1
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Pinsky MR, Bedoya A, Bihorac A, Celi L, Churpek M, Economou-Zavlanos NJ, Elbers P, Saria S, Liu V, Lyons PG, Shickel B, Toral P, Tscholl D, Clermont G. Use of artificial intelligence in critical care: opportunities and obstacles. Crit Care 2024; 28:113. [PMID: 38589940 PMCID: PMC11000355 DOI: 10.1186/s13054-024-04860-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 03/05/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND Perhaps nowhere else in the healthcare system than in the intensive care unit environment are the challenges to create useful models with direct time-critical clinical applications more relevant and the obstacles to achieving those goals more massive. Machine learning-based artificial intelligence (AI) techniques to define states and predict future events are commonplace activities of modern life. However, their penetration into acute care medicine has been slow, stuttering and uneven. Major obstacles to widespread effective application of AI approaches to the real-time care of the critically ill patient exist and need to be addressed. MAIN BODY Clinical decision support systems (CDSSs) in acute and critical care environments support clinicians, not replace them at the bedside. As will be discussed in this review, the reasons are many and include the immaturity of AI-based systems to have situational awareness, the fundamental bias in many large databases that do not reflect the target population of patient being treated making fairness an important issue to address and technical barriers to the timely access to valid data and its display in a fashion useful for clinical workflow. The inherent "black-box" nature of many predictive algorithms and CDSS makes trustworthiness and acceptance by the medical community difficult. Logistically, collating and curating in real-time multidimensional data streams of various sources needed to inform the algorithms and ultimately display relevant clinical decisions support format that adapt to individual patient responses and signatures represent the efferent limb of these systems and is often ignored during initial validation efforts. Similarly, legal and commercial barriers to the access to many existing clinical databases limit studies to address fairness and generalizability of predictive models and management tools. CONCLUSIONS AI-based CDSS are evolving and are here to stay. It is our obligation to be good shepherds of their use and further development.
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Affiliation(s)
- Michael R Pinsky
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, 638 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, 15261, USA.
| | - Armando Bedoya
- Algorithm-Based Clinical Decision Support (ABCDS) Oversight, Office of Vice Dean of Data Science, School of Medicine, Duke University, Durham, NC, 27705, USA
- Division of Pulmonary Critical Care Medicine, Duke University School of Medicine, Durham, NC, 27713, USA
| | - Azra Bihorac
- Department of Medicine, University of Florida College of Medicine Gainesville, Malachowsky Hall, 1889 Museum Road, Suite 2410, Gainesville, FL, 32611, USA
| | - Leo Celi
- Laboratory for Computational Physiology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Matthew Churpek
- Department of Medicine, University of Wisconsin, 600 Highland Ave, Madison, WI, 53792, USA
| | - Nicoleta J Economou-Zavlanos
- Algorithm-Based Clinical Decision Support (ABCDS) Oversight, Office of Vice Dean of Data Science, School of Medicine, Duke University, Durham, NC, 27705, USA
| | - Paul Elbers
- Department of Intensive Care, Amsterdam UMC, Amsterdam, NL, USA
- Amsterdam UMC, ZH.7D.167, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Suchi Saria
- Department of Computer Science, Whiting School of Engineering, Johns Hopkins Medical Institutions, Johns Hopkins University, 333 Malone Hall, 300 Wolfe Street, Baltimore, MD, USA
- Department of Medicine, Johns Hopkins School of Medicine, AI and Health Lab, Johns Hopkins University, Baltimore, MD, USA
- Bayesian Health, New york, NY, 10282, USA
| | - Vincent Liu
- Department of Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Mail Code UHN67, Portland, OR, 97239-3098, USA
- , 2000 Broadway, Oakland, CA, 94612, USA
| | - Patrick G Lyons
- Department of Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Mail Code UHN67, Portland, OR, 97239-3098, USA
| | - Benjamin Shickel
- Department of Medicine, University of Florida College of Medicine Gainesville, Malachowsky Hall, 1889 Museum Road, Suite 2410, Gainesville, FL, 32611, USA
- Amsterdam UMC, ZH.7D.167, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Patrick Toral
- Department of Intensive Care, Amsterdam UMC, Amsterdam, NL, USA
- Amsterdam UMC, ZH.7D.165, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - David Tscholl
- Institute of Anesthesiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
| | - Gilles Clermont
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, 638 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, 15261, USA
- VA Pittsburgh Health System, 131A Building 30, 4100 Allequippa St, Pittsburgh, PA, 15240, USA
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2
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Zhang J, Gallifant J, Pierce RL, Fordham A, Teo J, Celi L, Ashrafian H. Quantifying digital health inequality across a national healthcare system. BMJ Health Care Inform 2023; 30:e100809. [PMID: 38007224 PMCID: PMC10680008 DOI: 10.1136/bmjhci-2023-100809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/30/2023] [Indexed: 11/27/2023] Open
Abstract
OBJECTIVES Digital health inequality, observed as differential utilisation of digital tools between population groups, has not previously been quantified in the National Health Service (NHS). Deployment of universal digital health interventions, including a national smartphone app and online primary care services, allows measurement of digital inequality across a nation. We aimed to measure population factors associated with digital utilisation across 6356 primary care providers serving the population of England. METHODS We used multivariable regression to test association of population and provider characteristics (including patient demographics, socioeconomic deprivation, disease burden, prescribing burden, geography and healthcare provider resource) with activation of two independent digital services during 2021/2022. RESULTS We find a significant adjusted association between increased population deprivation and reduced digital utilisation across both interventions. Multivariable regression coefficients for most deprived quintiles correspond to 4.27 million patients across England where deprivation is associated with non-activation of the NHS App. CONCLUSION Results are concerning for technologically driven widening of healthcare inequalities. Targeted incentive to digital is necessary to prevent digital disparity from becoming health outcomes disparity.
