Comparative microanatomical and histochemical biodistribution profiles of different types of mucins in oesophageal gastric tract mucosa of some tetrapod representatives.

The microanatomical features of the oesophageal gastric tract in tetrapod representatives and their function, especially those related to the mucosal layer, have not yet been fully investigated. The mucosal layer cells and their function in the oesophageal gastric tract differ structurally and functionally in tetrapod representatives based on interspecies difference and the type of food and feeding habits. The present study was, therefore, postulated to compare the mucosal microanatomical structure and histochemical biodistribution of different mucin types in oesophageal gastric tract tissues of four tetrapod species. A representative of each tetrapod class was selected, as follows: the Egyptian toad Bufo regularis, the lizard Trachylepis quinquetaeniata, the domestic pigeon Columba livia domestica and the albino mouse Mus musculus for Amphibia, Reptilia, Aves and Mammalia, respectively. Microanatomically, in lower tetrapods (toad and lizard), the mucosal layer of the oesophagus was composed of simple ciliated columnar epithelium with goblet cells, whereas in higher tetrapods (pigeon and mouse) it was composed of stratified squamous epithelium, with non-keratinised epithelium in the pigeon but keratinised epithelium in the mouse. However, the gastric mucosal layer of the stomach in lower tetrapods consists of simple columnar epithelium and gastric glands. Similarly, the mucosa of the pigeon's proventriculus consists of simple columnar epithelium with proventricular glands opened into the lumen, whereas mouse mucosa consists of simple columnar epithelium which folds and forms gastric glands with gastric pits having a variety of cell types. Histochemically, the neutral mucin profile biodistribution in the oesophagus mucosal layer was variable. It was strongly positive in the toad and lizard, but was weak in the pigeon and completely negative in the mouse. In contrast it was strongly positive in the gastric mucosa of the toad, lizard and pigeon, but was weak in the mouse's gastric mucosa. On the other hand, the signals of carboxylated and sulfated mucins were found to be different. They were strong in the mucosa of the lizard oesophagus. In contrast, the carboxylated mucins in the gastric mucosa were positive in all representatives except the mouse. The sulfated mucins were, however, seen localised in the mucosal layer cells of the lizard and pigeon only. The study revealed that the microanatomical structures and functions as well as mucin distribution profiles in the oesophageal gastric tract are in line with interspecies difference and the type of food and feeding habits. However, this may need further investigations including more tetrapod representatives.

Tissue-engineered esophagus: recellular esophageal extracellular matrix based on perfusion-decellularized technique and mesenchymal stem cells.

Perfusion-decellularization was an interesting technique to generate a natural extracellular matrix (ECM) with the complete three-dimensional anatomical structure and vascular system. In this study, the esophageal ECM (E-ECM) scaffold was successfully constructed by perfusion-decellularized technique through the vascular system for the first time. And the physicochemical and biological properties of the E-ECM scaffolds were evaluated. The bone marrow mesenchymal stem cells (BMSCs) were induced to differentiate into myocytesin vitro. E-ECM scaffolds reseeded with myocytes were implanted into the greater omenta to obtain recellular esophageal ECM (RE-ECM), a tissue-engineered esophagus. The results showed that the cells of the esophagi were completely and uniformly removed after perfusion. E-ECM scaffolds retained the original four-layer organizational structure and vascular system with excellent biocompatibility. And the E-ECM scaffolds had no significant difference in mechanical properties comparing with fresh esophagi,p> 0.05. Immunocytochemistry showed positive expression ofα-sarcomeric actin, suggesting that BMSCs had successfully differentiated into myocytes. Most importantly, we found that in the RE-ECM muscularis, the myocytes regenerated linearly and continuously and migrated to the deep, and the tissue vascularization was obvious. The cell survival rates at 1 week and 2 weeks were 98.5 ± 3.0% and 96.4 ± 4.6%, respectively. It was demonstrated that myocytes maintained the ability for proliferation and differentiation for at least 2 weeks, and the cell activity was satisfactory in the RE-ECM. It follows that the tissue-engineered esophagus based on perfusion-decellularized technique and mesenchymal stem cells has great potential in esophageal repair. It is proposed as a promising alternative for reconstruction of esophageal defects in the future.

