Short segment Barrett's esophagus: relationship of age with extent of intestinal metaplasia.

OBJECTIVE: Short segment Barrett's esophagus (SSBE) is defined by the presence of intestinal metaplasia in biopsies obtained from mucosa with an appearance suggestive of Barrett's that extends <3 cm into the esophagus. It has been suggested that this lesion may represent a stage in an ongoing process of Barrett's esophagus progression. If so, then the prevalence of SSBE would be expected to decrease with advancing age, and patients followed over time should exhibit an increase in the extent of columnar-lined esophagus. The aim of this study was to determine whether SSBE length progresses or regresses over time by following a prospective cohort and by assessing the relationship between age and the length, as well as prevalence of SSBE. METHODS: The study included consecutive patients who were evaluated prospectively by an upper endoscopy and were found to have SSBE between October, 1983, and December, 1999, at the Southern Arizona VA Health Care System. All patients underwent a systematic biopsy protocol, and a designated pathologist who reviewed all specimens confirmed the diagnosis of Barrett's esophagus. Patients were subsequently interviewed for demographic information. In those patients who were enrolled into our surveillance program, SSBE length was remeasured and intestinal metaplasia reconfirmed on follow-up endoscopies. RESULTS: Of 343 patients with endoscopically proven Barrett's esophagus, 116 (33.8%) were found to have SSBE. Almost all were male (97.4%) and white (85.3%), with a mean age of 60.1+/-1.0 yr. The prevalence of SSBE increased with age and reached a plateau during the seventh decade of life. One-way analysis of variance showed that there was no significant difference in the mean length of SSBE among the various age groups (p = 0.84). This trend was maintained when only the white group was assessed. Follow-up endoscopies were performed in 57 patients, revealing a mean interval of 64 months to the latest endoscopy, with no significant difference in SSBE length between the first and last endoscopy (p = 0.16). CONCLUSIONS: The prevalence of SSBE increases with age until the seventh decade of life. Finding that SSBE length does not change across the various age groups and during a 64-month mean follow-up, suggests that SSBE does not progress over time.

Preferential repair by squamous epithelium of thermal induced injury to the proximal stomach in patients undergoing ablation of Barrett's esophagus.

BACKGROUND: The presence of extensions of squamous epithelium into the proximal stomach in patients undergoing routine upper endoscopy has recently been described. The factors that may favor development of squamous epithelium within the proximal stomach remain unknown. METHODS: Patients with Barrett's esophagus who agreed to undergo ablation of Barrett's epithelium by using multipolar electrocoagulation were included. Patients were treated with a high dose of a proton pump inhibitor. The columnar-appearing mucosa was systematically treated. Occasionally, thermal injury was inadvertently induced in the proximal stomach. On endoscopy performed 4 to 6 weeks after treatment, the presence of squamous epithelium extending into the proximal stomach was documented. The use of Lugol's stain assisted in confirming the squamous nature of the abnormal tissue, which was confirmed histologically by cytokeratin immunohistochemistry. RESULTS: The 12 patients included in the study had a mean length of Barrett's epithelium of 3.8 +/- 0.7 cm. Patients were treated with omeprazole, mean dose 66 +/- 6.0 mg, and had a mean percent total time that the pH was less than 4 of 1.9 +/- 0.8. The mean length and width of gastric squamous extensions were 1.7 +/- 0.2 cm and 0.8 +/- 0.1 cm, respectively. None of the squamous extensions into the stomach were documented before mucosal ablation. The extensions stained positively for cytokeratin 13 and negatively for cytokeratin 8, thereby confirming their squamous nature. CONCLUSIONS: Thermal injury to the proximal stomach in patients undergoing ablation of Barrett's epithelium and profound acid suppression results in repair by squamous epithelium. Recognition of this lesion is essential because it may lead to confusion as to the location of the esophagogastric junction in subsequent endoscopic evaluations.

Occurrence of Anopheles hermsi (Diptera: Culicidae) in Arizona and Colorado.

Historically, malaria was a significant cause of morbidity and mortality throughout the western United States, and Anopheles freeborni Aitken was thought to be the vector west of the Continental Divide. In 1989, Anopheles hermsi Barr & Guptavanij was described and subsequently found to be an effective laboratory vector of Plasmodium. The adults of these two species are morphologically indistinguishable, and therefore polymerase chain reaction was used to analyze the DNA from 48 mosquitoes collected in Arizona and Colorado (identified morphologically as An. freeborni). All specimens were identified as An. hermsi. This was the first report of An. hermsi in Arizona and Colorado and indicated that this Anopheles species historically may have been a malaria vector in these two western states.

Omeprazole 40 mg once a day is equally effective as lansoprazole 30 mg twice a day in symptom control of patients with gastro-oesophageal reflux disease (GERD) who are resistant to conventional-dose lansoprazole therapy-a prospective, randomized, multi-centre study.

BACKGROUND: Comparative studies of omeprazole and lansoprazole are scarce and even scarcer are comparisons of higher doses. Most of the comparative studies have assessed the effect of the two proton pump inhibitors (PPIs) on gastric acid secretion or gastric pH. Few studies have compared clinical end-points such as oesophageal healing and symptom control. AIM: To determine the clinical efficacy of omeprazole 40 mg daily as compared to lansoprazole 30 mg twice a day in symptom control of patients with severe symptomatic GERD. METHODS: Ninety-six patients who failed a standard dose of lansoprazole (30 mg once daily), were enrolled in a prospective fashion from three VA medical centres and were randomized to receive 6 weeks of either omeprazole 40 mg daily or lansoprazole 30 mg twice daily. Patients reported daily on symptom severity and frequency, antacid consumption and side-effects. RESULTS: Forty-six patients received omeprazole and 44 lansoprazole. Although not statistically significant, there was a consistent trend of better symptom control in the omeprazole group for daytime and night-time heartburn and acid regurgitation. There was no statistical difference between the two groups in mean antacid consumption overall and at the end of each of the 6 weeks of the study. In addition, there was no significant difference in the overall frequency of side-effects between the two groups nor for each individual side-effect. CONCLUSION: Omeprazole 40 mg once daily is equally effective and tolerated as lansoprazole 30 mg twice daily in symptom control of patients with GERD.

Failure of oesophageal acid control in candidates for Barrett's oesophagus reversal on a very high dose of proton pump inhibitor.

BACKGROUND: Normalization of oesophageal acid exposure using high dose proton pump inhibitors in patients who are candidates for ablation therapy has been suggested to be essential for successful Barrett's reversal. However, the success rate for achieving pH normalization has not been determined. METHODS: Patients with Barrett's oesophagus (2-6 cm in length) who were found to be eligible for ablation therapy using multipolar electrocoagulation were included in this prospective study. Patients underwent an upper endoscopy to determine Barrett's length and other anatomic characteristics. Biopsies were obtained to rule out dysplasia. Subsequently, patients were treated with omeprazole 40 mg b.d. Twenty-four hour oesophageal pH monitoring was performed after a mean period of 8.4 +/- 0.6 days of therapy. RESULTS: Twenty-five patients were enrolled into the study. The pH test was abnormal in four (16%) of the study subjects. An additional two (8%) patients had abnormal supine percentage time with pH less than 4. There was no significant difference in oesophageal acid control between patients with long vs. short segment Barrett's oesophagus. Elderly (> 60 years) patients tended to have less acid control than younger (