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Khan RI, McElhinney K, Dickson A, Kileen RP, Murphy C, O'Brien DF. Image-guided orbital surgery: a preclinical validation study using a high-resolution physical model. BMJ Open Ophthalmol 2024; 9:e001568. [PMID: 38575345 PMCID: PMC11002346 DOI: 10.1136/bmjophth-2023-001568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 03/23/2024] [Indexed: 04/06/2024] Open
Abstract
OBJECTIVE Preclinical validation study to assess the feasibility and accuracy of electromagnetic image-guided systems (EM-IGS) in orbital surgery using high-fidelity physical orbital anatomy simulators. METHODS EM-IGS platform, clinical software, navigation instruments and reference system (StealthStation S8, Medtronic) were evaluated in a mock operating theatre at the Royal Victoria Eye and Ear Hospital, a tertiary academic hospital in Dublin, Ireland. Five high-resolution 3D-printed model skulls were created using CT scans of five anonymised patients with an orbital tumour that previously had a successful orbital biopsy or excision. The ability of ophthalmic surgeons to achieve satisfactory system registration in each model was assessed. Subsequently, navigational accuracy was recorded using defined anatomical landmarks as ground truth. Qualitative feedback on the system was also attained. RESULTS Three independent surgeons participated in the study, one junior trainee, one fellow and one consultant. Across models, more senior participants were able to achieve a smaller system-generated registration error in a fewer number of attempts. When assessing navigational accuracy, submillimetre accuracy was achieved for the majority of points (16 landmarks per model, per participant). Qualitative surgeon feedback suggested acceptability of the technology, although interference from mobile phones near the operative field was noted. CONCLUSION This study suggests the feasibility and accuracy of EM-IGS in a preclinical validation study for orbital surgery using patient specific 3D-printed skulls. This preclinical study provides the foundation for clinical studies to explore the safety and effectiveness of this technology.
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Affiliation(s)
- Rizwana I Khan
- Royal Victoria Eye and Ear Hospital, Dublin, Ireland
- RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | | | - Andrew Dickson
- School of Mechanical & Materials Engineering, University College Dublin, Dublin, Ireland
| | - Ronan P Kileen
- Department of Radiology, St Vincent's University Hospital, Dublin, Ireland
| | - Conor Murphy
- Royal Victoria Eye and Ear Hospital, Dublin, Ireland
- RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Donncha F O'Brien
- RCSI University of Medicine and Health Sciences, Dublin, Ireland
- Department of Neurosurgery, Beaumont Hospital, Dublin, Ireland
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Clarke AJ, Dickson A, Dowling DP. Fabrication and Performance of Continuous 316 Stainless Steel Fibre-Reinforced 3D-Printed PLA Composites. Polymers (Basel) 2023; 16:63. [PMID: 38201728 PMCID: PMC10780637 DOI: 10.3390/polym16010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
This study investigates the feasibility of 3D printing continuous stainless steel fibre-reinforced polymer composites. The printing study was carried out using 316L stainless steel fibre (SSF) bundles with an approximate diameter of 0.15 mm. This bundle was composed of 90 fibres with a 14 μm diameter. This fibre bundle was first coated with polylactic acid (PLA) in order to produce a polymer-coated continuous stainless steel filament, with diameters tailored in the range from 0.5 to 0.9 mm. These filaments were then used to print composite parts using the material extrusion (MEX) technique. The SSF's volume fraction (Vf) was controlled in the printed composite structures in the range from 4 to 30 Vf%. This was facilitated by incorporating a novel polymer pressure vent into the printer nozzle, which allowed the removal of excess polymer. This thus enabled the control of the metal fibre content within the printed composites as the print layer height was varied in the range from 0.22 to 0.48 mm. It was demonstrated that a lower layer height yielded a more homogeneous distribution of steel fibres within the PLA polymer matrix. The PLA-SSF composites were assessed to evaluate their mechanical performance, volume fraction, morphology and porosity. Composite porosities in the range of 2-21% were obtained. Mechanical testing demonstrated that the stainless steel composites exhibited a twofold increase in interlaminar shear strength (ILSS) and a fourfold increase in its tensile strength compared with the PLA-only polymer prints. When comparing the 4 and 30 Vf% composites, the latter exhibited a significant increase in both the tensile strength and modulus. The ILSS values obtained for the steel composites were up to 28.5 MPa, which is significantly higher than the approximately 13.8 MPa reported for glass fibre-reinforced PLA composites.
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Affiliation(s)
- Alison J. Clarke
- I-Form Centre, School of Mechanical & Materials Engineering, University College Dublin, Belfield, D04 C1P1 Dublin, Ireland;
| | - Andrew Dickson
- Infraprint, Nova UCD, Belfield, D04 C1P1 Dublin, Ireland;
| | - Denis P. Dowling
- I-Form Centre, School of Mechanical & Materials Engineering, University College Dublin, Belfield, D04 C1P1 Dublin, Ireland;
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Kvalsvig A, Tuari-Toma B, Timu-Parata C, Bennett J, Sinnema C, Summers J, Davies C, Jackson C, Dickson A, Barnard LT, Baker MG. Protecting school communities from COVID-19 and other infectious disease outbreaks: the urgent need for healthy schools in Aotearoa New Zealand. N Z Med J 2023; 136:7-19. [PMID: 36893391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Affiliation(s)
- Amanda Kvalsvig
- Department of Public Health, University of Otago Wellington, New Zealand
| | - Belinda Tuari-Toma
- Tū Kotahi Māori Asthma and Research Trust, Lower Hutt, New Zealand. Ngāti Porou, Te Whānau-a-Apanui ki Upokorehe, Ngāti Tūwharetoa, Te Whenua Moemoeā
| | - Carmen Timu-Parata
- Department of Public Health, University of Otago Wellington, New Zealand. Ngāti Kahungunu
| | - Julie Bennett
- Department of Public Health, University of Otago Wellington, New Zealand
| | - Claire Sinnema
- Faculty of Education and Social Work, School of Learning, Development and Professional Practice, University of Auckland
| | - Jennifer Summers
- Department of Public Health, University of Otago Wellington, New Zealand
| | - Cheryl Davies
- Tū Kotahi Māori Asthma Trust, Lower Hutt, New Zealand; Department of Public Health, University of Otago Wellington, New Zealand. Ngāti Raukawa, Ngāti Mutunga ki te Wharekauri, Ngāti Pikiao
| | - Constanza Jackson
- Department of Public Health, University of Otago Wellington, New Zealand
| | | | | | - Michael G Baker
- Department of Public Health, University of Otago Wellington, New Zealand
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Dickson A, Asgari E, McHardy AC, Mofrad MRK. GO Bench: shared hub for universal benchmarking of machine learning-based protein functional annotations. Bioinformatics 2023; 39:7036335. [PMID: 36786404 PMCID: PMC10132473 DOI: 10.1093/bioinformatics/btad081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 01/13/2023] [Accepted: 02/13/2023] [Indexed: 02/15/2023]
Abstract
MOTIVATION Gene annotation is the problem of mapping proteins to their functions represented as Gene Ontology (GO) terms, typically inferred based on the primary sequences. Gene annotation is a multi-label multi-class classification problem, which has generated growing interest for its uses in the characterization of millions of proteins with unknown functions. However, there is no standard GO dataset used for benchmarking the newly developed new machine learning models within the bioinformatics community. Thus, the significance of improvements for these models remains unclear. RESULTS The Gene Benchmarking database is the first effort to provide an easy-to-use and configurable hub for the learning and evaluation of gene annotation models. It provides easy access to pre-specified datasets and takes the non-trivial steps of preprocessing and filtering all data according to custom presets using a web interface. The GO bench web application can also be used to evaluate and display any trained model on leaderboards for annotation tasks. AVAILABILITY AND IMPLEMENTATION The GO Benchmarking dataset is freely available at www.gobench.org. Code is hosted at github.com/mofradlab, with repositories for website code, core utilities and examples of usage (Supplementary Section S.7). SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Andrew Dickson
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA 94720, USA
| | - Ehsaneddin Asgari
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA 94720, USA.,Computational Biology of Infection Research, Helmholtz Centre for Infection Research, 38124 Brunswick, Germany
| | - Alice C McHardy
- Computational Biology of Infection Research, Helmholtz Centre for Infection Research, 38124 Brunswick, Germany
| | - Mohammad R K Mofrad
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA 94720, USA
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McKay F, van der Pligt P, Zinga J, Lindberg R, Dickson A. The path to evidence-based guidelines for food insecurity during pregnancy. Eur J Public Health 2022. [DOI: 10.1093/eurpub/ckac129.695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Food insecurity has negative health implications during and after pregnancy, however, identifying and then assisting women who are food insecure is complex. Successful screening programs are often embedded in practice guidelines that include referral and treatment guidance. Screening for food insecurity is vital to address food insecurity, however, it is not present in Australia, nor are there any guidelines for healthcare settings. This presentation will describe the steps taken to gather evidence to inform the development of practice guidelines.
Methods
The creation of practice guidelines for screening and responding to the needs of food insecure pregnant women was informed by 1) qualitative interviews with food insecure pregnant women, and 2) qualitative interviews with clinicians about their experiences of assisting hungry and food insecure pregnant women, 3) quantitative research with a cross-section of pregnant women about their experiences managing their food supply, 4) a systematic review describing the existing interventions addressing food insecurity during pregnancy, and 5) a modified Delphi to gather the opinions of experts on the best ways to address food insecurity in pregnancy.
Results
This work highlight the potential effectiveness of a food insecurity screening tool in the antenatal setting, the readiness of clinicians to respond to this need, the breadth and depth of current interventions to address food insecurity, and the opinions of experts on how this issue needs to be addressed. The combined impact of these 5 studies is the identification of a number of responces to food insecurity and hunger during pregnancy.
