bluuebunny/crossref_metadata_2025 huggingface dataset:
What do Consumers Want and Need to Know in Making Health Care Choices?
Authors: Lubalin James S. , Harris-Kojetin Lauren D.
Published: January 2017

This article assesses the presumption that consumer choice in health care is based on a rational weighing of alternatives—that informing consumers about plan or provider performance, when coupled with information on cost plus service scope and limitations, will lead consumers to select high-quality, low-priced plans or providers. The authors review research on what health care consumers know, what they want to know, and what others think they should know. They also consider how people use information in making decisions and what this implies for what consumers really need to know to make effective decisions. The article concludes that assuming a rational consumer does not account for choice among options in the increasingly complex health care context facing consumers today. Based on this review, the article identifies gaps in the knowledge and sketches out a prospective research agenda in the area of consumer health care decision making.
Neurologic Complications in Noncardiac Surgery
Authors: Murkin John M.
Published: January 2017

In this article, the incidence of nervous system injuries associated with noncardiac surgery is reviewed briefly. In general, these can be divided into injuries that are clinically apparent (eg, stroke or peripheral nerve damage), which may generally be detectable on clinical examination, and more subtle forms of brain injury (eg, personality changes and postoperative cognitive dysfunction), injuries that are primarily detected by neuropsychological testing.
Watching Battlestar Galactica in Australia and the Tyranny of Digital Distance
Authors: Leaver Tama
Published: January 2017

In an era where communication technologies can move digital media at close to the speed of light, this paper explores the rupture between this technical potential and the actual model by which international television screening dates are determined in Australia. As the delays between overseas and Australian airdates can be as long two years, and average over six months, the rapid rise in both official and fan-produced online material and interaction relating to television series has given rise to a massive but largely unfulfilled demand for simultaneous access to episodes across the globe. Using the case study of the critically acclaimed fan favourite Battlestar Galactica, this paper outlines some of the strategies by which producers build global fan loyalty — from official websites, blogs, commentary podcasts and online deleted scenes to exclusive webisodes and official participation in fan forums. The paper argues that these trends, combined with the time delay between release dates, are the largest factors contributing to the unlawful downloading of television via peer-to-peer file-sharing platforms such as BitTorrent. In attempting to maintain distribution models that began as geographic necessities, but have become exclusively political and economic decisions in an era of digital communication technologies, this paper argues that media corporations are perpetuating a ‘tyranny of digital distance’ and alienating their own audiences.
Regulating Service Providers' Access to an FTTN Network
Authors: Campbell L.H. , Holmes J.R.
Published: January 2017

To date, the major deployments of FTTN or its fibre-rich cousin, Fibre to the Premises, have been driven by clear government policy (Republic of Korea, Japan) or competitive pressure from cable television companies (US, Netherlands — planned). Without these pressures, the business case for deploying FTTN is uncertain. The additional revenues from higher-speed internet access are likely to be slight, and new revenues from pay television are uncertain and likely to develop only over the medium term. The business case for investing perhaps A$9 billion or more for an extensive FTTN deployment in Australia is therefore weak. National governments, however, see many benefits in widespread deployment of high internet access speeds and may provide incentives for FTTN deployments if competitive pressures are absent. This article explains some of these incentives in the Australian context, especially the steps taken so far to regulate access to the fibre networks proposed by Telstra and the so-called G9 consortium.
Ecomedia: Of Angelic Images and Environmental Values
Authors: van Vuuren Kitty , Lester Libby
Published: January 2017

The prominence of media events in 2006, including the release of former US Vice President Al Gore's documentary An Inconvenient Truth, the publication of the Stern Review on the Economics of Climate Change, the report of the Intergovernmental Panel on Climate Change, even the death of ‘eco-celebrity’ Steve Irwin, suggested a need to devote an issue of Media International Australia to media and the environment. The study of environmentalism through the lens of media, journalism and communication is all but absent in Australia, with some notable exceptions. This issue of MIA goes some way towards redressing the absences identified by Tom Jagtenberg and David McKie in their influential book Eco-Impacts and the Greening of Postmodernity, published more than 10 years ago, which claimed for the environment an equal status with traditional research foci: class, race and gender. The current public interest in environmental issues emphasises this point, although it is not unprecedented. History shows that environmental issues move in waves to and from the heart of public debate. As well as showcasing some of the field's distinct approaches and traditions, the articles in this issue contribute to a better understanding of this current wave and its likely aftermath. In doing so, it goes some way towards moving the environment in the direction of a more central position on the research and public agenda.
Environmental Narratives and Media Conventions: Strategic Frames and Value-Based Argument
Authors: Collins Catherine
Published: January 2017

