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Thompson DW, Barrett PB, Lefelhocz JP, Lock GA. Apparent Five-Coordinate Metal Complexes: Evidence for Trifunctional Bridge Bonding with the 3-Cyano-2,4-Pentanedionate Ligand in the Trichloro(3-Cyano-2,4-Pentanedionato) Complexes of Tin(IV) and Titanium(IV). J COORD CHEM 2006. [DOI: 10.1080/00958977308073796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- D. W. Thompson
- a Department of Chemistry , College of William and Mary , Williamsburg , Virginia , 23185
| | - P. B. Barrett
- a Department of Chemistry , College of William and Mary , Williamsburg , Virginia , 23185
| | - J. P. Lefelhocz
- a Department of Chemistry , College of William and Mary , Williamsburg , Virginia , 23185
| | - G. A. Lock
- a Department of Chemistry , College of William and Mary , Williamsburg , Virginia , 23185
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Davis LM, Compton JM, Kranbuehl DE, Thompson DW, Southward RE. Reflective and electrically conductive palladium surface-metallized polyimide nanocomposite membranes. J Appl Polym Sci 2006. [DOI: 10.1002/app.24162] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Davis LM, Thompson DS, Dean CJ, Pevzner M, Scott JL, Broadwater ST, Thompson DW, Southward RE. Silver–polyimide nanocomposite membranes: Macromolecular-matrix-mediated metallization of an aromatic, fluorinated polyimide yielding highly reflective films at low metal concentrations. J Appl Polym Sci 2006. [DOI: 10.1002/app.25384] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nosal WH, Thompson DW, Yan L, Sarkar S, Subramanian A, Woollam JA. Infrared optical properties and AFM of spin-cast chitosan films chemically modified with 1,2 Epoxy-3-phenoxy-propane. Colloids Surf B Biointerfaces 2005; 46:26-31. [PMID: 16199143 DOI: 10.1016/j.colsurfb.2005.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 08/04/2005] [Accepted: 08/06/2005] [Indexed: 11/26/2022]
Abstract
Chemical modification of spin-cast chitosan films has been performed. This modification involves the attachment of 1,2 Epoxy-3-phenoxy-propane, commonly known as glycidyl phenyl ether (GPE), to the amine group of the chitosan molecule. Optical properties of modified films have been determined in the infrared region of the spectrum using spectroscopic ellipsometry, and are reported in this paper. Special attention is paid to the infrared region where the index of refraction and extinction coefficients from 750 to 4000 cm(-1) were determined. Difference plots of IR optical data before and after chemical modification were generated to confirm that modification had occurred. Optical modeling of infrared spectroscopic ellipsometry (IRSE) data with respect to chemical bond vibrations has also been performed. This modeling involved curve fitting of resonant chemical bond absorptions using Lorentz oscillators. These oscillator models allow for comparison of modified chitosan to unmodified chitosan. The purpose of this research was to determine infrared optical constants of chemically modified chitosan films This work shows that surface chemistry of biomaterials can be studied quite sensitively with spectroscopy ellipsometry, detecting as little as 100 ng/cm(2) of GPE.
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Affiliation(s)
- W H Nosal
- Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, USA
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Nosal WH, Thompson DW, Yan L, Sarkar S, Subramanian A, Woollam JA. UV-vis-infrared optical and AFM study of spin-cast chitosan films. Colloids Surf B Biointerfaces 2005; 43:131-7. [PMID: 15935626 DOI: 10.1016/j.colsurfb.2004.08.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 08/24/2004] [Indexed: 11/27/2022]
Abstract
Optical properties of spin-cast chitosan films have been determined in the infrared, visible, and ultraviolet region of the spectrum using spectroscopic ellipsometry. Optical constants for the UV-vis-near IR spectra from 130 to 1700 nm were determined using Cauchy dispersion forms combined with Lorentzian oscillator models in the absorptive shorter wavelength regions. Infrared index of refraction and extinction coefficients from 750 to 4000 cm(-1) were determined using ellipsometric data fits to dispersion models based on harmonic oscillators. This modeling determined that optical anisotropy was present and measurable over all wavelength regions of ellipsometric data. To obtain information on the micro- and nano-scale surface structure, tapping mode atomic force microscopy (AFM) imaging was employed to determine morphology and roughness information of dry spin-cast chitosan films.
