JAMES N contact WEISS

Summary

Affiliation: University of California
Country: USA

Publications

  1. pmc "Good enough solutions" and the genetics of complex diseases
    James N Weiss
    Cardiovascular Research Laboratory and Atherosclerosis Research Unit, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
    Circ Res 111:493-504. 2012
  2. pmc Deducing topology of protein-protein interaction networks from experimentally measured sub-networks
    Ling Yang
    Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, California 90095, USA
    BMC Bioinformatics 9:301. 2008
  3. ncbi request reprint Role of the mitochondrial permeability transition in myocardial disease
    James N Weiss
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, Calif 90095 1760, USA
    Circ Res 93:292-301. 2003
  4. ncbi request reprint Novel approaches to identifying antiarrhythmic drugs
    James N Weiss
    Departments of Medicine Cardiology and Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 1760, USA
    Trends Cardiovasc Med 13:326-30. 2003
  5. pmc Beyond the implantable cardioverter-defibrillator: are we making progress?
    James N Weiss
    UCLA Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
    Heart Rhythm 5:S45-7. 2008
  6. ncbi request reprint Ventricular fibrillation: new insights into mechanisms
    James N Weiss
    David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
    Ann N Y Acad Sci 1015:122-32. 2004
  7. ncbi request reprint Systems biology approaches to metabolic and cardiovascular disorders: network perspectives of cardiovascular metabolism
    James N Weiss
    Cardiovascular Research Laboratory, Departments of Medicine Cardiology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
    J Lipid Res 47:2355-66. 2006
  8. ncbi request reprint Short-term cardiac memory and mother rotor fibrillation
    Ali Baher
    David Geffen School of Medicine at UCLA, Division of Cardiology, 47 123 CHS, 10833 LeConte Ave, Los Angeles, CA 90095 1679, USA
    Am J Physiol Heart Circ Physiol 292:H180-9. 2007
  9. ncbi request reprint From pulsus to pulseless: the saga of cardiac alternans
    James N Weiss
    Department of Medicine Cardiology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
    Circ Res 98:1244-53. 2006
  10. ncbi request reprint Factors determining the transition from ventricular tachycardia to ventricular fibrillation
    James N Weiss
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
    Heart Rhythm 2:1008-10. 2005

Research Grants

  1. Metabolic Oscillations in Heart
    JAMES N contact WEISS; Fiscal Year: 2010
  2. Cardiac Fibrillation: Mechanisms and Therapy
    James Weiss; Fiscal Year: 2007
  3. PROPERTIES OF INWARD RECTIFIER K CHANNELS
    James Weiss; Fiscal Year: 2007
  4. Mitochondria and Cardiac Cell Death
    James Weiss; Fiscal Year: 2007
  5. CARDIOVASCULAR SCIENTIST TRAINING PROGRAM
    James Weiss; Fiscal Year: 2007
  6. Afterdepolarizations and Cardiac Arrhythmias
    James N Weiss; Fiscal Year: 2010

Detail Information

Publications81

  1. pmc "Good enough solutions" and the genetics of complex diseases
    James N Weiss
    Cardiovascular Research Laboratory and Atherosclerosis Research Unit, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
    Circ Res 111:493-504. 2012
    ..If validated, GMAS may imply that common polygenic diseases are related as much to group interactions between normal genes, as to multiple gene mutations...
  2. pmc Deducing topology of protein-protein interaction networks from experimentally measured sub-networks
    Ling Yang
    Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, California 90095, USA
    BMC Bioinformatics 9:301. 2008
    ..However, whether topological information reaped from these experimentally-measured sub-networks can be extrapolated to complete protein-protein interaction networks is unclear...
  3. ncbi request reprint Role of the mitochondrial permeability transition in myocardial disease
    James N Weiss
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, Calif 90095 1760, USA
    Circ Res 93:292-301. 2003
    ..Investigations into this area are beginning to unravel some of the mechanistic links between cardioprotective signaling and mitochondria...
  4. ncbi request reprint Novel approaches to identifying antiarrhythmic drugs
    James N Weiss
    Departments of Medicine Cardiology and Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 1760, USA
    Trends Cardiovasc Med 13:326-30. 2003
    ..However, new insights into the mechanisms of ventricular fibrillation, particularly the role of dynamic factors that cause wave instability, are providing conceptual advances toward developing effective new pharmacotherapy...
  5. pmc Beyond the implantable cardioverter-defibrillator: are we making progress?
