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1.  Biological characterization of preclinical Bioluminescent Osteosarcoma Orthotopic Mouse (BOOM) model: A multi-modality approach 
Journal of bone oncology  2013;2(1):11-21.
Osteosarcoma (OS) is a bone malignancy that affects children and adolescents. It is a highly aggressive tumor and typically metastasizes to lungs. Despite aggressive chemotherapy and surgical treatments, the current 5 year survival rate is 60–70%. Clinically relevant models are needed to understand OS pathobiology, metastatic progression from bones to lungs, and ultimately, to develop more efficacious treatment strategies and improve survival rates in OS patients with metastasis. The main goal of this study was to develop and characterize an in vivo OS model that will allow non-invasive tracking of tumor progression in real time, and aid in studying OS pathobiology, and screening of potential therapeutic agents against OS. In this study, we have used a multi-modality approach using bioluminescent imaging, electron microscopy, micro-computed tomography, and histopathology to develop and characterize a preclinical Bioluminescent Osteosarcoma Orthotopic Mouse (BOOM) model, using 143B human OS cell line. The results of this study clearly demonstrate that the BOOM model represents the clinical disease as evidenced by a spectrum of changes associated with tumor establishment, progression and metastasis, and detection of known OS biomarkers in the primary and metastatic tumor tissue. Key novel findings of this study include: (a) multimodality approach for extensive characterization of the BOOM model using 143B human OS cell line; (b) evidence of renal metastasis in OS orthotopic model using 143B cells; (c) evidence of Runx2 expression in the metastatic lung tissue; and (d) evidence of the presence of extracellular membrane vesicles and myofibroblasts in the BOOM model.
PMCID: PMC4327846
Extra-cellular membrane vesicles; Bioluminescent; Myofibroblasts; Orthotopic; Osteosarcoma; Preclinical
2.  Rhabdomyosarcomatous Transformation of a Gastrointestinal Stromal Tumor following Treatment with Imatinib 
Rhabdomyosarcomatous dedifferentiation of GIST following tyrosine kinase inhibitor (TKI) therapy is rare, with only a handful of cases previously reported in the literature. Herein we present a case of metastatic GIST initially treated with imatinib that developed radiographic evidence of progression after 8 months of standard dose therapy with continued progression despite attempts at using dose-escalated imatinib 400 mg bid. Due to the patient's worsening clinical symptoms and radiographic concerns for colonic thickening, abscess, and extraluminal air, the patient underwent a palliative resection of a large heterogeneous mass arising from the posterior stomach and several metastatic foci. Pathology revealed a dedifferentiated GIST with rhabdomyosarcomatous features. This report will highlight the unique features of this case and review the existing literature.
PMCID: PMC4324915
3.  Severe non-traumatic bleeding events detected by computed tomography: do anticoagulants and antiplatelet agents have a role? 
Bleeding is the most common and most serious complication of anticoagulant (AC) and antiplatelet agents (APA) which are increasingly used in every day practice. The aim of this study was to enlist and analyze the most severe bleeding events revealed during computed tomography scanner (CT scan) examinations over a 1-year period at our University Hospital and to evaluate the role of ACs and APAs in their occurrence.
This descriptive monocentric retrospective study included all patients who benefited from an emergency CT scan with a diagnosis of severe non-traumatic bleeding. Patients were divided into two groups: those treated with ACs and/or APAs, and those not treated with ACs or APAs.
After applying the inclusion criteria, 93 patients were enrolled. Sixty-one patients received an anticoagulant or antiplatelet treatment, and 32 did not receive any AC or APA therapy. Seventy nine percent presented with an intracranial hemorrhage, 17% with a rectus sheath or iliopsoas bleeding or hematoma, and 4% with a quadriceps hematoma. Only patients who received ACs or APAs suffered a muscular hematoma (p <0.0001). Among patients treated with vitamin K antagonists, 6/43 (14%), had an international normalized ratio (INR) higher than the therapeutic range (INR >3).
In our series, intracranial hemorrhage was preponderant and muscular hematomas occurred exclusively in patients treated with ACs and/or APAs. This study needs to be extended to evaluate the impact of new anticoagulant and antiplatelet agents.
PMCID: PMC4200130  PMID: 25316373
Intracranial hemorrhage; Muscular hematoma; Anticoagulant; Antiplatelet agents; CT-scan
4.  A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010 
