241. What factors are involved in effective endoscopic monitoring?
M. Schapiro (Los Angeles)

242. Is alkaline reflux more common in patients with dysplasia?
T.C. Smyrk (Omaha)

243. Where should biopsies be made in a zone of Barrett's esophagus?
A.H. Holscher (Munich)

244. Can the use of vital staining limit the number of routine biopsies for detecting dysplasia?
E. Brossard, C. Fontolliet, J.-B. Ollyo, P. Monnier (Lausanne)

245. Which histologic methods are best for demonstrating architectural and cytologic details of dysplasia in Barrett's esophagus?
K.R. Geisinger (Winston-Salem)

246. What is the definition of dysplasia, as it applies to Barrett's mucosa?
R.H. Riddell (Hamilton)

247. Is there a great variation in histologic grading of dysplastic mucosa among highly-experienced gastrointestinal pathologists?
K. Geboes (Leuven)

248. Are there any histologic features of high-grade dysplasia which make this diagnosis equivocal?
M.D. Diebold (Reims)

249. Are there histological criteria that are capable of distinguishing high-grade dysplasia with biologic potential of invasion from high-grade dysplasia without invasive potential?
R.H. Riddell (Hamilton)

250. Is intense medical therapy necessary before taking biopsies for dysplasia?
M.F. Dixon (Leeds)

251. What is the definition of "indefinite for dysplasia" in Barrett's mucosa?
W.V. Bogomoletz (Reims)

252. Can medical treatment lead to regression of dysplasia?
R.E. Sampliner (Tucson)

253. Is it possible to demonstrate the impact of antireflux surgery on dysplastic changes of the mucosa?
T.C. Smyrk (Omaha)

254. Can dysplasia in Barrett's esophagus regress?
K.J. Lewin (Los Angeles)

255. Can low-grade dysplasia progress to adenocarcinoma?
K. Geboes, N. Ectors (Leuven)

256. Must the opinion of two pathologists be obtained before deciding on the treatment of high-grade dysplasia?
K.J. Lewin (Los Angeles)

257. Is high-grade dysplasia an indication for esophagectomy?
H. Obertop (Amsterdam)

258. How often are invasive carcinomas discovered in specimens resected for high-grade dysplasia alone?
V.F. Trastek (Rochester, Minnesota)

259. Is dysplasia an essential intermediate stage before adenocarcinoma?
R.H. Riddell (Hamilton)

260. Is the surface extent of the dysplastic zone related to the development of adenocarcinoma?
T.C. Smyrk (Omaha)

261. How can one define a subpopulation most at risk of degeneration?
R. W. McCallum (Charlottesville)