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Kennedy SM, Zheng CX, Jesson DE. Droplet Epitaxy Image Contrast in Mirror Electron Microscopy. Nanoscale Res Lett 2017; 12:68. [PMID: 28116613 PMCID: PMC5256635 DOI: 10.1186/s11671-017-1837-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/09/2017] [Indexed: 06/02/2023]
Abstract
Image simulation methods are applied to interpret mirror electron microscopy (MEM) images obtained from a movie of GaAs droplet epitaxy. Cylindrical symmetry of structures grown by droplet epitaxy is assumed in the simulations which reproduce the main features of the experimental MEM image contrast, demonstrating that droplet epitaxy can be studied in real-time. It is therefore confirmed that an inner ring forms at the droplet contact line and an outer ring (or skirt) occurs outside the droplet periphery. We believe that MEM combined with image simulations will be increasingly used to study the formation and growth of quantum structures.
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Affiliation(s)
- S. M. Kennedy
- School of Physics, Monash University, Melbourne, Victoria 3800 Australia
| | - C. X. Zheng
- Department of Civil Engineering, Monash University, Melbourne, Victoria 3800 Australia
| | - D. E. Jesson
- School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA UK
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Koehoorn M, Tamburic L, McLeod CB, Demers PA, Lynd L, Kennedy SM. Population-based surveillance of asthma among workers in British Columbia, Canada. ACTA ACUST UNITED AC 2013. [DOI: 10.24095/hpcdp.33.2.05] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Introduction
Population-based health databases were used for the surveillance of asthma among workers in British Columbia for the period 1999 to 2003. The purpose was to identify high-risk groups of workers with asthma for further investigation, education and prevention.
Methods
Workers were identified using an employer-paid health premium field in the provincial health registry, and were linked to their physician visit, hospitalization, workers' compensation and pharmaceutical records; asthma cases were defined by the presence of an asthma diagnosis (International Classification of Diseases [ICD]-9-493) in these health records. Workers were assigned to an ''at-risk'' exposure group based on their industry of employment.
Results
For males, significantly higher asthma rates were observed for workers in the Utilities, Transport/Warehousing, Wood and Paper Manufacturing (Sawmills), Health Care/Social Assistance and Education industries. For females, significantly higher rates were found for those working in the Waste Management/Remediation and Health Care/ Social Assistance industries.
Conclusion
The data confirm a high prevalence of active asthma in the working population of British Columbia, and in particular, higher rates among females compared to males and in industries with known respiratory sensitizers such as dust and chemical exposures.
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Affiliation(s)
- M Koehoorn
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - L Tamburic
- Centre for Health Services and Policy Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - CB McLeod
- Centre for Health Services and Policy Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - PA Demers
- Occupational Cancer Research Centre, Cancer Care Ontario, Toronto, Ontario, Canada
| | - L Lynd
- Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - SM Kennedy
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
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Koehoorn M, Tamburic L, McLeod CB, Demers PA, Lynd L, Kennedy SM. Population-based surveillance of asthma among workers in British Columbia, Canada. Chronic Dis Inj Can 2013; 33:88-94. [PMID: 23470174] [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: 06/01/2023]
Abstract
INTRODUCTION Population-based health databases were used for the surveillance of asthma among workers in British Columbia for the period 1999 to 2003. The purpose was to identify high-risk groups of workers with asthma for further investigation, education and prevention. METHODS Workers were identified using an employer-paid health premium field in the provincial health registry, and were linked to their physician visit, hospitalization, workers' compensation and pharmaceutical records; asthma cases were defined by the presence of an asthma diagnosis (International Classification of Diseases [ICD]-9-493) in these health records. Workers were assigned to an ''at-risk'' exposure group based on their industry of employment. RESULTS For males, significantly higher asthma rates were observed for workers in the Utilities, Transport/Warehousing, Wood and Paper Manufacturing (Sawmills), Health Care/Social Assistance and Education industries. For females, significantly higher rates were found for those working in the Waste Management/Remediation and Health Care/Social Assistance industries. CONCLUSION The data confirm a high prevalence of active asthma in the working population of British Columbia, and in particular, higher rates among females compared to males and in industries with known respiratory sensitizers such as dust and chemical exposures.
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Affiliation(s)
- M Koehoorn
- School of Population and Public Health, Centre for Health Services and Policy Research, University of British Columbia, Vancouver, British Columbia, Canada.
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Kennedy SM, Hjort M, Mandl B, Marsell E, Zakharov AA, Mikkelsen A, Paganin DM, Jesson DE. Characterizing the geometry of InAs nanowires using mirror electron microscopy. Nanotechnology 2012; 23:125703. [PMID: 22397834 DOI: 10.1088/0957-4484/23/12/125703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mirror electron microscopy (MEM) imaging of InAs nanowires is a non-destructive electron microscopy technique where the electrons are reflected via an applied electric field before they reach the specimen surface. However strong caustic features are observed that can be non-intuitive and difficult to relate to nanowire geometry and composition. Utilizing caustic imaging theory we can understand and interpret MEM image contrast, relating caustic image features to the properties and parameters of the nanowire. This is applied to obtain quantitative information, including the nanowire width via a through-focus series of MEM images.
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Affiliation(s)
- S M Kennedy
- School of Physics, Monash University, Victoria 3800, Australia
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Abstract
We extend the theory of Laplacian image contrast in mirror electron microscopy (MEM) to the case where the sample is illuminated by a parallel, collimated beam. This popular imaging geometry corresponds to a modern low energy electron microscope equipped with a magnetic objective lens. We show that within the constraints of the relevant approximations; the results for parallel illumination differ only negligibly from diverging MEM specimen illumination conditions.
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Affiliation(s)
- S. M. Kennedy
- School of Physics, Monash University, Victoria 3800, Australia
| | - C. X. Zheng
- School of Physics, Monash University, Victoria 3800, Australia
| | - W. X. Tang
- School of Physics, Monash University, Victoria 3800, Australia
| | - D. M. Paganin
- School of Physics, Monash University, Victoria 3800, Australia
| | - D. E. Jesson
- School of Physics, Monash University, Victoria 3800, Australia
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Abstract
We discuss an intuitive approach to interpreting mirror electron microscopy (MEM) images, whereby image contrast is primarily caused by the Laplacian of small height or potential variations across a sample surface. This variation is blurred slightly to account for the interaction of the electrons with the electrical potential away from the surface. The method is derived from the established geometrical theory of MEM contrast, and whilst it loses quantitative accuracy outside its domain of validity, it retains a simplicity that enables rapid interpretation of MEM images. A strong parallel exists between this method and out of focus contrast in transmission electron microscopy (TEM), which allows a number of extensions to be made, such as including the effects of spherical and chromatic aberration.
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Affiliation(s)
- S. M. Kennedy
- School of Physics, Monash University, Victoria 3800, Australia
| | - C. X. Zheng
- School of Physics, Monash University, Victoria 3800, Australia
| | - W. X. Tang
- School of Physics, Monash University, Victoria 3800, Australia
| | - D. M. Paganin
- School of Physics, Monash University, Victoria 3800, Australia
| | - D. E. Jesson
- School of Physics, Monash University, Victoria 3800, Australia
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Kingwell E, Prior JC, Ratner PA, Kennedy SM. Direct-to-participant feedback and awareness of bone mineral density testing results in a population-based sample of mid-aged Canadians. Osteoporos Int 2010; 21:307-19. [PMID: 19495825 DOI: 10.1007/s00198-009-0966-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 03/08/2009] [Accepted: 04/09/2009] [Indexed: 12/19/2022]
Abstract
UNLABELLED This population-based study of mid-aged Canadians assessed awareness of diagnosis by bone mineral density (BMD) following dual-energy X-ray absorptiometry (DXA) testing and compared the effects of feedback only to the physician with direct-to-participant feedback. Poor recall of osteoporosis results was observed irrespective of the feedback destination, but direct-to-participant feedback improved recall of borderline or normal results. INTRODUCTION BMD testing provides information about fracture risk. This study assessed whether awareness of results, in a random population sample of mid-aged Canadians, differed if results were provided to physicians only or directly to participants. METHODS Prospective cohort study of 2,678 women and men aged 40-60 years from the Canadian Multicentre Osteoporosis Study. Participants completed hip and spine DXA and interviewer-administered questionnaires regarding demographics and osteoporosis risk factors. Lateral spine X-rays were conducted on those > or =50 years of age. All test results were reported to the participant, the family physician or both. Associations between BMD results, feedback destination and correct self-report results, 3 years later, were assessed using logistic regression while adjusting for potential confounders. RESULTS Only 25% of men and 33% of women correctly reported their osteoporosis diagnoses. Direct-to-participant vs. physician-only reports did not improve recall of osteoporosis diagnosis but improved recall of borderline or normal BMD. Older (vs. younger) men and men with prevalent vertebral fractures demonstrated better recall of their osteoporosis diagnosis. CONCLUSIONS Recall of low BMD results was poor, despite direct-to-participant feedback and even in the presence of other osteoporosis risk factors. Direct-to-participant feedback may improve awareness of borderline or normal BMD results.
