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Fernández-Sanlés A, Carter A, Millard L, Smith D, Griffith G, Clayton G, Hughes R, Morris T, Lawlor D, Tilling K, Borges MC. 1484Selection bias in COVID-19 research: Prospective analyses of two UK cohort studies. Int J Epidemiol 2021. [PMCID: PMC8499831 DOI: 10.1093/ije/dyab168.442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background Non-random sampling could bias estimates of association in observational studies but the extent to which this occurs in studies of SARS-CoV-2 infection/COVID-19 severity is not well established. Methods Using ALSPAC and UK Biobank we investigated pre-pandemic predictors of selection (i.e. having data on SARS-CoV-2 infection and COVID-19 severity from self-report and/or health record linkage). We conducted empirical analyses and simulations to explore the potential presence, direction and magnitude of bias due to selection when estimating the association of BMI with SARS-CoV-2 infection and COVID-19 severity. Results A broad range of characteristics related to selection in both cohorts, sometimes in opposite directions. We found bias in all simulated scenarios, mostly of small magnitude. Both the direction and magnitude of bias was influenced by the presence of an effect of BMI on SARS-CoV-2 infection and COVID-19 severity and the control group definition used (e.g. assuming no effect of BMI on SARS-CoV-2 infection our main simulation showed bias equivalent to an estimated odds ratio of 0.99 when using non-infected controls but 1.16 when using controls combining non-infected and non-assessed). Conclusions Despite small amounts of bias in most scenarios, a control group definition including those non-assessed (e.g. non-tested) can induce more bias. In large samples such as UK Biobank the statistical power means incorrect conclusions could be made. Key messages Observational studies estimating associations of factors with SARS-CoV-2 or COVID-19 may be biased due to non-random selection into the analytic sample.
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Affiliation(s)
- Alba Fernández-Sanlés
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- These authors contributed equally
| | - Alice Carter
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- These authors contributed equally
| | - Louise Millard
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- These authors contributed equally
| | - Dan Smith
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Gareth Griffith
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Gemma Clayton
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Rachel Hughes
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Tim Morris
- MRC Clinical Trials Unit at UCL, London, United Kingdom
| | - Deborah Lawlor
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Kate Tilling
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Maria Carolina Borges
- MRC Integrative Epidemiology Unit (IEU) at the University of Bristol, Bristol, United Kingdom
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, United Kingdom
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Abstract
When non-random sampling collides with our understanding of Covid-19 risk, we must be careful not to draw incorrect conclusions about cause and effect. By Annie Herbert, Gareth Griffith, Gibran Hemani and Luisa Zuccolo.
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Affiliation(s)
- Annie Herbert
- Senior research associate at the MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol
| | - Gareth Griffith
- ESRC postdoctoral fellow at the MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol
| | - Gibran Hemani
- Senior research fellow at the MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol
| | - Luisa Zuccolo
- Senior lecturer in epidemiology at the MRC Integrative Epidemiology Unit, Bristol Medical School, University of Bristol
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Pugh SA, Bridgewater JA, Garden OJ, Cunningham D, Maughan T, Maishman T, Radford M, Whitehead A, Mellor J, Griffith G, Primrose JN. Surgical quality and the impact of liver resection on outcome in the New EPOC study. J Clin Oncol 2018. [DOI: 10.1200/jco.2018.36.15_suppl.3559] [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: 11/20/2022] Open
Affiliation(s)
| | | | | | | | - Tim Maughan
- CRUK/MRC Oxford Institute for Radiation Oncology, Oxford, United Kingdom
| | - Tom Maishman
- Southampton Clinical Trials Unit University of Southampton, Southampton, United Kingdom
| | - Mike Radford
- University of Southampton Clinical Trials Unit, Southampton, United Kingdom
| | - Amy Whitehead
- Southampton Clinical Trials Unit, University of Southampton, Southampton, United Kingdom
| | - Jane Mellor