Lim, Stephen S | Vos, Theo | Flaxman, Abraham D | Danaei, Goodarz | Shibuya, Kenji | Adair-Rohani, Heather | Amann, Markus | Anderson, H Ross | Andrews, Kathryn G | Aryee, Martin | Atkinson, Charles | Bacchus, Loraine J | Bahalim, Adil N | Balakrishnan, Kalpana | Balmes, John | Barker-Collo, Suzanne | Baxter, Amanda | Bell, Michelle L | Blore, Jed D | Blyth, Fiona | Bonner, Carissa | Borges, Guilherme | Bourne, Rupert | Boussinesq, Michel | Brauer, Michael | Brooks, Peter | Bruce, Nigel G | Brunekreef, Bert | Bryan-Hancock, Claire | Bucello, Chiara | Buchbinder, Rachelle | Bull, Fiona | Burnett, Richard T | Byers, Tim E | Calabria, Bianca | Carapetis, Jonathan | Carnahan, Emily | Chafe, Zoe | Charlson, Fiona | Chen, Honglei | Chen, Jian Shen | Cheng, Andrew Tai-Ann | Child, Jennifer Christine | Cohen, Aaron | Colson, K Ellicott | Cowie, Benjamin C | Darby, Sarah | Darling, Susan | Davis, Adrian | Degenhardt, Louisa | Dentener, Frank | Des Jarlais, Don C | Devries, Karen | Dherani, Mukesh | Ding, Eric L | Dorsey, E Ray | Driscoll, Tim | Edmond, Karen | Ali, Suad Eltahir | Engell, Rebecca E | Erwin, Patricia J | Fahimi, Saman | Falder, Gail | Farzadfar, Farshad | Ferrari, Alize | Finucane, Mariel M | Flaxman, Seth | Fowkes, Francis Gerry R | Freedman, Greg | Freeman, Michael K | Gakidou, Emmanuela | Ghosh, Santu | Giovannucci, Edward | Gmel, Gerhard | Graham, Kathryn | Grainger, Rebecca | Grant, Bridget | Gunnell, David | Gutierrez, Hialy R | Hall, Wayne | Hoek, Hans W | Hogan, Anthony | Hosgood, H Dean | Hoy, Damian | Hu, Howard | Hubbell, Bryan J | Hutchings, Sally J | Ibeanusi, Sydney E | Jacklyn, Gemma L | Jasrasaria, Rashmi | Jonas, Jost B | Kan, Haidong | Kanis, John A | Kassebaum, Nicholas | Kawakami, Norito | Khang, Young-Ho | Khatibzadeh, Shahab | Khoo, Jon-Paul | Kok, Cindy | Laden, Francine | Lalloo, Ratilal | Lan, Qing | Lathlean, Tim | Leasher, Janet L | Leigh, James | Li, Yang | Lin, John Kent | Lipshultz, Steven E | London, Stephanie | Lozano, Rafael | Lu, Yuan | Mak, Joelle | Malekzadeh, Reza | Mallinger, Leslie | Marcenes, Wagner | March, Lyn | Marks, Robin | Martin, Randall | McGale, Paul | McGrath, John | Mehta, Sumi | Mensah, George A | Merriman, Tony R | Micha, Renata | Michaud, Catherine | Mishra, Vinod | Hanafiah, Khayriyyah Mohd | Mokdad, Ali A | Morawska, Lidia | Mozaff arian, Dariush | Murphy, Tasha | Naghavi, Mohsen | Neal, Bruce | Nelson, Paul K | Nolla, Joan Miquel | Norman, Rosana | Olives, Casey | Omer, Saad B | Orchard, Jessica | Osborne, Richard | Ostro, Bart | Page, Andrew | Pandey, Kiran D | Parry, Charles D H | Passmore, Erin | Patra, Jayadeep | Pearce, Neil | Pelizzari, Pamela M | Petzold, Max | Phillips, Michael R | Pope, Dan | Pope III, C Arden | Powles, John | Rao, Mayuree | Razavi, Homie | Rehfuess, Eva A | Rehm, Jürgen T | Ritz, Beate | Rivara, Frederick P | Roberts, Thomas | Robinson, Carolyn | Rodriguez-Portales, Jose A | Romieu, Isabelle | Room, Robin | Rosenfeld, Lisa C | Roy, Ananya | Rushton, Lesley | Salomon, Joshua A | Sampson, Uchechukwu | Sanchez-Riera, Lidia | Sanman, Ella | Sapkota, Amir | Seedat, Soraya | Shi, Peilin | Shield, Kevin | Shivakoti, Rupak | Singh, Gitanjali M | Sleet, David A | Smith, Emma | Smith, Kirk R | Stapelberg, Nicolas J C | Steenland, Kyle | Stöckl, Heidi | Stovner, Lars Jacob | Straif, Kurt | Straney, Lahn | Thurston, George D | Tran, Jimmy H | Van Dingenen, Rita | van Donkelaar, Aaron | Veerman, J Lennert | Vijayakumar, Lakshmi | Weintraub, Robert | Weissman, Myrna M | White, Richard A | Whiteford, Harvey | Wiersma, Steven T | Wilkinson, James D | Williams, Hywel C | Williams, Warwick | Wilson, Nicholas | Woolf, Anthony D | Yip, Paul | Zielinski, Jan M | Lopez, Alan D | Murray, Christopher J L | Ezzati, Majid
Lancet  2012;380(9859):2224-2260.
Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk assessment in 2000, and no previous analysis has assessed changes in burden attributable to risk factors over time.
We estimated deaths and disability-adjusted life years (DALYs; sum of years lived with disability [YLD] and years of life lost [YLL]) attributable to the independent effects of 67 risk factors and clusters of risk factors for 21 regions in 1990 and 2010. We estimated exposure distributions for each year, region, sex, and age group, and relative risks per unit of exposure by systematically reviewing and synthesising published and unpublished data. We used these estimates, together with estimates of cause-specific deaths and DALYs from the Global Burden of Disease Study 2010, to calculate the burden attributable to each risk factor exposure compared with the theoretical-minimum-risk exposure. We incorporated uncertainty in disease burden, relative risks, and exposures into our estimates of attributable burden.
In 2010, the three leading risk factors for global disease burden were high blood pressure (7·0% [95% uncertainty interval 6·2–7·7] of global DALYs), tobacco smoking including second-hand smoke (6·3% [5·5–7·0]), and alcohol use (5·5% [5·0–5·9]). In 1990, the leading risks were childhood underweight (7·9% [6·8–9·4]), household air pollution from solid fuels (HAP; 7·0% [5·6–8·3]), and tobacco smoking including second-hand smoke (6·1% [5·4–6·8]). Dietary risk factors and physical inactivity collectively accounted for 10·0% (95% UI 9·2–10·8) of global DALYs in 2010, with the most prominent dietary risks being diets low in fruits and those high in sodium. Several risks that primarily affect childhood communicable diseases, including unimproved water and sanitation and childhood micronutrient deficiencies, fell in rank between 1990 and 2010, with unimproved water we and sanitation accounting for 0·9% (0·4–1·6) of global DALYs in 2010. However, in most of sub-Saharan Africa childhood underweight, HAP, and non-exclusive and discontinued breastfeeding were the leading risks in 2010, while HAP was the leading risk in south Asia. The leading risk factor in Eastern Europe, most of Latin America, and southern sub-Saharan Africa in 2010 was alcohol use; in most of Asia, North Africa and Middle East, and central Europe it was high blood pressure. Despite declines, tobacco smoking including second-hand smoke remained the leading risk in high-income north America and western Europe. High body-mass index has increased globally and it is the leading risk in Australasia and southern Latin America, and also ranks high in other high-income regions, North Africa and Middle East, and Oceania.
