Developing an instrument to assess the endoscopic severity of ulcerative colitis : The Ulcerative Colitis Endoscopic Index of Severity (UCEIS)

Full list of Investigators is given at the end of the article.Background: Variability in endoscopic assessment necessitates rigorous investigation of descriptors for scoring severity of ulcerative colitis (UC). Objective: To evaluate variation in the overall endoscopic assessment of severity, the intra- and interindividual variation of descriptive terms and to create an Ulcerative Colitis Endoscopic Index of Severity which could be validated. Design: A two-phase study used a library of 670 video sigmoidoscopies from patients with Mayo Clinic scores 0-11, supplemented by 10 videos from five people without UC and five hospitalised patients with acute severe UC. In phase 1, each of 10 investigators viewed 16/24 videos to assess agreement on the Baron score with a central reader and agreed definitions of 10 endoscopic descriptors. In phase 2, each of 30 different investigators rated 25/60 different videos for the descriptors and assessed overall severity on a 0-100 visual analogue scale. κ Statistics tested inter- and intraobserver variability for each descriptor. A general linear mixed regression model based on logit link and β distribution of variance was used to predict overall endoscopic severity from descriptors. Results: There was 76% agreement for 'severe', but 27% agreement for 'normal' appearances between phase I investigators and the central reader. In phase 2, weighted κ values ranged from 0.34 to 0.65 and 0.30 to 0.45 within and between observers for the 10 descriptors. The final model incorporated vascular pattern, (normal/patchy/ complete obliteration) bleeding (none/mucosal/luminal mild/luminal moderate or severe), erosions and ulcers (none/erosions/superficial/deep), each with precise definitions, which explained 90% of the variance (pR2, Akaike Information Criterion) in the overall assessment of endoscopic severity, predictions varying from 4 to 93 on a 100-point scale (from normal to worst endoscopic severity). Conclusion: The Ulcerative Colitis Endoscopic Index of Severity accurately predicts overall assessment of endoscopic severity of UC. Validity and responsiveness need further testing before it can be applied as an outcome measure in clinical trials or clinical practice.publishersversionPeer reviewe

GOUPEG : Application de la méthode « hybride » pour le calcul du comportement des groupes et des réseaux élémentaires de micropieux

International audienceLe programme de calcul de groupe ou de réseaux de (micro)pieux GOUPEG est fondé sur la méthode de calcul en déplacement, utilisée pour le calcul des micropieux. L'interaction mécanique entre les micropieux est prise en compte par application de la théorie du continuum élastique. Cette méthode « hybride » est présentée. GOUPEG a été développé pour étudier la prise en compte de l'effet d'inclinaison des micropieux. L'approche présentée ici montre que les méthodes développées pour les pieux, qui reposent sur les résultats des essais pressiométriques, sont applicables également aux groupes de micropieux. Les résultats de GOUPEG montrent que l'inclinaison des micropieux, dans un réseau élémentaire chargé verticalement, implique une augmentation de la portance par la mise en butée du sol sous les micropieux. GOUPEG a également permis de déterminer la reprise du chargement horizontal en tête par réaction transversale et par mobilisation des efforts de frottement axiaux

Sexual Conjugation in Yeast: A Paradigm to Study G-Protein-Coupled Receptor Domain Structure

The yeast Saccharomyces cerevisiae undergoes cell fusion during sexual conjugation to form diploid cells. The haploids participating in this process signal each other through secreted peptide-mating factors (α-factor and a-factor) that are recognized by G-protein-coupled receptors. The receptor (Ste2p) recognizing the tridecapeptide α-factor is used as a model system in our laboratory to understand various aspects of peptide-receptor interactions and receptor structure. Using chemical procedures we have synthesized peptides corresponding to the seven transmembrane domains of Ste2p and studied their structures in membrane mimetic environments. Extension of these studies requires preparation of longer fragments of Ste2p. This article discusses strategies used in our laboratory to prepare peptides containing multiple domains of Ste2p. Data are presented on the use of chemical synthesis, biosynthesis, and native chemical ligation. Using biosynthetic approaches fusion proteins have been expressed that contain single receptor domains, two transmembrane domains connected by the contiguous loop, and the tail connected to the seventh transmembrane domain. Tens of milligrams of fusion protein were obtained per liter, and multi-milligram quantities of the isotopically labeled target peptides were isolated using such biosynthetic approaches. Initial circular dichroism results on a chemically synthesized 64-residue peptide containing a portion of the cytosolic tail and the complete seventh transmembrane domain showed that the tail portion and the hydrophobic core of this peptide maintained individual conformational preferences. Moreover, this peptide could be studied at near millimolar concentrations in the presence of micelles and did not aggregate under these conditions. Thus, these constructs can be investigated using high-resolution nuclear magnetic resonance techniques, and the cytosolic tail of Ste2p can be used as a hydrophilic template to improve solubility of transmembrane peptides for structural analysis. © 2004 Wiley Periodicals, Inc

Incidencia de la escabiosis en la población escolar de la ciudad de Cuenca

Doctor en Medicina y CirugíaCuenc

Studies of Tubulin and Its Polymerisation under Hydrostatic Pressure

National audienc

Tubulin and Microtubule Study under Hydrostatic Pressure

International audienc

The influence of water on the nanomechanical behavior of the plant biopolyester cutin as studied by AFM and solid-state NMR

Atomic force microscopy and solid-state nuclear magnetic resonance have been used to investigate the effect of water absorption on the nanoscale elastic properties of the biopolyester, cutin, isolated from tomato fruit cuticle. Changes in the humidity and temperature at which fruits are grown or stored can affect the plant surface (cuticle) and modify its susceptibility to pathogenic attack by altering the cuticle's rheological properties. In this work, atomic force microscopy measurements of the surface mechanical properties of isolated plant cutin have been made as a first step to probing the impact of water uptake from the environment on surface flexibility. A dramatic decrease in surface elastic modulus (from similar to 32 to similar to6 MPa) accompanies increases in water content as small as 2 wt %. Complementary solid-state nuclear magnetic resonance measurements reveal enhanced local mobility of the acyl chain segments with increasing water content, even at molecular sites remote from the covalent cross-links that are likely to play a crucial role in cutin's elastic properties