The seroprevalence of cagA-positive Helicobacter pylori strains in the spectrum of gastroesophageal reflux disease

BACKGROUND & AIMS

The role of Helicobacter pylori in the pathogenesis of gastroesophageal reflux disease (GERD) is unknown. We determined the prevalence of cagA-positive (cagA+) H. pylori strains in patients with GERD or its complications compared with controls of similar age.

METHODS

A total of 153 consecutive patients with GERD, Barrett's esophagus, and Barrett's esophagus complicated by dysplasia or adenocarcinoma were compared with 57 controls who underwent upper endoscopy for reasons other than GERD. H. pylori infection and CagA antibody status were determined by histology and enzyme-linked immunosorbent assay.

RESULTS

H. pylori prevalence was lower (34%) in patients with GERD and its sequelae than in the control group (45.6%)(P = 0.15). Regardless of the group, increasing age was associated with higher prevalence of H. pylori (P = 0.003). When compared with controls (42.3%), the prevalence of cagA+ H. pylori strains decreased (P = 0.008) in patients with more severe complications of GERD (GERD, 36.7% [nonerosive GERD, 41.2%; erosive GERD, 30.8%]; Barrett's esophagus, 13.3%; and Barrett's with adenocarcinoma/dysplasia, 0%).

CONCLUSIONS

Prevalence of H. pylori in patients with GERD and its sequelae was lower but not significantly different than that of a control group. However, patients carrying cagA+ strains of H. pylori may be protected against the complications of GERD, especially Barrett's esophagus and its associated dysplasia and adenocarcinoma.

Esomeprazole improves healing and symptom resolution as compared with omeprazole in reflux oesophagitis patients: a randomized controlled trial. The Esomeprazole Study Investigators

BACKGROUND

The pharmacologic profile of the new proton pump inhibitor esomeprazole has demonstrated advantages over omeprazole that suggest clinical benefits for patients with acid-related disease.

METHODS

1960 patients with endoscopy-confirmed reflux oesophagitis (RO) were randomized to once daily esomeprazole 40 mg (n=654) or 20 mg (n=656), or omeprazole 20 mg (n=650), the standard recommended dose for RO, for up to 8 weeks in a US, multicentre, double-blind trial. The primary efficacy variable was the proportion of patients healed at week 8. Secondary variables included healing and heartburn resolution at week 4, time to first resolution and sustained resolution of heartburn, and per cent of heartburn-free days and nights. Safety and tolerability were also evaluated.

RESULTS

Significantly more patients were healed at week 8 with esomeprazole 40 mg (94.1%) and 20 mg (89.9%) vs. omeprazole 20 mg (86.9%), using cumulative life table estimates, ITT analysis (each P < 0.05). Esomeprazole 40 mg was also significantly more effective than omeprazole for healing at week 4 and for all secondary variables evaluating heartburn resolution. The most common adverse events in all treatment groups were headache, abdominal pain and diarrhoea.

CONCLUSION

Esomeprazole was more effective than omeprazole in healing and symptom resolution in GERD patients with reflux oesophagitis, and had a tolerability profile comparable to that of omeprazole.

Peritoneo-venous shunting for ascites

A new minor surgical procedure for ascites has been devised wherein a specially designated one way pressure activated valve is implanted to create a permanent peritoneo-venous shunt. The normally closed valves opens only when the peritoneal pressure rises 3-5 cm higher than the intrathoracic venous pressure thus preventing backflow of blood and closing the valve should the venous pressure rise from the over-infusion of ascitic fluid. The procedure has been performed on 45 patients but nine were terminal at the time of surgery. Prolonged relief of ascites occurred in 28 of 37 cases.

Jumbo biopsy forceps protocol still misses unsuspected cancer in Barrett's esophagus with high-grade dysplasia

BACKGROUND

The optimal management of high-grade dysplasia in patients with Barrett's esophagus is controversial. The aim of this study was to assess the prevalence of unsuspected carcinoma at esophagectomy in patients with Barrett's esophagus with high-grade dysplasia after endoscopic surveillance with jumbo biopsy forceps compared with standard biopsy forceps.

