G.H. Lo

Michael E. DeBakey VA Medical Center, Houston, Texas, United States

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Publications (81)390.14 Total impact


  • No preview · Article · Jan 2016 · Arthritis and Rheumatology
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    ABSTRACT: We evaluated whether accelerated knee osteoarthritis (AKOA) was associated with greater pain and other outcomes and if outcomes varied over time differently among those with incident AKOA or common knee osteoarthritis (KOA), which we defined as a gradual onset of disease. We conducted longitudinal analyses among participants in the Osteoarthritis Initiative who had no radiographic KOA at baseline (Kellgren-Lawrence [KL] <2). Participants were considered AKOA if ≥1 knees progressed to KL grade ≥3 and common KOA if ≥1 knees increased in radiographic scoring within 48 months. We defined the index visit as the study visit when they met the AKOA or common KOA criteria. Our observation period included up to 3 years before and after the index visit. Our primary outcome was WOMAC pain converted to an ordinal scale: none (pain score = 0/1 out of 20), mild (pain score = 2/3), and moderate-severe pain (pain score >3). We explored 11 other secondary outcome measures. We performed an ordinal logistic regression or linear models with generalized estimating equations. The predictors were group (AKOA or common KOA), time (seven visits), and a group-by-time interaction. Overall, individuals with AKOA (n = 54) had greater pain, functional disability, and global rating scale as well as slower chair-stand and walking pace compared with those with common KOA (n = 187). There was no significant interaction between group and time for knee pain; however, there was for chair-stand pace and global rating scale. In conclusion, AKOA may be a painful and disabling phenotype that warrants more attention by clinicians and researchers.
    No preview · Article · Nov 2015 · Clinical Rheumatology
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    ABSTRACT: Subchondral bone marrow lesions (BMLs) are related to structural and symptomatic osteoarthritis progression. However, it is unclear how sequence selection influences a quantitative BML measurement and its construct validity. We compared quantitative assessment of BMLs on intermediate-weighted fat suppressed (IW FS) turbo spin echo and 3-dimensional dual echo steady state (3D DESS) sequences. We used a customized software to measure 30 knees’ (24- and 48-month MR images) BMLs on both sequences. The results showed that the IW FS sequences have much larger BML volumes (median: IW FS = 1840 mm 3 ; DESS = 191 mm 3 ) and BML volume change (between 24 and 48 months) than DESS sequence and demonstrate more BML volume change. The 24-month BML volume on IW FS is correlated with BML volume on DESS ( r s = 0.83). BML volume change on IW FS is not significantly correlated with change on DESS. The 24-month WOMAC pain is correlated with the 24-month BMLs on IW FS ( r s = 0.39) but not DESS. The change in WOMAC pain is correlated with BML volume change on IW FS ( r s = 0.37) but not DESS. Overall, BML quantification on IW FS offers better validity and statistical power than BML quantification on a 3D DESS sequence.
    Preview · Article · Nov 2015
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    ABSTRACT: Objective: A prior knee osteoarthritis (OA) trial found that provider conveyed expectations for treatment success were associated with pain improvement. We hypothesized this relationship was mediated by patient self-efficacy since expectations of improvement may enhance one's ability to control health behaviors, and therefore health. Our aim was to examine whether self-efficacy was a mediator of the relationship observed in this trial. Methods: A secondary analysis of a three arm (traditional acupuncture, sham acupuncture, and wait list) trial for knee OA was conducted. Those in the acupuncture groups were equally randomized to acupuncturists trained to communicate a high or neutral expectation of treatment success (e.g. used language conveying high or unclear likelihood that acupuncture would reduce knee pain). A modified Arthritis Self-Efficacy Questionnaire and the Western Ontario McMasters (WOMAC) pain subscale were administered. Linear regression analyses were used to examine whether patient self-efficacy mediated the relationship between provider communication style and knee pain at 3 months. Results: High expectation provider communication was associated with patient self-efficacy, β coefficient of 0.14 (95%CI: 0.01, 0.28). Self-efficacy was associated with WOMAC pain, β coefficient of -9.29 (95%CI: -11.11, -7.47), while controlling for the provider communication style. The indirect effect a*b of -1.36 for high versus neutral expectation, (bootstrap 95% CI: -2.80, -0.15, does not include 0), supports that patient self-efficacy mediates the relationship between provider-communicated expectations of treatment effects and knee pain. Conclusion: Our findings suggest that clinician-conveyed expectations can enhance the benefit of treatments targeting knee OA symptoms, mediated by improved patient self-efficacy. This article is protected by copyright. All rights reserved.
