19 results on '"Devenish S"'
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2. Sir Neville Howse (VC), Private John Simpson Kirkpatrick and Private Martin O'Meara (VC) and their contributions to Australian military medicine.
- Author
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Devenish S and O'Meara P
- Abstract
Medical personnel serving with the Defence Forces have contributed to the evolution of trauma treatment and the advancement of prehospital care within the military environment. This paper investigates the stories of an Australian Medical Officer, Sir Neville Howse, and two stretcher bearers, Private John Simpson Kirkpatrick and Private Martin O'Meara, In particular it describes the gruelling conditions under which they performed their roles, and reflects on the legacy that they have left behind in Australian society. While it is widely acknowledged that conflicts such as World War One should never have happened, as civilian and defence force paramedics, we should never forget the service and sacrifice of defence force medical personnel and their contribution to the body of knowledge on the treatment of trauma. These men and women bravely provided emergency care in the most harrowing conditions possible. However, men like Martin O'Meara may not have been given the same status in society today as Sir Neville Howse or Simpson and his donkey, due to the public's lack of awareness and acceptance of war neurosis and conditions such as post traumatic stress disorder, reactive psychosis and somatoform disorders which were suffered by many soldiers during their wartime service and on their return home after fighting in war. [ABSTRACT FROM AUTHOR]
- Published
- 2010
3. Serological Markers of Clinical Improvement in MuSK Myasthenia Gravis.
- Author
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Spagni G, Vincent A, Sun B, Falso S, Jacobson LW, Devenish S, Evoli A, and Damato V
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- Humans, Female, Male, Middle Aged, Adult, Retrospective Studies, Aged, Longitudinal Studies, Autoantibodies blood, Receptor Protein-Tyrosine Kinases immunology, Receptor Protein-Tyrosine Kinases blood, HEK293 Cells, Rituximab pharmacology, Immunologic Factors pharmacology, Myasthenia Gravis blood, Myasthenia Gravis immunology, Myasthenia Gravis drug therapy, Myasthenia Gravis diagnosis, Immunoglobulin G blood, Biomarkers blood, Receptors, Cholinergic immunology
- Abstract
Background and Objectives: In this retrospective longitudinal study, we aimed at exploring the role of (a) MuSK-immunoglobulin G (IgG) levels, (b) predominant MuSK-IgG subclasses, and (c) antibody affinity as candidate biomarkers of severity and outcomes in MuSK-MG, using and comparing different antibody testing techniques., Methods: Total MuSK-IgGs were quantified with radioimmunoassay (RIA), ELISA, flow cytometry, and cell-based assay (CBA) serial dilutions using HEK293 cells transfected with MuSK-eGFP. MuSK-IgG subclasses were measured by flow cytometry. SAffCon assay was used for determining MuSK-IgG affinity., Results: Forty-three serum samples were obtained at different time points from 20 patients with MuSK-MG (median age at onset: 48 years, interquartile range = 27.5-72.5; women, 16/20), with 9 of 20 (45%) treated with rituximab. A strong correlation between MuSK-IgG levels measured by flow cytometry and RIA titers was found (r
s = 0.74, 95% CI 0.41-0.89, p = 0.0003), as well as a moderate correlation between CBA end-point titers and RIA titers (rs = 0.47, 95% CI 0.01-0.77, p = 0.0414). A significant correlation was found between MuSK-IgG flow cytometry levels and disease severity (rs = 0.39, 95% CI 0.06-0.64, p = 0.0175; mixed-effects model estimate: 2.296e-06, std. error: 1.024e-06, t = 2.243, p = 0.032). In individual patients, clinical improvement was associated with decrease in MuSK-IgG levels, as measured by either flow cytometry or CBA end-point titration. In all samples, MuSK-IgG4 was the most frequent isotype (mean ± SD: 90.95% ± 13.89). A significant reduction of MuSK-IgG4 and, to a lesser extent, of MuSK-IgG2, was seen in patients with favorable clinical outcomes. A similar trend was confirmed in the subgroup of rituximab-treated patients. In a single patient, MuSK-IgG affinity increased during symptom exacerbation ( KD values: 62 nM vs 0.6 nM) while total MuSK-IgG and IgG4 levels remained stable, suggesting that affinity maturation may be a driver of clinical worsening., Discussion: Our data support the quantification of MuSK antibodies by flow cytometry. Through a multimodal investigational approach, we showed that total MuSK-IgG levels, MuSK-IgG4 and MuSK-IgG2 levels, and MuSK-IgG affinity may represent promising biomarkers of disease outcomes in MuSK-MG.- Published
- 2024
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4. Exploring Paramedicine Models of Care: A Novel Macro Analysis Using the RESPIGHT Framework.
