1
|
Smargiassi A, Sidi EAL, Robert LE, Plante C, Haddad M, Gamache P, Burnett R, Goudreau S, Liu L, Fournier M, Pelletier E, Yankoty I. Exposure to ambient air pollutants and the onset of dementia in Québec, Canada. Environ Res 2020; 190:109870. [PMID: 32739624 DOI: 10.1016/j.envres.2020.109870] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/20/2020] [Accepted: 06/20/2020] [Indexed: 05/07/2023]
Abstract
BACKGROUND Effects of air pollutants are related to oxidative stress which is also linked to the pathogenesis of dementia including Alzheimer's and related diseases. OBJECTIVE We assessed associations between exposure to air pollutants and the onset of dementia; the association with the distance between residence and major roads was also assessed for the island of Montreal. METHODS We created an open cohort of adults aged 65 years and older starting in 2000 and ending in 2012 in the province of Québec, Canada using linked medico-administrative databases. New cases of dementia were defined based on a validated algorithm. Annual residential levels of nitrogen dioxide (NO2) and fine particles (PM2.5) at residential levels were estimated for each year of follow up using estimates based on satellite images and ground air monitoring data. Hazard ratios (HRs) were assessed with Extended (time dependent exposure) Cox models with age as the time axis and stratified for sex, for the annual exposure level at each residential address. Models were adjusted for the calendar year, area-wide social and material deprivation indexes and for NO2 or PM2.5; they were also indirectly adjusted for smoking. RESULTS 1,807,133 persons (13,242,270 person-years) were followed and 199,826 developed dementia. From models (adjusted for calendar year, social and material deprivation indexes), HRs for an interquartile range (IQR) increase in time-varying exposure to NO2 (IQR 13.26 ppb), PM2.5 (IQR 3.90 μg/m³), and distance to major roads (IQR 150 m, in Montreal only), were 1.005 (CI 95% 0.994-1.017), 1.016 (CI 95% 1.003-1.028) and 0.969 (CI 95% 0.958-0.980), respectively. CONCLUSIONS Results suggest that the onset of dementia may be related to residential exposure to PM2.5, NO2, and distance to major roads.
Collapse
Affiliation(s)
- Audrey Smargiassi
- School of Public Health, Centre of Public Health Research, University of Montreal and CIUSSS du Centre-Sud-de-l'Île-de-Montréal, Montreal, Canada; Institut national de la santé publique du Québec, Québec, Canada.
| | | | | | - Céline Plante
- Direction régionale de santé publique de Montréal, Québec, Canada
| | - Mona Haddad
- School of Public Health, Centre of Public Health Research, University of Montreal and CIUSSS du Centre-Sud-de-l'Île-de-Montréal, Montreal, Canada
| | - Philippe Gamache
- Institut national de la santé publique du Québec, Québec, Canada
| | - Rick Burnett
- Environmental Health Science and Research Bureau, Health, Canada
| | - Sophie Goudreau
- Direction régionale de santé publique de Montréal, Québec, Canada
| | - Ling Liu
- Environmental Health Science and Research Bureau, Health, Canada
| | - Michel Fournier
- Direction régionale de santé publique de Montréal, Québec, Canada
| | - Eric Pelletier
- Institut national de la santé publique du Québec, Québec, Canada
| | - Ines Yankoty
- School of Public Health, Centre of Public Health Research, University of Montreal and CIUSSS du Centre-Sud-de-l'Île-de-Montréal, Montreal, Canada
| |
Collapse
|
2
|
Hystad P, Larkin A, Rangarajan S, AlHabib KF, Avezum Á, Calik KBT, Chifamba J, Dans A, Diaz R, du Plessis JL, Gupta R, Iqbal R, Khatib R, Kelishadi R, Lanas F, Liu Z, Lopez-Jaramillo P, Nair S, Poirier P, Rahman O, Rosengren A, Swidan H, Tse LA, Wei L, Wielgosz A, Yeates K, Yusoff K, Zatoński T, Burnett R, Yusuf S, Brauer M. Associations of outdoor fine particulate air pollution and cardiovascular disease in 157 436 individuals from 21 high-income, middle-income, and low-income countries (PURE): a prospective cohort study. Lancet Planet Health 2020; 4:e235-e245. [PMID: 32559440 PMCID: PMC7457447 DOI: 10.1016/s2542-5196(20)30103-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/19/2020] [Accepted: 04/21/2020] [Indexed: 05/05/2023]
Abstract
BACKGROUND Most studies of long-term exposure to outdoor fine particulate matter (PM2·5) and cardiovascular disease are from high-income countries with relatively low PM2·5 concentrations. It is unclear whether risks are similar in low-income and middle-income countries (LMICs) and how outdoor PM2·5 contributes to the global burden of cardiovascular disease. In our analysis of the Prospective Urban and Rural Epidemiology (PURE) study, we aimed to investigate the association between long-term exposure to PM2·5 concentrations and cardiovascular disease in a large cohort of adults from 21 high-income, middle-income, and low-income countries. METHODS In this multinational, prospective cohort study, we studied 157 436 adults aged 35-70 years who were enrolled in the PURE study in countries with ambient PM2·5 estimates, for whom follow-up data were available. Cox proportional hazard frailty models were used to estimate the associations between long-term mean community outdoor PM2·5 concentrations and cardiovascular disease events (fatal and non-fatal), cardiovascular disease mortality, and other non-accidental mortality. FINDINGS Between Jan 1, 2003, and July 14, 2018, 157 436 adults from 747 communities in 21 high-income, middle-income, and low-income countries were enrolled and followed up, of whom 140 020 participants resided in LMICs. During a median follow-up period of 9·3 years (IQR 7·8-10·8; corresponding to 1·4 million person-years), we documented 9996 non-accidental deaths, of which 3219 were attributed to cardiovascular disease. 9152 (5·8%) of 157 436 participants had cardiovascular disease events (fatal and non-fatal incident cardiovascular disease), including 4083 myocardial infarctions and 4139 strokes. Mean 3-year PM2·5 at cohort baseline was 47·5 μg/m3 (range 6-140). In models adjusted for individual, household, and geographical factors, a 10 μg/m3 increase in PM2·5 was associated with increased risk for cardiovascular disease events (hazard ratio 1·05 [95% CI 1·03-1·07]), myocardial infarction (1·03 [1·00-1·05]), stroke (1·07 [1·04-1·10]), and cardiovascular disease mortality (1·03 [1·00-1·05]). Results were similar for LMICs and communities with high PM2·5 concentrations (>35 μg/m3). The population attributable fraction for PM2·5 in the PURE cohort was 13·9% (95% CI 8·8-18·6) for cardiovascular disease events, 8·4% (0·0-15·4) for myocardial infarction, 19·6% (13·0-25·8) for stroke, and 8·3% (0·0-15·2) for cardiovascular disease mortality. We identified no consistent associations between PM2·5 and risk for non-cardiovascular disease deaths. INTERPRETATION Long-term outdoor PM2·5 concentrations were associated with increased risks of cardiovascular disease in adults aged 35-70 years. Air pollution is an important global risk factor for cardiovascular disease and a need exists to reduce air pollution concentrations, especially in LMICs, where air pollution levels are highest. FUNDING Full funding sources are listed at the end of the paper (see Acknowledgments).
Collapse
Affiliation(s)
- Perry Hystad
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA; Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, ON, Canada.
| | - Andrew Larkin
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA
| | - Sumathy Rangarajan
- Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, ON, Canada
| | - Khalid F AlHabib
- Department of Cardiac Sciences, King Fahad Cardiac Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Álvaro Avezum
- Department of Medicine, Universidade de Santo Amaro, Hospital Alemão Oswaldo Cruz, São Paulo, Brazil
| | | | - Jephat Chifamba
- Department of Physiology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe
| | - Antonio Dans
- Department of Cardiac Sciences, University of Philippines, Manila, Philippines
| | - Rafael Diaz
- Estudios Clínicos Latinoamérica (ECLA), Rosario, Santa Fe, Argentina
| | - Johan L du Plessis
- Occupational Hygiene and Health Research Initiative, North-West University, Potchefstroom, South Africa
| | - Rajeev Gupta
- Eternal Heart Care Centre and Research Institute, Jaipur, India
| | - Romaina Iqbal
- Department of Community Health Sciences and Medicine, Aga Khan University, Karachi, Pakistan
| | - Rasha Khatib
- Institute for Community and Public Health, Birzeit University, Birzeit, Palestine; Advocate Health Care, Chicago, IL, USA
| | - Roya Kelishadi
- Isfahan Cardiovascular Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fernando Lanas
- Department of Medicine, Universidad de La Frontera, Temuco, Chile
| | - Zhiguang Liu
- Jockey Club School of Public Health and Primary Care, the Chinese University of Hong Kong, Prince of Wales Hospital, Sha Tin, Hong Kong
| | - Patricio Lopez-Jaramillo
- Fundación Oftalmológica de Santander Clínica Carlos Ardila Lulle (FOSCAL), Bucaramanga, Colombia; Escuela de Medicina, Universidad de Santander, Bucaramanga, Colombia
| | - Sanjeev Nair
- Health Action by People, Thiruvananthapuram, India
| | - Paul Poirier
- Faculty of Pharmacy, University Institute of Cardiology and Respirology of Quebec, Laval University, Québec, QC, Canada
| | | | - Annika Rosengren
- Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Hany Swidan
- Dubai Health Authority, Dubai, United Arab Emirates
| | - Lap Ah Tse
- Jockey Club School of Public Health and Primary Care, the Chinese University of Hong Kong, Prince of Wales Hospital, Sha Tin, Hong Kong
| | - Li Wei
- National Centre for Cardiovascular Diseases, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Andreas Wielgosz
- Department of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Karen Yeates
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Khalid Yusoff
- Faculty of Medicine, Universiti Teknologi MARA, Selangor, Malaysia; UCSI University, Cheras, Kuala Lumpur, Malaysia
| | - Tomasz Zatoński
- Department of Otolaryngology Head and Neck Surgery, Wrocław Medical University, Wrocław, Poland
| | - Rick Burnett
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Salim Yusuf
- Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, ON, Canada
| | - Michael Brauer
- School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
3
|
Ng N, Patton JT, Burnett R, Clement ND. Sagittal alignment of the cemented femoral component in revision total knee arthroplasty influences the anterior and posterior condylar offset: Stem length does not affect these variables. Knee 2020; 27:477-484. [PMID: 31892431 DOI: 10.1016/j.knee.2019.10.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 08/15/2019] [Accepted: 10/28/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND The position of the femoral component can influence knee kinematics by altering the posterior (PCO) and anterior condylar offset (ACO). The primary aim of this study was to assess whether the length of the cemented stem influences the sagittal position of the femoral component after revision total knee arthroplasty (rTKA). The secondary aim was to determine the influence of the sagittal position on PCO and ACO. METHODS There were 172 consecutive patients over a seven-year period that underwent rTKA with a cemented semi-constrained prosthesis. The 172 patients were separated into two groups: 115 with short stems (50 mm) and 57 with longer stems (100 or 150 mm). Using rotationally acceptable lateral radiographs, the degree of flexion(+)/extension(-) of the femoral components, PCO, and ACO were measured. RESULTS There was no significant difference (p > 0.25) between the two groups for sagittal position, PCO, or ACO. The average flexion of the femoral component with short stems was 2.2 ± 4.1° and 2.2 ± 3.4° for long stems (difference = 0.0, 95% confidence intervals (CI) -1.3 to 1.2). The average PCO ratio was 1.02 ± 0.15 for short stems and 0.99 ± 0.17 for long stems (difference = 0.03, 95% CI -0.02 to 0.08). The average ACO ratio was at 0.07 ± 0.08 for short stems and 0.08 ± 0.08 for long stems (difference = 0.01, 95% CI -0.01 to 0.04). There was a significant correlation between sagittal alignment of the femoral component and PCO (flexion increased PCO, r = 0.39, p < 0.0001) and ACO (flexion decreased ACO, r = -0.34, p < 0.0001). CONCLUSIONS Cemented stem length does not influence the position of femoral component in the sagittal axis, PCO, or ACO. Surgical technique and sizing of the femoral component may be more predictive.
