263 results found
Irving MJ, Tong A, Jan S, et al., 2012, Community attitudes to deceased organ donation: a focus group study., Transplantation, Vol: 93, Pages: 1064-1069
BACKGROUND: Despite broad community support for organ donation, there is a chronic shortage of donor organs for transplantation. This study elicited community attitudes on deceased organ donation and the current Australian organ donation system. METHODS: Thirteen focus groups with 114 participants aged between 18 and 75 years. Qualitative analysis using a grounded theory approach was used. RESULTS: Participants were generally positive toward deceased organ donation, but this did not always translate to decisions to be a donor. Three main categories of themes emerged. (1) Participants held core beliefs that both encouraged donation, such as "giving is good" and "saving lives," and discouraged donation, such as loss of body dignity, need for body wholeness, and differing medical care for donors. (2) A range of factors could influence how core beliefs were weighted in the decision-making process, including family, knowledge, information, media, grief, apathy, and fear. (3) Participants discussed the need for a simpler consent system where family members could not overrule their donation decision, greater public awareness for organ donation, and the availability of more information on the organ donation process. CONCLUSIONS: Opportunities exist to improve deceased organ donation rates by education to improve confidence in the donation process, positive media coverage, and clear information on each religion's stance on organ donation. Options for greater public recognition for organ donors should be explored. Finally, our findings suggest that aspects of the current donation consent system are not aligned with community values, and reforms should be debated publicly.
Radomska-Botelho Moniz A, Michelakis K, Trzebinski J, et al., 2012, Minimally Invasive Enzyme Microprobes: An Alternative Approach for Continuous Glucose Monitoring, Journal of Diabetes Science and Technology, Vol: 6, Pages: 479-480
Azarbadegan A, Eames I, Sharma S, et al., 2011, Computational study of parallel valveless micropumps, Sensors and Actuators B: Chemical: international journal devoted to research and development of physical and chemical transducers, Vol: 158, Pages: 432-440
An integrated study of parallel valveless micropumps is described which incorporates computations and a mathematical model. Two cylindrical pump chambers are driven out of phase and the circuit resistance is provided by an interconnecting pipe whose width is varied. A one-dimensional mathematical model, consistent with the pump configuration, is applied to provide a framework to interpret the results. In contrast to open circuit pumps, the maximum volume flux is determined by the properties of the diffuser/nozzle element and the pressure drop is determined by Darcy–Weisbach equation when it is controlled by the interconnecting pipe. The numerical results are in good agreement with mathematical models. The viability of such pumps to work with cells was examined by calculating the maximum shear stress and strain rate.
Cass T, Le T, Scott S, 2011, Exploiting conformational change in biosensor design, 36th FEBS Congress of the Biochemistry for Tomorrows Medicine, Publisher: WILEY-BLACKWELL, Pages: 30-30, ISSN: 1742-464X
Sharma S, Radomska-Botelho Moniz A, Triantis I, et al., 2011, An integrated silicon sensor with microfluidic chip for monitoring potassium and pH, Microfluidics and Nanofluidics, Vol: 10, Pages: 1119-1125
We present ion-sensitive field effect transistor-based sensors, integrated with a microfluidic chip, for monitoring pH and potassium cations. The sensor is strategically located at the base of a well so that the response time of the device depends both on the mean flow through the device and the diffusion coefficient of the analyte being monitored. This would enable monitoring of ions in the presence of larger molecules. The dependence of the device response time on diffusive transport of analytes was examined through a numerical study of the flow field and the passive diffusion of a chemical species. The predicted device response time was compared with the experimental measurements and reasonable agreement found. The general dependence of device response time on geometry, flow rate, and analyte diffusion coefficient was derived. These devices can be used with biological fluids where monitoring of pH and cations provide vital information about the well-being of patients.
