31 results for Conference poster, 2011

  • Talking Allowed!

    Davies, Maree; Sinclair, A (2011)

    Conference poster
    The University of Auckland Library

    Research on the Paideia Method (a method for discussing a topic) was conducted in 20 classrooms across five schools, of varying socioeconomic environments (ages 11-13) in Auckland, New Zealand, in 2010. The researchers sought to further examine the results from their pilot study of the Paideia Seminar, entitled 'Talking Allowed: I like it when the teacher lets us talk without telling us what to say', trialed in 2008 (Sinclair & Davies, 2011). In addition, in order to provide the optimum conditions to prepare the students for the face-to-face seminars, an online component (open source software) was added as an alternative medium to assist students in their preparation. The research questions were: What happens to the Nature of Interaction, and the Complexity of the Discussion when students participate in a Paideia Seminar, and an on-line discussion in preparation for the face-to-face seminar? What is the optimal role of the teacher when participating in a Paideia Seminar and an on-line discussion to increase complexity of discussion?

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  • High Pressure and Thermal Processing of kiwifruit puree: the effect on antioxidants and vitamin C

    Soloman, N; Oliveira, Maria (2011-11-30)

    Conference poster
    The University of Auckland Library

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  • Aged Residential Care Health Utilisation Study (ARCHUS). A randomised controlled trial to reduce acute hospitalisations from residential aged care.

    Broad, J.B; Foster, Susan; Boyd, M.; Kerse, N.; Lumley, T.; Connolly, M.J. (2011)

    Conference poster
    The University of Auckland Library

    Background and Aim Our aim is to reduce avoidable acute hospitalisations of residents of long-term care facilities. Such hospitalisations can cause distress, disruption, and complications for residents. Some conditions have been identified as better managed in the facility providing supports are in place. A randomised controlled trial is underway in Auckland, New Zealand of a targeted, multi-disciplinary team (MDT) to up-skill facility staff. We here outline the study design. Design Clustered randomised controlled trial (~1400 residents) of long-term care facilities, stratified by district health board (DHB). Randomisation and interventions commenced March 2011. Facilities certified for long-term care of older people in greater Auckland are eligible for selection if they have high levels of avoidable hospitalisation. Intervention MDTs supporting facility staff to provide evidence-based care. The supports and services provided comprise an initial stock-take assessment and development of facility plan, direct access to a geriatrician and gerontology nurse specialist (GNS), MDT meetings for individual cases, and provision of targeted education to facility nurses/caregivers, facilitated by a GNS. Education topics are based on modelling of risk factors for avoidable hospitalisation from long-term care in Auckland (2008-2010) and include recognition of illness, wound care, care planning, end-stage dementia care, nutrition/dehydration, family communication, specific clinical coaching with high-risk residents, role modelling of clinical reasoning processes, and provision of benchmarking systems. Control Usual care: the quality assurance, supports, and services routinely provided by the DHB Endpoints Primary endpoints include rate of hospitalisations in which the admission diagnosis code is one of a set pre-identified as being potentially avoidable (“Ambulatory Sensitive Hospitalisations”), emergency admission hospital bed days, and all-cause mortality. Secondary endpoints include number of emergency department presentations and number and type of medications prescribed. Residents’ outcomes will be tracked for 12 months from randomisation using their unique national health identifiers (NHIs).

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  • CUTE: CUTting Edge Diamond Optimization

    Downward, Anthony; Zakeri, G (2011)

    Conference poster
    The University of Auckland Library

    The Centenary Diamond, weighing 55g, was estimated to be worth $100 million when it was unveiled in 1991. This diamond was cut from a rough-stone weighing 120g; thus when cutting such a stone, it is imperative to orient the stone such that waste is minimized. Our interactive software allows a user to maximize the value of a diamond from a given rough-stone. As the user alters the orientation of the diamond, it solves optimization problems to scale and position the diamond within the rough-stone.

