A Randomised Controlled Trial Assessing the Effects of Peri-operative Fenofibrate Administration on Abdominal Aortic Aneurysm Pathology: Outcomes From the FAME Trial.

OBJECTIVE: Experimental studies suggest that fenofibrate prevents abdominal aortic aneurysm (AAA) development by lowering aortic osteopontin (OPN) concentration and reducing the number of macrophages infiltrating the aortic wall. The current study examined the effects of a short course of fenofibrate on AAA pathology in people with large AAAs awaiting aortic repair. METHODS: This randomised double blind parallel trial included male and female participants aged ≥ 60 years who had an asymptomatic AAA measuring ≥ 50 mm and were scheduled to undergo open AAA repair. Participants were allocated to fenofibrate (145 mg/day) or matching placebo for at least two weeks before elective AAA repair. Blood samples were collected at recruitment and immediately prior to surgery. AAA biopsies were obtained during aortic surgery. The primary outcomes were (1) AAA OPN concentration; (2) serum OPN concentration; and (3) number of AAA macrophages. Exploratory outcomes included circulating and aortic concentrations of other proteins previously associated with AAA. Outcomes assessed at a single time point were compared using logistic regression. Longitudinal outcomes were compared using linear mixed effects models. RESULTS: Forty-three participants were randomised. After three withdrawals, 40 were followed until the time of surgery (21 allocated fenofibrate and 19 allocated placebo). As expected, serum triglycerides reduced significantly from recruitment to the time of surgery in participants allocated fenofibrate. No differences in any of the primary and exploratory outcomes were observed between groups. CONCLUSION: A short course of 145 mg of fenofibrate/day did not lower concentrations of OPN or aortic macrophage density in people with large AAAs.

Relationship Between Disease Specific Quality of Life Measures, Physical Performance, and Activity in People with Intermittent Claudication Caused by Peripheral Artery Disease.

OBJECTIVE: The aims of this study were firstly to assess the correlation between disease specific measures of quality of life (QOL) and physical performance and activity, and secondly to identify demographic, clinical, functional, and physical activity measures independently associated with QOL in people with intermittent claudication. METHODS: This was a cross sectional observational study of 198 people with intermittent claudication caused by peripheral artery disease who were recruited prospectively. QOL was assessed with the intermittent claudication questionnaire (ICQ) and the eight-theme peripheral artery disease quality of life questionnaire. Physical performance was assessed with the six minute walk test (6MWT) and short physical performance battery (SPPB), and an accelerometer was used to measure seven day step count. The associations between QOL scores and 6MWT distance, SPPB scores and seven day step count were examined using Spearman Rho's (ρ) correlation and multivariable linear regression. RESULTS: ICQ scores were significantly correlated with 6MWT distance (ρ = 0.472, p < .001), all four SPPB scores (balance ρ = 0.207, p = .003; gait speed ρ = 0.303, p < .001; chair stand ρ = 0.167, p = .018; total ρ = 0.265, p < .001), and seven day step count (ρ = 0.254, p < .001). PADQOL social relationships and interactions (ρ = 0.343, p < .001) and symptoms and limitations in physical functioning (ρ = 0.355, p < .001) themes were correlated with 6MWT distance. The 6MWT distance was independently positively associated with ICQ and both PADQOL theme scores (ICQ: B 0.069, p < .001; PADQOL social relationships and interactions: B 0.077, p < .001; PADQOL symptoms and limitations in physical functioning: B 0.069, p < .001). CONCLUSION: Longer 6MWT distance independently predicted better physical and social aspects of QOL in people with intermittent claudication supporting its value as an outcome measure.

