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French AD, Melby KM, Hobbs KP, Cox RM, Eiden G, Hoppe EW, Arnquist IJ, Harouaka K. The importance of ion kinetic energy for interference removal in ICP-MS/MS. Talanta 2024; 272:125799. [PMID: 38422903 DOI: 10.1016/j.talanta.2024.125799] [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: 12/19/2023] [Revised: 02/02/2024] [Accepted: 02/13/2024] [Indexed: 03/02/2024]
Abstract
The effect of ion kinetic energy on gas phase ion reactivity with ICP-MS/MS was investigated in order to explore tuning strategies for interference removal. The collision/reaction gases CO2, N2O and O2 were used to observe the ion product distribution for 48 elements using an Agilent tandem ICP-MS (ICP-MS/MS) as a function of reaction gas flow rate (pressure) and ion kinetic energy. The kinetic energy of the incident ion was varied by adjusting the octopole bias (Voct). The three gases all form oxides (MO+) as the primary product with differing reaction enthalpies that result in distinct differences in the ion energies required for reaction with product ion distributions that vary with Voct. Consequently, by varying the ion kinetic energy (i.e., Voct), differences in interference reactivity can be used to achieve maximum separation. Three practical application examples were reported to demonstrate how the ion kinetic energy can be varied to achieve the ideal ion product distribution for interference resolution: CO2 for the removal of 238U in Pu analyses, CO2 for the removal of 40Ar16O vs. 56Fe, and O2 for the removal of Sm in Eu analyses, analogous to Pu/Am. The results demonstrate how the starting ion energy defined by Voct is an important factor to fully leverage the utility of any given reaction gas to remove interferences in the mass spectrum using ICP-MS/MS.
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Affiliation(s)
- Amanda D French
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA.
| | - Kali M Melby
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Kirby P Hobbs
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Richard M Cox
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Greg Eiden
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA; Idaho National Laboratory, Idaho Falls, ID, 83415, USA
| | - Eric W Hoppe
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA
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2
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Hobbs KP, French AD, Melby KM, Bylaska EJ, Harouaka K, Cox RM, Arnquist IJ, Beck CL. Assessing Gas-Phase Ion Reactivity of 50 Elements with NO and the Direct Application for 239Pu in Complex Matrices Using ICP-MS/MS. Anal Chem 2024; 96:5807-5814. [PMID: 38573874 DOI: 10.1021/acs.analchem.3c04774] [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: 04/06/2024]
Abstract
Understanding the reactivity of metal cations with various reaction gases in inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) is important to determine the best gas to use for a given analyte/interference pair. In this study, nitric oxide (NO) was investigated as the reaction gas following previous experimental designs. The reactions with 50 elements were investigated to examine periodic trends in reactivity, validate theoretical modeling of reaction enthalpies as a method to screen reactant gases, and provide a baseline data set for potential in-line gas separation methods. ICP-MS/MS studies involving actinides are typically limited to Th, U, and Pu, with analyses of Np and Am rarely reported in the literature. To date, only two previous methods have investigated the use of NO in ICP-MS/MS analyses. To showcase the utility of NO, a method was developed to measure 239Pu in the presence of environmental matrix constituent and other actinides, like what could be expected from postdetonation debris, with no chemical separation prior to analysis. 239Pu+ was reacted to form 239Pu16O+, eliminating interferences derived from the sample matrix by measuring the 239Pu+ intensity at m/z = 255 (239Pu16O+). To validate NO for 238U1H+ interference removal in environmental matrices, standard reference materials were diluted to 1 mg/g of solution and spiked to 0.05 pg/g of 239Pu and 1 μg/g 238U (Pu/U = 5 × 10-8). Measured 239Pu concentrations were within 6% of the spiked value. These results demonstrate that reliable 239Pu measurements can be made at levels relevant to nuclear forensics without the need for extensive chemical matrix separation prior to analysis.
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Affiliation(s)
- Kirby P Hobbs
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Amanda D French
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kali M Melby
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Eric J Bylaska
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Khadouja Harouaka
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Richard M Cox
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Isaac J Arnquist
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Chelsie L Beck
- Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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3
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Grainger MNC, Klaus H, Hewitt N, Gan H, French AD. Graphical Discrimination of New Zealand Honey from International Honey Using Elemental Analysis. Biol Trace Elem Res 2024; 202:754-764. [PMID: 37119341 PMCID: PMC10764415 DOI: 10.1007/s12011-023-03680-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/21/2023] [Indexed: 05/01/2023]
Abstract
This study investigated the potential of utilising the elemental fingerprinting of honey to differentiate New Zealand (NZ) honey from that of international origin. Twenty elements were analysed by ICP-MS in 352 honeys from 34 various countries. Of these, 323 honeys (245 New Zealand honeys, 78 international) and two subsets of data (NZ and European origin, n = 306, and, NZ and Denmark/Germany, n = 280) were visualised using principal component analysis (PCA). For the NZ/Europe subset, 42.2% of data was explained in the first two principal components. Statistical classification rules were also derived using linear discriminant analysis (LDA) and decision tree analysis. Various combinations of elements were explored for classification, considering the effect of soil-derived elements and those from anthropogenic sources. A high degree of accuracy (at least 90%) for the characterisation of New Zealand honey was observed for all statistical models, showing the robustness of these analyses. When using decision tree analysis to distinguish New Zealand samples from international samples, a tree with five terminal nodes (using Cs, Ba and Rb) was created with 92.4% accuracy. This work has demonstrated that elemental fingerprints of honey are a promising tool for categorising New Zealand honey from other geographical locations.
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Affiliation(s)
- Megan N C Grainger
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand.
| | - Hannah Klaus
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Nyssa Hewitt
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Han Gan
- Department of Mathematics, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Amanda D French
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
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4
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Cox RM, Melby KM, French AD, Rodriguez MJ. f-Block reactions of metal cations with carbon dioxide studied by inductively coupled plasma tandem mass spectrometry. Phys Chem Chem Phys 2023; 26:209-218. [PMID: 38054255 DOI: 10.1039/d3cp04180h] [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: 12/07/2023]
Abstract
f-Block chemistry offers an opportunity to test current knowledge of chemical reactivity. The energy dependence of lanthanide cation (Ln+ = Ce+, Pr+, Nd+-Eu+) and actinide cation (An+ = Th+, U+-Am+) oxidation reactions by CO2, was observed by inductively coupled plasma tandem mass spectrometry. This reaction is commonly spin-unallowed because the neutral reactant (CO2, 1Σ+g) and product (CO, 1Σ+) require the metal and metal oxide cations to have the same spin state. Correlation of the promotion energy (Ep) to the first state with two free d-electrons with the reaction efficiency indicates that spin conservation is not a primary factor in the reaction rate. The Ep likely influences the reaction rate by partially setting the crossing between the ground and reactive states. Comparison of Ln+ and An+ congener reactivity indicates that the 5f-orbitals play a small role in the An+ reactions.
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Affiliation(s)
- Richard M Cox
- Pacific Northwest National Laboratory, Richland, WA 99352 USA, USA.
| | - Kali M Melby
- Pacific Northwest National Laboratory, Richland, WA 99352 USA, USA.
| | - Amanda D French
- Pacific Northwest National Laboratory, Richland, WA 99352 USA, USA.
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5
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French AD. BASCD at 50. Community Dent Health 2023; 40:196-198. [PMID: 37812526 DOI: 10.1922/cdh_00098french03] [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] [Received: 05/08/2023] [Accepted: 07/06/2023] [Indexed: 10/11/2023]
Abstract
The British Association for the Study of Community Dentistry (BASCD) is marking its 50th anniversary in 2023. The author of this article has been a member of BASCD for those 50 years, including a number as a member of the Council, and offers his personal reflections on some of the range of activities of the Association.
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6
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Wolf A, Ersek V, Braun T, French AD, McGee D, Bernasconi SM, Skiba V, Griffiths ML, Johnson KR, Fohlmeister J, Breitenbach SFM, Pausata FSR, Tabor CR, Longman J, Roberts WHG, Chandan D, Peltier WR, Salzmann U, Limbert D, Trinh HQ, Trinh AD. Deciphering local and regional hydroclimate resolves contradicting evidence on the Asian monsoon evolution. Nat Commun 2023; 14:5697. [PMID: 37709741 PMCID: PMC10502020 DOI: 10.1038/s41467-023-41373-9] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 09/01/2023] [Indexed: 09/16/2023] Open
Abstract
The winter and summer monsoons in Southeast Asia are important but highly variable sources of rainfall. Current understanding of the winter monsoon is limited by conflicting proxy observations, resulting from the decoupling of regional atmospheric circulation patterns and local rainfall dynamics. These signals are difficult to decipher in paleoclimate reconstructions. Here, we present a winter monsoon speleothem record from Southeast Asia covering the Holocene and find that winter and summer rainfall changed synchronously, forced by changes in the Pacific and Indian Oceans. In contrast, regional atmospheric circulation shows an inverse relation between winter and summer controlled by seasonal insolation over the Northern Hemisphere. We show that disentangling the local and regional signal in paleoclimate reconstructions is crucial in understanding and projecting winter and summer monsoon variability in Southeast Asia.
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Affiliation(s)
- Annabel Wolf
- Department of Earth System Science, University of California, Irvine, CA, 92697, USA.
