ORCID Profile
0000-0002-3594-8585
Current Organisation
University of Tasmania
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Publisher: Wiley
Date: 24-03-2016
DOI: 10.1002/ASE.1607
Abstract: In an attempt to improve undergraduate medical student preparation for and learning from dissection sessions, dissection audio-visual resources (DAVR) were developed. Data from e-learning management systems indicated DAVR were accessed by 28% ± 10 (mean ± SD for nine DAVR across three years) of students prior to the corresponding dissection sessions, representing at most 58% ± 20 of assigned dissectors. Approximately 50% of students accessed all available DAVR by the end of semester, while 10% accessed none. Ninety percent of survey respondents (response rate 58%) generally agreed that DAVR improved their preparation for and learning from dissection when used. Of several learning resources, only DAVR usage had a significant positive correlation (P = 0.002) with feeling prepared for dissection. Results on cadaveric anatomy practical examination questions in year 2 (Y2) and year 3 (Y3) cohorts were 3.9% (P < 0.001, effect size d = -0.32) and 0.3% lower, respectively, with DAVR available compared to previous years. However, there were positive correlations between students' cadaveric anatomy question scores with the number and total time of DAVR viewed (Y2, r = 0.171, 0.090, P = 0.002, n.s., respectively and Y3, r = 0.257, 0.253, both P < 0.001). Students accessing all DAVR scored 7.2% and 11.8% higher than those accessing none (Y2, P = 0.015, d = 0.48 and Y3, P = 0.005, d = 0.77, respectively). Further development and promotion of DAVR are needed to improve engagement and learning outcomes of more students. Anat Sci Educ 9: 545-554. © 2016 American Association of Anatomists.
Publisher: Elsevier BV
Date: 2004
DOI: 10.1016/J.EXPNEUROL.2003.09.008
Abstract: In recent years, injection of olfactory ensheathing cells (ECs) into the spinal cord has been used as an experimental strategy to promote regeneration of injured axons. In this study, we have compared the effects of transplanting encapsulated ECs with those injected directly into the spinal cord. The dorsal columns of adult rats were cut at T(8-9) and rats in experimental groups received either EC-filled porous polymer capsules or culture medium (CM)-filled capsules with ECs injected at the injury site. Control rats were in three groups: (1) uninjured, (2) lesion with transplantation of CM-filled capsules and (3) lesion with transplantation of CM-filled capsules and injections of CM. Three weeks after injury, Fluororuby was injected into the hindlimb motor and somatosensory cortex to label corticospinal neurons. Observations indicated that there were a few regenerating fibres, up to 10, in the EC-treated groups. In rats that received encapsulated ECs, regenerating fibres were present in close association with the capsule. Rats that received EC injections demonstrated a significant increase in the number of collateral branches from the intact ventral corticospinal tract (vCST) compared with the corresponding control, CM-injected group (P=0.003), while a trend for increased collateral branches was observed in rats that received encapsulated ECs (P=0.07).
Publisher: Elsevier BV
Date: 12-1998
Abstract: Previously, we observed that an adenoviral (Ad) vector encoding human glial cell line-derived neurotrophic factor (GDNF), injected near the rat substantia nigra (SN), protects SN dopaminergic (DA) neuronal soma from 6-hydroxydopamine (6-OHDA)-induced degeneration. In the present study, the effects of Ad GDNF injected into the striatum, the site of DA nerve terminals, were assessed in the same lesion model. So that effects on cell survival could be assessed without relying on DA phenotypic markers, fluorogold (FG) was infused bilaterally into striatae to retrogradely label DA neurons. Ad GDNF or control treatment (Ad mGDNF, encoding a deletion mutant GDNF, Ad lacZ, vehicle, or no injection) was injected unilaterally into the striatum near one FG site. Progressive degeneration of DA neurons was initiated 7 days later by unilateral injection of 6-OHDA at this FG site. At 42 days after 6-OHDA, Ad GDNF prevented the death of 40% of susceptible DA neurons that projected to the lesion site. Ad GDNF prevented the development of behavioral asymmetries which depend on striatal dopamine, including limb use asymmetries during spontaneous movements along vertical surfaces and hetamine-induced rotation. Both behavioral asymmetries were exhibited by control-treated, lesioned rats. Interestingly, these behavioral protections occurred in the absence of an increase in the density of DA nerve fibers in the striatum of Ad GDNF-treated rats. ELISA measurements of transgene proteins showed that nanogram quantities of GDNF and lacZ transgene were present in the striatum for 7 weeks, and picogram quantities of GDNF in the SN due to retrograde transport of vector and/or transgene protein. These studies demonstrate that Ad GDNF can sustain increased levels of biosynthesized GDNF in the terminal region of DA neurons for at least 7 weeks and that this GDNF slows the degeneration of DA neurons and prevents the appearance of dopamine dependent motor asymmetries in a rat model of Parkinson's disease (PD). GDNF gene therapy targeted to the striatum, a more surgically accessible site than the SN, may be clinically applicable to humans with PD.