Collapse
Affiliation(s)
- N Ng
- University of Edinburgh Medical School, UK.
| | | | | | | |
Collapse
|
4
|
Crouse DL, Erickson AC, Christidis T, Pinault L, van Donkelaar A, Li C, Meng J, Martin RV, Tjepkema M, Hystad P, Burnett R, Pappin A, Brauer M, Weichenthal S. Evaluating the Sensitivity of PM2.5–Mortality Associations to the Spatial and Temporal Scale of Exposure Assessment. Epidemiology 2020; 31:168-176. [DOI: 10.1097/ede.0000000000001136] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
5
|
Steel ZL, Campos B, Frick WF, Burnett R, Safford HD. The effects of wildfire severity and pyrodiversity on bat occupancy and diversity in fire-suppressed forests. Sci Rep 2019; 9:16300. [PMID: 31806868 PMCID: PMC6895131 DOI: 10.1038/s41598-019-52875-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 10/11/2019] [Indexed: 11/12/2022] Open
Abstract
Wildfire is an important ecological process that influences species’ occurrence and biodiversity generally. Its effect on bats is understudied, creating challenges for habitat management and species conservation as threats to the taxa worsen globally and within fire-prone ecosystems. We conducted acoustic surveys of wildfire areas during 2014–2017 in conifer forests of California’s Sierra Nevada Mountains. We tested effects of burn severity and its variation, or pyrodiversity, on occupancy and diversity for the 17-species bat community while accounting for imperfect detection. Occupancy rates increased with severity for at least 6 species and with pyrodiversity for at least 3. Two other species responded negatively to pyrodiversity. Individual species models predicted maximum occupancy rates across burn severity levels but only one species occurred most often in undisturbed areas. Species richness increased from approximately 8 species in unburned forests to 11 in pyrodiverse areas with moderate- to high-severity. Greater accessibility of foraging habitats, as well as increased habitat heterogeneity may explain positive responses to wildfire. Many bat species appear well adapted to wildfire, while a century of fire suppression and forest densification likely reduced habitat quality for the community generally. Relative to other taxa, bats may be somewhat resilient to increases in fire severity and size; trends which are expected to continue with accelerating climate change.
Collapse
Affiliation(s)
- Z L Steel
- Department of Environmental Science and Policy, University of California, One Shields Avenue, Davis, CA, 95616, USA.
| | - B Campos
- Point Blue Conservation Science, Petaluma, CA, 94954, USA
| | - W F Frick
- Bat Conservation International, Austin, Texas, 78746, USA.,Department of Ecology and Evolutionary Biology, University of California Santa Cruz, California, 95060, USA
| | - R Burnett
- Point Blue Conservation Science, Petaluma, CA, 94954, USA
| | - H D Safford
- Department of Environmental Science and Policy, University of California, One Shields Avenue, Davis, CA, 95616, USA.,United States Department of Agriculture, Forest Service, Pacific Southwest Region, Vallejo, CA, 94592, USA
| |
Collapse
|
6
|
Stirling P, Clement ND, MacDonald D, Patton JT, Burnett R, Macpherson GJ. Early functional outcomes after condylar-stabilizing (deep-dish) versus standard bearing surface for cruciate-retaining total knee arthroplasty. Knee Surg Relat Res 2019; 31:3. [PMID: 32660531 PMCID: PMC7219520 DOI: 10.1186/s43019-019-0001-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 05/09/2019] [Indexed: 11/10/2022] Open
Abstract
AIMS The primary study aim was to compare early knee-specific function of patients undergoing cemented total knee arthroplasty (TKA) with either a cruciate-retaining (CR) polyethylene insert or a highly congruent condylar-stabilizing (CS) insert. Secondary aims were to compare general health and satisfaction between the groups. METHODS A total of 418 consecutive primary TKAs were identified retrospectively. Demographics and preoperative and 1-year postoperative patient-reported outcome measures (PROMs) were collected prospectively. PROMs consisted of Oxford Knee Scores, EuroQol-5 Dimensions scores, and Short Form-12 scores. RESULTS A total of 54 (12.9%) patients received a CS insert and 364 patients received a CR TKA. The CS group had a significantly (odds ratio (OR) 2.9; p = 0.002) greater proportion of females (77.8% versus 54.9%). The only significant difference in postoperative PROMs was a higher Short Form-12 physical component score in the CR group (difference 3.1; 95% confidence interval (CI) 0.1 to 6.1; p = 0.04). Linear regression analysis demonstrated no significant difference for all postoperative PROMs (p > 0.25). There was no significant difference in satisfaction rate (OR 0.94; 95% CI 0.42 to 2.12; p = 0.56) or pain visual analogue score (difference 6.1; 95% CI -1.9 to 14.0; p = 0.14) between the groups. CONCLUSION More congruent CS inserts have equivalent PROMs and patient satisfaction at 1 year compared with less congruent CR inserts. These represent an option for surgeons undertaking TKA where increased congruency is desired.
Collapse
Affiliation(s)
- P Stirling
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
| | - N D Clement
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - D MacDonald
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - J T Patton
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - R Burnett
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - G J Macpherson
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| |
Collapse
|
7
|
Clement ND, Howard TA, Immelman RJ, MacDonald D, Patton JT, Lawson GM, Burnett R. Patellofemoral arthroplasty versus total knee arthroplasty for patients with patellofemoral osteoarthritis: equal function and satisfaction but higher revision rate for partial arthroplasty at a minimum eight years’ follow-up. Bone Joint J 2019; 101-B:41-46. [PMID: 30601045 DOI: 10.1302/0301-620x.101b1.bjj-2018-0654.r2] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AIMS The primary aim of this study was to compare the knee-specific functional outcome of patellofemoral arthroplasty with total knee arthroplasty (TKA) in the management of patients with patellofemoral osteoarthritis. PATIENTS AND METHODS A total of 54 consecutive Avon patellofemoral arthroplasties were identified and propensity-score-matched to a group of 54 patients undergoing a TKA with patellar resurfacing for patellofemoral osteoarthritis. The Oxford Knee Score (OKS), the 12-Item Short-Form Health Survey (SF-12), and patient satisfaction were collected at a mean follow up of 9.2 years (8 to 15). Survival was defined by revision or intention to revise. RESULTS There was no significant difference in the mean OKS (p > 0.60) or SF-12 scores (p > 0.28) between the groups. There was a lower rate of satisfaction at the final follow-up for the TKA group (78% vs 87%) but this was not statistically significant (odds ratio 0.56, p = 0.21). Length of stay was significantly shorter (p = 0.008) for the Avon group (difference 1.8 days, 95% confidence interval (CI) 0.4 to 3.2). The ten-year survival for the Avon group was 92.3% (95% CI 87.1 to 97.5) and for the TKA group was 100% (95% CI 93.8 to 100). This difference was not statistically significant (log-rank test, p = 0.10). CONCLUSION Patients undergoing an Avon patellofemoral arthroplasty have a shorter length of stay, and a functional outcome and rate of satisfaction that is equal to that of TKA. The benefits of the Avon arthroplasty need to be balanced against the increased rate of revision when compared with TKA.
Collapse
Affiliation(s)
- N D Clement
- The Royal Infirmary of Edinburgh, Edinburgh, UK
| | - T A Howard
- The Royal Infirmary of Edinburgh, Edinburgh, UK
| | | | | | - J T Patton
- The Royal Infirmary of Edinburgh, Edinburgh, UK
| | - G M Lawson
- The Royal Infirmary of Edinburgh, Edinburgh, UK
| | - R Burnett
- The Royal Infirmary of Edinburgh, Edinburgh, UK
| |
Collapse
|
8
|
van den Bosch M, Brauer M, Burnett R, Davies HW, Davis Z, Guhn M, Jarvis I, Nesbitt L, Oberlander T, Rugel E, Sbihi H, Su JG, Jerrett M. Born to be Wise: a population registry data linkage protocol to assess the impact of modifiable early-life environmental exposures on the health and development of children. BMJ Open 2018; 8:e026954. [PMID: 30552286 PMCID: PMC6303566 DOI: 10.1136/bmjopen-2018-026954] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
INTRODUCTION Deficiencies in childhood development is a major global issue and inequalities are large. The influence of environmental exposures on childhood development is currently insufficiently explored. This project will analyse the impact of various modifiable early life environmental exposures on different dimensions of childhood development. METHODS Born to be Wise will study a Canadian cohort of approximately 34 000 children who have completed an early development test at the age of 5. Land use regression models of air pollution and spatially defined noise models will be linked to geocoded data on early development to analyse any harmful effects of these exposures. The potentially beneficial effect on early development of early life exposure to natural environments, as measured by fine-grained remote sensing data and various land use indexes, will also be explored. The project will use data linkages and analyse overall and age-specific impact, including variability depending on cumulative exposure by assigning time-weighted exposure estimates and by studying subsamples who have changed residence and exposure. Potentially moderating effects of natural environments on air pollution or noise exposures will be studied by mediation analyses. A matched case-control design will be applied to study moderating effects of natural environments on the association between low socioeconomic status and early development. The main statistical approach will be mixed effects models, applying a specific software to deal with multilevel random effects of nested data. Extensive confounding control will be achieved by including data on a range of detailed health and sociodemographic variables. ETHICS AND DISSEMINATION The study protocol has been ethically approved by the Behavioural Research Ethics Board at the University of British Columbia. The findings will be published in peer-reviewed journals and presented at scholarly conferences. Through stakeholder engagement, the results will also reach policy and a broader audience.
