Conference Presentations by WENDY PURCELL
Policy Report for COP28, 2023
Papers by WENDY PURCELL
The Plymouth Student Scientist, Jan 29, 2009
Journal of Chromatography B: Biomedical Sciences and Applications, Sep 1, 1999
This study presents a HPLC method for the separation and purification of p-bromophenylacetylurea ... more This study presents a HPLC method for the separation and purification of p-bromophenylacetylurea (BPAU) and its metabolites. The method effectively separated and purified BPAU and its metabolites. Three metabolites of BPAU, M1, M2 and M3 were characterised by mass spectroscopy and nuclear magnetic resonance. They are named as N′-hydroxy-p-bromophenylacetylurea, 4-(4-bromophenyl)-3-oxapyrrolidine-2,5-dione and N′-methyl-p-bromophenylacetylurea, respectively. The major metabolic pathways of BPAU were
Toxicology in Vitro, Feb 1, 2004
Multi-cellular spheroids are increasingly employed as in vitro sensors of toxicants and a single ... more Multi-cellular spheroids are increasingly employed as in vitro sensors of toxicants and a single spheroid can be used as a test object. An ultrasonic standing wave trap (USWT) can hold small particles in a medium-flowing system. This study investigated the conditions for holding HepG2 spheroids in an USWT and its relevance to use in toxicity testing. It can take many hours to reach a detectable end point of cell damage in a standard cellular in vitro toxicant assay and the process might be accelerated through increased sample flow past the spheroid. A USWT was employed here to levitate and hold HepG2 spheroids stationary against a flow of 3 mm s À1 when the acoustic pressure amplitude is 1.9 MPa. The ultrasonic drive frequency was 1.64 MHz. Acoustic microstreaming in the standing wave chamber generated 1 mm s À1 flow past a levitated spheroid-scale (80 mm diameter) latex particle in the absence of sample through-flow. The conditions required to form aggregates of cells of a HepG2 cell line in a single half wavelength ultrasonic standing wave mini-chambers are also described here. It is argued that the manipulation capabilities demonstrated may have potential in increasing the efficiency of in vitro toxicant detection by spheroids. Preliminary, visual (unquantified) fluorescence microscopy observations of spheroids levitated in the standing wave in the presence of the toxicant dl-propranolol do suggest accelerated loss of viability compared with controls.
COVID-19: Paving the Way for a More Sustainable World, 2021
The chapter reviews the education sector’s COVID-19 policy implementation for managing the impact... more The chapter reviews the education sector’s COVID-19 policy implementation for managing the impact of the coronavirus on school plans in South Africa. Complex and problematic policy issues emanate from the effects of the coronavirus and the quick-fix strategies used to implement policy without consideration of the contextual factors in underprivileged schools. Closure of schools as a short-term measure was not sustainable and had unintended consequences. On paper, the COVID-19 policy looks good, but it is devoid of the contextual realities of the places where it needs to be implemented. Gaps identified in the policy gave rise to protracted resistance by stakeholders due to lack of ownership. These challenges led to shifting of goals regarding the early reopening of schools. Systems thinking offers tools to improve on the implementation challenges faced by policy makers, while a systems dynamics approach seeks to bring understanding of the interconnection among stakeholders and the views they hold. The Soft Systems Methodology (SSM) provides a perspective for modelling the underlying problematic issues in structured manner. It shows the complex relationship that exists starting from the conception of the policy to its implementation. The SSM model addresses the challenges faced by policy makers in communicating the policy and engaging the stakeholders, and conceives the root cause of problematic issues in the implementation of the policy by proposing an ideal conceptual model.
Neurotoxicology
Neurotrophic factors (NTFs) such as nerve growth factor (NGF), brain-derived neurotrophic factor ... more Neurotrophic factors (NTFs) such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) are currently being explored as novel therapeutics in a range of neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease. To this end, animal studies and clinical trials have been conducted to assess the toxic effects of recombinant NTFs. It is apparent that both NGF and BDNF induce a range of adverse effects, for example inflammation, hyperalgesia, and disturbances in CNS biogenic amine levels which variously manifest as weight loss/gain, changes in feeding behaviour and general malaise. It has been demonstrated that NGF induces release of biologically active mediators, such as histamine, from rat peritoneal mast cells (RPMC). However, whether other NTFs do likewise or indeed are able to induce secretion from other mast cells types had not been explored. We have developed a novel protocol for dispe...
The Technical Activities Quarterly Report replaces the Physics Research Quarterly Report previous... more The Technical Activities Quarterly Report replaces the Physics Research Quarterly Report previously published by Battelle-Northwest's Reactor Physics Department and FFTF Reactor Physics Section. The objective of the report is to inform the scientific community in a timely manner of the technical progress made on the many phases of work within the Department. The report contains brief technical discussions of accomplishments in all areas where significant progress has been made during the quarter. The results presented should be considered preliminary, and do not constitute final publication of the work. A list of publications and papers by the Department staff is given in the report. Anyone wishing to obtain additional information on the work presented is encouraged to contact the author directly.