Conclusions
Given the lack of screening, standard care, and treatment of food insecurity in a clinical setting in Australia, it is essentail that guidelines are created that standardise patient care and control costs through efficient use of health care resources.
Key messages
• Food insecurity during pregnancy has significant implications for both mother and baby.
• Creating supportive evidence-based mechanisms to address food insecurity will lead to positive outcomes.
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Affiliation(s)
- F McKay
- School of Health and Social Development, Deakin University , Burwood, Australia
| | - P van der Pligt
- Institute for Physical Activity and Nutrition, Deakin University , Burwood, Australia
- Department of Nutrition and Dietetics, Western Health , Footscray, Australia
| | - J Zinga
- School of Health and Social Development, Deakin University , Burwood, Australia
- Royal Women’s Hospital, RWH , Parkville, Australia
| | - R Lindberg
- Institute for Physical Activity and Nutrition, Deakin University , Burwood, Australia
| | - A Dickson
- Institute for Physical Activity and Nutrition, Deakin University , Burwood, Australia
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Davis A, Dickson A, Daniel L, Nepal P, Zanussi J, Miller-Fleming T, Straub P, Wei WQ, Liu G, Cox N, Hung A, Feng Q, Stein CM, Chung CP. POS0393 ASSOCIATION BETWEEN GENETICALLY PREDICTED EXPRESSION OF TPMT AND AZATHIOPRINE ADVERSE EVENTS IN PATIENTS WITH INFLAMMATORY CONDITIONS. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundAzathioprine is a widely used immunosuppressant for the treatment of inflammatory conditions such as systemic lupus erythematosus (SLE), systemic vasculitis, dermatomyositis, and inflammatory bowel disease. However, its use is often limited by myelotoxicity. Variants in the gene encoding thiopurine-S-methyltransferase (TPMT), an enzyme in the metabolic pathway of azathioprine, increase the risk for myelotoxicity1. We know little about the relationship between the genetically predicted expression of TPMT and side effects of azathioprine.ObjectivesTo examine whether genetically predicted expression of TPMT in liver tissue is associated with azathioprine adverse effects.MethodsWe assembled a retrospective cohort of new users taking azathioprine for inflammatory conditions at a tertiary care center. We performed genotyping with Illumina Infinium Expanded Multi-Ethnic Genotyping Array plus custom content data, and we then used Michigan Imputation servers for genetic imputation and PrediXcan models trained with GTEx/Genotype-Tissue Expression Project version 8 data to impute TPMT expression in liver tissue. We prespecified nine groups of phecodes (comprised of ICD9 and ICD10 codes) corresponding to known adverse effects of azathioprine. We then tested the association between the predicted expression of TPMT and these adverse events; for outcomes significant in the Wilcoxon ranksum tests (p<0.05), each case was reviewed in clinical records for confirmation. Finally, we grouped the predicted expression of TPMT in liver tissue into tertiles and conducted logistic regressions to assess the associations between predicted expression and side effects. We conducted a sensitivity analysis restricted to patients with EHR-reported White race.ResultsThe cohort included 1034 patients (Table 1). Phecodes for 3 side effects—leukopenia (n=29), skin cancer (n=13), and rash (n=52)—were identified as associated with predicted TPMT expression in liver tissue. Of these, cases of side effects attributed to azathioprine were validated by chart review: leukopenia (96.6%; n=28), skin cancer (92.3%; n=12), and rash (9.6%; n=5) and used for analysis. When assessed by tertile of predicted TPMT expression, patients in the highest tertile had lower odds of having leukopenia (OR=0.35, 95%CI: 0.12-0.98, p=0.045) and a trend towards higher odds for skin cancer, but the number of cases was small (OR=3.56, 95%CI: 0.73-17.27, p=0.115). Confirmed cases of rash attributed to azathioprine were too few for meaningful analysis. We found similar results when restricted to patients with reported White race.Table 1.Characteristics of patients by TPMT expressionLowest TertileMiddle TertileHighest TertileN=345N=345N=344Female sex, n (%)228 (66.1)244 (70.7)238 (69.2)EHR-reported White race, n (%)306 (88.7)293 (84.9)290 (84.3)Age, median [IQR]42 [29-58]43 [30-55]46 [30-56]Indication, n (%)Systemic lupus erythematosus38 (11.0)42 (12.2)38 (11.0)Inflammatory bowel disease191 (55.3)185 (53.6)190 (55.2)Other connective tissue disorder/autoimmune92 (26.7)96 (27.8)100 (29.1)Other24 (7.0)22 (6.4)16 (4.7)Verified leukopenia attributed to azathioprine, n (%)14 (4.1)9 (2.6)5 (1.5)Verified skin cancer attributed to azathioprine, n (%)2 (0.6)3 (0.9)7 (2.0)Verified rash attributed to azathioprine, n (%)2 (0.6)3 (0.9)0 (0)ConclusionThis analysis suggests that PrediXcan may be useful for examining the association between gene expression and side effects of medications. Moreover, this approach successfully identified leukopenia as a side effect associated with predicted TPMT expression.AcknowledgementsNone to declare.Disclosure of InterestsNone declared.
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Shah S, Reese T, Zanussi J, Dickson A, Daniel L, Tao R, Miller-Fleming T, Straub P, Hung A, Nepal P, Wei WQ, Phillips E, Cox N, Stein CM, Feng Q, Chung CP. POS1444 FLT1 AND EPHB2 ARE NOVEL GENETIC MARKERS ASSOCIATED WITH PANCREATITIS IN PATIENTS TAKING AZATHIOPRINE FOR IMMUNE-MEDIATED CONDITIONS: INTEGRATING GENOME- AND TRANSCRIPTOME-WIDE ASSOCIATION STUDIES. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.4265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundAzathioprine (AZA) is a thiopurine immunosuppressant medication used to treat a variety of immune-mediated diseases. Unfortunately, its use is limited by adverse effects. Pancreatitis, a potentially severe, life-threatening side effect is independent of dose and necessitates AZA discontinuation given the high risk of recurrent pancreatitis with continued use or re-challenge. The mechanisms driving pancreatitis are unclear. While classic thiopurine-induced acute pancreatitis (TIAP) has been associated with HLA haplotypes, most patients taking AZA and presenting with pancreatitis do not fulfill the stringent criteria for TIAP.ObjectivesTo identify genetic risk factors for pancreatitis in patients taking azathioprine for immune-mediated conditions.MethodsUsing a biobank linked to electronic health records (EHR) from a tertiary center, we identified new users of AZA. Patients were excluded if the primary indication for AZA was organ transplant or if there was a history of pancreatitis prior to AZA use. The analysis was restricted to patients with EHR-reported race as White due to insufficient case counts for the non-White group. We then identified patients with amylase or lipase values that exceeded twice the upper limit of normal (“>2x ULN”) or with ICD-9/ICD-10 codes for acute pancreatitis. Each record was manually reviewed to confirm the timing of AZA use in relation to laboratory derangements or ICD coding, as well as to further classify patients into three increasingly strict, but not exclusive categories: 1) pancreatic injury (amylase or lipase >2x ULN); 2) acute pancreatitis1, or 3) TIAP2. We completed genotyping with Illumina Infinium Expanded Multi-Ethnic Genotyping Array plus custom content data, employed Michigan Imputation servers for genetic imputation, and used PrediXcan (GTEx v8) to impute gene expression. We then conducted genome-wide association and transcriptome-wide association studies (GWAS, TWAS). Acknowledging the relatively small overall cohort, and possible imbalance of cases vs controls, we used the Firth logistic regression method, which is a penalized likelihood-based method.ResultsWe studied 2127 AZA users (35.4% male; mean 44.5+/-17.2 years). The median AZA dose was 100mg/day (IQR: 50-125mg/day). Rheumatologic conditions (56.9%) and inflammatory bowel disease (40.4%) comprised the most common primary indications for AZA. Pancreatic injury, pancreatitis, and TIAP were diagnosed in 42 (2.0%), 16 (0.8%), and 9 (0.4%) patients, respectively. GWAS identified several significantly associated genes, many with overlapping TWAS findings in the pancreas and liver (Figure 1). From these, the two protein-encoding genes Fms Related Receptor Tyrosine Kinase-1 (FLT1) and Ephrin type-B receptor-2 (EPHB2) overlapped in two or more pancreatitis phenotypes in the TWAS and GWAS, respectively. EPHB2 was associated with a 8.6-fold (P=1.84 x 10-8) and a 31.4-fold (P=2.87x 10-8) higher likelihood of pancreatic injury and TIAP, respectively.Figure 1.ConclusionFLT1—a gene that encodes a receptor tyrosine kinase and is a member of the vascular endothelial growth factor receptor (VEGFR) family—and EPHB2—a gene that encodes a member of the Eph receptor family, which is the largest subgroup of the receptor tyrosine kinase family—are novel genetic markers associated with pancreatitis in patients taking AZA. VEGF can potentiate inflammation and the pancreas microenvironment is known to promote VEGF expression, which has been linked to pancreatic cancer development; anti-VEGF treatments have been investigated both for mitigating inflammation and also anti-pancreatic cancer treatment. Future studies validating our findings in AZA-induced pancreatitis are warranted.References[1]Crockett et al. Gastroenterology (2018). 154(4):1096-1101.[2]Heap et al. Nature Genetics (2014). 46:1131-1134Disclosure of InterestsShailja Shah Consultant of: ad hoc consultant for Phathom pharmaceuticals, Tyler Reese: None declared, Jacy Zanussi: None declared, Alyson Dickson: None declared, Laura Daniel: None declared, Ran Tao: None declared, Tyne Miller-Fleming: None declared, Peter Straub: None declared, Adriana Hung: None declared, Puran Nepal: None declared, Wei-Qi Wei: None declared, Elizabeth Phillips: None declared, Nancy Cox: None declared, Charles M. Stein: None declared, QiPeng Feng: None declared, Cecilia P. Chung: None declared
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Shepertycky M, Burton S, Dickson A, Liu YF, Li Q. Removing energy with an exoskeleton reduces the metabolic cost of walking. Science 2021; 372:957-960. [PMID: 34045349 DOI: 10.1126/science.aba9947] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 10/27/2020] [Accepted: 03/08/2021] [Indexed: 12/23/2022]
Abstract
Evolutionary pressures have led humans to walk in a highly efficient manner that conserves energy, making it difficult for exoskeletons to reduce the metabolic cost of walking. Despite the challenge, some exoskeletons have managed to lessen the metabolic expenditure of walking, either by adding or storing and returning energy. We show that the use of an exoskeleton that strategically removes kinetic energy during the swing period of the gait cycle reduces the metabolic cost of walking by 2.5 ± 0.8% for healthy male users while converting the removed energy into 0.25 ± 0.02 watts of electrical power. By comparing two loading profiles, we demonstrate that the timing and magnitude of energy removal are vital for successful metabolic cost reduction.