    James N Weiss
    UCLA Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
    Heart Rhythm 5:S45-7. 2008
    ..This brief review summarizes some of the recent progress in this direction...
  6. ncbi request reprint Ventricular fibrillation: new insights into mechanisms
    James N Weiss
    David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
    Ann N Y Acad Sci 1015:122-32. 2004
    ..New insights into the mechanisms of ventricular fibrillation, particularly the role of dynamic factors causing wave instability, are providing a promising avenue for developing novel therapies to prevent sudden cardiac death...
  7. ncbi request reprint Systems biology approaches to metabolic and cardiovascular disorders: network perspectives of cardiovascular metabolism
    James N Weiss
    Cardiovascular Research Laboratory, Departments of Medicine Cardiology and Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
    J Lipid Res 47:2355-66. 2006
    ..We speculate how this state of "metabolic fibrillation" leads to cell death if not corrected and discuss the implications for cardioprotection...
  8. ncbi request reprint Short-term cardiac memory and mother rotor fibrillation
    Ali Baher
    David Geffen School of Medicine at UCLA, Division of Cardiology, 47 123 CHS, 10833 LeConte Ave, Los Angeles, CA 90095 1679, USA
    Am J Physiol Heart Circ Physiol 292:H180-9. 2007
    ..This was due to progressive acceleration and stabilization of rotors as accumulation of memory shortened APD and flattened APD restitution slope nonuniformly throughout the tissue...
  9. ncbi request reprint From pulsus to pulseless: the saga of cardiac alternans
    James N Weiss
    Department of Medicine Cardiology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
    Circ Res 98:1244-53. 2006
    ..These insights have illuminated the mechanistic basis underlying the clinical association of cardiac alternans (eg, T wave alternans) with arrhythmia risk, which may lead to novel therapeutic approaches to avert sudden cardiac death...
  10. ncbi request reprint Factors determining the transition from ventricular tachycardia to ventricular fibrillation
    James N Weiss
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
    Heart Rhythm 2:1008-10. 2005
  11. ncbi request reprint Chaos and the transition to ventricular fibrillation: a new approach to antiarrhythmic drug evaluation
    J N Weiss
    Department of Medicine, UCLA Cardiovascular Research Laboratory, UCLA School of Medicine and Cedars Sinai Medical Center, Los Angeles, CA, USA
    Circulation 99:2819-26. 1999
    ....
  12. ncbi request reprint The dynamics of cardiac fibrillation
    James N Weiss
    Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095 1760, USA
    Circulation 112:1232-40. 2005
    ..As global properties, rather than local electrophysiological characteristics, dynamic factors represent an attractive target for novel therapies to prevent ventricular fibrillation...
  13. ncbi request reprint Ventricular fibrillation: how do we stop the waves from breaking?
    J N Weiss
    Cardiovascular Research Laboratory and the Departments of Medicine Cardiology, Physiology and Physiological Science, UCLA School of Medicine and Cedars Sinai Medical Center, Los Angeles, CA 90095 1760, USA
    Circ Res 87:1103-7. 2000
    ..Developing therapies that favorably alter electrical restitution properties have promise as a new paradigm for preventing fibrillation...
  14. ncbi request reprint Understanding biological complexity: lessons from the past
    James N Weiss
    The UCLA Cardiovascular Research Laboratory, and Department of Medicine Cardiology, UCLA School of Medicine, Los Angeles, California 90095 1760, USA
    FASEB J 17:1-6. 2003
    ..When combined, they are highly synergistic in analyzing the mechanisms underlying the behavior of complex biological systems. Their effective integration will be essential for unraveling the physical basis of the mysteries of life...
  15. pmc Alternans and arrhythmias: from cell to heart
    James N Weiss
    Department of Medicine, University of California at Los Angeles, 90095, USA
    Circ Res 108:98-112. 2011
    ..Throughout, we emphasize the qualitatively novel properties that emerge at each new scale of integration...
  16. pmc Early afterdepolarizations and cardiac arrhythmias
    James N Weiss
    UCLA Cardiovascular Research Laboratory, Departments of Medicine Cardiology, Physiology and Integrative Biology and Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
    Heart Rhythm 7:1891-9. 2010
    ....
  17. ncbi request reprint Electrical restitution and cardiac fibrillation
    James N Weiss
    Department of Medicine, UCLA School of Medicine, Cedars Sinai Medical Center, Los Angeles, California 90095 1760, USA
    J Cardiovasc Electrophysiol 13:292-5. 2002
    ..Developing therapies that favorably alter these cardiac electrical restitution properties are a promising new approach to preventing fibrillation...