    Full-text · Article · Nov 2015
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    ABSTRACT: Objective: Pain is not always correlated with radiographic osteoarthritis (OA) severity possibly because people modify activities to manage symptoms. Measures of symptoms that consider pain in the context of activity level may therefore provide greater discrimination than pain alone. Our objective was to compare discrimination of a measure of pain alone with combined measures of pain relative to physical activity across radiographic OA levels. Methods: This is a cross-sectional study of the Osteoarthritis Initiative accelerometer substudy, including those with and without knee OA. Two composite pain and activity knee symptom (PAKS) scores were calculated as Western Ontario and McMaster (WOMAC) Universities Osteoarthritis Pain Scale plus one divided by physical activity measures (step and activity counts). Symptom score discrimination across Kellgren and Lawrence (KL) grades were evaluated using histograms and quantile regression. Results: 1806 participants, mean age 65.1 (9.1) years, mean BMI 28.4 (4.8) kg/m(2) , and 55.6% female, were included. WOMAC, but not PAKS scores, exhibited a floor effect. Adjusted median WOMAC by KL grades 0 - 4 were 0, 0, 1, 1, and 3 respectively. Median PAKS1 and PAKS2 were 24.9, 26.0, 32.4, 46.1, 97.9, and 7.2, 7.2, 9.2, 12.9, 23.8, respectively. PAKS scores had more statistically significant comparisons between KL grades compared with WOMAC. Conclusions: Symptom assessments incorporating pain and physical activity did not exhibit a floor effect and were better able to discriminate radiographic severity than pain alone, particularly in milder disease. Pain in the context of physical activity level should be used to assess knee OA symptoms. This article is protected by copyright. All rights reserved.
    No preview · Article · Sep 2015 · Arthritis and Rheumatology
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    ABSTRACT: Knee osteoarthritis (KOA) is typically a slowly progressive disorder; however, a subset of knees progress with dramatic rapidity. We aimed to describe magnetic resonance imaging (MRI) findings that are associated with accelerated KOA. We conducted a longitudinal descriptive study in the Osteoarthritis Initiative (OAI) cohort. We selected participants who had no radiographic KOA at baseline with one of the following in the most severe knee: 1) accelerated KOA (progressed to end-stage KOA within 48 months), 2) common KOA, and 3) no KOA at all visits. We enriched the sample by selecting knees with a self-reported or suspected knee injury. A musculoskeletal radiologist blinded to group assignments but not to time sequence performed MRI readings for the visit before and after an injury. We assessed 38 participants (knees), 66% were female, mean age 61 (9) years, and mean body mass index 28.5 (4.9) kg/m(2) . Fifteen of 20 knees with no or common KOA, had no incident findings consistent with acute damage. Among the 18 knees with accelerated KOA most had incident findings: 13 (72%) had incident medial meniscal pathology with extrusion and 5 (28%) knees had subchondral damage. Incident MRI findings that are associated with incident accelerated KOA are characterized by structural damage that compromises subchondral bone or the function of the meniscus. Recognizing meniscal extrusion and/or change in shape, lateral meniscal tear, or acute subchondral damage may be vital for identifying individuals at risk for accelerated KOA. This article is protected by copyright. All rights reserved. © 2015 Wiley Periodicals, Inc.
    No preview · Article · Jul 2015 · Clinical Anatomy
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    ABSTRACT: We explored whether knee pain or a history of knee injury were associated with a knee injury in the following 12 months. We conducted longitudinal knee-based analyses among knees in the Osteoarthritis Initiative. We included both knees of all participants who had at least 1 followup visit with complete data. Our first sets of exposures were knee pain (chronic knee symptoms and severity) at baseline, 12-month, 24-month, and 36-month visits. Another exposure was a history of injury that we defined as a self-reported injury at any time prior to baseline, 12-month, 24-month, or 36-month visit. The outcome was self-reported knee injury during the past year at 12-month, 24-month, 36-month, and 48-month visits. We evaluated the association between ipsilateral and contralateral knee pain or history of injury and a new knee injury within 12 months of the exposure using generalized linear mixed model for repeated binary outcomes. A knee with reported chronic knee symptoms or ipsilateral or contralateral history of an injury was more likely to experience a new knee injury in the following 12 months than a knee without chronic knee symptoms (OR 1.84, 95% CI 1.57-2.16) or prior injury (prior ipsilateral knee injury: OR 1.81, 95% CI 1.56-2.09. Prior contralateral knee injury: OR 1.43, 95% CI 1.23-1.66). Knee pain and a history of injury are associated with new knee injuries. It may be beneficial for individuals with knee pain or a history of injury to participate in injury prevention programs.
    No preview · Article · Jun 2015 · The Journal of Rheumatology

