The application of microridge analysis in the diagnosis of gastro-oesophageal reflux disease

Microridges are apical epithelial projections formed of F-actin networks that organize the glycan layer

Apical projections are integral functional units of epithelial cells. Microvilli and stereocilia are cylindrical apical projections that are formed of bundled actin. Microridges on the other hand, extend laterally, forming labyrinthine patterns on surfaces of various kinds of squamous epithelial cells. So far, the structural organization and functions of microridges have remained elusive. We have analyzed microridges on zebrafish epidermal cells using confocal and electron microscopy methods including electron tomography, to show that microridges are formed of F-actin networks and require the function of the Arp2/3 complex for their maintenance. During development, microridges begin as F-actin punctae showing signatures of branching and requiring an active Arp2/3 complex. Using inhibitors of actin polymerization and the Arp2/3 complex, we show that microridges organize the surface glycan layer. Our analyses have unraveled the F-actin organization supporting the most abundant and evolutionarily conserved apical projection, which functions in glycan organization.

Updated guidelines for the diagnosis and treatment of gastroesophageal reflux disease

Guidelines for the diagnosis and treatment of gastroesophageal reflux disease (GERD) were published in 1995 and updated in 1999. These and other guidelines undergo periodic review. Advances continue to be made in the area of GERD, leading us to review and revise previous guideline statements. GERD is defined as symptoms or mucosal damage produced by the abnormal reflux of gastric contents into the esophagus. These guidelines were developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee, and approved by the Board of Trustees. Diagnostic guidelines address empiric therapy and the use of endoscopy, ambulatory reflux monitoring, and esophageal manometry in GERD. Treatment guidelines address the role of lifestyle changes, patient directed (OTC) therapy, acid suppression, promotility therapy, maintenance therapy, antireflux surgery, and endoscopic therapy in GERD. Finally, there is a discussion of the rare patient with refractory GERD and a list of areas in need of additional study.