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  • Impact of PCV7 on antibiotic susceptibiity of nasophayngeal Streptococcus pneumoniae in South Auckland children

    Sekikawa, E; Trenholme, A; Taylor, S; Lennon, Diana; McBride, C; Best, Emma (2011-03-17)

    Conference poster
    The University of Auckland Library

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  • Pregnancy Associated Changes in Insulin Signalling in Daughters of Adolescent Ewes

    Oliver, Mark; Hancock, SN; Kenyon, PR; Blair, HT; Pain, S; Morris, S; Phua, Hui; Bloomfield, Francis (2011-09)

    Conference poster
    The University of Auckland Library

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  • Test- retest reliability of an instrumented elastometer for measuring passive stiffness of the levator ani muscle

    Kruger, Jennifer; Nielsen, Poul; Dietz, HP; Taberner, Andrew (2011-08-31)

    Conference poster
    The University of Auckland Library

    Hypothesis / aims of study Clinical evidence demonstrates strong associations between vaginal birth, the incidence of levator ani (LA) muscle injury, and a decrease in muscle function (1). Imaging modalities such as ultrasound and magnetic resonance imaging have provided insight into the nature of LA injury, confirming that it is significantly implicated in the development of pelvic organ prolapse (2). Strain of the LA muscles during delivery of the fetal head is considerable, and childbirth related trauma to the muscle has been shown to occur in 10-30% of women delivering vaginally (1,2). Thus, developing measures to identify a-priori, those who are most likely to suffer from injury during vaginal birth should be a high research priority. The inherent elasticity of the muscle clearly plays a role in the ability of the muscle to accommodate the fetal head. However, measuring passive stiffness of the muscle in vivo remains challenging. The aim of this study was to further develop and test a novel elastometer (3), designed to estimate in vivo passive stiffness produced by the puborectalis component of the LA muscle, where it passes in close contact with the lateral walls of the vagina, from its origin on the pubic ramus. Study design, materials and methods The elastometer used in this study is a more sophisticated version of a previously developed first-generation device (3). The current version of this instrument (Figure 1) boasts enhanced aesthetics and patient friendliness compared to our previous device. Notably, our elastometer can now implement user-defined measurement protocols under automatic computer control in order to measure the force-displacement characteristics of the LA muscle. The device consists of a hand-piece comprising two aluminium arms, with detachable acetyl plastic speculum ends, actuated by a DC servo mechanism via a load cell. A load cell amplifier and displacement transducer are integrated into the hand-piece, providing force and speculum separation measurements. The hand-piece is connected to a control box that communicates with a laptop computer via a USB connection. The control box contains a data-acquisition device (USB-6009, National Instruments), motor drive circuit, and battery-based power supply. A custom MSWindows application implements a closed-loop motor control algorithm on the laptop, records measurements of speculum displacement and force, and provides feedback to the user. The laptop user-interface displays speculum separation and force on a strip chart, together with a force-displacement graph. The design of the speculum end of the elastometer is such that the tip is wider than the neck, (26mm compared to 18mm) to reduce the likelihood of perineal muscles confounding measurement of passive stiffness. Magnetic clips attach the speculum ends to the device which allows for easy cleaning, and provides the facility of attaching speculums of various sizes. Reliability and repeatability of the elastometer was assessed in 12 volunteers. None of the participants had had vaginal surgery, or any contraindications for vaginal examination. All participants were tested twice, 3 to 5 days apart using the same protocol. The speculum was inserted to the level of the puborectalis muscle (2-4 cm from the introitus) orientated in the coronal plane. After initial familiarisation with the device in situ, recording of the data commenced. All participants were encouraged to remain relaxed during the experiment. Data acquisition was automated with the device opening in 20 stepwise increments, to the desired separation, over 60 seconds. Data were collected at a frequency of 100 Hz. Averaged data over a three second period gave 21 data points per test. The procedure was repeated three times, with the initial run being considered as a preconditioning step and not used for data analysis. Statistical analysis was carried out using “R” version 2.12.2 (Copyright (C) 2011 The R Foundation for Statistical Computing). Results from Day 1 were compared with the re-test results using Bland/Altman repeated measures to determine any bias and limits of agreement and Intraclass correlation co-efficient (ICC) to determine reliability across tests and Days. Results The mean age of the 12 participants was 44.3 years (range 26 to 58 years), BMI 26 kg/m2 (range 20.4 to 33.7 kg/m2). Two of these were nulliparous, with the median number of vaginal delivery being 2. Data was visualised in graphic form for each subject across all tests for both days. A representative plot from one subject is shown in Figure 2. ICC’s for the second and third tests respectively were 0.92 (CI 0.89- 0.93), and 0.86 (CI 0.82-0.89). Limits of agreement (from repeated measures Bland Altman) were -2.79 N to +2.31 N, with a mean difference of -0.21 N. Interpretation of results Repeated Bland Altman demonstrates minimal bias with the mean difference close to zero at -0.12 N. The 95% limits of agreement range was slightly over 4 N, and likely to be due to biological variability. The high Intraclass correlation co-efficient for both tests between Days indicate minimal variability of the measurements. Concluding message This second generation elastometer has proved reliable and consistent in the measurement of passive stiffness of the puborectalis muscle in this group of volunteers. These results confirm satisfactory performance of the instrument in preparation for future studies validating this method in clinical and research settings. References 1. DeLancey JO. The hidden epidemic of pelvic floor dysfunction: achievable goals for improved prevention and treatment. Am J Obstet Gynecol. 2005 May;192(5):1488-95. 2. Dietz HP, Simpson JM. Levator trauma is associated with pelvic organ prolapse. BJOG. 2008 Jul;115(8):979-84. 3. Kruger J, et al.. Pelvic floor muscle compliance in Elite nulliparous Athletes. 38th Annual meeting of the International Continence Society. Cario 2008