Collapse
Affiliation(s)
- Matilda van den Bosch
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
- The Department of Forest and Conservation Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael Brauer
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Hugh W Davies
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Zoe Davis
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Martin Guhn
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Ingrid Jarvis
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lorien Nesbitt
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Tim Oberlander
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Emily Rugel
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Hind Sbihi
- The School of Population and Public Health, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Jason G Su
- Department of Statistics, University of California, Berkeley, California, USA
| | - Michael Jerrett
- Fielding School of Public Health, University of California, Los Angeles, California, USA
| |
Collapse
|
9
|
Makaram N, Clement ND, Hoo T, Nutton R, Burnett R. Survival of the low contact stress rotating platform total knee replacement is influenced by age: 1058 implants with a minimum follow-up of 10 years. Knee 2018; 25:1283-1291. [PMID: 30232026 DOI: 10.1016/j.knee.2018.08.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 07/19/2018] [Accepted: 08/27/2018] [Indexed: 02/02/2023]
Abstract
BACKGROUND The low contact stress (LCS) mobile-bearing total knee replacement (TKR) was designed to minimise polyethylene wear, aseptic loosening and osteolysis. However, registry data suggests there is a significantly greater revision rate associated. The primary aim of this study was to assess long-term survivorship of the LCS TKR performed at a single high-volume centre. Secondary aims were to assess survival by mechanism of failure and identify predictors of revision. METHODS During a 13-year period (1993-2006) 1091 LCS TKRs were performed by two senior surgeons. Thirty-three with incomplete data were excluded. The patients were retrospectively identified from an arthroplasty register. Mean age was 69 (range 30-96) years. Five hundred seventy-seven TKRs were performed in females, 481 in males. Mean follow-up was 14 years (SD 4.3). RESULTS There were 59 revisions during the study period: 14 (23.7%) for infection, 18 (30.5%) for instability, and 27 (45.8%) for polyethylene wear. Three hundred ninety-two patients died. All-cause survival at 10 years was 95% (95%CI 91.7-98.3) and at 15 years was 93% (95%CI 88.6-97.8). Survival at 10 years according to mechanism of failure was: infection 99% (95%CI 94-100%), instability 98% (95%CI 94-100%), and polyethylene wear 98% (95%CI 92-100). Of the 27 with polyethylene wear, only 19 (70.4%) had osteolysis requiring component revision, the other eight (29.6%) had polyethylene exchanges. Cox regression analysis identified younger age as the only predictor of revision (HR 0.96, 95%CI 0.94-0.99, p = 0.003), with a four percent decreased risk of revision for each increase in year of age. CONCLUSIONS The LCS TKR demonstrates excellent long-term survivorship with a low rate of revision for osteolysis, however this risk is increased in younger patients.
Collapse
Affiliation(s)
- N Makaram
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK.
| | - N D Clement
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - T Hoo
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - R Nutton
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| | - R Burnett
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK
| |
Collapse
|
10
|
Al-Kindi SG, Sarode A, Zullo M, Brook J, Burnett R, Huang W, Oliveira GH, Brook R, Rajagopalan S. AMBIENT AIR POLLUTION AND MORTALITY AFTER HEART TRANSPLANTATION. J Am Coll Cardiol 2018. [DOI: 10.1016/s0735-1097(18)31500-6] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
Shaddick G, Thomas ML, Green A, Brauer M, Donkelaar A, Burnett R, Chang HH, Cohen A, Dingenen RV, Dora C, Gumy S, Liu Y, Martin R, Waller LA, West J, Zidek JV, Prüss‐Ustün A. Data integration model for air quality: a hierarchical approach to the global estimation of exposures to ambient air pollution. J R Stat Soc Ser C Appl Stat 2017. [DOI: 10.1111/rssc.12227] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Carlos Dora
- World Health Organization Geneva Switzerland
| | - Sophie Gumy
- World Health Organization Geneva Switzerland
| | | | | | | | - Jason West
- University of North Carolina Chapel Hill USA
| | | | | |
Collapse
|
12
|
Clement ND, MacDonald DJ, Hamilton DF, Burnett R. Posterior condylar offset is an independent predictor of functional outcome after revision total knee arthroplasty. Bone Joint Res 2017; 6:172-178. [PMID: 28360083 PMCID: PMC5376661 DOI: 10.1302/2046-3758.63.bjr-2015-0021.r1] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 01/11/2017] [Indexed: 11/20/2022] Open
Abstract
Objectives Preservation of posterior condylar offset (PCO) has been shown to correlate with improved functional results after primary total knee arthroplasty (TKA). Whether this is also the case for revision TKA, remains unknown. The aim of this study was to assess the independent effect of PCO on early functional outcome after revision TKA. Methods A total of 107 consecutive aseptic revision TKAs were performed by a single surgeon during an eight-year period. The mean age was 69.4 years (39 to 85) and there were 59 female patients and 48 male patients. The Oxford Knee Score (OKS) and Short-form (SF)-12 score were assessed pre-operatively and one year post-operatively. Patient satisfaction was also assessed at one year. Joint line and PCO were assessed radiographically at one year. Results There was a significant improvement in the OKS (10.6 points, 95% confidence interval (CI) 8.8 to 12.3) and the SF-12 physical component score (5.9, 95% CI 4.1 to 7.8). PCO directly correlated with change in OKS (p < 0.001). Linear regression analysis confirmed the independent effect of PCO on the OKS (p < 0.001) and the SF-12 physical score (p = 0.02). The overall rate of satisfaction was 85% and on logistic regression analysis improvement in the OKS (p = 0.002) was a significant predictor of patient satisfaction, which is related to PCO; although this was not independently associated with satisfaction. Conclusion Preservation of PCO should be a major consideration when undertaking revision TKA. The option of increasing PCO to balance the flexion gap while maintaining the joint line should be assessed intra-operatively. Cite this article: N. D. Clement, D. J. MacDonald, D. F. Hamilton, R. Burnett. Posterior condylar offset is an independent predictor of functional outcome after revision total knee arthroplasty. Bone Joint Res 2017;6:172–178. DOI: 10.1302/2046-3758.63.BJR-2015-0021.R1.
Collapse
Affiliation(s)
- N D Clement
- Department of Orthopaedics, Royal Infirmary of Edinburgh, Little France Crescent, Edinburgh, EH16 4SA, UK
| | - D J MacDonald
- Department of Orthopaedics, University of Edinburgh, FU413, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH164SB, UK
| | - D F Hamilton
- Department of Orthopaedics, University of Edinburgh, FU413, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH164SB, UK
| | - R Burnett
- Department of Orthopaedics, Royal Infirmary of Edinburgh, Little France Crescent, Edinburgh, EH16 4SA, UK
| |
Collapse
|
13
|
Clement ND, Macdonald D, Burnett R, Simpson AHRW, Howie CR. A patient's perception of their hospital stay influences the functional outcome and satisfaction of total knee arthroplasty. Arch Orthop Trauma Surg 2017; 137:693-700. [PMID: 28331990 PMCID: PMC5401709 DOI: 10.1007/s00402-017-2661-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Indexed: 12/17/2022]
Abstract
INTRODUCTION To assess whether patient satisfaction with their hospital stay influences the early outcome of total knee arthroplasty (TKA). METHODS During a 5-year period patients undergoing primary TKA at the study centre had prospective outcome data recorded (n = 2264). The Oxford knee score (OKS) and the short form (SF)-12 were recorded pre-operatively and 1 year post-operatively when satisfaction with their TKA was also assessed. Patient satisfaction with their hospital stay was also evaluated and their reasons for it were qualitatively documented. RESULTS Decreasing level of satisfaction with their hospital stay was associated with a significantly worse post-operative OKS (p < 0.001) and SF-12 score (p < 0.001). Multivariable regression analysis confirmed that the patient's perceived level of satisfaction with their hospital stay was an independent predictor of change in the OKS (p < 0.001) and SF-12 score (p < 0.006) after adjusting for confounding variables. Patient satisfaction with their TKA was significantly influenced by their hospital experience, decreasing from 96% in those with an excellent experience to 42% in those with a poor experience. Food, staff/care, and the hospital environment were the most frequent reasons of why patients rated their hospital experience as fair or poor. CONCLUSION A patient's perception of their inpatient hospital experience after surgery is an important modifiable predictor of early functional outcome and satisfaction with TKA.
Collapse
Affiliation(s)
- N D Clement
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
| | - D Macdonald
- University of Edinburgh, Little France, Edinburgh, EH16 4SB, UK
| | - R Burnett
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - A H R W Simpson
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
- University of Edinburgh, Little France, Edinburgh, EH16 4SB, UK
| | - C R Howie
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| |
Collapse
|
14
|
Sanmartin C, Decady Y, Trudeau R, Dasylva A, Tjepkema M, Finès P, Burnett R, Ross N, Manuel DG. Linking the Canadian Community Health Survey and the Canadian Mortality Database: An enhanced data source for the study of mortality. Health Rep 2016; 27:10-18. [PMID: 28002578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BACKGROUND This study summarizes the linkage of the Canadian Community Health Survey (CCHS) and the Canadian Mortality Database (CMDB), which was performed to examine relationships between social determinants, health behaviours and mortality in the household population. DATA AND METHODS The 2000/2001-to-2011 Canadian Community Health Surveys were linked to the 2000-to-2011 CMDB using probabilistic methods based on common identifiers (names, date of birth, postal code and sex) for eligible respondents (85%; n = 614,774). Mortality records from January 1, 2000 through December 31, 2011 for people aged 12 or older were eligible for linkage (n = 2.774 million). The linkage was enhanced with information from the Historical Tax Summary File. Quality assessment consisted of internal and external validation. Cox survival analysis (age-adjusted) was conducted to estimate hazard ratios (HRs) associated with selected health behaviours. RESULTS Overall, 5.3% of eligible CCHS respondents linked to a mortality record; false positive and false negative rates were 0.04% and 2.43%, respectively. Linkage rates were higher among males (5.8%) and people aged 75 or older (20.2%), reflecting known mortality risks. Survival analyses confirmed elevated mortality risk associated with heavy (HR 2.36, CI 1.84, 2.89) and light smoking (HR 1.91, CI 1.52, 2.33), compared with not smoking; underweight and obesity, compared with normal and overweight; low fruit and vegetable consumption; and lack of physical activity. INTERPRETATION Linking health behaviour information from the CCHS to mortality data from the CMDB allows for a greater understanding of modifiable determinants of mortality.
Collapse
Affiliation(s)
| | - Yves Decady
- Health Statistics Division, Statistics Canada, Ottawa, Ontario
| | - Richard Trudeau
- Special Surveys Division, Statistics Canada, Ottawa, Ontario
| | - Abel Dasylva
- Household Survey Methods Division, Statistics Canada, Ottawa, Ontario
| | | | - Philippe Finès
- Health Analysis Division, Statistics Canada, Ottawa, Ontario
| | | | | | - Douglas G Manuel
- Health Analysis Division, Statistics Canada, and the Ottawa Hospital Research Institute, Ottawa, Ontario
| |
Collapse
|
15
|
Cakmak S, Hebbern C, Vanos J, Crouse DL, Burnett R. Ozone exposure and cardiovascular-related mortality in the Canadian Census Health and Environment Cohort (CANCHEC) by spatial synoptic classification zone. Environ Pollut 2016; 214:589-599. [PMID: 27131819 DOI: 10.1016/j.envpol.2016.04.067] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 04/16/2016] [Accepted: 04/17/2016] [Indexed: 05/29/2023]
Abstract
Our objective is to analyse the association between long term ozone exposure and cardiovascular related mortality while accounting for climate, location, and socioeconomic factors. We assigned subjects with 16 years of follow-up in the Canadian Census Health and Environment Cohort (CanCHEC) to one of seven regions based on spatial synoptic classification (SSC) weather types and examined the interaction of exposure to both fine particulate matter (PM2.5) and ground level ozone and cause of death using survival analysis, while adjusting for socioeconomic characteristics and individual confounders. Correlations between ozone and PM2.5 varied across SSC zones from -0.02 to 0.7. Comparing zones using the most populated SSC zone as a reference, a 10 ppb increase in ozone exposure was associated with increases in hazard ratios (HRs) that ranged from 1.007 (95% CI 0.99, 1.015) to 1.03 (95% CI 1.02, 1.041) for cardiovascular disease, 1.013 (95% CI 0.996, 1.03) to 1.058 (95% CI 1.034, 1.082) for cerebrovascular disease, and 1.02 (95% CI 1.006, 1.034) for ischemic heart disease. HRs remained significant after adjustment for PM2.5. Long term exposure to ozone is related to an increased risk of mortality from cardiovascular and cerebrovascular diseases; the risk varies by location across Canada and is not attenuated by adjustment for PM2.5. This research shows that the SSC can be used to define geographic regions and it demonstrates the importance of accounting for that spatial variability when studying the long term health effects of air pollution.