- Department of Geography and Environmental Sciences, Northumbria University Newcastle, Newcastle-upon-Tyne, NE1 8ST, UK.
| | - Vasile Ersek
- Department of Geography and Environmental Sciences, Northumbria University Newcastle, Newcastle-upon-Tyne, NE1 8ST, UK.
| | - Tobias Braun
- Potsdam Institute for Climate Impact Research, 14473, Potsdam, Germany
| | - Amanda D French
- Environmental Research Institute, Waikato University, Hamilton, 3240, New Zealand
| | - David McGee
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139-4307, USA
| | | | - Vanessa Skiba
- Potsdam Institute for Climate Impact Research, 14473, Potsdam, Germany
| | - Michael L Griffiths
- Department of Environmental Science, William Paterson University, Wayne, NJ, 07470, USA
| | - Kathleen R Johnson
- Department of Earth System Science, University of California, Irvine, CA, 92697, USA
| | - Jens Fohlmeister
- Federal Office for Radiations Protection, 10318, Berlin, Germany
| | - Sebastian F M Breitenbach
- Department of Geography and Environmental Sciences, Northumbria University Newcastle, Newcastle-upon-Tyne, NE1 8ST, UK
| | - Francesco S R Pausata
- Department of Earth and Atmospheric Sciences, Centre ESCER (Étude et la Simulation du Climat à l'Échelle Régionale) and GEOTOP (Research Center on the dynamics of the Earth System), University of Quebec in Montreal, Montréal, QC, Canada
| | - Clay R Tabor
- Department of Earth Sciences, University of Connecticut, Storrs, CT, 06269, USA
| | - Jack Longman
- Department of Geography and Environmental Sciences, Northumbria University Newcastle, Newcastle-upon-Tyne, NE1 8ST, UK
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Oldenburg, 26129, Germany
| | - William H G Roberts
- Department of Geography and Environmental Sciences, Northumbria University Newcastle, Newcastle-upon-Tyne, NE1 8ST, UK
| | - Deepak Chandan
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON, M5S1A7, Canada
| | - W Richard Peltier
- Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON, M5S1A7, Canada
| | - Ulrich Salzmann
- Department of Geography and Environmental Sciences, Northumbria University Newcastle, Newcastle-upon-Tyne, NE1 8ST, UK
| | | | - Hong Quan Trinh
- Institute of Chemistry, Vietnam Academy of Science and Technology, Ha Noi, 10072, Viet Nam
| | - Anh Duc Trinh
- Nuclear Training Center, Vietnam Atomic Energy Institute, 140 Nguyen Tuan, Thanh Xuan, Ha Noi, 11416, Viet Nam
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7
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Heller FD, Ahlers LRH, Nordquist ZE, Gunawardena NH, French AD, Lines AM, Nelson GL, Casella AJ, Bryan SA. Development of Online pH Monitoring for Lactic, Malonic, Citric, and Oxalic Acids Based on Raman Spectroscopy Using Hierarchical Chemometric Modeling. Anal Chem 2022; 94:17467-17476. [PMID: 36480638 DOI: 10.1021/acs.analchem.2c03624] [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: 12/13/2022]
Abstract
Online spectroscopic measurements can be used to provide unique insight into complex chemical systems, enabling new understanding and optimization of chemical processes. A key example of this is discussed here with the monitoring of pH of various acid systems in real-time. In this work the acids used in multiple chemical separations processes, such as TALSPEAK (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes) and oxalate precipitation, were characterized. Raman spectroscopy, a robust optical approach that can be integrated in corrosive processes, was used to follow the unique fingerprints of the various protonated and deprotonated acid species. This data was analyzed using a hierarchical modeling approach to build a consolidated model scheme using optical fingerprints from all weak acids to measure pH associated with any of the weak acid systems studied here. Validation of system performance included utilizing Raman spectroscopy under dynamic flow conditions to monitor solution pH under changing process conditions in-line. Overall, the Raman based approach provided accurate analysis of weak acid solution pH.
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Affiliation(s)
- Forrest D Heller
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Laura R H Ahlers
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Zoe E Nordquist
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Navindra H Gunawardena
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Amanda D French
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Amanda M Lines
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Gilbert L Nelson
- Chemistry Department, The College of Idaho, Caldwell, Idaho 83605, United States
| | - Amanda J Casella
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Samuel A Bryan
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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Grainger MNC, Klaus H, Hewitt N, French AD. Investigation of inorganic elemental content of honey from regions of North Island, New Zealand. Food Chem 2021; 361:130110. [PMID: 34033993 DOI: 10.1016/j.foodchem.2021.130110] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [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: 01/21/2021] [Revised: 05/02/2021] [Accepted: 05/12/2021] [Indexed: 01/28/2023]
Abstract
Determination of geographical origin of honey is important to consumers to confirm authenticity. This study investigated the elemental fingerprint of 181 honey samples collected from apiary sites in six regions of North Island, New Zealand to determine if differences were observed due to region of collection or land use surrounding the hive (e.g. agricultural, rural, urban). Using principal component analysis, soil related elements (Ca, K, Mg, Mn, Na) provided 75.2% discrimination of samples in the first two principal components. Overall, low concentrations of heavy metals were observed; lead was present in close proximity to highly trafficked roads (28.1% of samples; 9.50-76.5 µg kg-1) and cadmium was primarily present in honey collected from agricultural land in the Waikato (<51.6 µg kg-1). The use of an elemental fingerprint of New Zealand honey may be advantageous to determine the geographical origin compared to honey produced from other countries.
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Affiliation(s)
- Megan N C Grainger
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Hannah Klaus
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | - Nyssa Hewitt
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | - Amanda D French
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
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9
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French AD, Ragg NLC, Ericson JA, Goodwin E, McDougall DR, Mohammadi A, Vignier J. Balancing essential and non-essential metal bioavailability during hatchery rearing of Greenshell mussel (Perna canaliculus) larvae. Ecotoxicol Environ Saf 2021; 216:112194. [PMID: 33862436 DOI: 10.1016/j.ecoenv.2021.112194] [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] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/20/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
The use of ethylenediaminetetraacetic acid (EDTA) during bivalve hatchery production is thought to improve larval yields due to the reduced exposure to toxic metals (such as Cu); however, few studies have focused on the bioavailability of metals during the rearing process. Greenshell™ mussels (Perna canaliculus) were reared for 48 h with and without EDTA (12 µM) exposure and larvae were subsequently raised to 21 days post-fertilisation with and without EDTA exposure. Survival, shell length, algal ingestion rate, swimming activity, total metal concentration in water, bioavailable metal concentrations and larval metal accumulation were monitored for the 21 day period. Larval fitness (specifically D-yields) was improved on day 2 in the EDTA treatment, whereas an overall negative effect of EDTA treatment on fitness was observed on day 10 and 21. During the first 48 h, increased survival in the EDTA treatment is believed to be due to the reduction of bioavailable Zn concentrations in the rearing seawater. No other metal (essential or non-essential) displayed a consistent trend when comparing metal bioavailability to any of the fitness parameters measured throughout the experiment. Though the measured metal bioavailability was not clearly linked to fitness, the uptake of Al, P, Cr, Fe, Co, Ni, Zn, As, Cd, and Hg by P. canaliculus was reduced during the first 48 h, suggesting that the biological regulation of these elements is just as important as the bioavailability. Overall, treatment of the rearing seawater with 12 µM EDTA is effective for improving Greenshell™ mussel larval yields by decreasing metal bioavailability during the first two days of development but has minimal benefit between day 2 and 21.
