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Ghiles CW, Clark MD, Kuzminski SJ, Fraser MA, Petrella JR, Guskiewicz KM. Changes in resting state networks in high school football athletes across a single season. Br J Radiol 2023; 96:20220359. [PMID: 36607807 PMCID: PMC10078860 DOI: 10.1259/bjr.20220359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE The aim of this pilot cohort study was to examine changes in the organization of resting-state brain networks in high school football athletes and its relationship to exposure to on-field head impacts over the course of a single season. METHODS Seventeen male high school football players underwent functional magnetic resonance imaging and computerized neurocognitive testing (CNS Vital Signs) before the start of contact practices and again after the conclusion of the season. The players were equipped with helmet accelerometer systems (Head Impact Telemetry System) to record head impacts in practices and games. Graph theory analysis was applied to study intranetwork local efficiency and strength of connectivity within six anatomically defined brain networks. RESULTS We observed a significant decrease in the local efficiency (-24.9 ± 51.4%, r = 0.7, p < 0.01) and strength (-14.5 ± 26.8%, r = 0.5, p < 0.01) of functional connectivity within the frontal lobe resting-state network and strength within the parietal lobe resting-state network (-7.5 ± 17.3%, r = 0.1, p < 0.01), as well as a concomitant increase in the local efficiency (+55.0 +/- 59.8%, r = 0.5, p < 0.01) and strength (+47.4 +/- 47.3%, r = 0.5, p < 0.01) within the mediotemporal networks. These alterations in network organization were associated with changes in performance on verbal memory (p < 0.05) and executive function (p < 0.05). We did not observe a significant relationship between the frequency or cumulative magnitude of impacts sustained during the season and neurocognitive or imaging outcomes (p > 0.05). CONCLUSION Our findings suggest the efficiency and strength of resting-state networks are altered across a season of high school football, but the association of exposure levels to subconcussive impacts is unclear. ADVANCES IN KNOWLEDGE The efficiency of resting-state networks is dynamic in high school football athletes; such changes may be related to impacts sustained during the season, though further study is needed.
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Affiliation(s)
- Connor W Ghiles
- Wake Forest University School of Medicine, Winston-Salem, United States
| | - Michael D Clark
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, United States
| | | | - Melissa A Fraser
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, United States
| | | | - Kevin M Guskiewicz
- Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, United States
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Clark MD, Contreras GF, Bavi N, Haller PR, Perozo E. An optimized protocol for on-column nanodisc formation. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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3
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Plakas K, Rosch LE, Clark MD, Adbul-Rashed S, Shaffer TM, Harmsen S, Gambhir SS, Detty MR. Design and evaluation of Raman reporters for the Raman-silent region. Nanotheranostics 2022; 6:1-9. [PMID: 34976577 PMCID: PMC8671958 DOI: 10.7150/ntno.58965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Received: 02/02/2021] [Accepted: 03/08/2021] [Indexed: 01/09/2023] Open
Abstract
Rationale: Surface enhanced Raman scattering (SERS) is proving to be a useful tool for biomedical imaging. However, this imaging technique can suffer from poor signal-to-noise ratio, as the complexity of biological tissues can lead to overlapping of Raman bands from tissues and the Raman reporter molecule utilized. Methods: Herein we describe the synthesis of triple bond containing Raman reporters that scatter light in the biological silent window, between 1750 cm-1 and 2750 cm-1. Results: Our SERS nanoprobes are comprised of uniquely designed Raman reporters containing either alkyne- or cyano-functional groups, enabling them to be readily distinguished from background biological tissue. Conclusion: We identify promising candidates that eventually can be moved forward as Raman reporters in SERS nanoparticles for highly specific contrast-enhanced Raman-based disease or analyte detection in biological applications.
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Affiliation(s)
- Konstantinos Plakas
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Lauren E Rosch
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Michael D Clark
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Shukree Adbul-Rashed
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Travis M Shaffer
- Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, CA, USA.,Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Stefan Harmsen
- Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, CA, USA.,Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Radiology, Perelman School of Medicine, University of Pennsylvania, PA, USA
| | - Sanjiv S Gambhir
- Molecular Imaging Program at Stanford University (MIPS), Stanford University School of Medicine, Stanford, CA, USA.,Department of Radiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Bioengineering, Stanford University School of Medicine, Stanford, CA, USA.,Department of Material Science & Engineering, Stanford University School of Engineering, Stanford, CA, USA
| | - Michael R Detty
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA
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Pinto BI, Clark MD, Perozo E, Bezanilla F. Influence of Phospholipid Binding on Voltage Sensor-Pore Coupling in the KAT1 Potassium Channel. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Contreras GF, Clark MD, Shen R, Perozo E. A Molecular Mechanism for Gating Polarity in Non-Domain-Swapped Kv Channels. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Rahman R, Clark MD, Collins Z, Traore F, Dioukhane EM, Thiam H, Ndiaye Y, De Jesus EL, Danfakha N, Peters KE, Komarek T, Linn AM, Linn PE, Wallner KE, Charles M, Hasnain M, Peterson CE, Dykens JA. Cervical cancer screening decentralized policy adaptation: an African rural-context-specific systematic literature review. Glob Health Action 2019; 12:1587894. [PMID: 30938248 PMCID: PMC6450494 DOI: 10.1080/16549716.2019.1587894] [Citation(s) in RCA: 20] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Background: Worldwide, nearly 570,000 women are diagnosed with cervical cancer each year, with 85% of new cases in low- and middle-income countries. The African continent is home to 35 of 40 countries with the highest cervical cancer mortality rates. In 2014, a partnership involving a rural region of Senegal, West Africa, was facing cervical cancer screening service sustainability barriers and began adapting regional-level policy to address implementation challenges. Objective: This manuscript reports the findings of a systematic literature review describing the implementation of decentralized cervical cancer prevention services in Africa, relevant in context to the Senegal partnership. We report barriers and policy-relevant recommendations through Levesque’s Patient-Centered Access to Healthcare Framework and discuss the impact of this information on the partnership’s approach to shaping Senegal’s regional cervical cancer screening policy. Methods: The systematic review search strategy comprised two complementary sub-searches. We conducted an initial search identifying 4272 articles, then applied inclusion criteria, and ultimately 19 studies were included. Data abstraction focused on implementation barriers categorized with the Levesque framework and by policy relevance. Results: Our findings identified specific demand-side (clients and community) and supply-side (health service-level) barriers to implementation of cervical cancer screening services. We identify the most commonly reported demand- and supply-side barriers and summarize salient policy recommendations discussed within the reviewed literature. Conclusions: Overall, there is a paucity of published literature regarding barriers to and best practices in implementation of cervical cancer screening services in rural Africa. Many articles in this literature review did describe findings with notable policy implications. The Senegal partnership has consulted this literature when faced with various similar barriers and has developed two principal initiatives to address contextual challenges. Other initiatives implementing cervical cancer visual screening services in decentralized areas may find this contextual reporting of a literature review helpful as a construct for identifying evidence for the purpose of guiding ongoing health service policy adaptation.
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Affiliation(s)
- R Rahman
- a University of Toledo College of Medicine and Life Sciences , Toledo , OH , USA
| | - M D Clark
- b Library of the Health Sciences , University Library, University of Illinois at Chicago , Chicago , IL , USA.,c Department of Medical Education, College of Medicine , University of Illinois at Chicago , Chicago , IL , USA
| | - Z Collins
- d Department of Family Medicine, Institute for Health Research and Policy , University of Illinois at Chicago (UIC) , Chicago , IL , USA
| | - F Traore
- e Region medical de Kedougou , Bureau de la santé de la reproduction, prevention transmission mere enfant du VIH-SIDA , Kedougou , Senegal
| | | | - H Thiam
- g Region medical de Kedougou , Bureau régional de la formation, de la supervision et de la recherche , Kedougou , Senegal
| | - Y Ndiaye
- h Département de Recherche , Sénégal Ministère de la Santé et l'Action Sociale , Dakar , Sénégal
| | - E L De Jesus
- i School of Public Health (SPH) , University of Illinois at Chicago (UIC) , Chicago , IL , USA
| | | | - K E Peters
- k School of Public Health, Division of Community Health Sciences, Illinois Prevention Research Center, Institute for Health Research and Policy , University of Illinois at Chicago (UIC) , Chicago , IL , USA
| | - T Komarek
- l Uniformed Services University , Bethesda , MD , USA
| | - A M Linn
- m School of Public Health, Center for Communications Programs , Johns Hopkins University , Baltimore , MD , USA
| | - P E Linn
- n Logistics Management Institute , Tysons , VA , USA
| | - K E Wallner
- o Elizabeth Glaser Pediatric AIDS Foundation , Washington , DC , USA
| | - M Charles
- p Department of Internal Medicine , University of Illinois at Chicago , Chicago , IL , USA
| | - M Hasnain
- q Department of Family Medicine , University of Illinois at Chicago College of Medicine , Chicago , IL , USA
| | - C E Peterson
- r School of Public Health, Division of Epidemiology & Biostatistics, UI Cancer Center , University of Illinois at Chicago (UIC) , Chicago , IL , USA
| | - J A Dykens
- s Department of Family Medicine, Center for Global Health, Institute for Health Research and Policy, Cancer Center , University of Illinois at Chicago (UIC) , Chicago , IL , USA
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Clark MD, Szczepura A, Gumber A, Howard K, Moro D, Morton RL. Measuring trade-offs in nephrology: a systematic review of discrete choice experiments and conjoint analysis studies. Nephrol Dial Transplant 2019; 33:348-355. [PMID: 28158746 DOI: 10.1093/ndt/gfw436] [Citation(s) in RCA: 20] [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] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 11/18/2016] [Indexed: 12/27/2022] Open
Abstract
Background Discrete choice experiment (DCE), conjoint analysis or adaptive conjoint analysis methods are increasingly applied to obtain patient, clinician or community preferences in nephrology. This study systematically reviews the above-mentioned published choice studies providing an overview of the issues addressed, methods and findings. Methods Choice studies relating to nephrology were identified using electronic databases, including Medline, Embase, PsychINFO and Econlit from 1990 to 2015. For inclusion in the review, studies had to primarily relate to kidney disease and include results from statistical (econometric) analyses of respondents' choice or preference. Studies meeting the inclusion criteria were assessed against a range of systematic review criteria, and methods and results summarized. Results We identified 14 eligible studies from Europe, Australasia, North America and Asia, reporting preferences for treatment or screening, patient experiences, quality of life (QOL), health outcomes and priority-setting frameworks. Specific contexts included medical interventions in kidney transplantation and renal cell carcinoma, health policies for organ donation and allocation, dialysis modalities and end-of-life care, using a variety of statistical models. The characteristics of 'time' (i.e. transplant waiting time, dialysis hours, transport time) and QOL (pre- and post-transplant, or pre- and post-dialysis) consistently influenced patient and clinician preferences across the choice studies. Conclusions DCE are increasingly used to obtain information about key preferences in kidney transplantation and dialysis. These study methods provide quantitative information about respondents' trade-offs between conflicting clinical and policy objectives, and can establish how preferences vary among stakeholder groups.