  18. pmc Increased susceptibility of aged hearts to ventricular fibrillation during oxidative stress
    Norishige Morita
    Translational Arrhythmia Research Laboratory and Cardiovascular Research Laboratory, Division of Cardiology, Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, USA
    Am J Physiol Heart Circ Physiol 297:H1594-605. 2009
    ..We conclude that in aged ventricles exposed to oxidative stress, fibrosis facilitates the ability of cellular EADs to emerge and generate TA, VT, and VF at the tissue level...
  19. pmc Remodelling of action potential and intracellular calcium cycling dynamics during subacute myocardial infarction promotes ventricular arrhythmias in Langendorff-perfused rabbit hearts
    Chung Chuan Chou
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, CA, USA
    J Physiol 580:895-906. 2007
    ....
  20. pmc Molecular mechanism for ATP-dependent closure of the K+ channel Kir6.2
    Scott A John
    UCLA Cardiovascular Research Laboratory, Department of Physiology, UCLA School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
    J Physiol 552:23-34. 2003
    ..Binding of the alpha phosphate group of ATP to R201 then stabilizes the closed state. R50 on the N-terminus controls ATP binding by facilitating the interaction of the beta phosphate group of ATP with K185 to destabilize the open state...
  21. ncbi request reprint Cardiac alternans in embryonic mouse ventricles
    Carlos de Diego
    Division of Cardiology, David Geffen School of Medicine at UCLA, University of California Los Angeles, CA 90095, USA
    Am J Physiol Heart Circ Physiol 294:H433-40. 2008
    ..5 and older hearts. Embryonic mouse ventricles can develop cardiac alternans, which generally is well correlated with APD restitution slope and does not depend on fully functional SR Ca(i) cycling...
  22. ncbi request reprint Effects of early afterdepolarizations on reentry in cardiac tissue: a simulation study
    Ray B Huffaker
    Department of Computer Science, David Geffen School of Medicine at University of California, Los Angeles, CA 90095 1596, USA
    Am J Physiol Heart Circ Physiol 292:H3089-102. 2007
    ..These findings may explain many features of Torsades des pointes, such as perpetuation by focal excitations, rapidly changing electrical axis, frequent self-termination, and occasional degeneration to fibrillation...
  23. pmc Virtual electrodes and the induction of fibrillation in Langendorff-perfused rabbit ventricles: the role of intracellular calcium
    Hideki Hayashi
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, California, USA
    Am J Physiol Heart Circ Physiol 295:H1422-8. 2008
    ..However, the inhibition of the sarcoplasmic reticulum function also reduced VFT, indicating that the [Ca(2+)](i) dynamics modulate, but are not essential, to ventricular vulnerability...
  24. pmc Calcium transient dynamics and the mechanisms of ventricular vulnerability to single premature electrical stimulation in Langendorff-perfused rabbit ventricles
    Hideki Hayashi
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, California, USA
    Heart Rhythm 5:116-23. 2008
    ..We hypothesize that Ca current-mediated slow-response action potentials (APs) play a key role in the propagation in the central common pathway (CCP) of the reentry...
  25. pmc Cardiac alternans induced by fibroblast-myocyte coupling: mechanistic insights from computational models
    Yuanfang Xie
    Department of Medicine Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
    Am J Physiol Heart Circ Physiol 297:H775-84. 2009
    ..Thus, through their coupling with myocytes, fibroblasts alter repolarization and Ca(i) cycling alternans at both the cellular and tissue scales, which may play important roles in arrhythmogenesis in diseased cardiac tissue with fibrosis...
  26. doi request reprint Spatially discordant alternans in cardiomyocyte monolayers
    Carlos de Diego
    Cardiovascular Research Laboratory, Department of Medicine, Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
    Am J Physiol Heart Circ Physiol 294:H1417-25. 2008
    ....
  27. pmc Diastolic intracellular calcium-membrane voltage coupling gain and postshock arrhythmias: role of purkinje fibers and triggered activity
    Mitsunori Maruyama
    Krannert Institute of Cardiology and the Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, USA
    Circ Res 106:399-408. 2010
    ..Recurrent ventricular arrhythmias after initial successful defibrillation are associated with poor clinical outcome...
