1
|
Kim D, Ahn G, Schmehr J, Wilson SD, Moon SJ. Effects of the on-site energy on the electronic response of Sr3(Ir1−xMnx)2O7. Sci Rep 2022; 12:18957. [DOI: 10.1038/s41598-022-23593-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 11/02/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractWe investigated the doping and temperature evolutions of the optical response of Sr3(Ir1−xMnx)2O7 single crystals with 0 ≤ x ≤ 0.36 by utilizing infrared spectroscopy. Substitution of 3d transition metal Mn ions into Sr3Ir2O7 is expected to induce an insulator-to-metal transition via the decrease in the magnitude of the spin–orbit coupling and the hole doping. In sharp contrast, our data reveal the resilience of the spin–orbit coupling and the incoherent character of the charge transport. Upon Mn substitution, an incoherent in-gap excitation at about 0.25 eV appeared with the decrease in the strength of the optical transitions between the effective total angular momentum Jeff bands of the Ir ions. The resonance energies of the optical transitions between the Jeff bands which are directly proportional to the magnitude of the spin–orbit coupling hardly varied. In addition to these evolutions of the low-energy response, Mn substitution led to the emergence of a distinct high-energy optical excitation at about 1.2 eV which is larger than the resonance energies of the optical transitions between the Jeff bands. This observation indicates that the Mn 3d states are located away from the Ir 5d states in energy and that the large difference in the on-site energies of the transition metal ions is responsible for the incoherent charge transport and the robustness of the spin–orbit coupling. The effect of Mn substitution was also registered in the temperature dependence of the electronic response. The anomaly in the optical response of the parent compound observed at the antiferromagnetic transition temperature is notably suppressed in the Mn-doped compounds despite the persistence of the long-range antiferromagnetic ordering. The suppression of the spin-charge coupling could be related to charge disproportionation of the Ir ions.
Collapse
|
2
|
Sarte PM, Cruz-Kan K, Ortiz BR, Hong KH, Bordelon MM, Reig-i-Plessis D, Lee M, Choi ES, Stone MB, Calder S, Pajerowski DM, Mangin-Thro L, Qiu Y, Attfield JP, Wilson SD, Stock C, Zhou HD, Hallas AM, Paddison JAM, Aczel AA, Wiebe CR. Dynamical ground state in the XY pyrochlore Yb 2GaSbO 7. NPJ Quantum Mater 2021; 6:10.1038/s41535-021-00343-4. [PMID: 37588000 PMCID: PMC10428650 DOI: 10.1038/s41535-021-00343-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/31/2021] [Indexed: 08/18/2023]
Abstract
The magnetic ground state of the pyrochlore Yb2GaSbO7 has remained an enigma for nearly a decade. The persistent spin fluctuations observed by muon spin relaxation measurements at low temperatures have not been adequately explained for this material using existing theories for quantum magnetism. Here we report on the synthesis and characterisation of Yb2GaSbO7 to elucidate the central physics at play. Through DC and AC magnetic susceptibility, heat capacity, and neutron scattering experiments, we observe evidence for a dynamical ground state that makes Yb2GaSbO7 a promising candidate for disorder-induced spin-liquid or spin-singlet behaviour. This state is quite fragile, being tuned to a splayed ferromagnet in a modest magnetic field μ 0 H c ∼ 1.5 T .
Collapse
Affiliation(s)
- P. M. Sarte
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106-6105, USA
- Materials Department, University of California, Santa Barbara, CA 93106-5050, USA
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
| | - K. Cruz-Kan
- Department of Chemistry, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - B. R. Ortiz
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106-6105, USA
- Materials Department, University of California, Santa Barbara, CA 93106-5050, USA
| | - K. H. Hong
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
| | - M. M. Bordelon
- Materials Department, University of California, Santa Barbara, CA 93106-5050, USA
| | - D. Reig-i-Plessis
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - M. Lee
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
- National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E. S. Choi
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - M. B. Stone
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - S. Calder
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - D. M. Pajerowski
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - L. Mangin-Thro
- Institut Laue-Langevin, 71 avenue des Martyrs, 38000 Grenoble, France
| | - Y. Qiu
- NIST Center for Neutron Research, Gaithersburg, MD 20899-6102, USA
| | - J. P. Attfield
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
| | - S. D. Wilson
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106-6105, USA
- Materials Department, University of California, Santa Barbara, CA 93106-5050, USA
| | - C. Stock
- School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
| | - H. D. Zhou
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
| | - A. M. Hallas
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - J. A. M. Paddison
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, United Kingdom
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - A. A. Aczel
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
| | - C. R. Wiebe
- Department of Chemistry, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
| |
Collapse
|
3
|
Ahn G, Schmehr JL, Porter Z, Wilson SD, Moon SJ. Doping and temperature evolutions of optical response of Sr 3(Ir 1-xRu x) 2O 7. Sci Rep 2020; 10:22340. [PMID: 33339856 PMCID: PMC7749133 DOI: 10.1038/s41598-020-79263-5] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 12/01/2020] [Indexed: 11/09/2022] Open
Abstract
We report on optical spectroscopic study of the Sr3(Ir1-xRux)2O7 system over a wide doping regime. We find that the changes in the electronic structure occur in the limited range of the concentration of Ru ions where the insulator-metal transition occurs. In the insulating regime, the electronic structure associated with the effective total angular momentum Jeff = 1/2 Mott state remains robust against Ru doping, indicating the localization of the doped holes. Upon entering the metallic regime, the Mott gap collapses and the Drude-like peak with strange metallic character appears. The evolution of the electronic structure registered in the optical data can be explained in terms of a percolative insulator-metal transition. The phonon spectra display anomalous doping evolution of the lineshapes. While the phonon modes of the compounds deep in the insulating and metallic regimes are almost symmetric, those of the semiconducting compound with x = 0.34 in close proximity to the doping-driven insulator-metal transition show a pronounced asymmetry. The temperature evolution of the phonon modes of the x = 0.34 compound reveals the asymmetry is enhanced in the antiferromagnetic state. We discuss roles of the S = 1 spins of the Ru ions and charge excitations for the conspicuous lineshape asymmetry of the x = 0.34 compound.
Collapse
Affiliation(s)
- Gihyeon Ahn
- Department of Physics, Hanyang University, Seoul, 04763, Republic of Korea
| | - J L Schmehr
- Materials Department, University of California, Santa Barbara, CA, 93106, USA
| | - Z Porter
- Materials Department, University of California, Santa Barbara, CA, 93106, USA
| | - S D Wilson
- Materials Department, University of California, Santa Barbara, CA, 93106, USA
| | - S J Moon
- Department of Physics, Hanyang University, Seoul, 04763, Republic of Korea. .,Research Institute of Natural Science, Hanyang University, Seoul, 04763, Republic of Korea.
| |
Collapse
|
4
|
Ron A, Chaudhary S, Zhang G, Ning H, Zoghlin E, Wilson SD, Averitt RD, Refael G, Hsieh D. Ultrafast Enhancement of Ferromagnetic Spin Exchange Induced by Ligand-to-Metal Charge Transfer. Phys Rev Lett 2020; 125:197203. [PMID: 33216570 DOI: 10.1103/physrevlett.125.197203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 08/17/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
We theoretically predict and experimentally demonstrate a nonthermal pathway to optically enhance superexchange interaction energies in a material based on exciting ligand-to-metal charge-transfer transitions, which introduces lower-order virtual hopping contributions that are absent in the ground state. We demonstrate this effect in the layered ferromagnetic insulator CrSiTe_{3} by exciting Te-to-Cr charge-transfer transitions using ultrashort laser pulses and detecting coherent phonon oscillations that are impulsively generated by superexchange enhancement via magneto-elastic coupling. This mechanism kicks in below the temperature scale where short-range in-plane spin correlations begin to develop and disappears when the excitation energy is tuned away from the charge-transfer resonance, consistent with our predictions.
Collapse
Affiliation(s)
- A Ron
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel Aviv, 69978, Israel
| | - S Chaudhary
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - G Zhang
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
| | - H Ning
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - E Zoghlin
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, USA
| | - S D Wilson
- Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, USA
| | - R D Averitt
- Department of Physics, University of California, San Diego, La Jolla, California 92093, USA
| | - G Refael
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - D Hsieh
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| |
Collapse
|
5
|
Sarte PM, Wilson SD, Attfield JP, Stock C. Magnetic fluctuations and the spin-orbit interaction in Mott insulating CoO. J Phys Condens Matter 2020; 32:374011. [PMID: 32554874 DOI: 10.1088/1361-648x/ab8498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Motivated by the presence of an unquenched orbital angular momentum in CoO, a team at Chalk River, including a recently hired research officer Roger Cowley, performed the first inelastic neutron scattering experiments on the classic Mott insulator [Sakurai et al 1968 Phys. Rev. 167 510]. Despite identifying two magnon modes at the zone boundary, the team was unable to parameterise the low energy magnetic excitation spectrum below T N using conventional pseudo-bosonic approaches, instead achieving only qualitative agreement. It would not be for another 40 years that Roger, now at Oxford and motivated by the discovery of the high-T c cuprate superconductors [Bednorz and Muller 1986 Z. Phys. B 64 189], would make another attempt at the parameterisation of the magnetic excitation spectrum that had previously alluded him at the start of his career. Upon his return to CoO, Roger found a system embroiled in controversy, with some of its most fundamental parameters still remaining undetermined. Faced with such a formidable task, Roger performed a series of inelastic neutron scattering experiments in the early 2010s on both CoO and a magnetically dilute structural analogue Mg0.97Co0.03O. These experiments would prove instrumental in the determination of both single-ion [Cowley et al 2013 Phys. Rev. B 88 205117] and cooperative magnetic parameters [Sarte et al 2018 Phys. Rev. B 98 024415] for CoO. Both these sets of parameters would eventually be used in a spin-orbit exciton model [Sarte et al 2019 Phys. Rev. B 100 075143], developed by his longtime friend and collaborator Bill Buyers, to successfully parameterise the complex spectrum that both measured at Chalk River almost 50 years prior. The story of CoO is of one that has come full circle, one filled with both spectacular failures and intermittent, yet profound, little victories.