Our understanding of environmental issues and our contribution to environmental degradation are shaped by the way our stories are framed, the value hierarchies they advance and a familiarity with the chosen narratives that are so conventionalised that this may deter recognition of how narrative choices limit our interpretive process. Textual arguments and image choices within these narratives have the potential to expand or restrict the audience's commitment to and participation in the belief or action sought by the message. In this article, I am interested in televised documentaries that argue for environmental preservation. I argue that, guided by journalistic conventions and stock environmental narratives, well-meaning appeals frequently make the wrong strategic choices. By examining a case study of similar documentaries employing different narrative choices, we can begin to see how particular narrative structures and substantive appeals advance or restrict audience adherence to the proposed environmental action.
The Billion-Dollar Kyoto Botch-up: Climate Change Communication in New Zealand
Authors: Russill Chris
Published: January 2017

New Zealand's greenhouse gas emissions have increased significantly since 1990. This article examines how the fact of increasing emissions is discussed and given significance in New Zealand's national public discourse on climate change. Greenhouse gas emissions became a serious public concern on 17 June 2005, when the New Zealand government estimated a $307 million Kyoto Protocol liability in its 2005 financial statements. Conservative media coverage of this report emphasised governmental miscalculation, the financial liabilities generated by Kyoto Protocol regulations and a struggle between Climate Change Minister Peter Hodgson and industry voices over how to define the problem. This article links the arguments and discursive strategies used in the 17 June 2005 newspaper coverage of increasing greenhouse gas emissions to the institutional actors shaping New Zealand climate change policy. The increased effectiveness of industry challenges to government climate change policy is noted and discussed.
‘Not Attributable to Official Sources’: Counter-Propaganda and the Mass Media
Authors: McKnight David
Published: January 2017

During the Cold War in Australia, the political agenda was dominated by the threat of communism. One factor in building this agenda was the ‘counter-propaganda operations’ of the Australian Security Intelligence Organisation (ASIO) which regularly released unattributable information to selected mass media outlets. In the period when these activities were most prevalent (1960–72), ASIO officers had regular contact with editors and with selected journalists on major newspapers and television. This formed part of a broader ‘cultural Cold War’ in which anti-communism was an organising principle. This article outlines new information on these activities, suggests that these operations were more extensive than previously thought, and discusses this relationship in terms of the scholarly work on media sources, government-sponsored intervention in the media and classical theories of propaganda. It suggests that one way to understand the controversial media role in counter-propaganda operations lies in the relationship between police and crime reporters.
The other Climate Crisis: Digital Culture, Demography and Education
Authors: Robinson Ken
Published: January 2017

The world is facing two urgent crises. The first is the climate change crisis, a result of hundreds of years of problematic use of the planet's natural resources. The second, this article argues, is a crisis in public education, which is the result of an ‘exactly parallel’ misunderstanding and mismanagement of human resources. This article proposes that these crises need to be tackled together, and considers the emergence of digital cultures as presenting both significant challenges and opportunities.
Opening up Literacy with the Digital Turn: Ideas from Mobiles
Authors: Goggin Gerard
Published: January 2017

This paper argues that digital technologies offer an opportunity to open up and rethink cultural literacy. It discusses and critiques prevalent approaches to digital literacy, and examines the kinds of new literacies emerging from mobile phone culture and developments in mobile media. The paper concludes with suggestions for how mobiles can inform not only an understanding of digital literacy, but directions in literacy in general.
A Support Withdrawn: ‘Spain's 9/11’ and Australian Newspaper Framing
Authors: Donnar Glen
Published: January 2017

This study represents an attempt to redress the neglect of academic research into coverage of the Madrid train bombings through a content analysis of major Australian newspapers in the immediate aftermath (12–21 March 2004). It quantifies a sudden and significant shift in representation from a ‘support for Spain’ news frame following the bombings to a ‘criticism of Spain’ frame following the Spanish national election result only three days later. Australian newspapers made support for a terrorised Spain conditional on a politics of representation marked by the ‘war on terror’ as a master frame, and served to reflect the political interests and sponsored interpretation of government sources. The moral implications of this withdrawal of support for the Spanish cannot be under-estimated, for it suggests that Australian newspapers were prepared to contribute to an ‘erosion’ of compassion for recent victims of terrorism.
Nerds in the City: Flight of the Conchords Makes Good Television Humour
Authors: Lloyd Mike
Published: January 2017

First screened in 2007 on HBO television, Flight of the Conchords has received the best international reception of any New Zealand-based television comedy. The series shows the two Kiwis, Bret and Jemaine — a musical duo — bumbling their way through trying to make it in New York. The failure scenario could have led to the typical sitcom fare of conflicting personalities with specific character types as the butt of humour; however, Flight of the Conchords avoids this standard route, and this may partly explain its popularity. Details are provided of exactly how the series makes ‘good’ humour, with a beginning contrast made to the Australian television series Kath and Kim, which has ridicule at its heart. Turnbull (2004) has pinpointed some unease about comedy based on ridicule, and specifically identifies genre mixing as a source of concern in Kath and Kim. In contrast, Flight of the Conchords, while getting close to ridicule, successfully avoids condescension by a different mix of genres and material.
Limit of Maps? Locality and Cinema-Going in Australia
Authors: Bowles Kate
Published: January 2017