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Affiliation(s)
- E Kingwell
- Division of Neurology, Department of Medicine, University of British Columbia, UBC Hospital, 2211 Wesbrook Mall, Vancouver BCV6T2B5, Canada.
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Kennedy SM, Ji Z, Rockweiler NB, Hahn AR, Booske JH, Hagness SC. The Role of Plasmalemmal-Cortical Anchoring on the Stability of Transmembrane Electropores. IEEE Trans Dielectr Electr Insul 2009; 16:1251-1258. [PMID: 20490371 PMCID: PMC2873222 DOI: 10.1109/tdei.2009.5293935] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The structure of eukaryotic cells is maintained by a network of filamentous actin anchored subjacently to the plasma membrane. This structure is referred to as the actin cortex. We present a locally constrained surface tension model for electroporation in order to address the influence of plasmalemmal-cortical anchoring on electropore dynamics. This model predicts that stable electropores are possible under certain conditions. The existence of stable electropores has been suggested in several experimental studies. The electropore radius at which stability is achieved is a function of the characteristic radii of locally constrained regions about the plasma membrane. This model opens the possibility of using actin-modifying compounds to physically manipulate cortical density, thereby manipulating electroporation dynamics. It also underscores the need to improve electroporation models further by incorporating the influence of trans-electropore ionic and aqueous flow, cortical flexibility, transmembrane protein mobility, and active cellular wound healing mechanisms.
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Affiliation(s)
- S M Kennedy
- Department of Electrical and Computer Engineering, University of Wisconsin, Madison Madison, WI, 53706, USA
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Peters CE, Demers PA, Sehmer J, Karlen B, Kennedy SM. Early changes in respiratory health in trades' apprentices and physician visits for respiratory illnesses later in life. Occup Environ Med 2009; 67:237-43. [PMID: 19666935 DOI: 10.1136/oem.2008.042663] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES An inception cohort of trades' apprentices had rapid declines in lung function (forced expiratory volume in 1 s (FEV(1))) and rapid increases in bronchial responsiveness ( upward arrowBR) over the first 2 years of employment. We used physician visit data to assess respiratory health over the following 13 years. METHODS Construction painter, electrician, insulator and machinist apprentices beginning at a British Columbia trade school in 1988 were invited to participate and were followed up 2 years later. Subjects were linked to provincial medical databases to examine physician visits for asthma and other respiratory illnesses for the 13 years following. Multivariable models with rapid decline in FEV(1) and rapid increase in BR from years 1 to 3 were constructed. Respiratory symptoms were also examined as predictors of visit rates and meeting a case definition (for asthma or other respiratory illness). RESULTS The cohort included 281 apprentices (97% are men). Sixteen subjects met the asthma case definition (>or=2 visits coded as asthma in 1 year) and 20 met the other respiratory illness case definition (>or=3 visits for bronchitis, emphysema, respiratory symptoms in 1 year). In models controlling for demographic factors and smoking, subjects with bronchitis symptoms at baseline were more likely to develop other respiratory illness during follow-up (RR 4.4, 95% CI 1.6 to 11.9). Apprentices who developed asthma symptoms over the first 2 years were approximately six times more likely to become asthma cases (95% CI 1.9 to 18.8). Those with a rapid increase in BR were at increased risk of becoming asthma cases (RR 5.5, 95% CI 1.9 to 16.1), as well as having higher asthma visit rates (RR 6.5). Subjects with rapid decline in FEV(1) were 3.2 times more likely to become asthma cases (95% CI 0.8 to 12.1). CONCLUSIONS Changes in respiratory health early in adulthood, especially increased BR, are associated with respiratory physician visits. These findings are important for workplace screening and prevention and also suggest that physician visit databases are promising research tools in respiratory epidemiology.
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Affiliation(s)
- C E Peters
- School of Environmental Health, University of British Columbia, 3rd floor, 2206 East Mall, Vancouver, BC, Canada.
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Davies HW, Teschke K, Kennedy SM, Hodgson MR, Demers PA. A retrospective assessment of occupational noise exposures for a longitudinal epidemiological study. Occup Environ Med 2008; 66:388-94. [DOI: 10.1136/oem.2008.040881] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Suarthana E, Heederik D, Ghezzo H, Malo JL, Kennedy SM, Gautrin D. Risks for the development of outcomes related to occupational allergies: an application of the asthma-specific job exposure matrix compared with self-reports and investigator scores on job-training-related exposure. Occup Environ Med 2008; 66:256-63. [PMID: 19017693 DOI: 10.1136/oem.2008.041962] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND AIM Risks for development of occupational sensitisation, bronchial hyper-responsiveness, rhinoconjunctival and chest symptoms at work associated with continued exposure to high molecular weight (HMW) allergens were estimated with three exposure assessment methods. METHODS A Cox regression analysis with adjustment for atopy and smoking habit was carried out in 408 apprentices in animal health technology, pastry making, and dental hygiene technology with an 8-year follow-up after training. The risk of continued exposure after training, estimated by the asthma-specific job exposure matrix (JEM), was compared with self-reports and investigator scores on job-training-related exposure. Associations between outcomes and work duration in job(s) related to training were also evaluated. RESULTS Exposure to animal-derived HMW allergens, subsequent to the apprenticeship period, as estimated by the JEM, was associated with a significantly increased risk for occupational sensitisation (hazard ratio (HR) 6.4; 95% CI 2.3 to 18.2) and rhinoconjunctival symptoms at work (HR 2.6; 95% CI 1.1 to 6.2). Exposure to low molecular weight (LMW) agents significantly increased the risk of developing bronchial hyper-responsiveness (HR 2.3; 95% CI 1.1 to 5.4). Exposure verification appeared to be important to optimise the sensitivity and the specificity, as well as HRs produced by the JEM. Self-reports and investigator scores also indicated that further exposure to HMW allergens increased the risk of developing occupational allergies. The agreement between self-reports, investigator scores, and the JEM were moderate to good. There was no significant association between respiratory outcomes and work duration in jobs related to training. CONCLUSION The asthma-specific JEM could estimate the risk of various outcomes of occupational allergies associated with exposure to HMW and LMW allergens, but it is relatively labour intensive. Exposure verification is an important integrated step in the JEM that optimised the performance of the matrix.
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Affiliation(s)
- E Suarthana
- Department of Chest Medicine, Hôpital du Sacré-Coeur de Montreal, 5400 West Gouin Blvd, Montreal H4J 1C5, Canada
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Kennedy SM, Ji Z, Hedstrom JC, Booske JH, Hagness SC. Quantification of electroporative uptake kinetics and electric field heterogeneity effects in cells. Biophys J 2008; 94:5018-27. [PMID: 18339761 PMCID: PMC2397364 DOI: 10.1529/biophysj.106.103218] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [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: 12/15/2006] [Accepted: 02/20/2008] [Indexed: 01/04/2023] Open
Abstract
We have conducted experiments quantitatively investigating electroporative uptake kinetics of a fluorescent plasma membrane integrity indicator, propidium iodide (PI), in HL60 human leukemia cells resulting from exposure to 40 mus pulsed electric fields (PEFs). These experiments were possible through the use of calibrated, real-time fluorescence microscopy and the development of a microcuvette: a specialized device designed for exposing cell cultures to intense PEFs while carrying out real-time microscopy. A finite-element electrostatic simulation was carried out to assess the degree of electric field heterogeneity between the microcuvette's electrodes allowing us to correlate trends in electroporative response to electric field distribution. Analysis of experimental data identified two distinctive electroporative uptake signatures: one characterized by low-level, decelerating uptake beginning immediately after PEF exposure and the other by high-level, accelerating fluorescence that is manifested sometimes hundreds of seconds after PEF exposure. The qualitative nature of these fluorescence signatures was used to isolate the conditions required to induce exclusively transient electroporation and to discuss electropore stability and persistence. A range of electric field strengths resulting in transient electroporation was identified for HL60s under our experimental conditions existing between 1.6 and 2 kV/cm. Quantitative analysis was used to determine that HL60s experiencing transient electroporation internalized between 50 and 125 million nucleic acid-bound PI molecules per cell. Finally, we show that electric field heterogeneity may be used to elicit asymmetric electroporative PI uptake within cell cultures and within individual cells.
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Affiliation(s)
- S M Kennedy
- Department of Electrical and Computer Engineering, University of Wisconsin, Madison, Wisconsin 53706, USA.
