63. What is known about the intrinsic properties of resistance of the esophageal mucosa?
R.C. Orlando (New Orleans)

64. What is the role of epidermal growth factor in saliva in protecting the esophageal mucosa?
PJ. Kahrilas (Chicago)

65. What part do the mucous cells of submucosal mucous glands play in the esophageal pre-epithelial barrier?
J. Sarosiek, Z. Namiot, R. Piasclk, D.P. Hetzel, RM. Rourk, M.C. Edmunds, T.M. Daniel, R.W. McCallum (Charlottesville)

66. What is the role of the proliferative capability of the basal layer?
R.H. Riddell (Hamilton)

67. What part does blood bicarbonate play in the formation of the epithelial barrier?
NA. Tobey (New Orleans)

68. Is it possible to specify the factors of tissue repair during esophagitis?
C.W. Howden (Columbia)

69. What factors are evidenced by study of the mucins of the esophageal glands during esophagitis?
S.E.A. Attwood (Dublin)