Worldwide, the contribution of different risk factors to disease burden has changed substantially, with a shift away from risks for communicable diseases in children towards those for non-communicable diseases in adults. These changes are related to the ageing population, decreased mortality among children younger than 5 years, changes in cause-of-death composition, and changes in risk factor exposures. New evidence has led to changes in the magnitude of key risks including unimproved water and sanitation, vitamin A and zinc deficiencies, and ambient particulate matter pollution. The extent to which the epidemiological shift has occurred and what the leading risks currently are varies greatly across regions. In much of sub-Saharan Africa, the leading risks are still those associated with poverty and those that affect children.
Bill & Melinda Gates Foundation.
PMCID: PMC4156511  PMID: 23245609
5.  Reversal of Cellular Phenotypes in Neural Cells Derived from Huntington’s Disease Monkey-Induced Pluripotent Stem Cells 
Stem Cell Reports  2014;3(4):585-593.
Huntington’s disease (HD) is a dominant neurodegenerative disorder caused by the expansion of glutamine residues in the N-terminal region of the huntingtin (HTT) protein. The disease results in progressive neuronal loss, leading to motor, cognitive, and psychiatric impairment. Here, we report the establishment of neural progenitor cell (NPC) lines derived from induced pluripotent stem cells (iPSCs) of transgenic HD monkeys. Upon differentiation to neurons, HD neural cells develop cellular features of HD, including the formation of nuclear inclusions and oligomeric mutant HTT (mHTT) aggregates, as well as increased apoptosis. These phenotypes are rescued by genetic suppression of HTT and pharmacological treatment, demonstrating the ability of our HD cell model to respond to therapeutic treatment. The development and reversal of HD-associated phenotypes in neural cells from HD monkeys provides a unique nonhuman primate (NHP) model for exploring HD pathogenesis and evaluating therapeutics that could be assessed further in HD monkeys.
Graphical Abstract
•Neural progenitor cell lines were derived from HD monkey iPSCs•HD monkey neural progenitor cells are capable of differentiating into GABA+ neurons•HD monkey neural cells develop HD-associated cell phenotypes•HD monkey neural cells respond to genetic correction and pharmacological treatments
In this article, Chan and colleagues report the establishment of neural progenitor cells derived from pluripotent stem cells of transgenic Huntington’s disease (HD) monkeys. Differentiated HD neural cells develop cellular features of HD that can be rescued by genetic suppression of the huntingtin gene and pharmacological treatment, thus demonstrating disease modeling and drug screening possibilities for HD stem cell-based therapy.
PMCID: PMC4223707  PMID: 25358787
6.  Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants 
Lancet  2009;374(9707):2091-2103.
In this report we review the health effects of three short-lived greenhouse pollutants—black carbon, ozone, and sulphates. We undertook new meta-analyses of existing time-series studies and an analysis of a cohort of 352 000 people in 66 US cities during 18 years of follow-up. This cohort study provides estimates of mortality effects from long-term exposure to elemental carbon, an indicator of black carbon mass, and evidence that ozone exerts an independent risk of mortality. Associations among these pollutants make drawing conclusions about their individual health effects difficult at present, but sulphate seems to have the most robust effects in multiple-pollutant models. Generally, the toxicology of the pure compounds and their epidemiology diverge because atmospheric black carbon, ozone, and sulphate are associated and could interact with related toxic species. Although sulphate is a cooling agent, black carbon and ozone could together exert nearly half as much global warming as carbon dioxide. The complexity of these health and climate effects needs to be recognised in mitigation policies.
PMCID: PMC4059357  PMID: 19942276
7.  Acute effects of ambient ozone on mortality in Europe and North America: results from the APHENA study 
The “Air Pollution and Health: A Combined European and North American Approach” (APHENA) project is a collaborative analysis of multi-city time-series data on the association between air pollution and adverse health outcomes. The main objective of APHENA was to examine the coherence of findings of time-series studies relating short-term fluctuations in air pollution levels to mortality and morbidity in 125 cities in Europe, the US, and Canada. Multi-city time-series analysis was conducted using a two-stage approach. We used Poisson regression models controlling for overdispersion with either penalized or natural splines to adjust for seasonality. Hierarchical models were used to obtain an overall estimate of excess mortality associated with ozone and to assess potential effect modification. Potential effect modifiers were city-level characteristics related to exposure to other ambient air pollutants, weather, socioeconomic status, and the vulnerability of the population. Regionally pooled risk estimates from Europe and the US were similar; those from Canada were substantially higher. The pooled estimated excess relative risk associated with a 10 µg/m3 increase in 1 h daily maximum O3 was 0.26 % (95 % CI, 0.15 %, 0.37 %). Across regions, there was little consistent indication of effect modification by age or other effect modifiers considered in the analysis. The findings from APHENA on the effects of O3 on mortality in the general population were comparable with previously reported results and relatively robust to the method of data analysis. Overall, there was no indication of strong effect modification by age or ecologic variables considered in the analysis.
PMCID: PMC3668792  PMID: 23734168
Ozone; Mortality; Time-series; Multi-city; Cardiovascular; Respiratory
8.  Clinical Prediction Model Suitable for Assessing Hospital Quality for Patients Undergoing Carotid Endarterectomy 
Assessing hospital quality in the performance of carotid endarterectomy (CEA) requires appropriate risk adjustment across hospitals with varying case mixes. The aim of this study was to develop and validate a prediction model to assess the risk of in‐hospital stroke or death after CEA that could aid in the assessment of hospital quality.
Methods and Results
Patients from National Cardiovascular Data Registry (NCDR)'s Carotid Artery Revascularization and Endarterectomy (CARE) Registry undergoing CEA without acute evolving stroke from 2005 to 2013 were included. In‐hospital stroke or death was modeled using hierarchical logistic regression with 20 candidate variables and accounting for hospital‐level clustering. Internal validation was achieved with bootstrapping; model discrimination and calibration were assessed. A total of 213 (1.7%) primary end point events occurred during 12 889 procedures. Independent predictors of stroke or death included age, prior peripheral artery disease, diabetes mellitus, prior coronary artery disease, having a symptomatic carotid lesion, having a contralateral carotid occlusion, or having New York Heart Association Class III or IV heart failure. The model was well calibrated and demonstrated moderate discriminative ability (c‐statistic 0.65). The NCDR CEA score was then developed to support simple, prospective risk quantification in the clinical setting.