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Affiliation(s)
- Michael D Clark
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Ala Szczepura
- Faculty of Health & Life Sciences, Coventry University, Coventry, UK
| | - Anil Gumber
- Centre for Health and Social Care Research, Sheffield Hallam University, Sheffield, UK
| | - Kirsten Howard
- Sydney School of Public Health, The University of Sydney, Camperdown, NSW, Australia
| | - Domenico Moro
- Department of Economics, University of Birmingham, Birmingham, UK
| | - Rachael L Morton
- NHMRC Clinical Trials Centre, Sydney Medical School, The University of Sydney, Camperdown, NSW, Australia
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8
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Clark MD, Contreras G, Shen R, Perozo E. Structural Basis for Electromechanical Coupling in a Hyperpolarization-Activated Ion Channel. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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9
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Clark MD, Davis MP, Petschauer MA, Swartz EE, Mihalik JP. Delivering Chest Compressions and Ventilations With and Without Men's Lacrosse Equipment. J Athl Train 2018; 53:416-422. [PMID: 29565643 DOI: 10.4085/1062-6050-91-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Current management recommendations for equipment-laden athletes in sudden cardiac arrest regarding whether to remove protective sports equipment before delivering cardiopulmonary resuscitation are unclear. OBJECTIVE To determine the effect of men's lacrosse equipment on chest compression and ventilation quality on patient simulators. DESIGN Cross-sectional study. SETTING Controlled laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty-six licensed athletic trainers (18 women, 8 men; age = 25 ± 7 years; experience = 2.1 ± 1.6 years). INTERVENTION(S) In a single 2-hour session, participants were block randomized to 3 equipment conditions for compressions and 6 conditions for ventilations on human patient simulators. MAIN OUTCOME MEASURE(S) Data for chest compressions (mean compression depth, compression rate, percentage of correctly released compressions, and percentage of optimal compressions) and ventilations (ventilation rate, mean ventilation volume, and percentage of ventilations delivering optimal volume) were analyzed within participants across equipment conditions. RESULTS Keeping the shoulder pads in place reduced mean compression depth (all P values < .001, effect size = 0.835) and lowered the percentages of both correctly released compressions ( P = .02, effect size = 0.579) and optimal-depth compressions (all P values < .003, effect size = 0.900). For both the bag-valve and pocket masks, keeping the chinstrap in place reduced mean ventilation volume (all P values < .001, effect size = 1.323) and lowered the percentage of optimal-volume ventilations (all P values < .006, effect size = 1.038). Regardless of equipment, using a bag-valve versus a pocket mask increased the ventilation rate (all P values < .003, effect size = 0.575), the percentage of optimal ventilations (all P values < .002, effect size = 0.671), and the mean volume ( P = .002, effect size = 0.598) across all equipment conditions. CONCLUSIONS For a men's lacrosse athlete who requires cardiopulmonary resuscitation, the shoulder pads should be lifted or removed to deliver chest compressions. The facemask and chinstrap, or the entire helmet, should be removed to deliver ventilations, preferably with a bag-valve mask.
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Affiliation(s)
- Michael D Clark
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill.,Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine, University of North Carolina at Chapel Hill
| | - Mikaela P Davis
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill
| | - Meredith A Petschauer
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill
| | - Erik E Swartz
- Department of Kinesiology, University of New Hampshire, Durham
| | - Jason P Mihalik
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill.,Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine, University of North Carolina at Chapel Hill
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10
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Clark MD, Varangis EML, Champagne AA, Giovanello KS, Shi F, Kerr ZY, Smith JK, Guskiewicz KM. Effects of Career Duration, Concussion History, and Playing Position on White Matter Microstructure and Functional Neural Recruitment in Former College and Professional Football Athletes. Radiology 2018; 286:967-977. [PMID: 29087238 PMCID: PMC5834225 DOI: 10.1148/radiol.2017170539] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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] [Indexed: 12/13/2022]
Abstract
Purpose To better understand the relationship between exposure to concussive and subconcussive head impacts, white matter integrity, and functional task-related neural activity in former U.S. football athletes. Materials and Methods Between 2011 and 2013, 61 cognitively unimpaired former collegiate and professional football players (age range, 52-65 years) provided informed consent to participate in this cross-sectional study. Participants were stratified across three crossed factors: career duration, concussion history, and primary playing position. Fractional anisotropy (FA) and blood oxygen level-dependent (BOLD) percent signal change (PSC) were measured with diffusion-weighted and task-related functional magnetic resonance imaging, respectively. Analyses of variance of FA and BOLD PSC were used to determine main or interaction effects of the three factors. Results A significant interaction between career duration and concussion history was observed; former college players with more than three concussions had lower FA in a broadly distributed area of white matter compared with those with zero to one concussion (t29 = 2.774; adjusted P = .037), and the opposite was observed for former professional players (t29 = 3.883; adjusted P = .001). A separate interaction between concussion history and position was observed: Nonspeed players with more than three concussions had lower FA in frontal white matter compared with those with zero to one concussion (t25 = 3.861; adjusted P = .002). Analysis of working memory-task BOLD PSC revealed a similar interaction between concussion history and position (all adjusted P < .004). Overall, former players with lower FA tended to have lower BOLD PSC across three levels of a working memory task. Conclusion Career duration and primary playing position seem to modify the effects of concussion history on white matter structure and neural recruitment. The differences in brain structure and function were observed in the absence of clinical impairment, which suggested that multimodal imaging may provide early markers of onset of traumatic neurodegenerative disease. © RSNA, 2017 Online supplemental material is available for this article.
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Affiliation(s)
- Michael D. Clark
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - Eleanna M. L. Varangis
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - Allen A. Champagne
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - Kelly S. Giovanello
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - Feng Shi
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - Zachary Y. Kerr
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - J. Keith Smith
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
| | - Kevin M. Guskiewicz
- From the Departments of Exercise and Sport Science (M.D.C., Z.Y.K.,
K.M.G.), Psychology and Neuroscience (E.M.L.V., K.S.G.), and Radiology (J.K.S.),
University of North Carolina at Chapel Hill, 209 Fetzer Hall, CB 8700, Chapel Hill,
NC 27599; Centre for Neuroscience Studies, Queen’s University, Kingston, Ont,
Canada (A.A.C.); and Biomedical Imaging Research Institute, Cedars-Sinai Medical
Center, Los Angeles, Calif (F.S.)
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Kuzminski SJ, Clark MD, Fraser MA, Haswell CC, Morey RA, Liu C, Choudhury KR, Guskiewicz KM, Petrella JR. White Matter Changes Related to Subconcussive Impact Frequency during a Single Season of High School Football. AJNR Am J Neuroradiol 2018; 39:245-251. [PMID: 29269405 DOI: 10.3174/ajnr.a5489] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [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: 06/11/2017] [Accepted: 10/03/2017] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND PURPOSE The effect of exposing the developing brain of a high school football player to subconcussive impacts during a single season is unknown. The purpose of this pilot study was to use diffusion tensor imaging to assess white matter changes during a single high school football season, and to correlate these changes with impacts measured by helmet accelerometer data and neurocognitive test scores collected during the same period. MATERIALS AND METHODS Seventeen male athletes (mean age, 16 ± 0.73 years) underwent MR imaging before and after the season. Changes in fractional anisotropy across the white matter skeleton were assessed with Tract-Based Spatial Statistics and ROI analysis. RESULTS The mean number of impacts over a 10-g threshold sustained was 414 ± 291. Voxelwise analysis failed to show significant changes in fractional anisotropy across the season or a correlation with impact frequency, after correcting for multiple comparisons. ROI analysis showed significant (P < .05, corrected) decreases in fractional anisotropy in the fornix-stria terminalis and cingulum hippocampus, which were related to impact frequency. The effects were strongest in the fornix-stria terminalis, where decreases in fractional anisotropy correlated with worsening visual memory. CONCLUSIONS Our findings suggest that subclinical neurotrauma related to participation in American football may result in white matter injury and that alterations in white matter tracts within the limbic system may be detectable after only 1 season of play at the high school level.
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Affiliation(s)
- S J Kuzminski
- From the Department of Radiology (S.J.K., C.L., K.R.C., J.R.P.)