- Southampton Clinical Trials Unit, University of Southampton, Southampton, United Kingdom
| | - Gareth Griffith
- Southampton Clinical Trials Unit, University of Southampton, Southampton, United Kingdom
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Morales L, Griffith G, Wright V, Fleming E, Umberger W, Hoang N. Branding fresh food: Who is willing to pay more for beef? Acta Alimentaria 2017. [DOI: 10.1556/066.2016.0015] [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] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- L.E. Morales
- UNE Business School, W40 EBL Building, Armidale Campus, University of New England, Armidale, New South Wales 2351. Australia
| | - G. Griffith
- UNE Business School, W40 EBL Building, Armidale Campus, University of New England, Armidale, New South Wales 2351. Australia
- Faculty of Veterinary and Agricultural Sciences, 142 University of Melbourne, University Street, Parkville, Victoria 3053. Australia
- Global Food Studies Program, Faculty of the Professions, 5.05 NEXUS 10 Tower, The University of Adelaide, South Australia 5005. Australia
| | - V. Wright
- UNE Business School, W40 EBL Building, Armidale Campus, University of New England, Armidale, New South Wales 2351. Australia
| | - E. Fleming
- UNE Business School, W40 EBL Building, Armidale Campus, University of New England, Armidale, New South Wales 2351. Australia
| | - W. Umberger
- Global Food Studies Program, Faculty of the Professions, 5.05 NEXUS 10 Tower, The University of Adelaide, South Australia 5005. Australia
| | - N. Hoang
- UNE Business School, W40 EBL Building, Armidale Campus, University of New England, Armidale, New South Wales 2351. Australia
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Sharples LD, Jackson C, Wheaton E, Griffith G, Annema JT, Dooms C, Tournoy KG, Deschepper E, Hughes V, Magee L, Buxton M, Rintoul RC. Clinical effectiveness and cost-effectiveness of endobronchial and endoscopic ultrasound relative to surgical staging in potentially resectable lung cancer: results from the ASTER randomised controlled trial. Health Technol Assess 2012; 16:1-75, iii-iv. [PMID: 22472180 DOI: 10.3310/hta16180] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of endosonography (followed by surgical staging if endosonography was negative), compared with standard surgical staging alone, in patients with non-small cell lung cancer (NSCLC) who are otherwise candidates for surgery with curative intent. DESIGN A prospective, international, open-label, randomised controlled study, with a trial-based economic analysis. SETTING Four centres: Ghent University Hospital, Belgium; Leuven University Hospitals, Belgium; Leiden University Medical Centre, the Netherlands; and Papworth Hospital, UK. PARTICIPANTS INCLUSION CRITERIA known/suspected NSCLC, with suspected mediastinal lymph node involvement; otherwise eligible for surgery with curative intent; clinically fit for endosonography and surgery; and no evidence of metastatic disease. EXCLUSION CRITERIA previous lung cancer treatment; concurrent malignancy; uncorrected coagulopathy; and not suitable for surgical staging. INTERVENTIONS Study patients were randomised to either surgical staging alone (n = 118) or endosonography followed by surgical staging if endosonography was negative (n = 123). Endosonography diagnostic strategy used endoscopic ultrasound-guided fine-needle aspiration combined with endobronchial ultrasound-guided transbronchial needle aspiration, followed by surgical staging if these tests were negative. Patients with no evidence of mediastinal metastases or tumour invasion were referred for surgery with curative intent. If evidence of malignancy was found, patients were referred for chemoradiotherapy. MAIN OUTCOME MEASURES The main clinical outcomes were sensitivity (positive diagnostic test/nodal involvement during any diagnostic test or thoracotomy) and negative predictive value (NPV) of each diagnostic strategy for the detection of N2/N3 metastases, unnecessary thoracotomy and complication rates. The primary economic outcome was cost-utility of the endosonography strategy compared with surgical staging alone, up to 6 months after randomisation, from a UK NHS perspective. RESULTS Clinical and resource-use data were available for all 241 patients, and complete utilities were available for 144. Sensitivity for detecting N2/N3 metastases was 79% [41/52; 95% confidence interval (CI) 66% to 88%] for the surgical arm compared with 94% (62/66; 95% CI 85% to 98%) for the endosonography strategy (p = 0.02). Corresponding NPVs were 86% (66/77; 95% CI 76% to 92%) and 93% (57/61; 95% CI 84% to 97%; p = 0.26). There were 21/118 (18%) unnecessary thoracotomies in the surgical arm compared with 9/123 (7%) in the endosonography arm (p = 