METHODS

Twelve patients with high-grade dysplasia in Barrett's esophagus without gross or microscopic evidence of carcinoma underwent esophagectomy after preoperative endoscopy with 4-quadrant jumbo biopsies at 2-cm intervals. The findings in this group were compared with those in a group of patients with Barrett's esophagus who underwent esophagectomy for high-grade dysplasia after biopsies obtained at 2-cm intervals with standard biopsy forceps.

RESULTS

Unsuspected cancer was found in 4 of 12 (33%) patients in the jumbo biopsy group compared with 6 of 16 (38%) in the standard biopsy group (p = NS). All 6 cancers in the standard biopsy group were intramucosal, whereas 2 were intramucosal and 2 were submucosal in the jumbo biopsy group. No patients in either group had lymph node metastases.

CONCLUSIONS

Unsuspected cancer is found frequently in patients with Barrett's esophagus who are undergoing esophagectomy for high-grade dysplasia despite the use of a rigorous jumbo biopsy protocol. Esophageal resection is still indicated in appropriately selected patients with high-grade dysplasia until better markers of cancer risk are available.

Inflammation and intestinal metaplasia of the gastric cardia: the role of gastroesophageal reflux and H. pylori infection

BACKGROUND & AIMS

Whether inflammation of the cardia indicates gastroesophageal reflux disease (GERD) and/or is a manifestation of pangastritis caused by Helicobacter pylori infection is unknown. The aim of this study was to evaluate the relationship between cardia inflammation, H. pylori infection, and cardia intestinal metaplasia in patients with and without GERD.

METHODS

Patients with GERD were compared with controls undergoing endoscopy for a variety of other conditions. Endoscopic biopsy specimens from the distal esophagus and cardia, fundus, and antrum were evaluated for inflammation, H. pylori infection, and intestinal metaplasia.

RESULTS

Neither the prevalence of H. pylori infection (controls, 48%; GERD, 41%) nor cardia inflammation (controls, 41%; GERD, 40%) differed between groups. All 11 controls and 22 of 23 patients with GERD (96%) and cardia inflammation had H. pylori infection. Esophagitis was more common among GERD patients (33%) than controls (7%; P = 0.01). Cardia intestinal metaplasia was more common among controls (22%) than GERD patients (3%; P = 0.01); all had cardia inflammation, 7 had H. pylori infection, and 6 had metaplasia elsewhere in the stomach.

CONCLUSIONS

The prevalence of cardia inflammation is similar in patients with and without GERD and is associated with H. pylori infection (P < 0.001). Cardia intestinal metaplasia is associated with H. pylori-related cardia inflammation (P = 0.01) and intestinal metaplasia elsewhere in the stomach, indicating that it is distinct from Barrett's esophagus.

Glutamate receptors of rod bipolar cells are linked to a cyclic GMP cascade via a G-protein

Whole-cell patch-clamp recordings were obtained from light-responsive on-bipolar cells in retinal slices of the dogfish. Inclusion of the G-protein activator, GTP gamma S, in the intracellular patch solution mimicked the action of glutamate, inducing an increase in net outward current (interpreted as a decrease in inward current), a decrease in membrane conductance and block of light responses. Cyclic GMP (cGMP) in the patch pipette increased inward current and membrane conductance, and blocked light responses. Cyclic AMP had no effect. IBMX, a phosphodiesterase inhibitor, produced the same effect as cGMP, suggesting the presence of a cGMP phosphodiesterase in rod bipolar cells. These results indicate that the glutamate receptors of on-bipolar cells are coupled via a G-protein to regulate intracellular cGMP, which, in turn, results in the opening of sub-synaptic membrane channels. The similarity to phototransduction is striking, and the proposed scheme would account for the high gain in transmission of rod signals to on-bipolar cells.