Long non-coding RNA DDX11-AS1 promotes esophageal carcinoma cell proliferation and migration through regulating the miR-514b-3p/RBX1 axis.

Esophageal carcinoma (ESCA) is one of the most aggressive malignancies with extremely high morbidity and mortality. At present, limited advancement in ESCA treatment has achieved. Therefore, it is urgent to explore the pathogenesis and progression mechanism of ESCA to provide the basis for the formulation of novel therapeutic strategies. Previous studies have found that long non-coding RNA (lncRNA) DDX11-AS1 expression enhances the paclitaxel resistance of ESCA cells. However, the mechanisms underlying the drug resistance conferred by lncRNA DDX11-AS1 in ESCA remains to be elucidated. Our research aims to clarify the role and mechanism of lncRNA DDX11-AS1 in regulating the progression of ESCA. We found that the expression of lncRNA DDX11-AS1 in ESCA tissues and cell lines was significantly upregulated. Subsequently, silencing lncRNA DDX11-AS1 significantly inhibited the proliferation, migration and invasion of ESCA cells, and induced the level of cell apoptosis. In terms of mechanism, our data showed that miR-514b-3p/RING box protein 1 (RBX1) axis played a crucial role in the oncogenic function of lncRNA DDX11-AS1. LncRNA DDX11-AS1 expression impaired the inhibitory function of miR-514b-3p on RBX1 through sponging effect. Taken together, our data support the notion that lncRNA DDX11-AS1 promotes the progression of ESCA through miR-514b-3p/RBX1 axis. Our research uncovers the novel regulatory role of lncRNA DDX11-AS1 in ESCA and lays a theoretical basis for developing novel treatment strategy of ESCA.

Postreflux swallow-induced peristaltic wave index from pH-impedance monitoring associates with esophageal body motility and esophageal acid burden.

BACKGROUND: Postreflux swallow-induced peristaltic wave (PSPW) on pH-impedance monitoring and contraction vigor on high-resolution manometry (HRM) both assess esophageal peristaltic response. We aimed to evaluate relationships between PSPW and esophageal peristalsis on HRM in the context of reflux disease in this multicenter cohort study. METHODS: pH-impedance and HRM studies performed on patients with persisting reflux symptoms were reviewed from 6 centers (5 in Europe and 1 in US). Total, upright and supine acid exposure time (AET) were evaluated from pH-impedance studies; PSPW index (PSPWI) and mean nocturnal baseline impedance (MNBI) were calculated using standard methodology. Esophageal body contraction vigor was analyzed using distal contractile integral (DCI), and DCI ratio > 1 between single swallows and multiple rapid swallows (MRS) defined presence of contraction reserve. Student's t test, ANOVA, and linear regression were utilized to investigate relationships between PSPW, contraction vigor, and contraction reserve. KEY RESULTS: Of 296 patients (52.8 ± 0.8 yr, 63% F), median PSPWI was 0.475. Only 24.0% had intact DCI; the remainder had varying degrees of hypomotility. As hypomotility increased, PSPWI and MNBI decreased significantly, while total AET and reflux episodes had an inverse response (P ≤ .002 for each). MRS data were available in 167 (56.4%), 72.5% had contraction reserve. MRS cohorts with normal PSPWI had significantly lower reflux burden compared to low PSPWI, regardless of presence or absence of contraction reserve (P ≤ .001). CONCLUSIONS AND INFERENCES: PSPWI correlates with esophageal hypomotility and reflux burden, and complements clinical reflux evaluation. Intact PSPW is more relevant to esophageal reflux clearance than contraction reserve.

Establishing spectrochemical changes in the natural history of oesophageal adenocarcinoma from tissue Raman mapping analysis.