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  • Probing Student Approaches and Engagement in Learning Chemistry at University.

    Salter, David; Simpson, MC; Hamilton, R (2011-06)

    Conference poster
    The University of Auckland Library

    This project aims to identify students’ learning approaches, engagement, attitudes and success in chemistry classes that are service-taught as part of a specified health sciences programme and in chemistry classes that are taught as part of a chemistry major programme. It seeks to determine whether any differences exist in the learning approaches, motivational orientation and engagement, and compare the success of a cohort of students who are required to enrol in a compulsory chemistry course as part of a health sciences degree with that of a cohort of students who choose to enrol in a chemistry course with the possible intention of majoring in chemistry. It is intended that both cognitive and motivational individual difference variables are identified and relationships between students’ goal orientation and university academic success evaluated.

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  • An investigation into the teaching of extemporaneous compounding skills to pharmacy students in schools of pharmacy in Australia, Canada, New Zealand, South Africa and the United Kingdom

    Aspden, Trudi; Rew, A; Anderson, C; Tan, J; Woodrow, R; Zheng, Y (2011)

    Conference poster
    The University of Auckland Library

    Background: Many countries require that registered pharmacists are competent to extemporaneously compound. In general, however, there is a lack of opportunity for interns and new pharmacists to practice extemporaneous compounding due to the reduction in demand for extemporaneously compounded products in community pharmacy. Thus it falls to schools of pharmacy to prepare future pharmacist for this role. Objectives: With respect to extemporaneous compounding to pharmacy undergraduates- to determine what is taught, how it is taught, how it is assessed and the time allocated to teaching in the different schools of pharmacy in the five countries. Methodology: Thirty eight course coordinators involved in the teaching of extemporaneous compounding from 32 schools of pharmacy in Australia, Canada, New Zealand, South Africa and the United Kingdom were invited to complete an online survey using Survey MonkeyTM. Results: Twenty four responses were obtained from participants in all five countries (response rate 63.2%). Extemporaneous compounding was a compulsory component of all the BPharm programmes. However, there was a wide inter and intra-country variation in the teaching of the subject including the number of hours dedicated to its teaching, the dosage forms included and the teaching methods used. Many schools used extemporaneous compounding teaching to introduce transferrable skills, such as the ability to accurately calculate. A strong desire to retain the teaching of extemporaneous compounding was expressed by the course coordinators. Discussion: Our results highlight differences in the extemporaneous compounding teaching of the BPharm programmes in the five countries surveyed, but also uncover its use in developing related skills.

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  • Resources and strategies used in New Zealand community pharmacies to identify and assist patients with low literacy: An opportunity to improve health outcomes

    Aspden, Trudi; Sheridan, Jane; McKie, J (2011)

    Conference poster
    The University of Auckland Library

    Patients with lower literacy generally have less knowledge of health services, poorer health outcomes' and are more likely to have difficulty understanding prescription medication warning labels. To determine how pharmacy staff identify patients with limited literacy skills, the strategies used for identification, the resources available to help patients with low literacy and opportunities for up skilling. A questionnaire was adapted from one developed by Praska et al 20053. A random sample of 120 New Zealand pharmacies were sent information about the study. Those pharmacists willing to participate were interviewed by telephone. ....

