Effect of dietary arachidonic acid and n-3 polyunsaturated fatty acids on the production of eicosanoids

The major polyunsaturated fatty acid (PUFA) in the western diet is linoleic acid (LA), which is considered to be the major source of tissue arachidonic acid (AA), the principal precursor for the vaso-active eicosanoids via the cyclooxygenase enzymatic pathway. However, dietary AA may contribute significantly to tissue levels of AA in humans, leading to an increase in the production of eicosanoids, particularly the platelet aggregating, vasoconstricting, thromboxane (TXA2), hence increasing thrombosis risk. The aims of this study were to determine the extent to which dietary AA contributed to prostacyclin (PGI2) and TXA2 production in vivo and whether dietary long chain (LC) n-3 PUFA have a modulating influence on the metabolism of AA to these vaso-active eicosanoids. A gas chromatography -mass spectrometry (GCMS) method for urinary PGI2-M determination and a tandem GCMS/MS method for urinary TXA2-M determination were perfected for use within our laboratory (with the assistance of Dr Howard Knapp, University of Iowa and Professor Reinhard Lorenz, Ludwig Maximilian's University, Munich, respectively). An initial animal study compared the in vitro production of PGI2 by aorta segments with the whole body in vivo production of PGI2 in rats fed ethyl arachidonate or the ethyl ester of eicosapentaenoic acid (EPA), at levels many times higher than encountered in human diets. During AA feeding both measures of PGI2 increased, although in vitro TXA2 production was not affected. EPA feeding lowered in vitro TXA2 and in vivo PGI2. Prior to determining the effects of AA and LC n-3 PUFA in humans, a study was carried out to determine the AA and LC n-3 PUFA content of foods and from these, an estimate of the mean daily intake of AA and other LC PUFA. Eggs, organ meats and paté were found to be the richest sources of AA. Of the meat and fish analysed, white meat was found to be relatively rich in AA but poor in LC n-3 PUFA. Lean red meat, particularly kangaroo had similar LC n-3 PUFA and AA content. Fish, although rich in AA, had extremely high levels of LC n-3 PUFA. The calculated mean daily intakes of AA in Australian adults was 130mg (males) and 96mg (females). For total LC n-3 PUFA intake, the mean daily values were 247mg (males) and 197mg (females). Two human pilot studies involving dietary intervention trials examined the effects of dietary AA and AA plus long chain n-3 PUFA on thrombosis risk, gauged by the change in the ratio of PGI2 / TXA2 as well as alterations to other recognised risk factors, such as lipoprotein lipids and platelet aggregation. The desired dietary amounts of AA and LC n-3 PUFA were achieved in the first study by combining food items with known levels of each fatty acid. In the second study, where a diet with approximately equal quantities of AA and LC n-3 PUFA was being examined, kangaroo meat was consumed, following a low-fat vegetarian diet used as a baseline. Diets rich in AA alone (~500mg/day) increased plasma phospholipid (PL) AA levels, PGIi and TXA2 production. When foods containing equal quantities of AA and EPA (∼500mg/day of each) were fed to subjects PGI2 increased, with no change in TXAs production. Low fat vegetarian diets lowered PGI2 production, the level of which was reestablished by an AA rich diet (∼300mg AA/day + ∼260mg/day LC n-3 PUFA) of kangaroo meat. However, TXA2 production was not altered. A final, larger human dietary intervention trial then examined the effects of diets relatively rich in AA alone, AA plus LC n-3 PUFA and LC n-3 PUFA, on the ratio of PGI2/TXA2- The dietary sources of these fatty acids were white meat, red meat and fish, respectively. Each contained a mean level of AA of ∼140mg/day, with varying LC n-3 PUFA levels (59, 161 and 3380mg/day, respectively). Neither meat diet altered PGI2 or TXA2 production significantly, despite increasing serum PL AA levels. The fish diet resulted in a decrease in the serum and platelet PL AA/EPA ratio and TXA2 production, thus increasing the PGI2 / TXA2 ratio. These results would indicate that stores of AA in the body are sufficiently high to have effectively saturated the cyclooxygenase pathway for production of both PGI2 and TXA2, thus making any small change in the plasma level of AA due to 'normal' dietary levels, inconsequential. However, as seen in the rat study and the two pilot studies higher dietary levels of AA can increase both PGI2 and TXA2 production. Increases in platelet levels of EPA and DHA were associated with a decrease in TXA2 production, or the maintenance of a constant TXA2 level, while AA tissue levels and PGI2 production increased. This suggests a possible inhibitory effect of LC n-3 PUFA on the metabolism of AA to TXA2, particularly in platelets. From these short term studies, conducted over 2-3 week periods, it can be concluded that diets rich in lean meats can raise plasma AA levels but do not affect TXA2 or PGI2 production, hence are not pro-thrombotic. Diets rich in long chain n-3 PUFA from fish, raise plasma EPA and DHA levels, lower TXA2 production and are anti-thrombotic. Diets which combine equal quantities of AA and LC n-3 PUFA appear to increase PGI2 production while keeping TXA2 production constant. In order for these LC PUFA to have a significant effect on eicosanoid production the dietary intake of these fatty acids through foods such as red meat or white meat would have to be higher than average current Australian consumption levels.