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Affiliation(s)
- Joe Zhang
- Institute of Global Health Innovation, Imperial College London, London, UK
- Department of Critical Care, Guy's and St. Thomas' Hospital, London, UK
| | - Jack Gallifant
- Department of Critical Care, Guy's and St. Thomas' Hospital, London, UK
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Robin L Pierce
- University of Exeter Law School, University of Exeter, Exeter, UK
| | | | - James Teo
- Department of Neurology, Kings College Hospital NHS Foundation Trust, London, UK
- London Medical Imaging & AI Centre, Guy's and St. Thomas' Hospital, London, UK
| | - Leo Celi
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Hutan Ashrafian
- Institute of Global Health Innovation, Imperial College London, London, UK
- Leeds Business School, University of Leeds, Leeds, UK
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3
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Sobel J, Almog R, Celi L, Yablowitz M, Eytan D, Behar J. How to organise a datathon for bridging between data science and healthcare? Insights from the Technion-Rambam machine learning in healthcare datathon event. BMJ Health Care Inform 2023; 30:e100736. [PMID: 37696642 PMCID: PMC10496710 DOI: 10.1136/bmjhci-2023-100736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/25/2023] [Indexed: 09/13/2023] Open
Affiliation(s)
- Jonathan Sobel
- Biomedical Engineering, Technion Israel Institute of Technology, Haifa, Israel
| | - Ronit Almog
- Epidemiology and Pediatric Critical Care, Rambam Health Care Campus, Haifa, Israel
| | - Leo Celi
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Michal Yablowitz
- TIMNA- Israel's Ministry of Health Big Data Platform, State of Israel Ministry of Health, Jerusalem, Israel
| | - Danny Eytan
- Epidemiology and Pediatric Critical Care, Rambam Health Care Campus, Haifa, Israel
| | - Joachim Behar
- Biomedical Engineering, Technion Israel Institute of Technology, Haifa, Israel
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4
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Yarnell CJ, Angriman F, Ferreyro BL, Liu K, De Grooth HJ, Burry L, Munshi L, Mehta S, Celi L, Elbers P, Thoral P, Brochard L, Wunsch H, Fowler RA, Sung L, Tomlinson G. Oxygenation thresholds for invasive ventilation in hypoxemic respiratory failure: a target trial emulation in two cohorts. Crit Care 2023; 27:67. [PMID: 36814287 PMCID: PMC9944781 DOI: 10.1186/s13054-023-04307-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/06/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND The optimal thresholds for the initiation of invasive ventilation in patients with hypoxemic respiratory failure are unknown. Using the saturation-to-inspired oxygen ratio (SF), we compared lower versus higher hypoxemia severity thresholds for initiating invasive ventilation. METHODS This target trial emulation included patients from the Medical Information Mart for Intensive Care (MIMIC-IV, 2008-2019) and the Amsterdam University Medical Centers (AmsterdamUMCdb, 2003-2016) databases admitted to intensive care and receiving inspired oxygen fraction ≥ 0.4 via non-rebreather mask, noninvasive ventilation, or high-flow nasal cannula. We compared the effect of using invasive ventilation initiation thresholds of SF < 110, < 98, and < 88 on 28-day mortality. MIMIC-IV was used for the primary analysis and AmsterdamUMCdb for the secondary analysis. We obtained posterior means and 95% credible intervals (CrI) with nonparametric Bayesian G-computation. RESULTS We studied 3,357 patients in the primary analysis. For invasive ventilation initiation thresholds SF < 110, SF < 98, and SF < 88, the predicted 28-day probabilities of invasive ventilation were 72%, 47%, and 19%. Predicted 28-day mortality was lowest with threshold SF < 110 (22.2%, CrI 19.2 to 25.0), compared to SF < 98 (absolute risk increase 1.6%, CrI 0.6 to 2.6) or SF < 88 (absolute risk increase 3.5%, CrI 1.4 to 5.4). In the secondary analysis (1,279 patients), the predicted 28-day probability of invasive ventilation was 50% for initiation threshold SF < 110, 28% for SF < 98, and 19% for SF < 88. In contrast with the primary analysis, predicted mortality was highest with threshold SF < 110 (14.6%, CrI 7.7 to 22.3), compared to SF < 98 (absolute risk decrease 0.5%, CrI 0.0 to 0.9) or SF < 88 (absolute risk decrease 1.9%, CrI 0.9 to 2.8). CONCLUSION Initiating invasive ventilation at lower hypoxemia severity will increase the rate of invasive ventilation, but this can either increase or decrease the expected mortality, with the direction of effect likely depending on baseline mortality risk and clinical context.
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Affiliation(s)
- Christopher J. Yarnell
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.231844.80000 0004 0474 0428Department of Medicine, Division of Respirology, University Health Network and Sinai Health System, Toronto, Canada ,grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada
| | - Federico Angriman
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada ,grid.413104.30000 0000 9743 1587Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Bruno L. Ferreyro
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.231844.80000 0004 0474 0428Department of Medicine, Division of Respirology, University Health Network and Sinai Health System, Toronto, Canada ,grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada
| | - Kuan Liu
- grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada
| | - Harm Jan De Grooth
- grid.12380.380000 0004 1754 9227Department of Intensive Care Medicine, Laboratory for Critical Care Computational Intelligence, Amsterdam Medical Data Science, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Lisa Burry
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.492573.e0000 0004 6477 6457Department of Pharmacy and Medicine, Sinai Health System, Toronto, Canada ,grid.17063.330000 0001 2157 2938Leslie Dan Faculty of Pharmacy and Interdepartmental Division of Critical Care, University of Toronto, Toronto, ON Canada
| | - Laveena Munshi
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.231844.80000 0004 0474 0428Department of Medicine, Division of Respirology, University Health Network and Sinai Health System, Toronto, Canada
| | - Sangeeta Mehta
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.231844.80000 0004 0474 0428Department of Medicine, Division of Respirology, University Health Network and Sinai Health System, Toronto, Canada
| | - Leo Celi
- grid.116068.80000 0001 2341 2786Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02142 USA ,grid.239395.70000 0000 9011 8547Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215 USA ,grid.38142.3c000000041936754XDepartment of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115 USA
| | - Paul Elbers
- grid.12380.380000 0004 1754 9227Department of Intensive Care Medicine, Laboratory for Critical Care Computational Intelligence, Amsterdam Medical Data Science, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Patrick Thoral
- grid.12380.380000 0004 1754 9227Department of Intensive Care Medicine, Laboratory for Critical Care Computational Intelligence, Amsterdam Medical Data Science, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Laurent Brochard
- grid.415502.7Keenan Research Centre for Biomedical Research, Li Ka Shing Knowledge Institute, St Michael’s Hospital, Unity Health Toronto, Toronto, Canada ,grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada
| | - Hannah Wunsch
- grid.418647.80000 0000 8849 1617Institute for Clinical Evaluative Sciences, Toronto, Canada ,grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada ,grid.413104.30000 0000 9743 1587Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Robert A. Fowler
- grid.17063.330000 0001 2157 2938Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada ,grid.17063.330000 0001 2157 2938Department of Medicine, University of Toronto, Toronto, Canada ,grid.418647.80000 0000 8849 1617Institute for Clinical Evaluative Sciences, Toronto, Canada ,grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada ,grid.413104.30000 0000 9743 1587Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Lillian Sung
- grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada ,grid.42327.300000 0004 0473 9646Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, Canada
| | - George Tomlinson
- grid.231844.80000 0004 0474 0428Department of Medicine, University Health Network and Sinai Health System, Toronto, Canada ,grid.17063.330000 0001 2157 2938Institute of Health Policy, Management and Evaluation, University of Toronto, Medical-Surgical ICU, 10th floor, 585 University Avenue, Toronto, ON M5G 1X5 Canada
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5
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Reyes LF, Garcia-Gallo E, Pinedo J, Saenz-Valcarcel M, Celi L, Rodriguez A, Waterer G. Scores to Predict Long-term Mortality in Patients With Severe Pneumonia Still Lacking. Clin Infect Dis 2021; 72:e442-e443. [PMID: 32770177 DOI: 10.1093/cid/ciaa1140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Luis Felipe Reyes
- Universidad de La Sabana, Chía, Colombia.,Clínica Universidad de La Sabana, Chía, Colombia
| | | | | | | | - Leo Celi
- Laboratory of Computational Physiology, Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts, USA.,Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Alejandro Rodriguez
- Hospital Universitari Joan XXIII, Critical Care Medicine, Rovira and Virgili University, and CIBERES (Biomedical Research Network of Respiratory Disease), Tarragona, Spain
| | - Grant Waterer
- Royal Perth Bentley Hospital Group, University of Western Australia, Perth, Australia
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6
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Peine A, Hallawa A, Bickenbach J, Dartmann G, Fazlic LB, Schmeink A, Ascheid G, Thiemermann C, Schuppert A, Kindle R, Celi L, Marx G, Martin L. Development and validation of a reinforcement learning algorithm to dynamically optimize mechanical ventilation in critical care. NPJ Digit Med 2021; 4:32. [PMID: 33608661 PMCID: PMC7895944 DOI: 10.1038/s41746-021-00388-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 01/11/2021] [Indexed: 01/18/2023] Open
Abstract
The aim of this work was to develop and evaluate the reinforcement learning algorithm VentAI, which is able to suggest a dynamically optimized mechanical ventilation regime for critically-ill patients. We built, validated and tested its performance on 11,943 events of volume-controlled mechanical ventilation derived from 61,532 distinct ICU admissions and tested it on an independent, secondary dataset (200,859 ICU stays; 25,086 mechanical ventilation events). A patient “data fingerprint” of 44 features was extracted as multidimensional time series in 4-hour time steps. We used a Markov decision process, including a reward system and a Q-learning approach, to find the optimized settings for positive end-expiratory pressure (PEEP), fraction of inspired oxygen (FiO2) and ideal body weight-adjusted tidal volume (Vt). The observed outcome was in-hospital or 90-day mortality. VentAI reached a significantly increased estimated performance return of 83.3 (primary dataset) and 84.1 (secondary dataset) compared to physicians’ standard clinical care (51.1). The number of recommended action changes per mechanically ventilated patient constantly exceeded those of the clinicians. VentAI chose 202.9% more frequently ventilation regimes with lower Vt (5–7.5 mL/kg), but 50.8% less for regimes with higher Vt (7.5–10 mL/kg). VentAI recommended 29.3% more frequently PEEP levels of 5–7 cm H2O and 53.6% more frequently PEEP levels of 7–9 cmH2O. VentAI avoided high (>55%) FiO2 values (59.8% decrease), while preferring the range of 50–55% (140.3% increase). In conclusion, VentAI provides reproducible high performance by dynamically choosing an optimized, individualized ventilation strategy and thus might be of benefit for critically ill patients.