Raman spectroscopy is a fast and sensitive technique able to identify molecular changes in biological specimens. Herein, we report on three cases where Raman microspectroscopy was used to distinguish normal vs. oesophageal adenocarcinoma (OAC) (case 1) and Barrett's oesophagus vs. OAC (cases 2 and 3) in a non-destructive and highly accurate fashion. Normal and OAC tissues were discriminated using principal component analysis plus linear discriminant analysis (PCA-LDA) with 97% accuracy (94% sensitivity and 100% specificity) (case 1); Barrett's oesophagus vs. OAC tissues were discriminated with accuracies ranging from 98 to 100% (97-100% sensitivity and 100% specificity). Spectral markers responsible for class differentiation were obtained through the difference-between-mean spectrum for each group and the PCA loadings, where C-O-C skeletal mode in ß-glucose (900 cm-1), lipids (967 cm-1), phosphodioxy (1296 cm-1), deoxyribose (1456 cm-1) and collagen (1445, 1665 cm-1) were associated with normal and OAC tissue differences. Phenylalanine (1003 cm-1), proline/collagen (1066, 1445 cm-1), phospholipids (1130 cm-1), CH2 angular deformation (1295 cm-1), disaccharides (1462 cm-1) and proteins (amide I, 1672/5 cm-1) were associated with Barrett's oesophagus and OAC tissue differences. These findings show the potential of using Raman microspectroscopy imaging for fast and accurate diagnoses of oesophageal pathologies and establishing subtle molecular changes predisposing to adenocarcinoma in a clinical setting. Graphical abstract Graphical abstract demonstrating how oesophageal tissue is processed through Raman mapping analysis in order to detect spectral differences between stages of oesophageal transformation to adenocarcinoma.

Exacerbation of gastroesophageal reflux symptoms after discontinuation of proton pump inhibitors is not associated with increased esophageal acid exposure.

BACKGROUND: Discontinuation of long-term proton pump inhibitors (PPIs) on patients with reflux symptoms can be challenging, as symptoms often exacerbate after stopping. The mechanism remains unknown. Our aim was to evaluate the impact of stopping long-term PPIs on patients with heartburn, and its association with esophageal acid exposure. METHODS: Patients with heartburn on long-term PPIs underwent symptom questionnaire, high-resolution manometry, and 24h ambulatory impedance-pH studies, following a 7-day PPIs discontinuation. We investigated the association between exacerbation of symptoms and findings on ambulatory reflux studies. KEY RESULTS: We studied 37 patients. After stopping PPIs, 27 patients (73%) had exacerbation of heartburn. Esophageal acid exposure time% (AET) in patients with exacerbation of heartburn was not significantly higher than in patients without (3.5% [1.3-9.7] vs 2.5% [1.3-8.7], NS). Fourteen of 27 patients with exacerbation had physiological AET (<4%) as compared with 6 of 10 patients with physiological AET (NS). All questioned symptoms (heartburn, regurgitation, epigastric discomfort/pain, bloating/belch) worsened after stopping PPIs (NS). CONCLUSIONS & INFERENCES: Exacerbation of heartburn after discontinuation of PPIs does not appear to be due to increased esophageal acid exposure.

A clinical-grade acellular matrix for esophageal replacement.

In pathologies of the esophagus such as esophageal atresia, cancers, and caustic injuries, methods for full thickness esophageal replacement require the sacrifice of healthy intra-abdominal organs such as the stomach and the colon and are associated with high morbidity, mortality, and poor functional results. To overcome these problems, tissue engineering methods are developed to create a substitute with scaffolds and cells. The aim of this study was to develop a simple and safe decellularization process in order to obtain a clinical grade esophageal extracellular matrix. Following the decontamination step, porcine esophagi were decellularized in a bioreactor with sodium dodecyl sulfate and ethylenediaminetetraacetic acid for 3 days and were rinsed with deionized water. DNA was eliminated by a 3-hr DNase treatment. To remove any residual detergent, the matrix was then incubated with an absorbing resin. The resulting porcine esophageal matrix was characterized by the assessment of the efficiency of the decellularization process (DNA quantification), evaluation of sterility and absence of cytotoxicity, and its composition and biomechanical properties, as well as the possibility to be reseeded with mesenchymal stem cells. Complete decellularization with the preservation of the general structure, composition, and biomechanical properties of the native esophageal matrix was obtained. Sterility was maintained throughout the process, and the matrix showed no cytotoxicity. The resulting matrix met clinical grade criteria and was successfully reseeded with mesenchymal stem cells..

