92,971 results

  • TLR2, TLR4 and TLR9 polymorphisms and Crohn's disease in a New Zealand Caucasian cohort.

    Hong, Jiwon; Leung, Yee Fun; Fraser, Alan; Merriman, TR; Vishnu, P; Krissansen, Geoffrey (2007)

    Journal article
    The University of Auckland Library

    ACKGROUND AND AIM: Toll-like receptors (TLRs) have been identified as susceptibility genes for Crohn's disease (CD) in some, but not all, studies. Here we examined the association between candidate disease-susceptibility polymorphisms in the TLR2, TLR4 and TLR9 genes and CD in a New Zealand Caucasian population. METHODS: The frequency of gene polymorphisms was examined in 182 CD patients and in 188 ethnically matched controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: We could not detect any significant difference in the allele frequencies of polymorphisms in the TLR2 (R753Q, 0.029 vs 0.016, P = 0.25), TLR4 (D299G and T399I, 0.085 vs 0.071, P = 0.49; and 0.085 vs 0.082, P = 0.90), and TLR9 (-1237T/C, 0.154 vs 0.148, P = 0.82) genes between controls and patients, respectively. There was no evidence that the variant TLR alleles were associated with disease phenotype. However, combination of the datasets of published studies with our dataset confirmed that the TLR4 polymorphism 299G (P = 0.0005; OR of 1.42 [95% CI 1.17-1.74]) and the TLR9 polymorphism -1237C (P = 0.0416; OR of 1.33 [95% CI 1.01-1.75]) are associated with CD. CONCLUSIONS: There was no evidence that the above variants of the TLR2, TLR4 and TLR9 genes are major risk factors for CD or influence disease phenotype in our New Zealand case-control study. Nevertheless, the significance of the TLR4 299G and TLR9-1237C associations with CD worldwide was confirmed by a meta-analysis test using our datasets and datasets from previously published studies.

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  • Avian olfactory receptor gene repertoires: Evidence for a well-developed sense of smell in birds?

    Steiger, SS; Fidler, Andrew; Valcu, M; Kempenaers, B (2008-10-22)

    Journal article
    The University of Auckland Library

    Among vertebrates, the sense of smell is mediated by olfactory receptors (ORs) expressed in sensory neurons within the olfactory epithelium. Comparative genomic studies suggest that the olfactory acuity of mammalian species correlates positively with both the total number and the proportion of functional OR genes encoded in their genomes. In contrast to mammals, avian olfaction is poorly understood, with birds widely regarded as relying primarily on visual and auditory inputs. Here, we show that in nine bird species from seven orders (blue tit, Cyanistes caeruleus; black coucal, Centropus grillii; brown kiwi, Apteryx australis; canary, Serinus canaria; galah, Eolophus roseicapillus; red jungle fowl, Gallus gallus; kakapo, Strigops habroptilus; mallard, Anas platyrhynchos; snow petrel, Pagodroma nivea), the majority of amplified OR sequences are predicted to be from potentially functional genes. This finding is somewhat surprising as one previous report suggested that the majority of OR genes in an avian (red jungle fowl) genomic sequence are non-functional pseudogenes. We also show that it is not the estimated proportion of potentially functional OR genes, but rather the estimated total number of OR genes that correlates positively with relative olfactory bulb size, an anatomical correlate of olfactory capability. We further demonstrate that all the nine bird genomes examined encode OR genes belonging to a large gene clade, termed ??-c, the expansion of which appears to be a shared characteristic of class Aves. In summary, our findings suggest that olfaction in birds may be a more important sense than generally believed.

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  • Non-genomic transgenerational inheritance of disease risk

    Gluckman, Peter; Hanson, MA; Beedle, Alan (2007-02)

    Journal article
    The University of Auckland Library

    That there is a heritable or familial component of susceptibility to chronic non-communicable diseases such as type 2 diabetes, obesity and cardiovascular disease is well established, but there is increasing evidence that some elements of such heritability are transmitted non-genomically and that the processes whereby environmental influences act during early development to shape disease risk in later life can have effects beyond a single generation. Such heritability may operate through epigenetic mechanisms involving regulation of either imprinted or non-imprinted genes but also through broader mechanisms related to parental physiology or behaviour. We review evidence and potential mechanisms for non-genomic transgenerational inheritance of 'lifestyle' disease and propose that the 'developmental origins of disease' phenomenon is a maladaptive consequence of an ancestral mechanism of developmental plasticity that may have had adaptive value in the evolution of generalist species such as Homosapiens. (c) 2007 Wiley Periodicals, Inc.