0.02). Complications occurred in 7/118 (6%) in the surgical arm and 6/123 (5%) in the endosonography arm (p = 0.78): one pneumothorax related to endosonography and 12 complications related to surgical staging. Patients in the endosonography arm had greater EQ-5D (European Quality of Life-5 Dimensions) utility at the end of staging (0.117; 95% CI 0.042 to 0.192; p = 0.003). There were no other significant differences in utility. The main difference in resource use was the number of thoracotomies: 66% patients in the surgical arm compared with 53% in the endosonography arm. Resource use was similar between the groups in all other items. The 6-month cost of the endosonography strategy was £9713 (95% CI £7209 to £13,307) per patient versus £10,459 (£7732 to £13,890) for the surgical arm, mean difference £746 (95% CI -£756 to £2494). The mean difference in quality-adjusted life-year was 0.015 (95% CI -0.023 to 0.052) in favour of endosonography, so this strategy was cheaper and more effective. CONCLUSIONS Endosonography (followed by surgical staging if negative) had higher sensitivity and NPVs, resulted in fewer unnecessary thoracotomies and better quality of life during staging, and was slightly more effective and less expensive than surgical staging alone. Future work could investigate the need for confirmatory mediastinoscopy following negative endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), the diagnostic accuracy of EUS-FNA or EBUS-TBNA separately and the delivery of both EUS-FNA or EBUS-TBNA by suitably trained chest physicians. TRIAL REGISTRATION Current Controlled Trials ISRCTN 97311620. FUNDING This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 18. See the HTA programme website for further project information.
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Affiliation(s)
- L D Sharples
- Medical Research Council, Biostatistics Unit, Cambridge, UK.
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Griffith G. Let's protect life's silent majority. New Sci 2012. [DOI: 10.1016/s0262-4079(12)60555-7] [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: 11/26/2022]
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Rintoul RC, Annema JT, Tournoy KG, Dooms C, Wheaton E, Hughes V, Grant A, Griffith G, Buxton M, Sharples L. S55 Cost-effectiveness and quality of life results from the ASTER study: endobronchial and endoscopic ultrasound vs surgical staging in potentially resectable lung cancer. Thorax 2011. [DOI: 10.1136/thoraxjnl-2011-201054b.55] [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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Davies J, Griffith G. Preventing fires due to supplemental oxygen. Anaesthesia 2011; 66:320-1. [PMID: 21401559 DOI: 10.1111/j.1365-2044.2011.06665.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lorain S, Peccate C, Le Hir M, Griffith G, Voit T, Garcia L. O.14 Exon exchange approach to repair Duchenne dystrophin transcripts. Neuromuscul Disord 2010. [DOI: 10.1016/j.nmd.2010.07.138] [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: 10/19/2022]
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Lorain S, Peccate C, Griffith G, Voit T, Garcia L. T.P.1.05 Trans-splicing approaches to repair Duchenne dystrophin transcripts. Neuromuscul Disord 2009. [DOI: 10.1016/j.nmd.2009.06.110] [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: 11/27/2022]
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Griffith G, Welch C, Cardone A, Valdemoro A, Jo C. The global momentum for smokefree public places: best practice in current and forthcoming smokefree policies. Salud Publica Mex 2008; 50 Suppl 3:S299-308. [PMID: 18604350 DOI: 10.1590/s0036-36342008000900006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 04/28/2008] [Indexed: 11/21/2022] Open
Abstract
The Global Smokefree Partnership has recently prepared a map of smokefree campaigns and policies around the world. It focuses primarily on countries that are parties to the WHO Framework Convention on Tobacco Control, but other countries were included. The smokefree status of 172 countries was mapped. Of these countries, 31 (18.0%) have established comprehensive smokefree policies, either nationally or at state or city level - best practice; 25 (14.6%) are planning to implement smokefree policies in 2008 or 2009; and 51(29.6%) are making significant progress with smokefree policies. Only 65 countries (37.8%) have limited or no smokefree polices. A selection of countries representing best practices in smokefree policies or planning to implement smokefree policies in 2008 or 2009 is highlighted. They illustrate the significant global momentum for smokefree policies, the success of established policies, the importance of civil society and the sharing of experience between countries.