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Affiliation(s)
- Arne Peine
- Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstreet 30, Aachen, Germany
| | - Ahmed Hallawa
- Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstreet 30, Aachen, Germany.,Chair for Integrated Signal Processing Systems, RWTH Aachen University, Kopernikusstreet 16, Aachen, Germany
| | - Johannes Bickenbach
- Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstreet 30, Aachen, Germany
| | - Guido Dartmann
- Environmental Campus Birkenfeld, Trier University of Applied Sciences, Schneidershof, Trier, Germany
| | - Lejla Begic Fazlic
- Environmental Campus Birkenfeld, Trier University of Applied Sciences, Schneidershof, Trier, Germany
| | - Anke Schmeink
- Research Area Information Theory and Systematic Design of Communication Systems, RWTH Aachen University, Kopernikusstreet 16, Aachen, Germany
| | - Gerd Ascheid
- Chair for Integrated Signal Processing Systems, RWTH Aachen University, Kopernikusstreet 16, Aachen, Germany
| | - Christoph Thiemermann
- William Harvey Research Institute, Queen Mary University London, Charterhouse Square, London, United Kingdom
| | - Andreas Schuppert
- Joint Research Center for Computational Biomedicine, RWTH Aachen University, Pauwelsstreet 30, Aachen, Germany
| | - Ryan Kindle
- Laboratory for Computational Physiology, Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, USA.,Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Leo Celi
- Laboratory for Computational Physiology, Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, USA.,Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Department of Biostatistics Harvard T.H, Chan School of Public Health, Boston, MA, USA
| | - Gernot Marx
- Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstreet 30, Aachen, Germany
| | - Lukas Martin
- Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstreet 30, Aachen, Germany.
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7
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Balint R, Celi L, Barberis E, Prati M, Martin M. Organic phosphorus affects the retention of arsenite and arsenate by goethite. J Environ Qual 2020; 49:1655-1666. [PMID: 33135229 DOI: 10.1002/jeq2.20145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/08/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
The hazardous effects of arsenic are closely linked to its speciation and interaction with different soil minerals, which influence both As mobility and bioavailability. Adsorption onto iron (oxyhydr)oxides is one of the main processes controlling the partitioning of arsenite [As(III)] and arsenate [As(V)] between aqueous and solid phases. Arsenic retention can be affected by changes in soil pH and the presence of competing anions, like phosphate. Although competition with inorganic phosphorus (P) for sorption sites on mineral surfaces has been widely studied, little is known about the interactions with organic P (Po ) compounds, in particular inositol phosphates, even though they may represent a large fraction of total soil P. We quantified the effects of myo-inositol hexaphosphate (InsP6) on the adsorption and retention of As(III) and As(V) on goethite as influenced by pH, the order of anion addition, and residence time. The efficiency of InsP6 in displacing adsorbed As(III) decreased with increasing pH values and interaction time, which may be attributed to the increase in bonding strength of the As(III) complexes on the surface of goethite. Adsorption and retention of As(V) by goethite generally decreased with increasing pH, particularly in the presence of InsP6 due to the similar pKa values and the competition for the same binding sites. The addition of InsP6 before, together with, or after adsorption of As(III) and As(V) strongly reduced the amounts of sorbed As, suggesting that the addition of Po -rich matrices to As-contaminated soils may strongly enhance As mobility.
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Affiliation(s)
- R Balint
- Dep. of Agricultural, Forest and Food Sciences, Univ. of Turin, Largo Paolo Braccini 2, Grugliasco, TO, 10095, Italy
- Geological Institute of Romania, Str. Caransebes 1, Sector 1, Bucharest, 012271, Romania
| | - L Celi
- Dep. of Agricultural, Forest and Food Sciences, Univ. of Turin, Largo Paolo Braccini 2, Grugliasco, TO, 10095, Italy
| | - E Barberis
- Dep. of Agricultural, Forest and Food Sciences, Univ. of Turin, Largo Paolo Braccini 2, Grugliasco, TO, 10095, Italy
| | - M Prati
- Dep. of Agricultural, Forest and Food Sciences, Univ. of Turin, Largo Paolo Braccini 2, Grugliasco, TO, 10095, Italy
| | - M Martin
- Dep. of Agricultural, Forest and Food Sciences, Univ. of Turin, Largo Paolo Braccini 2, Grugliasco, TO, 10095, Italy
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8
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Alviar Restrepo C, Lui A, Jaramillo-Restrepo V, Celi L, Rico Mesa J, Quien M, Vargas A, Aiad N, Alabdallah K, Li B, Major V, Maselli D. Mechanical ventilation in cardiac arrest: association between hyperoxia, hypercarbia and positive end-expiratory pressure with mortality. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1854] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Optimization of mechanical ventilation (MV) in patients with cardiac arrest (CA) may help improve outcomes in these patients. We sought to investigate the association between hyperoxia, PCO2, and positive end-expiratory pressure (PEEP) with mortality in patients with CA.
Methods
Patients admitted to our medical center CICU from 2001 through 2012 (MIMIC-III database) who received MV with available information on MV parameters and had arterial blood gases sampling were included. Hyperoxia was defined as time-weighted mean of PaO2 >120 mmHg and non-hyperoxia as PaO2 ≤120 mmHg, while Hypercarbia was defined as PCO2 >35 mmHg during CICU admission. The primary outcome was in-hospital mortality. Multivariable logistic regression was used to assess the association between hyperoxia and in-hospital mortality adjusted for age, female sex, Oxford Acute Severity of Illness Score, creatinine, lactate, pH, PaO2/FiO2 ratio, PCO2, PEEP, and time spent on PEEP.
Results
Among 136 patients, PaO2 = 139±55 mmHg, PCO2 = 39±10 mmHg, and PEEP = 6.4±2.2cmH2O. Unadjusted mortality was higher in the hyperoxic group (51.4%) compared to the non-hyperoxic group (29.0%) (long rank test p=0.0034, figure). In multivariable analysis, hyperoxia was independently associated with higher in-hospital mortality (OR 4.046, 95% CI: 1.501–10.907, p=0.0057). Additionally, there was no association between the presence of hypercarbia and in-hospital mortality (OR 0.896, 95% CI: 0.319 to 2.521, p=0.836) nor when PCO2 was analyzed as a continuous variable (OR 1.063 per 1 mmHg increase in CO2, 95% CI: 0.111–10.145, p=0.957). Similarly, there was no assocation between PEEP and in-hospital mortality (OR 1.012 per 1cmH2O increase, 95% CI: 0.807 to 1.270, p=0.917). Post-hoc analysis with PaO2 as a continuous variable was consistent with the primary analysis (OR 1.214 per 10 mmHg increase in PaO2, 95% CI: 1.059–1.391, p=0.005).