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  • Changes in the Proteome after Neuronal Zif268 Overexpression

    Baumga??rtel, Karsten; Tweedie-Cullen, Ry; Grossmann, Jonas; Gehrig, Peter; Livingstone-Zatchej, Magdalena; Mansuy, Isabelle M (2009-07-06)

    Journal article
    The University of Auckland Library

    Long-lasting forms of brain plasticity are a cellular basis for long-term memory, and their disturbance underlies pathological conditions such as dementia and cognitive impairment. Neuronal plasticity is a complex process that utilizes molecular cascades in the cytoplasm and the nucleus and involves numerous transcription factors, in particular, immediate early genes (IEGs). The signaling cascades that control IEGs are fairly well described, but the downstream transcriptional response is poorly understood, especially its late components. Here, we investigated the response induced by the IEG Zif268 in the adult brain in relation to long-term memory. Using a mouse model with increased neuronal expression of Zif268 that leads to improved memory, we identified an ensemble of proteins regulated by Zif268 expression and differentiated between direct and indirect targets based on the presence of a consensus binding motif in their promoter. We show that Zif268 regulates numerous substrates with diverse biological functions including protein modification and degradation (proteasome???core complex), phosphorylation, cell division, sensory perception, metabolism, and metal ion transport. The results provide a comprehensive and quantitative data set characterizing the Zif268-dependent proteome in the adult mouse brain and offers biologically important new insight into activity-dependent pathways downstream of IEGs.

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  • Mirror symmetric bimanual movement priming can increase corticomotor excitability and enhance motor learning

    Byblow, Winston; Stinear, Cathy; Smith, Marie-Claire; Bjerre, L; Flaskager, BK; McCambridge, Alana (2012-03-22)

    Journal article
    The University of Auckland Library

    Repetitive mirror symmetric bilateral upper limb may be a suitable priming technique for upper limb rehabilitation after stroke. Here we demonstrate neurophysiological and behavioural after-effects in healthy participants after priming with 20 minutes of repetitive active-passive bimanual wrist flexion and extension in a mirror symmetric pattern with respect to the body midline (MIR) compared to an control priming condition with alternating flexion-extension (ALT). Transcranial magnetic stimulation (TMS) indicated that corticomotor excitability (CME) of the passive hemisphere remained elevated compared to baseline for at least 30 minutes after MIR but not ALT, evidenced by an increase in the size of motor evoked potentials in ECR and FCR. Short and long-latency intracortical inhibition (SICI, LICI), short afferent inhibition (SAI) and interhemispheric inhibition (IHI) were also examined using pairs of stimuli. LICI differed between patterns, with less LICI after MIR compared with ALT, and an effect of pattern on IHI, with reduced IHI in passive FCR 15 minutes after MIR compared with ALT and baseline. There was no effect of pattern on SAI or FCR H-reflex. Similarly, SICI remained unchanged after 20 minutes of MIR. We then had participants complete a timed manual dexterity motor learning task with the passive hand during, immediately after, and 24 hours after MIR or control priming. The rate of task completion was faster with MIR priming compared to control conditions. Finally, ECR and FCR MEPs were examined within a pre-movement facilitation paradigm of wrist extension before and after MIR. ECR, but not FCR, MEPs were consistently facilitated before and after MIR, demonstrating no degradation of selective muscle activation. In summary, mirror symmetric active-passive bimanual movement increases CME and can enhance motor learning without degradation of muscle selectivity. These findings rationalise the use of mirror symmetric bimanual movement as a priming modality in post-stroke upper limb rehabilitation. ?? 2012 Byblow et al.