- Author
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Weber A, Devenish S, and Lam L
- Abstract
Objective: To evaluate the alignment of undergraduate paramedicine curricula in Australia with the RESPIGHT model, focusing on diverse aspects such as emergency response, community engagement and governance., Design: Deductive thematic analysis was conducted to assess the alignment of curricula from 16 Australian universities with the RESPIGHT framework., Setting: The study reviewed undergraduate pre-registration paramedicine programmes across Australian universities., Participants: The study included a comprehensive analysis of curricula from 16 universities offering undergraduate paramedicine programmes., Main Outcome Measure: The degree of alignment of paramedicine curricula with the RESPIGHT categories: emergency response, community engagement, situated practice, primary healthcare, integration with health services, governance, leadership and treatment and transport., Results: The analysis revealed varying degrees of alignment across the RESPIGHT categories, with notable discrepancies in areas such as community engagement and governance. Some universities demonstrated strong alignment in emergency response and treatment, while others showed weaker integration with primary healthcare and community engagement., Conclusion: The study highlights significant disparities in the preparedness of paramedicine students for the broad scope of practice required in modern healthcare. The findings underscore the need for curriculum reform to better prepare students for community care models and the evolving healthcare landscape, ensuring a more comprehensive and integrated approach to paramedicine education in Australia., (© 2025 National Rural Health Alliance Ltd.)
- Published
- 2025
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5. Microfluidic Diffusional Sizing (MDS) Measurements of Secretory Neutralizing Antibody Affinity Against SARS-CoV-2.
- Author
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O'Mahoney C, Watt I, Fiedler S, Devenish S, Srikanth S, Justice E, Dover T, Dean D, and Peng C
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- Humans, Saliva immunology, Antibody Affinity, Antibodies, Monoclonal immunology, Antibodies, Monoclonal chemistry, Antibodies, Neutralizing immunology, SARS-CoV-2 immunology, Spike Glycoprotein, Coronavirus immunology, Spike Glycoprotein, Coronavirus chemistry, Angiotensin-Converting Enzyme 2 metabolism, Angiotensin-Converting Enzyme 2 immunology, Angiotensin-Converting Enzyme 2 chemistry, COVID-19 immunology, Antibodies, Viral immunology
- Abstract
SARS-CoV-2 has rampantly spread around the globe and continues to cause unprecedented loss through ongoing waves of (re)infection. Increasing our understanding of the protection against infection with SARS-CoV-2 is critical to ending the pandemic. Serological assays have been widely used to assess immune responses, but secretory antibodies, the essential first line of defense, have been studied to only a limited extent. Of particular interest and importance are neutralizing antibodies, which block the binding of the spike protein of SARS-CoV-2 to the human receptor angiotensin-converting enzyme-2 (ACE2) and thus are essential for immune defense. Here, we employed Microfluidic Diffusional Sizing (MDS), an immobilization-free technology, to characterize neutralizing antibody affinity to SARS-CoV-2 spike receptor-binding domain (RBD) and spike trimer in saliva. Affinity measurement was obtained through a contrived sample and buffer using recombinant SARS-CoV-2 RBD and monoclonal antibody. Limited saliva samples demonstrated that MDS applies to saliva neutralizing antibody measurement. The ability to disrupt a complex of ACE2-Fc and spike trimer is shown. Using a quantitative assay on the patient sample, we determined the affinity and binding site concentration of the neutralizing antibodies., (© 2024. The Author(s).)
- Published
- 2024
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6. Exploring the alignment between paramedicine's professional capabilities and competency frameworks for current and evolving scopes of practice: a literature review.