Cytokeratin subsets can reliably distinguish Barrett's esophagus from intestinal metaplasia of the stomach

The histological distinction between intestinal metaplasia involving the distal esophagus (Barrett's esophagus [BE]) and intestinal metaplasia of the stomach has important clinical implications and can be difficult even with the use of histochemical mucin stains. Cytokeratin (CK) 7 and 20 are cytoplasmic structural proteins that show restricted expression in normal and malignant epithelia of the gastrointestinal tract. The aim of this study was to determine the use of CK7 and 20 expression in the histological distinction of BE from gastric intestinal metaplasia. CK7 and 20 immunostaining was performed on randomly selected surgical resection (n = 31) and biopsy specimens (n = 34) from patients with long-segment BE and gastric resection specimens (n = 11) and gastric cardia biopsy specimens (n = 13) in patients with histological evidence of intestinal metaplasia. A unique pattern of immunoreactivity designated the Barrett's CK7/20 pattern showed superficial CK20 staining and strong CK7 staining of both superficial and deep glands in 29 of 31 (94%) esophageal resection specimens and 34 of 34 (100%) esophageal biopsy specimens form patients with long-segment BE. A Barrett's CK7/20 pattern was not observed in gastric cardia biopsy specimens (n = 13) or gastric resection specimens (n = 11) in patients with histological evidence of intestinal metaplasia. The sensitivity, specificity, and positive predictive value of a Barrett's CK7/20 pattern for a diagnosis of long-segment BE was 97%, 100%, and 100%, respectively. CK7 and 20 reactivity patterns can reliably identify the location of intestinal metaplasia in the esophagus and stomach using histological material from both routine endoscopic biopsy and surgical resection specimens.

The gastric cardia: fact or fiction?

OBJECTIVE

It is unclear whether the gastric cardia is present from birth or is metaplastic and develops as a result of gastroesophageal reflux disease. To this end, we evaluated the histology of the entire esophagogastric junction in consecutive pediatric autopsies to determine the presence and extent of cardiac mucosa.

METHODS

The entire esophagogastric junction of 33 consecutive pediatric (< or =18 yr) autopsies was examined. The precise location of the squamocolumnar junction and its relationship to the esophagogastric junction was noted in all cases. Slides were evaluated by two pathologists in a blinded fashion to look for cardiac mucosa, characterized by unequivocal periodic acid-Schiff (PAS)-positive mucous glands in a lobular configuration. Sections from the antrum and esophagogastric junction were examined for the presence of Helicobacter pylori.

RESULTS

Three cases were excluded due to autolysis. The mean age of the 30 remaining patients was 6.3 yr (range: 16 days-18 yr). A regular-appearing squamocolumnar junction was identified at the esophagogastric junction in all 30 cases. Cardiac mucosa was present in all specimens (mean length: 1.8 mm; range: 1.0-4.0 mm), always on the gastric side of the esophagogastric junction. There was no significant association between patient age or gender and length of cardiac mucosa. None of the patients had a known history of gastroesophageal reflux disease or Barrett's esophagus, and none were taking acid-suppressing medications before death. All were negative for Helicobacter pylori by Giemsa stain.

CONCLUSIONS

In an unselected pediatric patient population with little or no propensity for gastroesophageal reflux disease, a short segment of cardiac mucosa was consistently present on the gastric side of the esophagogastric junction, independent of gender or age. These results support the concept that the gastric cardia is present from birth as a normal structure.

Chemical acidification of wounds. An adjuvant to healing and the unfavorable action of alkalinity and ammonia

Images

Superficial adenocarcinoma of the esophagus

OBJECTIVE

Experience with treatment and outcome of superficial adenocarcinoma of the esophagus is limited. The purpose of this study was to evaluate the results of surgical management and identify predictors of survival.

METHODS

Between September 1985 and December 1999, 122 patients underwent resection. Eighty-nine percent were men (mean age 63 +/- 10 years; range 35-83 years). Sixty (49%) patients were in endoscopic surveillance programs and 48 (39%) had the preoperative diagnosis of high-grade dysplasia. Forced expiratory volume in 1 second was less than 2 L in 12 (12%). Seventy-five (61%) patients underwent transhiatal esophagectomy. Pathologic stage was N1 in 8 (7%). Pulmonary complications necessitating reintubation (respiratory failure) occurred in 10 (8%) patients. Time-related survival models were developed for decision-making (preoperative), prognosis (operative), and hospital care (postoperative).