- Department of Radiological Sciences (S.J.K.), University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - M D Clark
- Department of Exercise and Sport Science (M.D.C., M.A.F., K.M.G.), University of North Carolina, Chapel Hill, North Carolina
| | - M A Fraser
- Department of Exercise and Sport Science (M.D.C., M.A.F., K.M.G.), University of North Carolina, Chapel Hill, North Carolina
| | - C C Haswell
- Brain Imaging and Analysis Center (C.C.H., R.A.M., C.L., J.R.P.)
| | - R A Morey
- Brain Imaging and Analysis Center (C.C.H., R.A.M., C.L., J.R.P.)
- Department of Translational Neuroscience (R.A.M.), Duke University, Durham, North Carolina
| | - C Liu
- From the Department of Radiology (S.J.K., C.L., K.R.C., J.R.P.)
- Brain Imaging and Analysis Center (C.C.H., R.A.M., C.L., J.R.P.)
| | - K R Choudhury
- From the Department of Radiology (S.J.K., C.L., K.R.C., J.R.P.)
| | - K M Guskiewicz
- Department of Exercise and Sport Science (M.D.C., M.A.F., K.M.G.), University of North Carolina, Chapel Hill, North Carolina
| | - J R Petrella
- From the Department of Radiology (S.J.K., C.L., K.R.C., J.R.P.)
- Brain Imaging and Analysis Center (C.C.H., R.A.M., C.L., J.R.P.)
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Clark MD, Morris KR, Tomassone MS. Correlation of Solubility with the Metastable Limit of Nucleation Using Gauge-Cell Monte Carlo Simulations. Langmuir 2017; 33:9081-9090. [PMID: 28812905 DOI: 10.1021/acs.langmuir.7b01939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present a novel simulation-based investigation of the nucleation of nanodroplets from solution and from vapor. Nucleation is difficult to measure or model accurately, and predicting when nucleation should occur remains an open problem. Of specific interest is the "metastable limit", the observed concentration at which nucleation occurs spontaneously, which cannot currently be estimated a priori. To investigate the nucleation process, we employ gauge-cell Monte Carlo simulations to target spontaneous nucleation and measure thermodynamic properties of the system at nucleation. Our results reveal a widespread correlation over 5 orders of magnitude of solubilities, in which the metastable limit depends exclusively on solubility and the number density of generated nuclei. This three-way correlation is independent of other parameters, including intermolecular interactions, temperature, molecular structure, system composition, and the structure of the formed nuclei. Our results have great potential to further the prediction of nucleation events using easily measurable solute properties alone and to open new doors for further investigation.
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Affiliation(s)
- Michael D Clark
- Department of Chemical & Biochemical Engineering, Rutgers University , Piscataway, New Jersey 08854, United States
| | - Kenneth R Morris
- College of Pharmacy and Health Sciences, Long Island University , Brooklyn, New York 11201, United States
| | - Maria Silvina Tomassone
- Department of Chemical & Biochemical Engineering, Rutgers University , Piscataway, New Jersey 08854, United States
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Clark MD, Cox L, Mihalik J, Guskiewicz K. Reliability of the Head Impact Exposure Estimate in Former Professional Football Athletes. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000518046.95703.ff] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Powierza CS, Clark MD, Hughes JM, Carneiro KA, Mihalik JP. Validation of a Self-Monitoring Tool for Use in Exercise Therapy. PM R 2017; 9:1077-1084. [PMID: 28400221 DOI: 10.1016/j.pmrj.2017.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/06/2017] [Accepted: 03/23/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND Aerobic exercise at a subsymptom heart rate has been recommended as therapy for postconcussion syndrome. Assessing adherence with an accurate heart rate-monitoring instrument is difficult, limiting the proliferation of large-scale randomized controlled trials. OBJECTIVE To evaluate the validity of the Fitbit Charge HR compared with electrocardiogram (EKG) to monitor heart rate during a treadmill-based exercise protocol. DESIGN A methods comparison study. SETTING Sports medicine research center within a tertiary care institution. PARTICIPANTS A convenience sample of 22 healthy participants (12 female) aged 18-26 years (mean age: 22 ± 2 years). METHODS Fitbit Charge HR heart rate measurements were compared with EKG data concurrently collected while participants completed the Buffalo Concussion Treadmill Test. MAIN OUTCOME MEASURES Agreement between Fitbit Charge HR and EKG was assessed by intraclass correlation coefficients (ICC3,1), Bland-Altman limits of agreement, and percent error. RESULTS We observed a strong single-measure absolute agreement between Fitbit Charge HR and EKG (intraclass correlation coefficient = 0.83; 95% confidence interval 0.67-0.90). Fitbit Charge HR underestimated heart rate compared with EKG (mean difference = -6.04 bpm; standard deviation = 10.40 bpm; Bland-Altman 95% limits of agreement = -26.42 to 14.35 bpm). A total of 69.9% of Fitbit heart rate measurements were within 10% error compared with EKG, and 91.5% of all heart rate measurements were within 20% error. CONCLUSIONS Although the mean bias in measuring heart rate was relatively small, the limits of agreement between the Fitbit Charge HR and EKG were broad. Thus, the Fitbit Charge HR would not be a suitable option for monitoring heart rate within a narrow range. For the purposes of postconcussion exercise therapy, the relatively inexpensive cost, easy implementation, and low maintenance make Fitbit Charge HR a viable option for assessing adherence to an exercise program when expensive clinical equipment is unavailable. LEVEL OF EVIDENCE II.
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Affiliation(s)
- Camilla S Powierza
- School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC(∗)
| | - Michael D Clark
- School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC; the Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Human Movement Science Curriculum, Department of Allied Health Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC(†)
| | - Jaime M Hughes
- Program on Integrative Medicine and Department of Physical Medicine & Rehabilitation, The University of North Carolina at Chapel Hill, Chapel Hill, NC(‡)
| | - Kevin A Carneiro
- Department of Physical Medicine & Rehabilitation, The University of North Carolina at Chapel Hill, Chapel Hill, NC(§)
| | - Jason P Mihalik
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC; Human Movement Science Curriculum, Department of Allied Health Sciences, The University of North Carolina at Chapel Hill, 2201 Stallings-Evans Sports Medicine Center, Campus Box 8700, Chapel Hill, NC 27599(¶).
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Abstract
BACKGROUND Despite a high reported incidence rate of concussion, little is known about the on-field characteristics of injurious head impacts in National Football League (NFL) games. PURPOSE To characterize on-field features (location, player position, and time during game) and biomechanical features (anticipation status, closing distance, impact location and type) associated with concussions in NFL games over a 4-season period (2010-2011 to 2013-2014). STUDY DESIGN Descriptive epidemiology study. METHODS We analyzed video of a subset of reported, in-game concussions for the 2010-2011 to 2013-2014 seasons. These videos represented a sample of injuries that were diagnosed and reported on the same day and that could be clearly associated with an in-game collision as captured on video. We determined anticipation status, closing distance, impact location on the injured player's helmet, and impact type (helmet-to-helmet, helmet-to-body, or helmet-to-ground). Associations between these variables were analyzed by use of descriptive statistics and tests of association. RESULTS A total of 871 diagnosed concussions were reported as occurring during NFL preseason, regular season, and postseason games for the 2010-2011, 2011-2012, 2012-2013, and 2013-2014 seasons. A total of 1324 games were played during this period, giving a concussion incidence rate of 0.658 per game (95% CI, 0.61-0.70). From the video-reviewed subset (n = 429; 49.3%), the majority of injurious impacts occurred with good anticipation (57.3%) and <10 yards of closing distance (59.0%). An association was found between anticipation status and play type ([Formula: see text] = 27.398, P < .001), largely because injuries occurring on pass plays were more likely to be poorly anticipated than injuries during run plays (43.0% vs 21.4%; [Formula: see text] = 14.78, P < .001). Kick returns had the greatest proportion of well-anticipated impacts (78%) and the greatest proportion of impacts with ≥10 yards of closing distance (80%). The type of impact was approximately equally divided between helmet-to-helmet, helmet-to-body, and helmet-to-ground types. The impact location was broadly distributed over the helmet of the injured player. CONCLUSION In-game concussions in the NFL occurred through a diverse variety of mechanisms, surprisingly tended to be well-anticipated, and, also surprisingly, occurred with <10 yards of closing distance. The impacts causing concussion were broadly distributed over the helmet. More concussions occurred during the second half of game play, but we do not have evidence to explain this finding.