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Affiliation(s)
| | - Norman L C Ragg
- Cawthron Institute, 98 Halifax Street East, Nelson, New Zealand
| | | | - Eric Goodwin
- Cawthron Institute, 98 Halifax Street East, Nelson, New Zealand
| | - Daniel R McDougall
- Institute of Marine Science, University of Auckland, Private Bag, 92019 Auckland, New Zealand
| | - Amir Mohammadi
- University of Waikato, Hillcrest Rd, Hamilton, New Zealand
| | - Julien Vignier
- Cawthron Institute, 98 Halifax Street East, Nelson, New Zealand
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10
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Shaw KR, Lynch JM, Balazs GH, Jones TT, Pawloski J, Rice MR, French AD, Liu J, Cobb GP, Klein DM. Trace Element Concentrations in Blood and Scute Tissues from Wild and Captive Hawaiian Green Sea Turtles (Chelonia mydas). Environ Toxicol Chem 2021; 40:208-218. [PMID: 33103806 PMCID: PMC8452040 DOI: 10.1002/etc.4911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/06/2020] [Accepted: 10/16/2020] [Indexed: 05/04/2023]
Abstract
Sea turtles are exposed to trace elements through water, sediment, and food. Exposure to these elements has been shown to decrease immune function, impair growth, and decrease reproductive output in wildlife. The present study compares trace element concentrations in green turtles in captivity at Sea Life Park Hawaii (n = 6) to wild green turtles in Kapoho Bay, Hawaii, USA (n = 5-7). Blood and scute samples were collected and analyzed for 11 elements via inductively coupled plasma-mass spectrometry (ICP-MS). Selenium was significantly greater (p < 0.05) in the blood of captive turtles compared with wild turtles, whereas V, Ni, and Pb were significantly greater in the blood of wild turtles. In scute, V, Cu, Se, and Cr were significantly greater in captive turtles, whereas As was significantly greater in wild turtles. Pelleted food fed to the captive turtles and representative samples of the wild turtle diet were analyzed via ICP-MS to calculate trophic transfer factors and daily intake values. Wild turtles had greater estimated daily intake than captive turtles for all elements except Cu and Se. Because captive turtles are fed a diet very different from that of their wild counterparts, captive turtles do not represent control or reference samples for chemical exposure studies in wild turtles. No toxic thresholds are known for sea turtles, but rehabilitation and managed care facilities should monitor sea turtle elemental concentrations to ensure the animals' health. Environ Toxicol Chem 2021;40:208-218. © 2020 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Katherine R. Shaw
- Texas Tech University, Department of Environmental Toxicology, Lubbock, TX 79416, USA
- Address correspondence to
| | - Jennifer M. Lynch
- National Institute of Standards and Technology, Chemical Sciences Division, Waimanalo, HI 96744, USA
| | | | - T. Todd Jones
- National Oceanic and Atmospheric Administration Pacific Islands Fisheries Science Center, Honolulu, HI 96818, USA
| | | | - Marc R. Rice
- Hawaii Preparatory Academy, Kamuela, HI 96743, USA
| | - Amanda D. French
- Texas Tech University, Department of Environmental Toxicology, Lubbock, TX 79416, USA
| | - Jing Liu
- Baylor University, Department of Environmental Sciences, Waco, TX 76706, USA
| | - George P. Cobb
- Baylor University, Department of Environmental Sciences, Waco, TX 76706, USA
| | - David M. Klein
- Texas Tech University, Department of Environmental Toxicology, Lubbock, TX 79416, USA
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11
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Grainger MNC, Hewitt N, French AD. Optimised approach for small mass sample preparation and elemental analysis of bees and bee products by inductively coupled plasma mass spectrometry. Talanta 2020; 214:120858. [PMID: 32278432 DOI: 10.1016/j.talanta.2020.120858] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/20/2020] [Accepted: 02/20/2020] [Indexed: 12/31/2022]
Abstract
The elemental fingerprint of honey, pollen and bees are useful biomonitors of anthropogenic activities across the world. Elements in honey and pollen may also be analysed for their nutritional value and potential toxicity. There are currently limited studies that address the use of small sample masses while retaining good reproducibility and detection limits during elemental analysis. The aim of this study was to develop a simple analytical method to quantify 39 major, minor, trace and rare earth elements in small mass samples of bees, honey and pollen by inductively coupled plasma mass spectrometry. The final method was validated for 20-200 mg bee, 20-100 mg pollen or 50-200 mg of honey with 0.2 mL nitric acid followed by 0.1 mL hydrogen peroxide in a digestion block (80 °C, 2 h total); samples were made up to a final volume of approximately 6 mL. The method reduces the volume of chemicals used, limits sample manipulation and improves detection limits over traditional digestion methods. The sample preparation and analysis method were deemed to be satisfactory for the three matrices examined, with spike recoveries ranging from 96 (B) to 129% (As) for trace elements and 91 (Pr) to 112% (La) for rare earth elements, and acceptable detection limits (down to 5.07 μg kg-1 for Co using 30 mg sample mass, pollen). Precision was acceptable with the relative percent standard deviation of fully homogenised samples ranging from 0.53 (K, bee, 20 mg) to 24% (As, 30 mg, bee) across the three matrices and all masses analysed. This small mass digestion method enables the analysis of a single bee allowing a more distinctive elemental signature to be determined. Similarly, pollen from fewer flowers of the same species can be pooled together which is advantageous for analysis of flowers that produce little pollen.
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Affiliation(s)
- Megan N C Grainger
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand.
| | - Nyssa Hewitt
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Amanda D French
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
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12
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French AD, Shaw K, Barnes M, Cañas-Carrell JE, Conway WC, Klein DM. Bioaccessibility of antimony and other trace elements from lead shot pellets in a simulated avian gizzard environment. PLoS One 2020; 15:e0229037. [PMID: 32045468 PMCID: PMC7012451 DOI: 10.1371/journal.pone.0229037] [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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Many studies have used grit (in the form of lead (Pb) pellets) presence in avian gizzards as an indicator of Pb shot exposure. However, due to nearly complete pellet absorption in gizzards or rapid passage of pellets, the absence of Pb shot presence in a gizzard does not confirm lack of Pb shot exposure. This study provides the basis for an additional technique to identify if elevated tissue Pb concentration is due to Pb shot exposure. Bioaccessibility of Pb and trace elements (Sb, As, and Sn) present in Pb shot were quantified to determine if any of these elements would be useful as a secondary marker of Pb shot exposure. An avian physiologically based extraction test (PBET) was used to determine pellet dissolution rate and bioaccessible concentrations of Pb, Sb, As, and Sn in a simulated gizzard environment. Of the three trace elements, only Sb concentrations (44–302 μg/mL) extracted into the gizzard solution were greater than environmental background levels (US soil average 0.48 μg/g); thus, no natural source likely provides this amount of Sb. Therefore, there is evidence that Sb can be extracted from Pb shot in bird gizzards at detectable concentrations (above natural background). While further studies are needed to delineate the mechanisms of absorption and distribution, this study lends credence to the hypothesis that Sb may be a useful marker of Pb shot exposure in biological tissues, particularly when Pb pellets are not present nor observed in avian tissues.
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Affiliation(s)
- Amanda D. French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, United States of America
- * E-mail:
| | - Katherine Shaw
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, United States of America
| | - Melanie Barnes
- Department of Geosciences, Texas Tech University, Lubbock, Texas, United States of America
| | - Jaclyn E. Cañas-Carrell
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, United States of America
| | - Warren C. Conway
- Department of Natural Resources Management, Texas Tech University, Lubbock, Texas, United States of America
| | - David M. Klein
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, United States of America
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13
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Ashbaugh HM, Conway WC, Haukos DA, Collins DP, Comer CE, French AD. Evidence for exposure to selenium by breeding interior snowy plovers (Charadrius nivosus) in saline systems of the Southern Great Plains. Ecotoxicology 2018; 27:703-718. [PMID: 29845516 DOI: 10.1007/s10646-018-1952-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/09/2018] [Indexed: 06/08/2023]
Abstract
Interior snowy plover (Charadrius nivosus) population declines and deteriorating conditions throughout the Southern Great Plains (SGP) of Texas, New Mexico, and Oklahoma may be linked to environmental contaminants. Concentrations of V, As, Cd, Pb, and Se were quantified in breeding snowy plover blood, feathers (5th primary; P5), and potential prey (tiger beetles [Cicindela circumpicta and C. togata]). Se was (a) most commonly detected relative to other quantified elements and (b) frequently quantified at levels exceeding background or toxicity thresholds. Of samples greater than instrumentation detection limits, 98% of snowy plover blood and 22% of feather samples were greater than Se toxicity thresholds of 1 ppm ww for blood and 5 ppm dw for feathers (blood quantifiable range: 0.83-15.12 ppm; feathers quantifiable range: 1.90-27.47 ppm). Almost all tiger beetle Se concentrations were below reported invertebrate thresholds of 30 ppm dw (quantifiable range: 0.54-45.84 ppm). Snowy plover blood Se concentrations were related to sex, individual body condition, and local tiger beetle Se concentrations, while plover P5 Se concentrations were related to state, sex, and presence of body molt. Tiger beetle Se concentrations were related to individual study sites in Texas. These results provide some of the first evidence of Se exposure risk for interior snowy plovers nesting in saline lake and alkali flat environments of the SGP. Future efforts should focus upon specific Se uptake pathways during breeding and nonbreeding seasons, as snowy plovers breeding in the SGP appear to be exposed to Se throughout their annual cycle.
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Affiliation(s)
- H M Ashbaugh
- Department of Natural Resources Management, Texas Tech University, Lubbock, TX, 79409, USA.
| | - W C Conway
- Department of Natural Resources Management, Texas Tech University, Lubbock, TX, 79409, USA
| | - D A Haukos
- U. S. Geological Survey, Kansas Cooperative Fish and Wildlife Research Unit, Kansas State University, Manhattan, KS, 66506, USA
| | - D P Collins
- U. S. Fish and Wildlife Service - Region 2 Migratory Bird Program, P.O. Box 1306, Albuquerque, NM, 87103, USA
| | - C E Comer
- Arthur Temple College of Forestry and Agriculture, Stephen F. Austin State University, Nacogdoches, TX, 75962, USA
| | - A D French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, 79409, USA
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14
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Branch SD, French AD, Lines AM, Soderquist CZ, Rapko BM, Heineman WR, Bryan SA. In Situ Spectroscopic Analysis and Quantification of [Tc(CO) 3] + in Hanford Tank Waste. Environ Sci Technol 2018; 52:7796-7804. [PMID: 29895141 DOI: 10.1021/acs.est.7b05840] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The quantitative conversion of nonpertechnetate [Tc(CO)3]+ species in nuclear waste storage tank 241-AN-102 at the Hanford Site is demonstrated. A waste sample containing the [Tc(CO)3]+ species is added to a developer solution that rapidly converts the nonemissive species into a luminescent complex, which is detected spectroscopically. This method was first demonstrated using a [Tc(CO)3]+ sample of nonwaste containing matrix to determine a detection limit (LOD), resulting in a [Tc(CO)3]+ LOD of 2.20 × 10-7 M, very near the LOD of the independently synthesized standard (2.10 × 10-7 M). The method was then used to detect [Tc(CO)3]+ in a simulated waste using the standard addition method, resulting in a [Tc(CO)3]+ concentration of 1.89 × 10-5 M (within 27.7% of the concentration determined by β liquid scintillation counting). Three samples from 241-AN-102 were tested by the standard addition method: (1) a 5 M Na adjusted fraction, (2) a fraction depleted of 137Cs, and (3) an acid-stripped eluate. The concentrations of [Tc(CO)3]+ in these fractions were determined to be 9.90 × 10-6 M (1), 0 M (2), and 2.46 × 10-6 M (3), respectively. The concentration of [Tc(CO)3]+ in the as-received AN-102 tank waste supernatant was determined to be 1.84 × 10-5 M.