The NCDR CEA score, comprising 7 clinical variables, predicts in‐hospital stroke or death after CEA. This model can be used to estimate hospital risk‐adjusted outcomes for CEA and to assist with the assessment of hospital quality.
PMCID: PMC4309056  PMID: 24938712
carotid endarterectomy; risk prediction; stroke
9.  Traffic-related pollution and asthma prevalence in children. Quantification of associations with nitrogen dioxide 
Ambient nitrogen dioxide is a widely available measure of traffic-related air pollution and is inconsistently associated with the prevalence of asthma symptoms in children. The use of this relationship to evaluate the health impact of policies affecting traffic management and traffic emissions is limited by the lack of a concentration-response function based on systematic review and meta-analysis of relevant studies. Using systematic methods, we identified papers containing quantitative estimates for nitrogen dioxide and the 12 month period prevalence of asthma symptoms in children in which the exposure contrast was within-community and dominated by traffic pollution. One estimate was selected from each study according to an a priori algorithm. Odds ratios were standardised to 10 μg/m3 and summary estimates were obtained using random- and fixed-effects estimates. Eighteen studies were identified. Concentrations of nitrogen dioxide were estimated for the home address (12) and/or school (8) using a range of methods; land use regression (6), study monitors (6), dispersion modelling (4) and interpolation (2). Fourteen studies showed positive associations but only two associations were statistically significant at the 5 % level. There was moderate heterogeneity (I2 = 32.8 %) and the random-effects estimate for the odds ratio was 1.06 (95 % CI 1.00 to 1.11). There was no evidence of small study bias. Individual studies tended to have only weak positive associations between nitrogen dioxide and asthma prevalence but the summary estimate bordered on statistical significance at the 5 % level. Although small, the potential impact on asthma prevalence could be considerable because of the high level of baseline prevalence in many cities. Whether the association is causal or indicates the effects of a correlated pollutant or other confounders, the estimate obtained by the meta-analysis would be appropriate for estimating impacts of traffic pollution on asthma prevalence.
Electronic supplementary material
The online version of this article (doi:10.1007/s11869-014-0265-8) contains supplementary material, which is available to authorized users.
PMCID: PMC4239711  PMID: 25431630
Air Pollution; Asthma prevalence; Traffic; Meta-analysis; Review
10.  Standardized Cardiovascular Data for Clinical Research, Registries, and Patient Care 
Relatively little attention has been focused on standardization of data exchange in clinical research studies and patient care activities. Both are usually managed locally using separate and generally incompatible data systems at individual hospitals or clinics. In the past decade there have been nascent efforts to create data standards for clinical research and patient care data, and to some extent these are helpful in providing a degree of uniformity. Nevertheless these data standards generally have not been converted into accepted computer-based language structures that could permit reliable data exchange across computer networks. The National Cardiovascular Research Infrastructure (NCRI) project was initiated with a major objective of creating a model framework for standard data exchange in all clinical research, clinical registry, and patient care environments, including all electronic health records. The goal is complete syntactic and semantic interoperability. A Data Standards Workgroup was established to create or identify and then harmonize clinical definitions for a base set of standardized cardiovascular data elements that could be used in this network infrastructure. Recognizing the need for continuity with prior efforts, the Workgroup examined existing data standards sources. A basic set of 353 elements was selected. The NCRI staff then collaborated with the two major technical standards organizations in healthcare, the Clinical Data Interchange Standards Consortium and Health Level 7 International, as well as with staff from the National Cancer Institute Enterprise Vocabulary Services. Modeling and mapping were performed to represent (instantiate) the data elements in appropriate technical computer language structures for endorsement as an accepted data standard for public access and use. Fully implemented, these elements will facilitate clinical research, registry reporting, administrative reporting and regulatory compliance, and patient care.
PMCID: PMC3664644  PMID: 23500238
11.  Budd-Chiari Syndrome Caused by TIPS Malposition: A Case Report 
Case Reports in Medicine  2014;2014:267913.
Budd-Chiari syndrome refers to hepatic pathology secondary to diminished venous outflow, most commonly associated with venothrombotic disease. Clinically, patients with Budd-Chiari present with hepatomegaly, ascites, abdominal distension, and pain. On imaging, Budd-Chiari syndrome is hallmarked by occluded IVC and or hepatic veins, caudate lobe enlargement, heterogeneous liver enhancement, intrahepatic collaterals, and hypervascular nodules. Etiopathological factors for Budd-Chiari syndrome include several systemic thrombotic and nonthrombotic conditions that can cause venous outflow obstruction at hepatic veins and/or IVC. While the transjugular intrahepatic portosystemic shunt (TIPS) is used as a treatment option for Budd-Chiari syndrome, Budd-Chiari syndrome is not a well-known complication of TIPS procedure. We report a case of Budd-Chiari syndrome that occurred in a transplanted cirrhotic liver from malpositioned proximal portion of the TIPS in IVC causing occlusion of the ostia of hepatic veins which was subsequently diagnosed on contrast-enhanced CT.
PMCID: PMC4005056  PMID: 24822068
12.  An Integrated Risk Function for Estimating the Global Burden of Disease Attributable to Ambient Fine Particulate Matter Exposure 
Environmental Health Perspectives  2014;122(4):397-403.
Background: Estimating the burden of disease attributable to long-term exposure to fine particulate matter (PM2.5) in ambient air requires knowledge of both the shape and magnitude of the relative risk (RR) function. However, adequate direct evidence to identify the shape of the mortality RR functions at the high ambient concentrations observed in many places in the world is lacking.