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Affiliation(s)
- Michael D Clark
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina, USA.,Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Breton M Asken
- Department of Clinical and Health Psychology, Neuropsychology College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
| | - Stephen W Marshall
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina, USA.,Injury Prevention Research Center, University of North Carolina, Chapel Hill, North Carolina, USA.,Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Kevin M Guskiewicz
- Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, North Carolina, USA.,Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA.,Injury Prevention Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
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Szczepura A, Wild D, Khan AJ, Owen DW, Palmer T, Muhammad T, Clark MD, Bowman C. Antipsychotic prescribing in care homes before and after launch of a national dementia strategy: an observational study in English institutions over a 4-year period. BMJ Open 2016; 6:e009882. [PMID: 27650756 PMCID: PMC5051335 DOI: 10.1136/bmjopen-2015-009882] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [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] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES To assess associations between the launch of the National Dementia Strategy (NDS) and antipsychotic prescribing in long-term residential care (LTC) in England. SETTING AND PARTICIPANTS Retrospective analysis of prescribing patterns in 616 LTC institutions (31 619 residents) following launch of the NDS, using information from electronic medicines management system. PRIMARY AND SECONDARY OUTCOME MEASURES Antipsychotic prescribing point prevalence (PP) for all residents in a cross section of LTC settings over a 4-year period following NDS launch. Secondary outcomes included dosages, length of treatment and use of recommended second-generation antipsychotics (SGAs) versus first-generation antipsychotics (FGAs). Associations between facility-level PP values and institutional characteristics, resident demographics were explored. Variations across geographical areas examined. Prescription net ingredient costs calculated. RESULTS No statistically significant difference was observed in overall prescribing rates over the 4-year period (Kolmogorov-Smirnov (KS) test p=0.60), and there was no significant shift towards newer SGAs (KS test p=0.32). Dosages were above the maximum indicated in only 1.3% of cases, but duration of prescribing was excessive in 69.7% of cases. Care homes in the highest prescribing quintile were more likely to be located in a deprived area (rate ratio (Q5/Q1) RR=5.89, 95% CI 4.35 to 7.99), registered for dementia (RR=3.38, 95% CI 3.06 to 3.73) and those in the lowest quintile were more likely to be served by a single general practitioner (GP) practice (RR=0.48; 95% CI 0.37 to 0.63); p<0.001 all. A sixfold variation in PP levels was observed between geographical areas. The average annual expenditure on antipsychotics was £65.6 per person resident (2012 prices). CONCLUSIONS The NDS in England was not associated with reduced PP levels or the types of antipsychotic prescribing in care homes. Further research is needed to explore why. Clear standards specifying recommended agents, dosages and length of treatment, together with routine monitoring and greater accountability for antipsychotic prescribing, may be required.
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Affiliation(s)
- Ala Szczepura
- Faculty of Health and Life Sciences, Coventry University, Coventry, UK
| | - Deidre Wild
- Faculty of Health and Life Sciences, Coventry University, Coventry, UK
| | - Amir J Khan
- Faculty of Health and Life Sciences, Coventry University, Coventry, UK
| | - David W Owen
- Institute for Employment Research, University of Warwick, Coventry, UK
| | - Thomas Palmer
- Department Mathematics & Statistics, Lancaster University, Lancaster, UK
| | | | | | - Clive Bowman
- School of Health Sciences, City University London, London, UK
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Rosenthal D, Seagraves MA, Bisese JH, Clark MD, Lamis PA. Comparison of Aortography, Computed Tomography, and Magnetic Resonance in Abdominal Aortic Aneurysm. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/153857449102500307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
During a three-year period 51 patients with abdominal aortic aneurysm (AAA) underwent magnetic resonance imaging (MRI) computed tomography (CT) and aortography to evaluate the diagnostic accuracy and role of each study. Ct and MRI were 100% accurate in establishing the diagnosis of AAA, whereas aortography did not visualize the AAA in 3 patients nor the associated iliac aneurysms in 3 other patients. MRI and aortography were superior to CT in evaluating the celiac, superior mesenteric, and renal arteries. CT should be the screening method of choice to identify AAA, and when operation is contemplated, aortography will best demonstrate the mesenteric and renal anatomy. If aortography is deemed too hazardous, MRI will yield the most information and should then be the noninvasive test of choice.
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Rosenthal D, Hungerpiller JC, Seagraves MA, Erdoes LS, Baird DR, McKinsey JF, Lamis PA, Clark MD. Prophylactic Interruption of the Inferior Vena Cava: Immediate and Long-Term Results. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/153857449202600608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To determine the effects of prophylactic interruption of the inferior vena cava (IVC) the hospital course of 340 patients who underwent aortic operations with placement of a Moretz IVC clip between 1980 and 1988 was removed: 175 patients had had abdominal aortic aneurysm resection; 143, aortobifemoral by pass; and 22, aortobiiliac endarterectomy or bypass. There were no complica tions related to placement of the IVC clip. After operation, any clinical suspicion of deep vein thrombosis (DVT) or pulmonary embolus (PE) was docu mented by phlebography or pulmonary arteriography, respectively. In the im mediate postoperative period ( < thirty days), only 2 (0.5%) patients had a PE and 10 (2.9%) a DVT. For long-term follow-up extending to eight years (mean ± 42.8 months), 308 patients were available. During long-term follow-up, 2 (0.6%) patients had a PE and 7 (2.2%) a DVT. Limb edema without evidence of DVT occurred in another 7 (2.2%) patients. B-mode ultrasonography of the IVC was performed in 163 patients. The IVC was clearly patent in all but 5 (3%): 1 had had a documented PE in the immediate postoperative period, and the other 4, an asymptomatic occlusion of the IVC during late follow-up. Prophylactic IVC interruption in aortic surgical patients appears not to cause IVC thrombosis, to initiate DVT, or to cause chronic venous insufficiency. The results indicate that it is a safe method of decreasing the incidence of PE, without increasing operative morbidity.
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Affiliation(s)
- David Rosenthal
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - John C. Hungerpiller
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - Mary Annette Seagraves
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - Luke S. Erdoes
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - David R. Baird
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - James F. McKinsey
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - Pano A. Lamis
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - Michael D. Clark
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
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Rosenthal D, McKinsey JF, Erdoes LS, Hungerpillar JC, Clark MD, Lamis PA, Whitehead T, Laszlo Pallos L. Ruptured Abdominal Aortic Aneurysm: Factors Affecting Survival and Long-Term Results. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/153857449202600109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although elective resection of an abdominal aortic aneurysm (AAA) is now a safe operation, the mortality related to a ruptured abdominal aortic aneurysm (rAAA) remains significant. To evaluate factors affecting survival and the long- term results after rAAA, a ten-year review of 47 patients was performed. The operative mortality rate was 43% (20/47) compared with 2.6% for 147 elective AAA patients during this period. Factors adversely affecting survival were blood pressure <90 mmHg on arrival to the hospital, perioperative cardiac arrest, delay in time from diagnosis to treatment > six hours, age > seventy-five years, massive transfusion, and free intraperitoneal rupture. In follow-up extending to five years the survivors of rAAA at one (92%) and five (53%) years had no discernible differences in quality of life or long- term survival compared with age- and sex-matched patients who had elective AAA resection during the same time interval. When an rAAA occurs and any three of the adverse variables noted above are present, the mortality rate exceeds 90%. These patients remained ventilator dependent and in the ICU from one to sixty-seven days, accumulating hospital charges from $7,000 to $214,000. It appears that the most effective means of reducing mortality statistics in this inordinately low-salvage, yet high-cost sub group of patients, is to prevent rupture of an AAA by elective resection.
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Affiliation(s)
- David Rosenthal
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - James F. McKinsey
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - Luke S. Erdoes
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - John C. Hungerpillar
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - Michael D. Clark
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - Pano A. Lamis
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - Travis Whitehead
- Department of Vascular Surgery, Georgia Baptist Medical Center, Georgia State University
| | - L. Laszlo Pallos
- Department of Management, Georgia State University, Atlanta, Georgia
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Rosenthal D, McKinsey JF, Clark MD, Hungerpiller JC, Lamis PA, Laszlo Pallos L. Ischemic Colitis Following Ruptured Abdominal Aortic Aneurysm. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/153857449202600904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During a six-year period, 47 patients underwent operation for ruptured abdominal aortic aneurysm (rAAA) with a mortality rate of 38% (18/47): of the 39 patients surviving the initial surgery, 9 (23%) developed ischemic colitis. All 9 patients demonstrated hyperdynamic cardiovascular changes consistent with sepsis: decreased systemic vascular resistance (SVR) (mean 852 dynes/sec/cm2) and increased cardiac index (mean 3.8 L/min/m2). This "septic picture" in the postoperative period, before the onset of any gastrointestinal (GI) symptoms (diarrhea with/without blood), led the authors to question bowel viability. Flexible sigmoid colonoscopy identified ischemic colitis in all patients and sigmoid colectomy was performed in 4; 3 of these patients survived. Of the 5 remaining patients managed nonoperatively, 3 survived. When hyperdynamic cardiovascular changes were recognized "early" (< forty-eight hours) and ischemic colitis was diagnosed (5 patients), all patients survived. However, when ischemic colitis was diagnosed "late" (> forty-eight hours) after operation in 4 patients, only 1 (25%) survived. In patients who suffer an rAAA and demonstrate cardiodynamic signs of sepsis (especially falling SVR) in the immediate postoperative period (< forty-eight hours), immediate bedside sigmoid colonoscopy to rule out ischemic colitis is warranted. Similarly, when patients develop "late" cardiodynamic signs of sepsis during recuperation from rAAA, even before the onset of GI symptoms, sigmoid colonoscopy should be performed. If severe ischemic colitis is documented, aggressive management with frequent colonoscopy and possibly sigmoid resection is indicated, for this may offer the only chance of survival in these catastrophically ill patients.
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Affiliation(s)
- David Rosenthal
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - James F. McKinsey
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - Michael D. Clark
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - John C. Hungerpiller
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - Pano A. Lamis
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia
| | - L. Laszlo Pallos
- Department of Management, Georgia State University, Atlanta, Georgia
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Matsuura JH, Rosenthal D, Jerius H, Clark MD, Owens DS. Traumatic Carotid Artery Dissection and Pseudoaneurysm Treated with Endovascular Coils and Stent. J Endovasc Ther 2016; 4:339-43. [PMID: 9418195 DOI: 10.1177/152660289700400403] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose: To report a case of post-traumatic internal carotid artery dissection and pseudoaneurysm formation at the C-1 level successfully treated by a percutaneous endovascular technique. Methods and Results: A 20-year-old female presented 72 hours after a motor vehicle accident with incomplete occulosympathetic paresis (Horner's syndrome), carotidynia, and left-sided weakness. Arteriography confirmed the diagnosis of carotid dissection and an associated 1.5-cm × 2.5-cm pseudoaneurysm at the C-1 level. Neuroradiologists embolized the pseudoaneurysm with Guglielmi detachable coils and controlled the dissection with placement of a Wallstent. Conclusions: This report illustrates successful percutaneous endovascular treatment of a carotid dissection and pseudoaneurysm near the base of the skull.