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Affiliation(s)
- Shirmir D Branch
- Department of Chemistry , University of Cincinnati , Cincinnati , Ohio 45221-0172 , United States
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Amanda D French
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Amanda M Lines
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Chuck Z Soderquist
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Brian M Rapko
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - William R Heineman
- Department of Chemistry , University of Cincinnati , Cincinnati , Ohio 45221-0172 , United States
| | - Samuel A Bryan
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
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15
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Branch SD, French AD, Lines AM, Rapko BM, Heineman WR, Bryan SA. In Situ Quantification of [Re(CO) 3] + by Fluorescence Spectroscopy in Simulated Hanford Tank Waste. Environ Sci Technol 2018; 52:1357-1364. [PMID: 29240997 DOI: 10.1021/acs.est.7b04222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A pretreatment protocol is presented that allows for the quantitative conversion and subsequent in situ spectroscopic analysis of [Re(CO)3]+ species in simulated Hanford tank waste. In this test case, the nonradioactive metal rhenium is substituted for technetium (Tc-99), a weak beta emitter, to demonstrate proof of concept for a method to measure a nonpertechnetate form of technetium in Hanford tank waste. The protocol encompasses adding a simulated waste sample containing the nonemissive [Re(CO)3]+ species to a developer solution that enables the rapid, quantitative conversion of the nonemissive species to a luminescent species which can then be detected spectroscopically. The [Re(CO)3]+ species concentration in an alkaline, simulated Hanford tank waste supernatant can be quantified by the standard addition method. In a test case, the [Re(CO)3]+ species was measured to be at a concentration of 38.9 μM, which was a difference of 2.01% from the actual concentration of 39.7 μM.
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Affiliation(s)
- Shirmir D Branch
- Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221-0172, United States
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Amanda D French
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Amanda M Lines
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Brian M Rapko
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - William R Heineman
- Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221-0172, United States
| | - Samuel A Bryan
- Pacific Northwest National Laboratory , Richland, Washington 99352, United States
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16
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Cano AM, Maul JD, Saed M, Irin F, Shah SA, Green MJ, French AD, Klein DM, Crago J, Cañas-Carrell JE. Trophic Transfer and Accumulation of Multiwalled Carbon Nanotubes in the Presence of Copper Ions in Daphnia magna and Fathead Minnow (Pimephales promelas). Environ Sci Technol 2018; 52:794-800. [PMID: 29261302 DOI: 10.1021/acs.est.7b03522] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The increase in use of nanomaterials such as multiwalled carbon nanotubes (MWCNTs) presents a need to study their interactions with the environment. Trophic transfer was measured between Daphnia magna and Pimephales promelas (fathead minnow, FHM) exposed to MWCNTs with different outer diameter (OD) sizes (MWCNT1 = 8-15 nm OD and MWCNT2 = 20-30 nm OD) in the presence and absence of copper. Pristine FHM were fed D. magna, previously exposed for 3 d to MWCNT1 or MWCNT2 (0.1 mg/L) and copper (0.01 mg/L), for 7 d. D. magna bioaccumulated less MWCNT1 (0.02 μg/g) than MWCNT2 (0.06 μg/g), whereas FHM accumulated more MWCNT1 (0.81 μg/g) than MWCNT2 (0.04 μg/g). In the presence of copper, MWCNT bioaccumulation showed an opposite trend. Mostly MWCNT1 (0.03 μg/g) bioaccumulated in D. magna, however less MWCNT1 (0.21 μg/g) than MWCNT2 (0.32 μg/g) bioaccumulated in FHM. Bioaccumulation factors were higher for MWCNT1s than MWCNT2. However, an opposite trend was observed when copper was added. Plasma metallothionein-2 was measured among treatments; however concentrations were not statistically different from the control. This study demonstrates that trophic transfer of MWCNTs is possible in the aquatic environment and further exploration with mixtures can strengthen the understanding of MWCNT environmental behavior.
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Affiliation(s)
- Amanda M Cano
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States
| | - Jonathan D Maul
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States
| | - Mohammad Saed
- Department of Electrical and Computer Engineering, Texas Tech University , Lubbock, Texas United States
| | - Fahmida Irin
- Department of Chemical Engineering, Texas Tech University , Lubbock, Texas United States
| | - Smit A Shah
- Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas United States
| | - Micah J Green
- Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas United States
| | - Amanda D French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States
| | - David M Klein
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States
| | - Jordan Crago
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States
| | - Jaclyn E Cañas-Carrell
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States
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French AD, Conway WC, Cañas-Carrell JE, Klein DM. Exposure, Effects and Absorption of Lead in American Woodcock (Scolopax minor): A Review. Bull Environ Contam Toxicol 2017; 99:287-296. [PMID: 28710526 DOI: 10.1007/s00128-017-2137-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
Due to long term declines of American Woodcock (Scolopax minor) and widespread distribution of environmentally available lead (Pb) throughout their geographic range, it is important to assess if Pb exposure is a potential contributor to these declines. Woodcock are exposed to Pb through various environmental sources and are known to exhibit relatively high bone-Pb concentrations. Absorption of Pb by birds, and woodcock specifically, is not well understood. Some studies show that interactions among calcium, phosphorus, iron, zinc, and vitamin D levels may play an important role in Pb absorption. Therefore, when future Pb studies are performed for woodcock, and other birds, interactions among these elements should be considered. For example, these interactions are relevant in the acquisition and mobilization of calcium in female birds during egg development and shell calcification. These factors should be considered to understand potential mechanisms of Pb exposure, Pb absorption, and subsequent Pb toxicity to birds in general, and woodcock specifically. This review discusses Pb exposure routes, effects of Pb toxicity, and the distribution of Pb in American woodcock and identifies areas for future research in woodcock and other avian species.
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Affiliation(s)
- Amanda D French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, 79416, USA
| | - Warren C Conway
- Department of Natural Resources Management, Texas Tech University, Lubbock, TX, 79409, USA
| | - Jaclyn E Cañas-Carrell
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, 79416, USA
| | - David M Klein
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, 79416, USA.
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18
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Reátegui-Zirena EG, French AD, Klein DM, Salice CJ. Cadmium Compartmentalization in the Pulmonate Snail Lymnaea stagnalis: Improving Our Understanding of Exposure. Arch Environ Contam Toxicol 2017; 72:575-585. [PMID: 28470349 DOI: 10.1007/s00244-017-0407-8] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/21/2017] [Indexed: 06/07/2023]
Abstract
In ecotoxicology, analytical compartmentalization analysis can be used to better understand metal sequestration and detoxification. Metals are typically found in two main compartments, biologically detoxified metal (BDM) and metal sensitive fractions (MSF). The purpose of this study was to analyze the subcellular distribution of cadmium (Cd) in Lymnaea stagnalis. Adult snails were exposed to three concentrations of Cd for 56 days as part of a global ring test for L. stagnalis. At the end of the 56-day exposure, organisms were separated in two sections (viscera and foot). Each section was subsequently divided by differential centrifugation into five total fractions including (metal rich granules, debris, Organelles, heat denatured proteins, and heat stable proteins) followed by Cd analysis. The concentration in each compartment, BDM, MSF, and bioconcentration factors were estimated as well. There was significantly higher bioconcentration of Cd in the viscera section compared with the foot. Cadmium accumulation in all five fractions also increased with increasing exposure concentrations. Cadmium accumulated the most in the heat denatured protein fraction (enzymes) and accumulated the least in the heat stable protein fraction (metallothionein-like proteins). The MSF compartment (~65%) was in higher proportion than the BDM (~30%), but only in the lowest Cd exposure concentration was there a significant difference between these compartments. The results indicated that, in general, there was more Cd accumulated in the metal sensitive fractions, and that the detoxification mechanisms were not efficient enough to avoid toxicity at the two highest concentrations. This study provides evidence that improves our understanding of Cd tissue distribution in freshwater gastropods.