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Affiliation(s)
- Michael Shepertycky
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Sarah Burton
- Department of Electrical and Computer Engineering, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Andrew Dickson
- Department of Electrical and Computer Engineering, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Yan-Fei Liu
- Department of Electrical and Computer Engineering, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Qingguo Li
- Department of Mechanical and Materials Engineering, Queen's University, Kingston, ON K7L 3N6, Canada.
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Dickson A, Dickson S, Dickson P. Joan Patricia Wright. Assoc Med J 2020. [DOI: 10.1136/bmj.m3162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Dickson A, Manning J. A balanced opinion? Considering the role of the external clinical advisor in ACC processes. N Z Med J 2020; 133:97-103. [PMID: 32438381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The role of the external clinical advisor is critical to the adjudication of complex claims in the processes of the Accident Compensation Corporation (ACC). This is particularly true of claims for treatment injury that occur during birth, which are often very complicated. In most cases external clinical advisors are non-treating doctors, whose opinion strongly guides the hand of ACC. This viewpoint considers the impact of the role of the external clinical advisor by using extracts from an external clinical advisor's report to show how a power imbalance can be enacted in ACC decision making processes. Also considered are the way that the normal checks and balances in the system, particularly those provided by the Health & Disability Commissioner, are bypassed in most cases. Finally, a recommendation is made to potential external clinical advisors to precisely following the standards set by the Medical Council in all cases when writing reports for ACC.
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Affiliation(s)
- Andrew Dickson
- Senior Lecturer, School of People, Environment & Planning, College of Humanities & Social Sciences, Massey University, Palmerston North
| | - Joanna Manning
- Professor, Faculty of Law, University of Auckland, Auckland
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Murphy DT, Allen CM, Ghidan O, Dickson A, Hu W, Briggs E, Holder PW, Armstrong KF. Analysing Sr isotopes in low-Sr samples such as single insects with inductively coupled plasma tandem mass spectrometry using N 2 O as a reaction gas for in-line Rb separation. Rapid Commun Mass Spectrom 2020; 34:e8604. [PMID: 31756774 PMCID: PMC7050539 DOI: 10.1002/rcm.8604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 05/28/2023]
Abstract
RATIONALE Strontium isotopes are valuable markers of provenance in a range of disciplines. Limited amounts of Sr in low-mass samples such as insects mean that conventional Sr isotope analysis precludes their use for geographic origins in many ecological studies or in applications such as biosecurity. Here we test the viability of using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) with N2 O as a reaction gas for accurately determining Sr isotopes in insects with Sr < 100 ng. METHODS Strontium isotopes were determined in solution mode using ICP-MS/MS with 0.14 L/min N2 O as a reaction gas to convert Sr+ into SrO+ for in-line separation of 87 Sr from 87 Rb. The Sr isotope reference standards NIST SRM 987, NIST SRM 1570a and NIST SRM 1547 were used to assess accuracy and reproducibility. Ten insect species collected from the wild as a proof-of-principle application were analysed for Sr concentration and Sr isotopes. RESULTS Using ICP-MS/MS we show for the first time that internal mass bias correction of 87 Sr16 O/86 Sr16 O based on 88 Sr16 O/86 Sr16 O works to give for NIST SRM 987 a 87 Sr/86 Sr ratio of 0.7101 ± 0.012 (RSD = 0.17%) and for NIST SRM 1570a a 87 Sr/86 Sr ratio of 0.7100 ± 0.009 (RSD = 0.12%), which are within error of the accepted values. The first 87 Sr/86 Sr ratio of NIST SRM 1547 is 0.7596 ± 0.0014. Strontium analyses were run on 0.8 mL of 0.25-0.5 ppb Sr, which equates to 2-4 ng of Sr. Strontium isotope analysis with a precision of >99.8% can be achieved with in-line separation of 87 Sr from 87 Rb at least up to solutions with 25 ppb Rb. CONCLUSIONS A minimum of 5 mg of insect tissue is required for Sr isotope analysis. This new ICP-MS/MS method enables Sr isotope analysis in single insects, allowing population-scale studies to be feasible and making possible applications with time-critical uses such as biosecurity.
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Affiliation(s)
- David Thomas Murphy
- School of Earth, Environmental and Biological SciencesQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Charlotte M. Allen
- School of Earth, Environmental and Biological SciencesQueensland University of TechnologyBrisbaneQueenslandAustralia
- Institute for Future EnvironmentsQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Osama Ghidan
- Institute for Future EnvironmentsQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Andrew Dickson
- School of Earth, Environmental and Biological SciencesQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Wan‐Ping Hu
- Institute for Future EnvironmentsQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Ethan Briggs
- School of Biological SciencesUniversity of QueenslandBrisbaneQueenslandAustralia
| | - Peter W. Holder
- Bio‐Protection Research CentreLincoln UniversityLincolnNew Zealand
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Affiliation(s)
- Leon Salter
- School of Communication, Journalism & Marketing, Massey University, Wellington, New Zealand
| | - Andrew Dickson
- School of People, Environment & Planning, Massey University, Palmerston North, New Zealand
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Dickson A, Smith M, Smith F, Park J, King C, Currie K, Langdridge D, Davis M, Flowers P. Understanding the relationship between pet owners and their companion animals as a key context for antimicrobial resistance-related behaviours: an interpretative phenomenological analysis. Health Psychol Behav Med 2019; 7:45-61. [PMID: 34040838 PMCID: PMC8114347 DOI: 10.1080/21642850.2019.1577738] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 01/28/2019] [Indexed: 12/24/2022] Open
Abstract
Objectives: Drivers of antimicrobial resistance (AMR) are diffuse and complex including a range of interspecies behaviours between pet owners and their animals. We employed interpretative phenomenological analysis (IPA) to explore the relationship between pet owners and their companion animals in relation to AMR. Design: Cross sectional, qualitative study. Methods: Semi-structured interviews were conducted with twenty-three British pet owners, transcribed verbatim and subjected to Interpretative Phenomenological Analysis (IPA). Results: Three, inter-related Superordinate themes are presented 1) 'They're my fur babies': unconditional love and anthropomorphism; 2) 'They share everything with you': affection and transmission behaviours; and 3) 'We would err on the side of caution': decision making and antibiotic use'. Conclusions: Affectionate behaviours between companion animals and their owners pose a risk for AMR transmission but they are so deeply treasured that they are unlikely to be amenable to change. In contrast, the promotion of appropriate antibiotic stewardship for pet owners and vets may offer a viable pathway for intervention development, benefitting from synergies with other interventions that target prescribers.
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Affiliation(s)
- A. Dickson
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
| | - M. Smith
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
| | - F. Smith
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
| | - J. Park
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
| | - C. King
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
| | - K. Currie
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
| | - D. Langdridge
- Faculty of Arts and Social Sciences, Open University, Milton Keynes, England
| | - M. Davis
- School of Social Sciences, Monash University, Melbourne, Australia
| | - P. Flowers
- Safeguarding Health through Infection Prevention [SHIP] Research Group, Glasgow Caledonian University, Glasgow, Scotland
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King C, Smith M, Currie K, Dickson A, Smith F, Davis M, Flowers P. Exploring the behavioural drivers of veterinary surgeon antibiotic prescribing: a qualitative study of companion animal veterinary surgeons in the UK. BMC Vet Res 2018; 14:332. [PMID: 30404649 PMCID: PMC6223057 DOI: 10.1186/s12917-018-1646-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 10/11/2018] [Indexed: 11/30/2022] Open
Abstract
Background Multi-drug resistant bacteria are an increasing concern in both human and veterinary medicine. Inappropriate prescribing and use of antibiotics within veterinary medicine may be a contributory factor to antimicrobial resistance (AMR). The ‘One Health’ Initiative aims to work across species and environments to reduce AMR, however; little is currently known about the factors which influence antibiotic prescribing among veterinary surgeons in companion animal practice. This paper reports on qualitative data analysis of interviews with veterinary surgeons whose practice partially or wholly focuses on companion animals (N = 16). The objective of the research was to explore the drivers of companion animal veterinary surgeons’ antibiotic prescribing behaviours. The veterinary surgeons interviewed were all practising within the UK (England (n = 4), Scotland (n = 11), Northern Ireland (n = 1)). A behavioural thematic analysis of the data was undertaken, which identified barriers and facilitators to specific prescribing-related behaviours. Results Five components of prescribing behaviours were identified: 1) confirming clinical need for antibiotics; 2) responding to clients; 3) confirming diagnosis; 4) determining dose, duration and type of antibiotic; and 5) preventing infection around surgery (with attendant appropriate and inappropriate antibiotic prescribing behaviours). Barriers to appropriate prescribing identified include: business, diagnostic, fear, habitual practice and pharmaceutical factors. Facilitators include: AMR awareness, infection prevention, professional learning and regulation and government factors. Conclusion This paper uses a behavioural lens to examine drivers which are an influence on veterinary surgeons’ prescribing behaviours. The paper contributes new understandings about factors which influence antibiotic prescribing behaviours among companion animal veterinary surgeons. This analysis provides evidence to inform future interventions, which are focused on changing prescribing behaviours, in order to address the pressing public health concern of AMR.
