Discovery and characterization of IGFBP-mediated endocytosis in the human retinal pigment epithelial cell line ARPE-19

Insulin-like growth factor binding proteins (IGFBPs) are prime regulators of IGF-action in numerous cell types including the retinal pigment epithelium (RPE). The RPE performs several functions essential for vision, including growth factor secretion and waste removal via a phagocytic process mediated in part by vitronectin (Vn). In the course of studying the effects of IGFBPs on IGF-mediated VEGF secretion and Vn-mediated phagocytosis in the RPE cell line ARPE-19, we have discovered that these cells avidly ingest synthetic microspheres (2.0 μm diameter) coated with IGFBPs. Given the novelty of this finding and the established role for endocytosis in mediating IGFBP actions in other cell types, we have explored the potential role of candidate cell surface receptors. Moreover, we have examined the role of key IGFBP structural motifs, by comparing responses to three members of the IGFBP family (IGFBP-3, IGFBP-4 and IGFBP-5) which display overlapping variations in primary structure and glycosylation status. Coating of microspheres (FluoSpheres®, sulfate modified polystyrene filled with a fluorophore) was conducted at 37 °C for 1 h using 20 μg/mL of test protein, followed by extensive washing. Binding of proteins was confirmed using a microBCA assay. The negative control consisted of microspheres treated with 0.1% bovine serum albumin (BSA), and all test samples were post-treated with BSA in an effort to coat any remaining free protein binding sites, which might otherwise encourage non-specific interactions with the cell surface. Serum-starved cultures of ARPE-19 cells were incubated with microspheres for 24 h, using a ratio of approximately 100 microspheres per cell. Uptake of microspheres was quantified using a fluorometer and was confirmed visually by confocal fluorescence microscopy. The ARPE-19 cells displayed little affinity for BSA-treated microspheres, but avidly ingested large quantities of those pre-treated with Vn (ANOVA; p < 0.001). Strong responses were also observed towards recombinant formulations of non-glycosylated IGFBP-3, glycosylated IGFBP-3 and glycosylated IGFBP-5 (all p < 0.001), while glycosylated IGFBP-4 induced a relatively minor response (p < 0.05). The response to IGFBP-3 was unaffected in the presence of excess soluble IGFBP-3, IGF-I or Vn. Likewise, soluble IGFBP-3 did not induce uptake of BSA-treated microspheres. Antibodies to either the transferrin receptor or type 1 IGF-receptor displayed slight inhibitory effects on responses to IGFBPs and Vn. Heparin abolished responses to Vn, IGFBP-5 and non-glycosylated IGFBP-3, but only partially inhibited the response to glycosylated IGFBP-3. Our results demonstrate for the first time IGFBP-mediated endocytosis in ARPE-19 cells and suggest roles for the IGFBP-heparin-binding domain and glycosylation status. These findings have important implications for understanding the mechanisms of IGFBP actions on the RPE, and in particular suggest a role for IGFBP-endocytosis.

Approach to developing a 3D conceptual hydrogeology model, in a system with multiple bore logs, Howard East, Darwin, using in-house software (GVS)

The Howard East rural area has experienced a rapid growth of small block subdivisions and horticulture over the last 40 years, which has been based on groundwater supply. Early bores in the area provide part of the water supply for Darwin City and are maintained and monitored by NT Power & Water Corporation. The Territory government (NRETAS) has established a monitoring network, and now 48 bores are monitored. However, in the area there are over 2700 private bores that are unregulated.Although NRETAS has both FDM and FEM simulations for the region, community support for potential regulation is sought. To improve stakeholder understanding of the resource QUT was retained by the TRaCKconsortium to develop a 3D visualisation of the groundwater system.

