Effect of normalisation on detection of differentially expressed genes in cDNA microarray data analysis

Four different normalisation techniques were applied for the corrections of fluorescence data generated by a cDNA microarray experiment. Correction for inaccurate signals and possible bias induced by fluorescence intensity, background intensity and dye effect were used in different combinations. Results of the present study highlight a pronounced role for the normalisation techniques in the absolute number of genes different expressed and a low concordance between different methods. Moreover, a significant effect of the dependent variable used, mean or median fluorescence intensity, was observed

Effect of normalisation on detection of differentially expressed genes in cDNA microarray data analysis

Four different normalisation techniques were applied for the corrections of fluorescence data generated by a cDNA microarray experiment. Correction for inaccurate signals and possible bias induced by fluorescence intensity, background intensity and dye effect were used in different combinations. Results of the present study highlight a pronounced role for the normalisation techniques in the absolute number of genes different expressed and a low concordance between different methods. Moreover, a significant effect of the dependent variable used, mean or median fluorescence intensity, was observed

Use of a partial least squares regression model to predict Test Day of milk, fat and protein yields in dairy goats

A model able to predict missing test day data for milk, fat and protein yields on the basis of few recorded tests was proposed, based on the partial least squares (PLS) regression technique, a multivariate method that is able to solve problems related to high collinearity among predictors. A data set of 1731 lactations of Sarda breed dairy Goats was split into two data sets, one for model estimation and the other for the evaluation of PLS prediction capability. Eight scenarios of simplified recording schemes for fat and protein yields were simulated. Correlations among predicted and observed test day yields were quite high (from 050 to 088 and from 053 to 096 for fat and protein yields, respectively, in the different scenarios). Results highlight great flexibility and accuracy of this multivariate technique

Fit of different linear models to the lactation curve of Italian water buffalo

Mathematical modelling of lactation curve by suitable functions of time, widely used in the dairy cattle industry, can represent also for buffaloes a fundamental tool for management and breeding decision, where average curves are considered, and for genetic evaluation by random regression models, where individual patterns are fitted. Average lactation curves of Italian Buffalo cows have been fitted with good results (Catillo et al., 2002) whereas there is a lack of information on individual fitting.Aim of the present work is to check performances of some of the most currently used empirical models in fitting both average and individual lactation curves of Italian water buffaloes

Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques

Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS). The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P < 0.01) in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque and could provide a useful diagnostic tool, as well as information on the molecular mechanisms responsible for plaque instability

Pontage jugulaire antérieure: jugulaire interne pour sauvetage de fistule artério-veineuse

La thrombose du tronc veineux brachiocéphalique est une des complications possibles chez les malades avec insuffisance rénale soumis à dialyse à travers une fistule artério-veineuse. Cette complication peut déterminer un oedème du bras et de la main, une cyanose des doigts, une turgescence des veines du cou et de l'épaule, de graves céphalées, outre l'inutilisation de la fistule pour dialyser. L'abolition de la fistule peut être nécessaire pour faire reculer la symptomatologie et pratiquer la dialyse à travers un cathéter le temps nécessaire d'avoir une nouvelle fistule utilisable. Réussir à sauvegarder une fistule fonctionnelle est l'objectif à poursuivre en cas de sténose ou d'occlusion du tronc veineux brachiocéphalique, outre la rémission des symptômes cliniques. Dans ce but, la première tentative est l'utilisation des stents, dans le cas où le résultat n'est pas satisfaisant, on peut envisager plusieurs méthodes chirurgicales de pontage veineux pour sauver la fistule et éliminer la symptomatologie clinique