White SL, Dunstan DW, Polkinghorne KR, et al., 2011, Physical inactivity and chronic kidney disease in Australian adults: the AusDiab study., Nutr Metab Cardiovasc Dis, Vol: 21, Pages: 104-112
BACKGROUND AND AIMS: Physical inactivity is associated with cardiovascular risk however its relationship to chronic kidney disease is largely unknown. We examined the association between leisure-time physical activity and risk of chronic kidney disease in a prospective, population-based cohort of Australians aged ≥ 25 years (AusDiab). METHODS AND RESULTS: The baseline sample included 10,966 adults (4951 males and 6015 females). From this sample, 6318 participants with complete baseline and 5-year follow-up urinalysis and serum creatinine measurements formed the study population for longitudinal analysis. Self-reported leisure-time physical activity was measured using a validated, interviewer-administered questionnaire. Compared with sufficiently active individuals (≥ 150 min physical activity per week), those who were inactive (0 min/week) were more likely to have albuminuria at baseline (multivariate-adjusted OR=1.34, 95% CI 1.10-1.63). Inactivity (versus sufficient physical activity) was associated with increased age- and sex-adjusted odds of an estimated glomerular filtration rate <3rd percentile (OR=1.30, 95% CI 1.02-1.65), although this was not significant after multivariate adjustment (OR=1.17, 95% CI 0.91-1.50). Obese, inactive individuals were significantly more likely to have albuminuria at baseline (multivariate-adjusted OR=1.74, 95% CI 1.35-2.25), compared with sufficiently active, non-obese individuals. Baseline physical activity status was not significantly associated with longitudinal outcomes. CONCLUSIONS: Physical inactivity is cross-sectionally associated with albuminuria prevalence, particularly when combined with obesity. Future studies are needed to determine whether this association is causal and the importance of physical activity in CKD prevention.
Cass AEG, Zhang Y, 2011, Nucleic acid aptamers: ideal reagents for point-of-care diagnostics?, FARADAY DISCUSSIONS, Vol: 149, Pages: 49-61, ISSN: 1364-5498
Le TT, Wilde CP, Grossman N, et al., 2011, A simple method for controlled immobilization of proteins on modified SAMs, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 13, Pages: 5271-5278, ISSN: 1463-9076
Trzebinski J, Moniz A-B, Sharma S, et al., 2011, Hydrogel Membrane Improves Batch-to-Batch Reproducibility of an Enzymatic Glucose Biosensor, Electroanalysis
A permselective membrane is a critical component that defines the linear detection limits, the sensitivity, and thus the ultimate efficacy of an enzymatic biosensor. Although membranes like epoxy-polyurethane (epoxy-PU) and Nafion are widely used and provide the desired glucose detection limits of 2 to 30 mM, both the within batch and batch-to-batch variability of sensors that use these materials is a concern. The hypothesis for this study was that a crosslinked hydrogel would have a sufficiently uniform porosity and hydrophilicity to address the variability in sensor sensitivity. The hydrogel was prepared by crosslinking di-hydroxyethyl methacrylate, hydroxyethyl methacrylateand N-vinyl pyrrolidone with 2.5 mol% ethylene glycol dimethacrylate using water soluble initiators – ammonium persulfate and sodium metabisulfite under a nitrogen atmosphere. The hydrogel was applied to the sensor bydip coating during polymerisation. Electrochemical measurements revealed that the response characteristics of sensors coated with this membrane are highly consistent. Scanning electrochemical microscopy (SECM) was used tospatially resolve glucose diffusion through the membrane by measuring the consequent H2O2 release and compared with an epoxy-PU membrane. Hydrogen peroxide measurements using SECM revealed that the epoxy-PU membranes had uneven lateral diffusion profiles compared to the uniform profile of the hydrogel membranes. Theuneven diffusion profiles of epoxy-PU membranes are attributed to a fabrication method that results in uneven membrane properties, while the uniform diffusion profiles of the hydrogel membranes are primarily dictated by their uniform pore size.
Trzebinski J, Sharma S, Moniz A-B, et al., 2011, Microfluidic device to investigate factors affecting performance in biosensors designed for transdermal applications, Lab On a Chip: microfluidic and nanotechnologies for chemistry, biology, and bioengineering, Vol: 12, Pages: 348-352
In this work we demonstrate a novel microfluidic based platform to investigate the performance of 3D out-of-plane microspike array based glucose and lactate biosensors. The microspike array was bonded with a glass slide and modified with glucose oxidase or lactate oxidase using covalent coupling chemistry. An epoxy-polyurethane based membrane was used to extend the linear working range (from 0 to 25mM of substrate) of these biosensors. Both lactate and glucose sensors performed well in the clinically relevant substrate concentration range. Glucose microspikes were further investigated with respect to the effects of substrate transfer by incorporation into a microfluidic system. Data from the microfluidic system revealed that the sensor response is mainly dependent on enzyme kinetics rather than membrane permeability to glucose. The robustness of the sensors was demonstrated by its consistency in performance extending over 48 hours.