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Affiliation(s)
- C King
- Department of Nursing and Community Health, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK.
| | - M Smith
- Department of Nursing and Community Health, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK
| | - K Currie
- Department of Nursing and Community Health, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK
| | - A Dickson
- Department of Nursing and Community Health, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK
| | - F Smith
- Department of Nursing and Community Health, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK
| | - M Davis
- School of Social Sciences, Monash University, Melbourne, Australia
| | - P Flowers
- Department of Nursing and Community Health, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK
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Warbrick I, Came H, Dickson A. The shame of fat shaming in public health: moving past racism to embrace indigenous solutions. Public Health 2018; 176:128-132. [PMID: 30352699 DOI: 10.1016/j.puhe.2018.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 05/31/2018] [Accepted: 08/30/2018] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The aim of this article is to explore perceptions of weight and racism towards Māori, as an indigenous group, and the association between the two. We then propose indigenous solutions as pathways out of fat shaming. STUDY DESIGN This is a conceptual article supported by a review of literature in the fields of weight stigma, racism and indigenous (Māori) health. METHODS This article is taken from the perspective of three researchers involved in Māori health research, studies on institutional and societal racism and critical research on weight stigma and the weight loss industry. Indigenous peoples in developed nations are more likely to be overweight, obese and disproportionately affected by the comorbidities and physical disorders associated with weight when compared with their counterparts. Beyond the physical ailments are a variety of psychological, emotional and social issues, which are associated with being 'fat' and/or overweight and/or from subsequent stigmatisation. RESULTS Long before this world's populations reached the current alarming level of obesity, indigenous peoples in colonised countries were stigmatised because of the colour of their skin, their beliefs and their culture. Stigma is nothing new to indigenous peoples, and so when Māori, or any other indigenous groups are told they are fat and less productive (or moral) because of 'fatness', there is no surprise because they have been told the same thing (albeit for a different reason) for generations. Considering the relatively high proportion of indigenous people in New Zealand, North America and beyond who do not fit the 'recommended weight range', the justification for racist sentiment is seemingly strengthened. CONCLUSIONS A weight loss-centred approach to health has not improved the health of indigenous people. Initiatives that draw on, or are underpinned by local, traditional knowledge are more relevant for indigenous peoples and could lead to better health outcomes for these groups.
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Affiliation(s)
- I Warbrick
- Taupua Waiora Centre for Māori Health Research, Auckland University of Technology AUT University (Mail Code M-2), Private Bag 92006, Auckland, 1142, New Zealand.
| | - H Came
- Taupua Waiora Centre for Māori Health Research, Auckland University of Technology AUT University (Mail Code M-2), Private Bag 92006, Auckland, 1142, New Zealand.
| | - A Dickson
- School of Management, Massey University, Palmerston North, New Zealand.
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Currie K, King C, McAloney-Kocaman K, Roberts NJ, MacDonald J, Dickson A, Cairns S, Khanna N, Flowers P, Reilly J, Price L. Barriers and enablers to meticillin-resistant Staphylococcus aureus admission screening in hospitals: a mixed-methods study. J Hosp Infect 2018; 101:100-108. [PMID: 30098382 DOI: 10.1016/j.jhin.2018.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 08/03/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND To reduce the risk of transmission of meticillin-resistant Staphylococcus aureus (MRSA), international guidelines recommend admission screening to identify hospital patients at risk of colonization. However, routine monitoring indicates that optimum screening compliance levels are not always achieved. In order to enhance compliance, we must better understand those factors which influence staff screening behaviours. AIM To identify factors which influence staff compliance with hospital MRSA screening policies. METHODS A sequential two-stage mixed-methods design applied constructs from normalization process theory and the theoretical domains framework to guide data collection and analysis. Initial qualitative findings informed subsequent development of a national cross-sectional survey of nursing staff (N = 450). Multiple regression modelling identified which barriers and enablers best predict staff compliance. FINDINGS Three factors were significant in predicting optimum (>90%) compliance with MRSA screening: having MRSA screening routinized within the admission process; category of clinical area; feedback of MRSA screening compliance within the clinical area. Integration of data-sets indicated that organizational systems which 'make doing the right thing easy' influence compliance, as does local ward culture. Embedded values and beliefs regarding the relative (de)prioritization of MRSA screening are important. CONCLUSION To our knowledge, this is the first study to provide original evidence of barriers and enablers to MRSA screening, applying both sociological and psychological theory. As antimicrobial resistance is a global health concern, these findings have international relevance for screening programmes. Future policy recommendations or behaviour change interventions, based on the insights presented here, could have significant impact upon improving screening compliance.
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Affiliation(s)
- K Currie
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK.
| | - C King
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
| | - K McAloney-Kocaman
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
| | - N J Roberts
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
| | - J MacDonald
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
| | - A Dickson
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
| | - S Cairns
- NHS Health Protection Scotland, Glasgow, UK
| | - N Khanna
- NHS Greater Glasgow & Clyde, Glasgow, UK
| | - P Flowers
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
| | - J Reilly
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK; NHS Health Protection Scotland, Glasgow, UK
| | - L Price
- Safeguarding Health through Infection Prevention (SHIP) Research Group, Glasgow Caledonian University, Glasgow, UK
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Dickson A, Karatzias T, Gullone A, Grandison G, Allan D, Park J, Flowers P. Negotiating boundaries of care: an interpretative phenomenological analysis of the relational conflicts surrounding home mechanical ventilation following traumatic spinal cord injury. Health Psychol Behav Med 2018; 6:120-135. [PMID: 34040825 PMCID: PMC8114355 DOI: 10.1080/21642850.2018.1462708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Objectives: The aim of this study is to explore the phenomena of mechanical ventilation following traumatic spinal cord injury from three simultaneous perspectives; patients who require full-time mechanical ventilation (n = 8), their informal family carers (n = 8) and their formal carers (n = 11). We focus upon the intra and inter- personal challenges of establishing boundaries within the triad. Design: Qualitative study. Methods: Semi-structured interviews were transcribed verbatim and analysed using interpretative phenomenological analysis (IPA). In order to encapsulate the inter-subjective, multi-dimensional and relational aspects of the experience, we focussed on recurrent themes which were independently reported across all three participant groups. Results: One major inter-connected recurrent theme was identified: 1) 'Negotiating boundaries of care and finding a "fit"'. It centres around establishing a 'line', or a boundary, which was imperative for retaining a sense of independence (for patients), a sense of home and privacy (for informal carers) and difficulties balancing complex care provision with the needs of family members so as not to cross that 'line' (for formal carers). Conclusions: The findings highlight the need for focussing on a 'fit' within the triad, balancing boundaries of care in order to establish a productive, satisfactory psycho-social environment for all three participant groups to live and/or work within. Recommendations for both future care provision and future research are suggested.
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Affiliation(s)
- A Dickson
- School of Health & Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - T Karatzias
- School of Health and Social Care, Edinburgh Napier University, Edinburgh, UK
| | - A Gullone
- School of Health and Social Sciences, University of Edinburgh, Edinburgh, UK
| | - G Grandison
- School of Health and Social Care, Edinburgh Napier University, Edinburgh, UK
| | - D Allan
- Queen Elizabeth National Spinal Injuries for Scotland, Southern General Hospital, Glasgow, UK
| | - J Park
- School of Health & Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - P Flowers
- School of Health & Life Sciences, Glasgow Caledonian University, Glasgow, UK
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Abstract
Crystal structures of neurolysin, a zinc metallopeptidase, do not show a significant conformational change upon the binding of an allosteric inhibitor. Neurolysin has a deep channel where it hydrolyzes a short neuropeptide neurotensin to create inactive fragments and thus controls its level in the tissue. Neurolysin is of interest as a therapeutic target since changes in neurotensin level have been implicated in cardiovascular disorders, neurological disorders, and cancer, and inhibitors of neurolysin have been developed. An understanding of the dynamical and structural differences between apo and inhibitor-bound neurolysin will aid in further design of potent inhibitors and activators. For this purpose, we performed several molecular dynamics (MD) simulations for both apo and inhibitor-bound neurolysin. A machine learning method (Linear Discriminant Analysis) is applied to reveal differences between the apo and inhibitor-bound ensembles in an automated way, and large differences are observed on residues that are far from both the active site and the inhibitor binding site. The effects of inhibitor binding on the collective motions of neurolysin are extensively analyzed and compared using both Principal Component Analysis and Elastic Network Model calculations. We find that inhibitor binding induces additional low-frequency motions that are not observed in the apo form. ENM also reveals changes in inter- and intradomain communication upon binding. Furthermore, differences are observed in the inhibitor-bound neurolysin contact network that are far from the active site, revealing long-range allosteric behavior. This study also provides insight into the allosteric modulation of other neuropeptidases with similar folds.