Collapse
Affiliation(s)
- P M Sarte
- California NanoSystems Institute, University of California, Santa Barbara, California 93106-6105, United States of America. Materials Department, University of California, Santa Barbara, California 93106-5050, United States of America. School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom. Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
| | | | | | | |
Collapse
|
6
|
Hu Y, Chen X, Peng ST, Lane C, Matzelle M, Sun ZL, Hashimoto M, Lu DH, Schwier EF, Arita M, Wu T, Markiewicz RS, Shimada K, Chen XH, Shen ZX, Bansil A, Wilson SD, He JF. Spectroscopic Evidence for Electron-Boson Coupling in Electron-Doped Sr_{2}IrO_{4}. Phys Rev Lett 2019; 123:216402. [PMID: 31809181 DOI: 10.1103/physrevlett.123.216402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Indexed: 06/10/2023]
Abstract
The pseudogap, d-wave superconductivity and electron-boson coupling are three intertwined key ingredients in the phase diagram of the cuprates. Sr_{2}IrO_{4} is a 5d-electron counterpart of the cuprates in which both the pseudogap and a d-wave instability have been observed. Here, we report spectroscopic evidence for the presence of the third key player in electron-doped Sr_{2}IrO_{4}: electron-boson coupling. A kink in nodal dispersion is observed with an energy scale of ∼50 meV. The strength of the kink changes with doping, but the energy scale remains the same. These results provide the first noncuprate platform for exploring the relationship between the pseudogap, d-wave instability, and electron-boson coupling in doped Mott insulators.
Collapse
Affiliation(s)
- Yong Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiang Chen
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - S-T Peng
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - C Lane
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - M Matzelle
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - Z-L Sun
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - M Hashimoto
- Stanford Synchrotron Radiation Lightsource and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - D-H Lu
- Stanford Synchrotron Radiation Lightsource and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - E F Schwier
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - M Arita
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - T Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - R S Markiewicz
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - K Shimada
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - X-H Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Z-X Shen
- Stanford Synchrotron Radiation Lightsource and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, California 94305, USA
| | - A Bansil
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - S D Wilson
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - J-F He
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
7
|
Chu H, Zhao L, de la Torre A, Hogan T, Wilson SD, Hsieh D. A charge density wave-like instability in a doped spin-orbit-assisted weak Mott insulator. Nat Mater 2017; 16:200-203. [PMID: 28092687 DOI: 10.1038/nmat4836] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
Layered perovskite iridates realize a rare class of Mott insulators that are predicted to be strongly spin-orbit coupled analogues of the parent state of cuprate high-temperature superconductors. Recent discoveries of pseudogap, magnetic multipolar ordered and possible d-wave superconducting phases in doped Sr2IrO4 have reinforced this analogy among the single layer variants. However, unlike the bilayer cuprates, no electronic instabilities have been reported in the doped bilayer iridate Sr3Ir2O7. Here we show that Sr3Ir2O7 realizes a weak Mott state with no cuprate analogue by using ultrafast time-resolved optical reflectivity to uncover an intimate connection between its insulating gap and antiferromagnetism. However, we detect a subtle charge density wave-like Fermi surface instability in metallic electron doped Sr3Ir2O7 at temperatures (TDW) close to 200 K via the coherent oscillations of its collective modes, which is reminiscent of that observed in cuprates. The absence of any signatures of a new spatial periodicity below TDW from diffraction, scanning tunnelling and photoemission based probes suggests an unconventional and possibly short-ranged nature of this density wave order.
Collapse
Affiliation(s)
- H Chu
- Department of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
| | - L Zhao
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - A de la Torre
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - T Hogan
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - S D Wilson
- Materials Department, University of California, Santa Barbara, California 93106, USA
| | - D Hsieh
- Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
| |
Collapse
|
8
|
Ahn G, Song SJ, Hogan T, Wilson SD, Moon SJ. Infrared Spectroscopic Evidences of Strong Electronic Correlations in (Sr1-xLax)3Ir2O7. Sci Rep 2016; 6:32632. [PMID: 27599573 PMCID: PMC5013521 DOI: 10.1038/srep32632] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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] [Received: 05/09/2016] [Accepted: 08/11/2016] [Indexed: 11/09/2022] Open
Abstract
We report on infrared spectroscopic studies of the electronic response of the (Sr1-xLax)3Ir2O7 system. Our experiments revealed hallmarks of strong electronic correlations in the evolution of the electronic response across the filling-controlled insulator-metal transition. We observed a collapse of the Jeff = 1/2 Mott gap accompanying the transfer of the spectral weight from the high-energy region to the gap region with electron doping. The intraband conductivity at the metallic side of the transition was found to consist of coherent Drude-like and incoherent responses. The sum rule and the extended Drude model analyses further indicated a large mass enhancement. Our results demonstrate a critical role of the electronic correlations in the charge dynamics of the (Sr1-xLax)3Ir2O7 system.
Collapse
Affiliation(s)
- Gihyeon Ahn
- Department of Physics, Hanyang University, Seoul 04763, Korea
| | - S. J. Song
- Department of Physics, Hanyang University, Seoul 04763, Korea
| | - T. Hogan
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
- Department of Materials, University of California, Santa Barbara, California 93106, USA
| | - S. D. Wilson
- Department of Materials, University of California, Santa Barbara, California 93106, USA
| | - S. J. Moon
- Department of Physics, Hanyang University, Seoul 04763, Korea
| |
Collapse
|
9
|
He J, Hogan T, Mion TR, Hafiz H, He Y, Denlinger JD, Mo SK, Dhital C, Chen X, Lin Q, Zhang Y, Hashimoto M, Pan H, Lu DH, Arita M, Shimada K, Markiewicz RS, Wang Z, Kempa K, Naughton MJ, Bansil A, Wilson SD, He RH. Spectroscopic evidence for negative electronic compressibility in a quasi-three-dimensional spin-orbit correlated metal. Nat Mater 2015; 14:577-582. [PMID: 25915033 DOI: 10.1038/nmat4273] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/19/2015] [Indexed: 06/04/2023]
Abstract
Negative compressibility is a sign of thermodynamic instability of open or non-equilibrium systems. In quantum materials consisting of multiple mutually coupled subsystems, the compressibility of one subsystem can be negative if it is countered by positive compressibility of the others. Manifestations of this effect have so far been limited to low-dimensional dilute electron systems. Here, we present evidence from angle-resolved photoemission spectroscopy (ARPES) for negative electronic compressibility (NEC) in the quasi-three-dimensional (3D) spin-orbit correlated metal (Sr1-xLax)3Ir2O7. Increased electron filling accompanies an anomalous decrease of the chemical potential, as indicated by the overall movement of the deep valence bands. Such anomaly, suggestive of NEC, is shown to be primarily driven by the lowering in energy of the conduction band as the correlated bandgap reduces. Our finding points to a distinct pathway towards an uncharted territory of NEC featuring bulk correlated metals with unique potential for applications in low-power nanoelectronics and novel metamaterials.
Collapse
Affiliation(s)
- Junfeng He
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - T Hogan
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - Thomas R Mion
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - H Hafiz
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
| | - Y He
- Stanford Synchrotron Radiation Lightsource &Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J D Denlinger
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S-K Mo
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C Dhital
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - X Chen
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - Qisen Lin
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - Y Zhang
- International Center for Quantum Materials, Peking University, Beijing 100871, China
| | - M Hashimoto
- Stanford Synchrotron Radiation Lightsource &Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - H Pan
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - D H Lu
- Stanford Synchrotron Radiation Lightsource &Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Arita
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - K Shimada
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima 739-0046, Japan
| | - R S Markiewicz
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
| | - Z Wang
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - K Kempa
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - M J Naughton
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| | - A Bansil
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
| | - S D Wilson
- 1] Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA [2] Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Rui-Hua He
- Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA
| |
Collapse
|
10
|
Decker PA, Cohen EP, Doffek KM, Ashley BA, Bienemann ME, Zhu YR, Adams ME, Wilson SD, Demeure MJ. Subtotal Parathyroidectomy in Renal Failure: Still Needed after All These Years. World J Surg 2014; 25:708-12. [PMID: 11376403 DOI: 10.1007/s00268-001-0019-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There are scant data on the frequency of parathyroidectomy (PTX) for end-stage renal disease (ESRD). Medical therapy for ESRD and secondary hyperparathyroidism has evolved to include better dialytic urea removal and the use of calcitriol. The aim of this study was to determine whether medical therapy has changed the frequency or indications for PTX in the management of renal failure. Hospital and clinic records were analyzed to gather information on all patients undergoing PTX for secondary hyperparathyroidism (2HPT) (n = 48) and tertiary hyperparathyroidism (3HPT) (n = 26) from 1986 through 1998 at our institution. Prospective computer databases were queried for information concerning both chronic dialysis and renal transplant patients at our center. The patients were divided based on date of operation before or after 1991, a divider that separated the patients into groups before or after the widespread adoption of intravenous calcitriol treatment during hemodialysis at our institution. Over the 12 year period, the proportion of our chronic dialysis patients undergoing PTX did not change significantly, ranging from 0% to 2.5% per year. Comparing all patients undergoing PTX for 2HPT during 1986-1991 versus 1992-1998, there was no significant difference in time on dialysis [7.0 +/- 4.2 (n = 11) vs. 7.5 +/- 4.6 (n = 36) years, mean +/- SD]. The later group had higher intact parathyroid hormone (iPTH) levels [765 +/- 415 (n = 6) vs. 1377 +/- 636 (n = 28) pg/ml; p = 0.03], lower serum calcium [11.2 +/- 1.0 (n = 12) vs. 9.9 +/- 1.5 (n = 34) mg/dl; p = 0.006], and higher serum phosphate [5.7 +/- 1.6 (n = 12) vs. 7.2 +/- 2.3 (n = 31) mg/dl; p = 0.042]. Among the population of patients with transplants undergoing PTX for 3HPT, the average percent per year undergoing PTX ranged from 0% to 4.2% and did not change during the study period. Comparing the 1986-1991 group to the 1992-1998 group, the time from transplantation to PTX did not change during the study period (3.3 +/- 2.3 vs. 2.9 +/- 3.0 years; p = 0.391), and there were no significant differences between preoperative calcium levels or iPTH levels. Despite advances in dialysis technique and pharmacologic therapy, there has been no change in the proportion of dialysis patients requiring PTX for 2HPT or 3HPT. There was also no change in the time on dialysis for patients with 2HPT or the time from transplant to PTX for patients with 3HPT. Analysis of preoperative biochemical markers as evidence of disease severity suggests there was no change in indications for PTX during our study. From this information we conclude that parathyroid pathophysiology is incompletely understood and medical therapy is not optimal, resulting in a continuing need for PTX in some patients.