- Author
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Weber A, Devenish S, and Lam L
- Subjects
- Humans, Australia, Awareness, Benchmarking, Paramedicine, Accreditation
- Abstract
Background: To adequately prepare graduates for the dynamic demands of paramedic practice, adopting a contemporary educational approach is essential. This involves collaborating to identify crucial competencies through input from industry stakeholders, experienced practitioners, and discipline-specific experts. Accreditation assumes a central role within this framework, serving as a cornerstone to ensure that paramedicine curricula align with paramedics' diverse and evolving professional roles., Methods: A narrative review of the literature and a directed search of grey literature were performed to identify specific developments in paramedicine competencies and scope of practice and mapped to the professional capabilities published by the Paramedicine Board of Australia. In determining a competency map and accreditation's role in a competency framework specific to current and evolving paramedic practice, key documents were analysed using a qualitative approach based on content analysis to identify common traits among documents, countries and other professions., Results: The review process identified 278 themes that were further allocated to 22 major analytical groupings. These groupings could further be mapped to previously reported cognitive, technical, integrative, context, relationship, affective/moral competencies and habits of mind. At the same time, the highest-rated groupings were key competencies of intellectual skills, safety, accountability, clinical decision-making, professionalism, communications, team-based approach and situational awareness. Two groups were represented in the literature but not in the professional capabilities, namely Health and Social continuum and self-directed practice., Conclusions: This review highlights the importance of measuring and validating the professional capabilities of Paramedicine Practitioners. The study explores various metrics and competency frameworks used to assess competency, comparing them against national accreditation schemes' professional capability standards. The findings suggest that accreditation frameworks play a crucial role in improving the quality of paramedicine practice, encompassing intellectual skills, safety, accountability, clinical decision-making, professionalism, communication, teamwork, and situational awareness., (© 2024. The Author(s).)
- Published
- 2024
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7. Ambulance clinicians' attitudes to older patients' self-determination when the patient has impaired decision-making ability: A Delphi study.
- Author
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Svensson A, Bremer A, Rantala A, Andersson H, Devenish S, Williams J, and Holmberg M
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- Aged, Attitude of Health Personnel, Delphi Technique, Humans, Quality of Life, Ambulances, Emergency Medical Technicians
- Abstract
Objective: The proportion of older people is increasing and reflects in the demand on ambulance services (AS). Patients can be more vulnerable and increasingly dependent, especially when their decision-making ability is impaired. Self-determination in older people has a positive relation to quality of life and can raise ethical conflicts in AS. Hence, the aim of this study was to empirically explore attitudes among Swedish ambulance clinicians (ACs) regarding older patients' self-determination in cases where patients have impaired decision-making ability, and who are in urgent need of care., Materials and Methods: An explorative design was adopted. A Delphi technique was used, comprising four rounds, involving a group (N = 31) of prehospital emergency nurses (n = 14), registered nurses (n = 10) and emergency medical technicians (n = 7). Focus group conversations (Round 1) and questionnaires (Rounds 2-4) generated data. Round 1 was analysed using manifest content analysis, which ultimately resulted in the creation of discrete items. Each item was rated with a five-point Likert scale together with free-text answers. Consensus (≥70%) was calculated by trichotomising the Likert scale., Results: Round 1 identified 108 items which were divided into four categories: (1) attitudes regarding the patient (n = 35), (2) attitudes regarding the patient relationship (n = 8), (3) attitudes regarding oneself and one's colleagues (n = 45), and (4) attitudes regarding other involved factors (n = 20). In Rounds 2-4, one item was identified in the free text from Round 2, generating a total of 109 items. After four rounds, 72 items (62%) reached consensus., Conclusions: The findings highlight the complexity of ACs' attitudes towards older patients' self-determination. The respect of older patients' self-determination is challenged by the patient, other healthcare personnel, significant others and/or colleagues. The study provided a unique opportunity to explore self-determination and shared decision-making. AS have to provide continued ethical training, for example to increase the use of simulation-based training or moral case deliberations in order to strengthen the ACs' moral abilities within their professional practice., Implications for Practice: Ambulance services must develop opportunities to provide continued training within this topic. One option would be to increase the use of simulation-based training, focusing on ethical aspects of the care. Another option might be to facilitate moral case deliberations to strengthen the ACs' abilities to manage these issues while being able to share experiences with peers. These types of interventions should illuminate the importance of the topic for the individual AC, which, in turn, may strengthen and develop the caring abilities within an integrated care team., (© 2021 The Authors. International Journal of Older People Nursing published by John Wiley & Sons Ltd.)