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Affiliation(s)
- J H Matsuura
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, USA
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Rosenthal D, Matsuura JH, Jerius H, Clark MD. Iliofemoral Venous Thrombosis Caused by Compression of an Internal Iliac Artery Aneurysm: A Minimally Invasive Treatment. J Endovasc Ther 2016; 5:142-5. [PMID: 9633959 DOI: 10.1177/152660289800500209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose: To report the success of a minimally invasive treatment for phlegmasia cerulea dolens without gangrene caused by compression from an internal iliac artery aneurysm. Methods and Results: An 81-year-old male with a 1-month history of paralysis owing to a hemorrhagic stroke presented with massive edema and skin mottling of the right lower extremity. Imaging confirmed right iliofemoral deep vein thrombosis caused by compression from a 4-cm internal iliac artery aneurysm. With thrombolysis ruled out, a minimally invasive treatment plan was undertaken, featuring percutaneous coil embolization of the aneurysm and surgical venous thrombectomy with proximal arteriovenous fistula creation and iliac vein stent placement. Failure of the coils to embolize the iliac aneurysm prompted the use of an endovascular graft to exclude the aneurysm. The patient's symptoms subsided, and he has a patent right iliofemoral venous system and internal iliac artery at his latest (16-month) follow-up. Conclusions: This case demonstrates that minimally invasive endovascular and open techniques can be combined to achieve an optimum outcome in patients at high risk for standard surgical approaches.
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Affiliation(s)
- D Rosenthal
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta 30312, USA
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Rosenthal D, Atkins CP, Shuler FW, Jerius HS, Clark MD, Matsuura JH. Popliteal Artery Aneurysm Treated with a Minimally Invasive Endovascular Approach: An Initial Report. J Endovasc Ther 2016. [DOI: 10.1177/152660289800500112] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Purpose: To report a minimally invasive approach to popliteal artery aneurysm (PAA) treatment. Methods and Results: A 48-year-old male with a 3-cm PAA was treated electively with an endovascular in situ saphenous vein bypass and transluminal antegrade coil embolization of the PAA prior to completion of the proximal anastomosis. Two short incisions at the anastomosis sites resulted in no wound complications, and the patient was discharged after 2 days. After 14 months of follow-up, the patient is asymptomatic with continued patency of the in situ bypass and occlusion of the PAA. Conclusions: This endovascular approach for minimally invasive femoropopliteal in situ saphenous vein bypass grafting appears feasible for treatment of PAAs. This method may reduce the rate of wound complications attending classic open in situ bypass grafts.
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Affiliation(s)
- David Rosenthal
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia, USA
| | - Colby P. Atkins
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia, USA
| | - Frederick W. Shuler
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia, USA
| | - Hilde S. Jerius
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia, USA
| | - Michael D. Clark
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia, USA
| | - John H. Matsuura
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia, USA
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Clark MD, Carneiro K, Fraser M, Mihalik J, Guskiewicz K. Exacerbation of Anxiety and Depression Symptoms following Concussion in a High School Softball Athlete. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000487034.35335.88] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Powierza CS, Clark MD, Hughes JM, Carneiro KA, Mihalik JP. Validation Of A Self-monitoring Tool For Use In Post-concussion Syndrome Therapy. Med Sci Sports Exerc 2016. [DOI: 10.1249/01.mss.0000487390.22076.d1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Clark MD, Brien DW. The intersection of software and strengths: Using internet technology and case management software to assist Strength-Based Practice. Am Indian Alsk Native Ment Health Res 2016; 23:48-67. [PMID: 27383086 DOI: 10.5820/aian.2303.2016.48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The focus of this investigation is the helping professionals working within American Indian and Alaska Native (AI/AN) communities. This article looks at how innovative technology-in the form of automated case management software and Internet connectivity-can assist effective implementation of Strength-based Practice and agency services within tribal courts and the many other helping agencies that serve AI/AN populations. We seek to expand practice knowledge by reviewing the benefits that this software and Internet connectivity can offer to agency operations and exploring how they can assist case management services.
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Connelly SJ, Walling K, Wilbert SA, Catlin DM, Monaghan CE, Hlynchuk S, Meehl PG, Resch LN, Carrera JV, Bowles SM, Clark MD, Tan LT, Cody JA. UV-Stressed Daphnia pulex Increase Fitness through Uptake of Vitamin D3. PLoS One 2015; 10:e0131847. [PMID: 26147286 PMCID: PMC4492615 DOI: 10.1371/journal.pone.0131847] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/05/2015] [Indexed: 11/19/2022] Open
Abstract
Ultraviolet radiation is known to be highly variable in aquatic ecosystems. It has been suggested that UV-exposed organisms may demonstrate enough phenotypic plasticity to maintain the relative fitness of natural populations. Our long-term objective is to determine the potential photoprotective effect of vitamin D3 on Daphnia pulex exposed to acute or chronic UV radiation. Herein we report our initial findings in this endeavor. D. pulex survival and reproduction (fitness) was monitored for 5 d as a proof of concept study. Significantly higher fitness was observed in the D. pulex with D3 than those without (most extreme effects observed were 0% survival in the absence of D3 and 100% with 10 ppm D3). Vitamin D3 was isolated from the culture media, the algal food (Pseudokirchneriella), and the D. pulex and quantified using high performance liquid chromatography (HPLC). Vitamin D3 was fluorescently labeled using a phenothiazinium dye and added to cultures of D. pulex. Images demonstrating the uptake of D3 into the tissues and carapace of the D. pulex were acquired. Our initial findings suggest a positive role for D3 in ecosystems as both UV-stressed algae and Daphnia sequester D3, and D. pulex demonstrate increased fitness in the presence of D3.
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Affiliation(s)
- Sandra J. Connelly
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Kelly Walling
- School of Health Science and Technology, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Steven A. Wilbert
- College of Imaging Arts and Sciences, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Diane M. Catlin
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Cailin E. Monaghan
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Sofiya Hlynchuk
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Pamela G. Meehl
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Lauren N. Resch
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - J. Valerie Carrera
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Stephanie M. Bowles
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Michael D. Clark
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Loraine T. Tan
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
| | - Jeremy A. Cody
- School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York, United States of America
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Clark MD, Determann D, Petrou S, Moro D, de Bekker-Grob EW. Discrete choice experiments in health economics: a review of the literature. Pharmacoeconomics 2014; 32:883-902. [PMID: 25005924 DOI: 10.1007/s40273-014-0170-x] [Citation(s) in RCA: 488] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND Discrete choice experiments (DCEs) are increasingly used in health economics to address a wide range of health policy-related concerns. OBJECTIVE Broadly adopting the methodology of an earlier systematic review of health-related DCEs, which covered the period 2001-2008, we report whether earlier trends continued during 2009-2012. METHODS This paper systematically reviews health-related DCEs published between 2009 and 2012, using the same database as the earlier published review (PubMed) to obtain citations, and the same range of search terms. RESULTS A total of 179 health-related DCEs for 2009-2012 met the inclusion criteria for the review. We found a continuing trend towards conducting DCEs across a broader range of countries. However, the trend towards including fewer attributes was reversed, whilst the trend towards interview-based DCEs reversed because of increased computer administration. The trend towards using more flexible econometric models, including mixed logit and latent class, has also continued. Reporting of monetary values has fallen compared with earlier periods, but the proportion of studies estimating trade-offs between health outcomes and experience factors, or valuing outcomes in terms of utility scores, has increased, although use of odds ratios and probabilities has declined. The reassuring trend towards the use of more flexible and appropriate DCE designs and econometric methods has been reinforced by the increased use of qualitative methods to inform DCE processes and results. However, qualitative research methods are being used less often to inform attribute selection, which may make DCEs more susceptible to omitted variable bias if the decision framework is not known prior to the research project. CONCLUSIONS The use of DCEs in healthcare continues to grow dramatically, as does the scope of applications across an expanding range of countries. There is increasing evidence that more sophisticated approaches to DCE design and analytical techniques are improving the quality of final outputs. That said, recent evidence that the use of qualitative methods to inform attribute selection has declined is of concern.
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Affiliation(s)
- Michael D Clark
- Department of Economics, University of Warwick, Coventry, CV4 7AL, UK,
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Song CK, White AC, Zeng L, Leever BJ, Clark MD, Emery JD, Lou SJ, Timalsina A, Chen LX, Bedzyk MJ, Marks TJ. Systematic investigation of organic photovoltaic cell charge injection/performance modulation by dipolar organosilane interfacial layers. ACS Appl Mater Interfaces 2013; 5:9224-9240. [PMID: 23942417 DOI: 10.1021/am4030609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
With the goal of investigating and enhancing anode performance in bulk-heterojunction (BHJ) organic photovoltaic (OPV) cells, the glass/tin-doped indium oxide (ITO) anodes are modified with a series of robust silane-tethered bis(fluoroaryl)amines to form self-assembled interfacial layers (IFLs). The modified ITO anodes are characterized by contact angle measurements, X-ray reflectivity, ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, atomic force microscopy, and cyclic voltammetry. These techniques reveal the presence of hydrophobic amorphous monolayers of 6.68 to 9.76 Å thickness, and modified anode work functions ranging from 4.66 to 5.27 eV. Two series of glass/ITO/IFL/active layer/LiF/Al BHJ OPVs are fabricated with the active layer = poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester (P3HT:PC71BM) or poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]thi-eno[3,4-b]thiophenediyl]]:phenyl-C71-butyric acid methyl ester (PTB7:PC71BM). OPV analysis under AM 1.5G conditions reveals significant performance enhancement versus unmodified glass/ITO anodes. Strong positive correlations between the electrochemically derived heterogeneous electron transport rate constants (ks) and the device open circuit voltage (Voc), short circuit current (Jsc), hence OPV power conversion efficiency (PCE), are observed for these modified anodes. Furthermore, the strong functional dependence of the device response on ks increases as greater densities of charge carriers are generated in the BHJ OPV active layer, and is attributable to enhanced anode carrier extraction in the case of high-ks IFLs.
