1
|
Rossignol P, Silva-Cardoso J, Kosiborod MN, Brandenburg, Cleland JG, Hadimeri H, Hullin R, Makela S, Mörtl D, Paoletti E, Pollock C, Vogt L, Jadoul M, Butler J. Pragmatic Diagnostic and Therapeutic Algorithms to Optimize New Potassium Binder use in Cardiorenal Disease. Pharmacol Res 2022; 182:106277. [PMID: 35662631 DOI: 10.1016/j.phrs.2022.106277] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/16/2022] [Accepted: 05/22/2022] [Indexed: 10/18/2022]
Abstract
BACKGROUND Pivotal randomized trials demonstrating efficacy, safety and good tolerance, of two new potassium binders (patiromer and sodium zirconium cyclosilicate) led to their recent approval. A major hurdle to the implementation of these potassium-binders is understanding how to integrate them safely and effectively into the long-term management of cardiovascular and kidney disease patients using renin angiotensin aldosterone system inhibitors (RAASi), the latter being prone to induce hyperkalaemia. METHODS a multidisciplinary academic panel including nephrologists and cardiologists was convened to develop consensus therapeutic algorithm(s) aimed at optimizing the use of the two novel potassium binders (patiromer and sodium zirconium cyclosilicate) in stable adults who require treatment with RAASi and experience(d) hyperkalaemia in a non-emergent setting. RESULTS Two dedicated pragmatic algorithms are proposed. The lowest intervention threshold (i.e. 5.1mmol/L or greater) was the one used in the patiromer and sodium zirconium cyclosilicate) pivotal trials, both drugs being indicated to treat hyperkalaemia in a non -emergent setting. Acknowledging the heterogeneity across specialty guidelines in hyperkalaemia definition and thresholds to intervene when facing hyperkalaemia, we have been mindful to use soft language i.e. "it is to consider", not necessarily "to do". CONCLUSIONS Providing the clinical community with pragmatic algorithms may help optimize the management of high-risk patients by avoiding the risks of both hyper and hypokalaemia and of suboptimal RAASi therapy.
Collapse
Affiliation(s)
- P Rossignol
- Université de Lorraine, INSERM CIC Plurithématique 1433, Nancy CHRU, Inserm U1116, FCRIN INI-CRCT, Nancy, France.
| | - J Silva-Cardoso
- Heart Failure and Transplant Clinic, Cardiology Service, São João University Hospital Centre, Faculty of Medicine, University of Porto, CINTESIS - Centre for Health Technology and Services Research, Porto, Portugal
| | - M N Kosiborod
- Saint Luke's Mid America Heart Institute and University of Missouri-Kansas City, Kansas City, Missouri; The George Institute for Global Health, and University of New South Wales, Sydney, New South Wales, Australia
| | - Brandenburg
- Department of Cardiology and Nephrology, Rhein-Maas Klinikum, Würselen, Germany
| | - J G Cleland
- Robertson Centre for Biostatistics & Clinical Trials, University of Glasgow & National Heart & Lung Institute, Imperial College, London, United Kingdom
| | - H Hadimeri
- Department of Nephrology, Skaraborgs sjukhus, Skövde, Sweden
| | - R Hullin
- Service de Cardiologie, Département Coeur-Vaisseaux, Centre Hospitalier Universitaire Vaudois, Université de Lausanne, Lausanne, Suisse
| | - S Makela
- Department of Internal Medicine, Kidney Unit, Tampere University Hospital, Tampere, Finland
| | - D Mörtl
- Department of Internal Medicine 3, University Hospital St. Pölten, St. Pölten, Austria
| | - E Paoletti
- Nephrology, Dialysis, and Transplantation, Policlinico San Martino, Genova, Italy
| | - C Pollock
- Renal Research Laboratory, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia
| | - L Vogt
- Department of Internal Medicine, section Nephrology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - M Jadoul
- Division of Nephrology, Cliniques universitaires Saint-Luc, Brussels, Belgium;; Institut de Recherche Expérimentale et Clinique, UCLouvain, Brussels, Belgium
| | - J Butler
- Department of Medicine, University of Mississippi, Jackson, Mississippi, USA
| |
Collapse
|
2
|
McGree JM, Hockham C, Kotwal S, Wilcox A, Bassi A, Pollock C, Burrell LM, Snelling T, Jha V, Jardine M, Jones M. Controlled evaLuation of Angiotensin Receptor Blockers for COVID-19 respIraTorY disease (CLARITY): statistical analysis plan for a randomised controlled Bayesian adaptive sample size trial. Trials 2022; 23:361. [PMID: 35477480 PMCID: PMC9044378 DOI: 10.1186/s13063-022-06167-2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 03/10/2022] [Indexed: 11/10/2022] Open
Abstract
The CLARITY trial (Controlled evaLuation of Angiotensin Receptor Blockers for COVID-19 respIraTorY disease) is a two-arm, multi-centre, randomised controlled trial being run in India and Australia that investigates the effectiveness of angiotensin receptor blockers in addition to standard care compared to placebo (in Indian sites) with standard care in reducing the duration and severity of lung failure in patients with COVID-19. The trial was designed as a Bayesian adaptive sample size trial with regular planned analyses where pre-specified decision rules will be assessed to determine whether the trial should be stopped due to sufficient evidence of treatment effectiveness or futility. Here, we describe the statistical analysis plan for the trial and define the pre-specified decision rules, including those that could lead to the trial being halted. The primary outcome is clinical status on a 7-point ordinal scale adapted from the WHO Clinical Progression scale assessed at day 14. The primary analysis will follow the intention-to-treat principle. A Bayesian adaptive trial design was selected because there is considerable uncertainty about the extent of potential benefit of this treatment. Trial registration ClinicalTrials.gov NCT04394117. Registered on 19 May 2020Clinical Trial Registry of India CTRI/2020/07/026831 Version and revisions Version 1.0. No revisions.
Collapse
Affiliation(s)
- J M McGree
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia.
| | - C Hockham
- The George Institute for Global Health, University of New South Wales, Sydney, Australia.,The George Institute for Global Health, Imperial College London, London, UK
| | - S Kotwal
- The George Institute for Global Health, University of New South Wales, Sydney, Australia.,Prince of Wales Hospital, Sydney, Australia
| | - A Wilcox
- The George Institute for Global Health, University of New South Wales, Sydney, Australia.,NHMRC Clinical Trials Centre, The University of Sydney, Sydney, Australia
| | - A Bassi
- The George Institute for Global Health, New Delhi, India
| | - C Pollock
- Royal North Shore Hospital, Sydney, Australia.,Kolling Institute of Medical Research, The University of Sydney, Sydney, Australia
| | - L M Burrell
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - T Snelling
- Sydney School of Public Health, The University of Sydney, Sydney, Australia.,The Sydney Children's Hospitals Network, Westmead, Australia
| | - V Jha
- The George Institute for Global Health, University of New South Wales, Sydney, Australia.,The George Institute for Global Health, New Delhi, India
| | - M Jardine
- The George Institute for Global Health, University of New South Wales, Sydney, Australia.,NHMRC Clinical Trials Centre, The University of Sydney, Sydney, Australia.,Concord Repatriation General Hospital, Sydney, Australia
| | - M Jones
- Sydney School of Public Health, The University of Sydney, Sydney, Australia
| | | |
Collapse
|
3
|
Walker L, Constant J, Pollock C, Evans D, Jones A. An evaluation of a neuro out-patient physiotherapy service: Are we helping our patients to self-manage? Physiotherapy 2022. [DOI: 10.1016/j.physio.2021.12.318] [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: 11/25/2022]
|
4
|
Neuen BL, Oshima M, Perkovic V, Arnott C, Bakris G, Cannon CP, Charytan DM, Jardine M, Levin A, Neal B, Pollock C, Wheeler DC, Mahaffey KW, Heerspink HJL. Effects of canagliflozin on hyperkalaemia and serum potassium in people with diabetes and chronic kidney disease: insights from the CREDENCE trial. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.2647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Hyperkalaemia is a common complication of type 2 diabetes mellitus (T2DM) and limits the optimal use of agents that block the renin-angiotensin aldosterone system (RAAS), particularly in patients with chronic kidney disease (CKD). In patients with CKD, sodium glucose cotransporter 2 (SGLT2) inhibitors provide cardiorenal protection, but whether they affect the risk of hyperkalaemia remains uncertain.