Novel Screening Tests for Barrett's Esophagus.

PURPOSE OF REVIEW: There has been an exponential increase in the incidence of esophageal adenocarcinoma (EAC) over the last half century. Barrett's esophagus (BE) is the only known precursor lesion of EAC. Screening for BE in high-risk populations has been advocated with the aim of identifying BE, followed by endoscopic surveillance to detect dysplasia and early stage cancer, with the intent that treatment can improve outcomes. We aimed to review BE screening methodologies currently recommended and in development. RECENT FINDINGS: Unsedated transnasal endoscopy allows for visualization of the distal esophagus, with potential for biopsy acquisition, and can be done in the office setting. Non-endoscopic screening methods being developed couple the use of swallowable esophageal cell sampling devices with BE specific biomarkers, as well as trefoil factor 3, methylated DNA markers, and microRNAs. This approach has promising accuracy. Circulating and exhaled volatile organic compounds and the foregut microbiome are also being explored as means of detecting EAC and BE in a non-invasive manner. Non-invasive diagnostic techniques have shown promise in the detection of BE and may be effective methods of screening high-risk patients.

Characterization of a Schistosoma mansoni NDPK expressed in sexual and digestive organs.

Nucleoside diphosphate kinases (NDPKs) are crucial to keep the high triphosphate nucleotide levels in the biological process. The enzymatic mechanism has been extensively described; however, the structural characteristics and kinetic parameters have never been fully determined. In Schistosoma mansoni, NDPK (SmNDPK) is directly involved in the pyrimidine and purine salvage pathways, being essential for nucleotide metabolism. The SmNDPK enzymatic activity is the highest of the known purine metabolisms when compared to the mammalian NDPKs, suggesting the importance of this enzyme in the worm metabolism. Here, we report the recombinant expression of SmNDPK that resulted in 1.7 and 1.9 Å apo-form structure in different space-groups, as well as the 2.1 Å SmNDPK.ADP complex. The binding and kinetic assays reveal the ATP-dependence for enzyme activation. Moreover, in situ hybridization showed that SmNDPK transcripts are found in reproductive organs and in the esophagus gland of adult worms, which can be intrinsically related with the oviposition and digestive processes. These results will help us fully understand the crucial participation of this enzyme in Schistosoma mansoni and its importance for the pathology of the disease.

[The expressions and diagnostic values of miR-18a and miR-21 in esophageal cancer].

Objective: To investigate the expressional levels and diagnostic values of miR-18a and miR-21 in esophageal carcinoma. Methods: The expressions of miR-18a and miR-21 in esophageal cancer tissues and adjacent tissues from 45 esophageal cancer patients, peripheral blood from 45 esophageal cancer patients and 50 healthy donors respectively were detected by RT-PCR. The expressions of miR-18a and miR-21 in normal esophageal epithelial cell HET-1A, esophageal cancer cell lines including ECA109, KYSE150 and TE1 were also detected. Chemiluminescence immunoassay was used to quantitatively detect the concentrations of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), CYRFA21-1 and TPA (tissue polypeptide antigen) in peripheral blood serum from esophageal cancer patients and healthy controls. Meanwhile, the diagnostic effects of miR-18a and miR-21 on esophageal cancer were compared with those of tumor markers in serum. Results: The expression levels of miR-18a and miR-21 in esophageal cancer cells ECA109, KYSE150 and TE1 were 1.64±0.17, 1.62±0.19, 1.46±0.12 and 20.52±1.48, 6.73±0.73, 1.43±0.19, respectively, higher than those in normal esophageal epithelial cells (both P<0.01). The expressions of miR-18a and miR-21 in esophageal cancer tissues were 32.48±28.62 and 8.67±11.98, respectively, significantly higher than those in adjacent tissues (all P<0.001). The expression levels of miR-18a and miR-21 in peripheral blood of patients with esophageal cancer were 12.66±11.92 and 9.15±8.14, respectively, significantly higher than those in the normal control group (both P<0.001). The receiver operating characteristic (ROC) curve analysis showed that the area under the curve of miR-18a and miR-21 for diagnosis of esophageal cancer were 0.948 and 0.913 5, respectively. Compared with traditional esophageal tumor markers, the expressions of miR-18a and miR-21 were more sensitive in the diagnosis of esophageal cancer. The sensitivity and accuracy of the expressions of miR-18a and miR-21 combined with traditional esophageal tumor markers in diagnosis of esophageal cancer can be further improved to 97.8% and 68.4%, respectively. Conclusion: Our study reveals that the expressions of miR-18a and miR-21 play important roles in the diagnosis of esophageal cancer and may be potentially novel biomarkers.