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Affiliation(s)
- W H Nosal
- Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, USA
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Warner JD, Pevzner M, Dean CJ, Kranbuehl DE, Scott JL, Broadwater ST, Thompson DW, Southward RE. Synthesis of hexafluoroisopropylidene-containing polyimide-silver nanocomposite films evolving specularly reflective metal surfaces. ACTA ACUST UNITED AC 2003. [DOI: 10.1039/b212546c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zitzelberger TJ, Schiavelli MD, Thompson DW. A facile and selective methylation of 5-en-3-yn-1-ols with titanium tetrachloride-trimethylaluminum yielding (3Z)-4-methylalka-3,5-dien-1-ols. J Org Chem 2002. [DOI: 10.1021/jo00172a068] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Thompson DW, Munsey WRC, Harris TV. Preparation and characterization of chloro(alkoxy)bis(2,4-pentanedionato)titanium(IV) complexes. Inorg Chem 2002. [DOI: 10.1021/ic50127a053] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Schultz FW, Ferguson GS, Thompson DW. Transition metal-promoted alkylations of unsaturated alcohols: the ethylation of 3-butyn-1-ol and 3-buten-1-ol via titanium tetrachloride-organoaluminum Ziegler-Natta catalyst systems. J Org Chem 2002. [DOI: 10.1021/jo00184a014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
BACKGROUND Intravenous thrombolysis with tissue plasminogen activator is an approved and effective therapy for acute ischemic stroke within the first 3 hours from onset. In addition to the risk of hemorrhage, there is a risk of postrecanalization cerebral edema. The authors present the case of a patient with an ischemic stroke treated successfully with intra-arterial thrombolysis who subsequently developed massive brain edema in the face of clinical improvement. CASE An 81-year-old man presented within 1 hour of developing a full right middle cerebral artery (MCA) syndrome. Computed tomography (CT) was normal. A cerebral angiogram demonstrated an occlusion of the M1 segment of the right MCA. The patient was treated with intra-arterial urokinase 750,000 units. He recovered during the procedure. Serial CT scans demonstrated progressive edema with mass effect in the right MCA distribution. The patient remained asymptomatic except for a mild sensory deficit. DISCUSSION Postrecanalization cerebral edema is an uncommon but potentially lethal complication of thrombolysis. It is postulated that the edema is due to ischemic injury aggravated by reperfusion with vasogenic edema. The presence of this massive edema is usually associated with clinical worsening. The present case illustrates that this disorder can be associated with good outcome.
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Affiliation(s)
- S Cruz-Flores
- Souers Stroke Institute, Department of Neurology, Saint Louis University Health Sciences Center, 3635 Vista Avenue, St. Louis, MO, USA.
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Scaltrito DV, Fry HC, Showalter BM, Thompson DW, Liang HC, Zhang CX, Kretzer RM, Kim E, Toscano JP, Karlin KD, Meyer GJ. Reversible carbon monoxide photodissociation from Cu(I) coordination compounds. Inorg Chem 2001; 40:4514-5. [PMID: 11511192 DOI: 10.1021/ic010684r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- D V Scaltrito
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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Abstract
The Northern Hemisphere annular mode (NAM) (also known as the North Atlantic Oscillation) is shown to exert a strong influence on wintertime climate, not only over the Euro-Atlantic half of the hemisphere as documented in previous studies, but over the Pacific half as well. It affects not only the mean conditions, but also the day-to-day variability, modulating the intensity of mid-latitude storms and the frequency of occurrence of high-latitude blocking and cold air outbreaks throughout the hemisphere. The recent trend in the NAM toward its high-index polarity with stronger subpolar westerlies has tended to reduce the severity of winter weather over most middle- and high-latitude Northern Hemisphere continental regions.