Fenofibrate in the management of AbdoMinal aortic anEurysm (FAME): study protocol for a randomised controlled trial.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a slowly progressive destructive process of the main abdominal artery. Experimental studies indicate that fibrates exert beneficial effects on AAAs by mechanisms involving both serum lipid modification and favourable changes to the AAA wall. METHODS/DESIGN: Fenofibrate in the management of AbdoMinal aortic anEurysm (FAME) is a multicentre, randomised, double-blind, placebo-controlled clinical trial to assess the effect of orally administered therapy with fenofibrate on key pathological markers of AAA in patients undergoing open AAA repair. A total of 42 participants scheduled for an elective open AAA repair will be randomly assigned to either 145 mg of fenofibrate per day or identical placebo for a minimum period of 2 weeks prior to surgery. Primary outcome measures will be macrophage number and osteopontin (OPN) concentration within the AAA wall as well as serum concentrations of OPN. Secondary outcome measures will include levels of matrix metalloproteinases and proinflammatory cytokines within the AAA wall, periaortic fat and intramural thrombus and circulating concentrations of AAA biomarkers. DISCUSSION: At present, there is no recognised medical therapy to limit AAA progression. The FAME trial aims to assess the ability of fenofibrate to alter tissue markers of AAA pathology. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12612001226897 . Registered on 20 November 2012.

Efficacy of brief behavioral counselling by allied health professionals to promote physical activity in people with peripheral arterial disease (BIPP): study protocol for a multi-center randomized controlled trial.

BACKGROUND: Physical activity is recommended for people with peripheral arterial disease (PAD), and can improve walking capacity and quality of life; and reduce pain, requirement for surgery and cardiovascular events. This trial will assess the efficacy of a brief behavioral counselling intervention delivered by allied health professionals to improve physical activity in people with PAD. METHODS: This is a multi-center randomised controlled trial in four cities across Australia. Participants (N = 200) will be recruited from specialist vascular clinics, general practitioners and research databases and randomised to either the control or intervention group. Both groups will receive usual medical care, a written PAD management information sheet including advice to walk, and four individualised contacts from a protocol-trained allied health professional over 3 months (weeks 1, 2, 6, 12). The control group will receive four 15-min telephone calls with general discussion about PAD symptoms and health and wellbeing. The intervention group will receive behavioral counselling via two 1-h face-to-face sessions and two 15-min telephone calls. The counselling is based on the 5A framework and will promote interval walking for 3 × 40 min/week. Assessments will be conducted at baseline, and 4, 12 and 24 months by staff blinded to participant allocation. Objectively assessed outcomes include physical activity (primary), sedentary behavior, lower limb body function, walking capacity, cardiorespiratory fitness, event-based claudication index, vascular interventions, clinical events, cardiovascular function, circulating markers, and anthropometric measures. Self-reported outcomes include physical activity and sedentary behavior, walking ability, pain severity, and health-related quality of life. Data will be analysed using an intention-to-treat approach. An economic evaluation will assess whether embedding the intervention into routine care would likely be value for money. A cost-effectiveness analysis will estimate change in cost per change in activity indicators due to the intervention, and a cost-utility analysis will assess change in cost per quality-adjusted life year. A full uncertainty analysis will be undertaken, including a value of information analysis, to evaluate the economic case for further research. DISCUSSION: This trial will evaluate the efficacy and cost-effectiveness of a brief behavioral counselling intervention for a common cardiovascular disease with significant burden. TRIAL REGISTRATION: ACTRN 12614000592640 Australian New Zealand Clinical Trials Registry. Registration Date 4 June 2014.

Adaptive dosing approaches to the individualization of 13-cis-retinoic acid (isotretinoin) treatment for children with high-risk neuroblastoma.

