Mary Barnes

Adherence to a Mediterranean diet and Alzheimer's disease risk in an Australian population.

The Mediterranean diet (MeDi), due to its correlation with a low morbidity and mortality for many chronic diseases, has been widely recognised as a healthy eating model. We aimed to investigate, in a cross-sectional study, the association between adherence to a MeDi and risk for Alzheimer’s disease (AD) and mild cognitive impairment (MCI) in a large, elderly, Australian cohort. Subjects in the Australian Imaging, Biomarkers and Lifestyle Study of Ageing cohort (723 healthy controls (HC), 98 MCI and 149 AD participants) completed the Cancer Council of Victoria Food Frequency Questionnaire. Adherence to the MeDi (0- to 9-point scale with higher scores indicating higher adherence) was the main predictor of AD and MCI status in multinominal logistic regression models that were adjusted for cohort age, sex, country of birth, education, apolipoprotein E genotype, total caloric intake, current smoking status, body mass index, history of diabetes, hypertension, angina, heart attack and stroke. There was a significant difference in adherence to the MeDi between HC and AD subjects (P<0.001), and in adherence between HC and MCI subjects (P<0.05). MeDi is associated with change in Mini-Mental State Examination score over an 18-month time period (P<0.05) in HCs. We conclude that in this Australian cohort, AD and MCI participants had a lower adherence to the MeDi than HC participants.

A Model to Predict Outcomes for Endovascular Aneurysm Repair Using Preoperative Variables

PURPOSE Models have been developed to predict the likely outcomes of endovascular aneurysm repair (EVAR) for patients, based on a longitudinal Australian audit. METHODOLOGY Mid-term progress of 961 Australian patients who underwent EVAR has been collected and used to develop predictive models for 17 outcomes. Stepwise forward logistic regressions determined the significant preoperative patient variables to be included in each outcome model. An interactive program was subsequently developed to allow surgeons to review the predicted success rates for patients about to undergo the procedure. Each model was assessed using a global goodness of fit test and was internally validated using bootstrapping. RESULTS Eight pre-operative variables were included in the interactive model for 17 outcomes. The eight variables used were aneurysm size, age, ASA, gender, creatinine, aortic neck angle, infrarenal neck diameter and infrarenal neck length. The outcomes predicted included perioperative mortality, perioperative morbidity, mid-term survival and reintervention rates. All outcome models achieved reasonable goodness of fit, with the exception of the model for conversion to open repair (p=0.04). With respect to validation, survival, aneurysm related deaths, migrations, ruptures and conversions to open repair performed best in terms of predictive discrimination. Models for survival, migrations and conversions to open repairs performed best in terms of bias corrected R-squared index. The models with the smallest calibration error were 3 and 5 year survival, early deaths and mid-term type I endoleaks. CONCLUSIONS An interactive model is available, which can assist vascular surgeons to evaluate the expected outcomes for a particular patient undergoing EVAR. The validated model is useful for counselling and pre-operative decision making.

Soil factors controlling the toxicity of copper and zinc to microbial processes in Australian soils

Abstract-Two soil microbial processes, substrate-induced nitrification (SIN) and substrate-induced respiration (SIR), were measured in the topsoils of 12 Australian field trials that were amended separately with increasing concentrations of ZnSO4 or CuSO4. The median effect concentration (EC50) values for Zn and Cu based on total metal concentrations varied between 107 and 8,298 mg kg(-1) for Zn and 108 and 2,155 mg kg(-1) Cu among soils. The differences in both Zn and Cu toxicity across the 12 soils were not explained by either the soil solution metal concentrations or CaCl2-extractable metal concentrations, because the variation in the EC50 values was larger than those using total concentrations. Toxicity of Zn and Cu decreased with increasing soil pH for SIN. For Cu, also increasing cation exchange capacity (CEC) and percent clay decreased the toxicity towards SIN. In contrast to SIN, soil pH had no significant effect on toxicity values of SIR. Significant relationships were found between the EC50 values for SIR and background Zn and CEC for Zn, and percent clay and log CEC for Cu. Relationships such as those developed in this study will permit Australian environmental regulation to move from single-value national soil quality guidelines to soil-specific quality guidelines and permit soil-specific risk assessments to be undertaken.

Dietary patterns and cognitive decline in an Australian study of ageing

The aim of this paper was to investigate the association of three well-recognised dietary patterns with cognitive change over a 3-year period. Five hundred and twenty-seven healthy participants from the Australian Imaging, Biomarkers and Lifestyle study of ageing completed the Cancer Council of Victoria food frequency questionnaire at baseline and underwent a comprehensive neuropsychological assessment at baseline, 18 and 36 months follow-up. Individual neuropsychological test scores were used to construct composite scores for six cognitive domains and a global cognitive score. Based on self-reported consumption, scores for three dietary patterns, (1) Australian-style Mediterranean diet (AusMeDi), (2) western diet and (3) prudent diet were generated for each individual. Linear mixed model analyses were conducted to examine the relationship between diet scores and cognitive change in each cognitive domain and for the global score. Higher baseline adherence to the AusMeDi was associated with better performance in the executive function cognitive domain after 36 months in apolipoprotein E (APOE) ɛ4 allele carriers (P<0.01). Higher baseline western diet adherence was associated with greater cognitive decline after 36 months in the visuospatial cognitive domain in APOE ɛ4 allele non-carriers (P<0.01). All other results were not significant. Our findings in this well-characterised Australian cohort indicate that adherence to a healthy diet is important to reduce risk for cognitive decline, with the converse being true for the western diet. Executive function and visuospatial functioning appear to be particularly susceptible to the influence of diet.