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Heederik D, Suarthana E, Meijer E, Cherry NM, Beach J, Burstyn I, Kapur N, Kennedy SM, McLeod C, Koehoorn M, Kennedy SM, Demers PA, Tamburic L, Garzia NA, Koehoorn M, Demers PA, Kennedy SM, Turner S, McNamee R, Roberts C, Lines S, Henson M, Bradshaw L, Curran A, Fishwick D, Agius R. Asthma surveillance. Occup Environ Med 2007. [DOI: 10.1136/oem.64.12.e5] [Citation(s) in RCA: 1] [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: 11/03/2022]
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Turner CJ, Kennedy SM, Buechte SF, Morfeld P, Bicker HJ, Lenaerts H, Kalkowsky B, Pohlplatz J, Koesters A, Piekarski C, Radon K, Schulze A, Ehrenstein V, van Strien RT, Praml G, Nowak D, Bonde JP, Christensen SW, Omland O, Pronk A, Preller L, Doekes G, Wouters I, Rooijackers J, Lammers JW, Heederik D. Lung function. Occup Environ Med 2007. [DOI: 10.1136/oem.64.12.e23] [Citation(s) in RCA: 1] [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: 11/03/2022]
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Greven FE, Duijm F, Kerstjens HAM, Heederik D, Greven FE, Meijer E, Suarthana E, Moons KGM, de Monchy J, Meijster T, Heederik D, Sun Y, Yamanaka M, Guidotti TL, Koehncke N, Nakano M, Kikuchi Y, Tanaka A, Hirata M, Sano Y, Yoshioka N, Nishiwaki Y, Takebayashi T, Omae K, Nakano M, Zinszer KA, Gagne V, Guernsey JR, Peters CE, Demers PA, Kennedy SM, Chaiear N, Ngoencharee J, Saejiw N. Respiratory. Occup Environ Med 2007. [DOI: 10.1136/oem.64.12.e26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Rideout K, Teschke K, Dimich-Ward H, Kennedy SM. Considering risks to healthcare workers from glutaraldehyde alternatives in high-level disinfection. J Hosp Infect 2005; 59:4-11. [PMID: 15571847 DOI: 10.1016/j.jhin.2004.07.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Accepted: 06/16/2004] [Indexed: 10/26/2022]
Abstract
Due to concerns over glutaraldehyde's toxicity, two substitutes have recently been introduced; ortho-phthalaldehyde (OPA), and a mixture of hydrogen peroxide and peracetic acid. There is limited information about the health effects for employees from these products. This study assesses the current practices regarding the use of high-level disinfectants in British Columbian hospitals and predicts the relative toxicities of each product. Industry practices were compiled using a comprehensive survey of current practices and decision processes in all hospitals in British Columbia. Of 95 hospitals, 64 returned surveys; 80% of these used high-level disinfection. Among user hospitals, 49% used glutaraldehyde alone and 51% had introduced alternatives. Concern about staff health was the most common reason for substituting, but this was frequently not considered when choosing specific alternatives. Hospitals that involved occupational health, infection control or regional staff in high-level disinfectant decisions used glutaraldehyde alternatives less often. In most hospitals, it was difficult to find individuals who were knowledgeable about the use of disinfectants. Potential health effects associated with each type of high-level disinfectant were assessed by review of the published literature and available manufacturers' data along with qualitative structure-activity relationship analysis. Results indicated that although all products irritate the skin and respiratory tract, OPA is a potential dermal and respiratory sensitizer but hydrogen peroxide and peracetic acid do not cause allergic reactions. Despite little being known about the risks to employees from glutaraldehyde alternatives, their use is widespread. The potential risks of all high-level disinfectants are serious; thus regulators and users are faced with important risk management decisions before and after they have been introduced into the workplace.
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Affiliation(s)
- K Rideout
- School of Occupational and Environmental Hygiene, Faculty of Graduate Studies, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Enarson DA, Kennedy SM, Miller DL, Bakke P. Interpreting and reporting results. Int J Tuberc Lung Dis 2004; 8:1506-9. [PMID: 15636499] [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: 05/01/2023] Open
Abstract
Creating and disseminating knowledge is the goal of research. This is accomplished through critical analysis of systematically collected and clearly reported information. Critical analysis begins with the simple step of looking at the data collected prior to applying complex statistical analysis to make comparisons. Statistical analysis is approached in a standardised manner, depending on the type of data that has been collected. When a careful, stepwise standardised approach is applied to comparisons needed to address the research question, new knowledge is created and erroneous conclusions avoided. Following careful examination and analysis of the data, critical review is an important additional step to ensure that conclusions are correctly drawn. The process of peer review involved in publishing the research in the scientific literature is an important step to disseminating the new knowledge and ensuring its quality. Research is never complete without submitting it for publication in the peer-reviewed literature.
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Affiliation(s)
- D A Enarson
- Scientific Activities Unit, International Union Against Tuberculosis and Lung Disease, Paris, France.
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Enarson DA, Kennedy SM, Miller DL. Conducting research: practical steps. Int J Tuberc Lung Dis 2004; 8:1377-81. [PMID: 15581209] [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: 05/01/2023] Open
Abstract
Developing a research protocol and obtaining funding for carrying out the research are only the first steps in doing research. Understanding the means to conduct the research is equally important. As research is a joint effort of a team, a mechanism of collaboration must be developed to engage all those with an interest in the research. This includes the community in which the research is to be undertaken, representatives of those who will participate in the research, the academic community who will be involved in the research, and those who will sponsor the research. These individuals can be formed into a 'steering committee' to guide the development, conduct, analysis and communication of the research. Careful consideration must be given to the benefits and risks of the research. These must be precisely spelled out in the research protocol, and all aspects of the research must be independently evaluated for technical competence, accuracy, communication and liability for injury by an ethics review committee. The research must follow precisely the protocol developed. Administrative procedures, including recruitment and management of staff, outlining standard procedures and quality assurance procedures must be clearly outlined and followed. Carefully handling the information collected in a research project is vital to ensuring the quality and validity of the research.
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Affiliation(s)
- D A Enarson
- Unit of Scientific Activities, International Union Against Tuberculosis and Lung Disease, Paris, France.
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Enarson DA, Kennedy SM, Miller DL. Measurement in epidemiology. Int J Tuberc Lung Dis 2004; 8:1269-73. [PMID: 15527162] [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: 05/01/2023] Open
Abstract
Data (information) are the building blocks of epidemiological research. Careful measurement, recording and handling of information are crucial to the research process. The nature of the data required must be precisely defined and its collection requires the use of reliable tools or instruments. Standardisation of definitions and procedures used in measurement helps to ensure comparability. Care in undertaking measurements and rigorous training of personnel carrying out the measurements help to ensure precision. Special care is necessary to ensure completeness and accuracy in recording the data. Information may be obtained from routine or especially designed forms and evaluated by counting deaths or cases of disease or measures of dysfunction. Questionnaires are a frequently used instrument for collecting information. They should include data identifying the individual being studied, followed by specific questions concerning diseases and determinants. To be useful, such questionnaires must be carefully structured. Diseases are usually compared by calculating 'rates' or 'risks', consisting of numerators (cases, events) and denominators (population). Prevalence and incidence are standard measures of 'risk'. The collection of high quality information (data) and its use to construct estimates of 'risk' or risk ratios form the basis of epidemiology.
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Affiliation(s)
- D A Enarson
- Scientific Activities Unit, International Union Against Tuberculosis and Lung Disease, Paris, France.
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Enarson DA, Kennedy SM, Miller DL. Choosing a research study design and selecting a population to study. Int J Tuberc Lung Dis 2004; 8:1151-6. [PMID: 15455605] [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: 04/30/2023] Open
Abstract
Epidemiological studies have been standardised into a group of 'designs'. The descriptive study describes disease by time, place and person and can develop hypotheses about associations between disease and possible determinants. The analytic study tests these hypotheses. The cross-sectional study measures the disease and determinants at a single point in time. The cohort study identifies those within a group with or without a determinant, and observes the occurrence of disease in the two groups. The case-control study identifies a group of patients with a disease and selects a group of persons from the same population who do not have the disease, comparing the presence of a determinant in the two groups. The experimental study, a type of cohort study, is one in which the investigator 'assigns' the determinant (a treatment) to one subgroup in a population and compares the occurrence of a disease between those with and those without the determinant. All such studies must ensure that the comparisons made have relevance to a defined population. This is done by selecting a 'representative' sample from that population. Carefully selecting a study design and population facilitates the creation of new knowledge while avoiding, as far as possible, important errors.
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Affiliation(s)
- D A Enarson
- Scientific Activities Unit, International Union Against Tuberculosis and Lung Disease, Paris, France.