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Affiliation(s)
- Evelyn G Reátegui-Zirena
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, Lubbock, TX, USA.
| | - Amanda D French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, Lubbock, TX, USA
| | - David M Klein
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, Lubbock, TX, USA
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19
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Hettick BE, Cañas-Carrell JE, Martin K, French AD, Klein DM. Arsenic Uptake by Muskmelon (Cucumis melo) Plants from Contaminated Water. Bull Environ Contam Toxicol 2016; 97:395-400. [PMID: 27460822 DOI: 10.1007/s00128-016-1893-5] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 07/16/2016] [Indexed: 06/06/2023]
Abstract
Arsenic is a carcinogenic element that occurs naturally in the environment. High levels of arsenic are found in water in some parts of the world, including Texas. The aims of this study were to determine the distribution of arsenic in muskmelon (Cucumis melo) plants accumulated from arsenic spiked water and to observe effects on plant biomass. Plants were grown and irrigated using water spiked with variable concentrations of arsenic. Inductively coupled plasma mass spectrometry was used to quantify arsenic in different parts of the plant and fruit. Under all conditions tested in this study, the highest concentrations of arsenic were found in the leaves, soil, and roots. Arsenic in the water had no significant effect on plant biomass. Fruits analyzed in this study had arsenic concentrations of 101 μg/kg or less. Consuming these fruits would result in less arsenic exposure than drinking water at recommended levels.
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Affiliation(s)
- Bryan E Hettick
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, PO Box 41163, Lubbock, TX, 79409-1163, USA
| | - Jaclyn E Cañas-Carrell
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, PO Box 41163, Lubbock, TX, 79409-1163, USA
| | - Kirt Martin
- Department of Natural Sciences, Lubbock Christian University, 5601 19th Street, Lubbock, TX, 79407, USA
| | - Amanda D French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, PO Box 41163, Lubbock, TX, 79409-1163, USA
| | - David M Klein
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, PO Box 41163, Lubbock, TX, 79409-1163, USA.
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20
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Hettick BE, Cañas-Carrell JE, French AD, Klein DM. Arsenic: A Review of the Element's Toxicity, Plant Interactions, and Potential Methods of Remediation. J Agric Food Chem 2015; 63:7097-107. [PMID: 26241522 DOI: 10.1021/acs.jafc.5b02487] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Arsenic is a naturally occurring element with a long history of toxicity. Sites of contamination are found worldwide as a result of both natural processes and anthropogenic activities. The broad scope of arsenic toxicity to humans and its unique interaction with the environment have led to extensive research into its physicochemical properties and toxic behavior in biological systems. The purpose of this review is to compile the results of recent studies concerning the metalloid and consider the chemical and physical properties of arsenic in the broad context of human toxicity and phytoremediation. Areas of focus include arsenic's mechanisms of human toxicity, interaction with plant systems, potential methods of remediation, and protocols for the determination of metals in experimentation. This assessment of the literature indicates that controlling contamination of water sources and plants through effective remediation and management is essential to successfully addressing the problems of arsenic toxicity and contamination.
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Affiliation(s)
- Bryan E Hettick
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, 1207 Gilbert Drive, Box 41163, Lubbock, Texas 79409-1163, United States
| | - Jaclyn E Cañas-Carrell
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, 1207 Gilbert Drive, Box 41163, Lubbock, Texas 79409-1163, United States
| | - Amanda D French
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, 1207 Gilbert Drive, Box 41163, Lubbock, Texas 79409-1163, United States
| | - David M Klein
- Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, 1207 Gilbert Drive, Box 41163, Lubbock, Texas 79409-1163, United States
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21
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Weimer PJ, Hackney JM, French AD. Effects of chemical treatments and heating on the crystallinity of celluloses and their implications for evaluating the effect of crystallinity on cellulose biodegradation. Biotechnol Bioeng 2012; 48:169-78. [PMID: 18623473 DOI: 10.1002/bit.260480211] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Chemical treatments similar to those routinely used to extract cellulose from plant biomass caused significant increases in the relative crystallinity index (RCI) of Sig-macell 100 (a commercial cellulose of moderate crystallinity), as measured by x-ray powder diffraction in both the reflectance and transmittance modes. In general, the largest increases in RCI were observed following higher (rather than lower) temperature treatments. Substantial increases in crystalliity were also observed upon resuspension in water prior to drying, with higher temperatures again resulting in the greatest increases in RCI. Measurement of the RCIs of wetted Sigmacell 100 samples by acid hydrolysis kinetics revealed that most of the increased crystallinity occurred rapidly upon contact with water. In contrast to Sigmacell 100, a cellulose of higher initial crystallinity (the microcrystalline cellulose Sigmacell 50) showed little change in crystallinity following the above treatments. The results provide a partial explanation for the inconsistent relationships reported between cellulose crystallinity and cellulose biodegradation. (c) 1995 John Wiley & Sons, Inc.
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Affiliation(s)
- P J Weimer
- Agricultural Research Service, United States, Department of Agriculture, U.S. Dairy Forago Research Center, Madison, Wisconsin
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22
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O'Connell MP, Fiori JL, Xu M, Carter AD, Frank BP, Camilli TC, French AD, Dissanayake SK, Indig FE, Bernier M, Taub DD, Hewitt SM, Weeraratna AT. The orphan tyrosine kinase receptor, ROR2, mediates Wnt5A signaling in metastatic melanoma. Oncogene 2009; 29:34-44. [PMID: 19802008 PMCID: PMC2803338 DOI: 10.1038/onc.2009.305] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tyrosine kinase receptors represent targets of great interest for cancer therapy. Here we demonstrate, for the first time, the importance of the orphan tyrosine kinase receptor, ROR2, in melanoma progression. Using melanoma tissue microarrays we show that ROR2 is expressed predominantly in metastatic melanoma. Because ROR2 has been shown to specifically interact with the non-canonical Wnt ligand, Wnt5A, this corroborates our previous data implicating Wnt5A as a mediator of melanoma metastasis. We show here that increases in Wnt5A cause increases in ROR2 expression, as well as the PKC-dependent, clathrin-mediated internalization of ROR2. WNT5A knockdown by siRNA decreases ROR2 expression, but silencing of ROR2 has no effect on WNT5A levels. ROR2 knockdown does, however, result in a decrease in signaling downstream of Wnt5A. Using in vitro and in vivo metastasis assays we demonstrate that ROR2 is necessary for the Wnt5A-mediated metastasis of melanoma cells. These data imply that ROR2 may represent a novel target for melanoma therapy.
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Affiliation(s)
- M P O'Connell
- Laboratory of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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Abstract
Wnt5A has been implicated in melanoma metastasis, and the progression of other cancers including pancreatic, gastric, prostate, and lung cancers. Assays to test motility and invasion include both in vivo assays and in vitro assays. The in vivo assays include the use of tail vein or footpad injections of metastatic cells, and are often laborious and expensive. In vitro invasion assays provide quick readouts that can help to establish conditions that either activate or inhibit melanoma cell motility, and to assess whether the conditions in question are worth translating into an in vivo model. Here we describe two standard methods for assaying motility and invasion in vitro including wound healing assays and Matrigel invasion assays (Boyden chamber assays). In addition, we and several other laboratories have previously shown that melanoma cells require matrix metalloproteinase (MMP)-2 for their invasion, and have recently shown that Wnt5A treatment can increase the levels of this enzyme in melanoma cells, as demonstrated by gelatin zymography. The use of these techniques can help to assess the migratory capacity of melanoma cells in response to Wnt treatment.
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Affiliation(s)
- Michael P O'Connell
- Laboratory of Immunology, National Institutes of Health, National Institute on Aging, Gerontology Research Center, Baltimore, MD, USA
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24
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Dissanayake SK, Olkhanud PB, O'Connell MP, Carter A, French AD, Camilli TC, Emeche CD, Hewitt KJ, Rosenthal DT, Leotlela PD, Wade MS, Yang SW, Brant L, Nickoloff BJ, Messina JL, Biragyn A, Hoek KS, Taub DD, Longo DL, Sondak VK, Hewitt SM, Weeraratna AT. Wnt5A regulates expression of tumor-associated antigens in melanoma via changes in signal transducers and activators of transcription 3 phosphorylation. Cancer Res 2009; 68:10205-14. [PMID: 19074888 DOI: 10.1158/0008-5472.can-08-2149] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [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] [Indexed: 11/16/2022]
Abstract
There are currently no effective therapies for metastatic melanoma and targeted immunotherapy results in the remission of only a very small percentage of tumors. In this study, we show that the noncanonical Wnt ligand, Wnt5A, can increase melanoma metastasis in vivo while down-regulating the expression of tumor-associated antigens important in eliciting CTL responses (e.g., MART-1, GP100, and tyrosinase). Melanosomal antigen expression is governed by MITF, PAX3, and SOX10 and is inhibited upon signal transducers and activators of transcription 3 (STAT3) activation, via decreases in PAX3 and subsequently MITF expression. Increasing Wnt5A in Wnt5A-low cells activated STAT3, and STAT3 was decreased upon Wnt5A knockdown. Downstream targets such as PAX3, MITF, and MART-1 were also affected by Wnt5A treatment or knockdown. Staining of a melanoma tissue array also highlighted the inverse relationship between MART-1 and Wnt5A expression. PKC activation by phorbol ester mimicked Wnt5A effects, and Wnt5A treatment in the presence of STAT3 or PKC inhibitors did not lower MART-1 levels. CTL activation studies showed that increases in Wnt5A correspond to decreased CTL activation and vice versa, suggesting that targeting Wnt5A before immunotherapy may lead to the enhancement of current targeted immunotherapy for patients with metastatic melanoma.