- Published
- 2022
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8. Paramedic occupational violence mitigation: a comprehensive systematic review of emergency service worker prevention strategies and experiences for use in prehospital care.
- Author
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Drew P, Tippett V, and Devenish S
- Subjects
- Humans, Occupational Exposure prevention & control, Emergency Medical Services organization & administration, Emergency Medical Technicians, Workplace Violence prevention & control
- Abstract
Occupational violence is a significant issue within the context of prehospital healthcare with the majority of paramedics reporting some form of abuse, intimidation, physical or sexual assault during their career. Though the paramedic literature acknowledges the severity of this issue, there is limited literature examining occupational violence mitigation strategies. Despite this, the operational and environmental similarities that exist between paramedics and other emergency service workers such as the police and firefighters, provide an opportunity to review relatable occupational violence mitigation strategies and experiences.This review used Joanna Briggs Institute guidance for systematic reviews of both qualitative evidence and effectiveness. Studies included in this review incorporated those published in English from 1990 to January 2020.Two qualitative studies met the criteria for review. From these, a total of 22 findings were extracted and combined to form four categories from which two syntheses were developed. Twenty-four quantitative studies, encompassing six unique fields, met the criteria for review.Mitigation strategies for emergency service worker occupational violence are not easily defined. They are dynamic, multilayered and encompass a variety of complex social, medical and psychological influences. In spite of this, there are clear benefits to their application in regard to the approaches and training of violence mitigation. The paramedic environment would benefit from strategies that are flexible to the ongoing needs of the workers and the specific cultural, environmental and social factors that encompass the paramedic organisation., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2021
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9. Machine learning-aided protein identification from multidimensional signatures.
- Author
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Zhang Y, Wright MA, Saar KL, Challa P, Morgunov AS, Peter QAE, Devenish S, Dobson CM, and Knowles TPJ
- Subjects
- Machine Learning
- Abstract
The ability to determine the identity of specific proteins is a critical challenge in many areas of cellular and molecular biology, and in medical diagnostics. Here, we present a macine learning aided microfluidic protein characterisation strategy that within a few minutes generates a three-dimensional fingerprint of a protein sample indicative of its amino acid composition and size and, thereby, creates a unique signature for the protein. By acquiring such multidimensional fingerprints for a set of ten proteins and using machine learning approaches to classify the fingerprints, we demonstrate that this strategy allows proteins to be classified at a high accuracy, even though classification using a single dimension is not possible. Moreover, we show that the acquired fingerprints correlate with the amino acid content of the samples, which makes it is possible to identify proteins directly from their sequence without requiring any prior knowledge about the fingerprints. These findings suggest that such a multidimensional profiling strategy can lead to the development of a novel method for protein identification in a microfluidic format.
- Published
- 2021
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10. Rapid highly sensitive general protein quantification through on-chip chemiluminescence.
- Author
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Chiu HK, Kartanas T, Saar KL, Luxhøj CM, Devenish S, and Knowles TPJ
- Abstract
Protein detection and quantification is a routinely performed procedure in research laboratories, predominantly executed either by spectroscopy-based measurements, such as NanoDrop, or by colorimetric assays. The detection limits of such assays, however, are limited to μ M concentrations. To establish an approach that achieves general protein detection at an enhanced sensitivity and without necessitating the requirement for signal amplification steps or a multicomponent detection system, here, we established a chemiluminescence-based protein detection assay. Our assay specifically targeted primary amines in proteins, which permitted characterization of any protein sample and, moreover, its latent nature eliminated the requirement for washing steps providing a simple route to implementation. Additionally, the use of a chemiluminescence-based readout ensured that the assay could be operated in an excitation source-free manner, which did not only permit an enhanced sensitivity due to a reduced background signal but also allowed for the use of a very simple optical setup comprising only an objective and a detection element. Using this assay, we demonstrated quantitative protein detection over a concentration range of five orders of magnitude and down to a high sensitivity of 10 pg mL - 1 , corresponding to pM concentrations. The capability of the platform presented here to achieve a high detection sensitivity without the requirement for a multistep operation or a multicomponent optical system sets the basis for a simple yet universal and sensitive protein detection strategy., (© 2021 Author(s).)