Spurious precision : variability in procedural validity of diagnostic procedures in psychotic disorders and implications for research and treatment

Very few studies have quantified the level of agreement among alternative diagnostic procedures that use a common set of fixed operational criteria. The authors examined the procedural validity of four independent methods of assigning DSM-III-R diagnoses of psychotic disorders. METHOD: The research was conducted as a satellite study to the DSM-IV Field Trial for Schizophrenia and Related Psychotic Disorders. The setting was the National Health and Medical Research Council Schizophrenia Research Unit's Early Psychosis Prevention and Intervention Centre, which focuses on first-episode psychosis. Consecutively admitted patients (N = 50) were assessed by independent raters who used four different procedures to determine a DSM-III-R diagnosis. These procedures were 1) the diagnostic instrument developed for the DSM-IV field trial, 2) the Royal Park Multidiagnostic Instrument for Psychosis, 3) the Munich Diagnostic Checklists, and 4) a consensus DSM-III-R diagnosis assigned by a team of clinician researchers who were expert in the use of diagnostic criteria. RESULTS: Concordance between pairs of diagnostic procedures was only moderate. Corresponding levels of percent agreement, however, ranged from 66% to 76%, with converse misclassification rates of 24%-34% (assuming one procedure to be "correct"). CONCLUSIONS: These findings have significant research and clinical implications. Despite the introduction of operationally defined diagnoses, there remained an appreciable level of differential classification or misclassification arising from variability in the method of assigning the diagnostic criteria rather than the criteria themselves. Such misclassification may impede neurobiological research and have harmful clinical effects on patients with first-episode psychosis.

Canadian nursing students' coping strategies for learning online

This research reports on the experiences of Canadian nursing students as they coped with learning online, exploring the strategies that they used to learn effectively. The findings identified aspects of course design and online facilitation that will help students cope with the lack of social presence in the online environment.

Spectres in the city –De Chirico’s mythologized streetscapes

It is generally accepted that some of the unsettling scenes of the Italian metaphysical painter Giorgio de Chirico, arose from his response to the northern Italian city of Turin, a city he claimed a great affinity with. While de Chirico’s paintings and commentary of this period abound with references to Turin, there has been little investigation into how genuine these citied locations really are. We know that de Chirico’s preference for Turin arose from his passionate engagement with the writings of the philosopher
Friedrich Nietzsche and Nietzsche’s fondness for the city. Yet there is much evidence to suggest that Munich, the city of de Chirico’s early art school days permeated his imagery more completely; whereas Turin reflected his philosophical and aesthetic concerns. This article examines how cities have operated for the artist and how using iconography from both the world of the real and imagined produced powerful enigmatic images that evoked a profound mood of illusion and revelation.

Semantic and layered protein function prediction from PPI networks

Background The past few years have seen a rapid development in novel high-throughput technologies that have created large-scale data on protein-protein interactions (PPI) across human and most model species. This data is commonly represented as networks, with nodes representing proteins and edges representing the PPIs. A fundamental challenge to bioinformatics is how to interpret this wealth of data to elucidate the interaction of patterns and the biological characteristics of the proteins. One significant purpose of this interpretation is to predict unknown protein functions. Although many approaches have been proposed in recent years, the challenge still remains how to reasonably and precisely measure the functional similarities between proteins to improve the prediction effectiveness.