Objective: We developed RR functions over the entire global exposure range for causes of mortality in adults: ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), and lung cancer (LC). We also developed RR functions for the incidence of acute lower respiratory infection (ALRI) that can be used to estimate mortality and lost-years of healthy life in children < 5 years of age.
Methods: We fit an integrated exposure–response (IER) model by integrating available RR information from studies of ambient air pollution (AAP), second hand tobacco smoke, household solid cooking fuel, and active smoking (AS). AS exposures were converted to estimated annual PM2.5 exposure equivalents using inhaled doses of particle mass. We derived population attributable fractions (PAFs) for every country based on estimated worldwide ambient PM2.5 concentrations.
Results: The IER model was a superior predictor of RR compared with seven other forms previously used in burden assessments. The percent PAF attributable to AAP exposure varied among countries from 2 to 41 for IHD, 1 to 43 for stroke, < 1 to 21 for COPD, < 1 to 25 for LC, and < 1 to 38 for ALRI.
Conclusions: We developed a fine particulate mass–based RR model that covered the global range of exposure by integrating RR information from different combustion types that generate emissions of particulate matter. The model can be updated as new RR information becomes available.
Citation: Burnett RT, Pope CA III, Ezzati M, Olives C, Lim SS, Mehta S, Shin HH, Singh G, Hubbell B, Brauer M, Anderson HR, Smith KR, Balmes JR, Bruce NG, Kan H, Laden F, Prüss-Ustün A, Turner MC, Gapstur SM, Diver WR, Cohen A. 2014. An integrated risk function for estimating the global burden of disease attributable to ambient fine particulate matter exposure. Environ Health Perspect 122:397–403;
PMCID: PMC3984213  PMID: 24518036
13.  Associations between daily mortality in London and combined oxidant capacity, ozone and nitrogen dioxide 
Both nitrogen dioxide (NO2) and ozone (O3) are powerful oxidants in ambient air that are intimately linked through atmospheric chemistry and which continuously interchange over very short timescales. Based upon atmospheric chemistry alone, there is a strong, a priori, reason for considering O3 and NO2 together in epidemiological studies, rather than either of the two pollutants separately in single-pollutant models. This paper compares two approaches to this, using Ox, defined as O3 + NO2, as a single metric and also using O3 and NO2 together in two-pollutant models. We hypothesised that the magnitude of the association between Ox and daily mortality would be greater than for NO2 and O3 individually. Using collocated hourly measurements for O3 and NO2 in London, from 2000 to 2005, we carried out a time series analysis of daily mortality. We investigated O3, NO2 and Ox individually in single-pollutant Poisson regression models and NO2 and O3 jointly in two-pollutant models in both all-year and season-specific analyses. We observed larger associations for mean 24-h concentrations of Ox (1.30 % increase in mortality per 10 ppb) than for O3 (0.87 %) and NO2 (0 %) individually. However, when analysed jointly in two-pollutant models, associations for O3 (1.54 %) and NO2 (1.07 %) were comparable to the Ox association. Season-specific analyses broadly followed this pattern irrespective of whether the Ox concentrations were driven by O3 production (summer) or depletion (winter). This novel approach in air pollution epidemiology captures the simultaneous impact of both oxidants whilst avoiding many of the statistical issues associated with two-pollutant models and potentially simplifies health impact calculations.
Electronic supplementary material
The online version of this article (doi:10.1007/s11869-014-0249-8) contains supplementary material, which is available to authorized users.
PMCID: PMC4239710  PMID: 25431629
Time series; Mortality; Oxidants; Ozone; Nitrogen dioxide
14.  Mammography casting-type calcification and risk of local recurrence in DCIS: analyses from a randomised study 
British Journal of Cancer  2013;108(4):812-819.
We studied the association between mammographic calcifications and local recurrence in the ipsilateral breast.
Case-cohort study within a randomised trial of radiotherapy in breast conservation for ductal cancer in situ of the breast (SweDCIS). We studied mammograms from cases with an ipsilateral breast event (IBE) and from a subcohort randomly sampled at baseline. Lesions were classified as a density without calcifications, architectural distortion, powdery, crushed stone-like or casting-type calcifications.
Calcifications representing necrosis were found predominantly in younger women. Women with crushed stone or casting-type microcalcifications had higher histopathological grade and more extensive disease. The relative risk (RR) of a new IBE comparing those with casting-type calcifications to those without calcifications was 2.10 (95% confidence interval (CI) 0.92–4.80). This risk was confined to in situ recurrences; the RR of an IBE associated with casting-type calcifications on the mammogram adjusted for age and disease extent was 16.4 (95% CI 2.20–140).
Mammographic appearance of ductal carcinoma in situ of the breast is prognostic for the risk of an in situ IBE and may also be an indicator of responsiveness to RT in younger women.
PMCID: PMC3590664  PMID: 23370209
DCIS; ipsilateral recurrence; mammographic calcifications; radiotherapy; breast-conserving surgery; randomised trial
15.  Low Diagnostic Yield of Elective Coronary Angiography 
The New England journal of medicine  2010;362(10):886-895.
Guidelines for triaging patients for cardiac catheterization recommend a risk assessment and noninvasive testing. We determined patterns of noninvasive testing and the diagnostic yield of catheterization among patients with suspected coronary artery disease in a contemporary national sample.
From January 2004 through April 2008, at 663 hospitals in the American College of Cardiology National Cardiovascular Data Registry, we identified patients without known coronary artery disease who were undergoing elective catheterization. The patients’ demographic characteristics, risk factors, and symptoms and the results of noninvasive testing were correlated with the presence of obstructive coronary artery disease, which was defined as stenosis of 50% or more of the diameter of the left main coronary artery or stenosis of 70% or more of the diameter of a major epicardial vessel.