Cinema-going is a cultural experience shaped by logistics and mobility, as film distributors and exhibitors operate to enable films to be screened in places and at times when audiences can physically assemble to view them together. A historical understanding of the geography of cinema distribution, exhibition and attendance can therefore help us to understand what factors other than the choice of film title may have shaped the experience of the cinema audience. This article uses samples of trade commentary on small country cinemas in the late 1920s from the Australian trade journal Everyones, and suggests that historical GIS maps could help us to understand regional differences in the cinema-going experience, or track phenomena such as the diffusion of racial and social segregation in cinemas. Nevertheless, we need to remain mindful of the limits of maps to adequately explain the cultural experience of encountering these phenomena.
Hot for Teacher: The Cultural Erotics and Anxieties of Adolescent Sexuality
Authors: Angelides Steven
Published: January 2017

This article takes popular media scandals surrounding cases of female secondary school teachers charged with sexual offences against male students as its point of inquiry. Using the infamous story of former American schoolteacher Debra Lafave as a case study, it examines the over-determined dynamics of fascination, eroticisation and anxiety structuring the representation and reception of this case and others like it. The article argues that the ‘sex panic’ over female teacher sex offenders is often less about the women than it is about male adolescent sexuality.
Chinese Media Studies: A Belated Introduction?
Authors: Donald Stephanie Hemelryk
Published: January 2017

The past several years have seen the emergence of Chinese media studies as a sub-field in communications and media studies worldwide, as an increasingly popular aspect of area and language-specific culture studies, and as a growing focus within Chinese research and teaching institutions in the People's Republic of China, Hong Kong Special Autonomous Region and Taiwan, as well as in non-Chinese institutions. This collection of articles puts forward the claim that Chinese media studies has become a new ‘proof of life’ for the necessary relationship between humanities and social sciences broadly taken, and research and education in the media.
Meanings of Integration in the Australian Press Coverage of Muslims: Implications for Social Inclusion and Exclusion
Authors: Rane Halim , Hersi Abdi
Published: January 2017

This article uses a framing perspective to analyse the Australian press coverage of Muslim Australians with regard to the issue of their integration into Australian society. Taking a qualitative approach, this study is based on analysis of articles published in The Australian, the Sydney Morning Herald, The Age and the Courier-Mail in alternate years from 2002 to 2010. Of particular focus are the themes and definitions associated with integration that arise in the context of the coverage. The study finds the coverage of Muslim integration to contain both favourable and pejorative representations of Muslims. However, the coverage tends to focus on certain themes that represent only a minority of Muslims, such as radicalisation and terrorism. Muslim integration also features as central to debates concerning multiculturalism, Australian values and the citizenship test. The coverage uses narrow definitions of integration that are based mainly on cultural indicators rather than other definitions prevalent in the scholarly literature on integration, such as economic, political and broader social indicators. Overall, the article suggests that these limitations to the coverage have the potential to impact on public perceptions of social inclusion and exclusion in relation to Muslim Australians.
Masterchef‘s Amateur Makeovers
Authors: Seale Kirsten
Published: January 2017

The media industries are becoming increasingly reliant on amateur labour, and Australia's highest rating television program, MasterChef Australia, is no exception. The show's grand narrative of ‘making over’ home cooks into professionals is at odds with its calculatedly ambivalent representation and deployment of the trope of the amateur. This article proposes that MasterChef is instead invested in deferring the attainment of professional status so as to ensure the continued provision of inexpensive labour and content provided by amateurs.
Negotiating Paternalism and the Enterprising Self in Taiwanese Talent Shows
Authors: Jian Miaoju
Published: January 2017

Talent shows have rocketed to popularity in Taiwan in recent years, as demonstrated in the high rating programs, One Million Star (超級星光大道) and Super Idol (超級偶像). This article focuses on the Taiwan talent show phenomenon as an exemplar of today's contradictory and exploitable reality TV ‘celebrity economy’. Through the oft-repeated assertion of ‘yes, teacher’ (謝謝老師), Taiwan's talent shows manage to combine a globalising self-enterprising ethos of neo-liberal labour conditions with a Confucian-patriarchal culture. Within this context, powerful judges become mentors, with obedient contestants positioned as their apprentices. This article scrutinises the interdependence between this power-laden relationship in the talent shows and the self-enterprising practices of Taiwan's entertainment industry. It argues that, rather than democratising the TV empire, these shows have, paradoxically, contributed to the revival and consolidation of the previously presumed to be outmoded figure of the ‘star authority’.
Citizen Contributions to Professional News Circuits: The Case of the Photo Agency Citizenside
Authors: Nicey Jérémie
Published: January 2017