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Affiliation(s)
- D W Thompson
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, USA.
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Zangooie S, Schubert M, Trimble C, Thompson DW, Woollam JA. Infrared ellipsometry characterization of porous silicon bragg reflectors. Appl Opt 2001; 40:906-912. [PMID: 18357071 DOI: 10.1364/ao.40.000906] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We investigate porous silicon Bragg reflectors in a nondestructive manner using variable angle-of-incidence infrared spectroscopic ellipsometry. In addition to the thickness, volume porosity, inhomogeneity, and optical anisotropy, properties of the solid content of the porous material are investigated in terms of dielectric function and surface chemistry. The material was found to have positive birefringence. The high sensitivity of the technique is employed to detect and identify infrared resonant absorptions related to different Si-H as well as Si-O-Si vibrational modes. The average electrical resistivity of the solid content of the porous material is determined to be 0.03 Omega cm, which is larger than the corresponding bulk value of 0.019 Omega cm. Furthermore the average carrier concentration in the porous material shows a decrease from 6.2 x 10(18) cm(-3) to 4 x 10(18) cm(-3).
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Affiliation(s)
- M Yang
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
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Hartmann DL, Wallace JM, Limpasuvan V, Thompson DW, Holton JR. Can ozone depletion and global warming interact to produce rapid climate change? Proc Natl Acad Sci U S A 2000; 97:1412-7. [PMID: 10677475 PMCID: PMC26447 DOI: 10.1073/pnas.97.4.1412] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/1999] [Indexed: 11/18/2022] Open
Abstract
The atmosphere displays modes of variability whose structures exhibit a strong longitudinally symmetric (annular) component that extends from the surface to the stratosphere in middle and high latitudes of both hemispheres. In the past 30 years, these modes have exhibited trends that seem larger than their natural background variability, and may be related to human influences on stratospheric ozone and/or atmospheric greenhouse gas concentrations. The pattern of climate trends during the past few decades is marked by rapid cooling and ozone depletion in the polar lower stratosphere of both hemispheres, coupled with an increasing strength of the wintertime westerly polar vortex and a poleward shift of the westerly wind belt at the earth's surface. Annular modes of variability are fundamentally a result of internal dynamical feedbacks within the climate system, and as such can show a large response to rather modest external forcing. The dynamics and thermodynamics of these modes are such that strong synergistic interactions between stratospheric ozone depletion and greenhouse warming are possible. These interactions may be responsible for the pronounced changes in tropospheric and stratospheric climate observed during the past few decades. If these trends continue, they could have important implications for the climate of the 21st century.
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Affiliation(s)
- D L Hartmann
- Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195-1640, USA
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Thompson DW, Furlan AJ. Clinical epidemiology of stroke. Neurosurg Clin N Am 1997; 8:265-9. [PMID: 9113708] [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: 02/04/2023]
Abstract
The effect of stroke as a major health issue in the United States is well established. Well-designed epidemiologic studies have contributed important information about the natural history of stroke and its associated risk factors. These cerebrovascular profiles have provided the foundation for many of the current ischemic stroke trials, but the cause and prevention of the hemorrhagic subtypes remain elusive.
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Affiliation(s)
- D W Thompson
- Department of Neurology, St. Louis University Health Sciences Center, St. Louis, Missouri 63110-0250, USA
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Abstract
The effect of stroke as a major health issue in the United States is well established. Well-designed epidemiologic studies have contributed important information about the natural history of stroke and its associated risk factors. These cerebrovascular profiles have provided the foundation for many of the current ischemic stroke trials, but the cause and prevention of the hemorrhagic subtypes remain elusive.
