Many of the present definitions of @entity355 are based on the dogma that 2 to 3 cm of @entity299 normally line the distal esophagus and proximal stomach. Recent autopsy data refute this dogma. @entity299 has been shown to be frequently absent from the squamocolumnar junctional zone. When present, its extent is less than 0.5 cm in almost all @entity1 and most adults. Cardiac mucosal length increases with age. @entity1 who have @entity299 are significantly more likely to have abnormal acid exposure in the esophagus as measured by 24-hour pH studies. The length of the @entity299 correlates significantly with the amount of reflux: the greater the length of the @entity299 , the more reflux there is. These new data provide insights into the pathology of @entity354 . Normalcy is defined as an esophagus lined by squamous epithelium and a stomach lined by gastric mucosa. @entity354 is defined by the presence of @entity299 in a junctional biopsy. The severity of @entity354 is quantifiable by the length of @entity299 present. Mutational @entity354 ( @entity355 ) is defined by the occurrence of intestinal metaplasia in @entity299 and is quantitated by the amount of intestinal metaplasia present. @entity5 is defined as the occurrence of low grade @entity1141 , high grade @entity1141 , and @entity420 in @entity355 . An attempt is made here to develop a rational grading system for reflux based on these highly objective histologic criteria.

Pathological basis of XXXX .

@entity1 :: ('9606', 'Species') :: ['children', 'Patients'] @entity355 :: ('MESH:D001471', 'Disease') :: ["Barrett's esophagus"] @entity5 :: ('MESH:D009369', 'Disease') :: ['Neoplastic reflux disease'] @entity354 :: ('MESH:D005764', 'Disease') :: ['gastroesophageal reflux', 'Reflux disease', 'reflux disease'] @entity299 :: ('MESH:D006331', 'Disease') :: ['cardiac mucosa', 'Cardiac mucosa'] @entity420 :: ('MESH:D000230', 'Disease') :: ['adenocarcinoma'] @entity1141 :: ('MESH:C535662', 'Disease') :: ['dysplasia']
@entity354 :: (MESH:D005764,Disease) :: ['gastroesophageal reflux disease']