Publisher: Emerald
Date: 18-04-2017
DOI: 10.1108/ITSE-02-2016-0006
Abstract: This study aims to evaluate factors influencing undergraduate students’ acceptance of a computer-aided learning resource using the Phantom Omni haptic stylus to enable rotation, touch and kinaesthetic feedback and display of names of three-dimensional (3D) human anatomical structures on a visual display. The software was developed using the software development life cycle, and was tested by students enrolled in various bachelor degrees at three stages of development within the technology acceptance model, action research and design research methodology frameworks, using mixed methods of quantitative and qualitative analysis. The learning system was generally well-accepted, with usefulness (72 ± 18, mean ± standard deviation, 0-100 visual analogue scale) rated higher ( p 0.001) than ease of use (57 ± 22). Ease of use ratings declined across the three versions as modules were added and complexity increased. Students with prior experience with 3D interfaces had higher intention to use the system, and scored higher on identification of anatomical structures. Students with greater kinaesthetic learning preferences tended to rate the system higher. Haptic feedback was considered the best aspect of the system, but students wanted higher spatial resolution and lower response times. Previous research relating to haptic devices in medical and health sciences has largely focused on advanced trainees learning surgical or procedural skills. The present research suggests that incorporating haptic feedback into virtual anatomical models may provide useful multisensory information in learning anatomy at the undergraduate level.
Publisher: Wiley
Date: 06-2016
DOI: 10.1002/ASE.1549
Abstract: Gross anatomy instruction in medical curricula involve a range of resources and activities including dissection, prosected specimens, anatomical models, radiological images, surface anatomy, textbooks, atlases, and computer-assisted learning (CAL). These resources and activities are underpinned by the expectation that students will actively engage in self-directed study (SDS) to enhance their knowledge and understanding of anatomy. To gain insight into preclinical versus clinical medical students' preferences for SDS resources for learning gross anatomy, and whether these vary on demographic characteristics and attitudes toward anatomy, students were surveyed at two Australian medical schools, one undergraduate-entry and the other graduate-entry. Lecture/tutorial ractical notes were ranked first by 33% of 156 respondents (mean rank ± SD, 2.48 ± 1.38), textbooks by 26% (2.62 ± 1.35), atlases 20% (2.80 ± 1.44), videos 10% (4.34 ± 1.68), software 5% (4.78 ± 1.50), and websites 4% (4.24 ± 1.34). Among CAL resources, Wikipedia was ranked highest. The most important factor in selecting CAL resources was cost (ranked first by 46%), followed by self-assessment, ease of use, alignment with curriculum, and excellent graphics (each 6-9%). Compared with preclinical students, clinical students ranked software and Acland's Video Atlas of Human Anatomy higher and felt radiological images were more important in selecting CAL resources. Along with other studies reporting on the quality, features, and impact on learning of CAL resources, the ersity of students' preferences and opinions on usefulness and ease of use reported here can help guide faculty in selecting and recommending a range of CAL and other resources to their students to support their self-directed study.