Stripping Sight Bare : Alison Jones’ ‘Portraits by Proxy’

In this paper I analyse UK artist Alison Jones’ sonic interventions Portrait of the Artist by Proxy (2008), Voyeurism by Proxy (2008) and Art, Lies and Audio Tapes (2009). In Portrait of the Artist by Proxy, Jones – who, due to deteriorating vision, has not seen her reflection in a mirror in years – asks and trusts participants to audio-describe her own image back to her. In Voyeurism by Proxy, Jones asks participants to audio-describe erotic drawings by Gustav Klimt. In Art, Lies and Audio Tapes, Jones asks participants to audio-describe other artworks, such as W.F. Yeames’ And When Did You Last see Your Father?. In these portraits by proxy, Jones opens her image, and other images, to interpretation. In doing so, Jones draws attention to the way sight is privileged as a mode of access to fixed, fundamental truths in Western culture – a mode assumed to be untainted by filters that skew perception of the object. “In a culture where vision is by far the dominant sense,” Jones says, “and as a visual artist with a visual impairment, I am reliant on audio-description …Inevitably, there are limitations imposed by language, time and the interpreter’s background knowledge of the subject viewed, as well as their personal bias of what is deemed important to impart in their description” . In these works, Jones strips these background knowledges, biases and assumptions bare. She reveals different perceptions, as well as tendencies or censor, edit or exaggerate descriptions. In this paper, I investigate how, by revealing unconscious biases, Jones’ works renders herself and her participants vulnerable to a change of perception. I also examine how Jones’ later editing of the audio-descriptions allows her to show the instabilities of sight, and, in Portrait of the Artist by Proxy, to reclaim authorship of her own image.

Humanitarianism or self-serving hypocrisy? : the provision of aid to South Africa under the Hawke-Keating and Howard governments

General perceptions of foreign aid commonly engender images of humanitarianism and altruism, whereby the humanitarian needs of the recipient of development assistance are of the utmost priority of the aid donor. However, the Australian governments led by Hawke, Keating and Howard often gave humanitarianism a low emphasis, frequently placing Australia’s own foreign policy and economic concerns at the forefront of aid allocation – often unashamedly. This self-interest met through aid meant that most was provided to Australia’s regional neighbourhood, neglecting some of the poorest, most struggling states, including South Africa. Other issues and events, including the Cold War, apartheid, terrorism and HIV/AIDS also affected Australia’s aid policy; mostly, they were used as excuses to limit aid to states like South Africa.

Louis Nowra, 'Radiance' (Sydney: Currency Press, 1993)

Louis Nowra wrote 'Radiance' especially for the three actors who performed it in the play’s premier season at Belvoir Street Theatre in September 1993. And the Currency Press playscript / programme produced for that season foregrounds these three performers – Rachael Maza, Lydia Miller and Rhoda Roberts – in such a way that the usual distinction between dramatis personae and the actors who play them is considerably diminished. Both the blurb on the back cover and Nowra’s introduction emphasise this special relationship between text and actors, but it is the front cover shot which particularly reflects the conjunction between the two. Rather than depicting a scene from performance, or a ‘graphic’ suggesting something of the play’s thematic content, the front cover of Radiance features the three actors in a posed promotional shot. Arms joined warmly, lovingly, about each other’s waist, bodies turned away from but faces towards the camera, it is the actors we see, not their characters. It’s a very joyful image; they’re positively beaming. Radiant. They look as if they could really be the three half-sisters they portray, except that such moments of blithe sorority are just about non-existent in the play.

'The black hole of our history' : a conversation with Louis Nowra

This is an edited version of an interview recorded for Canadian Theatre Review in 1992. By that time Nowra had established a reputation as one of Australia's foremost playwrights. Part of the generation which succeeded the New Wave of the late 1960s and early 1970s, Nowra became known for a stylistic inventiveness which placed him outside the tradition of realist playwriting in Australia. The international outlook in his early plays, and the fact that he was not exclusively preoccupied with Australian settings and subject matter, was often a focal point in critical accounts of his work. In this interview Nowra discusses his 'internationalism', and a range of topics including the playwriting process; the presence of landscape in his plays; and the autobiographical elements in his work.