Collapse
Affiliation(s)
- P A Decker
- Department of Surgery, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, Wisconsin 53226, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Bayrakci SP, Tennant DA, Leininger P, Keller T, Gibson MCR, Wilson SD, Birgeneau RJ, Keimer B. Lifetimes of antiferromagnetic magnons in two and three dimensions: experiment, theory, and numerics. Phys Rev Lett 2013; 111:017204. [PMID: 23863025 DOI: 10.1103/physrevlett.111.017204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Indexed: 06/02/2023]
Abstract
A high-resolution neutron spectroscopic technique is used to measure momentum-resolved magnon lifetimes in the prototypical two- and three-dimensional antiferromagnets Rb(2)MnF(4) and MnF(2), over the full Brillouin zone and a wide range of temperatures. We rederived theories of the lifetime resulting from magnon-magnon scattering, thereby broadening their applicability beyond asymptotically small regions of wave vector and temperature. Corresponding computations, combined with a small contribution reflecting collisions with domain boundaries, yield excellent quantitative agreement with the data. Comprehensive understanding of magnon lifetimes in simple antiferromagnets provides a solid foundation for current research on more complex magnets.
Collapse
Affiliation(s)
- S P Bayrakci
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Grant SW, Grayson AD, Purkayastha D, Wilson SD, McCollum C. Logistic risk model for mortality following elective abdominal aortic aneurysm repair. Br J Surg 2011; 98:652-8. [DOI: 10.1002/bjs.7463] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2011] [Indexed: 11/08/2022]
Abstract
Abstract
Background
The aim was to develop a multivariable risk prediction model for 30-day mortality following elective abdominal aortic aneurysm (AAA) repair.
Methods
Data collected prospectively on 2765 consecutive patients undergoing elective open and endovascular AAA repair from September 1999 to October 2009 in the North West of England were split randomly into development (1936 patients) and validation (829) data sets. Logistic regression analysis was undertaken to identify risk factors for 30-day mortality.
Results
Ninety-eight deaths (5·1 per cent) were recorded in the development data set. Variables associated with 30-day mortality included: increasing age (P = 0·005), female sex (P = 0·002), diabetes (P = 0·029), raised serum creatinine level (P = 0·006), respiratory disease (P = 0·031), antiplatelet medication (P < 0·001) and open surgery (P = 0·002). The area under the receiver operating characteristic (ROC) curve for predicted probability of 30-day mortality in the development and validation data sets was 0·73 and 0·70 respectively. Observed versus expected 30-day mortality was 3·2 versus 2·0 per cent (P = 0·272) in low-risk, 6·1 versus 5·1 per cent (P = 0·671) in medium-risk and 11·1 versus 10·7 per cent (P = 0·879) in high-risk patients.
Conclusion
This multivariable model for predicting 30-day mortality following elective AAA repair can be used clinically to calculate patient-specific risk and is useful for case-mix adjustment. The model predicted well across all risk groups in the validation data set.
Collapse
Affiliation(s)
- S W Grant
- University of Manchester, Manchester Academic Health Science Centre, University Hospital of South Manchester, Academic Surgery Unit, Education and Research Centre, Manchester, UK
| | - A D Grayson
- Southport and Ormskirk NHS Hospitals, Southport, UK
| | - D Purkayastha
- University of Manchester, Manchester Academic Health Science Centre, University Hospital of South Manchester, Academic Surgery Unit, Education and Research Centre, Manchester, UK
| | - S D Wilson
- University of Manchester, Manchester Academic Health Science Centre, University Hospital of South Manchester, Academic Surgery Unit, Education and Research Centre, Manchester, UK
| | - C McCollum
- University of Manchester, Manchester Academic Health Science Centre, University Hospital of South Manchester, Academic Surgery Unit, Education and Research Centre, Manchester, UK
| |
Collapse
|
13
|
Woodburn KW, Wilson SD, Fong KL, Schatz PJ, Ferrell T, Spainhour CB, Norton D. Chronic preclinical safety evaluation of HematideTM, a pegylated peptidic erythropoiesis stimulating agent in monkeys. Haematologica 2008; 93:1376-9. [DOI: 10.3324/haematol.12896] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
14
|
Abstract
Maternal recognition of pregnancy in marsupials occurs in more subtle ways than it does in eutherians. For instance, unlike in eutherians, the plasma progesterone profiles of pregnant and non-pregnant animals are similar during the luteal phase. It is typically during the brief luteal phase that both gestation and parturition occur in marsupials. Yet histological and physiological changes have been documented between gravid and non-gravid uteri in certain monovular marsupials and between pregnant and non-pregnant animals in polyovular marsupials. Early pregnancy factor (EPF), a 10.8-kDa serum protein known to be homologous to chaperonin 10, is associated with maternal immunosuppression, embryonic development and pregnancy in eutherian mammals. It has been reported in two Australian marsupials: the dasyurid Sminthopsis macroura and the phalangerid Trichosurus vulpecula. This paper documents its occurrence in the New World didelphid Monodelphis domestica. EPF is detectable by rosette inhibition assay in the peripheral circulation of pregnant but not of non-pregnant or pseudopregnant animals. Our work focuses on the embryo–maternal signalling role of EPF during pregnancy. Because progesterone-driven changes are similar in pregnant and non-pregnant marsupials, these animals are an excellent laboratory model in which to investigate the role of EPF in orchestrating the physiological changes necessary to sustain pregnancy.
Collapse
|
15
|
Pinnaduwage LA, Thundat T, Gehl A, Wilson SD, Hedden DL, Lareau RT. Desorption characteristics of uncoated silicon microcantilever surfaces for explosive and common nonexplosive vapors. Ultramicroscopy 2004; 100:211-6. [PMID: 15231312 DOI: 10.1016/j.ultramic.2003.11.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2003] [Revised: 11/18/2003] [Accepted: 11/18/2003] [Indexed: 11/29/2022]
Abstract
We measured the desorption of explosive trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), and hexahydro-1,3,5-triazine (RDX) vapors from piezoresistive silicon microcantilevers under ambient air. Depending on the amount of vapor loaded on the cantilever, TNT desorption took a few minutes to tens of minutes (for nanogram quantities). On the other hand, no significant loss of PETN or RDX was observed after many hours. We also measured desorption of common "nonexplosive" compounds (water, acetone, and ethyl alcohol) and observed that desorption was too fast to be measured. There is a good correlation between the desorption time and the melting point (or the vapor pressure) of a particular substance. In principle, this method can be used to measure desorption rates of various substances from cantilever surfaces.
Collapse
Affiliation(s)
- L A Pinnaduwage
- Department of Physics, University of Tennessee, Oak Ridge National Laboratory, P. O. Box 2008, Oak Ridge, TN 37831-6123, Knoxville, TN 37996, USA.
| | | | | | | | | | | |
Collapse
|
16
|
Wilson SD, Squires SG, Deeks SL, King A. Investigating the Risk of Bacterial Meningitis Among Canadian Children With Cochlear Implants. Paediatr Child Health 2003. [DOI: 10.1093/pch/8.suppl_b.16ba] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
17
|
Wilson SD, McCay JA, Butterworth LF, Munson AE, White KL. Correlation of suppressed natural killer cell activity with altered host resistance models in B6C3F1 mice. Toxicol Appl Pharmacol 2001; 177:208-18. [PMID: 11749120 DOI: 10.1006/taap.2001.9298] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A number of methods have been developed to assess the impact of a xenobiotic on the various components of the immune system. For risk analysis, it is necessary to determine what degree of chemically induced immune perturbation translates into altered host resistance. Natural killer (NK) cells play a pivotal role in the innate immune system with the ability to lyse cells infected with intracellular pathogens and certain tumors without previous exposure to the antigen. Spontaneous NK activity in B6C3F1 mice could be incrementally and consistently decreased by 20 to > or =80% by the intravenous administration of a range of dilutions of anti-asialo GM1 (AAGM1) antibody. The decrease in spontaneous NK activity following a single iv administration of AAGM1 antibody persisted for up to approximately 3 weeks when the initial suppression (e.g., 24 h after AAGM1 antibody injection) was almost 100%. Treatment with AAGM1, however, did not appear to perturb the function of other immune cells, based on results of the plaque assay, the mixed lymphocyte response, the cytotoxic T lymphocyte assay, the reticuloendothelial system clearance of sRBC assay, and the Streptococcus pneumoniae host resistance assay. Following a > or =80% decrease in spontaneous NK activity in mice, challenge with > or =1 x 10(3) B16F10 melanoma cells resulted in an increase in tumor burden based on the number of lung nodules. However, following challenge with 1 x 10(5) melanoma cells, a significant increase in tumor burden in mice was not observed until spontaneous NK activity had been decreased by > or =50-60%. Altered host resistance is a function not only of the magnitude of the decrease in NK activity but also of the magnitude of the challenge to the host.
