Copyright (C) 2010 S. Karger AG, Basel”
“Introduction: Total volume of distribution (V(T)) determined by graphical Givinostat analysis (GA) of PET data suffers from a noise-dependent bias. Likelihood estimation in GA (LEGA) eliminates this bias at the region of interest (ROI) level, but at voxel noise levels, the variance of estimators is high, yielding noisy images. We hypothesized that incorporating LEGA V(T) estimation in a Bayesian framework would shrink estimators towards prior means, reducing variability and producing meaningful and useful voxel images.
Methods:
Empirical Bayesian estimation in GA (EBEGA) determines prior distributions using a two-step k-means clustering of voxel activity.
Results obtained on eight [(11)C]-DASB studies are compared with estimators computed by ROI-based LEGA. Results: EBEGA reproduces the results obtained by ROI LEGA while providing low-variability V(T) images. Correlation coefficients between average EBEGA V(T) and corresponding ROI LEGA V(T) range from 0.963 to 0.994.
Conclusions: EBEGA is a fully automatic and general approach that can be applied to voxel-level V(T) image creation and to any modeling strategy to reduce voxel-level
estimation variability without prefiltering of the PET data. (C) 2010 Elsevier Inc. find more All rights reserved.”
“We retrospectively analyzed etiological, pathological and clinical
features of the patients with hemolytic uremic syndrome (HUS) observed in the Pediatric Nephrology Unit at AOU Meyer of Florence. From January 1997 to December 2008, 22 cases were identified, with an annual incidence of 0.05 cases per 100,000 inhabitants, and 0.34 cases per 100,000 children <15 years old. 60% of the patients were D+ and 40% were D-, with an age distribution from 12 days to 13 years. Twenty patients (90%) had oligoanuria, lasting 6.4 +/- 4 days for D+ patients versus 11.8 +/- 4 days for D-patients. The development of chronic kidney disease positively XL184 ic50 correlates with the initial blood pressure value, the length of oligoanuria, and hospitalization. Microbiological investigations showed an association of D+HUS with different strains of Shiga toxin-producing Escherichia coli in 54% of the cases. D-HUS was associated with complement factor H deficiency in one patient. In the other cases, the triggering factors were pertussis, urinary tract infections and upper airway infections. While clinical and prognostic features correspond with literature data, in Tuscany the annual incidence is lower, and the percentage of D-HUS patients is higher than that observed in other studies. Copyright (C) 2010 S.