Conclusions
In patients with CA, hyperoxia was associated with increased mortality, while PCO2 and PEEP levels were not. Optimal MV parameters are important in the management of patients with CA. Further research is warranted to confirm this association and explore the mechanisms behind these observations. These studies can help establish the best MV strategies for patients with CA.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- C Alviar Restrepo
- New York University Langone Medical Center, New York, United States of America
| | - A.Y Lui
- New York University School of Medicine, New York, United States of America
| | | | - L Celi
- Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, United States of America
| | - J.S Rico Mesa
- University of Texas Health Science Center, San Antonio, United States of America
| | - M Quien
- New York University Langone Medical Center, New York, United States of America
| | - A Vargas
- New York University Langone Medical Center, New York, United States of America
| | - N Aiad
- New York University Langone Medical Center, New York, United States of America
| | - K Alabdallah
- Lincoln Hospital Center, New York, United States of America
| | - B Li
- New York University Langone Medical Center, New York, United States of America
| | - V Major
- New York University Langone Medical Center, New York, United States of America
| | - D.J Maselli
- University of Texas Health Science Center, San Antonio, United States of America
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9
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Lui A, Garber L, Vincent M, Celi L, Masip J, Sionis A, Serpa Neto A, Keller N, Morrow D, Miller P, Van Diepen S, Smilowitz N, Alviar Restrepo C. Hyperoxia is associated with adverse outcomes in the cardiac intensive care unit: insights from the Medical Information Mart for Intensive Care (MIMI-III) database. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1837] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Hyperoxia produces reactive oxygen species, apoptosis, and vasoconstriction, and is associated with adverse outcomes in patients with heart failure and cardiac arrest. Our aim was to evaluate the association between hyperoxia and mortality in patients (pts) receiving positive pressure ventilation (PPV) in the cardiac intensive care unit (CICU).
Methods
Patients admitted to our medical center CICU who received any PPV (invasive or non-invasive) from 2001 through 2012 were included. Hyperoxia was defined as time-weighted mean of PaO2 >120mmHg and non-hyperoxia as PaO2 ≤120mmHg during CICU admission. Primary outcome was in-hospital mortality. Multivariable logistic regression was used to assess the association between hyperoxia and in-hospital mortality adjusted for age, female sex, Oxford Acute Severity of Illness Score, creatinine, lactate, pH, PaO2/FiO2 ratio, PCO2, PEEP, and estimated time spent on PEEP.
Results
Among 1493 patients, hyperoxia (median PaO2 147mmHg) during the CICU admission was observed in 702 (47.0%) pts. In-hospital mortality was 29.7% in the non-hyperoxia group and 33.9% in the hyperoxia group ((log rank test, p=0.0282, see figure). Using multivariable logistic regression, hyperoxia was independently associated with in-hospital mortality (OR 1.507, 95% CI 1.311–2.001, p=0.00508). Post-hoc analysis with PaO2 as a continuous variable was consistent with the primary analysis (OR 1.053 per 10mmHg increase in PaO2, 95% CI 1.024–1.082, p=0.0002).
Conclusions
In a large CICU cohort, hyperoxia was associated with increased mortality. Trials of titration of supplemental oxygen across the full spectrum of critically ill cardiac patients are warranted.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- A.Y Lui
- New York University School of Medicine, New York, United States of America
| | - L Garber
- New York University Langone Medical Center, New York, United States of America
| | - M Vincent
- New York University Langone Medical Center, New York, United States of America
| | - L Celi
- Beth Israel Deaconess Medical Center & Harvard Medical School, Critical Care Medicine, Boston, United States of America
| | - J Masip
- Hospital Sanitas CIMA, Barcelona, Spain
| | - A Sionis
- Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - A Serpa Neto
- Hospital Israelita Albert Einstein, Sao Paulo, Brazil
| | - N Keller
- New York University Langone Medical Center, New York, United States of America
| | - D.A Morrow
- Brigham and Women'S Hospital, Harvard Medical School, Boston, United States of America
| | - P.E Miller
- Yale University, New Haven, United States of America
| | | | - N.R Smilowitz
- New York University Langone Medical Center, New York, United States of America
| | - C Alviar Restrepo
- New York University Langone Medical Center, New York, United States of America
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10
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Fernández A, Beratarrechea A, Rojo M, Ridao M, Celi L. Starting the path of Digital Transformation in Health Innovation in Digital Health: Conference proceeding. Cienc Innov Salud 2020; e74:68-75. [PMID: 32656302 DOI: 10.17081/innosa.74] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Ariel Fernández
- IECS. Instituto de Efectividad Clínica Sanitaria. Buenos Aires, Argentina
| | | | - Marina Rojo
- Instituto de Salud Pública. FMED-UBA. Buenos Aires, Argentina
| | - Marina Ridao
- Instituto de Salud Pública. FMED-UBA. Buenos Aires, Argentina
| | - Leo Celi
- Massachusetts Institute of Technology. Cambridge, MA, USA
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11
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Danziger J, Ángel Armengol de la Hoz M, Li W, Komorowski M, Deliberato RO, Rush BNM, Mukamal KJ, Celi L, Badawi O. Temporal Trends in Critical Care Outcomes in U.S. Minority-Serving Hospitals. Am J Respir Crit Care Med 2020; 201:681-687. [PMID: 31948262 PMCID: PMC7263391 DOI: 10.1164/rccm.201903-0623oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 12/20/2019] [Indexed: 12/30/2022] Open
Abstract
Rationale: Whether critical care improvements over the last 10 years extend to all hospitals has not been described.Objectives: To examine the temporal trends of critical care outcomes in minority and non-minority-serving hospitals using an inception cohort of critically ill patients.Measurements and Main Results: Using the Philips Health Care electronic ICU Research Institute Database, we identified minority-serving hospitals as those with an African American or Hispanic ICU census more than twice its regional mean. We examined almost 1.1 million critical illness admissions among 208 ICUs from across the United States admitted between 2006 and 2016. Adjusted hospital mortality (primary) and length of hospitalization (secondary) were the main outcomes. Large pluralities of African American (25%, n = 27,242) and Hispanic individuals (48%, n = 26,743) were cared for in minority-serving hospitals, compared with only 5.2% (n = 42,941) of white individuals. Over the last 10 years, although the risk of critical illness mortality steadily decreased by 2% per year (95% confidence interval [CI], 0.97-0.98) in non-minority-serving hospitals, outcomes within minority-serving hospitals did not improve comparably. This disparity in temporal trends was particularly noticeable among African American individuals, where each additional calendar year was associated with a 3% (95% CI, 0.96-0.97) lower adjusted critical illness mortality within a non-minority-serving hospital, but no change within minority-serving hospitals (hazard ratio, 0.99; 95% CI, 0.97-1.01). Similarly, although ICU and hospital lengths of stay decreased by 0.08 (95% CI, -0.08 to -0.07) and 0.16 (95% CI, -0.16 to -0.15) days per additional calendar year, respectively, in non-minority-serving hospitals, there was little temporal change for African American individuals in minority-serving hospitals.Conclusions: Critically ill African American individuals are disproportionately cared for in minority-serving hospitals, which have shown significantly less improvement than non-minority-serving hospitals over the last 10 years.
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Affiliation(s)
- John Danziger
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Miguel Ángel Armengol de la Hoz
- Cardiovascular Research Center, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts
- MIT Critical Data, Laboratory for Computational Physiology, Institute for Medical Engineering and Science, Cambridge, Massachusetts
- Biomedical Engineering and Telemedicine Group, Biomedical Technology Centre CTB, ETSI Telecomunicación, Universidad Politécnica de Madrid, Madrid, Spain
| | - Wenyuan Li
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Matthieu Komorowski
- Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, United Kingdom
- Big Data Analytics Department and
- Laboratory for Critical Care Research, Critical Care Department, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Rodrigo Octávio Deliberato
- MIT Critical Data, Laboratory for Computational Physiology, Institute for Medical Engineering and Science, Cambridge, Massachusetts
- Big Data Analytics Department and
- Laboratory for Critical Care Research, Critical Care Department, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Barret N. M. Rush
- Department of Critical Care Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kenneth J. Mukamal
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Leo Celi
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- MIT Critical Data, Laboratory for Computational Physiology, Institute for Medical Engineering and Science, Cambridge, Massachusetts
| | - Omar Badawi
- Philips Healthcare, Baltimore, Maryland; and
- Department of Pharmacy Practice and Science, University of Maryland School of Pharmacy, Baltimore, Maryland
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12
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Girkar U, Uchimido R, Lehman LWH, Szolovits P, Celi L, Weng WH. Abstract 448: Predicting Blood Pressure Response to Fluid Bolus Therapy Using Neural Networks with Clinical Interpretability. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Fluid bolus therapy (FBT), the rapid infusion of fluid, has been recommended as the primary-line treatment for acute hypotensive episode (AHE) that occurs in about 41% of patients in ICU. However, previous studies have reported that approximately one-third of the acute hypotensive patients do not successfully respond to FBT treatment. Avoiding the administration of FBT that will not successfully resolve AHE might prevent an inappropriate increase of the total fluid volume administered to ICU patients, potentially reducing their risk for severe organ dysfunction and increased mortality.