  28. ncbi request reprint Intracellular calcium and vulnerability to fibrillation and defibrillation in Langendorff-perfused rabbit ventricles
    Gyo Seung Hwang
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA
    Circulation 114:2595-603. 2006
    ..The role of intracellular calcium (Ca(i)) in defibrillation and vulnerability is unclear...
  29. pmc A rabbit ventricular action potential model replicating cardiac dynamics at rapid heart rates
    Aman Mahajan
    UCLA Cardiovascular Research Laboratory, Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
    Biophys J 94:392-410. 2008
    ....
  30. ncbi request reprint Influence of channel subunit composition on L-type Ca2+ current kinetics and cardiac wave stability
    Vadim Gudzenko
    Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine, University of California Los Angeles 90095 7115, USA
    Am J Physiol Heart Circ Physiol 293:H1805-15. 2007
    ..These results imply that subunit modification of L-type Ca(2+) channels can potentially be used as an antifibrillatory strategy...
  31. ncbi request reprint A tale of two fibrillations
    Peng Sheng Chen
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, Calif, USA
    Circulation 108:2298-303. 2003
  32. pmc Bifurcation and chaos in a model of cardiac early afterdepolarizations
    Diana X Tran
    Department of Medicine, Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
    Phys Rev Lett 102:258103. 2009
    ..During period pacing, chaos always occurs at the transition from no EAD to EADs as the stimulation frequency decreases, providing a distinct explanation for the irregular EAD behavior frequently observed in experiments...
  33. ncbi request reprint Two types of ventricular fibrillation in isolated rabbit hearts: importance of excitability and action potential duration restitution
    Tsu Juey Wu
    Division of Cardiology, Department of Medicine, Taichung Veterans General Hospital and Institute of Clinical Medicine, Cardiovascular Research Center, National Yang Ming University School of Medicine, Taipei, Taiwan
    Circulation 106:1859-66. 2002
    ..The combined effects of excitability and action potential duration (APD) restitution on wavefront dynamics remain unclear...
  34. doi request reprint Vulnerability to re-entry in simulated two-dimensional cardiac tissue: effects of electrical restitution and stimulation sequence
    Diana X Tran
    Cardiovascular Research Laboratories, Department of Physiological Science, David Geffen School of Medicine at UCLA, University of California, Los Angeles, California 90095, USA
    Chaos 17:043115. 2007
    ..When APD restitution is even steeper, the vulnerable window is reduced due to collision of the spiral tips...
  35. pmc A simulation study of the effects of cardiac anatomy in ventricular fibrillation
    Fagen Xie
    Department of Medicine Cardiology, Cardiovascular Research Laboratory, University of California, Los Angeles UCLA, Los Angeles, California 90095 1679, USA
    J Clin Invest 113:686-93. 2004
    ..Thus, interventions that promote dynamical wave stability show promise as an antifibrillatory strategy in this more realistic setting...
  36. ncbi request reprint Effects of metabolic inhibition on conduction, Ca transients, and arrhythmia vulnerability in embryonic mouse hearts
    Fuhua Chen
    Cardiovascular Research Laboratory, David Geffen School of Medicine at University of California, Los Angeles, California 90095 1760, USA
    Am J Physiol Heart Circ Physiol 293:H2472-8. 2007
    ..These data support the idea that both glycolysis and oxidative phosphorylation play critical metabolic roles in regulating cardiac function in the embryonic mouse heart...
  37. ncbi request reprint Intracellular Ca dynamics in ventricular fibrillation
    Chikaya Omichi
    Division of Cardiology, Cedars Sinai Medical Center and Center for Health Sciences, University of California Los Angeles Cardiovascular Research Laboratory, David Geffen School of Medicine, UCLA, Los Angeles, California 90095 1760, USA
    Am J Physiol Heart Circ Physiol 286:H1836-44. 2004
    ..Cai is closely associated with Vm closely during pacing and VT but not during VF. These findings suggest that during VF, non-voltage-gated Cai release events occur and may influence wavebreak by altering Vm and APD locally...
  38. pmc Glycolytic oscillations in isolated rabbit ventricular myocytes
    Jun Hai Yang
    Cardiovascular Research Laboratory, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90095 1760, USA
    J Biol Chem 283:36321-7. 2008
    ....
  39. pmc Multisite phosphorylation and network dynamics of cyclin-dependent kinase signaling in the eukaryotic cell cycle
    Ling Yang
    Departments of Medicine Cardiology and Physiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, California 90095, USA
    Biophys J 86:3432-43. 2004
    ..In summary, our findings suggest that multisite phosphorylation of proteins is a critical biological mechanism in generating the essential dynamics and ensuring robust behavior of the cell cycle...