Collapse
Affiliation(s)
- S D Wilson
- Milestone Biomedical Associates, Frederick, Maryland 21701, USA
| | | | | | | | | |
Collapse
|
18
|
Abstract
Despite the rapid growth in pediatric hospitalist services, there is little empiric information about the impact of pediatric hospitalists. This study compared process and outcome variables related to the inpatient care of 182 pediatric patients, half of whom were cared for by hospitalists and half by their primary care providers (PCP). Results indicated that, while hospitalists cared for patients of substantially lower socioeconomic status, they delivered care more economically for patients with asthma, with no significant differences in rates of return to the emergency room or rehospitalizations. Children in both services demonstrated equivalent levels of returning to their PCP for follow-up visits and were in equally good health 1 month after discharge. Additionally, no negative impact was evident on patient satisfaction at discharge; in fact, the hospitalists' patients were more satisfied with aspects of their care. Hospitalists may, therefore, provide a vital service by ensuring quality inpatient care for low-income children.
Collapse
Affiliation(s)
- R D Wells
- Valley Children's Hospital, 9300 Valley Children's Place, Madera, CA 93638, USA.
| | | | | |
Collapse
|
19
|
Affiliation(s)
- S D Wilson
- Department of Pediatrics, Valley Children's Hospital, University of California, San Francisco, 93638, USA.
| |
Collapse
|
20
|
Brown HM, Ahrendt SA, Komorowski RA, Doffek KM, Wilson SD, Demeure MJ. Immunohistochemistry and molecular detection of nodal micrometastases in pancreatic cancer. J Surg Res 2001; 95:141-6. [PMID: 11162037 DOI: 10.1006/jsre.2000.6026] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE Assays based on polymerase chain reaction (PCR) demonstrate mutated Kiras in the regional nodes of a majority of patients with node-negative stage I or II (T(1-3), N(0), M(0)) pancreatic adenocarcinoma. The hypothesis that the presence of mutated Kiras equates with micrometastases has not been validated by detailed histologic examination nor has an impact on survival been demonstrated. METHODS We examined the paraffin blocks of the primary tumor and regional lymph nodes from all 30 patients from 1984 to 1998 with resected pN(0) stage I or II pancreatic adenocarcinoma. DNA was analyzed for mutations in codon 12 of the Kiras oncogene by PCR and restriction digest with BstN1 (RFLP). All nodes were examined by histology of 4 hematoxylin and eosin-stained step sections and immunohistochemistry (HPE/IHC) with AE3/AE1 epithelial cell marker antibody. RESULTS Examination of the regional lymph nodes of the 30 patients demonstrated nodal metastases in 9 (30%) by step-section histology alone, 14 (46.7%) by HPE/IHC, 19 (63.3%) by PCR/RFLP, and 25 (83.3%) by a combination of PCR/RFLP and HPE/IHC. Seven cases were HPE/IHC positive yet PCR/RFLP negative while 10 cases were PCR/RFLP positive and HPE/IHC negative. Median survival (months) did not differ if nodes were negative or positive by HPE/IHC (20.5 vs 17.5) or PCR/RFLP (20.0 vs 19.0) or a combination of these techniques (25 vs 18.5). CONCLUSIONS A great majority (83.3%) of patients with pathologic stage I or II pancreatic cancer had metastases in their regional nodes. Step-sectioning with immunohistochemistry and PCR/RFLP are complementary tests in detection of metastatic cancer cells. Nodal micrometastases did not adversely influence survival.
Collapse
Affiliation(s)
- H M Brown
- Department of Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA
| | | | | | | | | | | |
Collapse
|
21
|
Ahrendt SA, Brown HM, Komorowski RA, Zhu YR, Wilson SD, Erickson BA, Ritch PS, Pitt HA, Demeure MJ. p21WAF1 expression is associated with improved survival after adjuvant chemoradiation for pancreatic cancer. Surgery 2000; 128:520-30. [PMID: 11015084 DOI: 10.1067/msy.2000.108052] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND Cell cycle arrest after DNA damage is partly mediated through the transcriptional activation of p21(WAF1) by the p53 tumor suppressor gene. p21(WAF1) and p53 are both critical in maintaining cell cycle control in response to DNA damage from radiation or chemotherapy. Therefore, we examined the role of p21(WAF1) and p53 in the determination of outcome for patients who receive radiation and/or chemotherapy for pancreatic cancer. METHODS p21(WAF1) and p53 protein expression were determined (with the use of immunohistochemistry) in specimens from 90 patients with pancreatic cancer. Forty-four patients underwent surgical resection, and 46 patients had either locally unresectable tumors (n = 9 patients) or distant metastases (n = 37 patients). Seventy-three percent of the patients who underwent resection and 63% of the patients who did not undergo resection received radiation and/or chemotherapy. RESULTS p21(WAF1) expression was present in 48 of 86 tumors (56%) and was significantly (P<.05) associated with advanced tumor stage. Median survival among patients with resected pancreatic cancer who received adjuvant chemoradiation with p21(WAF1)-positive tumors was significantly longer than in patients with no p21(WAF1) staining (25 vs. 11 months; P = .01). Fifty of 89 tumors (56%) stained positive for p53 protein. p53 overexpression was associated with decreased survival in patients who did not undergo resection. CONCLUSIONS Normal p21(WAF1) expression may be necessary for a beneficial response to current adjuvant chemoradiation protocols for pancreatic cancer. Alternate strategies for adjuvant therapy should be explored for patients with pancreatic cancer who lack functional p21(WAF1).
Collapse
Affiliation(s)
- S A Ahrendt
- Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Abstract
An assay for respiratory syncytial virus (RSV)-specific IgG in saliva is described. The assay was used to examine the incidence of RSV infection in schoolchildren 7-10 years old during one RSV season. One hundred and twenty-one volunteer children provided saliva samples in October 1997 and March 1998; 18% of the children showed a fourfold or greater rise in anti-RSV IgG in the second sample. This prevalence of antibody increase is similar to that described in previous studies that measured CFT levels in serum samples. Overall, the children who showed rises in antibody levels, indicating that they had experienced an RSV infection, had lower levels of RSV-specific antibody in their preseason samples than those who showed no increase (P = 0.0018). These results show that saliva is an adequate substitute for serum in some antibody tests and may be useful for community studies. Such studies may provide surrogate markers for susceptibility to infection, which should benefit the planning of vaccination strategies.
Collapse
Affiliation(s)
- S D Wilson
- Division of Immunity and Infection, University of Birmingham Medical School, Birmingham, England
| | | | | | | | | |
Collapse
|
23
|
Brown HM, Komorowski RA, Wilson SD, Demeure MJ, Zhu YR. Predicting metastasis of pheochromocytomas using DNA flow cytometry and immunohistochemical markers of cell proliferation: A positive correlation between MIB-1 staining and malignant tumor behavior. Cancer 1999; 86:1583-9. [PMID: 10526289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND In the absence of metastases, there are no reliable microscopic features that distinguish malignant from benign pheochromocytomas. Because a common feature of malignancy is the loss of cell cycle regulation and normal growth arrest, the authors hypothesized that analysis of the cell cycle could be used to aid in the diagnosis of malignant pheochromocytoma. METHODS Cell cycle analysis of archival samples of 51 pheochromocytomas (40 sporadic, 11 familial) from 45 patients, including 6 malignant and 45 benign tumors, was conducted. Flow cytometry data and immunohistochemistry for markers of cell proliferation (proliferating cell nuclear antigen [PCNA] and MIB-1 [Ki-67]) were correlated with the authors' clinical data base records, with a mean follow-up of 66 months. RESULTS No correlation of DNA ploidy, S-phase fraction by flow cytometry, or PCNA with malignancy was observed. Staining for the MIB-1 nuclear proliferation marker was positive in 3 of 6 (50%) of the malignant pheochromocytomas and negative in all 45 benign tumors (P< 0.01). CONCLUSIONS Contrary to some previous reports, a diploid DNA pattern does not necessarily predict benign behavior of pheochromocytoma. In this study, cell cycle analysis and, in particular, assessment of the MIB-1 nuclear proliferation marker was useful in the histologic evaluation of pheochromocytoma, as MIB-1 was expressed only in malignant tumors.
Collapse
Affiliation(s)
- H M Brown
- Department of Pathology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
| | | | | | | | | |
Collapse
|
24
|
Wilson SD, Munson AE, Meade BJ. Assessment of the functional integrity of the humoral immune response: the plaque-forming cell assay and the enzyme-linked immunosorbent assay. Methods 1999; 19:3-7. [PMID: 10525432 DOI: 10.1006/meth.1999.0821] [Citation(s) in RCA: 18] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The plaque-forming cell (PFC) assay and enzyme-linked immunosorbent assay (ELISA) appear to have comparable sensitivity and reproducibility for measuring IgM antibody production in mice and rats immunized with sheep red blood cells (sRBCs). Both assays can be manipulated, with respect to the immunizing antigen (e.g., T-dependent vs T-independent antigen), to provide evidence as to which cell type(s) may be adversely affected by a given compound. However, the PFC assay has more utility in dissecting out the target cell(s) involved. Since both the PFC assay and the ELISA may be readily conducted in the rat, it is feasible to incorporate either of these assays into standard acute and repeat dose toxicology studies. This may be accomplished by inclusion of satellite groups in the study. However, it has been suggested that the primary antibody response to sRBCs, as measured by an ELISA, may also be evaluated in the main group of animals in a toxicology study without compromise to the integrity of other toxicological endpoints (e.g., hematology, clinical chemistry, histopathology). Both approaches will provide a more extensive delineation of the safety profile of a drug or chemical. The latter approach will also reduce the number of animals needed and the cost of the study.