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Affiliation(s)
- D W Thompson
- Department of Neurology, Saint Louis University Health Sciences Center, Missouri, USA
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Thompson DW, Wood DE, Lipa M, Miyazaki JH, Khatri N. Gynecologic cytology from the perspective of the Laboratory Proficiency Testing Program, Ontario, Canada. Acta Cytol 1995; 39:207-21. [PMID: 7887068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The accumulated test results from annual proficiency testing of approximately 150 cytology laboratories during the period 1977-1992 were analyzed. Several features of the test program are presented, including the adaptability of the uniform diagnostic terminology that was in use throughout. Observations include the impact of screening by a technologist; the better diagnostic performance generally, but not exclusively, in larger-volume laboratories; the degree of reproducibility of reporting in the laboratory; the ease of diagnosis in some diagnostic categories; and patterns observed in "false negative" and "false positive" rates. The follow-up analysis of suboptimal performance is recorded, and remedial and educational aspects are emphasized. The impact of levels of performance on the specific population being screened is correlated with the data on laboratory caseloads and with hospital vs. nonhospital laboratories.
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Affiliation(s)
- D W Thompson
- Laboratory Proficiency Testing Program, Toronto, Ontario, Canada
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Lipa M, Geddie W, Fletcher WA, Thompson DW, Turner-Smith L, Wood DE. Papanicolaou smear. CMAJ 1994; 150:1756-8. [PMID: 8054023 PMCID: PMC1337039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Thompson DW. Determination of volatile organic contaminants in bulk oils (edible, injectable, and other internal medicinal) by purge-and-trap gas chromatography/mass spectrometry. J AOAC Int 1994; 77:647-54. [PMID: 8012214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Purge-and-trap gas chromatography/mass spectrometry is evaluated for the quantitation of part-per-billion levels of volatile organic contaminants in bulk vegetable oils. Results using 2 purge techniques (direct purging of the heated oil and purging after dispersing the oil on an aluminum oxide powder) and 2 quantitative methods (standard curve and deuterium-labeled internal standard addition) are reported. Twenty volatile compounds and 8 vegetable oils were investigated. Recovery data and estimated detection limits for each compound are reported for each purge technique. Generally acceptable recoveries (70-130% for more than 90% of the analyte spikes) and acceptable detection levels (approximately 4-10 ppb) were obtained for all compounds using either the external standard curve or the deuterium-isotope-labeled internal standard. The use of a dispersant (such as alumina) for sample purging resulted in poor recoveries of the highly volatile contaminants.
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Affiliation(s)
- D W Thompson
- U.S. Food and Drug Administration, Southeast Regional Laboratory, Atlanta, GA 30309
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Narod SA, Thompson DW, Jain M, Wall C, Green LM, Miller AB. Dysplasia and the natural history of cervical cancer: early results of the Toronto Cohort Study. Eur J Cancer 1991; 27:1411-6. [PMID: 1835857 DOI: 10.1016/0277-5379(91)90022-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A sample of 176,808 Pap smears, taken from 70,236 women, was constructed from the records of a large cytopathology laboratory between 1962 and 1981. The prevalence of cervical dysplasia, based on the distribution of initial smear results, rose from 42.7 to 94.9 per 1000 during the study period. The relative risks (RR) for the manifestation of a malignancy (carcinoma in situ or worse) in a subsequent cervical smear were 1.48, 3.42, 20.9 and 71.5 for women with minimal, mild, moderate and severe dysplasia, respectively, compared with the entire cohort. The initial degree of dysplasia for women developing a malignancy was much more likely to be interpreted as moderate (RR = 5.0) or severe (RR = 42.3) than were those for controls. These results are strongly supportive of the hypothesis that the degree of dysplasia is related to the risk of development of cancer of the cervix.
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Affiliation(s)
- S A Narod
- McGill Centre for Human Genetics, Montreal General Hospital, Canada
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Thompson DW. The role of histologic assessment of endometrium and cytohormonal applications in the diagnosis and treatment of infertility. Curr Opin Obstet Gynecol 1990; 2:863-8. [PMID: 2130990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Thompson DW. Separation technology, edited by Norman N. Li and Heiner Strathmann, 1988, 633 pages. Published by the Engineering Foundation, New York, and distributed by the American Institute of Chemical Engineers, 345 East 47th St., New York, NY 10017. CAN J CHEM ENG 1989. [DOI: 10.1002/cjce.5450670524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Thompson DW. Canadian experience in cytology proficiency testing. Acta Cytol 1989; 33:484-6. [PMID: 2546350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The mandatory Laboratory Proficiency Testing Program (LPTP) of the province of Ontario as applied to cytology laboratories is briefly described. LPTP evaluates reporting of test slides to identify laboratories that have deficiencies. Such laboratories receive an on-site visit, followed by recommendations on means of improvement (especially educational) and subsequent monitoring. Most of the 18 cytology laboratories visited to date have shown an improved level of performance on later tests.