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MESH Headings
- Animals
- Antigens, Neoplasm/biosynthesis
- Antigens, Neoplasm/genetics
- Humans
- Lymphocyte Activation
- MART-1 Antigen
- Melanoma/genetics
- Melanoma/immunology
- Melanoma/metabolism
- Melanoma/pathology
- Melanoma, Experimental/genetics
- Melanoma, Experimental/immunology
- Melanoma, Experimental/metabolism
- Melanoma, Experimental/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Neoplasm Metastasis
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Phosphorylation
- RNA, Small Interfering/genetics
- STAT3 Transcription Factor/metabolism
- T-Lymphocytes/immunology
- Transcription, Genetic
- Transfection
- Wnt Proteins/biosynthesis
- Wnt Proteins/genetics
- Wnt Proteins/metabolism
- Wnt-5a Protein
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Affiliation(s)
- Samudra K Dissanayake
- Laboratory of Immunology and the Research Resources Branch, Gerontology Research Center, National Institute on Aging, NIH, Baltimore, Maryland 21224, USA
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French AD, Fiori JL, Camilli TC, Leotlela PD, O'Connell MP, Frank BP, Subaran S, Indig FE, Taub DD, Weeraratna AT. PKC and PKA phosphorylation affect the subcellular localization of claudin-1 in melanoma cells. Int J Med Sci 2009; 6:93-101. [PMID: 19305641 PMCID: PMC2658888 DOI: 10.7150/ijms.6.93] [Citation(s) in RCA: 85] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 03/12/2009] [Indexed: 12/13/2022] Open
Abstract
Cytoplasmic expression of claudin-1 in metastatic melanoma cells correlates to increased migration, and increased secretion of MMP-2 in a PKC dependent manner, whereas claudin-1 nuclear expression is found in benign nevi. Melanoma cells were transfected with a vector expressing CLDN-1 fused to a nuclear localization signal (NLS). Despite significant nuclear localization of claudin-1, there was still transport of claudin-1 to the cytoplasm. Phorbol ester treatment of cells transfected with NLS-claudin-1 resulted in an exclusion of claudin-1 from the nucleus, despite the NLS. To ascertain whether PKC or PKA were involved in this translocation, we mutated the putative phosphorylation sites within the protein. We found that mutating the PKC phosphorylation sites to mimic a non-phosphorylated state did not cause a shift of claudin-1 to the nucleus of the cells, but mutating the PKA sites did. Mutations of either site to mimic constitutive phosphorylation resulted in cytoplasmic claudin-1 expression. Stable claudin-1 transfectants containing non-phosphorylatable PKA sites exhibited decreased motility. These data imply that subcellular localization of claudin-1 can be controlled by phosphorylation, dicating effects on metastatic capacity.
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Affiliation(s)
- Amanda D French
- Laboratory of Immunology, National Institute on Aging, Baltimore, MD 21124, USA
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26
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Ghosh MC, Collins GD, Carter A, Vandanmagsar B, Brill M, Lustig A, Becker KG, Wood WW, Emeche CD, French AD, O'Connell MP, Dissanayake SK, Weeraratne AT, Taub DD. CXCL12 mediates T‐cell migration via activation of the non‐canonical Wnt signaling pathway. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.1070.16] [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: 11/11/2022]
Affiliation(s)
- Manik C. Ghosh
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | - Gary D Collins
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | - Arnell Carter
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | | | - Margaret Brill
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | - Ana Lustig
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | - Kevin G Becker
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | - William W Wood
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | | | - Amanda D French
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
| | | | | | | | - Dennis D Taub
- Laboratory of ImmunologyNational Institute of AgingBaltimoreMD
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27
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Dissanayake SK, Wade M, Johnson CE, O’Connell MP, Leotlela PD, French AD, Shah KV, Hewitt KJ, Rosenthal DT, Indig FE, Jiang Y, Nickoloff BJ, Taub DD, Trent JM, Moon RT, Bittner M, Weeraratna AT. The Wnt5A/protein kinase C pathway mediates motility in melanoma cells via the inhibition of metastasis suppressors and initiation of an epithelial to mesenchymal transition. J Biol Chem 2007; 282:17259-71. [PMID: 17426020 PMCID: PMC2263117 DOI: 10.1074/jbc.m700075200] [Citation(s) in RCA: 274] [Impact Index Per Article: 16.1] [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] [Indexed: 12/11/2022] Open
Abstract
We have shown that Wnt5A increases the motility of melanoma cells. To explore cellular pathways involving Wnt5A, we compared gain-of-function (WNT5A stable transfectants) versus loss-of-function (siRNA knockdown) of WNT5A by microarray analysis. Increasing WNT5A suppressed the expression of several genes, which were re-expressed after small interference RNA-mediated knockdown of WNT5A. Genes affected by WNT5A include KISS-1, a metastasis suppressor, and CD44, involved in tumor cell homing during metastasis. This could be validated at the protein level using both small interference RNA and recombinant Wnt5A (rWnt5A). Among the genes up-regulated by WNT5A was the gene vimentin, associated with an epithelial to mesenchymal transition (EMT), which involves decreases in E-cadherin, due to up-regulation of the transcriptional repressor, Snail. rWnt5A treatment increases Snail and vimentin expression, and decreases E-cadherin, even in the presence of dominant-negativeTCF4, suggesting that this activation is independent of Wnt/beta-catenin signaling. Because Wnt5A can signal via protein kinase C (PKC), the role of PKC in Wnt5A-mediated motility and EMT was also assessed using PKC inhibition and activation studies. Treating cells expressing low levels of Wnt5A with phorbol ester increased Snail expression inhibiting PKC in cells expressing high levels of Wnt5A decreased Snail. Furthermore, inhibition of PKC before Wnt5A treatment blocked Snail expression, implying that Wnt5A can potentiate melanoma metastasis via the induction of EMT in a PKC-dependent manner.
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Affiliation(s)
- Samudra K. Dissanayake
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Michael Wade
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | | | - Michael P. O’Connell
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Poloko D. Leotlela
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Amanda D. French
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Kavita V. Shah
- Department of Pharmacology, Howard Hughes Medical Institute, and Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, Washington 98195
| | - Kyle J. Hewitt
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Devin T. Rosenthal
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Fred E. Indig
- Research Resources Branch, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Yuan Jiang
- Cancer Genetics Branch, NHGRI, NIH, Bethesda, Maryland 20892
| | - Brian J. Nickoloff
- Department of Pathology, Loyola University Medical Center, Maywood, Illinois 60153
| | - Dennis D. Taub
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
| | - Jeffrey M. Trent
- The Translational Genomics Research Institute, Phoenix, Arizona 85004
| | - Randall T. Moon
- Department of Pharmacology, Howard Hughes Medical Institute, and Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, Washington 98195
| | - Michael Bittner
- The Translational Genomics Research Institute, Phoenix, Arizona 85004
| | - Ashani T. Weeraratna
- Laboratory of Immunology, Gerontology Research Center, NIA, National Institutes of Health (NIH), Baltimore, Maryland 21224
- To whom correspondence should be addressed: Laboratory of Immunology, NIA, NIH, 5600 Nathan Shock Dr., Baltimore, MD 21224. Tel.: 410-558-8506; Fax: 410-558-8284; E-mail:
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French AD. George Alan Jeffrey. Adv Carbohydr Chem Biochem 2002; 57:1-9. [PMID: 11836940 DOI: 10.1016/s0065-2318(01)57013-4] [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: 10/26/2022]
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Abstract
Extensive variations of the ring structures of three deoxyaldohexopyranoses, L-fucose, D-quinovose, and L-rhamnose, and four dideoxyaldohexopyranoses, D-digitoxose, abequose, paratose, and tyvelose, were studied by energy minimization with the molecular mechanics algorithm MM3(92). Chair conformers, 4C(1) in D-quinovose and the equivalent 1C(4) in L-fucose and L-rhamnose, overwhelmingly dominate in the three deoxyhexoses; in the D-dideoxyhexoses, 4C(1) is again dominant, but with increased amounts of 1C(4) forms in the alpha anomers of the three 3,6-dideoxyhexoses, abequose, paratose, and tyvelose and in both alpha and beta anomers of the 2,6-dideoxyhexose D-digitoxose. In general, modeled proton-proton coupling constants agreed well with experimental values. Computed anomeric ratios strongly favor the beta configuration except for D-digitoxose, which is almost equally divided between alpha and beta configurations, and L-rhamnose, where the beta configuration is somewhat favored. MM3(92) appears to overstate the prevalence of the equatorial beta anomer in all three deoxyhexoses, as earlier found with fully oxygenated aldohexopyranoses.
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Affiliation(s)
- W M Rockey
- Department of Chemical Engineering, Iowa State University, Ames, IA 50011, USA
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30
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Abstract
Both ab initio quantum mechanics (QM) and molecular mechanics (MM) were used to produce a hybrid energy surface for sucrose that simultaneously provides low energies for conformations that are observed in crystal structures and high energies for most unobserved structures. HF/6-31G* QM energies were calculated for an analogue based on tetrahydropyran (THP) and tetrahydrofuran (THF). Remaining contributions to the potential energy of sucrose were calculated with MM. To do this, the MM surface for the analogue was subtracted from the MM surface for the disaccharide, and the QM surface for the analogue was added. Prediction of the distribution of observable geometries was enhanced by reducing the strength of the hydrogen bonding. Reduced hydrogen-bonding strength is probably useful because many crystalline sucrose moieties do not have intramolecular hydrogen bonds between the fructose and glucose residues. Therefore, hydrogen bonding does not play a large role in determining the molecular conformation. On the hybrid energy surface that was constructed with a dielectric constant of 3.5, the average potential energy of 23 sucrose moieties from crystal structures is 1.16 kcal/mol, and the population of observed structures drops off exponentially as the energy increases.