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Enarson DA, Kennedy SM, Miller DL. Getting started in research: the research protocol. Int J Tuberc Lung Dis 2004; 8:1036-40. [PMID: 15305491] [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: 04/30/2023] Open
Abstract
To be efficient and precise, research needs a 'road map', called the 'research protocol', which follows a standard format. It includes an abstract, study description, ethical considerations, significance of the study, the budget and a description of the investigators. Study description spells out the study question, the rationale for the study, including previous studies on the subject, the objectives, hypotheses and aims, design and methods, project management, strengths and limitations and a list of references. The objectives, hypotheses and aims are developed by outlining a general research topic (the objective), developing a hypothesis from the broad objective, translating it into the null hypothesis and then listing the steps by which the null hypothesis will be refuted or accepted (the aims). The design and methods describe the type of study to be undertaken, the population in which the study is carried out, including the sample size and statistical power, the selection of subjects, the methods of data collection, and outline of data management and statistical analysis. The detail of the protocol ensures that the study will be carried out successfully and is essential for all health research.
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Affiliation(s)
- D A Enarson
- Department of Scientific Activities, International Union Against Tuberculosis and Lung Disease, Paris, France.
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Abstract
AIMS To assess the impact of newly introduced point-of-sale glass bottle recycling on indoor air quality and employee health. METHODS Airborne exposures and both chronic and acute respiratory and somatic symptoms were surveyed among 226 employees at 36 randomly selected liquor stores with bottle recycling and in-house glass breaking. Each store was visited twice; between visits glass breaking was discontinued for one month in half the stores (selected at random), although bottles were still collected and stored on site. Rates of chronic symptoms were compared to an external, unexposed control population. RESULTS Geometric mean exposure levels were 0.18 mg/m3 for inhalable particulate matter and 3.6 EU/m3 for endotoxin (270 personal samples); 1064 CFU/m3 for viable fungi (648 area samples). Fungal levels were associated with visibly mouldy bottles being broken, outdoor fungal counts, and uncovered glass bins. Exposures were not altered by the intervention of shutting down glass breaking machinery. Compared to controls, employees reported more work related chronic chest tightness and chronic nasal symptoms. Acute chest symptoms were associated with breaking visibly mouldy bottles, but not with measured fungal counts. Inhalable particulate matter levels >0.2 mg/m3 were associated with acute upper airway irritation. Somatic symptoms were associated with measures of psychosocial job strain. CONCLUSION Results suggest that this type of recycling programme may generate fungal exposures sufficient to elicit upper airway and chest symptoms.
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Affiliation(s)
- S M Kennedy
- School of Occupational and Environmental Hygiene, University of British Columbia, Vancouver BC, Canada.
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Enarson DA, Kennedy SM, Miller DL. Research methods for promotion of lung health. Int J Tuberc Lung Dis 2004; 8:915-9. [PMID: 15260288] [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: 04/30/2023] Open
Abstract
The goal of health research is to develop new knowledge for action to improve health. Relevant health research includes study of diseases, their causes and their treatment/prevention as well as structure and utilisation of health services and policies to improve lung health. As resources are not infinite, priorities must be established. These are determined by the relative frequency of a condition, how much dysfunction or disability it produces and whether there are cost-effective means to deal with it. Epidemiology is the discipline used to address these issues. Using it, one can describe the distribution and relative importance of a condition (the descriptive study), identify determinants and define its natural history (the analytical study), assess methods of prevention, cure and amelioration (the experimental study) and evaluate the process and outcome of services (health services or operational research). Epidemiology addresses itself to determining causation among associated variables. Characteristics associated with causation include consistency, strength of association, specificity, dose response, temporal relationship, coherence, and experimental evidence. Epidemiology can truly be described as the 'basic science of public health.' When used strategically, it can create the new knowledge that is the cornerstone for improving the health of the whole population.
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Affiliation(s)
- D A Enarson
- Scientific Activities, International Union Against Tuberculosis and Lung Disease, Paris, France.
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O'Driscoll L, Cronin D, Kennedy SM, Purcell R, Linehan R, Glynn S, Larkin A, Scanlon K, McDermott EW, Hill AD, O'Higgins NJ, Parkinson M, Clynes M. Expression and prognostic relevance of Mcl-1 in breast cancer. Anticancer Res 2004; 24:473-82. [PMID: 15152946] [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: 04/29/2023]
Abstract
BACKGROUND Bcl-2, an anti-apoptotic protein, is frequently associated with favourable prognosis in breast cancer. The potential role of mcl-1, another bcl-2 family member, in breast cancer has not yet been defined. PATIENTS AND METHODS This study examined the expression of mcl-1 and bcl-2 in 170 cases of invasive primary breast carcinoma, using reverse-transcriptase polymerase chain reaction and immunohistochemical analyses. RESULTS Expression of bcl-2 mRNA and protein were found to be favourably associated with outcome for patients, supporting a prognostic role for bcl-2 in breast cancer, whereas mcl-1 expression, at the mRNA or protein level, did not correlate with tumour size, grade, lymph node or ER status, age of patient at diagnosis, or disease outcome. CONCLUSION As these analyses of mcl-1 expression may have co-detected mcl-1(S/deltaTM) (a more recently identified, shorter variant, that may be pro-apoptotic) with the anti-apoptotic wild-type of mcl-1, it is possible that future studies may indicate some significant clinical correlations if the isoforms can be independently investigated.
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Affiliation(s)
- L O'Driscoll
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland.
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Peck FH, Kennedy SM, Watson JS, Lees VC. An evaluation of the influence of practitioner-led hand clinics on rupture rates following primary tendon repair in the hand. ACTA ACUST UNITED AC 2004; 57:45-9. [PMID: 14672677 DOI: 10.1016/j.bjps.2003.10.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [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: 11/18/2022]
Abstract
Practitioner-led hand clinics were introduced in our unit in the year 2000 as a response to the high and increasing number of postoperative hand trauma patients coming to consultant clinics. The aim of this study was to evaluate the influence of these clinics on rupture rates following primary tendon repair in the hand. The study specifically examined:zone II flexor tendon repairsflexor pollicis longus (FPL) tendon repairsextensor pollicis longus (EPL) tendon repairs. Prospective data collection were undertaken for these particular operations over a 17-month study period. Prior to the introduction of the practitioner-led hand clinics previous audits had demonstrated rupture rates of 30% zone II flexor tendon repairs, 16% for FPL repairs and 5% for EPL repairs. Rupture rates after the introduction of practitioner-led hand clinics fell in all of the study categories-to 17% for zone II flexor tendon repairs, 4% for FPL repairs and 0% for EPL repairs. It is suggested that improved continuity of care by experienced hand therapists may have contributed to the observed improvements in outcome.
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Affiliation(s)
- F H Peck
- Department of Burns and Plastic Surgery Outpatient, Wythenshawe Hospital, Southmoor Road, Wythenshawe, Manchester M23 9LT, UK
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Kennedy SM, O'Driscoll L, Purcell R, Fitz-Simons N, McDermott EW, Hill AD, O'Higgins NJ, Parkinson M, Linehan R, Clynes M. Prognostic importance of survivin in breast cancer. Br J Cancer 2003; 88:1077-83. [PMID: 12671708 PMCID: PMC2376388 DOI: 10.1038/sj.bjc.6600776] [Citation(s) in RCA: 185] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Survivin is a member of the inhibitor of apoptosis (IAP) family, and is also involved in the regulation of cell division. Survivin is widely expressed in foetal tissues and in human cancers, but generally not in normal adult tissue. This study examined the expression of surviving protein in a series of 293 cases of invasive primary breast carcinoma. Survivin immunoreactivity was assessed using two different polyclonal antibodies, and evaluated semiquantitatively according to the percentage of cells demonstrating distinct nuclear and/or diffuse cytoplasmic staining. Overall, 60% of tumours were positive for survivin: 31% demonstrated nuclear staining only, 13% cytoplasmic only, and 16% of tumour cells demonstrated both nuclear and cytoplasmic staining. Statistical analysis revealed that survivin expression was independent of patient's age, tumour size, histological grade, nodal status, and oestrogen receptor status. In multivariate analysis, nuclear survivin expression was a significant independent prognostic indicator of favourable outcome both in relapse-free and overall survival (P<0.001 and P=0.01, respectively). In conclusion, our results show that survivin is frequently overexpressed in primary breast cancer. Nuclear expression is most common and is an independent prognostic indicator of good prognosis.
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Affiliation(s)
- S M Kennedy
- Department of Pathology and Research Foundation, Royal Eye and Ear Hospital, Dublin, Ireland.