pH-neutralizing esophageal irrigations as a novel mitigation strategy for button battery injury.

OBJECTIVES/HYPOTHESIS: Ingestion of button batteries (BB) can rapidly lead to caustic esophageal injury in infants and children, resulting in significant morbidity and mortality. To identify novel mitigation strategies, we tested common weakly acidic household beverages, viscous liquids, and Carafate® for their ability to act as protective esophageal irrigations until endoscopic removal of the BB. STUDY DESIGN: Cadaveric and live animal model. METHODS: Apple juice, orange juice, Gatorade®, POWERADE®, pure honey, pure maple syrup, and Carafate® were screened using a 3 V lithium (3 V-CR2032) BB on cadaveric porcine esophagus. The most promising in vitro options were tested against a saline control in live American Yorkshire piglets with anode-facing placement of the BB on the posterior wall of the proximal esophagus for 60 minutes. BB voltage and tissue pH were measured before battery placement and after removal. The 10 mL irrigations occurred every 10 minutes from t = 5 minutes. Gross and histologic assessment was performed on the esophagus of piglets euthanized 7 ± 0.5 days following BB exposure. RESULTS: Honey and Carafate® demonstrated to a significant degree the most protective effects in vitro and in vivo. Both neutralized the tissue pH increase and created more localized and superficial injuries; observed in vivo was a decrease in both full-thickness injury (i.e., shallower depths of necrotic and granulation tissue) and outward extension of injury in the deep muscle beyond surface ulcer margins (P < .05). CONCLUSIONS: In the crucial period between BB ingestion and endoscopic removal, early and frequent ingestion of honey in the household setting and Carafate® in the clinical setting has the potential to reduce injury severity and improve patient outcomes. LEVEL OF EVIDENCE: NA Laryngoscope, 129:49-57, 2019.

Relationship between extralaryngeal endoscopic findings, proton pump inhibitor (PPI) response, and pH measures in suspected laryngopharyngeal reflux.

Laryngopharyngeal reflux (LPR) is a clinical entity diagnosed by history laryngoscopic findings that has a variable response to empiric proton-pump inhibitor (PPI) therapy. While the reflux finding score (RFS), an endoscopic scoring scheme, has been advanced as a measure of LPR, it has not been externally validated against symptom severity in practice. Extralaryngeal pharyngeal endoscopic findings may have diagnostic utility but remain underexplored. This study assesses the correlation between extralaryngeal findings and (1) 24-hour oropharyngeal pH & (2) PPI response in patients with suspected LPR. Subjects presented to a tertiary care center with laryngeal symptoms ≥1 month and reflux symptom index (RSI) ≥13. Following baseline questionnaires, laryngoscopy, and a 24-hour oropharyngeal pH probe study, subjects were prescribed 8-12 week omeprazole trials. Baseline endoscopic findings were scored in a blinded fashion using the RFS and extralaryngeal score criteria, summatively the 'ELS.' PPI response was defined as ≥50% improvement in RSI. Thirty-three subjects with flexible endoscopic recordings completed baseline and follow-up questionnaires. The cohort's baseline mean RSI was 23.0 ± 7.2 with a ΔRSI = 9.8 after PPI therapy. The baseline RFS score averaged 5.3 ± 2.7. 45% of our subjects was found to be PPI responsive. The Cohen's kappa for the ELS but not the RFS was significant. There were no significant differences between the RFS (P = 0.10) or ELS (P = 0.07) for PPI responders & nonresponders. Oropharyngeal pH measures did not correlate with the RFS or ELS. In conclusion, endoscopic scores of laryngeal and extralaryngeal findings did not predict PPI response or oropharyngeal acid exposure in suspected LPR.