Predictors of outcome after elective endovascular abdominal aortic aneurysm repair and external validation of a risk prediction model

INTRODUCTION Endovascular abdominal aortic aneurysm (AAA) repair (EVAR) has been associated with lower operative mortality and morbidity than open surgery but comparable long-term mortality and higher delayed complication and reintervention rates. Attention has therefore been directed to identifying preoperative and operative variables that influence outcomes after EVAR. Risk-prediction models, such as the EVAR Risk Assessment (ERA) model, have also been developed to help surgeons plan EVAR procedures. The aims of this study were (1) to describe outcomes of elective EVAR at the Royal Brisbane and Womens Hospital (RBWH), (2) to identify preoperative and operative variables predictive of outcomes after EVAR, and (3) to externally validate the ERA model. METHODS All elective EVAR procedures at the RBWH before July 1, 2009, were reviewed. Descriptive analyses were performed to determine the outcomes. Univariate and multivariate analyses were performed to identify preoperative and operative variables predictive of outcomes after EVAR. Binomial logistic regression analyses were used to externally validate the ERA model. RESULTS Before July 1, 2009, 197 patients (172 men), who were a mean age of 72.8 years, underwent elective EVAR at the RBWH. Operative mortality was 1.0%. Survival was 81.1% at 3 years and 63.2% at 5 years. Multivariate analysis showed predictors of survival were age (P = .0126), American Society of Anesthesiologists (ASA) score (P = .0180), and chronic obstructive pulmonary disease (P = .0348) at 3 years and age (P = .0103), ASA score (P = .0006), renal failure (P = .0048), and serum creatinine (P = .0022) at 5 years. Aortic branch vessel score was predictive of initial (30-day) type II endoleak (P = .0015). AAA tortuosity was predictive of midterm type I endoleak (P = .0251). Female sex was associated with lower rates of initial clinical success (P = .0406). The ERA model fitted RBWH data well for early death (C statistic = .906), 3-year survival (C statistic = .735), 5-year survival (C statistic = .800), and initial type I endoleak (C statistic = .850). CONCLUSIONS The outcomes of elective EVAR at the RBWH are broadly consistent with those of a nationwide Australian audit and recent randomized trials. Age and ASA score are independent predictors of midterm survival after elective EVAR. The ERA model predicts mortality-related outcomes and initial type I endoleak well for RBWH elective EVAR patients.

Response and recovery of acetylcholinesterase activity in freshwater shrimp, Paratya australiensis (Decapoda: Atyidae) exposed to selected anti-cholinesterase insecticides

The toxicity of carbaryl, chlorpyrifos, dimethoate and profenofos to the freshwater shrimp, Paratya australiensis was assessed by measuring acetylcholinesterase (AChE) inhibition after 96h exposures. Shrimp exposed to these pesticides exhibited significant AChE inhibition, with mortality in shrimp corresponding to 70-90% AChE inhibition. The sensitivity of P. australiensis to the four pesticides based on AChE inhibition can be given as chlorpyrifos > profenofos > carbaryl > dimethoate. Recovery of AChE activity was followed in shrimp after 96 h exposures to carbaryl, chlorpyrifos and dimethoate. Recovery after exposure to the carbamate pesticide carbaryl was more rapid than for the two organophosphorus pesticides, chlorpyrifos and dimethoate. The slow recovery of depressed AChE activity may mean that affected organisms in the natural system are unable to sustain physical activities such as searching for food or eluding predators. To investigate the ecological significance of AChE inhibition, chemotaxis behaviour was assessed in shrimp exposed to profenofos for 24h. Abnormal chemotaxis behaviour in the exposed shrimp was observed at concentrations representing 30-50% AChE inhibition. A clear relationship existed between the depression of AChE activity and observed chemotaxis responses, such as approaching and grasping the chemoattractant source. These results suggest that in vivo toxicity tests based on this specific biomarker are sensitive and present advantages over conventional acute tests based on mortality. Behavioural studies of test organisms conducted in conjunction with measurement of AChE inhibition will provide data to clarify the toxic effects caused by sublethal chemical concentrations of anti-cholinesterase compounds.