Citizenside, a French participatory news photo agency, is analysed here to measure the changing production of news. How do traditional circuits respond to new flows of news provided by ‘amateurs’? Is the latter term still valid? The concept of citizen news content is examined: its image largely depends on established media, which may feel threatened in the digital era. Citizenside, as a news agency, conducts its operations with established media. This model is of interest because of the technical tools employed to ensure the checking of photos and videos (reliable profiles, metadata, geo-location, web tracking of photos) and because of its ‘community management’, which strengthens the performance of contributors. Until 2013, Agence France-Presse held a 34 per cent stake in the company, which was acquired by Matilda Media subsidiary Newzulu.com . Citizenside exemplifies the move from user-generated content (UGC) to user-certified content (UCC).
Raising the Golden Goose: A Retrospective Analysis of the State's Role in China's Online Game Industry
Authors: Liu Chun
Published: January 2017

Through a retrospective account of the evolution of China's online game industry, this article examines the political, economic and cultural factors that have shaped the industry, with an emphasis on formal policy-making. Drawing on the theory of fragmented authoritarianism, this study finds that Chinese online games are deeply shaped by the political environment of the autocratic Chinese system, which features inter-ministerial competition, and intertwined state control and commercial interests. The current Chinese online market is combined with a strong private sector presence and a considerable government role. The Chinese government seems to have achieved its policy goal of helping Chinese companies to dominate the domestic market. However, to some extent the extensive and ambiguous government policy and regulations have restrained innovation. To that end, whether China can accomplish its three-stepped importation–substitution– creation strategy in this highly creative industry remains to be seen and warrants future investigation.
Land, Listening and Voice: Investigating Community and Media Representations of the Queensland Struggle for Land Rights and Equality
Authors: Foxwell-Norton Kerrie , Forde Susan , Meadows Michael
Published: January 2017

For the most part, the story of the Australian Indigenous land rights struggle has been told by the Australian media – media that have attracted consistent criticism for their portrayal of Indigenous Australians. On the other hand, Australia boasts a vibrant and accomplished Indigenous media sector that has also told the land rights story from a different perspective, albeit to a much smaller audience. The authors are currently a part of a research team seeking to provide a critical analysis of historical and contemporary representations of the land rights movement and the broader struggle for indigenous rights and equality in Queensland. The project seeks to challenge the prevailing dialogue by focusing on the perspectives of people who have been (and still are) involved in the land rights movement. Prioritising and exploring such alternative perspectives will not only present the opportunity to reconsider the role of media representations, but will also enable an Indigenous ‘take’ on them to emerge. This article presents our approach and rationale, discussing the methodological possibilities and challenges of research with Indigenous communities, which ultimately seeks to redress media imbalance and injustice by a retelling that elevates Indigenous voices, stories and pictures.
Manufacturing a Crime Wave: The Gold Coast Saga
Authors: Schindeler Emily , Ewart Jacqui
Published: January 2017

Crime waves make great headlines, and can be an ongoing source of stories for news media. In this article, we track the news media promotion of the spectre of a crime wave at Queensland's Gold Coast and the interplay between politics and policy responses to the media campaign. By analysing news media reports, government, local government and police-documented responses, we explore how the media framed this crime wave and the politically driven policy responses that were disproportionate to the reported (statistical) level of crime. Despite attempts by the Queensland Police Service to defuse the claims of an out-of-control crime problem, followed by its attempts at managing community responses, the local news media continued their campaign with significant consequences. Our findings are important for those charged with publicly managing responses to media-driven crime waves.
Broadband Futures: Content, Connectivity and Control
Authors: Allen Matthew , Park Sora , Middleton Catherine , Thompson Peter
Published: January 2017

This introduction to the Broadband Futures: Content, Connectivity and Control special issue begins with the claim that we are at the start of a new period of debate and analysis about network infrastructure and use that declares government failure and reinvigorates the drive to a free-market solution in Australia and New Zealand. But questions remain about the effectiveness and social value of network developments, regardless of the degree of government investment and regulation. As canvassed in this introduction, and the articles that make up the special issue, we can only move forward, both in research and practical implementation, if we accept the intricate weaving together of past, present and future interactions between governments, service providers and their consumers in broadband development.
Broadband as Civic Infrastructure: The Australian Case
Authors: McShane Ian , Wilson Chris , Meredyth Denise
Published: January 2017

Australian municipal governments have lagged behind many of their international counterparts in local public broadband provision. However, by 2014 there are signs that the gap is closing, with significant new investment in public wi-fi by city governments across Australia. This article contextualises the current interest in public wi-fi by analysing international developments in municipal broadband and the spasmodic involvement of Australian local authorities in this field. We argue that the rhetoric of broadband as a ‘fourth utility’ unduly prioritises the role of higher governments in Australia, constraining a full exploration of how broadband might be imagined as a form of civic infrastructure.
The Listening Key: Unlocking the Democratic Potential of Indigenous Participatory Media
Authors: Waller Lisa , Dreher Tanja , McCallum Kerry
Published: January 2017

