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Sample records for cardiovascular system model

  1. Model Systems for Cardiovascular Regenerative Biology

    PubMed Central

    Garbern, Jessica C.; Mummery, Christine L.

    2013-01-01

    There is an urgent clinical need to develop new therapeutic approaches to treat heart failure, but the biology of cardiovascular regeneration is complex. Model systems are required to advance our understanding of biological mechanisms of cardiac regeneration as well as to test therapeutic approaches to regenerate tissue and restore cardiac function following injury. An ideal model system should be inexpensive, easily manipulated, easily reproducible, physiologically representative of human disease, and ethically sound. In this review, we discuss computational, cell-based, tissue, and animal models that have been used to elucidate mechanisms of cardiovascular regenerative biology or to test proposed therapeutic methods to restore cardiac function following disease or injury. PMID:23545574

  2. Computer model of cardiovascular control system responses to exercise

    NASA Technical Reports Server (NTRS)

    Croston, R. C.; Rummel, J. A.; Kay, F. J.

    1973-01-01

    Approaches of systems analysis and mathematical modeling together with computer simulation techniques are applied to the cardiovascular system in order to simulate dynamic responses of the system to a range of exercise work loads. A block diagram of the circulatory model is presented, taking into account arterial segments, venous segments, arterio-venous circulation branches, and the heart. A cardiovascular control system model is also discussed together with model test results.

  3. A novel approach to modeling and diagnosing the cardiovascular system

    SciTech Connect

    Keller, P.E.; Kangas, L.J.; Hashem, S.; Kouzes, R.T.; Allen, P.A.

    1995-07-01

    A novel approach to modeling and diagnosing the cardiovascular system is introduced. A model exhibits a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. Potentially, a model will be incorporated into a cardiovascular diagnostic system. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the variables of an individual at a given time are used for diagnosis. This approach also exploits sensor fusion to optimize the utilization of biomedical sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  4. A Computer Model of the Cardiovascular System for Effective Learning.

    ERIC Educational Resources Information Center

    Rothe, Carl F.

    1980-01-01

    Presents a model of the cardiovascular system which solves a set of interacting, possibly nonlinear, differential equations. Figures present a schematic diagram of the model and printouts that simulate normal conditions, exercise, hemorrhage, reduced contractility. The nine interacting equations used to describe the system are described in the…

  5. A Computer Model of the Cardiovascular System for Effective Learning.

    ERIC Educational Resources Information Center

    Rothe, Carl F.

    1980-01-01

    Presents a model of the cardiovascular system which solves a set of interacting, possibly nonlinear, differential equations. Figures present a schematic diagram of the model and printouts that simulate normal conditions, exercise, hemorrhage, reduced contractility. The nine interacting equations used to describe the system are described in the

  6. A Computer Model of the Cardiovascular System for Effective Learning.

    ERIC Educational Resources Information Center

    Rothe, Carl F.

    1979-01-01

    Described is a physiological model which solves a set of interacting, possibly nonlinear, differential equations through numerical integration on a digital computer. Sample printouts are supplied and explained for effects on the components of a cardiovascular system when exercise, hemorrhage, and cardiac failure occur. (CS)

  7. Multi-scale modeling of hemodynamics in the cardiovascular system

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Liang, Fuyou; Wong, Jasmin; Fujiwara, Takashi; Ye, Wenjing; Tsubota, Ken-iti; Sugawara, Michiko

    2015-08-01

    The human cardiovascular system is a closed-loop and complex vascular network with multi-scaled heterogeneous hemodynamic phenomena. Here, we give a selective review of recent progress in macro-hemodynamic modeling, with a focus on geometrical multi-scale modeling of the vascular network, micro-hemodynamic modeling of microcirculation, as well as blood cellular, subcellular, endothelial biomechanics, and their interaction with arterial vessel mechanics. We describe in detail the methodology of hemodynamic modeling and its potential applications in cardiovascular research and clinical practice. In addition, we present major topics for future study: recent progress of patient-specific hemodynamic modeling in clinical applications, micro-hemodynamic modeling in capillaries and blood cells, and the importance and potential of the multi-scale hemodynamic modeling.

  8. Isolated heart models: cardiovascular system studies and technological advances.

    PubMed

    Olejnickova, Veronika; Novakova, Marie; Provaznik, Ivo

    2015-07-01

    Isolated heart model is a relevant tool for cardiovascular system studies. It represents a highly reproducible model for studying broad spectrum of biochemical, physiological, morphological, and pharmaceutical parameters, including analysis of intrinsic heart mechanics, metabolism, and coronary vascular response. Results obtained in this model are under no influence of other organ systems, plasma concentration of hormones or ions and influence of autonomic nervous system. The review describes various isolated heart models, the modes of heart perfusion, and advantages and limitations of various experimental setups. It reports the improvements of perfusion setup according to Langendorff introduced by the authors. PMID:25773369

  9. A forward model-based validation of cardiovascular system identification

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Cohen, R. J.

    2001-01-01

    We present a theoretical evaluation of a cardiovascular system identification method that we previously developed for the analysis of beat-to-beat fluctuations in noninvasively measured heart rate, arterial blood pressure, and instantaneous lung volume. The method provides a dynamical characterization of the important autonomic and mechanical mechanisms responsible for coupling the fluctuations (inverse modeling). To carry out the evaluation, we developed a computational model of the cardiovascular system capable of generating realistic beat-to-beat variability (forward modeling). We applied the method to data generated from the forward model and compared the resulting estimated dynamics with the actual dynamics of the forward model, which were either precisely known or easily determined. We found that the estimated dynamics corresponded to the actual dynamics and that this correspondence was robust to forward model uncertainty. We also demonstrated the sensitivity of the method in detecting small changes in parameters characterizing autonomic function in the forward model. These results provide confidence in the performance of the cardiovascular system identification method when applied to experimental data.

  10. An integrated mathematical model of the cardiovascular and respiratory systems.

    PubMed

    Trenhago, Paulo Roberto; Fernandes, Luciano Gonalves; Mller, Lucas Omar; Blanco, Pablo Javier; Feijo, Ral Antonino

    2016-01-01

    This study presents a lumped model for the human cardiorespiratory system. Specifically, we incorporate a sophisticated gas dissociation and transport system to a fully integrated cardiovascular and pulmonary model. The model provides physiologically consistent predictions in terms of hemodynamic variables such as pressure, flow rate, gas partial pressures, and pH. We perform numerical simulations to evaluate the behavior of the partial pressures of oxygen and carbon dioxide in different vascular and pulmonary compartments. For this, we design the rest condition with low oxygen requirements and carbon dioxide production and exercise conditions with high oxygen demand and carbon dioxide production. Furthermore, model sensitivity to more relevant model parameters is studied. Copyright 2015 John Wiley & Sons, Ltd. PMID:26198626

  11. Mathematical modelling of flow distribution in the human cardiovascular system

    NASA Technical Reports Server (NTRS)

    Sud, V. K.; Srinivasan, R. S.; Charles, J. B.; Bungo, M. W.

    1992-01-01

    The paper presents a detailed model of the entire human cardiovascular system which aims to study the changes in flow distribution caused by external stimuli, changes in internal parameters, or other factors. The arterial-venous network is represented by 325 interconnected elastic segments. The mathematical description of each segment is based on equations of hydrodynamics and those of stress/strain relationships in elastic materials. Appropriate input functions provide for the pumping of blood by the heart through the system. The analysis employs the finite-element technique which can accommodate any prescribed boundary conditions. Values of model parameters are from available data on physical and rheological properties of blood and blood vessels. As a representative example, simulation results on changes in flow distribution with changes in the elastic properties of blood vessels are discussed. They indicate that the errors in the calculated overall flow rates are not significant even in the extreme case of arteries and veins behaving as rigid tubes.

  12. Reintrepreting the cardiovascular system as a mechanical model

    NASA Astrophysics Data System (ADS)

    Lemos, Diogo; Machado, José; Minas, Graça; Soares, Filomena; Barros, Carla; Leão, Celina Pinto

    2013-10-01

    The simulation of the different physiological systems is very useful as a pedagogical tool, allowing a better understanding of the mechanisms and the functions of the processes. The observation of the physiological phenomena through mechanical simulators represents a great asset. Furthermore, the development of these simulators allows reinterpreting physiological systems, with the advantage of using the same transducers and sensors that are commonly used in diagnostic and therapeutic cardiovascular procedures for the monitoring of system' parameters. The cardiovascular system is one of the most important systems of the human body and has been the target of several biomedical studies. The present work describes a mechanical simulation of the cardiovascular system, in particularly, the systemic circulation, which can be described in terms of its hemodynamic variables. From the mechanical process and parameters, physiological system's behavior was reproduced, as accurately as possible.

  13. Mathematical modeling of human cardiovascular system for simulation of orthostatic response

    NASA Technical Reports Server (NTRS)

    Melchior, F. M.; Srinivasan, R. S.; Charles, J. B.

    1992-01-01

    This paper deals with the short-term response of the human cardiovascular system to orthostatic stresses in the context of developing a mathematical model of the overall system. It discusses the physiological issues involved and how these issues have been handled in published cardiovascular models for simulation of orthostatic response. Most of the models are stimulus specific with no demonstrated capability for simulating the responses to orthostatic stimuli of different types. A comprehensive model incorporating all known phenomena related to cardiovascular regulation would greatly help to interpret the various orthostatic responses of the system in a consistent manner and to understand the interactions among its elements. This paper provides a framework for future efforts in mathematical modeling of the entire cardiovascular system.

  14. Space physiology IV: mathematical modeling of the cardiovascular system in space exploration.

    PubMed

    Keith Sharp, M; Batzel, Jerry Joseph; Montani, Jean-Pierre

    2013-08-01

    Mathematical modeling represents an important tool for analyzing cardiovascular function during spaceflight. This review describes how modeling of the cardiovascular system can contribute to space life science research and illustrates this process via modeling efforts to study postflight orthostatic intolerance (POI), a key issue for spaceflight. Examining this application also provides a context for considering broader applications of modeling techniques to the challenges of bioastronautics. POI, which affects a large fraction of astronauts in stand tests upon return to Earth, presents as dizziness, fainting and other symptoms, which can diminish crew performance and cause safety hazards. POI on the Moon or Mars could be more critical. In the field of bioastronautics, POI has been the dominant application of cardiovascular modeling for more than a decade, and a number of mechanisms for POI have been investigated. Modeling approaches include computational models with a range of incorporated factors and hemodynamic sophistication, and also physical models tested in parabolic and orbital flight. Mathematical methods such as parameter sensitivity analysis can help identify key system mechanisms. In the case of POI, this could lead to more effective countermeasures. Validation is a persistent issue in modeling efforts, and key considerations and needs for experimental data to synergistically improve understanding of cardiovascular responses are outlined. Future directions in cardiovascular modeling include subject-specific assessment of system status, as well as research on integrated physiological responses, leading, for instance, to assessment of subject-specific susceptibility to POI or effects of cardiovascular alterations on muscular, vision and cognitive function. PMID:23539439

  15. Chronic stress impacts the cardiovascular system: animal models and clinical outcomes.

    PubMed

    Golbidi, Saeid; Frisbee, Jefferson C; Laher, Ismail

    2015-06-15

    Psychological stresses are associated with cardiovascular diseases to the extent that cardiovascular diseases are among the most important group of psychosomatic diseases. The longstanding association between stress and cardiovascular disease exists despite a large ambiguity about the underlying mechanisms. An array of possibilities have been proposed including overactivity of the autonomic nervous system and humoral changes, which then converge on endothelial dysfunction that initiates unwanted cardiovascular consequences. We review some of the features of the two most important stress-activated systems, i.e., the humoral and nervous systems, and focus on alterations in endothelial function that could ensue as a result of these changes. Cardiac and hematologic consequences of stress are also addressed briefly. It is likely that activation of the inflammatory cascade in association with oxidative imbalance represents key pathophysiological components of stress-induced cardiovascular changes. We also review some of the commonly used animal models of stress and discuss the cardiovascular outcomes reported in these models of stress. The unique ability of animals for adaptation under stressful conditions lessens the extrapolation of laboratory findings to conditions of human stress. An animal model of unpredictable chronic stress, which applies various stress modules in a random fashion, might be a useful solution to this predicament. The use of stress markers as indicators of stress intensity is also discussed in various models of animal stress and in clinical studies. PMID:25888514

  16. A cardiovascular system model for lower-body negative pressure response

    NASA Technical Reports Server (NTRS)

    Mitchell, B. A., Jr.; Giese, R. P.

    1971-01-01

    Mathematical models used to study complex physiological control systems are discussed. Efforts were made to modify a model of the cardiovascular system for use in studying lower body negative pressure. A computer program was written which allows orderly, straightforward expansion to include exercise, metabolism (thermal stress), respiration, and other body functions.

  17. Mathematical modelling of the human cardiovascular system in the presence of stenosis

    NASA Technical Reports Server (NTRS)

    Sud, V. K.; Srinivasan, R. S.; Charles, J. B.; Bungo, M. W.

    1993-01-01

    This paper reports a theoretical study on the distribution of blood flow in the human cardiovascular system when one or more blood vessels are affected by stenosis. The analysis employs a mathematical model of the entire system based on the finite element method. The arterial-venous network is represented by a large number of interconnected segments in the model. Values for the model parameters are based upon the published data on the physiological and rheological properties of blood. Computational results show how blood flow through various parts of the cardiovascular system is affected by stenosis in different blood vessels. No significant changes in the flow parameters of the cardiovascular system were found to occur when the reduction in the lumen diameter of the stenosed vessels was less than 65%.

  18. Study report on guidelines and test procedures for investigating stability of nonlinear cardiovascular control system models

    NASA Technical Reports Server (NTRS)

    Fitzjerrell, D. G.

    1974-01-01

    A general study of the stability of nonlinear as compared to linear control systems is presented. The analysis is general and, therefore, applies to other types of nonlinear biological control systems as well as the cardiovascular control system models. Both inherent and numerical stability are discussed for corresponding analytical and graphic methods and numerical methods.

  19. Review of Zero-D and 1-D Models of Blood Flow in the Cardiovascular System

    PubMed Central

    2011-01-01

    Background Zero-dimensional (lumped parameter) and one dimensional models, based on simplified representations of the components of the cardiovascular system, can contribute strongly to our understanding of circulatory physiology. Zero-D models provide a concise way to evaluate the haemodynamic interactions among the cardiovascular organs, whilst one-D (distributed parameter) models add the facility to represent efficiently the effects of pulse wave transmission in the arterial network at greatly reduced computational expense compared to higher dimensional computational fluid dynamics studies. There is extensive literature on both types of models. Method and Results The purpose of this review article is to summarise published 0D and 1D models of the cardiovascular system, to explore their limitations and range of application, and to provide an indication of the physiological phenomena that can be included in these representations. The review on 0D models collects together in one place a description of the range of models that have been used to describe the various characteristics of cardiovascular response, together with the factors that influence it. Such models generally feature the major components of the system, such as the heart, the heart valves and the vasculature. The models are categorised in terms of the features of the system that they are able to represent, their complexity and range of application: representations of effects including pressure-dependent vessel properties, interaction between the heart chambers, neuro-regulation and auto-regulation are explored. The examination on 1D models covers various methods for the assembly, discretisation and solution of the governing equations, in conjunction with a report of the definition and treatment of boundary conditions. Increasingly, 0D and 1D models are used in multi-scale models, in which their primary role is to provide boundary conditions for sophisticate, and often patient-specific, 2D and 3D models, and this application is also addressed. As an example of 0D cardiovascular modelling, a small selection of simple models have been represented in the CellML mark-up language and uploaded to the CellML model repository http://models.cellml.org/. They are freely available to the research and education communities. Conclusion Each published cardiovascular model has merit for particular applications. This review categorises 0D and 1D models, highlights their advantages and disadvantages, and thus provides guidance on the selection of models to assist various cardiovascular modelling studies. It also identifies directions for further development, as well as current challenges in the wider use of these models including service to represent boundary conditions for local 3D models and translation to clinical application. PMID:21521508

  20. Adaptive life simulator: A novel approach to modeling the cardiovascular system

    SciTech Connect

    Kangas, L.J.; Keller, P.E.; Hashem, S.

    1995-06-01

    In this paper, an adaptive life simulator (ALS) is introduced. The ALS models a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. These models are developed for use in applications that require simulations of cardiovascular systems, such as medical mannequins, and in medical diagnostic systems. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the actual variables of an individual can subsequently be used for diagnosis. This approach also exploits sensor fusion applied to biomedical sensors. Sensor fusion optimizes the utilization of the sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  1. Flow and pressure regulation in the cardiovascular system. [engineering systems model

    NASA Technical Reports Server (NTRS)

    Iberall, A.

    1974-01-01

    Principles and descriptive fragments which may contribute to a model of the regulating chains in the cardiovascular system are presented. Attention is given to the strain sensitivity of blood vessels, the law of the autonomy of the heart beat oscillator, the law of the encapsulation of body fluids, the law of the conservation of protein, the law of minimum 'arterial' pressure, the design of the 'mammalian' kidney, questions of homeokinetic organization, and the development of self-regulatory chains. Details concerning the development program for the heart muscle are considered along with the speed of response of the breathing rate and the significance of the pulmonary vascular pressure-flow characteristics.

  2. Modeling the cardiovascular system using a nonlinear additive autoregressive model with exogenous input

    NASA Astrophysics Data System (ADS)

    Riedl, M.; Suhrbier, A.; Malberg, H.; Penzel, T.; Bretthauer, G.; Kurths, J.; Wessel, N.

    2008-07-01

    The parameters of heart rate variability and blood pressure variability have proved to be useful analytical tools in cardiovascular physics and medicine. Model-based analysis of these variabilities additionally leads to new prognostic information about mechanisms behind regulations in the cardiovascular system. In this paper, we analyze the complex interaction between heart rate, systolic blood pressure, and respiration by nonparametric fitted nonlinear additive autoregressive models with external inputs. Therefore, we consider measurements of healthy persons and patients suffering from obstructive sleep apnea syndrome (OSAS), with and without hypertension. It is shown that the proposed nonlinear models are capable of describing short-term fluctuations in heart rate as well as systolic blood pressure significantly better than similar linear ones, which confirms the assumption of nonlinear controlled heart rate and blood pressure. Furthermore, the comparison of the nonlinear and linear approaches reveals that the heart rate and blood pressure variability in healthy subjects is caused by a higher level of noise as well as nonlinearity than in patients suffering from OSAS. The residue analysis points at a further source of heart rate and blood pressure variability in healthy subjects, in addition to heart rate, systolic blood pressure, and respiration. Comparison of the nonlinear models within and among the different groups of subjects suggests the ability to discriminate the cohorts that could lead to a stratification of hypertension risk in OSAS patients.

  3. Computational Models of the Cardiovascular System and Its Response to Microgravity

    NASA Technical Reports Server (NTRS)

    Kamm, Roger D.

    1999-01-01

    Computational models of the cardiovascular system are powerful adjuncts to ground-based and in-flight experiments. We will provide NSBRI with a model capable of simulating the short-term effects of gravity on cardiovascular function. The model from this project will: (1) provide a rational framework which quantitatively defines interactions among complex cardiovascular parameters and which supports the critical interpretation of experimental results and testing of hypotheses. (2) permit predictions of the impact of specific countermeasures in the context of various hypothetical cardiovascular abnormalities induced by microgravity. Major progress has been made during the first 18 months of the program: (1) We have developed an operational first-order computer model capable of simulating the cardiovascular response to orthostatic stress. The model consists of a lumped parameter hemodynamic model and a complete reflex control system. The latter includes cardiopulmonary and carotid sinus reflex limbs and interactions between the two. (2) We have modeled the physiologic stress of tilt table experiments and lower body negative pressure procedures (LBNP). We have verified our model's predictions by comparing them with experimental findings from the literature. (3) We have established collaborative efforts with leading investigators interested in experimental studies of orthostatic intolerance, cardiovascular control, and physiologic responses to space flight. (4) We have established a standardized method of transferring data to our laboratory from the ongoing NSBRI bedrest studies. We use this data to estimate input parameters to our model and compare our model predictions to actual data to further verify our model. (5) We are in the process of systematically simulating current hypotheses concerning the mechanism underlying orthostatic intolerance by matching our simulations to stand test data from astronauts pre- and post-flight. (6) We are in the process of developing a JAVA version of the simulator which will be distributed amongst the cardiovascular team members. Future work on this project involves modifications of the model to represent a rodent (rat) model, further evaluation of the bedrest astronaut and animal data, and systematic investigation of specific countermeasures.

  4. A coupled hydrodynamic model of the cardiovascular and cerebrospinal fluid system.

    PubMed

    Martin, Bryn A; Reymond, Philippe; Novy, Jan; Balédent, Olivier; Stergiopulos, Nikolaos

    2012-04-01

    Coupling of the cardiovascular and cerebrospinal fluid (CSF) system is considered to be important to understand the pathophysiology of cerebrovascular and craniospinal disease and intrathecal drug delivery. A coupled cardiovascular and CSF system model was designed to examine the relation of spinal cord (SC) blood flow (SCBF) and CSF pulsations along the spinal subarachnoid space (SSS). A one-dimensional (1-D) cardiovascular tree model was constructed including a simplified SC arterial network. Connection between the cardiovascular and CSF system was accomplished by a transfer function based on in vivo measurements of CSF and cerebral blood flow. A 1-D tube model of the SSS was constructed based on in vivo measurements in the literature. Pressure and flow throughout the cardiovascular and CSF system were determined for different values of craniospinal compliance. SCBF results indicated that the cervical, thoracic, and lumbar SC each had a signature waveform shape. The cerebral blood flow to CSF transfer function reproduced an in vivo-like CSF flow waveform. The 1-D tube model of the SSS resulted in a distribution of CSF pressure and flow and a wave speed that were similar to those in vivo. The SCBF to CSF pulse delay was found to vary a great degree along the spine depending on craniospinal compliance and vascular anatomy. The properties and anatomy of the SC arterial network and SSS were found to have an important impact on pressure and flow and perivascular fluid movement to the SC. Overall, the coupled model provides predictions about the flow and pressure environment in the SC and SSS. More detailed measurements are needed to fully validate the model. PMID:22268106

  5. Object-oriented modeling and simulation of the closed loop cardiovascular system by using SIMSCAPE.

    PubMed

    de Canete, J Fernandez; del Saz-Orozco, P; Moreno-Boza, D; Duran-Venegas, E

    2013-05-01

    The modeling of physiological systems via mathematical equations reflects the calculation procedure more than the structure of the real system modeled, with the simulation environment SIMULINK™ being one of the best suited to this strategy. Nevertheless, object-oriented modeling is spreading in current simulation environments through the use of the individual components of the model and its interconnections to define the underlying dynamic equations. In this paper we describe the use of the SIMSCAPE™ simulation environment in the object-oriented modeling of the closed loop cardiovascular system. The described approach represents a valuable tool in the teaching of physiology for graduate medical students. PMID:23428370

  6. Modeling of the aorta artery aneurysms and renal artery stenosis using cardiovascular electronic system

    PubMed Central

    Hassani, Kamran; Navidbakhsh, Mahdi; Rostami, Mostafa

    2007-01-01

    Background The aortic aneurysm is a dilatation of the aortic wall which occurs in the saccular and fusiform types. The aortic aneurysms can rupture, if left untreated. The renal stenosis occurs when the flow of blood from the arteries leading to the kidneys is constricted by atherosclerotic plaque. This narrowing may lead to the renal failure. Previous works have shown that, modelling is a useful tool for understanding of cardiovascular system functioning and pathophysiology of the system. The present study is concerned with the modelling of aortic aneurysms and renal artery stenosis using the cardiovascular electronic system. Methods The geometrical models of the aortic aneurysms and renal artery stenosis, with different rates, were constructed based on the original anatomical data. The pressure drop of each section due to the aneurysms or stenosis was computed by means of computational fluid dynamics method. The compliance of each section with the aneurysms or stenosis is also calculated using the mathematical method. An electrical system representing the cardiovascular circulation was used to study the effects of these pressure drops and the compliance variations on this system. Results The results showed the decreasing of pressure along the aorta and renal arteries lengths, due to the aneurysms and stenosis, at the peak systole. The mathematical method demonstrated that compliances of the aorta sections and renal increased with the expansion rate of the aneurysms and stenosis. The results of the modelling, such as electrical pressure graphs, exhibited the features of the pathologies such as hypertension and were compared with the relevant experimental data. Conclusion We conclude from the study that the aortic aneurysms as well as renal artery stenosis may be the most important determinant of the arteries rupture and failure. Furthermore, these pathologies play important rules in increase of the cardiovascular pulse pressure which leads to the hypertension. PMID:17559685

  7. Development of a mathematical model of the human cardiovascular system: An educational perspective

    NASA Astrophysics Data System (ADS)

    Johnson, Bruce Allen

    A mathematical model of the human cardiovascular system will be a useful educational tool in biological sciences and bioengineering classrooms. The goal of this project is to develop a mathematical model of the human cardiovascular system that responds appropriately to variations of significant physical variables. Model development is based on standard fluid statics and dynamics principles, pressure-volume characteristics of the cardiac cycle, and compliant behavior of blood vessels. Cardiac cycle phases provide the physical and logical model structure, and Boolean algebra links model sections. The model is implemented using VisSim, a highly intuitive and easily learned block diagram modeling software package. Comparisons of model predictions of key variables to published values suggest that the model reasonably approximates expected behavior of those variables. The model responds plausibly to variations of independent variables. Projected usefulness of the model as an educational tool is threefold: independent variables which determine heart function may be easily varied to observe cause and effect; the model is used in an interactive setting; and the relationship of governing equations to model behavior is readily viewable and intuitive. Future use of this model in classrooms may give a more reasonable indication of its value as an educational tool.* *This dissertation includes a CD that is multimedia (contains text and other applications that are not available in a printed format). The CD requires the following applications: CorelPhotoHouse, CorelWordPerfect, VisSinViewer (included on CD), Internet access.

  8. Fluctuations in a coupled-oscillator model of the cardiovascular system

    NASA Astrophysics Data System (ADS)

    González, Jorge A.; Suárez-Vargas, Jose J.; Stefanovska, Aneta; McClintock, Peter V. E.

    2007-06-01

    We present a model of the cardiovascular system (CVS) based on a system of coupled oscillators. Using this approach we can describe several complex physiological phenomena that can have a range of applications. For instance, heart rate variability (HRV), can have a new deterministic explanation. The intrinsic dynamics of the HRV is controlled by deterministic couplings between the physiological oscillators in our model and without the need to introduce external noise as is commonly done. This new result provides potential applications not only for physiological systems but also for the design of very precise electronic generators where the frequency stability is crucial. Another important phenomenon is that of oscillation death. We show that in our CVS model the mechanism leading to the quenching of the oscillations can be controlled, not only by the coupling parameter, but by a more general scheme. In fact, we propose that a change in the relative current state of the cardiovascular oscillators can lead to a cease of the oscillations without actually changing the strength of the coupling among them. We performed real experiments using electronic oscillators and show them to match the theoretical and numerical predictions. We discuss the relevance of the studied phenomena to real cardiovascular systems regimes, including the explanation of certain pathologies, and the possible applications in medical practice.

  9. Model of human cardiovascular system with a loop of autonomic regulation of the mean arterial pressure.

    PubMed

    Karavaev, Anatoly S; Ishbulatov, Yurii M; Ponomarenko, Vladimir I; Prokhorov, Mikhail D; Gridnev, Vladimir I; Bezruchko, Boris P; Kiselev, Anton R

    2016-03-01

    A model of human cardiovascular system is proposed which describes the main heart rhythm, the regulation of heart function and blood vessels by the autonomic nervous system, baroreflex, and the formation of arterial blood pressure. The model takes into account the impact of respiration on these processes. It is shown that taking into account nonlinearity and introducing the autonomous loop of mean arterial blood pressure in the form of self-oscillating time-delay system allow to obtain the model signals whose statistical and spectral characteristics are qualitatively and quantitatively similar to those for experimental signals. The proposed model demonstrates the phenomenon of synchronization of mean arterial pressure regulatory system by the signal of respiration with the basic period close to 10 seconds, which is observed in the physiological experiments. PMID:26847603

  10. Optimization in Cardiovascular Modeling

    NASA Astrophysics Data System (ADS)

    Marsden, Alison L.

    2014-01-01

    Fluid mechanics plays a key role in the development, progression, and treatment of cardiovascular disease. Advances in imaging methods and patient-specific modeling now reveal increasingly detailed information about blood flow patterns in health and disease. Building on these tools, there is now an opportunity to couple blood flow simulation with optimization algorithms to improve the design of surgeries and devices, incorporating more information about the flow physics in the design process to augment current medical knowledge. In doing so, a major challenge is the need for efficient optimization tools that are appropriate for unsteady fluid mechanics problems, particularly for the optimization of complex patient-specific models in the presence of uncertainty. This article reviews the state of the art in optimization tools for virtual surgery, device design, and model parameter identification in cardiovascular flow and mechanobiology applications. In particular, it reviews trade-offs between traditional gradient-based methods and derivative-free approaches, as well as the need to incorporate uncertainties. Key future challenges are outlined, which extend to the incorporation of biological response and the customization of surgeries and devices for individual patients.

  11. Development of the Patient-specific Cardiovascular Modeling System Using Immersed Boundary Technique

    NASA Astrophysics Data System (ADS)

    Tay, Wee-Beng; Lin, Liang-Yu; Tseng, Wen-Yih; Tseng, Yu-Heng

    2010-05-01

    A computational fluid dynamics (CFD) based, patient-specific cardiovascular modeling system is under-developed. The system can identify possible diseased conditions and facilitate physicians' diagnosis at early stage through the hybrid CFD simulation and time-resolved magnetic resonance imaging (MRI). The CFD simulation is initially based on the three-dimensional heart model developed by McQueen and Peskin, which can simultaneously compute fluid motions and elastic boundary motions using the immersed boundary method. We extend and improve the three-dimensional heart model for the clinical application by including the patient-specific hemodynamic information. The flow features in the ventricles and their responses are investigated under different inflow and outflow conditions during diastole and systole phases based on the quasi-realistic heart model, which takes advantage of the observed flow scenarios. Our results indicate distinct differences between the two groups of participants, including the vortex formation process in the left ventricle (LV), as well as the flow rate distributions at different identified sources such as the aorta, vena cava and pulmonary veins/artery. We further identify some key parameters which may affect the vortex formation in the LV. Thus it is hypothesized that disease-related dysfunctions in intervals before complete heart failure can be observed in the dynamics of transmitral blood flow during early LV diastole.

  12. An Integrated Model of the Cardiovascular and Central Nervous Systems for Analysis of Microgravity Induced Fluid Redistribution

    NASA Technical Reports Server (NTRS)

    Price, R.; Gady, S.; Heinemann, K.; Nelson, E. S.; Mulugeta, L.; Ethier, C. R.; Samuels, B. C.; Feola, A.; Vera, J.; Myers, J. G.

    2015-01-01

    A recognized side effect of prolonged microgravity exposure is visual impairment and intracranial pressure (VIIP) syndrome. The medical understanding of this phenomenon is at present preliminary, although it is hypothesized that the headward shift of bodily fluids in microgravity may be a contributor. Computational models can be used to provide insight into the origins of VIIP. In order to further investigate this phenomenon, NASAs Digital Astronaut Project (DAP) is developing an integrated computational model of the human body which is divided into the eye, the cerebrovascular system, and the cardiovascular system. This presentation will focus on the development and testing of the computational model of an integrated model of the cardiovascular system (CVS) and central nervous system (CNS) that simulates the behavior of pressures, volumes, and flows within these two physiological systems.

  13. Long-term regulation in the cardiovascular system - Cornerstone in the development of a composite physiological model

    NASA Technical Reports Server (NTRS)

    White, R. J.

    1974-01-01

    The present work discusses a model of the cardiovascular system and related subsystems capable of long-term simulations of the type desired for in-space hypogravic human physiological performance prediction. The discussion centers around the model of Guyton and modifications of it. In order to draw attention to the fluid handling capabilities of the model, one of several transfusion simulations performed is presented, namely, the isotonic saline transfusion simulation.

  14. Modelling of cardiovascular system: development of a hybrid (numerical-physical) model.

    PubMed

    Ferrari, G; Kozarski, M; De Lazzari, C; Górczyńska, K; Mimmo, R; Guaragno, M; Tosti, G; Darowski, M

    2003-12-01

    Physical models of the circulation are used for research, training and for testing of implantable active and passive circulatory prosthetic and assistance devices. However, in comparison with numerical models, they are rigid and expensive. To overcome these limitations, we have developed a model of the circulation based on the merging of a lumped parameter physical model into a numerical one (producing therefore a hybrid). The physical model is limited to the barest essentials and, in this application, developed to test the principle, it is a windkessel representing the systemic arterial tree. The lumped parameters numerical model was developed in LabVIEW environment and represents pulmonary and systemic circulation (except the systemic arterial tree). Based on the equivalence between hydraulic and electrical circuits, this prototype was developed connecting the numerical model to an electrical circuit--the physical model. This specific solution is valid mainly educationally but permits the development of software and the verification of preliminary results without using cumbersome hydraulic circuits. The interfaces between numerical and electrical circuits are set up by a voltage controlled current generator and a voltage controlled voltage generator. The behavior of the model is analyzed based on the ventricular pressure-volume loops and on the time course of arterial and ventricular pressures and flow in different circulatory conditions. The model can represent hemodynamic relationships in different ventricular and circulatory conditions. PMID:14738194

  15. A computational physiology approach to personalized treatment models: the beneficial effects of slow breathing on the human cardiovascular system

    PubMed Central

    Fonoberova, Maria; Mezić, Igor; Buckman, Jennifer F.; Fonoberov, Vladimir A.; Mezić, Adriana; Vaschillo, Evgeny G.; Mun, Eun-Young; Vaschillo, Bronya

    2014-01-01

    Heart rate variability biofeedback intervention involves slow breathing at a rate of ∼6 breaths/min (resonance breathing) to maximize respiratory and baroreflex effects on heart period oscillations. This intervention has wide-ranging clinical benefits and is gaining empirical support as an adjunct therapy for biobehavioral disorders, including asthma and depression. Yet, little is known about the system-level cardiovascular changes that occur during resonance breathing or the extent to which individuals differ in cardiovascular benefit. This study used a computational physiology approach to dynamically model the human cardiovascular system at rest and during resonance breathing. Noninvasive measurements of heart period, beat-to-beat systolic and diastolic blood pressure, and respiration period were obtained from 24 healthy young men and women. A model with respiration as input was parameterized to better understand how the cardiovascular processes that control variability in heart period and blood pressure change from rest to resonance breathing. The cost function used in model calibration corresponded to the difference between the experimental data and model outputs. A good match was observed between the data and model outputs (heart period, blood pressure, and corresponding power spectral densities). Significant improvements in several modeled cardiovascular functions (e.g., blood flow to internal organs, sensitivity of the sympathetic component of the baroreflex, ventricular elastance) were observed during resonance breathing. Individual differences in the magnitude and nature of these dynamic responses suggest that computational physiology may be clinically useful for tailoring heart rate variability biofeedback interventions for the needs of individual patients. PMID:25063789

  16. Bayesian network modeling: A case study of an epidemiologic system analysis of cardiovascular risk.

    PubMed

    Fuster-Parra, P; Tauler, P; Bennasar-Veny, M; Ligęza, A; López-González, A A; Aguiló, A

    2016-04-01

    An extensive, in-depth study of cardiovascular risk factors (CVRF) seems to be of crucial importance in the research of cardiovascular disease (CVD) in order to prevent (or reduce) the chance of developing or dying from CVD. The main focus of data analysis is on the use of models able to discover and understand the relationships between different CVRF. In this paper a report on applying Bayesian network (BN) modeling to discover the relationships among thirteen relevant epidemiological features of heart age domain in order to analyze cardiovascular lost years (CVLY), cardiovascular risk score (CVRS), and metabolic syndrome (MetS) is presented. Furthermore, the induced BN was used to make inference taking into account three reasoning patterns: causal reasoning, evidential reasoning, and intercausal reasoning. Application of BN tools has led to discovery of several direct and indirect relationships between different CVRF. The BN analysis showed several interesting results, among them: CVLY was highly influenced by smoking being the group of men the one with highest risk in CVLY; MetS was highly influence by physical activity (PA) being again the group of men the one with highest risk in MetS, and smoking did not show any influence. BNs produce an intuitive, transparent, graphical representation of the relationships between different CVRF. The ability of BNs to predict new scenarios when hypothetical information is introduced makes BN modeling an Artificial Intelligence (AI) tool of special interest in epidemiological studies. As CVD is multifactorial the use of BNs seems to be an adequate modeling tool. PMID:26777431

  17. [Cardiovascular system and aging].

    PubMed

    Saner, H

    2005-12-01

    Aging is one of the most important cardiovascular risk factors. Age-related morphologic changes in large resistance vessels include an intima-media-thickening and increased deposition of matrix substance, ultimately leading to a reduced compliance and an increased stiffness of the vessels. Aging of the heart is mainly characterized by an increase of the left ventricular mass in relation to the chamber volume and a decrease of diastolic function. There is some controversy in regard to the question if these changes in the vessel wall are the consequence of aging or if a decrease in physical activity is a major contributor of this process. With age the cardiovascular profile is changing. Whereas smoking is less prominent, arterial hypertension and diabetes mellitus are more often encountered. Primary and secondary prevention through cardiovascular risk factor management is also very important in the aging population due to the increased risk of acute vascular complications with age. Preventive measures have to include life style factor interventions as well as optimized drug therapy. There is no scientific evidence that vascular aging can be prevented by administration of supplements such as antioxidant vitamins. Aspirin is effective for cardiovascular prevention up to a higher age. Betablockers and ACE-inhibitors are generally underused in older patients after myocardial infarctions. Statins are effective in reducing cardiovascular complications up to an age of 80 years. Myocardial infarction in elderly patients is often characterized by atypical symptoms and may be even silent. Interventional therapy in elderly patients is as successful as in younger patients but has an increased complication rate. Ambulatory cardiac rehabilitation in elderly patients leads to significant improvements of physical capacity, well-being and quality of life and may help to prevent social isolation. PMID:16405288

  18. Towards patient-specific cardiovascular modeling system using the immersed boundary technique

    PubMed Central

    2011-01-01

    Background Previous research shows that the flow dynamics in the left ventricle (LV) reveal important information about cardiac health. This information can be used in early diagnosis of patients with potential heart problems. The current study introduces a patient-specific cardiovascular-modelling system (CMS) which simulates the flow dynamics in the LV to facilitate physicians in early diagnosis of patients before heart failure. Methods The proposed system will identify possible disease conditions and facilitates early diagnosis through hybrid computational fluid dynamics (CFD) simulation and time-resolved magnetic resonance imaging (4-D MRI). The simulation is based on the 3-D heart model, which can simultaneously compute fluid and elastic boundary motions using the immersed boundary method. At this preliminary stage, the 4-D MRI is used to provide an appropriate comparison. This allows flexible investigation of the flow features in the ventricles and their responses. Results The results simulate various flow rates and kinetic energy in the diastole and systole phases, demonstrating the feasibility of capturing some of the important characteristics of the heart during different phases. However, some discrepancies exist in the pulmonary vein and aorta flow rate between the numerical and experimental data. Further studies are essential to investigate and solve the remaining problems before using the data in clinical diagnostics. Conclusions The results show that by using a simple reservoir pressure boundary condition (RPBC), we are able to capture some essential variations found in the clinical data. Our approach establishes a first-step framework of a practical patient-specific CMS, which comprises a 3-D CFD model (without involving actual hemodynamic data yet) to simulate the heart and the 4-D PC-MRI system. At this stage, the 4-D PC-MRI system is used for verification purpose rather than input. This brings us closer to our goal of developing a practical patient-specific CMS, which will be pursued next. We anticipate that in the future, this hybrid system can potentially identify possible disease conditions in LV through comprehensive analysis and facilitates physicians in early diagnosis of probable cardiac problems. PMID:21682851

  19. Lymphatic System in Cardiovascular Medicine.

    PubMed

    Aspelund, Aleksanteri; Robciuc, Marius R; Karaman, Sinem; Makinen, Taija; Alitalo, Kari

    2016-02-01

    The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the blood vascular circulation, the lymphatic system forms a unidirectional transit pathway from the extracellular space to the venous system. It actively regulates tissue fluid homeostasis, absorption of gastrointestinal lipids, and trafficking of antigen-presenting cells and lymphocytes to lymphoid organs and on to the systemic circulation. The cardinal manifestation of lymphatic malfunction is lymphedema. Recent research has implicated the lymphatic system in the pathogenesis of cardiovascular diseases including obesity and metabolic disease, dyslipidemia, inflammation, atherosclerosis, hypertension, and myocardial infarction. Here, we review the most recent advances in the field of lymphatic vascular biology, with a focus on cardiovascular disease. PMID:26846644

  20. Cardiovascular Biology of the Incretin System

    PubMed Central

    Ussher, John R.; Drucker, Daniel J.