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Affiliation(s)
- A Uyar
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
| | - V T Karamyan
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center , Amarillo, Texas 79106, United States
| | - A Dickson
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States.,Department of Computational Mathematics, Science and Engineering, Michigan State University , East Lansing, Michigan 48824, United States
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Ruth D, Wilson S, Alakavuklar O, Dickson A. Anxious academics: talking back to the audit culture through collegial, critical and creative autoethnography. Culture and Organization 2017. [DOI: 10.1080/14759551.2017.1380644] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Damian Ruth
- Massey Business School, Massey University, Palmerston North, New Zealand
| | - Suze Wilson
- Massey Business School, Massey University, Palmerston North, New Zealand
| | - Ozan Alakavuklar
- Massey Business School, Massey University, Palmerston North, New Zealand
| | - Andrew Dickson
- Massey Business School, Massey University, Palmerston North, New Zealand
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Holland K, Dickson A, Dickson A. ‘To the horror of experts’: reading beneath scholarship on pro-ana online communities. Critical Public Health 2017. [DOI: 10.1080/09581596.2017.1382681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Kate Holland
- Faculty of Arts & Design, News & Media Research Centre, University of Canberra , Canberra, Australia
| | - Andrew Dickson
- School of Management, Massey Business School, Massey University , Palmerston North, New Zealand
| | - Anna Dickson
- Independent Academic , Palmerston North, New Zealand
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Singh M, Burrows AC, Dickson A, Komal K, Pal D, Summers MK. Abstract 496: Ubiquitin specific peptidases 37 promotes constitutive replication fork movement by stabilizing Chk1 via its deubiquitination. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Protein deubiquitination controls many intracellular processes, including cell cycle progression, transcriptional activation, and signal transduction. Ubiquitin specific peptidases (USPs) remove ubiqiuitin tags from target proteins to control both protein fate and function. USP37 (Ubiquitin specific peptidase 37) has been implicated in cancer and we have previously shown that antagonizes the tumor suppressor APCCDH1and promotes S phase entry. However, the role of USP37 during S-phase was unknown. Here, we report that in cells experiencing replication stress USP37 overexpression confers survival advantage while its depletion enhances sensitivity. USP37 overexpressing cells were able to resolve different DNA damage markers much more effectively then the control cells or cells in which USP37 was depleted. Mechanistically, our data indicate that USP37 binds and stabilizes the active form of CHK1 and deubiquitinates Chk1 to increase its stability and promote the checkpoint response. USP37 overexpression results in constitutive replication fork movement and long tract DNA synthesis while USP37 depleted cells were unable to carry out long tract DNA synthesis. Notably, expression of low level of Chk1 in USP37 depleted cells rescues cell survival and DNA damage response. Overall our data suggest that inhibition of USP37 may represent a novel mechanism to modulate Chk1 activity.
Note: This abstract was not presented at the meeting.
Citation Format: Mayank Singh, Amy C. Burrows, Andrew Dickson, Komal Komal, Debjani Pal, Matthew K. Summers. Ubiquitin specific peptidases 37 promotes constitutive replication fork movement by stabilizing Chk1 via its deubiquitination [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 496. doi:10.1158/1538-7445.AM2017-496
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singh M, Burrows AC, Dickson A, Summers M. Abstract 2742: USP37 promote oncogenesis by stabilizing protein involved in DNA damage repair pathway and provides a novel way to modulate Chk1 activity. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-2742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Dysregulation of the Ubiquitin proteasome system (UPS), which comprises nearly 1000 different components is associated with many aspects of oncogenesis and has emerged as a novel therapeutic target. We have previously shown that USP37 (Ubiquitin specific peptidase 37) antagonizes the tumor suppressor APCCDH1and it promotes S phase entry while data from other groups have shown that it stabilizes oncoproteins, such as c-Myc. We have found USP37 protein levels to be high in many cancerous cell lines as compared to untransformed cells and it appears to help tumor survive the high level of replication stress associated with oncogene expression. It was found that USP37 over expression confers survival advantage to cancer cells while its depletion enhances chemo sensitization in response to variety of replication stresses. USP37 over expressing cells were able to resolve γ-H2AX foci much more effectively then the wild type or cells in which USP37 was depleted. Our data indicate that USP37 binds and stabilizes the active form of CHK1 as evident by its protein levels when USP37 over expressing or depleted cells were exposed to replication stress. Mechanistically, our analyses indicate that USP37 stabilizes CHK1 by its deubiquitination, preventing its degradation. As CHK1 has been pursued as a therapeutic target with limited success our work defines a novel way to modulate activity of CHK1 while simultaneously targeting multiple oncogenes and thereby providing a rationale to evaluate USP37 inhibitor over CHK1 inhibitor as a potential therapeutic target in different cancers.
Citation Format: mayank singh, Amy C. Burrows, Andrew Dickson, Matthew Summers. USP37 promote oncogenesis by stabilizing protein involved in DNA damage repair pathway and provides a novel way to modulate Chk1 activity. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2742.
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Warbrick I, Dickson A, Prince R, Heke I. The biopolitics of Māori biomass: towards a new epistemology for Māori health in Aotearoa/New Zealand. Critical Public Health 2015. [DOI: 10.1080/09581596.2015.1096013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Cserni T, Cervellione RM, Hajnal D, Varga G, Kubiak R, Rakoczy G, Kaszaki J, Boros M, Goyal A, Dickson A. Alternative ileal flap for bladder augmentation if mesentery is short. J Pediatr Urol 2015; 11:64.e1-6. [PMID: 25824877 DOI: 10.1016/j.jpurol.2014.10.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 10/07/2014] [Indexed: 11/16/2022]
Abstract
PURPOSE To date the clam ileocystoplasty is the preferred method of bladder augmentation in children when the urodynamic problem is non-compliance and/or detrusor overactivity. The key to this technique is the incision of the bladder wall deep into the pelvis down to the trigone in order to avoid a diverticulum like neobladder and to provide adequate margin for augmentation. The detubularised ileum flap therefore has to reach to the bottom of the divided bladder on a reliable vascular pedicle without significant tension. A short ileal mesentery caused by previous surgery, peritonitis, peritoneal dialysis or ventriculo-peritoneal shunt may complicate surgery and compromise outcome. We hypothesized we can rely on the communication of the intramural vessels within the intestine and can detubularise the ileum adjacent to the mesentery rather than along the antimesenteric line and this could be combined with ligation of some vasa recta (VR) in order to create alternative ileum flaps, which reach further into the pelvis. Our aim was to assess the viability of the alternative flaps detubularised along the paramesenteric line and measure how many VR could be sacrificed beyond the tertiary arcades. MATERIALS AND METHODS After ethical approval adjacent ileal segments were detubulirased along the antimesenteric line (Group 1) and along the paramesenteric line (Group 2) in 5 minipigs in general anaesthesia. Ligation of 0,1,2,3 and 4 VR has been performed starting from the free end of the segments. The length of the ileal flaps was recorded. The microcirculation of flap edges was detected by in vivo microscopy using orthogonal polarising spectral imaging (Cytoscan A/R Cytometrics, PA, USA). Clam ileocystoplasty was performed with the ileum detubularised along the paramesenteric line without ligation of VR. Specimens of the augmented bladder were obtained after 4 weeks and stained with Hematoxilin + Eosin. RESULTS No alteration in capillary red blood cell velocity (RBCV) and perfusion rate (PR) was observed after paramesenteric detubularisation. The flaps in Group 2 reached 20.25 ± 0.5 mm longer vs. CONTROL This is 98% of the mean bowel width (20.5 ± 0.57 mm) measured in the animals. Ligation of each VR further increased the length of both flaps (mean: 10.59 ± 3.18 mm) however ligation of more than 2 VR gradually decreased the microcirculation in both groups. All animals augmented with alternative flap survived, there was no urine leak or suture break down. Histology confirmed viable bowel flaps. CONCLUSION Paramesenteric detubularisation of the ileum is fully tolerated and results in longer reaching ileal flap vs. CONTROL Only limited ligation of VR is tolerated. DISCUSSION This study showed the first time that clam ileocystoplasty is feasible with ileal flap detubularised along the paramesenteric line. The use of the animal model and the relative short postoperative observation are the main limitations of this study.
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Affiliation(s)
- T Cserni
- Department of Paediatric Urology, Royal Manchester Children's Hospital, UK; Institute for Surgical Research, University of Szeged, Hungary.
| | - R M Cervellione
- Department of Paediatric Urology, Royal Manchester Children's Hospital, UK; Institute for Surgical Research, University of Szeged, Hungary.
| | - D Hajnal
- Institute for Surgical Research, University of Szeged, Hungary.
| | - G Varga
- Institute for Surgical Research, University of Szeged, Hungary.
| | - R Kubiak
- Department of Paediatric Surgery, Royal Manchester Children's Hospital, UK.
| | - G Rakoczy
- Department of Paediatric Surgery, Royal Manchester Children's Hospital, UK.
| | - J Kaszaki
- Institute for Surgical Research, University of Szeged, Hungary.
| | - M Boros
- Institute for Surgical Research, University of Szeged, Hungary.
| | - A Goyal
- Department of Paediatric Urology, Royal Manchester Children's Hospital, UK.
| | - A Dickson
- Department of Paediatric Urology, Royal Manchester Children's Hospital, UK.
