Cleavage of E-Cadherin Contributes to Defective Barrier Function in Neosquamous Epithelium.

BACKGROUND: After ablation of Barrett's esophagus (BE), the esophagus heals with neosquamous epithelium (NSE). Despite normal endoscopic appearance, NSE exhibits defective barrier function with similarities to defects noted in the distal esophageal epithelium in patients with gastroesophageal reflux disease (GERD). AIM: To determine whether patients with NSE, unlike patients with healthy esophageal epithelium, have C-terminal fragments (CTFs) of e-cad detectable on tissue biopsy. Secondly, to determine whether patients with NSE have elevated levels of N-terminal fragments (NTFs) of e-cad in the serum. METHODS: Fifteen patients with ablated long-segment BE, who had healing with formation of NSE, were enrolled in this pilot study. Western blots for CTFs and NTFs were performed on biopsies of NSE. Venous blood was obtained to assess levels of NTFs. Endoscopic distal esophageal biopsies from patients without esophageal disease served as tissue controls. Control blood samples were obtained from healthy subjects. RESULTS: Blots of NSE were successful in 14/15 patients, and all 14 (100 %) had a 35-kD CTF of e-cad, while CTFs were absent in healthy control tissues. Despite CTFs in NSE, serum NTFs of e-cad in NSE were similar to controls, p > 0.05. However, unlike healthy controls, blots of NSE also showed NTFs with molecular weights of 70-90 kD. CONCLUSIONS: Cleavage of e-cad, as evidenced by the presence of CTFs and NTFs on biopsy, contributes to defective barrier function in NSE. However, unlike findings reported in GERD patients, serum NTFs are not elevated in NSE patients. This difference may reflect poor absorption with tissue entrapment of NTFs in previously ablated areas with poorly perfused NSE.

Comparing racial and ethnic populations based on Healthy People 2010 objectives.

Objective - The Healthy People 2010 initiative (HP2010) specified objectives for improving the health of the nation, established baseline values, and set specific targets to be achieved by 2010. HP2010 objectives are based on two overarching goals: First, to increase years and quality of life, and second, to eliminate disparities among subgroups of the population. In this report racial and ethnic populations are compared based on progress toward targets, the size of disparities, and changes in disparity for specific sets of objectives. Methods - Progress is measured in terms of movement toward or away from the target between the HP2010 baseline and the most recent data point. Disparities are measured as the percent difference between the rate for the racial and ethnic population with the best or most favorable rate and the rates for the other racial and ethnic populations. Changes in disparity are measured in terms of the percentage point change in the percent difference from the best group rate between the baseline and the most recent data point. Some comparisons can be made based on objectives with data for five populations (American Indian or Alaska Native, Asian, Hispanic or Latino, non-Hispanic black, and non-Hispanic white). Additional comparisons can be made for objectives with data for the three larger populations (Hispanic or Latino, non-Hispanic black, and non-Hispanic white). Results - Differences between populations in progress toward the targets for HP2010 objectives are observed; however, the majority of objectives was moving toward or had reached their targets for each population. Greater differences between racial and ethnic populations are evident in the size of disparities. Disparities for the American Indian or Alaska Native, the Hispanic or Latino and non-Hispanic black populations are greater than those for the Asian and non-Hispanic white populations. Between the baseline and the most recent data point, the number of objectives with increasing disparities was similar to the number of objectives with decreasing disparities and there was no change in disparity for most objectives. In order to achieve the two goals of HP2010, rates must improve and relative differences between populations must be reduced.