  40. ncbi request reprint Intracellular calcium cycling, early afterdepolarizations, and reentry in simulated long QT syndrome
    Ray Huffaker
    Department of Computer Science, University of California, Los Angeles, 90095, USA
    Heart Rhythm 1:441-8. 2004
    ..The purpose of this study was to investigate interactions between early afterdepolarizations (EADs) and reentry in long QT (LQT) syndromes...
  41. pmc Arrhythmogenic consequences of intracellular calcium waves
    Lai Hua Xie
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
    Am J Physiol Heart Circ Physiol 297:H997-H1002. 2009
    ..These findings link Ca(i)(2+) waves directly to a variety of arrhythmogenic phenomena relevant to the intact heart...
  42. pmc Long polyamines act as cofactors in PIP2 activation of inward rectifier potassium (Kir2.1) channels
    Lai Hua Xie
    Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, CA 90095, USA
    J Gen Physiol 126:541-9. 2005
    ..Sustained pore block by polyamines was neither sufficient nor necessary for this effect. We conclude that long polyamines serve a dual role as both blockers and coactivators (with PIP2) of Kir2.1 channels...
  43. pmc Dynamic origin of spatially discordant alternans in cardiac tissue
    Hideki Hayashi
    Division of Cardiology, Cedars Sinai Medical Center, Los Angeles, California, USA
    Biophys J 92:448-60. 2007
    ..Our results support the viewpoint that spatially discordant alternans in the heart can be formed via a dynamical pattern formation process which does not require tissue heterogeneity...
  44. ncbi request reprint Frequency analysis of ventricular fibrillation in Swine ventricles
    Miguel Valderrabano
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, CA, USA
    Circ Res 90:213-22. 2002
    ..In conclusion, stable intramural reentry as the engine of fibrillation was not observed. Our findings support the idea that dynamic wavebreak plays a fundamental role in the generation and maintenance of ventricular fibrillation...
  45. pmc Intracellular Ca alternans: coordinated regulation by sarcoplasmic reticulum release, uptake, and leak
    Lai Hua Xie
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at the University of California, Los Angeles, California 90095, USA
    Biophys J 95:3100-10. 2008
    ..Thus, BayK8644 promotes, whereas Ad-SERCA2a overexpression, ryanodine, and FK506 suppress, Ca(i) alternans under AP clamp conditions...
  46. ncbi request reprint Dispersion of refractoriness and induction of reentry due to chaos synchronization in a model of cardiac tissue
    Yuanfang Xie
    Department of Medicine Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
    Phys Rev Lett 99:118101. 2007
    ..These regions of increased refractoriness create localized conduction block, which induces spiral wave reentry...
  47. pmc Protection of cardiac mitochondria by diazoxide and protein kinase C: implications for ischemic preconditioning
    Paavo Korge
    University of California Cardiovascular Research Laboratory and Department of Medicine Cardiology, University of California School of Medicine, Los Angeles, CA 90095, USA
    Proc Natl Acad Sci U S A 99:3312-7. 2002
    ....
  48. pmc Superiority of biphasic over monophasic defibrillation shocks is attributable to less intracellular calcium transient heterogeneity
    Gyo Seung Hwang
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, California, USA
    J Am Coll Cardiol 52:828-35. 2008
    ..The purpose of this study was to test the hypothesis that superiority of biphasic waveform (BW) over monophasic waveform (MW) defibrillation shocks is attributable to less intracellular calcium (Ca(i)) transient heterogeneity...
  49. pmc Spark-induced sparks as a mechanism of intracellular calcium alternans in cardiac myocytes
    Robert Rovetti
    Department of Mathematics, Loyola Marymount University, Los Angeles, Calif, USA
    Circ Res 106:1582-91. 2010
    ..Intracellular calcium (Ca) alternans has been widely studied in cardiac myocytes and tissue, yet the underlying mechanism remains controversial...
  50. pmc Inward rectification by polyamines in mouse Kir2.1 channels: synergy between blocking components
    Lai Hua Xie
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA
    J Physiol 550:67-82. 2003
    ..1, is consistent with longer polyamines binding at their positively charged ends to the E224 and E299 positions in the same subunit, potentially accommodating four polyamine molecules per channel...
  51. pmc Effects of fibroblast-myocyte coupling on cardiac conduction and vulnerability to reentry: A computational study
    Yuanfang Xie
    Department of Medicine Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California 90095, USA
    Heart Rhythm 6:1641-9. 2009
    ....