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Arkwright JW, Dickson A, Maunder S, Blenman N, Lim J, O’Grady G, Archer R, Costa M, Spencer NJ, Brookes S, Pullan A, Dinning PG. The effect of luminal content and rate of occlusion on the interpretation of colonic manometry. Neurogastroenterol Motil 2013; 25:e52-9. [PMID: 23228077 PMCID: PMC3539177 DOI: 10.1111/nmo.12051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Manometry is commonly used for diagnosis of esophageal and anorectal motility disorders. In the colon, manometry is a useful tool, but clinical application remains uncertain. This uncertainty is partly based on the belief that manometry cannot reliably detect non-occluding colonic contractions and, therefore, cannot identify reliable markers of dysmotility. This study tests the ability of manometry to record pressure signals in response to non-lumen-occluding changes in diameter, at different rates of wall movement and with content of different viscosities. METHODS A numerical model was built to investigate pressure changes caused by localized, non-lumen-occluding reductions in diameter, similar to those caused by contraction of the gut wall. A mechanical model, consisting of a sealed pressure vessel which could produce localized reductions in luminal diameter, was used to validate the model using luminal segments formed from; (i) natural latex; and (ii) sections of rabbit proximal colon. Fluids with viscosities ranging from 1 to 6800 mPa s(-1) and luminal contraction rates over the range 5-20 mmHg s(-1) were studied. KEY RESULTS Manometry recorded non-occluding reductions in diameter, provided that they occurred with sufficiently viscous content. The measured signal was linearly dependent on the rate of reduction in luminal diameter and also increased with increasing viscosity of content (R(2) = 0.62 and 0.96 for 880 and 1760 mPa s(-1), respectively). CONCLUSIONS & INFERENCES Manometry reliably registers non-occluding contractions in the presence of viscous content, and is therefore a viable tool for measuring colonic motility. Interpretation of colonic manometric data, and definitions based on manometric results, must consider the viscosity of luminal content.
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Affiliation(s)
- J. W. Arkwright
- CSIRO Materials Science and Engineering, Bradfield Road, Lindfield, NSW 2070, Australia
| | - A. Dickson
- CSIRO Materials Science and Engineering, Bradfield Road, Lindfield, NSW 2070, Australia,Queensland University of Technology, Science and Engineering Faculty, PO Box 2434, Brisbane, QLD 4001
| | - S. Maunder
- CSIRO Materials Science and Engineering, Bradfield Road, Lindfield, NSW 2070, Australia
| | - N. Blenman
- CSIRO Materials Science and Engineering, Bradfield Road, Lindfield, NSW 2070, Australia
| | - J. Lim
- University of Auckland, Bioengineering Institute, University of Auckland, New Zealand
| | - G. O’Grady
- University of Auckland, Bioengineering Institute, University of Auckland, New Zealand,Dept of Surgery & Bioengineering Institute, University of Auckland, New Zealand
| | - R. Archer
- University of Auckland, Department of Engineering Science, University of Auckland, New Zealand
| | - M. Costa
- Department of Human Physiology, Flinders University, Bedford Park, Australia
| | - N. J. Spencer
- Department of Human Physiology, Flinders University, Bedford Park, Australia
| | - S. Brookes
- Department of Human Physiology, Flinders University, Bedford Park, Australia
| | - A. Pullan
- University of Auckland, Bioengineering Institute, University of Auckland, New Zealand,University of Auckland, Department of Engineering Science, University of Auckland, New Zealand
| | - P. G. Dinning
- Department of Human Physiology, Flinders University, Bedford Park, Australia
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Pausé C, Brown S, Carryer J, Wolber F, Finn L, Longhurst R, Hunter L, Fitzpatrick K, Cain T, Burrows L, Hoverd W, Dickson A. Response to letter 'New Zealand's shocking diabetes rates can be reduced--9 urgently needed actions'. N Z Med J 2011; 124:87-89. [PMID: 21964020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Dickson A, Toft A, O'Carroll RE. Neuropsychological functioning, illness perception, mood and quality of life in chronic fatigue syndrome, autoimmune thyroid disease and healthy participants. Psychol Med 2009; 39:1567-1576. [PMID: 19144216 DOI: 10.1017/s0033291708004960] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND This study attempted to longitudinally investigate neuropsychological function, illness representations, self-esteem, mood and quality of life (QoL) in individuals with chronic fatigue syndrome (CFS) and compared them with both healthy participants and a clinical comparison group of individuals with autoimmune thyroid disease (AITD). METHOD Neuropsychological evaluation was administered at two time points, five weeks apart. Twenty-one individuals with CFS, 20 individuals with AITD and 21 healthy participants were matched for age, pre-morbid intelligence, education level and socio-economic status (SES). All groups also completed measures of illness perceptions, mood, self-esteem and QoL at both time points. RESULTS The CFS group showed significantly greater impairment on measures of immediate and delayed memory, attention and visuo-constructional ability, and reported significantly higher levels of anxiety and depression. After controlling for the effects of mood, the CFS group still demonstrated significant impairment in attention. The CFS group also reported significantly lower self-reported QoL than the AITD and healthy participants. In terms of illness perceptions, the AITD group believed that their condition would last longer, that they had more treatment control over their condition, and reported less concern than the CFS group. CONCLUSIONS These results suggest that the primary cognitive impairment in CFS is attention and that this is not secondary to affective status. The lower treatment control perceptions and greater illness concerns that CFS patients report may be causally related to their affective status.
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Affiliation(s)
- A Dickson
- School of Health and Social Sciences, Napier University, Edinburgh, UK.
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Cao C, Lin X, Zhang C, Dickson A, Mamcarz M, Wang L, Arendash G, Potter H. IC‐P3‐174: Plasma Aβ level can be used as marker for AD treatment in PS1/APP Alzheimer's mouse model. Alzheimers Dement 2008. [DOI: 10.1016/j.jalz.2008.05.118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Chuanhai Cao
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
- University of South FloridaTampaFLUSA
| | - X. Lin
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
| | - C. Zhang
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
| | - A. Dickson
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
- University of South FloridaTampaFLUSA
| | - M. Mamcarz
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
- University of South FloridaTampaFLUSA
| | | | - G. Arendash
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
- University of South FloridaTampaFLUSA
| | - H. Potter
- Johnnie B. Bryd Sr. Alzheimer's Center & Research InstituteTampaFLUSA
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Abstract
Uro-genital bleeding in pre-menarcheal girls always raises concerns regarding child abuse. There are serious social issues involved; however, before labeling it as sexual abuse, all efforts must be made to rule out an organic pathology. We recently encountered two young girls of Afro-Caribbean origin who presented with vaginal bleeding with concerns from referring physicians about child/sexual abuse. On examination both had a rare condition of urethral prolapse. One of them underwent four-quadrant excision and the other was treated conservatively with urethral catherization.
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Affiliation(s)
- S Agarwal
- Department of Obstetrics and Gynaecology, Royal Bolton Hospital, Bolton, BL4 0JR, UK
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Arendash GW, Jensen MT, Salem N, Hussein N, Cracchiolo J, Dickson A, Leighty R, Potter H. A diet high in omega-3 fatty acids does not improve or protect cognitive performance in Alzheimer’s transgenic mice. Neuroscience 2007; 149:286-302. [PMID: 17904756 DOI: 10.1016/j.neuroscience.2007.08.018] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Revised: 07/17/2007] [Accepted: 08/04/2007] [Indexed: 10/23/2022]
Abstract
Although a number of epidemiologic studies reported that higher intake of omega-3 fatty acids (largely associated with fish consumption) is protective against Alzheimer's disease (AD), other human studies reported no such effect. Because retrospective human studies are problematic and controlled longitudinal studies over decades are impractical, the present study utilized Alzheimer's transgenic mice (Tg) in a highly controlled study to determine whether a diet high in omega-3 fatty acid, equivalent to the 13% omega-3 fatty acid diet of Greenland Eskimos, can improve cognitive performance or protect against cognitive impairment. Amyloid precursor protein (APP)-sw+PS1 double transgenic mice, as well as nontransgenic (NT) normal littermates, were given a high omega-3 supplemented diet or a standard diet from 2 through 9 months of age, with a comprehensive behavioral test battery administered during the final 6 weeks. For both Tg and NT mice, long-term n-3 supplementation resulted in cognitive performance that was no better than that of mice fed a standard diet. In NT mice, the high omega-3 diet increased cortical levels of omega-3 fatty acids while decreasing omega-6 levels. However, the high omega-3 diet had no effect on cortical fatty acid levels in Tg mice. Irrespective of diet, no correlations existed between brain omega-3 levels and cognitive performance for individual NT or Tg mice. In contrast, brain levels of omega-6 fatty acids were strongly correlated with cognitive impairment for both genotypes. Thus, elevated brain levels of omega-3 fatty acids were not relevant to cognitive function, whereas high brain levels of omega-6 were associated with impaired cognitive function. In Tg mice, the omega-3 supplemental diet did not induce significant changes in soluble/insoluble Abeta within the hippocampus, although strong correlations were evident between hippocampal Abeta(1-40) levels and cognitive impairment. While these studies involved a genetically manipulated mouse model of AD, our results suggest that diets high in omega-3 fatty acids, or use of fish oil supplements (DHA+EPA), will not protect against AD, at least in high-risk individuals. However, normal individuals conceivably could derive cognitive benefits from high omega-3 intake if it corrects an elevation in the brain level of n-6 fatty acids as a result. Alternatively, dietary fish may contain nutrients, other than DHA and EPA, that could provide some protection against AD.
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Affiliation(s)
- G W Arendash
- The Florida Alzheimer's Disease Research Center and The Byrd Alzheimer's Institute, Tampa, FL 33613, USA.