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Mitchell SC, Kennedy SM, Williams PJ, DeMont ME. Morphometrics and estimates of force generation by the chelae of a North American population of the invasive green crab,Carcinus maenas(L.). CAN J ZOOL 2003. [DOI: 10.1139/z02-236] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The European green crab, Carcinus maenas, is an invasive species in eastern North America and has the potential to significantly impact wild and aquaculture shellfish in the southern Gulf of St. Lawrence, Canada. To examine potential predation effects on local shellfish and assess the appropriateness of extrapolating results from studies conducted elsewhere, the morphometry of chelae from a recently established population of C. maenas in Nova Scotia was examined for comparison with the presumed founding (European) population, and forces generated by the chelae over a range of crab sizes were estimated. The Nova Scotia population was found to be morphologically very similar to European populations with respect to chela structure. Force generation by the chelae was found to scale with isometry in the female crab and with positive allometry in the male. Estimated forces compare well with previously reported forces, and force generation is calculated to increase in a nonlinear manner proceeding from the chela tips proximally toward the fulcrum. The calculated forces generated by the chelae are clearly sufficient for outright crushing of some shells (e.g., Mya arenaria), even for small crabs, but appear to be too low for crushing those of other molluscs. There is a complex interplay between gape and maximum force along the length of the dactyl that allows great variability in force application, and thus also in the size of prey consumed and prey-handling behaviour. We suggest that for such a lever system, the gape angle of the chelae, which does not change with crab size, is optimal with respect to the resultant force generated.
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Kennedy SM, Lytle FE. p-Bis(o-methylstyryl)benzene as a power-squared sensor for two-photon absorption measurements between 537 and 694 nm. Anal Chem 2002. [DOI: 10.1021/ac00126a014] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [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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Ainscough EW, Brodie AM, Burrell AK, Kennedy SM. An unusual reduction of an imine bond: the isolation of a stable pi-iminium intermediate. J Am Chem Soc 2001; 123:10391-2. [PMID: 11603992 DOI: 10.1021/ja0109996] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- E W Ainscough
- Chemistry--Institute of Fundamental Sciences Massey University, Private Bag 11 222 Palmerston North, New Zealand
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Abstract
BACKGROUND Isolated granulomatous appendicitis is uncommon and previously was considered to be a form of localised Crohn's disease. However more recent series have noted that relapse is rare after appendicectomy and concluded that the condition is a distinct entity unrelated to Crohn's disease. Following a case of granulomatous appendicitis at St. Vincent's University Hospital Dublin, the condition was reviewed and the results are detailed herein. METHODS A case of granulomatous appendicitis is presented with discussion of 4 previous cases encountered in our practice and the literature is reviewed. RESULTS The clinical presentation was sub-acute appendicitis with a mass palpable in the right iliac fossa. At operation an enlarged, inflamed appendix with a broad base was noted and appendicectomy performed. Histopathology showed numerous granulomata on microscopic examination. The yersinia serology tests were negative. Review of computerised histopathology records in the hospital for the last 7 years showed 4 additional cases of granulomatous appendicitis. This is a total of 5 of 1,615 appendectomies (an incidence of 0.31%). In all cases, the post-operative course was uneventful and the patients have had no further complaints. CONCLUSION This small series provides further evidence that granulomatous appendicitis is a distinct clinical entity unrelated to Crohn's disease and is cured by appendicectomy. It should be suspected when there is a sub-acute onset of appendicitis and an enlarged, broad-based appendix is found at operation.
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Affiliation(s)
- M J Higgins
- Department of Surgery, St. Vincent's University Hospital, Dublin, Ireland
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Abstract
Much evidence indicates that atherosclerotic lesions are largely of an inflammatory nature. Activated macrophages and macrophage-derived foam cells laden with cholesterol esters are a major constituent of these lesions and can influence lesion formation via several potential mechanisms. One such mechanism is Fcgamma receptor activation and/or Fcgamma receptor-mediated clearance of immune complexes containing cholesterol, such as lipoprotein immune complexes. That this mechanism contributes to lesion formation would be further supported if Fcgamma receptor expression in arterial lesions were demonstrated. We therefore used monoclonal antibodies and immunocytochemical methods to analyze frozen sections of human arterial lesions for expression of each of the three primary classes of mononuclear phagocyte Fcgamma receptors. Approximately 800 sections of aorta, carotid, and coronary arteries obtained from five elderly donors were analyzed. The presence of macrophages was determined by assaying reactivity of a monoclonal antibody specific to CD163, which is expressed only on cells of the human mononuclear phagocyte lineage. Results indicate that highly cellular preatheromatous lesions contained numerous macrophages in the zone of proliferation that expressed each class of Fcgamma receptor (FcgammaRIA, FcgammaRIIA, and FcgammaRIIIA). Fcgamma receptor-positive cells were also present in medial and adventitial areas. Fcgamma receptor staining was both punctate and diffuse, the latter suggesting that soluble receptors were present in the extracellular matrix. These data further support that Fcgamma receptor-mediated clearance of immune complexes can occur in arterial lesions during atherogenesis. Expression of both the high affinity (FcgammaRIA) and lower affinity (FcgammaRIIA/FcgammaRIIIA) receptors indicates that mono- and multivalent IgG-containing immune complexes could engage Fcgamma receptors and influence lesion formation through several different inflammatory mechanisms triggered by receptor activation.
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Affiliation(s)
- N R Ratcliffe
- Department of Veterans Affairs Medical Center, Veterans Administration Hospital, Research 151, White River Jct., VT 05009, USA
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Eisen EA, Smith TJ, Kriebel D, Woskie SR, Myers DJ, Kennedy SM, Shalat S, Monson RR. Respiratory health of automobile workers and exposures to metal-working fluid aerosols: lung spirometry. Am J Ind Med 2001; 39:443-53. [PMID: 11333406 DOI: 10.1002/ajim.1038] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [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: 11/11/2022]
Abstract
BACKGROUND Despite substantial evidence that workers exposed to metal-working fluids (MWF) have increased respiratory morbidity, the few studies of chronic effects on lung function have not been conclusive. METHODS Lung spirometry was measured and both current and past exposures to metal-working fluid (MWF) aerosols were estimated in this cross-sectional cohort of 1,811 male automobile workers. Satisfactory exposure data were available for 1,745 (96%): 239 assemblers (never-exposed to MWF), 487 assemblers (previously exposed), 352 machinists currently exposed to straight oils, 441 to soluble oils, and 226 to synthetic fluids. Operations were classified as either grinding or non-grinding machining. RESULTS Current exposure was not found to be associated with either forced expiratory volume in 1 second (FEV(1)) or forced ventilatory capacity (FVC). Nor was past exposure to water-based fluids (soluble or synthetic MWF) related to pulmonary function. Past exposure to straight oils, however, was significantly associated with FVC. This association was more obvious among older workers and among workers who had never transferred from MWF exposed jobs to assembly. CONCLUSIONS The magnitude of the association between FVC and lifetime exposure to straight MWF was slightly larger than the estimated cigarette effect, suggesting that the impact of an additional year of exposure to 1 mg/m(3) of mineral oil particulate in the thoracic particle size range, has the same impact on FVC as smoking one pack per day for one more year.
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Affiliation(s)
- E A Eisen
- Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA
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Kennedy SM, Le Moual N, Choudat D, Kauffmann F. Development of an asthma specific job exposure matrix and its application in the epidemiological study of genetics and environment in asthma (EGEA). Occup Environ Med 2000; 57:635-41. [PMID: 10935945 PMCID: PMC1740014 DOI: 10.1136/oem.57.9.635] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.8] [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: 11/04/2022]
Abstract
OBJECTIVES To develop a method suitable for estimating exposure risks in population studies of asthma from job titles and international codes, by combining a new job exposure matrix (JEM) with the expert judgement approach. The method was applied in the French epidemiological study of the genetics and environment in asthma (EGEA). METHODS The JEM contains 22 exposure groups including 18 high risk groups based on known risk factors for occupational asthma, divided into high molecular weight agents, low molecular weight agents, and mixed environments. After applying the JEM to job codes, exposure estimates for each subject were re-evaluated by examining job title texts. Three high risk exposure estimates for asthma were compared: firstly, applying the JEM to original codes (from different coders in each study centre); secondly, applying the JEM to revised codes (from one experienced coder); and thirdly, after reviewing JEM exposure estimates in the light of job title texts. RESULTS The study comprised 173 cases with asthma and 285 controls (age 18-65). Odds ratios (ORs) for asthma for high risk jobs were 1.0 (95% confidence interval (95% CI) 0.6 to 1.7), applying the JEM to original codes; 1.4 (95% CI 0.8 to 2.3), applying the JEM to revised codes; and 1.7 (95% CI 1.1 to 2.7), applying the JEM and subsequently re-evaluating exposure estimates from job title texts. Asthma ORs were 1.4 (95% CI 0.6 to 2.9) for high molecular weight agents, 2.3 (95% CI 1.2 to 4.4) for low molecular weight agents, and 2.1 (95% CI 0.9 to 5.2) for mixed environments. CONCLUSIONS This asthma JEM, when enhanced by expert re-evaluation of exposure estimates from job title texts, may be a useful tool in general population studies of asthma. In this study, a 1.7-fold increase in prevalence odds of high risk exposures was found among asthmatic workers compared with controls, with risk magnitude varying for different classes of exposure.
