9 results on '"Vidler D"'
Search Results
2. Analysis of organometallic compounds in environment and biological samples
- Author
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Harrington, Christopher F., Vidler, D. S., and Jenkins, R. O.
- Subjects
vapor generation ,ICP-MS ,chemical speciation ,ESI-MS/MS ,organometallics - Abstract
Measurement of the different physicochemical forms of metals and metalloids is a necessary pre-requisite for the detailed understanding of an element’s interaction with environmental and biological systems. Such chemical speciation data is important in a range of areas, including toxicology, ecotoxicology, biogeochemistry, food safety and nutrition. This chapter considers developments in the speciation analysis of organometallic compounds (OMCs), focusing on those of As, Hg, Se and Sn. Typically, organometallic analysis requires a chromatographic separation prior to analyte detection and gas chromatography (GC), high performance liquid chromatography (HPLC) or capillary electrophoresis (CE) can serve this purpose. Following separation, detection is achieved using element specific detectors (ESDs) such as inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectroscopy (ICP-OES), atomic fluorescence spectrometry (AFS), atomic absorption spectrometry (AAS) or atmospheric pressure ionization mass spectrometry (API-MS). Techniques employing a vapor generation (VG) stage prior to detection are also discussed. Complementary structural and quantitative data may be acquired through the combination of elemental and molecular mass spectrometry. The advantages and disadvantages of the various analytical systems are discussed, together with issues related to quantification and quality management.
- Published
- 2010
3. Determination of metallothionein bound zinc from pacific giant clam kidney using conventional and isotope dilution inductively coupled plasma mass spectrometry
- Author
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Vidler, D. S., Jenkins, R. O., Fairman, B., Hall, J. F., and Harrington, Christopher F.
- Subjects
zinc ,ICP-MS ,metallothionein - Published
- 2003
4. Accuracy of substance exposure history in patients attending emergency departments after substance misuse; a comparison with biological sample analysis.
- Author
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Virmani I, Oteo A, Dunn M, Vidler D, Roper C, Officer J, Hardy G, Dargan PI, Eddleston M, Cooper JG, Hill SL, Macfarlane R, Keating L, Haden M, Hudson S, and Thomas SHL
- Subjects
- Adult, Male, Humans, Adolescent, Young Adult, Middle Aged, Aged, Female, Cannabinoid Receptor Agonists, Mass Spectrometry, Emergency Service, Hospital, Substance Abuse Detection methods, Illicit Drugs toxicity, Substance-Related Disorders diagnosis, Substance-Related Disorders epidemiology
- Abstract
Context: Acute toxicity caused by illicit substance use is a common reason for emergency department (ED) presentation. Knowledge of the substances involved is helpful for predicting and managing potential toxicity, but limited information is available about the accuracy of patient-reported substance exposure. This study assessed the accuracy of the history of exposure in those reporting use of a single substance by comparison with those identified by detailed toxicological analysis, focusing on synthetic cannabinoid receptor agonists (SCRA)., Methods: Adults (≥16 years) presenting between March 2015 and July 2021 to participating UK hospitals with toxicity after reporting use of a single illicit substance were included. Exposure details were documented from medical records and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry (HRAM LCMS). Sensitivity, specificity, and positive and negative predictive values of the exposure history were calculated by comparison with biological sample analysis ("gold standard")., Results: Single substance exposure was reported for 474 (median age 33 years, IQR: 18 range 16-75, 80% males) patients. Analysis commonly identified multiple substances (Median 3, IQR 2-5). A history of exposure was documented for 121 of 151 patients where a SCRA or metabolite was detected on analysis (sensitivity 80.1%, 95% CI 72.9, 86.2%). Corresponding proportions were lower for 3,4-methylenedioxymethamphetamine (MDMA, 44/70, 62.9%., 95% CI 50.5%, 74.1%), heroin 41/108 (38.0% 95% CI 28.8-47.8%) and cocaine (22/56, 31.3%, 95% CI 20.9, 43.6%)., Conclusions: Multiple undeclared substances were detected analytically in most patients reporting single substance use. Clinicians should be alert to the potential presence and toxicity of unreported substances when managing patients presenting after substance misuse.
- Published
- 2023
- Full Text
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5. Trends in hospital presentations following analytically confirmed synthetic cannabinoid receptor agonist exposure before and after implementation of the 2016 UK Psychoactive Substances Act.