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Affiliation(s)
- L A Dierauf
- Alliance of Veterinarians for the Environment, USA
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14
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Rosenberg AR, Delamarre L, Pique C, Le Blanc I, Griffith G, Dokhélar MC. Early assembly step of a retroviral envelope glycoprotein: analysis using a dominant negative assay. J Biophys Biochem Cytol 1999; 145:57-68. [PMID: 10189368 PMCID: PMC2148214 DOI: 10.1083/jcb.145.1.57] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
As for most integral membrane proteins, the intracellular transport of retroviral envelope glycoproteins depends on proper folding and oligomeric assembly in the ER. In this study, we considered the hypothesis that a panel of 22 transport-defective mutants of the human T cell leukemia virus type 1 envelope glycoprotein might be defective in ER assembly. Upon cell cotransfection with wild-type envelope, however, the vast majority of these transport-defective mutants (21 of 22) exerted a specific trans-dominant negative effect. This effect was due to random dimerization of the mutated and wild-type glycoproteins that prevented the intracellular transport of the latter. This unexpected result suggests that association of glycoprotein monomers precedes the completion of folding. The only mutation that impaired this early assembly was located at the NH2 terminus of the protein. COOH-terminally truncated, soluble forms of the glycoprotein were also trans-dominant negative provided that their NH2 terminus was intact. The leucine zipper-like domain, although involved in oligomerization of the envelope glycoproteins at the cell surface, did not contribute to their intracellular assembly. We propose that, at a step subsequent to translation, but preceding complete folding of the monomers, glycoproteins assemble via their NH2-terminal domains, which, in turn, permits their cooperative folding.
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Affiliation(s)
- A R Rosenberg
- Institut National de la Santé et de la Recherche Medicale U332, Institut Cochin de Génétique Moléculaire, 75014 Paris, France.
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Stephan JS, McLaughlin RM, Griffith G. Water content and glycosaminoglycan disaccharide concentration of the canine meniscus. Am J Vet Res 1998; 59:213-6. [PMID: 9492939] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To determine the regional composition of water and glycosaminoglycan (GAG) disaccharides of the canine meniscus. SAMPLE POPULATION 52 menisci from the stifle of dogs. PROCEDURE Regional sections of each meniscus were weighed, dried, and reweighed to determine water content. Dried tissue specimens were subjected to enzymatic digestion. Analysis and quantification of disaccharide degradation products were performed, using high-performance liquid chromatography. RESULTS Water content was approximately 65% in polar and central regions of the canine meniscus. Water content of the central region of the lateral meniscus was significantly higher than that of the medial meniscus (P = 0.0090). Chondroitinase digestion of canine meniscal tissue yielded detectable delta Di-HA, delta Di-4S, and delta Di-6S GAG disaccharides. Disaccharides specific to dermatan sulfate and chondroitin D or E sulfate were not detected. Concentrations of delta Di-4S and delta Di-6S were significantly greater in the lateral central region, compared with the medial central region (P = 0.0005 and 0.0002, respectively). CONCLUSION Water content and delta Di-4S and delta Di-6S concentrations were significantly lower in the central region of the medial meniscus, compared with the central region of the lateral meniscus. Reduced tissue hydration of the medial central region may have been a direct result of its overall decrease in total GAG content. CLINICAL RELEVANCE The ability to evaluate subtle differences in tissue GAG composition by analytical measurement of their constituent disaccharides may aid in the understanding of the complex material properties of the normal and diseased meniscus, which may be applied to the study of meniscal healing and biomechanics.