Purpose
We sought to assess the effect of canagliflozin on hyperkalaemia and other potassium-related outcomes in people with T2DM and CKD by conducting a post-hoc analysis of the CREDENCE trial.
Methods
The CREDENCE trial randomized 4401 participants with T2DM and CKD to the SGLT2 inhibitor canagliflozin or matching placebo. In this post-hoc analysis using an intention-to-treat approach, we assessed the effect of canagliflozin on a composite outcome of time to either investigator-reported hyperkalaemia or the initiation of potassium binders. We also analysed effects on central laboratory-determined hyper- and hypokalaemia (serum potassium ≥6.0 and <3.5 mmol/L, respectively) and change in serum potassium.
Results
At baseline the mean serum potassium in canagliflozin and placebo arms was 4.5 mmol/L; 4395 (99.9%) participants were receiving renin angiotensin system blockade. Canagliflozin reduced the risk of investigator-reported hyperkalaemia or initiation of potassium binders (HR 0.78, 95% CI 0.64–0.95, p=0.014; Figure 1). The incidence of laboratory-determined hyperkalaemia was similarly reduced (HR 0.77, 95% CI 0.61–0.98, p=0.031; Figure 2); the risk of hypokalaemia (HR 0.92, 95% CI 0.71–1.20, p=0.53) was not increased. Mean serum potassium over time with canagliflozin was similar to that of placebo.
Conclusion
Among patients treated with RAAS inhibitors, SGLT2 inhibition with canagliflozin may reduce the risk of hyperkalaemia in people with T2DM and CKD without increasing the risk of hypokalaemia.
Funding Acknowledgement
Type of funding sources: None. Figure 1Figure 2
Collapse
Affiliation(s)
- B L Neuen
- The George Institute for Global Health, Sydney, Australia
| | - M Oshima
- The George Institute for Global Health, Sydney, Australia
| | - V Perkovic
- University of New South Wales Sydney, Sydney, Australia
| | - C Arnott
- The George Institute for Global Health, Sydney, Australia
| | - G Bakris
- University of Chicago Medicine, Chicago, United States of America
| | - C P Cannon
- Harvard Medical School, Boston, United States of America
| | - D M Charytan
- New York University Langone Medical Center, New York, United States of America
| | - M Jardine
- University of Sydney, Sydney, Australia
| | - A Levin
- University of British Columbia, Vancouver, Canada
| | - B Neal
- The George Institute for Global Health, Sydney, Australia
| | - C Pollock
- University of Sydney, Sydney, Australia
| | - D C Wheeler
- University College London, London, United Kingdom
| | - K W Mahaffey
- Stanford University Medical Center, Stanford, United States of America
| | - H J L Heerspink
- University Medical Center Groningen, Groningen, Netherlands (The)
| |
Collapse
|
5
|
ARNOLD M, Garcia Sanchez J, Carrero J, James G, Heerspink H, Abdul Sultan A, Lam C, Chen T, Nolan S, Pollock C, Pecoits-Filho R. POS-327 THE COST OF END OF LIFE INPATIENT ENCOUNTERS IN PATIENTS WITH CHRONIC KIDNEY DISEASE IN THE UNITED STATES. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.343] [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: 10/21/2022] Open
|
6
|
GARCIA SANCHEZ J, Carrero J, Arnold M, Heerspink H, James G, Lam C, Abdul Sultan A, Pollock C, Chen T, Nolan S, Pecoits-Filho R. POS-319 EMERGENCY AND CRITICAL HEALTHCARE RESOURCE UTILISATION OF PATIENTS WITH CHRONIC KIDNEY DISEASE ACCORDING TO SEVERITY OF ALBUMINURIA: A REPORT FROM THE DISCOVER CKD RETROSPECTIVE COHORT. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.335] [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: 11/15/2022] Open
|
7
|
JAMES G, Carrero J, Kumar S, Fishbane S, Wittbrodt E, Kanda E, Hedman K, Kashihara N, Kosiborod M, Lainscak M, Lam C, Pollock C, Stenvinkel P, Wheeler D, Pecoits-Filho R. POS-328 THE BURDEN OF HYPERKALEMIA IN PATIENTS WITH CHRONIC KIDNEY DISEASE: A REPORT FROM THE DISCOVER CKD RETROSPECTIVE COHORT. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.344] [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: 11/17/2022] Open
|
8
|
JAMES G, Carrero J, Kumar S, Fishbane S, Wittbrodt E, Kanda E, Hedman K, Kashihara N, Kosiborod M, Lainscak M, Lam C, Pollock C, Stenvinkel P, Wheeler D, Pecoits-Filho R. POS-329 TREATMENT PATTERNS IN CHRONIC KIDNEY DISEASE PATIENTS WITH HYPERKALEMIA: A REPORT FROM THE DISCOVER CKD RETROSPECTIVE COHORT. Kidney Int Rep 2021. [DOI: 10.1016/j.ekir.2021.03.345] [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: 10/21/2022] Open
|
9
|
Mahaffey K, Li J, Chang T, Sarraju A, Agarwal R, Charytan D, Greene T, Heerspink H, Levin A, Neal B, Pollock C, Yavin Y, Jardine M, Perkovic V, Cannon C. Independent predictors of heart failure in patients with type 2 diabetes and chronic kidney disease: modeling from the CREDENCE trial. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1175] [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: 11/12/2022] Open
Abstract
Abstract
Background
SGLT2 inhibitors have been shown to reduce hospitalization for heart failure (HHF). We sought to determine independent baseline predictors for HHF specifically in a population with type 2 diabetes and chronic kidney disease (CKD).
Methods
CREDENCE randomized 4401 participants with type 2 diabetes and CKD to canagliflozin 100 mg versus placebo. We evaluated the baseline clinical and demographic factors using multivariate regression modeling to identify the independent predictors of HHF.
Results
Overall, 230 participants (89 canagliflozin; 141 placebo) had at least 1 HHF event. Canagliflozin reduced the incidence of HHF compared with placebo (4.0% vs 6.4%; HR 0.61; 95% CI 0.47–0.80). Participants with HHF events postrandomization were older (65.8 vs 62.9 y), and had a longer duration of diabetes (17.4 vs 15.7 y), higher prevalence of prior HF (30.4% vs 14.0%), higher urinary albumin:creatinine ratio (1347 vs 904 mg/g), lower estimated glomerular filtration rate (51.5 vs 56.4 mL/min/1.73m2), and higher prevalence of prior cardiovascular disease (65.7% vs 49.6%) compared to those without HHF. Independent predictors of HHF are shown in the Table.
Conclusions
HHF is common in patients with type 2 diabetes and CKD. Canagliflozin reduces HHF by 39% compared with placebo. Higher urinary albumin:creatinine ratio was the most potent predictor of HHF and should be part of patient risk assessment.