Collapse
Affiliation(s)
- S D Wilson
- Division of Anti-inflammatory, Analgesic, and Ophthalmic Drug Products, Food and Drug Administration, 5600 Fishers Lane, HFD-550, Rockville, Maryland 20857, USA.
| | | | | |
Collapse
|
25
|
White WI, Wilson SD, Palmer-Hill FJ, Woods RM, Ghim SJ, Hewitt LA, Goldman DM, Burke SJ, Jenson AB, Koenig S, Suzich JA. Characterization of a major neutralizing epitope on human papillomavirus type 16 L1. J Virol 1999; 73:4882-9. [PMID: 10233949 PMCID: PMC112531 DOI: 10.1128/jvi.73.6.4882-4889.1999] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Persistent infection with human papillomavirus type 16 (HPV-16) is strongly associated with the development of cervical cancer. Neutralizing epitopes present on the major coat protein, L1, have not been well characterized, although three neutralizing monoclonal antibodies (MAbs) had been identified by using HPV-16 pseudovirions (R. B. Roden et al., J. Virol. 71:6247-6252, 1997). Here, two of these MAbs (H16.V5 and H16.E70) were demonstrated to neutralize authentic HPV-16 in vitro, while the third (H16.U4) did not. Binding studies were conducted with the three MAbs and virus-like particles (VLPs) composed of the reference L1 sequence (114K) and three variant L1 sequences: Rochester-1k (derived from viral stock DNA), GU-1 (derived from cervical biopsy DNA), and GU-2 (derived from biopsy DNA, but containing some sequence changes likely to be artifactual). While all three MAbs bound to 114K and Rochester-1k VLPs, GU-1 VLPs were not recognized by H16.E70, and both H16.E70 and H16.V5 failed to bind to GU-2 VLPs. Site-directed mutagenesis was used to replace disparate amino acids in the GU-2 L1 with those found in the 114K L1. Alteration of the amino acid at position 50, from L to F, completely restored H16.V5 binding and partially restored H16.E70 binding, while complete restoration of H16.E70 binding occurred with GU-2 VLPs containing both L50F and T266A alterations. Immunization of mice with L1 variant VLPs revealed that GU-2 VLPs were poorly immunogenic. The L50F mutant of GU-2 L1, in which the H16.V5 epitope was restored, elicited HPV-16 antibody responses comparable to those obtained with 114K VLPs. These results demonstrate the importance of the H16.V5 epitope in the generation of potent HPV-16 neutralizing antibody responses.
Collapse
Affiliation(s)
- W I White
- MedImmune, Inc., Gaithersburg, Maryland 20878, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Marriott AC, Wilson SD, Randhawa JS, Easton AJ. A single amino acid substitution in the phosphoprotein of respiratory syncytial virus confers thermosensitivity in a reconstituted RNA polymerase system. J Virol 1999; 73:5162-5. [PMID: 10233981 PMCID: PMC112563 DOI: 10.1128/jvi.73.6.5162-5165.1999] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 11/20/2022] Open
Abstract
The single amino acid change Gly172 to Ser in the phosphoprotein (P) of respiratory syncytial virus (RSV) has previously been shown to be responsible for the thermosensitivity and protein-negative phenotype of tsN19, a mutant of the B subgroup RSN-2 strain. This single change was inserted into the P gene of the A subgroup virus RSS-2, and the resulting phenotype was observed in a plasmid-driven reconstituted RSV RNA polymerase system. Expression from a genome analogue containing two reporter genes was thermosensitive when directed by plasmids containing the N, L, M2, and mutant P genes cloned under the control of T7 promoters. Analysis of RNA synthesis showed that mutant P protein was unable to produce genome, antigenome, or mRNA at the restrictive temperature. At a semipermissive temperature, genome, antigenome, and mRNA synthesis were all reduced, 6- to 30-fold, relative to synthesis directed by a wild-type P plasmid. Binding of the mutant P protein to N protein in the absence of other viral proteins was unaffected by temperature, indicating that the lesion did not produce a large enough structural change to disrupt this binding. These data suggest that the plasmid rescue system is suitable for investigation of the role of thermosensitive mutations in RSV polymerase components in RNA synthesis.
Collapse
Affiliation(s)
- A C Marriott
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | | | | | | |
Collapse
|
27
|
Abstract
BACKGROUND Stage I (T1-2NOM0) adenocarcinoma of the pancreas is associated with a 5-year survival rate of 15-25%. Despite apparently curative resection and pathologic staging indicating localized disease, these cancers recur. The authors hypothesized that there exists microscopic regional disease that is not detected by surgical exploration or routine histopathology. METHODS Because 90-95% of pancreatic cancers exhibit codon 12 K-ras mutations, the authors examined regional lymph nodes for mutated K-ras as a marker of metastasis. DNA was extracted from paraffin embedded archival specimens (primary tumors and histologically negative lymph nodes) of patients with Stage I pancreatic adenocarcinoma. The target region of K-ras was amplified by polymerase chain reaction (PCR) and tested for codon 12 mutation by BstN1 restriction digestion (restriction fragment length polymorphism [RFLP]) that recognized normal but not mutated sequences. Cell lines that harbored normal or mutated K-ras and resected jejunum or gallbladder were used as controls. The regional lymph nodes of 22 patients whose tumors harbored mutated K-ras were tested. RESULTS Dilution experiments with normal and mutant control cell line DNA demonstrated an assay sensitivity for mutated K-ras of 0.1%. Mutated K-ras was found in at least 1 regional lymph node in 16 (73%) of 22 patients with pathologic Stage I pancreatic adenocarcinoma, which suggested metastases not detected by routine histopathology. DNA sequence analysis was performed in four patients and confirmed identical point mutations in the primary tumor and accompanying PCR/RFLP positive lymph nodes. CONCLUSIONS Pathologic examination of regional lymph nodes in pancreatic adenocarcinoma specimens fails to detect metastases in many patients. Lymph node micrometastasis is one reason for the poor survival rates observed among patients with Stage I cancers. PCR/RFLP may have a role in staging early pancreatic cancers.
Collapse
Affiliation(s)
- M J Demeure
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226, USA
| | | | | | | |
Collapse
|
28
|
Demeure MJ, Doffek KM, Komorowski RA, Redlich PN, Zhu YR, Erickson BA, Ritch PS, Pitt HA, Wilson SD. Molecular metastases in stage I pancreatic cancer: improved survival with adjuvant chemoradiation. Surgery 1998; 124:663-9. [PMID: 9780986 DOI: 10.1067/msy.1998.91487] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Reports of improved survival rates for patients with resected adenocarcinoma of the pancreas coincide with the adoption of adjuvant chemoradiation protocols. The impact of nodal micrometastases demonstrated by molecular assays and adjuvant therapy on survival of patients with stage I pancreatic cancer has not been adequately assessed. METHODS A retrospective analysis of postoperative chemoradiation on survival in 61 patients undergoing resection of pancreatic adenocarcinomas from 1984 to 1997 was performed. Archival tumors and regional nodes from 25 patients with stage I cancers were tested for a Kiras oncogene mutation using polymerase chain reaction and analysis for restriction fragment length polymorphisms (PCR/RFLP). RESULTS Adjuvant chemoradiation was associated with improved survival for stage I (P < .01), but not stage III, disease. Seventeen (68%) of 25 patients with stage I disease tested had evidence of mutant Kiras in one or more regional nodes. Survival did not differ for patients with molecular micrometastases. Six of 17 (35%) patients with micrometastases received adjuvant chemoradiation and had improved survival (P < .05). CONCLUSIONS The majority of patients with stage I pancreatic cancer have PCR/RFLP evidence of lymph node micrometastases. Adjuvant chemoradiation improves survival in these patients by treating micrometastases not detected by histology. Adjuvant chemoradiation should be used for patients with stage I pancreatic cancers.
Collapse
Affiliation(s)
- M J Demeure
- Medical College of Wisconsin, Department of Surgery, Milwaukee 53226, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
White WI, Wilson SD, Bonnez W, Rose RC, Koenig S, Suzich JA. In vitro infection and type-restricted antibody-mediated neutralization of authentic human papillomavirus type 16. J Virol 1998; 72:959-64. [PMID: 9444988 PMCID: PMC124566 DOI: 10.1128/jvi.72.2.959-964.1998] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.0] [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: 02/05/2023] Open
Abstract
Human papillomavirus type 16 (HPV-16) is strongly associated with the development of cervical cancer. Studies of model systems with animal papillomaviruses have demonstrated the importance of neutralizing antibodies in preventing papillomavirus-associated disease. The assessment of neutralizing antibody responses against HPV-16, previously hampered by the lack of a viral source, was enabled by the recent propagation of an HPV-16 stock in xenografted severe combined immunodeficiency (SCID) mice. HPV-16 infection of an immortalized human keratinocyte cell line was demonstrated by detection of an HPV-16-specific spliced mRNA amplified by reverse transcriptase PCR. Infection was blocked by preincubation of the virus with antiserum generated against HPV-16 virus-like particles (VLPs) composed of the major capsid protein, L1. To examine potential cross-neutralizing activity among the different genital HPV types, rabbit antisera to L1 VLPs corresponding to HPV-6, -11, -18, -31, -33, -35, -39, and -45 were assayed for the ability to block the HPV-16 infection of cultured cells. Antiserum raised against HPV-33 L1 VLPs was the only heterologous antiserum which inhibited HPV-16 infection. Thus, a neutralization assay for HPV-16 may help to characterize the components required to compose a broadly efficacious genital HPV vaccine.