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  • Biocompatible silk fibroin scaffold prepared by reactive inkjet printing

    Rider, P; Zhang, Y; Tse, C; Jayawardane, D; Stringer, Jonathan; Callaghan, J; Brook, IM; Miller, CA; Zhao, X; Smith, PJ (2016)

    Journal article
    The University of Auckland Library

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  • Primary school teachers' uptake of professional readings: Understanding the factors affecting teachers' learning

    Kitchen, Margaret; Jeurissen, Maree; Gray, Susan (2015-11)

    Journal article
    The University of Auckland Library

    Professional reading is a core source of input in teacher professional development. This article describes 47 primary school teachers??? reports of their professional reading both in their schools and during the first year of a university TESOL (Teaching English to Speakers of Other languages) in-service qualification. One third of these teachers are bilingual. Both motivation and engagement are explored and vignettes of two bilingual teachers illustrate these factors. The findings show the frequency of participation in professional learning through professional readings is beneficial but low, however teacher professional reading attitudes are dynamic, the variables being relevancy and agency.

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  • Recent progress in solar thermal energy storage using nanomaterials

    Ahmed, SF; Khalid, M; Rashmi, W; Chan, A; Shahbaz, Kaveh (2017-01)

    Journal article
    The University of Auckland Library

    Use of thermal energy storage (TES) materials in solar collectors is known to be the most effective way of storing thermal energy. The most conventional and traditional heat storage element is water. However, due to low thermal conductivity (TC) in vapor state its applications as a heat storage medium are limited. An alternative option is to utilize organic and inorganic TES materials as they both operate at low and medium temperature ranges. Organic TES materials such as paraffins are non-corrosive and possess high latent heat capacity. On the contrary, inorganic TES materials possess high density and appreciable specific heat capacity (SHC). Due to rapid progress and advancement in nanotechnology, varieties of nanomaterials were dispersed in various base fluid(s) to enhance thermo-physical properties. This review paper presents the current status and future development trends of TES materials. Furthermore, an extensive research on enhancement of TC and SHC of various TES material doped with nanomaterials has been discussed.

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  • Core outcome domains for clinical trials on somatic symptom disorder, bodily distress disorder, and functional somatic syndromes: European Network on Somatic Symptom Disorders recommendations

    Rief, W; Burton, C; Frostholm, L; Henningsen, P; Kleinst??uber, Maria; Kop, WJ; L??we, B; Martin, A; Malt, U; Rosmalen, J; Schr??der, A; Shedden-Mora, M; Toussaint, A; van der Feltz-Cornelis, C; EURONET-SOMA Group (2017-11)

    Journal article
    The University of Auckland Library

    OBJECTIVE: The harmonization of core outcome domains in clinical trials facilitates comparison and pooling of data, and simplifies the preparation and review of research projects and comparison of risks and benefits of treatments. Therefore, we provide recommendations for the core outcome domains that should be considered in clinical trials on the efficacy and effectiveness of interventions for somatic symptom disorder, bodily distress disorder, and functional somatic syndromes. METHODS: The European Network on Somatic Symptom Disorders group of more than 20 experts in the field met twice in Hamburg to discuss issues of assessment and intervention research in somatic symptom disorder, bodily distress disorder, and functional somatic syndromes. The consensus meetings identified core outcome domains that should be considered in clinical trials evaluating treatments for somatic symptom disorder and associated functional somatic syndromes. RESULTS: The following core domains should be considered when defining ascertainment methods in clinical trials: a) classification of somatic symptom disorder/bodily distress disorder, associated functional somatic syndromes, and comorbid mental disorders (using structured clinical interviews), duration of symptoms, medical morbidity, and prior treatments; b) location, intensity, and interference of somatic symptoms; c) associated psychobehavioral features and biological markers; d) illness consequences (quality of life, disability, health care utilization, health care costs; e) global improvement and treatment satisfaction; and f) unwanted negative effects. CONCLUSIONS: The proposed criteria are intended to improve synergies of clinical trials and to facilitate decision making when comparing different treatment approaches. These recommendations should not result in inflexible guidelines, but increase consistency across investigations in this field.