    2012-01-01

    Glucagon-like peptide-1 (GLP-1) is an incretin hormone that enhances glucose-stimulated insulin secretion and exerts direct and indirect actions on the cardiovascular system. GLP-1 and its related incretin hormone, glucose-dependent insulinotropic polypeptide (GIP), are rapidly inactivated by the enzyme dipeptidyl peptidase 4 (DPP-4), a key determinant of incretin bioactivity. Two classes of medications that enhance incretin action, GLP-1R agonists and DPP-4 inhibitors, are used for the treatment of type 2 diabetes mellitus (T2DM). We review herein the cardiovascular biology of GLP-1R agonists and DPP-4 inhibitors, including direct and indirect effects on cardiomyocytes, blood vessels, adipocytes, the control of blood pressure and postprandial lipoprotein secretion. Both GLP-1R activation and DPP-4 inhibition exert multiple cardioprotective actions in preclinical models of cardiovascular dysfunction, and short term studies in human subjects appear to demonstrate modest yet beneficial actions on cardiac function in subjects with ischemic heart disease. Incretin-based agents control body weight, improve glycemic control with a low risk of hypoglycemia, decrease blood pressure, inhibit the secretion of intestinal chylomicrons, and reduce inflammation in preclinical studies. Nevertheless, there is limited information on the cardiovascular actions of these agents in patients with diabetes and established cardiovascular disease. Hence, a more complete understanding of the cardiovascular risk:benefit ratio of incretin-based therapies will require completion of long term cardiovascular outcome studies currently underway in patients with T2DM. PMID:22323472

  1. Construction of a model demonstrating cardiovascular principles.

    PubMed

    Rodenbaugh, D W; Collins, H L; Chen, C Y; DiCarlo, S E

    1999-12-01

    We developed a laboratory exercise that involves the construction and subsequent manipulation of a model of the cardiovascular system. The laboratory was designed to engage students in interactive, inquiry-based learning and to stimulate interest for future science study. The model presents a concrete means by which cardiovascular mechanics can be understood as well as a focal point for student interaction and discussion of cardiovascular principles. The laboratory contains directions for the construction of an inexpensive, easy-to-build model as well as an experimental protocol. From this experience students may gain an appreciation fo science that cannot be obtained by reading a book or interacting with a computer. Students not only learn the significant physiological concepts but also appreciate the importance of laboratory experimentation for understanding complex concepts. Model construction provides a hands-on experience that may substantially improve performance in science processes. We believe that model construction is an appropriate method for teaching advanced concepts. PMID:10644263

  2. PPARs and the Cardiovascular System

    PubMed Central

    Hamblin, Milton; Chang, Lin; Fan, Yanbo; Zhang, Jifeng

    2009-01-01

    Abstract Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone-receptor superfamily. Originally cloned in 1990, PPARs were found to be mediators of pharmacologic agents that induce hepatocyte peroxisome proliferation. PPARs also are expressed in cells of the cardiovascular system. PPARγ appears to be highly expressed during atherosclerotic lesion formation, suggesting that increased PPARγ expression may be a vascular compensatory response. Also, ligand-activated PPARγ decreases the inflammatory response in cardiovascular cells, particularly in endothelial cells. PPARα, similar to PPARγ, also has pleiotropic effects in the cardiovascular system, including antiinflammatory and antiatherosclerotic properties. PPARα activation inhibits vascular smooth muscle proinflammatory responses, attenuating the development of atherosclerosis. However, PPARδ overexpression may lead to elevated macrophage inflammation and atherosclerosis. Conversely, PPARδ ligands are shown to attenuate the pathogenesis of atherosclerosis by improving endothelial cell proliferation and survival while decreasing endothelial cell inflammation and vascular smooth muscle cell proliferation. Furthermore, the administration of PPAR ligands in the form of TZDs and fibrates has been disappointing in terms of markedly reducing cardiovascular events in the clinical setting. Therefore, a better understanding of PPAR-dependent and -independent signaling will provide the foundation for future research on the role of PPARs in human cardiovascular biology. Antioxid. Redox Signal. 11, 1415–1452. PMID:19061437

  3. Hormonal contraception and cardiovascular system.

    PubMed

    Brito, Milena Bastos; Nobre, Fernando; Vieira, Carolina Sales

    2011-04-01

    Hormonal contraception is the most widely used method to prevent unplanned pregnancies. The literature has shown an association between cardiovascular risk and use of hormone therapy. With the purpose of providing better guidelines on contraception methods for women with risk factors for cardiovascular disease, we have reviewed the literature on the subject. This review describes the latest data from the scientific literature concerning the influence of hormonal contraceptives on arterial thrombosis, venous thrombosis and systemic high blood pressure, which are diseases that have become increasingly prevalent among young females. PMID:21359483

  4. Bioengineering and the cardiovascular system

    PubMed Central

    Nerem, Robert M

    2013-01-01

    The development of the modern era of bioengineering and the advances in our understanding of the cardiovascular system have been intertwined over the past one-half century. This is true of bioengineering as an area for research in universities. Bioengineering is ultimately the beginning of a new engineering discipline, as well as a new discipline in the medical device industry. PMID:24688999

  5. Closed-loop real-time simulation model of hemodynamics and oxygen transport in the cardiovascular system

    PubMed Central

    2013-01-01

    Background Computer technology enables realistic simulation of cardiovascular physiology. The increasing number of clinical surgical and medical treatment options imposes a need for better understanding of patient-specific pathology and outcome prediction. Methods A distributed lumped parameter real-time closed-loop model with 26 vascular segments, cardiac modelling with time-varying elastance functions and gradually opening and closing valves, the pericardium, intrathoracic pressure, the atrial and ventricular septum, various pathological states and including oxygen transport has been developed. Results Model output is pressure, volume, flow and oxygen saturation from every cardiac and vascular compartment. The model produces relevant clinical output and validation of quantitative data in normal physiology and qualitative directions in simulation of pathological states show good agreement with published data. Conclusion The results show that it is possible to build a clinically relevant real-time computer simulation model of the normal adult cardiovascular system. It is suggested that understanding qualitative interaction between physiological parameters in health and disease may be improved by using the model, although further model development and validation is needed for quantitative patient-specific outcome prediction. PMID:23842033

  6. Large animal models of cardiovascular disease.

    PubMed

    Tsang, H G; Rashdan, N A; Whitelaw, C B A; Corcoran, B M; Summers, K M; MacRae, V E

    2016-04-01

    The human cardiovascular system is a complex arrangement of specialized structures with distinct functions. The molecular landscape, including the genome, transcriptome and proteome, is pivotal to the biological complexity of both normal and abnormal mammalian processes. Despite our advancing knowledge and understanding of cardiovascular disease (CVD) through the principal use of rodent models, this continues to be an increasing issue in today's world. For instance, as the ageing population increases, so does the incidence of heart valve dysfunction. This may be because of changes in molecular composition and structure of the extracellular matrix, or from the pathological process of vascular calcification in which bone-formation related factors cause ectopic mineralization. However, significant differences between mice and men exist in terms of cardiovascular anatomy, physiology and pathology. In contrast, large animal models can show considerably greater similarity to humans. Furthermore, precise and efficient genome editing techniques enable the generation of tailored models for translational research. These novel systems provide a huge potential for large animal models to investigate the regulatory factors and molecular pathways that contribute to CVD in vivo. In turn, this will help bridge the gap between basic science and clinical applications by facilitating the refinement of therapies for cardiovascular disease. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26914991

  7. Leptin and the cardiovascular system.

    PubMed

    Rahmouni, Kamal; Haynes, William G

    2004-01-01

    Obesity is associated with increased cardiovascular morbidity and mortality, in part through development of hypertension. Recent observations suggest that the cardiovascular actions of leptin may help explain the link between excess fat mass and cardiovascular diseases. Leptin is an adipocyte-derived hormone that acts in the central nervous system to promote weight loss by decreasing food intake and increasing metabolic rate. Leptin causes a significant increase in overall sympathetic nervous activity, which appears to be due to direct hypothalamic effects and is mediated by neuropeptide systems such as the melanocortin system and corticotropin-releasing hormone. Renal sympathoactivation to leptin is preserved in the presence of obesity, despite resistance to the metabolic effects of leptin. Such selective leptin resistance, in the context of circulating hyperleptinemia, could predispose to obesity-related hypertension. Some in vitro studies have suggested that leptin may have peripheral actions such as endothelium-mediated vasodilation that might oppose sympathetically induced vasoconstriction. However, we and others have shown that leptin does not have direct vasodilator effects in vivo. The fact that chronic leptin administration or overexpression of leptin produces hypertension supports the concept that the hemodynamic actions of leptin are due predominantly to sympathetic activation. Exploration of the sites and mechanisms of leptin resistance should provide novel therapeutic strategies for obesity, insulin resistance, and hypertension. PMID:14749504

  8. Cardiovascular system simulation in biomedical engineering education.

    NASA Technical Reports Server (NTRS)

    Rideout, V. C.

    1972-01-01

    Use of complex cardiovascular system models, in conjunction with a large hybrid computer, in biomedical engineering courses. A cardiovascular blood pressure-flow model, driving a compartment model for the study of dye transport, was set up on the computer for use as a laboratory exercise by students who did not have the computer experience or skill to be able to easily set up such a simulation involving some 27 differential equations running at 'real time' rate. The students were given detailed instructions regarding the model, and were then able to study effects such as those due to septal and valve defects upon the pressure, flow, and dye dilution curves. The success of this experiment in the use of involved models in engineering courses was such that it seems that this type of laboratory exercise might be considered for use in physiology courses as an adjunct to animal experiments.

  9. Computational fluid dynamics modelling in cardiovascular medicine.

    PubMed

    Morris, Paul D; Narracott, Andrew; von Tengg-Kobligk, Hendrik; Silva Soto, Daniel Alejandro; Hsiao, Sarah; Lungu, Angela; Evans, Paul; Bressloff, Neil W; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

    2016-01-01

    This paper reviews the methods, benefits and challenges associated with the adoption and translation of computational fluid dynamics (CFD) modelling within cardiovascular medicine. CFD, a specialist area of mathematics and a branch of fluid mechanics, is used routinely in a diverse range of safety-critical engineering systems, which increasingly is being applied to the cardiovascular system. By facilitating rapid, economical, low-risk prototyping, CFD modelling has already revolutionised research and development of devices such as stents, valve prostheses, and ventricular assist devices. Combined with cardiovascular imaging, CFD simulation enables detailed characterisation of complex physiological pressure and flow fields and the computation of metrics which cannot be directly measured, for example, wall shear stress. CFD models are now being translated into clinical tools for physicians to use across the spectrum of coronary, valvular, congenital, myocardial and peripheral vascular diseases. CFD modelling is apposite for minimally-invasive patient assessment. Patient-specific (incorporating data unique to the individual) and multi-scale (combining models of different length- and time-scales) modelling enables individualised risk prediction and virtual treatment planning. This represents a significant departure from traditional dependence upon registry-based, population-averaged data. Model integration is progressively moving towards 'digital patient' or 'virtual physiological human' representations. When combined with population-scale numerical models, these models have the potential to reduce the cost, time and risk associated with clinical trials. The adoption of CFD modelling signals a new era in cardiovascular medicine. While potentially highly beneficial, a number of academic and commercial groups are addressing the associated methodological, regulatory, education- and service-related challenges. PMID:26512019

  10. Computational fluid dynamics modelling in cardiovascular medicine

    PubMed Central

    Morris, Paul D; Narracott, Andrew; von Tengg-Kobligk, Hendrik; Silva Soto, Daniel Alejandro; Hsiao, Sarah; Lungu, Angela; Evans, Paul; Bressloff, Neil W; Lawford, Patricia V; Hose, D Rodney; Gunn, Julian P

    2016-01-01

    This paper reviews the methods, benefits and challenges associated with the adoption and translation of computational fluid dynamics (CFD) modelling within cardiovascular medicine. CFD, a specialist area of mathematics and a branch of fluid mechanics, is used routinely in a diverse range of safety-critical engineering systems, which increasingly is being applied to the cardiovascular system. By facilitating rapid, economical, low-risk prototyping, CFD modelling has already revolutionised research and development of devices such as stents, valve prostheses, and ventricular assist devices. Combined with cardiovascular imaging, CFD simulation enables detailed characterisation of complex physiological pressure and flow fields and the computation of metrics which cannot be directly measured, for example, wall shear stress. CFD models are now being translated into clinical tools for physicians to use across the spectrum of coronary, valvular, congenital, myocardial and peripheral vascular diseases. CFD modelling is apposite for minimally-invasive patient assessment. Patient-specific (incorporating data unique to the individual) and multi-scale (combining models of different length- and time-scales) modelling enables individualised risk prediction and virtual treatment planning. This represents a significant departure from traditional dependence upon registry-based, population-averaged data. Model integration is progressively moving towards ‘digital patient’ or ‘virtual physiological human’ representations. When combined with population-scale numerical models, these models have the potential to reduce the cost, time and risk associated with clinical trials. The adoption of CFD modelling signals a new era in cardiovascular medicine. While potentially highly beneficial, a number of academic and commercial groups are addressing the associated methodological, regulatory, education- and service-related challenges. PMID:26512019

  11. KATP Channels in the Cardiovascular System.

    PubMed

    Foster, Monique N; Coetzee, William A

    2016-01-01

    KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease. PMID:26660852

  12. Cardiovascular disease in systemic sclerosis

    PubMed Central

    Cannarile, Francesca; Valentini, Valentina; Mirabelli, Giulia; Alunno, Alessia; Terenzi, Riccardo; Luccioli, Filippo; Bartoloni, Elena

    2015-01-01

    Cardiovascular (CV) system involvement is a frequent complication of autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). It still remains unclear if a premature atherosclerosis (ATS) occurs even in systemic sclerosis (SSc). Although microvascular disease is a hallmark of SSc, in the last few years a number of studies highlighted a higher prevalence of macrovascular disease in SSc patients in comparison to healthy individuals and these data have been correlated with a poorer prognosis. The mechanisms promoting ATS in SSc are not fully understood, but it is believed to be secondary to multi-system organ inflammation, endothelial wall damage and vasculopathy. Both traditional risk factors and endothelial dysfunction have been proposed to participate to the onset and progression of ATS in such patients. In particular, endothelial cell injury induced by anti-endothelial antibodies, ischemia/reperfusion damage, immune-mediated cytotoxicity represent the main causes of vascular injury together with an impaired vascular repair mechanism that determine a defective vasculogenesis. Aim of this review is to analyse both causes and clinical manifestations of macrovascular involvement and ATS in SSc. PMID:25705640

  13. Patient-specific Modeling of Cardiovascular Mechanics

    PubMed Central

    Taylor, C.A.; Figueroa, C.A.

    2015-01-01

    Advances in numerical methods and three-dimensional imaging techniques have enabled the quantification of cardiovascular mechanics in subject-specific anatomic and physiologic models. Patient-specific models are being used to guide cell culture and animal experiments and test hypotheses related to the role of biomechanical factors in vascular diseases. Furthermore, biomechanical models based on noninvasive medical imaging could provide invaluable data on the in vivo service environment where cardiovascular devices are employed and the effect of the devices on physiologic function. Finally, the patient-specific modeling has enabled an entirely new application of cardiovascular mechanics, namely predicting outcomes of alternate therapeutic interventions for individual patients. We will review methods to create anatomic and physiologic models, obtain properties, assign boundary conditions, and solve the equations governing blood flow and vessel wall dynamics. Applications of patient-specific models of cardiovascular mechanics will be presented followed by a discussion of the challenges and opportunities that lie ahead. PMID:19400706

  14. Efficacy of Female Rat Models in Translational Cardiovascular Aging Research

    PubMed Central

    Rice, K. M.; Fannin, J. C.; Gillette, C.; Blough, E. R.

    2014-01-01

    Cardiovascular disease is the leading cause of death in women in the United States. Aging is a primary risk factor for the development of cardiovascular disease as well as cardiovascular-related morbidity and mortality. Aging is a universal process that all humans undergo; however, research in aging is limited by cost and time constraints. Therefore, most research in aging has been done in primates and rodents; however it is unknown how well the effects of aging in rat models translate into humans. To compound the complication of aging gender has also been indicated as a risk factor for various cardiovascular diseases. This review addresses the systemic pathophysiology of the cardiovascular system associated with aging and gender for aging research with regard to the applicability of rat derived data for translational application to human aging. PMID:25610649

  15. Feedback control of mean aortic pressure in a dynamic model of the cardiovascular system.

    PubMed

    O'Leary, D S; Pantalos, G M; Sharp, M K

    1999-01-01

    Orbital measurements of the cardiac function of Space Shuttle crew members have shown an initial increase in cardiac stroke volume upon entry into weightlessness, followed by a gradual reduction in stroke volume to a level approximately 15% less than preflight values. In an effort to explain this response, it was hypothesized that gravity plays a role in cardiac filling. A mock circulatory system was designed to investigate this effect. Preliminary studies carried out with this system on the NASA KC-135 aircraft, which provides brief periods of weightlessness, showed a strong correlation between cardiac filling, stroke volume, and the presence or absence of gravity. The need for extended periods of high quality zero gravity was identified to verify this observation. To accomplish this, the aircraft version of the experiment was reduced in size and fully automated for eventual integration into a Get Away Special canister to conduct an orbital version of the experiment. This article describes the automated system, as well as the development and implementation of a control algorithm for the servoregulation of the mean aortic pressure in the orbital experiment. Three nonlinearities that influence the ability of the apparatus to regulate to a mean aortic pressure of 95 mm Hg were identified and minimized. In preparation for a Space Shuttle flight, the successful function of the servoregulatory scheme was demonstrated during ground tests and additional test flights aboard the KC-135. The control algorithm was successful in carrying out the experimental protocol, including regulation of mean aortic pressure. The algorithm could also be used for the automated operation of long-term tests of circulatory support systems, which may require a scheduled cycling of the pumping conditions on a daily basis. PMID:10593691

  16. [Hormones and the cardiovascular system].

    PubMed

    Lacka, Katarzyna; Czyzyk, Adam

    2008-01-01

    Hormones have an influence on many tissues and organs, including the cardio-vascular system (CVS). Depending on their activity on CVS, they can be divided into 4 groups: having hypertensive or hypotensive influence and chronotropic positive or negative action. Endocrine regulation in CVS may occur in many ways. Apart from hormones usually connected with CVS regulation, other more recently, discovered ones can act on it. A few of these act directly through specific receptors in heart or vessel wall cells, whereas some act indirectly - stimulating other neuroendocrine factors. Additionally, novel mechanisms of signal transduction have been discovered for steroid and thyroid hormones, which are independent of gene transcription regulation and are - known as "nongenomic". Hormones which increase blood pressure include: urotensin II, endothelins, angiotensin II, catecholamines, aldosterone, antidiuretic hormone, glucocorticosteroids, thyroid hormones, growth hormone and leptin. On the other hand, blood pressure can be decreased by: natriuretic peptides, the calcitonin gene-related peptide (CGRP) family, angiotensin 1-7, substance P, neurokinin A, ghrelin, Parathyroid hormone-related protein (PTHrP), oxytocin, and, sex hormones. Hormones which when appearing in excess increase the heart rate are: catecholamines, endothelins, glucocorticosteroids, thyroid hormones, leptin and PTHrP. Those which decrease the heart rate include: natriuretic peptides, substance P, neurokinin A, oxytocin, angiotensin 1-7. This paper describes the contemporary view of the functions of hormones which act on the vessel tree and heart. The particular effect of mediator depends on many circumstances i.e.: hormone concentration, receptor type. It may also undergo contraregulation. The majority of those hormones play an important role in the pathogenesis of CVS diseases', which can result in the development of new medicines. PMID:18979453

  17. Cardiovascular magnetic resonance in systemic hypertension

    PubMed Central

    2012-01-01

    Systemic hypertension is a highly prevalent potentially modifiable cardiovascular risk factor. Imaging plays an important role in the diagnosis of underlying causes for hypertension, in assessing cardiovascular complications of hypertension, and in understanding the pathophysiology of the disease process. Cardiovascular magnetic resonance (CMR) provides accurate and reproducible measures of ventricular volumes, mass, function and haemodynamics as well as uniquely allowing tissue characterization of diffuse and focal fibrosis. In addition, CMR is well suited for exclusion of common secondary causes for hypertension. We review the current and emerging clinical and research applications of CMR in hypertension. PMID:22559053

  18. Exercise and the Cardiovascular System

    PubMed Central

    Golbidi, Saeid; Laher, Ismail

    2012-01-01

    There are alarming increases in the incidence of obesity, insulin resistance, type II diabetes, and cardiovascular disease. The risk of these diseases is significantly reduced by appropriate lifestyle modifications such as increased physical activity. However, the exact mechanisms by which exercise influences the development and progression of cardiovascular disease are unclear. In this paper we review some important exercise-induced changes in cardiac, vascular, and blood tissues and discuss recent clinical trials related to the benefits of exercise. We also discuss the roles of boosting antioxidant levels, consequences of epicardial fat reduction, increases in expression of heat shock proteins and endoplasmic reticulum stress proteins, mitochondrial adaptation, and the role of sarcolemmal and mitochondrial potassium channels in the contributing to the cardioprotection offered by exercise. In terms of vascular benefits, the main effects discussed are changes in exercise-induced vascular remodeling and endothelial function. Exercise-induced fibrinolytic and rheological changes also underlie the hematological benefits of exercise. PMID:22701195

  19. Evaluating the Hemodynamical Response of a Cardiovascular System under Support of a Continuous Flow Left Ventricular Assist Device via Numerical Modeling and Simulations

    PubMed Central

    Safak, Koray K.

    2013-01-01

    Dilated cardiomyopathy is the most common type of the heart failure which can be characterized by impaired ventricular contractility. Mechanical circulatory support devices were introduced into practice for the heart failure patients to bridge the time between the decision to transplant and the actual transplantation which is not sufficient due to the state of donor organ supply. In this study, the hemodynamic response of a cardiovascular system that includes a dilated cardiomyopathic heart under support of a newly developed continuous flow left ventricular assist device—Heart Turcica Axial—was evaluated employing computer simulations. For the evaluation, a numerical model which describes the pressure-flow rate relations of Heart Turcica Axial, a cardiovascular system model describing the healthy and pathological hemodynamics, and a baroreflex model regulating the heart rate were used. Heart Turcica Axial was operated between 8000 rpm and 11000 rpm speeds with 1000 rpm increments for assessing the pump performance and response of the cardiovascular system. The results also give an insight about the range of the possible operating speeds of Heart Turcica Axial in a clinical application. Based on the findings, operating speed of Heart Turcica Axial should be between 10000 rpm and 11000 rpm. PMID:24363780

  20. A reduced-order model-based study on the effect of intermittent pneumatic compression of limbs on the cardiovascular system.

    PubMed

    Maffiodo, Daniela; De Nisco, Giuseppe; Gallo, Diego; Audenino, Alberto; Morbiducci, Umberto; Ferraresi, Carlo

    2016-04-01

    This work investigates the effect that the application of intermittent pneumatic compression to lower limbs has on the cardiovascular system. Intermittent pneumatic compression can be applied to subjects with reduced or null mobility and can be useful for therapeutic purposes in sports recovery, deep vein thrombosis prevention and lymphedema drainage. However, intermittent pneumatic compression performance and the effectiveness are often difficult to predict. This study presents a reduced-order numerical model of the interaction between the cardiovascular system and the intermittent pneumatic compression device. The effect that different intermittent pneumatic compression operating conditions have on the overall circulation is investigated. Our findings confirm (1) that an overall positive effect on hemodynamics can be obtained by properly applying the intermittent pneumatic compression device and (2) that using intermittent pneumatic compression for cardiocirculatory recovery is feasible in subjects affected by lower limb disease. PMID:26867780

  1. Modeling of Cardiovascular Response to Weightlessness

    NASA Technical Reports Server (NTRS)

    Sharp, M. Keith

    1999-01-01

    It was the hypothesis of this Project that the Simple lack of hydrostatic pressure in microgravity generates several purely physical reactions that underlie and may explain, in part, the cardiovascular response to weightlessness. For instance, hydrostatic pressure within the ventricles of the heart may improve cardiac performance by promoting expansion of ventricular volume during diastole. The lack of hydrostatic pressure in microgravity might, therefore, reduce diastolic filling and cardiac performance. The change in transmural pressure is possible due to the difference in hydrostatic pressure gradients between the blood inside the ventricle and the lung tissue surrounding the ventricle due to their different densities. On the other hand, hydrostatic pressure within the vasculature may reduce cardiac inlet pressures because of the typical location of the heart above the hydrostatic indifference level (the level at which pressure remains constant throughout changes in gravity). Additional physical responses of the body to changing gravitational conditions may influence cardiovascular performance. For instance, fluid shifts from the lower body to the thorax in microgravity may serve to increase central venous pressure (CVP) and boost cardiac output (CO). The concurrent release of gravitational force on the rib cage may tend to increase chest girth and decrease pedcardial pressure, augmenting ventricular filling. The lack of gravity on pulmonary tissue may allow an upward shifting of lung mass, causing a further decrease in pericardial pressure and increased CO. Additional effects include diuresis early in the flight, interstitial fluid shifts, gradual spinal extension and movement of abdominal mass, and redistribution of circulatory impedance because of venous distention in the upper body and the collapse of veins in the lower body. In this project, the cardiovascular responses to changes in intraventricular hydrostatic pressure, in intravascular hydrostatic pressure and, to a limited extent, in extravascular and pedcardial hydrostatic pressure were investigated. A complete hydraulic model of the cardiovascular system was built and flown aboard the NASA KC-135 and a computer model was developed and tested in simulated microgravity. Results obtained with these models have confirmed that a simple lack of hydrostatic pressure within an artificial ventricle causes a decrease in stroke volume. When combined with the acute increase in ventricular pressure associated with the elimination of hydrostatic pressure within the vasculature and the resultant cephalad fluid shift with the models in the upright position, however, stroke volume increased in the models. Imposition of a decreased pedcardial pressure in the computer model and in a simplified hydraulic model increased stroke volume. Physiologic regional fluid shifting was also demonstrated by the models. The unifying parameter characterizing of cardiac response was diastolic ventricular transmural pressure (DVDELTAP) The elimination of intraventricular hydrostatic pressure in O-G decreased DVDELTAP stroke volume, while the elimination of intravascular hydrostatic pressure increased DVDELTAP and stroke volume in the upright posture, but reduced DVDELTAP and stroke volume in the launch posture. The release of gravity on the chest wall and its associated influence on intrathoracic pressure, simulated by a drop in extraventricular pressure4, increased DVDELTAP ans stroke volume.

  2. A Population Model of Integrative Cardiovascular Physiology

    PubMed Central

    Pruett, William A.; Husband, Leland D.; Husband, Graham; Dakhlalla, Muhammad; Bellamy, Kyle; Coleman, Thomas G.; Hester, Robert L.

    2013-01-01

    We present a small integrative model of human cardiovascular physiology. The model is population-based; rather than using best fit parameter values, we used a variant of the Metropolis algorithm to produce distributions for the parameters most associated with model sensitivity. The population is built by sampling from these distributions to create the model coefficients. The resulting models were then subjected to a hemorrhage. The population was separated into those that lost less than 15 mmHg arterial pressure (compensators), and those that lost more (decompensators). The populations were parametrically analyzed to determine baseline conditions correlating with compensation and decompensation. Analysis included single variable correlation, graphical time series analysis, and support vector machine (SVM) classification. Most variables were seen to correlate with propensity for circulatory collapse, but not sufficiently to effect reasonable classification by any single variable. Time series analysis indicated a single significant measure, the stressed blood volume, as predicting collapse in situ, but measurement of this quantity is clinically impossible. SVM uncovered a collection of variables and parameters that, when taken together, provided useful rubrics for classification. Due to the probabilistic origins of the method, multiple classifications were attempted, resulting in an average of 3.5 variables necessary to construct classification. The most common variables used were systemic compliance, baseline baroreceptor signal strength and total peripheral resistance, providing predictive ability exceeding 90%. The methods presented are suitable for use in any deterministic mathematical model. PMID:24058546

  3. Role of TRP channels in the cardiovascular system

    PubMed Central

    Yue, Zhichao; Xie, Jia; Yu, Albert S.; Stock, Jonathan; Du, Jianyang

    2014-01-01

    The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca2+-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca2+ entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases. PMID:25416190

  4. Role of TRP channels in the cardiovascular system.

    PubMed

    Yue, Zhichao; Xie, Jia; Yu, Albert S; Stock, Jonathan; Du, Jianyang; Yue, Lixia

    2015-02-01

    The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca(2+)-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca(2+) entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases. PMID:25416190

  5. [Cardiovascular disease and systemic inflammatory diseases].

    PubMed

    Cuende, José I; Pérez de Diego, Ignacio J; Godoy, Diego

    2016-01-01

    More than a century of research has shown that atherosclerosis is an inflammatory process more than an infiltrative or thrombogenic process. It has been demonstrated epidemiologically and by imaging techniques, that systemic inflammatory diseases (in particular, but not exclusively, rheumatoid arthritis and systemic lupus erythematosus) increase the atherosclerotic process, and has a demonstrated pathophysiological basis. Furthermore, treatments to control inflammatory diseases can modify the course of the atherosclerotic process. Although there are no specific scales for assessing cardiovascular risk in patients with these diseases, cardiovascular risk is high. A number of specific risk scales are being developed, that take into account specific factors such as the degree of inflammatory activity. PMID:26364962

  6. Modelling of long-term and short-term mechanisms of arterial pressure control in the cardiovascular system: an object-oriented approach.

    PubMed

    Fernandez de Canete, J; Luque, J; Barbancho, J; Munoz, V

    2014-04-01

    A mathematical model that provides an overall description of both the short- and long-term mechanisms of arterial pressure regulation is presented. Short-term control is exerted through the baroreceptor reflex while renal elimination plays a role in long-term control. Both mechanisms operate in an integrated way over the compartmental model of the cardiovascular system. The whole system was modelled in MODELICA, which uses a hierarchical object-oriented modelling strategy, under the DYMOLA simulation environment. The performance of the controlled system was analysed by simulation in light of the existing hypothesis and validation tests previously performed with physiological data, demonstrating the effectiveness of both regulation mechanisms under physiological and pathological conditions. PMID:24561348

  7. Multifractal heart rate dynamics in human cardiovascular model

    NASA Astrophysics Data System (ADS)

    Kotani, Kiyoshi; Takamasu, Kiyoshi; Safonov, Leonid; Yamamoto, Yoshiharu

    2003-05-01

    Human cardiovascular and/or cardio-respiratory systems are shown to exhibit both multifractal and synchronous dynamics, and we recently developed a nonlinear, physiologically plausible model for the synchronization between heartbeat and respiration (Kotani, et al. Phys. Rev. E 65: 051923, 2002). By using the same model, we now show the multifractality in the heart rate dynamics. We find that beat-to-beat monofractal noise (fractional Brownian motion) added to the brain stem cardiovascular areas results in significantly broader singularity spectra for heart rate through interactions between sympathetic and parasympathetic nervous systems. We conclude that the model proposed here would be useful in studying the complex cardiovascular and/or cardio- respiratory dynamics in humans.

  8. A Mechanical System to Reproduce Cardiovascular Flows

    NASA Astrophysics Data System (ADS)

    Lindsey, Thomas; Valsecchi, Pietro

    2010-11-01

    Within the framework of the "Pumps&Pipes" collaboration between ExxonMobil Upstream Research Company and The DeBakey Heart and Vascular Center in Houston, a hydraulic control system was developed to accurately simulate general cardiovascular flows. The final goal of the development of the apparatus was the reproduction of the periodic flow of blood through the heart cavity with the capability of varying frequency and amplitude, as well as designing the systolic/diastolic volumetric profile over one period. The system consists of a computer-controlled linear actuator that drives hydraulic fluid in a closed loop to a secondary hydraulic cylinder. The test section of the apparatus is located inside a MRI machine, and the closed loop serves to physically separate all metal moving parts (control system and actuator cylinder) from the MRI-compatible pieces. The secondary cylinder is composed of nonmetallic elements and directly drives the test section circulatory flow loop. The circulatory loop consists of nonmetallic parts and several types of Newtonian and non-Newtonian fluids, which model the behavior of blood. This design allows for a periodic flow of blood-like fluid pushed through a modeled heart cavity capable of replicating any healthy heart condition as well as simulating anomalous conditions. The behavior of the flow inside the heart can thus be visualized by MRI techniques.

  9. User's instructions for the cardiovascular Walters model

    NASA Technical Reports Server (NTRS)

    Croston, R. C.

    1973-01-01

    The model is a combined, steady-state cardiovascular and thermal model. It was originally developed for interactive use, but was converted to batch mode simulation for the Sigma 3 computer. The model has the purpose to compute steady-state circulatory and thermal variables in response to exercise work loads and environmental factors. During a computer simulation run, several selected variables are printed at each time step. End conditions are also printed at the completion of the run.

  10. Testosterone Replacement Therapy and the Cardiovascular System.

    PubMed

    Naderi, Sahar

    2016-04-01

    As testosterone replacement therapy (TRT) has emerged as a commonly prescribed therapy for symptomatic low testosterone, conflicting data have been reported in terms of both its efficacy and potential adverse outcomes. One of the most controversial associations has been that of TRT and cardiovascular morbidity and mortality. This review briefly provides background on the history of TRT, the indications for TRT, and the data behind TRT for symptomatic low testosterone. It then specifically delves into the rather limited data for cardiovascular outcomes of those with low endogenous testosterone and those who receive TRT. The available body of literature strongly suggests that more work, by way of clinical trials, needs to be done to better understand the impact of testosterone and TRT on the cardiovascular system. PMID:26932226

  11. Exercise and the cardiovascular system: clinical science and cardiovascular outcomes.

    PubMed

    Lavie, Carl J; Arena, Ross; Swift, Damon L; Johannsen, Neil M; Sui, Xuemei; Lee, Duck-Chul; Earnest, Conrad P; Church, Timothy S; O'Keefe, James H; Milani, Richard V; Blair, Steven N

    2015-07-01

    Substantial evidence has established the value of high levels of physical activity, exercise training (ET), and overall cardiorespiratory fitness in the prevention and treatment of cardiovascular diseases. This article reviews some basics of exercise physiology and the acute and chronic responses of ET, as well as the effect of physical activity and cardiorespiratory fitness on cardiovascular diseases. This review also surveys data from epidemiological and ET studies in the primary and secondary prevention of cardiovascular diseases, particularly coronary heart disease and heart failure. These data strongly support the routine prescription of ET to all patients and referrals for patients with cardiovascular diseases, especially coronary heart disease and heart failure, to specific cardiac rehabilitation and ET programs. PMID:26139859

  12. Effect of zero magnetic field on cardiovascular system and microcirculation.

    PubMed

    Gurfinkel, Yu I; At'kov, O Yu; Vasin, A L; Breus, T K; Sasonko, M L; Pishchalnikov, R Yu

    2016-02-01

    The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling "ARFA" has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions. PMID:26948007

  13. Physiological homology between Drosophila melanogaster and vertebrate cardiovascular systems

    PubMed Central

    Choma, Michael A.; Suter, Melissa J.; Vakoc, Benjamin J.; Bouma, Brett E.; Tearney, Guillermo J.

    2011-01-01

    SUMMARY The physiology of the Drosophila melanogaster cardiovascular system remains poorly characterized compared with its vertebrate counterparts. Basic measures of physiological performance remain unknown. It also is unclear whether subtle physiological defects observed in the human cardiovascular system can be reproduced in D. melanogaster. Here we characterize the cardiovascular physiology of D. melanogaster in its pre-pupal stage by using high-speed dye angiography and optical coherence tomography. The heart has vigorous pulsatile contractions that drive intracardiac, aortic and extracellular-extravascular hemolymph flow. Several physiological measures, including weight-adjusted cardiac output, body-length-adjusted aortic velocities and intracardiac shear forces, are similar to those in the closed vertebrate cardiovascular systems, including that of humans. Extracellular-extravascular flow in the pre-pupal D. melanogaster circulation drives convection-limited fluid transport. To demonstrate homology in heart dysfunction, we showed that, at the pre-pupal stage, a troponin I mutant, held-up2 (hdp2), has impaired systolic and diastolic heart wall velocities. Impaired heart wall velocities occur in the context of a non-dilated phenotype with a mildly depressed fractional shortening. We additionally derive receiver operating characteristic curves showing that heart wall velocity is a potentially powerful discriminator of systolic heart dysfunction. Our results demonstrate physiological homology and support the use of D. melanogaster as an animal model of complex cardiovascular disease. PMID:21183476

  14. Estimation of cardiac output and systemic vascular resistance using a multivariate regression model with features selected from the finger photoplethysmogram and routine cardiovascular measurements

    PubMed Central

    2013-01-01

    Background Cardiac output (CO) and systemic vascular resistance (SVR) are two important parameters of the cardiovascular system. The ability to measure these parameters continuously and noninvasively may assist in diagnosing and monitoring patients with suspected cardiovascular diseases, or other critical illnesses. In this study, a method is proposed to estimate both the CO and SVR of a heterogeneous cohort of intensive care unit patients (N=48). Methods Spectral and morphological features were extracted from the finger photoplethysmogram, and added to heart rate and mean arterial pressure as input features to a multivariate regression model to estimate CO and SVR. A stepwise feature search algorithm was employed to select statistically significant features. Leave-one-out cross validation was used to assess the generalized model performance. The degree of agreement between the estimation method and the gold standard was assessed using Bland-Altman analysis. Results The Bland-Altman bias precision (1.96 times standard deviation) for CO was -0.01 2.70 L min-1 when only photoplethysmogram (PPG) features were used, and for SVR was -0.87 412 dyn.s.cm-5 when only one PPG variability feature was used. Conclusions These promising results indicate the feasibility of using the method described as a non-invasive preliminary diagnostic tool in supervised or unsupervised clinical settings. PMID:23452705

  15. Principal Component Analysis of HPLC Retention Data and Molecular Modeling Structural Parameters of Cardiovascular System Drugs in View of Their Pharmacological Activity

    PubMed Central

    Stasiak, Jolanta; Koba, Marcin; Bober, Leszek; Bączek, Tomasz

    2010-01-01

    Evaluation of relationships between molecular modeling structural parameters and high-performance liquid chromatography (HPLC) retention data of 11 cardiovascular system drugs by principal component analysis (PCA) in relation to their pharmacological activity was performed. The six retention data parameters were determined on three different HPLC columns (Nucleosil C18 AB with octadecylsilica stationary phase, IAM PC C10/C3 with chemically bounded phosphatidylcholine, and Nucleosil 100-5 OH with chemically bounded propanodiole), and using isocratically acetonitrile: Britton-Robinson buffer as the mobile phase. Additionally, molecular modeling studies were performed with the use of HyperChem software and MM+ molecular mechanics with the semi-empirical AM1 method deriving 20 structural descriptors. Factor analysis obtained with the use of various sets of parameters: structural parameters, HPLC retention data, and all 26 considered parameters, led to the extraction of two main factors. The first principal component (factor 1) accounted for 44–57% of the variance in the data. The second principal component (factor 2) explained 29–33% of data variance. Moreover, the total data variance explained by the first two factors was at the level of 73–90%. More importantly, the PCA analysis of the HPLC retention data and structural parameters allows the segregation of circulatory system drugs according to their pharmacological (cardiovascular) properties as shown by the distribution of the individual drugs on the plane determined by the two principal components (factors 1 and 2). PMID:20717530

  16. Clinical models of cardiovascular regulation after weightlessness

    NASA Technical Reports Server (NTRS)

    Robertson, D.; Jacob, G.; Ertl, A.; Shannon, J.; Mosqueda-Garcia, R.; Robertson, R. M.; Biaggioni, I.

    1996-01-01

    After several days in microgravity, return to earth is attended by alterations in cardiovascular function. The mechanisms underlying these effects are inadequately understood. Three clinical disorders of autonomic function represent possible models of this abnormal cardiovascular function after spaceflight. They are pure autonomic failure, baroreflex failure, and orthostatic intolerance. In pure autonomic failure, virtually complete loss of sympathetic and parasympathetic function occurs along with profound and immediate orthostatic hypotension. In baroreflex failure, various degrees of debuffering of blood pressure occur. In acute and complete baroreflex failure, there is usually severe hypertension and tachycardia, while with less complete and more chronic baroreflex impairment, orthostatic abnormalities may be more apparent. In orthostatic intolerance, blood pressure fall is minor, but orthostatic symptoms are prominent and tachycardia frequently occurs. Only careful autonomic studies of human subjects in the microgravity environment will permit us to determine which of these models most closely reflects the pathophysiology brought on by a period of time in the microgravity environment.

  17. Effect of photochemotherapy on the cardiovascular system.

    PubMed

    Prens, E P; Smeenk, G

    1983-01-01

    The effect of PUVA therapy on the cardiovascular system was studied in 2 groups of patients. The first group consisted of 9 otherwise healthy patients, who were treated without airconditioning. The second group was formed by 15 otherwise healthy psoriasis patients, who were treated with photochemotherapy, using airconditioning. In both groups the cabinet-skin and rectal temperature rose significantly. The most marked finding however was the rise in heart rate. By applying airconditioning, significantly smaller increases in the measured parameters occurred. In none of the patients changes in the electrocardiograms were observed. The effects on the cardiovascular system can evidently be limited by applying airconditioning and by keeping the time of light exposure as short as possible. PMID:6642037

  18. Mathematical biomarkers for the autonomic regulation of cardiovascular system

    PubMed Central

    Campos, Luciana A.; Pereira, Valter L.; Muralikrishna, Amita; Albarwani, Sulayma; Brás, Susana; Gouveia, Sónia

    2013-01-01

    Heart rate and blood pressure are the most important vital signs in diagnosing disease. Both heart rate and blood pressure are characterized by a high degree of short term variability from moment to moment, medium term over the normal day and night as well as in the very long term over months to years. The study of new mathematical algorithms to evaluate the variability of these cardiovascular parameters has a high potential in the development of new methods for early detection of cardiovascular disease, to establish differential diagnosis with possible therapeutic consequences. The autonomic nervous system is a major player in the general adaptive reaction to stress and disease. The quantitative prediction of the autonomic interactions in multiple control loops pathways of cardiovascular system is directly applicable to clinical situations. Exploration of new multimodal analytical techniques for the variability of cardiovascular system may detect new approaches for deterministic parameter identification. A multimodal analysis of cardiovascular signals can be studied by evaluating their amplitudes, phases, time domain patterns, and sensitivity to imposed stimuli, i.e., drugs blocking the autonomic system. The causal effects, gains, and dynamic relationships may be studied through dynamical fuzzy logic models, such as the discrete-time model and discrete-event model. We expect an increase in accuracy of modeling and a better estimation of the heart rate and blood pressure time series, which could be of benefit for intelligent patient monitoring. We foresee that identifying quantitative mathematical biomarkers for autonomic nervous system will allow individual therapy adjustments to aim at the most favorable sympathetic-parasympathetic balance. PMID:24109456

  19. Drug releasing systems in cardiovascular tissue engineering

    PubMed Central

    Spadaccio, Cristiano; Chello, Massimo; Trombetta, Marcella; Rainer, Alberto; Toyoda, Yoshiya; Genovese, Jorge A

    2009-01-01

    Abstract Heart disease and atherosclerosis are the leading causes of morbidity and mortality worldwide. The lack of suitable autologous grafts has produced a need for artificial grafts; however, current artificial grafts carry significant limitations, including thrombosis, infection, limited durability and the inability to grow. Tissue engineering of blood vessels, cardiovascular structures and whole organs is a promising approach for creating replacement tissues to repair congenital defects and/or diseased tissues. In an attempt to surmount the shortcomings of artificial grafts, tissue-engineered cardiovascular graft (TECVG), constructs obtained using cultured autologous vascular cells seeded onto a synthetic biodegradable polymer scaffold, have been developed. Autologous TECVGs have the potential advantages of growth, durability, resistance to infection, and freedom from problems of rejection, thrombogenicity and donor scarcity. Moreover polymers engrafted with growth factors, cytokines, drugs have been developed allowing drug-releasing systems capable of focused and localized delivery of molecules depending on the environmental requirements and the milieu in which the scaffold is placed. A broad range of applications for compound-releasing, tissue-engineered grafts have been suggested ranging from drug delivery to gene therapy. This review will describe advances in the development of drug-delivery systems for cardiovascular applications focusing on the manufacturing techniques and on the compounds delivered by these systems to date. PMID:19379142

  20. O-GlcNAc and the Cardiovascular System

    PubMed Central

    Dassanayaka, Sujith; Jones, Steven P.