- Published
- 2021
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11. Multidimensional protein characterisation using microfluidic post-column analysis.
- Author
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Scheidt T, Kartanas T, Peter Q, Schneider MM, Saar KL, Müller T, Challa PK, Levin A, Devenish S, and Knowles TPJ
- Subjects
- Electrophoresis, Lab-On-A-Chip Devices, Microfluidic Analytical Techniques, Microfluidics, Proteins analysis
- Abstract
The biological function of proteins is dictated by the formation of supra-molecular complexes that act as the basic machinery of the cell. As such, measuring the properties of protein species in heterogeneous mixtures is of key importance for understanding the molecular basis of biological function. Here, we describe the combination of analytical microfluidic tools with liquid chromatography for multidimensional characterisation of biomolecules in complex mixtures in the solution phase. Following chromatographic separation, a small fraction of the flow-through is distributed to multiple microfluidic devices for analysis. The microfluidic device developed here allows the simultaneous determination of the hydrodynamic radius, electrophoretic mobility, effective molecular charge and isoelectric point of isolated protein species. We demonstrate the operation principle of this approach with a mixture of three unlabelled model proteins varying in size and charge. We further extend the analytical potential of the presented approach by analysing a mixture of interacting streptavidin with biotinylated BSA and fluorophores, which form a mixture of stable complexes with diverse biophysical properties and stoichiometries. The presented microfluidic device positioned in-line with liquid chromatography presents an advanced tool for characterising multidimensional physical properties of proteins in biological samples to further understand the assembly/disassembly mechanism of proteins and the nature of complex mixtures.
- Published
- 2020
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12. Cannabichromene is a cannabinoid CB 2 receptor agonist.
- Author
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Udoh M, Santiago M, Devenish S, McGregor IS, and Connor M
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- Animals, Cannabinoid Receptor Agonists chemistry, Cannabinoids chemistry, Dose-Response Relationship, Drug, Humans, Indoles pharmacology, Mice, Molecular Structure, Pertussis Toxin pharmacology, Signal Transduction drug effects, Structure-Activity Relationship, Tumor Cells, Cultured, Cannabinoid Receptor Agonists pharmacology, Cannabinoids pharmacology, Receptor, Cannabinoid, CB2 agonists
- Abstract
Background and Purpose: Cannabichromene (CBC) is one of the most abundant phytocannabinoids in Cannabis spp. It has modest antinociceptive and anti-inflammatory effects and potentiates some effects of Δ
9 -tetrahydrocannabinol in vivo. How CBC exerts these effects is poorly defined and there is little information about its efficacy at cannabinoid receptors. We sought to determine the functional activity of CBC at cannabinoid CB1 and CB2 receptors., Experimental Approach: AtT20 cells stably expressing haemagglutinin-tagged human CB1 and CB2 receptors were used. Assays of cellular membrane potential and loss of cell surface receptors were performed., Key Results: CBC activated CB2 but not CB1 receptors to produce hyperpolarization of AtT20 cells. This activation was inhibited by a CB2 receptor antagonist AM630, and sensitive to Pertussis toxin. Application of CBC reduced activation of CB2 , but not CB1 , receptors by subsequent co-application of CP55,940, an efficacious CB1 and CB2 receptor agonist. Continuous CBC application induced loss of cell surface CB2 receptors and desensitization of the CB2 receptor-induced hyperpolarization., Conclusions and Implications: CBC is a selective CB2 receptor agonist displaying higher efficacy than tetrahydrocannabinol in hyperpolarizing AtT20 cells. CBC can also recruit CB2 receptor regulatory mechanisms. CBC may contribute to the potential therapeutic effectiveness of some cannabis preparations, potentially through CB2 receptor-mediated modulation of inflammation., (© 2019 The British Pharmacological Society.)- Published
- 2019
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13. Effectiveness of mitigation interventions on occupational violence against emergency service workers: a mixed methods systematic review protocol.