This article explores how a listening approach might address the complex challenges of researching the relationship between Indigenous participation in media and mainstream policy-making processes. An overview of contemporary Indigenous media demonstrates how digital and social media have built on the vibrant and innovative Indigenous media tradition, and enabled a proliferation of new Indigenous voices. But do the powerful listen to Indigenous-produced media, and does this constitute meaningful participation in the political process? The article distinguishes between participation as involvement in the production and dissemination of media, and participation as political influence. It argues that both meanings are crucial for fully realising the potential of Indigenous participatory media, and contends that a listening approach might offer ways to research and unlock the democratic potential of Indigenous media participation.
Reframing Surfing: Physical Culture in Online Spaces
Authors: Olive Rebecca
Published: January 2017

The social media app Instagram has become a popular everyday way to share visual representations of surfing culture and experiences. Providing an alternative to mainstream surf media, images posted on Instagram by women who surf recreationally both disrupt and reinforce the existing sexualisation and differentiation of women in surf culture. Images themselves are not necessarily resistant, yet women are asserting themselves as a voice of surf cultural authority through processes of posting, sharing and engaging with images. While ‘big data’ research about Instagram is proving useful in terms of mapping spaces and movements, this article adopts an ethnographic approach to explore the notion that social media developments are changing possible ways of knowing and representing the world in which we live. Also considered is how lived experiences and social media shape each other in everyday lives and communities.
Afterword: Media Sport — Coming to a Screen near and on You
Authors: Rowe David
Published: January 2017

The complex, often unpredictable and shifting media sport landscape demands a reinvigorated concern with consumption and innovation. But it also must embrace production, adaptation, resistance, reproduction, and the exercise of power – as well as pleasure, identity and strategic citizen mobilisation. This theme section exemplifies these tensions between change and continuity, and the purpose of this article is to provide further observation on the themes and issues that have emerged through the various articles in the issue.
Do ‘we’ really live in rapidly changing times? Questions concerning time, childhood, technology and education
Authors: Gibbons Andrew
Published: January 2017

The arrival of digital media in early education appears to have been both the cause and effect of an idea of a universal experience of rapidly changing time. In this article, the role and purpose of the phrase ‘we live in rapidly changing times’ is of critical concern. The phrase is questioned in order to avoid taking its meaning for granted, arguing for an openness to the ways in which such a phrase might impact on teaching and learning, adulthood and childhood, education and school. The article engages with time as a universalising and colonising experience, and looks at how the times and time are talked about in particular ways and for particular purposes. The analysis in this article theorises time in relation to technology, economics, development and the broader politics of progress. These ideas are situated as critical to how the times are seen as rapidly changing. In exploring a range of texts and contexts, the article makes apparent the politics of the phrase. The article argues for questioning and resisting claims regarding the times on the grounds that studying and teaching childhood and technology will be more open to the ways in which their educational subjectivities are constructed. The article concludes with a turn to resistance to ideas about the inevitability of the times in which the teacher finds herself. Looking briefly at the writing of Albert Camus, strategies for resistance are offered that promote to teachers the idea of playing with time.
Becoming “babies” in real time: Temporal emergence in the classroom mangle
Authors: Myers Casey Y
Published: January 2017

Through multimodal retellings of kindergarten children’s performances of “baby,” this article aims to contribute to the emerging “posthuman conversation” within early childhood studies. Specifically, this work makes moves toward reconceptualizing children’s becomings within educational contexts by, first, interrogating the ways in which adult notions of “time” came to bear upon children’s enactments of “babies” within classroom pretend play performances and, second, exploring how posthuman conceptions of temporality—specifically Pickering’s “mangle”—can disrupt developmental analyses of children’s (un)timely performances and accommodate a more nuanced version of childhood becoming(s).
Veiling and management
Authors: Arar Khalid , Shapira Tamar
Published: January 2017

This article explores the motivations of Arab Muslim women managers in Israel who adopt the veil just before or soon after their nomination to management positions. We used narrative research in order to understand this growing phenomenon and its meaning for the women managers in different life spheres. While the research findings stress the different motivations for adopting or rejecting veiling, all the women managers perceived veiling as a phenomenon that has direct consequences for their status in Arab Muslim society and for their ability to function effectively as managers and to introduce far-reaching changes with the support of their community and the staff. The article contributes to our understanding of Muslim women’s visibility in private venues and in the public sphere and reinforces the need for more in-depth comparative cultural studies of veiling perceptions.
Role of Heme Oxygenase-1 in the Regulation of Blood Pressure and Cardiac Function
Authors: Chen Yen-Hsu , Yet Shaw-Fang , Perrella Mark A.
Published: January 2017