    2014-01-01

    The cardiovascular system is capable of robust changes in response to physiologic and pathologic stimuli through intricate signaling mechanisms. The area of metabolism has witnessed a veritable renaissance in the cardiovascular system. In particular, the post-translational β-O-linkage of N-acetylglucosamine (O-GlcNAc) to cellular proteins represents one such signaling pathway that has been implicated in the pathophysiology of cardiovascular disease. This highly dynamic protein modification may induce functional changes in proteins and regulate key cellular processes including translation, transcription, and cell death. In addition, its potential interplay with phosphorylation provides an additional layer of complexity to post-translational regulation. The hexosamine biosynthetic pathway generally requires glucose to form the nucleotide sugar, UDP-GlcNAc. Accordingly, O-GlcNAcylation may be altered in response to nutrient availability and cellular stress. Recent literature supports O-GlcNAcylation as an autoprotective response in models of acute stress (hypoxia, ischemia, oxidative stress). Models of sustained stress, such as pressure overload hypertrophy, and infarct-induced heart failure, may also require protein O-GlcNAcylation as a partial compensatory mechanism. Yet, in models of Type II diabetes, O-GlcNAcylation has been implicated in the subsequent development of vascular, and even cardiac, dysfunction. This review will address this apparent paradox and discuss the potential mechanisms of O-GlcNAc-mediated cardioprotection and cardiovascular dysfunction. This discussion will also address potential targets for pharmacologic interventions and the unique considerations related to such targets. PMID:24287310

  1. Cardiovascular imaging: what have we learned from animal models?

    PubMed Central

    Santos, Arnoldo; Fernández-Friera, Leticia; Villalba, María; López-Melgar, Beatriz; España, Samuel; Mateo, Jesús; Mota, Ruben A.; Jiménez-Borreguero, Jesús; Ruiz-Cabello, Jesús

    2015-01-01

    Cardiovascular imaging has become an indispensable tool for patient diagnosis and follow up. Probably the wide clinical applications of imaging are due to the possibility of a detailed and high quality description and quantification of cardiovascular system structure and function. Also phenomena that involve complex physiological mechanisms and biochemical pathways, such as inflammation and ischemia, can be visualized in a non-destructive way. The widespread use and evolution of imaging would not have been possible without animal studies. Animal models have allowed for instance, (i) the technical development of different imaging tools, (ii) to test hypothesis generated from human studies and finally, (iii) to evaluate the translational relevance assessment of in vitro and ex-vivo results. In this review, we will critically describe the contribution of animal models to the use of biomedical imaging in cardiovascular medicine. We will discuss the characteristics of the most frequent models used in/for imaging studies. We will cover the major findings of animal studies focused in the cardiovascular use of the repeatedly used imaging techniques in clinical practice and experimental studies. We will also describe the physiological findings and/or learning processes for imaging applications coming from models of the most common cardiovascular diseases. In these diseases, imaging research using animals has allowed the study of aspects such as: ventricular size, shape, global function, and wall thickening, local myocardial function, myocardial perfusion, metabolism and energetic assessment, infarct quantification, vascular lesion characterization, myocardial fiber structure, and myocardial calcium uptake. Finally we will discuss the limitations and future of imaging research with animal models. PMID:26539113

  2. User's instructions for the high speed version of the cardiovascular exercise model

    NASA Technical Reports Server (NTRS)

    Croston, R. C.

    1973-01-01

    A mathematical model and digital computer simulation of the human cardiovascular system and its controls were developed to simulate transient responses to bicycle ergometer exercise. The purpose of the model was to provide a method to analyze cardiovascular control hypotheses which cannot be easily tested in an animal or human or in a spaceflight environment.

  3. A Pulsatile Cardiovascular Computer Model for Teaching Heart-Blood Vessel Interaction.

    ERIC Educational Resources Information Center

    Campbell, Kenneth; And Others

    1982-01-01

    Describes a model which gives realistic predictions of pulsatile pressure, flow, and volume events in the cardiovascular system. Includes computer oriented laboratory exercises for veterinary and graduate students; equations of the dynamic and algebraic models; and a flow chart for the cardiovascular teaching program. (JN)

  4. An electro-fluid-dynamic simulator for the cardiovascular system.

    PubMed

    Felipini, Celso Luiz; de Andrade, Aron Jos Pazin; Lucchi, Jlio Csar; da Fonseca, Jeison Willian Gomes; Nicolosi, Denys

    2008-04-01

    This work presents the initial studies and the proposal for a cardiovascular system electro-fluid-dynamic simulator to be applied in the development of left ventricular assist devices (LVADs). The simulator, which is being developed at University Sao Judas Tadeu and at Institute Dante Pazzanese of Cardiology, is composed of three modules: (i) an electrical analog model of the cardiovascular system operating in the PSpice electrical simulator environment; (ii) an electronic controller, based on laboratory virtual instrumentation engineering workbench (LabVIEW) acquisition and control tool, which will act over the physical simulator; and (iii) the physical simulator: a fluid-dynamic equipment composed of pneumatic actuators and compliance tubes for the simulation of active cardiac chambers and big vessels. The physical simulator (iii) is based on results obtained from the electrical analog model (i) and physiological parameters. PMID:18370952

  5. [Thyroid hormone and the cardiovascular system].

    PubMed

    Fraczek, Magdalena Maria; Łacka, Katarzyna

    2014-09-01

    It is well established that thyroid hormones affect the cardiovascular system through genomic and nongenomic actions. TRalpha1 is the major thyroid hormone receptor in the heart. T3 suppresses increased mitotic activity of stimulated cardiomyocytes. Hyperthyroidism induces a hyperdynamic cardiovascular state, which is associated with enhanced left ventricular systolic and diastolic function and the chronotropic and inotropic properties of thyroid hormones. Hypothyroidism, however, is characterized by opposite changes. In addition, thyroid hormones decrease peripheral vascular resistance, influence the rennin-angiotensin system (RAS), and increase blood volume and erythropoetin secretion with subsequent increased preload and cardiac output. Thyroid hormones play an important role in cardiac electrophysiology and have both pro- and anti-arrhytmic potential. Thyroid hormone deficiency is associated with a less favorable lipid profile. Selective modulation of the TRbeta1 receptor is considered as a potential therapeutic target to treat dyslipidemia without cardiac side effects. Thyroid hormones have a beneficial effect on limiting myocardial ischemic injury, preventing and reversing cardiac remodeling and improving cardiac hemodynamics in endstage heart failure. This is crucial because a low T3 syndrome accompanies both acute and chronic cardiac diseases. PMID:25345279

  6. Degradation Model of Bioabsorbable Cardiovascular Stents

    PubMed Central

    Luo, Qiyi; Liu, Xiangkun; Li, Zhonghua; Huang, Chubo; Zhang, Wen; Meng, Juan; Chang, Zhaohua; Hua, Zezhao

    2014-01-01

    This study established a numerical model to investigate the degradation mechanism and behavior of bioabsorbable cardiovascular stents. In order to generate the constitutive degradation material model, the degradation characteristics were characterized with user-defined field variables. The radial strength bench test and analysis were used to verify the material model. In order to validate the numerical degradation model, in vitro bench test and in vivo implantation studies were conducted under physiological and normal conditions. The results showed that six months of degradation had not influenced the thermodynamic properties and mechanical integrity of the stent while the molecular weight of the stents implanted in the in vivo and in vitro models had decreased to 61.8% and 68.5% respectively after six month's implantation. It was also found that the degradation rate, critical locations and changes in diameter of the stents in the numerical model were in good consistency in both in vivo and in vitro studies. It implies that the numerical degradation model could provide useful physical insights and prediction of the stent degradation behavior and evaluate, to some extent, the in-vivo performance of the stent. This model could eventually be used for design and optimization of bioabsorbable stent. PMID:25365310

  7. Space weather and cardiovascular system. New findings

    NASA Astrophysics Data System (ADS)

    Gurfinkel, Yury; Breus, Tamara

    2014-05-01

    Researches of last two decades have shown that the cardiovascular system represents the most probable target for influence of helio - and geomagnetic activity. Both cardiovascular system and system of blood are connected very closely: one system cannot exist without another. For the same reason the effects perceived by one system, are easily transferred to another. Laboratory tests such as blood coagulation, platelet aggregation, and capillary blood velocity (CBV) performed in Scientific Clinical Center JSC "Russian Railways in patients suffering from coronary heart disease (CHD) revealed a high dependence with a level of geomagnetic activity. Results of these and other findings allow to assume that blood itself can be a sensor of geomagnetic fields variations because erythrocytes, platelets, and leucocytes bearing electric charge on membranes, and in a comparable magnetic field can change as own properties and properties of blood flow. It is interesting that not only geomagnetic disturbances, but also the periods of very quiet geomagnetic conditions affect a capillary blood velocity, slowing down it. It was shown during long-term experiment with isolation named 'MARS-500' in spatial facility of the Institute of Biomedical Problems in Moscow as imitation of an extended space mission to Mars. Using digital capillaroscope 'Russia', two crewmembers - medical doctors made records of microcirculation parameters at themselves and other four participants of 'Martian' team. Capillary records were performed before, during, and after period of isolation in medical module of MARS-500 facility. At the period of experiment nobody of crewmembers knew about real geomagnetic conditions. In days of active geomagnetic conditions average CBV has registered as 389 ± 167 μm/s, that statistically significant (p

  8. "TRP inflammation" relationship in cardiovascular system.

    PubMed

    Numata, Tomohiro; Takahashi, Kiriko; Inoue, Ryuji

    2016-05-01

    Despite considerable advances in the research and treatment, the precise relationship between inflammation and cardiovascular (CV) disease remains incompletely understood. Therefore, understanding the immunoinflammatory processes underlying the initiation, progression, and exacerbation of many cardiovascular diseases is of prime importance. The innate immune system has an ancient origin and is well conserved across species. Its activation occurs in response to pathogens or tissue injury. Recent studies suggest that altered ionic balance, and production of noxious gaseous mediators link to immune and inflammatory responses with altered ion channel expression and function. Among plausible candidates for this are transient receptor potential (TRP) channels that function as polymodal sensors and scaffolding proteins involved in many physiological and pathological processes. In this review, we will first focus on the relevance of TRP channel to both exogenous and endogenous factors related to innate immune response and transcription factors related to sustained inflammatory status. The emerging role of inflammasome to regulate innate immunity and its possible connection to TRP channels will also be discussed. Secondly, we will discuss about the linkage of TRP channels to inflammatory CV diseases, from a viewpoint of inflammation in a general sense which is not restricted to the innate immunity. These knowledge may serve to provide new insights into the pathogenesis of various inflammatory CV diseases and their novel therapeutic strategies. PMID:26482920

  9. The human cardiovascular system during space flight

    NASA Astrophysics Data System (ADS)

    Grigoriev, A. I.; Kotovskaya, A. R.; Fomina, G. A.

    2011-05-01

    Purpose of the work is to analyze and to summarize the data of investigations into human hemodynamics performed over 20 years aboard orbital stations Salyut-7 and Mir with participation of 26 cosmonauts on space flights (SF) from 8 to 438 days in duration. The ultrasonic techniques and occlusive plethysmography demonstrated dynamics of changes in the cardiovascular system during SF of various durations. The parameters of general hemodynamics, the pumping function of the heart and arterial circulation in the brain remained stable in all the space flights; however, there were alterations in peripheral circulation associated with blood redistribution and hypovolemie in microgravity. The anti-gravity distribution of the vascular tone decayed gradually as unneeded. The most considerable changes were observed in leg vessels, equally in arteries (decrease in resistance) and veins (increase in maximum capacity). The lower body negative pressure test (LBNP) revealed deterioration of the gravity-dependent reactions that changed for the worse as SF duration extended. The cardiovascular deconditioning showed itself as loss of descent acceleration tolerance and orthostatic instability in the postflight period.

  10. A Web Based Cardiovascular Disease Detection System.

    PubMed

    Alshraideh, Hussam; Otoom, Mwaffaq; Al-Araida, Aseel; Bawaneh, Haneen; Bravo, José

    2015-10-01

    Cardiovascular Disease (CVD) is one of the most catastrophic and life threatening health issue nowadays. Early detection of CVD is an important solution to reduce its devastating effects on health. In this paper, an efficient CVD detection algorithm is identified. The algorithm uses patient demographic data as inputs, along with several ECG signal features extracted automatically through signal processing techniques. Cross-validation results show a 98.29 % accuracy for the decision tree classification algorithm. The algorithm has been integrated into a web based system that can be used at anytime by patients to check their heart health status. At one end of the system is the ECG sensor attached to the patient's body, while at the other end is the detection algorithm. Communication between the two ends is done through an Android application. PMID:26293754

  11. Corticosteroids: do they damage the cardiovascular system?

    PubMed Central

    Maxwell, S. R.; Moots, R. J.; Kendall, M. J.

    1994-01-01

    Since their introduction for the treatment of rheumatoid arthritis, corticosteroids have become widely used as effective agents in the control of inflammatory diseases. Although there have been undoubted benefits upon mortality in diseases such as systemic lupus erythematosus, many patients survive only to suffer a high incidence of premature atherosclerosis. There is also evidence of increased rates of vascular mortality in other corticosteroid-treated diseases, such as rheumatoid arthritis, reversible airways obstruction and transplant recipients. Possible mechanisms of damage include elevated blood pressure, impaired glucose tolerance, dyslipidaemia, and imbalances in thrombosis and fibrinolysis. This paper reviews the clinical evidence supporting the contention that there is an excess cardiovascular mortality in steroid-treated patients and the underlying mechanisms, and points to further areas of research. PMID:7870631

  12. Differentiation of hemangioblasts from embryonic mesothelial cells? A model on the origin of the vertebrate cardiovascular system.

    PubMed

    Muñoz-Chápuli, R; Pérez-Pomares, J M; Macías, D; García-Garrido, L; Carmona, R; González, M

    1999-03-01

    The existence of the hemangioblast, a common progenitor of the endothelial and hematopoietic cell lineages, was proposed at the beginning of the century. Although recent findings seem to confirm its existence, it is still unknown when and how the hemangioblasts differentiate. We propose a hypothesis about the origin of hemangioblasts from the embryonic splanchnic mesothelium. The model is based on observations collected from the literature and from our own studies. These observations include: (1) the extensive population of the splanchnic mesoderm by mesothelial-derived cells coinciding with the emergence of the endothelial and hematopoietic progenitors; (2) the transient localization of cytokeratin, the main mesothelial intermediate filament protein, in some embryonic vessels and endothelial progenitors; (3) the possible origin of cardiac vessels from epicardial-derived cells; (4) the origin of endocardial cells from the splanchnic mesoderm when this mesoderm is an epithelium; (5) the evidence that mesothelial cells migrate to the hemogenic areas of the dorsal aorta. (6) Biochemical and antigenic similarities between mesothelial and endothelial cells. We suggest that the endothelium-lined vascular system arose as a specialization of the phylogenetically older coelomic cavities. The origin of the hematopoietic cells might be related to the differentiation, reported in some invertebrates, of coelomocytes from the coelomic epithelium. Some types of coelomocytes react against microbial invasion and other types transport respiratory pigments. We propose that this phylogenetic origin is recapitulated in the vertebrate ontogeny and explains the differentiation of endothelial and blood cells from a common mesothelial-derived progenitor. PMID:10234810

  13. Predictions of cardiovascular responses during STS reentry using mathematical models

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.; Srinivasan, R.

    1985-01-01

    The physiological adaptation to weightless exposure includes cardiovascular deconditioning arising in part from a loss of total circulating blood volume and resulting in a reduction of orthostatic tolerance. The crew of the Shuttle orbiter are less tolerant to acceleration forces in the head-to-foot direction during the reentry phase of the flight at a time they must function at a high level of performance. The factors that contribute to orthostatic intolerance during and following reentry and to predict the likelihood of impaired crew performance are evaluated. A computer simulation approach employing a mathematical model of the cardiovascular system is employed. It is shown that depending on the severity of blood volume loss, the reentry acceleration stress may be detrimental to physiologic function and may place the physiologic status of the crew near the borderline of some type of impairment. They are in agreement with conclusions from early ground-based experiments and from observations of early Shuttle flights.

  14. A mock circulation model for cardiovascular device evaluation.

    PubMed

    Schampaert, S; Pennings, K A M A; van de Molengraft, M J G; Pijls, N H J; van de Vosse, F N; Rutten, M C M

    2014-04-01

    The aim of this study was to develop an integrated mock circulation system that functions in a physiological manner for testing cardiovascular devices under well-controlled circumstances. In contrast to previously reported mock loops, the model includes a systemic, pulmonary, and coronary circulation, an elaborate heart contraction model, and a realistic heart rate control model. The behavior of the presented system was tested in response to changes in left ventricular contractile states, loading conditions, and heart rate. For validation purposes, generated hemodynamic parameters and responses were compared to literature. The model was implemented in a servo-motor driven mock loop, together with a relatively simple lead-lag controller. The pressure and flow signals measured closely mimicked human pressure under both physiological and pathological conditions. In addition, the system's response to changes in preload, afterload, and heart rate indicate a proper implementation of the incorporated feedback mechanisms (frequency and cardiac function control). Therefore, the presented mock circulation allows for generic in vitro testing of cardiovascular devices under well-controlled circumstances. PMID:24622168

  15. Regulation of sympathetic nervous system function after cardiovascular deconditioning

    NASA Technical Reports Server (NTRS)

    Hasser, E. M.; Moffitt, J. A.

    2001-01-01

    Humans subjected to prolonged periods of bed rest or microgravity undergo deconditioning of the cardiovascular system, characterized by resting tachycardia, reduced exercise capability, and a predisposition for orthostatic intolerance. These changes in cardiovascular function are likely due to a combination of factors, including changes in control of body fluid balance or cardiac alterations resulting in inadequate maintenance of stroke volume, altered arterial or venous vascular function, reduced activation of cardiovascular hormones, and diminished autonomic reflex function. There is evidence indicating a role for each of these mechanisms. Diminished reflex activation of the sympathetic nervous system and subsequent vasoconstriction appear to play an important role. Studies utilizing the hindlimb-unloaded (HU) rat, an animal model of deconditioning, evaluated the potential role of altered arterial baroreflex control of the sympathetic nervous system. These studies indicate that HU results in blunted baroreflex-mediated activation of both renal and lumbar sympathetic nerve activity in response to a hypotensive stimulus. HU rats are less able to maintain arterial pressure during hemorrhage, suggesting that diminished ability to increase sympathetic activity has functional consequences for the animal. Reflex control of vasopressin secretion appears to be enhanced following HU. Blunted baroreflex-mediated sympathoexcitation appears to involve altered central nervous system function. Baroreceptor afferent activity in response to changes in arterial pressure is unaltered in HU rats. However, increases in efferent sympathetic nerve activity for a given decrease in afferent input are blunted after HU. This altered central nervous system processing of baroreceptor inputs appears to involve an effect at the rostral ventrolateral medulla (RVLM). Specifically, it appears that tonic GABAA-mediated inhibition of the RVLM is enhanced after HU. Augmented inhibition apparently arises from sources other than the caudal ventrolateral medulla. If similar alterations in control of the sympathetic nervous system occur in humans in response to cardiovascular deconditioning, it is likely that they play an important role in the observed tendency for orthostatic intolerance. Combined with potential changes in vascular function, cardiac function, and hypovolemia, the predisposition for orthostatic intolerance following cardiovascular deconditioning would be markedly enhanced by blunted ability to reflexly activate the sympathetic nervous system.

  16. Common swine models of cardiovascular disease for research and training.

    PubMed

    Crisstomo, Vernica; Sun, Fei; Maynar, Manuel; Bez-Daz, Claudia; Blanco, Virginia; Garcia-Lindo, Monica; Usn-Gargallo, Jess; Snchez-Margallo, Francisco Miguel

    2016-01-27

    Cardiovascular diseases are a major health concern and therefore an important topic in biomedical research. Large animal models allow researchers to assess the safety and efficacy of new cardiovascular procedures in systems that resemble human anatomy; additionally, they can be used to emulate scenarios for training purposes. Among the many biomedical models that are described in published literature, it is important that researchers understand and select those that are best suited to achieve the aims of their research, that facilitate the humane care and management of their research animals and that best promote the high ethical standards required of animal research. In this resource the authors describe some common swine models that can be easily incorporated into regular practices of research and training at biomedical institutions. These models use both native and altered vascular anatomy of swine to carry out research protocols, such as testing biological reactions to implanted materials, surgically creating aneurysms using autologous tissue and inducing myocardial infarction through closed-chest procedures. Such models can also be used for training, where native and altered vascular anatomy allow medical professionals to learn and practice challenging techniques in anatomy that closely simulates human systems. PMID:26814353

  17. Model-referenced cardiovascular circulatory simulator: construction and control.

    PubMed

    Gwak, Kwan-Woong

    2015-04-01

    Physiological feasibility is the most important requirement for cardiovascular circulatory simulators (CCSs). However, previous simulators have been validated by a comparison with specific human data sets, which are valid only for very limited conditions, and so it is difficult to validate the fidelity of a CCS for various body conditions. To overcome this critical limitation, we propose a model-referenced CCS that reproduces the behavior of an electrical-analog model of the cardiovascular circulatory system, for which physiological fidelity is well established over a wide range. In this study, the electrical-analog reference model was realized in the hardware simulator using fluidic element modeling and by the feedback control of a mock ventricle. The proposed simulator showed a good match with the reference model behavior, and its physiological validity was thereby verified. The proposed simulator is able to show responsiveness to various body conditions as well. To the best of the author's knowledge, this is the first report of an in vitro CCS verified to be consistent with reference model behavior. PMID:25345617

  18. Gravitational Force and the Cardiovascular System

    NASA Technical Reports Server (NTRS)

    Pendergast, D. R.; Olszowka, A. J.; Rokitka, M. A.; Farhi, L. E.

    1991-01-01

    Cardiovascular responses to changes in gravitational force are considered. Man is ideally suited to his 1-g environment. Although cardiovascular adjustments are required to accommodate to postural changes and exercise, these are fully accomplished for short periods (min). More challenging stresses are those of short-term microgravity (h) and long-term microgravity (days) and of gravitational forces greater than that of Earth. The latter can be simulated in the laboratory and quantitative studies can be conducted.

  19. [Assessing the cardiovascular risk in patients with systemic lupus erythematosus].

    PubMed

    Arnaud, L; Mathian, A; Bruckert, E; Amoura, Z

    2014-11-01

    Multiple factors contribute to the increased cardiovascular risk observed in patients with systemic lupus erythematosus (SLE). Among these are the so-called classical cardiovascular risk factors, the disease itself through its activity, treatments, and complications, and the thrombotic risk due to antiphospholipid antibodies (aPL). Observational studies suggest that most classical cardiovascular risk factors are observed more frequently in SLE patients than in the general population, and that these are insufficient to explain the increased cardiovascular risk observed in most studies. Given this high risk, adequate management of cardiovascular risk factors should be recommended in SLE patients. Paradoxically, the benefit due to the anti-inflammatory properties of treatments such as corticosteroids may exceed, in certain cases, their pro-atherogenic effect. Importantly, the tools that were developed for the estimation of cardiovascular risk at the individual level among the general population cannot be used reliably in SLE patients, as these tools appear to underestimate the true cardiovascular risk. The adequate indications and targets of cardiovascular treatments are therefore not fully known in SLE. A better understanding of the determinants of the cardiovascular risk in SLE will allow the identification and more tailored management of these high-risk patients. PMID:25234464

  20. Cardiovascular model for the simulation of exercise, lower body negative pressure, and tilt experiments

    NASA Technical Reports Server (NTRS)

    Croston, R. C.; Fitzjerrell, D. G.

    1974-01-01

    A mathematical model and digital computer simulation of the human cardiovascular system and its controls have been developed to simulate pulsatile dynamic responses to the cardiovascular experiments of the Skylab missions and to selected physiological stresses of manned space flight. Specific model simulations of the bicycle ergometry, lower body negative pressure, and tilt experiments have been developed and verified for 1-g response by comparison with available experimental data. The zero-g simulations of two Skylab experiments are discussed.

  1. The paleopathology of the cardiovascular system.

    PubMed Central

    Zimmerman, M R

    1993-01-01

    Paleopathology, the study of disease in ancient remains, adds the dimension of time to our study of health and disease. The oldest preserved heart is from a mummified rabbit of the Pleistocene epoch, over 20,000 years old. Cardiovascular disease has been identified in human mummies from Alaska and Egypt, covering a time span ranging from approximately 3,000 to 300 years ago. An experimental study suggests that the potential exists for identifying a wide range of cardiovascular pathologic conditions in mummified remains. The antiquity and ubiquity of arteriosclerotic heart disease is considered in terms of pathogenesis. Images PMID:8298320

  2. Tracking stem cells in the cardiovascular system.

    PubMed

    Chemaly, Elie R; Yoneyama, Ryuichi; Frangioni, John V; Hajjar, Roger J

    2005-11-01

    Stem cells are a promising approach to cardiovascular therapeutics. Animal experiments have assessed the fate of injected stem cells through ex vivo methods on sacrificed animals. Approaches are needed for in vivo tracking of stem cells. Various imaging techniques and contrast agents for stem cell tracking will be reviewed. PMID:16297767

  3. Cardiovascular Events in Systemic Lupus Erythematosus

    PubMed Central

    Fernández-Nebro, Antonio; Rúa-Figueroa, Íñigo; López-Longo, Francisco J.; Galindo-Izquierdo, María; Calvo-Alén, Jaime; Olivé-Marqués, Alejandro; Ordóñez-Cañizares, Carmen; Martín-Martínez, María A.; Blanco, Ricardo; Melero-González, Rafael; Ibáñez-Rúan, Jesús; Bernal-Vidal, José Antonio; Tomero-Muriel, Eva; Uriarte-Isacelaya, Esther; Horcada-Rubio, Loreto; Freire-González, Mercedes; Narváez, Javier; Boteanu, Alina L.; Santos-Soler, Gregorio; Andreu, José L.; Pego-Reigosa, José M.

    2015-01-01

    Abstract This article estimates the frequency of cardiovascular (CV) events that occurred after diagnosis in a large Spanish cohort of patients with systemic lupus erythematosus (SLE) and investigates the main risk factors for atherosclerosis. RELESSER is a nationwide multicenter, hospital-based registry of SLE patients. This is a cross-sectional study. Demographic and clinical variables, the presence of traditional risk factors, and CV events were collected. A CV event was defined as a myocardial infarction, angina, stroke, and/or peripheral artery disease. Multiple logistic regression analysis was performed to investigate the possible risk factors for atherosclerosis. From 2011 to 2012, 3658 SLE patients were enrolled. Of these, 374 (10.9%) patients suffered at least a CV event. In 269 (7.4%) patients, the CV events occurred after SLE diagnosis (86.2% women, median [interquartile range] age 54.9 years [43.2–66.1], and SLE duration of 212.0 months [120.8–289.0]). Strokes (5.7%) were the most frequent CV event, followed by ischemic heart disease (3.8%) and peripheral artery disease (2.2%). Multivariate analysis identified age (odds ratio [95% confidence interval], 1.03 [1.02–1.04]), hypertension (1.71 [1.20–2.44]), smoking (1.48 [1.06–2.07]), diabetes (2.2 [1.32–3.74]), dyslipidemia (2.18 [1.54–3.09]), neurolupus (2.42 [1.56–3.75]), valvulopathy (2.44 [1.34–4.26]), serositis (1.54 [1.09–2.18]), antiphospholipid antibodies (1.57 [1.13–2.17]), low complement (1.81 [1.12–2.93]), and azathioprine (1.47 [1.04–2.07]) as risk factors for CV events. We have confirmed that SLE patients suffer a high prevalence of premature CV disease. Both traditional and nontraditional risk factors contribute to this higher prevalence. Although it needs to be verified with future studies, our study also shows—for the first time—an association between diabetes and CV events in SLE patients. PMID:26200625

  4. Radiological features of uncommon aneurysms of the cardiovascular system

    PubMed Central

    Kalisz, Kevin; Rajiah, Prabhakar

    2016-01-01

    Although aortic aneurysms are the most common type encountered clinically, they do not span the entire spectrum of possible aneurysms of the cardiovascular system. As cross sectional imaging techniques with cardiac computed tomography and cardiac magnetic resonance imaging continue to improve and becomes more commonplace, once rare cardiovascular aneurysms are being encountered at higher rates. In this review, a series of uncommon, yet clinically important, cardiovascular aneurysms will be presented with review of epidemiology, clinical presentation and complications, imaging features and relevant differential diagnoses, and aneurysm management.

  5. The role of epoxyeicosatrienoic acids in the cardiovascular system

    PubMed Central

    Yang, L; Mäki-Petäjä, K; Cheriyan, J; McEniery, C; Wilkinson, I B

    2015-01-01

    There is increasing evidence suggesting that epoxyeicosatrienoic acids (EETs) play an important role in cardioprotective mechanisms. These include regulating vascular tone, modulating inflammatory responses, improving cardiomyocyte function and reducing ischaemic damage, resulting in attenuation of animal models of cardiovascular risk factors. This review discusses the current knowledge on the role of EETs in endothelium-dependent control of vascular tone in the healthy and in subjects with cardiovascular risk factors, and considers the pharmacological potential of targeting this pathway. PMID:25655310

  6. Zebrafish models of cardiovascular diseases and their applications in herbal medicine research.

    PubMed

    Seto, Sai-Wang; Kiat, Hosen; Lee, Simon M Y; Bensoussan, Alan; Sun, Yu-Ting; Hoi, Maggie P M; Chang, Dennis

    2015-12-01

    The zebrafish (Danio rerio) has recently become a powerful animal model for cardiovascular research and drug discovery due to its ease of maintenance, genetic manipulability and ability for high-throughput screening. Recent advances in imaging techniques and generation of transgenic zebrafish have greatly facilitated in vivo analysis of cellular events of cardiovascular development and pathogenesis. More importantly, recent studies have demonstrated the functional similarity of drug metabolism systems between zebrafish and humans, highlighting the clinical relevance of employing zebrafish in identifying lead compounds in Chinese herbal medicine with potential beneficial cardiovascular effects. This paper seeks to summarise the scope of zebrafish models employed in cardiovascular studies and the application of these research models in Chinese herbal medicine to date. PMID:26494630

  7. A clinical decision support system prototype for cardiovascular intensive care.

    PubMed

    Lau, F

    1994-08-01

    This paper describes the development and validation of a decision-support system prototype that can help manage hypovolemic hypotension in the Cardiovascular Intensive Care Unit (CVICU). The prototype uses physiologic pattern-matching, therapeutic protocols, computational drug-dosage response modeling and expert reasoning heuristics in its selection of intervention strategies and choices. As part of model testing, the prototype simulated real-time operation by processing historical physiologic and intervention data on a patient sequentially, generating alerts on questionable data, critiques of interventions instituted and recommendations on preferred interventions. Bench-testing with 399 interventions from 13 historical cases showed therapies for bleeding and fluid replacement proposed by the prototype were significantly more consistent (p < 0.0001) than those instituted by the staff when compared against expert critiques (80% versus 44%). This study has demonstrated the feasibility of formalizing hemodynamic management of CVICU patients in a manner that may be implemented and evaluated in a clinical setting. PMID:7829934

  8. Physiological system integrations with emphasis on the respiratory-cardiovascular system

    NASA Technical Reports Server (NTRS)

    Gallagher, R. R.

    1975-01-01

    The integration of two types of physiological system simulations is presented. The long term model is a circulatory system model which simulates long term blood flow variations and compartmental fluid shifts. The short term models simulate transient phenomena of the respiratory, thermoregulatory, and pulsatile cardiovascular systems as they respond to stimuli such as LBNP, exercise, and environmental gaseous variations. An overview of the interfacing approach is described. Descriptions of the variable interface for long term to short term and between the three short term models are given.

  9. RhoA/Rho-Kinase in the Cardiovascular System.

    PubMed

    Shimokawa, Hiroaki; Sunamura, Shinichiro; Satoh, Kimio

    2016-01-22

    Twenty years ago, Rho-kinase was identified as an important downstream effector of the small GTP-binding protein, RhoA. Thereafter, a series of studies demonstrated the important roles of Rho-kinase in the cardiovascular system. The RhoA/Rho-kinase pathway is now widely known to play important roles in many cellular functions, including contraction, motility, proliferation, and apoptosis, and its excessive activity induces oxidative stress and promotes the development of cardiovascular diseases. Furthermore, the important role of Rho-kinase has been demonstrated in the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, and heart failure. Cyclophilin A is secreted by vascular smooth muscle cells and inflammatory cells and activated platelets in a Rho-kinase-dependent manner, playing important roles in a wide range of cardiovascular diseases. Thus, the RhoA/Rho-kinase pathway plays crucial roles under both physiological and pathological conditions and is an important therapeutic target in cardiovascular medicine. Recently, functional differences between ROCK1 and ROCK2 have been reported in vitro. ROCK1 is specifically cleaved by caspase-3, whereas granzyme B cleaves ROCK2. However, limited information is available on the functional differences and interactions between ROCK1 and ROCK2 in the cardiovascular system in vivo. Herein, we will review the recent advances about the importance of RhoA/Rho-kinase in the cardiovascular system. PMID:26838319

  10. Cardiovascular and nervous system changes during meditation

    PubMed Central

    Steinhubl, Steven R.; Wineinger, Nathan E.; Patel, Sheila; Boeldt, Debra L.; Mackellar, Geoffrey; Porter, Valencia; Redmond, Jacob T.; Muse, Evan D.; Nicholson, Laura; Chopra, Deepak; Topol, Eric J.

    2015-01-01

    Background: A number of benefits have been described for the long-term practice of meditation, yet little is known regarding the immediate neurological and cardiovascular responses to meditation. Wireless sensor technology allows, for the first time, multi-parameter and quantitative monitoring of an individual's responses during meditation. The present study examined inter-individual variations to meditation through continuous monitoring of EEG, blood pressure, heart rate and its variability (HRV) in novice and experienced meditators. Methods: Participants were 20 experienced and 20 novice meditators involved in a week-long wellness retreat. Monitoring took place during meditation sessions on the first and last full days of the retreat. All participants wore a patch that continuously streamed ECG data, while half of them also wore a wireless EEG headset plus a non-invasive continuous blood pressure monitor. Results: Meditation produced variable but characteristic EEG changes, significantly different from baseline, even among novice meditators on the first day. In addition, although participants were predominately normotensive, the mean arterial blood pressure fell a small (2–3 mmHg) but significant (p < 0.0001) amount during meditation. The effect of meditation on HRV was less clear and influenced by calculation technique and respiration. No clear relationship between EEG changes, HRV alterations, or mean blood pressure during meditation was found. Conclusion: This is the first study to investigate neurological and cardiovascular responses during meditation in both novice and experienced meditators using novel, wearable, wireless devices. Meditation produced varied inter-individual physiologic responses. These results support the need for further investigation of the short- and long-term cardiovascular effects of mental calm and individualized ways to achieve it. PMID:25852526

  11. Gravitational force and the cardiovascular system

    NASA Technical Reports Server (NTRS)

    Pendergast, D. R.; Olszowka, A. J.; Rokitka, M. A.; Farhi, L. E.

    1991-01-01

    Ground-based simulation studies have been conducted to clarify the problems of the cardiovascular adaptation to alterations in gravitational force. Simulated microgravity experiments resulted in increases in cardiac stretch, urine flow, and sodium excretion, which were accompanied by lower plasma renin, aldosterone, and ADH. There appears to be a decrease in plasma volume as well as in sympathetic tone after 2-3 days of 0 Gz. Complete adjustment to 0 Gz is found within 8 h without a decrease in plasma volume, when subjects are allowed to dehydrate mildly.

  12. Reactive Oxygen Species and the Cardiovascular System

    PubMed Central

    Taverne, Yannick J. H. J.; Bogers, Ad J. J. C.; Duncker, Dirk J.; Merkus, Daphne

    2013-01-01

    Ever since the discovery of free radicals, many hypotheses on the deleterious actions of reactive oxygen species (ROS) have been proposed. However, increasing evidence advocates the necessity of ROS for cellular homeostasis. ROS are generated as inherent by-products of aerobic metabolism and are tightly controlled by antioxidants. Conversely, when produced in excess or when antioxidants are depleted, ROS can inflict damage to lipids, proteins, and DNA. Such a state of oxidative stress is associated with many pathological conditions and closely correlated to oxygen consumption. Although the deleterious effects of ROS can potentially be reduced by restoring the imbalance between production and clearance of ROS through administration of antioxidants (AOs), the dosage and type of AOs should be tailored to the location and nature of oxidative stress. This paper describes several pathways of ROS signaling in cellular homeostasis. Further, we review the function of ROS in cardiovascular pathology and the effects of AOs on cardiovascular outcomes with emphasis on the so-called oxidative paradox. PMID:23738043

  13. A Cardiovascular Mathematical Model of Graded Head-Up Tilt

    PubMed Central

    Lim, Einly; Chan, Gregory S. H.; Dokos, Socrates; Ng, Siew C.; Latif, Lydia A.; Vandenberghe, Stijn; Karunanithi, Mohan; Lovell, Nigel H.

    2013-01-01

    A lumped parameter model of the cardiovascular system has been developed and optimized using experimental data obtained from 13 healthy subjects during graded head-up tilt (HUT) from the supine position to . The model includes descriptions of the left and right heart, direct ventricular interaction through the septum and pericardium, the systemic and pulmonary circulations, nonlinear pressure volume relationship of the lower body compartment, arterial and cardiopulmonary baroreceptors, as well as autoregulatory mechanisms. A number of important features, including the separate effects of arterial and cardiopulmonary baroreflexes, and autoregulation in the lower body, as well as diastolic ventricular interaction through the pericardium have been included and tested for their significance. Furthermore, the individual effect of parameter associated with heart failure, including LV and RV contractility, baseline systemic vascular resistance, pulmonary vascular resistance, total blood volume, LV diastolic stiffness and reflex gain on HUT response have also been investigated. Our fitted model compares favorably with our experimental measurements and published literature at a range of tilt angles, in terms of both global and regional hemodynamic variables. Compared to the normal condition, a simulated congestive heart failure condition produced a blunted response to HUT with regards to the percentage changes in cardiac output, stroke volume, end diastolic volume and effector response (i.e., heart contractility, venous unstressed volume, systemic vascular resistance and heart rate) with progressive tilting. PMID:24204817

  14. Computational modeling of cardiovascular response to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Heldt, Thomas; Shim, Eun B.; Kamm, Roger D.; Mark, Roger G.

    2002-01-01

    The objective of this study is to develop a model of the cardiovascular system capable of simulating the short-term (< or = 5 min) transient and steady-state hemodynamic responses to head-up tilt and lower body negative pressure. The model consists of a closed-loop lumped-parameter representation of the circulation connected to set-point models of the arterial and cardiopulmonary baroreflexes. Model parameters are largely based on literature values. Model verification was performed by comparing the simulation output under baseline conditions and at different levels of orthostatic stress to sets of population-averaged hemodynamic data reported in the literature. On the basis of experimental evidence, we adjusted some model parameters to simulate experimental data. Orthostatic stress simulations are not statistically different from experimental data (two-sided test of significance with Bonferroni adjustment for multiple comparisons). Transient response characteristics of heart rate to tilt also compare well with reported data. A case study is presented on how the model is intended to be used in the future to investigate the effects of post-spaceflight orthostatic intolerance.

  15. The effects of sighing on the cardiovascular system

    PubMed Central

    Vaschillo, Evgeny G.; Vaschillo, Bronya; Buckman, Jennifer F.; Nguyen-Louie, Tam; Heiss, Sydney; Pandina, Robert J.; Bates, Marsha E.

    2015-01-01

    Elicitation of high-amplitude oscillations in the cardiovascular system may serve to dampen psychophysiological reactivity to emotional and cognitive loading. Prior work has used paced breathing to impose clinically valuable high-amplitude ~0.1Hz oscillations. In this study, we investigated whether rhythmical sighing could likewise produce high-amplitude cardiovascular oscillations in the very low frequency range (0.003–0.05Hz). ECG, respiration, skin conductance, and beat-to-beat blood pressure were collected in 24 healthy participants during baseline, 0.1Hz paced breathing, and 0.02Hz paced sighing (1 sigh every 50 seconds, with normal breathing interspersed). Results showed that each sigh elicited a strong, well-defined reaction in the cardiovascular system. This reaction did not habituate when participants repeatedly sighed for 8.5 minutes. The result was a high-amplitude 0.02Hz oscillation in multiple cardiovascular parameters. Thus, paced sighing is a reliable method for imposing very low frequency oscillations in the cardiovascular system, which has research and clinical implications that warrant further study. PMID:25720947

  16. In Vivo Wireless Monitoring System of Cardiovascular Force Data.

    PubMed

    Bechsgaard, Tommy; Honge, Jesper Langhoff; Nygaard, Hans; Jensen, Morten Olgaard

    2015-03-01

    Biotelemetry provides the possibility to measure physiological data in awake, free-ranging animals without the effects of anesthesia and repeated surgery. In this project a fully implantable, telemetric system to measure biomechanical force data of the moving structures of the heart along with the ECG of experimental animals was developed. The system is based on a microcontroller with a built in bidirectional radio frequency transceiver, which allows for the implant to both receive and send data wirelessly. ECG was acquired using electrodes placed directly onto the heart, and the forces were collected using a miniature force transducer. The system was tested in a porcine model (60 kg body weight), where the system transmitted ECG and force data at a range of 5 m between the implant and the receiver. The data was displayed and saved to the hard drive of a laptop computer using a custom built software user interface. It was shown feasible to wirelessly measure forces simultaneously with physiological data from the cardiovascular system of living animals. The current system was optimized to measure forces and ECG, and more channels can be added to increase the number of parameters recorded. PMID:26577097

  17. Toxic effects of marijuana on the cardiovascular system.

    PubMed

    Pratap, Balaji; Korniyenko, Aleksandr

    2012-06-01

    We present a case of marijuana-induced ST segment elevation mimicking Brugada syndrome in a young man. Cannabis can have a multitude of effects on the different organ systems of the body; we take a closer look at its effects on the cardiovascular system, including acute coronary syndrome, arrhythmias and congestive heart failure. PMID:22194141

  18. Clinical Application of Stem Cells in the Cardiovascular System

    NASA Astrophysics Data System (ADS)

    Stamm, Christof; Klose, Kristin; Choi, Yeong-Hoon

    Regenerative medicine encompasses "tissue engineering" - the in vitro fabrication of tissues and/or organs using scaffold material and viable cells - and "cell therapy" - the transplantation or manipulation of cells in diseased tissue in vivo. In the cardiovascular system, tissue engineering strategies are being pursued for the development of viable replacement blood vessels, heart valves, patch material, cardiac pacemakers and contractile myocardium. Anecdotal clinical applications of such vessels, valves and patches have been described, but information on systematic studies of the performance of such implants is not available, yet. Cell therapy for cardiovascular regeneration, however, has been performed in large series of patients, and numerous clinical studies have produced sometimes conflicting results. The purpose of this chapter is to summarize the clinical experience with cell therapy for diseases of the cardiovascular system, and to analyse possible factors that may influence its outcome.

  19. O-GlcNAc Signaling in the Cardiovascular System

    PubMed Central

    Ngoh, Gladys A.; Facundo, Heberty T.; Zafir, Ayesha; Jones, Steven P.