- Author
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Craft S, Dunn M, Vidler D, Officer J, Blagbrough IS, Pudney CR, Henderson G, Abouzeid A, Dargan PI, Eddleston M, Cooper J, Hill SL, Roper C, Freeman TP, and Thomas SHL
- Subjects
- Chromatography, Liquid, Female, Hospitals, Humans, Male, United Kingdom epidemiology, Cannabinoid Receptor Agonists adverse effects, Personality
- Abstract
Background and Aims: The United Kingdom (UK) Psychoactive Substances Act (PSA), implemented on the 26
th May 2016, made the production, supply and sale of all non-exempted psychoactive substances illegal. The aim of this study was to measure trends in hospital presentations for severe toxicity following analytically confirmed synthetic cannabinoid receptor agonist (SCRA) exposure before and after implementation of the PSA., Design: Observational study., Setting: Thirty-four hospitals across the UK participating in the Identification of Novel Psychoactive Substances (IONA) study., Participants: A total of 627 (79.9% male) consenting individuals who presented to participating hospitals between July 2015 and December 2019 with severe acute toxicity and suspected novel psychoactive substances exposure., Measurements: Toxicological analyses of patient samples were conducted using liquid-chromatography tandem mass-spectrometry. Time-series analysis was conducted on the monthly number of patients with and without analytically confirmed SCRA exposure using Poisson segmented regression., Findings: SCRAs were detected in 35.7% (n = 224) of patients. After adjusting for seasonality and the number of active sites, models showed no clear evidence of an upward or downward trend in the number of SCRA exposure cases in the period before (incidence rate ratio [IRR], 1.12; 95% CI, 0.99-1.26; P = 0.068) or after (IRR, 0.97; 95% CI, 0.94-1.01; P = 0.202) the implementation of the PSA. There was also no clear evidence of an upward or downward trend in non-SCRA exposure cases before (IRR, 1.12; 95% CI, 0.98-1.27; P = 0.105) or after (IRR, 1.01; 95% CI, 0.98-1.04; P = 0.478) implementation of the PSA., Conclusions: There is no clear evidence of an upward or downward trend in the number of patients presenting to UK hospitals with severe acute toxicity following analytically confirmed synthetic cannabinoid receptor agonist exposure since the implementation of the Psychoactive Substances Act., (© 2022 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.)- Published
- 2022
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6. Acute toxicity from the synthetic cathinone N -ethylpentylone (ephylone) in the United Kingdom.
- Author
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Blanco G, Vidler D, Roper C, Wood DM, Dargan PI, Keating L, Macfarlane R, Emmett S, Johnson G, Eddleston M, Hill SL, and Thomas SHL
- Subjects
- Adult, Alkaloids, Humans, Psychotropic Drugs toxicity, United Kingdom epidemiology, Benzodioxoles, Butylamines
- Abstract
Introduction: Acute toxicity caused by New Psychoactive Substances (NPS) has created a significant burden for Emergency Departments (EDs). Here we report characteristics of people presenting with toxicity after exposure to the synthetic cathinone N -ethylpentylone (NEP)., Methods: Adults presenting to hospital with severe acute toxicity after suspected NPS use were recruited between March 2015 and October 2020. Clinical features were recorded using consistent methodology and biological samples analysed using liquid chromatography-tandem mass-spectrometry., Results: NEP was detected in at least one sample from 9 of 893 patients recruited during the period of study, all presenting between 2016 and 2019 and 8 presenting in southern England. Commonly reported clinical features included tachycardia (6), agitation (6), confusion (6), mydriasis (5), hallucinations (4), acidosis (3) and elevated creatine kinase (3). Co-used drugs, detected in 6 patients, may have contributed to these features, but agitation and hallucinations were also reported in all 3 patients without analytical evidence of co-use., Conclusions: NEP was detected infrequently in episodes of drug toxicity in the UK between 2016 and 2019, especially in southern England. Clinical characteristics of toxicity are similar to those of other cathinones, although co-use of other drugs is common and may contribute to the features observed.
- Published
- 2021
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7. The methylimidazolium ionic liquid M8OI is detectable in human sera and is subject to biliary excretion in perfused human liver.