A total of 398,978 patients were included in the study. The median age was 61 years; 52.7% of the patients were men, 26.0% had diabetes, and 69.6% had hypertension. Noninvasive testing was performed in 83.9% of the patients. At catheterization, 149,739 patients (37.6%) had obstructive coronary artery disease. No coronary artery disease (defined as <20% stenosis in all vessels) was reported in 39.2% of the patients. Independent predictors of obstructive coronary artery disease included male sex (odds ratio, 2.70; 95% confidence interval [CI], 2.64 to 2.76), older age (odds ratio per 5-year increment, 1.29; 95% CI, 1.28 to 1.30), presence of insulin-dependent diabetes (odds ratio, 2.14; 95% CI, 2.07 to 2.21), and presence of dyslipidemia (odds ratio, 1.62; 95% CI, 1.57 to 1.67). Patients with a positive result on a noninvasive test were moderately more likely to have obstructive coronary artery disease than those who did not undergo any testing (41.0% vs. 35.0%; P<0.001; adjusted odds ratio, 1.28; 95% CI, 1.19 to 1.37).
In this study, slightly more than one third of patients without known disease who underwent elective cardiac catheterization had obstructive coronary artery disease. Better strategies for risk stratification are needed to inform decisions and to increase the diagnostic yield of cardiac catheterization in routine clinical practice.
PMCID: PMC3920593  PMID: 20220183
16.  Mortality Associations with Long-Term Exposure to Outdoor Air Pollution in a National English Cohort 
Rationale: Cohort evidence linking long-term exposure to outdoor particulate air pollution and mortality has come largely from the United States. There is relatively little evidence from nationally representative cohorts in other countries.
Objectives: To investigate the relationship between long-term exposure to a range of pollutants and causes of death in a national English cohort.
Methods: A total of 835,607 patients aged 40–89 years registered with 205 general practices were followed from 2003–2007. Annual average concentrations in 2002 for particulate matter with a median aerodynamic diameter less than 10 (PM10) and less than 2.5 μm (PM2.5), nitrogen dioxide (NO2), ozone, and sulfur dioxide (SO2) at 1 km2 resolution, estimated from emission-based models, were linked to residential postcode. Deaths (n = 83,103) were ascertained from linkage to death certificates, and hazard ratios (HRs) for all- and cause-specific mortality for pollutants were estimated for interquartile pollutant changes from Cox models adjusting for age, sex, smoking, body mass index, and area-level socioeconomic status markers.
Measurements and Main Results: Residential concentrations of all pollutants except ozone were positively associated with all-cause mortality (HR, 1.02, 1.03, and 1.04 for PM2.5, NO2, and SO2, respectively). Associations for PM2.5, NO2, and SO2 were larger for respiratory deaths (HR, 1.09 each) and lung cancer (HR, 1.02, 1.06, and 1.05) but nearer unity for cardiovascular deaths (1.00, 1.00, and 1.04).
Conclusions: These results strengthen the evidence linking long-term ambient air pollution exposure to increased all-cause mortality. However, the stronger associations with respiratory mortality are not consistent with most US studies in which associations with cardiovascular causes of death tend to predominate.
PMCID: PMC3734610  PMID: 23590261
air pollution; mortality; cohort study; respiratory
17.  A Standardized Patient Counseling Rubric for a Pharmaceutical Care and Communications Course 
Objective. To restructure a required pharmaceutical care and communications course to place greater emphasis on communication skills and include a high-stakes assessment.
Design. A standardized counseling rubric was developed for use throughout the pharmacy curriculum and the counseling laboratory practicals were changed to high-stakes assessments.
Assessment. An annual mid-semester and end-of-semester high-stakes patient-counseling objective structured clinical examination (OSCE) conducted prior to and after revision of the course and counseling rubric documented improvements in students’ scores. Performance on the post-course annual assessment patient counseling OSCE improved compared to that on the pre-course (p<0.001).
Conclusion. The 2010 course revision improved students’ medication counseling abilities and readiness to practice. Major course revisions should be undertaken only after input from all stakeholders and with data to support the need for change.
PMCID: PMC3776906  PMID: 24052655
medication counseling; rubric; pharmaceutical care; communications; objective structured clinical examination
18.  Histological characterization of bone marrow in ectopic bone, induced by devitalized Saos-2 human osteosarcoma cells 
Devitalized Saos-2, cultured human osteosarcoma cells, or guanidinium-hydrochloride (GuHCl) extracts of these cells, induce ectopic bone and marrow formation when implanted subcutaneously in Nu/Nu mice. The aim of the present study was to characterize the bone marrow induced by Saos-2 cell extracts, specifically to determine which of the four major hematopoietic cell lineages: erythropoietic, granulopoietic, lymphopoietic and megakaryocytic, are induced by Saos-2 cell derivatives. Methods: Immunohistochemical localization of specific antigens was used to determine the presence of each major cell type (glycophorin A for erythropoietic, neutrophil elastase for granulopoietic, factor-VIII related antigen for megakaryocytes, and CD79a for B lymphocytes). Results: Standard H & E stains confirmed the presence of normally organized apparently complete bone marrow within all newly induced bone at 3 weeks post-implantation of devitalized Saos-2 cells. Immunohistochemistry confirmed the presence of erythropoietic cells, granulopoietic cells, megakaryocytes and B lymphocytes in the ectopic marrow. Conclusion: Saos-2 cells (freeze-dried) or their extracts, implanted subcutaneously into Nu/Nu mice, can induce normal marrow that is host-derived, and contains all major hematopoietic cell lineages. Clinical Significance: Saos-2 induced marrow could potentially restore deficient marrow and promote bone repair.
PMCID: PMC3560492  PMID: 23386915
Bone marrow induction; bone tumors; hematopoiesis; lineage-specific biomarkers; osteosarcoma
19.  Hospital PCI Appropriateness and In-Hospital Procedural Outcomes: Insights from the NCDR® 
Measurement of hospital quality has traditionally focused on processes of care and post-procedure outcomes. Appropriateness measures for percutaneous coronary intervention (PCI) assess quality as it relates to patient selection in the context of anticipated benefits relative to potential harm. The association, if any, between patient selection for PCI and processes of care and post-procedural outcomes is unknown. Defining whether these measures are redundant or complementary can inform the optimal range of metrics for monitoring quality.