- Author
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Drew P, Tippett V, and Devenish S
- Subjects
- Emergency Medical Services, Humans, Systematic Reviews as Topic, Allied Health Personnel, Emergency Responders, Occupational Exposure, Occupational Health, Violence prevention & control
- Abstract
Review Question/objective: The objective of this review is to develop an aggregated synthesis of qualitative and quantitative data on occupational violence (OV) mitigation interventions for Emergency Service Workers (ESW), to cultivate useful conclusions and recommendations for paramedic occupational safety and policy development. Emergency Service Worker is a broad term encompassing all elements of community-based emergency support and includes paramedics, firefighters, and police.The objective of the quantitative component of this review is to quantify the effectiveness of OV mitigation interventions for ESW.The objective of the qualitative component of this review is to explore the perceptions and experiences of ESW on the effectiveness of OV mitigation interventions.This review seeks to address the following questions.
- Published
- 2018
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14. On-chip label-free protein analysis with downstream electrodes for direct removal of electrolysis products.
- Author
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Saar KL, Zhang Y, Müller T, Kumar CP, Devenish S, Lynn A, Łapińska U, Yang X, Linse S, and Knowles TPJ
- Subjects
- Animals, Electrodes, Humans, Models, Chemical, Proteins analysis, Proteins chemistry, Proteins isolation & purification, Electrolysis instrumentation, Lab-On-A-Chip Devices, Microfluidic Analytical Techniques instrumentation
- Abstract
The ability to apply highly controlled electric fields within microfluidic devices is valuable as a basis for preparative and analytical processes. A challenge encountered in the context of such approaches in conductive media, including aqueous buffers, is the generation of electrolysis products at the electrode/liquid interface which can lead to contamination, perturb fluid flows and generally interfere with the measurement process. Here, we address this challenge by designing a single layer microfluidic device architecture where the electric potential is applied outside and downstream of the microfluidic device while the field is propagated back to the chip via the use of a co-flowing highly conductive electrolyte solution that forms a stable interface at the separation region of the device. The co-flowing electrolyte ensures that all the generated electrolysis products, including Joule heat and gaseous products, are flowed away from the chip without coming into contact with the analytes while the single layer fabrication process where all the structures are defined lithographically allows producing the devices in a simple yet highly reproducible manner. We demonstrate that by allowing stable and effective application of electric fields in excess of 100 V cm
-1 , the described platform provides the basis for rapid separation of heterogeneous mixtures of proteins and protein complexes directly in their native buffers as well as for the simultaneous quantification of their charge states. We illustrate this by probing the interactions in a mixture of an amyloid forming protein, amyloid-β, and a molecular chaperone, Brichos, known to inhibit the process of amyloid formation. The availability of a platform for applying stable electric fields and its compatibility with single-layer soft-lithography processes opens up the possibility of separating and analysing a wide range of molecules on chip, including those with similar electrophoretic mobilities.- Published
- 2017
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15. The direct actions of cannabidiol and 2-arachidonoyl glycerol at GABA A receptors.
- Author
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Bakas T, van Nieuwenhuijzen PS, Devenish SO, McGregor IS, Arnold JC, and Chebib M
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- Animals, Humans, Protein Subunits metabolism, Xenopus, Anticonvulsants pharmacology, Arachidonic Acids pharmacology, Cannabidiol pharmacology, Cannabinoid Receptor Agonists pharmacology, Endocannabinoids pharmacology, Glycerides pharmacology, Receptors, GABA-A metabolism
- Abstract
Cannabidiol (CBD) is a major non-intoxicating component of cannabis and possesses anti-epileptic, anxiolytic and anti-hyperalgesic properties. The mechanism of action of CBD in producing such effects remains unclear. Despite evidence that some endogenous and synthetic cannabinoids interact with GABA
A receptors, no-one has yet investigated the effects of CBD. Here we used two-electrode voltage clamp electrophysiology to compare the actions of CBD with those of the major central endocannabinoid, 2-arachidonoyl glycerol (2-AG) on human recombinant GABAA receptors (synaptic α1-6βγ2 and extrasynaptic α4β2δ) expressed on Xenopus oocytes. CBD and 2-AG were positive allosteric modulators at α1-6βγ2 receptors, with low micromolar potencies. The maximal level of enhancement seen with either CBD or 2-AG were on α2-containing GABAA receptor subtypes, with approximately a 4-fold enhancement of the GABA EC5 evoked current, more than twice the potentiation seen with other α-subunit receptor combinations. Further we observed β-subunit selectivity, whereby modulatory activity was higher at β2/β3 over β1 subunits. The β1-subunit homologous mutant β2(V436T) substantially diminished the efficacy of both drugs to a third of that obtained with wild-type β2 subunit combinations, but without changing potency. The potency of CBD increased and efficacy preserved in binary α1/α2β2 receptors indicating that their effects do not involve the classic benzodiazepine site. Exploration of extrasynaptic α4β2δ receptors revealed that both compounds enhanced GABA EC5 evoked currents at concentrations ranging from 0.01-1μM. Taken together these results reveal a mode of action of CBD on specifically configured GABAA receptors that may be relevant to the anticonvulsant and anxiolytic effects of the compound., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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16. Limiting radiation exposure during percutaneous nephrolithotomy.