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Affiliation(s)
- J S Stephan
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan 66506, USA
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Neary WJ, Newton VE, Laoide-Kemp SN, Ramsden RT, Griffith G, Evans DG, Harris R, Strachan T. A clinical, genetic and audiological study of patients and families with unilateral vestibular schwannomas. I. Clinical features of neurofibromatosis in patients with unilateral vestibular schwannomas. J Laryngol Otol 1996; 110:634-40. [PMID: 8759535] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Ninety-three patients with unilateral vestibular schwannomas were examined in a clinical, genetic and audiological study, to determine whether they had features associated with neurofibromatosis Type 1 or neurofibromatosis Type 2. In 91 families, one patient only was found to be affected with a unilateral vestibular schwannoma. Patients did have a few café-au-lait macules, but fewer than six in number. None of the patients satisfied the cutaneous diagnostic criteria for neurofibromatosis Type 1. Neither Lisch nodules nor presenile posterior subcapsular lenticular opacities or cortical opacities were a feature. Five patients with unilateral vestibular schwannomas are described where the clinical findings raised the possibility of neurofibromatosis Type 2. It is suggested that certain individuals with unilateral vestibular schwannomas are at risk of developing neurofibromatosis Type 2. Furthermore, the possibility of neurofibromatosis Type 2 should be considered if more than one individual in a family is found to be affected with a unilateral vestibular schwannoma.
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Affiliation(s)
- W J Neary
- Centre for Audiology, Education of the Deaf and Speech Pathology (CAEDSP), University of Manchester, UK
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Watura R, Harding JR, Clements DG, Griffith G, Solomon A. The role of pre-operative thallium-technetium subtraction scintigraphy in the surgical management of patients with solitary parathyroid adenoma. Clin Radiol 1996; 51:383. [PMID: 8641112 DOI: 10.1016/s0009-9260(96)80127-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Melgarejo T, Williams DA, Griffith G. Isolation and characterization of alpha 1-protease inhibitor from canine plasma. Am J Vet Res 1996; 57:258-63. [PMID: 8669751] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To improve a previously described purification process by producing a higher yield and purity of alpha 1-protease inhibitor (alpha 1-PI) from canine plasma. ANIMALS Plasma pool from 10 clinically normal male dogs. PROCEDURE Canine alpha 1-PI was purified by use of ammonium sulfate precipitation, ion-exchange chromatography, and 3 affinity chromatographic procedures: concanavalin A-Sepharose, thiol, and hemoglobin-Sepharose. Characterization was performed by gel electrophoresis, isoelectric focusing, and immunoblot analysis. The N-terminal amino acid sequence was obtained by use of the Edman degradation method and a gas amino acid sequencer. RESULTS Canine alpha 1-PI was purified with a yield of approximately 7% and a 54-fold increase in specific inhibitory activity. The inhibitor had a molecular weight of 59,000 and had 2 major patterns after isoelectric focusing: fast and intermediate in homozygous and/or heterozygous forms. Edman degradation revealed glutamic acid as the starting amino acid from the N-terminal sequence. Homologies of the N-terminal sequence of canine alpha 1-PI with those of sheep, horse, and human alpha 1-protease inhibitors were 54, 46, and 41%, respectively. CONCLUSIONS Canine protease inhibitor is analogous to the alpha 1-protease inhibitors of sheep, human beings, and mice in terms of molecular weight, amino acid composition, and inhibitory activity against trypsin. Although the method described had a yield of 7%, the final product retained inhibitory activity and was pure. CLINICAL RELEVANCE The availability of pure canine alpha 1-PI, as well as the specific antibodies, will facilitate studies on the fecal excretion and structural heterogeneity of this protein in dogs with naturally acquired protein-losing enteropathy.