    2010-01-01

    Cardiovascular function is regulated at multiple levels. Some of the most important aspects of such regulation involve alterations in an ever-growing list of post-translational modifications. One such modification orchestrates input from numerous metabolic cues to modify proteins and alter their localization and/or function. Known as the beta-O-linkage of N-acetylglucosamine (i.e. O-GlcNAc) to cellular proteins, this unique monosaccharide is involved in a diverse array of physiologic and pathologic functions. This Review will introduce readers to the general concepts related to O-GlcNAc, the regulation of this modification, and its role in primary pathophysiology. Much of the existing literature regarding the role of O-GlcNAcylation in disease addresses the protracted elevations in O-GlcNAcylation observed during diabetes. In this Review, we will focus on the emerging evidence of its involvement in the cardiovascular system. In particular, we will highlight evidence of protein O-GlcNAcylation as an autoprotective alarm or stress response. We will discuss recent literature supporting the idea that promoting O-GlcNAcylation improves cell survival during acute stress (e.g. hypoxia, ischemia, oxidative stress), whereas limiting O-GlcNAcylation exacerbates cell damage in similar models. In addition to addressing the potential mechanisms of O-GlcNAc-mediated cardioprotection, we will discuss technical issues related to studying protein O-GlcNAcylation in biological systems. The reader should gain an understanding of what protein O-GlcNAcylation is, and, that its roles in the acute and chronic disease settings appear distinct. PMID:20651294

  20. Hydroxybenzoic acid isomers and the cardiovascular system

    PubMed Central

    2014-01-01

    Today we are beginning to understand how phytochemicals can influence metabolism, cellular signaling and gene expression. The hydroxybenzoic acids are related to salicylic acid and salicin, the first compounds isolated that have a pharmacological activity. In this review we examine how a number of hydroxyphenolics have the potential to ameliorate cardiovascular problems related to aging such as hypertension, atherosclerosis and dyslipidemia. The compounds focused upon include 2,3-dihydroxybenzoic acid (Pyrocatechuic acid), 2,5-dihydroxybenzoic acid (Gentisic acid), 3,4-dihydroxybenzoic acid (Protocatechuic acid), 3,5-dihydroxybenzoic acid (α-Resorcylic acid) and 3-monohydroxybenzoic acid. The latter two compounds activate the hydroxycarboxylic acid receptors with a consequence there is a reduction in adipocyte lipolysis with potential improvements of blood lipid profiles. Several of the other compounds can activate the Nrf2 signaling pathway that increases the expression of antioxidant enzymes, thereby decreasing oxidative stress and associated problems such as endothelial dysfunction that leads to hypertension as well as decreasing generalized inflammation that can lead to problems such as atherosclerosis. It has been known for many years that increased consumption of fruits and vegetables promotes health. We are beginning to understand how specific phytochemicals are responsible for such therapeutic effects. Hippocrates’ dictum of ‘Let food be your medicine and medicine your food’ can now be experimentally tested and the results of such experiments will enhance the ability of nutritionists to devise specific health-promoting diets. PMID:24943896

  1. Acetaldehyde, polymorphisms and the cardiovascular system.

    PubMed

    Yin, Shih-Jiun; Peng, Giia-Sheun

    2007-01-01

    To date, the only genes that have been consistently replicated across racial and ethnic groups to influence alcoholism vulnerability are polymorphisms in the alcohol-metabolizing enzymes, i.e. cytosolic alcohol dehydrogenase 1B (ADH1B) and mitochondrial aldehyde dehydrogenase 2 (ALDH2). Both the variant ADHIB*2 and ALDH2*2 alleles significantly protect against developing alcoholism. The protection has been thought to result from accumulation of acetaldehyde after drinking. Unlike ALDH2*2, direct correlation between ADHI1B*2 and blood acetaldehyde has not been verified. ALDH2*2/*2 homozygosity appeared to almost completely protect against alcoholism, whereas ALDH2* 1/*2 heterozygosity appeared to reduce risk of the disease only about threefold. Direct correlations of blood ethanol and acetaldehyde concentrations, cardiovascular haemodynamic responses, and the subjective perceptions after challenge with low (0.2g/kg) to moderate (0.5g/kg) alcohol in individuals with different ALDH2 genotypes support the notion that full protection against alcoholism byALDH2*2/*2 may derive from either abstinence or deliberate moderation in alcohol consumption due to strong discomfort from physiological and psychological responses caused by persistently elevated blood acetaldehyde after ingestion of a small amount of alcohol, and that the partial protection by ALDH2*1/*2 can be ascribed to significantly lower acetaldehyde build-up in blood and the according adverse reactions. PMID:17590986

  2. [Mathematical modeling for conditionality of cardiovascular disease by housing conditions].

    PubMed

    Meshkov, N A

    2014-01-01

    There was studied the influence of living conditions (housing area per capita, availability of housing water supply, sewerage and central heating) on the morbidity of the cardiovascular diseases in child and adult population. With the method of regression analysis the morbidity rate was established to significantly decrease with the increase in the area of housing, constructed models are statistically significant, respectively, p = 0.01 and p = 0.02. There was revealed the relationship of the morbidity rate of cardiovascular diseases in children and adults with the supply with housing central heating (p = 0.02 and p = 0.009). PMID:25950060

  3. 76 FR 62164 - VASRD Improvement Forum-Updating Disability Criteria for the Respiratory System, Cardiovascular...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... AFFAIRS VASRD Improvement Forum--Updating Disability Criteria for the Respiratory System, Cardiovascular...) Improvement Forum-- Updating Disability Criteria for the Respiratory System, Cardiovascular System, Hearing... four body systems: (1) Respiratory System (38 CFR 4.96-4.97), (2) the Cardiovascular System (38 CFR...

  4. The emerging role of the endocannabinoid system in cardiovascular disease

    PubMed Central

    2009-01-01

    Endocannabinoids are endogenous bioactive lipid mediators present both in the brain and various peripheral tissues, which exert their biological effects via interaction with specific G-protein-coupled cannabinoid receptors, the CB1 and CB2. Pathological overactivation of the endocannabinoid system (ECS) in various forms of shock and heart failure may contribute to the underlying pathology and cardiodepressive state by the activation of the cardiovascular CB1 receptors. Furthermore, tonic activation of CB1 receptors by endocannabinoids has also been implicated in the development of various cardiovascular risk factors in obesity/metabolic syndrome and diabetes, such as plasma lipid alterations, abdominal obesity, hepatic steatosis, inflammation, and insulin and leptin resistance. In contrast, activation of CB2 receptors in immune cells exerts various immunomodulatory effects, and the CB2 receptors in endothelial and inflammatory cells appear to limit the endothelial inflammatory response, chemotaxis, and inflammatory cell adhesion and activation in atherosclerosis and reperfusion injury. Here, we will overview the cardiovascular actions of endocannabinoids and the growing body of evidence implicating the dysregulation of the ECS in a variety of cardiovascular diseases. We will also discuss the therapeutic potential of the modulation of the ECS by selective agonists/antagonists in various cardiovascular disorders associated with inflammation and tissue injury, ranging from myocardial infarction and heart failure to atherosclerosis and cardiometabolic disorders. PMID:19357846

  5. Electronic circuit detects left ventricular ejection events in cardiovascular system

    NASA Technical Reports Server (NTRS)

    Gebben, V. D.; Webb, J. A., Jr.

    1972-01-01

    Electronic circuit processes arterial blood pressure waveform to produce discrete signals that coincide with beginning and end of left ventricular ejection. Output signals provide timing signals for computers that monitor cardiovascular systems. Circuit operates reliably for heart rates between 50 and 200 beats per minute.

  6. Decadal Cycles in the Human Cardiovascular System

    PubMed Central

    Halberg, Franz; Cornelissen, Germaine; Sothern, Robert B.; Hillman, Dewayne; Watanabe, Yoshihiko; Haus, Erhard; Schwartzkopff, Othild; Best, William R.

    2013-01-01

    Seven of the eight authors of this report each performed physiologic self-surveillance, some around the clock for decades. We here document the presence of long cycles (decadals, including circaundecennians) in the time structure of systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR). Because of the non-stationary nature in time and space of these and other physiologic and environmental periodic components that, like the wind, can appear and disappear in a given or other geographic location at one or another time, they have been called “Aeolian”. The nonlinear estimation of the uncertainties of the periods (τs) of two or more variables being compared has been used to determine whether these components are congruent or not, depending on whether their CIs (95% confidence intervals) overlap or not. Among others, congruence has been found for components with τs clustering around 10 years in us and around us. There is a selective assortment among individuals, variables and cycle characteristics (mean and circadian amplitude and acrophase). Apart from basic interest, like other nonphotic solar signatures such as transyears with periods slightly longer than one year or about 33-year Brückner-Egeson-Lockyer (BEL) cycles, about 10-year and longer cycles present in 7 of 7 self-monitoring individuals are of interest in the diagnosis of Vascular Variability Anomalies (VVAs), including MESOR-hypertension, and others. Some of the other VVAs, such as a circadian overswing, i.e., CHAT (Circadian Hyper-Aplitude-Tension), or an excessive pulse pressure, based on repeated 7-day around-the-clock records, can represent a risk of severe cardiovascular events, greater than that of a high BP. The differential diagnosis of physiologic cycles, infradians (components with a τ longer than 28 hours) as well as circadians awaits the collection of reference values for the infradian parameters of the cycles described herein. Just as in stroke-prone spontaneously hypertensive rats during the weeks after weaning CHAT precedes an elevation of the BP MESOR, a decadal overswing seems to precede the occurrence of high BP in two of the subjects here examined. Only around-the-clock monitoring in health for the collection of reference values will allow on their basis the differential diagnosis of the onsets of a circadian versus a circadecadal overswing in BP and the specification whether, and if so, when to initiate hypotensive non-drug or drug treatment. PMID:24860279

  7. Parasympathetic Stimuli on Bronchial and Cardiovascular Systems in Humans

    PubMed Central

    Zannin, Emanuela; Pellegrino, Riccardo; Di Toro, Alessandro; Antonelli, Andrea; Dellacà, Raffaele L.; Bernardi, Luciano

    2015-01-01

    Background It is not known whether parasympathetic outflow simultaneously acts on bronchial tone and cardiovascular system waxing and waning both systems in parallel, or, alternatively, whether the regulation is more dependent on local factors and therefore independent on each system. The aim of this study was to evaluate the simultaneous effect of different kinds of stimulations, all associated with parasympathetic activation, on bronchomotor tone and cardiovascular autonomic regulation. Methods Respiratory system resistance (Rrs, forced oscillation technique) and cardio-vascular activity (heart rate, oxygen saturation, tissue oxygenation index, blood pressure) were assessed in 13 volunteers at baseline and during a series of parasympathetic stimuli: O2 inhalation, stimulation of the carotid sinus baroreceptors by neck suction, slow breathing, and inhalation of methacholine. Results Pure cholinergic stimuli, like O2 inhalation and baroreceptors stimulation, caused an increase in Rrs and a reduction in heart rate and blood pressure. Slow breathing led to bradycardia and hypotension, without significant changes in Rrs. However slow breathing was associated with deep inhalations, and Rrs evaluated at the baseline lung volumes was significantly increased, suggesting that the large tidal volumes reversed the airways narrowing effect of parasympathetic activation. Finally inhaled methacholine caused marked airway narrowing, while the cardiovascular variables were unaffected, presumably because of the sympathetic activity triggered in response to hypoxemia. Conclusions All parasympathetic stimuli affected bronchial tone and moderately affected also the cardiovascular system. However the response differed depending on the nature of the stimulus. Slow breathing was associated with large tidal volumes that reversed the airways narrowing effect of parasympathetic activation. PMID:26046774

  8. User's instructions for the GE cardiovascular model to simulate LBNP and tilt experiments, with graphic capabilities

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The present form of this cardiovascular model simulates both 1-g and zero-g LBNP (lower body negative pressure) experiments and tilt experiments. In addition, the model simulates LBNP experiments at any body angle. The model is currently accessible on the Univac 1110 Time-Shared System in an interactive operational mode. Model output may be in tabular form and/or graphic form. The graphic capabilities are programmed for the Tektronix 4010 graphics terminal and the Univac 1110.

  9. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure

    EPA Science Inventory

    This paper shows that rat models of cardiovascular diseases have differential degrees of underlying pathologies at a young age. Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. How...

  10. Differential Role of Leptin and Adiponectin in Cardiovascular System

    PubMed Central

    Ghantous, C. M.; Azrak, Z.; Hanache, S.; Abou-Kheir, W.; Zeidan, A.

    2015-01-01

    Leptin and adiponectin are differentially expressed adipokines in obesity and cardiovascular diseases. Leptin levels are directly associated with adipose tissue mass, while adiponectin levels are downregulated in obesity. Although significantly produced by adipocytes, leptin is also produced by vascular smooth muscle cells and cardiomyocytes. Plasma leptin concentrations are elevated in cases of cardiovascular diseases, such as hypertension, congestive heart failure, and myocardial infarction. As for the event of left ventricular hypertrophy, researchers have been stirring controversy about the role of leptin in this form of cardiac remodeling. In this review, we discuss how leptin has been shown to play an antihypertrophic role in the development of left ventricular hypertrophy through in vitro experiments, population-based cross-sectional studies, and longitudinal cohort studies. Conversely, we also examine how leptin may actually promote left ventricular hypertrophy using in vitro analysis and human-based univariate and multiple linear stepwise regression analysis. On the other hand, as opposed to leptin's generally detrimental effects on the cardiovascular system, adiponectin is a cardioprotective hormone that reduces left ventricular and vascular hypertrophy, oxidative stress, and inflammation. In this review, we also highlight adiponectin signaling and its protective actions on the cardiovascular system. PMID:26064110

  11. Growth hormone, insulin-like growth factor-1 and the aging cardiovascular system.

    PubMed

    Khan, Amir S; Sane, David C; Wannenburg, Thomas; Sonntag, William E

    2002-04-01

    There is a large body of evidence that biological aging is related to a series of long-term catabolic processes resulting in decreased function and structural integrity of several physiological systems, among which is the cardiovascular system. These changes in the aging phenotype are correlated with a decline in the amplitude of pulsatile growth hormone secretion and the resulting decrease in plasma levels of its anabolic mediator, insulin like growth factor-1 (IGF-1). The relationship between growth hormone and biological aging is supported by studies demonstrating that growth hormone administration to old animals and humans raises plasma IGF-1 and results in increases in skeletal muscle and lean body mass, a decrease in adiposity, increased immune function, improvements in learning and memory, and increases in cardiovascular function. Since growth hormone and IGF-1 exert potent effects on the heart and vasculature, the relationship between age-related changes in cardiovascular function and the decline in growth hormone levels with age have become of interest. Among the age-related changes in the cardiovascular system are decreases in myocyte number, accumulation of fibrosis and collagen, decreases in stress-induced cardiac function through deterioration of the myocardial conduction system and beta-adrenergic receptor function, decreases in exercise capacity, vessel rarefaction, decreased arterial compliance and endothelial dysfunction leading to alterations in blood flow. Growth hormone has been found to exert potent effects on cardiovascular function in young animals and reverses many of the deficits in cardiovascular function in aged animals and humans. Nevertheless, it has been difficult to separate the effects of growth hormone deficiency from age-related diseases and associated pathologies. The development of novel animal models and additional research are required in order to elucidate the specific effects of growth hormone deficiency and assess its contribution to cardiovascular impairments and biological aging. PMID:12062358

  12. Evaluating a decision making system for cardiovascular dysautonomias diagnosis.

    PubMed

    Idri, Ali; Kadi, Ilham

    2016-01-01

    Autonomic nervous system (ANS) is the part of the nervous system that is involved in homeostasis of the whole body functions. A malfunction in this system can lead to a cardiovascular dysautonomias. Hence, a set of dynamic tests are adopted in ANS units to diagnose and treat patients with cardiovascular dysautonomias. The purpose of this study is to develop and evaluate a decision tree based cardiovascular dysautonomias prediction system on a dataset collected from the ANS unit of the Moroccan university hospital Avicenne. We collected a dataset of 263 records from the ANS unit of the Avicenne hospital. This dataset was split into three subsets: training set (123 records), test set (55 records) and validation set (85 records). C4.5 decision tree algorithm was used in this study to develop the prediction system. Moreover, Java Enterprise Edition platform was used to implement a prototype of the developed system which was deployed in the Avicenne ANS unit so as to be clinically validated. The performance of the decision tree-based prediction system was evaluated by means of the error rate criterion. The error rates were measured for each classifier and have achieved an average value of 1.46, 2.24 and 0.89 % in training, test, and validation sets respectively. The results obtained were encouraging but further replicated studies are still needed to be performed in order to confirm the findings of this study. PMID:26844028

  13. Short-term cardiovascular oscillations in man: measuring and modelling the physiologies

    PubMed Central

    Cohen, Michael A; Taylor, J Andrew

    2002-01-01

    Research into cardiovascular variabilities intersects both human physiology and quantitative modelling. This is because respiratory and Mayer wave (or 10 s) cardiovascular oscillations represent the integrated control of a system through both autonomic branches by systemic haemodynamic changes within a fluid-filled, physical system. However, our current precise measurement of short-term cardiovascular fluctuations does not necessarily mean we have an adequate understanding of them. Empirical observation suggests that both respiratory and Mayer wave fluctuations derive from mutable autonomic and haemodynamic inputs. Evidence strongly suggests that respiratory sinus arrhythmia both contributes to and buffers respiratory arterial pressure fluctuations. Moreover, even though virtual abolition of all R-R interval variability by cholinergic blockade suggests that parasympathetic stimulation is essential for expression of these variabilities, respiratory sinus arrhythmia does not always reflect a purely vagal phenomenon. The arterial baroreflex has been cited as the mechanism for both respiratory and Mayer wave frequency fluctuations. However, data suggest that both cardiac vagal and vascular sympathetic fluctuations at these frequencies are independent of baroreflex mechanisms and, in fact, contribute to pressure fluctuations. Results from cardiovascular modelling can suggest possible sources for these rhythms. For example, modelling originally suggested low frequency cardiovascular rhythms derived from intrinsic delays in baroreceptor control, and experimental evidence subsequently corroborated this possibility. However, the complex stochastic relations between and variabilities in these rhythms indicate no single mechanism is responsible. If future study of cardiovascular variabilities is to move beyond qualitative suggestions of determinants to quantitative elucidation of critical physical mechanisms, both experimental design and model construction will have to be more trenchant. PMID:12154170

  14. A Multiscale Model of Cardiovascular System Including an Immersed Whole Heart in the Cases of Normal and Ventricular Septal Defect (VSD).

    PubMed

    Lee, Wanho; Jung, Eunok

    2015-07-01

    A mathematical and computational model combining the heart and circulatory system has been developed to understand the hemodynamics of circulation under normal conditions and ventricular septal defect (VSD). The immersed boundary method has been introduced to describe the interaction between the moving two-dimensional heart and intracardiac blood flow. The whole-heart model is governed by the Navier-Stokes system; this system is combined with a multi-compartment model of circulation using pressure-flow relations and the linearity of the discretized Navier-Stokes system. We investigate the velocity field, flowmeters, and pressure-volume loop in both normal and VSD cases. Simulation results show qualitatively good agreements with others found in the literature. This model, combining the heart and circulation, is useful for understanding the complex, hemodynamic mechanisms involved in normal circulation and cardiac diseases. PMID:26223734

  15. Optimizing Cardiovascular Benefits of Exercise: A Review of Rodent Models

    PubMed Central

    Davis, Brittany; Moriguchi, Takeshi; Sumpio, Bauer

    2013-01-01

    Although research unanimously maintains that exercise can ward off cardiovascular disease (CVD), the optimal type, duration, intensity, and combination of forms are yet not clear. In our review of existing rodent-based studies on exercise and cardiovascular health, we attempt to find the optimal forms, intensities, and durations of exercise. Using Scopus and Medline, a literature review of English language comparative journal studies of cardiovascular benefits and exercise was performed. This review examines the existing literature on rodent models of aerobic, anaerobic, and power exercise and compares the benefits of various training forms, intensities, and durations. The rodent studies reviewed in this article correlate with reports on human subjects that suggest regular aerobic exercise can improve cardiac and vascular structure and function, as well as lipid profiles, and reduce the risk of CVD. Findings demonstrate an abundance of rodent-based aerobic studies, but a lack of anaerobic and power forms of exercise, as well as comparisons of these three components of exercise. Thus, further studies must be conducted to determine a truly optimal regimen for cardiovascular health. PMID:24436579

  16. Patient-specific modeling of cardiovascular and respiratory dynamics during hypercapnia

    PubMed Central

    Ellwein, L.M.; Pope, S.R.; Xie, A.; Batzel, J.J.; Kelley, C.T.; Olufsen, M.S.

    2014-01-01

    This study develops a lumped cardiovascular-respiratory system-level model that incorporates patient-specific data to predict cardiorespiratory response to hyper-capnia (increased CO2 partial pressure) for a patient with congestive heart failure (CHF). In particular, the study focuses on predicting cerebral CO2 reactivity, which can be defined as the ability of vessels in the cerebral vasculature to expand or contract in response CO2 induced challenges. It is difficult to characterize cerebral CO2 reactivity directly from measurements, since no methods exist to dynamically measure vasomotion of vessels in the cerebral vasculature. In this study we show how mathematical modeling can be combined with available data to predict cerebral CO2 reactivity via dynamic predictions of cerebral vascular resistance, which can be directly related to vasomotion of vessels in the cerebral vasculature. To this end we have developed a coupled cardiovascular and respiratory model that predicts blood pressure, flow, and concentration of gasses (CO2 and O2) in the systemic, cerebral, and pulmonary arteries and veins. Cerebral vascular resistance is incorporated via a model parameter separating cerebral arteries and veins. The model was adapted to a specific patient using parameter estimation combined with sensitivity analysis and subset selection. These techniques allowed estimation of cerebral vascular resistance along with other cardiovascular and respiratory parameters. Parameter estimation was carried out during eucapnia (breathing room air), first for the cardiovascular model and then for the respiratory model. Then, hypercapnia was introduced by increasing inspired CO2 partial pressure. During eucapnia, 7 cardiovascular parameters and 4 respiratory parameters was be identified and estimated, including cerebral and systemic resistance. During the transition from eucapnia to hypercapnia, the model predicted a drop in cerebral vascular resistance consistent with cerebral vasodilation. PMID:23046704

  17. Xenobiotic pulmonary exposure and systemic cardiovascular response via neurological links.

    PubMed

    Stapleton, Phoebe A; Abukabda, Alaeddin B; Hardy, Steven L; Nurkiewicz, Timothy R

    2015-11-15

    The cardiovascular response to xenobiotic particle exposure has been increasingly studied over the last two decades, producing an extraordinary scope and depth of research findings. With the flourishing of nanotechnology, the term "xenobiotic particles" has expanded to encompass not only air pollution particulate matter (PM) but also anthropogenic particles, such as engineered nanomaterials (ENMs). Historically, the majority of research in these fields has focused on pulmonary exposure and the adverse physiological effects associated with a host inflammatory response or direct particle-tissue interactions. Because these hypotheses can neither account entirely for the deleterious cardiovascular effects of xenobiotic particle exposure nor their time course, the case for substantial neurological involvement is apparent. Indeed, considerable evidence suggests that not only is neural involvement a significant contributor but also a reality that needs to be investigated more thoroughly when assessing xenobiotic particle toxicities. Therefore, the scope of this review is several-fold. First, we provide a brief overview of the major anatomical components of the central and peripheral nervous systems, giving consideration to the potential biologic targets affected by inhaled particles. Second, the autonomic arcs and mechanisms that may be involved are reviewed. Third, the cardiovascular outcomes following neurological responses are discussed. Lastly, unique problems, future risks, and hurdles associated with xenobiotic particle exposure are discussed. A better understanding of these neural issues may facilitate research that in conjunction with existing research, will ultimately prevent the untoward cardiovascular outcomes associated with PM exposures and/or identify safe ENMs for the advancement of human health. PMID:26386111

  18. Therapeutic applications of circadian rhythms for the cardiovascular system

    PubMed Central

    Tsimakouridze, Elena V.; Alibhai, Faisal J.; Martino, Tami A.

    2015-01-01

    The cardiovascular system exhibits dramatic time-of-day dependent rhythms, for example the diurnal variation of heart rate, blood pressure, and timing of onset of adverse cardiovascular events such as heart attack and sudden cardiac death. Over the past decade, the circadian clock mechanism has emerged as a crucial factor regulating these daily fluctuations. Most recently, these studies have led to a growing clinical appreciation that targeting circadian biology offers a novel therapeutic approach toward cardiovascular (and other) diseases. Here we describe leading-edge therapeutic applications of circadian biology including (1) timing of therapy to maximize efficacy in treating heart disease (chronotherapy); (2) novel biomarkers discovered by testing for genomic, proteomic, metabolomic, or other factors at different times of day and night (chronobiomarkers); and (3) novel pharmacologic compounds that target the circadian mechanism with potential clinical applications (new chronobiology drugs). Cardiovascular disease remains a leading cause of death worldwide and new approaches in the management and treatment of heart disease are clearly warranted and can benefit patients clinically. PMID:25941487

  19. Cardiovascular Changes in Animal Models of Metabolic Syndrome

    PubMed Central

    Lehnen, Alexandre M.; Rodrigues, Bruno; Irigoyen, Maria Cláudia; De Angelis, Kátia; Schaan, Beatriz D'Agord

    2013-01-01

    Metabolic syndrome has been defined as a group of risk factors that directly contribute to the development of cardiovascular disease and/or type 2 diabetes. Insulin resistance seems to have a fundamental role in the genesis of this syndrome. Over the past years to the present day, basic and translational research has used small animal models to explore the pathophysiology of metabolic syndrome and to develop novel therapies that might slow the progression of this prevalent condition. In this paper we discuss the animal models used for the study of metabolic syndrome, with particular focus on cardiovascular changes, since they are the main cause of death associated with the condition in humans. PMID:23691518

  20. Human Induced Pluripotent Stem Cell Models of Inherited Cardiovascular Diseases.

    PubMed

    Jiang, Wenjian; Lan, Feng; Zhang, Hongjia

    2014-10-16

    Cardiovascular cells derived from patient specific induced Pluripotent Stem Cell (iPSC) harbor gene mutations associated with the pathogenesis of inherited cardiac diseases and congenital heart diseases (CHD). Numerous reports have demonstrated the utilization of human induced Pluripotent Stem Cell (hiPSC) to model cardiac diseases as a means of investigating their underlying mechanisms. So far, they have been shown to investigate the molecular mechanisms of many cardiac disorders, such as long-QT syndrome (LQT), catecholaminergic polymorphic ventricular tachycardia (CPVT), dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), LEOPARD syndrome (LS), arrhythmogenic cardiomyopathy (ACM), Friedreich ataxia (FRDA), Barth syndrome (BTHS), hypoplastic left heart syndrome (HLHS), Marfan syndrome (MFS) and other CHD. This article summarizes the growing body of research related to modeling various cardiac diseases using hiPSCs. Moreover, by reviewing the methods used in previous studies, we propose multiple novel applications of hiPSCs to investigate comprehensive cardiovascular disorders and facilitate drug discovery. PMID:25322695

  1. 38 CFR 4.104 - Schedule of ratings-cardiovascular system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Schedule of ratings-cardiovascular system. 4.104 Section 4.104 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Cardiovascular System § 4.104 Schedule of ratings—cardiovascular system. Diseases...

  2. Heart Rate, Life Expectancy and the Cardiovascular System: Therapeutic Considerations.

    PubMed

    Boudoulas, Konstantinos Dean; Borer, Jeffrey S; Boudoulas, Harisios

    2015-01-01

    It has long been known that life span is inversely related to resting heart rate in most organisms. This association between heart rate and survival has been attributed to the metabolic rate, which is greater in smaller animals and is directly associated with heart rate. Studies have shown that heart rate is related to survival in apparently healthy individuals and in patients with different underlying cardiovascular diseases. A decrease in heart rate due to therapeutic interventions may result in an increase in survival. However, there are many factors regulating heart rate, and it is quite plausible that these may independently affect life expectancy. Nonetheless, a fast heart rate itself affects the cardiovascular system in multiple ways (it increases ventricular work, myocardial oxygen consumption, endothelial stress, aortic/arterial stiffness, decreases myocardial oxygen supply, other) which, in turn, may affect survival. In this brief review, the effects of heart rate on the heart, arterial system and survival will be discussed. PMID:26305771

  3. Patient-specific system for prognosis of surgical treatment outcomes of human cardiovascular system

    NASA Astrophysics Data System (ADS)

    Golyadkina, Anastasiya A.; Kalinin, Aleksey A.; Kirillova, Irina V.; Kossovich, Elena L.; Kossovich, Leonid Y.; Menishova, Liyana R.; Polienko, Asel V.

    2015-03-01

    Object of study: Improvement of life quality of patients with high stroke risk ia the main goal for development of system for patient-specific modeling of cardiovascular system. This work is dedicated at increase of safety outcomes for surgical treatment of brain blood supply alterations. The objects of study are common carotid artery, internal and external carotid arteries and bulb. Methods: We estimated mechanical properties of carotid arteries tissues and patching materials utilized at angioplasty. We studied angioarchitecture features of arteries. We developed and clinically adapted computer biomechanical models, which are characterized by geometrical, physical and mechanical similarity with carotid artery in norm and with pathology (atherosclerosis, pathological tortuosity, and their combination). Results: Collaboration of practicing cardiovascular surgeons and specialists in the area of Mathematics and Mechanics allowed to successfully conduct finite-element modeling of surgical treatment taking into account various features of operation techniques and patching materials for a specific patient. Numerical experiment allowed to reveal factors leading to brain blood supply decrease and atherosclerosis development. Modeling of carotid artery reconstruction surgery for a specific patient on the basis of the constructed biomechanical model demonstrated the possibility of its application in clinical practice at approximation of numerical experiment to the real conditions.

  4. Impact of Diet-Induced Obesity and Testosterone Deficiency on the Cardiovascular System: A Novel Rodent Model Representative of Males with Testosterone-Deficient Metabolic Syndrome (TDMetS)

    PubMed Central

    Donner, Daniel G.; Elliott, Grace E.; Beck, Belinda R.; Bulmer, Andrew C.; Du Toit, Eugene F.

    2015-01-01

    Introduction Current models of obesity utilise normogonadic animals and neglect the strong relationships between obesity-associated metabolic syndrome (MetS) and male testosterone deficiency (TD). The joint presentation of these conditions has complex implications for the cardiovascular system that are not well understood. We have characterised and investigated three models in male rats: one of diet-induced obesity with the MetS; a second using orchiectomised rats mimicking TD; and a third combining MetS with TD which we propose is representative of males with testosterone deficiency and the metabolic syndrome (TDMetS). Methods Male Wistar rats (n = 24) were randomly assigned to two groups and provided ad libitum access to normal rat chow (CTRL) or a high fat/high sugar/low protein “obesogenic” diet (OGD) for 28 weeks (n = 12/group). These groups were further sub-divided into sham-operated or orchiectomised (ORX) animals to mimic hypogonadism, with and without diet-induced obesity (n = 6/group). Serum lipids, glucose, insulin and sex hormone concentrations were determined. Body composition, cardiovascular structure and function; and myocardial tolerance to ischemia-reperfusion were assessed. Results OGD-fed animals had 72% greater fat mass; 2.4-fold greater serum cholesterol; 2.3-fold greater serum triglycerides and 3-fold greater fasting glucose (indicative of diabetes mellitus) compared to CTRLs (all p<0.05). The ORX animals had reduced serum testosterone and left ventricle mass (p<0.05). In addition to the combined differences observed in each of the isolated models, the OGD, ORX and OGD+ORX models each had greater CK-MB levels following in vivo cardiac ischemia-reperfusion insult compared to CTRLs (p<0.05). Conclusion Our findings provide evidence to support that the MetS and TD independently impair myocardial tolerance to ischemia-reperfusion. The combined OGD+ORX phenotype described in this study is a novel animal model with associated cardiovascular risk factors and complex myocardial pathology which may be representative of male patients presenting with TDMetS. PMID:26366723

  5. Perspectives of induced pluripotent stem cells for cardiovascular system regeneration.

    PubMed

    Csöbönyeiová, Mária; Polák, Štefan; Danišovič, L'uboš

    2015-05-01

    Induced pluripotent stem cells (iPSCs) hold great promise for basic research and regenerative medicine. They offer the same advantages as embryonic stem cells (ESCs) and moreover new perspectives for personalized medicine. iPSCs can be generated from adult somatic tissues by over-expression of a few defined transcription factors, including Oct4, Sox2, Klf4, and c-myc. For regenerative medicine in particular, the technology provides great hope for patients with incurable diseases or potentially fatal disorders such as heart failure. The endogenous regenerative potentials of adult hearts are extremely limited and insufficient to compensate for myocardial loss occurring after myocardial infarction. Recent discoveries have demonstrated that iPSCs have the potential to significantly advance future cardiovascular regenerative therapies. Moreover, iPSCs can be generated from somatic cells of patients with genetic basis for their disease. This human iPSC derivates offer tremendous potential for new disease models. This paper reviews current applications of iPSCs in cardiovascular regenerative medicine and discusses progress in modeling cardiovascular diseases using iPSCs-derived cardiac cells. PMID:25595188

  6. 76 FR 47143 - Approval for Manufacturing Authority, Foreign-Trade Zone 153; Abbott Cardiovascular Systems, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ...); Whereas, notice inviting public comment has been given in the Federal Register (76 FR 4283, 1/25/2011) and... Cardiovascular Systems, Inc., (Cardiovascular Devices), Riverside County, CA Pursuant to its Authority Under the... 153, has requested manufacturing authority on behalf of Abbott Cardiovascular Systems, Inc.,...

  7. The human cardiovascular system in the absence of gravity

    NASA Technical Reports Server (NTRS)

    Bungo, M. W.; Charles, J. B.

    1985-01-01

    The data collected from a Space Shuttle crew to investigate cardiovascular changes due to microgravity are presented. The experimental procedures which involved preflight, immediate postflight, and one week following postflight echocardiograms of 13 individuals are described. The immediate postflight results reveal a 20 percent decrease in stroke volume, a 16 percent decrease in left ventricular diastolic volume index (LVDVI), no change in systolic volume, blood pressure, or cardiac index, and a 24 percent increase in heart rate. One week later a 17 percent stroke volume increase, a 29 percent increase in cardiac index, and normal blood pressure, and LVDVI were observed. It is concluded that upon reexposure to gravity a readaptation process for the cardiovascular system occurs.

  8. Biologics and the cardiovascular system: a double-edged sword.

    PubMed

    Roubille, Camille; Martel-Pelletier, Johanne; Haraoui, Boulos; Tardif, Jean-Claude; Pelletier, Jean-Pierre

    2013-01-01

    Patients with chronic inflammatory diseases such as rheumatoid arthritis have a higher risk of cardiovascular diseases and related mortality compared to the general population. This risk is first due to classical cardiovascular risk factors but also due to systemic inflammation which is independently involved, causing accelerated atherosclerosis, myocardial infarction, cerebrovascular disease and heart failure (HF). Pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 and IL-6 could be major actors on this pathophysiology. Biologics are effective specific treatments in the management of inflammatory rheumatic and systemic diseases. In this review, beneficial and deleterious effects on the heart and vessels of the biologics used in the management of inflammatory arthritis and vasculitides will be discussed, focusing on TNF-alpha, IL-6 and IL-1 blockades, and anti-CD20. Noninflammatory cardiac conditions, such as heart failure, myocardial infarction, and cardiovascular conditions such as atherosclerosis, as well as inflammatory diseases including vasculitides will be discussed. PMID:23286291

  9. Rational macromodeling of 1D blood flow in the human cardiovascular system.

    PubMed

    Ferranti, Francesco; Tamburrelli, Vincenzopio; Antonini, Giulio

    2015-03-01

    In this paper, we present a novel rational macromodeling approach for the description of 1D blood flow in the human cardiovascular system, which is suitable for time-domain simulations. Using the analogy of the blood flow propagation problem with transmission lines and considering the hypothesis of linearized Navier-Stokes equations, a frequency-domain rational macromodel for each arterial segment has been built. The poles and the residues of each arterial segment macromodel have been calculated by means of the Vector Fitting technique. Finally, the rational macromodel of the whole cardiovascular system is obtained by properly combining the macromodels of the single arterial segments using an interconnect matrix. The rational form of the proposed cardiovascular model leads to a state-space or electrical circuit model suitable for time-domain analysis. The stability and passivity properties of the global cardiovascular model are discussed to guarantee stable time-domain simulations. The proposed macromodeling approach has been validated by pertinent numerical results. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25656004

  10. Role of AGEs-RAGE system in cardiovascular disease.

    PubMed

    Fukami, Kei; Yamagishi, Sho-Ichi; Okuda, Seiya

    2014-01-01

    Advanced glycation end products (AGEs) are a heterogenous group of molecules formed during a non-enzymatic reaction between proteins and sugar residues. Recently, AGEs and their receptor (receptor for AGEs; RAGE) play a central role in the pathogenesis of cardiovascular disease (CVD), which accounts for disability and high mortality rate in patients with diabetes. AGEs initiate diabetic micro- and macrovascular complications through the structural modification and functional alteration of the extracellular matrix proteins as well as intracellular signaling molecules. Engagement of RAGEs with AGEs elicits intracellular reactive oxygen species (ROS) generation and subsequently activates mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling, followed by production of several inflammatory and/or profibrotic factors such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), plasminogen activator inhibitor-1 (PAI-1) and monocyte chemoattractant protein-1 (MCP-1), thereby being involved in the progression of atherosclerosis. Administration of soluble form of RAGE (sRAGE) could work as a decoy receptor for AGEs and might inhibit the binding of AGEs to RAGE, preventing the development and progression of atherosclerosis in animal models. Furthermore, AGEs/high mobility group box-1 (HMGB-1)-RAGE interaction is involved in heart failure, abdominal aortic aneurysm (AAA) and vascular calcification as well. Thus, blockade of the AGEs/HMGB-1-RAGE system may be a promising therapeutic target for preventing diabetes- and/or age-related CVD. We review here the pathological role of the AGEs/HMGB-1-RAGE system in various types of CVD. PMID:23844818

  11. Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Afford New Opportunities in Inherited Cardiovascular Disease Modeling

    PubMed Central

    Bayzigitov, Daniel R.; Medvedev, Sergey P.; Dementyeva, Elena V.; Bayramova, Sevda A.; Pokushalov, Evgeny A.; Karaskov, Alexander M.; Zakian, Suren M.

    2016-01-01

    Fundamental studies of molecular and cellular mechanisms of cardiovascular disease pathogenesis are required to create more effective and safer methods of their therapy. The studies can be carried out only when model systems that fully recapitulate pathological phenotype seen in patients are used. Application of laboratory animals for cardiovascular disease modeling is limited because of physiological differences with humans. Since discovery of induced pluripotency generating induced pluripotent stem cells has become a breakthrough technology in human disease modeling. In this review, we discuss a progress that has been made in modeling inherited arrhythmias and cardiomyopathies, studying molecular mechanisms of the diseases, and searching for and testing drug compounds using patient-specific induced pluripotent stem cell-derived cardiomyocytes. PMID:27110425

  12. Consequences of Circadian and Sleep Disturbances for the Cardiovascular System.

    PubMed

    Alibhai, Faisal J; Tsimakouridze, Elena V; Reitz, Cristine J; Pyle, W Glen; Martino, Tami A

    2015-07-01

    Circadian rhythms play a crucial role in our cardiovascular system. Importantly, there has been a recent flurry of clinical and experimental studies revealing the profound adverse consequences of disturbing these rhythms on the cardiovascular system. For example, circadian disturbance worsens outcome after myocardial infarction with implications for patients in acute care settings. Moreover, disturbing rhythms exacerbates cardiac remodelling in heart disease models. Also, circadian dyssynchrony is a causal factor in the pathogenesis of heart disease. These discoveries have profound implications for the cardiovascular health of shift workers, individuals with circadian and sleep disorders, or anyone subjected to the 24/7 demands of society. Moreover, these studies give rise to 2 new frontiers for translational research: (1) circadian rhythms and the cardiac sarcomere, which sheds new light on our understanding of myofilament structure, signalling, and electrophysiology; and (2) knowledge translation, which includes biomarker discovery (chronobiomarkers), timing of therapies (chronotherapy), and other new promising approaches to improve the management and treatment of cardiovascular disease. Reconsidering circadian rhythms in the clinical setting benefits repair mechanisms, and offers new promise for patients. PMID:26031297

  13. Leukocytes Link Local and Systemic Inflammation in Ischemic Cardiovascular Disease: An Expanded "Cardiovascular Continuum".

    PubMed

    Libby, Peter; Nahrendorf, Matthias; Swirski, Filip K

    2016-03-01

    Physicians have traditionally viewed ischemic heart disease in a cardiocentric manner: plaques grow in arteries until they block blood flow, causing acute coronary and other ischemic syndromes. Recent research provides new insight into the integrative biology of inflammation as it contributes to ischemic cardiovascular disease. These results have revealed hitherto unsuspected inflammatory signaling networks at work in these disorders that link the brain, autonomic nervous system, bone marrow, and spleen to the atherosclerotic plaque and to the infarcting myocardium. A burgeoning clinical published data indicates that such inflammatory networks-far from a mere laboratory curiosity-operate in our patients and can influence aspects of ischemic cardiovascular disease that determine decisively clinical outcomes. These new findings enlarge the circle of the traditional "cardiovascular continuum" beyond the heart and vessels to include the nervous system, the spleen, and the bone marrow. PMID:26940931

  14. A systematic review of image segmentation methodology, used in the additive manufacture of patient-specific 3D printed models of the cardiovascular system

    PubMed Central

    Byrne, N; Velasco Forte, M; Tandon, A; Valverde, I

    2016-01-01

    Background Shortcomings in existing methods of image segmentation preclude the widespread adoption of patient-specific 3D printing as a routine decision-making tool in the care of those with congenital heart disease. We sought to determine the range of cardiovascular segmentation methods and how long each of these methods takes. Methods A systematic review of literature was undertaken. Medical imaging modality, segmentation methods, segmentation time, segmentation descriptive quality (SDQ) and segmentation software were recorded. Results Totally 136 studies met the inclusion criteria (1 clinical trial; 80 journal articles; 55 conference, technical and case reports). The most frequently used image segmentation methods were brightness thresholding, region growing and manual editing, as supported by the most popular piece of proprietary software: Mimics (Materialise NV, Leuven, Belgium, 1992–2015). The use of bespoke software developed by individual authors was not uncommon. SDQ indicated that reporting of image segmentation methods was generally poor with only one in three accounts providing sufficient detail for their procedure to be reproduced. Conclusions and implication of key findings Predominantly anecdotal and case reporting precluded rigorous assessment of risk of bias and strength of evidence. This review finds a reliance on manual and semi-automated segmentation methods which demand a high level of expertise and a significant time commitment on the part of the operator. In light of the findings, we have made recommendations regarding reporting of 3D printing studies. We anticipate that these findings will encourage the development of advanced image segmentation methods. PMID:27170842

  15. Methodologic issues in policy modeling for cardiovascular disease.

    PubMed

    Weinstein, M C

    1989-09-01

    Clinical decision models are intended to guide the choices of individual clinicians; policy models are intended to guide the choices of persons and organizations that affect the aggregate allocations of resources to health care problems. Although it is difficult to identify any single policymaker in the United States who can alter the aggregate effect of the millions (or billions) of individual clinical decisions, there are many potential users of policy models: payers, providers, state and local health departments, the National Institutes of Health, professional organizations, hospitals and producers of medical devices, among others. Policy models deal with populations of individuals, may be static or dynamic and may be descriptive or prescriptive. Two types of policy models that have been applied to cardiovascular disease with a focus on coronary artery bypass surgery are discussed: 1) economic evaluation models, specifically cost-effectiveness, cost utility and cost-benefit analyses; and 2) population simulation models. Cost-effectiveness models are preferable for reasons that are discussed. PMID:2504801

  16. TRPV4 channels: physiological and pathological role in cardiovascular system.

    PubMed

    Randhawa, Puneet Kaur; Jaggi, Amteshwar Singh

    2015-11-01

    TRPV4 channels are non-selective cation channels permeable to Ca(2+), Na(+), and Mg(2+) ions. Recently, TRPV4 channels have received considerable attention as these channels are widely expressed in the cardiovascular system including endothelial cells, cardiac fibroblasts, vascular smooth muscles, and peri-vascular nerves. Therefore, these channels possibly play a pivotal role in the maintenance of cardiovascular homeostasis. TRPV4 channels critically regulate flow-induced arteriogenesis, TGF-β1-induced differentiation of cardiac fibroblasts into myofibroblasts, and heart failure-induced pulmonary edema. These channels also mediate hypoxia-induced increase in proliferation and migration of pulmonary artery smooth muscle cells and progression of pulmonary hypertension. These channels also maintain flow-induced vasodilation and preserve vascular function by directly activating Ca(2+)-dependent KCa channels. Furthermore, these may also induce vasodilation and maintain blood pressure indirectly by evoking the release of NO, CGRP, and substance P. The present review discusses the evidences and the potential mechanisms implicated in diverse responses including arteriogenesis, cardiac remodeling, congestive heart failure-induced pulmonary edema, pulmonary hypertension, flow-induced dilation, regulation of blood pressure, and hypoxic preconditioning. PMID:26415881

  17. Preservation Of Native Aortic Valve Flow And Full Hemodynamic Support With The TORVAD™ Using A Computational Model Of The Cardiovascular System

    PubMed Central

    Gohean, Jeffrey R.; George, Mitchell J.; Chang, Kay-Won; Larson, Erik R.; Pate, Thomas D.; Kurusz, Mark; Longoria, Raul G.; Smalling, Richard W.