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Affiliation(s)
- S M Kennedy
- School of Occupational and Environmental Hygiene, University of British Columbia, 2206 East Mall, Vancouver, BC, Canada V6T 1Z3.
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Abstract
A study to assess exposure to potential respiratory hazards in a large lumber mill processing spruce (Picea engelmannii and glauca), pine (Pinus contorta), and fir (Abies lasiocarpa) used a random sampling strategy to assess exposures for all jobs in the sawmill, planer mills, and yard. Personal samples for inhalable particulate were collected to measure exposure to dust and resin acids (abietic acid and pimaric acid). To estimate wood dust exposure, rather than overall dust, the resin acid content within dust was used in combination with observations of job tasks and proximity to dust sources. Passive dosimeters were used to measure exposure to alpha-pinene, beta-pinene, delta3-carene, and other unidentified wood volatiles suspected to be monoterpenes. The GM of the 220 inhalable particulate samples was 1.0 mg/m3 whereas the mean abietic acid, pimaric acid, and estimated wood dust levels were 7.2 microg/m3, 0.6 microg/m3, and 0.5 mg/m3, respectively. The GMs of the 222 monoterpene samples were 0.1 mg/m3 for alpha-pinene, 0.3 mg/m3 for beta-pinene, 0.1 mg/m3 for delta3-carene, and 0.5 mg/m3 for the unidentified wood volatiles. Monoterpene exposures were much lower than those observed in other studies conducted in Sweden and Finland. The results of this exposure assessment highlight the importance of considering the content of airborne particulates in lumber mills as well as potential exposure to wood chemicals.
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Affiliation(s)
- P A Demers
- School of Occupational and Environmental Hygiene, University of British Columbia, Vancouver, Canada.
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Morganelli PM, Kennedy SM, Mitchell TI. Differential effects of interferon-gamma on metabolism of lipoprotein immune complexes mediated by specific human macrophage Fcgamma receptors. J Lipid Res 2000; 41:405-15. [PMID: 10706588] [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: 02/15/2023] Open
Abstract
The objectives were to determine whether there are differences in the mechanisms of lipoprotein metabolism associated with different FcgammaRs and how metabolism associated with FcgammaRs compares to that mediated by scavenger receptors (SRA). To analyze lipoprotein metabolism in a receptor-specific manner, bispecific antibodies were used to target low density lipoproteins (LDL) labeled with (125)I or [(3)H]cholesterol linoleate to FcgammaRI or FcgammaRIIA in human macrophages. Interferon-gamma (IFN-gamma), which stimulates expression of FcgammaRI while inhibiting expression of SRA, was used to help delineate differences in metabolism between each receptor. For each receptor, the total amount of lipoprotein degradation paralleled changes in receptor expression induced by IFN-gamma. In particular, while SRA-mediated degradation typically exceeded degradation mediated by FcgammaRI, in IFN-gamma-treated cells degradation associated with FcgammaRI and SRA was similar. Assay of [(3)H]cholesterol linoleate-labeled lipoproteins indicated that total uptake and hydrolysis of [(3)H]cholesterol linoleate was similar for each class of receptor, and inhibited by IFN-gamma. For FcgammaRI versus FcgammaRIIA, in the presence or absence of IFN-gamma, the [(3)H]cholesterol derived from FcgammaRIIA-mediated uptake was preferentially targeted for re-esterification to [(3)H]cholesterol oleate, in comparison to that resulting from hydrolysis of [(3)H]cholesterol linoleate incorporated by selective uptake. For SRA, the formation of [(3)H]cholesterol oleate, which was substantial in control cells, was significantly inhibited in the presence of IFN-gamma. We conclude that there may be differences in cholesterol trafficking with respect to lipoprotein immune complex metabolism mediated by different classes of FcgammaRs.
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Affiliation(s)
- P M Morganelli
- United States Department of Veterans Affairs, White River Junction, VT 05009, USA
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Le Moual N, Bakke P, Orlowski E, Heederik D, Kromhout H, Kennedy SM, Rijcken B, Kauffmann F. Performance of population specific job exposure matrices (JEMs): European collaborative analyses on occupational risk factors for chronic obstructive pulmonary disease with job exposure matrices (ECOJEM). Occup Environ Med 2000; 57:126-32. [PMID: 10711281 PMCID: PMC1739909 DOI: 10.1136/oem.57.2.126] [Citation(s) in RCA: 39] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To compare the performance of population specific job exposure matrices (JEMs) and self reported occupational exposure with data on exposure and lung function from three European general populations. METHODS Self reported occupational exposure (yes or no) and present occupation were recorded in the three general population surveys conducted in France, The Netherlands, and Norway. Analysis was performed on subjects, aged 25-64, who provided good forced expiratory volume in 1 second (FEV1) tracings and whose occupations were performed by at least two people, in the French (6217 men and 5571 women), the Dutch (men from urban (854) and rural (780) areas), and the Norwegian (395 men) surveys. Two population specific JEMs, based on the percentage of subjects who reported themselves exposed in each job, were constructed for each survey and each sex. The first matrix classified jobs into three categories of exposure according to the proportion of subjects who reported themselves exposed in each job (P10-50 JEM, low < 10%, moderate 10-49%, high > or = 50%). For the second matrix, a dichotomous variable was constructed to have the same statistical power as the self reported exposure--that is, the exposure prevalence (p) was the same with both exposure assessment methods (Pp JEM). Relations between occupational exposure, as estimated by the two JEMs and self reported exposure, and age, height, city, and smoking adjusted FEV1 score were compared. RESULTS Significant associations between occupational exposure estimated by the population specific JEM and lung function were found in the French and the rural Dutch surveys, whereas no significant relation was found with self reported exposure. In populations with few subjects in most jobs, exposure cannot be estimated with sufficient precision by a population specific JEM, which may explain the lack of relation in the Norwegian and the Dutch (urban area) surveys. CONCLUSION The population specific JEM, which was easy to construct and cost little, seemed to perform better than crude self reported exposures, in populations with sufficient numbers of subjects per job.
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Affiliation(s)
- N Le Moual
- INSERM Epidemiology and Biostatistics Unit 472, Villejuif, France
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Burstyn I, Heederik D, Bartlett K, Doekes G, Houba R, Teschke K, Kennedy SM. Wheat antigen content of inhalable dust in bakeries: modeling and an inter-study comparison. Appl Occup Environ Hyg 1999; 14:791-8. [PMID: 10590553 DOI: 10.1080/104732299302224] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The purposes of this study were (a) to compare wheat antigen content of inhalable bakery dust in Canada and the Netherlands and, (b) to evaluate the validity of dust exposure measurement as a surrogate of specific antigen exposure. Wheat antigen exposure data from the studies of Canadian and Dutch bakeries were used to explore the correlation between dust and antigen levels, and identify factors explaining variability of the antigen content of bakery dust. Direct comparison and pooling of the data were possible because the same antigen assay was used in both studies. Wheat antigen exposure samples totaling 544 were available, all originating from personal full-shift monitoring of bakery workers. The wheat antigen content of bakery dust varied greatly between the two studies and with different products within each study. Bakery dust from the Canadian study had a much higher wheat antigen content. Therefore, the interstudy difference in the wheat antigen content of bakery dust was by far the most significant in undermining the validity of the use of dust levels as a surrogate measures of wheat antigen exposure. The production of croissants, wheat bread and buns, puff pastry, bagels, and cinnamon buns was associated with increased wheat antigen content of bakery dust, while in rye bread production, bakery dust with less wheat antigen content was emitted. Although we can, in part, account for the pattern of variability in the wheat antigen content of bakery dust (explaining 49% of it), we concluded that the effort involved in modeling it accurately would probably exceed that expended in direct measurement of the antigen level. Therefore, for the exposure assessments carried out for the purpose of managing occupational risks of aeroallergen exposure in bakeries, we recommend the use of analytical techniques that can directly measure antigen exposure.
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Affiliation(s)
- I Burstyn
- Wageningen University, The Netherlands.