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: We explored whether age and body mass index (BMI) can help identify a subset of individuals who are at high risk for accelerated knee osteoarthritis (AKOA) compared with common knee osteoarthritis (KOA). In the Osteoarthritis Initiative, a multicenter observational cohort study of KOA (n = 4796), we studied participants without KOA at baseline (Kellgren-Lawrence (KL) <2). Participants could have one of three outcomes: (1) AKOA, ≥1 knee progressed to end-stage KOA within 48 months; (2) common KOA, ≥1 knee increased in radiographic scoring within 48 months (excluding those with AKOA); and (3) no KOA, no change in KL grade in either knee. After verifying an interaction between age, BMI, and recent knee injury, we determined if we could identify a specific subset of individuals at high risk for AKOA instead of KOA. First, we reviewed three-dimensional graphs with age, BMI, and probability of AKOA versus KOA on the axes. We then conducted a logistic regression with AKOA as the outcome and age-BMI groups as the predictor. In our main analyses, we found that older individuals with a BMI <35 kg/m(2) were more likely to develop AKOA than common KOA (n = 64; mean [SD] BMI = 27.3 [3.1] kg/m(2); odds ratio = 3.47, 95 % confidence interval = 1.70 to 7.10), especially if they had a recent knee injury. While older age and greater BMI are independently associated with AKOA, we found that older individuals who had a higher BMI, particularly if they have an injury, were more likely to develop AKOA than common KOA.
    No preview · Article · Apr 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: Background It is unknown if different types of meniscal pathology are associated with knee osteoarthritis (OA). Objectives To explore the association of different types of knee meniscal pathology with bone marrow lesion (BML) volume, change in BML volume over 2 years, and a proxy for total knee arthroplasty (TKA). Methods We selected a convenience sample of the Osteoarthritis Initiative (OAI) who had symptomatic knee OA and complete data for the OAI Bone Ancillary Project. A musculoskeletal radiologist reviewed the 24-month OAI magnetic resonance (MR) images for meniscal pathology by location within the medial and lateral menisci using a modified International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine (ISAKOS) meniscal tear classification system. For analyses, we reclassified the 10 original ISAKOS categories into 5 categories: normal, degenerative signal, morphological deformity, any tear (i.e., horizontal, horizontal flap, longitudinal-vertical, radial, vertical-flap, complex tear), and maceration. Total number of regions affected by meniscal pathology (0-6) was calculated by counting the number of regions that had pathologic findings. BML volume assessment was performed using a semi-automated segmentation method at 24 and 48 month visits. We categorized the 24-month BML volume into 3 categories: 1) no meaningful BML volume (<1cm3), 2) ≥1 cm3 and below median (2.15cm3) and 3) above median of BML volume. Change in BML volume was categorized to 4 groups: 1) no meaningful BML volume (<1cm3) at both time points, 2) lowest quartile of meaningful BML volume change (BML volume change ≤-0.75 cm3), 3) middle 2 quartile of the BML volume change (BML volume change >-0.75 cm3&≤1.00 cm3), 4) highest quartile of the BML volume change (BML volume change >1.00 cm3). We categorized the proxy for TKA into appropriate and non-appropriate based on the algorithm developed by Escobar et al and adapted to OAI1. Results 400 participants were included in the analysis with mean age of 63 (9.2) years, 53% male, body mass index 29.6 (4.6) kg/m2, 71% Kellgren-Lawrence grade ≥2, and with 86% having any meniscal pathology. There was a significant association between any meniscal pathology with BML volume (OR:3.87) and change in BML volume (OR:2.32) but not with proxy for TKA. Having more number of regions of the menisci affected with pathology was associated with greater BML volume, change in BML volume, and proxy for TKA than those with a normal meniscus. Morphological deformity and maceration were associated with BML volume, change in BML volume, and proxy for TKA. Removing surgery or injury cases did not change our results. Conclusions Among the five categories of meniscal pathologies, disruptive pathology rather than degenerative or discrete tear was associated with structural changes and a later clinical state that is proxy for TKA. This suggests that pathologies that impair normal load distribution properties of meniscus can cause damage to the knee joint. References Disclosure of Interest None declared
    No preview · Article · Apr 2015 · Osteoarthritis and Cartilage