Collapse
Affiliation(s)
- Sabit Cakmak
- Population Studies Division, Environmental Health Science & Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, ON K1A 0K9, Canada.
| | - Chris Hebbern
- Population Studies Division, Environmental Health Science & Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, ON K1A 0K9, Canada
| | - Jennifer Vanos
- Department of Geosciences, Texas Tech University, Box 41053, Lubbock, TX 79409-1053, USA
| | - Dan L Crouse
- Department of Sociology, University of New Brunswick, PO Box 4400, Fredericton, NB E3B 5A3, Canada
| | - Rick Burnett
- Population Studies Division, Environmental Health Science & Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, ON K1A 0K9, Canada
| |
Collapse
|
16
|
Hamilton DF, Howie CR, Burnett R, Simpson AHRW, Patton JT. Dealing with the predicted increase in demand for revision total knee arthroplasty: challenges, risks and opportunities. Bone Joint J 2015; 97-B:723-8. [PMID: 26033049 DOI: 10.1302/0301-620x.97b6.35185] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Worldwide rates of primary and revision total knee arthroplasty (TKA) are rising due to increased longevity of the population and the burden of osteoarthritis. Revision TKA is a technically demanding procedure generating outcomes which are reported to be inferior to those of primary knee arthroplasty, and with a higher risk of complication. Overall, the rate of revision after primary arthroplasty is low, but the number of patients currently living with a TKA suggests a large potential revision healthcare burden. Many patients are now outliving their prosthesis, and consideration must be given to how we are to provide the necessary capacity to meet the rising demand for revision surgery and how to maximise patient outcomes. The purpose of this review was to examine the epidemiology of, and risk factors for, revision knee arthroplasty, and to discuss factors that may enhance patient outcomes.
Collapse
Affiliation(s)
- D F Hamilton
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH164SB, UK
| | - C R Howie
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH164SB, UK
| | - R Burnett
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH164SB, UK
| | - A H R W Simpson
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH164SB, UK
| | - J T Patton
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH164SB, UK
| |
Collapse
|
17
|
Clement ND, MacDonald D, Moran M, Burnett R, Howie CR, Patton JT. Mega prosthetic distal femoral arthroplasty for non-tumour indications: does the indication affect the functional outcome and survivorship? Knee Surg Sports Traumatol Arthrosc 2015; 23:1330-1336. [PMID: 24482215 DOI: 10.1007/s00167-014-2861-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 01/20/2014] [Indexed: 11/27/2022]
Abstract
PURPOSE To report the functional outcome, implant survival, and patient mortality after mega prosthetic distal femoral arthroplasty according to the surgical indication. METHODS A prospective database was compiled for 45 consecutive patients undergoing distal femoral arthroplasty, of which 26 had fractures of the distal femur (group 1) and 19 underwent revision of a total knee arthroplasty (group 2). There were 17 males and 28 females with a median age of 74.5 years. Short form (SF)-12 scores were recorded pre-operatively (before the fracture or revision) and 1 year post-operatively, at which point a Toronto Extremity Salvage Score (TESS) was also obtained. Length of hospital stay and return to place of domicile was obtained from the hospital database. Mortality status was obtained from the General Register Office for Scotland. No patient was lost to follow-up. RESULTS The 1-year physical (52.4) and mental (63.4) components of the SF-12 score and the TESS (70.5 %) did not significantly differ between the groups (n.s.). The fracture group, however, had a longer length of stay (8 vs. 19 days, p = 0.001) and were also less likely to return to their original domicile (odds ratio 9.5, p = 0.02). The overall implant survival rate was 85 % at 5 years, which was worse for the fracture group (80 vs. 90 %, n.s.). The 5-year mortality rate for the revision group was 17 %, whereas the fracture group demonstrated a greater mortality rate of 43 % (n.s.). CONCLUSION The functional outcome, revision rate, and mortality of patients undergoing distal femoral arthroplasty for non-tumour reasons are not influenced by indication, but patients undergoing surgery for fractures of the distal femur have a longer length of stay and are less likely to return home. Distal femoral arthroplasty should be considered as a management option for non-tumour salvage procedures of the distal femur. LEVEL OF EVIDENCE Retrospective comparative study, Level III.
Collapse
Affiliation(s)
- N D Clement
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
| | | | - M Moran
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - R Burnett
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - C R Howie
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| | - J T Patton
- Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK
| |
Collapse
|
18
|
Hamilton DF, Burnett R, Patton JT, Howie CR, Moran M, Simpson AHRW, Gaston P. Implant design influences patient outcome after total knee arthroplasty: a prospective double-blind randomised controlled trial. Bone Joint J 2015; 97-B:64-70. [PMID: 25568415 DOI: 10.1302/0301-620x.97b1.34254] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Total knee arthroplasty (TKA) is an established and successful procedure. However, the design of prostheses continues to be modified in an attempt to optimise the functional outcome of the patient. The aim of this study was to determine if patient outcome after TKA was influenced by the design of the prosthesis used. A total of 212 patients (mean age 69; 43 to 92; 131 female (62%), 81 male (32%)) were enrolled in a single centre double-blind trial and randomised to receive either a Kinemax (group 1) or a Triathlon (group 2) TKA. Patients were assessed pre-operatively, at six weeks, six months, one year and three years after surgery. The outcome assessments used were the Oxford Knee Score; range of movement; pain numerical rating scales; lower limb power output; timed functional assessment battery and a satisfaction survey. Data were assessed incorporating change over all assessment time points, using repeated measures analysis of variance longitudinal mixed models. Implant group 2 showed a significantly greater range of movement (p = 0.009), greater lower limb power output (p = 0.026) and reduced report of 'worst daily pain' (p = 0.003) over the three years of follow-up. Differences in Oxford Knee Score (p = 0.09), report of 'average daily pain' (p = 0.57) and timed functional performance tasks (p = 0.23) did not reach statistical significance. Satisfaction with outcome was significantly better in group 2 (p = 0.001). These results suggest that patient outcome after TKA can be influenced by the prosthesis used.
Collapse
Affiliation(s)
- D F Hamilton
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - R Burnett
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - J T Patton
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - C R Howie
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - M Moran
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - A H R W Simpson
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - P Gaston
- University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| |
Collapse
|
19
|
Hamilton DF, Burnett R, Patton JT, Howie CR, Simpson AHRW. The identification and quantification of instability in a primary total knee replacement prior to revision. Bone Joint J 2014; 96-B:1339-43. [DOI: 10.1302/0301-620x.96b10.33654] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Instability is the reason for revision of a primary total knee replacement (TKR) in 20% of patients. To date, the diagnosis of instability has been based on the patient’s symptoms and a subjective clinical assessment. We assessed whether a measured standardised forced leg extension could be used to quantify instability. A total of 25 patients (11 male/14 female, mean age 70 years; 49 to 85) who were to undergo a revision TKR for instability of a primary implant were assessed with a Nottingham rig pre-operatively and then at six and 26 weeks post-operatively. Output was quantified (in revolutions per minute (rpm)) by accelerating a stationary flywheel. A control group of 183 patients (71 male/112 female, mean age 69 years) who had undergone primary TKR were evaluated for comparison. Pre-operatively, all 25 patients with instability exhibited a distinctive pattern of reduction in ‘mid-push’ speed. The mean reduction was 55 rpm (sd 33.2). Post-operatively, no patient exhibited this pattern and the reduction in ‘mid-push’ speed was 0 rpm. The change between pre- and post-operative assessment was significant (p < 0.001). No patients in the control group exhibited this pattern at any of the intervals assessed. The between-groups difference was also significant (p < 0.001). This suggests that a quantitative diagnostic test to assess the unstable primary TKR could be developed. Cite this article: Bone Joint J 2014;96-B:1339–43.
Collapse
Affiliation(s)
- D. F. Hamilton
- University of Edinburgh, FU413, Chancellor’s
Building, 49 Little France Crescent, Edinburgh, EH16
4SB, UK
| | - R. Burnett
- University of Edinburgh, Department
of Trauma and Orthopaedics, Edinburgh, EH16 4SB, UK
| | - J. T. Patton
- University of Edinburgh, Department
of Trauma and Orthopaedics, Edinburgh, EH16 4SB, UK
| | - C. R. Howie
- University of Edinburgh, Department
of Trauma and Orthopaedics, Edinburgh, EH16 4SB, UK
| | - A. H. R. W. Simpson
- University of Edinburgh, Department
of Trauma and Orthopaedics, Edinburgh, EH16 4SB, UK
| |
Collapse
|
20
|
Ayala-Lopez N, Martini M, Jackson WF, Darios E, Burnett R, Seitz B, Fink GD, Watts SW. Perivascular adipose tissue contains functional catecholamines. Pharmacol Res Perspect 2014; 2:e00041. [PMID: 24904751 PMCID: PMC4041285 DOI: 10.1002/prp2.41] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The sympathetic nervous system and its neurotransmitter effectors are undeniably important to blood pressure control. We made the novel discovery that perivascular adipose tissue (PVAT) contains significant concentrations of catecholamines. We hypothesized that PVAT contains sufficient releasable catecholamines to affect vascular function. High-pressure liquid chromatography, isometric contractility, immunohistochemistry, whole animal approaches, and pharmacology were used to test this hypothesis. In normal rat thoracic aorta and superior mesenteric artery, the indirect sympathomimetic tyramine caused a concentration-dependent contraction that was dependent on the presence of PVAT. Tyramine stimulated release of norepinephrine (NA), dopamine (DA) and the tryptamine serotonin (5-hydroxytryptamine [5-HT]) from PVAT isolated from both arteries. In both arteries, tyramine-induced concentration-dependent contraction was rightward-shifted and reduced by the noradrenaline transporter inhibitor nisoxetine (1 μmol/L), the vesicular monoamine transporter inhibitor tetrabenazine (10 μmol/L), and abolished by the α adrenoreceptor antagonist prazosin (100 nmol/L). Inhibitors of the DA and 5-HT transporter did not alter tyramine-induced, PVAT-dependent contraction. Removal of the celiac ganglion as a neuronal source of catecholamines for superior mesenteric artery PVAT did not significantly reduce the maximum or shift the concentration-dependent contraction to tyramine. Electrical field stimulation of the isolated aorta was not affected by the presence of PVAT. These data suggest that PVAT components that are independent of sympathetic nerves can release NA in a tyramine-sensitive manner to result in arterial contraction. Because PVAT is intimately apposed to the artery, this raises the possibility of local control of arterial function by PVAT catecholamines.