Funding Acknowledgement
Type of funding source: Private company. Main funding source(s): Janssen Research & Development, LLC
Collapse
Affiliation(s)
- K.W Mahaffey
- Stanford Center for Clinical Research, Dept of Medicine, Stanford University School of Medicine, Stanford, CA, United States of America
| | - J Li
- The George Institute for Global Health, UNSW Sydney, Sydney, Australia
| | - T.I Chang
- Stanford Center for Clinical Research, Dept of Medicine, Stanford University School of Medicine, Stanford, CA, United States of America
| | - A Sarraju
- Stanford Center for Clinical Research, Dept of Medicine, Stanford University School of Medicine, Stanford, CA, United States of America
| | - R Agarwal
- Indiana University School of Medicine and VA Medical Center, Indianapolis, IN, United States of America
| | - D.M Charytan
- Nephrology Division, NYU School of Medicine and NYU Langone Medical Center, New York, NY, United States of America
| | - T Greene
- Division of Biostatistics, Department of Population Health Sciences, University of Utah, Salt Lake City, UT, United States of America
| | - H.J.L Heerspink
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands (The)
| | - A Levin
- Division of Nephrology, University of British Columbia, Vancouver, BC, Canada
| | - B Neal
- The George Institute for Global Health, UNSW Sydney, Sydney, Australia
| | - C Pollock
- Kolling Institute of Medical Research, Sydney Medical School, University of Sydney, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Y Yavin
- Janssen Research & Development, LLC, Raritan, NJ, United States of America
| | - M Jardine
- The George Institute for Global Health, UNSW Sydney, Sydney, Australia
| | - V Perkovic
- The George Institute for Global Health, UNSW Sydney, Sydney, Australia
| | - C.P Cannon
- Cardiovasular Division, Brigham & Women's Hospital and Baim Institute for Clinical Research, Boston, MA, United States of America
| |
Collapse
|
10
|
Chen LJ, Wang S, Le Contel O, Rager A, Hesse M, Drake J, Dorelli J, Ng J, Bessho N, Graham D, Wilson LB, Moore T, Giles B, Paterson W, Lavraud B, Genestreti K, Nakamura R, Khotyaintsev YV, Ergun RE, Torbert RB, Burch J, Pollock C, Russell CT, Lindqvist PA, Avanov L. Lower-Hybrid Drift Waves Driving Electron Nongyrotropic Heating and Vortical Flows in a Magnetic Reconnection Layer. Phys Rev Lett 2020; 125:025103. [PMID: 32701350 DOI: 10.1103/physrevlett.125.025103] [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] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 06/11/2020] [Indexed: 06/11/2023]
Abstract
We report measurements of lower-hybrid drift waves driving electron heating and vortical flows in an electron-scale reconnection layer under a guide field. Electrons accelerated by the electrostatic potential of the waves exhibit perpendicular and nongyrotropic heating. The vortical flows generate magnetic field perturbations comparable to the guide field magnitude. The measurements reveal a new regime of electron-wave interaction and how this interaction modifies the electron dynamics in the reconnection layer.
Collapse
Affiliation(s)
- L-J Chen
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - S Wang
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- University of Maryland, College Park, Maryland 20747, USA
| | - O Le Contel
- CNRS/Ecole Polytechnique/Sorbonne Université/Univ. Paris Sud/Observatoire de Paris, Paris F91128, France
| | - A Rager
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - M Hesse
- University of Bergen, Bergen 5020, Norway
| | - J Drake
- University of Maryland, College Park, Maryland 20747, USA
| | - J Dorelli
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - J Ng
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- University of Maryland, College Park, Maryland 20747, USA
| | - N Bessho
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- University of Maryland, College Park, Maryland 20747, USA
| | - D Graham
- Swedish Institute of Space Physics, Uppsala SE-75121, Sweden
| | - Lynn B Wilson
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - T Moore
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - B Giles
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - W Paterson
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - B Lavraud
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse (UPS), CNRS, CNES, Toulouse 31027 Cedex 4, France
| | - K Genestreti
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - R Nakamura
- Space Research Institute, Austrian Academy of Sciences, Graz A-8042, Austria
| | | | - R E Ergun
- University of Colorado, Boulder, Colorado 80305, USA
| | - R B Torbert
- University of New Hampshire, Durham, New Hampshire 03824, USA
| | - J Burch
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - C Pollock
- Denali Scientific, Healy, Alaska 99743, USA
| | - C T Russell
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - P-A Lindqvist
- KTH Royal Institute of Technology, Stockholm SE-11428, Sweden
| | - L Avanov
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- University of Maryland, College Park, Maryland 20747, USA
| |
Collapse
|
11
|
OSHIMA M, Wong M, Hara A, Toyama T, Jun M, Jardine M, Pollock C, Woodward M, Chalmers J, Perkovic V, Wada T. SUN-161 CIRCULATING AUTOANTIBODIES TO ERYTHROPOIETIN RECEPTOR AND KIDNEY DISEASE PROGRESSION IN TYPE 2 DIABETES MELLITUS: RESULTS FROM THE ADVANCE STUDIES. Kidney Int Rep 2020. [DOI: 10.1016/j.ekir.2020.02.690] [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: 11/26/2022] Open
|
12
|
Pollock C, Pardo F, Imboden M, Bishop DJ. Open loop control theory algorithms for high-speed 3D MEMS optical switches. Opt Express 2020; 28:2010-2019. [PMID: 32121900 DOI: 10.1364/oe.367554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
There is a world-wide push to create the next-generation all-optical transmission and switching technologies for exascale data centers. In this paper we focus on the switching fabrics. Many different types of 2D architectures are being explored including MEMS/waveguides and semiconductor optical amplifiers. However, these tend to suffer from high, path-dependent losses and crosstalk issues. The technologies with the best optical properties demonstrated to date in large fabrics (>100 ports) are 3D MEMS beam steering approaches. These have low average insertion losses and, equally important, a narrow loss distribution. However, 3D MEMS fabrics are generally dismissed from serious consideration for this application because of their slow switching speeds (∼few milliseconds) and high costs ($100/port). In this paper we show how novel feedforward open loop controls can solve both problems by improving MEMS switching speeds by two orders of magnitude and costs by a factor of three. With these improvements in hand, we believe 3D MEMS fabrics can become the technology of choice for data centers.