Trajectory assessment is useful when day-to-day esophageal acid exposure varies in prolonged wireless pH monitoring.

Acid exposure time commonly varies from day-to-day in prolonged wireless pH monitoring. Thus, diagnosis based on the number of days with abnormal acid burden may be misleading or inconclusive. We hypothesize that assessing longitudinal patterns of acid exposure may be diagnostically useful. Therefore, this study aims to describe acid exposure trajectories and evaluate agreement between identified trajectory patterns and conventional grouping. In this retrospective cohort study, we assessed patients with nonresponse to proton pump inhibitor therapy who underwent wireless pH monitoring (≥72 h) off therapy between August 2010 and September 2016. The primary outcome was esophageal acid exposure time. Subjects were grouped as 0, 1, 2, and 3+ days positive based on number of days with an acid exposure time >5.0%. Latent class group-based mixture model identified distinct longitudinal acid exposure trajectory groups. Of 212 subjects included 44%, 18%, 14%, and 24% had 0, 1, 2, 3+ days positive, respectively. Group-based modeling identified three significantly stable acid exposure trajectories: low (64%), middle (28%), and high (8%). Trajectory grouping and days positive grouping agreed substantially (weighted K 0.69; 95% CI: 0.63-0.76). Trajectory grouping identified 62% of subjects with conventionally inconclusive studies (one or two days positive) into the low trajectory. Agreement between trajectory groups when using three versus four days of monitoring was substantial (K 0.70; CI: 0.61-0.78). In summary, we found that patients with nonresponse to proton pump inhibitors follow three acid exposure trajectories over prolonged pH-monitoring periods: low, middle, and high. Compared to conventional day positive grouping, the trajectory modeling identified the majority of inconclusive days positive into the low trajectory group. Analyzing prolonged wireless pH data according to trajectories may be a complimentary method to conventional grouping, and may increase precision and accuracy in identifying acid burden.

Temporospatial localization of telocytes during esophageal morphogenesis in rabbit.

Telocytes (TCs) are CD34 and Vimentin positive (+) immunoreactive stromal cells with a small-sized body and several extremely long telopodes. TCs have been described to provide a mechanical support throughout the tissue by making cellular connections (homo- or hetero) to form a 3D network. Such network can transmit the intercellular signaling. Recently, TCs have been described in the esophageal wall. However, information concerning the role of these cells in esophageal organization and development is rare. Thus, we aimed to record the temporo-spatial localization pattern of TCs during esophageal morphogenesis in rabbit. Embryos and fetuses of New Zealand White rabbits (10th-30th gestational days) were collected. Using CD34 immunostaining, TCs have not been demonstrated in the wall of the developing esophagus till the end of the second third of pregnancy. On 24th gestational day, CD34+ TCs were organized in the adventitia of the esophageal wall specifically in close association with the endothelial cells lining the micro vessels. Later on 26th gestational day, CD34+TCs were additionally expressed in the sub-mucosa and in lamina propria (sub-epithelial). On 28th gestational day, additional CD34+TCs were detected among the smooth muscle bundles of the muscular layer. Reaching the last gestational day, CD34+TCs formed several sheaths in the esophageal wall namely sub epithelial sheath, sub-mucosal, muscular (circular and longitudinal) and inter-muscular sheaths and an outer adventitial one. On the other hand, vimentin immunohistochemistry revealed wider spread TCs positivity in all developmental ages. Presumptively, arrangement of CD34 and vimentin positive TCs in all layers of the developing esophageal wall hypothesizes that TC may play a potential role as a progenitor cell initially in differentiation of the epithelial and muscular precursors and finally in shaping of the various layers of the rabbit esophageal wall during its morphogenesis. TCs are also proposed to be involved in the angiogenesis of the esophageal blood capillaries.

Esophageal IgG4: Clinical, Endoscopic, and Histologic Correlations in Eosinophilic Esophagitis.