Collapse
Affiliation(s)
- W I White
- MedImmune, Inc., Gaithersburg, Maryland 20878, USA.
| | | | | | | | | | | |
Collapse
|
30
|
Demeure MJ, Doffek KM, Wilson SD. Defective thyrotropin receptor G-protein cyclic adenosine monophosphate signaling mechanism in the FTC human follicular thyroid cancer cell line. Surgery 1997; 122:1195-201; discussion 1201-2. [PMID: 9426438 DOI: 10.1016/s0039-6060(97)90227-0] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Several studies report the effect of thyrotropin (thyroid-stimulating hormone [TSH]) on FTC-133) and aggressively invasive (FTC-238) clones of a human follicular thyroid cancer cell line. Specifically, TSH induces fibronectin secretion by FTC-133, possibly as a result of increased cyclic adenosine monophosphate (cAMP), yet induces in vitro invasion through a protein kinase C-dependent mechanism. In normal thyrocytes, TSH activates cAMP through a stimulatory G-protein (Gs)-linked pathway. In the FTC model we studied the effect of TSH on adenylate cyclase activation. METHODS TSH receptor (TSH-R) mRNA was studied by reverse transcriptase polymerase chain reaction. Fibronectin transcription was analyzed by Northern blot and densitometry. cAMP levels were determined by an enzyme immunoassay. Gs alpha expression was determined by Western blot and a possible activating mutation at position 201 in Gs alpha sought by direct sequencing. RESULTS Reverse transcriptase polymerase chain reaction confirmed the presence of TSH-R mRNA in FTC-133 and FTC-238. TSH did not increase transcription of fibronectin mRNA. FTC-133 cells exhibited higher cAMP levels than did FTC-238 cells: 30.4 +/- 8.0 versus 13.0 +/- 3.5 femtomoles/10(4) cells (mean +/- SD; p < 0.001, Mann-Whitney rank-sum test). TSH did not raise cAMP levels in either clone. Gs alpha expression is equal in both cell lines and is not increased by TSH; sequencing showed no position 201 mutations in Gs alpha. CONCLUSIONS Prototypical TSH-Gs-cAMP signal transduction is not functional in FTC-133 or FTC-238. Our findings implicate perturbation in TSH-R.
Collapse
Affiliation(s)
- M J Demeure
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226, USA
| | | | | |
Collapse
|
31
|
Demeure MJ, Jordan M, Zeihen M, Wilson SD. Endoscopic retroperitoneal right adrenalectomy with the patient in the lateral decubitus position. Surg Laparosc Endosc Percutan Tech 1997; 7:307-9. [PMID: 9282762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We present a case of a right adrenal aldosterone-producing adenoma resected by a novel surgical approach. We describe the technique of an endoscopic retroperitoneal adrenalectomy done with the patient in the lateral decubitus position.
Collapse
Affiliation(s)
- M J Demeure
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226, U.S.A
| | | | | | | |
Collapse
|
32
|
Wilson SD. Products liability: Supreme Court denies federal preemption claims under MDA. J Law Med Ethics 1997; 25:76-77. [PMID: 11066484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
33
|
Randhawa JS, Wilson SD, Tolley KP, Cavanagh D, Pringle CR, Easton AJ. Nucleotide sequence of the gene encoding the viral polymerase of avian pneumovirus. J Gen Virol 1996; 77 ( Pt 12):3047-51. [PMID: 9000096 DOI: 10.1099/0022-1317-77-12-3047] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We report here the nucleotide sequence of the L gene of avian pneumovirus (APV). This is the second pneumovirus L gene and the second avian paramyxovirus L gene, following that of Newcastle disease virus, to be sequenced. The APV L gene is 6099 nucleotides long and encodes a single large ORF of 2004 amino acids. This makes the APV L protein the smallest to be described for any nonsegmented, negative-strand RNA virus. The protein contains six linear non-contiguous domains, a putative ATP-binding site and four polymerase motifs previously described for the L proteins of negative-strand RNA viruses. Phylogenetic analysis of domain III of 14 different L proteins suggests the pneumoviruses to be as distant in evolutionary terms from the other members of the Paramyxoviridae as are the Filoviridae.
Collapse
Affiliation(s)
- J S Randhawa
- Department of Biological Sciences, University of Warwick, UK
| | | | | | | | | | | |
Collapse
|
34
|
Edmiston CE, Suarez EC, Walker AP, Demeure MP, Frantzides CT, Schulte WJ, Wilson SD. Penetration of ciprofloxacin and fleroxacin into biliary tract. Antimicrob Agents Chemother 1996; 40:787-91. [PMID: 8851613 PMCID: PMC163200 DOI: 10.1128/aac.40.3.787] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Forty patients with chronic cholecystitis or cholelithiasis were prospectively randomized for therapy with either ciprofloxacin or fleroxacin to study the penetration of these two agents into gallbladder tissue, plasma, and bile. Patients received a 3-day course of ciprofloxacin (500 mg twice a day) or fleroxacin (400 mg once daily) and were subdivided into four groups reflecting intraoperative sample collection at 4, 7, 14, and 25 to 26 h following the last quinolone dose. Mean concentrations in plasma for ciprofloxacin and fleroxacin at 4 and 25 to 26 h postdose were 2.5 and 10 micrograms/ml and 0.3 and 1.8 micrograms/ml, respectively. The concentrations of ciprofloxacin and fleroxacin in bile and gallbladder wall tissue at 25 to 26 h postdose were 4.5 and 8.6 micrograms/ml and 1.2 and 4.4 micrograms/ml, respectively. Both agents demonstrate rapid tissue penetration with persistence at levels appropriate for treatment of biliary pathogens.
Collapse
Affiliation(s)
- C E Edmiston
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226, USA.
| | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
A theoretical model is developed in which the force that restores a soft hydrogel lens to its centered position is ascribed to flexure of the lens. It is shown that flexure makes the dominant contribution to the strain energy in the displaced position. The restoring force is calculated explicitly. The return speed is estimated explicitly, assuming that the dominant resisting force is the viscous drag offered by the postlens tear film. Satisfactory agreement with observations is found.
Collapse
Affiliation(s)
- A J Taylor
- Department of Mathematics, University of Manchester, UK
| | | |
Collapse
|
36
|
Wilson SD, Munson AE. Silicone-induced modulation of natural killer cell activity. Curr Top Microbiol Immunol 1996; 210:199-208. [PMID: 8565558 DOI: 10.1007/978-3-642-85226-8_20] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Current controversy regarding the effects of silicone gel mammary implants on the immune system has led to increased focus on the potential biological activity of silicone materials. Studies were undertaken in the B6C3F1 mouse to evaluate the immunotoxicological effects of the following components of a mammary gel prosthesis: polydimethylsiloxane fluid, silicone gel, elastomer shell and a polyurethane implant cover. Material was implanted subcutaneously (s.c.) for either 10 or 180 days. The only toxicological or immunological parameter which differed from control values was the natural killer (NK) cell activity in gel implanted mice. In these animals, basal NK activity was decreased. NK activity was comparably inhibited in female Fischer 344 rats implanted with silicone gel following short term (14 or 30 days) as well as chronic (1 year) exposure. The response was variable in both the rat and mouse. Host resistance to B16F10 melanoma in the mouse is known to be related to NK activity. Despite suppression of NK activity following gel implantation, host resistance was unaltered. Inhibition of NK activity by the administration of anti-asialo GM1 indicated that resistance was not adversely affected until NK activity was decreased by 40 to 50%. As with basal NK activity, augmented NK activity was inhibited in gel implanted rats when compared to controls. Administration of polyinosinic:polycytidylic acid to gel implanted rats resulted in an increase of approximately 65% in NK activity compared to gel implanted controls. This level of augmented NK activity was significantly less than the level of augmented NK activity in vehicle implanted animals where 100% enhancement in NK activity was noted. The results of these studies indicate that (1) NK cytolytic activity is altered in two animal models, the mouse and rat, although the results were variable, that (2) the level of suppression noted in the mouse is ineffective when compared to the level of suppression required to alter host resistance to B16F10 melanoma and that (3) the gel implanted animals exhibit a suppressed response to NK augmentation.
Collapse
Affiliation(s)
- S D Wilson
- Department of Pharmacology/Toxicology, Medical College of Virginia/Virginia Commonwealth University, Richmond, USA
| | | |
Collapse
|
37
|
Packman KS, Demeure MJ, Doffek KM, Wilson SD. Increased plasminogen activator and type IV collagenase activity in invasive follicular thyroid carcinoma cells. Surgery 1995; 118:1011-6; discussion 1016-7. [PMID: 7491516 DOI: 10.1016/s0039-6060(05)80107-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND An essential difference between benign and malignant follicular thyroid tumors is the ability to invade and metastasize. Thyrotropin (TSH) stimulates invasion of cultured human follicular thyroid cancer cells (FTC-133) via a protein kinase C (PKC) dependent mechanism. Tumor invasion depends on degradation of extracellular matrix by proteases. METHODS We analyzed protease activity in FTC-133 and its more invasive clone, FTC-238. Cells were treated with TSH or 12-0-tetradecanoyl-phorbol-13-acetate (TPA), a PKC agonist, for 24 hours. Conditioned medium and cellular extract were subjected to substrate gel zymography with either casein-plasminogen or gelatin (collagen). Western blot and immunohistochemistry confirmed protease identity. RESULTS We found increased 50 kd urokinase-like plasminogen activator (uPA) and 62 kd gelatinase activity by FTC-238 cells compared with the less invasive FTC-133 cells. There was no effect of TSH on uPA or collagenase activity at concentrations of 0.01 to 10 mU/ml. In both FTC-133 and FTC-238, TPA incubations of 0.1 to 100 ng/ml caused a dose-dependent increase in uPA and a 94 kd type IV collagenase. CONCLUSIONS These findings show that TSH-stimulated invasion may be due to PKC-induced activation of uPA and 94 kd type IV collagenase. uPA and basement membrane type IV collagenase warrant investigation as markers for follicular thyroid cancer.