  52. ncbi request reprint Spatiotemporal correlation between phase singularities and wavebreaks during ventricular fibrillation
    Yen Bin Liu
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, California, USA
    J Cardiovasc Electrophysiol 14:1103-9. 2003
    ..Phase Singularity and Wavebreak...
  53. pmc Irregularly appearing early afterdepolarizations in cardiac myocytes: random fluctuations or dynamical chaos?
    Daisuke Sato
    Department of Medicine Cardiology, David Geffen School of Medicine at University of California, Los Angeles, California, USA
    Biophys J 99:765-73. 2010
    ..We conclude that the irregular dynamics of EADs is intrinsically chaotic, with random fluctuations playing a nonessential, auxiliary role potentiating the complex dynamics...
  54. ncbi request reprint Action potential duration restitution and ventricular fibrillation due to rapid focal excitation
    Moshe Swissa
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, California 90048, USA
    Am J Physiol Heart Circ Physiol 282:H1915-23. 2002
    ..In this model of focal source VF, the VT-to-VF transition occurred due to a wave break outside the aconitine site, and drugs that flattened the APD restitution slope converted VF to VT despite continuous activation from aconitine site...
  55. pmc Intracellular calcium dynamics and acceleration of sinus rhythm by beta-adrenergic stimulation
    Boyoung Joung
    Krannert Institute of Cardiology and the Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, USA
    Circulation 119:788-96. 2009
    ..Here we test the hypothesis that sinus rate acceleration by beta-adrenergic stimulation involves synergistic interactions between these clock mechanisms...
  56. ncbi request reprint Atrioventricular ring reentry in embryonic mouse hearts
    Miguel Valderrabano
    Department of Medicine, David Geffen School of Medicine at UCLA, 675 Charles Young Dr So, 3645 MRL, Los Angeles, Calif 90095 1760, USA
    Circulation 114:543-9. 2006
    ..We studied AV conduction during this transition and its sensitivity to autonomic modulation...
  57. ncbi request reprint Nitric oxide donors protect murine myocardium against infarction via modulation of mitochondrial permeability transition
    Guangwu Wang
    Department of Physiology, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
    Am J Physiol Heart Circ Physiol 288:H1290-5. 2005
    ..These data suggest that a critical process during NO donor-induced cardioprotection is to prevent MPT pore opening potentially via targeting of the adenine nucleotide translocator...
  58. pmc Hysteresis and cell cycle transitions: how crucial is it?
    Zhangang Han
    Cardiovascular Research Laboratory, Department of Medicine Cardiology, David Geffen School of Medicine at the University of California, Los Angeles, California 90095, USA
    Biophys J 88:1626-34. 2005
    ..Thus, although a hysteretic response is neither necessary nor sufficient, it is in general a much more robust mechanism for generating cell cycle dynamics than nonhysteretic mechanisms...
  59. ncbi request reprint Autonomic regulation of calcium cycling in developing embryonic mouse hearts
    Fuhua Chen
    Department of Pediatrics and the Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 675 Charles Young Drive So 3754 MRL, Los Angeles, CA 90095 7045, USA
    Cell Calcium 39:375-85. 2006
    ..These results define the functional and structural sequence of autonomic regulation of Ca(2+) transient in the embryonic mouse heart...
  60. ncbi request reprint The pinwheel experiment revisited: effects of cellular electrophysiological properties on vulnerability to cardiac reentry
    Ming Jim Yang
    Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California, Los Angeles 90095, USA
    Am J Physiol Heart Circ Physiol 293:H1781-90. 2007
    ..We derive an analytical treatment that shows good agreement with numerical simulation results...
  61. pmc Modifying L-type calcium current kinetics: consequences for cardiac excitation and arrhythmia dynamics
    Aman Mahajan
    UCLA Cardiovascular Research Laboratory, Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
    Biophys J 94:411-23. 2008
    ..These findings provide a proof-of-concept test that I(Ca,L) can be targeted to increase dynamic wave stability without depressing contractility, which may have promise as an antifibrillatory strategy...
  62. pmc Tachycardia-induced early afterdepolarizations: insights into potential ionic mechanisms from computer simulations
    Ray B Huffaker
    Department of Computer Science, University of California, 405 Hilgard Avenue, Los Angeles, CA 90095 1596, USA
    Comput Biol Med 38:1140-51. 2008
    ..Using two previously suggested spontaneous release morphologies, we found two distinct tachycardia-induced EAD mechanisms: one mechanistically similar to bradycardia-induced EADs, the other to delayed afterdepolarizations (DADs)...