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Dickson A, Avelino A, Cruz F, Ribeiro-da-Silva A. Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis. Neuroscience 2006; 139:671-85. [PMID: 16413132 DOI: 10.1016/j.neuroscience.2005.11.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Revised: 11/09/2005] [Accepted: 11/20/2005] [Indexed: 01/23/2023]
Abstract
In this study, we used a well-established animal model to investigate changes in the peptidergic and parasympathetic innervation of the bladder following chronic bladder inflammation. Adult female Sprague-Dawley rats were injected with either 70 mg/kg cyclophosphamide diluted in saline, i.p., once every 3 days or saline. After 10 days, all animals were tested for urinary frequency and number of low volume voids, as well as symptoms of spontaneous pain. At the end of 12 days, all animals were perfused with histological fixatives and the urinary bladders processed for immunofluorescence using antibodies against calcitonin gene-related peptide and the vesicular acetylcholine transporter as markers, respectively, of peptidergic primary afferent fibers and parasympathetic efferent fibers. We show that animals treated with cyclophosphamide had inflamed bladders and displayed high urinary frequency as well as some indicators of spontaneous pain, such as piloerection and a rounded-back posture. Furthermore, they had a significant increase in the density of both parasympathetic and peptidergic sensory fibers in the bladder mucosa and an increase in peptidergic sensory fibers in the detrusor muscle. Based on these results, we suggest that peripheral sprouting of parasympathetic and peptidergic fibers could be a mechanism responsible for sensitization of the bladder, leading to urinary symptoms. Since we observed that the parasympathetic and peptidergic fibers often wrapped around one another and that their varicosities were very close, these two fiber populations may be interacting with each other to lead to and maintain sensitization. Future studies are required to establish the role of this fiber sprouting in bladder symptoms.
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Affiliation(s)
- A Dickson
- Department of Pharmacology and Therapeutics, 3655 Promenade-Sir-William-Osler, Montreal, Quebec, Canada H3G 1Y6
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35
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Dickson A, Avelino A, Cruz F, Ribeiro-da-Silva A. Erratum to “Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis”. Neuroscience 2006. [DOI: 10.1016/j.neuroscience.2006.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Dickson A, Avelino A, Cruz F, Ribeiro-da-Silva A. Peptidergic sensory and parasympathetic fiber sprouting in the mucosa of the rat urinary bladder in a chronic model of cyclophosphamide-induced cystitis. Neuroscience 2006; 141:1633-47. [PMID: 16989017 DOI: 10.1016/j.neuroscience.2006.06.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In this study, we used a well-established animal model to investigate changes in the peptidergic and parasympathetic innervation of the bladder following chronic bladder inflammation. Adult female Sprague-Dawley rats were injected with either 70 mg/kg cyclophosphamide diluted in saline, i.p., once every 3 days or saline. After 10 days, all animals were tested for urinary frequency and number of low volume voids, as well as symptoms of spontaneous pain. At the end of 12 days, all animals were perfused with histological fixatives and the urinary bladders processed for immunofluorescence using antibodies against calcitonin gene-related peptide and the vesicular acetylcholine transporter as markers, respectively, of peptidergic primary afferent fibers and parasympathetic efferent fibers. We show that animals treated with cyclophosphamide had inflamed bladders and displayed high urinary frequency as well as some indicators of spontaneous pain, such as piloerection and a rounded-back posture. Furthermore, they had a significant increase in the density of both parasympathetic and peptidergic sensory fibers in the bladder mucosa and an increase in peptidergic sensory fibers in the detrusor muscle. Based on these results, we suggest that peripheral sprouting of parasympathetic and peptidergic fibers could be a mechanism responsible for sensitization of the bladder, leading to urinary symptoms. Since we observed that the parasympathetic and peptidergic fibers often wrapped around one another and that their varicosities were very close, these two fiber populations may be interacting with each other to lead to and maintain sensitization. Future studies are required to establish the role of this fiber sprouting in bladder symptoms.
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Affiliation(s)
- A Dickson
- Department of Pharmacology and Therapeutics, Montreal, Canada
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37
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McColl KEL, Murray LS, Gillen D, Walker A, Wirz A, Fletcher J, Mowat C, Henry E, Kelman A, Dickson A. Randomised trial of endoscopy with testing for Helicobacter pylori compared with non-invasive H pylori testing alone in the management of dyspepsia. BMJ 2002; 324:999-1002. [PMID: 11976239 PMCID: PMC102780 DOI: 10.1136/bmj.324.7344.999] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To compare the efficacy of non-invasive testing for Helicobacter pylori with that of endoscopy (plus H pylori testing) in the management of patients referred for endoscopic investigation of upper gastrointestinal symptoms. DESIGN Randomised controlled trial with follow up at 12 months. SETTING Hospital gastroenterology unit. PARTICIPANTS 708 patients aged under 55 referred for endoscopic investigation of dyspepsia, randomised to non-invasive breath test for H pylori or endoscopy plus H pylori testing. MAIN OUTCOME MEASURE Glasgow dyspepsia severity score at one year. Use of medical resources, patient oriented outcomes, and safety were also assessed. RESULTS In 586 patients followed up at 12 months the mean change in dyspepsia score was 4.8 in the non-invasive H pylori test group and 4.6 in the endoscopy group (95% confidence interval for difference -0.7 to 0.5, P=0.69). Only 8.2% of patients followed up who were randomised to breath test alone were referred for subsequent endoscopy. The use of non-endoscopic resources was similar in the two groups. Reassurance value, concern about missed pathology, overall patient satisfaction, and quality of life were similar in the two groups. The patients found the non-invasive breath test procedure less uncomfortable and distressing than endoscopy with or without sedation. No potentially serious pathology requiring treatment other than eradication of H pylori was missed. CONCLUSION In this patient group, non-invasive testing for H pylori is as effective and safe as endoscopy and less uncomfortable and distressing for the patient. Non-invasive H pylori testing should be the preferred mode of investigation.
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Affiliation(s)
- K E L McColl
- University Department of Medicine and Therapeutics, Western Infirmary, Glasgow G11 6NT.
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38
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Davis M, Brown R, Dickson A, Horton H, James D, Laing N, Marston R, Norgate M, Perlman D, Pollock N, Stowell K. Malignant hyperthermia associated with exercise-induced rhabdomyolysis or congenital abnormalities and a novel RYR1 mutation in New Zealand and Australian pedigrees. Br J Anaesth 2002; 88:508-15. [PMID: 12066726 DOI: 10.1093/bja/88.4.508] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Malignant hyperthermia (MH) is rarely associated with specific myopathies or musculoskeletal abnormalities. Three clinical investigations of MH associated with either non-specific myopathies or congenital disorders in three separate families are presented. Two of these cases also show evidence of exercise-induced rhabdomyolysis. In each case MH susceptibility was confirmed by in vitro contracture testing of quadriceps muscle. DNA sequence analysis of each kindred revealed the presence of a common novel mutation that results in an arginine401-cysteine substitution in the skeletal muscle ryanodine receptor gene (RYR1). Haplotype analysis using chromosome 19q markers indicated that the three families are likely to be unrelated, providing confirmation that the MH/central core disease region 1 of RYR1 is a mutation hot spot.
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Affiliation(s)
- M Davis
- Department of Neuropathology, Royal Perth Hospital, Western Australia
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39
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Harris C, Jellinek E, Gutteridge B, Dickson A, Leigh J, Madeley D, Savla S, Smart R, Morgan D, Walmsley A. Temple Theodore "Tim" Stamm Chalmers Davidson Trevor Davies John Wanless Dickson Richard Leigh Joyce McQuillin B K Naik Shirley Storrier (nee Clarke) Cecil Henry Wilkinson Jonathan Alun Williams. West J Med 2001. [DOI: 10.1136/bmj.323.7322.1190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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40
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Hoye W, Dickson A, Banos H, Gierok S. Executive functions and Continuous Visual Memory Test performance in a general neuropsychological sample. Arch Clin Neuropsychol 2000. [DOI: 10.1093/arclin/15.8.685a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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41
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Matheny J, Dickson A, Gierok S, Schiehser D. Uncued and cued category fluency in elderly alzheimer's patients and normal elderly. Arch Clin Neuropsychol 2000. [DOI: 10.1093/arclin/15.8.738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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McColl KE, Dickson A, El-Nujumi A, El-Omar E, Kelman A. Symptomatic benefit 1-3 years after H. pylori eradication in ulcer patients: impact of gastroesophageal reflux disease. Am J Gastroenterol 2000; 95:101-5. [PMID: 10638566 DOI: 10.1111/j.1572-0241.2000.01706.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Eradication of Helicobacter pylori (H. pylori) infection markedly reduces the recurrence of duodenal and gastric ulcers. However, there is little information regarding its efficacy in resolving dyspeptic symptoms in ulcer patients. The primary aim of this study was to assess the effect of eradicating H. pylori infection on dyspeptic symptoms in ulcer patients. The secondary aim was to identify predictors of symptomatic response to H. pylori eradication. METHODS A total of 97 dyspeptic patients with active duodenal and/or gastric ulceration associated with H. pylori infection and unrelated to NSAID use had the severity and character of their dyspeptic symptoms measured before and again 1-3 yr after H. pylori eradication therapy. RESULTS Pretreatment, the median dyspepsia score was 12 (4-16). Posttreatment, 55% of those eradicated of H. pylori had resolution of dyspepsia (score <2) compared with 18% of those not eradicated of the infection (95% CI for difference, 11-62%). Of the ulcer patients 31% had symptoms and/or endoscopic evidence of coexisting gastroesophageal reflux disease (GERD) at initial presentation and this influenced the symptomatic response to eradication of H. pylori. Of the 22 patients with heartburn or acid reflux as the predominant presenting symptom, but no endoscopic esophagitis, only 27% experienced resolution of dyspepsia after H. pylori eradication, compared with 68% of the 59 without those as predominant symptoms (95% CI for difference, 18-63%). Only one of the five patients with coexisting endoscopic esophagitis at initial presentation experienced resolution of dyspepsia after H. pylori eradication. Symptomatic benefit was unrelated to time lapsed since the infection was eradicated. Only three of 50 subjects developed de novo GERD symptoms after eradication of H. pylori, whereas 21 of 36 subjects experienced resolution of GERD symptoms after eradication of the infection. CONCLUSIONS A substantial proportion of ulcer patients have symptoms and/or signs of coexisting GERD at initial presentation and this reduces the symptomatic benefit from H. pylori eradication. However, we have found no evidence that eradicating H. pylori induces de novo GERD symptoms in ulcer patients.