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Affiliation(s)
- Charles Kiseok Song
- Department of Chemistry and the Argonne-Northwestern Solar Energy Research Center, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
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Clark MD, Jespersen ML, Patel RJ, Leever BJ. Predicting vertical phase segregation in polymer-fullerene bulk heterojunction solar cells by free energy analysis. ACS Appl Mater Interfaces 2013; 5:4799-4807. [PMID: 23683311 DOI: 10.1021/am4003777] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Blends of poly(3-hexylthiophene) (P3HT) and C61-butyric acid methyl ester (PCBM) are widely used as a model system for bulk heterojunction active layers developed for solution-processable, flexible solar cells. In this work, vertical concentration profiles within the P3HT:PCBM active layer are predicted based on a thermodynamic analysis of the constituent materials and typical solvents. Surface energies of the active layer components and a common transport interlayer blend, poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), are first extracted using contact angle measurements coupled with the acid-base model. From this data, intra- and interspecies interaction free energies are calculated, which reveal that the thermodynamically favored arrangement consists of a uniformly blended "bulk" structure capped with a P3HT-rich air interface and a slightly PCBM-rich buried interface. Although the "bulk" composition is solely determined by P3HT:PCBM ratio, composition near the buried interface is dependent on both the blend ratio and interaction free energy difference between solvated P3HT and PCBM deposition onto PEDOT:PSS. In contrast, the P3HT-rich overlayer is independent of processing conditions, allowing kinetic formation of a PCBM-rich sublayer during film casting due to limitations in long-range species diffusion. These thermodynamic calculations are experimentally validated by angle-resolved X-ray photoelectron spectroscopy (XPS) and low energy XPS depth profiling, which show that the actual composition profiles of the cast and annealed films closely match the predicted behavior. These experimentally derived profiles provide clear evidence that typical bulk heterojunction active layers are predominantly characterized by thermodynamically stable composition profiles. Furthermore, the predictive capabilities of the comprehensive free energy approach are demonstrated, which will enable investigation of structurally integrated devices and novel active layer systems including low band gap polymers, ternary systems, and small molecule blends.
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Affiliation(s)
- Michael D Clark
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, USA
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Clark MD, Leech D, Gumber A, Moro D, Szczepura A, West N, Higgins R. Who should be prioritized for renal transplantation?: Analysis of key stakeholder preferences using discrete choice experiments. BMC Nephrol 2012; 13:152. [PMID: 23173887 PMCID: PMC3576250 DOI: 10.1186/1471-2369-13-152] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 10/29/2012] [Indexed: 11/23/2022] Open
Abstract
Background Policies for allocating deceased donor kidneys have recently shifted from allocation based on Human Leucocyte Antigen (HLA) tissue matching in the UK and USA. Newer allocation algorithms incorporate waiting time as a primary factor, and in the UK, young adults are also favoured. However, there is little contemporary UK research on the views of stakeholders in the transplant process to inform future allocation policy. This research project aimed to address this issue. Methods Discrete Choice Experiment (DCE) questionnaires were used to establish priorities for kidney transplantation among different stakeholder groups in the UK. Questionnaires were targeted at patients, carers, donors / relatives of deceased donors, and healthcare professionals. Attributes considered included: waiting time; donor-recipient HLA match; whether a recipient had dependents; diseases affecting life expectancy; and diseases affecting quality of life. Results Responses were obtained from 908 patients (including 98 ethnic minorities); 41 carers; 48 donors / relatives of deceased donors; and 113 healthcare professionals. The patient group demonstrated statistically different preferences for every attribute (i.e. significantly different from zero) so implying that changes in given attributes affected preferences, except when prioritizing those with no rather than moderate diseases affecting quality of life. The attributes valued highly related to waiting time, tissue match, prioritizing those with dependents, and prioritizing those with moderate rather than severe diseases affecting life expectancy. Some preferences differed between healthcare professionals and patients, and ethnic minority and non-ethnic minority patients. Only non-ethnic minority patients and healthcare professionals clearly prioritized those with better tissue matches. Conclusions Our econometric results are broadly supportive of the 2006 shift in UK transplant policy which emphasized prioritizing the young and long waiters. However, our findings suggest the need for a further review in the light of observed differences in preferences amongst ethnic minorities, and also because those with dependents may be a further priority.
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Affiliation(s)
- Michael D Clark
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
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Abstract
We present a theoretical description of how continuous monomer production affects the focusing of nanocrystal size distributions in solution. We show that sufficiently high monomer production rates can drive a decrease in the polydispersity even as the average nanocrystal size increases. This is in sharp contrast to Ostwald ripening, where polydispersity increases with mean crystal size. We interpret several experimental nanocrystal studies through our model and show how production-controlled growth promises exquisite control over the size and polydispersity of functional nanocrystals.
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Affiliation(s)
- Michael D Clark
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
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Abstract
The aim was to examine pharmacological treatment of migraine patients admitted to a tertiary care pain clinic. A retrospective review of 100 consecutive migraine patients admitted to The Wasser Pain Management Centre was conducted. Patients included met the 2nd Edition of the International Classification of Headache Disorders criteria for diagnosis of migraine. Data were collected with regard to nicotine and alcohol consumption, family history of migraine headaches, other pain diagnoses and pharmacological treatment. Twenty-two per cent of these patients were male as opposed to 78% female. The mean age of patients admitted for migraine was 43.4 years. Of the patients admitted, 48% had tried at least one triptan in the past and only 31% were actively using triptan(s). The most commonly used triptan in the past had been sumatriptan, whereas the most common triptan used on admission was rizatriptan. Opiate use was much more prevalent; 72% of admitted patients were using an opiate and 27% used multiple opiates. A significant number of patients had not yet been tried on a triptan despite meeting the diagnostic criteria for migraine and having significant disability. More education of the general medical community may be beneficial in implementing a stratified care approach to migraine management.
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Affiliation(s)
- S S Nijjar
- Wasser Pain Management Centre, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
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Lamb SE, Pepper J, Lall R, Jørstad-Stein EC, Clark MD, Hill L, Fereday-Smith J. Group treatments for sensitive health care problems: a randomised controlled trial of group versus individual physiotherapy sessions for female urinary incontinence. BMC Womens Health 2009; 9:26. [PMID: 19751517 PMCID: PMC2754423 DOI: 10.1186/1472-6874-9-26] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 09/14/2009] [Indexed: 11/25/2022]
Abstract
Background The aim was to compare effectiveness of group versus individual sessions of physiotherapy in terms of symptoms, quality of life, and costs, and to investigate the effect of patient preference on uptake and outcome of treatment. Methods A pragmatic, multi-centre randomised controlled trial in five British National Health Service physiotherapy departments. 174 women with stress and/or urge incontinence were randomised to receive treatment from a physiotherapist delivered in a group or individual setting over three weekly sessions. Outcome were measured as Symptom Severity Index; Incontinence-related Quality of Life questionnaire; National Health Service costs, and out of pocket expenses. Results The majority of women expressed no preference (55%) or preference for individual treatment (36%). Treatment attendance was good, with similar attendance with both service delivery models. Overall, there were no statistically significant differences in symptom severity or quality of life outcomes between the models. Over 85% of women reported a subjective benefit of treatment, with a slightly higher rating in the individual compared with the group setting. When all health care costs were considered, average cost per patient was lower for group sessions (Mean cost difference £52.91 95%, confidence interval (£25.82 - £80.00)). Conclusion Indications are that whilst some women may have an initial preference for individual treatment, there are no substantial differences in the symptom, quality of life outcomes or non-attendance. Because of the significant difference in mean cost, group treatment is recommended. Trial Registration Trial Registration number: ISRCTN 16772662
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Affiliation(s)
- S E Lamb
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
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Matsuura JH, White RA, Kopchok G, Nishinian G, Woody JD, Rosenthal D, Clark MD. Vena caval filter placement by intravascular ultrasound. Cardiovasc Surg 2001; 9:571-4. [PMID: 11604340 DOI: 10.1016/s0967-2109(01)00031-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
OBJECTIVE Placement of vena caval filters under fluoroscopic surveillance incurs significant expense and potential risks associated with the transportation of critically ill patients. Intravascular ultrasound (IVUS) allows direct intraluminal visualization of the vena cava and the renal veins. The purpose of this study is to evaluate the accuracy of vena caval filter placement under IVUS in an animal model. METHODS Fifteen Simon-Nitinol venal cava filters (C.R. Bard, Inc., Covington, GA) were placed under IVUS guidance into four anesthetized sheep. Twelve were placed transfemorally, and three were placed transjugularly. Accuracy of placement was confirmed with fluoroscopy by measurement between the filter tip and the targeted side branch. RESULTS The vena caval filters placed femorally averaged 0.33+/-0.42 cm distance from the target vein side branch. Jugular approach filter placement was less accurate. Although two out of three filters placed from the jugular vein were correctly positioned, the distance from the target vein side branch was much greater averaging 2.5+/-1.04 cm. CONCLUSION Femoral placement of vena caval filters under IVUS is extremely accurate. The transjugular route, however, was technically challenging and standard fluoroscopic vena caval filter placement appears to be more appropriate. Our success with the femoral approach merits further clinical investigation in the use of IVUS for critically ill patients that would benefit from bedside vena caval filter placement.