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: The purpose of this study was to expand and validate the cartilage damage index (CDI) to detect cartilage damage in the lateral tibiofemoral compartment. We used an iterative 3-step process to develop and validate the lateral CDI: development (100 knees), testing (80 knees), and validation (100 knees). The validation set included 100 knees from the Osteoarthritis Initiative that was enriched to include all grades of lateral joint space narrowing (JSN, 0–3). Measurement of the CDI was rapid at 7.4 (s.d. 0.73) minutes per knee pair (baseline and follow-up of one knee). The intratester reliability is good (intraclass correlation coefficient (3, 1 model) = 0.86 to 0.98). At baseline, knees with greater KL grade and lateral JSN had a lower mean CDI (i.e., greater cartilage damage). Baseline lateral CDI is associated with both lateral JSW ( r = 0.81 to 0.85, p < 0.01 ) and HKA ( r = - 0.30 to −0.33, p < 0.05 ). The SRM is good (lateral femur SRM = −0.76; lateral tibia SRM = −0.73; lateral tibiofemoral total SRM = −0.87). The lateral tibiofemoral CDI quantification allows for rapid evaluation and is reliable and responsive, with good construct validity. It may be an efficient method to measure lateral tibiofemoral articular cartilage in large clinical and epidemiologic studies.
    Preview · Article · Apr 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: Background Meniscal pathology is only weakly related to knee pain. The associations between different types of meniscal pathology and knee pain are unknown. Objectives To explore the association of different types of knee meniscal pathology with knee pain and change in knee pain over 2 years. Methods We selected a convenience sample of the Osteoarthritis Initiative (OAI) who had complete data for the OAI Bone Ancillary Project. A musculoskeletal radiologist reviewed the 24-month OAI magnetic resonance (MR) images for meniscal pathology by location within the medial and lateral menisci using a modified International Society of Arthroscopy, Knee Surgery, and Orthopaedic Sports Medicine (ISAKOS) meniscal tear classification system. For analyses, we reclassified the 10 original ISAKOS categories into 5 categories: normal, degenerative signal, morphological deformity, any tear (i.e., horizontal, horizontal flap, longitudinal-vertical, radial, vertical-flap, complex tear), and maceration. Total number of regions affected by meniscal pathology for each knee (0-6) was calculated by counting the number of regions that had any pathology. Knee pain was assessed using Western Ontario and McMaster Osteoarthritis Index (WOMAC) scale at 24 and 48 months. Knee pain at 24 months was categorized into 3 categories: 1) no or little pain (WOMAC pain score 0 or 1), 2) mild pain (WOMAC pain score 2 or 3), 3) moderate-severe pain (WOMAC pain score >3). Longitudinally, we categorized the change in pain into 3 categories based on the presence or absence of pain and a clinically meaningful change in pain (absolute change of 2 or relative change of 40%): 1) no pain or a meaningful decrease in pain (reference category), 2) pain but no change over time, and 3) meaningful increase in pain. Results 465 participants were included in the analysis with mean age of 63.2 (9.1) years, 53% male, mean body mass index 29.5 (4.5) kg/m2, 71% Kellgren-Lawrence grade ≥2, and 86% with any meniscal pathology. There was no association between presence of any meniscal pathology with knee pain or change in knee pain. Having all six meniscal regions affected with any pathology was associated with greater pain (OR:2.65) compared to those with normal menisci. However, having more affected meniscal regions was not related to an increase in pain. This pattern persisted when the number of regions affected by maceration was analyzed cross-sectionally and longitudinally. When we assessed the types of meniscal pathology, cross-sectionally, the only significant association was between meniscal maceration and greater knee pain (OR:2.89). Longitudinally, there was a significant association between morphological deformity (OR:1.46) and increase in knee pain over 2 years. Removing surgery or injury cases did not change our results. Conclusions These results suggest that meniscal maceration is associated with higher knee pain that may not change over time. We hypothesize that morphological deformity may lead to maceration over time, which may explain why morphologic deformity is associated with increased pain over time. Further prospective studies are warranted to determine if discrete tear incidence is related to acute knee pain and if a subset of knees can then function without pain. Disclosure of Interest None declared
    No preview · Article · Apr 2015 · Osteoarthritis and Cartilage

