52. Does measurement of esophageal mucosal potential difference allow early recognition of injury?
R.C. Orlando (New Orleans)

53. Is it necessary to perform a biopsy in erosive esophagitis?
C.E. Pope II (Seattle)

54. What are the histologic changes in reflux esophagitis?
P. Bechi, A. Amorosi, P. Romagnoli (Florence)

55. Does histochemistry offer better experimental definition of the effects of reflux on the mucosa than light microscopy alone?
D. Hopwood (Dundee)

56. Does electron microscopy of the esophageal mucosa add useful information?
C.E. Pope II (Seattle)

57. What is the correlation between severity of mucosal damage and motor disorders of the esophagus?
R. Bumm (Munich)

58. May loss of sphincter function occur without mucosal injury?
C. Iascone, A. Moraldi, D. Castiglia, M. Barreca (Rome)

59. What is the relationship between esophageal exposure to gastric acidity and the severity of mucosal injury?
G. Zaninotto, M. Costantini, M. Anselmino, E. Ancona (Padua)

60. Are the bile acids themselves toxic to the esophageal mucosa or mainly in the presence of acid?
J. W. Harmon, B.L. Bass, S. Batzri (Washington)

61. How can the sensitivity of the esophageal mucosa to acid be assessed quantitatively?
RM. Bremner, T.R. DeMeester (Los Angeles)

62. How is esophageal sensitivity impaired with age?
D.O. Castell (Philadelphia)