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Affiliation(s)
- D W Thompson
- Department of Pathology, University of Toronto, Ontario, Canada
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Hunter AG, D'Alton M, Ivey B, Wang HS, Thompson DW. Maternal sex chromosome mosaicism diagnosed by amniocentesis and percutaneous umbilical cord sampling. Prenat Diagn 1988; 8:673-5. [PMID: 3211856 DOI: 10.1002/pd.1970080907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 01/04/2023]
Abstract
We present a remarkable chain of events in which percutaneous umbilical cord sampling was performed in an attempt to clarify a situation of possible fetal sex chromosome mosaicism in an amniotic fluid culture and led to the discovery that the mother herself had a 45,X/46,XX/47,XXX chromosome constitution. This may have simply represented the chance concurrence of pseudo-mosaicism in the amniotic fluid culture of a woman with an abnormal sex chromosome constitution, but it is also possible that the 45,X colony was maternal in origin. Although clearly a most unusual circumstance, the possibility should be kept in mind when termination of a pregnancy is being considered because of apparent mosaicism in a prenatal diagnostic study.
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Affiliation(s)
- A G Hunter
- Division of Genetics, Children's Hospital of Eastern Ontario, Canada
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Thompson DW. Fluid mechanics and transfer processes, J. M. Kay and R. M. Nedderman, 1985, 602 pages. Published by Cambridge University Press, $69.50 US (hardcover), $29.95 US (paperback). CAN J CHEM ENG 1987. [DOI: 10.1002/cjce.5450650328] [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: 11/11/2022]
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Curry H, Thompson DW, Dietrich M, Lipa M, Massarella GR, Taves IR, Wood DE, Zuber E. Proficiency testing in cytology laboratories in Ontario, Canada: a decade of experience. II. Results of initial surveys. Acta Cytol 1987; 31:215-9. [PMID: 3296593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The results of the initial surveys in the cytology proficiency testing of the medical laboratories in the Province of Ontario, Canada, showed a high correlation between the opinions of the testing committee and the participants in the categories of "no abnormal cells," "metaplasia" and forms of "benign atypia." The proportion of times that slides were tested in the categories of dysplasia and malignancy in the surveys increased from 38% by the end of survey 3 to 46% by the end of survey 5. A progressive improvement in the diagnostic accuracy was demonstrated in the categories of malignancy and severe dysplasia while results were more variable in the categories of moderate and mild dysplasia. Several educational activities were initiated following survey 3, including development and circulation of demonstration sets of marked glass slides for repeated circulation to participants as well as copies of a slide/tape presentation describing the program and specific case material.
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Curry H, Thompson DW, Dietrich M, Lipa M, Massarella GR, Taves IR, Wood DE, Zuber E. Proficiency testing in cytology laboratories in Ontario, Canada: a decade of experience. III. A precision study of consistency and reproducibility in cytology reporting. Acta Cytol 1987; 31:220-5. [PMID: 3296594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The Ontario Laboratory Proficiency Testing Program's testing model and the results of early surveys of cytology laboratories have been previously described. To test consistency and accuracy, the same slides from one survey were recirculated to the same laboratory in the next survey. There was no statistical difference in either the accuracy or consistency in reporting by the various categories of personnel. Analysis of the data by category of diagnosis showed the reporting of "no abnormal cells" and "benign atypia" to be slightly more accurate and "moderate dysplasia" and "severe dysplasia" to be slightly less accurate than the reporting in other categories. Consistency in reporting appeared to be slightly less accurate in severe dysplasia than in the other categories. The analysis, which includes the results from all licensed cytology laboratories in Ontario, provides evidence that, in the reporting of cervical cytologic material, it is feasible to differentiate among the various categories within the spectrum of squamous epithelial abnormalities with a general level of accuracy and consistency that, although satisfactory, is not yet ideal.