    2014-01-01

    This paper describes the stroke volume selection and operational design for the TORVAD™, a synchronous, positive-displacement ventricular assist device (VAD). A lumped parameter model was used to simulate hemodynamics with the TORVAD™ compared to those under continuous flow VAD support. Results from the simulation demonstrated that a TORVAD™ with a 30 mL stroke volume ejecting with an early diastolic counterpulse provides comparable systemic support to the HeartMate II® (HMII) (cardiac output 5.7 L/min up from 3.1 L/min in simulated heart failure). By taking advantage of synchronous pulsatility, the TORVAD™ delivers full hemodynamic support with nearly half the VAD flow rate (2.7 L/min compared to 5.3 L/min for the HMII) by allowing the left ventricle to eject during systole, thus preserving native aortic valve flow (3.0 L/min compared to 0.4 L/min for the HMII, down from 3.1 L/min at baseline). The TORVAD™ also preserves pulse pressure (26.7 mmHg compared to 12.8 mmHg for the HMII, down from 29.1 mmHg at baseline). Preservation of aortic valve flow with synchronous pulsatile support could reduce the high incidence of aortic insufficiency and valve cusp fusion reported in patients supported with continuous flow VADs. PMID:25485562

  18. Preservation of native aortic valve flow and full hemodynamic support with the TORVAD using a computational model of the cardiovascular system.

    PubMed

    Gohean, Jeffrey R; George, Mitchell J; Chang, Kay-Won; Larson, Erik R; Pate, Thomas D; Kurusz, Mark; Longoria, Raul G; Smalling, Richard W

    2015-01-01

    This article describes the stroke volume selection and operational design for the toroidal ventricular assist device (TORVAD), a synchronous, positive-displacement ventricular assist device (VAD). A lumped parameter model was used to simulate hemodynamics with the TORVAD compared with those under continuous-flow VAD support. Results from the simulation demonstrated that a TORVAD with a 30 ml stroke volume ejecting with an early diastolic counterpulse provides comparable systemic support to the HeartMate II (HMII) (cardiac output 5.7 L/min up from 3.1 L/min in simulated heart failure). By taking the advantage of synchronous pulsatility, the TORVAD delivers full hemodynamic support with nearly half the VAD flow rate (2.7 L/min compared with 5.3 L/min for the HMII) by allowing the left ventricle to eject during systole and thus preserving native aortic valve flow (3.0 L/min compared with 0.4 L/min for the HMII, down from 3.1 L/min at baseline). The TORVAD also preserves pulse pressure (26.7 mm Hg compared with 12.8 mm Hg for the HMII, down from 29.1 mm Hg at baseline). Preservation of aortic valve flow with synchronous pulsatile support could reduce the high incidence of aortic insufficiency and valve cusp fusion reported in patients supported with continuous-flow VADs. PMID:25485562

  19. Animal Models in Cardiovascular Research: Hypertension and Atherosclerosis

    PubMed Central

    Ng, Chun-Yi; Jaarin, Kamsiah

    2015-01-01

    Hypertension and atherosclerosis are among the most common causes of mortality in both developed and developing countries. Experimental animal models of hypertension and atherosclerosis have become a valuable tool for providing information on etiology, pathophysiology, and complications of the disease and on the efficacy and mechanism of action of various drugs and compounds used in treatment. An animal model has been developed to study hypertension and atherosclerosis for several reasons. Compared to human models, an animal model is easily manageable, as compounding effects of dietary and environmental factors can be controlled. Blood vessels and cardiac tissue samples can be taken for detailed experimental and biomolecular examination. Choice of animal model is often determined by the research aim, as well as financial and technical factors. A thorough understanding of the animal models used and complete analysis must be validated so that the data can be extrapolated to humans. In conclusion, animal models for hypertension and atherosclerosis are invaluable in improving our understanding of cardiovascular disease and developing new pharmacological therapies. PMID:26064920

  20. Epidermal Growth Factor Receptor Transactivation: Mechanisms, Pathophysiology, and Potential Therapies in the Cardiovascular System.

    PubMed

    Forrester, Steven J; Kawai, Tatsuo; O'Brien, Shannon; Thomas, Walter; Harris, Raymond C; Eguchi, Satoru

    2016-01-01

    Epidermal growth factor receptor (EGFR) activation impacts the physiology and pathophysiology of the cardiovascular system, and inhibition of EGFR activity is emerging as a potential therapeutic strategy to treat diseases including hypertension, cardiac hypertrophy, renal fibrosis, and abdominal aortic aneurysm. The capacity of G protein-coupled receptor (GPCR) agonists, such as angiotensin II (AngII), to promote EGFR signaling is called transactivation and is well described, yet delineating the molecular processes and functional relevance of this crosstalk has been challenging. Moreover, these critical findings are dispersed among many different fields. The aim of our review is to highlight recent advancements in defining the signaling cascades and downstream consequences of EGFR transactivation in the cardiovascular renal system. We also focus on studies that link EGFR transactivation to animal models of the disease, and we discuss potential therapeutic applications. PMID:26566153

  1. Stress, depression, and cardiovascular dysregulation: A review of neurobiological mechanisms and the integration of research from preclinical disease models

    PubMed Central

    Grippo, Angela J.; Johnson, Alan Kim

    2008-01-01

    A bidirectional association between mood disorders such as depression, and cardiovascular diseases such as myocardial infarction and congestive heart failure, has been described; however, the precise neurobiological mechanisms that underlie these associations have not been fully elucidated. This review is focused on the neurobiological processes and mediators that are common to both mood and cardiovascular disorders, with an emphasis on the role of exogenous stressors in addition to: (a) neuroendocrine and neurohumoral changes involving dysfunction of the hypothalamic-pituitary-adrenal axis and activation of the renin-angiotensin-aldosterone system, (b) immune alterations including activation of pro-inflammatory cytokines, (c) autonomic and cardiovascular dysregulation including increased sympathetic drive, withdrawal of parasympathetic tone, cardiac rate and rhythm disturbances, and altered baroreceptor reflex function, (d) central neurotransmitter system dysfunction including dopamine, norepinephrine and serotonin, and (e) behavioral changes including fatigue and physical inactivity. We also focus specifically on experimental investigations with preclinical disease models, conducted to elucidate the neurobiological mechanisms underlying the link between mood disorders and cardiovascular disease. These include: (a) the chronic mild stress model of depression, (b) a model of congestive heart failure, a model of cardiovascular deconditioning, (d) pharmacological manipulations of body fluid and sodium balance, and (e) pharmacological manipulations of the central serotonergic system. In combination with the extensive literature describing findings from human research, the investigation of mechanisms underlying mood and cardiovascular regulation using animal models will enhance our understanding of the association of depression and cardiovascular disease, and can promote the development of better treatments and interventions for individuals with these co-morbid conditions. PMID:19116888

  2. Viability assessment after conventional coronary angiography using a novel cardiovascular interventional therapeutic CT system: Comparison with gross morphology in a subacute infarct swine model

    PubMed Central

    Hartaigh, Bríain W.Ó.; Park, Se-Il; Hong, Youngtaek; Shin, Sanghoon; Ha, Seongmin; Jeon, Byunghwan; Jung, Hoyup; Shim, Hackjoon; Min, James K.; Chang, Hyuk-Jae; Jang, Yangsoo; Chung, Namsik

    2015-01-01

    Background Given the lack of promptness and inevitable use of additional contrast agents, the myocardial viability imaging procedures have not been used widely for determining the need to performing revascularization. Objective This study is aimed to evaluate the feasibility of myocardial viability assessment, consecutively with diagnostic invasive coronary angiography (ICA) without use of additional contrast agent, using a novel hybrid system comprising ICA and multislice CT (MSCT). Methods In all, 14 Yucatan miniature swine models (female; age, 3 months; weight, 28–30 kg) were subjected to ICA followed by balloon occlusion (90 minutes) and reperfusion of the left anterior descending coronary artery. Two weeks after induction of myocardial infarction, delayed hyperenhancement (DHE) images were obtained, using a novel combined machine comprising ICA and 320-channel MSCT scanner (Aquilion ONE, Toshiba), after 2, 5, 7, 10, 15, and 20 minutes after conventional ICA. The heart was sliced in 10-mm consecutive sections in the short-axis plane and was embedded in a solution of 1% triphenyltetrazolium chloride (TTC). Infarct size was determined as TTC-negative areas as a percentage of total left ventricular area. On MSCT images, infarct size per slice was calculated by dividing the DHE area by the total slice area (%) and compared with histochemical analyses. Results Serial MSCT scans revealed a peak CT attenuation of the infarct area (222.5 ± 36.5 Hounsfield units) with a maximum mean difference in CT attenuation between the infarct areas and normal myocardium of at 2 minutes after contrast injection (106.4; P for difference = 0.002). Furthermore, the percentage difference of infarct size by MSCT vs histopathologic specimen was significantly lower at 2 (8.5% ± 1.8%) and 5 minutes (9.5% ± 1.9%) than those after 7 minutes. Direct comparisons of slice-matched DHE area by MSCT demonstrated excellent correlation with TTC-derived infarct size (r = 0.952; P < .001). Bland-Altman plots of the differences between DHE by MSCT and TTC-derived infarct measurements plotted against their means showed good agreement between the 2 methods. Conclusion The feasibility of myocardial viability assessment by DHE using MSCT after conventional ICA was proven in experimental models, and the optimal viability images were obtained after 2 to 5 minutes after the final intracoronary injection of contrast agent for conventional ICA. PMID:26088379

  3. Cardiovascular Event Risk Dynamics Over Time in Older Patients on Dialysis: A Generalized Multiple-Index Varying Coefficient Model Approach

    PubMed Central

    Estes, Jason P.; Nguyen, Danh V.; Dalrymple, Lorien S.; Mu, Yi; Şentürk, Damla

    2014-01-01

    Among patients on dialysis, cardiovascular disease and infection are leading causes of hospitalization and death. Although recent studies have found that the risk of cardiovascular events is higher after an infection-related hospitalization, studies have not fully elucidated how the risk of cardiovascular events changes over time for patients on dialysis. In this work, we characterize the dynamics of cardiovascular event risk trajectories for patients on dialysis while conditioning on survival status via multiple time indices: (1) time since the start of dialysis, (2) time since the pivotal initial infection-related hospitalization and (3) the patient’s age at the start of dialysis. This is achieved by using a new class of generalized multiple-index varying coefficient (GM-IVC) models. The proposed GM-IVC models utilize a multiplicative structure and one-dimensional varying coefficient functions along each time and age index to capture the cardiovascular risk dynamics before and after the initial infection-related hospitalization among the dynamic cohort of survivors. We develop a two-step estimation procedure for the GM-IVC models based on local maximum likelihood. We report new insights on the dynamics of cardiovascular events risk using the United States Renal Data System database, which collects data on nearly all patients with end-stage renal disease in the U.S. Finally, simulation studies assess the performance of the proposed estimation procedures. PMID:24766178

  4. Role of silver nanoparticles (AgNPs) on the cardiovascular system.

    PubMed

    Gonzalez, Carmen; Rosas-Hernandez, Hector; Ramirez-Lee, Manuel Alejandro; Salazar-García, Samuel; Ali, Syed F

    2016-03-01

    With the advent of nanotechnology, the use and applications of silver nanoparticles (AgNPs) have increased, both in consumer products as well as in medical devices. However, little is known about the effects of these nanoparticles on human health, more specific in the cardiovascular system, since this system represents an important route of action in terms of distribution, bioaccumulation and bioavailability of the different circulating substances in the bloodstream. A collection of studies have addressed the effects and applications of different kinds of AgNPs (shaped, sized, coated and functionalized) in several components of the cardiovascular system, such as endothelial cells, isolated vessels and organs as well as integrative animal models, trying to identify the underlying mechanisms involved in their actions, to understand their implication in the field of biomedicine. The purpose of the present review is to summarize the most relevant studies to date of AgNPs effects in the cardiovascular system and provide a broader picture of the potential toxic effects and exposure risks, which in turn will allow pointing out the directions of further research as well as new applications of these versatile nanomaterials. PMID:25543135

  5. Surveillance of cardiovascular diseases using a multivariate dynamic screening system.

    PubMed

    Qiu, Peihua; Xiang, Dongdong

    2015-06-30

    In the SHARe Framingham Heart Study of the National Heart, Lung and Blood Institute, one major task is to monitor several health variables (e.g., blood pressure and cholesterol level) so that their irregular longitudinal pattern can be detected as soon as possible and some medical treatments applied in a timely manner to avoid some deadly cardiovascular diseases (e.g., stroke). To handle this kind of applications effectively, we propose a new statistical methodology called multivariate dynamic screening system (MDySS) in this paper. The MDySS method combines the major strengths of the multivariate longitudinal data analysis and the multivariate statistical process control, and it makes decisions about the longitudinal pattern of a subject by comparing it with other subjects cross sectionally and by sequentially monitoring it as well. Numerical studies show that MDySS works well in practice. PMID:25757653

  6. Use of implantable telemetry systems for study of cardiovascular phenomena.

    NASA Technical Reports Server (NTRS)

    Sandler, H.; Fryer, T. B.; Westbrook, R. M.; Stone, H. L.

    1972-01-01

    Preliminary observations of cardiovascular function have been made in four chimpanzees using multichannel implantable units. Measurements of right- and left-sided pressures were periodically made in these animals over a four-month period, including continuous observations for selected 24-hour periods. Pressures recorded with animals in an awake, unanesthetized, unrestrained state were much lower than pressures reported for restrained animals in similar situations. Diurnal variations of pressure tended to occur, but were not as clear-cut as those reported to occur for humans. The ability to implant a transmitter chronically and receive useful multichannel information in the chimpanzee encourages the future use of such implant devices as part of the control system for an artificial heart or directly for use in man.

  7. Impact of atrial fibrillation on the cardiovascular system through a lumped-parameter approach.

    PubMed

    Scarsoglio, Stefania; Guala, Andrea; Camporeale, Carlo; Ridolfi, Luca

    2014-11-01

    Atrial fibrillation (AF) is the most common arrhythmia affecting millions of people in the Western countries and, due to the widespread impact on the population and its medical relevance, is largely investigated in both clinical and bioengineering sciences. However, some important feedback mechanisms are still not clearly established. The present study aims at understanding the global response of the cardiovascular system during paroxysmal AF through a lumped-parameter approach, which is here performed paying particular attention to the stochastic modeling of the irregular heartbeats and the reduced contractility of the heart. AF can be here analyzed by means of a wide number of hemodynamic parameters and avoiding the presence of other pathologies, which usually accompany AF. Reduced cardiac output with correlated drop of ejection fraction and decreased amount of energy converted to work by the heart during blood pumping, as well as higher left atrial volumes and pressures are some of the most representative results aligned with the existing clinical literature and here emerging during acute AF. The present modeling, providing new insights on cardiovascular variables which are difficult to measure and rarely reported in literature, turns out to be an efficient and powerful tool for a deeper comprehension and prediction of the arrythmia impact on the whole cardiovascular system. PMID:25192922

  8. A Large-Scale, Energetic Model of Cardiovascular Homeostasis Predicts Dynamics of Arterial Pressure in Humans

    PubMed Central

    Roytvarf, Alexander; Shusterman, Vladimir

    2008-01-01

    The energetic balance of forces in the cardiovascular system is vital to the stability of blood flow to all physiological systems in mammals. Yet, a large-scale, theoretical model, summarizing the energetic balance of major forces in a single, mathematically closed system has not been described. Although a number of computer simulations have been successfully performed with the use of analog models, the analysis of energetic balance of forces in such models is obscured by a big number of interacting elements. Hence, the goal of our study was to develop a theoretical model that represents large-scale, energetic balance in the cardiovascular system, including the energies of arterial pressure wave, blood flow, and the smooth muscle tone of arterial walls. Because the emphasis of our study was on tracking beat-to-beat changes in the balance of forces, we used a simplified representation of the blood pressure wave as a trapezoidal pressure-pulse with a strong-discontinuity leading front. This allowed significant reduction in the number of required parameters. Our approach has been validated using theoretical analysis, and its accuracy has been confirmed experimentally. The model predicted the dynamics of arterial pressure in human subjects undergoing physiological tests and provided insights into the relationships between arterial pressure and pressure wave velocity. PMID:18269976

  9. Animal Models to Study Links between Cardiovascular Disease and Renal Failure and Their Relevance to Human Pathology

    PubMed Central

    Hewitson, Tim D.; Holt, Stephen G.; Smith, Edward R.

    2015-01-01

    The close association between cardiovascular pathology and renal dysfunction is well documented and significant. Patients with conventional risk factors for cardiovascular disease like diabetes and hypertension also suffer renal dysfunction. This is unsurprising if the kidney is simply regarded as a “modified blood vessel” and thus, traditional risk factors will affect both systems. Consistent with this, it is relatively easy to comprehend how patients with either sudden or gradual cardiac and or vascular compromise have changes in both renal hemodynamic and regulatory systems. However, patients with pure or primary renal dysfunction also have metabolic changes (e.g., oxidant stress, inflammation, nitric oxide, or endocrine changes) that affect the cardiovascular system. Thus, cardiovascular and renal systems are intimately, bidirectionally and inextricably linked. Whilst we understand several of these links, some of the mechanisms for these connections remain incompletely explained. Animal models of cardiovascular and renal disease allow us to explore such mechanisms, and more importantly, potential therapeutic strategies. In this article, we review various experimental models used, and examine critically how representative they are of the human condition. PMID:26441970

  10. Modeling and Simulation Approaches for Cardiovascular Function and Their Role in Safety Assessment

    PubMed Central

    Collins, TA; Bergenholm, L; Abdulla, T; Yates, JWT; Evans, N; Chappell, MJ; Mettetal, JT

    2015-01-01

    Systems pharmacology modeling and pharmacokinetic-pharmacodynamic (PK/PD) analysis of drug-induced effects on cardiovascular (CV) function plays a crucial role in understanding the safety risk of new drugs. The aim of this review is to outline the current modeling and simulation (M&S) approaches to describe and translate drug-induced CV effects, with an emphasis on how this impacts drug safety assessment. Current limitations are highlighted and recommendations are made for future effort in this vital area of drug research. PMID:26225237

  11. Neural Control of the Cardiovascular System in Space

    NASA Technical Reports Server (NTRS)

    Levine, Benjamin D.; Pawelczyk, James A.; Zuckerman, Julie; Zhang, Rong; Fu, Qi; Iwasaki, Kenichi; Ray, Chet; Blomqvist, C. Gunnar; Lane, Lynda D.; Giller, Cole A.

    2003-01-01

    During the acute transition from lying supine to standing upright, a large volume of blood suddenly moves from the chest into the legs. To prevent fainting, the blood pressure control system senses this change immediately, and rapidly adjusts flow (by increasing heart rate) and resistance to flow (by constricting the blood vessels) to restore blood pressure and maintain brain blood flow. If this system is inadequate, the brain has a backup plan. Blood vessels in the brain can adjust their diameter to keep blood flow constant. If blood pressure drops, the brain blood vessels dilate; if blood pressure increases, the brain blood vessels constrict. This process, which is called autoregulation, allows the brain to maintain a steady stream of oxygen, even when blood pressure changes. We examined what changes in the blood pressure control system or cerebral autoregulation contribute to the blood pressure control problems seen after spaceflight. We asked: (1) does the adaptation to spaceflight cause an adaptation in the blood pressure control system that impairs the ability of the system to constrict blood vessels on return to Earth?; (2) if such a defect exists, could we pinpoint the neural pathways involved?; and (3) does cerebral autoregulation become abnormal during spaceflight, impairing the body s ability to maintain constant brain blood flow when standing upright on Earth? We stressed the blood pressure control system using lower body negative pressure, upright tilt, handgrip exercise, and cold stimulation of the hand. Standard cardiovascular parameters were measured along with sympathetic nerve activity (the nerve activity causing blood vessels to constrict) and brain blood flow. We confirmed that the primary cardiovascular effect of spaceflight was a postflight reduction in upright stroke volume (the amount of blood the heart pumps per beat). Heart rate increased appropriately for the reduction in stroke volume, thereby showing that changes in heart rate regulation alone cannot be responsible for orthostatic hypotension after spaceflight. All of the astronauts in our study had an increase in sympathetic nerve activity during upright tilting on Earth postflight. This increase was well calibrated for the reduction in stroke volume induced by the upright posture. The results obtained from stimulating the sympathetic nervous system using handgrip exercise or cold stress were also entirely normal during and after spaceflight. No astronaut had reduced cerebral blood flow during upright tilt, and cerebral autoregulation was normal or even enhanced inflight. These experiments show that the cardiovascular adaptation to spaceflight does not lead to a defect in the regulation of blood vessel constriction via sympathetic nerve activity. In addition, cerebral autoregulation is well-maintained. It is possible that despite the increased sympathetic nerve activity, blood vessels did not respond with a greater degree of constriction than occurred preflight, possibly uncovering a limit of vasoconstrictor reserve.

  12. Prediction and management of cardiovascular outcomes in systemic lupus erythematosus.

    PubMed

    Frostegård, Johan

    2015-02-01

    Atherosclerosis is the major cause of cardiovascular disease (CVD), which represents the major cause of death. During recent years, it has become clear that atherosclerosis is a chronic inflammatory condition where immunity could play an important role. Usually, it is when atherosclerotic plaques rupture that CVD follows, but some cases of CVD can occur without apparent atherosclerosis. In systemic lupus erythematosus, the risk of CVD is very high and the prevalence of atherosclerotic plaques, including vulnerable ones, is increased. A combination of traditional and non-traditional risk factors is implicated for the prediction of CVD in systemic lupus erythematosus. Traditional risk factors include hypertension, dyslipidemia, smoking and diabetes, though the exact importance of each of these in systemic lupus erythematosus is not clear. Anti-phospholipid antibodies, systemic inflammation and low levels of natural antibodies such as those against phosphorylcholine (anti-PC) are examples of non-traditional risk factors. Control of disease activity and disease manifestations and of established risk factors is important. PMID:25517760

  13. Weighted Hurdle Regression Method for Joint Modeling of Cardiovascular Events Likelihood and Rate in the U.S. Dialysis Population

    PubMed Central

    Şentürk, Damla; Dalrymple, Lorien S.; Mu, Yi; Nguyen, Danh V.

    2014-01-01

    SUMMARY We propose a new weighted hurdle regression method for modeling count data, with particular interest in modeling cardiovascular events in patients on dialysis. Cardiovascular disease remains one of the leading causes of hospitalization and death in this population. Our aim is to jointly model the relationship/association between covariates and (a) the probability of cardiovascular events, a binary process and (b) the rate of events once the realization is positive - when the ‘hurdle’ is crossed - using a zero-truncated Poisson distribution. When the observation period or follow-up time, from the start of dialysis, varies among individuals the estimated probability of positive cardiovascular events during the study period will be biased. Furthermore, when the model contains covariates, then the estimated relationship between the covariates and the probability of cardiovascular events will also be biased. These challenges are addressed with the proposed weighted hurdle regression method. Estimation for the weighted hurdle regression model is a weighted likelihood approach, where standard maximum likelihood estimation can be utilized. The method is illustrated with data from the United States Renal Data System. Simulation studies show the ability of proposed method to successfully adjust for differential follow-up times and incorporate the effects of covariates in the weighting. PMID:24930810

  14. National Training Course. Emergency Medical Technician. Paramedic. Instructor's Lesson Plans. Module VI. Cardiovascular System.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This instructor's lesson plan guide on the cardiovascular system is one of fifteen modules designed for use in the training of emergency medical technicians (paramedics). Seven units of study are presented: (1) the anatomy and physiology of the cardiovascular system; (2) patient assessment for the cardiac patient; (3) pathophysiology; (4) reading…

  15. Influence of physical fields of active geological faults on the human cardiovascular system

    NASA Astrophysics Data System (ADS)

    Shitov, A. V.; Borodin, A. S.; Tuzhilkin, D. A.; Apryatkina, M. L.

    2014-12-01

    Results of studying the human cardiovascular system within zones of Altai Mountain geological faults are presented. It is shown that features of the geological-geophysical characteristics have an effect on different control circuits of the human cardiovascular system and cause a change in its functioning.

  16. [Simulation Analysis of the Pulse Signal on the Electricity Network of Cardiovascular System].

    PubMed

    Liu, Ying; Yin, Yanfei; Zhang, Defa; Wang, Menghong; Bi, Yongqiang

    2015-12-01

    Pulse waves contain abundant physiological and pathological information of human body. Research of the relationship between pulse wave and human cardiovascular physiological parameters can not only help clinical diagnosis and treatment of cardiovascular diseases, but also contribute to develop many new medical instruments. Based on the traditional double elastic cavity model, the human cardiovascular system was established by using the electric network model in this paper. The change of wall pressure and blood flow in artery was simulated. And the influence of the peripheral resistance and vessel compliance to the distribution of blood flow in artery was analyzed. The simulation results were compared with the clinical monitoring results to predict the physiological and pathological state of human body. The result showed that the simulation waveform of arterial wall pressure and blood flow was stabile after the second cardiac cycle. With the increasing of peripheral resistance, the systolic blood pressure of artery increased, the diastolic blood pressure had no significant change, and the pulse pressure of artery increased gradually. With the decreasing of vessel compliance, the vasoactivity became worse and the pulse pressure increased correspondingly. The simulation results were consistent with the clinical monitoring results. The increasing of peripheral resistance and decreasing of vascular compliance indicated that the incidence of hypertension and atherosclerosis was increased. PMID:27079088

  17. Cell Systems to Investigate the Impact of Polyphenols on Cardiovascular Health

    PubMed Central

    Grootaert, Charlotte; Kamiloglu, Senem; Capanoglu, Esra; Van Camp, John

    2015-01-01

    Polyphenols are a diverse group of micronutrients from plant origin that may serve as antioxidants and that contribute to human health in general. More specifically, many research groups have investigated their protective effect against cardiovascular diseases in several animal studies and human trials. Yet, because of the excessive processing of the polyphenol structure by human cells and the residing intestinal microbial community, which results in a large variability between the test subjects, the exact mechanisms of their protective effects are still under investigation. To this end, simplified cell culture systems have been used to decrease the inter-individual variability in mechanistic studies. In this review, we will discuss the different cell culture models that have been used so far for polyphenol research in the context of cardiovascular diseases. We will also review the current trends in cell culture research, including co-culture methodologies. Finally, we will discuss the potential of these advanced models to screen for cardiovascular effects of the large pool of bioactive polyphenols present in foods and their metabolites. PMID:26569293

  18. An integrative model of respiratory and cardiovascular control in sleep-disordered breathing

    PubMed Central

    Cheng, Limei; Ivanova, Olga; Fan, Hsing-Hua; Khoo, Michael C. K.

    2010-01-01

    While many physiological control models exist in the literature, none thus far has focused on characterizing the interactions among the respiratory, cardiovascular and sleep-wake regulation systems that occur in sleep-disordered breathing. The model introduced in this study integrates the autonomic control of the cardiovascular system, chemoreflex and state-related control of respiration, including respiratory and upper airway mechanics, along with a model of circadian and sleep-wake regulation. The integrative model provides realistic predictions of the physiological responses under a variety of conditions including: the sleep-wake cycle, hypoxia-induced periodic breathing, Cheyne-Stokes respiration in chronic heart failure, and obstructive sleep apnoea (OSA). It can be used to investigate the effects of a variety of interventions, such as isocapnic and hypercapnic and/or hypoxic gas administration, the Valsalva and Mueller maneuvers, and the application of continuous positive airway pressure on OSA subjects. By being able to delineate the influences of the various interacting physiological mechanisms, the model is useful in providing a more lucid understanding of the complex dynamics that characterize state-cardiorespiratory control in the different forms of sleep-disordered breathing. PMID:20542148

  19. Chemokines and Heart Disease: A Network Connecting Cardiovascular Biology to Immune and Autonomic Nervous Systems

    PubMed Central

    Dusi, Veronica; Ghidoni, Alice; Ravera, Alice; De Ferrari, Gaetano M.; Calvillo, Laura

    2016-01-01

    Among the chemokines discovered to date, nineteen are presently considered to be relevant in heart disease and are involved in all stages of cardiovascular response to injury. Chemokines are interesting as biomarkers to predict risk of cardiovascular events in apparently healthy people and as possible therapeutic targets. Moreover, they could have a role as mediators of crosstalk between immune and cardiovascular system, since they seem to act as a “working-network” in deep linkage with the autonomic nervous system. In this paper we will describe the single chemokines more involved in heart diseases; then we will present a comprehensive perspective of them as a complex network connecting the cardiovascular system to both the immune and the autonomic nervous systems. Finally, some recent evidences indicating chemokines as a possible new tool to predict cardiovascular risk will be described.

  20. Theory and Developments in an Unobtrusive Cardiovascular System Representation: Ballistocardiography

    PubMed Central

    Pinheiro, Eduardo; Postolache, Octavian; Girão, Pedro

    2010-01-01

    Due to recent technological improvements, namely in the field of piezoelectric sensors, ballistocardiography – an almost forgotten physiological measurement – is now being object of a renewed scientific interest. Transcending the initial purposes of its development, ballistocardiography has revealed itself to be a useful informative signal about the cardiovascular system status, since it is a non-intrusive technique which is able to assess the body’s vibrations due to its cardiac, and respiratory physiological signatures. Apart from representing the outcome of the electrical stimulus to the myocardium – which may be obtained by electrocardiography – the ballistocardiograph has additional advantages, as it can be embedded in objects of common use, such as a bed or a chair. Moreover, it enables measurements without the presence of medical staff, factor which avoids the stress caused by medical examinations and reduces the patient’s involuntary psychophysiological responses. Given these attributes, and the crescent number of systems developed in recent years, it is therefore pertinent to revise all the information available on the ballistocardiogram’s physiological interpretation, its typical waveform information, its features and distortions, as well as the state of the art in device implementations. PMID:21673836

  1. Effects of Tetrodotoxin on the Mammalian Cardiovascular System

    PubMed Central

    Zimmer, Thomas

    2010-01-01

    The human genome encodes nine functional voltage-gated Na+ channels. Three of them, namely Nav1.5, Nav1.8, and Nav1.9, are resistant to nanomolar concentrations of tetrodotoxin (TTX; IC50 ≥ 1 μM). The other isoforms, which are predominantly expressed in the skeletal muscle and nervous system, are highly sensitive to TTX (IC50 ~ 10 nM). During the last two decades, it has become evident that in addition to the major cardiac isoform Nav1.5, several of those TTX sensitive isoforms are expressed in the mammalian heart. Whereas immunohistochemical and electrophysiological methods demonstrated functional expression in various heart regions, the physiological importance of those isoforms for cardiac excitation in higher mammals is still debated. This review summarizes our knowledge on the systemic cardiovascular effects of TTX in animals and humans, with a special focus on cardiac excitation and performance at lower concentrations of this marine drug. Altogether, these data strongly suggest that TTX sensitive Na+ channels, detected more recently in various heart tissues, are not involved in excitation phenomena in the healthy adult heart of higher mammals. PMID:20411124

  2. G-protein Coupled Receptor Signaling in Pluripotent Stem Cell-derived Cardiovascular Cells: Implications for Disease Modeling

    PubMed Central

    Dolatshad, Nazanin F.; Hellen, Nicola; Jabbour, Richard J.; Harding, Sian E.; Földes, Gabor

    2015-01-01

    Human pluripotent stem cell derivatives show promise as an in vitro platform to study a range of human cardiovascular diseases. A better understanding of the biology of stem cells and their cardiovascular derivatives will help to understand the strengths and limitations of this new model system. G-protein coupled receptors (GPCRs) are key regulators of stem cell maintenance and differentiation and have an important role in cardiovascular cell signaling. In this review, we will therefore describe the state of knowledge concerning the regulatory role of GPCRs in both the generation and function of pluripotent stem cell derived-cardiomyocytes, -endothelial, and -vascular smooth muscle cells. We will consider how far the in vitro disease models recapitulate authentic GPCR signaling and provide a useful basis for discovery of disease mechanisms or design of therapeutic strategies. PMID:26697426

  3. Community-Based ECG Monitoring System for Patients with Cardiovascular Diseases.

    PubMed

    Lin, Bor-Shyh; Wong, Alice M; Tseng, Kevin C

    2016-04-01

    This study aims to develop a community-based electrocardiogram (ECG) monitoring system for cardiac outpatients to wirelessly detect heart rate, provide personalized healthcare, and enhance interactive social contact because of the prevalence of deaths from cardiovascular disease and the growing problem of aging in the world. The system not only strengthens the performance of the ECG monitoring system but also emphasizes the ergonomic design of wearable devices and user interfaces. In addition, it enables medical professionals to diagnose cardiac symptoms remotely and electronically manage medical reports and suggestions. The experimental result shows high performance of the dry electrode, even in dynamic conditions. The comparison result with different ECG healthcare systems shows the essential factors that the system should possess and the capability of the proposed system. Finally, a user survey was conducted based on the unified theory of acceptance and users of technology (UTAUT) model. PMID:26802010

  4. How did Haly Abbas look at the cardiovascular system?

    PubMed

    Dalfardi, Behnam; Mahmoudi Nezhad, Golnoush Sadat; Mehdizadeh, Alireza

    2014-03-01

    Persian scholars, especially those who lived during the Golden Age of Islamic Medicine (9th-12th century AD), made significant contributions to the healing arts and secured a place of honor for themselves in the history of this science. Abū l-Ḥasan Alī ibn al-'Abbās al-Majūsī Ahvazi (? 930-994AD), with the Latinized name of Haly Abbas, was a scientist from this part of the world who contributed to the advancement of medicine. He is the author of Kāmil al-Sinā'ah al-Tibbīyah (The Perfect Book of the Art of Medicine), also commonly known as al-Kitāb al-Malikī (The Royal Book), a medical encyclopedia renowned for its systematic and precise content. This textbook covers a wide variety of medical issues, among them topics related to the science of cardiology. This paper reviews the main points of Haly Abbas' knowledge of the cardiovascular system, of which little has been written until now. PMID:24452226

  5. Peroxisome proliferator-activated receptors in the cardiovascular system

    PubMed Central

    Bishop-Bailey, David

    2000-01-01

    Peroxisome proliferator-activated receptor (PPAR)s are a family of three nuclear hormone receptors, PPARα, -δ, and -γ, which are members of the steriod receptor superfamily. The first member of the family (PPARα) was originally discovered as the mediator by which a number of xenobiotic drugs cause peroxisome proliferation in the liver. Defined functions for all these receptors, until recently, mainly concerned their ability to regulate energy balance, with PPARα being involved in β-oxidation pathways, and PPARγ in the differentiation of adipocytes. Little is known about the functions of PPARδ, though it is the most ubiquitously expressed. Since their discovery, PPARs have been shown to be expressed in monocytes/macrophages, the heart, vascular smooth muscle cells, endothelial cells, and in atherosclerotic lesions. Furthermore, PPARs can be activated by a vast number of compounds including synthetic drugs, of the clofibrate, and anti-diabetic thiazoldinedione classes, polyunsaturated fatty acids, and a number of eicosanoids, including prostaglandins, lipoxygenase products, and oxidized low density lipoprotein. This review will aim to introduce the field of PPAR nuclear hormone receptors, and discuss the discovery and actions of PPARs in the cardiovascular system, as well as the source of potential ligands. PMID:10696077

  6. Vasopressin and Oxytocin in Control of the Cardiovascular System

    PubMed Central

    Japundžić-Žigon, Nina

    2013-01-01

    Vasopressin (VP) and oxytocin (OT) are mainly synthesized in the magnocellular neurons of the paraventricular (PVN) and supraoptic nucleus (SON) of the hypothalamus. Axons from the magnocellular part of the PVN and SON project to neurohypophysis where VP and OT are released in blood to act like hormones. Axons from the parvocellular part of PVN project to extra-hypothalamic brain areas (median eminence, limbic system, brainstem and spinal cord) where VP and OT act like neurotransmitters/modulators. VP and OT act in complementary manner in cardiovascular control, both as hormones and neurotransmitters. While VP conserves water and increases circulating blood volume, OT eliminates sodium. Hyperactivity of VP neurons and quiescence of OT neurons in PVN underlie osmotic adjustment to pregnancy. In most vascular beds VP is a potent vasoconstrictor, more potent than OT, except in the umbilical artery at term. The vasoconstriction by VP and OT is mediated via V1aR. In some vascular beds, i.e. the lungs and the brain, VP and OT produce NO dependent vasodilatation. Peripherally, VP has been found to enhance the sensitivity of the baro-receptor while centrally, VP and OT increase sympathetic outflow, suppresse baro-receptor reflex and enhance respiration. Whilst VP is an important mediator of stress that triggers ACTH release, OT exhibits anti-stress properties. Moreover, VP has been found to contribute considerably to progression of hypertension and heart failure while OT has been found to decrease blood pressure and promote cardiac healing. PMID:23997756

  7. The Utility of Animal Models in Understanding Links between Psychosocial Processes and Cardiovascular Health

    PubMed Central

    Grippo, Angela J.

    2011-01-01

    A bidirectional association between mood disorders and cardiovascular disease has been described; however, the neurobiological mechanisms that underlie this link have not been fully elucidated. The purpose of this review is first to describe some of the important behavioral neurobiological processes that are common to both mood and cardiovascular disorders. Second, this review focuses on the value of conducting research with animal models (primarily rodents) to investigate potential behavioral, physiological, and neural processes involved in the association of mood disorders and cardiovascular disease. In combination with findings from human research, the study of mechanisms underlying mood and cardiovascular regulation using animal models will enhance our understanding of the association of depression and cardiovascular disease, and can promote the development of novel interventions for individuals with these comorbid conditions. PMID:21949540

  8. A method to construct a points system to predict cardiovascular disease considering repeated measures of risk factors

    PubMed Central

    Carbayo-Herencia, Julio Antonio; Vigo, Maria Isabel; Gil-Guillén, Vicente Francisco

    2016-01-01

    Current predictive models for cardiovascular disease based on points systems use the baseline situation of the risk factors as independent variables. These models do not take into account the variability of the risk factors over time. Predictive models for other types of disease also exist that do consider the temporal variability of a single biological marker in addition to the baseline variables. However, due to their complexity these other models are not used in daily clinical practice. Bearing in mind the clinical relevance of these issues and that cardiovascular diseases are the leading cause of death worldwide we show the properties and viability of a new methodological alternative for constructing cardiovascular risk scores to make predictions of cardiovascular disease with repeated measures of the risk factors and retaining the simplicity of the points systems so often used in clinical practice (construction, statistical validation by simulation and explanation of potential utilization). We have also applied the system clinically upon a set of simulated data solely to help readers understand the procedure constructed. PMID:26893963

  9. Systemic Inflammation in Cardiovascular and Periodontal Disease: Comparative Study

    PubMed Central

    Glurich, Ingrid; Grossi, Sara; Albini, Boris; Ho, Alex; Shah, Rashesh; Zeid, Mohamed; Baumann, Heinz; Genco, Robert J.; De Nardin, Ernesto

    2002-01-01

    Epidemiological studies have implicated periodontal disease (PD) as a risk factor for the development of cardiovascular disease (CVD). These studies addressed the premise that local infection may perturb the levels of systemic inflammatory mediators, thereby promoting mechanisms of atherosclerosis. Levels of inflammatory mediators in the sera of subjects with only PD, only CVD, both diseases, or neither condition were compared. Subjects were assessed for levels of C-reactive protein (CRP), serum amyloid A (SAA), ceruloplasmin, α1-acid-glycoprotein (AAG), α1-antichymotrypsin (ACT), and the soluble cellular adhesion molecules sICAM-1 and sVCAM by enzyme-linked immunoabsorbent and/or radial immunodiffusion assays. CRP levels in subjects with either condition alone were elevated twofold above subjects with neither disease, whereas a threefold increase was noted in subjects with both diseases (P = 0.0389). Statistically significant increases in SAA and ACT were noted in subjects with both conditions compared to those with one or neither condition (P = 0.0162 and 0.0408, respectively). Ceruloplasmin levels were increased in subjects with only CVD (P = 0.0001). Increases in sVCAM levels were noted in all subjects with CVD (P = 0.0054). No differences in sICAM levels were noted among subject groups. A trend toward higher levels of AAG was noted in subjects with both conditions and for ACT in subjects with only PD. Immunohistochemical examination of endarterectomy specimens of carotid arteries from subjects with atherosclerosis documented SAA and CRP deposition in association with atheromatous lesions. The data support the hypothesis that localized persistent infection may influence systemic levels of inflammatory mediators. Changes in inflammatory mediator levels potentially impact inflammation-associated atherosclerotic processes. PMID:11874889

  10. Feasability of a ARFI/B-mode/Doppler system for real-time, freehand scanning of the cardiovascular system

    NASA Astrophysics Data System (ADS)

    Dumont, Douglas M.; Lee, Seung-Yun; Doherty, Joshua R.; Trahey, Gregg E.

    2011-03-01

    Acoustic radiation force impulse (ARFI) imaging has been previously described for the visualization of the cardiovascular system, including assessment of cerebral and lower-limb vascular disease, myocardial function, and cardiac RF ablation monitoring. Given that plaque imposes a 3-dimensional burden on the artery and that accurate visualization of all lesion borders are important for ablation guidance, it would be convenient if an entire plaque or lesion volume could be acquired, either using a 3D system or 2D freehand scanning. Currently, ARFI imaging uses single-frame acquisition, with acquisition times ranging from 100-200ms. Such a system would be cumbersome for real-time, freehand scanning. In this work, we evaluate the feasibility of using ARFI for freehand, real-time scanning of the cardiovascular system. New techniques are presented which acquire B-mode / ARFI/ and Color-flow Doppler (BACD) information in less than 50 ms. Freehand feasibility is evaluated by sweeping the BACD system across lesion phantoms and vascular phantoms modeling a thin-cap fibroatheroma at sweep rates currently utilized in conventional B-mode systems. Stationary in vivo BACD images were then formed from the carotid artery of a canine model, demonstrating the system's potential. The results suggest that little loss in either ARFI or Doppler quality occurs during translational-stage controlled, quasi-freehand sweeps.

  11. Pulmonary Transcriptional Response to Ozone in Healthy and Cardiovascular Compromised Rat Models

    EPA Science Inventory

    The genetic cardiovascular disease (CVD) and associated metabolic impairments can influence the lung injury from inhaled pollutants. We hypothesized that comparative assessment of global pulmonary expression profile of healthy and CVD-prone rat models will provide mechanistic ins...