Collapse
Affiliation(s)
- K S Packman
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226, USA
| | | | | | | |
Collapse
|
38
|
Abstract
An attempt is made to gain a greater understanding of lens binding during overnight wear. To do this, a mathematical model is used to investigate the motion of a rigid gas permeable (RGP) lens normal to the eye surface, when the eye is closed. Graphs of the displacement of the lens as a function of time are computed for different lens designs. The rate of apical tear film thinning is found to depend upon the central fitting relation, with lenses that are fitted flatter giving the highest rate of thinning. The model also suggests the relevance of other factors such as eyelid muscle tension and tear-layer composition during sleep to the clinical phenomenon of lens binding.
Collapse
Affiliation(s)
- A J Taylor
- Department of Mathematics, University of Manchester, UK
| | | |
Collapse
|
39
|
Reader RJ, Wilson SD, Belcher JW, Wisheu I, Keddy PA, Tilman D, Morris EC, Grace JB, McGraw JB, Olff H, Turkington R, Klein E, Leung Y, Shipley B, van Hulst R, Johansson ME, Nilsson C, Gurevitch J, Grigulis K, Beisner BE. Plant Competition in Relation to Neighbor Biomass: An Intercontinental Study with POA Pratensis. Ecology 1994. [DOI: 10.2307/1939634] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
40
|
Demeure MJ, Doffek KM, Rezaee M, Goretzki PE, Wilson SD. Diminished expression of the alpha 5 beta 1 integrin (fibronectin receptor) by invasive clones of a human follicular thyroid cancer cell line. World J Surg 1994; 18:569-75; discussion 575-6. [PMID: 7725746 DOI: 10.1007/bf00353767] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Altered adhesion plaques have been observed in transformed cell lines and are associated with enhanced metastatic potential. The prototypical adhesion plaque is formed by alpha 5 beta 1 fibronectin receptors (FnRs) interacting with the cellular actin network. We have found differences in the actin networks of noninvasive (FTC-133) and invasive (FTC-236, FTC-238) clones of a human follicular thyroid cancer cell line. Furthermore, thyroid-stimulating hormone (TSH) induces stress fibers in FTC-133. In order to investigate differences in adhesion plaques, expression of fibronectin (FN) and its receptor by these cells was analyzed. For these studies FTC-133, FTC-236, and FTC-238 were cultured in serum-depleted DME-H21 medium for 24 hours before the addition of TSH 30 mU/ml. No quantitative differences were noted in FN expression on Western blot in either the conditioned medium or cellular extracts. Western blots and immunohistochemical studies indicated that TSH induced secretion of FN only in FTC-133. Flow cytometry with an alpha 5 antibody demonstrated a 52% and 45% reduction (p < 0.01) in expression of FnR by FTC-236 and FTC-238, respectively, compared to FTC-133; this finding was supported by immunohistochemistry results. TSH treatment did not alter FnR expression. From these studies, we conclude that invasive clones of FTC decrease their expression of FnRs without changing their expression of FN. Furthermore, TSH treatment may promote FN secretion by FTC-133, although it does not seem to affect FnR or absolute FN expression. The diminished expression of FnR adhesion plaques may enhance metastatic potential in some follicular thyroid cancers.
Collapse
Affiliation(s)
- M J Demeure
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226, USA
| | | | | | | | | |
Collapse
|
41
|
Carlson MA, Ludwig KA, Frantzides CT, Cattey RP, Henry LG, Walker AP, Schulte WJ, Wilson SD. Routine or selective intraoperative cholangiography in laparoscopic cholecystectomy. J Laparoendosc Surg 1993; 3:27-33. [PMID: 8453125 DOI: 10.1089/lps.1993.3.27] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The routine versus selective use of intraoperative cholangiography has been the subject of debate for some time. Most authors currently advocate routine intraoperative cholangiography with laparoscopic cholecystectomy. The authors report their experience with the selective and routine utilization of intraoperative cholangiography at two institutions. At institution A, 155 laparoscopic cholecystectomies were attempted, and 21 cholangiograms were performed (based on preoperative criteria of ultrasound, liver function tests, and history of jaundice, or intraoperative anatomical uncertainty). At institution B, 164 laparoscopic cholecystectomies were attempted and 127 cholangiograms were performed (a routine intraoperative cholangiography policy). At institution A, there were no common bile duct injuries but there was one retained stone. At institution B, there was one common bile duct injury and no retained stones. The patient with the retained stone from institution A had a preoperative indication (total bilirubin = 4.4 mg/dl) for a cholangiogram, but it was not performed due to technical difficulties. This patient later required endoscopic sphincterotomy with stone extraction. One patient at institution B had a choledochotomy which was detected by intraoperative cholangiography (IOC). This was managed with a T-tube. The selective use of cholangiograms in laparoscopic cholecystectomy will not yield a higher incidence of common bile duct injuries or retained stones compared to routine use. Further, a cholangiogram may not necessarily prevent choledochotomy but can prevent extension of common bile duct injury. Thus, it should always be performed when there is anatomic uncertainty.
Collapse
Affiliation(s)
- M A Carlson
- Department of Surgery, Medical College of Wisconsin, Milwaukee
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Wilson SD. Zollinger-Ellison syndrome in children: a 25-year follow-up. Surgery 1991; 110:696-702; discussion 702-3. [PMID: 1925958] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The influence of gastric resection on the Zollinger-Ellison syndrome (ZES) in eight children was first reported to the Central Surgical Association 26 years ago. That report showed that the three children who had less than total gastrectomy were all dead with complications of gastric acid hypersecretion, although the five children who had total gastrectomy were living and well. During the past quarter of the century, the development of effective gastric acid inhibitors has prompted a greater emphasis on medical management in the ZES. The role of the surgeon and total gastrectomy remains controversial. Follow-up of the five young patients who had total gastrectomy shows that only one patient was dead with tumor 14 years after total gastrectomy and that the remaining four patients were alive 30, 29, 28, and 27 years, respectively, after total gastrectomy. Growth and activity have been near normal. All patients have had proven metastatic islet-cell carcinoma documented at some time in the course of the disease (lymph nodes in three patients and liver metastasis in two patients). Only one of the four living patients with total gastrectomy had a normal serum gastrin level and no apparent tumor. Gastrinoma tumor growth appears to be less aggressive in children than in adults. Complete excision of gastrinomas is possible in some patients with ZES. When hypergastrinemia persists, total gastrectomy may be preferable to lifelong medical management with gastric acid inhibitors in children and young adults with ZES.
Collapse
Affiliation(s)
- S D Wilson
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226
| |
Collapse
|
43
|
Jackson CE, Norum RA, Boyd SB, Talpos GB, Wilson SD, Taggart RT, Mallette LE. Hereditary hyperparathyroidism and multiple ossifying jaw fibromas: a clinically and genetically distinct syndrome. Surgery 1990; 108:1006-12; discussion 1012-3. [PMID: 2123361] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A large previously reported family with hyperparathyroidism has been reinvestigated recently because of the occurrence of multiple ossifying jaw fibromas in two affected members of the third generation similar to the jaw tumors of four of five affected members of the first generation. These maxillary and mandibular tumors can be differentiated from the "brown tumors" of hyperparathyroidism because they can appear and enlarge even though the hypercalcemia is surgically corrected. These tumors are histologically distinct fibroosseous lesions without the giant cells seen in "brown tumors." The parathyroid enlargement was mostly uniglandular, with multiple tumors found occasionally. Studies in DNA linkage were performed within this large family and a similar family in Houston to determine if the gene for this syndrome, termed HRPT2, is linked to DNA markers on chromosome 11, to which the gene for multiple endocrine neoplasia (MEN) type 1 has been linked. (This linkage is supported by our findings in one family with MEN 1 reported here.) Linkage studies were also performed with markers on chromosome 10, to which the genes for MEN 2A and MEN 2B have been linked. Evidence against close linkage with chromosome 10 and chromosome 11 markers suggests that this clinically distinct syndrome is also genetically distinct.
Collapse
Affiliation(s)
- C E Jackson
- Department of Medicine, Henry Ford Hospital, Detroit, MI 48202
| | | | | | | | | | | | | |
Collapse
|
44
|
Miller MD, Wilson SD, Dorf ME, Seuanez HN, O'Brien SJ, Krangel MS. Sequence and chromosomal location of the I-309 gene. Relationship to genes encoding a family of inflammatory cytokines. The Journal of Immunology 1990. [DOI: 10.4049/jimmunol.145.8.2737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
We previously reported the isolation and characterization of a cDNA clone, I-309, that encodes a small secreted protein produced by activated human T lymphocytes. This protein is structurally related to a large number of recently identified proteins that are secreted upon cellular activation. In this report we describe the isolation and characterization of the gene encoding I-309. The genomic organization is essentially identical to that found in the genes encoding the structurally similar proteins TCA-3, hJE/MCP-1, and mJE, strengthening the hypothesis that these genes are evolutionarily related. The region of the I-309 gene 5' of the mRNA cap site exhibits extensive nucleotide sequence homology with the same region of the murine gene TCA-3, providing additional evidence that I-309 and TCA-3 are likely to be homologs. Finally, panels of rodent-human somatic cell hybrids were used to map the I-309 gene to human chromosome 17. In conjunction with recent mapping data from other laboratories, this result suggests the presence of a cluster of related genes on this chromosome.