Publisher: Wiley
Date: 29-08-2010
DOI: 10.1111/J.1463-1326.2010.01253.X
Abstract: Intracerebroventricular (ICV) administration of a nitric oxide synthase (NOS) inhibitor to rats has been reported to raise blood pressure (BP) and cause insulin resistance, suggestive of a central effect of insulin that is NO dependent. Herein we test whether ICV insulin has peripheral haemodynamic and metabolic effects and whether peripheral effects of systemic insulin are affected by the ICV administration of the NOS inhibitor N(G) -methyl-l-arginine (l-NMMA). Anaesthetized rats were fitted with an ICV cannula for insulin, artificial cerebrospinal fluid (aCSF) or l-NMMA infusion. Rats receiving ICV l-NMMA (500 µg) underwent systemic insulin cl (10 mU/min/kg) or saline treatment for 70 min and were compared with animals receiving an equal amount of l-NMMA infused systemically. ICV aCSF or insulin (135 mU/min/kg brain) for 70 min or systemic l-NMMA (500 µg) had no effect on BP, heart rate (HR), femoral blood flow (FBF), glucose infusion rate, muscle 2-deoxyglucose uptake, microvascular perfusion or plasma insulin. However, ICV l-NMMA reduced systemic insulin-mediated increases in FBF (2.05 ± 0.08 to 1.55 ± 0.15 ml/min), 2-deoxyglucose uptake (17.7 ± 0.15 to 10.0 ± 0.03 µg/g/min) and microvascular perfusion (10.5 ± 0.5 to 6.6 ± 1.1 mol/min) (each mean ± SE, p < 0.05) plasma insulin, HR and BP were unaffected. Central insulin administration had no effect on skeletal muscle haemodynamics or glucose metabolism. However, systemic insulin-mediated increases in limb blood flow, muscle microvascular perfusion and glucose uptake may be regulated by a central pathway that is NO dependent.
Publisher: Wiley
Date: 2007
DOI: 10.1002/GLIA.20512
Abstract: The primary olfactory nerves provide uninterrupted conduits for neurotropic pathogens to access the brain from the nasal cavity, yet infection via this route is uncommon. It is conceivable that olfactory ensheathing cells (OECs), which envelope the olfactory nerves along their entire length, provide a degree of immunological protection against such infections. We hypothesized that cultured OECs would be able to mount a biologically significant response to bacteria and pathogen-associated molecular patterns (PAMPs). The response of OECs to Escherichia coli (E. coli) and various PAMPs was compared to that of Schwann cells (SCs), astrocytes (ACs), and microglia (MG). A subset of OECs displayed nuclear localization of nuclear factor kappaB), an inflammatory transcription factor, after treatment with E. coli (20% +/- 5%), lipopolysacchride (33% +/- 9%), and Poly I:C (25% +/- 5%), but not with peptidoglycan or CpG oligonucleotides. ACs displayed a similar level of activation to these treatments, and in addition responded to peptidoglycan. The activation of OECs and ACs was enhanced by coculture with MG (56% +/- 16% and 85% +/- 13%, respectively). In contrast, SCs did not respond to any treatment or to costimulation by MG. Immunostaining for the chemokine Gro demonstrated a functional response that was consistent with NF kappaB activation. OECs expressed mRNA for Toll-like receptors (TLRs) 2 and 4, but only TLR4 protein was detected by Western blotting and immunohistochemistry. The results demonstrate that OECs possess the cellular machinery that permits them to respond to certain bacterial ligands, and may have an innate immune function in protecting the CNS against infection.