Personalised Predictions of Endovascular Aneurysm Repair Success Rates: Validating the ERA Model with UK Vascular Institute Data

OBJECTIVE The objective of this study was to externally validate the existing Australian Endovascular aneurysm repair Risk Assessment (ERA) Model using data from a major vascular centre in the United Kingdom. METHODS Data collected from 312 endovascular abdominal aortic aneurysm repair patients at St Georges Vascular Institute, London, UK were fitted to the ERA Model. RESULTS Despite St Georges patients being sicker (p < 0.001), having larger aneurysms (p < 0.001) and being more likely to die (p < 0.05) than the Australian patients, their data fitted the ERA Model well for the risk factors early death, aneurysm-related death, three-year survival and type I endoleaks as evidenced by higher area under ROC curves and/or higher R(2) goodness of fit statistics than the Australian data. CONCLUSIONS The first external validation of the ERA Model using data from St Georges Vascular Institute suggests that this tool can be used in different countries and hospital settings. The authors believe the ERA Model is robust and allows valid personalised predictions of outcomes by surgeons treating routine aneurysms as well as those in tertiary referral practices with more adverse outcomes.

International trends in patient selection for elective endovascular aneurysm repair: sicker patients with safer anatomy leading to improved 1-year survival.

BACKGROUND To review the trends in patient selection and early death rate for patients undergoing elective endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) in 3 countries. For this study, audit data from 4,163 patients who had undergone elective infrarenal EVAR were amalgamated. The data originated from Australia, Canada (Ontario), and England (London, Cambridge, and Leicester). METHODS Statistical analyses were undertaken to determine whether patient characteristics and early death rate varied between and within study groups and over time. The study design was retrospective analysis of data collected prospectively between 1999 and 2012. RESULTS One-year survival improved over time (P = 0.0013). Canadian patients were sicker than those in Australia or England (P < 0.001). American Society of Anesthesiologists classification (ASA) increased over time across all countries although more significantly in Canada. Age at operation remained constant, although older patients were treated more recently in London (P < 0.001). English centers treated larger aneurysms compared with Australia and Canada (P < 0.001). Australian centers treated a much larger proportion of aneurysms that were <55 mm than other countries. Preoperative creatinine levels decreased over time for all countries and centers (P < 0.001). Infrarenal neck angles have significantly decreased over time (P < 0.001). Recent data from London (UK) showed that operations were performed on longer (P < 0.001) and wider (P < 0.001) infrarenal necks than elsewhere. CONCLUSIONS In this international comparison, several trends were noted including improved 1-year survival despite declining patient health (as measured by increasing ASA status). This may reflect greater knowledge regarding EVAR that centers from different countries have gained over the last decade and improved medical management of patients with aneurysmal disease.

External validation of the Endovascular aneurysm repair Risk Assessment model in predicting survival, reinterventions, and endoleaks after endovascular aneurysm repair

OBJECTIVE The Endovascular aneurysm repair Risk Assessment (ERA) model predicts survival (early death, 3-year survival, and 5-year survival), reinterventions, and endoleaks after elective endovascular aneurysm repair. We externally validated the ERA model in our cohort of patients. METHODS This was a retrospective validation study of 433 consecutive patients with an asymptomatic abdominal aortic aneurysm treated with endovascular aneurysm repair in three hospitals (Amsterdam, The Netherlands) between 1997 and 2010. The area under the receiver operating characteristic curve was used as measure of accuracy (>0.70 was considered as sufficiently accurate). RESULTS The early death rate was 1% (3 of 433; 95% confidence interval [CI], 0%-2%), the 5-year survival rate was 65% (95% CI, 61%-70%), the 5-year reintervention rate was 18% (95% CI, 14-78%), and the 5-year rate of type I, II, or III endoleak was 25% (95% CI, 20%-29%). The areas under the curve varied between 0.64 and 0.66 for predictions of survival and between 0.47 and 0.61 for reinterventions and endoleaks. CONCLUSIONS The predictions of survival, reinterventions, and endoleaks made by the ERA model were not sufficiently accurate to be used in our clinical practice.

Ecological Risk Assessment for Terrestrial Ecosystems: The Summary of Discussions and Recommendations from the Adelaide Workshop (April 2004)

ABSTRACT The Ecological Risk Assessment (ERA) workshop focused on the anthropogenic contaminants in the terrestrial environment, addressing various components of the ERA process. These included sources, exposure pathways, bioavailability, and toxicity to receptor organisms as well as risk communication. It was concluded that although the overseas experience on ERA for terrestrial ecosystems (e.g., International Standards or guidelines from the European Union and the United States) is very useful, it is not directly applicable to Australia due to the differences in receptor organisms, contaminants, soil, and environmental conditions. Workshop discussions stressed on the need for making ERA locally relevant (in terms of choice of receptor organisms, sampling strategy, and bioavailability considerations). The workshop discussions highlighted the need of better appreciation of both the similarities and the clear differences between aquatic and terrestrial ERAs. The availability of reliable data, problems with databases, estimation of bioavailability, and extrapolations from laboratory to field were noted among the key limitations. ERA—being inherently complex and involving a range of environmental compartments, target receptor, and exposure pathways—at a minimum requires a multidisciplinary approach to address the complexities. Bringing a multidisciplinary team together often proves a major challenge in ERA. The delegates called for continued efforts in this area and formation of a network or working group in Australia.