RESULTS

Operative mortality was 2.5%. Survival at 1, 5, and 10 years was 89%, 77%, and 68%. Preoperative decision-making factors associated with ideal outcome were 1-second forced expiratory volume of more than 2 L, surveillance, preoperative diagnosis of high-grade dysplasia, and planned transhiatal esophagectomy. Prognosis was decreased in younger patients and in those with N1 disease. Postoperative respiratory failure increased mortality.

CONCLUSIONS

Surgery is the treatment of choice for superficial adenocarcinoma of the esophagus. The ideal patient has a preoperative diagnosis of high-grade dysplasia found at surveillance, good pulmonary function, and undergoes a transhiatal esophagectomy. Discovery of N1 disease or development of postoperative respiratory failure reduces the benefits of surgery.

Responses of rod bipolar cells in the dark-adapted retina of the dogfish, Scyliorhinus canicula

1. Responses to light were recorded from bipolar cells in the retina of the dogfish, Scyliorhinus canicula, under dark-adapted conditions. The identity of the cells was confirmed by Procion Yellow staining.2. More than 95% of the bipolar cells sampled were of the type which depolarized to a spot of light. These are termed depolarizing bipolar cells. In most cells, illumination of the surround had little effect on the responses elicited from the central receptive field.3. The mean flash sensitivity of the depolarizing bipolar cells was 270 mV/Rh(**) (where Rh(**) signifies rhodopsin photoisomerization per rod for full field illumination).4. The mean flash sensitivity of horizontal cells under the same conditions was 8 mV/Rh(**). In a limited sample of hyperpolarizing bipolar cells the highest flash sensitivity was 42 mV/Rh(**).5. The high flash sensitivity of the depolarizing bipolar cells indicates a large voltage gain at its synapse with rods. On the assumption of a rod flash sensitivity of 2 mV/Rh(**) the mean gain at the synapse was 135, but for some cells the gain was in excess of 500.6. Responses of depolarizing bipolar cells to dim flashes could be approximated by the impulse response of a 12-16 stage low-pass filter, whereas horizontal cell responses could be fitted by a low-pass filter of six sections. The implied filter at the rod-bipolar cell synapse is tuned to the higher frequency components of rod signals, thereby improving temporal resolution in the rod pathway.7. Depolarizing bipolar cell responses to test flashes are reduced by weak background illumination (less than 0.1 Rh(**)/sec). This desensitization, which would not be expected to affect rod responses, could be explained by a shift in the operating point to a less sensitive region of the intensity-response curve as a result of the large depolarization elicited by the background.8. The results of current injection into the cell in darkness and during the response to light are consistent with the release by rod terminals of a transmitter which closes ionic channels in a conductance path having a reversal potential of - 8 mV, transmitter release being suppressed by light.

Rhodopseudomonas blastica atp operon. Nucleotide sequence and transcription

The nucleotide sequence has been determined of a 12,368 base-pair region of DNA cloned from the non-sulphur photosynthetic bacterium Rhodopseudomonas blastica. It contains a cluster of six genes of which five encode the subunits of F1-ATPase; the sixth codes for an unknown protein. The genes are arranged in the same order as in the Escherichia coli unc operon, except that the unknown gene is placed between those for gamma and beta subunits. Neither the genes for F0 subunits, nor a homologue of the E. coli uncI gene is associated with this locus. The six genes are transcribed from a single promoter and we have designated this region the R. blastica atp operon. The two distal genes, beta and epsilon, may also be transcribed from a second promoter. Initiation and termination points for transcription have been identified by primer extensions and S1 nuclease mapping experiments. Signals involved in initiation of translation (Shine and Dalgarno sequences) and termination of transcription in the photosynthetic bacterium resemble those in E. coli. However, no common features can be identified in these two bacteria between 5' regions adjacent to sites of initiation of transcription. The sequence also contains a gene that encodes a protein homologous to discoidin, a cell surface lectin of Dictyostelium discoideum thought to be involved in cell--cell aggregation. Seven other reading frames have not been identified.