We included patients undergoing non-acute (elective) PCI within the NCDR CathPCI Registry® between July 2009 and April 2011. We examined the association between a hospital’s proportion of non-acute PCIs categorized as inappropriate by the 2009 Appropriate Use Criteria (AUC) for Coronary Revascularization and in-hospital mortality, bleeding complications, and use of optimal guideline-directed medical therapy at discharge (i.e. aspirin, thienopyridines, and statins).
A total of 203,531 non-acute PCIs from 779 hospitals were classified by the AUC. Of these, 101,779 (50.0%) were classified as appropriate, 77,220 (35.5%) as uncertain, and 24,532 (12.1%) as inappropriate. When categorized as hospital tertiles, the range of inappropriate PCI was 0.0 to 8.1% in the lowest-tertile, 8.1 to 15.2% in the middle-tertile, and 15.2 to 58.6% in the highest-tertile. Compared with lowest-tertile hospitals, mortality was not significantly different at middle-tertile (adjusted odds ratio [OR] 0.93; 95% confidence interval [CI] 0.73 to 1.19) or highest-tertile hospitals (OR 1.12; 95% CI 0.88 to 1.43; p=0.35 for differences between any tertile). Similarly, risk-adjusted bleeding did not vary significantly (middle-tertile OR 1.13; 95% CI 1.02 to 1.16; highest-tertile OR 1.02; 95% CI 0.91 to 1.16; p=0.07 for differences between any tertile) nor did use of optimal therapy at discharge after PCI (85.3% vs. 85.7% vs. 85.2%; P=0.58).
In a national cohort of non-acute PCIs, a hospital’s proportion of inappropriate PCIs was not associated with in-hospital mortality, bleeding, or medical therapy at discharge. These findings suggest that PCI appropriateness measures aspects of hospital PCI quality that are independent of, and complementary to, traditional quality metrics.
PMCID: PMC3520092  PMID: 22576845
Appropriateness criteria; Coronary artery disease; Percutaneous coronary intervention; Utilization; Hospital; Quality of care; Health services research
20.  Concentration–Response Function for Ozone and Daily Mortality: Results from Five Urban and Five Rural U.K. Populations 
Environmental Health Perspectives  2012;120(10):1411-1417.
Background: Short-term exposure to ozone has been associated with increased daily mortality. The shape of the concentration–response relationship—and, in particular, if there is a threshold—is critical for estimating public health impacts.
Objective: We investigated the concentration–response relationship between daily ozone and mortality in five urban and five rural areas in the United Kingdom from 1993 to 2006.
Methods: We used Poisson regression, controlling for seasonality, temperature, and influenza, to investigate associations between daily maximum 8-hr ozone and daily all-cause mortality, assuming linear, linear-threshold, and spline models for all-year and season-specific periods. We examined sensitivity to adjustment for particles (urban areas only) and alternative temperature metrics.
Results: In all-year analyses, we found clear evidence for a threshold in the concentration–response relationship between ozone and all-cause mortality in London at 65 µg/m3 [95% confidence interval (CI): 58, 83] but little evidence of a threshold in other urban or rural areas. Combined linear effect estimates for all-cause mortality were comparable for urban and rural areas: 0.48% (95% CI: 0.35, 0.60) and 0.58% (95% CI: 0.36, 0.81) per 10-µg/m3 increase in ozone concentrations, respectively. Seasonal analyses suggested thresholds in both urban and rural areas for effects of ozone during summer months.
Conclusions: Our results suggest that health impacts should be estimated across the whole ambient range of ozone using both threshold and nonthreshold models, and models stratified by season. Evidence of a threshold effect in London but not in other study areas requires further investigation. The public health impacts of exposure to ozone in rural areas should not be overlooked.
PMCID: PMC3491921  PMID: 22814173
concentration–response function; daily mortality; ozone; U.K. population
21.  Tumour response evaluation with fluorodeoxyglucose positron emission tomography: research technique or clinical tool? 
Cancer Imaging  2010;10(1A):S68-S72.
The evaluation of treatment response is an established role for imaging in oncologic research and clinical practice. In early phase trials, imaging response criteria are used to determine the presence and magnitude of the drug effect on tumour to aid decisions concerning progress to late phase trials, and to inform dose selection and scheduling. In late phase trials and clinical practice, the imaging response is used as a surrogate for clinical outcome. Due to the limitations of current anatomic response criteria, there is growing interest in the use of [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) to assess treatment response. The technique is beginning to be adopted within mainstream approaches for evaluation of response in solid tumours and lymphoma. Difficulties with standardisation across PET centres and tumour types combined with uncertainty concerning the timing of assessment relative to treatment, have limited the use of quantitative measurements of FDG uptake to research applications. However, with a growing body of evidence that qualitative criteria such as the development of new PET lesions or complete metabolic response following treatment can provide surrogates marker for clinical outcome, [18F]FDG-PET is becoming established as a clinical technique for assessing tumour response, especially for FDG-avid lymphoma subtypes. Multimodality imaging using perfusion computed tomography/PET is an exciting novel technique with the potential to define treatment response in a new way.
PMCID: PMC2967135  PMID: 20880775
Fluorodeoxyglucose positron emission tomography; tumour response
22.  Satellite-based Estimates of Ambient Air Pollution and Global Variations in Childhood Asthma Prevalence 
Environmental Health Perspectives  2012;120(9):1333-1339.
Background: The effect of ambient air pollution on global variations and trends in asthma prevalence is unclear.
Objectives: Our goal was to investigate community-level associations between asthma prevalence data from the International Study of Asthma and Allergies in Childhood (ISAAC) and satellite-based estimates of particulate matter with aerodynamic diameter < 2.5 µm (PM2.5) and nitrogen dioxide (NO2), and modelled estimates of ozone.
Methods: We assigned satellite-based estimates of PM2.5 and NO2 at a spatial resolution of 0.1° × 0.1° and modeled estimates of ozone at a resolution of 1° × 1° to 183 ISAAC centers. We used center-level prevalence of severe asthma as the outcome and multilevel models to adjust for gross national income (GNI) and center- and country-level sex, climate, and population density. We examined associations (adjusting for GNI) between air pollution and asthma prevalence over time in centers with data from ISAAC Phase One (mid-1900s) and Phase Three (2001–2003).