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Affiliation(s)
- T Melgarejo
- Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907-1248, USA
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19
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Ferguson C, Shandall A, Griffith G. Out-of-hours workload of junior and senior house surgeons in a district general hospital. Ann R Coll Surg Engl 1994; 76:53-6. [PMID: 8017802] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The objective of this study was to assess the out-of-hours workload of junior and senior house officers in general surgery working in a busy DGH in relation to the 'New Deal' guidelines on junior doctors' hours of work. We also wanted to identify safe levels of manning for these grades of staff and to collect accurate data on workload upon which decisions could be made regarding any change in manning levels consequent upon the 'New Deal'. The study is a prospective audit of all work undertaken by 11 junior and senior house surgeons attached to six consultants between 1700 hrs and 0800 hrs during a 16-day period in August 1992. The results showed that the out-of-hours workload of the five JHOs and six SHOs proved to be very onerous. The rotas were 1:5 or 1:6 for emergencies depending on grade plus 1:11 for ward cover. The JHOs were occupied for 70 per cent of the period between 1700 hrs and 2400 hrs and 32.5 per cent of the period after 2400 hrs. For the same periods the SHOs were busy for 61 per cent and 29 per cent respectively. The doctors covering ward duties were occupied for 48 per cent of the period up to midnight when the duty period ended. Both grades got four hours sleep on five of 16 nights. Non-medical tasks accounted for 29 per cent of the ward doctors working time but were a small part of the other doctors work. It was concluded that in this typical busy DGH junior and senior house officers work extremely hard when on call, and that they cannot be reasonably be asked to further increase their level of activity. It follows that a reduction in the hours of work will require additional staff if the standard of care delivered to the patients is to be maintained.
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Affiliation(s)
- C Ferguson
- Department of Surgery, Royal Gwent Hospital, Newport
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20
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Coyne CP, Fenwick BW, Iandola J, Williams D, Griffith G. Isolation of an inhibitor of tumor necrosis factor-alpha-mediated cytotoxicity liberated from chemotaxin-stimulated equine white blood cell populations. Am J Vet Res 1993; 54:845-55. [PMID: 8323051] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Objectives of this investigation were to extract and isolate protein fractions inhibitory to the cytotoxic properties of tumor necrosis factor-alpha (TNF-alpha). In this context, mixed populations of WBC were harvested from equine blood and were stimulated with a combination of a synthetic chemotactic peptide and a calcium ionophore. Several methods were subsequently applied for the initial preparation of cell-free crude protein extracts, including fractional precipitation with gradient concentrations of ammonium sulfate and preparative-scale isoelectric focusing. In addition, protein fractions were harvested from extracts of concentrated equine urine. Protein extracts of urinary origin were further separated by gel-filtration column chromatography. Identification of protein fractions possessing properties inhibitory to the cytotoxic characteristics of TNF-alpha was facilitated by a tissue culture-based technique for the biological assay of TNF-alpha-mediated cytotoxicity. Purified protein extracts possessed a marked ability to inhibit or neutralize the cytotoxic properties of TNF-alpha, on the basis of survival of murine fibrosarcoma cell populations, compared with appropriate negative and positive reference controls. Relative purity of inhibitors and estimation of approximate molecular weight were established by conventional reducing and nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Equine inhibitory protein fractions from mixed WBC populations, purified in the manner described, had molecular weights of 70,000 to 80,000 and 28,000. An analogous protein fraction of 28 kDa also was isolated from equine concentrated urine. Estimated isoelectric point of TNF-alpha inhibitor protein fractions was between pH of 5.5 and 6.1. These physical characteristics of equine TNF-alpha inhibitor protein fractions were similar to those described for a membrane-associated TNF-alpha receptor protein shed from chemotaxin- and calcium-ionophor-stimulated human WBC populations.
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Affiliation(s)
- C P Coyne
- Department of Clinical Science, College of Veterinary Medicine, Kansas State University, Manhattan 66502
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Affiliation(s)
- D L Lamm
- Department of Urology, Health Science Center, West Virginia University, Morgantown
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Abstract
Of 60 patients presenting with acute obstructing carcinoma of the left colon, 49 underwent immediate resection either by radical subtotal/total colectomy (31 patients, group I) or by radical segmental resection (18 patients, group II) of whom three had immediate anastomosis after on-table bowel irrigation and 15 had a planned staged procedure. The operative mortality rate was 3 per cent in group I and 11 per cent in group II (not a statistically significant difference). However, substantial differences were found for major morbidity (6 versus 44 per cent in groups I and II respectively; P less than 0.01) and mean length of hospital stay (17 days in group I versus 35 days in group II; P less than 0.05). All three patients who had on-table lavage developed anastomotic leaks which necessitated a second operation to form a stoma. Six patients (19 per cent) in group I required antidiarrhoeal medication in the immediate postoperative period. However, subsequent improvement in stool frequency was noted in all patients. It is concluded that subtotal/total colectomy is an acceptable means of managing patients with obstructing carcinoma of the left colon in that it is associated with a low morbidity and mortality rate and good functional results.