Results We used a Semantic and Layered Protein Function Prediction (SLPFP) framework to more effectively predict unknown protein functions at different functional levels. The framework relies on a new protein similarity measurement and a clustering-based protein function prediction algorithm. The new protein similarity measurement incorporates the topological structure of the PPI network, as well as the protein's semantic information in terms of known protein functions at different functional layers. Experiments on real PPI datasets were conducted to evaluate the effectiveness of the proposed framework in predicting unknown protein functions.

Conclusion The proposed framework has a higher prediction accuracy compared with other similar approaches. The prediction results are stable even for a large number of proteins. Furthermore, the framework is able to predict unknown functions at different functional layers within the Munich Information Center for Protein Sequence (MIPS) hierarchical functional scheme. The experimental results demonstrated that the new protein similarity measurement reflects more reasonably and precisely relationships between proteins.

Experiencing indigenous East African dance songs : reflections from North West University (South Africa)

After democracy (1994) the doors of teaching and learning in music opened widely to include local indigenous music and culture in South Africa. Since 2005, African music has been a vibrant aspect of the music curriculum within the School of Music, North West University, South Africa. Globally tertiary music educators are challenged to include informal pedagogy of indigenous musics within the formal context of university courses. University music courses in South Africa are still predisposed towards ‘western’ music pedagogies. In October 2012, the School of Music invited a visiting expert in African music and dance to offer onsite teaching and learning of Ugandan dance songs to tertiary students. The initiative to include Ugandan music as part of the teaching and learning workshops on African music at the School of Music was funded by the South African Music Rights Organization. The School of Music has an ongoing policy to invite and include culture bearers to share their skills and expertise with students and academics. Such sharing provides culture bearers the opportunity to transmit much needed skills, which are not often offered by academics. UNESCO (2012) identifies scarce knowledge and skills as intangible heritage.

Community music making in Australia : creating, improvising and performing at the 2012 Lake Bolac Eel Festival

Lake Bolac is a freshwater lake, resulting from one of the volcanic eruptions in the Western district of regional Victoria (Australia). There is an annual migration of eels to it and they have been a local indigenous food source for very many years. Since 2004 there has been a festival to celebrate this event culminating at the Lake Bolac Eel Festival (LBEF). Since 2012, the festival included creative art works and a music workshop by academics from Deakin University (Melbourne, Australia) as a regional partnership with Lake Bolac. The opportunity to exhibit, workshop and perform works as academics and practitioners brought the community together where both contemporary and traditional arts can be preserved, protected and promoted. My paper forms part of a larger creative research project called Flows and Catchments at Deakin University which started in 2011. My study situates itself in creative music making and soundscape within the larger project.

Exhibit review : Focus on strangers: photo albums of World War II, Stadtmuseum, Jena, Germany, 2011

Focus on Strangers: Photo Albums of World War II is based on a collaborative research project conducted by two German universities (Carl von Ossietzky Universität Oldenburg and Friedrich Schiller Universität Jena) and was conceptualized in cooperation with four German city museums in Oldenburg, Munich, Frankfurt, and Jena. While the exhibition continues a tradition of museological projects examining Germany’s war history, such as the Wehrmachtsaustellung, which provoked fi erce public debate, Focus on Strangers moves beyond most conventional approaches in a signifi cant way. Th e exhibition pays tribute to the recent development in which private traces of memory have become part of the public perception of history, in this case the history of World War II.

Book review: The Postwar Legacy of Appeasement: British Foreign Policy since 1945. By R. Gerald Hughes (London: Bloomsbury, 2014), pp. xii +331pp, AU$40.99 (pb).

“Appeaser”; since the Second World War there is perhaps no other label that prime ministers and presidents in the English-speaking world have strived so hard to avoid. It is extraordinary how powerful and long-lasting the term appeasement, the name Neville Chamberlain and the place Munich have been in the discourse of post-war international relations. It is a reflection of the all-powerful historical legacy of the Second World War that these terms still resonate with policy makers and their publics well into the twenty-first century. Such a phenomenon deserves scholarly attention and R. Gerald Hughes has done justice to this topic in his very fine book The Postwar Legacy of Appeasement: British Foreign Policy Since 1945.