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  • Studying Autism Spectrum Disorder with Structural and Diffusion Magnetic Resonance Imaging: A Survey

    Ismail, MM; Keynton, RS; Mostapha, MM; ElTanboly, AH; Casanova, MF; Gimel'farb, Georgy; El-Baz, A (2016-05)

    Journal article
    The University of Auckland Library

    Magnetic resonance imaging (MRI) modalities have emerged as powerful means that facilitate non-invasive clinical diagnostics of various diseases and abnormalities since their inception in the 1980s. Multiple MRI modalities, such as different types of the sMRI and DTI, have been employed to investigate facets of ASD in order to better understand this complex syndrome. This paper reviews recent applications of structural magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI), to study autism spectrum disorder (ASD). Main reported findings are sometimes contradictory due to different age ranges, hardware protocols, population types, numbers of participants, and image analysis parameters. The primary anatomical structures, such as amygdalae, cerebrum, and cerebellum, associated with clinical-pathological correlates of ASD are highlighted through successive life stages, from infancy to adulthood. This survey demonstrates the absence of consistent pathology in the brains of autistic children and lack of research investigations in patients under 2 years of age in the literature. The known publications also emphasize advances in data acquisition and analysis, as well as significance of multimodal approaches that combine resting-state, task-evoked, and sMRI measures. Initial results obtained with the sMRI and DTI show good promise toward the early and non-invasive ASD diagnostics.

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  • Prospective surveillance of hospitalisations associated with varicella in New Zealand children

    Wen, SC-H; Best, Emma; Walls, T; Dickson, N; McCay, H; Wilson, E (2015-11)

    Journal article
    The University of Auckland Library

    Aim: Varicella is a vaccine-preventable disease not notifiable in New Zealand (NZ), and varicella vaccine is not funded in the National Immunisation Schedule (NIS). Hospitalisations can occur because of bacterial secondary infection and other complications, which can result in long-term sequelae. Varicella may not be acknowledged in discharge coding when complications occur weeks after infection. Using the New Zealand Paediatric Surveillance Unit (NZPSU), the aim of this study was to document the hospitalisation burden of this disease. Methods: Cases (0???14years) of varicella and post-varicella complications requiring hospitalisation, including stroke syndromes where varicella occurred in the preceding 6 months, were notified to NZPSU between 1 November 2011 and 31 October 2013. Herpes zoster cases were excluded. Questionnaires were used to capture demographics, clinical features, management and short-term outcomes. Results: One hundred seventy-eight notifications were received and 144 were confirmed cases. Overall incidence was 8.3/100???000 children per year. Fifty-two???per???cent were women with a median age of 2.4 years. M??ori and Pacific Island (PI) children accounted for 74% of hospitalisations, with incidence rate ratios compared with European children of 2.8 and 3.9, respectively (P < 0.01). Complications included: infection (75%), respiratory (11%), neurological (11%), electrolyte disturbance (6%) and haemorrhagic varicella (4%). Nine???per???cent were immunocompromised. Median duration of hospital admission was 4 days with 9% requiring intensive care admission. There were no reported deaths; however, 19% had ongoing problems at discharge. Conclusion: Varicella has more associated morbidity than commonly perceived in immunocompetent children. M??ori and PI children are more likely to have complications. This surveillance gives support for inclusion of universal varicella vaccine in the NZ NIS.

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  • 3-D Lung Segmentation by Incremental Constrained Nonnegative Matrix Factorization

    Hosseini-Asl, E; Zurada, JM; Gimelfarb, G; El-Baz, A (2016)

    Journal article
    The University of Auckland Library

    Accurate lung segmentation from large-size 3-D chest-computed tomography images is crucial for computer-assisted cancer diagnostics. To efficiently segment a 3-D lung, we extract voxel-wise features of spatial image contexts by unsupervised learning with a proposed incremental constrained nonnegative matrix factorization (ICNMF). The method applies smoothness constraints to learn the features, which are more robust to lung tissue inhomogeneities, and thus, help to better segment internal lung pathologies than the known state-of-the-art techniques. Compared to the latter, the ICNMF depends less on the domain expert knowledge and is more easily tuned due to only a few control parameters. Also, the proposed slice-wise incremental learning with due regard for interslice signal dependencies decreases the computational complexity of the NMF-based segmentation and is scalable to very large 3-D lung images. The method is quantitatively validated on simulated realistic lung phantoms that mimic different lung pathologies (seven datasets), in vivo datasets for 17 subjects, and 55 datasets from the Lobe and Lung Analysis 2011 (LOLA11) study. For the in vivo data, the accuracy of our segmentation w.r.t. the ground truth is 0.96 by the Dice similarity coefficient, 9.0 mm by the modified Hausdorff distance, and 0.87% by the absolute lung volume difference, which is significantly better than for the NMF-based segmentation. In spite of not being designed for lungs with severe pathologies and of no agreement between radiologists on the ground truth in such cases, the ICNMF with its total accuracy of 0.965 was ranked fifth among all others in the LOLA11. After excluding the nine too pathological cases from the LOLA11 dataset, the ICNMF accuracy increased to 0.986.