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage

  • No preview · Article · Apr 2015 · Osteoarthritis and Cartilage
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    ABSTRACT: Knee osteoarthritis causes functional limitation and disability in the elderly. Vitamin D has biological functions on multiple knee joint structures and can play important roles in the progression of knee osteoarthritis. The metabolism of vitamin D is regulated by parathyroid hormone (PTH). The objective was to investigate whether serum concentrations of 25-hydroxyvitamin D [25(OH)D] and PTH, individually and jointly, predict the progression of knee osteoarthritis. Serum 25(OH)D and PTH were measured at the 30- or 36-mo visit in 418 participants enrolled in the Osteoarthritis Initiative (OAI) who had ≥1 knee with both symptomatic and radiographic osteoarthritis. Progression of knee osteoarthritis was defined as any increase in the radiographic joint space narrowing (JSN) score between the 24- and 48-mo OAI visits. The mean concentrations of serum 25(OH)D and PTH were 26.2 μg/L and 54.5 pg/mL, respectively. Approximately 16% of the population had serum 25(OH)D < 15 μg/L. Between the baseline and follow-up visits, 14% progressed in JSN score. Participants with low vitamin D [25(OH)D < 15 μg/L] had >2-fold elevated risk of knee osteoarthritis progression compared with those with greater vitamin D concentrations (≥15 μg/L; OR: 2.3; 95% CI: 1.1, 4.5). High serum PTH (≥73 pg/mL) was not associated with a significant increase in JSN score. However, participants with both low vitamin D and high PTH had >3-fold increased risk of progression (OR: 3.2; 95%CI: 1.2, 8.4). Our results suggest that individuals deficient in vitamin D have an increased risk of knee osteoarthritis progression. © 2014 American Society for Nutrition.
    No preview · Article · Dec 2014 · Journal of Nutrition
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    ABSTRACT: Objective: We aimed to evaluate whether a recent knee injury was associated with accelerated knee osteoarthritis (OA) progression. Methods: In the Osteoarthritis Initiative, we studied participants free of knee OA on their baseline radiographs (Kellgren/Lawrence [K/L] <2). We compared 3 groups as follows: 1) individuals with accelerated progression of knee OA: defined as having at least 1 knee that progressed to end-stage knee OA (K/L grade 3 or 4) within 48 months, 2) common knee OA progression: at least 1 knee increased in radiographic scoring within 48 months (excluding those defined as accelerated knee OA), and 3) no knee OA: no change in K/L grade in either knee. At baseline, participants were asked if their knees had ever been injured, and at each annual visit they were asked about injuries during the prior 12 months. We used multinomial logistic regressions to determine whether a new knee injury was associated with the outcome of accelerated knee OA or common knee OA progression, after adjusting for age, sex, body mass index, static knee malalignment, and systolic blood pressure. Results: A knee injury during the total observation period was associated with accelerated knee OA progression (n = 54; odds ratio [OR] 3.14) but not common knee OA progression (n = 187; OR 1.08). Furthermore, a more recent knee injury (within a year of the outcome) was associated with accelerated (OR 8.46) and common knee OA progression (OR 3.12). Conclusion: Recent knee injuries are associated with accelerated knee OA. Most concerning is that certain injuries may be associated with a rapid cascade toward joint failure in less than 1 year.