OBJECTIVE: Recent studies show increased serum and esophageal IgG4 in patients with eosinophilic esophagitis (EoE), suggesting a possible IgG4-involved process. The role of IgG4 in pediatric EoE has not been extensively investigated. Our aim was to analyze IgG4 in esophageal tissue in children in parallel to that in adults with EoE. METHODS: In a retrospective institutional review board-approved study, we performed immunohistochemical staining of IgG4 in esophageal biopsy specimens from 39 subjects: children with EoE (n = 16), adults with EoE (n = 15), children with reflux esophagitis (n = 4), and pediatric controls (n = 4). We assessed the relationships between IgG4 staining and clinical, endoscopic, and histopathologic characteristics. RESULTS: Patients with EoE were significantly more likely to stain positively for IgG4 than children with reflux esophagitis or controls (P = 0.015). Fifteen of 31 (48%) EoE cases stained positively for IgG4. None of the reflux esophagitis or control cases stained positively. IgG4 staining had 48% sensitivity and 100% specificity for EoE. There was a trend toward IgG4 staining being associated with foreign body/food impaction (P = 0.153). There was a strong association between distal IgG4 staining and basal zone hyperplasia (P = 0.003). CONCLUSIONS: Our study suggests IgG4 is not a consistent finding of EoE at disease diagnosis. Although IgG4 staining was specific for EoE, it had a poor sensitivity with positive staining in only 48% of EoE patients. Further studies are warranted to fully elucidate the role of IgG4 in EoE.

Advanced Imaging for Barrett's Esophagus and Early Neoplasia: Surface and Subsurface Imaging for Diagnosis and Management.

PURPOSE OF REVIEW: Esophageal adenocarcinoma bears one of the fastest rising incidence of any cancers and generally arises in the setting of gastroesophageal reflux and Barrett's esophagus. However, early detection of neoplasia can be challenging since most patients are asymptomatic until they progress to more advanced and less curable stages, and early dysplastic lesions can be small, multifocal, and difficult to detect. Clearly, new imaging tools are needed in light of sampling error associated with random biopsies, the current standard of practice. RECENT FINDINGS: Advances in endoscopic imaging including virtual chromoendoscopy, confocal laser endomicroscopy, and subsurface imaging with optical coherence tomography have ushered in a new era for detecting subtle neoplastic lesions. Moreover, in light of esophagus-sparing treatments for neoplastic lesions, such tools are likely to guide ablation and follow-up management. While there is no ideal single imaging modality to facilitate improved detection, staging, ablation, and follow-up of patients with dysplastic Barrett's esophagus, new advances in available technology, the potential for multimodal imaging, and the use of computer-aided diagnosis and biomarkers all hold great promise for improving detection and treatment.

Esophageal pH and impedance reflux parameters in relation to body mass index, obesity-related hormones, and bariatric procedures.

Introduction Obese patients have a higher risk of gastroesophageal reflux disease (GERD), but obesity­related hormonal changes associated with GERD and the effects of bariatric therapy on reflux are unclear. Objectives The aim of the study was to assess reflux parameters in relation to bariatric therapy and hormonal changes in obese patients. Patients and methods This prospective observational study with a 1­year follow­up included 53 obese patients undergoing bariatric therapies. Esophageal pH and impedance monitoring tests were performed and circulating hormone levels were analyzed. Results Esophageal acid exposure time (%AET) and the number of refluxes correlated positively with body mass index. There were several significant, although weak, correlations of pH and impedance parameters with ghrelin and omentin levels. Patients with abnormal %AET had lower ghrelin levels and those with abnormal reflux number had lower omentin levels than patients with normal parameters. Although we observed certain changes including increased %AET and bolus clearance time (BCT) after laparoscopic sleeve gastrectomy, a reduced BCT and number of refluxes after gastric band, and nonsignificant changes after intragastric balloon, the overall bariatric therapy did not significantly impact on the final GERD diagnosis. GERD before and after therapy was present in 42% of patients. De novo GERD developed in 17.8% of patients, while a similar percentage of patients with initial GERD had normal pH and impedance after therapy. Patients with de novo or persistent GERD had a similar percentage of weight loss as patients without GERD. Conclusions Bariatric therapy and percentage of weight loss do not significantly affect GERD. The observed hormonal changes alone do not fully explain the high prevalence of GERD in obese patients.