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Affiliation(s)
- J H Matsuura
- Department of Surgery, Atlanta Medical Center, Medical College of Georgia, Atlanta, GA, USA.
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Clark MD, Hennig S, Herwig R, Clifton SW, Marra MA, Lehrach H, Johnson SL. An oligonucleotide fingerprint normalized and expressed sequence tag characterized zebrafish cDNA library. Genome Res 2001; 11:1594-602. [PMID: 11544204 PMCID: PMC311136 DOI: 10.1101/gr.186901] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [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] [Indexed: 01/23/2023]
Abstract
The zebrafish is a powerful system for understanding the vertebrate genome, allowing the combination of genetic, molecular, and embryological analysis. Expressed sequence tags (ESTs) provide a rapid means of identifying an organism's genes for further analysis, but any EST project is limited by the availability of suitable libraries. Such cDNA libraries must be of high quality and provide a high rate of gene discovery. However, commonly used normalization and subtraction procedures tend to select for shorter, truncated, and internally primed inserts, seriously affecting library quality. An alternative procedure is to use oligonucleotide fingerprinting (OFP) to precluster clones before EST sequencing, thereby reducing the re-sequencing of common transcripts. Here, we describe the use of OFP to normalize and subtract 75,000 clones from two cDNA libraries, to a minimal set of 25,102 clones. We generated 25,788 ESTs (11,380 3' and 14,408 5') from over 16,000 of these clones. Clustering of 10,654 high-quality 3' ESTs from this set identified 7232 clusters (likely genes), corresponding to a 68% gene diversity rate, comparable to what has been reported for the best normalized human cDNA libraries, and indicating that the complete set of 25,102 clones contains as many as 17,000 genes. Yet, the library quality remains high. The complete set of 25,102 clones is available for researchers as glycerol stocks, filters sets, and as individual EST clones. These resources have been used for radiation hybrid, genetic, and physical mapping of the zebrafish genome, as well as positional cloning and candidate gene identification, molecular marker, and microarray development.
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Affiliation(s)
- M D Clark
- Max-Planck-Institut für Molekulare Genetik, 14195 Berlin, Germany.
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Rosenthal D, Schubart PJ, Kinney EV, Martin JD, Sharma R, Matsuura JH, Clark MD. Remote superficial femoral artery endarterectomy: Multicenter medium-term results. J Vasc Surg 2001; 34:428-32; discussion 432-3. [PMID: 11533593 DOI: 10.1067/mva.2001.116300] [Citation(s) in RCA: 26] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The results of percutaneous transluminal angioplasty, atherectomy, and laser angioplasty for the treatment of long-segment (>10 cm) superficial femoral artery (SFA) occlusive disease have proved disappointing. Remote superficial femoral artery endarterectomy (RSFAE) is a minimally invasive procedure, performed through a single limited groin incision that may offer patency rates comparable with those of above-knee femoropopliteal (AKFP) bypass graft. In this retrospective multicenter study the medium-term results of RSFAE are examined. METHODS Sixty patients were included in this study. Indications for the procedure were claudication in 52 patients and limb salvage in eight patients. RSFAE was performed with the MollRing Cutter device through a femoral arteriotomy. The distal "flap" of atheroma was anchored by balloon/stent angioplasty through the femoral arteriotomy. All patients underwent a follow-up examination with serial color flow ultrasound scanning. RESULTS Ten patients with heavily calcified SFAs failed as "intentions to treat"; these patients underwent AKFP bypass grafting. The mean length of the endarterectomized SFAs was 22.3 cm (range, 8-37 cm). The primary cumulative patency rate by means of life-table analysis was 61.4% +/- 9% (SE), (mean, 12.9 months; range, 3-36 months). During follow-up, percutaneous transluminal angioplasty was necessary in 14 patients, for a primary-assisted patency rate of 82.6% +/- 8%. The locations of the restenoses after RSFAE were evenly distributed along the endarterectomized SFAs. There were no deaths and one wound complication (hematoma), and the mean hospital length of stay was 1.4 days +/- 0.8 days. CONCLUSIONS RSFAE is a safe and moderately durable procedure. If long-term patency rates are similar to those of AKFP bypass graft, RSFAE may prove to be a minimally invasive adjunct for the treatment of SFA occlusive disease that will lower operative morbidity, reduce hospital LOS, and shorten recuperation.
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Affiliation(s)
- D Rosenthal
- Department of Vascular Surgery, Atlanta Medical Center, The Medical College of Georgia, USA.
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Abstract
In December 1997, Arkansas Medicaid in cooperation with Title V and Children's Medical Services (CMS) implemented guidelines for the preauthorization of therapy services for Children with Special Health Care Needs (CSHCN). The University of Arkansas for Medical Sciences (UAMS) in partnership with Arkansas Medicaid (MCD), and Chidren's Medical Services (CMS) were given the charge of developing clinical practice guidelines for physical therapy (PT), occupational therapy (OT), and speech/language therapy (SLP) for this population based on primary diagnosis and age appropriateness. This process involved the implementation of a statewide, internet-based, clinical information support network. The objective of this article is to describe KIDSCARE, a clinical information support network, currently under development, for the determination of medical necessity and allocation of therapy services for CSHCN.
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Affiliation(s)
- D M Mooney
- The University of Arkansas for Medical Sciences, Department of Pediatrics, USA
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Gillingham MB, Clark MD, Dahly EM, Krugner-Higby LA, Ney DM. A comparison of two opioid analgesics for relief of visceral pain induced by intestinal resection in rats. Contemp Top Lab Anim Sci 2001; 40:21-6. [PMID: 11300671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
While developing a rat model for human short bowel syndrome, we noted that untreated rats as well as rats administered buprenorphine after intestinal resection exhibited behavior and appearance consistent with visceral pain and distress. To provide appropriate analgesics, we developed criteria to assess pain-related behavioral changes and conducted an experiment to evaluate the effectiveness of buprenorphine versus oxymorphone to alleviate the pain induced by intestinal resection. Rats underwent either small-bowel resection or transection surgery; in addition, animals received jugular catheterization for the delivery of total parenteral nutrition (TPN). Rats treated with buprenorphine received 0.5 mg/kg every 6 h subcutaneously, and rats treated with oxymorphone received 0.03 mg/kg hourly for 32 h via continuous intravenous (i.v.) infusion with TPN solution. Rats treated with buprenorphine exhibited behavior and appearance consistent with pain and distress for as long as 32 h postoperatively, whereas animals treated with oxymorphone exhibited behavior and appearance similar to their preoperative state. Thus, oxymorphone alleviated the pain-related behavioral changes after intestinal resection far better than did buprenorphine. Of interest, we observed that the buprenorphine was associated with a decrease in the volume of urine collected, whereas oxymorphone was associated with urine volumes similar to those of nonresected rats maintained with TPN. Because oxymorphone appeared to be a superior analgesic, we also evaluated three routes for administering this drug. Pain-related behavior changes were alleviated by the administration of oxymorphone by either Alzet mini-pump, bolus i.v. injection, or continuous i.v. infusion. We conclude that compared with buprenorphine, oxymorphone is a superior analgesic for the alleviation of visceral pain due to intestinal resection.
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Affiliation(s)
- M B Gillingham
- Department of Nutritional Sciences, University of Wisconsin-Madison, 1415 Linden Drive, Nutritional Sciences, Madison, Wisconsin 53706, USA
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Abstract
PURPOSE To describe an endovascular method of performing femoropopliteal in situ saphenous vein (SV) bypass and popliteal artery aneurysm (PAA) embolization. METHODS Twenty-two patients underwent PAA operations. Twelve patients had conventional SV bypasses with PAA proximal and distal ligation, whereas 10 underwent PAA embolization and an endovascular in situ SV bypass (EISB). The endovascular procedure was performed using an angioscopically guided side branch coil occlusion system. The PAAs were coil embolized under fluoroscopic surveillance. RESULTS No deaths or wound complications occurred in the EISB group. The mean hospital length of stay (LOS) was 2.1 days. Seven EISB procedures were performed through 2 incisions, whereas 3 operations required an additional incision. One graft occluded at 3 months. All PAAs remained occluded by color-flow ultrasonography at follow-up ranging from 4 to 23 months (mean 13.6); cumulative primary patency was 89%. In the conventional bypass group, no deaths occurred, but 3 (25%) patients had wound complications. The mean LOS was 6.2 days, and 1 graft occluded, giving an 86% cumulative primary patency at 42 months. CONCLUSIONS This minimally invasive technique obviates an extensive incision to harvest the SV and ligate the PAA proximally and distally. If long-term endovascular bypass graft patency and PAA occlusion rates prove to be similar to open operative results, the benefits of reduced wound complications, decreased hospital LOS, and increased health care savings support further investigation of this endovascular approach for the treatment of PAA.
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Affiliation(s)
- D Rosenthal
- Georgia Baptist Medical Center, Medical College of Georgia, Department of Vascular Surgery, Atlanta, USA.