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  • Orientation to dissection: Assisting students through the transition

    Lamdin, Rain; Weller, Jennifer; Kerse, Ngaire (2012-03)

    Journal article
    The University of Auckland Library

    Human dissection continues to be strongly argued for teaching human anatomy to medical students and is technically and emotionally demanding. An orientation to dissection and the laboratory are provided for students before beginning their work because students' and families' reactions to dissection are often complex. This study explored medical students' experiences of attending an orientation to human dissection and the anatomy laboratory. Students' reactions, feelings, and thoughts were enquired about 1 year after beginning dissection at the University of Auckland, New Zealand. Qualitative research methods, specifically one-on-one semistructured interview were utilized. Third-year medical students self-selected into the study and were interviewed 1 year after entering the laboratory. Transcribed audiotapes of the interviews were analyzed for themes across the interviews. One year after dissection students have vivid memories with differing ways of viewing the body that may help or hinder with dissection. The themes presented include orientation, student anticipation, psychological approach to the body, normalizing-continuing disquiet, and social reference. The orientation eases student entry into the laboratory. There can be ongoing feelings of ambivalence regards the body for some students. Novel findings include that students not only have their own feelings to deal with but also those of friends and family who question them and may feel uncomfortable with the idea of them dissecting. Even one year after beginning dissection, students may emotionally struggle with their work and may require further support, including how they talk about sensitive topics with other people.

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  • Image-driven constitutive modeling of myocardial fibrosis

    Wang, Yang; Niestrawska, JA; Wilson, AJ; Sands, Gregory; Young, Alistair; Le Grice, Ian; Nash, Martyn (2016)

    Journal article
    The University of Auckland Library

    Myocardial fibrosis is a pathological process that occurs during heart failure (HF). It involves microstructural remodeling of normal myocardial tissue, and consequent changes in both cardiac geometry and function. The role of myocardial structural remodeling in the progression of HF remains poorly understood. We propose a constitutive modeling framework, informed by high-resolution images of cardiac tissue structure, to model the mechanical response of normal and fibrotic myocardium. This image-driven constitutive modeling approach allows us to better reproduce and understand the relationship between structural and functional remodeling of ventricular myocardium during HF.

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  • Stability of Bovine Lactoferrin in Luminal Extracts and Mucosal Homogenates from Rat Intestine: A Prelude to Oral Absorption

    Yao, Xudong; Bunt, C; Cornish, Jillian; Quek, Siew-Young; Wen, Jingyuan (2014-12)

    Journal article
    The University of Auckland Library

    Oral delivery is the most common method for bovine lactoferrin (bLf) administration. However, the presence of proteolytic enzymes in the stomach and intestine limits the effective absorption of bLf within the gastrointestinal (GI) tract. To determine the extent of bLf proteolysis, several digestion models were developed using luminal extracts and mucosal homogenates isolated from four regions of rat intestine: duodenum, jejunum, ileum, and proximal colon. The kinetics of bLf degradation followed a pseudo-first-order rate, and almost complete hydrolysis of bLf was observed in the luminal extracts, indicating that bLf is more susceptive to luminal peptidases rather than mucosal enzymes. Moreover, a significant reduction in bLf proteolysis was observed in the presence of soybean trypsin inhibitor (SBTI), bestatin, and bacitracin, suggesting that there exist trypsin-like and aminopeptidase-like proteases, which play a key role in the degradation of bLf in the intestine. Lactoferrin was then encapsulated in several lipid-based delivery systems including liposomes and solid lipid particles (SLPs) with polymer modification, showing at least 50% of intact bLf remaining after 6 h of digestion compared with native bLf. These findings suggest that particle encapsulation may modulate protein digestion and possibly achieve sufficient oral bioavailability of bLf.