Yue X, Drakakis EM, Mantalaris A, et al., 2010, Generation of spatio-temporal concentration profiles for cell culture systems: A case study in ammonia, Measurement, Vol: 43, Pages: 1207-1216, ISSN: 0263-2241
Techanukul T, Pereira F, Lipka A, et al., 2010, CE-based sample quality assessment prior to 2-D gel electrophoresis: Towards the standardization of gel-based proteomics, JOURNAL OF SEPARATION SCIENCE, Vol: 33, Pages: 2536-2546, ISSN: 1615-9306
Jun M, Foote C, Lv J, et al., 2010, Effects of fibrates on cardiovascular outcomes: a systematic review and meta-analysis., Lancet, Vol: 375, Pages: 1875-1884
BACKGROUND: Several clinical trials have reported inconsistent findings for the effect of fibrates on cardiovascular risk. We undertook a systematic review and meta-analysis to investigate the effects of fibrates on major clinical outcomes. METHODS: We systematically searched Medline, Embase, and the Cochrane Library for trials published between 1950 and March, 2010. We included prospective randomised controlled trials assessing the effects of fibrates on cardiovascular outcomes compared with placebo. Summary estimates of relative risk (RR) reductions were calculated with a random effects model. Outcomes analysed were major cardiovascular events, coronary events, stroke, heart failure, coronary revascularisation, all-cause mortality, cardiovascular death, non-vascular death, sudden death, new onset albuminuria, and drug-related adverse events. FINDINGS: We identified 18 trials providing data for 45 058 participants, including 2870 major cardiovascular events, 4552 coronary events, and 3880 deaths. Fibrate therapy produced a 10% RR reduction (95% CI 0-18) for major cardiovascular events (p=0.048) and a 13% RR reduction (7-19) for coronary events (p<0.0001), but had no benefit on stroke (-3%, -16 to 9; p=0.69). We noted no effect of fibrate therapy on the risk of all-cause mortality (0%, -8 to 7; p=0.92), cardiovascular mortality (3%, -7 to 12; p=0.59), sudden death (11%, -6 to 26; p=0.19), or non-vascular mortality (-10%, -21 to 0.5; p=0.063). Fibrates reduced the risk of albuminuria progression by 14% (2-25; p=0.028). Serious drug-related adverse events were not significantly increased by fibrates (17 413 participants, 225 events; RR 1.21, 0.91-1.61; p=0.19), although increases in serum creatinine concentrations were common (1.99, 1.46-2.70; p<0.0001). INTERPRETATION: Fibrates can reduce the risk of major cardiovascular events predominantly by prevention of coronary events, and might have a role in individuals at high risk of cardiovascular events and in those
Cass T, 2010, MOLECULES TO DEVICES The Role of Engineering in Next Generation Point of Care Tests, 3rd International Conference on Health Informatics (HEALTHINF 2010), Publisher: INSTICC-INST SYST TECHNOLOGIES INFORMATION CONTROL & COMMUNICATION, Pages: IS9-IS9
Zoungas S, Ninomiya T, Huxley R, et al., 2009, Systematic review: sodium bicarbonate treatment regimens for the prevention of contrast-induced nephropathy., Ann Intern Med, Vol: 151, Pages: 631-638
BACKGROUND: Intravenous sodium bicarbonate has been proposed to reduce the risk for contrast-induced nephropathy (CIN). PURPOSE: To determine the effect of sodium bicarbonate on the risk for CIN. DATA SOURCES: MEDLINE, PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from 1950 to December 2008; conference proceedings; and ClinicalTrials.gov, without language restriction. STUDY SELECTION: Randomized, controlled trials of intravenous sodium bicarbonate that prespecified the outcome of CIN as a 25% increase in baseline serum creatinine level or an absolute increase of 44 micromol/L (0.5 mg/dL) after radiocontrast administration. DATA EXTRACTION: Using standardized protocols, 2 reviewers serially abstracted data for each study. DATA SYNTHESIS: 23 published and unpublished trials with information on 3563 patients and 396 CIN events were