Remodeling of cardiac passive electrical properties and susceptibility to ventricular and atrial arrhythmias

• Record Nr.: UNINA9910137093003321
• Autore: George E. Billman
• Pubbl/distr/stampa: Frontiers Media SA, 2015
• Descrizione fisica: 1 online resource (141 p.)
• Collana: Frontiers Research Topics
• Soggetti: Physiology
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Sommario/riassunto: The effective management of cardiac arrhythmias, either of atrial or of ventricular origin, remains a major challenge. Sudden cardiac death due to ventricular tachyarrhythmias remains the leading cause of death in industrialized countries while atrial fibrillation is the most common rhythm disorder; an arrhythmia that's prevalence is increasing and accounts for nearly one quarter of ischemic stokes the elderly population. Yet, despite the enormity of the problem, effective therapeutic interventions remain elusive. In fact, several initially promising antiarrhythmic agents were found to increase rather than decrease mortality in patients recovering from myocardial infarction. The question then is what went wrong, why have these interventions proven to be so ineffective? An obvious answer is the drugs were designed to attack the wrong therapeutic target. Clearly, targeting single ion channels (using either isolated ion channels or single myocytes preparations) has proven to be less than effective. What then is the appropriate target? It is well established that cardiac electrical properties can vary substantially between single cells and intact preparations. One obvious example is the observation that action potential duration is much longer in isolated cells as compared to multi-cellular preparations or intact hearts. Due to the low electrical resistance between adjacent myocytes, the cells act in coordinated fashion producing "electrotonic interdependence" between neighboring cells. Myocardial infarction and/or acute ischemia provoke profound ; changes in the passive electrical properties of cardiac muscle. In particular, electrotonic uncoupling of the myocytes disrupts the coordinated activation and repolarization of cardiac tissue. The resulting compensatory changes in ionic currents decrease cardiac electrical stability increasing the risk for life-threatening changes in the cardiac rhythm. Thus, the electrical properties of myocardial cells must be considered as a unit rather than in isolation. It is the purpose of this Research Topic to evaluate the largely neglected relationship between changes in passive electrical properties of cardiac muscle and arrhythmia formation.

Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery

• Record Nr.: UNINA9910482867603321
• Autore: Naletoski Ivancho
• Pubbl/distr/stampa: Springer Nature, 2021; Berlin, Heidelberg : , : Springer Berlin / Heidelberg, , 2021; ©2021
• ISBN: 3-662-63021-4
• Descrizione fisica: 1 online resource (206 pages)
• Classificazione: MED003010MED078000MED089000SCI007000SCI020000
• Altri autori (Persone): LuckinsAnthony G; ViljoenGerrit
• Soggetti: Contaminació radioactiva; Producció animal; Veterinària preventiva; Veterinary medicine; Public health & preventive medicine; Accident & emergency medicine; Animal ecology; Biochemistry; Llibres electrònics
• Lingua di pubblicazione: Inglese
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Nota di contenuto: Intro -- Foreword -- Acknowledgements -- Introduction -- Contents -- About the Contributors -- Abbreviations -- Chapter 1: National Veterinary Services Roles and Responsibilities in Preparing for and Responding to Nuclear and Radiological Emergencies -- References -- Chapter 2: Short Refresher of Radiobiology -- 2.1 Atoms and Isotopes -- 2.2 Definition of Radiation -- 2.3 Types of Ionizing Radiation -- 2.3.1 ß− Decay -- 2.3.2 ß+ Decay -- 2.3.3 Electron Capture -- 2.4 Physical Half-Life of Radioactive Isotopes -- 2.5 Biological Half-Life of the Radioactive Isotopes -- 2.6 Effective Half-Life of the Radioactive Isotopes in the Body of Animals -- 2.7 Decay Chains and Ingrowth -- 2.8 Units of Radioactivity -- 2.9 Specific Radioactivity -- 2.10 Radiation Dose -- 2.11 Effective Dose Equivalent -- 2.12 Lethal Dose -- 2.13 Interaction of the Ionizing Radiation with the Matter -- 2.14 The Sources of Man-Made Environmental Contamination -- References -- Chapter 3: Measurement of Radioactivity -- 3.1 Measuring Instruments -- 3.1.1 Personnel Dosimeters -- 3.2 Measuring Contamination Levels in Live Farm Animals -- References -- Chapter 4: Preparedness and Response to Nuclear and Radiological Emergencies in Animal Production Systems in the Context of IAEA Safety Standards -- 4.1 Relevant IAEA Publications on Emergency Preparedness and Response for Animal Production Systems -- 4.2 Phases of a Nuclear or Radiological Emergency -- 4.2.1 The Preparedness Stage -- 4.2.1.1 Hazard Assessment -- 4.2.1.2 Development, Justification and Optimisation of a Protection Strategy -- 4.2.1.3 International Trade of Food Following a Nuclear or Radiological Emergency -- 4.2.1.4 OILs for Triggering Food, Milk and Drinking Water Restrictions -- 4.2.1.5 Emergency Planning Zones and Emergency Planning Distances -- 4.2.2 Emergency Exposure Situation -- 4.2.2.1 The Urgent Response Phase.; 4.2.2.2 The Early Response Phase -- 4.2.2.3 The Transition Phase -- 4.2.2.4 Radioactive Waste Management -- 4.2.2.5 Dealing with Non-radiological Consequences -- 4.2.3 The Termination of a Nuclear or Radiological Emergency -- 4.2.4 Planned or Existing Exposure Situation -- 4.2.4.1 Restrictions on Food, Milk and Drinking Water After the Termination of an Emergency -- References -- Chapter 5: Environmental Pathways of Radionuclides to Animal Products in Different Farming and Harvesting Systems -- 5.1 Major Nuclear or Radiological Emergencies Causing Animal and Animal Product Contamination -- 5.2 Key Environmental Processes Controlling Animal Product Contamination -- 5.2.1 Vegetation Interception -- 5.2.2 Chemical Form of the Released Radionuclides -- 5.2.3 Radionuclide Behaviour in Soils -- 5.2.4 Radionuclide Transfer from Soil to Crops -- 5.2.5 Quantification of Radionuclide Transfer to Plants and Fodder Crops -- 5.2.6 Intake and Absorption of Radionuclides by Animals -- 5.2.7 Gastrointestinal Absorption -- 5.2.8 Quantification of Radionuclide Transfer to Animal Products -- 5.2.9 Quantification of the Time Dependency of Radionuclide Activity Concentrations in Animal Products -- 5.2.10 Biological Half-Life () in Animal Tissues -- 5.2.11 Ecological and Effective Half-Lives -- 5.3 Monitoring Animal Food Products -- 5.4 Radionuclide Transfer to Intensively Farmed Agricultural Animals -- 5.4.1 Soil and Plant Aspects -- 5.4.1.1 Radioiodine -- 5.4.1.2 Radiocaesium -- 5.4.1.3 Radiostrontium -- 5.4.1.4 Other Radionuclides -- 5.4.2 Dairy Production -- 5.4.2.1 Radioiodine -- 5.4.2.2 Radiocaesium -- 5.4.2.3 Radiostrontium -- 5.4.3 Meat and Offal Production -- 5.4.3.1 Transfer of Radionuclides to Meat -- 5.4.3.2 Other Accumulating Tissues -- 5.4.3.3 Target Tissues for Different Radionuclides -- 5.5 Radionuclide Transfer in Non-intensive Animal Production.; 5.5.1 Dairy Production in Low-Productivity Areas -- 5.5.2 Meat Production in Low-Productivity Areas -- 5.6 Radionuclide Transfer to Game Animals -- 5.6.1 Forest Environments -- 5.7 Impacts on the Health of Livestock Exposed to Nuclear Contamination -- 5.8 Routes of Radionuclide Intake via Aquatic Pathways -- 5.8.1 Radionuclides in Freshwater Fish -- 5.9 The Risk for Public Health (Placement on the Market for Human Consumption) -- 5.9.1 Radioiodine -- 5.9.2 Radiocaesium -- 5.9.3 Other Radionuclides -- References -- Chapter 6: Management Options for Animal Production Systems: Which Ones to Choose in the Event of a Nuclear or Radiological Emergency? -- 6.1 Introduction -- 6.2 Management Options -- 6.3 Radionuclides of Importance -- 6.4 Seasonality and Radioecological Zoning -- 6.5 Decision-Aiding Handbooks for Food Production Systems -- 6.5.1 Decision-Aiding Framework -- 6.5.2 Selection Tables (Step 2) -- 6.5.3 Applicability of Management Options for Different Radionuclides (Step 3) -- 6.5.4 Key Constraints Affecting Management Options (Step 4) -- 6.5.4.1 Technical Feasibility and Capacity -- 6.5.4.2 Timescales for Implementation -- 6.5.4.3 Waste Generation -- 6.5.4.4 Environmental Impact -- 6.5.4.5 Cost -- 6.5.5 Effectiveness of Management Options (Step 5) -- 6.5.6 Management Options Incurring an Additional Dose to Implementers (Step 6) -- 6.5.7 Consideration of the Datasheets (Step 7) -- 6.5.8 Selecting and Combining Options to Develop the Management Strategy (Step 8) -- References -- Chapter 7: Information Systems in Support of the Decision-Making Tools -- 7.1 The IAEA Unified System for Information Exchange in Incidents and Emergencies (USIE) -- 7.2 Decision Support System for Nuclear Emergencies Affecting Food and Agriculture (DSS4NAFA) -- 7.3 iVetNet -- References.; Correction to: Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery -- Correction to: I. Naletoski et al. (eds.), Nuclear and Radiological Emergencies in Animal Production Systems, Preparedness, Response and Recovery, https://doi.org/10.1007/978-3-662-63021-1 -- Annexes -- Annex A: Datasheets on the Management Options -- Annex B: Worked Examples to Illustrate Decision-Aiding Framework.
• Sommario/riassunto: This Open Access volume explains how major nuclear and radiological emergencies (NREs) can have implications at local, national and international level. The response to NREs requires a competent decision-making structure, clear communication and effective information exchange. National veterinary services have the responsibility to plan, design and manage animal production system in their countries. These activities cover animal health, animal movement control, production control and improvement, and control of the products of animal origin before their placement on the market. Release of radionuclides after NREs can cause substantial contamination in the animal production systems. Critical responsibility of veterinary authorities is therefore to prevent such contamination, establish early response mechanisms to mitigate the consequences and prevent placement of contaminated products of animal origin on the market for human consumption. This work summarizes the critical technical points for effective management of NREs for national veterinary services.