Regeneration of the oesophageal muscle layer from oesophagus acellular matrix scaffold using adipose-derived stem cells.

This study explored the feasibility of constructing a tissue engineered muscle layer in the oesophagus using oesophageal acellular matrix (OAM) scaffolds and human aortic smooth muscle cells (hASMCs) or human adipose-derived stem cells (hASCs). The second objective was to investigate the effect of hypoxic preconditioning of seeding cells on cell viability and migration depth. Our results demonstrated that hASMCs and hASCs could attach and adhere to the decellularized OAM scaffold and survive and proliferate for at least 7 days depending on the growth conditions. This indicates adipose-derived stem cells (ASCs) have the potential to substitute for smooth muscle cells (SMCs) in the construction of tissue engineered oesophageal muscle layers.

Decellularized and matured esophageal scaffold for circumferential esophagus replacement: Proof of concept in a pig model.

Surgical resection of the esophagus requires sacrificing a long portion of it. Its replacement by the demanding gastric pull-up or colonic interposition techniques may be avoided by using short biologic scaffolds composed of decellularized matrix (DM). The aim of this study was to prepare, characterize, and assess the in vivo remodeling of DM and its clinical impact in a preclinical model. A dynamic chemical and enzymatic decellularization protocol of porcine esophagus was set up and optimized. The resulting DM was mechanically and biologically characterized by DNA quantification, histology, and histomorphometry techniques. Then, in vitro and in vivo tests were performed, such as DM recellularization with human or porcine adipose-derived stem cells, or porcine stromal vascular fraction, and maturation in rat omentum. Finally, the DM, matured or not, was implanted as a 5-cm-long esophagus substitute in an esophagectomized pig model. The developed protocol for esophageal DM fulfilled previously established criteria of decellularization and resulted in a scaffold that maintained important biologic components and an ultrastructure consistent with a basement membrane complex. In vivo implantation was compatible with life without major clinical complications. The DM's scaffold in vitro characteristics and in vivo implantation showed a pattern of constructive remodeling mimicking major native esophageal characteristics.

Improved Progression Prediction in Barrett's Esophagus With Low-grade Dysplasia Using Specific Histologic Criteria.

Risk stratification of patients with Barrett's esophagus (BE) is based on diagnosis of low-grade dysplasia (LGD). LGD has a poor interobserver agreement and a limited value for prediction of progression to high-grade dysplasia or esophageal adenocarcinoma. Specific reproducible histologic criteria may improve the predictive value of LGD. Four gastrointestinal pathologists examined 12 histologic criteria associated with LGD in 84 BE patients with LGD (15 progressors and 69 nonprogressors). The criteria with at least a moderate (kappa, 0.4 to 0.6) interobserver agreement were validated in an independent cohort of 98 BE patients with LGD (30 progressors and 68 nonprogressors). Hazard ratios (HR) were calculated by Cox proportional hazard regression analysis using time-dependent covariates correcting for multiple endoscopies during follow-up. Agreement was moderate or good for 4 criteria, that is, loss of maturation, mucin depletion, nuclear enlargement, and increase of mitosis. Combination of the criteria differentiated high-risk and low-risk group amongst patients with LGD diagnosis (P<0.001). When ≥2 criteria were present, a significantly higher progression rate to high-grade dysplasia or esophageal adenocarcinoma was observed (discovery set: HR, 5.47; 95% confidence interval [CI], 1.81-17; P=0.002; validation set: HR, 3.52; 95% CI, 1.56-7.97; P=0.003). Implementation of p53 immunohistochemistry and histologic criteria optimized the prediction of progression (area under the curve, 0.768; 95% CI, 0.656-0.881). We identified and validated a clinically applicable panel of 4 histologic criteria, segregating BE patients with LGD diagnosis into defined prognostic groups. This histologic panel can be used to improve clinical decision making, although additional studies are warranted.