- Author
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Leitch AC, Ibrahim I, Abdelghany TM, Charlton A, Roper C, Vidler D, Palmer JM, Wilson C, Jones DE, Blain PG, and Wright MC
- Subjects
- Adult, Aged, Alcohol Dehydrogenase antagonists & inhibitors, Aldehyde Oxidoreductases antagonists & inhibitors, Cells, Cultured, Cytochrome P-450 Enzyme Inhibitors pharmacology, Enzyme Inhibitors pharmacology, Female, Hepatocytes drug effects, Hepatocytes metabolism, Humans, Hydroxylation, In Vitro Techniques, Ketoconazole pharmacology, Male, Middle Aged, Primary Cell Culture, Young Adult, Hepatobiliary Elimination, Imidazoles blood, Imidazoles pharmacokinetics
- Abstract
A methylimidizolium ionic liquid (M8OI) was recently found to be contaminating the environment and to be related to and/or potentially a component of an environmental trigger for the autoimmune liver disease primary biliary cholangitis (PBC). The aims of this study were to investigate human exposure to M8OI, hepatic metabolism and excretion. PBC patient and control sera were screened for the presence of M8OI. Human livers were perfused with 50μM M8OI in a closed circuit and its hepatic disposition examined. Metabolism was examined in cultured human hepatocytes and differentiated HepaRG cells by the addition of M8OI and metabolites in the range 10-100 μM. M8OI was detected in the sera from 5/20 PBC patients and 1/10 controls. In perfused livers, M8OI was cleared from the plasma with its appearance - primarily in the form of its hydroxylated (HO8IM) and carboxylated (COOH7IM) products - in the bile. Metabolism was reflected in cultured hepatocytes with HO8IM production inhibited by the cytochrome P450 inhibitor ketoconazole. Further oxidation of HO8IM to COOH7IM was sequentially inhibited by the alcohol and acetaldehyde dehydrogenase inhibitors 4-methyl pyrazole and disulfiram respectively. Hepatocytes from 1 donor failed to metabolise M8OI to COOH7IM over a 24 h period. These results demonstrate exposure to M8OI in the human population, monooxygenation by cytochromes P450 followed by alcohol and acetaldehyde dehydrogenase oxidation to a carboxylic acid that are excreted, in part, via the bile in human liver., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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8. DNA structure control by polycationic species: polyamine, cobalt ammines, and di-metallo transition metal chelates.
- Author
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Rodger A, Sanders KJ, Hannon MJ, Meistermann I, Parkinson A, Vidler DS, and Haworth IS
- Subjects
- Models, Molecular, Polyelectrolytes, Spectrometry, Fluorescence, Chelating Agents chemistry, Cobalt chemistry, DNA chemistry, Nucleic Acid Conformation, Polyamines chemistry
- Abstract
Many polycationic species bind to DNA and induce structural changes. The work reported here is the first phase of a program whose long-term aim is to create a class of simple and inexpensive sequence-selective compounds that will enable enhanced DNA structure control for a wide range of applications. Three classes of molecule have been included in this work: the polyamine spermine (charge: 4(+)) and spermidine (charge: 3(+)) (which are known to induce a wide range of DNA conformational changes but whose binding modes are still not well understood); cobalt (III) amine transition metal complexes as potential polyamine mimics and [Fe(H(2)O)(6)](3+); and the first member of a new class of di-metallo tris-chelated cylinders of helical structure (charge 4(+)). Temperature-dependent absorption, circular dichroism, linear dichroism, gel electrophoresis, and molecular modeling data are presented. The cobalt amines prove to be effective polyamine mimics, although their binding appears to be restricted to backbone and major groove. All the ligands stabilize the DNA, but the 4(+) di-iron tris-chelate does so comparatively weakly and seems to have a preference for single-stranded DNA. All the molecules studied bend the DNA, with the di-iron tris-chelate having a particularly dramatic effect even at very low drug load., (Copyright 2000 Wiley-Liss, Inc.)
- Published
- 2000
- Full Text
- View/download PDF
9. A study of curiosity, divergent thinking, and test-anxiety.
- Author
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Vidler DC and Karan VE
- Subjects
- Adolescent, Adult, Female, Humans, Male, Test Anxiety Scale, Anxiety, Creativity, Exploratory Behavior
- Abstract
A review of the literature suggested that curiosity was positively related to divergent thinking, and negatively related to test-anxiety. Subjects were male and female 9th and 10th graders (N = 67), 11th and 12th graders (N = 67), and college undergraduates (N = 69). Curiosity was measured by an 80-item self-report scale and an adjective checklist, test-anxiety by a 37-item self-report scale, and divergent thinking by two verbal paper-and-pencil test. The results showed that both measures of curiosity were positively related to divergent thinking in all three groups studied, but that test-anxiety was not significantly related to either curiosity or divergent thinking. Differences in performance by the three groups of subjects were discussed.
- Published
- 1975
- Full Text
- View/download PDF
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