  12. Pulmonary Complications Resulting from Genetic Cardiovascular Disease in Two Rat Models

    EPA Science Inventory

    Underlying cardiovascular disease (CVD) has been considered a risk factor for exacerbation of air pollution health effects. Therefore, rodent models of CVD are increasingly used to examine mechanisms of variation in susceptibility. Pulmonary complications and altered iron homeost...

  13. Pulmonary oxidative stress, inflammation and dysregulated iron homeostatis in rat models of cardiovascular disease

    EPA Science Inventory

    Underlying cardiovascular disease (CVD) is considered a risk factor for the exacerbation of air pollution health effects. Therefore, rodent models of CVD are increasingly used to examine mechanisms ofvariation in susceptibility. Pulmonary oxidative stress, inflammation and altere...

  14. P2 receptor subtypes in the cardiovascular system.

    PubMed Central

    Kunapuli, S P; Daniel, J L

    1998-01-01

    Extracellular nucleotides have been implicated in a number of physiological functions. Nucleotides act on cell-surface receptors known as P2 receptors, of which several subtypes have been cloned. Both ATP and ADP are stored in platelets and are released upon platelet activation. Furthermore, nucleotides are also released from damaged or broken cells. Thus during vascular injury nucleotides play an important role in haemostasis through activation of platelets, modulation of vascular tone, recruitment of neutrophils and monocytes to the site of injury, and facilitation of adhesion of leucocytes to the endothelium. Nucleotides also moderate these functions by generating nitric oxide and prostaglandin I2 through activation of endothelial cells, and by activating different receptor subtypes on vascular smooth muscle cells. In the heart, P2 receptors regulate contractility through modulation of L-type Ca2+ channels, although the molecular mechanisms involved are still under investigation. Classical pharmacological studies have identified several P2 receptor subtypes in the cardiovascular system. Molecular pharmacological studies have clarified the nature of some of these receptors, but have complicated the picture with others. In platelets, the classical P2T receptor has now been resolved into three P2 receptor subtypes: the P2Y1, P2X1 and P2TAC receptors (the last of these, which is coupled to the inhibition of adenylate cyclase, is yet to be cloned). In peripheral blood leucocytes, endothelial cells, vascular smooth muscle cells and cardiomyocytes, the effects of classical P2X, P2Y and P2U receptors have been found to be mediated by more than one P2 receptor subtype. However, the exact functions of these multiple receptor subtypes remain to be understood, as P2-receptor-selective agonists and antagonists are still under development. PMID:9841859

  15. Cardiovascular-renal and metabolic characterization of a rat model of polycystic ovary syndrome

    PubMed Central

    Yanes, Licy L.; Romero, Damian G.; Moulana, Mohaddetheh; Lima, Roberta; Davis, Deborah D.; Zhang, Huimin; Lockhart, Rachel; Reckelhoff, Jane F.

    2011-01-01

    Background Polycystic ovary syndrome (PCOS) is the most common reproductive dysfunction in premenopausal women. PCOS is also associated with increased risk of cardiovascular disease at the time of PCOS and later in life. Hypertension, a common finding in women with PCOS, is a leading risk factor for cardiovascular disease. The mechanisms responsible for hypertension in women with PCOS has not been elucidated. Objectives To characterize the cardiovascular-renal consequences of hyperandrogenemia in a female rat model. Methods Female Sprague Dawley rats, aged 4–6 weeks, were implanted with DHT or placebo pellets lasting 90 days. Following 10–12 weeks, blood pressure (by radiotelemetry), renal function (glomerular filtration rate, morphology, protein and albumin excretion), metabolic parameters (plasma insulin, glucose, leptin, cholesterol, oral glucose tolerance test), inflammation (plasma TNF-α), oxidative stress (mRNA expression of NADPH oxidase subunits, p22phox, p47phox, gp91phox, and NOX4, nitrate/nitrite excretion), and mRNA expression of components of the renin-angiotensin system (RAS) (angiotensinogen, angiotensin-I-converting enzyme (ACE), AT1 receptor) were determined. Results Plasma DHT was increased 3-fold in hyperandrogenemic female 1 rats, whereas plasma estradiol levels were not different compared to control females. HAF rats exhibited estrus cycle dysfunction. They also had increased food intake and body weight, increased visceral fat, glomerular filtration rate, renal injury, insulin resistance and metabolic dysfunction, oxidative stress, and increased expression of angiotensinogen and ACE and reduced AT1 receptor expression. Conclusions The HAF rat is a unique model that exhibits many of the characteristics of PCOS in women and is a useful model in order to study the mechanisms responsible for hypertension. PMID:21536229

  16. Biochemistry, Physiology and Pathophysiology of NADPH Oxidases in the Cardiovascular System

    PubMed Central

    Lassègue, Bernard; San Martín, Alejandra; Griendling, Kathy K.

    2012-01-01

    The NADPH oxidase (Nox) enzymes are critical mediators of cardiovascular physiology and pathophysiology. These proteins are expressed in virtually all cardiovascular cells, and regulate such diverse functions as differentiation, proliferation, apoptosis, senescence, inflammatory responses and oxygen sensing. They target a number of important signaling molecules, including kinases, phosphatases, transcription factors, ion channels and proteins that regulate the cytoskeleton. Nox enzymes have been implicated in many different cardiovascular pathologies: atherosclerosis, hypertension, cardiac hypertrophy and remodeling, angiogenesis and collateral formation, stroke and heart failure. In this review, we discuss in detail the biochemistry of Nox enzymes expressed in the cardiovascular system (Nox1, 2, 4 and 5), their roles in cardiovascular cell biology, and their contributions to disease development. PMID:22581922

  17. Cardiovascular system identification: Simulation study using arterial and central venous pressures.

    PubMed

    Karamolegkos, Nikolaos; Vicario, Francesco; Chbat, Nicolas W

    2015-08-01

    The paper presents a study of the identifiability of a lumped model of the cardiovascular system. The significance of this work from the existing literature is in the potential advantage of using both arterial and central venous (CVP) pressures, two signals that are frequently monitored in the critical care unit. The analysis is done on the system's state-space representation via control theory and system identification techniques. Non-parametric state-space identification is preferred over other identification techniques as it optimally assesses the order of a model, which best describes the input-output data, without any prior knowledge about the system. In particular, a recent system identification algorithm, namely Observer Kalman Filter Identification with Deterministic Projection, is used to identify a simplified version of an existing cardiopulmonary model. The outcome of the study highlights the following two facts. In the deterministic (noiseless) case, the theoretical indicators report that the model is fully identifiable, whereas the stochastic case reveals the difficulty in determining the complete system's dynamics. This suggests that even with the use of CVP as an additional pressure signal, the identification of a more detailed (high order) model of the circulatory system remains a challenging task. PMID:26736432

  18. ANIMAL MODELS: CARDIOVASCULAR DISEASE, CNS INJURY AND ULTRAFINE PARTICLE BIOKINETICS

    EPA Science Inventory

    The Animal Core studies will help to answer the question of why subpopulations are at increased risk of adverse health outcomes following PM exposure. They will identify the cellular and molecular mechanisms which underlie cardiovascular susceptibility. Exposure-response rel...

  19. Systemic adiponectin malfunction as a risk factor for cardiovascular disease.

    PubMed

    Lau, Wayne Bond; Tao, Ling; Wang, Yajing; Li, Rong; Ma, Xin L

    2011-10-01

    Adiponectin (Ad) is an abundant protein hormone regulatory of numerous metabolic processes. The 30 kDa protein originates from adipose tissue, with full-length and globular domain circulatory forms. A collagenous domain within Ad leads to spontaneous self-assemblage into various oligomeric isoforms, including trimers, hexamers, and high-molecular-weight multimers. Two membrane-spanning receptors for Ad have been identified, with differing concentration distribution in various body tissues. The major intracellular pathway activated by Ad includes phosphorylation of AMP-activated protein kinase, which is responsible for many of Ad's metabolic regulatory, anti-inflammatory, vascular protective, and anti-ischemic properties. Additionally, several AMP-activated protein kinase-independent mechanisms responsible for Ad's anti-inflammatory and anti-ischemic (resulting in cardioprotective) effects have also been discovered. Since its 1995 discovery, Ad has garnered considerable attention for its role in diabetic and cardiovascular pathology. Clinical observations have demonstrated the association of hypoadiponectinemia in patients with obesity, cardiovascular disease, and insulin resistance. In this review, we elaborate currently known information about Ad malfunction and deficiency pertaining to cardiovascular disease risk (including atherosclerosis, endothelial dysfunction, and cardiac injury), as well as review evidence supporting Ad resistance as a novel risk factor for cardiovascular injury, providing insight about the future of Ad research and the protein's potential therapeutic benefits. PMID:21091079

  20. Applicability of implantable telemetry systems in cardiovascular research.

    NASA Technical Reports Server (NTRS)

    Krutz, R. W.; Rader, R. D.; Meehan, J. P.; Henry, J. P.

    1971-01-01

    This paper briefly describes the results of an experimental program undertaken to develop and apply implanted telemetry to cardiovascular research. Because of the role the kidney may play in essential hypertension, emphasis is placed on telemetry's applicability in the study of renal physiology. Consequently, the relationship between pressure, flow, and hydraulic impedance are stressed. Results of an exercise study are given.

  1. Systemic Adiponectin Malfunction as a Risk Factor for Cardiovascular Disease

    PubMed Central

    Lau, Wayne Bond; Tao, Ling; Wang, Yajing; Li, Rong

    2011-01-01

    Abstract Adiponectin (Ad) is an abundant protein hormone regulatory of numerous metabolic processes. The 30?kDa protein originates from adipose tissue, with full-length and globular domain circulatory forms. A collagenous domain within Ad leads to spontaneous self-assemblage into various oligomeric isoforms, including trimers, hexamers, and high-molecular-weight multimers. Two membrane-spanning receptors for Ad have been identified, with differing concentration distribution in various body tissues. The major intracellular pathway activated by Ad includes phosphorylation of AMP-activated protein kinase, which is responsible for many of Ad's metabolic regulatory, anti-inflammatory, vascular protective, and anti-ischemic properties. Additionally, several AMP-activated protein kinase-independent mechanisms responsible for Ad's anti-inflammatory and anti-ischemic (resulting in cardioprotective) effects have also been discovered. Since its 1995 discovery, Ad has garnered considerable attention for its role in diabetic and cardiovascular pathology. Clinical observations have demonstrated the association of hypoadiponectinemia in patients with obesity, cardiovascular disease, and insulin resistance. In this review, we elaborate currently known information about Ad malfunction and deficiency pertaining to cardiovascular disease risk (including atherosclerosis, endothelial dysfunction, and cardiac injury), as well as review evidence supporting Ad resistance as a novel risk factor for cardiovascular injury, providing insight about the future of Ad research and the protein's potential therapeutic benefits. Antioxid. Redox Signal. 15, 18631873. PMID:21091079

  2. Regulation of NAD(P)H oxidases by AMPK in cardiovascular systems

    PubMed Central

    Song, Ping; Zou, Ming-Hui

    2012-01-01

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are ubiquitously produced in cardiovascular systems. Under physiological conditions, ROS/RNS function as signaling molecules that are essential in maintaining cardiovascular function. Aberrant concentrations of ROS/RNS have been demonstrated in cardiovascular diseases due to increased production or decreased scavenging, which have been considered as common pathways for the initiation and progression of cardiovascular diseases such as atherosclerosis, hypertension, (re)stenosis, and congestive heart failure. NAD(P)H oxidases are primary sources of ROS and can be induced or activated by all known cardiovascular risk factors. Stresses, hormones, vasoactive agents, and cytokines via different signaling cascades control the expression and activity of these enzymes and of their regulatory subunits. But the molecular mechanisms by which NAD(P)H oxidase is regulated in cardiovascular systems remain poorly characterized. Investigations by us and others suggest that adenosine monophosphate-activated protein kinase (AMPK), as an energy sensor and modulator, is highly sensitive to ROS/RNS. We have also obtained convincing evidence that AMPK is a physiological suppressor of NAD(P)H oxidase in multiple cardiovascular cell systems. In this review, we summarize our current understanding of how AMPK functions as a physiological repressor of NAD(P)H oxidase. PMID:22357101

  3. Cardiovascular Disease Modeling Using Patient-Specific Induced Pluripotent Stem Cells

    PubMed Central

    Tanaka, Atsushi; Yuasa, Shinsuke; Node, Koichi; Fukuda, Keiichi

    2015-01-01

    The generation of induced pluripotent stem cells (iPSCs) has opened up a new scientific frontier in medicine. This technology has made it possible to obtain pluripotent stem cells from individuals with genetic disorders. Because iPSCs carry the identical genetic anomalies related to those disorders, iPSCs are an ideal platform for medical research. The pathophysiological cellular phenotypes of genetically heritable heart diseases such as arrhythmias and cardiomyopathies, have been modeled on cell culture dishes using disease-specific iPSC-derived cardiomyocytes. These model systems can potentially provide new insights into disease mechanisms and drug discoveries. This review focuses on recent progress in cardiovascular disease modeling using iPSCs, and discusses problems and future perspectives concerning their use. PMID:26274955

  4. Usefulness of serum interleukin-18 in predicting cardiovascular mortality in patients with chronic kidney disease – systems and clinical approach

    PubMed Central

    Formanowicz, Dorota; Wanic-Kossowska, Maria; Pawliczak, Elżbieta; Radom, Marcin; Formanowicz, Piotr

    2015-01-01

    The aim of this study was to check if serum interleukin-18 (IL-18) predicts 2-year cardiovascular mortality in patients at various stages of chronic kidney disease (CKD) and history of acute myocardial infarction (AMI) within the previous year. Diabetes mellitus was one of the key factors of exclusion. It was found that an increase in serum concentration of IL-18 above the cut-off point (1584.5 pg/mL) was characterized by 20.63-fold higher risk of cardiovascular deaths among studied patients. IL-18 serum concentration was found to be superior to the well-known cardiovascular risk parameters, like high sensitivity C-reactive protein (hsCRP), carotid intima media thickness (CIMT), glomerular filtration rate, albumins, ferritin, N-terminal prohormone of brain natriuretic peptide (NT-proBNP) in prognosis of cardiovascular mortality. The best predictive for IL-18 were 4 variables, such as CIMT, NT-proBNP, albumins and hsCRP, as they predicted its concentration at 89.5%. Concluding, IL-18 seems to be important indicator and predictor of cardiovascular death in two-year follow-up among non-diabetic patients suffering from CKD, with history of AMI in the previous year. The importance of IL-18 in the process of atherosclerotic plaque formation has been confirmed by systems analysis based on a formal model expressed in the language of Petri nets theory. PMID:26669254

  5. Usefulness of serum interleukin-18 in predicting cardiovascular mortality in patients with chronic kidney disease - systems and clinical approach.

    PubMed

    Formanowicz, Dorota; Wanic-Kossowska, Maria; Pawliczak, Elżbieta; Radom, Marcin; Formanowicz, Piotr

    2015-01-01

    The aim of this study was to check if serum interleukin-18 (IL-18) predicts 2-year cardiovascular mortality in patients at various stages of chronic kidney disease (CKD) and history of acute myocardial infarction (AMI) within the previous year. Diabetes mellitus was one of the key factors of exclusion. It was found that an increase in serum concentration of IL-18 above the cut-off point (1584.5 pg/mL) was characterized by 20.63-fold higher risk of cardiovascular deaths among studied patients. IL-18 serum concentration was found to be superior to the well-known cardiovascular risk parameters, like high sensitivity C-reactive protein (hsCRP), carotid intima media thickness (CIMT), glomerular filtration rate, albumins, ferritin, N-terminal prohormone of brain natriuretic peptide (NT-proBNP) in prognosis of cardiovascular mortality. The best predictive for IL-18 were 4 variables, such as CIMT, NT-proBNP, albumins and hsCRP, as they predicted its concentration at 89.5%. Concluding, IL-18 seems to be important indicator and predictor of cardiovascular death in two-year follow-up among non-diabetic patients suffering from CKD, with history of AMI in the previous year. The importance of IL-18 in the process of atherosclerotic plaque formation has been confirmed by systems analysis based on a formal model expressed in the language of Petri nets theory. PMID:26669254

  6. [The functional state of the cardiovascular and central nervous system in patients with occupational deafness].

    PubMed

    Tin'kov, A N; Raĭtselis, I V

    2009-01-01

    The workers of the Orenburg gas-processing plant have been found to be at high risk for concomitant diseases of the cardiovascular, central nervous, and other systems in the presence of occupational sensorineural deafness. Among the comorbidities in deaf patients, cardiovascular disease heads the list (63%), of them autonomic vascular dystonia is most common (22%); diseases of the central nervous system and lung rank second (13%) and third (11%), respectively. PMID:19802944

  7. Laser micro-processing of cardiovascular stent with fiber laser cutting system

    NASA Astrophysics Data System (ADS)

    Meng, Hongyun; Liao, Jianhong; Zhou, Yongheng; Zhang, Qingmao

    2009-04-01

    A metallic cardiovascular stent cutting system based on fiber laser was designed in this study. In order to achieve the cutting of stent, the main modules and the key technologies were analyzed and achieved. Then with the cutting system, the kerf width size was studied for different cutting parameters including laser output power, pulse length, repeat frequency, cutting speed and assisting gas pressure. Finally, a high quality of cutting of 316L stainless steel cardiovascular stent was achieved.

  8. Endogenous Sulfur Dioxide: A New Member of Gasotransmitter Family in the Cardiovascular System.

    PubMed

    Huang, Yaqian; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2016-01-01

    Sulfur dioxide (SO2) was previously regarded as a toxic gas in atmospheric pollutants. But it has been found to be endogenously generated from metabolism of sulfur-containing amino acids in mammals through transamination by aspartate aminotransferase (AAT). SO2 could be produced in cardiovascular tissues catalyzed by its synthase AAT. In recent years, studies revealed that SO2 had physiological effects on the cardiovascular system, including vasorelaxation and cardiac function regulation. In addition, the pathophysiological effects of SO2 were also determined. For example, SO2 ameliorated systemic hypertension and pulmonary hypertension, prevented the development of atherosclerosis, and protected against myocardial ischemia-reperfusion (I/R) injury and isoproterenol-induced myocardial injury. These findings suggested that endogenous SO2 was a novel gasotransmitter in the cardiovascular system and provided a new therapy target for cardiovascular diseases. PMID:26839635

  9. Oxidative stress-mediated effects of angiotensin II in the cardiovascular system

    PubMed Central

    Wen, Hairuo; Gwathmey, Judith K; Xie, Lai-Hua

    2014-01-01

    Angiotensin II (Ang II), an endogenous peptide hormone, plays critical roles in the pathophysiological modulation of cardiovascular functions. Ang II is the principle effector of the renin-angiotensin system for maintaining homeostasis in the cardiovascular system, as well as a potent stimulator of NAD(P)H oxidase, which is the major source and primary trigger for reactive oxygen species (ROS) generation in various tissues. Recent accumulating evidence has demonstrated the importance of oxidative stress in Ang II-induced heart diseases. Here, we review the recent progress in the study on oxidative stress-mediated effects of Ang II in the cardiovascular system. In particular, the involvement of Ang II-induced ROS generation in arrhythmias, cell death/heart failure, ischemia/reperfusion injury, cardiac hypertrophy and hypertension are discussed. Ca2+/calmodulin-dependent protein kinase II is an important molecule linking Ang II, ROS and cardiovascular pathological conditions. PMID:24587981

  10. Endogenous Sulfur Dioxide: A New Member of Gasotransmitter Family in the Cardiovascular System

    PubMed Central

    Huang, Yaqian; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2016-01-01

    Sulfur dioxide (SO2) was previously regarded as a toxic gas in atmospheric pollutants. But it has been found to be endogenously generated from metabolism of sulfur-containing amino acids in mammals through transamination by aspartate aminotransferase (AAT). SO2 could be produced in cardiovascular tissues catalyzed by its synthase AAT. In recent years, studies revealed that SO2 had physiological effects on the cardiovascular system, including vasorelaxation and cardiac function regulation. In addition, the pathophysiological effects of SO2 were also determined. For example, SO2 ameliorated systemic hypertension and pulmonary hypertension, prevented the development of atherosclerosis, and protected against myocardial ischemia-reperfusion (I/R) injury and isoproterenol-induced myocardial injury. These findings suggested that endogenous SO2 was a novel gasotransmitter in the cardiovascular system and provided a new therapy target for cardiovascular diseases. PMID:26839635

  11. The effects of music on the cardiovascular system and cardiovascular health.

    PubMed

    Trappe, Hans-Joachim

    2010-12-01

    Music may not only improve quality of life but may also effect changes in heart rate and heart rate variability. It has been shown that cerebral flow was significantly lower when listening to 'Va pensiero' from Verdi's 'Nabucco' (70.4±3.3 cm/s) compared with 'Libiam nei lieti calici' from Verdi's 'La Traviata' (70.2±3.1 cm/s) (p<0.02) or Bach's Cantata No. 169 'Gott soll allein mein Herze haben' (70.9±2.9 cm/s) (p<0.02). There was no significant difference in cerebral flow during rest (67.6±3.3 cm/s) or when listening to Beethoven's Ninth Symphony (69.4±3.1 cm/s). It was reported that relaxing music significantly decreases the level of anxiety of patients in a preoperative setting (State-Trait Anxiety Inventory (STAI)-X-1 score 34)-to a greater extent even than orally administered midazolam (STAI-X-1 score 36) (p<0.001). In addition the score was better after surgery in the music group (STAI-X-1 score 30) compared with the midazolam group (STAI-X-1 score 34) (p<0.001). Higher effectiveness and absence of apparent adverse effects make relaxing, preoperative music a useful alternative to midazolam for premedication. In addition, there is sufficient practical evidence of stress reduction suggesting that a proposed regimen of listening to music while resting in bed after open-heart surgery is important in clinical use. After 30 min of bed rest, there was a significant difference in cortisol levels between the music (484.4 mmol/l) and the non-music group (618.8 mmol/l) (p<0.02). Vocal and orchestral music produce significantly better correlations between cardiovascular or respiratory signals compared with music with a more uniform emphasis (p<0.05). The greatest benefit on health is visible with classical music and meditation music, whereas heavy metal music or techno are not only ineffective but possibly dangerous and can lead to stress and/or life-threatening arrhythmias. The music of many composers most effectively improves quality of life, will increase health and probably prolong life, particularly music by Bach, Mozart or Italian composers. PMID:21062776

  12. Cardiovascular system and microgravity simulation and inflight results

    NASA Astrophysics Data System (ADS)

    Pottier, J. M.; Patat, F.; Arbeille, P.; Pourcelot, L.; Massabuau, P.; Guell, A.; Gharib, C.

    Main results of cardiovascular investigation, performed with ultrasound methods during the common French/Soviet flight aboard Salyut VII in June 1982, are compared to variations of the same parameters studied during ground-based simulations on the same subject or observed by other investigators during various ground-based experiences. The antiorthostatic bed rest simulation partly reproduces microgravity conditions and seems to be better adaptated to cardiac hemodynamics, despite some differences, and to the cerebral circulation, than to the inferior limb circulation.

  13. [Adverse effects of ultrafine particles on the cardiovascular system and its mechanisms].

    PubMed

    Yi, Tie-ci; Li, Jian-ping

    2014-12-18

    Cardiovascular disease is one of the major threats to human. Air pollution, which , as it become a problem too serious to be ignored in China, is known to be an important risk factor for cardiovascular disease. Among all pollutants, ultrafine particles ( UFPs) , defined as particles with their diameter less than 0. 1 f.Lm, are a specific composition. They are very small in size, large in quantity and surface area, and most important, capable of passing through the air-blood barrier. These unique features of UFPs make them special in their impact on cardiovascular system. Nowadays, the influence of UFPs on the cardiovascular system has become a hot topic. On the one side, studies have shown that UFPs can cause inflammation and oxidative stress in the lung, and then induce systemic inflammation by releasing cytokine and reactive oxygen species into the circulation. On the other side, UFPs themselves can "spillout"into the circulation and interact with their targets. By this way, UFPs directly affect endothelial cells, myocardial cells and the autonomic nervous system, which ultimately result in increased cardiovascular events. We intend to make an overview about the recent progress about the influence of UFPs on human cardiovascular disease and the related mechanisms, and argue for more attention to this issue. PMID:25651605

  14. Androgenic anabolic steroid abuse and the cardiovascular system.

    PubMed

    Vanberg, Paul; Atar, Dan

    2010-01-01

    Abuse of anabolic androgenic steroids (AAS) has been linked to a variety of different cardiovascular side effects. In case reports, acute myocardial infarction is the most common event presented, but other adverse cardiovascular effects such as left ventricular hypertrophy, reduced left ventricular function, arterial thrombosis, pulmonary embolism and several cases of sudden cardiac death have also been reported. However, to date there are no prospective, randomized, interventional studies on the long-term cardiovascular effects of abuse of AAS. In this review we have studied the relevant literature regarding several risk factors for cardiovascular disease where the effects of AAS have been scrutinized:(1) Echocardiographic studies show that supraphysiologic doses of AAS lead to both morphologic and functional changes of the heart. These include a tendency to produce myocardial hypertrophy (Fig. 3), a possible increase of heart chamber diameters, unequivocal alterations of diastolic function and ventricular relaxation, and most likely a subclinically compromised left ventricular contractile function. (2) AAS induce a mild, but transient increase of blood pressure. However, the clinical significance of this effect remains modest. (3) Furthermore, AAS confer an enhanced pro-thrombotic state, most prominently through an activation of platelet aggregability. The concomitant effects on the humoral coagulation cascade are more complex and include activation of both pro-coagulatory and fibrinolytic pathways. (4) Users of AAS often demonstrate unfavorable measurements of vascular reactivity involving endothelial-dependent or endothelial-independent vasodilatation. A degree of reversibility seems to be consistent, though. (5) There is a comprehensive body of evidence documenting that AAS induce various alterations of lipid metabolism. The most prominent changes are concomitant elevations of LDL and decreases of HDL, effects that increase the risk of coronary artery disease. And finally, (6) the use of AAS appears to confer an increased risk of life-threatening arrhythmia leading to sudden death, although the underlying mechanisms are still far from being elucidated. Taken together, various lines of evidence involving a variety of pathophysiologic mechanisms suggest an increased risk for cardiovascular disease in users of anabolic androgenic steroids. PMID:20020375

  15. The role of the renin-angiotensin-aldosterone system in cardiovascular progenitor cell function.

    PubMed

    Qian, Cheng; Schoemaker, Regien G; van Gilst, Wiek H; Roks, Anton J M

    2009-02-01

    Intervention in the RAAS (renin-angiotensin-aldosterone system) is one of the leading pharmacotherapeutic strategies, among others, used for the treatment of cardiovascular disease to improve the prognosis after myocardial infarction and to reduce hypertension. Recently, regenerative progenitor cell therapy has emerged as a possible alternative for pharmacotherapy in patients after myocardial infarction or ischaemic events elsewhere, e.g. in the limbs. Angiogenic cell therapy to restore the vascular bed in ischaemic tissues is currently being tested in a multitude of clinical studies. This has prompted researchers to investigate the effect of modulation of the RAAS on progenitor cells. Furthermore, the relationship between hypertension and endothelial progenitor cell function is being studied. Pharmacotherapy by means of angiotensin II type 1 receptor antagonists or angiotensin-converting enzyme inhibitors has varying effects on progenitor cell levels and function. These controversial effects may be explained by involvement of multiple mediators, e.g. angiotensin II and angiotensin-(1-7), that have differential effects on mesenchymal stem cells, haematopoietic progenitor cells and endothelial progenitor cells. Importantly, angiotensin II can either stimulate endothelial progenitor cells by improvement of vascular endothelial growth factor signalling, or invoke excessive production of reactive oxygen species causing premature senescence of these cells. On the other hand, angiotensin-(1-7) stimulates haematopoietic cells and possibly also endothelial progenitor cells. Furthermore, aldosterone, bradykinin and Ac-SDKP (N-acetyl-Ser-Asp-Lys-Pro) may also affect progenitor cell populations. Alternatively, the variability in effects of angiotensin II type 1 receptor and angiotensin-converting enzyme inhibition on cardiovascular progenitor cells might reflect differences between the various models or diseases with respect to circulating and local tissue RAAS activation. In the present review we discuss what is currently known with respect to the role of the RAAS in the regulation of cardiovascular progenitor cells. PMID:19138171

  16. Autonomic Nervous System Dysfunction and Inflammation Contribute to the Increased Cardiovascular Mortality Risk Associated With Depression

    PubMed Central

    Kop, Willem J.; Stein, Phyllis K.; Tracy, Russell P.; Barzilay, Joshua I.; Schulz, Richard; Gottdiener, John S.

    2011-01-01

    Objective To investigate prospectively whether autonomic nervous system (ANS) dysfunction and inflammation play a role in the increased cardiovascular disease (CVD)-related mortality risk associated with depression. Methods Participants in the Cardiovascular Health Study (n = 907; mean age, 71.3 ± 4.6 years; 59.1% women) were evaluated for ANS indices derived from heart rate variability (HRV) analysis (frequency and time domain HRV, and nonlinear indices, including detrended fluctuation analysis (DFA1) and heart rate turbulence). Inflammation markers included C-reactive protein, interleukin-6, fibrinogen, and white blood cell count). Depressive symptoms were assessed, using the 10-item Centers for Epidemiological Studies Depression scale. Cox proportional hazards models were used to investigate the mortality risk associated with depression, ANS, and inflammation markers, adjusting for demographic and clinical covariates. Results Depression was associated with ANS dysfunction (DFA1, p = .018), and increased inflammation markers (white blood cell count, p = .012, fibrinogen p = .043) adjusting for covariates. CVD-related mortality occurred in 121 participants during a median follow-up of 13.3 years. Depression was associated with an increased CVD mortality risk (hazard ratio, 1.88; 95% confidence interval, 1.23–2.86). Multivariable analyses showed that depression was an independent predictor of CVD mortality (hazard ratio, 1.72; 95% confidence interval, 1.05–2.83) when adjusting for independent HRV and inflammation predictors (DFA1, heart rate turbulence, interleukin-6), attenuating the depression-CVD mortality association by 12.7% (p < .001). Conclusion Autonomic dysfunction and inflammation contribute to the increased cardiovascular mortality risk associated with depression, but a large portion of the predictive value of depression remains unexplained by these neuroimmunological measures. PMID:20639389

  17. A universal number for wave reflection optimization of the mammalian cardiovascular system.

    NASA Astrophysics Data System (ADS)

    Pahlevan, Niema; Gharib, Morteza

    2015-11-01

    Quantifying the optimum arterial wave reflection and systemic arterial function is essential to the evaluation of optimal cardiovascular system (CVS) operation. The CVS function depends on both the dynamics of the heart and wave dynamics of the arterial network. Here, we are introducing a universal dimensionless number, called wave condition number (α) that quantifies the arterial wave reflection. An in-vitro experimental approach, utilizing a unique hydraulic model was used to quantify α in human aortas with a wide range of aortic rigidities. Our results indicate that the optimum value of the wave condition number is 0.1 at each level of aortic rigidity. Looking into mammals of various size (from mice to elephant), our results show that the optimum wave condition number remains 0.1 and is universal among all mammals. Clinical applications and the relevancy of the wave condition number will also be discussed.

  18. Nonlinear effects of respiration on the crosstalk between cardiovascular and cerebrovascular control systems.

    PubMed

    Bari, Vlasta; Marchi, Andrea; De Maria, Beatrice; Rossato, Gianluca; Nollo, Giandomenico; Faes, Luca; Porta, Alberto

    2016-05-13

    Cardiovascular and cerebrovascular regulatory systems are vital control mechanisms responsible for guaranteeing homeostasis and are affected by respiration. This work proposes the investigation of cardiovascular and cerebrovascular control systems and the nonlinear influences of respiration on both regulations through joint symbolic analysis (JSA), conditioned or unconditioned on respiration. Interactions between cardiovascular and cerebrovascular regulatory systems were evaluated as well by performing correlation analysis between JSA indexes describing the two control systems. Heart period, systolic and mean arterial pressure, mean cerebral blood flow velocity and respiration were acquired on a beat-to-beat basis in 13 subjects experiencing recurrent syncope episodes (SYNC) and 13 healthy individuals (non-SYNC) in supine resting condition and during head-up tilt test at 60° (TILT). Results showed that JSA distinguished conditions and groups, whereas time domain parameters detected only the effect of TILT. Respiration affected cardiovascular and cerebrovascular regulatory systems in a nonlinear way and was able to modulate the interactions between the two control systems with different outcome in non-SYNC and SYNC groups, thus suggesting that the analysis of the impact of respiration on cardiovascular and cerebrovascular regulatory systems might improve our understanding of the mechanisms underpinning the development of postural-related syncope. PMID:27044988

  19. Physiological interdependence of the cardiovascular and postural control systems under orthostatic stress.

    PubMed

    Garg, Amanmeet; Xu, Da; Laurin, Alexandre; Blaber, Andrew P

    2014-07-15

    The cardiovascular system has been observed to respond to changes in human posture and the environment. On the same lines, frequent fallers have been observed to suffer from cardiovascular deficits. The present article aims to demonstrate the existence of interactions between the cardiovascular and postural control systems. The behavior of the two systems under orthostatic challenge was studied through novel adaptations of signal processing techniques. To this effect, the interactions between the two systems were assessed with two metrics, coherence and phase lock value, based on the wavelet transform. Measurements from the cardiovascular system (blood pressure), lower limb muscles (surface electromyography), and postural sway (center of pressure) were acquired from young healthy adults (n = 28, men = 12, age = 20-28 yr) during quiet stance. The continuous wavelet transform was applied to decompose the representative signals on a time-scale basis in a frequency region of 0.01 to 0.1 Hz. Their linear coupling was quantified through a coherence metric, and the synchrony was characterized via the phase information. The outcomes of this study present evidence that the cardiovascular and postural control systems work together to maintain homeostasis under orthostatic challenge. The inferences open a new direction of study for effects under abnormalities and extreme environmental conditions. PMID:24858845

  20. Bushehr Elderly Health (BEH) Programme, phase I (cardiovascular system)

    PubMed Central

    Ostovar, Afshin; Nabipour, Iraj; Larijani, Bagher; Heshmat, Ramin; Darabi, Hossein; Vahdat, Katayoun; Ravanipour, Maryam; Mehrdad, Neda; Raeisi, Alireza; Heidari, Gholamreza; Shafiee, Gita; Haeri, Mohammadjavad; Pourbehi, Mohammadreza; Sharifi, Farshad; Noroozi, Azita; Tahmasebi, Rahim; Aghaei Meybodi, Hamidreza; Assadi, Majid; Farrokhi, Shokrollah; Nemati, Reza; Amini, Mohammad Reza; Barekat, Maryam; Amini, Abdullatif; Salimipour, Houman; Dobaradaran, Sina; Moshtaghi, Darab

    2015-01-01

    Purpose The main objective of the Bushehr Elderly Health Programme, in its first phase, is to investigate the prevalence of cardiovascular risk factors and their association with major adverse cardiovascular events. Participants Between March 2013 and October 2014, a total of 3000 men and women aged ≥60 years, residing in Bushehr, Iran, participated in this prospective cohort study (participation rate=90.2%). Findings to date Baseline data on risk factors, including demographic and socioeconomic status, smoking and medical history, were collected through a modified WHO MONICA questionnaire. Vital signs and anthropometric measures, including systolic and diastolic blood pressure, weight, height, and waist and hip circumference, were also measured. 12-lead electrocardiography and echocardiography were conducted on all participants, and total of 10 cc venous blood was taken, and sera was separated and stored at –80°C for possible future use. Preliminary data analyses showed a noticeably higher prevalence of risk factors among older women compared to that in men. Future plans Risk factor assessments will be repeated every 5 years, and the participants will be followed during the study to measure the occurrence of major adverse cardiac events. Moreover, the second phase, which includes investigation of bone health and cognition in the elderly, was started in September 2015. Data are available at the Persian Gulf Biomedical Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran, for any collaboration. PMID:26674503

  1. 2015 Guidelines for Establishing Genetically Modified Rat Models for Cardiovascular Research.

    PubMed

    Flister, Michael J; Prokop, Jeremy W; Lazar, Jozef; Shimoyama, Mary; Dwinell, Melinda; Geurts, Aron

    2015-06-01

    The rat has long been a key physiological model for cardiovascular research, most of the inbred strains having been previously selected for susceptibility or resistance to various cardiovascular diseases (CVD). These CVD rat models offer a physiologically relevant background on which candidates of human CVD can be tested in a more clinically translatable experimental setting. However, a diverse toolbox for genetically modifying the rat genome to test molecular mechanisms has only recently become available. Here, we provide a high-level description of several strategies for developing genetically modified rat models of CVD. PMID:25920443

  2. Measurement of blood flow and perfusion in the cardiovascular system.

    PubMed

    Higgins, C B; Caputo, G; Wendland, M F; Saeed, M

    1992-12-01

    Complete evaluation of cardiovascular disease by a single imaging technique requires measurement of bulk flow in blood vessels and estimation of relative or ideally absolute perfusion at the tissue level. Magnetic resonance (MR) measurement of blood flow in arteries and veins has been done using the velocity-encoded phase cine gradient echo technique. This technique has been applied with cine MR to measure normal and pathologically high velocities. Measurement of relative perfusion in the myocardium has used the intravenous injection of T1 relaxation enhancing and magnetic susceptibility MR contrast media with rapid image acquisition using echoplanar imaging. MR images (MRIs) acquired during steady-state distribution or during the first passage of these contrast media have depicted ischemic myocardial regions. PMID:1468878

  3. Modeling cardiovascular hemodynamics using the lattice Boltzmann method on massively parallel supercomputers

    NASA Astrophysics Data System (ADS)

    Randles, Amanda Elizabeth

    Accurate and reliable modeling of cardiovascular hemodynamics has the potential to improve understanding of the localization and progression of heart diseases, which are currently the most common cause of death in Western countries. However, building a detailed, realistic model of human blood flow is a formidable mathematical and computational challenge. The simulation must combine the motion of the fluid, the intricate geometry of the blood vessels, continual changes in flow and pressure driven by the heartbeat, and the behavior of suspended bodies such as red blood cells. Such simulations can provide insight into factors like endothelial shear stress that act as triggers for the complex biomechanical events that can lead to atherosclerotic pathologies. Currently, it is not possible to measure endothelial shear stress in vivo, making these simulations a crucial component to understanding and potentially predicting the progression of cardiovascular disease. In this thesis, an approach for efficiently modeling the fluid movement coupled to the cell dynamics in real-patient geometries while accounting for the additional force from the expansion and contraction of the heart will be presented and examined. First, a novel method to couple a mesoscopic lattice Boltzmann fluid model to the microscopic molecular dynamics model of cell movement is elucidated. A treatment of red blood cells as extended structures, a method to handle highly irregular geometries through topology driven graph partitioning, and an efficient molecular dynamics load balancing scheme are introduced. These result in a large-scale simulation of the cardiovascular system, with a realistic description of the complex human arterial geometry, from centimeters down to the spatial resolution of red-blood cells. The computational methods developed to enable scaling of the application to 294,912 processors are discussed, thus empowering the simulation of a full heartbeat. Second, further extensions to enable the modeling of fluids in vessels with smaller diameters and a method for introducing the deformational forces exerted on the arterial flows from the movement of the heart by borrowing concepts from cosmodynamics are presented. These additional forces have a great impact on the endothelial shear stress. Third, the fluid model is extended to not only recover Navier-Stokes hydrodynamics, but also a wider range of Knudsen numbers, which is especially important in micro- and nano-scale flows. The tradeoffs of many optimizations methods such as the use of deep halo level ghost cells that, alongside hybrid programming models, reduce the impact of such higher-order models and enable efficient modeling of extreme regimes of computational fluid dynamics are discussed. Fourth, the extension of these models to other research questions like clogging in microfluidic devices and determining the severity of co-arctation of the aorta is presented. Through this work, a validation of these methods by taking real patient data and the measured pressure value before the narrowing of the aorta and predicting the pressure drop across the co-arctation is shown. Comparison with the measured pressure drop in vivo highlights the accuracy and potential impact of such patient specific simulations. Finally, a method to enable the simulation of longer trajectories in time by discretizing both spatially and temporally is presented. In this method, a serial coarse iterator is used to initialize data at discrete time steps for a fine model that runs in parallel. This coarse solver is based on a larger time step and typically a coarser discretization in space. Iterative refinement enables the compute-intensive fine iterator to be modeled with temporal parallelization. The algorithm consists of a series of prediction-corrector iterations completing when the results have converged within a certain tolerance. Combined, these developments allow large fluid models to be simulated for longer time durations than previously possible.

  4. Central oxytocin systems may mediate a cardiovascular response to acute stress in rats.

    PubMed

    Callahan, M F; Kirby, R F; Cunningham, J T; Eskridge-Sloop, S L; Johnson, A K; McCarty, R; Gruber, K A

    1989-05-01

    The role of central nervous system arginine vasopressin (AVP) and oxytocin (OXY) in the cardiovascular response to acute stress was examined using three experimental models: pharmacological antagonism of central AVP-OXY receptors; lesions of the paraventricular nucleus (PVN); and rats genetically lacking in AVP synthesis, i.e., the Brattleboro strain. Central administration of an AVP-OXY antagonist abolished the increase in heart rate (HR) seen following acute footshock stress. The group receiving centrally administered antagonist increased HR 15 +/- 17 (SE) beats/min, whereas, in contrast, the group receiving intravenous administration of the antagonist showed a 66 +/- 17 beats/min increase, and the group receiving intraventricular antagonist vehicle showed a 101 +/- 14 beats/min increase in response to stress. In a second study, electrolytic lesions of the PVN also blocked the increase in HR seen following stress, 20 +/- 12 beats/min for PVN-lesioned rats, 74 +/- 25 beats/min for sham lesion rats, and 93 +/- 7 beats/min for rats with a lesion not destroying the PVN. In the final study, the responses of Brattleboro rats, i.e., rats genetically deficient in vasopressin synthesis, were equivalent to their Long-Evans controls (131 +/- 13 and 147 +/- 12 beats/min, respectively). In each of these studies, the blood pressure responses to the stressor were equivalent for control and experimental groups. The results of these studies suggest that a neuropeptide system originating in or passing through the PVN may play an important role in the cardiovascular responses to stress and further suggest that the central OXY system may be one pathway mediating this response. PMID:2719134

  5. Regulation of the Apelinergic System and Its Potential in Cardiovascular Disease: Peptides and Small Molecules as Tools for Discovery.

    PubMed

    Narayanan, Sanju; Harris, Danni L; Maitra, Rangan; Runyon, Scott P

    2015-10-22

    Apelin peptides and the apelin receptor represent a relatively new therapeutic axis for the potential treatment of cardiovascular disease. Several reports suggest apelin receptor activation with apelin peptides results in cardioprotection as noted through positive ionotropy, angiogenesis, reduction of mean arterial blood pressure, and apoptosis. Considering the potential therapeutic benefit attainable through modulation of the apelinergic system, research is expanding to develop novel therapies that limit the inherent rapid degradation of endogenous apelin peptides and produce metabolically stable small molecule agonists and antagonists to more rigorously interrogate the apelin receptor system. This review details the structure-activity relationships for chemically modified apelin peptides and recent disclosures of small molecule agonists and antagonists and summarizes the peer reviewed and patented literature. Development of metabolically stable ligands of apelin receptor and their effects in various models over the coming years will hopefully lead to establishment of this receptor as a validated target for cardiovascular indications. PMID:26102594

  6. The effects of exercise on blood flow with reference to the human cardiovascular system: a finite element study

    NASA Technical Reports Server (NTRS)

    Sud, V. K.; Srinivasan, R. S.; Charles, J. B.; Bungo, M. W.