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Hand CK, Harmon DL, Kennedy SM, FitzSimon JS, Collum LM, Parfrey NA. Localization of the gene for autosomal recessive congenital hereditary endothelial dystrophy (CHED2) to chromosome 20 by homozygosity mapping. Genomics 1999; 61:1-4. [PMID: 10512674 DOI: 10.1006/geno.1999.5920] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [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]
Abstract
Congenital hereditary endothelial dystrophy (CHED) is a corneal disorder that presents with diffuse bilateral corneal clouding. Vision may be severely impaired, and many patients require corneal transplantation. Both autosomal dominant (AD) and autosomal recessive (AR) forms of the disorder have been described. The gene responsible for AD CHED (HGMW-approved symbol CHED1) has been mapped to the pericentromeric region of chromosome 20. Investigating a large, consanguineous Irish pedigree with autosomal recessive CHED, we have previously excluded linkage to this AD CHED locus. We now describe a genome-wide search using homozygosity mapping and DNA pooling. Evidence of linkage to chromosome 20p was demonstrated with a maximum lod score of 9.30 at a recombination fraction of 0.0 using microsatellite marker D20S482. A region of homozygosity in all affected individuals was identified, narrowing the disease gene locus to an 8-cM region flanked by markers D20S113 and D20S882. This AR CHED (HGMW-approved symbol CHED2) disease gene locus is physically and genetically distinct from the AD CHED locus.
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Affiliation(s)
- C K Hand
- Department of Pathology, University College Dublin and St. Vincent's Hospital, Dublin, 4, Ireland
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Teschke K, Demers PA, Davies HW, Kennedy SM, Marion SA, Leung V. Determinants of exposure to inhalable particulate, wood dust, resin acids, and monoterpenes in a lumber mill environment. Ann Occup Hyg 1999; 43:247-55. [PMID: 10432869] [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: 02/13/2023]
Abstract
In a lumber mill in the northern inland region of British Columbia, Canada, we measured inhalable particulate, resin acid, and monoterpene exposures, and estimated wood dust exposures. Potential determinants of exposure were documented concurrently, including weather conditions, tree species, wood conditions, jobs, tasks, equipment used, and certain control measures. Over 220 personal samples were taken for each contaminant. Geometric mean concentrations were 0.98 mg/m3 for inhalable particulate, 0.49 mg/m3 for estimated wood dust, 8.04 micrograms/m3 for total resin acids, and 1.11 mg/m3 for total monoterpenes. Multiple regression models for all contaminants indicated that spruce and pine produced higher exposures than alpine fir or mixed tree species, cleaning up sawdust increased exposures, and personnel enclosure was an effective means of reducing exposures. Sawing wood in the primary breakdown areas of the mill was the main contributor to monoterpene exposures, so exposures were highest for the barker operator, the head rig operator, the canter operator, the board edgers, and a roving utility worker in the sawmill, and lowest in the planer mills (after kiln drying of the lumber) and yard. Cleaning up sawdust, planing kiln-dried lumber, and driving mobile equipment in the yard substantially increased exposures to both inhalable particulate and estimated wood dust. Jobs at the front end of the sawmill where primary breakdown of the logs takes place had lower exposures. Resin acid exposures followed a similar pattern, except that yard driving jobs did not increase exposures.
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Affiliation(s)
- K Teschke
- Department of Health Care and Epidemiology, University of British Columbia, Vancouver, Canada
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Abstract
PURPOSE To report a case of a recurring mass with an unusual origin on the eyelid of a 34-year-old man. METHOD Case report. RESULT Histology demonstrated that the mass was a pilomatrix carcinoma. CONCLUSION An atypical mass with unusual symptoms or signs needs definitive treatment and diagnostic confirmation with histology.
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Affiliation(s)
- M T Cahill
- The Research Foundation, The Royal Victoria Eye and Ear Hospital, Dublin, Republic of Ireland.
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Abstract
Diethyldithiocarbamate (DDTC) exhibits chemoprotective effects via reduced myelosuppression in mice treated with various chemotherapeutic agents. The mechanism of DDTC-mediated chemoprotection is believed to involve the induction and release of several cytokines, including interleukin-1 beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and granulocyte colony-stimulating factor (G-CSF). In the present study the roles of IL-1beta and TNF-alpha in DDTC-mediated G-CSF induction were examined using human long-term bone marrow cultures (hLTBMCs). Administration of IL-1 receptor antagonist (IL-1ra) to DDTC-treated hLTBMCs obviated the G-CSF induction profile and blocked the resultant colony proliferation, indicating that IL-1beta mediates DDTC-induced G-CSF release and hematopoiesis. IL-1beta mRNA levels were increased threefold over control following DDTC treatment of hLTBMCs, implying that DDTC induces IL-1beta at the level of transcription. Conversely, studies involving inhibition of DDTC-induced TNF-alpha synthesis, with the inhibitor MNX 160, had no effect on DDTC-induced G-CSF release or colony proliferation. These findings taken together strongly suggest that IL-1beta mediates the chemoprotective effects of DDTC.
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Affiliation(s)
- S M Kennedy
- Department of Pharmacology and Physiology, University of Rochester, NY, USA
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Abstract
The MDR-3-encoded P-glycoprotein (Pgp) is highly expressed in liver and is thought to function as a hepatic transporter of phospholipids into bile. However its role, if any, in other tissues remains undefined. Although transfection experiments have indicated that it may be unable to confer drug resistance, there is evidence that it may be involved in drug resistance in certain B-cell leukaemias. To date, most work on clinical samples has been performed at the mRNA level; limited work has been performed using polyclonal antibodies raised to MDR-3 and mdr-2 (the murine equivalent of MDR-3). We have generated a new monoclonal antibody, termed 6/1G, which specifically recognises the human MDR-3 gene-encoded product. Antibody 6/1G was produced by in vitro immunisation of spleen cells from BALB/c mice with a synthetic 12-amino acid peptide. Cells from MDR-3 transgenic mice showed consistent membranous staining with antibody 6/1G. Immunoblotting with 6/1G identified a band at 170 kDa on lysates of MDR-3 transgenic cells. Preliminary results with a range of B-cell leukaemias suggest that MDR-3 Pgp positivity may be a marker for a more malignant phenotype in B-CLL. Antibody 6/1G may be useful in defining a role for MDR-3 in malignancy and drug resistance, as well as in certain liver diseases such as progressive familial intracholeostasis.
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Affiliation(s)
- A Larkin
- National Cell and Tissue Culture Centre, Bioresearch Ireland, Dublin City University, Glasnevin, Dublin, Ireland.
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Callaghan M, Hand CK, Kennedy SM, FitzSimon JS, Collum LM, Parfrey NA. Homozygosity mapping and linkage analysis demonstrate that autosomal recessive congenital hereditary endothelial dystrophy (CHED) and autosomal dominant CHED are genetically distinct. Br J Ophthalmol 1999; 83:115-9. [PMID: 10209448 PMCID: PMC1722772 DOI: 10.1136/bjo.83.1.115] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [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: 11/03/2022]
Abstract
BACKGROUND Congenital hereditary endothelial dystrophy (CHED) is a corneal dystrophy characterised by diffuse bilateral corneal clouding resulting in impaired vision. It is inherited in either an autosomal dominant (AD) or autosomal recessive (AR) manner. The AD form of CHED has been mapped to the pericentromeric region of chromosome 20. Another endothelial dystrophy, posterior polymorphous dystrophy (PPM), has been linked to a larger but overlapping region on chromosome 20. A large, Irish, consanguineous family with AR CHED was investigated to determine if there was linkage to this region. METHODS The technique of linkage analysis with polymorphic microsatellite markers amplified by polymerase chain reaction (PCR) was used. In addition, a DNA pooling approach to homozygosity mapping was employed to demonstrate the efficiency of this method. RESULTS Conventional genetic analysis in addition to a pooled DNA strategy excludes linkage of AR CHED to the AD CHED and larger PPMD loci. CONCLUSION This demonstrates that AR CHED is genetically distinct from AD CHED and PPMD.
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Affiliation(s)
- M Callaghan
- Department of Pathology, University College Dublin, Ireland
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Abstract
To investigate early pulmonary responses to metalworking fluid exposure, we enrolled first-year machinist apprentices and apprentices in three other trades into a 2-yr longitudinal study. We obtained complete data for 82 machinists and 159 control subjects. Tests included respiratory questionnaires, spirometry, methacholine challenge, and allergy skin tests. Details on duration of exposure were collected by interview and 68 representative full shift personal samples for "total aerosol" were obtained from 13 shops (mean: 0.46 mg/m3, range: < 0.7 to 3.65 mg/m3). Machinists and control subjects did not differ at baseline. At follow-up, average change in bronchial responsiveness was double in machinists compared with control subjects (p = 0.05), and machinists were more likely to have developed new bronchial hyperresponsiveness (BHR) with asthmalike symptoms. In linear regression analysis, for predictors of methacholine slope, increased BHR was associated with duration of exposure to both synthetic and soluble metalworking fluids (p < 0.05); in logistic regression analysis, for predictors of BHR, only duration of exposure to synthetic fluids was a significant predictor. Results were not changed when workers with PC20 < 8 mg/ml at baseline were excluded. We conclude that exposure to water-based metalworking fluids (especially synthetic fluids) is associated with increasing BHR during the first 2 yr of exposure.