Publisher: Elsevier BV
Date: 03-1995
DOI: 10.1016/0165-3806(94)00197-8
Abstract: Glial cell line-derived neurotrophic factor (GDNF) is a member of the transforming growth factor-beta family isolated from the rat glial tumor cell line, B49. In embryonic dopaminergic (DA) neurons in vitro, GDNF promotes survival, high-affinity dopamine uptake, and neurite outgrowth. We have used a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) with primers specific to GDNF to study the developmental expression of GDNF mRNA in central nervous system (CNS) and peripheral organs of embryonic rat on gestational days E11.5, E13.5 and E18, neonatal rat on postnatal days P0 and P10, and adult rat. GDNF mRNA is expressed throughout the CNS, with highest levels in P0 spinal cord and in P0 and P10 striatum. Lower levels are present in the brainstem (including the ventral mesencephalon, which contains the DA neurons of the substantia nigra), cerebellum, diencephalon, and telencephalon, as well as in primary cultures of cerebellar granule cells prepared from P7 cerebellum and astrocytes prepared from P1 cortex. The cerebellum has an unusual temporal pattern of expression, high at birth and in the adult, but undetectable at P10. GDNF mRNA is also expressed in many peripheral tissues at higher levels than in brain. These include embryonic limb bud, kidney and gut neonatal kidney, gut, lung and testis and adult lung, liver and ovary. In addition to the predicted RT-PCR product, we also observed a minor band which was shown to be identical to GDNF in the mature peptide sequence, but which has a 78 base pair deletion in the preproprotein sequence.(ABSTRACT TRUNCATED AT 250 WORDS)
Publisher: Informa UK Limited
Date: 17-05-2013
Publisher: Elsevier BV
Date: 2000
DOI: 10.1016/S0896-6273(00)80886-7
Abstract: alpha-Synuclein (alpha-Syn) is a 14 kDa protein of unknown function that has been implicated in the pathophysiology of Parkinson's disease (PD). Here, we show that alpha-Syn-/- mice are viable and fertile, exhibit intact brain architecture, and possess a normal complement of dopaminergic cell bodies, fibers, and synapses. Nigrostriatal terminals of alpha-Syn-/- mice display a standard pattern of dopamine (DA) discharge and reuptake in response to simple electrical stimulation. However, they exhibit an increased release with paired stimuli that can be mimicked by elevated Ca2+. Concurrent with the altered DA release, alpha-Syn-/- mice display a reduction in striatal DA and an attenuation of DA-dependent locomotor response to hetamine. These findings support the hypothesis that alpha-Syn is an essential presynaptic, activity-dependent negative regulator of DA neurotransmission.
Publisher: Elsevier BV
Date: 04-1999
Publisher: Springer Science and Business Media LLC
Date: 03-08-2009
Abstract: Homer proteins are post-synaptic density proteins with known functions in receptor trafficking and calcium homeostasis. While they are key mediators of synaptic plasticity, they are also known to function in axon guidance, albeit by mechanisms that are yet to be elucidated. Homer proteins couple extracellular receptors – such as metabotropic glutamate receptors and the transient receptor potential canonical family of cation channels – to intracellular receptors such as inositol triphosphate and ryanodine receptors on intracellular calcium stores and, therefore, are well placed to regulate calcium dynamics within the neural growth cone. Here we used growth cones from dorsal root ganglia, a well established model in the field of axon guidance, and a growth cone turning assay to examine Homer1 function in axon guidance. Homer1 knockdown reversed growth cone turning from attraction to repulsion in response to the calcium-dependent guidance cues brain derived neurotrophic factor and netrin-1. Conversely, Homer1 knockdown had no effect on repulsion to the calcium-independent guidance cue Semaphorin-3A. This reversal of attractive turning suggested a requirement for Homer1 in a molecular switch. Pharmacological experiments confirmed that the operational state of a calcium-calmodulin dependent protein kinase II/calcineurin phosphatase molecular switch was dependent on Homer1 expression. Calcium imaging of motile growth cones revealed that Homer1 is required for guidance-cue-induced rise of cytosolic calcium and the attenuation of spontaneous cytosolic calcium transients. Homer1 knockdown-induced calcium transients and turning were inhibited by antagonists of store-operated channels. In addition, immunocytochemistry revealed the close association of Homer1 with the store-operated proteins TRPC1 and STIM1 within dorsal root ganglia growth cones. These experiments provide evidence that Homer1 is an essential component of the calcium signalling repertoire within motile growth cones, regulating guidance-cue-induced calcium release and maintaining basal cytosolic calcium.