Collapse
Affiliation(s)
- N Ayala-Lopez
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - M Martini
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - W F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - E Darios
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - R Burnett
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - B Seitz
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - G D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| | - S W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824-1317
| |
Collapse
|
21
|
Clement ND, MacDonald D, Simpson AHRW, Burnett R. Total knee replacement in patients with concomitant back pain results in a worse functional outcome and a lower rate of satisfaction. Bone Joint J 2013; 95-B:1632-9. [DOI: 10.1302/0301-620x.95b12.31684] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This study assessed the effect of concomitant back pain on the Oxford knee score (OKS), Short-Form (SF)-12 and patient satisfaction after total knee replacement (TKR). It involved a prospectively compiled database of demographics and outcome scores for 2392 patients undergoing primary TKR, of whom 829 patients (35%) reported back pain. Compared with those patients without back pain, those with back pain were more likely to be female (odds ratio (OR) 1.5 (95% confidence interval (CI) 1.3 to 1.8)), have a greater level of comorbidity, a worse pre-operative OKS (2.3 points (95% CI 1.7 to 3.0)) and worse SF-12 physical (2.0 points (95% CI 1.4 to 2.6)) and mental (3.3 points (95% CI 2.3 to 4.3)) components. One year post-operatively, those with back pain had significantly worse outcome scores than those without with a mean difference in the OKS of 5 points (95% CI 3.8 to 5.4), in the SF-12 physical component of 6 points (95% CI 5.4 to 7.1) and in the mental component of 4 points (95% CI 3.1 to 4.9). Patients with back pain were less likely to be satisfied (OR 0.62, 95% CI 0.5 to 0.78). After adjusting for confounding variables, concomitant back pain was an independent predictor of a worse post-operative OKS, and of dissatisfaction. Clinicians should be aware that patients suffering concomitant back pain pre-operatively are at an increased risk of being dissatisfied post-operatively. Cite this article: Bone Joint J 2013;95-B:1632–9.
Collapse
Affiliation(s)
- N. D. Clement
- Royal Infirmary of Edinburgh, Department
of Orthopaedics and Trauma, 51 Little France
Crescent, Edinburgh EH16 4SU, UK
| | - D. MacDonald
- University of Edinburgh, Department
of Orthopaedics and Trauma, 51 Little France Crescent, Edinburgh
EH16 4SU, UK
| | - A. H. R. W. Simpson
- University of Edinburgh, Department
of Orthopaedics and Trauma, 51 Little France Crescent, Edinburgh
EH16 4SU, UK
| | - R. Burnett
- Royal Infirmary of Edinburgh, Department
of Orthopaedics and Trauma, 51 Little France
Crescent, Edinburgh EH16 4SU, UK
| |
Collapse
|
22
|
Clement ND, MacDonald D, Burnett R, Breusch SJ. Diabetes does not influence the early outcome of total knee replacement: a prospective study assessing the Oxford knee score, short form 12, and patient satisfaction. Knee 2013; 20:437-41. [PMID: 23993274 DOI: 10.1016/j.knee.2013.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 07/16/2013] [Accepted: 07/25/2013] [Indexed: 02/02/2023]
Abstract
BACKGROUND There is conflicting evidence as to whether diabetes mellitus influences the functional outcome and patient satisfaction after a total knee replacement (TKR). The aim of this study was to assess the effect of diabetes upon the Oxford knee score (OKS), short form (SF)-12, and patient satisfaction after TKR. METHODS Prospective pre- and post-operative (one year) OKS and SF-12 scores for 2389 patients undergoing primary TKR were compiled, of which 275 (12%) patients suffered with diabetes. Patient satisfaction was assessed at one year. RESULTS Patients with diabetes were more likely to have a greater level of comorbidity (p<0.001), and a worse pre-operative OKS and SF-12 score (p<0.02), compared to those patients without diabetes. Diabetes was not a significant (p>0.41) independent predictor of post-operative OKS or the SF-12 physical score on multivariable analysis. Although, factors more prevalent within the diabetic cohort (heart disease, vascular disease, liver disease, anaemia, depression, back pain, worse pre-operative OKS and SF-12 score) were found to be independent predictors of post-operative OKS and SF-12 physical score. Interestingly, diabetes was associated with a significantly greater improvement in mental wellbeing (SF-12 mental component), which was confirmed on multivariable analysis. Patient satisfaction was not influenced by a concomitant diagnosis of diabetes (p=0.57). CONCLUSION The outcome of TKR as assessed by the OKS, SF-12, and overall patient satisfaction rates are not influenced by diabetes per se, although factors more prevalent within this population result in a worse post-operative outcome. LEVEL OF EVIDENCE prospective cohort study, level III.
Collapse
Affiliation(s)
- N D Clement
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK.
| | | | | | | |
Collapse
|
23
|
Clement ND, Burnett R. Patient satisfaction after total knee arthroplasty is affected by their general physical well-being. Knee Surg Sports Traumatol Arthrosc 2013; 21:2638-46. [PMID: 23670127 DOI: 10.1007/s00167-013-2523-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 04/29/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE We hypothesise that patients with a worse post-operative generic physical health, and those with a subclinical improvement, will have a greater rate of dissatisfaction with their total knee arthroplasty (TKA) despite improvement in their knee function. METHODS Prospectively complied data for 2,330 primary TKA were used. Patient demographics, comorbidity, and pre- and post-operative (1 year) Oxford knee scores (OKS) and Short Form (SF-) 12 scores were collected. Patient satisfaction was also assessed 1 year post-operatively. The satisfaction rate of patients with a poor post-operative SF-12 physical component summary (PCS score) (≤40 points) and those with a subclinical improvement (<4 points) in the score were compared to those with a score of more than 40 and a clinically significant improvement, respectively. RESULTS More than half of the patients (n = 1,220) had a poor post-operative SF-12 PCS, and a third (n = 722) had a subclinical improvement in their general physical health after TKA. These patients were more likely to be older in age, suffer with concomitant back pain, and pain in other joints, and have a significantly worse pre-operative mental well-being score (SF-12) and OKS (all p < 0.04 on regression analysis). Both groups had a clinically significant improvement in their OKS post-operatively (p < 0.001), but it was 10 and 8 points less, respectively, than those patients with a SF-12 PCS of more than 40, and a clinical significant improvement in their PCS score (p < 0.001). Logistic regression analysis demonstrated that patients who had a poor post-operative SF-12 PCS (odds ratio 7.9, p < 0.001) and those with a subclinical improvement in their general physical health (odds ratio 5.1, p < 0.001) after TKA were significantly less likely to be satisfied. CONCLUSION Despite benefitting from a significant improvement in their OKS after TKA, patients with a poor post-operative SF-12 PCS and those with a subclinical improvement in their general physical well-being are significantly less likely to be satisfied at 1 year.
Collapse
Affiliation(s)
- N D Clement
- Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh, EH16 4SA, UK,
| | | |
Collapse
|
24
|
Sanmartin C, Finès P, Khan S, Peters P, Tjepkema M, Bernier J, Burnett R. Modelling risk factor information for linked census data: The case of smoking. Health Rep 2013; 24:9-15. [PMID: 24258239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Statistics Canada has initiated a series of data linkages of Census of Population long form and health outcome data. These linked data lack risk factor information. This study assesses the feasibility of using statistical modelling techniques to assign smoking status to census respondents. DATA AND METHODS The 2000/2001 Canadian Community Health Survey (CCHS) was used to develop age-/sex-specific predictive models to model smoking status based on variables available on the 1991 Census. The 2002/2003 CCHS was used to validate the modelled variable. Data from the 2002/2003 CCHS linked to data from the Hospital Morbidity Database (2001/2002 to 2004/2005) were used to evaluate the use of modelled versus self-reported smoking status on smoking-related hospitalizations. RESULTS For the current daily smoker models, income, education, marital status, dwelling ownership and region of birth were significant predictors. For the never smoker models, marital status, dwelling ownership, Aboriginal identity and region of birth were significant predictors. Modelled current daily smoker status was associated with increased odds of smoking-related hospitalization, compared with being a never smoker, even when adjusting for covariates. INTERPRETATION This study demonstrates the feasibility of using statistical modelling techniques to assign smoking status to census data, provided socio-economic and identity information is available.
Collapse
Affiliation(s)
- Claudia Sanmartin
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, K1A 0T6.
| | | | | | | | | | | | | |
Collapse
|
25
|
Clement ND, Burnett R, Breusch SJ. Should single- or two-stage revision surgery be used for the management of an infected total knee replacement? A critical review of the literature. ACTA ACUST UNITED AC 2013. [DOI: 10.13172/2052-9627-1-1-528] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
26
|
Clement ND, MacDonald D, Burnett R. Primary total knee replacement in patients with mental disability improves their mental health and knee function: a prospective study. Bone Joint J 2013; 95-B:360-6. [PMID: 23450021 DOI: 10.1302/0301-620x.95b3.29563] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We assessed the effect of mental disability on the outcome of total knee replacement (TKR) and investigated whether mental health improves post-operatively. Outcome data were prospectively recorded over a three-year period for 962 patients undergoing primary TKR for osteoarthritis. Pre-operative and one year Short-Form (SF)-12 scores and Oxford knee scores (OKS) were obtained. The mental component of the SF-12 was stratified into four groups according to level of mental disability (none ≥ 50, mild 40 to 49, moderate 30 to 39, severe < 30). Patients with any degree of mental disability had a significantly greater subjective physical disability according to the SF-12 (p = 0.06) and OKS (p < 0.001). The improvement in the disease-specific score (OKS) was not affected by a patient's mental health (p = 0.33). In contrast, patients with mental disability had less of an improvement in their global physical health (SF-12) (p < 0.001). However, patients with any degree of mental disability had a significant improvement in their mental health post-operatively (p < 0.001). Despite a similar improvement in their disease-specific scores and improvement in their mental health, patients with mental disability were significantly more likely to be dissatisfied with their TKR at one year (p = 0.001). Patients with poor mental health do benefit from improvements in their mental health and knee function after TKR, but also have a higher rate of dissatisfaction.
Collapse
Affiliation(s)
- N D Clement
- University of Edinburgh, Department of Orthopaedics, The Royal Infirmary of Edinburgh, Little France, Old Dalkeith Road, Edinburgh EH16 4SU, UK.
| | | | | |
Collapse
|
27
|
Mehta S, Shin H, Burnett R, North T, Cohen AJ. Ambient particulate air pollution and acute lower respiratory infections: a systematic review and implications for estimating the global burden of disease. Air Qual Atmos Health 2013; 6:69-83. [PMID: 23450182 PMCID: PMC3578732 DOI: 10.1007/s11869-011-0146-3] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 05/05/2011] [Indexed: 05/19/2023]
Abstract
Acute lower respiratory infections (ALRI) account for nearly one fifth of mortality in young children worldwide and have been associated with exposures to indoor and outdoor sources of combustion-derived air pollution. A systematic review was conducted to identify relevant articles on air pollution and ALRI in children. Using a Bayesian approach to meta-analysis, a summary estimate of 1.12 (1.03, 1.30) increased risk in ALRI occurrence per 10 μg/m3 increase in annual average PM2.5 concentration was derived from the longer-term (subchronic and chronic) effects studies. This analysis strengthens the evidence for a causal relationship between exposure to PM2.5 and the occurrence of ALRI and provides a basis for estimating the global attributable burden of mortality due to ALRI that is not influenced by the wide variation in regional case fatality rates. Most studies, however, have been conducted in settings with relatively low levels of PM2.5. Extrapolating their results to other, more polluted, regions will require a model that is informed by evidence from studies of the effects on ALRI of exposure to PM2.5 from other combustion sources, such as secondhand smoke and household solid fuel use.
