Confocal laser endomicroscopy in diagnosing indeterminate biliary strictures and pancreatic lesions a prospective pilot study.

INTRODUCTION: An accurate histopathological diagnosis of indeterminate biliary strictures and pancreatic lesions is challenging because of insufficient quali-ty of tissue specimen taken during ERCP (brush cytology), cholangioscopy (biopsies) or endosonography (EUS, FNAB). Confocal laser endomicroscopy (CLE) allows virtual histopathological diagnosis with the potential to either replace or increase the diagnostic yield of standard histopathological diagnosis in patients presenting with biliary strictures and pancreatic lesions. The aims of our prospective pilot study were to: 1. Assess the diagnostic yield of standard histopathology compared to CLE in patients referred for cholangioscopy or for EUS of the pancreas; 2. Evaluate the cost of CLE in these indications. METHODS: CLE was performed (during cholangioscopy or EUS), followed by standard tissue sampling. CLE-based diagnosis was compared with standard histopathology/cytology. CLE probe was introduced through the working channel of the cholangioscope or through the FNAB needle. RESULTS: A total of 23 patients were enrolled (12 women, mean age 61 years); 13 patients underwent cholangioscopy and 10 patients underwent EUS. Cholangioscopy: CLE diagnosed correctly all 4 malignant strictures (histology 2 of them only as 2 patients had insufficient quality of the tissue specimen). Agreement between standard histopathology and CLE was achieved in 85 %. EUS: All 3 cases of pancreatic cancer were correctly diagnosed by both CLE and FNAB. All remaining (premalignant and benign) lesions were also correctly diagnosed by both methods. The cost of CLE examination is higher compared to FNAB but comparable with tissue sampling during digital cholangioscopy. CONCLUSION: CLE demonstrated sufficient diagnostic accuracy in patients with indeterminate biliary strictures or pancreatic lesions and, therefore, might improve diagnostic accuracy or even replace standard histopathology in these indications.

Stable room-temperature ferromagnetic phase at the FeRh(100) surface.

Interfaces and low dimensionality are sources of strong modifications of electronic, structural, and magnetic properties of materials. FeRh alloys are an excellent example because of the first-order phase transition taking place at ~400 K from an antiferromagnetic phase at room temperature to a high temperature ferromagnetic one. It is accompanied by a resistance change and volume expansion of about 1%. We have investigated the electronic and magnetic properties of FeRh(100) epitaxially grown on MgO by combining spectroscopies characterized by different probing depths, namely X-ray magnetic circular dichroism and photoelectron spectroscopy. We find that the symmetry breaking induced at the Rh-terminated surface stabilizes a surface ferromagnetic layer involving five planes of Fe and Rh atoms in the nominally antiferromagnetic phase at room temperature. First-principles calculations provide a microscopic description of the structural relaxation and the electron spin-density distribution that support the experimental findings.