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  • Molecular basis for binding and subtype selectivity of 1,4-benzodiazepine antagonist ligands of the cholecystokinin receptor

    Cawston, Erin; Sexton, PM; Miller, LJ (2011-01)

    Conference poster
    The University of Auckland Library

    Allosteric intramembranous binding pockets in peptide-binding GPCRs create opportunities to develop novel small molecule drugs with substantial benefit over orthosteric-acting drugs. To gain insights into the molecular determinants of the allosteric binding pocket within cholecystokinin (CCK) receptors, we prepared and characterized a series of receptor constructs in which residues proposed to line this pocket that are distinct in each receptor were reversed (chimeric constructs). Two novel ligands were studied, representing 1,4-benzodiazepine antagonists that differ only in the stereochemistry (S or R) of the 3-position side chain, while exhibiting binding selectivity for either CCK1R or CCK2R, respectively. Radioiodinated 1,4-benzodiazepine ligands were used as tracers in the binding assays. Six mutations within four transmembrane segments of CCK1R and CCK2R were studied. When all six residues were mutated in CCK1R to the corresponding residues in CCK2R, the selectivity of this receptor was completely reversed, yet its peptide-binding selectivity was unaffected. To further investigate which regions may be responsible for this change in selectivity, mutagenesis of the residues within individual transmembrane segments within CCK1R and CCK2R was performed and resulted in minimal impact in binding to the iodinated 1,4-benzodiazepines. Therefore, combining the residue changes within two or three segments were also prepared and studied. This detailed mutational analysis provides important information on the benzodiazepine allosteric binding site present within the CCK receptors and provides insight into ligand-receptor interactions that may be important in selectivity of this allosteric binding pocket within CCK receptors.

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  • Targeting synthetic glycopeptides to MGL on Dermal Dendritic cells

    McIntosh, Julie; Angel, CE; Chen, CJJ; Manning, K; Mansell, Claudia; Agrawai, S; Harris, Paul; Williams, Geoffrey; Squire, Christopher; Brimble, Margaret; Dunbar, Peter (2011-02-14)

    Conference poster
    The University of Auckland Library

    The ability of a peptide vaccine to stimulate T cells in vivo might be improved by specifically targeting the peptide to dendritic cells (DC). The C-type lectin Macrophage Galactose-type lectin, MGL (CD301), has been shown to bind to N-acetyl-galactosamine (GalNAc) and small peptides bearing O-linked GalNAc. Synthetic GalNAc can be produced using relatively simple organic chemistry when compared with the complicated branched sugars that are recognised by other C-type lectins. MGL therefore represents a promising target for the design of synthetic peptide vaccines. We have identified that antigen-presenting cells in human skin express MGL and have confirmed that CD14+ dermal DCs might be targeted via MGL. The intracellular fate of MGL following internalisation was tracked by confocal microscopy. MGL traffics through early endosomes to late endosomes/lysosomes, and colocalises with MHC class I and class II. Synthetic glycopeptides were produced incorporating either native O-linked GalNAc or GalNAc residues linked to the peptide chain via non-native “Click” chemistry. Biophysical analysis of the ability of both “Click” and native glycopeptides peptides with recombinant MGL confirmed the ability of both these peptides to bind MGL. Ongoing work aims to determine whether targeting to MGL using these synthetic peptides results in efficient presentation of antigen to T cells.

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  • A Structure-Based Model Analysis Of Ventilation And Contrast Gas Distribution In The Ovine Lung

    Mitchell, JH; Hoffman, EA; Mitchell, Jennine (2011-05-23)

    Conference poster
    The University of Auckland Library

    Rationale: Sheep are increasingly used as a model for human ventilation, however there are substantive anatomical differences between human and ovine lungs that may affect the gravitational distribution of tissue at rest and during ventilation. Understanding ventilation and gas transport in the ovine lung is important for interpreting measurements acquired via in vivo gas contrast imaging, such as xenon enhanced computed tomography (Xe-CT). In this study a computational model that integrates finite elastic deformation of the soft tissue with distribution of inspired air was applied to the ovine lung to determine whether a model that is consistent with human ventilation and gas distribution in also suitable for the simulation of ventilation in experimental animals. Methods: Xe-CT imaging was acquired in three sheep at the University of Iowa Division of Physiologic Imaging. Image based finite element meshes were constructed for each lung and the airway tree at a positive end expiratory pressure (PEEP) of 25 cmH 20 in prone and supine postures. Ventilation and gas transport were simulated for each animal using a computational model that includes finite deformation elasticity to define the pressure volume relationship of the lung, and time-dependent advective and diffusive transport of inhaled Xe gas. Gravitational deformation was simulated prone and supine, and ventilation was simulated for the prone lung. The specific volume change predicted from the advective flow simulation was compared to specific ventilation calculated using the time constant method that is used in Xe-CT analysis. Results: The finite deformation model accurately predicts the regional tissue density in prone but underestimates the supine gradient. Ventilation simulated in the prone posture for each of the three animals indicates that the ventilation distribution predicted by an advective flow model typically differs from that predicted from the time constant method of analysis. The R 2 correlations between the simulations and time constant calculations were 0.7824, 0.3423 and 0.42881 for each of the three animals. Conclusions: The human-consistent model is inadequate for predicting ventilation in supine sheep, because the model does not include movement of the heart or fluid shifts that were evident in the imaging. However the model is sufficiently predictive for the prone ovine lung. That advective ventilation differs from inert gas transport is consistent with experimental findings that show a correlation of R 2 of 0.66 between specific volume and ventilation calculated from tracer gas mixing (1). Fuld et al (2008) J. Appl. Physiol 104:1174-1184 This abstract is funded by: NIH Grant ROI-HL-064368-06A1