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Affiliation(s)
- S M Kennedy
- Occupational Hygiene Program, Respiratory Division, Department of Medicine, and Department of Health Care and Epidemiology, University of British Columbia, Vancouver, British Columbia, Canada
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Moran E, Larkin A, Cleary I, Barnes C, Kennedy SM, Kelehan P, Clynes M. Monoclonal antibodies raised to paraffin wax embedded archival tissue; feasibility study of their potential to detect novel antigenic markers. J Immunol Methods 1998; 219:151-9. [PMID: 9831396 DOI: 10.1016/s0022-1759(98)00134-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/28/2022]
Abstract
A study to determine the feasibility of using archival paraffin wax embedded tissue to generate monoclonal antibodies is described. Specifically, monoclonal antibodies were raised to paraffin wax embedded normal human kidney tissue to test the possibility of producing antibodies to such tissue samples prior to attempting generation of antibodies to valuable archival tissue. Multiple sections (10 x 5 microm) were pooled and dewaxed as for immunohistochemical procedures and combined with Freund's adjuvant for immunization of BALB/c mice in vivo. Immunized spleen cells were fused with SP2 myeloma cells and subsequent clones screened on paraffin wax embedded normal human kidney sections, a range of cell lines and normal mouse tissue. Supernatants from 11 wells (from a total of 90 wells screened) showed different staining patterns on sections of paraffin wax embedded kidney. One clone, 1/11C, (isotype IgG1) which exhibited strong staining on all kidney tubules by immunohistochemical studies (glomeruli interstitium and vessels were unstained) and identified a band at 52 kDa on immunoblots of dewaxed kidney tissue (as used for immunogen) was chosen for further characterization. Immunoblotting of five mammalian cell lines showed differential expression of this 52 kDa band (distinct expression on 3/5, weak expression on 2/5 cell lines) whereas, all cell lines displayed a band at 44 kDa and a third band at 70 kDa was observed on 2/5 cell lines. In mouse tissue extracts, the 52 kDa band was identified in kidney tissue only (not in the lung, liver or spleen) with the 44 kDa and 70 kDa bands weakly expressed in all tissues. This preliminary investigation of a novel approach to identifying possible new antigenic markers or producing monoclonal antibodies which react better to known antigens on sections of paraffin wax embedded tissue showed that this method is feasible. The need to have a comprehensive screening system in place and the ability to identify potentially useful clones after the initial screening is paramount due to the relative scarcity of screening material (archival tissue sections) and the tedious nature of the screening method.
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Affiliation(s)
- E Moran
- National Cell and Tissue Culture Centre, BioResearch Ireland, Dublin City University, Ireland.
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Davies HW, Kennedy SM, Teschke K, Jenny P, Quintana E. Cytogenetic analysis of South Asian berry pickers in British Columbia using the micronucleus assay in peripheral lymphocytes. Mutat Res 1998; 416:101-13. [PMID: 9725996 DOI: 10.1016/s1383-5718(98)00071-0] [Citation(s) in RCA: 24] [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: 11/17/2022]
Abstract
Micronuclei in peripheral blood lymphocytes from British Columbia seasonal farmworkers and controls were evaluated using the cytokinesis-block technique. The farmworkers harvested berry crops and were likely occupationally exposed to pesticides. Subjects were 39 female subjects of South Asian descent; 18 farmworkers employed during 1993 and 21 age-matched controls. The mean age was 55.9 years. Micronuceli were also scored for the presence of kinetochores. No significant difference was found between the frequency of micronucleated binucleates in the farmworkers group (19.20/1000 binucleates), and the control group (21.76/1000 binucleates). However, among the farmworkers employed in 1993, there was a positive, but not statistically significant, association between micronucleated cell frequency and weeks worked: 16.44/1000 binucleates in those working less than 20 weeks; 23.78/1000 binucleates in those working 20 to 23 weeks; and 25.43/1000 binucleates in those working more than 23 weeks. In those who had ever been employed as farmworkers, there was an elevated frequency of micronucleated cells in the group with the longest history of employment as a farmworker (25.28/1000 binucleates) compared to those with the shortest employment history (16.48/1000 binucleates). This trend remained evident after adjusting for age, red blood cell folate, meat consumption, coffee consumption and recent vaccination. A positive association between the consumption of meat and micronucleus frequency was also observed. Non-meat eaters were likely life-long vegetarians. Micronuclei in farmworkers had a lower frequency of kinetochore positive micronuclei than controls. This study indicates that South Asian berry pickers in British Columbia may be at risk for genetic damage. More studies in other ethnic groups and in males are needed to generalize the findings of this study. More direct measures of exposure are needed to elucidate the sources of genotoxicity.
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Affiliation(s)
- H W Davies
- Occupational Hygiene Programme, University of British Columbia, Vancouver, Canada.
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Abstract
Metastatic uveal melanoma is profoundly chemoresistant and has a very poor outcome. We have previously shown that the MDR1 gene and its gene product P-glycoprotein (P-gp), which are known to cause drug resistance in cancer cells, are expressed in ocular melanoma. Overexpression of MDR1 has been associated with a poor survival in some tumor types treated by chemotherapy and in some untreated tumours. To assess whether MDR1 expression is of prognostic value in uveal melanoma, we evaluated the expression of MDR1 by immunohistochemistry in 108 cases. Three semiquantitative grades were used to evaluate positive staining. We detected MDR1 expression in 80% of cases; 28% showed grade I staining; 30%, grade II staining; and 22%, grade III staining. There was a statistically significant association (P=.004) between MDR1 expression by tumor cells and shorter survival times (n=96), which was most striking at grade III levels of expression. Multivariate analysis showed that MDR1 expression is an independent prognostic indicator of poor survival. We conclude that (1) MDR1 may be involved in chemoresistance and tumor propagation in primary uveal melanoma, and (2) increasing levels of expression are prognostically significant and may prove a useful marker of tumor invasiveness, independent of established prognostic factors.
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Affiliation(s)
- B M Dunne
- National Ophthalmic Pathology Laboratory, Royal Victoria Eye & Ear Hospital, Dublin, Ireland
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Abstract
The study's objectives were to measure flour antigen exposure in bakeries and define the determinants of exposure. Ninety-six bakery workers, employed in seven different bakeries, participated in the study. Two side-by-side full-shift inhalable dust samples were obtained from each study participant on a single occasion. The flour antigen exposure was measured as wheat antigen and fungal alpha-amylase content of the water-soluble fraction of inhalable dust, assayed via enzyme-linked immunosorbent assays. During the entire sampling period bakers were observed and information on 14 different tasks was recorded at 15-minute intervals. Other production characteristics were also recorded for each sampling day and used in statistical modeling to identify significant predictors of exposure. The mean alpha-amylase antigen exposure was 22.0 ng/m3 (ranging from below the limit of detection of 0.1 ng/m3 to 307.1 ng/m3) and the mean wheat antigen exposure was 109 micrograms/m3 (ranging from below the limit of detection of 1 microgram/m3 to 1018 micrograms/m3). Regression models that explained 74% of variability in wheat antigen and alpha-amylase antigen exposures were constructed. The models indicated that tasks such as weighing, pouring, and operating dough-brakers increased flour antigen exposure, while packing and decorating resulted in lower exposures. Croissant, puff-pastry, and bread/bun production lines were associated with increased exposure, while cake production and substitution of dusting with the use of divider oil were associated with decreased exposure. Exposure levels can be reduced by the automation of forming tasks, alteration of tasks requiring pouring of flour, and changes to the types of products manufactured.
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Affiliation(s)
- I Burstyn
- University of British Columbia, Vancouver, Canada.
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Abstract
We report the recurrence of a localized conjunctival lymphoma arising in mucosal-associated lymphoid tissue (MALToma) in the psoas muscle, 18 months after initial treatment with radiotherapy. Findings from systemic investigations demonstrated MALToma recurrences in the psoas muscle and the stomach. Ocular adnexal MALTomas typically manifest as localized tumors, which respond well to radiotherapy, but a proportion may recur in typical MALT sites. To our knowledge, this is the first report of a recurrence in the psoas muscle, and the clinical implication is that all patients with ocular adnexal lymphomas need to be followed up for an indefinite period.
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Affiliation(s)
- M T Cahill
- The Research Foundation, The Royal Victoria Eye and Ear Hospital, Dublin, Ireland
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