Collapse
|
13
|
Pollock C, Wheeler D, Rossing P, Sjostrom D, Stefansson B, Reyner D, Langkilde A, Heerspink H. SAT-300 EFFECTS OF DAPAGLIFLOZIN AND DAPAGLIFLOZIN PLUS SAXAGLIPTIN ON HbA1c AND ALBUMINURIA IN PATIENTS WITH TYPE 2 DIABETES AND CHRONIC KIDNEY DISEASE: PHASE II/III DELIGHT STUDY. Kidney Int Rep 2019. [DOI: 10.1016/j.ekir.2019.05.340] [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: 11/26/2022] Open
|
14
|
Dansie K, Davies C, Hawley C, Johnson D, Craig J, Chapman J, Cooper B, Pollock C, Harris D, McDonald S. SAT-022 ASSOCIATION BETWEEN PUBLICATION OF THE INITIATING DIALYSIS EARLY AND LATE (IDEAL) STUDY AND CHANGE IN DIALYSIS INITIATION PRACTICE. Kidney Int Rep 2019. [DOI: 10.1016/j.ekir.2019.05.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
15
|
Huang C, Yi H, Shi Y, Cao Q, Chen X, Pollock C. SAT-293 KCA3.1 INHIBITION ATTENUATES DIABETIC RENAL FIBROSIS THROUGH MODULATION OF MITOCHONDRIAL QUALITY CONTROL. Kidney Int Rep 2019. [DOI: 10.1016/j.ekir.2019.05.333] [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: 10/26/2022] Open
|
16
|
Pollock C, Javor J, Stange A, Barrett LK, Bishop DJ. Extreme angle, tip-tilt MEMS micromirror enabling full hemispheric, quasi-static optical coverage. Opt Express 2019; 27:15318-15326. [PMID: 31163729 DOI: 10.1364/oe.27.015318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/01/2019] [Indexed: 06/09/2023]
Abstract
Beam steering is essential for a variety of optical applications such as communication, LIDAR, and imaging. Microelectromechanical system (MEMS) mirrors are an effective method of achieving modest speeds and angular range at low cost. Typically there are a number of tradeoffs considered when designing a tip-tilt mirror, such as tilt angle and speed. For example, many mirrors are designed to scan at their resonant frequency to achieve large angles. This is effective for a scanning mode; however, this makes the device slow and ineffective as a galvo (quasi-static). Here, we present a magnetic MEMS mirror with extreme quasi-static mechanical tilt angles of ±60° (±120° optical) about two rotation axes. This micromirror enables full hemispheric optical coverage without compromising speed; settling in 4.5 ms using advanced drive techniques. This mirror will enable new applications for MEMS micromirrors previously thought impossible due to their limited angular range and speed.
Collapse
|
17
|
Phan TD, Eastwood JP, Shay MA, Drake JF, Sonnerup BUÖ, Fujimoto M, Cassak PA, Øieroset M, Burch JL, Torbert RB, Rager AC, Dorelli JC, Gershman DJ, Pollock C, Pyakurel PS, Haggerty CC, Khotyaintsev Y, Lavraud B, Saito Y, Oka M, Ergun RE, Retino A, Le Contel O, Argall MR, Giles BL, Moore TE, Wilder FD, Strangeway RJ, Russell CT, Lindqvist PA, Magnes W. Publisher Correction: Electron magnetic reconnection without ion coupling in Earth's turbulent magnetosheath. Nature 2019; 569:E9. [PMID: 31073227 DOI: 10.1038/s41586-019-1208-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Change history: In this Letter, the y-axis values in Fig. 3f should go from 4 to -8 (rather than from 4 to -4), the y-axis values in Fig. 3h should appear next to the major tick marks (rather than the minor ticks), and in Fig. 1b, the arrows at the top and bottom of the electron-scale current sheet were going in the wrong direction; these errors have been corrected online.
Collapse
Affiliation(s)
- T D Phan
- Space Sciences Laboratory, University of California, Berkeley, CA, USA.
| | - J P Eastwood
- The Blackett Laboratory, Imperial College London, London, UK
| | - M A Shay
- University of Delaware, Newark, DE, USA
| | - J F Drake
- University of Maryland, College Park, MD, USA
| | | | | | - P A Cassak
- West Virginia University, Morgantown, WV, USA
| | - M Øieroset
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - J L Burch
- Southwest Research Institute, San Antonio, TX, USA
| | - R B Torbert
- University of New Hampshire, Durham, NH, USA
| | - A C Rager
- Catholic University of America, Washington, DC, USA.,NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J C Dorelli
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - D J Gershman
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | | | | | | | - B Lavraud
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, Toulouse, France
| | - Y Saito
- ISAS/JAXA, Sagamihara, Japan
| | - M Oka
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - R E Ergun
- University of Colorado LASP, Boulder, CO, USA
| | - A Retino
- CNRS/Ecole Polytechnique, Paris, France
| | | | - M R Argall
- University of New Hampshire, Durham, NH, USA
| | - B L Giles
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - T E Moore
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - F D Wilder
- University of Colorado LASP, Boulder, CO, USA
| | - R J Strangeway
- University of California, Los Angeles, Los Angeles, CA, USA
| | - C T Russell
- University of California, Los Angeles, Los Angeles, CA, USA
| | | | - W Magnes
- Space Research Institute, Austrian Academy of Sciences, Graz, Austria
| |
Collapse
|
18
|
Liu H, Zong QG, Zhang H, Xiao CJ, Shi QQ, Yao ST, He JS, Zhou XZ, Pollock C, Sun WJ, Le G, Burch JL, Rankin R. MMS observations of electron scale magnetic cavity embedded in proton scale magnetic cavity. Nat Commun 2019; 10:1040. [PMID: 30833556 PMCID: PMC6399300 DOI: 10.1038/s41467-019-08971-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [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: 09/04/2018] [Accepted: 02/13/2019] [Indexed: 11/09/2022] Open
Abstract
Magnetic cavities (sometimes referred to as magnetic holes) at electron kinetic scale are thought to be one of the extremely small intermittent structures formed in magnetized turbulent plasmas, where the turbulence energy cascaded down to electron scale may finally be dissipated and consequently energize the electrons. However, the geometry and formation of these structures remain not definitively resolved. Here we discuss an electron scale magnetic cavity embedded in a proton scale magnetic cavity observed by the MMS spacecraft in the magnetosheath. By applying an innovative particle sounding technique, we directly depict the boundary of the electron scale magnetic cavity and uncover the geometry. We find that this structure is nearly circular with a radius of 10.0 km and its formation is due to the diamagnetic current. Investigation of the electron scale structure is only recently made possible by the high spatial and temporal resolution provided by MMS observations.
Collapse
Affiliation(s)
- H Liu
- Institute of Space Physics and Applied Technology, Peking University, Beijing, 100871, China.,Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Q-G Zong
- Institute of Space Physics and Applied Technology, Peking University, Beijing, 100871, China.
| | - H Zhang
- Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - C J Xiao
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, 100871, China
| | - Q Q Shi
- Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209, China
| | - S T Yao
- Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209, China
| | - J S He
- Institute of Space Physics and Applied Technology, Peking University, Beijing, 100871, China
| | - X-Z Zhou
- Institute of Space Physics and Applied Technology, Peking University, Beijing, 100871, China
| | - C Pollock
- Denali Scientific, 3771 Mariposa Lane, Fairbanks, AK, 99709, USA
| | - W J Sun
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - G Le
- NASA, Goddard Space Flight Center, Greenbelt, MD, 20771, USA
| | - J L Burch
- Southwest Research Institute, San Antonio, TX, 78238, USA
| | - R Rankin
- Department of Physics, University of Alberta, Edmonton, T6G 2G7, AB, Canada
| |
Collapse
|
19
|
Chen LJ, Wang S, Wilson LB, Schwartz S, Bessho N, Moore T, Gershman D, Giles B, Malaspina D, Wilder FD, Ergun RE, Hesse M, Lai H, Russell C, Strangeway R, Torbert RB, F-Vinas A, Burch J, Lee S, Pollock C, Dorelli J, Paterson W, Ahmadi N, Goodrich K, Lavraud B, Le Contel O, Khotyaintsev YV, Lindqvist PA, Boardsen S, Wei H, Le A, Avanov L. Electron Bulk Acceleration and Thermalization at Earth's Quasiperpendicular Bow Shock. Phys Rev Lett 2018; 120:225101. [PMID: 29906189 DOI: 10.1103/physrevlett.120.225101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 03/30/2018] [Indexed: 06/08/2023]
Abstract
Electron heating at Earth's quasiperpendicular bow shock has been surmised to be due to the combined effects of a quasistatic electric potential and scattering through wave-particle interaction. Here we report the observation of electron distribution functions indicating a new electron heating process occurring at the leading edge of the shock front. Incident solar wind electrons are accelerated parallel to the magnetic field toward downstream, reaching an electron-ion relative drift speed exceeding the electron thermal speed. The bulk acceleration is associated with an electric field pulse embedded in a whistler-mode wave. The high electron-ion relative drift is relaxed primarily through a nonlinear current-driven instability. The relaxed distributions contain a beam traveling toward the shock as a remnant of the accelerated electrons. Similar distribution functions prevail throughout the shock transition layer, suggesting that the observed acceleration and thermalization is essential to the cross-shock electron heating.