CagA-positive strains of Helicobacter pylori may protect against Barrett's esophagus

OBJECTIVE

Helicobacter pylori (H. pylori) colonization is associated with chronic gastritis, peptic ulcer disease, and adenocarcinoma of the distal stomach. However, the role of H. pylori strain variation in complicated gastroesophageal reflux disease, especially Barrett's esophagus, is unknown. Therefore, the aim of this study was to evaluate the prevalence of colonization by cagA+ and cagA- H. pylori strains in the spectrum of gastroesophageal reflux disease, including Barrett's esophagus.

METHODS

A total of 251 patients undergoing endoscopy were categorized into four groups: controls, patients with gastroesophageal reflux disease alone, and patients with short- and long-segment Barrett's esophagus. All patients underwent upper endoscopies with biopsies and serum collections. H. pylori and degree of mucosal inflammation in gastric biopsies were assessed and serological assessment made for H. pylori and cagA status.

RESULTS

The overall prevalence of H. pylori colonization in the study population was 35% (95% confidence interval = 29.5-41.4%) which did not differ significantly among the groups. However, colonization by cagA+ H. pylori strains was significantly more prevalent among controls (11/25; 44%) and patients with gastroesophageal reflux disease (13/36; 36%) than in patients with short-segment (2/10; 20%) or long-segment Barrett's esophagus (0/18; 0%). Patients with Barrett's esophagus were less likely to be colonized by cagA+ H. pylori strains than reflux patients without Barrett's esophagus (odds ratio = 0.27, 95% confidence interval = 0.11-0.67, p = 0.004).

CONCLUSIONS

Colonization by cagA+ H. pylori strains may be protective against the formation of short- and long-segment Barrett's esophagus and its malignant complications.

Nucleotide sequence of the Rhodospirillum rubrum atp operon

The nucleotide sequence was determined of a 8775-base-pair region of DNA cloned from the photosynthetic non-sulphur bacterium Rhodospirillum rubrum. It contains a cluster of five genes encoding F1-ATPase subunits. The genes are arranged in the same order as F1 genes in the Escherichia coli unc operon. However, as in the related organism Rhodopseudomonas blastica, neither genes for components of F0, the membrane sector of ATP synthase, nor a homologue of the E. coli uncI gene are associated with this locus, as they are in E. coli.

Practice patterns for surveillance of Barrett's esophagus in the united states

BACKGROUND

Endoscopic surveillance of Barrett's esophagus is recommended to detect dysplasia or cancer at an early and potentially treatable stage. However, little is known about the clinical practice patterns for endoscopic surveillance in the United States.

METHODS

A questionnaire regarding surveillance intervals, techniques and management approaches for patients with Barrett's esophagus was mailed to 1000 randomly selected members of the Clinical Practice Section of the American Gastroenterological Association.

RESULTS

The response rate was 455 of 1000 (45%). Not all respondents answered all questions. Seventy-nine percent of respondents were in community practices, and 21% were in academic practices. Nearly all (96%) performed endoscopic surveillance, but it was practiced more commonly in the community (334 of 341 [98%]) than in the academic setting (83 of 93 [89%], p < 0.001). For patients without dysplasia, endoscopic surveillance was most commonly performed every 2 years (264 of 415 [64%]). Patients with low-grade dysplasia usually had surveillance endoscopy at 6-month intervals (215 of 413 [52%]), whereas those with high-grade dysplasia most commonly had endoscopy every 3 months (201 of 404 [50%]). These surveillance patterns did not differ between the academic and community groups. Random biopsies were performed by 93 of 403 (23%), 4-quadrant biopsies by 310 (77%). Most physicians (83%) used standard capacity forceps. Brush cytology was done uncommonly (69 of 414 [17%]). The most common indications for esophagectomy were high-grade dysplasia by 82% and cancer by 83%. Ablation therapy was performed for Barrett's esophagus without dysplasia by 3.5%, Barrett's with dysplasia by 20%, and cancer by 8%.

