Erratum - Analysis of extracellular superoxide dismutase and Akt in ascending aortic aneurysm with tricuspid or bicuspid aortic valve.

This correct the article published on European Journal of Histochemistry 2014;58:200-206 doi: 10.4081/ejh.2014.2383.

Analysis of extracellular superoxide dismutase and Akt in ascending aortic aneurysm with tricuspid or bicuspid aortic valve.

Ascending aortic aneurysm (AsAA) is a consequence of medial degeneration (MD), deriving from apoptotic loss of smooth muscle cells (SMC) and fragmentation of elastin and collagen fibers. Alterations of extracellular matrix structure and protein composition, typical of medial degeneration, can modulate intracellular pathways. In this study we examined the relevance of superoxide dismutase (SOD3) and Akt in AsAA pathogenesis, evaluating their tissue distribution and protein levels in ascending aortic tissues from controls (n=6), patients affected by AsAA associated to tricuspid aortic valve (TAV, n=9) or bicuspid aortic valve (BAV, n=9). The results showed a significant reduction of SOD3, phospho-Akt and Akt protein levels in AsAA tissues from patients with BAV, compared to controls, whereas the differences observed between controls and patients with TAV  were not significant. The decreased levels of SOD3 and Akt in BAV aortic tissues are associated with decreased Erk1/Erk2 phosphorylation and MMP-9 levels increase. The authors suggest a role of decreased SOD3 protein levels in the progression of AsAA with BAV and a link between ECM modifications of aortic media layer and impaired Erk1/Erk2 and Akt signaling in the late stages of the aortopathy associated with BAV.

The central dusty torus in the active nucleus of NGC 1068.

Active galactic nuclei (AGNs) display many energetic phenomena--broad emission lines, X-rays, relativistic jets, radio lobes--originating from matter falling onto a supermassive black hole. It is widely accepted that orientation effects play a major role in explaining the observational appearance of AGNs. Seen from certain directions, circum-nuclear dust clouds would block our view of the central powerhouse. Indirect evidence suggests that the dust clouds form a parsec-sized torus-shaped distribution. This explanation, however, remains unproved, as even the largest telescopes have not been able to resolve the dust structures. Here we report interferometric mid-infrared observations that spatially resolve these structures in the galaxy NGC 1068. The observations reveal warm (320 K) dust in a structure 2.1 parsec thick and 3.4 parsec in diameter, surrounding a smaller hot structure. As such a configuration of dust clouds would collapse in a time much shorter than the active phase of the AGN, this observation requires a continual input of kinetic energy to the cloud system from a source coexistent with the AGN.