Collapse
Affiliation(s)
- L-J Chen
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- Department of Astronomy, University of Maryland, College Park, Maryland 20747, USA
| | - S Wang
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- Department of Astronomy, University of Maryland, College Park, Maryland 20747, USA
| | - L B Wilson
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - S Schwartz
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80305, USA
| | - N Bessho
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- Department of Astronomy, University of Maryland, College Park, Maryland 20747, USA
| | - T Moore
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - D Gershman
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - B Giles
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - D Malaspina
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80305, USA
| | - F D Wilder
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80305, USA
| | - R E Ergun
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80305, USA
| | - M Hesse
- University of Bergen, Bergen 5020, Norway
| | - H Lai
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - C Russell
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - R Strangeway
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - R B Torbert
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - A F-Vinas
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - J Burch
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - S Lee
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - C Pollock
- Denali Scientific, Healy, Alaska 99743, USA
| | - J Dorelli
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - W Paterson
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - N Ahmadi
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80305, USA
| | - K Goodrich
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80305, USA
| | - B Lavraud
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse (UPS), CNRS, CNES, Toulouse, 31028 Cedex 4, France
| | - O Le Contel
- Laboratoire de Physique des Plasmas (UMR7648), CNRS/Ecole Polytechnique/Sorbonne Université/Univ. Paris Sud/Observatoire de Paris, Paris, F91128 Palaiseau Cedex, France
| | | | - P-A Lindqvist
- KTH Royal Institute of Technology, Stockholm SE-11428, Sweden
| | - S Boardsen
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- Department of Astronomy, University of Maryland, College Park, Maryland 20747, USA
| | - H Wei
- University of California, Los Angeles, Los Angeles, California 90095, USA
| | - A Le
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L Avanov
- NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
- Department of Astronomy, University of Maryland, College Park, Maryland 20747, USA
| |
Collapse
|
20
|
Abstract
Peritoneal sclerosis is an almost invariable consequence of peritoneal dialysis. In most circumstances it is “simple” sclerosis, manifesting clinically with an increasing peritoneal transport rate and loss of ultrafiltration capacity. In contrast, encapsulating peritoneal sclerosis is a life threatening and usually irreversible condition, associated with bowel obstruction, malnutrition and death. It is unknown whether common etiological factors underlie the development of these 2 clinically and pathologically distinct forms of peritoneal sclerosis. The majority of studies to date have investigated factors that contribute to “simple” sclerosis, although it remains possible that similar mechanisms are amplified in patients who develop encapsulated peritoneal sclerosis. The cellular elements that promote peritoneal sclerosis include the mesothelial cells, peritoneal fibroblasts and inflammatory cells. Factors that stimulate these cells to promote peritoneal fibrosis and neoangiogenesis, both inherent in the development of peritoneal sclerosis, include cytokines that are induced by exposure of the peritoneal membrane to high concentrations of glucose, advanced glycation of the peritoneal membrane and oxidative stress. The cumulative exposure to bioincompatible dialysate is likely to have an etiological role as the duration of dialysis correlates with the likelihood of developing peritoneal sclerosis. Indeed peritoneal dialysis using more biocompatible fluids has been shown to reduce the development of peritoneal sclerosis. The individual contribution of the factors implicated in the development of peritoneal sclerosis will only be determined by large scale peritoneal biopsy registries, which will be able to prospectively incorporate clinical and histological data and support clinical decision making.
Collapse
Affiliation(s)
- C Pollock
- Royal North Shore Hospital, University of Sydney, St Leonards, NSW 2065 Australia.
| |
Collapse
|
21
|
Sampalis J, Psaradellis E, Pollock C, Rickard J, Rampakakis E, Fonknechten G, Toni C, Lefay D. P759Post-hoc analysis of Confidence II, Protect I, Shake the habit I and Shake the habit II studies in mild to moderate hypertensive patients treated with perindopril and atorvastatin concomitantly. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx501.p759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
22
|
Hart KM, Iverson AR, Benscoter AM, Fujisaki I, Cherkiss MS, Pollock C, Lundgren I, Hillis-Starr Z. Resident areas and migrations of female green turtles nesting at Buck Island Reef National Monument, St. Croix, US Virgin Islands. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00793] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
23
|
Abstract
This paper presents an overview of some of the pitfalls and suggests ways of improving the quality of research into rehabilitation after stroke. The aims of rehabilitation are outlined and methodological problems inherent in this area discussed, including spontaneous recovery, multidimensional outcomes, definition of treatment and placebo effects. Major weaknesses found in the rehabilitation literature are identified and recommendations for improvement made, including the need for comparable controls, adequate numbers, appropriate outcome measures, clear definition of therapy, generalizability, and a concern for the cost-effectiveness of stroke rehabilitation packages. The field of rehabilitation is still relatively new and idiosyncratic in form and content. Thus it still provides opportunities for research into its relative effectiveness before current practices in rehabilitation become entrenched in medical practice and folklore. Adequate funding support for improved, multicentre clinical trials in rehabilitation is essential.
Collapse
Affiliation(s)
- C. Pollock
- School of Public Health, University of Leeds
| | | | - T. Sheldon
- School of Public Health, University of Leeds
| | - F. Song
- School of Public Health, University of Leeds
| | - JM Mason
- Centre for Health Economics, University of York
| |
Collapse
|
24
|
Eastwood JP, Phan TD, Cassak PA, Gershman DJ, Haggerty C, Malakit K, Shay MA, Mistry R, Øieroset M, Russell CT, Slavin JA, Argall MR, Avanov LA, Burch JL, Chen LJ, Dorelli JC, Ergun RE, Giles BL, Khotyaintsev Y, Lavraud B, Lindqvist PA, Moore TE, Nakamura R, Paterson W, Pollock C, Strangeway RJ, Torbert RB, Wang S. Ion-scale secondary flux ropes generated by magnetopause reconnection as resolved by MMS. Geophys Res Lett 2016; 43:4716-4724. [PMID: 27635105 PMCID: PMC5001194 DOI: 10.1002/2016gl068747] [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] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 06/06/2023]
Abstract
New Magnetospheric Multiscale (MMS) observations of small-scale (~7 ion inertial length radius) flux transfer events (FTEs) at the dayside magnetopause are reported. The 10 km MMS tetrahedron size enables their structure and properties to be calculated using a variety of multispacecraft techniques, allowing them to be identified as flux ropes, whose flux content is small (~22 kWb). The current density, calculated using plasma and magnetic field measurements independently, is found to be filamentary. Intercomparison of the plasma moments with electric and magnetic field measurements reveals structured non-frozen-in ion behavior. The data are further compared with a particle-in-cell simulation. It is concluded that these small-scale flux ropes, which are not seen to be growing, represent a distinct class of FTE which is generated on the magnetopause by secondary reconnection.