Judge George W Paul's Japanese house : a case study

In the late 1880s a pre-fabricated Japanese house was shipped from Kobe, Japan, to Brisbane, Australia, and erected in the up-market suburb of New Farm by Japanese tradesmen. This paper is developed from a broader project researching the life of G W Paul, the man who had the house built and subsequently lived in it for the remainder of his life. Paul’s motivation in importing the house represented a unique, but unfulfilled effort to develop a future, hybrid culture for Queensland. This effort took the form of a commercial venture to construct Japanese houses as desirable and climatically suitable dwellings. Against the backdrop of this ambition, this paper presents new research to elucidate and extend previous knowledge, assesses the reception of the house by its nineteenth century Brisbane audience, and considers possible reasons for the limited response which signalled the cancellation of the commercial venture.

The Attack on Political Correctness: Islamophobia and the Erosion of Multiculturalism In Australia Under the Howard Regime

This article reports on civil society in Australia between 1996 and 2007 related to former Prime Minister John Howard. The article discusses Howard's neo-conservative ideology and Liberal-National coalition, noting his views on political correctness. Howard's administration is also discussed in terms of immigration, multiculturalism, indigenous land rights, othering, and Islamaphobia. Information on the effect of Islamaphobia on Australian perceptions and the treatment of Muslims is also provided

Et tu, George? Campaign journalism and the politics of compromise

There is a category of film about journalism in which journalism is not the star, but the supporting player, and journalists not the protagonists but the Greek chorus, commenting on and also changing the realities they report. In such films the news media are a structuring presence driving the plot, shaping the narrative, constructing what we might think of as a pseudo-reality. Like Daniel Boorstin’s notion of the pseudo-event (introduced in his still-relevant book The Image, 1962), this pseudo-reality is so-named because it would not exist were it not for the demands of the news media’s hunger for stories, and knowledge of the damage they can do with those stories, on the calculations and actions of the key actors. Pseudo-realities form as responses to what political actors think journalists and their organisations need and want, or as efforts to shape journalistic accounts in ways favourable to themselves. Films about politics often feature pseudorealities of this kind, in which the events and actions driving the plot have only a tenuous relationship with important things going on in the everyday world beyond the political arena. Everything we see is about image, perception, appearance.

Risk factors for malnutrition in community-dwelling people with Parkinson’s disease

In the elderly, the risks for protein-energy malnutrition from older age, dementia, depression and living alone have been well-documented. Other risk factors including anorexia, gastrointestinal dysfunction, loss of olfactory and taste senses and early satiety have also been suggested to contribute to poor nutritional status. In Parkinson’s disease (PD), it has been suggested that the disease symptoms may predispose people with PD to malnutrition. However, the risks for malnutrition in this population are not well-understood. The current study’s aim was to determine malnutrition risk factors in community-dwelling adults with PD. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment (PG-SGA). Data about age, time since diagnosis, medications and living situation were collected. Levodopa equivalent doses (LDED) and LDED per kg body weight (mg/kg) were calculated. Depression and anxiety were measured using the Beck’s Depression Inventory (BDI) and Spielberger Trait Anxiety questionnaire, respectively. Cognitive function was assessed using the Addenbrooke’s Cognitive Examination (ACE-R). Non-motor symptoms were assessed using the Scales for Outcomes in Parkinson's disease-Autonomic (SCOPA-AUT) and Modified Constipation Assessment Scale (MCAS). A total of 125 community-dwelling people with PD were included, average age of 70.2±9.3(35-92) years and average time since diagnosis of 7.3±5.9(0–31) years. Average body mass index (BMI) was 26.0±5.5kg/m2. Of these, 15% (n=19) were malnourished (SGA-B). Multivariate logistic regression analysis revealed that older age (OR=1.16, CI=1.02-1.31), more depressive symptoms (OR=1.26, CI=1.07-1.48), lower levels of anxiety (OR=.90, CI=.82-.99), and higher LDED per kg body weight (OR=1.57, CI=1.14-2.15) significantly increased malnutrition risk. Cognitive function, living situation, number of prescription medications, LDED, years since diagnosis and the severity of non-motor symptoms did not significantly influence malnutrition risk. Malnutrition results in poorer health outcomes. Proactively addressing the risk factors can help prevent declines in nutritional status. In the current study, older people with PD with depression and greater amounts of levodopa per body weight were at increased malnutrition risk.