Hemin, copper and amyloid-β: A medley involved in Alzheimer's disease. An interaction that fine regulates the reactivity.

Metal ions have been shown to play a critical role in amyloid-β (Aβ) neurotoxicity and plaque formation which are key hallmarks of Alzheimer's disease. Amyloid-β peptides can bind both copper and hemin and this interaction modulates the redox chemistry of these metals. The characterization of the binding of hemin through UV-Vis spectroscopic titration with Aβ(4-16) shows a significantly higher affinity than that with Aβ(1-16).

Biological Oxidations and Nitrations Promoted by the Hemin-Aβ Complex.

Both β-amyloid (Aβ) peptides and oxidative stress conditions play key roles in Alzheimer's disease. Hemin contributes to the development of the disease as it possesses redox properties and its level increases in pathological conditions or traumatic brain injuries. The aim of this work was to deepen the investigation of the reactivity of the hemin-Aβ complex, considering its ability to catalyze oxidation and nitration reactions.

A prediction rule for estimating the risk of bacteremia in patients with community-acquired pneumonia.

Background: We endeavored to construct a simple score based entirely on epidemiological and clinical variables that would stratify patients who require hospital admission because of community-acquired pneumonia into groups with a low or high risk of developing bacteremia.

Methods: Derivation and internal validation cohorts were obtained by retrospective analysis of a database that included 3116 consecutive patients with community-acquired pneumonia from 2 university hospitals. Potential predictive factors were determined by means of a multivariate logistic regression equation applied to a cohort consisting of 60% of the patients.