Copyright (c) 2012 All rights reserved. http://works.bepress.com/peter_johnson Recent documents in Peter J Johnson en-us Mon, 26 Nov 2012 07:54:50 PST 3600 http://works.bepress.com/peter_johnson/2 http://works.bepress.com/peter_johnson/2 Sun, 07 Oct 2012 23:30:15 PDT Pyocyanin, a virulence factor produced by Pseudomonas aeruginosa, has many damaging effects on mammalian cells. Several lines of evidence suggest that this damage is primarily mediated by its ability to generate ROS and deplete host antioxidant defence mechanisms. However, a causal role for oxidative stress has not yet been demonstrated conclusively. Parallel measures of ROS production, antioxidant levels and cytotoxicity provide convincing evidence that pyocyanin-induced cytotoxicity in A549 respiratory cells is mediated by acute ROS production and subsequent oxidative stress. Pyocyanin increased ROS levels in A549 cells as measured by the fluorescent H2O2 probes Amplex Red and DCFH-DA. These effects were attenuated by the antioxidant N-acetylcysteine. Furthermore, pyocyanin-induced depletion of intracellular GSH levels 24 h after exposure was also prevented by pre-treatment of cells with NAC. Under these conditions, NAC protected cells against pyocyanin-induced cytotoxicity as measured by resazurin reduction to resorufin and viable cell counts, strongly supporting a causal role for oxidative stress. Finally, we also show that pyocyanin-induced activation of the immune and inflammatory transcription factor NF-?B in A549 cells is likely mediated by increased ROS. This increased understanding of mechanisms underlying pyocyanin-induced cytotoxicity may ultimately lead to better strategies for reducing the virulence associated with chronic P. aeruginosa infection.

]]> Lee S. Gloyne et al. http://works.bepress.com/peter_johnson/1 http://works.bepress.com/peter_johnson/1 Wed, 02 Sep 2009 16:08:42 PDT This paper details the implementation and educational impacts of the "Pharm- First" program - a series of workshops for first semester pharmacy students at Griffith University. In first year, this cohort enrols in foundation level biomedical science courses alongside students from a number of other health programs, and has little formal contact with pharmacy academics. The "Pharm-First" program was developed in response to survey data indicating that students were disengaged with their early learning and social environments. It comprised a series of workshop activities conducted fortnightly over semester one by Pharmacy academics and recent graduates. Content was directly aligned with the four foundation year courses and linked to specific topics in Pharmacy practice. Workshops also included activities that promoted professional development. The success of the program in enhancing orientation and engagement was indicated by a higher academic performance of students who regularly participated, and marked improvements in student survey responses.

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