Publisher: Wiley
Date: 03-1996
DOI: 10.1002/(SICI)1097-4547(19960301)43:5<576::AID-JNR7>3.0.CO;2-F
Abstract: In cells, organs and whole organisms, nutrient sensing is key to maintaining homeostasis and adapting to a fluctuating environment
Publisher: American Association for the Advancement of Science (AAAS)
Date: 18-07-1997
DOI: 10.1126/SCIENCE.277.5324.389
Abstract: People with functional disability endure barriers to health and other services and to full participation in social life. In the context of COVID-19, this discrimination has been intensified worldwide. We examine how the experience of COVID-19 lockdown was depicted in comments to a video about functional disability and COVID published on VICE's YouTube channel. We analysed the first 100 comments on the video, which was posted in spring 2020, during the first COVID-19 lockdown (roughly from March to June 2020, with some variations around the world). We identified four themes: lack of access to care and services, isolation and lifestyle changes, mental health consequences, and peer support. Legal regulations regarding COVID-19 and people with functional disability have not been sufficient in most countries. The COVID-19 pandemic has exposed inadequate care systems, even in Western countries with advanced social protection policies.
Publisher: Elsevier BV
Date: 02-2018
DOI: 10.1016/J.BJA.2017.11.075
Abstract: Significant cardiorespiratory events are frequent in patients undergoing gastrointestinal endoscopy. Central to the occurrence of respiratory events is an unsecured airway. This study sought to determine the efficacy of a new laryngeal mask airway, the LMA In a prospective, open label, observational study, 292 ASA physical status classification 1 and 2 patients at low risk of pulmonary aspiration undergoing upper gastrointestinal endoscopy received i.v. propofol anaesthesia and standardized insertion of the LMA Per protocol analysis (n=290), the endoscopy success rate amongst the cohort with successful LMA The LMA ACTRN12616001464459.
Publisher: Mary Ann Liebert Inc
Date: 05-1999
DOI: 10.1089/10430349950018166
Abstract: Transgene expression in the brain of St. Kitts green monkey, Cercopithecus aethiops sabeus, was studied following injection of a serotype 5 adenoviral vector deleted in E1 and E3. The vector harbored the transgene for Escherichia coli beta-galactosidase (beta-Gal) with the simian virus 40 (SV40) nuclear localization signal under control of the Rous sarcoma viral (RSV) long terminal repeat. Several titers ranging from 5 x 10(7) to 2 x 10(9) plaque-forming units (PFU) in volumes ranging from 5 to 250 microl were injected into the caudate nuclei of 18 monkeys. Monkeys were treated with dexamethasone for 9 days, beginning the day prior to surgery, and were sacrificed at 1 week or at 1, 2, or 3 months. At 1 week, beta-Gal was expressed in thousands of cells, including both neurons and astrocytes. In addition, some dopaminergic neurons in the substantia nigra expressed transgene, suggesting retrograde transport of the vector. At 1 month 162,000+/-68,000 (SEM) or 65,000+/-29,000 beta-Gal-expressing cells persisted in striatum injected with 6 x 10(8) PFU in 30 microl or 5 x 10(7) PFU in 5 microl, respectively. Transgene expression was also observed in one of two monkeys sacrificed at 2 months and in a single monkey sacrificed at 3 months. No transgene expression was observed at 1 month in striatum injected with a higher titer (2 x 10(9) PFU in 100 microl) or more dilute vector (5 x 10(7) PFU in 30 microl). Staining for the major histocompatibility complex II (MHC II) subtype DR showed intense staining in sites injected with a higher vector titer, in which no transgene persisted at 1 month, whereas low to moderate staining was present in sites with high transgene expression. These observations suggest that there is an optimal range of vector titers for obtaining persistent transgene expression from E1E3-deleted adenovirus in primate brain, above which host responses limit transgene stability.