    1992-01-01

    This paper reports on a theoretical investigation into the effects of vasomotion on blood through the human cardiovascular system. The finite element method has been used to analyse the model. Vasoconstriction and vasodilation may be effected either through the action of the central nervous system or autoregulation. One of the conditions responsible for vasomotion is exercise. The proposed model has been solved and quantitative results of flows and pressures due to changing the conductances of specific networks of arterioles, capillaries and venules comprising the arms, legs, stomach and their combinations have been obtained.

  7. [Interaction of octapeptide of cholecystokinin, vasoactive intestinal peptide and substance P on dynamics of biliary system and cardiovascular system].

    PubMed

    Zhang, J; Zou, S; Qiu, F

    1997-01-01

    We tested in vivo: (a) the effect of an i.v. infusion of cholecystokinin octapeptide, vasoactive intestinal peptide or substance P on dynamics of biliary system and cardiovascular system, (b) the relation of dynamics of biliary system and cardiovascular system. In 91 anesthetized guinea pigs, left ventricle motility of heart, sphincter of Oddi motility and common bile duct pressure were monitored during the intravenous administration of cholecystokinin octapeptide (CCK-OP), vasoactive intestinal peptide (VIP), substance P (SP) and combination of CCK-OP and VIP. Intravenous CCK-OP increased fasting Oddis sphincter motility index, decreased the basal pressure in sphincter of Oddi, increased common bile duct pressure, and decreased the left ventricle of heart motility. VIP alone showed no significant effect on biliary system and cardiovascular system, but in conjunction with CCK-OP it produced inhibition on the effects of CCK-OP on both sides. Exogenous SP acted like CCK-OP on both biliary system and cardiovascular system, but it was less potent. We conclude that it may be an important interaction between dynamics of biliary system and cardiovascular system; and gastrointestinal peptide plays an important role in this interaction in guinea pigs. PMID:10374510

  8. Measurement Error Case Series Models with Application to Infection-Cardiovascular Risk in OlderPatients on Dialysis

    PubMed Central

    Mohammed, Sandra M.; Şentürk, Damla; Dalrymple, Lorien S.; Nguyen, Danh V.

    2012-01-01

    Infection and cardiovascular disease are leading causes of hospitalization and death in older patients on dialysis. Our recent work found an increase in the relative incidence of cardiovascular outcomes during the ~ 30 days after infection-related hospitalizations using the case series model, which adjusts for measured and unmeasured baseline confounders. However, a major challenge in modeling/assessing the infection-cardiovascular risk hypothesis is that the exact time of infection, or more generally “exposure,” onsets cannot be ascertained based on hospitalization data. Only imprecise markers of the timing of infection onsets are available. Although there is a large literature on measurement error in the predictors in regression modeling, to date there is no work on measurement error on the timing of a time-varying exposure to our knowledge. Thus, we propose a new method, the measurement error case series (MECS) models, to account for measurement error in time-varying exposure onsets. We characterized the general nature of bias resulting from estimation that ignores measurement error and proposed a bias-corrected estimation for the MECS models. We examined in detail the accuracy of the proposed method to estimate the relative incidence. Hospitalization data from United States Renal Data System, which captures nearly all (> 99%) patients with end-stage renal disease in the U.S. over time, is used to illustrate the proposed method. The results suggest that the estimate of the cardiovascular incidence following the 30 days after infections, a period where acute effects of infection on vascular endothelium may be most pronounced, is substantially attenuated in the presence of infection onset measurement error. PMID:23650442

  9. Measurement Error Case Series Models with Application to Infection-Cardiovascular Risk in OlderPatients on Dialysis.

    PubMed

    Mohammed, Sandra M; Sentürk, Damla; Dalrymple, Lorien S; Nguyen, Danh V

    2012-12-01

    Infection and cardiovascular disease are leading causes of hospitalization and death in older patients on dialysis. Our recent work found an increase in the relative incidence of cardiovascular outcomes during the ~ 30 days after infection-related hospitalizations using the case series model, which adjusts for measured and unmeasured baseline confounders. However, a major challenge in modeling/assessing the infection-cardiovascular risk hypothesis is that the exact time of infection, or more generally "exposure," onsets cannot be ascertained based on hospitalization data. Only imprecise markers of the timing of infection onsets are available. Although there is a large literature on measurement error in the predictors in regression modeling, to date there is no work on measurement error on the timing of a time-varying exposure to our knowledge. Thus, we propose a new method, the measurement error case series (MECS) models, to account for measurement error in time-varying exposure onsets. We characterized the general nature of bias resulting from estimation that ignores measurement error and proposed a bias-corrected estimation for the MECS models. We examined in detail the accuracy of the proposed method to estimate the relative incidence. Hospitalization data from United States Renal Data System, which captures nearly all (> 99%) patients with end-stage renal disease in the U.S. over time, is used to illustrate the proposed method. The results suggest that the estimate of the cardiovascular incidence following the 30 days after infections, a period where acute effects of infection on vascular endothelium may be most pronounced, is substantially attenuated in the presence of infection onset measurement error. PMID:23650442

  10. Imaging the small animal cardiovascular system in real-time with multispectral optoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Taruttis, Adrian; Herzog, Eva; Razansky, Daniel; Ntziachristos, Vasilis

    2011-03-01

    Multispectral Optoacoustic Tomography (MSOT) is an emerging technique for high resolution macroscopic imaging with optical and molecular contrast. We present cardiovascular imaging results from a multi-element real-time MSOT system recently developed for studies on small animals. Anatomical features relevant to cardiovascular disease, such as the carotid arteries, the aorta and the heart, are imaged in mice. The system's fast acquisition time, in tens of microseconds, allows images free of motion artifacts from heartbeat and respiration. Additionally, we present in-vivo detection of optical imaging agents, gold nanorods, at high spatial and temporal resolution, paving the way for molecular imaging applications.

  11. An Adaptive and Implicit Immersed Boundary Method for Cardiovascular Device Modeling

    NASA Astrophysics Data System (ADS)

    Bhalla, Amneet Pal S.; Griffith, Boyce E.

    2015-11-01

    Computer models and numerical simulations are playing an increasingly important role in understanding the mechanics of fluid-structure interactions (FSI) in cardiovascular devices. To model cardiac devices realistically, there is a need to solve the classical fluid-structure interaction equations efficiently. Peskin's explicit immersed boundary method is one such approach to model FSI equations for elastic structures efficiently. However, in the presence of rigid structures the IB method faces a severe timestep restriction. To overcome this limitation, we are developing an implicit version of immersed boundary method on adaptive Cartesian grids. Higher grid resolution is employed in spatial regions occupying the structure while relatively coarser discretization is used elsewhere. The resulting discrete system is solved using geometric multigrid solver for the combined Stokes and elasticity operators. We use a rediscretization approach for standard finite difference approximations to the divergence, gradient, and viscous stress. In contrast, coarse grid versions of the Eulerian elasticity operator are constructed via a Galerkin approach. The implicit IB method is tested for a pulse duplicator cardiac device system that consists of both rigid mountings and elastic membrane.

  12. Cardiovascular physiology in space flight

    NASA Technical Reports Server (NTRS)

    Charles, John B.; Bungo, Michael W.

    1991-01-01

    The effects of space flight on the cardiovascular system have been studied since the first manned flights. In several instances, the results from these investigations have directly contradicted the predictions based on established models. Results suggest associations between space flight's effects on other organ systems and those on the cardiovascular system. Such findings provide new insights into normal human physiology. They must also be considered when planning for the safety and efficiency of space flight crewmembers.

  13. P2X receptors in the cardiovascular system and their potential as therapeutic targets in disease.

    PubMed

    Ralevic, Vera

    2015-01-01

    This review considers the expression and roles of P2X receptors in the cardiovascular system in health and disease and their potential as therapeutic targets. P2X receptors are ligand gated ion channels which are activated by the endogenous ligand ATP. They are formed from the assembly of three P2X subunit proteins from the complement of seven (P2X1-7), which can associate to form homomeric or heteromeric P2X receptors. The P2X1 receptor is widely expressed in the cardiovascular system, being located in the heart, in the smooth muscle of the majority of blood vessels and in platelets. P2X1 receptors expressed in blood vessels can be activated by ATP coreleased with noradrenaline as a sympathetic neurotransmitter, leading to smooth muscle depolarisation and contraction. There is evidence that the purinergic component of sympathetic neurotransmission is increased in hypertension, identifying P2X1 receptors as a possible therapeutic target in this disorder. P2X3 and P2X2/3 receptors are expressed on cardiac sympathetic neurones and may, through positive feedback of neuronal ATP at this prejunctional site, amplify sympathetic neurotransmission. Activation of P2X receptors expressed in the heart increases cardiac myocyte contractility, and an important role of the P2X4 receptor in this has been identified. Deletion of P2X4 receptors in the heart depresses contractile performance in models of heart failure, while overexpression of P2X4 receptors has been shown to be cardioprotective, thus P2X4 receptors may be therapeutic targets in the treatment of heart disease. P2X receptors have been identified on endothelial cells. Although immunoreactivity for all P2X1-7 receptor proteins has been shown on the endothelium, relatively little is known about their function, with the exception of the endothelial P2X4 receptor, which has been shown to mediate endothelium-dependent vasodilatation to ATP released during shear stress. The potential of P2X receptors as therapeutic targets in the treatment of cardiovascular disease is discussed. PMID:25515516

  14. Estrogen receptor β actions in the female cardiovascular system: A systematic review of animal and human studies.

    PubMed

    Muka, Taulant; Vargas, Kris G; Jaspers, Loes; Wen, Ke-Xin; Dhana, Klodian; Vitezova, Anna; Nano, Jana; Brahimaj, Adela; Colpani, Veronica; Bano, Arjola; Kraja, Bledar; Zaciragic, Asija; Bramer, Wichor M; Dijk, Gaby M van; Kavousi, Maryam; Franco, Oscar H

    2016-04-01

    Five medical databases were searched for studies that assessed the role of ERβ in the female cardiovascular system and the influence of age and menopause on ERβ functioning. Of 9472 references, 88 studies met our inclusion criteria (71 animal model experimental studies, 15 human model experimental studies and 2 population based studies). ERβ signaling was shown to possess vasodilator and antiangiogenic properties by regulating the activity of nitric oxide, altering membrane ionic permeability in vascular smooth muscle cells, inhibiting vascular smooth muscle cell migration and proliferation and by regulating adrenergic control of the arteries. Also, a possible protective effect of ERβ signaling against left ventricular hypertrophy and ischemia/reperfusion injury via genomic and non-genomic pathways was suggested in 27 studies. Moreover, 5 studies reported that the vascular effects of ERβ may be vessel specific and may differ by age and menopause status. ERβ seems to possess multiple functions in the female cardiovascular system. Further studies are needed to evaluate whether isoform-selective ERβ-ligands might contribute to cardiovascular disease prevention. PMID:26921926

  15. Klinefelter syndrome, cardiovascular system, and thromboembolic disease: review of literature and clinical perspectives.

    PubMed

    Salzano, Andrea; Arcopinto, Michele; Marra, Alberto M; Bobbio, Emanuele; Esposito, Daniela; Accardo, Giacomo; Giallauria, Francesco; Bossone, Eduardo; Vigorito, Carlo; Lenzi, Andrea; Pasquali, Daniela; Isidori, Andrea M; Cittadini, Antonio

    2016-07-01

    Klinefelter syndrome (KS) is the most frequently occurring sex chromosomal aberration in males, with an incidence of about 1 in 500-700 newborns. Data acquired from large registry-based studies revealed an increase in mortality rates among KS patients when compared with mortality rates among the general population. Among all causes of death, metabolic, cardiovascular, and hemostatic complication seem to play a pivotal role. KS is associated, as are other chromosomal pathologies and genetic diseases, with cardiac congenital anomalies that contribute to the increase in mortality. The aim of the current study was to systematically review the relationships between KS and the cardiovascular system and hemostatic balance. In summary, patients with KS display an increased cardiovascular risk profile, characterized by increased prevalence of metabolic abnormalities including Diabetes mellitus (DM), dyslipidemia, and alterations in biomarkers of cardiovascular disease. KS does not, however, appear to be associated with arterial hypertension. Moreover, KS patients are characterized by subclinical abnormalities in left ventricular (LV) systolic and diastolic function and endothelial function, which, when associated with chronotropic incompetence may led to reduced cardiopulmonary performance. KS patients appear to be at a higher risk for cardiovascular disease, attributing to an increased risk of thromboembolic events with a high prevalence of recurrent venous ulcers, venous insufficiency, recurrent venous and arterial thromboembolism with higher risk of deep venous thrombosis or pulmonary embolism. It appears that cardiovascular involvement in KS is mainly due to chromosomal abnormalities rather than solely on low serum testosterone levels. On the basis of evidence acquisition and authors' own experience, a flowchart addressing the management of cardiovascular function and prognosis of KS patients has been developed for clinical use. PMID:26850445

  16. Fuzzy model approach for estimating time of hospitalization due to cardiovascular diseases.

    PubMed

    Coutinho, Karine Mayara Vieira; Rizol, Paloma Maria Silva Rocha; Nascimento, Luiz Fernando Costa; de Medeiros, Andréa Paula Peneluppi

    2015-08-01

    A fuzzy linguistic model based on the Mamdani method with input variables, particulate matter, sulfur dioxide, temperature and wind obtained from CETESB with two membership functions each was built to predict the average hospitalization time due to cardiovascular diseases related to exposure to air pollutants in São José dos Campos in the State of São Paulo in 2009. The output variable is the average length of hospitalization obtained from DATASUS with six membership functions. The average time given by the model was compared to actual data using lags of 0 to 4 days. This model was built using the Matlab v. 7.5 fuzzy toolbox. Its accuracy was assessed with the ROC curve. Hospitalizations with a mean time of 7.9 days (SD = 4.9) were recorded in 1119 cases. The data provided revealed a significant correlation with the actual data according to the lags of 0 to 4 days. The pollutant that showed the greatest accuracy was sulfur dioxide. This model can be used as the basis of a specialized system to assist the city health authority in assessing the risk of hospitalizations due to air pollutants. PMID:26221823

  17. Role Models and the Psychological Characteristics That Buffer Low-Socioeconomic-Status Youth from Cardiovascular Risk

    ERIC Educational Resources Information Center

    Chen, Edith; Lee, William K.; Cavey, Lisa; Ho, Amanda

    2013-01-01

    Little is understood about why some youth from low-socioeconomic-status (SES) environments exhibit good health despite adversity. This study tested whether role models and "shift-and-persist" approaches (reframing stressors more benignly while persisting with future optimism) protect low-SES youth from cardiovascular risk. A total of 163

  18. Role Models and the Psychological Characteristics That Buffer Low-Socioeconomic-Status Youth from Cardiovascular Risk

    ERIC Educational Resources Information Center

    Chen, Edith; Lee, William K.; Cavey, Lisa; Ho, Amanda

    2013-01-01

    Little is understood about why some youth from low-socioeconomic-status (SES) environments exhibit good health despite adversity. This study tested whether role models and "shift-and-persist" approaches (reframing stressors more benignly while persisting with future optimism) protect low-SES youth from cardiovascular risk. A total of 163…

  19. Strain Differences in Antioxidants in Rat Models of Cardiovascular Disease Exposed to Ozone

    EPA Science Inventory

    We examined the hypothesis that antioxidant substances and enzymes in lung, heart and in bronchoalveolar lavage fluid (BALF) are altered in response to 03 in cardiovascular disease and/or metabolic syndrome (CVD)-prone rat models. CVD strains [spontaneously hypertensive (SH), SH ...

  20. Variability in Ozone-Induced Pulmonary Injury and Inflammation in Healthy and Cardiovascular Compromised Rat Models

    EPA Science Inventory

    The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure depe...

  1. Influence of mitochondrion-toxic agents on the cardiovascular system.

    PubMed

    Finsterer, Josef; Ohnsorge, Peter

    2013-12-01

    Cardiovascular disease may be induced or worsened by mitochondrion-toxic agents. Mitochondrion-toxic agents may be classified as those with or without a clinical effect, those which induce cardiac disease only in humans or animals or both, as prescribed drugs, illicit drugs, exotoxins, or nutritiants, as those which affect the heart exclusively or also other organs, as those which are effective only in patients with a mitochondrial disorder or cardiac disease or also in healthy subjects, or as solid, liquid, or volatile agents. In humans, cardiotoxic agents due to mitochondrial dysfunction include anthracyclines (particularly doxorubicin), mitoxantrone, cyclophosphamide, cisplatin, fluorouracil, imatinib, bortezomib, trastuzumab, arsenic trioxide, cyclosporine-A, zidovudine, lamotrigine, glycosides, lidocain, isoproterenol, nitroprusside, pivalic acid, alcohol, cocaine, pesticides, cadmium, mycotoxins, cyanotoxins, meat meal, or carbon monoxide. Even more agents exhibit cardiac abnormalities due to mitochondrion-toxicity only in animals or tissue cultures. The mitochondrion-toxic effect results from impairment of the respiratory chain, the oxidative phosphorylation, the Krebs cycle, or the β-oxidation, from decrease of the mitochondrion-membrane potential, from increased oxidative stress, reduced anti-oxidative capacity, or from induction of apoptosis. Cardiac abnormalities induced via these mechanisms include cardiomyopathy, myocarditis, coronary heart disease, arrhythmias, heart failure, or Takotsubo syndrome. Discontinuation of the cardiotoxic agent results in complete recovery in the majority of the cases. Antioxidants and nutritiants may be of additional help. Particularly coenzyme-Q, riboflavin, vitamin-E, vitamin-C, L-carnitine, vitamin-D, thiamin, folic acid, omega-3 fatty acids, and D-ribose may alleviate mitochondrial cardiotoxic effects. PMID:24036395

  2. Therapeutic targeting of two-pore-domain potassium (K2P) channels in the cardiovascular system.

    PubMed

    Wiedmann, Felix; Schmidt, Constanze; Lugenbiel, Patrick; Staudacher, Ingo; Rahm, Ann-Kathrin; Seyler, Claudia; Schweizer, Patrick A; Katus, Hugo A; Thomas, Dierk

    2016-05-01

    The improvement of treatment strategies in cardiovascular medicine is an ongoing process that requires constant optimization. The ability of a therapeutic intervention to prevent cardiovascular pathology largely depends on its capacity to suppress the underlying mechanisms. Attenuation or reversal of disease-specific pathways has emerged as a promising paradigm, providing a mechanistic rationale for patient-tailored therapy. Two-pore-domain K(+) (K2P) channels conduct outward K(+) currents that stabilize the resting membrane potential and facilitate action potential repolarization. K2P expression in the cardiovascular system and polymodal K2P current regulation suggest functional significance and potential therapeutic roles of the channels. Recent work has focused primarily on K2P1.1 [tandem of pore domains in a weak inwardly rectifying K(+) channel (TWIK)-1], K2P2.1 [TWIK-related K(+) channel (TREK)-1], and K2P3.1 [TWIK-related acid-sensitive K(+) channel (TASK)-1] channels and their role in heart and vessels. K2P currents have been implicated in atrial and ventricular arrhythmogenesis and in setting the vascular tone. Furthermore, the association of genetic alterations in K2P3.1 channels with atrial fibrillation, cardiac conduction disorders and pulmonary arterial hypertension demonstrates the relevance of the channels in cardiovascular disease. The function, regulation and clinical significance of cardiovascular K2P channels are summarized in the present review, and therapeutic options are emphasized. PMID:26993052

  3. Baroreflex and metaboreflex control of cardiovascular system during exercise in space.

    PubMed

    Pagani, Massimo; Pizzinelli, Paolo; Beltrami, Silvia; Massaro, Michele; Lucini, Daniela; Iellamo, Ferdinando

    2009-10-01

    This brief review summarizes current knowledge on the neural mechanisms of cardiovascular regulation during exercise in space, with specific emphasis on the role of the arterial baroreflex and the muscle metaboreflex, with the attendant modifications in autonomic nervous system activity, in determining the cardiovascular responses to exercise in microgravity conditions. Available data suggest that the muscle metaboreflex is enhanced during dynamic exercise in space and that the potentiation of the muscle metaboreflex affects the vagally mediated arterial baroreflex contribution to HR control. PMID:19446046

  4. Regulation of signal transduction by reactive oxygen species in the cardiovascular system

    PubMed Central

    Brown, David I.; Griendling, Kathy K.

    2015-01-01

    Oxidative stress has long been implicated in cardiovascular disease, but more recently, the role of reactive oxygen species in normal physiological signaling has been elucidated. Signaling pathways modulated by reactive oxygen species (ROS) are complex and compartmentalized, and we are only beginning to identify the molecular modifications of specific targets. Here we review the current literature regarding ROS signaling in the cardiovascular system, focusing on the role of ROS in normal physiology and how dysregulation of signaling circuits contributes to cardiovascular diseases including atherosclerosis, ischemia-reperfusion injury, cardiomyopathy and heart failure. In particular, we consider how ROS modulate signaling pathways related to phenotypic modulation, migration and adhesion, contractility, proliferation and hypertrophy, angiogenesis, endoplasmic reticulum stress, apoptosis and senescence. Understanding the specific targets of ROS may guide the development of the next generation of ROS-modifying therapies to reduce morbidity and mortality associated with oxidative stress. PMID:25634975

  5. Protective actions of melatonin and growth hormone on the aged cardiovascular system.

    PubMed

    Paredes, Sergio D; Forman, Katherine A; García, Cruz; Vara, Elena; Escames, Germaine; Tresguerres, Jesús A F

    2014-05-01

    Epidemiological studies indicate that certain aspects of lifestyle and genetics act as risk factors for a variety of cardiovascular disorders, including coronary disease, hypertension, heart failure and stroke. Aging, however, appears to be the major contributor for morbidity and mortality of the impaired cardiovascular system. Growth hormone (GH) and melatonin seem to prevent cardiac aging, as they contribute to the recovery of several physiological parameters affected by age. These hormones exhibit antioxidant properties and decrease oxidative stress and apoptosis. This paper summarizes a set of studies related to the potential role that therapy with GH and melatonin may play in the protection of the altered cardiac function due to aging, with a focus on experiments performed in our laboratory using the senescence-accelerated mouse as an aging model. In general, we observed significantly increased inflammation, oxidative stress and apoptosis markers in hearts from senescence-accelerated prone 10-month-old animals compared to 2-month-old controls, while anti-inflammatory and antiapoptotic markers as well as endothelial nitric oxide synthase were decreased. Senescence-accelerated resistant animals showed no significant changes with age. GH or melatonin treatment prevented the age-dependent cardiac alterations observed in the senescence-accelerated prone group. Combined administration of GH plus melatonin reduced the age-related changes in senescence-accelerated prone hearts in an additive fashion that was different to that displayed when administered alone. GH and melatonin may be potential agents for counteracting oxidative stress, apoptosis and inflammation in the aging heart. PMID:25390004

  6. Magnetic Resonance Cardiorhythmography as a Method of Study of Human's Cardiovascular System Condition

    NASA Astrophysics Data System (ADS)

    Protasov, E. A.; Ryzhkova, A. V.

    In this article a highly sensitive method for graphic recording of cardiogram by detecting the signal of nuclear magnetic resonance (NMR) of human finger has been developed and signals directly related to movement of blood ejected by the heart into the vessels have been studied. Changes in the behavior of signals depending on the condition of the cardiovascular system of person have been discovered.

  7. TEMPORAL ASSOCIATION BETWEEN PULMONARY AND SYSTEMIC EFFECTS OF PARTICULATE MATTER IN HEALTHY AND CARDIOVASCULAR COMPROMISED RATS

    EPA Science Inventory

    Temporal association between pulmonary and systemic effects of particulate matter in healthy and cardiovascular compromised rats

    Urmila P. Kodavanti, Mette C. Schladweiler, Allen D. Ledbetter, Russ Hauser*, David C. Christiani*, John McGee, Judy R. Richards, Daniel L. Co...

  8. System identification of closed-loop cardiovascular control: effects of posture and autonomic blockade

    NASA Technical Reports Server (NTRS)

    Mullen, T. J.; Appel, M. L.; Mukkamala, R.; Mathias, J. M.; Cohen, R. J.

    1997-01-01

    We applied system identification to the analysis of fluctuations in heart rate (HR), arterial blood pressure (ABP), and instantaneous lung volume (ILV) to characterize quantitatively the physiological mechanisms responsible for the couplings between these variables. We characterized two autonomically mediated coupling mechanisms [the heart rate baroreflex (HR baroreflex) and respiratory sinus arrhythmia (ILV-HR)] and two mechanically mediated coupling mechanisms [the blood pressure wavelet generated with each cardiac contraction (circulatory mechanics) and the direct mechanical effects of respiration on blood pressure (ILV-->ABP)]. We evaluated the method in humans studied in the supine and standing postures under control conditions and under conditions of beta-sympathetic and parasympathetic pharmacological blockades. Combined beta-sympathetic and parasympathetic blockade abolished the autonomically mediated couplings while preserving the mechanically mediated coupling. Selective autonomic blockade and postural changes also altered the couplings in a manner consistent with known physiological mechanisms. System identification is an "inverse-modeling" technique that provides a means for creating a closed-loop model of cardiovascular regulation for an individual subject without altering the underlying physiological control mechanisms.

  9. A Follow-Up Study of Medical Students' Biomedical Understanding and Clinical Reasoning Concerning the Cardiovascular System

    ERIC Educational Resources Information Center

    Ahopelto, Ilona; Mikkila-Erdmann, Mirjamaija; Olkinuora, Erkki; Kaapa, Pekka

    2011-01-01

    Novice medical students usually hold initial conceptions concerning medical domains, such as the cardiovascular system, which may contradict scientific explanations and thus hinder learning. The purpose of this study was to investigate which kinds of biomedical representations medical students constructed of the central cardiovascular system in…

  10. Increasing blood flow to exercising muscle attenuates systemic cardiovascular responses during dynamic exercise in humans.

    PubMed

    Ichinose, Masashi; Ichinose-Kuwahara, Tomoko; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-11-15

    Reducing blood flow to working muscles during dynamic exercise causes metabolites to accumulate within the active muscles and evokes systemic pressor responses. Whether a similar cardiovascular response is elicited with normal blood flow to exercising muscles during dynamic exercise remains unknown, however. To address that issue, we tested whether cardiovascular responses are affected by increases in blood flow to active muscles. Thirteen healthy subjects performed dynamic plantarflexion exercise for 12 min at 20%, 40%, and 60% of peak workload (EX20, EX40, and EX60) with their lower thigh enclosed in a negative pressure box. Under control conditions, the box pressure was the same as the ambient air pressure. Under negative pressure conditions, beginning 3 min after the start of the exercise, the box pressure was decreased by 20, 45, and then 70 mmHg in stepwise fashion with 3-min step durations. During EX20, the negative pressure had no effect on blood flow or the cardiovascular responses measured. However, application of negative pressure increased blood flow to the exercising leg during EX40 and EX60. This increase in blood flow had no significant effect on systemic cardiovascular responses during EX40, but it markedly attenuated the pressor responses otherwise seen during EX60. These results demonstrate that during mild exercise, normal blood flow to exercising muscle is not a factor eliciting cardiovascular responses, whereas it elicits an important pressor effect during moderate exercise. This suggests blood flow to exercising muscle is a major determinant of cardiovascular responses during dynamic exercise at higher than moderate intensity. PMID:26377556

  11. Altered Nitric Oxide System in Cardiovascular and Renal Diseases

    PubMed Central

    Bae, Eun Hui; Ma, Seong Kwon; Kim, Soo Wan

    2016-01-01

    Nitric oxide (NO) is synthesized by a family of NO synthases (NOS), including neuronal, inducible, and endothelial NOS (n/i/eNOS). NO-mediated effects can be beneficial or harmful depending on the specific risk factors affecting the disease. In hypertension, the vascular relaxation response to acetylcholine is blunted, and that to direct NO donors is maintained. A reduction in the activity of eNOS is mainly responsible for the elevation of blood pressure, and an abnormal expression of iNOS is likely to be related to the progression of vascular dysfunction. While eNOS/nNOS-derived NO is protective against the development of atherosclerosis, iNOS-derived NO may be proatherogenic. eNOS-derived NO may prevent the progression of myocardial infarction. Myocardial ischemia/reperfusion injury is significantly enhanced in eNOS-deficient animals. An important component of heart failure is the loss of coronary vascular eNOS activity. A pressure-overload may cause severer left ventricular hypertrophy and dysfunction in eNOS null mice than in wild-type mice. iNOS-derived NO has detrimental effects on the myocardium. NO plays an important role in regulating the angiogenesis and slowing the interstitial fibrosis of the obstructed kidney. In unilateral ureteral obstruction, the expression of eNOS was decreased in the affected kidney. In triply n/i/eNOS null mice, nephrogenic diabetes insipidus developed along with reduced aquaporin-2 abundance. In chronic kidney disease model of subtotal-nephrectomized rats, treatment with NOS inhibitors decreased systemic NO production and induced left ventricular systolic dysfunction (renocardiac syndrome). PMID:27231671

  12. Space Weather and a State of Cardiovascular System of Human Being with a Weakened Adaptation System

    NASA Astrophysics Data System (ADS)

    Samsonov, S. N.

    As has been shown in [Samsonov et al., 2013] even at the considerable disturbances of space weather parameters a healthy human being did not undergo painful symptoms although measurements of objective physiological indices showed their changes. At the same time the state of health of people with the weakened adaptation system under the same conditions can considerably be deteriorated up to fatal outcome. The analysis of results of the project "Heliomed" and the number of calls for the emergency medical care (EMC) around Yakutsk as to cardiovascular diseases (CVD) has shown:- the total number of calls for EMC concerning myocardial infarction (MI) per year near the geomagnetic disturbance maximum (1992) exceeds the number of calls per year near the geomagnetic activity minimum (1998) by a factor of 1,5 and concerning to strokes - by a factor of 1,8.- maxima of MI are observed during spring and autumn periods coinciding with maxima of geophysical disturbance;- the coincidence of 30-32 daily periods in a power spectrum of MI with the same periods in power spectra of space weather parameters (speeds and density of the solar wind, interplanetary magnetic field, geophysical disturbance);- the existence of 3 maxima of the number of calls for EMC: a) at the moment of disturbance on the Sun; during a geophysical disturbance (in 2-4 days after a disturbance on the Sun); in 2-4 days after a geophysical disturbance;- the availability of coincidence of insignificant disturbances of space weather parameters with changes of the functional state of cardiovascular system of a human being with the weakened adaptation system and the occurrence of MI and strokes at considerable values of such disturbances is explained by a quasi-logarithmic dependence of the response of human being organisms to the environment disturbance intensity.

  13. [Significance of endogenous sulfur dioxide in the regulation of cardiovascular system].

    PubMed

    Jin, Hong Fang; DU, Shu Xu; Zhao, Xia; Zhang, Su Qing; Tian, Yue; Bu, Ding Fang; Tang, Chao Shu; DU, Jun Bao

    2007-08-18

    Since the 1980's nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H(2)S), the endogenous gas molecules produced from metabolic pathway, have been realized as signal molecules to be involved in the regulation of body homeostasis and to play important roles under physiological and pathophysiological conditions. The researches on these endogenous gas signal molecules opened a new avenue in life science. To explore the new member of gasotransmitter family, other endogenous gas molecules which have been regarded as metabolic waste up to date, and their biological regulatory effects have been paid close attention to in the current fields of life science and medicine. Sulfur dioxide (SO(2)) can be produced endogenously from normal metabolism of sulfur-containing amino acids. L-cysteine is oxidized via cysteine dioxygenase to L-cysteinesulfinate, and the latter can proceed through transamination by glutamate oxaloacetate transaminase (GOT) to beta-sulfinyl pyruvate which decomposes spontaneously to pyruvate and SO(2). In mammals, activated neutrophils by oxidative stress can convert H(2)S to sulfite through a reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase-dependent process. The authors detected endogenous production of SO(2) in all cardiovascular tissues, including in heart, aorta, pulmonary artery, mesenteric artery, renal artery, tail artery and the plasma SO(2) content. As the key enzyme producing SO(2), GOT mRNA in cardiovascular system was detected and found to be located enriched in endothelial cells and vascular smooth muscle cells near the endothelial layer. When the normal rats were treated with hydroxamate(HDX), a GOT inhibitor, at a dose of 3.7 mg/kg body weight, the blood pressure (BP) went high markedly, the ratio of wall thickness to lumen radius was increased by 18.34%, and smooth muscle cell proliferation was enhanced. The plasma SO(2) level in the rats injected with 125 micromol/kg body weight SO(2) donor was increased to 721.98+/-30.11 micromol/L at the end of 30 seconds, while the blood pressure was decreased to the lowest point 65.0+/- 4.9 mm Hg at the end of 1 minute. The above results showed that endogenous SO(2) might be involved in the maintenance of blood pressure and normal vascular structure. In spontaneous hypertensive rat (SHR) animal model, exogenous supplement of SO(2) donor decreased the BP, the media cross-sectional area, and pressure of the media and the ratio of wall thickness to lumen radius in the SHR. Moreover, the proliferative index of aortic smooth muscle cells was decreased in the SHR treated with SO(2) donor compared with that in SHR. The above data showed that SO(2) could prevent the aortic structural remodeling by inhibiting the proliferation of aortic smooth muscle cells. The authors observed the direct vasorelaxant effects of SO(2) on the aortic ring pre-treated with norepinephrine (NE). SO(2) donor at a concentration of 25-100 micromol/L relaxed the aortic ring temporarily and slightly, but SO(2) donor at a concentration of 1-12 mmol/L induced relaxation of the ring in a concentration-dependent manner. Administration with nicardipine, an L-type calcium channel blocker other than glibenclamide, an ATP sensitive potassium channel (K(ATP) channel) blocker or removal of vascular endothelium could decrease the SO(2)-induced vasorelaxation. In hypoxic pulmonary hypertension animal model, SO(2) donor decreased the mean pulmonary artery pressure and the systolic pulmonary artery pressure (P<0.01), respectively as compared with hypoxic group, and alleviated obviously the hypoxic pulmonary vascular structural remodeling. The percentage of muscularized arteries of small pulmonary vessels was significantly decreased in hypoxia+SO(2) donor-treated rats compared with that of hypoxic rats (P<0.01), while the percentage of non-muscularized vessels was obviously higher in hypoxia with SO(2) donor-treated rats than that of hypoxic rats (P<0.01). Similarly, SO(2) obviously decreased relative media area and relative media thickness of small muscularized pulmonary arteries in hypoxic rats (P<0.01). The above data showed that SO(2) might play an important role in development of hypoxic pulmonary hypertension. Perfusion with SO(2) donor (10(-6)-10(-3) mol/L) to the isolated rat heart obviously inhibited the left ventricular peak rate of contraction ( + LV dp/ dtmax) , peak rate of relaxation (-LV dp/ dtmax) and difference of left ventricular pressure ( DeltaLVP) in a concentration dependent manner. Nicardipine, an L-type calcium channel blocker, could partly antagonize the inhibitory effect of SO(2) on the heart function. In a word, SO(2) could be endogenously generated in cardiovascular tissues and exert important cardiovascular effects such as vasorelaxant effect and negative inotropic effects. Moreover, SO(2) might play considerable roles in the regulation of systemic circulatory pressure, pulmonary circulatory pressure and vascular structural remodeling in the pathogenesis of hypertension and hypoxic pulmonary hypertension. On the basis of the above findings, we presumed that endogenous SO(2) might be a novel cardiovascular functional regulatory gasotransmitter. More studies on the significance of endogenous SO(2) in cardiovascular system under physiological and pathophysiological conditions need to be investigated. PMID:17657274

  14. Meeting report from the 2nd International Symposium on New Frontiers in Cardiovascular Research. Protecting the cardiovascular system from ischemia: between bench and bedside.

    PubMed

    Cabrera-Fuentes, Hector A; Alba-Alba, Corina; Aragones, Julian; Bernhagen, Jürgen; Boisvert, William A; Bøtker, Hans E; Cesarman-Maus, Gabriela; Fleming, Ingrid; Garcia-Dorado, David; Lecour, Sandrine; Liehn, Elisa; Marber, Michael S; Marina, Nephtali; Mayr, Manuel; Perez-Mendez, Oscar; Miura, Tetsuji; Ruiz-Meana, Marisol; Salinas-Estefanon, Eduardo M; Ong, Sang-Bing; Schnittler, Hans J; Sanchez-Vega, Jose T; Sumoza-Toledo, Adriana; Vogel, Carl-Wilhelm; Yarullina, Dina; Yellon, Derek M; Preissner, Klaus T; Hausenloy, Derek J

    2016-01-01

    Recent advances in basic cardiovascular research as well as their translation into the clinical situation were the focus at the last "New Frontiers in Cardiovascular Research meeting". Major topics included the characterization of new targets and procedures in cardioprotection, deciphering new players and inflammatory mechanisms in ischemic heart disease as well as uncovering microRNAs and other biomarkers as versatile and possibly causal factors in cardiovascular pathogenesis. Although a number of pathological situations such as ischemia-reperfusion injury or atherosclerosis can be simulated and manipulated in diverse animal models, also to challenge new drugs for intervention, patient studies are the ultimate litmus test to obtain unequivocal information about the validity of biomedical concepts and their application in the clinics. Thus, the open and bidirectional exchange between bench and bedside is crucial to advance the field of ischemic heart disease with a particular emphasis of understanding long-lasting approaches in cardioprotection. PMID:26667317

  15. Central Nervous System Serotonin and Clustering of Hostility, Psychosocial, Metabolic and Cardiovascular Endophenotypes in Men

    PubMed Central

    Williams, Redford B.; Surwit, Richard S.; Siegler, Ilene C.; Ashley-Koch, Allison E.; Collins, Ann L.; Helms, Michael J.; Georiades, Anastasia; Boyle, Stephen H.; Brummett, Beverly H.; Barefoot, John C.; Grichnik, Katherine; Stafford-Smith, Mark; Kuhn, Cynthia M.

    2013-01-01

    Objective To use measures of CSF 5HIAA and MAOA-uVNTR genotype to study the role of central nervous system (CNS) serotonin in clustering of hostility, and other psychosocial, metabolic and cardiovascular endophenotypes. Methods In 86 healthy men, we evaluated cerebrospinal fluid (CSF) levels of the primary serotonin metabolite 5-hydroxyindoleacetic acid (5HIAA) and genotype on a functional promoter polymorphism of the monoamine oxidase A gene (M-uVNTR) for association with 29 variables assessing hostility, other psychosocial, metabolic, neuroendocrine and cardiovascular endophenotypes. Results The correlations of 5HIAA with these endophenotypes in men with more active MAOA-uVNTR alleles were significantly different from those with less active alleles for 15 of 29 endophenotypes. MAOA-uVNTR phenotype and CSF 5HIAA interacted to explain 20% and 22% of the variance, respectively, in scores on one factor wherein high scores reflected a less healthy psychosocial profile and a second factor wherein high score reflected increased insulin resistance, BMI, blood pressure and hostility. In men with less active alleles, higher 5HIAA was associated with more favorable profiles of hostility, other psychosocial, metabolic and cardiovascular endophenotypes; in men with more active alleles, higher 5HIAA was associated with less favorable profiles. Conclusions These findings indicate that in men indices of CNS serotonin function influence the expression and clustering of hostility, other psychosocial, metabolic and cardiovascular endophenotypes that have been shown to increase risk of developing cardiovascular disease. The findings are consistent with the hypothesis that increased CNS serotonin is associated with a more favorable psychosocial/metabolic/cardiovascular profile, while decreased CNS serotonin function is associated with a less favorable profile. PMID:20595415

  16. Unmasking Silent Endothelial Activation in the Cardiovascular System Using Molecular Magnetic Resonance Imaging

    PubMed Central

    Belliere, Julie; Martinez de Lizarrondo, Sara; Choudhury, Robin P.; Quenault, Aurélien; Le Béhot, Audrey; Delage, Christine; Chauveau, Dominique; Schanstra, Joost P.; Bascands, Jean-Loup; Vivien, Denis; Gauberti, Maxime

    2015-01-01

    Endothelial activation is a hallmark of cardiovascular diseases, acting either as a cause or a consequence of organ injury. To date, we lack suitable methods to measure endothelial activation in vivo. In the present study, we developed a magnetic resonance imaging (MRI) method allowing non-invasive endothelial activation mapping in the vasculature of the main organs affected during cardiovascular diseases. In clinically relevant contexts in mice (including systemic inflammation, acute and chronic kidney diseases, diabetes mellitus and normal aging), we provided evidence that this method allows detecting endothelial activation before any clinical manifestation of organ failure in the brain, kidney and heart with an exceptional sensitivity. In particular, we demonstrated that diabetes mellitus induces chronic endothelial cells activation in the kidney and heart. Moreover, aged mice presented activated endothelial cells in the kidneys and the cerebrovasculature. Interestingly, depending on the underlying condition, the temporospatial patterns of endothelial activation in the vascular beds of the cardiovascular system were different. These results demonstrate the feasibility of detecting silent endothelial activation occurring in conditions associated with high cardiovascular risk using molecular MRI. PMID:26379785

  17. Noninvasive assessment of the developing Xenopus cardiovascular system using optical coherence tomography

    PubMed Central

    Boppart, Stephen A.; Tearney, Gary J.; Bouma, Brett E.; Southern, James F.; Brezinski, Mark E.; Fujimoto, James G.