Methods:
Our study utilized regression models and attention-based recurrent neural network (RNN) algorithms and two large-scale information system databases, the multi-clinical MIMIC-ICU one and the multi-center Philips eICU CRD one, to predict the successful response to FBT among hypotensive patients in ICUs. We investigated both time-aggregated modeling and time-series modeling using RNN with the attention mechanism (AM) for clinical interpretability. The successful FBT is defined by intensive care experts as the presence of the maximum mean atrial pressure (MAP) > 1.15 * average (MAP) at least once, where maximum(MAP) is the maximal MAP from the FBT starting time to two hours after FBT, and average (MAP) is the average MAP from 30 minutes before FBT until 10 minutes after FBT.
Results:
The stacked RNN with AM yielded the highest accuracy of 0.852 and area under the curve (AUC) value of 0.925 when trained and tested on the MIMIC-ICU dataset. The top features learned from regression include the patient's respiratory rate, diastolic pressure, temperature, and bicarbonate and base excess levels in blood. Preliminary results from training and testing the RNN on the Philips eICU-CRD database yielded an accuracy of 0.812 and AUC value of 0.769. We were also able to identify timesteps close to the time of FBT administration as clinically meaningful using the RNN models with AM.
Conclusion:
This is the first study that utilizes machine learning for identifying hypotensive patients in ICUs who will have sufficient blood pressure recovery after FBT. Utilizing AM and identifying the top features learned also provided clinical interpretability to the models we used.
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Affiliation(s)
- Uma Girkar
- Massachusetts Institute of Technology (MIT), Cambridge, MA
| | | | | | | | - Leo Celi
- Massachusetts Institute of Technology (MIT), Cambridge, MA
| | - Wei-Hung Weng
- Massachusetts Institute of Technology (MIT), Cambridge, MA
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13
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Fuchs L, Feng M, Novack V, Lee J, Taylor J, Scott D, Howell M, Celi L, Talmor D. The Effect of ARDS on Survival: Do Patients Die From ARDS or With ARDS? J Intensive Care Med 2017; 34:374-382. [PMID: 28681644 DOI: 10.1177/0885066617717659] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 11/17/2022]
Abstract
OBJECTIVE: To investigate the contribution of acute respiratory distress syndrome (ARDS) in of itself to mortality among ventilated patients. DESIGN AND SETTING: A longitudinal retrospective study of ventilated intensive care unit (ICU) patients. PATIENTS: The analysis included patients ventilated for more than 48 hours. Patients were classified as having ARDS on admission (early-onset ARDS), late-onset ARDS (ARDS not present during the first 24 hours of admission), or no ARDS. Primary outcomes were mortality at 28 days, and secondary outcomes were 2-year mortality rate from ICU admission. RESULTS: A total of 1411 ventilated patients were enrolled: 41% had ARDS on admission, 28.5% developed ARDS during their ICU stay, and 30.5% did not meet the ARDS criteria prior to ICU discharge or death. The non-ARDS group was used as the control. We also divided the cohort based on the severity of ARDS. After adjusting for covariates, mortality risk at 28 days was not significantly different among the different groups. Both early- and late-onset ARDS as well as the severity of ARDS were found to be significant risk factors for 2 years from ICU survival. CONCLUSION: Among patients who were ventilated on ICU admission, neither the presence, the severity, or the timing of ARDS contribute independently to the short-term mortality risk. However, acute respiratory distress syndrome does contribute significantly to 2-year mortality risk. This suggests that patients may not die acutely from ARDS itself but rather from the primary disease, and during the acute phase of ARDS, clinicians should focus on improving treatment strategies for the diseases that led to ARDS.
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Affiliation(s)
- Lior Fuchs
- 1 Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,2 Clinical Research Center, Soroka University Medical Center, Beersheba, Israel
| | - Mengling Feng
- 3 The Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA.,4 Institute for Infocomm Research, Agency for Science, Technology and Research, Singapore, Singapore
| | - Victor Novack
- 1 Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,2 Clinical Research Center, Soroka University Medical Center, Beersheba, Israel
| | - Joon Lee
- 3 The Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA.,6 School of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada
| | - Jonathan Taylor
- 7 Medical School for International Health, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Daniel Scott
- 3 The Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Michael Howell
- 5 Department of Pulmonary and Critical Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,8 Department of Medicine, University of Chicago, Chicago, USA
| | - Leo Celi
- 3 The Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA.,5 Department of Pulmonary and Critical Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Daniel Talmor
- 1 Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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14
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Vanguelova EI, Bonifacio E, De Vos B, Hoosbeek MR, Berger TW, Vesterdal L, Armolaitis K, Celi L, Dinca L, Kjønaas OJ, Pavlenda P, Pumpanen J, Püttsepp Ü, Reidy B, Simončič P, Tobin B, Zhiyanski M. Sources of errors and uncertainties in the assessment of forest soil carbon stocks at different scales-review and recommendations. Environ Monit Assess 2016; 188:630. [PMID: 27770347 DOI: 10.1007/s10661-016-5608-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 09/21/2016] [Indexed: 06/06/2023]
Abstract
Spatially explicit knowledge of recent and past soil organic carbon (SOC) stocks in forests will improve our understanding of the effect of human- and non-human-induced changes on forest C fluxes. For SOC accounting, a minimum detectable difference must be defined in order to adequately determine temporal changes and spatial differences in SOC. This requires sufficiently detailed data to predict SOC stocks at appropriate scales within the required accuracy so that only significant changes are accounted for. When designing sampling campaigns, taking into account factors influencing SOC spatial and temporal distribution (such as soil type, topography, climate and vegetation) are needed to optimise sampling depths and numbers of samples, thereby ensuring that samples accurately reflect the distribution of SOC at a site. Furthermore, the appropriate scales related to the research question need to be defined: profile, plot, forests, catchment, national or wider. Scaling up SOC stocks from point sample to landscape unit is challenging, and thus requires reliable baseline data. Knowledge of the associated uncertainties related to SOC measures at each particular scale and how to reduce them is crucial for assessing SOC stocks with the highest possible accuracy at each scale. This review identifies where potential sources of errors and uncertainties related to forest SOC stock estimation occur at five different scales-sample, profile, plot, landscape/regional and European. Recommendations are also provided on how to reduce forest SOC uncertainties and increase efficiency of SOC assessment at each scale.
