HCAP is associated with worse outcomes than CAP. MDR pathogens were implicated in only a small fraction of HCAP cases. In our study, unlike CAP, non-respect of current HCAP guidelines had no adverse effect on the ultimate outcome. Strategies for the empirical management of HCAP should be tailored to the local epidemiological context.

Background: G protein-coupled receptors (GPCRs) modulate a plethora of physiological processes. Results: The determination of 38 ligand/receptor contacts enabled the evidence-based modeling of a GPCR structure. Conclusion: The proposed GPCR structure assumes four interaction clusters with its ligand, which adopts a vertical binding mode. Significance: Elucidating the structure of GPCRs is central to their understanding and has several implications, e.g. rational drug design.

Background:The N111G and N111W mutations make the AT 1 receptor constitutively active and inactivable, respectively. Results: The orientation and interactions of D74 2.50 are influenced by the residue at position 111 3.35 . Conclusion: H-bond formation between D742.50 and N46 1.50 is critical for AT 1 receptor activation. Significance: This novel molecular switch could be involved in the GPCR activation mechanism as it involves highly conserved residues D 2.50 and N 1.50 .

Background: The N111G and D74N mutations bias the AT 1 receptor for the G q/11 and ␤-arrestin pathways, respectively. Results: Structural rearrangements of theAT 1 receptor are induced by the N111G mutation and AngII. Conclusion: Activation of the G q/11 and ␤-arrestin pathways is associated with a decreased and increased stability, respectively, of the ground state of the receptor. Significance: Distinct conformations of AT 1 receptor are associated with distinct pathways.