PURPOSE: To investigate the feasibility of adaptive dosing and the impact of pharmacogenetic variation on 13-cis-retinoic acid (13-cisRA) disposition in high-risk patients with neuroblastoma. EXPERIMENTAL DESIGN: 13-cisRA (160 mg/m(2) or 5.33 mg/kg/d) was administered to 103 patients ages 21 years or less and plasma concentrations of 13-cisRA and 4-oxo-13-cisRA quantitated on day 14 of treatment. Seventy-one patients were recruited to a dose adjustment group, targeting a 13-cisRA C(max) of 2 µmol/L, with dose increases of 25% to 50% implemented for patients with C(max) values less than 2 µmol/L. A population pharmacokinetic model was applied and polymorphisms in relevant cytochrome P450 genes analyzed. RESULTS: 13-cisRA C(max) values ranged from 0.42 to 11.2 µmol/L, with 34 of 103 (33%) patients failing to achieve a C(max) more than 2 µmol/L. Dose increases carried out in 20 patients in the dose adjustment study group led to concentrations more than 2 µmol/L in 18 patients (90%). Eight of 11 (73%) patients less than 12 kg, receiving a dose of 5.33 mg/kg, failed to achieve a C(max) of 2 µmol/L or more. Significantly, lower C(max) values were observed for patients treated with 5.33 mg/kg versus 160 mg/m(2) (1.9 ± 1.2 vs. 3.1 ± 2.0 µmol/L; mean ± SD; P = 0.023). C(max) was higher in patients who swallowed 13-cisRA capsules as compared with receiving the drug extracted from capsules (4.0 ± 2.2 vs. 2.6 ± 1.8 µmol/L; P = 0.0012). The target C(max) was achieved by 93% (25/27) versus 55% (42/76) of patients in these 2 groups, respectively. No clear relationships were found between genetic variants and 13-cisRA pharmacokinetic parameters. CONCLUSIONS: Dosing regimen and method of administration have a marked influence on 13-cisRA plasma concentrations. Body weight-based dosing should not be implemented for children less than 12 kg and pharmacologic data support higher doses for children unable to swallow 13-cisRA capsules.

Relevance of nonsynonymous CYP2C8 polymorphisms to 13-cis retinoic acid and paclitaxel hydroxylation.

CYP2C8 has a major role in the metabolism of the anticancer agents 13-cis retinoic acid (13cisRA) and paclitaxel. There is evidence that polymorphisms in the CYP2C8 gene contribute to observed interindividual differences in paclitaxel metabolism. However, no studies have been performed to determine the relevance of CYP2C8 polymorphisms to 13cisRA metabolism. In the current study, the effect of two common nonsynonymous CYP2C8 polymorphisms, CYP2C8*3 (R139K and K399R) and *4 (I264M), on the metabolism of 13cisRA and paclitaxel was examined using an Escherichia coli expression system with coexpression of human cytochrome P450 reductase. No statistically significant differences in the level of 13cisRA 4-hydroxylase activity were associated with either CYP2C8 allelic variant compared with the wild-type CYP2C8.1 enzyme. Furthermore, no differences were observed for the CYP2C8.3 or CYP2C8.4 enzymes with respect to paclitaxel 6alpha-hydroxylase kinetics compared with wild-type CYP2C8.1. However, when the effects of the individual polymorphisms making up the CYP2C8*3 allele were considered, a significantly lower level of paclitaxel 6alpha-hydroxylase activity was associated with the K399R enzyme. A lower level of activity was also seen for the R139K enzyme, although this difference was not significant. No differences were observed with respect to 13cisRA 4-hydroxylase activity. We conclude that common CYP2C8 polymorphisms are unlikely to explain reported interindividual variation in 13cisRA or paclitaxel pharmacokinetics.

Role of UDP-glucuronosyltransferase isoforms in 13-cis retinoic acid metabolism in humans.