Results: For the 13- to 14-year age group (128 centers in 28 countries), the estimated average within-country change in center-level asthma prevalence per 100 children per 10% increase in center-level PM2.5 and NO2 was –0.043 [95% confidence interval (CI): –0.139, 0.053] and 0.017 (95% CI: –0.030, 0.064) respectively. For ozone the estimated change in prevalence per parts per billion by volume was –0.116 (95% CI: –0.234, 0.001). Equivalent results for the 6- to 7-year age group (83 centers in 20 countries), though slightly different, were not significantly positive. For the 13- to 14-year age group, change in center-level asthma prevalence over time per 100 children per 10% increase in PM2.5 from Phase One to Phase Three was –0.139 (95% CI: –0.347, 0.068). The corresponding association with ozone (per ppbV) was –0.171 (95% CI: –0.275, –0.067).
Conclusion: In contrast to reports from within-community studies of individuals exposed to traffic pollution, we did not find evidence of a positive association between ambient air pollution and asthma prevalence as measured at the community level.
PMCID: PMC3440118  PMID: 22548921
air pollution; asthma prevalence; children; epidemiology; global; nitrogen dioxide; ozone; particulate matter; satellite observations
23.  Nfat1 Regulates Adult Articular Chondrocyte Function through Its Age-Dependent Expression Mediated by Epigenetic Histone Methylation 
Journal of Bone and Mineral Research  2011;26(8):1974-1986.
The development of disease-modifying pharmacologic therapy for osteoarthritis (OA) currently faces major obstacles, largely because the regulatory mechanisms for the function of adult articular chondrocytes remain unclear. We previously demonstrated that lack of Nfat1, one of the NFAT (nuclear factor of activated T cells) transcription factors, causes OA-like changes in adult mice. This study aimed to identify whether Nfat1 specifically regulates adult articular chondrocyte function and its age-dependent regulatory mechanism using both Nfat1-deficient and wild-type mice. Deletion of Nfat1 did not induce OA-like articular chondrocyte dysfunction (e.g., overexpression of proinflammatory cytokines and matrixdegrading proteinases) until the adult stage. RNAi-mediated Nfat1 knockdown caused dysfunction of wild-type adult articular chondrocytes. Nfat1 expression in wild-type articular chondrocytes was low in the embryonic, but high in the adult stage. Chromatin immunoprecipitation assays demonstrated that an increase in Nfat1 expression in articular chondrocytes was associated with increased H3K4me2 (a histone modification linked to transcriptional activation); while a decrease in Nfat1 expression in articular chondrocytes was correlated with increased H3K9me2 (a histone modification linked to transcriptional repression). Knockdown of lysine-specific demethylase-1 (Lsd1) in embryonic articular chondrocytes up-regulated Nfat1 expression concomitant with increased H3K4me2 at the Nfat1 promoter. Knockdown of Jmjc-containing histone demethylase-2a (Jhdm2a) in 6-month articular chondrocytes down-regulated Nfat1 expression concomitant with increased H3K9me2 at the Nfat1 promoter. These results suggest that Nfat1 is an essential transcriptional regulator of chondrocyte homeostasis in adult articular cartilage. Age-dependent Nfat1 expression in articular chondrocytes is regulated by dynamic histone methylation, one of the epigenetic mechanisms that regulate gene transcription.
PMCID: PMC3353550  PMID: 21452283
Articular chondrocyte; Nfat1; gene expression; histone modifications; epigenetics
24.  Reliability and Credibility of Progress Test Criteria Developed by Alumni, Faculty, and Mixed Alumni-Faculty Judge Panels 
Objective. To compare the reliability and credibility of Angoff-based, absolute criteria derived by faculty, alumni, and a combination of alumni and faculty judge panels.
Methods. Independently, faculty, alumni, and mixed faculty-alumni judge panels developed pass/fail criteria for an 86-item test. Generalizability and decision studies were performed. Root mean square errors (RMSE) and 95% confidence intervals were calculated for reliability and credibility assessment. School graduate performance upon the North American Licensure Examination (NAPLEX) was the comparator for credibility assessment.
Results. RMSEs were 1.06%, 1.42%, and 2.32% for the alumni, faculty, and mixed judge panels respectively. The school's NAPLEX pass rate was 97.5%. This rate triangulated well with the faculty judge panel (pass rate = 93.9%, CI95% = 87.1% - 98.2%), but did not with either mixed judge or alumni judge panels.
Conclusions. Faculty-derived criteria offer superior pass/fail decision defensibility relative to both alumni derived and mixed faculty-alumni derived criteria.
PMCID: PMC3279012  PMID: 22345719
25.  Black Carbon as an Additional Indicator of the Adverse Health Effects of Airborne Particles Compared with PM10 and PM2.5 
Environmental Health Perspectives  2011;119(12):1691-1699.
Background: Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM10) or ≤ 2.5 μm (PM2.5)] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration.
Objectives: We evaluated the value of black carbon particles (BCP) as an additional indicator in air quality management.
Methods: We performed a systematic review and meta-analysis of health effects of BCP compared with PM mass based on data from time-series studies and cohort studies that measured both exposures. We compared the potential health benefits of a hypothetical traffic abatement measure, using near-roadway concentration increments of BCP and PM2.5 based on data from prior studies.
Results: Estimated health effects of a 1-μg/m3 increase in exposure were greater for BCP than for PM10 or PM2.5, but estimated effects of an interquartile range increase were similar. Two-pollutant models in time-series studies suggested that the effect of BCP was more robust than the effect of PM mass. The estimated increase in life expectancy associated with a hypothetical traffic abatement measure was four to nine times higher when expressed in BCP compared with an equivalent change in PM2.5 mass.
Conclusion: BCP is a valuable additional air quality indicator to evaluate the health risks of air quality dominated by primary combustion particles.
PMCID: PMC3261976  PMID: 21810552
air quality management; black carbon; combustion particles; health effects; particulate matter; review

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