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Curry H, Thompson DW, Dietrich M, Lipa M, Massarella GR, Taves IR, Wood DE, Zuber E. Proficiency testing in cytology laboratories in Ontario, Canada: a decade of experience. I. Introduction and description of the testing model. Acta Cytol 1987; 31:203-14. [PMID: 3296592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
There are few formally documented proficiency testing programs for cytology laboratories, and those that have been documented are not entirely comparable in format. The first of three papers documenting a mandatory universal proficiency testing program for cytology laboratories in the Province of Ontario, Canada, presents data on the structure and function of the participating laboratories (including a comparison of the data for 1974 and 1980) and on the organization of the testing model (including selection of terminology, construction and use of the survey and assessment of responses). In 1980, of the 463 medical laboratories in Ontario, 91 of 222 hospital laboratories and 65 of 216 nonhospital laboratories were licensed in cytology. In that year, the 156 cytology laboratories processed 1.48 million cytology specimens, 92% of which were gynecologic. Hospital laboratories processed 87.5% of the nongynecologic cytology specimens and 30% of the gynecologic cytology specimens. These proportions have been virtually constant for several years. Between 1974 and 1980, there was a trend in Ontario to fewer laboratories processing less than 5,000 cytology specimens per annum. Subsequent papers in this series describe the results of the initial surveys in this program and a precision study to evaluate the consistency of reporting by individual laboratories.
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Thompson DW. Reverse Osmosis and Ultrafiltration, S. Sourirajan and Takeshi Matsuura, editors. ACS Symposium Series No. 281, based on a symposium sponsored by the Division of Industrial and Engineering Chemistry, 188th meeting of the ACS, Philadelphia, August 1984. Published by the American Chemical Society, July 1985, consisting of 35 separate papers together with an author and a subject index, total 508 pages, $89.95 (U.S.). CAN J CHEM ENG 1986. [DOI: 10.1002/cjce.5450640529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Thompson DW. Evaluation of capillary gas chromatography for multicomponent drug analysis. J Assoc Off Anal Chem 1986; 69:811-3. [PMID: 2876979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Capillary gas chromatography is evaluated for multicomponent drug analysis. A 0.32 mm id X 30 m fused silica column and a 0.75 mm id X 30 m borosilicate glass column (both with OV-1 bonded phase) are investigated. Retention times (relative to caffeine) are presented for 39 drug components representing a variety of chemical classes and pharmacological activities. Reproducibility data are presented for both isothermal and programmed temperature runs on selected drug mixtures. Recovery data are provided for 2 multicomponent drug mixtures prepared to approximate over-the-counter antihistaminic and antitussive preparations.
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Abstract
Seventeen mutants of Streptococcus sanguis FW213 nonadherent to saliva-coated spheroidal hydroxyapatite were isolated after mutagenesis with ethyl methanesulfonate, nitrosoguanidine, nitrous acid, hydroxylamine, or 2-aminopurine. Enrichment for nonadherent mutants was accomplished by successive adsorptions of the adherent strains to saliva-coated hydroxyapatite. After enrichment, variant colonial morphology on tryptic agar was used as a screening technique for selection of nonadherent mutants, with loss of colonial opacity frequently associated with loss of adherence ability. These mutants were further characterized for additional surface properties, including twitching motility, saliva-induced aggregation, coaggregation with Actinomyces species, surface hydrophobicity, and presence of fimbriae. Results from these assays indicated that the nonadherent mutants fell into six phenotypic groups. A correlation between the loss of adherence ability, a decrease in cell fimbriation, and a decrease in surface hydrophobicity is apparent.