included. The pooled relative risk was 0.62 (95% CI, 0.45 to 0.86), with evidence of significant heterogeneity across studies (I(2) = 49.1%; P = 0.004). Some heterogeneity was due to the difference in the estimates between published and unpublished studies: relative risk, 0.43 (CI, 0.25 to 0.75) versus 0.78 (CI, 0.52 to 1.17), respectively. Meta-regression showed that small, poor-quality studies that assessed outcomes soon after radiocontrast administration were more likely to suggest benefit (P < 0.05 for all). No clear effects of treatment on the risk for dialysis, heart failure, and total mortality were identified. LIMITATION: Power to assess clinical end points was limited. CONCLUSION: The effectiveness of sodium bicarbonate treatment to prevent CIN in high-risk patients remains uncertain. Earlier reports probably overestimated the magnitude of any benefit, whereas larger, more recent trials have had neutral results. Large multicenter trials are required to clarify whether sodium bicarbonate has value for prevention of CIN before routine use can be recommended. PRIMARY FUNDING SOURCE: None.
Bellomo R, Cass A, Cole L, et al., 2009, Intensity of continuous renal-replacement therapy in critically ill patients, New England Journal of Medicine, Vol: 361, Pages: 1627-1638, ISSN: 0028-4793
BACKGROUND: The optimal intensity of continuous renal-replacement therapy remains unclear. We conducted a multicenter, randomized trial to compare the effect of this therapy, delivered at two different levels of intensity, on 90-day mortality among critically ill patients with acute kidney injury. METHODS: We randomly assigned critically ill adults with acute kidney injury to continuous renal-replacement therapy in the form of postdilution continuous venovenous hemodiafiltration with an effluent flow of either 40 ml per kilogram of body weight per hour (higher intensity) or 25 ml per kilogram per hour (lower intensity). The primary outcome measure was death within 90 days after randomization. RESULTS: Of the 1508 enrolled patients, 747 were randomly assigned to higher-intensity therapy, and 761 to lower-intensity therapy with continuous venovenous hemodiafiltration. Data on primary outcomes were available for 1464 patients (97.1%): 721 in the higher-intensity group and 743 in the lower-intensity group. The two study groups had similar baseline characteristics and received the study treatment for an average of 6.3 and 5.9 days, respectively (P = 0.35). At 90 days after randomization, 322 deaths had occurred in the higher-intensity group and 332 deaths in the lower-intensity group, for a mortality of 44.7% in each group (odds ratio, 1.00; 95% confidence interval [CI], 0.81 to 1.23; P = 0.99). At 90 days, 6.8% of survivors in the higher-intensity group (27 of 399), as compared with 4.4% of survivors in the lower-intensity group (18 of 411), were still receiving renal-replacement therapy (odds ratio, 1.59; 95% CI, 0.86 to 2.92; P = 0.14). Hypophosphatemia was more common in the higher-intensity group than in the lower-intensity group (65% vs. 54%, P<0.001). CONCLUSIONS: In critically ill patients with acute kidney injury, treatment with higher-intensity continuous renal-replacement therapy did not reduce mortality at 90 days. (ClinicalTrials. gov number, NCT00221013)
Nigwekar SU, Cass A, Gallagher MP, et al., 2009, Interventions for lowering plasma homocysteine levels in dialysis patients, Cochrane Database of Systematic Reviews, ISSN: 1469-493X
Webster RJ, Heeley EL, Peiris DP, et al., 2009, Gaps in cardiovascular disease risk management in Australian general practice., Med J Aust, Vol: 191, Pages: 324-329, ISSN: 0025-729X