Heme oxygenase (HO) is a cytoprotective enzyme that degrades heme (a potent oxidant) to generate carbon monoxide (a vasodilatory gas that has anti-inflammatory properties), bilirubin (an antioxidant derived from biliverdin), and iron (sequestered by ferritin). Because of the properties of inducible HO (HO-1) and its products, we hypothesized that HO-1 would play an important role in the regulation of cardiovascular function. In this article, we will review the role of HO-1 in the regulation of blood pressure and cardiac function and highlight previous studies from our laboratory using gene deletion and gene overexpression transgenic approaches in mice. These studies will include the investigation of HO-1 in the setting of hypertension (renovascular), hypotension (endotoxemia), and ischemia/reperfusion injury (heart). In a chronic renovascular hypertension model, hypertension, cardiac hypertrophy, acute renal failure, and acute mortality induced by one kidney–one clip surgery were more severe in HO-1-null mice. In addition, HO-1-null mice with endotoxemia had earlier resolution of hypotension, yet the mortality and the incidence of end-organ damage were higher in the absence of HO-1. In contrast, mice with cardiac-specific overexpression of HO-1 had an improvement in cardiac function, smaller myocardial infarctions, and reduced inflammatory and oxidative damage after coronary artery ligation and reperfusion. Taken together, these studies suggest that an absence of HO-1 has detrimental consequences, whereas overexpression of HO-1 plays a protective role in hypoperfusion and ischemia/reperfusion injury.
Effects of Tin-Protoporphyrin IX on Blood Flow in a Rat Tumor Model
Authors: Khelifi Amel F. , Prise Vivien E. , Tozer Gillian M.
Published: January 2017

Carbon monoxide (CO), one of the products of heme oxygenase (HO) catalyzed heme degradation, is a vasodilator. The aim of the present study was to clarify the role of HO in blood flow maintenance in tumors. Male BD9 rats bearing subcutaneous transplants of the P22 carcinosarcoma tumor were treated intraperitoneally (ip) with either tin-protoporphyrin IX (SnPP; 45 μmol/kg), a selective inhibitor of HO or copper-protoporphyrin IX (CuPP; 45 μmol/kg), used as a negative control. The extent of HO activity inhibition was measured using a spectrophotometric assay of bilirubin production and blood flow rates to the tumor and a range of normal tissues were assessed using the uptake of the radiolabelled tracer, iodo-antipyrine (125I-IAP). The animals were cannulated under fentanyl citrate/fluanisone (Hypnorm)/midazolam anesthesia. In the P22 tumor, SnPP, but not CuPP, caused a complete inhibition of HO activity 15 min post-treatment. Administration of SnPP 15 min before blood flow measurements reduced tumor blood flow by 17%, with no effects in any of the normal tissues studied. However, CuPP induced a greater reduction in tumor blood flow than SnPP (45% decrease). Furthermore, CuPP caused a reduction in blood flow to the skin and small intestine but a significant increase to skeletal muscle. The current findings conclusively establish only a minor role played by the HO/CO system in the maintenance of blood flow in this tumor system, despite relatively high levels of HO-1 protein and HO activity. The results also highlight the potential usefulness of CuPP as a tumor blood flow modifier.
Novel Inhibitors of Neuronal Nitric Oxide Synthase
Authors: Di Giacomo C. , Sorrenti V. , Salerno L. , Cardile V. , Guerrera F. , Siracusa M.A. , Avitabile M. , Vanella A.
Published: January 2017

Selective inhibitors of neuronal nitric oxide synthase (nNOS), which are devoid of any effect on the endothelial isoform (eNOS), may be required for the treatment of some neurological disorders. In our search for novel nNOS inhibitors, we recently described some 1-[(Aryloxy)ethyl]-1 H-imidazoles as interesting molecules for their selectivity for nNOS against eNOS. This work reports a new series of 1-[(Aryloxy)alkyl]-1 H-imidazoles in which a longer methylene chain is present between the imidazole and the phenol part of molecule. Some of these molecules were found to be more potent nNOS inhibitors than the parent ethylenic compounds, although this increase in potency resulted in a partial loss of selectivity. The most interesting compound was investigated to establish its mechanism of action and was found to interact with the tetrahydrobiopterin (BH4) binding site of nNOS, without interference with any other cofactors or substrate binding sites.
Regulation of Heme Oxygenase Expression by Cyclopentenone Prostaglandins
Authors: Zhuang Hean , Pin Sokhon , Li Xiaoling , Doré Sylvain
Published: January 2017