- Author
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Hanna L, Walmsley BH, Devenish S, Rogers A, and Keoghane SR
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- Child, Cohort Studies, Female, Humans, Male, Middle Aged, Retrospective Studies, Time Factors, Fluoroscopy statistics & numerical data, Kidney Calculi surgery, Nephrostomy, Percutaneous methods, Radiation Dosage, Radiation Exposure statistics & numerical data
- Abstract
Background and Purpose: An increase in the prevalence of urologic stone disease and the refinement of endourologic techniques has seen a concomitant rise in the use of fluoroscopy during surgery. As such, there has been increasing concern in regard to the intraoperative radiation exposure to both clinicians and patients. The objective of the study was to audit contemporary data on radiation exposure during percutaneous nephrolithotomy (PCNL), in comparison with published series, and demonstrate that relatively low levels are achievable with clinical vigilance and attention to technique Methods: A retrospective analysis was performed of all PCNLs undertaken between July 2005 and December 2011. The primary outcome measure was fluoroscopy times and associated radiation exposure, measured as dose area product (DAP). No statistical analysis was undertaken., Results: Between July 2005 and October 2011, 376 PCNLs were performed. Data were available on 348 patients including 16 pediatric patients. Mean DAP and screening time (ST) over the whole study period were 45 cGy/cm(2) and 96s, respectively. On a year by year basis, the ST and DAP reduced from 917 to 375 and from 180 to 65, respectively. We acknowledge the limitation of this being a retrospective case series., Conclusions: This study represents the largest series to date on radiation exposure during PCNL and compares favorably with other published series, including those purporting novel techniques. Subtle changes in surgical technique and experience over time can lead to low screening times and can be potentially achieved by all operators performing PCNL within a high throughput center. It is now recognized that surgical outcome in stone surgery is related to caseload. The radiation dose the patient receives during PCNL is increasingly recognized to be an important factor and can be reduced by careful technique and experience.
- Published
- 2015
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17. Atomic resolution structure of EhpR: phenazine resistance in Enterobacter agglomerans Eh1087 follows principles of bleomycin/mitomycin C resistance in other bacteria.
- Author
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Yu S, Vit A, Devenish S, Mahanty HK, Itzen A, Goody RS, and Blankenfeldt W
- Subjects
- Anti-Bacterial Agents biosynthesis, Bacterial Proteins genetics, Bacterial Proteins metabolism, Crystallography, X-Ray, Databases, Protein, Dimerization, Drug Resistance, Bacterial, Lactoylglutathione Lyase chemistry, Lactoylglutathione Lyase genetics, Lactoylglutathione Lyase metabolism, Phenazines chemistry, Phenazines metabolism, Protein Binding, Protein Structure, Tertiary, Anti-Bacterial Agents pharmacology, Bacteria drug effects, Bacteria metabolism, Bacterial Proteins chemistry, Bleomycin pharmacology, Enterobacter drug effects, Enterobacter metabolism, Mitomycin pharmacology, Phenazines pharmacology
- Abstract
Background: The phenazines are redox-active secondary metabolites that a large number of bacterial strains produce and excrete into the environment. They possess antibiotic activity owing to the fact that they can reduce molecular oxygen to toxic reactive oxygen species. In order to take advantage of this activity, phenazine producers need to protect themselves against phenazine toxicity. Whereas it is believed that phenazine-producing pseudomonads possess highly active superoxide dismutases and catalases, it has recently been found that the plant-colonizing bacterium Enterobacter agglomerans expresses a small gene ehpR to render itself resistant towards D-alanyl-griseoluteic acid, the phenazine antibiotic produced by this strain., Results: To understand the