Collapse
Affiliation(s)
| | - T. D. Phan
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - P. A. Cassak
- Department of Physics and AstronomyWest Virginia UniversityMorgantownWest VirginiaUSA
| | - D. J. Gershman
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| | - C. Haggerty
- Department of Physics and AstronomyUniversity of DelawareNewarkDelawareUSA
| | - K. Malakit
- Department of PhysicsMahidol UniversityBangkokThailand
| | - M. A. Shay
- Department of Physics and AstronomyUniversity of DelawareNewarkDelawareUSA
| | - R. Mistry
- Blackett LaboratoryImperial College LondonLondonUK
| | - M. Øieroset
- Space Sciences LaboratoryUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - C. T. Russell
- Department of Earth, Planetary and Space SciencesUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - J. A. Slavin
- Department of Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMichiganUSA
| | - M. R. Argall
- Institute for the Study of Earth, Oceans and SpaceUniversity of New HampshireDurhamNew HampshireUSA
| | - L. A. Avanov
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| | - J. L. Burch
- Southwest Research InstituteSan AntonioTexasUSA
| | - L. J. Chen
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| | - J. C. Dorelli
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | - R. E. Ergun
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderColoradoUSA
| | - B. L. Giles
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | | | - B. Lavraud
- Institut de Recherche en Astrophysique et PlanétologieUniversité de ToulouseToulouseFrance
- Centre National de la Recherche Scientifique, UMR 5277ToulouseFrance
| | - P. A. Lindqvist
- School of Electrical EngineeringRoyal Institute of TechnologyStockholmSweden
| | - T. E. Moore
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | - R. Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - W. Paterson
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | | | - R. J. Strangeway
- Department of Earth, Planetary and Space SciencesUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - R. B. Torbert
- Institute for the Study of Earth, Oceans and SpaceUniversity of New HampshireDurhamNew HampshireUSA
- Southwest Research InstituteSan AntonioTexasUSA
| | - S. Wang
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
- Department of AstronomyUniversity of MarylandCollege ParkMarylandUSA
| |
Collapse
|
25
|
Straker L, Campbell A, Howie E, Smith A, Piek J, Jensen L, Pollock C. Can active video games enhance motor coordination in children with developmental coordination disorder? Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.3523] [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: 10/23/2022]
|
26
|
Harris C, Straker L, Pollock C. The influence of age, gender and other information technology use on young people's computer use at school and home. Work 2013; 44 Suppl 1:S61-71. [DOI: 10.3233/wor-121494] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- C. Harris
- School of Physiotherapy, Curtin University, Perth, Australia
- Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - L. Straker
- School of Physiotherapy, Curtin University, Perth, Australia
- Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - C. Pollock
- Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
- School of Psychology, Curtin University, Perth, Australia
| |
Collapse
|
27
|
Pollock C, McKenna J, O’Neill J, Thapliyal R, Lamont J, McKeown S, Crockard M, Coyle P, Fitzgerald SP. P24 Combating Inappropriate Use of Antibiotics Through Rapid, Accurate and Comprehensive Detection of Respiratory Pathogens Using a Respiratory Multiplex Array: Abstract P24 Table 1. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.165] [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: 11/03/2022]
|
28
|
Harris C, Straker L, Smith A, Pollock C. A proposed model representing the relationships between user characteristics, computer exposure and musculoskeletal symptoms in children. Work 2012; 41 Suppl 1:838-45. [DOI: 10.3233/wor-2012-0251-838] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- C. Harris
- School of Occupational Therapy and Social Work, Curtin University, Perth, WA 6845, Australia
- School of Physiotherapy, Curtin University, Perth, WA 6845, Australia
| | - L. Straker
- School of Physiotherapy, Curtin University, Perth, WA 6845, Australia
| | - A. Smith
- School of Physiotherapy, Curtin University, Perth, WA 6845, Australia
| | - C. Pollock
- School of Psychology and Speech Pathology, Curtin University, Perth, WA 6845, Australia
| |
Collapse
|
29
|
Slusarczyk A, Kamath R, Wang C, Anchel D, Pollock C, Lewandowska MA, Fitzpatrick T, Bazett-Jones DP, Huang S. Structure and function of the perinucleolar compartment in cancer cells. Cold Spring Harb Symp Quant Biol 2011; 75:599-605. [PMID: 21289045 DOI: 10.1101/sqb.2010.75.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The perinucleolar compartment (PNC) is a subnuclear body that forms in cancer cells. In vivo analyses using human tumor tissues demonstrate a close correlation between PNC prevalence and disease progress in colorectal carcinoma, and a high PNC prevalence is associated with poor patient outcome. These findings are consistent with previous observations in breast cancer and cancer cell lines in vitro. The PNC is composed of thick strands that form a filamental meshwork often extending into the nucleolus. Although it appears to be electron dense as observed by transmission electron microscopy (TEM), the actual density of the structure imaged by electron spectroscopy is much lower, similar to that of the interchromatin space, and is lined with ribonucleoproteins (RNPs). In situ detections show that the PNC is highly enriched with a subset of small RNAs of polymerase III (Pol III) origins and RNA-binding proteins primarily implicated in pre-mRNA processing. A novel gel-shifting approach demonstrates that the addition of PNC-associated RNAs into HeLa cell lysates increases the mobility of polypyrimidine tract-binding (PTB) protein in a native gel electrophoresis, suggesting an interaction between these RNAs and PTB proteins. On the basis of these and other findings, we propose a working model in which novel RNPs have a key role in regulating gene expression at the PNC in cancer cells.
Collapse
Affiliation(s)
- A Slusarczyk
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60614, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Straker L, Abbott R, Pollock C, Piek J, Coleman J. Electronic game access may decrease or increase physical activity in children. J Sci Med Sport 2010. [DOI: 10.1016/j.jsams.2009.10.285] [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: 11/17/2022]
|
31
|
Abstract
Computer use by children at home and school is now common in many countries. Child computer exposure varies with the type of computer technology available and the child's age, gender and social group. This paper reviews the current exposure data and the evidence for positive and negative effects of computer use by children. Potential positive effects of computer use by children include enhanced cognitive development and school achievement, reduced barriers to social interaction, enhanced fine motor skills and visual processing and effective rehabilitation. Potential negative effects include threats to child safety, inappropriate content, exposure to violence, bullying, Internet 'addiction', displacement of moderate/vigorous physical activity, exposure to junk food advertising, sleep displacement, vision problems and musculoskeletal problems. The case for child specific evidence-based guidelines for wise use of computers is presented based on children using computers differently to adults, being physically, cognitively and socially different to adults, being in a state of change and development and the potential to impact on later adult risk. Progress towards child-specific guidelines is reported. Finally, a set of guideline principles is presented as the basis for more detailed guidelines on the physical, cognitive and social impact of computer use by children. The principles cover computer literacy, technology safety, child safety and privacy and appropriate social, cognitive and physical development. The majority of children in affluent communities now have substantial exposure to computers. This is likely to have significant effects on child physical, cognitive and social development. Ergonomics can provide and promote guidelines for wise use of computers by children and by doing so promote the positive effects and reduce the negative effects of computer-child, and subsequent computer-adult, interaction.