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  • Synthesis of truncated analogues of preptin-(1-16), and investigation of their ability to stimulate osteoblast proliferation

    Kowalczyk, Renata; Yang, Sung Hyun; Brimble, Margaret; Callon, Karen; Watson, Maureen; Park, Y-E; Cornish, Jillian (2014-07-15)

    Journal article
    The University of Auckland Library

    Preptin, a 34-amino acid residue peptide hormone is co-secreted with insulin from the ??-pancreatic cells and is active in fuel metabolism. We have previously established that a shorter fragment of preptin, namely preptin-(1???16), stimulates bone growth by proliferation and increasing the survival rate of osteoblasts. This was demonstrated in both in vitro and in vivo models. These findings suggest that preptin-(1???16) could play an important role in the anabolic therapy of osteoporosis. However, due to the large size of the peptide it is not an ideal therapeutic agent. The aim of this study was to identify the shortest preptin analogue that retains or even increases the bone anabolic activity as compared to the parent preptin-(1???16) peptide. Truncations were made in a methodical manner from both the N-terminus and the C-terminus of the peptide, and the effect of these deletions on the resulting biological activity was assessed. In order to improve the enzymatic stability of the shortest yet active analogue identified, ruthenium-catalysed ring closing metathesis was used to generate a macrocyclic peptide using allylglycine residues as handles for ring formation. We have successfully identified a short 8-amino acid preptin (1???8) fragment that retains an anabolic effect on the proliferation of primary rat osteoblasts and enhances bone nodule formation. Preptin (1???8) is a useful lead compound for the development of orally active therapeutics for the treatment of osteoporosis.

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  • Uropathogenic Escherichia coli Releases Extracellular Vesicles That Are Associated with RNA

    Blenkiron, Cherie; Simonov, Denis; Muthukaruppan, Anitadevi; Tsai, Peter; Dauros Singorenko, Priscila; Green, S; Hong, Jiwon; Print, Cristin; Swift, Simon; Phillips, Anthony (2016-08-08)

    Journal article
    The University of Auckland Library

    BACKGROUND: Bacterium-to-host signalling during infection is a complex process involving proteins, lipids and other diffusible signals that manipulate host cell biology for pathogen survival. Bacteria also release membrane vesicles (MV) that can carry a cargo of effector molecules directly into host cells. Supported by recent publications, we hypothesised that these MVs also associate with RNA, which may be directly involved in the modulation of the host response to infection. METHODS AND RESULTS: Using the uropathogenic Escherichia coli (UPEC) strain 536, we have isolated MVs and found they carry a range of RNA species. Density gradient centrifugation further fractionated and characterised the MV preparation and confirmed that the isolated RNA was associated with the highest particle and protein containing fractions. Using a new approach, RNA-sequencing of libraries derived from three different 'size' RNA populations (<50nt, 50-200nt and 200nt+) isolated from MVs has enabled us to now report the first example of a complete bacterial MV-RNA profile. These data show that MVs carry rRNA, tRNAs, other small RNAs as well as full-length protein coding mRNAs. Confocal microscopy visualised the delivery of lipid labelled MVs into cultured bladder epithelial cells and showed their RNA cargo labelled with 5-EU (5-ethynyl uridine), was transported into the host cell cytoplasm and nucleus. MV RNA uptake by the cells was confirmed by droplet digital RT-PCR of csrC. It was estimated that 1% of MV RNA cargo is delivered into cultured cells. CONCLUSIONS: These data add to the growing evidence of pathogenic bacterial MV being associated a wide range of RNAs. It further raises the plausibility for MV-RNA-mediated cross-kingdom communication whereby they influence host cell function during the infection process.