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  • Characterisation of a transgenic ovine model of Huntington’s disease

    Reid, Susanne; Handley, R; Patassini, S; Rudiger, S; Keynes, P; McLaughlan, C; Waldvogel, H; Jacobsen, J; MacDonald, M; Gusella, J; Morton, J; Bawden, S; Faull, R; Snell, R (2011-09-11)

    Conference poster
    The University of Auckland Library

    A transgenic ovine model of Huntington’s disease has been developed to enable the examination of the earliest disease changes in a large mammal. Ovis aries were selected because their basal ganglia and cortex is similar to analogous regions of the human brain. Importantly, they live for more than a decade, allowing for the study of the chronic effects of a fulllength HTT expressing transgene. Microinjection of a fulllength human HD cDNA containing 73 polyglutamine repeats under the control of the human promoter, resulted in six transgenic founders varying in copy-number of the transgene.

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  • Examination of miRNAs involved in programming human T cells

    Sheppard, Hilary; Feisst, Vaughan; Brooks, Anna; Dunbar, R (2011-09)

    Conference poster
    The University of Auckland Library

    The differentiation state of CD8+ T cells is an important determinant of their ability to eradicate tumours and infection; progressive differentiation appears to lead to a decreased effectiveness. Therefore the development of effective immunotherapies depends on a better understanding of the molecular mechanisms that underlie T cell differentiation. Several key cell surface markers are down regulated as differentiation progresses so we can define CD8+ T cells into 4 main subsets (see Fig. 1). Each subset is generated by a specific transcriptional programme. Our hypothesis is that miRNAs are important in this process of T cell differentation. If you take a cancer patient’s cells, expand in vitro, and re-infuse to the patient, the phenotype of the T cell will determine its efficacy in vivo. We have found that we can pre-condition T cells using the cytokine IL21 to have a more favourable phenotype than using the traditionally used cytokine IL2 (data not shown). We aim to explore this cytokine driven differentiation process by examining the miRNAs involved.

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  • Resources and strategies used in New Zealand community pharmacies to identify and assist patients with low literacy: An opportunity to improve health outcomes.

    Aspden, Trudi; Sheridan, JL; McKie, J (2011)

    Conference poster
    The University of Auckland Library

    Background: Patients with lower literacy generally have less knowledge of health services, poorer health outcomes[1] and are more likely to have difficulty understanding prescription medication warning labels[2]. Objectives: To determine how pharmacy staff identify patients with limited literacy skills, the strategies used for identification, the resources available to help patients with low literacy and opportunities for upskilling. Methodology: A questionnaire was adapted from one developed by Praska et al 2005 [3]. A random sample of 120 New Zealand pharmacies were sent information about the study. Those pharmacists willing to participate were interviewed by telephone. Results: The response rate was 64% (n=77). Almost 38% of respondents reported that they used measures to identify patients with low literacy, most often during patient counselling. The most common strategy used to optimise the health care of patients with low literacy was spending extra time explaining the information. Written information in the form of Self Care cards and information leaflets was the resource most commonly available. However, 4% of respondents had no resources available in their pharmacy.

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  • Prolonged Exposure to S-Adenosylhomocysteine (SAH) Perturbs Adipocyte Biology

    Ngo, Sherry; Roberts, R; Castro, L; Bhoothpoor, C; Gluckman, P; Sheppard, A (2011-06)

    Conference poster
    The University of Auckland Library

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  • Preclinical characterization of PWT33597, a dual inhibitor of PI3-kinase alpha and mTOR.

