Increasing incidence of Barrett's oesophagus: a population-based study

Oesophageal adenocarcinoma, a highly fatal cancer, has risen in incidence in Western societies, but it is unclear whether this is due to increasing incidence of its pre-cursor condition, Barrett's oesophagus (BO) or whether the proportion of BO patients undergoing malignant progression has increased in the face of unchanged BO incidence. Data from population-based studies of BO incidence is limited, with equivocal results to date difficult to distinguish from changes in endoscopic practices. The aim of this study was to assess population trends in Barrett's oesophagus (BO) diagnoses in relation to endoscopy and biopsy rates over a 13 year period. The Northern Ireland Barrett's oesophagus Register (NIBR) is a population-based register of all 9,329 adults diagnosed with columnar epithelium of the oesophagus in Northern Ireland between 1993 and 2005, of whom 58.3% were male. European age-standardised annual BO incidence rates were calculated per 100,000 of the population, per 100 endoscopies and per 100 endoscopies including an oesophageal biopsy. Average annual BO incidence rates rose by 159% during the study period, increasing from 23.9/100,000 during 1993-1997 to 62.0/100,000 during 2002-2005. This elevation far exceeded corresponding increases in rates of endoscopies and oesophageal biopsies being conducted. BO incidence increased most markedly in individuals aged <60 years, and most notably amongst males aged <40 years. This study points towards a true increase in the incidence of BO which would appear to be most marked in young males. These findings have significant implications for future rates of oesophageal adenocarcinoma and surveillance programmes. © 2011 Springer Science+Business Media B.V.

Polarization Closure in PbZr(0.42)Ti(0.58)O3 Nanodots

Domain states in PbZr(0.42)Ti(0.58)O3 single-crystal ferroelectric nanodots, formed on cooling through the Curie temperature, were imaged by transmission electron microscopy. In the majority of cases, 90o stripe domains were found to form into four distinct “bundles” or quadrants. Detailed analysis of the dipole orientations in the system was undertaken, using both dark-field imaging and an assumption that charged domain walls were energetically unfavorable in comparison to uncharged walls. On this basis, we conclude that the dipoles in these nanodots are arranged such that the resultant polarizations, associated with the four quadrant domain bundles, form into a closed loop. This “polarization closure” pattern is reminiscent of the flux-closure already commonly observed in soft ferromagnetic microdots but to date unseen in analogous ferroelectric dots.