    No preview · Article · Nov 2014
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    ABSTRACT: Background Cartilage morphometry based on magnetic resonance images (MRIs) is an emerging outcome measure for clinical trials among patients with knee osteoarthritis (KOA). However, current methods for cartilage morphometry take many hours per knee and require extensive training on the use of the associated software. In this study we tested the feasibility, reliability, and construct validity of a novel osteoarthritis cartilage damage quantification method (Cartilage Damage Index [CDI]) that utilizes informative locations on knee MRIs. Methods We selected 102 knee MRIs from the Osteoarthritis Initiative that represented a range of KOA structural severity (Kellgren Lawrence [KL] Grade 0 – 4). We tested the intra- and inter-tester reliability of the CDI and compared the CDI scores against different measures of severity (radiographic joint space narrowing [JSN] grade, KL score, joint space width [JSW]) and static knee alignment, both cross-sectionally and longitudinally. Results Determination of the CDI took on average14.4 minutes (s.d. 2.1) per knee pair (baseline and follow-up of one knee). Repeatability was good (intra- and inter-tester reliability: intraclass correlation coefficient >0.86). The mean CDI scores related to all four measures of osteoarthritis severity (JSN grade, KL score, JSW, and knee alignment; all p values < 0.05). Baseline JSN grade and knee alignment also predicted subsequent 24-month longitudinal change in the CDI (p trends <0.05). During 24 months, knees with worsening in JSN or KL grade (i.e. progressors) had greater change in CDI score. Conclusions The CDI is a novel knee cartilage quantification method that is rapid, reliable, and has construct validity for assessment of medial tibiofemoral osteoarthritis structural severity and its progression. It has the potential to addresses the barriers inherent to studies requiring assessment of cartilage damage on large numbers of knees, and as a biomarker for knee osteoarthritis progression.
    Full-text · Article · Aug 2014 · BMC Musculoskeletal Disorders

Publication Stats

1k Citations
390.14 Total Impact Points

Institutions

  • 2012-2015
    • Michael E. DeBakey VA Medical Center
      Houston, Texas, United States
  • 2010-2015
    • Baylor College of Medicine
      • Department of Medicine
      Houston, Texas, United States
  • 2011
    • Stanford University
      Palo Alto, California, United States
  • 2008-2011
    • Tufts University
      Бостон, Georgia, United States
  • 2006-2010
    • Tufts Medical Center
      • Division of Rheumatology
      Boston, Massachusetts, United States
  • 2009
    • Beverly Hospital, Boston MA
      BVY, Massachusetts, United States
  • 2005
    • University of Massachusetts Boston
      • Clinical Epidemiology Research and Training Unit
      Boston, Massachusetts, United States
  • 2004
    • Boston University
      Boston, Massachusetts, United States