  63. pmc ATP-sensitive K+ channels: regulation of bursting by the sulphonylurea receptor, PIP2 and regions of Kir6.2
    Bernard Ribalet
    University of California Los Angeles Cardiovascular Research Laboratory, 90095, USA
    J Physiol 571:303-17. 2006
    ..In conjunction with this PIP2-dependent process, SUR1 also regulates channel activity via a PIP2-independent, but MgADP-dependent process...
  64. pmc Dynamics of the cell cycle: checkpoints, sizers, and timers
    Zhilin Qu
    Cardiovascular Research Laboratory, Departments of Medicine Cardiology and Physiology, David Geffen School of Medicine at University of California, Los Angeles, California 90095, USA
    Biophys J 85:3600-11. 2003
    ..This model successfully reproduces sizer, timer, and the restriction point features of the eukaryotic cell cycle, in addition to other experimental findings...
  65. pmc Atrioventricular conduction and arrhythmias at the initiation of beating in embryonic mouse hearts
    Fuhua Chen
    UCLA Cardiovascular Research Laboratory, David Geffen School of Medicine, University of California Los Angeles, 675 Charles Young Drive South, Los Angeles, CA 90095, USA
    Dev Dyn 239:1941-9. 2010
    ..In summary, at the onset of beating, I(f)-dependent pacemaking drives both AP propagation and Ca(i) transient generation through activation of voltage-dependent Ca channels. Na channels and intracellular Ca cycling have minor roles...
  66. ncbi request reprint Redox regulation of endogenous substrate oxidation by cardiac mitochondria
    Paavo Korge
    Cardiovascular Research Laboratory, Department of Medicine, David Geffen University of California Los Angeles, School of Medicine, 3641 MRL Bldg, Los Angeles, CA 90095, USA
    Am J Physiol Heart Circ Physiol 291:H1436-45. 2006
    ..Incapacitation of this mechanism may potentially contribute to mitochondrial dysfunction during oxidative stress...
  67. pmc Anisotropic conduction block and reentry in neonatal rat ventricular myocyte monolayers
    Carlos de Diego
    Cardiovascular Research Laboratory, Department of Medicine Cardiology and Physiology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095, USA
    Am J Physiol Heart Circ Physiol 300:H271-8. 2011
    ....
  68. pmc Phosphatidylinositol-4,5-bisphosphate (PIP2) regulation of strong inward rectifier Kir2.1 channels: multilevel positive cooperativity
    Lai Hua Xie
    Cardiovascular Research Laboratory, Rm 3645 MRL Building, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
    J Physiol 586:1833-48. 2008
    ..Interaction with additional subunits exerts positive cooperativity at multiple levels to further enhance channel availability and promote the fully open state...
  69. ncbi request reprint Effects of amiodarone on wave front dynamics during ventricular fibrillation in isolated swine right ventricle
    Chikaya Omichi
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, University of California at Los Angeles School of Medicine, Los Angeles, California 90048 1865, USA
    Am J Physiol Heart Circ Physiol 282:H1063-70. 2002
    ..We conclude that amiodarone reduced spontaneous wave breaks. It might terminate VF or convert VF to VT. These effects were associated with the flattening of APD restitution slope and increased core size of reentrant wave fronts...
  70. ncbi request reprint Coexistence of two types of ventricular fibrillation during acute regional ischemia in rabbit ventricle
    Yen Bin Liu
    Division of Cardiology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, California 90048, USA
    J Cardiovasc Electrophysiol 15:1433-40. 2004
    ..We hypothesize that the two types of VF can coexist in acutely ischemic ventricles...
  71. doi request reprint Calcium dynamics and ventricular fibrillation
    Masahiro Ogawa
    Circ Res 102:e52. 2008
  72. ncbi request reprint Mother rotors and the mechanisms of D600-induced type 2 ventricular fibrillation
    Tsu Juey Wu
    Cardiovascular Center, Taichung Veterans General Hospital and Institute of Clinical Medicine, National Yang Ming University School of Medicine, Taipei, Taiwan
    Circulation 110:2110-8. 2004
    ..Type 1 VF is characterized by the presence of multiple, wandering wavelets, whereas type 2 VF shows local spatiotemporal periodicity. We hypothesized that a single mother rotor underlies type 2 VF...