Collapse
Affiliation(s)
- L Straker
- Curtin University of Technology, Perth, WA, Australia.
| | | | | |
Collapse
|
32
|
Straker L, Burgess-Limerick R, Pollock C, Maslen B. The influence of desk and display design on posture and muscle activity variability whilst performing information technology tasks. Appl Ergon 2009; 40:852-859. [PMID: 18973874 DOI: 10.1016/j.apergo.2008.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 03/17/2008] [Accepted: 09/03/2008] [Indexed: 05/27/2023]
Abstract
Desk design and computer display height can affect posture and muscle activation during computer use. Amplitudes of postural variables and muscle activity during computer use do not explain the results from epidemiological studies of musculoskeletal discomfort and disorders related to computer use. The purpose of this study was to assess variability of posture and muscle activity during work with two computer display heights and book/paper, in conjunction with a curved desk designed to provide forearm support and a traditional, straight desk. 18 male and 18 female participants performed 10-min tasks involving keying, mousing, reading and writing in six desk/display conditions. 3D posture and surface emg were assessed for the final 2 min of each task. The curved desk resulted in greater postural and muscle activity variation, suggesting an advantage of this supportive surface over the straight desk. There was little difference in variability associated with the two display heights. However, greater variability of posture and muscle activity was evident with the book/paper condition. Non-touch typists had greater neck flexion variation. The design of information technology tasks and workstations can influence the short term variation in posture and muscle activity. Variation is influenced independently of mean postures and muscle amplitudes and therefore needs to be considered to adequately assess the risk of musculoskeletal disorders.
Collapse
Affiliation(s)
- L Straker
- School of Physiotherapy, Curtin University of Technology, Perth 6845, Australia.
| | | | | | | |
Collapse
|
33
|
Straker L, Pollock C, Burgess-Limerick R, Skoss R, Coleman J. The impact of computer display height and desk design on muscle activity during information technology work by young adults. J Electromyogr Kinesiol 2008; 18:606-17. [PMID: 17329126 DOI: 10.1016/j.jelekin.2006.09.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 09/09/2006] [Accepted: 09/11/2006] [Indexed: 11/20/2022] Open
Abstract
Computer display height and desk design are believed to be important workstation features and are included in international standards and guidelines. However, the evidence base for these guidelines is lacking a comparison of neck/shoulder muscle activity during computer and paper tasks and whether forearm support can be provided by desk design. This study measured the spinal and upper limb muscle activity in 36 young adults whilst they worked in different computer display, book and desk conditions. Display height affected spinal muscle activity with paper tasks resulting in greater mean spinal and upper limb muscle activity. A curved desk resulted in increased proximal muscle activity. There was no substantial interaction between display and desk.
Collapse
Affiliation(s)
- L Straker
- School of Physiotherapy, Curtin University of Technology, Perth 6845, Australia.
| | | | | | | | | |
Collapse
|
34
|
Straker L, Burgess-Limerick R, Pollock C, Murray K, Netto K, Coleman J, Skoss R. The impact of computer display height and desk design on 3D posture during information technology work by young adults. J Electromyogr Kinesiol 2008; 18:336-49. [PMID: 17188894 DOI: 10.1016/j.jelekin.2006.10.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 09/09/2006] [Accepted: 10/18/2006] [Indexed: 11/24/2022] Open
Abstract
Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.
Collapse
Affiliation(s)
- L Straker
- School of Physiotherapy, Curtin University of Technology, Perth 6845, Australia.
| | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
This paper outlines the major changes in the lives of children in industrially advanced countries associated with the increased interaction with information and communication technologies. The potential opportunities and threats to the cognitive, social, physical and visual development of children are reviewed to emphasize the importance of optimizing the interaction. The change in children's use of technology also poses opportunities and threats for ergonomics that should be noted if the profession is to continue being relevant and useful into this century. The paper ends with a pathway to the development and implementation of guidelines about child information and communication technology use for different groups of guideline users.
Collapse
Affiliation(s)
- L Straker
- School of Physiotherapy, Curtin University of Technology, GPO Box U1987, Perth, 6845, Western Australia.
| | | |
Collapse
|
36
|
Straker L, Burgess-Limerick R, Pollock C, Egeskov R. A randomized and controlled trial of a participative ergonomics intervention to reduce injuries associated with manual tasks: physical risk and legislative compliance. Ergonomics 2004; 47:166-188. [PMID: 14660211 DOI: 10.1080/00140130310001617949] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A participative ergonomics approach to reducing injuries associated with manual tasks is widely promoted; however only limited evidence from uncontrolled trials has been available to support the efficacy of such an approach. This paper reports on a randomized and controlled trial of PErforM, a participative ergonomics intervention designed to reduce the risks of injury associated with manual tasks. One hundred and seventeen small to medium sized food, construction, and health workplaces were audited by government inspectors using a manual tasks risk assessment tool (ManTRA). Forty-eight volunteer workplaces were then randomly assigned to Experimental and Control groups with the Experimental group receiving the PErforM program. Inspectors audited the workplaces again, 9 months following the intervention. The results showed a significant decrease in estimates of manual task risk and suggested better legal compliance in the Experimental group.
Collapse
Affiliation(s)
- L Straker
- School of Physiotherapy, Curtin University of Technology, Australia.
| | | | | | | |
Collapse
|
37
|
Pollock C. Sierra Leone 1914. J ROY ARMY MED CORPS 2001; 147:195-6. [PMID: 11464413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
|
38
|
Abstract
A debilitated 9-yr-old female red panda (Ailurus fulgens fulgens) with a recent history of corticosteroid administration displayed anorexia, depression, and diarrhea for 2 days. Blood work revealed a moderate nonregenerative anemia, leukocytosis, hypokalemia, hyperbilirubinemia, and mildly elevated alanine aminotransferase and aspartate aminotransferase. Serology was negative for occult heartworm, Toxoplasma gondii, feline leukemia virus, feline infectious peritonitis, feline immunodeficiency virus, and canine distemper virus. Electron microscopy of the feces demonstrated corona-like virus particles. The panda died 3 days after initial presentation. Histologic findings included multifocal, acute, hepatic necrosis and diffuse, necrotizing colitis. Liver and colon lesions contained intracellular, curved, spore-forming, gram-negative, silver-positive rods morphologically consistent with Clostridium piliforme. This panda most likely contracted Tyzzer's disease subsequent to having a compromised immune system after corticosteroid administration and concurrent disease.
Collapse
Affiliation(s)
- J Langan
- Department of Comparative Medicine, College of Veterinary Medicine, The University of Tennessee, Knoxville 37901-1071, USA
| | | | | | | | | |
Collapse
|
39
|
Langan JN, Schumacher J, Pollock C, Orosz SE, Jones MP, Harvey RC. Cardiopulmonary and anesthetic effects of medetomidine-ketamine-butorphanol and antagonism with atipamezole in servals (Felis serval). J Zoo Wildl Med 2000; 31:329-34. [PMID: 11237139 DOI: 10.1638/1042-7260(2000)031[0329:caaeom]2.0.co;2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Seven (three male and four female) 4-7-yr old captive servals (Felis serval) weighing 13.7 +/- 2.3 kg were used to evaluate the cardiopulmonary and anesthetic effects of combined intramuscular injections of medetomidine (47.4 +/- 10.3 microg/kg), ketamine (1.0 +/- 0.2 mg/kg), and butorphanol (0.2 +/- 0.03 mg/kg). Inductions were smooth and rapid (11.7 +/- 4.3 min) and resulted in good muscle relaxation. Significant decreases in heart rate (85 +/- 12 beats/min) at 10 min after injection and respiratory rate (27 +/- 10 breaths/min) at 5 min after injection continued throughout the immobilization period. Rectal temperature and arterial blood pressure did not change significantly. The PaO2 decreased significantly, and PaCO2 increased significantly during immobilization but remained within clinically acceptable limits. Hypoxemia (PaO2 < 60 mm Hg) was not noted, and arterial blood oxygen saturation (SaO2) was greater than 90% at all times. Relative arterial oxygen saturation (SpO2) values, indicated by pulse oximetry, were lower than SaO2 values. All animals could be safely handled while sedated. Administration of atipamezole (236.8 +/- 51.2 microg/kg half i.v. and half s.c.), an alpha2 antagonist, resulted in rapid (4.1 +/- 3 min to standing) and smooth recoveries.