13-cis Retinoic acid (13cisRA, isotretinoin) is an important drug in both dermatology, and the treatment of high-risk neuroblastoma. 13cisRA is known to undergo cytochrome P450-mediated oxidation, mainly by CYP2C8, but phase II metabolic pathways have not been characterized. In the present study, the glucuronidation activities of human liver (HLM) and intestinal microsomes (HIM), as well as a panel of human UDP-glucuronosyltransferases (UGTs) toward both 13cisRA and the 4-oxo metabolite, 4-oxo 13cisRA, were compared using high-performance liquid chromatography. Both HLM and, to a greater extent, HIM catalyzed the glucuronidation of 13cisRA and 4-oxo 13cisRA. Based on the structures of 13cisRA and 4-oxo 13cisRA, the glucuronides formed are conjugated at the terminal carboxylic acid. Further analysis revealed that UGT1A1, UGT1A3, UGT1A7, UGT1A8, and UGT1A9 were the major isoforms responsible for the glucuronidation of both substrates. For 13cisRA, a pronounced substrate inhibition was observed with individual UGTs and with HIM. UGT1A3 exhibited the highest rate of activity toward both substrates, and a high rate of activity toward 13cisRA glucuronidation was also observed with UGT1A7. However, for both substrates, K(m) values were above concentrations reported in clinical studies. Therefore, UGT1A9 is likely to be the most important enzyme in the glucuronidation of both substrates as this enzyme had the lowest K(m) and is expressed in both the intestine and at high levels in the liver.

Changes in functional properties of the caffeine-sensitive Ca2+ store during differentiation of human SH-SY5Y neuroblastoma cells.

We have used single cell fluorescence imaging techniques to examine how functional properties of the caffeine-sensitive Ca(2+) store change during differentiation of a sub-population of caffeine-sensitive SH-SY5Y cells. Application of caffeine (30 mM) 1-10.5 min after a 'priming' depolarisation pulse of 55 mM K(+) revealed that the caffeine-sensitive store in undifferentiated cells remained replete, whereas that in 9-cis retinoic acid (9cRA)-differentiated cells spontaneously dissipated with a t(1/2) of 2.8 min, and was essentially completely depleted approximately 10 min after priming. In 9cRA-differentiated cells that were stimulated with methacholine (10 microM) 1 min after priming, the amplitude, rate of rise and propagation velocity of the Ca(2+) wave in the neurites were all constant, whereas these kinetic parameters all progressively decreased as the wave travelled along the neurites in cells that were stimulated 10 min after priming. Use-dependent block with ryanodine inhibited the global Ca(2+) signal in 9cRA-differentiated cells stimulated with methacholine 1 min after priming (71+/-8%) but not 10 min after priming. Depolarisation was more effective at priming the caffeine-sensitive Ca(2+) store in 9cRA-differentiated cells, which lack a functional store-operated Ca(2+) entry pathway. We conclude that differentiation of caffeine-sensitive SH-SY5Y cells is accompanied by an increase in lability of the caffeine-sensitive Ca(2+) store, and that spontaneous dissipation of Ca(2+) from the store limits the time course of its molecular 'memory' during which it can amplify the hormone-induced Ca(2+) signal by Ca(2+)-induced Ca(2+) release.

Release and sequestration of Ca2+ by a caffeine- and ryanodine-sensitive store in a sub-population of human SH-SY5Y neuroblastoma cells.

We have used single cell fluorescence imaging techniques to examine the role that ryanodine receptors play in the stimulus-induced Ca(2+) responses of SH-SY5Y cells. The muscarinic agonist methacholine (1mM) resulted in a Ca(2+) signal in 95% of all cells. Caffeine (30 mM) however stimulated a Ca(2+) signal in only 1-7% of N-type (neuroblastic) cells within any given field. The caffeine response was independent of extracellular Ca(2+), regenerative in nature, and abolished in a use-dependent fashion by ryanodine. In caffeine-responsive cells, the magnitude of the methacholine-induced Ca(2+) signal was inhibited by 75.07 +/- 5.51% by pretreatment with caffeine and ryanodine, suggesting that the caffeine-sensitive store may act as a Ca(2+) source after muscarinic stimulation. When these data were combined with equivalent data from non-caffeine-responsive cells, the degree of apparent inhibition was significantly reduced. In contrast, after store depletion by caffeine, the Ca(2+) signal induced by 55 mM K(+) was potentiated 2.5-fold in the presence of ryanodine, suggesting that the store may act a Ca(2+) sink after depolarisation. We conclude that a caffeine- and ryanodine-sensitive store can act as a Ca(2+) source and sink in SH-SY5Y cells, and that effects of the store can become obscured if data from caffeine-insensitive cells are not excluded.