CONCLUSIONS

Surveillance for Barrett's esophagus is widely practiced in the United States but there is considerable variation in interval and technique. A clearer consensus on endoscopic surveillance is warranted to optimize care of patients with Barrett's esophagus.

Surveillance of patients with Barrett's esophagus for dysplasia and cancer with balloon cytology

BACKGROUND & AIMS

A less costly cancer surveillance method for Barrett's esophagus is desirable. The aim of this study was to compare nonendoscopic balloon cytology with biopsy and brush cytology for detecting dysplasia and carcinoma in patients with Barrett's esophagus.

METHODS

Patients in a surveillance program underwent balloon cytology before endoscopy with biopsy and brush cytology. Results of cytology were compared with those of histology.

RESULTS

Adequate columnar epithelium was obtained in 52 of 63 (83%) patients with balloon cytology and 59 of 61 (97%) with brush cytology. Balloon cytology obtained abnormal cells in 6 of 8 patients with adenocarcinoma, 2 of 2 patients with high-grade dysplasia, and 2 of 8 patients with low-grade dysplasia. Sensitivity of balloon cytology for high-grade dysplasia or carcinoma was 80% but only 25% for low-grade dysplasia. No patients without dysplasia or carcinoma had abnormal cells. Brush cytology was abnormal in all 11 patients with high-grade dysplasia or carcinoma but only 2 of 9 patients with low-grade dysplasia (sensitivity, 22%). Two of 39 patients without dysplasia had abnormal cells (specificity, 95%). Balloon cytology cost was sixfold less than endoscopy with biopsy.

CONCLUSIONS

Balloon cytology detected 80% of patients with high-grade dysplasia or carcinoma when sampling was adequate. Brush cytology data suggest that a more abrasive balloon may improve balloon cytology sensitivity. The potential cost savings of balloon cytology compared with endoscopic cancer surveillance in Barrett's esophagus support further studies of this technique.

Two genes encoding immune-regulatory molecules (LAG3 and IL7R) confer susceptibility to multiple sclerosis

Multiple sclerosis (MS) is a T-cell-mediated disease of the central nervous system, characterized by damage to myelin and axons, resulting in progressive neurological disability. Genes may influence susceptibility to MS, but results of association studies are inconsistent, aside from the identification of HLA class II haplotypes. Whole-genome linkage screens in MS have both confirmed the importance of the HLA region and uncovered non-HLA loci that may harbor susceptibility genes. In this two-stage analysis, we determined genotypes, in up to 672 MS patients and 672 controls, for 123 single-nucleotide polymorphisms (SNPs) in 66 genes. Genes were chosen based on their chromosomal positions or biological functions. In stage one, 22 genes contained at least one SNP for which the carriage rate for one allele differed significantly (P<0.08) between patients and controls. After additional genotyping in stage two, two genes--each containing at least three significantly (P<0.05) associated SNPs--conferred susceptibility to MS: LAG3 on chromosome 12p13, and IL7R on 5p13. LAG3 inhibits activated T cells, while IL7R is necessary for the maturation of T and B cells. These results imply that germline allelic variation in genes involved in immune homeostasis--and, by extension, derangement of immune homeostasis--influence the risk of MS.

Cytokeratin immunoreactivity patterns in the diagnosis of short-segment Barrett's esophagus

BACKGROUND & AIMS

The origin of intestinal metaplasia in short segments of columnar mucosa at the esophagogastric junction has clinical importance but can be difficult to determine at endoscopy. Cytokeratin (CK) 7 and 20 patterns are specific for long-segment Barrett's esophagus; however, their utility in short-segment Barrett's esophagus has not been assessed.

METHODS

Endoscopic biopsy specimens from patients with long-segment Barrett's esophagus (n = 49), suspected short-segment Barrett's esophagus (n = 43), and gastric intestinal metaplasia (n = 26) were immunostained for CK7 and CK20. Comprehensive clinical data were obtained, including age, gender, and hiatal hernia and Helicobacter pylori status.