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Affiliation(s)
- E I Vanguelova
- Centre for Ecosystems, Society and Biosecurity, Forest Research, Alice Holt Lodge, Farnham, GU10 4LH, UK.
| | - E Bonifacio
- DISAFA, Chimica Agraria e Pedologia, University of Torino, Via P. Braccini 2, 10095, Grugliasco, TO, Italy
| | - B De Vos
- Environment & Climate Unit, Research Institute for Nature and Forest (INBO), Gaverstraat 4, 9500, Geraardsbergen, Belgium
| | - M R Hoosbeek
- Department of Soil Quality, Wageningen University, P.O. Box 47, 6700AA, Wageningen, The Netherlands
| | - T W Berger
- Department of Forest- and Soil Sciences, Institute of Forest Ecology, University of Natural Resources and Live Sciences (BOKU), Peter Jordan-Strasse 82, 1190, Vienna, Austria
| | - L Vesterdal
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958, Frederiksberg, Denmark
| | - K Armolaitis
- Department of Ecology, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepu 1, Girionys, LT-53101 Kaunas distr, Lithuania
| | - L Celi
- DISAFA, Chimica Agraria e Pedologia, University of Torino, Via P. Braccini 2, 10095, Grugliasco, TO, Italy
| | - L Dinca
- National Institute for Research and Development in Forestry "Marin Dracea", Brasov, Romania
| | - O J Kjønaas
- Norwegian Institute of Bioeconomy Research (NIBIO), Pb 115, NO-1431, Ås, Norway
| | - P Pavlenda
- National Forest Centre - Forest Research Institute, T.G. Masaryka 22, 962 92, Zvolen, Slovakia
| | - J Pumpanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, FI-70211, Kuopio, Finland
| | - Ü Püttsepp
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51014, Tartu, Estonia
| | - B Reidy
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - P Simončič
- Forest Ecology Department, Slovenian Foresty Institute, Vecna pot 2, SI 1000, Ljubljana, Slovenia
| | - B Tobin
- UCD Forestry, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - M Zhiyanski
- Forest Research Institute - BAS 132, "Kl. Ohridski" Blvd., 1756, Sofia, Bulgaria
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15
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Byamba K, Syed-Abdul S, García-Romero M, Huang CW, Nergyi S, Nyamdorj A, Nguyen PA, Iqbal U, Paik K, Celi L, Nikore V, Somai M, Jian WS, Li YC. Mobile teledermatology for a prompter and more efficient dermatological care in rural Mongolia. Br J Dermatol 2015; 173:265-7. [PMID: 25494968 DOI: 10.1111/bjd.13607] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- K Byamba
- Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia
| | - S Syed-Abdul
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | | | - C-W Huang
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - S Nergyi
- Dermatology Center of Mongolia, Ulaanbaatar, Mongolia
| | - A Nyamdorj
- Allergymed Hospital, Ulaanbaatar, Mongolia
| | - P-A Nguyen
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - U Iqbal
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - K Paik
- Massachusetts Institute of Technology, Cambridge, MA, U.S.A
| | - L Celi
- Massachusetts Institute of Technology, Cambridge, MA, U.S.A
| | - V Nikore
- Massachusetts Institute of Technology, Cambridge, MA, U.S.A
| | - M Somai
- Department of Clinical Informatics, Harvard Medical School, Boston, MA, U.S.A
| | - W-S Jian
- School of Health Care Administration, Taipei Medical University, Taipei, Taiwan
| | - Y-C Li
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Department of Dermatology, Wan Fang Hospital, Taipei, Taiwan
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16
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Musso GE, Bottinelli E, Celi L, Magnacca G, Berlier G. Influence of surface functionalization on the hydrophilic character of mesoporous silica nanoparticles. Phys Chem Chem Phys 2015; 17:13882-94. [PMID: 25946487 DOI: 10.1039/c5cp00552c] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the synthesis and surface functionalization of MCM-41-like mesoporous silica nanoparticles (MSNs) with spheroidal shape and particle size of 141 ± 41 nm. The success of surface functionalization with aminopropyl and sodium ethylcarboxylate groups (giving amino-MSN and carboxy-MSN, respectively) was ascertained by infrared spectroscopy and ζ potential measurements. The former showed the decrease of surface silanol groups and the corresponding appearance of signals related to NH2 bending mode (δNH2) at 1595 cm(-1) and COO(-) stretching (νas and νsym) at 1562 and 1418 cm(-1). The latter showed a change in surface charge, in that the isoelectric point (IEP) changed from pH 3-4.5 to 8.5 when the MSN was functionalized with the amino groups, while carboxy-MSN showed a more negative charge in the whole pH range with respect to MSN. The hydrophilic character of the prepared materials was ascertained by quantitative microgravimetric measurements, allowing the calculation of the average isosteric adsorption heat (q[combining macron]st). This was found to be 51 ± 3 kJ mol(-1), 61 ± 4, and 65 ± 3 kJ mol(-1) for MSN, amino-MSN, and carboxy-MSN samples, respectively. The increase in q[combining macron]st after functionalization can be ascribed to the specific interaction of water molecules with the functionalizing agents, in agreement with a higher basicity with respect to silanol groups. Moreover, the possibility of multiple H-bonding interactions of water molecules with the carboxylate anion is put forward to account for the higher water uptake with respect to parent MSN.
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Affiliation(s)
- G E Musso
- Università di Torino, Dipartimento di Chimica and NIS Centre, Via P. Giuria 7, 10125 Torino, Italy.
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17
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Hameed M, Maruthappu M, Marshall D, Pimentel M, Celi L, Salciccioli J, Shalhoub J. Retrospective observational cohort study of mortality and length of stay for surgical ICU admissions. Crit Care 2015. [PMCID: PMC4473044 DOI: 10.1186/cc14599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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18
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Velasquez A, Ghassemi M, Szolovits P, Park S, Osorio J, Dejam A, Celi L. Long-term outcomes of minor troponin elevations in the intensive care unit. Anaesth Intensive Care 2014; 42:356-64. [PMID: 24794476 DOI: 10.1177/0310057x1404200313] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of our study is to determine the short-term and long-term outcomes of intensive care unit (ICU) patients with minor troponin elevations. The retrospective study compared ICU patients with peak troponin elevation less than 0.1 ng/ml to those with only negative tests during their hospital stay. Data were gathered from ICUs at Beth Israel Deaconess Medical Center between 2001 and 2008. A total of 4224 patients (2547 controls and 1677 positives) were analysed. The primary outcome was mortality at one year. Secondary outcomes were 30-day mortality and hospital and ICU lengths of stay. After adjusting for age, sex, Simplified Acute Physiology Score, Sequential Organ Failure Assessment and combined Elixhauser score, we found that minor troponin elevations (peak troponin elevation between 0.01 and 0.09 ng/ml) were associated with a higher one-year mortality (Hazard Ratio 1.22, P <0.001 for binary troponin presence; Hazard Ratio 1.03, P <0.001 for each 0.01 ng/ml troponin increment). This relationship held for the subgroup of seven-day post-discharge survivors (Hazard Ratio 1.26, P <0.001). Minor elevations of troponin also significantly increased the net reclassification index over traditional risk markers for mortality prediction (net reclassification score 0.12, P <0.001). Minor troponin elevation was also associated with 30-day mortality (odds ratio 1.33, P=0.003). Importantly, troponin testing did not increase the adjusted mortality odds (P=0.9). Minor elevations in troponin substantially increase one-year, all-cause mortality in a stepwise fashion; it was also independently associated with 30-day mortality. We propose that minor elevations in troponin should not be regarded as clinically unimportant, but rather be included as a prognostic element if measured. We recommend prospective ICU studies to assess prognostic value of routine troponin determination.
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Affiliation(s)
- A Velasquez
- Leadership Preventive Medicine and Division of Critical Care, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
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19
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Fuchs L, Lee J, Novack V, Baumfeld Y, Scott D, Celi L, Mandelbaum T, Howell M, Talmor D. Severity of acute kidney injury and two-year outcomes in critically ill patients. Chest 2014; 144:866-875. [PMID: 23681257 DOI: 10.1378/chest.12-2967] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The association between levels of acute kidney injury (AKI) during ICU admission and long-term mortality are not well defined. METHODS We examined medical records of adult patients admitted to a large tertiary medical center with no history of end-stage renal disease who survived 60 days from ICU admission between 2001 and 2007. Demographic, clinical, physiologic, and date of death data were extracted. RESULTS Among 15,048 patients, 12,399 (82.4%) survived 60 days from ICU admission and comprised the study population. AKI did not develop in 5,663 (45.7%) during ICU admission, whereas progressively severe levels of AKI as defined by Acute Kidney Injury Network (AKIN) criteria AKIN 1, AKIN 2, and AKIN 3 developed in 4,589 (37.0%), 1,613 (13.0%), and 534 (4.3%), respectively. Only 42.5% of patients with AKIN 3 survived 2 years from ICU admission. Patients with AKIN 3 had a 61% higher mortality risk 2 years from ICU discharge compared with patients in whom AKI did not develop. Patients with AKIN 1 and AKIN 2 had similar increased mortality risk 2 years from ICU admission (hazard ratio, 1.26 and 1.28, respectively). The level of estimated glomerular filtration rate on ICU discharge and chronic kidney disease were associated with long-term mortality. CONCLUSIONS Patients in whom AKI develops during ICU admission have significantly increased risks of death that extend beyond their high ICU mortality rates. These increased risks of death continue for at least 2 years after the index ICU admission.