resistance mechanism installed by EhpR we have determined its crystal structure in the apo form at 2.15 Å resolution and in complex with griseoluteic acid at 1.01 Å, respectively. While EhpR shares a common fold with glyoxalase-I/bleomycin resistance proteins, the ligand binding site does not contain residues that some related proteins employ to chemically alter their substrates. Binding of the antibiotic is mediated by π-stacking interactions of the aromatic moiety with the side chains of aromatic amino acids and by a few polar interactions. The dissociation constant KD between EhpR and griseoluteic acid was quantified as 244 ± 45 μM by microscale thermophoresis measurements., Conclusions: The data accumulated here suggest that EhpR confers resistance by binding D-alanyl-griseoluteic acid and acting as a chaperone involved in exporting the antibiotic rather than by altering it chemically. It is tempting to speculate that EhpR acts in concert with EhpJ, a transport protein of the major facilitator superfamily that is also encoded in the phenazine biosynthesis operon of E. agglomerans. The low affinity of EhpR for griseoluteic acid may be required for its physiological function.
- Published
- 2011
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18. Characterisation of dihydrodipicolinate synthase (DHDPS) from Bacillus anthracis.
- Author
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Domigan LJ, Scally SW, Fogg MJ, Hutton CA, Perugini MA, Dobson RC, Muscroft-Taylor AC, Gerrard JA, and Devenish SR
- Subjects
- Allosteric Regulation, Animals, Bacillus anthracis drug effects, Bacillus anthracis genetics, Bacillus anthracis pathogenicity, Crystallography, X-Ray, Drug Design, Enzyme Inhibitors pharmacology, Enzyme Stability, Escherichia coli enzymology, Escherichia coli genetics, Feedback, Physiological, Genes, Bacterial, Humans, Hydro-Lyases antagonists & inhibitors, Hydro-Lyases genetics, Hydrophobic and Hydrophilic Interactions, Kinetics, Ligands, Recombinant Proteins antagonists & inhibitors, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins metabolism, Thermodynamics, Bacillus anthracis enzymology, Hydro-Lyases chemistry, Hydro-Lyases metabolism
- Abstract
Bacillus anthracis is a Gram-positive spore-forming bacterium that is the causative agent of anthrax disease. The use of anthrax as a bioweapon has increased pressure for the development of an effective treatment. Dihydrodipicolinate synthase (DHDPS) catalyses the first committed step in the biosynthetic pathway yielding two essential bacterial metabolites, meso-diaminopimelate (DAP) and (S)-lysine. DHDPS is therefore a potential antibiotic target, as microbes require either lysine or DAP as a component of the cell wall. This paper is the first biochemical description of DHDPS from B. anthracis. Enzyme kinetic analyses, isothermal titration calorimetry (ITC), mass spectrometry and differential scanning fluorimetry (DSF) were used to characterise B. anthracis DHDPS and compare it with the well characterised Escherichia coli enzyme. B. anthracis DHDPS exhibited different kinetic behaviour compared with E. coli DHDPS, in particular, substrate inhibition by (S)-aspartate semi-aldehyde was observed for the B. anthracis enzyme (K(si(ASA))=5.4+/-0.5 mM), but not for the E. coli enzyme. As predicted from a comparison of the X-ray crystal structures, the B. anthracis enzyme was not inhibited by lysine. The B. anthracis enzyme was thermally stabilised by the first substrate, pyruvate, to a greater extent than its E. coli counterpart, but has a weaker affinity for pyruvate based on enzyme kinetics and ITC studies. This characterisation will provide useful information for the design of inhibitors as new antibiotics targeting B. anthracis.
- Published
- 2009
- Full Text
- View/download PDF
19. Home births: the midwife's dilemma.
- Author
-
Devenish S
- Subjects
- Female, Humans, Pregnancy, Surveys and Questionnaires, Choice Behavior, Health Knowledge, Attitudes, Practice, Home Childbirth nursing, Nurse Midwives education, Nurse Midwives psychology
- Published
- 1995
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