Collapse
Affiliation(s)
- Sumi Mehta
- Health Effects Institute, 101 Federal Street, Suite 500, Boston, MA 02110 USA
| | - Hwashin Shin
- Population Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON Canada
- Institute of Population Health, University of Ottawa, Ottawa, ON Canada
| | - Rick Burnett
- Population Studies Division, Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON Canada
- Institute of Population Health, University of Ottawa, Ottawa, ON Canada
| | - Tiffany North
- Health Effects Institute, 101 Federal Street, Suite 500, Boston, MA 02110 USA
| | - Aaron J. Cohen
- Health Effects Institute, 101 Federal Street, Suite 500, Boston, MA 02110 USA
| |
Collapse
|
28
|
Shin HH, Stieb D, Burnett R, Takahara G, Jessiman B. Tracking national and regional spatial-temporal mortality risk associated with NO2 concentrations in Canada: a Bayesian hierarchical two-level model. Risk Anal 2012; 32:513-530. [PMID: 21980998 DOI: 10.1111/j.1539-6924.2011.01684.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The association between daily variations in urban air quality and mortality has been well documented using time series statistical methods. This approach assumes a constant association over time. We develop a space-time dynamic model that relaxes this assumption, thus more directly examining the hypothesis that improvements in air quality translate into improvements in public health. We postulate a Bayesian hierarchical two-level model to estimate annual mortality risks at regional and national levels and to track both risk and heterogeneity of risk within and between regions over time. We illustrate our methods using daily nitrogen dioxide concentrations (NO2) and nonaccidental mortality data collected for 1984-2004 in 24 Canadian cities. Estimates of risk and heterogeneity are compared by cause of mortality (cardio-pulmonary [CP] versus non-CP) and season, respectively. Over the entire period, the NO2 risk for CP mortality was slightly lower but with a narrower credible interval than that for non-CP mortality, mainly due to an unusually low risk for a single year (1998). Warm season NO2 risk was higher than cold season risk for both CP and non-CP mortality. For 21 years overall there were no significant differences detected among the four regional NO2 risks. We found overall that there was no strong evidence for time trends in NO2 risk at national or regional levels. However, an increasing linear time trend in the annual between-region heterogeneities was detected, which suggests the differences in risk among the four regions are getting larger, and further studies are necessary to understand the increasing heterogeneity.
Collapse
Affiliation(s)
- Hwashin Hyun Shin
- Population Studies Division, Environmental Health Science and Research Bureau, Health Canada.
| | | | | | | | | |
Collapse
|
29
|
Carlsten KS, London CA, Haney S, Burnett R, Avery AC, Thamm DH. Multicenter prospective trial of hypofractionated radiation treatment, toceranib, and prednisone for measurable canine mast cell tumors. J Vet Intern Med 2011; 26:135-41. [PMID: 22176473 DOI: 10.1111/j.1939-1676.2011.00851.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 10/18/2011] [Accepted: 11/10/2011] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Mast cell tumors (MCT) are common cutaneous tumors in dogs and when not amenable to surgical excision can present a therapeutic challenge. New treatment protocols for unresectable MCT are needed. HYPOTHESIS The combination of toceranib, prednisone, and hypofractionated radiation treatment (RT) will be well tolerated and efficacious. ANIMALS Seventeen client-owned dogs with measurable MCT amenable to RT. METHODS Prospective clinical trial. All dogs received prednisone, omeprazole, diphenhydramine, and toceranib. Toceranib was administered for 1 week before initiating RT, consisting of 24 Gy delivered in 3 or 4 fractions. RESULTS On an intent-to-treat basis, the overall response rate was 76.4%, with 58.8% of dogs achieving a complete response and 17.6% a partial response. The median time to best response was 32 days, and the median progression-free interval was 316 days. The overall median survival time was not reached with a median follow-up of 374 days. The most common toxicoses were gastrointestinal and hepatic. CONCLUSIONS AND CLINICAL IMPORTANCE The combination of hypofractionated RT, toceranib, and prednisone was tolerated and efficacious in the majority of dogs. Response rates and durations were higher than those reported for toceranib as a single-agent treatment for MCT. This combination is a viable treatment option for unresectable MCT.
Collapse
Affiliation(s)
- K S Carlsten
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | | | | | | | | | | |
Collapse
|
30
|
Ramakrishnan S, Collier J, Oyetunji R, Stutts B, Burnett R. Enzymatic hydrolysis of cellulose dissolved in N-methyl morpholine oxide/water solutions. Bioresour Technol 2010; 101:4965-70. [PMID: 19793649 DOI: 10.1016/j.biortech.2009.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 08/30/2009] [Accepted: 09/01/2009] [Indexed: 05/24/2023]
Abstract
In situ hydrolysis of cellulose (dissolving pulp) in N-methyl morpholine oxide (NMMO) solutions by commercially available Accellerase1000 is carried out. The yield of reducing sugars is followed as a function of time at three different temperatures and four different enzyme loadings to study the effect of system parameters on enzymatic hydrolysis. Initial results show that rates of hydrolysis of cellulose and yields of reducing sugars in the presence of NMMO-water is superior initially (ratio of initial reaction rates approximately 4) and comparable to that of regenerated cellulose (for times greater than 5h) when suspended in aqueous solutions. The usage of Accellerase1000 results predominantly in the formation of glucose with minimal amounts of cellobiose. This study proves the ability of cellulases to remain active in NMMO to carry out an in situ saccharification of cellulose thus eliminating the need to recover regenerated cellulose. Thus this work will form the basis for developing a continuous process for conversion of biomass to hydrogen, ethanol and other hydrocarbons.
Collapse
Affiliation(s)
- S Ramakrishnan
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL 32312, USA.
| | | | | | | | | |
Collapse
|
31
|
Ungerfeld EM, Rust SR, Burnett R. The effects of thiamine inhibition on ruminal fermentation: a preliminary study. Folia Microbiol (Praha) 2010; 54:521-6. [PMID: 20140720 DOI: 10.1007/s12223-009-0075-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 11/09/2009] [Indexed: 11/29/2022]
Abstract
Inhibition of methanogenesis in ruminal cultures was attempted by hindering thiamine availability through its degradation by 'polyphenols' and competition for active sites on enzymes and transporters using thiamine structural analogs. Effects on fermentation were small and not consistently reversed by adding thiamine. Lack of major effects of the compounds evaluated could be due to intracellular synthesis of thiamine covering most requirements.
Collapse
Affiliation(s)
- E M Ungerfeld
- Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA.
| | | | | |
Collapse
|
32
|
Sahsuvaroglu T, Jerrett M, Sears MR, McConnell R, Finkelstein N, Arain A, Newbold B, Burnett R. Spatial analysis of air pollution and childhood asthma in Hamilton, Canada: comparing exposure methods in sensitive subgroups. Environ Health 2009; 8:14. [PMID: 19338672 PMCID: PMC2669065 DOI: 10.1186/1476-069x-8-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 04/01/2009] [Indexed: 05/26/2023]
Abstract
BACKGROUND Variations in air pollution exposure within a community may be associated with asthma prevalence. However, studies conducted to date have produced inconsistent results, possibly due to errors in measurement of the exposures. METHODS A standardized asthma survey was administered to children in grades one and eight in Hamilton, Canada, in 1994-95 (N approximately 1467). Exposure to air pollution was estimated in four ways: (1) distance from roadways; (2) interpolated surfaces for ozone, sulfur dioxide, particulate matter and nitrous oxides from seven to nine governmental monitoring stations; (3) a kriged nitrogen dioxide (NO2) surface based on a network of 100 passive NO2 monitors; and (4) a land use regression (LUR) model derived from the same monitoring network. Logistic regressions were used to test associations between asthma and air pollution, controlling for variables including neighbourhood income, dwelling value, state of housing, a deprivation index and smoking. RESULTS There were no significant associations between any of the exposure estimates and asthma in the whole population, but large effects were detected the subgroup of children without hayfever (predominately in girls). The most robust effects were observed for the association of asthma without hayfever and NO2LUR OR = 1.86 (95%CI, 1.59-2.16) in all girls and OR = 2.98 (95%CI, 0.98-9.06) for older girls, over an interquartile range increase and controlling for confounders. CONCLUSION Our findings indicate that traffic-related pollutants, such as NO2, are associated with asthma without overt evidence of other atopic disorders among female children living in a medium-sized Canadian city. The effects were sensitive to the method of exposure estimation. More refined exposure models produced the most robust associations.
Collapse
Affiliation(s)
- Talar Sahsuvaroglu
- School of Geography and Earth Sciences, 1280 King St West, Hamilton, L8S 4K1, Canada
| | - Michael Jerrett
- School of Public Health, University of California, Berkeley, 140 Warren Hall, Berkeley, CA, 94720-7360, USA
| | - Malcolm R Sears
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare, 50 Charlton Avenue East, Hamilton, ON, L8N 4A6, Canada
| | - Rob McConnell
- Department of Preventive Medicine, School of Medicine, University of Southern California, 1540 Alcazar Street, Los Angeles, CA, 90089-9010, USA
| | - Norm Finkelstein
- School of Geography and Earth Sciences, 1280 King St West, Hamilton, L8S 4K1, Canada
| | - Altaf Arain
- School of Geography and Earth Sciences, 1280 King St West, Hamilton, L8S 4K1, Canada
| | - Bruce Newbold
- School of Geography and Earth Sciences, 1280 King St West, Hamilton, L8S 4K1, Canada
| | - Rick Burnett
- Biostatistics and Epidemiology Division, Health Canada, Tunney's Pasture, Ottawa, ON, K1A 0T6, Canada
| |
Collapse
|
33
|
Said HM, Ahmed K, Burnett R, Allan BR, Williamson AL, Hoosen AA. HPV genotypes in women with squamous intraepithelial lesions and normal cervixes participating in a community-based microbicide study in Pretoria, South Africa. J Clin Virol 2009; 44:318-21. [PMID: 19269889 DOI: 10.1016/j.jcv.2009.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 01/29/2009] [Accepted: 02/03/2009] [Indexed: 11/24/2022]
Abstract
BACKGROUND Little is known regarding the human papillomaviruses (HPV) genotypes prevalent in women in South Africa, a country with a high incidence of cervical cancer. OBJECTIVE To determine the prevalence and HPV genotypes in women with squamous abnormalities and normal cervixes participating in a community-based microbicide study. STUDY DESIGN A total of 159 cervical specimens, including 56 specimens from women with abnormal cytology (cases) and 103 randomly selected specimens from women with normal cytology (controls), were collected. HPV was detected by consensus PCR primers and HPV genotypes were determined by Roche Linear Array HPV genotyping assay. RESULTS HPV genotypes were found in 91% of cases and 40% of controls (p<0.005). High-risk HPV was detected in all high-grade squamous intraepithelial lesions (HSILs), 69% of low-grade squamous intraepithelial lesions (LSILs), 57% of atypical squamous cells of undetermined significance (ASCUS), and 86% of ASCUS in which HSIL could not be excluded (ASCUS-H), and 73% of HPV positive controls. HPV-35 was the predominant genotype in HSILs; HPV-18 in ASCUS; HPV-58 in ASCUS-H and HPV-16 in LSILs and controls. CONCLUSION High-risk HPV prevalence was high in both cases and controls. HPV genotype distribution in HSILs was different from that reported worldwide and from other studies in South Africa.