Collapse
Affiliation(s)
- J N Langan
- Department of Comparative Medicine, College of Veterinary Medicine, University of Tennessee, Knoxville 37901-1071, USA
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
We consider the hypothesis that sucrose is a signal as well as a substrate. We suggest that the significance of sugar sensing in plants is the integration of whole-plant carbon flux so that the capacity of sources to produce sucrose matches the capacity of sinks to consume it. We pay particular attention to difficulties with this hypothesis and the areas where further or better evidence is needed. We conclude that there is strong correlative evidence for a link between sucrose metabolism and the level of expression of key genes, but that a number of different mechanisms may be involved.
Collapse
Affiliation(s)
- J Farrar
- School of Biological Sciences, University of Wales, Bangor, UK
| | | | | |
Collapse
|
41
|
Hilton-Taylor C, Mace GM, Capper DR, Collar NJ, Stuart SN, Bibby CJ, Pollock C, Thomsen JB. Assessment mismatches must be sorted out: they leave species at risk. Nature 2000; 404:541. [PMID: 10766211 DOI: 10.1038/35007238] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
42
|
Abstract
Baccalaureate nursing faculty sought new ways to teach maternity nursing to expose health care practices that affect, define, and limit women's experiences of reproductive health care. By blending science, story, and spirituality within a feminist philosophy, the faculty created an atmosphere of chaos that transformed the classroom and clinical experiences of students. The students' awakened engagement with maternity nursing practice was evidenced by their connection to woman-centered care issues, and passing rates on the National Council Licensing Examination remained between 97-100%, indicating adequate learning of standard core content.
Collapse
Affiliation(s)
- G Giarratano
- Louisiana State University Medical Center, New Orleans 70112-2262, USA
| | | | | |
Collapse
|
43
|
Abstract
We report a case of polyglandular autoimmune deficiency presenting during pregnancy which was associated with a favourable outcome for both mother and fetus (apart from fetal growth retardation) with appropriate replacement therapy and adequate steroid cover at the time of delivery.
Collapse
Affiliation(s)
- G Mathur
- Royal North Shore Hospital, Sydney, St Leonards, New South Wales
| | | | | | | |
Collapse
|
44
|
Affiliation(s)
- E Stone
- Department of Renal Medicine, Royal North Shore Hospital, St Leonards NSW, Australia
| | | | | | | |
Collapse
|
45
|
Wilson AE, Pollock C, Weekes T, Dowell A. Can general practice provide useful information?--evaluation of a primary health care information project in northern England. J Epidemiol Community Health 1995; 49:227-30. [PMID: 7629454 PMCID: PMC1060788 DOI: 10.1136/jech.49.3.227] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVE To develop a computerised primary care information gathering network capable of producing reliable risk factor and morbidity data from a wide diversity of general practice software systems. METHOD Fourteen practices from the Wakefield and Pontefract district collaborated in sharing information and solving technical difficulties associated with collecting data on coronary heart disease (CHD) risk factors, diabetes, and asthma. Practices also participated in rheumatology and mental health needs assessment projects. RESULTS Data could be transferred by diskette in only five of the systems and paper reports had to be used to post process the data into a standard format. Not all data were complete or comparable. Crude estimates only of smoking prevalence and smoking cessation interventions were possible, as well as of age and sex specific prevalences for asthma and diabetes. The rheumatology health needs assessment, using the prospective collection of consultation based data, highlighted an unmet need for rheumatology services in the community. CONCLUSIONS Although practices have been willing to devote considerable time and effort to the project, the diversity of software has precluded a simple methodology for data collection and analysis. The amount of useful information retrieved so far, has been limited but a number of important lessons have been learned which have implications for similar information projects and the use of primary care information in service planning.
Collapse
Affiliation(s)
- A E Wilson
- Centre for Research in Primary Care, Leeds
| | | | | | | |
Collapse
|
46
|
Pollock C, Gyory AZ, Hawkins T, Ross M, Ibels L. Comparison of simultaneous renal clearances of true endogenous creatinine and subcutaneously administered iothalamate in man. Am J Nephrol 1995; 15:277-82. [PMID: 7573183 DOI: 10.1159/000168849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 01/26/2023]
Abstract
125I-iothalamate and true endogenous creatinine clearances, measured over two short collections periods of 1 and 2 h, were compared simultaneously in 70 patients with a variety of renal diseases and a wide range of renal function. Reproducibility of the iothalamate clearance was 18.5% and that of the creatinine clearance 12.2%. The slope of the regression was not significantly different from 1 (95% confidence interval, CI, 0.964-1.155) for the whole group, nor in any subgroup chosen. The intercept at 12.6 ml/min (CI = 5.0-20.2) indicates that there is some creatinine secretion, but this was constant at all levels of GFR. It is concluded that although the clearance of true creatinine obtained during short collection periods consistently overestimates GFR by a constant proportion, it is a reproducible and accurate measure of GFR suitable for use in the clinical setting.
Collapse
Affiliation(s)
- C Pollock
- Department of Medicine, Sydney University and Renal Medicine, Royal North Shore Hospital, St. Leonards, Australia
| | | | | | | | | |
Collapse
|
47
|
Reddy S, Györy AZ, Dyne M, Salipan-Moore N, Pollock C, Field MJ, Cockayne DJ. Effect of atrial natriuretic peptide on cellular element concentrations in rat proximal tubules: evidence for inhibition of the sodium pump. Clin Exp Pharmacol Physiol 1994; 21:775-80. [PMID: 7867228 DOI: 10.1111/j.1440-1681.1994.tb02445.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 01/27/2023]
Abstract
1. In order to further define the action of atrial natriuretic peptide (ANP) on proximal tubular (PT) transport, combined clearance and electron microprobe X-ray (EMPX) experiments were performed on five male Wistar rats infused with ANP (0.16 nmol/kg per h) and nine control animals. 2. Electron microprobe X-ray analysis of PT cell electrolytes (mmol/kg wet weight) revealed a similar [Na]i in both the control and ANP treated groups (16.4 +/- 0.4 vs 16.5 +/- 0.4; P = 0.894). [Cl]i was lower in the ANP treated animals (14.8 +/- 0.3 vs 12.0 +/- 0.3; P < 0.0001) as was [K]i (131.4 +/- 1.4 vs 114 +/- 1.7; P < 0.0001). The PT cells in the ANP treated group had a significant reduction in dry weight (20.1 +/- 0.3 g% vs 19.0 +/- 0.3 g%; P < 0.024), indicating significant cell swelling. Thus, despite a normal [Na]i, there was net accumulation of Nai following ANP treatment. 3. These results are consistent with accumulation of Nai due to inhibition of the Na pump followed by cell swelling and subsequent regulatory volume decrease with exit of K and Cl. These results are the first to show the effect of ANP on PT intracellular electrolytes.
Collapse
Affiliation(s)
- S Reddy
- Department of Medicine, Sydney University, St Leonards, Australia
| | | | | | | | | | | | | |
Collapse
|
48
|
Ganguli G, Keskinen MJ, Romero H, Heelis R, Moore T, Pollock C. Coupling of microprocesses and macroprocesses due to velocity shear: An application to the low-altitude ionosphere. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93ja03181] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
49
|
|
50
|
Freemantle N, Pollock C. Infant science, adult problem. Health Serv J 1992; 102:29. [PMID: 10119350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|