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Gillingham MB, Dahly EM, Carey HV, Clark MD, Kritsch KR, Ney DM. Differential jejunal and colonic adaptation due to resection and IGF-I in parenterally fed rats. Am J Physiol Gastrointest Liver Physiol 2000; 278:G700-9. [PMID: 10801262 DOI: 10.1152/ajpgi.2000.278.5.g700] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Patients with severe short-bowel syndrome (SBS) often require long-term total parenteral nutrition (TPN) to maintain their nutritional status because of limited intestinal adaptation. Growth factors, including insulin-like growth factor I (IGF-I), are under investigation to promote intestinal adaptation and tolerance to oral feeding. We investigated structural and functional adaptation of the jejunum and colon in four groups of rats maintained with TPN for 7 days after a 60% jejunoileal resection and cecectomy or sham surgery and treatment with IGF-I or vehicle. Resection alone did not stimulate jejunal growth. IGF-I significantly increased jejunal mucosal mass, enterocyte proliferation, and migration rates. IGF-I decreased jejunal sucrase specific activity and reduced active ion transport and ionic permeability; resection alone had no effect. In contrast, resection significantly increased colonic mass and crypt depth but had no effect on active ion transport or ionic permeability. IGF-I had minimal effects on colonic structure. IGF-I but not resection stimulates jejunal adaptation, whereas resection but not IGF-I stimulates colonic growth in rats subjected to a model for human SBS. IGF-I treatment may improve intestinal adaptation in humans with SBS.
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Affiliation(s)
- M B Gillingham
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA
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45
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Abstract
Improved survival of patients with renal failure has led to the need for complex angioaccess procedures. The use of cryopreserved femoral vein for angioaccess when prosthetic arteriovenous grafts (AVG) could not be placed, owing to infection or the loss of conventional angioaccess sites from multiple AVG failures, was prospectively evaluated. Forty-eight cryopreserved femoral vein AVGs were placed in 44 patients. Thirty-eight (82%) of the cryopreserved femoral vein AVGs were placed for infection, whereas the other 10 (18%) were placed for multiple graft failures with compromised venous outflow. Even with implantation of the cryoveins into infected patients, there were no cryopreserved femoral vein AVG infections. The 1-year primary graft patency rate was 49% and the secondary graft patency rate was 75%. During the same time interval, 68 prosthetic brachial artery-to-axillary vein AVGs were placed. The 1-year primary and secondary patency rates for the prosthetic AVGs were 65 and 78%, respectively. In this study the overall patency rate of the cryopreserved femoral vein AVGs was similar to that for the PTFE AVGs (p = 0.519). In conclusion, the cryopreserved femoral vein proved useful in difficult angioaccess cases. The lack of infection after cryovein implantation around an infected area shows promise for salvaging an angioaccess site that would otherwise have been abandoned.
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Affiliation(s)
- J H Matsuura
- Department of Surgery, The Atlanta Medical Center, Medical College of Georgia, Atlanta, GA, USA
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46
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Affiliation(s)
- D Rosenthal
- Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, GA 30312, USA
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47
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Kirby LB, Rosenthal D, Atkins CP, Brown GA, Matsuura JH, Clark MD, Pallos L. Comparison between the transabdominal and retroperitoneal approaches for aortic reconstruction in patients at high risk. J Vasc Surg 1999; 30:400-5. [PMID: 10477632 DOI: 10.1016/s0741-5214(99)70066-2] [Citation(s) in RCA: 27] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE The purpose of this study was to compare the transabdominal approach with the retroperitoneal approach for elective aortic reconstruction in the patient who is at high risk. METHODS From January 1992 through January 1997, 148 patients underwent aortic operations: 92 of the patients were classified as American Society of Anesthesia (ASA) class IV. Forty-four operations on the patients of ASA class IV were performed with the transabdominal approach (25 for abdominal aortic aneurysms and 19 for aortoiliac occlusive disease), and 48 operations were performed with the retroperitoneal approach (27 for abdominal aortic aneurysms and 21 for aortoiliac occlusive disease). There were no significant differences between the groups for comorbid risk factors or perioperative care. RESULTS Among the patients of ASA class IV, eight (8.7%) died after operation (retroperitoneal, 3 [6.26%]; transabdominal, 5 [11.3%]; P =.5). There was no difference between groups in the number of pulmonary complications (retroperitoneal, 23 [47.9%]; transabdominal, 19 [43.2%]; P =.7) or in the development of incisional hernias (retroperitoneal, 6 [12.5%]; transabdominal, 5 [11.3%]; P =.5). The retroperitoneal approach was associated with a significant reduction in cardiac complications (retroperitoneal, 6 [12.5%]; transabdominal, 10 [22.7%]; P =.004) and in gastrointestinal complications (retroperitoneal, 5 [8.3%]; transabdominal, 15 [34.1%]). Operative time was significantly longer in the retroperitoneal group (retroperitoneal, 3.35 hours; transabdominal, 2.98 hours; P =.006), as was blood loss (retroperitoneal, 803 mL; transabdominal, 647 mL; P =.012). The patients in the retroperitoneal group required less intravenous narcotics (retroperitoneal, 36.6 +/- 21 mg; transabdominal, 49.5 +/- 28.5 mg; P =.004) and less epidural analgesics (retroperitoneal, 39.5 +/- 6.4 mg; transabdominal, 56.6 +/- 9.5 mg; P =.004). Hospital length of stay (retroperitoneal, 7.2 +/- 1.6 days; transabdominal, 12.8 +/- 2.3 days; P =.024) and hospital charges (retroperitoneal, $35,587 +/- $980; transabdominal, $54,832 +/- $1105; P =.04) were significantly lower in the retroperitoneal group. The survival rates at the 40-month follow-up period were similar between the groups (retroperitoneal, 81.3%; transabdominal, 78.7%; P =.53). CONCLUSION In this subset of patients who were at high risk for aortic reconstruction, the postoperative complications were common. However, the number of complications was significantly lower in the retroperitoneal group. Aortic reconstruction in patients of ASA class IV appears to be more safely and economically performed with the retroperitoneal approach.
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Affiliation(s)
- L B Kirby
- Georgia Baptist Medical Center, Division of Health Studies Center for Disease Control, Atlanta, 30312, USA
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48
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Abstract
For any attempt to understand the biology of an organism the incorporation of a cDNA-based approach is unavoidable, because it is a major approach to studying gene function. The complete sequence of the genome alone is not sufficient to understand any organism; its gene regulation, expression, splice variation, posttranslational modifications, and protein-protein interactions all need to be addressed. Because the majority of vertebrate genes have probably been identified as ESTs the next stage of the Human Genome Project is attributing functional information to these sequences. In most cases hybridization-based approaches on arrayed pieces of DNA represent the most efficient way to study the expression level and splicing of a gene in a given tissue. Similar technology, now being applied at the protein level using protein expression libraries, high-density protein membranes, and antibody screening, should allow studies of protein localization and modifications. Coupled to these approaches is the use of technologies, which although lacking the highly parallel nature of hybridization, can potentially characterize large numbers of samples individually and with high accuracy. Automated gel-based DNA sequencing is an example of such a technique; protein sequencing and mass fingerprinting are further examples. In the case of mass spectroscopic analysis, the speed and sensitivity are vastly superior to that of gel-based approaches; however, the preparation of samples is more tedious. Our laboratory is developing a system to characterize DNA samples by mass spectrometry, allowing more rapid genotyping than is currently possible using gel-based technologies ([symbol: see text]. Gut, [symbol: see text]. Berlin and H. Lehrach, personal communication, 1998). Such technology would make information on gene polymorphisms widely accessible. Data generated using all of these techniques at the DNA and protein level will be connected by both protein expression libraries and database comparisons; finally, two hybrid library screens will identify many of the protein-protein interactions, linking genes together. In this way we will start to understand the interplay between genes on a global scale, both at the level of molecular interaction and the biological processes they regulate.
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Affiliation(s)
- M D Clark
- Max Planck Institut für Molekulare Genetik, Berlin, Dahlem, Germany
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49
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Abstract
A study was conducted to provide an up-to-date analysis of the costs associated with operating an MRI facility in a mainstream National Health Service (NHS) setting. This paper presents an analysis of the costs associated with the acquisition and operation of an MRI scanner installed at the Walsgrave NHS Trust in Coventry in 1988. Costs arising immediately after the introduction of the MRI facility in 1988 are compared with the costs arising towards the end of the scanner's useful life during the 1995/96 financial year. The findings suggest that although the nominal total costs of MRI have increased marginally, from 403,223 Pounds to 434,037 Pounds (an increase of 30,814 Pounds), the increase in total costs is below the rate of inflation, and the nominal average costs of MRI have fallen from 179.20 Pounds to 115.77 Pounds over the period.
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Affiliation(s)
- J Fletcher
- Centre for Health Services Studies, Warwick Business School, Coventry, UK
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50
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Panopoulou GD, Clark MD, Holland LZ, Lehrach H, Holland ND. AmphiBMP2/4, an amphioxus bone morphogenetic protein closely related to Drosophila decapentaplegic and vertebrate BMP2 and BMP4: insights into evolution of dorsoventral axis specification. Dev Dyn 1998; 213:130-9. [PMID: 9733108 DOI: 10.1002/(sici)1097-0177(199809)213:1<130::aid-aja13>3.0.co;2-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [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: 11/11/2022] Open
Abstract
Amphioxus AmphiBMP2/4 appears to be a single gene closely related to vertebrate BMP2 and BMP4. In amphioxus embryos, the expression patterns of AmphiBMP2/4 suggest patterning roles in the ectodermal dorsoventral axis (comparable to dorsoventral axis establishment in the ectoderm by Drosophila decapentaplegic and vertebrate BMP4). In addition AmphiBMP2/4 may be involved in somite evagination, tail bud growth, pharyngeal differentiation (resulting in club-shaped gland morphogenesis), hindgut regionalization, differentiation of olfactory epithelium, patterning of the anterior central nervous system, and establishment of the heart primordium. One difference between the developmental role of amphioxus AmphiBMP2/4 and vertebrate BMP4 is that the former does not appear to be involved in the initial establishment of the dorsoventral polarity of the mesoderm.
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Affiliation(s)
- G D Panopoulou
- Max-Planck-Institut für Molekulare Genetik, Berlin (Dahlem), Germany
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