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Affiliation(s)
- Lior Fuchs
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
| | - Joon Lee
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA; School of Public Health and Health Systems, University of Waterloo, Waterloo, ON, Canada
| | - Victor Novack
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; Clinical Research Center, Soroka University Medical Center, Beer-Sheva, Israel
| | - Yael Baumfeld
- Clinical Research Center, Soroka University Medical Center, Beer-Sheva, Israel
| | - Daniel Scott
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA
| | - Leo Celi
- Department of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA
| | - Tal Mandelbaum
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Michael Howell
- Department of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Daniel Talmor
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
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Fuchs L, Chronaki CE, Park S, Novack V, Baumfeld Y, Scott D, McLennan S, Talmor D, Celi L. ICU admission characteristics and mortality rates among elderly and very elderly patients. Intensive Care Med 2012; 38:1654-61. [PMID: 22797350 DOI: 10.1007/s00134-012-2629-6] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 06/13/2012] [Indexed: 12/14/2022]
Abstract
PURPOSE The effect of advanced age per se versus severity of chronic and acute diseases on the short- and long-term survival of older patients admitted to the intensive care unit (ICU) remains unclear. METHODS Intensive care unit admissions to the surgical ICU and medical ICU of patients older than 65 years were analyzed. Patients were divided into three age groups: 65-74, 75-84, and 85 and above. The primary endpoints were 28-day and 1-year mortality. RESULTS The analysis focused on 7,265 patients above the age of 65, representing 45.7 % of the total ICU population. From the first to third age group there was increased prevalence of heart failure (25.9-40.3 %), cardiac arrhythmia (24.6-43.5 %), and valvular heart disease (7.5-15.8 %). There was reduced prevalence of diabetes complications (7.5-2.4 %), alcohol abuse (4.1-0.6 %), chronic obstructive pulmonary disease (COPD) (24.4-17.4 %), and liver failure (5.0-1.0 %). Logistic regression analysis adjusted for gender, sequential organ failure assessment, do not resuscitate, and Elixhauser score found that patients from the second and third age group had odds ratios of 1.38 [95 % confidence interval (CI) 1.19-1.59] and 1.53 (95 % CI 1.29-1.81) for 28-day mortality as compared with the first age group. Cox regression analysis for 1-year mortality in all populations and in 28-day survivors showed the same trend. CONCLUSIONS The proportion of elderly patients from the total ICU population is high. With advancing age, the proportion of various preexisting comorbidities and the primary reason for ICU admission change. Advanced age should be regarded as a significant independent risk factor for mortality, especially for ICU patients older than 75.
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Affiliation(s)
- Lior Fuchs
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, 1 Deaconess Rd. CC-470, Boston, MA 02215, USA.
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Fialho A, Cismondi F, Vieira S, Reti S, Celi L, Howell M, Sousa J, Finkelstein S. Customized modeling to predict the use of vasopressors in ICUs. Crit Care 2012. [PMCID: PMC3363683 DOI: 10.1186/cc10872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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22
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Costa CM, Gondim DD, Gondim DD, Soares HB, Ribeiro AGCD, Silva I, Winkler E, Celi L, Guerreiro AMG, Leite CRM. S2DIA: a diagnostic system for Diabetes mellitus using SANA platform. Annu Int Conf IEEE Eng Med Biol Soc 2012; 2012:6078-6081. [PMID: 23367315 PMCID: PMC5679197 DOI: 10.1109/embc.2012.6347380] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Currently, Diabetes is a very common disease around the world, and with an increase in sedentary lifestyles, obesity and an aging population the number of people with Diabetes worldwide will increase by more than 50%. In this context, the MIT (Massachusetts Institute of Technology) developed the SANA platform, which brings the benefits of information technology to the field of healthcare. It offers healthcare delivery in remote areas, improves patient access to medical specialists for faster, higher quality, and more cost effective diagnosis and intervention. For these reasons, we developed a system for diagnosis of Diabetes using the SANA platform, called S2DIA. It is the first step towards knowing the risks for type 2 Diabetes, and it will be evaluated, especially, in remote/poor areas of Brazil.
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Affiliation(s)
- Clayton M Costa
- Laboratory of software engineering of the Universidade do Estado do Rio Grande do Norte (UERN) Mossoro, RN, Brazil.
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23
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Peebles KC, Richards AM, Celi L, McGrattan K, Murrell CJ, Ainslie PN. Human cerebral arteriovenous vasoactive exchange during alterations in arterial blood gases. J Appl Physiol (1985) 2008; 105:1060-8. [DOI: 10.1152/japplphysiol.90613.2008] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cerebral blood flow (CBF) is highly regulated by changes in arterial Pco2and arterial Po2. Evidence from animal studies indicates that various vasoactive factors, including release of norepinephrine, endothelin, adrenomedullin, C-natriuretic peptide (CNP), and nitric oxide (NO), may play a role in arterial blood gas-induced alterations in CBF. For the first time, we directly quantified exchange of these vasoactive factors across the human brain. Using the Fick principle and transcranial Doppler ultrasonography, we measured CBF in 12 healthy humans at rest and during hypercapnia (4 and 8% CO2), hypocapnia (voluntary hyperventilation), and hypoxia (12 and 10% O2). At each level, blood was sampled simultaneously from the internal jugular vein and radial artery. With the exception of CNP and NO, the simultaneous quantification of norepinephrine, endothelin, or adrenomedullin showed no cerebral uptake or release during changes in arterial blood gases. Hypercapnia, but not hypocapnia, increased CBF and caused a net cerebral release of nitrite (a marker of NO), which was reflected by an increase in the venous-arterial difference for nitrite: 57 ± 18 and 150 ± 36 μmol/l at 4% and 8% CO2, respectively (both P < 0.05). Release of cerebral CNP was also observed during changes in CO2(hypercapnia vs. hypocapnia, P < 0.05). During hypoxia, there was a net cerebral uptake of nitrite, which was reflected by a decreased venous-arterial difference for nitrite: −96 ± 14 μmol/l at 10% O2( P < 0.05). These data indicate that there is a differential exchange of NO across the brain during hypercapnia and hypoxia and that CNP may play a complementary role in CO2-induced CBF changes.
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Ainslie PN, Celi L, McGrattan K, Peebles K, Ogoh S. Dynamic cerebral autoregulation and baroreflex sensitivity during modest and severe step changes in arterial PCO2. Brain Res 2008; 1230:115-24. [DOI: 10.1016/j.brainres.2008.07.048] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 07/10/2008] [Accepted: 07/11/2008] [Indexed: 11/29/2022]
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25
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Ainslie PN, Ogoh S, Burgess K, Celi L, McGrattan K, Peebles K, Murrell C, Subedi P, Burgess KR. Differential effects of acute hypoxia and high altitude on cerebral blood flow velocity and dynamic cerebral autoregulation: alterations with hyperoxia. J Appl Physiol (1985) 2007; 104:490-8. [PMID: 18048592 DOI: 10.1152/japplphysiol.00778.2007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We hypothesized that 1) acute severe hypoxia, but not hyperoxia, at sea level would impair dynamic cerebral autoregulation (CA); 2) impairment in CA at high altitude (HA) would be partly restored with hyperoxia; and 3) hyperoxia at HA and would have more influence on blood pressure (BP) and less influence on middle cerebral artery blood flow velocity (MCAv). In healthy volunteers, BP and MCAv were measured continuously during normoxia and in acute hypoxia (inspired O2 fraction = 0.12 and 0.10, respectively; n = 10) or hyperoxia (inspired O2 fraction, 1.0; n = 12). Dynamic CA was assessed using transfer-function gain, phase, and coherence between mean BP and MCAv. Arterial blood gases were also obtained. In matched volunteers, the same variables were measured during air breathing and hyperoxia at low altitude (LA; 1,400 m) and after 1-2 days after arrival at HA ( approximately 5,400 m, n = 10). In acute hypoxia and hyperoxia, BP was unchanged whereas it was decreased during hyperoxia at HA (-11 +/- 4%; P < 0.05 vs. LA). MCAv was unchanged during acute hypoxia and at HA; however, acute hyperoxia caused MCAv to fall to a greater extent than at HA (-12 +/- 3 vs. -5 +/- 4%, respectively; P < 0.05). Whereas CA was unchanged in hyperoxia, gain in the low-frequency range was reduced during acute hypoxia, indicating improvement in CA. In contrast, HA was associated with elevations in transfer-function gain in the very low- and low-frequency range, indicating CA impairment; hyperoxia lowered these elevations by approximately 50% (P < 0.05). Findings indicate that hyperoxia at HA can partially improve CA and lower BP, with little effect on MCAv.