Neurochemical Research, 1995
Mast cells are located in close proximity to neurons in the peripheral and central nervous system... more Mast cells are located in close proximity to neurons in the peripheral and central nervous systems, suggesting a functional role in normal and aberrant neurodegenerative states. They also possess many of the features of neurons, in terms of monoaminergic systems, responsiveness to neurotrophins and neuropeptides and the ability to synthesise and release bioactive neurotrophic factors. Mast cells are able to secrete an array of potent mediators which may orchestrate neuroinflammation and affect the integrity of the blood-brain barrier. The 'cross-talk' between mast cells, lymphocytes, neurons and glia constitutes a neuroimmune axis which is implicated in a range of neurodegenerative diseases with an inflammatory and/or autoimmune component, such as multiple sclerosis and Alzheimer's disease. Mast cells appear to make an important contribution to developing, mature and degenerating nervous systems and this should now be recognised when assessing the neurotoxic potential of xenobiotics.
International Archives of Allergy and Immunology, 1989
Drug Dosage The authors and the publisher have exerted every effort to ensure that drug selection... more Drug Dosage The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time o f publication. However, in view o f ongoing research, changes in government regulations, and the constant flow o f information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precau tions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. All rights reserved. N o part o f this publication may be translated into other languages, repro duced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the pub lisher or, in the case o f photocopying, direct payment o f a specified fee to the Copyright Clearance Center (sec 'Information for Readers and Sub scribers').
Human & Experimental Toxicology, 1994
1 In both the developing and adult nervous systems, nerve growth factor (NGF) influences neuronal... more 1 In both the developing and adult nervous systems, nerve growth factor (NGF) influences neuronal survival, differentiation and recovery following insult, 2 The effect of NGF upon human placental mast cells (HPMC) was investigated, since it is known that rodent mast cells express a functional receptor for NGF and secrete histamine upon challenge with this neurotrophic factor. Furthermore, human placental tissue contains a significant amount of NGF and expresses a NGF receptor. 3 HPMC were shown to secrete histamine in a concentration dependent manner in response to NGF (0.001-10.0 μg ml-1) in the presence of the lipid cofactor phosphatidylserine (10.0 μg ml-1). 4 NGF induced histamine release from isolated HPMC with an EC50 of 0.1 μg ml -1 NGF and maximal secretion of total cellular histamine of 22.3 ± 3.4% at 3.0 μg ml-1. 5 The response was shown to be a secretory process, dependent upon the presence of exogenous calcium ions and to be pH- and temperature-sensitive. 6 HPMC are sugg...
In the last decade, in particular, empirical research has brought evidence of the measurable payo... more In the last decade, in particular, empirical research has brought evidence of the measurable payoff of CSR initiatives to companies as well as their stakeholders. Companies have a variety of reasons for being attentive to CSR. This section documents some of the potential bottom-line benefits: reducing cost and risk, gaining competitive advantage, developing and maintaining legitimacy and reputational capital, and achieving win-win outcomes through synergistic value creation.
Horizonti. Serija A. Opštestveni i humanistički nauki, Dec 10, 2021
The scale of the ongoing COVID-19 pandemic is unprecedented in the 21st century. One of the large... more The scale of the ongoing COVID-19 pandemic is unprecedented in the 21st century. One of the largest shocks related to the COVID-19 crisis was not only the lethality of the virus itself, but also the chaotic and ad hoc response to it from so many sectors of society. When it became clear in early March 2020 that COVID-19 was spreading rapidly on a global scale, most governments began shutting down businesses, schools, and universities. Many higher education institutions switched to online classes after only a few days of preparation. Many have struggled to decide how to assess student learning remotely, whether to postpone or cancel final exams. A big concern for many higher education institutions has been to avoid increased cheating and plagiarism during online examinations. How higher education institutions will move forward after the pandemic? Will universities return to a "business as usual" or, will use this disruption to transform the education?
The Business & Management Collection, Dec 31, 2019
PubMed, 1999
Colony stimulating factors (CSFs) are now widely used in cancer treatment and immunological disea... more Colony stimulating factors (CSFs) are now widely used in cancer treatment and immunological disease therapy. Both granulocyte CSF (G-CSF) and granulocyte-macrophage CSF (GM-CSF) are used to increase neutrophil counts in Felty syndrome. In the present study, the effects of macrophage CSF (M-CSF), G-CSF, GM-CSF and interleukin-3 (IL-3) (10 ng/ml) on the production of nitric oxide and prostaglandin E2 (PGE2) by cartilage explants were examined over 24 and 48 h. The effects of these CSFs were also measured in combination with IL-1 beta (10 ng/ml). M-CSF, GM-CSF and IL-3 had no effect on nitrite production. However, both IL-1 beta and G-CSF caused a significant increase (p < 0.05) in nitrite levels at 48 h. NG-L-arginine-methyl-ester was used to inhibit nitrite production induced by G-CSF and this implicated nitric oxide synthase activity. When G-CSF and IL-1 beta were used in a combined treatment, nitrite levels were significantly increased (p < 0.05) at both 24 and 48 h. Both IL-3 alone and in combination with IL-1 beta caused elevated PGE2 production in this model. PGE2 levels were also significantly increased by stimulation with GM-CSF and IL-3 combined with IL-1 beta. These findings demonstrate that GM-CSF, G-CSF and IL-3 may induce changes in the production of inflammatory mediators such nitric oxide and PGE2 in cartilage chondrocytes. Hence, CSFs may play a vital role in influencing cartilage metabolism in rheumatoid and osteoarthritis.
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Conference Presentations by WENDY PURCELL
Papers by WENDY PURCELL