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Affiliation(s)
- B M Stephenson
- Department of Surgery, Royal Gwent Hospital, Newport, UK
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Abstract
The laryngograph was used to record and compare the voice changes in 11 thyroidectomy patients and 14 controls. The frequency histogram was studied and the change in its spread following surgery used to identify abnormal vocal fold movements due to recurrent laryngeal nerve damage. It also demonstrated changes which occur in thyroidectomy patients and not in patients having other operations. The possible causes include external laryngeal nerve damage.
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Affiliation(s)
- R G Williams
- Department of Otolaryngology, Royal Gwent Hospital, Newport, UK
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Evans J, O'Connor GE, Griffith G, Howieson J. Rhizobial inoculant for iprodione-treated lupin seed: evaluation of an iprodine-resistant Rhizobium lupini. ACTA ACUST UNITED AC 1989. [DOI: 10.1071/ea9890641] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Lupin nodulation is reduced when seed of this legume is treated with commercial inoculant (Rhizobium lupini WU425) and the fungicide Rovral (a.i. iprodione). The number of WU425 colonising soil beneath lupin seedlings established without iprodione was greater than where iprodione was used. R. lupini CC606B has greater tolerance of iprodione than WU425; 85% of CC606B survived 15 min in iprodione (Rovral 16 g/L), compared with <1% survival of WU425. CC606B fixed as much nitrogen as WU425 on serradella grown in sand culture, but it nodulated lupin poorly in the field. It was shown that CC606B comprised bacteria that were either positive or negative for nodulation of serradella and lupin. Thus, an isolate of CC606B (CC606B/1), able to form nodules on lupin and serradella and also tolerant of iprodione (Rovral 16 g/L), was selected and compared with WU425 as inoculants of lupin, in field trials with and without iprodione seed treatment. In the treatments without the fungicide, CC606B/1, like its parent, failed to nodulate lupin as extensively as WU425. CC606B/1 was unable to colonise soil beneath lupin crops as well as WU425. With iprodione, nodulation by CC606B/1 was significantly worse than without the fungicide; so the tolerance level of CC606B/1 to iprodione was insufficient. With these treatments it was shown that nodule abundance in late winter was related to the abundance of rhizobia in the soil beneath lupin seedlings in early winter. When there were fewer nodules, less dry matter was produced; but grain yield was not affected by the reductions in nodulation and dry matter. The implications of these changes on N2 fixation and lupin effects on soil N are discussed. Other species and strains of Rhizobium varied in their ability to survive iprodione.
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Abstract
This study compared plasma lipoprotein fraction profiles and lipid composition in the calf at 3 d, 3 wk, and 12 wk (weaned). For all ages the major plasma lipoprotein fraction was high density lipoproteins (52 to 73%), followed by very high density lipoproteins (10 to 22%), low density lipoproteins (13 to 18%), and chylomicrons plus very low density lipoproteins (5 to 9%). Most plasma lipid was cholesterol esters (41 to 49%) and phosphatidylcholine (21 to 29%). Most cholesterol esters (66 to 81%) and phosphatidylcholine (68 to 80%) were in high density lipoproteins; free fatty acids (83 to 96%) and lysophosphatidylcholine (75 to 85%) in very high density lipoproteins; and triglycerides (93 to 98%) in the remaining lipoprotein fractions. Of the three ages studied, 3-d-old calves had comparatively low plasma total lipids, high density lipoproteins, cholesterol esters, phosphatidylcholine, and linoleic acid in all lipid classes; they had relatively high plasma very high density lipoproteins, triglycerides, free fatty acids, phosphatidylethanolamine, and 20:3 n-9 fatty acid (indicative of essential fatty acids deficiency). Lipoprotein classes and lipid composition were similar at wk 3 and 12. Comparison of fatty acid profiles for phosphatidylcholine with those for lysophosphatidylcholine and cholesterol esters indicated plasma lecithin-cholesterol acyltransferase was active in calves at all three ages studied.