Prostaglandins (PGs) originate from the degradation of membranar arachidonic acid by cyclooxygenases (COX-1 and COX-2). The prostaglandin actions in the nervous system are multiple and have been suggested to play a significant role in neurodegenerative disorders. Some PGs have been reported to be toxic and, interestingly, the cyclopentenone PGs have been reported to be cytoprotective at low concentration and could play a significant role in neuronal plasticity. They have been shown to be protective against oxidative stress injury; however, the cellular mechanisms of protection afforded by these PGs are still unclear. It is postulated that the cascade leading to neuronal cell death in acute and chronic neurodegenerative conditions, such as cerebral ischemia and Alzheimer’s disease, would be mediated by free radical damage. We tested the hypothesis that the neuroprotective action of cyclopentanone could be caused partially by an induction of heme oxygenase 1 (HO-1). We and others have previously reported that modulation of HO total activity may well have direct physiological implications in stroke and in Alzheimer’s disease. HO acts as an antioxidant enzyme by degrading heme into iron, carbon monoxide, and biliverdin that is rapidly converted into bilirubin. Using mouse primary neuronal cultures, we demonstrated that PGs of the J series induce HO-1 in a dose-dependent manner (0, 0.5, 5, 10, 20, and 50 μg/ml) and that PGJ2and dPGJ2were more potent than PGA2, dPGA2, PGD2, and PGE2. No significant effects were observed for HO-2 and actin expression. In regard to HO-3 expression found in rat, with its protein deducted sequence highly homologous to HO-2, no detection was observed in HO-2−/−mice, suggesting that HO-3 protein would not be present in mouse brain. We are proposing that several of the protective effects of PGJ2could be mediated through beneficial actions of heme degradation and its metabolites. The design of new mimetics based on the cyclopentenone structure could be very useful as neuroprotective agents and be tested in animal models of stroke and Alzheimer’s disease.
Nonproteic Antioxidant Status in Plasma of Subjects with Colon Cancer
Authors: Di Giacomo Claudia , Acquaviva Rosaria , Lanteri Raffaele , Licata Francesca , Licata Antonio , Vanella Angelo
Published: January 2017

Reactive oxygen species (ROS) could be important causative agents of a number of human diseases, including cancer. Thus, antioxidants, which control the oxidative stress state, represent a major line of defense regulating overall health. Human plasma contains many different nonenzymatic antioxidants. Because of their number, it is difficult to measure each of these different antioxidants separately. In addition, the antioxidant status in human plasma is dynamic and may be affected by many factors. Thus, the relationship between nonenzymatic antioxidant capacity of plasma and levels of well-known markers of oxidative stress (oxidized proteins, lipid hydroperoxides, decreases in thiol groups) better reflects health status. The present study considers antioxidant capacity and oxidative stress in human plasma of patients with colon cancer or precancerous lesions, as well as before and after surgical removal of tumors and/or chemo/radiation therapy. Healthy blood donors were used as controls. Colon cancer patients demonstrated a significant decrease in nonproteic antioxidant status and in total thiol groups with respect to healthy controls, whereas oxidized proteins and lipid hydroperoxide levels were significantly increased. In patients with precancerous lesions, the only unmodified parameter was the thiol group level. After surgery, the levels of oxidized proteins, lipid hydroperoxides, and total thiol groups were restored to those seen in healthy subjects, whereas nonproteic antioxidant capacity remained unmodified from that determined before surgery. Conversely, chemo/radiation therapy increased both nonproteic antioxidant capacity and levels of oxidized proteins and lipid hydroperoxides and significantly decreased total thiol groups. These results further support the hypothesis that oxidative stress correlates to the risk of some forms of cancer, not only in the initial stages but also during progression.
Heme Oxygenase Expression in Selected Regions of Term Human Placenta
Authors: McLaughlin Brian E. , Lash Gendie E. , Smith Graeme N. , Marks Gerald S. , Nakatsu Kanji , Graham Charles H. , Brien James F.
Published: January 2017

Carbon monoxide (CO), formed during heme oxygenase (HO)-catalyzed oxidation of heme, has been proposed to play a complementary role with nitric oxide in the regulation of placental hemodynamics. The objective of this study was to elucidate HO enzymatic activity and HO-1 (inducible) and HO-2 (constitutive) protein content in the microsomal subcellular fraction of homogenate of selected regions of placenta from normotensive and mild pre-eclamptic pregnancies. HO enzymatic activity was measured under optimized conditions by gas chromatography using CO formation as an index of activity, and HO-1 and HO-2 protein content were determined by Western immunoblot analysis. Microsomal HO activity in each of the four placental regions was not different between normotensive and mild pre-eclamptic pregnancies. Microsomal HO-2 protein content was not different between normotensive and mild pre-eclamptic pregnancies, whereas there was increased expression of microsomal HO-1 protein in chorionic villi and fetal membranes from pre-eclamptic pregnancy compared with normotensive pregnancy. Microsomal HO enzymatic activity correlated with HO-2, but not HO-1, protein content.
Does Heme Oxygenase-1 Have a Role in Caco-2 Cell Cycle Progression?
Authors: Uc Aliye , Britigan Bradley E.
Published: January 2017