Publisher: F1000 Research Ltd
Date: 20-10-2023
DOI: 10.12688/MEP.19856.1
Publisher: Informa UK Limited
Date: 22-08-2019
Publisher: Wiley
Date: 10-2001
DOI: 10.1046/J.0953-816X.2001.01724.X
Abstract: Exogenous glial cell line-derived neurotrophic factor (GDNF) exhibits potent survival-promoting effects on dopaminergic neurons of the nigrostriatal pathway that is implicated in Parkinson's disease and also protects neurons in forebrain ischemia of animal models. However, a role for endogenous GDNF in brain function has not been established. Although mice homozygous for a targeted deletion of the GDNF gene have been generated, these mice die within hours of birth because of deficits in kidney morphogenesis, and, thus, the effect of the absence of GDNF on brain function could not be studied. Herein, we sought to determine whether adult mice, heterozygous for a GDNF mutation on two different genetic backgrounds, demonstrate alterations in the nigrostriatal dopaminergic system or in cognitive function. While both neurochemical and behavioural measures suggested that reduction of GDNF gene expression in the mutant mice does not alter the nigrostriatal dopaminergic system, it led to a significant and selective impairment of performance in the spatial version of the Morris water maze. A standard panel of blood chemistry tests and basic pathological analyses did not reveal alterations in the mutants that could account for the observed performance deficit. These results suggest that endogenous GDNF may not be critical for the development and functioning of the nigrostriatal dopaminergic system but it plays an important role in cognitive abilities.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-02-1997
DOI: 10.1126/SCIENCE.275.5301.838
Abstract: Glial cell line-derived neurotrophic factor (GDNF) supports growth and survival of dopaminergic (DA) neurons. A replication-defective adenoviral (Ad) vector encoding human GDNF injected near the rat substantia nigra was found to protect DA neurons from the progressive degeneration induced by the neurotoxin 6-hydroxydopamine (6-OHDA) injected into the striatum. Ad GDNF gene therapy reduced loss of DA neurons approximately threefold 6 weeks after 6-OHDA lesion, as compared with no treatment or injection of Ad lacZ or Ad mGDNF (encoding a biologically inactive deletion mutant GDNF). These results suggest that Ad vector-mediated GDNF gene therapy may slow the DA neuronal cell loss in humans with Parkinson's disease.
Publisher: Wiley
Date: 17-04-2017
DOI: 10.1002/ASE.1693
Abstract: The Anatomy Learning Experiences Questionnaire (ALEQ) was designed by Smith and Mathias to explore students' perceptions and experiences of learning anatomy. In this study, the psychometric properties of a slightly altered 34-item ALEQ (ALEQ-34) were evaluated, and correlations with learning outcomes investigated, by surveying first- and second-year undergraduate medical students 181 usable responses were obtained (75% response rate). Psychometric analysis demonstrated overall good reliability (Cronbach's alpha of 0.85). Exploratory factor analysis yielded a 27-item, three-factor solution (ALEQ-27, Cronbach's alpha of 0.86), described as: (Factor 1) (Reversed) challenges in learning anatomy, (Factor 2) Applications and importance of anatomy, and (Factor 3) Learning in the dissection laboratory. Second-year students had somewhat greater challenges and less positive attitudes in learning anatomy than first-year students. Females reported slightly greater challenges and less confidence in learning anatomy than males. Total scores on summative gross anatomy examination questions correlated with ALEQ-27, Pearson's r = 0.222 and 0.271, in years 1 and 2, respectively, and with Factor 1, r = 0.479 and 0.317 (all statistically significant). Factor 1 also had similar correlations across different question types (multiple choice short answer or essay cadaveric and anatomical models, bones, or radiological images). In a retrospective analysis, Factor 1 predicted poor end-of-semester anatomy examination results in year 1 with a sensitivity of 88% and positive predictive value of 33%. Further development of ALEQ-27 may enable deeper understanding of students' learning of anatomy, and its ten-item Factor 1 may be a useful screening tool to identify at-risk students. Anat Sci Educ 10: 514-527. © 2017 American Association of Anatomists.
No related grants have been discovered for Derek Choi-Lundberg.