Zoning of mucosal phenotype, dysplasia, and telomerase activity measured by telomerase repeat assay protocol in Barrett's esophagus

Glandular dysplasia in Barrett's esophagus may regress spontaneously but can also progress to cancer. The human telomerase RNA template and the human telomerase reverse transcriptase enzyme which do not, of themselves, correlate strongly with telomerase activity, are too often overexpressed in Barrett's dysplasia to predict individual cancer risk. This study relates telomerase activity, mucosal phenotype, and dysplasia in Barrett's esophagus. Biopsies (n = 256) from squamous esophagus, columnar-lined esophagus every 2 cm, esophago-gastric junction, gastric body, and antrum from 32 patients with long-segment Barrett's esophagus were evaluated by telomerase repeat assay protocol (TRAP). Three biopsies for histology (n = 794) were simultaneously taken at each anatomical level. These and all prior and subsequent biopsies (n = 1917) were reviewed for mucosal phenotypes and dysplasia severity. Intestinal-type Barrett's mucosa was present at all levels in Barrett's esophagus. At least one Barrett's biopsy was TRAP(+) in 22 of 32 patients. TRAP positivity of intestinal-type Barrett's mucosa increased distally, possibly as a consequence of mucosal exposure to acid or bile reflux. Native gastric mucosa was rarely TRAP(+) (1/31 corpus, 2/32 antrum), whereas native squamous mucosa usually was TRAP(+) (31/32). Dysplasia almost always involved intestinal-type Barrett's mucosa (85/87; P</p

Ecological Specialization of Two Photobiont- Specific Maritime Cyanolichen Species of the Genus Lichina

22 páginas, 4 tablas, 4 figurasAll fungi in the class Lichinomycetes are lichen-forming and exclusively associate with cyanobacteria. Two closely related maritime species of the genus Lichina (L. confinis and L. pygmaea) show similar distribution ranges in the Northeast Atlantic, commonly co-occurring at the same rocky shores but occupying different littoral zones. By means of 16S rRNA and phycocyanin operon markers we studied a) the phylogenetic relationships of cyanobionts associated with these species, b) the match of divergence times between both symbionts, and c) whether Lichina species differ in photobiont association and in how geography and ecology affect selectivity. The cyanobionts studied are closely related to both marine and freshwater strains of the genus Rivularia.We found evidence of a high specificity to particular cyanobiont lineages in both species: Lichina pygmaea and L. confinis incorporate specific lineages of Rivularia that do not overlap at the haplotype nor the OTU levels. Dating divergences of the fungal and cyanobacterial partners revealed an asynchronous origin of both lineages. Within each fungal species, selectivity varied across the studied area, influenced by environmental conditions (both atmospheric and marine), although patterns were highly correlated between both lichen taxa. Ecological speciation due to the differential association of photobionts to each littoral zone is suspected to have occurred in marine Lichina.Both ROA (BES-2013-066105) and SPO (CTM2012-38222-C02-02) were supported in the form of salary by grants from the Spanish Ministry of Economy and Competitiveness.Peer reviewe

Perception and synthesis of sound-generating materials

The auditory perception of materials is a popular topic in the study of non-vocal sound-source perception. In this chapter, we review the empirical evidence on the mechanical and acoustical correlates of the perception of impacted stiff materials, and of the state of matter of sound-generating substances (solids, liquids, gases). As a whole, these studies suggest that recognition abilities are only highly accurate when differentiating between widely diverse materials (e.g. liquids vs. solids or plastics vs. metals) and that limitations in the auditory system, along with the possible internalization of biased statistics in the acoustical environment (e.g. clinking-glass sounds tend to be produced by small objects), might account for the less-than-perfect ability to differentiate between mechanically similar materials. This review is complemented by a summary of studies concerning the perception of deformable materials (fabrics and liquids) and the perceptual and motor-behaviour effects of auditory material-related information in audio-haptic contexts. The results of perceptual studies are the starting point for the development of interactive sound synthesis techniques for rendering the main auditory correlates of material properties, starting from physical models of the involved mechanical interactions. We review the recent literature dealing with contact sound synthesis in such fields as sonic interaction design and virtual reality. Special emphasis is given to softness/hardness correlates in impact sounds, associated with solid object resonances excited through impulsive contact. Synthesis methods for less studied sound-generating systems such as deformable objects (e.g. fabrics and liquids) and aggregate materials are also described

Perception and synthesis of sound-generating materials

The auditory perception of materials is a popular topic in the study of non-vocal sound-source perception. In this chapter, we review the empirical evidence on the mechanical and acoustical correlates of the perception of impacted stiff materials, and of the state of matter of sound-generating substances (solids, liquids, gases). As a whole, these studies suggest that recognition abilities are only highly accurate when differentiating between widely diverse materials (e.g. liquids vs. solids or plastics vs. metals) and that limitations in the auditory system, along with the possible internalization of biased statistics in the acoustical environment (e.g. clinking-glass sounds tend to be produced by small objects), might account for the less-than-perfect ability to differentiate between mechanically similar materials. This review is complemented by a summary of studies concerning the perception of deformable materials (fabrics and liquids) and the perceptual and motor-behaviour effects of auditory material-related information in audio-haptic contexts. The results of perceptual studies are the starting point for the development of interactive sound synthesis techniques for rendering the main auditory correlates of material properties, starting from physical models of the involved mechanical interactions. We review the recent literature dealing with contact sound synthesis in such fields as sonic interaction design and virtual reality. Special emphasis is given to softness/hardness correlates in impact sounds, associated with solid object resonances excited through impulsive contact. Synthesis methods for less studied sound-generating systems such as deformable objects (e.g. fabrics and liquids) and aggregate materials are also described