OBJECTIVE: To evaluate the management of cardiovascular disease (CVD) risk in Australian general practice. DESIGN, SETTING AND PARTICIPANTS: National cross-sectional survey of 99 Australian general practitioners participating in the Bettering the Evaluation and Care of Health (BEACH) program. Data on 2618 consecutive adult patients presenting to the participating GPs over a 5-week period from September to October 2006 were analysed. MAIN OUTCOME MEASURES: Proportions of patients screened, treated and reaching targets according to (1) current Australian CVD risk guidelines and (2) overall or absolute CVD risk. RESULTS: Blood pressure (BP) had not been recorded for 13% of the sample. Of 1400 patients not prescribed antihypertensive medication, treatment was indicated for 8%. Of 821 patients already prescribed antihypertensive medication, 59% were achieving target BPs. Data on low-density lipoprotein (LDL) cholesterol levels were not available for 53% of the 2175 patients who should have had lipid screening according to the guidelines. Of 624 patients not prescribed a statin, treatment was indicated for 41%. Of 368 already prescribed a statin, 62% were achieving target LDL cholesterol levels. Sufficient data for calculation of absolute risk had been recorded for 74% of the 1736 patients for whom such calculation was recommended by the guidelines. The remaining 26% either had at least one required variable unmeasured (20%) or missing from the data collection (6%). For those at high absolute CVD risk (without established disease) and those with established CVD, 23% and 53%, respectively, had been prescribed both antihypertensive medication and a statin. CONCLUSIONS: Gaps between guideline recommendations and practice in recording and managing BP were relatively low compared with gaps for lipids. When stratified by absolute risk, patients at high risk of a cardiovascular event were found to be substantially undertreated.
Peiris DP, Patel AA, Cass A, et al., 2009, Cardiovascular disease risk management for Aboriginal and Torres Strait Islander peoples in primary health care settings: findings from the Kanyini Audit., Med J Aust, Vol: 191, Pages: 304-309, ISSN: 0025-729X
OBJECTIVE: To describe cardiovascular disease (CVD) risk management in Indigenous primary health care. DESIGN, SETTING AND PARTICIPANTS: Review of 1165 randomly selected case records of Indigenous Australian adults, aged >/= 18 years, regularly attending eight health services in diverse settings in New South Wales, Queensland and Central Australia, October 2007 - May 2008. MAIN OUTCOME MEASURE: Adherence to CVD risk screening and management guidelines, especially with respect to overall or absolute CVD risk. RESULTS: More than half the people in the sample (53%) were not adequately screened for CVD risk according to national recommendations. Underscreening was significantly associated with younger age, less frequent attendance, and lower uptake of the Medicare Health Assessment. Of the sample, 9% had established CVD, and 29% of those aged >/= 30 years were classified as high risk according to the 2004 National Heart Foundation of Australia (NHFA) adjusted Framingham equation. Of those with CVD, 40% (95% CI, 30%-50%) were not prescribed a combination of blood pressure (BP) medicines, statins and antiplatelet agents, and 56% (95% CI, 49%-62%) of high-risk individuals without CVD were not prescribed BP medicines and statins. For high-risk individuals not prescribed BP medicines or statins, 74% (95% CI, 64%-84%) and 30% (95% CI, 23%-39%) respectively, did not meet 2004 NHFA criteria for prescribing of these medications, and of those already prescribed BP medicines or statins, 41% (95% CI, 36%-47%) and 59% (95% CI, 52%-66%) did not meet respective guideline targets. CONCLUSIONS: These management gaps are similar to those found in non-Indigenous health care settings, suggesting deficiencies across the health system. Prescribing guidelines which exclude many high-risk individuals contribute to suboptimal management. Guideline reform and improved health service capacity could substantially improve Indigenous vascular health.