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Ruda MM, Thompson DW. Comparison of primal and dual solution methods for the chemical equilibrium problem using GRG and sensitivity analysis. CAN J CHEM ENG 1985. [DOI: 10.1002/cjce.5450630118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Heap PF, Berkovitz BK, Gillett MS, Thompson DW. An analytical ultrastructural study of the iron-rich surface layer in rat-incisor enamel. Arch Oral Biol 1983; 28:195-200. [PMID: 6574731 DOI: 10.1016/0003-9969(83)90147-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Electron-dense particles, approximately 4 nm (40 A) in diameter were present. Evidence is offered that these particles represent iron probably in the form of amorphous hydrous ferric hydroxide. From X-ray probe analytical data, it is suggested that this iron component is accommodated through the process of adsorption rather than by direct substitution of calcium and phosphorus. The iron-rich surface layer was more resistant to acid etching than subsurface enamel. Reported areas of reduced mineral density of enamel at the enamel-dentine junction appear to be preparation artifacts.
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Walton RJ, Allen HH, Anderson GH, Boyes DA, Blanchet M, Carmichael J, Gellman DD, Hill GB, Miller AB, Thompson DW, Kassirer E. [Detection of cervical cancer: report of the Canadian Working Group, 1982]. Union Med Can 1982; 111:856-61, 865-7. [PMID: 7179581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Abstract
A GLC method is described for the determination of iminodibenzyl and desipramine impurities in imipramine hydrochloride and its formulated products. These impurities were extracted from an alkaline solution with a mixture of 30% methylene chloride in hexane for chromatography on a 3% OV-17 GLC column. Iminodibenzyl was determined using anthracene as an internal standard and desipramine was determined (after derivatization) using nortriptyline as an internal standard. Based on spiked excipient mixtures typically used to compound imipramine tablets, recoveries were 93-109% for iminodibenzyl and 93-107% for desipramine at 0.2-0.4% of the labeled claim of imipramine. Minimum detection levels were approximately 0.02% for each impurity, and procedural standards gave coefficients of variation of less than 1% for each impurity. The method was linear in the 0.05-0.5 microgram range and typically gave correlation coefficients greater than or equal to 0.999.
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Berger ME, Thompson DW, Ricks RC, Kaufmann D. The medical technologist and the radiation-accident victim. Am J Med Technol 1981; 47:829-34. [PMID: 7332015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Radiation accidents may produce external or internal contamination with radionuclides, local or whole-body exposure to penetrating radiation, or a combination of these. Trauma and medical problems which require rapid diagnosis and treatment may accompany a radiation injury. The role of the medical technologist in the early post-injury period may include the use of precautions in handling of contaminated specimens, prompt and repeated determinations of the absolute lymphocyte count, establishment of baseline values of the cellular and chemical components of the blood, and urinalysis. Following significant whole-body exposure to penetrating radiation, laboratory tests are required to monitor the development of granulocytopenia and thrombocytopenia and to provide information necessary for the prevention, control, and treatment of infection and/or bleeding. Chromosome analysis may aid in dosimetry, and a procedure for collecting and shipping blood for analysis by experts in radiation cytogenetics is described.
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Bachman WJ, Alpert MY, Bargo E, Draper RE, Hock WH, Illuminati J, Lookabaugh M, Margosis M, Thompson DW. High pressure liquid chromatographic determination of antihistamine-adrenergic combination products: collaborative study. J Assoc Off Anal Chem 1981; 64:564-9. [PMID: 6113232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A reverse phase high pressure liquid chromatographic method in which ion-pairing is used for the determination of combinations of pseudoephedrine hydrochloride with triprolidine hydrochloride or chlorpheniramine maleate in syrups and tablets was collaboratively studied by 8 laboratories. Collaborators were supplied with 12 samples including synthetic and commercial syrup formulations and commercial tablet composites. Mean recoveries of pseudoephedrine hydrochloride and triprolidine hydrochloride from synthetic syrup formulations were 100.5 and 99.6%, respectively. Mean recoveries of pseudoephedrine hydrochloride and chlorpheniramine maleate from synthetic syrups were 98.8 and 100.5%, respectively. Mean coefficients of variation for syrups and tablets ranged from 1.68 to 3.07% for pseudoephedrine hydrochloride, from 2.92 to 3.85% for triprolidine hydrochloride, and from 1.34 to 2.15% for chlorpheniramine maleate. The method has been adopted official first action.