  73. pmc Mechanism of inward rectification in Kir channels
    Scott A John
    J Gen Physiol 123:623-5. 2004
  74. ncbi request reprint The chicken or the egg? Voltage and calcium dynamics in the heart
    Zhilin Qu
    Am J Physiol Heart Circ Physiol 293:H2054-5. 2007
  75. pmc Molecular basis for Kir6.2 channel inhibition by adenine nucleotides
    Bernard Ribalet
    UCLA Cardiovascular Research Laboratory, Department of Physiology, University of California Los Angeles School of Medicine, 90095, USA
    Biophys J 84:266-76. 2003
    ..Based on these results a structural scheme is proposed, which includes features of other recently published models...
  76. pmc Reactive oxygen species production in energized cardiac mitochondria during hypoxia/reoxygenation: modulation by nitric oxide
    Paavo Korge
    Cardiovascular Research Laboratory, Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
    Circ Res 103:873-80. 2008
    ....
  77. pmc Systems approach to understanding electromechanical activity in the human heart: a national heart, lung, and blood institute workshop summary
    Yoram Rudy
    Cardiac Bioelectricity and Arrhythmia Center, The Fred Saigh Distinguished Professor, Washington University, Campus Box 1097, Whitaker Hall Room 290B, One Brookings Dr, St Louis, MO 63130 4899, USA
    Circulation 118:1202-11. 2008
    ..The recommendations can be found on the NHLBI Web site at http://www.nhlbi.nih.gov/meetings/workshops/electro.htm...
  78. ncbi request reprint Electrophysiological characterization of cardiac veins in humans
    David A Cesario
    UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles CA
    J Interv Card Electrophysiol 10:241-7. 2004
    ..The purpose of this study was to evaluate the electrical activity of the coronary sinus (CS), great cardiac vein (GCV) and related structures, such as the Vein of Marshall (VOM)...
  79. pmc Regulation of gating by negative charges in the cytoplasmic pore in the Kir2.1 channel
    Lai Hua Xie
    Cardiovascular Research Laboratory, Department of Medicine, David Geffen School of Medicine at UCLA, 675 Young Drive South, MRL 3645, Los Angeles, CA 90095, USA
    J Physiol 561:159-68. 2004
    ..1 channels. By suppressing fast gating, these negative charges facilitate polyamine block and unblock, which may be their physiologically important role...
  80. pmc Inferring the cellular origin of voltage and calcium alternans from the spatial scales of phase reversal during discordant alternans
    Daisuke Sato
    Biophys J 92:L33-5. 2007
    ..These results show that experimentally accessible measurements of Ca(i) and V(m) in cardiac tissue can be used to shed light on the cellular origin of alternans...
  81. pmc Calsequestrin-mediated mechanism for cellular calcium transient alternans
    Juan G Restrepo
    Physics Department and Center for Interdisciplinary Research in Complex Systems, Northeastern University, Boston, Massachusetts, USA
    Biophys J 95:3767-89. 2008
    ..The ability to link microscopic properties of the calcium release units to whole cell behavior makes this model a powerful tool to investigate the arrhythmogenic role of abnormal calcium handling in many pathological settings...

Research Grants11

  1. Metabolic Oscillations in Heart
    JAMES N contact WEISS; Fiscal Year: 2010
    ..These insights may suggest novel therapies to protect the heart from injury during metabolic stresses such as heart attacks. ..
  2. Cardiac Fibrillation: Mechanisms and Therapy
    James Weiss; Fiscal Year: 2007
    ....
  3. PROPERTIES OF INWARD RECTIFIER K CHANNELS
    James Weiss; Fiscal Year: 2007
    ..Together, these studies in Kir channels will provide important insights into the regulation of excitability in ventricular and atrial cardiac muscle, as well as in other excitable tissues. ..
  4. Mitochondria and Cardiac Cell Death
    James Weiss; Fiscal Year: 2007
    ....
  5. CARDIOVASCULAR SCIENTIST TRAINING PROGRAM
    James Weiss; Fiscal Year: 2007
    ..D.), the UCLA Cardiology STAR Program provides graduates with the rigorous research background essential to translate advances in molecular health sciences into modern molecular medicine. ..
  6. Afterdepolarizations and Cardiac Arrhythmias
    James N Weiss; Fiscal Year: 2010
    ..S. citizens each year. The goal is to use this information to develop novel therapies to prevent this deadly manifestation of heart disease. ..