RESULTS

A Barrett's CK7/20 pattern was present in 48 (98%) of 49 patients with long-segment Barrett's esophagus, 35 (82%) of 43 with suspected short-segment Barrett's esophagus, and 0 (0%) of 26 patients with gastric intestinal metaplasia. Patients with suspected short-segment Barrett's esophagus with a Barrett's CK7/20 pattern were clinically similar to those with long-segment Barrett's esophagus. In contrast, patients with suspected short-segment Barrett's esophagus with no Barrett's CK7/20 pattern were clinically similar to those with gastric intestinal metaplasia.

CONCLUSIONS

A Barrett's CK7/20 pattern identifies a subset of patients with suspected short-segment Barrett's esophagus who have a patient profile similar to that seen in long-segment Barrett's esophagus. A Barrett's CK7/20 pattern is an objective marker of Barrett's mucosa that in conjunction with appropriate clinical and endoscopic data can be used by clinicians to better define patients with short-segment Barrett's esophagus.

Natural history of eosinophilic esophagitis: a systematic review of epidemiology and disease course

Eosinophilic esophagitis is a chronic immune-mediated esophageal disorder. For its timely diagnosis, clinicians must recognize common symptoms, and understand differences in symptoms across patient groups. The aim of this study is to systematically review the epidemiology and natural history of eosinophilic esophagitis. The MEDLINE, Embase, and Cochrane databases were searched from 1974 to February 2017 for studies describing the epidemiology and natural history of eosinophilic esophagitis. Congress abstracts from 2014 to 2016 were also searched. Search results were screened against predetermined inclusion/exclusion criteria by two independent reviewers, and data extraction was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 1376 articles identified, 47 met the inclusion criteria: 20 on epidemiology and 27 on natural history. Incidence and prevalence of eosinophilic esophagitis varied widely across North America and Europe, and increased over time. Incidence increased 131-fold in the Netherlands (1996-2010), 20-fold in Denmark (1997-2006), and 5.1-fold in Calgary, Canada (2004-2008). The most commonly reported symptoms were emesis and abdominal pain in children, and dysphagia and food impaction in adults. Age at diagnosis was 5.9-12.0 years in children, and approximately 30 years in adults. Time between symptom onset and diagnosis was 1.2-3.5 years in children and 3.0-8.0 years in adults. Diagnostic delay was associated with an increased risk of endoscopic features of fibrostenosis. Symptoms of eosinophilic esophagitis differed significantly by age and race. In conclusion, there is an increasing incidence and prevalence of eosinophilic esophagitis. The considerable delay between symptom onset and diagnosis suggests that clinicians do not readily recognize the disease, which may have important clinical ramifications.

Optical coherence tomography of the esophagus and proximal stomach in health and disease

OBJECTIVE

Surveillance of Barrett's esophagus is problematic, as high-grade dysplasia cannot be recognized endoscopically. Endoscopic ultrasound lacks the resolution to detect high-grade dysplasia. Optical coherence tomography (OCT) employs infrared light reflectance to provide in vivo tissue images at resolution far superior to endoscopic ultrasound, nearly at the level of histology. We have developed a catheter-based system well suited for study of the GI tract. The purpose of this study was to test this catheter-based OCT system and characterize the OCT appearance of normal squamous mucosa, gastric cardia, Barrett's esophagus, and carcinoma.

METHODS

The OCT catheter was passed through the operating channel of the endoscope and placed in contact with the esophageal mucosa. Image acquisition occurred in approximately 3 s. OCT images were correlated with biopsy and/or resection specimens.

RESULTS

OCT was used to construct 477 images of the esophagus and stomach in 69 patients. There were unique, distinct OCT appearances of squamous mucosa, gastric cardia, Barrett's esophagus, and carcinoma. Further, these OCT images were accurately recognized by observers unaware of their site of origin.