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Affiliation(s)
- A D French
- Southern Regional Research Center, Agricultural Research Service, US Department of Agriculture, New Orleans, LA 70179-0687, USA.
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31
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Abstract
This paper focuses on the methods used to construct Ramachandran plots for disaccharides. Our recent work based on a hybrid of molecular mechanics and quantum mechanics energies pointed to the need to take extra care when making these maps. Care is also important in the quantitative validation of these energy surfaces with linkage conformations that were determined by crystallography. To successfully predict conformations that have been observed experimentally, the calculation of the energy should include stereoelectronic effects and correctly weight the hydrogen bonding. Technical concerns include the method used to scan the range of conformations, starting geometries, and finding the zero of relative potential energy on a surface where the values were collected at regular intervals. The distributions of observed conformations on energy maps of sucrose, maltose, and laminarabiose at dielectric constants of 1.5 and 7.5 illustrate the effects of an elevated dielectric constant for the MM3 component of the hybrid energy calculations. At dielectric constants of 3.5 and 7.5, the overall average energies of observed conformations of sucrose and seven disaccharides of glucose were less than 1.0 kcal mol-1. The distribution of corresponding energies of the various crystalline conformations conformed well to a Boltzmann-like equation.
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Affiliation(s)
- A D French
- Southern Regional Research Center, U.S. Department of Agriculture, New Orleans, Louisiana, USA.
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32
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Hillman L, French AD, Treasure E. Changing trends in South Wales fluoride prescription dispensing (1993-7). Community Dent Health 1999; 16:145-8. [PMID: 10641072] [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: 02/15/2023]
Abstract
OBJECTIVE To observe patterns of fluoride preparation dispensing by primary care practitioners in a health authority. DESIGN Observational study. SETTING The Prescription Pricing Agency of the Welsh Health Common Services Authority (WHCSA). SUBJECTS Individuals who had exchanged a prescription for a fluoride preparation at a pharmacy in Bro Taf Health Authority in the six months from 1 January 1997 to 30 June 1997. METHOD Information from each prescription including a fluoride preparation, passed to WHCSA from pharmacists during the study, was entered onto a database, including the prescriber's postcode and profession, the recipient's postcode and product information. Numbers of dental prescriptions were correlated to local levels of NHS primary dental care provision and caries prevalence data. Comparisons were made with a similar study undertaken in 1993. RESULTS 415 dentists' prescriptions were dispensed within the area, of which 38.8% originated from five dentists. At least one prescription had been made by 89 of the 253 local primary dental care providers (35%). Within the area monitored in both 1993 and 1997, dental prescribing rates had almost halved. Of the 122 doctors' prescriptions that were dispensed over the six-month period, 98 were mouthwash preparations for adult patients and four were for children. CONCLUSION NHS provision of fluoride supplementation was low and remained related to prescribing patterns of individuals rather than to evidence on local variations in dental caries prevalence.
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33
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Abstract
The molecular mechanics method MM3(92) was used to study the puckering of the nine inositol isomers. Energy surfaces were generated based on the Cremer-Pople puckering definitions and the geometric plate carree representations of Pickett and Strauss. Chair forms are favoured for all the inositol isomers in agreement with experiment. The lowest energy non-chair form, more than 10 kJ/mol in free energy above the chair, is a skew of muco-inositol , in which all the hydroxyls are oriented either equatorially or pseudo-equatorially. Hydrogen-hydrogen coupling constants are in good agreement with experiment. The predicted order of stability for the isomers is scyllo - > myo - > chiro - > neo- > � epi -> muco - ≈ allo -> cis-inositol. This order generally agrees with Angyal's proposed stability order based on the number and type of gauche and 1,3-diaxial ring substituents. In contrast with recent ab initio calculations and values calculated with Angyal's method, the MM3 � gas-phase free energy of scyllo-inositol was lower than that of myo-inositol by 5.5 kJ/mol. The calculated transition energy for the chair-to-chair conversion of cis-inositol differs by 12.5-17.2 kJ/mol from the experimental value, depending on the strength of the electrostatic field.
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34
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Allison PJ, French AD, Kay EJ. A study of the dietary fluoride supplementation prescribing pattern of south Glamorgan dentists. Community Dent Health 1994; 11:202-7. [PMID: 7850638] [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: 01/27/2023]
Abstract
Following the inclusion of dietary fluoride supplements in the Dental Practitioners Formulary on 1st January 1993, the aims of this study were to observe the fluoride supplementation prescribing pattern of South Glamorgan general dental practitioners and relate it to the latest caries prevalence data. The analysis was carried out on the prescribers and recipients of the prescriptions using post codes to locate all members of both groups into one of 26 dental planning areas (DPA) within the district. As the age of a minority of recipients could not be substantiated, an assumption that they were all 14 years or under was used to calculate a prescription to population ratio for each DPA. These ratios were correlated against the latest available caries prevalence data for each DPA to ascertain any relationship between the level of fluoride supplement prescription and the caries prevalence within South Glamorgan. Data were collected via the Prescription Pricing Division of Welsh Health Common Services Authority for the six month period, 1st January to 30th June 1993. Of 623 prescriptions dispensed within South Glamorgan, 581 were issued by dentists working in the District for patients living in the District. Of the 163 dentists registered within South Glamorgan FHSA, (boundary coterminous with the DHA) 49 made one or more prescription. Of these, 10 dentists wrote 20 prescriptions or more, totalling 401, during the study period, i.e. 6 per cent of the dentists made 69 per cent of the prescriptions. The correlation of the number of prescriptions issued per DPA (according to the dentists' location) with whole time equivalents in that DPA was 0.58 (P < 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P J Allison
- Department of Dental Public Health, South Glamorgan District Health Authority, Cardiff, UK
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35
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Abstract
Isoenergy surfaces were calculated for the alpha- and beta-anomers of isomaltose and gentiobiose, based on 46,656 conformers for each disaccharide. Low-energy regions exist for each of the three staggered positions about the C-5'-C-6' bonds, and known crystal structures lie in two of these regions. As expected, the molecular partition function showed greater flexibility for these three-bond-linked disaccharides than for comparable two-bond-linked structures. A model miniature crystal of gentiobiose accounts for most of the remaining structural differences between the modeled isolated molecule and the crystal structure. Based on models of isolated molecules of isomaltose and gentiobiose, the predicted Boltzmann-weighted nmr coupling constants were satisfactory, as were predicted optical rotations for gentiobiose.
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Affiliation(s)
- M K Dowd
- Department of Chemical Engineering, Iowa State University, Ames 50011
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36
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French AD. Let me through! I'm a helicopter. Nurs Stand 1994; 8:40. [PMID: 27669802 DOI: 10.7748/ns.8.27.40.s51] [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: 06/06/2023]
Abstract
I enjoyed Pat Goodwin's article about the helicopter emergency medical services in London (Flying to the rescue, Features, March 16). But in a spirit of inquiry and not criticism, would she tell me why, in the case she described of a man who had fallen down basement steps where 'a paramedic team was present', the HEMS team had to clear an airway, intubate and set up an infusion. Surely the paramedic team should have already done all that as a bare minimum?
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37
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Abstract
Nystose, O-beta-D-fructofuranosyl-(2-->1)-O-beta-D-fructofuranosyl-(2-->1)- beta-D-fructofuranosyl alpha-D-glucopyranoside, was modeled with the rigid-residue program PFOS and with MM3. The three furanose rings of crystalline nystose trihydrate all are within the 1 kcal.mol-1 contour on an MM3 energy surface that was calculated with a dielectric constant of 4. The calculations showed that in the extended conformation found in the crystal, there was a small influence of the remainder of the residues on the conformation of any given disaccharide segment. Even accounting for intramolecular, interresidue forces, however, the central inulobiose and the sucrose linkages appear to be distorted. These discrepancies are apparently due to crystal packing forces and, for the sucrose linkage, miscalculation of the energy of an overlapping exoanomeric effect, as indicated by studies of a model miniature crystal. The different conformations of the central and terminal inulobiose linkages in the crystal show that conformations in higher oligosaccharides will not always correspond to the global minima on conformational maps for isolated disaccharides.
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Affiliation(s)
- A D French
- Southern Regional Research Center, New Orleans, Louisiana 70179
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Abstract
Previous calculations with the molecular mechanics program MM3 gave unusually high energies (as much as 5.5 kcal/mol) for sucrosyl geometries found in single-crystal diffraction studies of oligosaccharides. Comparable MM3 energies for observed interresidue linkage conformations of disaccharides such as maltose and cellobiose are all within 2.8 kcal/mol. These results suggest that some energies calculated by MM3 for the linkage between anomeric centers of a pyranose ring and a furanose ring are too high. In the present paper, ab initio calculations at the 4-21G level and MM3 were used to study the conformational energies and geometry of a sucrose analogue, tetrahydro-2-[(tetrahydro-2-furanyl)oxy]-2H-pyran. The range of energies of the observed structures was substantially reduced (to 2.4 kcal/mol) with the 4-21G calculations for the analogue despite an increase for the analogue (to 7.5 kcal/mol) based on new MM3 calculations. Besides the improved energy values, the 4-21G calculations also reproduced the observed variations in the endocyclic C-O bond lengths better than did MM3.