Collapse
Affiliation(s)
- M D Miller
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - S D Wilson
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - M E Dorf
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - H N Seuanez
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - S J O'Brien
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | - M S Krangel
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| |
Collapse
|
45
|
Wilson SD, Kuchroo VK, Israel DI, Dorf ME. Expression and characterization of TCA3: a murine inflammatory protein. J Immunol 1990; 145:2745-50. [PMID: 2212660] [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: 12/30/2022]
Abstract
TCA3 is a cDNA originally isolated from activated T cells. Transcription of this gene has been shown to correlate with Ag-induced cellular activation of both T cells and mast cells. Based on the predicted amino acid sequence encoded by the cDNA, we previously proposed that TCA3 represents a cytokine. In this report we have used rDNA technology to express TCA3 in two mammalian cell lines. In both cases, TCA3 was expressed as a secreted molecule with an apparent molecular mass of 16 kDa. Digestion of the (rTCA3) with the enzyme N-glycanase revealed that approximately 8 kDa is caused by N-linked glycosylation. Intradermal injection of rTCA3 into mouse footpads resulted in a rapid swelling response. The sites of injection were characterized histologically by a local accumulation of neutrophils. These findings are discussed with particular attention to a family of related proteins, some of whose members also have inflammatory properties.
Collapse
Affiliation(s)
- S D Wilson
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | | | | | | |
Collapse
|
46
|
Wilson SD, Kuchroo VK, Israel DI, Dorf ME. Expression and characterization of TCA3: a murine inflammatory protein. The Journal of Immunology 1990. [DOI: 10.4049/jimmunol.145.8.2745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
TCA3 is a cDNA originally isolated from activated T cells. Transcription of this gene has been shown to correlate with Ag-induced cellular activation of both T cells and mast cells. Based on the predicted amino acid sequence encoded by the cDNA, we previously proposed that TCA3 represents a cytokine. In this report we have used rDNA technology to express TCA3 in two mammalian cell lines. In both cases, TCA3 was expressed as a secreted molecule with an apparent molecular mass of 16 kDa. Digestion of the (rTCA3) with the enzyme N-glycanase revealed that approximately 8 kDa is caused by N-linked glycosylation. Intradermal injection of rTCA3 into mouse footpads resulted in a rapid swelling response. The sites of injection were characterized histologically by a local accumulation of neutrophils. These findings are discussed with particular attention to a family of related proteins, some of whose members also have inflammatory properties.
Collapse
Affiliation(s)
- S D Wilson
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - V K Kuchroo
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - D I Israel
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - M E Dorf
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| |
Collapse
|
47
|
Miller MD, Wilson SD, Dorf ME, Seuanez HN, O'Brien SJ, Krangel MS. Sequence and chromosomal location of the I-309 gene. Relationship to genes encoding a family of inflammatory cytokines. J Immunol 1990; 145:2737-44. [PMID: 2212659] [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: 12/30/2022]
Abstract
We previously reported the isolation and characterization of a cDNA clone, I-309, that encodes a small secreted protein produced by activated human T lymphocytes. This protein is structurally related to a large number of recently identified proteins that are secreted upon cellular activation. In this report we describe the isolation and characterization of the gene encoding I-309. The genomic organization is essentially identical to that found in the genes encoding the structurally similar proteins TCA-3, hJE/MCP-1, and mJE, strengthening the hypothesis that these genes are evolutionarily related. The region of the I-309 gene 5' of the mRNA cap site exhibits extensive nucleotide sequence homology with the same region of the murine gene TCA-3, providing additional evidence that I-309 and TCA-3 are likely to be homologs. Finally, panels of rodent-human somatic cell hybrids were used to map the I-309 gene to human chromosome 17. In conjunction with recent mapping data from other laboratories, this result suggests the presence of a cluster of related genes on this chromosome.
Collapse
Affiliation(s)
- M D Miller
- Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
| | | | | | | | | | | |
Collapse
|
48
|
Wilson SD, Billings PR, D'Eustachio P, Fournier RE, Geissler E, Lalley PA, Burd PR, Housman DE, Taylor BA, Dorf ME. Clustering of cytokine genes on mouse chromosome 11. J Exp Med 1990; 171:1301-14. [PMID: 1969921 PMCID: PMC2187827 DOI: 10.1084/jem.171.4.1301] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The presence of positionally conserved amino acid residues suggests that the mouse proteins TCA3, P500, MIP1-alpha, MIP1-beta, and JE are members of a single gene family. These proteins are activation specific and can be expressed by both myeloid and lymphoid cells. MIP1-alpha/MIP1-beta and MCAF (the putative human homologue of JE) act as chemotactic and activating agents for neutrophils and macrophages, respectively. The functions of TCA3 and P500 are unknown. We have used interspecies somatic cell hybrids and recombinant inbred mouse strains to show that the genes encoding TCA3, MIP1-alpha, MIP1-beta, and JE (provisionally termed Tca3, Mip-1a, Mip-1b, and Sigje, respectively) map as a cluster on the distal portion of mouse chromosome 11 near the Hox-2 gene complex. DNA sequence analysis indicates that the P500 and TCA3 proteins are encoded by alternative splicing products of one genomic gene. Additionally, the genes encoding TCA3 and JE are found to be strikingly similar with respect to the positions of intron-exon boundaries. Together, these data support the model that the cytokines TCA3, P500, MIP1-alpha, MIP1-beta, and JE are encoded by a single cluster of related genes. The gene encoding IL-5 (Il-5), which acts as a T cell-replacing factor, a B cell growth factor, and an eosinophil differentiation factor, is also mapped to mouse chromosome 11.Il-5 maps approximately 25 cM proximal to the Tca-3 gene and appears tightly linked to a previously described gene cluster that includes Il-3, Il-4, and Csfgm. We discuss the potential relevance of the two cytokine gene clusters described here with particular attention to specific human hematologic malignancies associated with chromosomal aberrations at corresponding locations on human chromosomes 5 and 17.
Collapse
Affiliation(s)
- S D Wilson
- Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115
| | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Cattey RP, Wilson SD. Cholelithiasis follows total gastrectomy in Zollinger-Ellison syndrome. Surgery 1989; 106:1070-3. [PMID: 2588114] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The frequent occurrence of cholelithiasis noted in the follow-up of patients who underwent total gastrectomy because of Zollinger-Ellison syndrome prompted us to study this phenomenon. Cholelithiasis is known to be more common after truncal vagotomy, with or without concomitant subtotal gastric resection, and the prevalence of gallstones in these patients is reported to be 16% to 38%. To date, however, no long-term study has investigated the prevalence of gallstones after total gastrectomy in patients with the Zollinger-Ellison syndrome. Since 1961, 26 patients with the Zollinger-Ellison syndrome have undergone total gastrectomy and were enrolled in a Medical College of Wisconsin Clinical Research Center protocol that allowed follow-up to assess the development of cholelithiasis. Eight patients had cholecystectomy at the time of total gastrectomy (seven patients had stones), leaving 18 patients with a normal gallbladder and no gallstones at the time of total gastrectomy. Four patients died early, two of surgical complications, one of tumor progression, and one of alcohol-related trauma. During follow-up, cholelithiasis has developed in 10 of 14 patients (71%) at risk; the mean time to gallstones was 6.3 years (range, 1.2 to 12.9 years). The predictable occurrence of cholelithiasis after total gastrectomy in patients with the Zollinger-Ellison syndrome suggests that cholecystectomy should be performed at the time of total gastrectomy.
Collapse
Affiliation(s)
- R P Cattey
- Department of Surgery, Medical College of Wisconsin, Milwaukee 53226
| | | |
Collapse
|
50
|
Krubsack AJ, Wilson SD, Lawson TL, Kneeland JB, Thorsen MK, Collier BD, Hellman RS, Isitman AT. Prospective comparison of radionuclide, computed tomographic, sonographic, and magnetic resonance localization of parathyroid tumors. Surgery 1989; 106:639-44; discussion 644-6. [PMID: 2678555] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The appropriate choice of imaging techniques to localize parathyroid tumors preoperatively remains controversial. We report the first prospective, blinded study to compare the efficacy of four imaging modalities in 100 patients with primary hyperparathyroidism (pHPT). Patients were examined by computer-assisted thallium 201/technetium 99m subtraction scintigraphy (TTS), computed tomography (CT), ultrasonography (US), and magnetic resonance (MR). Each study was performed and interpreted independently. Subsequent neck exploration and "curative" parathyroidectomy allowed correlation of surgical findings with imaging reports to score their accuracy. Overall sensitivities of the four imaging modalities were TTS, 73%, CT, 68%, US, 55%; and MR, 57%; with respective specificities of 94%, 92%, 95%, and 87%. Sensitivities for lesions located below the thyroid gland (thymic tongue and mediastinum) were TTS, 90%; CT, 46%; US, 44%; and MR, 50%; with respective specificities of 100%, 99%, 100%, and 94%. There was a significant increase in overall sensitivity when TTS and CT (90%, p less than 0.01) or TTS and US (85%, p less than 0.05) were used together; however, the combination of any three or even four imaging modalities did not increase sensitivity further. For small parathyroid tumors (less than or equal to 250 mg), no imaging technique had a sensitivity of more than 50%. None of the imaging studies accurately localized small hyperplastic parathyroid glands found in patients with multiple gland disease. Preoperative parathyroid imaging may not be indicated in pHPT patients undergoing first-time neck exploration because surgeons experienced in parathyroid surgery have a 93% to 96% cure rate.
Collapse
Affiliation(s)
- A J Krubsack
- Department of Radiology, Medical College of Wisconsin, Milwaukee 53226
| | | | | | | | | | | | | | | |
Collapse
|