Intestinal epithelium undergoes a rapid self-renewal process characterized by the proliferation of the crypt cells, their differentiation into mature enterocytes as they migrate up to the villi, followed by their shedding as they become senescent villus enterocytes. The exact mechanism that regulates the intestinal epithelium renewal process is not well understood, but the differential expression of regulatory genes along the crypt-villus axis may have a role. Heme oxygenase-1 (HO-1) is involved in endothelial cell cycle progression, but its role in the intestinal epithelial cell turnover has not been explored. With its effects on cell proliferation and its differential expression along the crypt-villus axis, HO-1 may play a role in the intestinal epithelial cell renewal process. In this study, we examined the role of HO-1 in the proliferation and differentiation of Caco-2 cells, a well-established in vitro model for human enterocytes. After confluence, Caco-2 cells undergo spontaneous differentiation and mimic the crypt to villus maturation observed in vivo. In preconfluent and confluent Caco-2 cells, HO-1 protein expression was determined with the immunoblot. HO-1 activity was determined by the ability of the enzyme to generate bilirubin from hemin. The effect of a HO-1 enzyme activity inhibitor, tin protoporphyrin (SnPP), on Caco-2 cell proliferation and differentiation was examined. In preconfluent cells, cell number was determined periodically as a marker of proliferation. Cell viability was measured with MTT assay. Cell differentiation was assessed by the expression of a brush border enzyme, alkaline phophatase (ALP). HO-1 was expressed in subconfluent Caco-2 cells and remained detectable until 2 days postconfluency. This timing was consistent with cells starting their differentiation and taking the features of normal intestinal epithelial cells. HO-1 was inducible in confluent Caco-2 cells by the enzyme substrate, hemin in a dose- and time-dependent manner. SnPP decreased the cell number and viability of preconfluent cells and delayed the ALP enzyme activity of confluent cells. HO-1 may be involved in intestinal cell cycle progression.
Vitamin E Stimulates Luteinizing Hormone-Releasing Hormone and Ascorbic Acid Release from Medial Basal Hypothalami of Adult Male Rats
Authors: Karanth S. , Yu W.H. , Mastronardi C.A. , McCann S.M.
Published: January 2017

Vitamin E, a dietary factor, is essential for reproduction in animals. It is an antioxidant present in all mammalian cells. Previously, we showed that ascorbic acid (AA) acted as an inhibitory neurotransmitter in the hypothalamus by scavenging nitric oxide (NO). Earlier studies have shown the antioxidant synergism between vitamin E and ascorbic acid (AA). Therefore, it was of interest to evaluate the effect of vitamin E on luteinizing hormone-releasing hormone (LHRH) and AA release. Medial basal hypothalami from adult male rats of the Sprague Dawley strain were incubated with Krebs-Ringer bicarbonate buffer or graded concentrations of a water soluble form of vitamin E, tocopheryl succinate polyethylene glycol 1000 (TPGS, 22–176 μM) for 1 hr. Subsequently, the tissues were incubated with vitamin E or combinations of vitamin. E + N-methyl-D-aspartic acid (NMDA), an excitatory amino acid for 30 min to study the effect of prior and continued exposure to vitamin E on NMDA-induced LHRH release. AA and LHRH released into the incubation media were determined by high-performance liquid chromatography and radioimmunoassay, respectively. Vitamin E stimulated both LHRH and AA release. The minimal effective concentrations were 22 and 88 μM, respectively. NMDA stimulated LHRH release as previously shown and this effect was not altered in the combined presence of vitamin E plus NMDA. However, AA release was significantly reduced in the combined presence of vitamin E plus NMDA. To evaluate the role of NO in vitamin E-induced LHRH and AA release, the tissues were incubated with vitamin E or combinations of vitamin E + NG-monomethyl-L-arginine (NMMA), a competitive inhibitor of NO synthase. NMMA significantly suppressed vitamin E-induced LHRH and AA release indicating a role of NO in the release of both LHRH and AA. The data suggest that vitamin E plays a role in the hypothalamic control of LHRH and AA release and that the release is mediated by NO.
Prolactin, Cortisol, and Insulin Regulation of Nucleoside Uptake Into Mouse Mammary Gland Explants
Authors: Rillema James A. , Houston Tammy L. , John-Pierre-Louis Kila
Published: January 2017

Nucleosides are essential components of milk that are used for the nourishment of newborns. Effects of the three primary lactogenic hormones, including prolactin (PRL), insulin (I), and cortisol (H), on nucleoside uptake and incorporation into cultured mammary tissues taken from 12- to 14-day pregnant mice were determined; most experiments focused on the regulation of uridine uptake. Insulin alone, as well as PRL in the presence of insulin and cortisol, was shown to stimulate uridine uptake and incorporation into RNA in mammary explants taken from 12- to 14-day pregnant mice. The PRL effects were expressed at concentrations of 25 ng/ml and above, which are physiological plasma concentrations. In the absence of sodium, uridine uptake and incorporation were diminished, suggesting the presence of a sodium-dependent uridine transporter. In kinetic studies the apparent Km for uridine uptake was calculated to be 312 μM, and the Vmax 2.90 μmol/hr/L cell water; PRL had no effect on the Km but increased the Vmax to 5.88 μmol/hr/L cell water. When assessing uridine uptake in the presence of the other nucleosides at 0.1 mM, only cytidine competed with uridine uptake. The fact that distribution ratios of greater than 15:1 were achieved with uridine indicates that uridine uptake may be via an active transporter. These studies show that PRL enhances uridine update in mammary tissues by stimulating the activity, and probably synthesis, of a sodium-dependent, active uridine and cytosine transporter.