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Affiliation(s)
- K J Jenkins
- Animal Research Centre, Agriculture Canada, Ottawa, Ontario
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Pritchard JA, Sutherland WH, Siddall JE, Bater AJ, Kerby IJ, Deeley TJ, Griffith G, Sinclair R, Davies BH, Rimmer A, Webster DJ. A clinical assessment of fluorescence polarisation changes in lymphocytes stimulated by phytohaemagglutinin (PHA) in malignant and benign diseases. Eur J Cancer Clin Oncol 1982; 18:651-659. [PMID: 6751831 DOI: 10.1016/0277-5379(82)90211-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The modified double-zone SCM technique, developed in these laboratories as an in vitro test for cancer, is based on the differential response to PHA of lymphocytes harvested from two regions of a Ficoll-Triosil gradient. Lymphocyte responses are measured by changes in intracellular fluorescein fluorescence polarisation. We report its continued clinical evaluation in patients hospitalised with malignant and non-malignant diseases, including a blind trial of 78 patients with disorders of the gastrointestinal tract, breast and lung. Overall "false' negative and "false' positive rates from 336 blood samples were 1.8 and 3.3% respectively.
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LeBel GL, Williams DT, Griffith G, Benoit FM. Isolation and concentration of organophosphorus pesticides from drinking water at the ng/L level, using macroreticular resin. J Assoc Off Anal Chem 1979; 62:241-9. [PMID: 447594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A screening method has been developed for determining organophosphorus pesticides at ng/L levels in drinking water. Sixteen organophosphorus pesticides, diazinon, diazinon-oxon, dimethoate, ronnel, beta-phosphamidon, methyl parathion, ethyl parathion, malathion, chlorpyrifos, fenitrothion, ruelene, methidathion, ethion, EPN, phosalone, and phosmet, were extracted by Amberlite XAD-2 resin from 100 and 200 L drinking water previously spiked with these pesticides. The pesticides were eluted from the XAD-2 resin with acetone-hexane (15+85). The concentrated extract was analyzed by gas chromatography using a nitrogen-phosphorus selective detector and by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries at the 10 and 100 ng/L spiking levels were greater than 90%, except recoveries for dimethoate and phosphamidon were 37 and 42%, respectively. The analysis of 300 L Ottawa tap water showed no detectable amounts (less than 1 ng/L) of any of the 16 organophosphorus pesticides.
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Muga L, Clem A, Griffith G, Plendl H, Eaker R, Holub R. Luminescence response of thin plastic scintillator detectors to fission fragments from proton-induced fission of 232Th, 235U, and 238U. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/0029-554x(74)90761-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Suzuki N, Carlson J, Griffith G, Gholson RK. Studies on the de novo biosynthesis of NAD in Escherichia coli. V. Properties of the quinolinic acid synthetase system. Biochim Biophys Acta 1973; 304:309-15. [PMID: 4351074 DOI: 10.1016/0304-4165(73)90249-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Griffith G. Respiratory difficulties in low birth-weight infants. Nurs Mirror Midwives J 1972; 135:17-8. [PMID: 4484802] [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: 01/10/2023]
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Griffith G, Morris A, Pritchard R. Diarrhoea and Light Therapy in Neonates. West J Med 1970. [DOI: 10.1136/bmj.1.5697.692-b] [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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Griffith G. Case of Pili Torti. Proc R Soc Med 1944; 37:154. [PMID: 19992778 PMCID: PMC2180912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Hancock GLR, Griffith G. The Mosquitoes of Namanve Swamp, Uganda: With an Appendix on the Estimation of Organic Carbon in Waters. J Anim Ecol 1934. [DOI: 10.2307/1144] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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