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  • The Impact of Macronutrients on Retinal Microvasculature among Singapore Pregnant Women during the Mid-Late Gestation

    Li, LJ; Ong, PG; Colega, MT; Han, CY; Chen, LW; Man Eyn Kidd, R; Lamoureux, E; Gluckman, Peter; Kwek, K; Chong, YS; Saw, SM; Godfrey, KM; Wong, TY; Chong Foong-Fong, M; GUSTO study group (2016)

    Journal article
    The University of Auckland Library

    BACKGROUND: Imbalanced macronutrient intakes can induce impairment of endothelial and vascular function, and further lead to metabolic and cardiovascular disease. However, little is known about the influence of such diets on endothelial and vascular dysfunction in pregnant women, even though high-fat diet is a known risk for pregnancy complications such as gestational diabetes and pre-eclampsia. OBJECTIVE: We aimed to assess the association between maternal macronutrient intakes (protein, fat and carbohydrates), dietary quality and retinal microvascular changes in a multi-ethnic Asian mother-offspring cohort. METHODS: Pregnant women (n = 614) with singleton pregnancies were recruited during their first trimester from June 2009 to Sep 2010. Maternal diet quality and macronutrient intakes, expressed as a percentage of total energy during pregnancy, were ascertained using 24 hr recalls and 3 d food diaries at 26-28 weeks gestation. Retinal examination was completed at the same clinic visit. Dietary quality was assessed and scored using the Health Eating Index in Asian Pregnant women (HEI-AP), while macronutrients intakes ware expressed as percentages of total energy and further log transformed for analysis. Associations were examined cross-sectionally by substitution models with the use of multiple linear regression. RESULTS: In adjusted model, each 20 points decrease in HEI-AP score was associated with a significant increase of 1.70 ??m (p<0.01) in retinal venular caliber. CONCLUSIONS: In this cross-sectional study, we found that women with higher fat and lower protein intakes, and lower diet quality tended to have wider retinal venular caliber, which is suggestive of suboptimal microvasculature.

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  • Hybrid additive manufacturing of 3D electronic systems

    Li, J; Wasley, T; Nguyen, TT; Ta, VD; Shephard, JD; Stringer, Jonathan; Smith, P; Esenturk, E; Connaughton, C; Kay, R (2016)

    Journal article
    The University of Auckland Library

    A novel hybrid additive manufacturing (AM) technology combining digital light projection (DLP) stereolithography (SL) with 3D micro-dispensing alongside conventional surface mount packaging is presented in this work. This technology overcomes the inherent limitations of individual AM processes and integrates seamlessly with conventional packaging processes to enable the deposition of multiple materials. This facilitates the creation of bespoke end-use products with complex 3D geometry and multi-layer embedded electronic systems. Through a combination of four-point probe measurement and non-contact focus variation microscopy, it was identified that there was no obvious adverse effect of DLP SL embedding process on the electrical conductivity of printed conductors. The resistivity maintained to be less than 4??????????????10???4 ?? centerdot cm before and after DLP SL embedding when cured at 100 ??C for 1???h. The mechanical strength of SL specimens with thick polymerized layers was also identified through tensile testing. It was found that the polymerization thickness should be minimised (less than 2???mm) to maximise the bonding strength. As a demonstrator a polymer pyramid with embedded triple-layer 555 LED blinking circuitry was successfully fabricated to prove the technical viability.

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  • Structure activity relationship study on the peptide hormone preptin, a novel bone-anabolic agent for the treatment of osteoporosis

    Amso, Z; Kowalczyk, Renata; Watson, M; Park, YE; Callon, Karen; Musson, David; Cornish, Jillian; Brimble, Margaret (2016-10-21)

    Journal article
    The University of Auckland Library

    Preptin is a 34-residue pancreatic hormone shown to be anabolic to bone in vitro and in vivo. The bone activity of preptin resides within the (1-16) N-terminal fragment. Due to its peptidic nature, the truncated fragment of preptin is enzymatically unstable; however it provides an attractive framework for the creation of stable analogues using various peptidomimetic techniques. An alanine scan of preptin (1-16) was undertaken which showed that substitution of Ser at position 3 or Pro at position 14 did not inhibit the proliferative activity of preptin in primary rat osteoblasts (bone-forming cells). Importantly, Ser-3 to Ala substitution also showed a significant activity on osteoblast differentiation in vitro and increased the formation of mineralised bone matrix. Additional modifications with non-proteinogenic amino acids at position 3 improved the stability in liver microsomes, but diminished the osteoblast proliferative activity. In addition, to provide greater structural diversity, a series of macrocyclic preptin (1-16) analogues was synthesised using head-to-tail and head-to-side chain macrolactamisation as well as ring-closing metathesis. However, a detrimental effect on osteoblast activity was observed upon macrocyclisation.

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