Kang A, Nigwekar SU, Perkovic V, et al., 2009, Interventions for lowering plasma homocysteine levels in kidney transplant recipients, Cochrane Database of Systematic Reviews, ISSN: 1469-493X
Astuti Y, Topoglidis E, Cass AG, et al., 2009, Direct spectroelectrochemistry of peroxidases immobilised on mesoporous metal oxide electrodes: Towards reagentless hydrogen peroxide sensing, ANALYTICA CHIMICA ACTA, Vol: 648, Pages: 2-6, ISSN: 0003-2670
Oliver NS, Toumazou C, Cass AEG, et al., 2009, Glucose sensors: a review of current and emerging technology, DIABETIC MEDICINE, Vol: 26, Pages: 197-210, ISSN: 0742-3071
Cass T, 2009, Bionanotechnology II: From Biomolecular Assembly to Applications, IDRUGS, Vol: 12, Pages: 163-164, ISSN: 1369-7056
Gielen F, deMello AJ, Cass T, et al., 2009, Increasing the Trapping Efficiency of Particles in Microfluidic Planar Platforms by Means of Negative Dielectrophoresis, JOURNAL OF PHYSICAL CHEMISTRY B, Vol: 113, Pages: 1493-1500, ISSN: 1520-6106
Scott S, Cass AEG, Patel J, 2009, A microfluidic sensor platform for detection of pharmaceuticals in saliva using electrochemical detection, Pages: 320-322
This paper reports a microfluidic flow cell, housing an electrochemical sensor for the quantification of paracetamol in saliva. Saliva is an attractive matrix due to ease of sampling. We use double step chronocoulometry to record currents in a potential window with low intrinsic background in saliva with a limit of detection of 65μM. The prototype device consists of a PDMS microchannel bonded to glass substrate supporting planar 1.71mm2 Indium tin oxide (ITO) working electrode and electroplated Iridium oxide (Ir(O x)) pseudo-reference/counter electrode. Su-8 PDMS masters were laser ablation micromachined to form mixers allowing efficient on-chip sample preparation during sensor development. © 2009 CBMS.
Anderson K, Devitt J, Cunningham J, et al., 2008, "All they said was my kidneys were dead": Indigenous Australian patients' understanding of their chronic kidney disease., Med J Aust, Vol: 189, Pages: 499-503, ISSN: 0025-729X
OBJECTIVES: To explore the understanding of both Indigenous and non-Indigenous Australians with end-stage kidney disease (ESKD) about the cause of their disease, and how this understanding could affect patients' engagement with their treatment. DESIGN, SETTING AND PARTICIPANTS: Qualitative study conducted in 2005-2006 in nine hospital renal units and 17 associated dialysis centres in four states and the Northern Territory as part of the IMPAKT (Improving Access to Kidney Transplants) study. In-depth interviews were conducted with 146 Indigenous and 95 non-Indigenous Australians with ESKD, covering personal history of illness, social and psychosocial context, attitudes to treatments including transplantation, adequacy of information and communication, and satisfaction with services. RESULTS: Indigenous Australians were less certain about the cause of their illness and reported feeling uninformed but eager for information. They commonly reported lifestyle factors as potentially causal, with profound confusion about the role of alcohol. Indigenous Australians had considerable ambivalence towards biomedical explanations. CONCLUSIONS: Indigenous Australians are confused, frustrated and feel poorly informed about their illness. This study confirms the need to develop shared understandings about chronic kidney disease and to put in place the high-quality and appropriate educational resources that patients need.
Winkle RF, Nagy JM, Cass AEG, et al., 2008, Towards microfluidic technology-based MALDI-MS platforms for drug discovery: a review, EXPERT OPINION ON DRUG DISCOVERY, Vol: 3, Pages: 1281-1292, ISSN: 1746-0441
Nagy J, Kang Y, Cass A, et al., 2008, Finding proteins in cell-conditioned media, Genetic Engineering and Biotechnology News, Vol: 28, ISSN: 1935-472X
Pereira F, Hassard S, Cass A, et al., 2008, CZE of peptides using a multi-pixel detector array, Chimica Oggi, Vol: 26, Pages: 40-42, ISSN: 0392-839X
Capillary electrophoresis has been used in the analysis of peptides for decades, however traditional methods show excessive variability due to composition and sequence of the peptide, and variation in the interaction of the peptide with the separation medium. Multi-pixel detection along with the associated data analysis software improves reproducibility and sensitivity beyond current methods using UV absorption detection. The reproducibility of the data and the sensitivity of this 'no-label' multi-pixel detection approach are investigated using a mixture of known peptides. In the near future this will enable peptide mass finger printing based on the ability to assign molecular weight values to the peptides separated by charge.
Pereira F, Hassard S, Cass A, et al., 2008, CZE of peptides using a multi-pixel detector array, CHIMICA OGGI-CHEMISTRY TODAY, Vol: 26, Pages: 40-42, ISSN: 0392-839X
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