CONCLUSIONS

OCT provides a highly detailed view of the GI wall, with clear delineation of a multiple layered structure. It is able to distinguish squamous mucosa, gastric cardia, Barrett's esophagus, and cancer. This technique holds great potential as an adjunct to the surveillance of patients with Barrett's esophagus, ulcerative pancolitis, and other premalignant conditions.

Alginate therapy is effective treatment for GERD symptoms: a systematic review and meta-analysis

In patients with gastroesophageal reflux disease (GERD) and erosive esophagitis, treatment with proton pump inhibitors (PPIs) is highly effective. However, in some patients, especially those with nonerosive reflux disease or atypical GERD symptoms, acid-suppressive therapy with PPIs is not as successful. Alginates are medications that work through an alternative mechanism by displacing the postprandial gastric acid pocket. This study performed a systematic review and meta-analysis to examine the benefit of alginate-containing compounds in the treatment of patients with symptoms of GERD. PubMed/MEDLINE, Embase, and the Cochrane library electronic databases were searched through October 2015 for randomized controlled trials comparing alginate-containing compounds to placebo, antacids, histamine-2 receptor antagonists (H2RAs), or PPIs for the treatment of GERD symptoms. Additional studies were identified through a bibliography review. Non-English studies and those with pediatric patients were excluded. Meta-analyses were performed using random-effect models to calculate odds ratios (OR). Heterogeneity between studies was estimated using the I2 statistic. Analyses were stratified by type of comparator. The search strategy yielded 665 studies and 15 (2.3%) met inclusion criteria. Fourteen were included in the meta-analysis (N = 2095 subjects). Alginate-based therapies increased the odds of resolution of GERD symptoms when compared to placebo or antacids (OR: 4.42; 95% CI 2.45-7.97) with a moderate degree of heterogeneity between studies (I2 = 71%, P = .001). Compared to PPIs or H2RAs, alginates appear less effective but the pooled estimate was not statistically significant (OR: 0.58; 95% CI 0.27-1.22). Alginates are more effective than placebo or antacids for treating GERD symptoms.

Endosonography in the evaluation of patients with Barrett's esophagus and high-grade dysplasia

Endosonography, which provides high-resolution images of the esophageal wall, could potentially detect carcinoma not visible endoscopically in patients with Barrett's esophagus and high-grade dysplasia. We studied the ability of endosonography to detect early esophageal carcinoma in 9 patients with Barrett's esophagus and high-grade dysplasia who were candidates for esophagectomy. Pre-operative endoscopy and biopsy revealed high-grade dysplasia without evidence of carcinoma in all patients. Pre-operative endosonographic evaluations were compared to the pathologic diagnoses of resected specimens. Post-operatively, 3 of the 9 patients were found to have intra-mucosal carcinoma. Endosonography identified a tumor in only 1 of these 3 patients and over-staged it as invasive carcinoma (T2, N1). In 2 of the 6 patients without intra-mucosal carcinoma, endosonography predicted invasive carcinoma (T2, N0). Endoscopy revealed mucosal nodularity in each of the 3 over-staged patients. We conclude that recommendation of the routine use of endosonography to determine the need for surgery in patients with Barrett's esophagus and high-grade dysplasia would be premature, because the current generation of echo-endoscopes does not reliably differentiate between benign and malignant wall thickening.

Retinal on-bipolar cells contain a nitric oxide-sensitive guanylate cyclase

Retinal on-bipolar cells possess specialized glutamate receptors which are coupled via a G-protein to the control of a cyclic GMP (cGMP) cascade. Whole-cell voltage clamp recordings were obtained from light-responsive on-bipolar cells in retinal slices of the dogfish. Inclusion of nitroprusside in the patch-pipette solution induced effects in on-bipolar cells which were consistent with a rise in intracellular cGMP and thus stimulation of guanylate cyclase (GC) activity. Conversely, the soluble GC inhibitors, methylene blue and ferricyanide, induced effects consistent with a fall in intracellular cGMP. Activators of particulate GC had no effect. We conclude that cGMP synthesis in on-bipolar cells is catalysed by a NO-sensitive cyclase.