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26
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Peebles K, Celi L, McGrattan K, Murrell C, Thomas K, Ainslie PN. Human cerebrovascular and ventilatory CO2 reactivity to end-tidal, arterial and internal jugular vein PCO2. J Physiol 2007; 584:347-57. [PMID: 17690148 PMCID: PMC2277051 DOI: 10.1113/jphysiol.2007.137075] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This study examined cerebrovascular reactivity and ventilation during step changes in CO(2) in humans. We hypothesized that: (1) end-tidal P(CO(2)) (P(ET,CO(2))) would overestimate arterial P(CO(2)) (P(a,CO(2))) during step variations in P(ET,CO(2)) and thus underestimate cerebrovascular CO(2) reactivity; and (2) since P(CO(2)) from the internal jugular vein (P(jv,CO(2))) better represents brain tissue P(CO(2)), cerebrovascular CO(2) reactivity would be higher when expressed against P(jv,CO(2)) than with P(a,CO(2)), and would be related to the degree of ventilatory change during hypercapnia. Incremental hypercapnia was achieved through 4 min administrations of 4% and 8% CO(2). Incremental hypocapnia involved two 4 min steps of hyperventilation to change P(ET,CO(2)), in an equal and opposite direction, to that incurred during hypercapnia. Arterial and internal jugular venous blood was sampled simultaneously at baseline and during each CO(2) step. Cerebrovascular reactivity to CO(2) was expressed as the percentage change in blood flow velocity in the middle cerebral artery (MCAv) per mmHg change in P(a,CO(2)) and P(jv,CO(2)). During hypercapnia, but not hypocapnia, P(ET,CO(2)) overestimated P(a,CO(2)) by +2.4 +/- 3.4 mmHg and underestimated MCAv-CO(2) reactivity (P < 0.05). The hypercapnic and hypocapnic MCAv-CO(2) reactivity was higher ( approximately 97% and approximately 24%, respectively) when expressed with P(jv,CO(2)) than P(a,CO(2)) (P < 0.05). The hypercapnic MCAv-P(jv,CO(2)) reactivity was inversely related to the increase in ventilatory change (R(2) = 0.43; P < 0.05), indicating that a reduced reactivity results in less central CO(2) washout and greater ventilatory stimulus. Differences in the P(ET,CO(2)), P(a,CO(2)) and P(jv,CO(2))-MCAv relationships have implications for the true representation and physiological interpretation of cerebrovascular CO(2) reactivity.
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Affiliation(s)
- Karen Peebles
- Department of Physiology, University of Otago, Dunedin, New Zealand
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27
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Wu G, Sijnja B, Celi L, Wright P, Van Rij A. Patient with a leg ulcer. Aust Fam Physician 2003; 32:739-40. [PMID: 14524216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Affiliation(s)
- Gary Wu
- Dunedin School of Medicine, New Zealand
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28
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Petruzzelli L, Celi L, Cignetti A, Marsan FA. Influence of soil organic matter on the leaching of polycyclic aromatic hydrocarbons in soil. J Environ Sci Health B 2002; 37:187-199. [PMID: 12009190 DOI: 10.1081/pfc-120003097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are one of the main classes of contaminants in the terrestrial environment. Aside from total organic carbon, the ratio among the different organic matter fractions [dissolved organic matter, fulvic acid (FA), humic acid (HA) and humin] can also affect the mobility of these hydrocarbons in soils. In this study the effect of the whole organic carbon pool has been compared with that of HA and FA on the translocation of four PAHs (biphenyl, fluorene, phenanthrene and pyrene) in soil columns. Oxidized and untreated soil columns with and without HA or FA, were prepared, spilled with hydrocarbons and leached with a 0.01 M CaCl2 solution. The influence of HA and FA on PAH translocation was investigated through determinations of the PAH contents and total organic carbon (TOC) in the layers of the columns. All molecules were moved vertically by the percolating solutions, their concentrations decreasing with depths. The nonoxidized soil tended to retain more PAHs (96%) than the oxidized one (60%), confirming that organic matter plays an important role in controlling PAH leaching. The whole organic matter pool reduced the translocation of pollutants downward the profile. The addition of HA enhanced this behaviour by increasing the PAH retention in the top layers (7.55 mg and 4.00 mg in the top two layers, respectively) while FA increased their mobility (only 2.30 and 2.90 mg of PAHs were found in the top layers) and favoured leaching. In fact, in the presence of HA alone, the higher amounts of PAHs retained at the surface and the good correlation (r2=0.936) between TOC and hydrocarbon distribution can be attributed to a parallel distribution of PAHs and HA, while in the presence of FA, the higher mobility of PAHs can be attributed to the high mobility of the humic material, as expected by its extensive hydrophilic characteristics.
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Affiliation(s)
- L Petruzzelli
- Dipartimento di Valorizzazione e Protezione delle Risorse Agroforestali, Torino, Italy.
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Bergelson JM, Krithivas A, Celi L, Droguett G, Horwitz MS, Wickham T, Crowell RL, Finberg RW. The murine CAR homolog is a receptor for coxsackie B viruses and adenoviruses. J Virol 1998; 72:415-9. [PMID: 9420240 PMCID: PMC109389 DOI: 10.1128/jvi.72.1.415-419.1998] [Citation(s) in RCA: 273] [Impact Index Per Article: 10.5] [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: 02/05/2023] Open
Abstract
Complementary DNA clones encoding the murine homolog (mCAR) of the human coxsackievirus and adenovirus receptor (CAR) were isolated. Nonpermissive CHO cells transfected with mCAR cDNA became susceptible to infection by coxsackieviruses B3 and B4 and showed increased susceptibility to adenovirus-mediated gene transfer. These results indicate that the same receptor is responsible for virus interactions with both murine and human cells. Analysis of receptor expression in human and murine tissues should be useful in defining factors governing virus tropism in vivo.
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Affiliation(s)
- J M Bergelson
- Division of Infectious Diseases, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
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Abstract
A microbial mixed culture able to grow on fluazifop-butyl and fluazifop was isolated. Fluazifop degradation by this microbial population was studied either when the herbicide was applied as the sole carbon source or in the presence of a second carbon source (sodium acetate or sodium propionate). The degradation rate was enhanced by sodium propionate. The degradation was found to be stereoselective. The S-enantiomer of fluazifop was degraded at a much higher rate than the R-enantiomer. Fluazifop disappearance was accompanied by formation of three metabolites which were identified by UV, IR, MS and NMR analyses. The metabolites were shown to be: 4-(5-trifluoromethyl-2-pyridyl)oxyphenol, 5-trifluoromethyl-2- hydroxypyridine and 2-(5-trifluoro-methyl pyridyl)hydroxy acetate.
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Affiliation(s)
- M Nègre
- Dipartimento di Valorizzazione e Protezione delle, Risorse Agroforestali Università di Torino, Italy
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