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Affiliation(s)
- A D French
- Southern Regional Research Center, U.S. Department of Agriculture, New Orleans, Louisiana 70179
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39
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Abstract
Miniature crystal models of cellulose and other carbohydrates were evaluated with the molecular mechanics program MM3. The models consisted of groups of 24 to 32 monosaccharide residues, with the models of mono- and disaccharides based on well-established, single-crystal work. Structures of the cellulose forms and cellotetraose were based on published work using fibre diffraction methods. A structure for the single-chain I alpha cellulose unit cell was also tested. A dielectric constant of about 4 was best for this type of work. Calculated intra- and intermolecular energy for glucose agreed with literature values for the heat of combustion. Cellulose II had the lowest calculated energy for a cellulose form, followed by I alpha, cellulose III(I), ramie I, IV(II) and IV(I). Optimization of cellulose IV caused larger mean atomic movements from the original crystallographic positions than the other cellulose forms, and cellotetraose had larger movements than any of the other structures. Lattice energies for the cellulose forms were about 20 kcal/mol of glucose residues, with a dominant van der Waals component.
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Affiliation(s)
- A D French
- Southern Regional Research Center, New Orleans, Lousiana 70179
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40
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Abstract
Relaxed-residue energy maps based on the MM3 force-field were computed for relative orientations of the pyranosyl rings of sophorose, laminarabiose, and cellobiose, respectively the (1----2)-beta-; (1----3)-beta-; and (1----4)-beta-linked D-glucosyl disaccharides. Sixteen starting conformations of the rotatable exocyclic side-groups were considered for each molecule. All of the energy surfaces have two intersecting low-energy troughs and illustrate the importance of exo-anomeric effects in determining disaccharide conformation. Local minima were found by relaxed minimization without restriction. The energy surfaces of these disaccharides are very similar to the energy surfaces of their corresponding 6-methyltetrahydropyran analogues. There is good agreement between disaccharide structures having minimal MM3 energy and those found by crystallography.
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Affiliation(s)
- M K Dowd
- Department of Chemical Engineering, Iowa State University, Ames 50011
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41
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French AD. Presidential address to the British Association for the Study of Community Dentistry, Cardiff, March 1992. Community Dent Health 1992; 9:307-9. [PMID: 1451004] [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: 12/27/2022]
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Abstract
Energy surfaces were computed for relative orientations of the relaxed pyranosyl rings of the two anomeric forms of kojibiose, nigerose, and maltose, the (1----2)-alpha, (1----3)-alpha, and (1----4)-alpha-linked D-glucosyl disaccharides, respectively. Twenty-four combinations of starting conformations of the rotatable side-groups were considered for each disaccharide. Optimized structures were calculated using MM3 on a 20 degree grid spacing of the torsional angles about the glycosidic bonds. The energy surfaces of the six disaccharides were similar in many respects but differed in detail within the low-energy regions. The maps also illustrate the importance of the exo-anomeric effect and linkage type in determining the conformational flexibility of disaccharides. Torsional conformations of known crystal structures of maltosyl-containing molecules lie in a lower MM3 energy range than previously reported.
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Affiliation(s)
- M K Dowd
- Department of Chemical Engineering, Iowa State University, Ames 50011
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Abstract
In addition to its usual native crystalline form (cellulose I), cellulose can exist in a variety of alternative crystalline forms (allomorphs) which differ in their unit cell dimensions, chain packing schemes, and hydrogen bonding relationships. We prepared, by various chemical treatments, four different alternative allomorphs, along with an amorphous (noncrystalline) cellulose which retained its original molecular weight. We then examined the kinetics of degradation of these materials by two species of ruminal bacteria and by inocula from two bovine rumens.
Ruminococcus flavefaciens
FD-1 and
Fibrobacter succinogenes
S85 were similar to one another in their relative rates of digestion of the different celluloses, which proceeded in the following order: amorphous > III
I
> IV
I
> III
II
> I > II. Unlike
F. succinogenes, R. flavefaciens
did not degrade cellulose II, even after an incubation of 3 weeks. Comparisons of the structural features of these allomorphs with their digestion kinetics suggest that degradation is enhanced by skewing of adjacent sheets in the microfibril, but is inhibited by intersheet hydrogen bonding and by antiparallelism in adjacent sheets. Mixed microflora from the bovine rumens showed in vitro digestion rates quite different from one another and from those of both of the two pure bacterial cultures, suggesting that
R. flavefaciens
and
F. succinogenes
(purportedly among the most active of the cellulolytic bacteria in the rumen) either behave differently in the ruminal ecosystem from the way they do in pure culture or did not play a major role in cellulose digestion in these ruminal samples.
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Affiliation(s)
- P J Weimer
- U.S. Dairy Forage Research Center, Agricultural Research Service, U.S. Department of Agriculture, and Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, and Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana 70179
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44
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Abstract
Models of the trisaccharide, 1-kestose [beta-D-fructofuranosyl-(2----1)-beta-D-fructofuranosyl-(2 in equilibrium with 1)-alpha-D -glucopyranoside], were analyzed with the molecular mechanics computer program MM2(87) to ascertain their inter-ring torsion angles, primary alcohol side-group orientations, and ring puckering. The most striking result was that the modeling predicted and n.m.r. spectroscopy corroborated that the central fructofuranose ring takes a different form from that previously observed in the crystal. No other studies of fructofuranoses have observed that crystallographic form, thus suggesting that the 18 hydrogen bonds created upon crystallization of 1-kestose support the ring deformation. Because this trisaccharide is too complex for a complete study of conformation space, only structures having inter-ring conformations that were at energetic valleys in previous studies of the constituent disaccharides were analyzed. The model of the model disaccharides, although they were generally close to the linkage conformations observed in the crystal structure, differing by an average of 19 degrees.
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Affiliation(s)
- A L Waterhouse
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
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45
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Abstract
An epidemiological study was carried out involving 677 children and young adults aged between 3 and 19 years who were attending special schools in South Glamorgan. The children and young adults were examined for caries and periodontal disease. Their dental attendance pattern and the dental service they used were recorded, and their mobility and posture, and comprehension and cooperation, were assessed. The results showed that the majority were receiving regular dental care and that the caries experience of 12- and 14-year-old children was lower than that of children of the same ages in other state schools. Five-year-old children were found to have a dmft of 4.18, which was significantly higher than that of similar-aged children attending state schools. Forty-seven per cent of the children and young adults were found to have periodontal disease; the greatest percentage (60%) was found in the young adults in the 15-19-year-old age group. Caries experience and gingival health were not related to the subjects' mobility and posture but caries experience was greater and gingival health was poorer in subjects who had reduced comprehension and cooperation. The study highlighted deficiencies in the service provided for this group, especially for pre-school children.
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Affiliation(s)
- D J Evans
- Department of Community Dental Health, South Glamorgan Health Authority
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46
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Abstract
Conformational energies for inulobiose [beta-D-fructofuranosyl-(2----1)-beta-D-fructofuranoside], a model for inulin, were computed with the molecular mechanics program MMP2(85). The torsion angles of the three linkage bonds were driven in 20 degree increments, and the steric energy of all other parameters was minimized. The linkage torsion angles defined by C-1'-C-2'-O-C-1 (phi) and O-C-1-C-2-O-2 (omega) have minima at +60 degrees and -60 degrees, respectively, regardless of side group orientation; accessible minima exist at other staggered conformations. The torsion angle at the central bond C-2'-O-1-C-1-C-2 (psi) was approximately 180 degrees in all the low-energy conformers. This appears to be generally true for rings linked by three bonds. The fructofuranose rings initially had low-energy 4/3T conformations (angle of pseudorotation, phi 2 = 265 degrees) that were retained except when the linkage conformations created severe inter-residue conflicts. In those cases, almost all puckerings of the furanose rings were found.
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Affiliation(s)
- T M Calub
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
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47
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Murray JJ, Gordon PH, Carmichael CL, French AD, Furness JA. Dental caries and enamel opacities in 10-year-old children in Newcastle and Northumberland. Br Dent J 1984; 156:255-8. [PMID: 6584160 DOI: 10.1038/sj.bdj.4805332] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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48
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Carmichael CL, French AD, Rugg-Gunn AJ, Furness JA. The relationship between social class and caries experience in five-year-old children in Newcastle and Northumberland after twelve years' fluoridation. Community Dent Health 1984; 1:47-54. [PMID: 6598088] [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: 01/20/2023]
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49
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French AD, Carmichael CL, Furness JA, Rugg-Gunn AJ. The relationship between social class and dental health in 5-year-old children in the north and south of England. Br Dent J 1984; 156:83-6. [PMID: 6582893 DOI: 10.1038/sj.bdj.4805282] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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50
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French AD, Carmichael CL, Rugg-Gunn AJ, Furness JA. Fluoridation and dental caries experience in 5-year-old children in Newcastle and Northumberland in 1981. Br Dent J 1984; 156:54-7. [PMID: 6582886 DOI: 10.1038/sj.bdj.4805273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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