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Nelems JM, McEwan JD, Thompson DW, Walker GR, Pearson FG. Detection, localization, and treatment of occult bronchogenic carcinoma in nickel workers. J Thorac Cardiovasc Surg 1979; 77:522-5. [PMID: 423585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Asymptomatic men exposed to nickel sulfide prior to 1963 were studied prospectively to investigate cytologic abnormalities in the sputum. We discovered a considerably greater incidence of squamous cell tumors that would have been expected from subjects exposed only to cigarette smoke.
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Thompson DW, Kaplan W, Phillips BJ. The effect of freezing and the influence of isolation medium on the recovery of pathogenic fungi from sputum. Mycopathologia 1977; 61:105-9. [PMID: 335251 DOI: 10.1007/bf00443838] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The primary objective of this study was to determine whether freezing sputa in dry ice had any effect on the recovery of pathogenic fungi. Sputa seeded with each of five fungi (Histoplasma capsulatum, Blastomyces dermatitidis, Cryptococus neoformans, Coccidioides immitis, and Aspergillus fumigatus) were frozen and stored for 24, 48, and 72 hours on dry ice. H. capsulatum was killed, and only a few colonies of B. dermatitidis and C. neoformans were isolated from these sputa. However, A. fumigatus and C. immitis withstood the effects of freezing. A second objective was to compare the recovery of all five fungi from seeded sputa stored at room temperature for 24, 48, and 72 hours, on yeast extract-phosphate agar with NH4OH and on Sabhi agar. The yeast extract-phosphate agar with NH4OH was superior to Sabhi agar, for the isolation of all fungi studied, except A. fumigatus.
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Abstract
A case of laboratory-acquired sporotrichosis was diagnosed by immunofluorescence and by culture. The patient was then cured by treatment with oral potassium iodide. The need to handle cultures of Sporothrix schenckii with due caution is stressed.
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Thompson DW. Cervical cancer screening programs. Can Med Assoc J 1976; 115:725-729. [PMID: 20312792 PMCID: PMC1878845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Walton RJ, Blanchet M, Boyes DA, Carmichael J, Marshall KG, Miller AB, Thompson DW. [Detection of cancer of the cervix uteri]. Union Med Can 1976; 105:997-1047. [PMID: 960289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Doran TA, Malone RM, Benzie RJ, Owen VJ, Thompson DW, New ML. Amniotic fluid tests for fetal maturity in normal and abnormal pregnancies. Am J Obstet Gynecol 1976; 125:586-92. [PMID: 820200 DOI: 10.1016/0002-9378(76)90777-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Amniotic fluid creatinine, percentage of lipid-positive cells, and L/S ratio were determined on 285 samples from normal pregnancies and 222 samples from abnormal pregnancy states (Rh isoimmunization, diabetes, hypertensive disorders, intrauterine growth retardation, and hydramnios). In normal pregnancy the coefficient of correlation between true gestational age and estimated period of gestation (EPG) based on the three parameters was 0.94, in Rh isoimmunization 0.77, in diabetes 0.67, and in hypertensive disorders 0.59. In intrauterine growth retardation both the L/S ratio and creatinine were depressed, the coefficient was 0.61, and the EPG was consistently less than the true gestational age. The mean L/S ratio in pre-eclampsia was slightly below the normal mean and in diabetes the mean L/S ratio was also depressed. In 150 samples taken within 48 hours of delivery L/S ratios were accurate in assessing fetal pulmonary maturity although there was a 20 per cent incidence over all of false-immature values. There were no false-mature values except in diabetes (2/9).
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Thompson DW, Bass D, Abu-Goukh ME. Rate models for cyclic separation processes - comparison with experimental results in cyclic electrodialysis. CAN J CHEM ENG 1974. [DOI: 10.1002/cjce.5450520408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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