Host-pathogen interactions that allow Helicobacter pylori to survive and persist in the stomach of susceptible individuals remain unclear. Human ␤-defensins (hBDs), epithelial-derived antimicrobial peptides are critical components of host-defense at mucosal surfaces. The role of H. pylori-mediated NF-B and epidermal growth factor receptor (EGFR) activation on ␤-defensin expression was investigated. Transient transfection studies utilizing ␤-defensin promoter constructs were conducted in gastric cells with contribution of individual signaling events evaluated by the addition of specific inhibitors, small interference nucleotide-binding oligomerization domain 1 (NOD1) RNA or plasmids encoding Vaccinia virus proteins that interrupt interleukin-1 and Toll-like receptor signaling. The role of individual MAPK pathways was further delineated in HEK-293 cells expressing conditional MAPK mutants. We found hBD2 expression exclusively dependent on the presence of the bacterial cag pathogenicity island, with NOD1 a critical host sensor. Impairment of murine ␤-defensin 4 (an orthologue of hBD2) expression in NOD1-deficient mice 7-days post-infection further confirmed the role of this cytoplasmic pattern-recognition receptor in eliciting host innate immunity. In contrast to hBD2, hBD3 expression was NOD1-independent but EGFR and ERK pathway-dependent. Importantly, Toll-like receptor signaling was not implicated in H. pylori-mediated hBD2 and hBD3 gene expression. The divergent signaling events governing hBD2 and hBD3 expression suggest temporal functional variation, such that hBD2 may contribute to antimicrobial barrier function during the inflammatory phase with hBD3 playing a greater role during the repair, wound healing phase of infection.

This paper describes country-wide special measures undertaken for interventional radiology (IR) staff during the current coronavirus Q3 disease 2019 (COVID-19) pandemic. Although each IR service around the world faces unique challenges, the principles outlined in this paper will be useful when designing or strengthening individual practices and integrating them within wider hospital and national Q4measures. Moving beyond the current outbreak, these measures will be useful for any future infectious diseases which are likely to arise.

Although Pd/Ti/Pd/Au contacts are similar to their Pt/Ti/Pt/Au counterparts in providing low specific contact resistance, ρc, the former exhibits long-term thermal stability. Their projected mean times to 50% increase in ρc(μ50) at 150 °C to p+-GaAs (⩾3.43×1015 h) are higher than those of the latter by over five orders of magnitude. Contacts to p+-In0.53Ga0.47As are not as thermally stable, with a much lower albeit respectable μ50 at 150 °C of ⩾2.25×105 h. Contacts with an interfacial Pd layer provide ρc’s that are at least two times lower than those without, and the presence of an oxide layer (GaxTiyOz) at the Ti/GaAs interface is identified as a possible cause. Pd–Ga–As phases are formed at the Pd/GaAs interface, being As-rich (PdxGayAs) initially and convert to Ga-rich phases (PduGavAs) upon a high temperature anneal and the eventual composition depends on the evaporated interfacial Pd thickness and annealing conditions. This could probably explain the existence of an optimum interfacial Pd layer thickness of 100 Å for achieving the lowest ρc. The Ga-rich PduGavAs phases formed are inferred to cause the liberation of As atoms from the GaAs lattice, thus enabling them to diffuse out to the Ti and react to form TixAsy phases that bind the As from further out-diffusion. This has in turn led to the accumulation of As at the Pd/Ti interface.

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New-onset psychotic symptoms presenting late in life can be caused by various medical and psychiatric conditions. The index of suspicion for an organic cause for psychotic symptoms in an elderly person should be high, and every presenting patient should undergo a detailed history-taking and evaluation before attributing these symptoms to a primary psychiatric condition. Hyperparathyroidism is one condition that can present with psychiatric symptoms such as low mood and anxiety. While psychiatric symptoms are not uncommon in hyperparathyroidism, acute psychosis is rare. This case report highlights the importance of a thorough evaluation of an elderly person presenting with a new onset of psychosis.

Clinical Radiology j o ur n a l ho m e p a g e : w w w . c l i ni c a l ra d i o l og y o nl i n e . n e t

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