    Matthews, DJ; O’Farrell, M; James, J; Giddens, Anna; Rewcastle, Gordon; Denny, William (2011-04-05)

    Conference poster
    The University of Auckland Library

    4485: Phosphoinositide-3-kinase (PI3K) is an important mediator of tumor cell growth, survival and proliferation. In particular, PI3K alpha is important for signaling downstream of receptor tyrosine kinases and is also frequently amplified or mutationally activated in tumors, suggesting that selective inhibitors of this isoform may have therapeutic utility in the treatment of cancer. Downstream of PI3K, the mTOR kinase also plays a critical role in cellular growth and metabolism, and inhibitors of mTOR have demonstrated clinical benefit in several tumor types. We report here the discovery and characterization of PWT33597, a dual inhibitor of PI3K alpha and mTOR. PWT33597 inhibits PI3K alpha and mTOR in biochemical assays with IC50 values of 19 and 14 nM respectively, and is approximately 10-fold selective with respect to PI3K gamma and PI3K delta. Profiling of PWT33597 against 442 protein kinases (Ambit Kinomescan) revealed little or no cross-reactivity with either serine/threonine or tyrosine kinases, and there was little cross-reactivity with an additional panel of 64 pharmacologically relevant targets. In NCI-H460 and HCT116 tumor cells with mutationally activated PI3K alpha, PWT33597 inhibits phosphorylation of PI3K and mTOR pathway proteins with cellular IC50 values similar to its biochemical IC50 values. PWT33597 has good pharmacokinetic properties in multiple preclinical species, is not extensively metabolized in vivo and shows little potential for interaction with cytochrome P450 enzymes. Following a single oral dose in vivo, PWT33597 shows durable inhibition of PI3K and mTOR pathway signaling in xenograft tumors. High compound distribution into tumors and potent anti-tumor activity has been observed in multiple tumor xenograft models with activated PI3K/mTOR pathways. Also, administration of PWT33597 in mice is associated with transient increases in plasma insulin, consistent with an effect on PI3K/AKT signaling. A robust PK/PD relationship has been defined, which will guide interpretation of the planned phase I clinical study. IND-enabling studies with PWT33597 are currently in progress.

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  • Delayed Cerebral Post-arteriole Dilation is Consistent with Observations at Multiple Spatial and Temporal Scales: Evidence from Mathematical Modelling

    Barrett, MJP; Tawhai, MH; Suresh, Vinod (2011-05-25)

    Conference poster
    The University of Auckland Library

    Background and aims: Observations from different neurovascular imaging modalities provide conflicting evidence about the presence and/or extent of volume changes in post-arteriole blood vessels. At the level of individual vessels, two-photon imaging during functional activation shows a rapid increase in arteriolar diameter, but little or no increase in capillaries or venules 1 . In contrast, 'bulk' measurements of flow-volume relationships show large increases in arterial volume 2 , and smaller - but still significant - increases in venous volume 3 . Here, we reconcile these competing observations using a dynamic, biophysically based mathematical model of the hemodynamic response. Methods: We use the widely known Windkessel model that represents blood flow as analogous to electrical current, and networks of blood vessels as analogous to electrical resistances and capacitances. The model also includes a novel description of vascular compliance, viscoelastic effects, and stimulus-driven vasodilation. Experimental observations at progressively more detailed scales are used to constrain and validate the model, following a 'top down' approach. In addition, we test the assumption that post-arteriole vessels do not dilate, and use the model to predict observations at progressively more aggregated scales, following a 'bottom up' approach. Results: Model predictions of the total, arterial, and venous steady state flow-volume relationships agree well with experimental observations, as do predictions of transient changes in flow and volume during functional activation. The model also predicts rapid arteriole dilation during activation. Interestingly, this is accompanied by slow increases in capillary and venule diameter that - for brief stimulation - are near indistinguishable from baseline noise. When assuming no dilation of capillaries or venules, there are only minor differences between the model predictions at the single vessel scale. However, predictions at more aggregated scales are qualitatively and quantitatively different from experimental observations. Conclusions: The model presented here is able to reproduce the main features of experimental observations over a range of spatial and temporal scales. These results suggest that arterial dilation represents the majority of regional cerebral blood volume increases during functional activation, especially during brief stimulation. However, passive dilation in capillaries and venules may be increasingly significant during extended stimulation. This is an important consideration when interpreting or comparing results from neurovascular imaging modalities, such as optical methods and magnetic resonance imaging.

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  • Household Characteristics of Children Under Two Years Admitted with Lower Respiratory Infection in South Auckland

    Vogel, A; Trenholme, A; Lennon, Diana; McBride, C; Stewart, Joanna; Best, Emma; Mason, H; Siatu'u, Teuila (2011-04-02)

    Conference poster
    The University of Auckland Library

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