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Affiliation(s)
- K E McColl
- University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, Scotland
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McColl K, Murray L, El-Omar E, Dickson A, El-Nujumi A, Wirz A, Kelman A, Penny C, Knill-Jones R, Hilditch T. Symptomatic benefit from eradicating Helicobacter pylori infection in patients with nonulcer dyspepsia. N Engl J Med 1998; 339:1869-74. [PMID: 9862941 DOI: 10.1056/nejm199812243392601] [Citation(s) in RCA: 295] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The eradication of Helicobacter pylori infection is beneficial in patients with gastric or duodenal ulcers. The value of eradicating the infection in patients with dyspepsia and no evidence of ulcer disease is not known. METHODS We performed a randomized, placebo-controlled trial comparing the efficacy of treatment for two weeks with 20 mg of omeprazole orally twice daily, 500 mg of amoxicillin three times daily (with 500 mg of tetracycline three times daily substituted for amoxicillin in patients allergic to penicillin), and 400 mg of metronidazole three times daily (160 patients) with that of omeprazole alone (158 patients) for resolving symptoms of dyspepsia in patients with H. pylori infection but no evidence of ulcer disease on upper gastrointestinal endoscopy. Symptoms were assessed with the Glasgow Dyspepsia Severity Score, with resolution of symptoms defined as a score of 0 or 1 in the preceding six months (maximal score, 20). One year later the patients were assessed to determine the frequency of the resolution of symptoms. RESULTS One month after the completion of treatment, 132 of 150 patients (88 percent) in the group assigned to received omeprazole and antibiotics had a negative test for H. pylori, as compared with 7 of 152 (5 percent) in the group assigned to receive omeprazole alone. One year later, dyspepsia had resolved in 33 of 154 patients (21 percent) in the group given omeprazole and antibiotics, as compared with 11 of 154 (7 percent) in the group given omeprazole alone (95 percent confidence interval for the difference, 7 to 22 percent; P<0.001). Among the patients in the group given omeprazole and antibiotics, the symptoms resolved in 26 of the 98 patients (27 percent) who had had symptoms for five years or less, as compared with 7 of the 56 patients (12 percent) who had had symptoms for more than five years (P=0.03). CONCLUSIONS In patients with H. pylori infection and nonulcer, or functional, dyspepsia, treatment with omeprazole and antibiotics to eradicate the infection is more likely to resolve symptoms than treatment with omeprazole alone.
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Affiliation(s)
- K McColl
- Department of Medicine and Therapeutics, Western Infirmary, Glasgow, United Kingdom
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44
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McColl KE, el-Nujumi A, Murray LS, el-Omar EM, Dickson A, Kelman AW, Hilditch TE. Assessment of symptomatic response as predictor of Helicobacter pylori status following eradication therapy in patients with ulcer. Gut 1998; 42:618-22. [PMID: 9659153 PMCID: PMC1727091 DOI: 10.1136/gut.42.5.618] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND Helicobacter pylori eradication therapy is routinely used for treating patients with peptic ulcer disease. AIMS To assess the value of symptomatic response to H pylori eradication therapy as a marker of post-treatment H pylori status. PATIENTS AND METHODS One hundred and nine dyspeptic patients with active duodenal or gastric ulceration association with H pylori infection had their symptoms measured by a validated questionnaire before and three months following H pylori eradication therapy. The symptomatic response was compared with post-treatment H pylori status as determined by the 14C urea breath test. RESULTS An eradication rate of 84% was achieved. Of the 92 patients eradicated of H pylori, 47% experienced complete or near complete resolution of dyspepsia. Of the 17 patients in whom the infection was not eradicated, only one (6%) experienced resolution of dyspepsia. Resolution of dyspepsia was therefore a powerful predictor of eradication of H pylori with a predictive value of 98%. In contrast, persistence of dyspepsia was a weak predictor of persisting infection with a predictive value of only 25%. Excluding patients with endoscopic evidence of coexisting oesophagitis and/or retrosternal discomfort or reflux at initial presentation did not increase the predictive value of persisting dyspepsia for persisting infection. CONCLUSIONS Complete resolution of dyspeptic symptoms is a powerful predictor of eradication of H pylori infection in ulcer patients. Persistence of symptoms is a weak predictor of persisting infection and patients with persisting dyspepsia must have their H pylori status rechecked to guide future management.
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Affiliation(s)
- K E McColl
- University Department of Medicine and Therapeutics, Western Infirmary, Glasgow, UK
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45
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Affiliation(s)
- M V Suresh-Babu
- Department of Paediatric Gastroenterology, Booth Hall Children's Hospital, Manchester, United Kingdom
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46
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Dickson A. Globus pallidus syndrome: A case study. Arch Clin Neuropsychol 1998. [DOI: 10.1016/s0887-6177(98)90571-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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47
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Abstract
Feeding difficulties are common in neurologically impaired children, often leading to great distress and frustration in the child and family. A gastrostomy may be advocated if oral intake is inadequate causing poor weight gain or when there is significant aspiration during feeding, or if feeding is very distressing. To find out if caregivers were happy with the outcome of gastrostomy (with fundoplication, when indicated), a 35-item questionnaire was developed and sent to 38 of them. Twenty-nine replies were received and appeared to be representative of the whole group. Coughing, choking, and vomiting improved in most cases. Weight gain improved in all in whom it had been a problem. In the majority, it became easier to give the children their medications although control of epilepsy was unchanged overall. Time spent feeding the child was reduced and many caregivers had more time to devote to other children and themselves. Only one parent regretted the operation. In children with severe disability and feeding problems, a gastrostomy (with fundoplication if there is significant reflux) can reduce symptoms of vomiting, coughing, and choking, help growth and improve quality of life in the child, when patients are properly selected.
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Affiliation(s)
- R Tawfik
- Paediatric Gastroenterology, Booth Hall Children's Hospital, Manchester, UK
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48
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McColl KE, el-Nujumi A, Murray L, el-Omar E, Gillen D, Dickson A, Kelman A, Hilditch TE. The Helicobacter pylori breath test: a surrogate marker for peptic ulcer disease in dyspeptic patients. Gut 1997; 40:302-6. [PMID: 9135516 PMCID: PMC1027077 DOI: 10.1136/gut.40.3.302] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND There is interest in noninvasive H pylori testing as a means of predicting diagnosis and determining management in dyspeptic patients. AIMS To assess the value of the 14C urea breath test as a predictor of peptic ulcer disease in patients presenting with dyspepsia. PATIENTS AND METHODS 327 consecutive patients referred for investigation of dyspepsia had a 14C urea breath test performed before endoscopy. Patients were not included if they had previously confirmed ulcer disease, previous gastric surgery, or were taking non-steroidal anti-inflammatory drugs. RESULTS Of the 182 patients with a positive 14C urea breath test, duodenal and/or gastric ulcers were present in 45% and erosive duodenitis in a further 2%. Oesophagitis was present in 12% of the breath test positive patients with two thirds of the oesophagitis patients having co-existent ulcer disease. The prevalence of ulcer disease in the H pylori positive dyspeptic patients was independently related to smoking and previous investigation status. If previously uninvestigated, the prevalence of ulcers was 67% in smokers and 46% in non-smokers. If previous upper gastrointestinal investigations were negative, the prevalence of ulcers was 53% in smokers and 28% in non-smokers. Of the 136 patients with a negative breath test, only 5% had peptic ulcers. The most frequent endoscopic finding in these H pylori negative subjects was oesophagitis, being present in 17%. CONCLUSIONS This study demonstrates that a positive H pylori test is a powerful predictor of the presence of underlying ulcer disease in dyspeptic patients, especially if smokers, and that a negative H pylori test is a powerful predictor of the absence of ulcer disease. It also indicates that a negative upper gastrointestinal investigation does not preclude subsequent presentation with ulcer disease.
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Affiliation(s)
- K E McColl
- University Department of Medicine and Therapeutics, Western Infirmary, Glasgow
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Anderson R, Dickson A, Lee S. Clinical staff development: a two-way solution. Nurs Times 1997; 93:36-8. [PMID: 9043333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This paper explains how a trust worked with a higher education institution to provide continuing education for clinical staff. The result was a staff development award that carries 60 CATS points at level 2. Evaluation shows that the award has not only helped staff in their practice but has also been cost-effective. In addition there have been benefits in terms of professional development for staff involved in running the programme.
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Abstract
OBJECTIVE To assess the efficacy of the Whitaker diathermy hook in the treatment of posterior urethral valves (PUV). PATIENTS AND METHODS Seventeen patients with PUV underwent primary treatment under general anaesthesia using a diathermy hook. The results were assessed by the clinical course of the patient, serial measurements of serum creatinine level and repeat cystography 6 weeks and 6 months after treatment. RESULTS There were no complications in 12 patients and they required no further treatment of the valves. Three patients required a repeat procedure which resolved the urethral obstruction. Two patients continued to show incomplete disruption of the valves and required endoscopic treatment. Two patients developed ureteric obstruction after disruption of the valves, which was treated by supravesical diversion and later reversed with no further treatment of the valves. CONCLUSIONS The Whitaker diathermy hook is a safe and effective instrument which has not gained its rightful place in the treatment of patients with PUV.
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Affiliation(s)
- S Chandna
- Department of Urology, Manchester Children's Hospitals, UK
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