Collapse
Affiliation(s)
- H M Said
- Faculty of Health Science, Department of Medical Microbiology, University of Pretoria, South Africa.
| | | | | | | | | | | |
Collapse
|
34
|
Samoli E, Peng R, Ramsay T, Pipikou M, Touloumi G, Dominici F, Burnett R, Cohen A, Krewski D, Samet J, Katsouyanni K. Acute effects of ambient particulate matter on mortality in Europe and North America: results from the APHENA study. Environ Health Perspect 2008; 116:1480-6. [PMID: 19057700 PMCID: PMC2592267 DOI: 10.1289/ehp.11345] [Citation(s) in RCA: 211] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 06/26/2008] [Indexed: 05/02/2023]
Abstract
BACKGROUND THE APHENA (AIR POLLUTION AND HEALTH: A Combined European and North American Approach) study is a collaborative analysis of multicity time-series data on the effect of air pollution on population health, bringing together data from the European APHEA (Air Pollution and Health: A European Approach) and U.S. NMMAPS (National Morbidity, Mortality and Air Pollution Study) projects, along with Canadian data. OBJECTIVES The main objective of APHENA was to assess the coherence of the findings of the multicity studies carried out in Europe and North America, when analyzed with a common protocol, and to explore sources of possible heterogeneity. We present APHENA results on the effects of particulate matter (PM) < or = 10 microm in aerodynamic diameter (PM(10)) on the daily number of deaths for all ages and for those < 75 and > or = 75 years of age. We explored the impact of potential environmental and socioeconomic factors that may modify this association. METHODS In the first stage of a two-stage analysis, we used Poisson regression models, with natural and penalized splines, to adjust for seasonality, with various degrees of freedom. In the second stage, we used meta-regression approaches to combine time-series results across cites and to assess effect modification by selected ecologic covariates. RESULTS Air pollution risk estimates were relatively robust to different modeling approaches. Risk estimates from Europe and United States were similar, but those from Canada were substantially higher. The combined effect of PM(10) on all-cause mortality across all ages for cities with daily air pollution data ranged from 0.2% to 0.6% for a 10-microg/m(3) increase in ambient PM(10) concentration. Effect modification by other pollutants and climatic variables differed in Europe and the United States. In both of these regions, a higher proportion of older people and higher unemployment were associated with increased air pollution risk. CONCLUSIONS Estimates of the increased mortality associated with PM air pollution based on the APHENA study were generally comparable with results of previous reports. Overall, risk estimates were similar in Europe and in the United States but higher in Canada. However, PM(10) effect modification patterns were somewhat different in Europe and the United States.
Collapse
Affiliation(s)
- Evangelia Samoli
- Department of Hygiene and Epidemiology, University of Athens Medical School, Athens, Greece.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Cooke NJ, Burnett R. An aid to tibial alignment in total knee replacement. Ann R Coll Surg Engl 2008; 90:73-4. [PMID: 18213743 DOI: 10.1308/rcsann.2008.90.1.73b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- N J Cooke
- Department of Orthopaedics, Royal Infirmary of Edinburgh, Edinburgh, UK.
| | | |
Collapse
|
36
|
Ungerfeld EM, Rust SR, Burnett R. Increases in microbial nitrogen production and efficiency in vitro with three inhibitors of ruminal methanogenesis. Can J Microbiol 2007; 53:496-503. [PMID: 17612604 DOI: 10.1139/w07-008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [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: 11/22/2022]
Abstract
It was hypothesized that the addition of crotonic acid or 3-butenoic acid would relieve constraints in digestibility observed when methane formation is inhibited by lumazine, propynoic acid, or ethyl 2-butynoate. In six incubations, one of the three methanogenesis inhibitors, at three different concentrations, was combined with either crotonic acid or 3-butenoic acid at two different concentrations. A mixture of buffer and ruminal fluid (4:1) was incubated with grass hay in Erlenmeyer flasks for 72 h. Initial concentrations were 0, 0.6, and 1.2 mmol/L for lumazine; 0, 2, and 4 mmol/L for propynoic acid; and 0, 4, and 8 mmol/L for ethyl 2-butynoate. 15Nitrogen (N) incorporation was used as a microbial marker. All three methanogenesis inhibitors decreased proteolysis. Propynoic acid and ethyl 2-butynoate at 8 mmol/L also decreased the digestibility of organic matter and neutral detergent fibre. However, all three inhibitors of methanogenesis increased the production of microbial N through an improvement of synthetic efficiency. Crotonic acid and 3-butenoic acid were generally ineffective in compensating digestibility decreases caused by the inhibitors of methanogenesis. It is of interest to elucidate the mechanisms by which these compounds increased the efficiency of microbial N production. Lumazine and the addition of low levels of ethyl 2-butynoate could potentially benefit animal production by lowering methane emissions, decreasing ruminal proteolysis, and increasing microbial N production without affecting organic matter digestibility.
Collapse
Affiliation(s)
- E M Ungerfeld
- Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA.
| | | | | |
Collapse
|
37
|
Abstract
AIMS Inhibition of ruminal methanogenesis often causes accumulation of H(2), formate and ethanol, which are not energy substrates for ruminants. It was hypothesized that the addition of butyrate precursors would avoid the formation of these products and relocate electrons into butyrate. METHODS AND RESULTS In four ruminal 24-h incubations, two inhibitors of methanogenesis, each at three different initial concentrations (0, 2 or 4 mmol l(-1) for propynoic acid, and 0, 4 or 8 mmol l(-1) for ethyl 2-butynoate), were combined with two butyrate precursors at two different initial concentrations (0 or 4 mmol l(-1) for crotonic acid or 3-butenoic acid). Ground lucerne hay was the substrate. Propynoic acid at 4 mmol l(-1) decreased CH(4) formation by more than two-thirds. Ethyl 2-butynoate at 8 mmol l(-1) suppressed methanogenesis by more than 90%. Butyrate precursors generally did not decrease the accumulation of H(2) and formate or ethanol production. CONCLUSIONS Butyrate precursors were ineffective as electron acceptors because they were not completely converted to butyrate and were also metabolized through other pathways. SIGNIFICANCE AND IMPACT OF THE STUDY Effectiveness of butyrate precursors may be improved by adding them to the fermentation continuously or by enhancing the kinetics of their conversion into butyrate.
Collapse
Affiliation(s)
- E M Ungerfeld
- Department of Animal Science, Michigan State University, Michigan, USA.
| | | | | |
Collapse
|
38
|
Fung K, Krewski D, Burnett R, Dominici F. Testing the harvesting hypothesis by time-domain regression analysis. I: baseline analysis. J Toxicol Environ Health A 2005; 68:1137-54. [PMID: 16024493 DOI: 10.1080/15287390590936003] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Although the association between air pollution and daily mortality is well established, the mechanisms by which air pollution results in excess mortality are not yet well understood. In particular, there exists debate over whether air pollution has a direct effect on mortality in the general population or simply shortens the life span of frail individuals, a hypothesis referred to as "harvesting." The goal of this investigation is to test the harvesting hypothesis using the time-domain regression method of Dominici et al. (2003a). We conducted simulations based on a two-compartment model that divides the population into a larger group of healthy individuals and a frail subpopulation. Death from air pollution is assumed to take place in two steps, by first moving from healthy population to the frail pool, then death with probability related to the level of air pollution. Using time-domain analysis, we seek to identify data patterns that would be characteristic of harvesting under different scenarios. For a pure harvesting model, time-domain analysis indicates that mortality is associated with a short-term air pollution episode of less than 2 d if the mean residency time in the frail pool is short. If both entrants and deaths depend on the level of air pollution and the rates of entry to and exit from the frail pool are about the same, the log relative risk estimates are essentially unchanged at all time scales. If pollution affects mortality in the frail pool more than entrants, larger effects will occur at shorter time scales.
Collapse
Affiliation(s)
- Karen Fung
- Department of Mathematics and Statistics, University of Windsor, Windsor, Ontario, Canada
| | | | | | | |
Collapse
|
39
|
Fung K, Krewski D, Burnett R, Ramsay T, Chen Y. Testing the harvesting hypothesis by time-domain regression analysis. II: covariate effects. J Toxicol Environ Health A 2005; 68:1155-65. [PMID: 16024494 DOI: 10.1080/15287390590936021] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This article extends the previous work of Fung et al. (2004) investigating the ability of the time-scale log-linear regression model, proposed by Dominici et al. (2003), to detect mortality displacement (sometimes known as harvesting) in time-series data relating air pollution to excess mortality. We conducted a simulation study based on two different compartment models of the death process: pure frailty model and mixed frailty model. We assume that nonaccidental death only affects frail population in a pure frailty model and affects both frail people and other individuals in the mixed frailty model. With a pure frailty model and a moderate-size pollution effect, we identified a characteristic mortality displacement pattern in the different time-scale coefficients of log relative risk. However, once a covariate like temperature was introduced into the model, such a mortality displacement pattern disappeared. Furthermore, a false mortality displacement effect was present in the incorrectly specified model, when temperature was not taken into account. We believe that time-scale regression has limited value for detecting mortality displacement in time-series data.
Collapse
Affiliation(s)
- Karen Fung
- Department of Mathematics and Statistics, University of Windsor, Windsor, Ontario, Canada
| | | | | | | | | |
Collapse
|
40
|
Affiliation(s)
- A Maden
- Academic Centre, West London Mental Health NHS Trust Headquarters, Southall, Middlesex UB1 3EU.
| | | | | | | | | |
Collapse
|
41
|
Fung KY, Krewski D, Chen Y, Burnett R, Cakmak S. Comparison of time series and case-crossover analyses of air pollution and hospital admission data. Int J Epidemiol 2004; 32:1064-70. [PMID: 14681275 DOI: 10.1093/ije/dyg246] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Time series analysis is the most commonly used technique for assessing the association between counts of health events over time and exposure to ambient air pollution. Recently, case-crossover analysis has been proposed as an alternative analytical approach. While each technique has its own advantages and disadvantages, there remains considerable uncertainty as to which statistical methodology is preferable for evaluating data of this type. METHODS The objective of this paper is to evaluate the performance of different variations of these two procedures using computer simulation. Hospital admission data were generated under realistic models with known parameters permitting estimates based on time series and case-crossover analyses to be compared with these known values. RESULTS While accurate estimates can be achieved with both methods, both methods require some decisions to be made by the researcher during the course of the analysis. With time series analysis, it is necessary to choose the time span in the LOESS smoothing process, or degrees of freedom when using natural cubic splines. For case-crossover studies using either uni- or bi-directional control selection strategies, the choice of time intervals needs to be made. CONCLUSIONS We prefer the times series approach because the best estimates of risk that can be obtained with time series analysis are more precise than the best estimates based on case-crossover analysis.
Collapse
Affiliation(s)
- Karen Y Fung
- Department of Mathematics & Statistics, University of Windsor, Windsor, Ontario N9B 3P4, Canada.
| | | | | | | | | |
Collapse
|
42
|
Abstract
The inhibition of pyruvate oxidative decarboxylation as a means of decreasing ruminal methanogenesis in vitro was studied. In the first experiment, the addition of adenosine and adenine (with and without ribose) to ruminal batch cultures did not decrease methanogenesis. In the second experiment, the addition of oxythiamin decreased methanogenesis by 23%. In the third experiment, three pyruvate derivatives did not inhibit methanogenesis, although hydroxypyruvate improved organic matter fermentation from 57.8% to 64.2%. The additives did not seem to inhibit pyruvate oxidative decarboxylation.Key words: methane, inhibition, rumen, pyruvate decarboxylation, thiamin.
