissue type by quantitative reverse transcription polymerase chain reaction. Consistent with its known function, Cdx-2 gene expression levels were highest in duodenal mucosa and nearly absent in squamous epithelium. There was a stepwise increase in Cdx-2 gene expression from cardiac to Barrett's epithelium (P < 0.001). Expression levels of Cdx-2 in cardiac and oxynto-cardiac mucosa were 40-70 times higher and Barrett's mucosa 400 times higher than that found in squamous epithelium. Relative expression of the homeobox gene Cdx-2, known to induce differentiation of intestinal type epithelium, increases in a stepwise fashion during the phenotypic transformation of distal esophageal squamous mucosa to cardiac columnar mucosa and to the intestinalized columnar mucosa of Barrett's esophagus. Therefore, Cdx-2 may be a potential biomarker to detect the early transition to Barrett's esophagus.

Interstitial cells of cajal in reflux esophagitis: role in the pathogenesis of the disease.

BACKGROUND: Interstitial cells of Cajal (ICCs) are claimed to be involved in gut electromotor activity. We investigated whether absent or diminished ICCs in the esophagogastric junction (EGJ) may be responsible for EGJ incompetence in gastro-esophageal reflux disease (GERD). MATERIAL/METHODS: Endoscopic specimens were obtained from the upper and mid third of the esophagus and from the EGJ of 29 patients (17 men, 12 women, mean age: 46.7 years) with GERD (5 grade A, 5 B, 6 C, and 13 D, Los Angeles classification) and from 8 controls. Sections were prepared for inmunohistochemical investigation using an ICC marker c-kit. Controls had normal rabbit serum substituted for the primary antiserum. RESULTS: C-kit-positive branched ICC-like cells were detected in the esophageal and EGJ musculature of the controls. They were distinguishable from the c-kit-negative unbranched smooth muscle cells and from the c-kit-positive unbranched mast cells. Immunoreactivity was absent in the negative controls. ICCs in the esophageal body existed in GERD and in controls, but were absent from the EGJ of 12 patients (2 grade C, 10 D) and occasionally detected in 5 of group A, 5 of B, 4 of C, and 3 of group D patients. CONCLUSIONS: ICCs were demonstrated in the esophageal body and EGJ of controls. In GERD patients they were detected in the esophageal body, but were deficient or absent in the EGJ. It is postulated that ICC absence or deficiency is responsible for EGJ incompetence and GER. The cause of ICC deficiency or absence needs to be investigated.

The effect of rabeprazole on regional gastric acidity and the postprandial cardia/gastro-oesophageal junction acid layer in normal subjects: a randomized, double-blind, placebo-controlled study.

BACKGROUND: Postprandial intragastric acidity is not uniform. Postprandial proximal gastric acid pockets have been described in the present study. AIM: To determine the effects of rabeprazole on regional intragastric acidity and proximal acid pockets. METHODS: Ten normal subjects underwent two 8-day oral dosing regimens with placebo or rabeprazole 20 mg each morning in a randomized, double-blind protocol. Oesophago-gastric pH monitoring was performed on days 1 and 8. RESULTS: Rabeprazole increased fasting and postprandial gastric pH to above 4 in each area of the stomach on days 1 and 8. With placebo, acid pockets were identified at the cardia/gastro-oesophageal junction in 62 and 50 of 150 pull-throughs on days 1 and 8, respectively. Acid pockets were detected postprandially 3.1 +/- 0.2-5.8 +/- 0.1 cm below the proximal border of the lower oesophageal sphincter with a mean pH drop from 4.6 +/- 0.1 to 1.5 +/- 0.1. Rabeprazole decreased the number of acid pockets to 30 and 27 on days 1 and 8, respectively. Rabeprazole also decreased their length and magnitude of the pH drop. CONCLUSIONS: Rabeprazole increased intragastric pH on day 1 and 8 and maintained an elevated pH during and after meals. Postprandial acid pockets, identified in the region of the cardia/gastro-oesophageal junction area postprandially, were decreased in number, length and magnitude by rabeprazole.

Synergistic action of advanced glycation end products and endogenous nitric oxide leads to neuronal apoptosis in vitro: a new insight into selective nitrergic neuropathy in diabetes.

AIMS/HYPOTHESIS: We have previously shown that in diabetes nitrergic neurones innervating the urogenital and gastrointestinal organs undergo a selective degenerative process. This comprises an initial insulin-reversible decrease in neuronal nitric oxide synthase (nNOS) in the axons, followed by apoptosis of the nitrergic neurones, a process that is not reversible by insulin. Since apoptosis was independent of serum glucose concentrations, and advanced glycation endproducts (AGEs) have been implicated in the pathogenesis of diabetic complications, we have now measured AGEs in the serum and penis, pyloric sphincter and pelvic ganglia of diabetic animals at different times after streptozotocin treatment. Furthermore, we have studied their effect in vitro on human neuroblastoma (SH-SY5Y) cells in the presence or absence of nNOS expression. METHODS: Serum AGEs were measured using fluorometry and ELISA. Accumulation of AGEs in the tissues was evaluated with immunohistochemistry. The viability, apoptosis and oxidative stress in SH-SY5Y cells were measured upon exposure to AGEs or high concentrations of glucose. RESULTS: AGEs increased gradually in the serum and tissues of streptozotocin-induced diabetic rats; this process was not affected by delayed insulin treatment. In SH-SY5Y cells, AGEs, but not high glucose concentrations, increased the reactive oxygen species and caspase-3-dependent apoptosis in a synergistic fashion with endogenous nitric oxide (NO). Apoptosis was prevented by treatment with a NOS inhibitor, a pan-caspase inhibitor, a soluble receptor of AGEs or an anti-oxidant, but not an inhibitor of soluble guanylate cyclase. CONCLUSIONS/INTERPRETATION: The synergistic actions of NO and AGEs account for the irreversible nitrergic degeneration in diabetes.