Collapse
Affiliation(s)
- E M Ungerfeld
- Department of Animal Science, Michigan State University, East Lansing 48824, USA
| | | | | |
Collapse
|
43
|
Arbuckle TE, Burnett R, Cole D, Teschke K, Dosemeci M, Bancej C, Zhang J. Predictors of herbicide exposure in farm applicators. Int Arch Occup Environ Health 2002; 75:406-14. [PMID: 12070637 DOI: 10.1007/s00420-002-0323-7] [Citation(s) in RCA: 74] [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: 08/29/2001] [Accepted: 02/02/2002] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Most epidemiological studies of pesticides have used self-reports rather than quantitative measurements to assess exposures. The purpose of this study was to identify factors likely to affect exposure under actual field conditions and to measure the sensitivity and specificity of self-reported indications of exposure against urinary measures of herbicide exposure. METHODS A sub-set of the participants in a retrospective cohort study of Ontario farm families volunteered for a pesticide exposure assessment study. Immediately prior, and subsequent to, handling the phenoxy-herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) or 4-chloro-2-methylphenoxyacetic acid (MCPA) for the first time during the season, 126 pesticide applicators provided pre-exposure spot urine samples and a subsequent consecutive 24-h urine sample. At the same time, they completed a questionnaire on pesticide use and handling practices for the first day of pesticide application. RESULTS Assuming that the presence of 2,4-D in the urine was a measure of true exposure and that questionnaire indications of 2,4-D use were the exposure classification subject to error, then the questionnaire's prediction of exposure had a sensitivity of 56.7% and specificity of 86.4%. The comparable values for MCPA were sensitivity and specificity of 91.6% and 67.4%, respectively. In multivariate models, the variables pesticide formulation, protective clothing/gear, application equipment, handling practice, and personal hygiene practice were significant as predictors of urinary herbicide levels in the first 24 h after application (or spraying) had been initiated (adjusted R(2)=44% for MCPA and 39% for 2,4-D). CONCLUSIONS Although similar domains of factors were associated with exposure in both models, the specific factors identified and the signs of the coefficients were sufficiently different between the final models for each herbicide that additional investigations appear to be warranted to determine the sources of the differences and assess the validity of the models and their ability to be generalised.
Collapse
Affiliation(s)
- Tye E Arbuckle
- Health Surveillance and Epidemiology Division, Population and Public Health Branch, Health Canada, A.L. 0701D, Ottawa, Ontario, K1A 0L2, Canada.
| | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
The new Ionising Radiation (Medical Exposure) Regulations 2000 (IR (ME)ER) were implemented in January 2001. These regulations state that "the referrer must record in the patient's notes that a radiograph was taken and what it showed". As a result it is now incumbent upon the orthopaedic surgeon to document formally the findings of all requested radiographs. We present a case in which a left upper bronchial carcinoma was detected initially on a radiograph of the left shoulder. It highlights the importance of careful examination of the entire radiographic image and the documenting of the findings.
Collapse
Affiliation(s)
- M Kelly
- Princess Margaret Hospital, Edinburgh, Scotland, UK
| | | | | |
Collapse
|
45
|
Ravel G, Christ M, Ruat C, Burnett R, Descotes J. Effect of murine recombinant IL-2 on the course of lupus-like disease in (NZBxNZW) F1 female mice. Immunopharmacol Immunotoxicol 2002; 24:409-21. [PMID: 12375737 DOI: 10.1081/iph-120014726] [Citation(s) in RCA: 5] [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: 11/03/2022]
Abstract
The exacerbation of pre-existing autoimmune diseases is a potential toxic effect of immunoactive drugs. An increase in the incidence of autoimmune thyroiditis has been noted in patients treated with human recombinant interleukin-2 (rIL-2). In contrast, human rIL-2 tends to protect mice from autoimmunity. As the effects of murine rIL-2 on autoimmunity have not been reported in mice, lupus-prone female (NZBxNZW) F1 mice were treated with 20,000 IU murine rIL-2 intraperitoneally, twice weekly for 13 weeks, beginning at 15 weeks of age. No evidence of an exacerbating effect of murine IL-2 on the lupus disease of (NZBxNZW) F1 mice was observed as no change in the following parameters were seen, namely mean survival time, mean body weight, anti-DNA and antinuclear antibody production. These results show that: 1) like human rIL-2, murine rIL-2 does not exacerbate autoimmunity in mice; 2) the biological effects of human as well as murine rIL-2 in mice differ from those seen with human rIL-2 in man. These latter findings suggest that the selection of the relevant animal species for immunotoxicity studies with recombinant cytokines and derivatives may be less straightforward than previously thought.
Collapse
Affiliation(s)
- G Ravel
- MDS Pharma Services, St Germain sur l'Arbresle, France
| | | | | | | | | |
Collapse
|
46
|
Burnett R, Ma R, Jerrett M, Goldberg MS, Cakmak S, Pope CA, Krewski D. The spatial association between community air pollution and mortality: a new method of analyzing correlated geographic cohort data. Environ Health Perspect 2001; 109 Suppl 3:375-380. [PMID: 11427386 DOI: 10.2307/3434784] [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: 05/28/2023]
Abstract
We present a new statistical model for linking spatial variation in ambient air pollution to mortality. The model incorporates risk factors measured at the individual level, such as smoking, and at the spatial level, such as air pollution. We demonstrate that the spatial autocorrelation in community mortality rates, an indication of not fully characterizing potentially confounding risk factors to the air pollution-mortality association, can be accounted for through the inclusion of location in the model assessing the effects of air pollution on mortality. Our methods are illustrated with an analysis of the American Cancer Society cohort to determine whether all cause mortality is associated with concentrations of sulfate particles. The relative risk associated with a 4.2 microg/m(3) interquartile range of sulfate distribution for all causes of death was 1.051 (95% confidence interval 1.036-1.066) based on the Cox proportional hazards survival model, assuming subjects were statistically independent. Inclusion of community-based random effects yielded a relative risk of 1.055 (1.033, 1.077), which represented a doubling in the residual variance compared to that estimated by the Cox model. Residuals from the random-effects model displayed strong evidence of spatial autocorrelation (p = 0.0052). Further inclusion of a location surface reduced the sulfate relative risk and the evidence for autocorrelation as the complexity of the location surface increased, with a range in relative risks of 1.055-1.035. We conclude that these data display both extravariation and spatial autocorrelation, characteristics not captured by the Cox survival model. Failure to account for extravariation and spatial autocorrelation can lead to an understatement of the uncertainty of the air pollution association with mortality.
Collapse
Affiliation(s)
- R Burnett
- Healthy Environments and Consumer Safety Branch, Health Canada, 200 Environmental Health Centre, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2.
| | | | | | | | | | | | | |
Collapse
|
47
|
Burnett R, Ma R, Jerrett M, Goldberg MS, Cakmak S, Pope CA, Krewski D. The spatial association between community air pollution and mortality: a new method of analyzing correlated geographic cohort data. Environ Health Perspect 2001; 109 Suppl 3:375-80. [PMID: 11427386 PMCID: PMC1240554 DOI: 10.1289/ehp.01109s3375] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a new statistical model for linking spatial variation in ambient air pollution to mortality. The model incorporates risk factors measured at the individual level, such as smoking, and at the spatial level, such as air pollution. We demonstrate that the spatial autocorrelation in community mortality rates, an indication of not fully characterizing potentially confounding risk factors to the air pollution-mortality association, can be accounted for through the inclusion of location in the model assessing the effects of air pollution on mortality. Our methods are illustrated with an analysis of the American Cancer Society cohort to determine whether all cause mortality is associated with concentrations of sulfate particles. The relative risk associated with a 4.2 microg/m(3) interquartile range of sulfate distribution for all causes of death was 1.051 (95% confidence interval 1.036-1.066) based on the Cox proportional hazards survival model, assuming subjects were statistically independent. Inclusion of community-based random effects yielded a relative risk of 1.055 (1.033, 1.077), which represented a doubling in the residual variance compared to that estimated by the Cox model. Residuals from the random-effects model displayed strong evidence of spatial autocorrelation (p = 0.0052). Further inclusion of a location surface reduced the sulfate relative risk and the evidence for autocorrelation as the complexity of the location surface increased, with a range in relative risks of 1.055-1.035. We conclude that these data display both extravariation and spatial autocorrelation, characteristics not captured by the Cox survival model. Failure to account for extravariation and spatial autocorrelation can lead to an understatement of the uncertainty of the air pollution association with mortality.
Collapse
Affiliation(s)
- R Burnett
- Healthy Environments and Consumer Safety Branch, Health Canada, 200 Environmental Health Centre, Tunney's Pasture, Ottawa, Ontario, Canada K1A 0L2.
| | | | | | | | | | | | | |
Collapse
|
48
|
McGrory BJ, Lawhead BA, Ruterbories J, Burnett R, White R. Removal of incarcerated braided titanium cables. Orthopedics 2001; 24:27-8. [PMID: 11199346 DOI: 10.3928/0147-7447-20010101-13] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- B J McGrory
- Orthopaedic Associates of Portland, PA, ME, USA
| | | | | | | | | |
Collapse
|
49
|
Affiliation(s)
- D Oxorn
- Department of Anesthesiology, University of Washington Medical Center, Box 356540, Seattle, WA 98195-6540, USA.
| | | | | |
Collapse
|
50
|
Hofmann WK, Kell WJ, Fenaux P, Castaigne S, Ganser A, Chomienne C, Burnett R, Kowal C, Hoelzer D, Burnett AK. Oral 9-cis retinoic acid (Alitretinoin) in the treatment of myelodysplastic syndromes: results from a pilot study. Leukemia 2000; 14:1583-8. [PMID: 10995004 DOI: 10.1038/sj.leu.2401873] [Citation(s) in RCA: 8] [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: 11/08/2022]
Abstract
A multicenter phase II study was initiated to investigate the efficacy, toxicity and tolerability of an oral regimen of 9-cis retinoic acid (9CRA) as a differentiation-inducing agent stimulating both retinoic acid receptor (RAR) and retinoic X receptor (RXR). Thirty patients with myelodysplastic syndromes (MDS) were enrolled into the study. The MDS subtypes were distributed as follows: 14 refractory anaemia (RA), four refractory anaemia with ringed sideroblasts (RARS), and 12 refractory anaemia with excess blasts (RAEB). The age ranged from 40 to 81 years (median 70). None of these had previously received treatment for MDS other than supportive therapy. 9CRA (Alitretinoin capsules, kindly provided by Allergan-Ligand Retinoid Therapeutics) was given daily at 60 mg/m2 p.o. for 1 week, followed by an intra-patient escalation to 100 mg/m2 during the second week, up to a maximum of 140 mg/m2. The planned treatment duration was 48 weeks. Twenty-five were available for assessment. One patient (4%) with RA achieved complete hematological remission. Four (16%), two with RA, two with RAEB, had minor responses resulting in decreased transfusion requirements or increased neutrophils. Thus, the overall response rate was 20% in evaluable patients with MDS and 17% in the study group on an intention-to-treat basis. The most frequent side-effects included headache (77%), dry skin (57%), arthralgias (30%), and rash (23%). In conclusion, although modest responses were noted in this study, the treatment tolerability was suboptimal. It is conceivable that a lower dosage schedule may be efficacious and better tolerated so enabling prolonged exposure which may be required to induce a differentiation effect.
Collapse
Affiliation(s)
- W K Hofmann
- Department of Hematology/Oncology, University of Frankfurt/Main, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|