    1997-01-01

    Studies investigating normal and abnormal cardiac development are frequently limited by an inability to assess cardiovascular function within the intact organism. In this work, optical coherence tomography (OCT), a new method of micron-scale, noninvasive imaging based on the measurement of backscattered infrared light, was introduced for the high resolution assessment of structure and function in the developing Xenopus laevis cardiovascular system. Microstructural details, such as ventricular size and wall positions, were delineated with OCT at 16-μm resolution and correlated with histology. Three-dimensional representation of the cardiovascular system also was achieved by repeated cross-sectional imaging at intervals of 25 μm. In addition to structural information, OCT provides high speed in vivo axial ranging and imaging, allowing quantitative dynamic activity, such as ventricular ejection fraction, to be assessed. The sensitivity of OCT for dynamic assessment was demonstrated with an inotropic agent that altered cardiac function and dimensions. Optical coherence tomography is an attractive new technology for assessing cardiovascular development because of its high resolution, its ability to image through nontransparent structures, and its inexpensive portable design. In vivo and in vitro imaging are performed at a resolution approaching that of histopathology without the need for animal killing. PMID:9113976

  18. Using a human cardiovascular-respiratory model to characterize cardiac tamponade and pulsus paradoxus

    PubMed Central

    Ramachandran, Deepa; Luo, Chuan; Ma, Tony S; Clark, John W

    2009-01-01

    Background Cardiac tamponade is a condition whereby fluid accumulation in the pericardial sac surrounding the heart causes elevation and equilibration of pericardial and cardiac chamber pressures, reduced cardiac output, changes in hemodynamics, partial chamber collapse, pulsus paradoxus, and arterio-venous acid-base disparity. Our large-scale model of the human cardiovascular-respiratory system (H-CRS) is employed to study mechanisms underlying cardiac tamponade and pulsus paradoxus. The model integrates hemodynamics, whole-body gas exchange, and autonomic nervous system control to simulate pressure, volume, and blood flow. Methods We integrate a new pericardial model into our previously developed H-CRS model based on a fit to patient pressure data. Virtual experiments are designed to simulate pericardial effusion and study mechanisms of pulsus paradoxus, focusing particularly on the role of the interventricular septum. Model differential equations programmed in C are solved using a 5th-order Runge-Kutta numerical integration scheme. MATLAB is employed for waveform analysis. Results The H-CRS model simulates hemodynamic and respiratory changes associated with tamponade clinically. Our model predicts effects of effusion-generated pericardial constraint on chamber and septal mechanics, such as altered right atrial filling, delayed leftward septal motion, and prolonged left ventricular pre-ejection period, causing atrioventricular interaction and ventricular desynchronization. We demonstrate pericardial constraint to markedly accentuate normal ventricular interactions associated with respiratory effort, which we show to be the distinct mechanisms of pulsus paradoxus, namely, series and parallel ventricular interaction. Series ventricular interaction represents respiratory variation in right ventricular stroke volume carried over to the left ventricle via the pulmonary vasculature, whereas parallel interaction (via the septum and pericardium) is a result of competition for fixed filling space. We find that simulating active septal contraction is important in modeling ventricular interaction. The model predicts increased arterio-venous CO2 due to hypoperfusion, and we explore implications of respiratory pattern in tamponade. Conclusion Our modeling study of cardiac tamponade dissects the roles played by septal motion, atrioventricular and right-left ventricular interactions, pulmonary blood pooling, and the depth of respiration. The study fully describes the physiological basis of pulsus paradoxus. Our detailed analysis provides biophysically-based insights helpful for future experimental and clinical study of cardiac tamponade and related pericardial diseases. PMID:19656411

  19. Cardiovascular and other dynamic systems in long-term space flight

    NASA Technical Reports Server (NTRS)

    Tipton, David A.

    1987-01-01

    The paper examines the physiology of the cardiovascular system, and to a lesser extent the endocrine, renal, and hematopoietic systems. The paper highlights the aspects of these areas that are most pertinent to space manufacturing, i.e., working in space. Areas covered include the physiological costs of working in microgravity and partial gravity (e.g., the moon or Mars), countermeasures to potentially adverse physiological adaptations, and problems associated with return to earth after long periods of weightlessness.

  20. A plausible radiobiological model of cardiovascular disease at low or fractionated doses

    NASA Astrophysics Data System (ADS)

    Little, Mark; Vandoolaeghe, Wendy; Gola, Anna; Tzoulaki, Ioanna

    Atherosclerosis is the main cause of coronary heart disease and stroke, the two major causes of death in developed society. There is emerging evidence of excess risk of cardiovascular disease at low radiation doses in various occupationally-exposed groups receiving small daily radia-tion doses. Assuming that they are causal, the mechanisms for effects of chronic fractionated radiation exposures on cardiovascular disease are unclear. We outline a spatial reaction-diffusion model for atherosclerosis, and perform stability analysis, based wherever possible on human data. We show that a predicted consequence of multiple small radiation doses is to cause mean chemo-attractant (MCP-1) concentration to increase linearly with cumulative dose. The main driver for the increase in MCP-1 is monocyte death, and consequent reduction in MCP-1 degradation. The radiation-induced risks predicted by the model are quantitatively consistent with those observed in a number of occupationally-exposed groups. The changes in equilibrium MCP-1 concentrations with low density lipoprotein cholesterol concentration are also consistent with experimental and epidemiologic data. This proposed mechanism would be experimentally testable. If true, it also has substantive implications for radiological protection, which at present does not take cardiovascular disease into account. The Japanese A-bomb survivor data implies that cardiovascular disease and can-cer mortality contribute similarly to radiogenic risk. The major uncertainty in assessing the low-dose risk of cardiovascular disease is the shape of the dose response relationship, which is unclear in the Japanese data. The analysis of the present paper suggests that linear extrapo-lation would be appropriate for this endpoint.

  1. The Applicability of Nonlinear Systems Dynamics Chaos Measures to Cardiovascular Physiology Variables

    NASA Technical Reports Server (NTRS)

    Hooker, John C.

    1991-01-01

    Three measures of nonlinear chaos (fractal dimension, Approximate Entropy (ApEn), and Lyapunov exponents) were studied as potential measures of cardiovascular condition. It is suggested that these measures have potential in the assessment of cardiovascular condition in environments of normal cardiovascular stress (normal gravity on the Earth surface), cardiovascular deconditioning (microgravity of space), and increased cardiovascular stress (lower body negative pressure (LBNP) treatments).

  2. Prototype for an organ system (liver) localization cardiovascular catheter

    NASA Astrophysics Data System (ADS)

    Ballerstadt, Ralph; Dahn, Michael S.; Lange, M. Patricia; Schultz, Jerome S.

    1999-07-01

    This study describes the function and potential clinical utility of a sensor which can serve as a guidance mechanism allowing for the selective cannulation of the hepatic venous system without the need for additional imaging technology. The sensor is based upon a homogeneous affinity fluorescence assay system utilizing the lectin Ricinus cummunis agglutinin I and covalently linked to the fluorophol Alexa 488 and its conjugate polydextran labeled with rhodamine and lactose. The affinity between these two macromolecules is sensitive to ambient galactose concentration which exists as a steep gradient at the hepatic venous/vena caval junction allowing this anatomic region to be discriminated from irrelevant regions. This sensor system permits venous access for additional monitoring approaches such as venous oximetry.

  3. What Research Says: The Cardiovascular System: Children's Conceptions and Misconceptions.

    ERIC Educational Resources Information Center

    Arnaudin, Mary W.; Mintzes, Joel J.

    1986-01-01

    Reports findings of a study on children's perceptions and alternate conceptions about the human circulatory system. Summarizes the responses of fifth and eighth grade students on questions dealing with the heart and blood. Offers examples of hands-on activities and confrontation strategies that address common misconceptions on circulation. (ML)

  4. S-Nitrosothiols and the S-Nitrosoproteome of the Cardiovascular System

    PubMed Central

    Maron, Bradley A.; Tang, Shiow-Shih

    2013-01-01

    Abstract Significance: Since their discovery in the early 1990's, S-nitrosylated proteins have been increasingly recognized as important determinants of many biochemical processes. Specifically, S-nitrosothiols in the cardiovascular system exert many actions, including promoting vasodilation, inhibiting platelet aggregation, and regulating Ca2+ channel function that influences myocyte contractility and electrophysiologic stability. Recent Advances: Contemporary developments in liquid chromatography–mass spectrometry methods, the development of biotin- and His-tag switch assays, and the availability of cyanide dye-labeling for S-nitrosothiol detection in vitro have increased significantly the identification of a number of cardiovascular protein targets of S-nitrosylation in vivo. Critical Issues: Recent analyses using modern S-nitrosothiol detection techniques have revealed the mechanistic significance of S-nitrosylation to the pathophysiology of numerous cardiovascular diseases, including essential hypertension, pulmonary hypertension, ischemic heart disease, stroke, and congestive heart failure, among others. Future Directions: Despite enhanced insight into S-nitrosothiol biochemistry, translating these advances into beneficial pharmacotherapies for patients with cardiovascular diseases remains a primary as-yet unmet goal for investigators within the field. Antioxid. Redox Signal. 18, 270–287. PMID:22770551

  5. Model simulations of cardiovascular changes at the onset of moderate exercise in humans

    PubMed Central

    Elstad, Maja; Toska, Karin; Walløe, Lars

    2002-01-01

    We have tested whether the cardiovascular changes at the onset of exercise could be simulated only by an increase in the baroreflex set point and locally induced vasodilatation in the exercising muscles. The mathematical model consists of a heart, a linear elastic arterial reservoir and two parallel resistive vascular beds. The arterial baroreflex loop is modelled by three separate time domain processing objects, each with its own gain, time constant and delay. These are intended to simulate the action of a sympathetic signal to the peripheral vascular bed, a parasympathetic signal to the heart and a sympathetic signal to the heart. We used this model with previously published experimental data to estimate the unknown parameters in the reflex control loop. In all 10 subjects and in the global averaged response, the short-term cardiovascular responses were adequately simulated by using individual sets of parameters in the model. An increase in the baroreflex set point and locally induced vasodilatation in the exercising muscles can explain almost all of the cardiovascular changes in the recorded variables (mean arterial pressure, RR interval and stroke volume) at the onset of exercise. PMID:12205203

  6. Construction of an odds model of coronary heart disease using published information: the Cardiovascular Health Improvement Model (CHIME)

    PubMed Central

    Martin, Christopher J; Taylor, Paul; Potts, Henry WW

    2008-01-01

    Background There is a need for a new cardiovascular disease model that includes a wider range of relevant risk factors, in particular lifestyle factors, to aid targeting of interventions and improve population models of the impact of cardiovascular disease and preventive strategies. The model needs to be applicable to a wider population including different ethnic groups, different countries and to those with and without cardiovascular disease. This paper describes the construction of the Cardiovascular Health Improvement Model that aims to meet these requirements. Method An odds model is used. Information was taken from 2003 mortality statistics for England and Wales, the Health Survey for England 2003 and published data on relative risk in those with and without CVD and mean blood pressure values in hypertensives. The odds ratios used were taken from the INTERHEART study. Results A worked example is given calculating the 10-year coronary heart disease risk for a 57 year-old non-diabetic male with no personal or family history of cardiovascular disease, who smokes 30 cigarettes a day and has a systolic blood pressure of 137 mmHg, a total cholesterol (TC) of 6.2 mmol/l, a high density lipoprotein (HDL) of 1.3 mol/l, and a body mass index of 21. He neither drinks regularly nor exercises. He can give no reliable information about his mental health or fruit and vegetable intake. His 10-year risk of CHD death is 2.47%. Conclusion This paper demonstrates a method for developing a CHD risk model. Further improvements could be made to the model with additional information. The method is applicable to other causes of death. PMID:18976488

  7. Systolic time interval data acquisition system. Specialized cardiovascular studies

    NASA Technical Reports Server (NTRS)

    Baker, J. T.

    1976-01-01

    The development of a data acquisition system for noninvasive measurement of systolic time intervals is described. R-R interval from the ECG determines instantaneous heart rate prior to the beat to be measured. Total electromechanical systole (Q-S2) is measured from the onset of the ECG Q-wave to the onset of the second heart sound (S2). Ejection time (ET or LVET) is measured from the onset of carotid upstroke to the incisure. Pre-ejection period (PEP) is computed by subtracting ET from Q-S2. PEP/ET ratio is computed directly.

  8. A New Oxidative Stress Model, 2,2-Azobis(2-Amidinopropane) Dihydrochloride Induces Cardiovascular Damages in Chicken Embryo

    PubMed Central

    Li, Xiao-Di; Yi, Ruo-Nan; Wang, Xiao-Yu; Tsoi, Bun; Lee, Kenneth Ka Ho; Abe, Keiichi; Yang, Xuesong; Kurihara, Hiroshi

    2013-01-01

    It is now well established that the developing embryo is very sensitive to oxidative stress, which is a contributing factor to pregnancy-related disorders. However, little is known about the effects of reactive oxygen species (ROS) on the embryonic cardiovascular system due to a lack of appropriate ROS control method in the placenta. In this study, a small molecule called 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH), a free radicals generator, was used to study the effects of oxidative stress on the cardiovascular system during chick embryo development. When nine-day-old (stage HH 35) chick embryos were treated with different concentrations of AAPH inside the air chamber, it was established that the LD50 value for AAPH was 10 µmol/egg. At this concentration, AAPH was found to significantly reduce the density of blood vessel plexus that was developed in the chorioallantoic membrane (CAM) of HH 35 chick embryos. Impacts of AAPH on younger embryos were also examined and discovered that it inhibited the development of vascular plexus on yolk sac in HH 18 embryos. AAPH also dramatically repressed the development of blood islands in HH 3+ embryos. These results implied that AAPH-induced oxidative stress could impair the whole developmental processes associated with vasculogenesis and angiogenesis. Furthermore, we observed heart enlargement in the HH 40 embryo following AAPH treatment, where the left ventricle and interventricular septum were found to be thickened in a dose-dependent manner due to myocardiac cell hypertrophy. In conclusion, oxidative stress, induced by AAPH, could lead to damage of the cardiovascular system in the developing chick embryo. The current study also provided a new developmental model, as an alternative for animal and cell models, for testing small molecules and drugs that have anti-oxidative activities. PMID:23469224

  9. Minimizing Risk of Nephrogenic systemic fibrosis in Cardiovascular Magnetic Resonance

    PubMed Central

    2012-01-01

    Nephrogenic Systemic Fibrosis is a rare condition appearing only in patients with severe renal impairment or failure and presents with dermal lesions and involvement of internal organs. Although many cases are mild, an estimated 5 % have a progressive debilitating course. To date, there is no known effective treatment thus stressing the necessity of ample prevention measures. An association with the use of Gadolinium based contrast agents (GBCA) makes Nephrogenic Systemic Fibrosis a potential side effect of contrast enhanced magnetic resonance imaging and offers the opportunity for prevention by limiting use of gadolinium based contrast agents in renal failure patients. In itself toxic, Gadolinium is embedded into chelates that allow its safe use as a contrast agent. One NSF theory is that Gadolinium chelates distribute into the extracellular fluid compartment and set Gadolinium ions free, depending on multiple factors among which the duration of chelates exposure is directly related to the renal function. Major medical societies both in Europe and in North America have developed guidelines for the usage of GBCA. Since the establishment of these guidelines and the increased general awareness of this condition, the occurrence of NSF has been nearly eliminated. Giving an overview over the current knowledge of NSF pathobiochemistry, pathogenesis and treatment options this review focuses on the guidelines of the European Medicines Agency, the European Society of Urogenital Radiology, the FDA and the American College of Radiology from 2008 up to 2011 and the transfer of this knowledge into every day practice. PMID:22607376

  10. Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System

    PubMed Central

    Nagpure, B. V.; Bian, Jin-Song

    2016-01-01

    Historically acknowledged as toxic gases, hydrogen sulfide (H2S) and nitric oxide (NO) are now recognized as the predominant members of a new family of signaling molecules, “gasotransmitters” in mammals. While H2S is biosynthesized by three constitutively expressed enzymes (CBS, CSE, and 3-MST) from L-cysteine and homocysteine, NO is generated endogenously from L-arginine by the action of various isoforms of NOS. Both gases have been transpired as the key and independent regulators of many physiological functions in mammalian cardiovascular, nervous, gastrointestinal, respiratory, and immune systems. The analogy between these two gasotransmitters is evident not only from their paracrine mode of signaling, but also from the identical and/or shared signaling transduction pathways. With the plethora of research in the pathophysiological role of gasotransmitters in various systems, the existence of interplay between these gases is being widely accepted. Chemical interaction between NO and H2S may generate nitroxyl (HNO), which plays a specific effective role within the cardiovascular system. In this review article, we have attempted to provide current understanding of the individual and interactive roles of H2S and NO signaling in mammalian cardiovascular system, focusing particularly on heart contractility, cardioprotection, vascular tone, angiogenesis, and oxidative stress. PMID:26640616

  11. Effects of exercise training on cardiovascular adrenergic system

    PubMed Central

    Leosco, Dario; Parisi, Valentina; Femminella, Grazia D.; Formisano, Roberto; Petraglia, Laura; Allocca, Elena; Bonaduce, Domenico

    2013-01-01

    In heart failure (HF), exercise has been shown to modulate cardiac sympathetic hyperactivation which is one of the earliest features of neurohormonal derangement in this syndrome and correlates with adverse outcome. An important molecular alteration related to chronic sympathetic overstimulation in HF is represented by cardiac β-adrenergic receptor (β-AR) dysfunction. It has been demonstrated that exercise reverses β-AR dysfunction by restoring cardiac receptor membrane density and G-protein-dependent adenylyl cyclase activation. In particular, several evidence indicate that exercise reduces levels of cardiac G-protein coupled receptor kinase-2 (GRK2) which is known to be involved in both β1-AR and β2-AR dysregulation in HF. Similar alterations of β-AR system have been described also in the senescent heart. It has also been demonstrated that exercise training restores adrenal GRK2/α-2AR/catecholamine (CA) production axis. At vascular level, exercise shows a therapeutic effect on age-related impairment of vascular reactivity to adrenergic stimulation and restores β-AR-dependent vasodilatation by increasing vascular β-AR responsiveness and reducing endothelial GRK2 activity. Sympathetic nervous system overdrive is thought to account for >50% of all cases of hypertension and a lack of balance between parasympathetic and sympathetic modulation has been observed in hypertensive subjects. Non-pharmacological, lifestyle interventions have been associated with reductions in SNS overactivity and blood pressure in hypertension. Several evidence have highlighted the blood pressure lowering effects of aerobic endurance exercise in patients with hypertension and the significant reduction in sympathetic neural activity has been reported as one of the main mechanisms explaining the favorable effects of exercise on blood pressure control. PMID:24348425

  12. Numerical fatigue life assessment of cardiovascular stents: A two-scale plasticity-damage model

    NASA Astrophysics Data System (ADS)

    Santos, H. A. F. A.; Auricchio, F.; Conti, M.

    2013-07-01

    Cardiovascular disease has become a major global health care problem in the last decades. To tackle this problem, the use of cardiovascular stents has been considered a promising and effective approach. Numerical simulations to evaluate the in vivo behavior of stents are becoming more and more important to assess potential failures. As the material failure of a stent device has been often associated with fatigue issues, numerical approaches for fatigue life assessment of stents have gained special interest in the engineering community. Numerical fatigue life predictions can be used to modify the design and prevent failure without making and testing numerous physical devices, thus preventing from undesired fatigue failures. We present a numerical fatigue life model for the analysis of cardiovascular balloon-expandable stainless steel stents that can hopefully provide useful information either to be used for product improvement or for clinicians to make life-saving decisions. This model incorporates a two-scale continuum damage mechanics model and the so-called Soderberg fatigue failure criterion. We provide numerical results for both Palmaz-Schatz and Cypher stent designs and demonstrate that a good agreement is found between the numerical and the available experimental results.

  13. The Importance of Biological Sex and Estrogen in Rodent Models of Cardiovascular Health and Disease.

    PubMed

    Blenck, Christa L; Harvey, Pamela A; Reckelhoff, Jane F; Leinwand, Leslie A

    2016-04-15

    Nearly one-third of deaths in the United States are caused by cardiovascular disease (CVD) each year. In the past, CVD was thought to mainly affect men, leading to the exclusion of women and female animals from clinical studies and preclinical research. In light of sexual dimorphisms in CVD, a need exists to examine baseline cardiac differences in humans and the animals used to model CVD. In humans, sex differences are apparent at every level of cardiovascular physiology from action potential duration and mitochondrial energetics to cardiac myocyte and whole-heart contractile function. Biological sex is an important modifier of the development of CVD with younger women generally being protected, but this cardioprotection is lost later in life, suggesting a role for estrogen. Although endogenous estrogen is most likely a mediator of the observed functional differences in both health and disease, the signaling mechanisms involved are complex and are not yet fully understood. To investigate how sex modulates CVD development, animal models are essential tools and should be useful in the development of therapeutics. This review will focus on describing the cardiovascular sexual dimorphisms that exist both physiologically and in common animal models of CVD. PMID:27081111

  14. Cardiovascular Surgery Residency Program: Training Coronary Anastomosis Using the Arroyo Simulator and UNIFESP Models

    PubMed Central

    Maluf, Miguel Angel; Gomes, Walter José; Bras, Ademir Massarico; de Araújo, Thiago Cavalcante Vila Nova; Mota, André Lupp; Cardoso, Caio Cesar; Coutinho, Rafael Viana dos S.

    2015-01-01

    OBJECTIVE Engage the UNIFESP Cardiovascular Surgery residents in coronary anastomosis, assess their skills and certify results, using the Arroyo Anastomosis Simulator and UNIFESP surgical models. METHODS First to 6th year residents attended a weekly program of technical training in coronary anastomosis, using 4 simulation models: 1. Arroyo simulator; 2. Dummy with a plastic heart; 3. Dummy with a bovine heart; and 4. Dummy with a beating pig heart. The assessment test was comprised of 10 items, using a scale from 1 to 5 points in each of them, creating a global score of 50 points maximum. RESULTS The technical performance of the candidate showed improvement in all items, especially manual skill and technical progress, critical sense of the work performed, confidence in the procedure and reduction of the time needed to perform the anastomosis after 12 weeks practice. In response to the multiplicity of factors that currently influence the cardiovascular surgeon training, there have been combined efforts to reform the practices of surgical medical training. CONCLUSION 1 - The four models of simulators offer a considerable contribution to the field of cardiovascular surgery, improving the skill and dexterity of the surgeon in training. 2 - Residents have shown interest in training and cooperate in the development of innovative procedures for surgical medical training in the art. PMID:26735604

  15. Toxic Effects of Mercury on the Cardiovascular and Central Nervous Systems

    PubMed Central

    Fernandes Azevedo, Bruna; Barros Furieri, Lorena; Peçanha, Franck Maciel; Wiggers, Giulia Alessandra; Frizera Vassallo, Paula; Ronacher Simões, Maylla; Fiorim, Jonaina; Rossi de Batista, Priscila; Fioresi, Mirian; Rossoni, Luciana; Stefanon, Ivanita; Alonso, María Jesus; Salaices, Mercedes; Valentim Vassallo, Dalton

    2012-01-01

    Environmental contamination has exposed humans to various metal agents, including mercury. This exposure is more common than expected, and the health consequences of such exposure remain unclear. For many years, mercury was used in a wide variety of human activities, and now, exposure to this metal from both natural and artificial sources is significantly increasing. Many studies show that high exposure to mercury induces changes in the central nervous system, potentially resulting in irritability, fatigue, behavioral changes, tremors, headaches, hearing and cognitive loss, dysarthria, incoordination, hallucinations, and death. In the cardiovascular system, mercury induces hypertension in humans and animals that has wide-ranging consequences, including alterations in endothelial function. The results described in this paper indicate that mercury exposure, even at low doses, affects endothelial and cardiovascular function. As a result, the reference values defining the limits for the absence of danger should be reduced. PMID:22811600

  16. OCT imaging of the musculoskeletal and cardiovascular systems

    NASA Astrophysics Data System (ADS)

    Li, Xing D.; Stamper, Debra L.; Patel, Nirlep A.; Saunders, Kathleen; Plummer, Sam; Schenck, John; Rogowska, Ika; Fujimoto, James G.; Brezinski, Mark E.

    2002-07-01

    In this presentation, the application of optical coherence tomography (OCT) to the prevention of myocardial infarction and early identification of osteoarthritis is discussed. Myocardial infarction or a heart attack is the leading cause of death worldwide. It results from an acute loss of blood flow to a region of the heart resulting in death to that heart tissue. Most heart attacks are caused by small, thin walled lipid filled plaques which can not be detected by currently available imaging technologies. This paper outlines some of the advances demonstrating the potential of OCT for the identification of high risk plaque. Osteoarthritis is a major cause of mobility in the industrialized world. The hallmark of the disease is a degradation of articular cartilage. As new therapeutics have been shown to be effective in animal models, there effectiveness in humans remains unclear as there is no effective method for accurate monitoring changes in cartilage. In the second part of this manuscript, the effectiveness of OCT for monitoring articular cartilage is described.

  17. Physiology and pharmacology of the cardiovascular adrenergic system

    PubMed Central

    Lymperopoulos, Anastasios

    2013-01-01

    Heart failure (HF), the leading cause of death in the western world, ensues in response to cardiac injury or insult and represents the inability of the heart to adequately pump blood and maintain tissue perfusion. It is characterized by complex interactions of several neurohormonal mechanisms that get activated in the syndrome in order to try and sustain cardiac output in the face of decompensating function. The most prominent among these neurohormonal mechanisms is the adrenergic (or sympathetic) nervous system (ANS), whose activity and outflow are greatly elevated in HF. Acutely, provided that the heart still works properly, this activation of the ANS will promptly restore cardiac function according to the fundamental Frank-Starling law of cardiac function. However, if the cardiac insult persists over time, this law no longer applies and ANS will not be able to sustain cardiac function. This is called decompensated HF, and the hyperactive ANS will continue to “push” the heart to work at a level much higher than the cardiac muscle can handle. From that point on, ANS hyperactivity becomes a major problem in HF, conferring significant toxicity to the failing heart and markedly increasing its morbidity and mortality. The present review discusses the role of the ANS in cardiac physiology and in HF pathophysiology, the mechanisms of regulation of ANS activity and how they go awry in chronic HF, and, finally, the molecular alterations in heart physiology that occur in HF along with their pharmacological and therapeutic implications for the failing heart. PMID:24027534

  18. Nonlinear systems dynamics in cardiovascular physiology: The heart rate delay map and lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Hooker, John C.

    1990-01-01

    A preliminary study of the applicability of nonlinear dynamic systems analysis techniques to low body negative pressure (LBNP) studies. In particular, the applicability of the heart rate delay map is investigated. It is suggested that the heart rate delay map has potential as a supplemental tool in the assessment of subject performance in LBNP tests and possibly in the determination of susceptibility to cardiovascular deconditioning with spaceflight.

  19. An integrated mathematical model of the human cardiopulmonary system: model development.

    PubMed

    Albanese, Antonio; Cheng, Limei; Ursino, Mauro; Chbat, Nicolas W

    2016-04-01

    Several cardiovascular and pulmonary models have been proposed in the last few decades. However, very few have addressed the interactions between these two systems. Our group has developed an integrated cardiopulmonary model (CP Model) that mathematically describes the interactions between the cardiovascular and respiratory systems, along with their main short-term control mechanisms. The model has been compared with human and animal data taken from published literature. Due to the volume of the work, the paper is divided in two parts. The present paper is on model development and normophysiology, whereas the second is on the model's validation on hypoxic and hypercapnic conditions. The CP Model incorporates cardiovascular circulation, respiratory mechanics, tissue and alveolar gas exchange, as well as short-term neural control mechanisms acting on both the cardiovascular and the respiratory functions. The model is able to simulate physiological variables typically observed in adult humans under normal and pathological conditions and to explain the underlying mechanisms and dynamics. PMID:26683899

  20. The endothelin system as a therapeutic target in cardiovascular disease: great expectations or bleak house?

    PubMed Central

    Kirkby, N S; Hadoke, P W F; Bagnall, A J; Webb, D J

    2007-01-01

    There is considerable evidence that the potent vasoconstrictor endothelin-1 (ET-1) contributes to the pathogenesis of a variety of cardiovascular diseases. As such, pharmacological manipulation of the ET system might represent a promising therapeutic goal. Many clinical trials have assessed the potential of ET receptor antagonists in cardiovascular disease, the most positive of which have resulted in the licensing of the mixed ET receptor antagonist bosentan, and the selective ETA receptor antagonists, sitaxsentan and ambrisentan, for the treatment of pulmonary arterial hypertension (PAH). In contrast, despite encouraging data from in vitro and animal studies, outcomes in human heart failure have been disappointing, perhaps illustrating the risk of extrapolating preclinical work to man. Many further potential applications of these compounds, including resistant hypertension, chronic kidney disease, connective tissue disease and sub-arachnoid haemorrhage are currently being investigated in the clinic. Furthermore, experience from previous studies should enable improved trial design and scope remains for development of improved compounds and alternative therapeutic strategies. Although ET-converting enzyme inhibitors may represent one such alternative, there have been relatively few suitable compounds developed, and consequently, clinical experience with these agents remains extremely limited. Recent advances, together with an increased understanding of the biology of the ET system provided by improved experimental tools (including cell-specific transgenic deletion of ET receptors), should allow further targeting of clinical trials to diseases in which ET is involved and allow the therapeutic potential for targeting the ET system in cardiovascular disease to be fully realized. PMID:17965745

  1. The use of animal models in developing the discipline of cardiovascular tissue engineering: a review.

    PubMed

    Rashid, S Tawqeer; Salacinski, Henryk J; Hamilton, George; Seifalian, Alexander M

    2004-04-01

    Cardiovascular disease remains one of the major causes of death and disability in the Western world. Tissue engineering offers the prospect of being able to meet the demand for replacement of heart valves, vessels for coronary and lower limb bypass surgery and the generation of cardiac tissue for addition to the diseased heart. In order to test prospective tissue-engineered devices, these constructs must first be proven in animal models before receiving CE marking or FDA approval for a clinical trial. The choice of animal depends on the nature of the tissue-engineered construct being tested. Factors that need to be considered include technical requirements of implanting the construct, availability of the animal, cost and ethical considerations. In this paper, we review the history of animal studies in cardiovascular tissue engineering and the uses of animal tissue as sources for tissue engineering. PMID:14697864

  2. Nnuclear uptake and retention of a synthetic progestin in the cardiovascular system of the baboon

    SciTech Connect

    Sheridan, P.J.; McGill, H.C. Jr.

    1984-06-01

    It has long been known that there is a sexual dimorphism in the incidence of coronary heart disease. This observation, together with more recent reports of increased cardiovascular disease associated with the use of oral contraceptives, led to a search for steroid receptors in the cardiovascular system. In this study the nuclear uptake and retention of a synthetic progestin was examined in the cardiovascular system of the baboons. Long term oophorectomized baboons were primed with estradiol benzoate for 3 days before the experiment (50 micrograms/kg, im) and adrenalectomized 2 days before the experiment. On the day of the experiment, the animals were injected under anesthesia with 2.5 micrograms/kg BW (/sup 3/H)ORG 2058 (16 alpha-ethyl-21-hydroxy-19-nor-(6,7-/sup 3/H)pregn-4-ene-3,20-dione) or with (/sup 3/H) ORG 2058 plus a 1000-fold excess of unlabeled progesterone (control). One hour after the injection, the animals were rapidly exsanguinated, and parts of the cardiovascular system were removed and processed for autoradiography. Localization of the synthetic progestin was found in nuclei of between 25-75% of all smooth muscle cells of the media of all arteries examined and to a lesser extent in the nuclei of the fibroblasts and others cells of the adventitia. Localization of the synthetic progestin in the heart was limited to approximately 1% of the myocardial cells and less than 5% of interstitial cell nuclei. The pattern of localization found differs from that for estrogen and androgen and suggests the possible presence of estrogen-independent progesterone receptors in smooth muscle cells of the media of the aorta and coronary arteries.

  3. Improving the Prevention of Cardiovascular Disease in Primary Health Care: The Model for Prevention Study Protocol

    PubMed Central

    Davey, Rachel C; Cochrane, Thomas; Williams, Lauren T; Clancy, Tanya

    2014-01-01

    Background Cardiovascular disease (CVD) is the leading cause of death globally, and accounted for nearly 31% of all deaths in Australia in 2011. The primary health care sector is at the frontline for addressing CVD, however, an evidence-to-practice gap exists in CVD risk assessment and management. General practice plays a key role in CVD risk assessment and management, but this sector cannot provide ongoing lifestyle change support in isolation. Community-based lifestyle modification services and programs provided outside the general practice setting have a key role in supporting and sustaining health behavior change. Fostering linkages between the health sector and community-based lifestyle services, and creating sustainable systems that support these sectors is important. Objective The objective of the study Model for Prevention (MoFoP) is to take a case study approach to examine a CVD risk reduction intervention in primary health care, with the aim of identifying the key elements required for an effective and sustainable approach to coordinate CVD risk reduction across the health and community sectors. These elements will be used to consider a new systems-based model for the prevention of CVD that informs future practice. Methods The MoFoP study will use a mixed methods approach, comprising two complementary research elements: (1) a case study, and (2) a pre/post quasi-experimental design. The case study will consider the organizations and systems involved in a CVD risk reduction intervention as a single case. The pre/post experimental design will be used for HeartLink, the intervention being tested, where a single cohort of patients between 45 and 74 years of age (or between 35 and 74 years of age if Aboriginal or Torres Strait Islander) considered to be at high risk for a CVD event will be recruited through general practice, provided with enhanced usual care and additional health behavior change support. A range of quantitative and qualitative data will be collected. This will include individual health and well being data collected at baseline and again at 12 months for HeartLink participants, and systems related data collected over the period of the intervention to inform the case study. Results The intervention is currently underway, with results expected in late 2015. Conclusions Gaining a better understanding of CVD prevention in primary health care requires a research approach that can capture and express its complexity. The MoFoP study aims to identify the key elements for effective CVD prevention across the health and community sectors, and to develop a model to better inform policy and practice in this key health priority area for Australia. PMID:25008232

  4. Palm oil taxes and cardiovascular disease mortality in India: economic-epidemiologic model

    PubMed Central

    Babiarz, Kim S; Ebrahim, Shah; Vellakkal, Sukumar; Stuckler, David; Goldhaber-Fiebert, Jeremy D

    2013-01-01

    Objective To examine the potential effect of a tax on palm oil on hyperlipidemia and on mortality due to cardiovascular disease in India. Design Economic-epidemiologic model. Modeling methods A microsimulation model of mortality due to myocardial infarction and stroke among Indian populations was constructed, incorporating nationally representative data on systolic blood pressure, total cholesterol, tobacco smoking, diabetes, and cardiovascular event history, and stratified by age, sex, and urban/rural residence. Household expenditure data were used to estimate the change in consumption of palm oil following changes in oil price and the potential substitution of alternative oils that might occur after imposition of a tax. A 20% excise tax on palm oil purchases was simulated over the period 2014-23. Main outcome measures The model was used to project future mortality due to myocardial infarction and stroke, as well as the potential effect of a tax on food insecurity, accounting for the effect of increased food prices. Results A 20% tax on palm oil purchases would be expected to avert approximately 363 000 (95% confidence interval 247 000 to 479 000) deaths from myocardial infarctions and strokes over the period 2014-23 in India (1.3% reduction in cardiovascular deaths) if people do not substitute other oils for reduced palm oil consumption. Given estimates of substitution of palm oil with other oils following a 20% price increase for palm oil, the beneficial effects of increased polyunsaturated fat consumption would be expected to enhance the projected reduction in deaths to as much as 421 000 (256 000 to 586 000). The tax would be expected to benefit men more than women and urban populations more than rural populations, given differential consumption and cardiovascular risk. In a scenario incorporating the effect of taxation on overall food expenditures, the tax may increase food insecurity by <1%, resulting in 16 000 (95% confidence interval 12 000 to 22 000) deaths. Conclusions Curtailing palm oil intake through taxation may modestly reduce hyperlipidemia and cardiovascular mortality, but with potential distributional consequences differentially benefiting male and urban populations, as well as affecting food security. PMID:24149818

  5. Mechanosensitive Channels in Striated Muscle and the Cardiovascular System: Not Quite a Stretch Anymore

    PubMed Central

    Stiber, Jonathan A.; Seth, Malini; Rosenberg, Paul B.

    2013-01-01

    Stretch-activated or mechanosensitive channels transduce mechanical forces into ion fluxes across the cell membrane. These channels have been implicated in several aspects of cardiovascular physiology including regulation of blood pressure, vasoreactivity, and cardiac arrhythmias as well as the adverse remodeling associated with cardiac hypertrophy and heart failure. This review discusses mechanosensitive channels in skeletal muscle and the cardiovascular system and their role in disease pathogenesis. We describe the regulation of gating of mechanosensitive channels including direct mechanisms and indirect activation by signaling pathways, as well as the influence on activation of these channels by the underlying cytoskeleton and scaffolding proteins. We then focus on the role of transient receptor potential channels, several of which have been implicated as mechanosensitive channels, in the pathogenesis of adverse cardiac remodeling and as potential therapeutic targets in the treatment of heart failure. PMID:19597371

  6. Causes and Mechanisms of Intrauterine Hypoxia and Its Impact on the Fetal Cardiovascular System: A Review

    PubMed Central

    Hutter, Damian; Kingdom, John; Jaeggi, Edgar

    2010-01-01

    Until today the role of oxygen in the development of the fetus remains controversially discussed. It is still believed that lack of oxygen in utero might be responsible for some of the known congenital cardiovascular malformations. Over the last two decades detailed research has given us new insights and a better understanding of embryogenesis and fetal growth. But most importantly it has repeatedly demonstrated that oxygen only plays a minor role in the early intrauterine development. After organogenesis has taken place hypoxia becomes more important during the second and third trimester of pregnancy when fetal growth occurs. This review will briefly adress causes and mechanisms leading to intrauterine hypoxia and their impact on the fetal cardiovascular system. PMID:20981293

  7. Some preliminary observations on the effects of kola nut on the cardiovascular system.

    PubMed

    Agatha, M; Breckenridge, C; Soyemi, E A

    1978-11-01

    The prevalence of kola nut chewing and the effects attributed to it are briefly reviewed. Except for a generalisation that its effects are probably due to its caffeine content, no attempts have been made to quantify its specific actions. Preliminary observations on the cardiovascular system of the cat show that aqueous extracts of the nut evoke a dose dependent differential response - the 8 - 9% hypertensive effect of 0.01 ug - 1mg/ml doses contrasting with the 18--71% hypotensive response of 10--1000mgs/ml doses. Adrenergic receptor blockade showed no significant alteration of the response. With larger doses a bradycardia developed and cardiac arrythmias were observed as a terminal event. These results are compatible with the action of xanthines on the heart and peripheral vasculature. The possible role of the habitually chewed kola nut in the pathophysiology of cardiovascular disease and its implications have been briefly discussed. PMID:753053

  8. Cholinergic signal activated renin angiotensin system associated with cardiovascular changes in the ovine fetus

    PubMed Central

    Geng, Chunsong; Mao, Caiping; Wu, Lei; Cheng, Yu; Liu, Rulu; Chen, Bingxin; Chen, Ling; Zhang, Lubo; Xu, Zhice

    2010-01-01

    Aim Cholinergic regulation is important in the control of cardiovascular and endocrine responses. The mechanisms behind cardiovascular responses induced by cholinergic activation are explored by studying hormonal systems, including renin-angiotensin and vasopressin (VP). Results In chronically prepared fetal sheep, intravenous infusion of the cholinergic agonist carbachol increased fetal systolic, diastolic, and mean arterial pressure accompanied with bradycardia at near-term. Although intravenous administration of carbachol had no effect on plasma VP concentrations, this agonist increased angiotensin I and angiotensin II levels in fetal plasma. Fetal blood values, including sodium, osmolality, nitric oxide, hemoglobin, and hematocrit were unchanged by intravenous carbachol. Conclusion Cholinergic activation by carbachol controls fetal blood pressure and heart rate in utero. An over-activated fetal renin-angiotensin-system (RAS) is associated with changes in vascular pressure following intravenous administration of carbachol, indicating that the cholinergic stimulation-mediated hormonal mechanism in the fetus might play a critical role in the regulation of cardiovascular homeostasis. PMID:19921993

  9. Injected nanoparticles: the combination of experimental systems to assess cardiovascular adverse effects.

    PubMed

    Vlasova, Maria A; Tarasova, Olga S; Riikonen, Joakim; Raula, Janne; Lobach, Anatoly S; Borzykh, Anna A; Smirin, Boris V; Kauppinen, Esko I; Eletskii, Alexander V; Herzig, Karl-Heinz; Salonen, Jarno; Tavi, Pasi; Lehto, Vesa-Pekka; Järvinen, Kristiina

    2014-05-01

    When nanocarriers are used for drug delivery they can often achieve superior therapeutic outcomes over standard drug formulations. However, concerns about their adverse effects are growing due to the association between exposure to certain nanosized particles and cardiovascular events. Here we examine the impact of intravenously injected drug-free nanocarriers on the cardiovasculature at both the systemic and organ levels. We combine in vivo and in vitro methods to enable monitoring of hemodynamic parameters in conscious rats, assessments of the function of the vessels after sub-chronic systemic exposure to nanocarriers and evaluation of the direct effect of nanocarriers on vascular tone. We demonstrate that nanocarriers can decrease blood pressure and increase heart rate in vivo via various mechanisms. Depending on the type, nanocarriers induce the dilation of the resistance arteries and/or change the responses induced by vasoconstrictor or vasodilator drugs. No direct correlation between physicochemical properties and cardiovascular effects of nanoparticles was observed. The proposed combination of methods empowers the studies of cardiovascular adverse effects of the nanocarriers. PMID:24530427

  10. Magnetic resonance imaging of the cardiovascular system: present state of the art and future potential

    SciTech Connect

    Jacobson, H.G.

    1988-01-08

    State-of-the-art magnetic resonance imaging (MRI) generates high-resolution images of the cardiovascular system. Conventional MRI techniques provide images in six to ten minutes per tomographic slice. New strategies have substantially improved the speed of imaging. The technology is relatively expensive, and its cost-effectiveness remains to be defined in relation to other effective, less expensive, and noninvasive technologies, such as echocardiography and nuclear medicine. The ultimate role of MRI will depend on several factors, including the development of specific applications such as (1) noninvasive angiography, especially of the coronary arteries;(2) noninvasive, high-resolution assessment of regional myocardial blood flow distribution (e.g., using paramagnetic contrast agents); (3) characterization of myocardial diseases using proton-relaxation property changes; and (4) evaluation of in vivo myocardial biochemistry. The three-dimensional imaging capability and the ability to image cardiovascular structures without contrast material give MRI a potential advantage over existing noninvasive diagnostic imaging techniques. This report analyzes current applications of MRI to the cardiovascular system and speculates on their future.

  11. Hemodynamic effects of various support modes of continuous flow LVADs on the cardiovascular system: A numerical study

    PubMed Central

    Song, Zhiming; Gu, Kaiyun; Gao, Bin; Wan, Feng; Chang, Yu; Zeng, Yi

    2014-01-01

    Background The aim of this study was to determine the hemodynamic effects of various support modes of continuous flow left ventricular assist devices (CF-LVADs) on the cardiovascular system using a numerical cardiovascular system model. Material/Methods Three support modes were selected for controlling the CF-LVAD: constant flow mode, constant speed mode, and constant pressure head mode of CF-LVAD. The CF-LVAD is established between the left ventricular apex and the ascending aorta, and was incorporated into the numerical model. Various parameters were evaluated, including the blood assist index (BAI), the left ventricular external work (LVEW), the energy of blood flow (EBF), pulsatility index (PI), and surplus hemodynamic energy (SHE). Results The results show that the constant flow mode, when compared to the constant speed mode and the constant pressure head mode, increases LVEW by 31% and 14%, and EBF by 21% and 15%, respectively, indicating that this mode achieved the best ventricular unloading among the 3 support modes. As BAI is increased, PI and SHE are gradually decreased, whereas PI of the constant pressure head reaches the maximum value. Conclusions The study demonstrates that the continuous flow control mode of the CF-LVAD may achieve the highest ventricular unloading. In contrast, the constant rotational speed mode permits the optimal blood perfusion. Finally, the constant pressure head strategy, permitting optimal pulsatility, should optimize the vascular function. PMID:24793178

  12. Cardiovascular system

    MedlinePlus Videos and Cool Tools

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  13. Cardiovascular prevention model from Kenyan slums to migrants in the Netherlands.

    PubMed

    van de Vijver, Steven; Oti, Samuel; Moll van Charante, Eric; Allender, Steven; Foster, Charlie; Lange, Joep; Oldenburg, Brian; Kyobutungi, Catherine; Agyemang, Charles

    2015-01-01

    Cardiovascular diseases (CVD) are the main cause of morbidity and mortality worldwide. As prevention and treatment of CVD often requires active screening and lifelong follow up it is a challenge for health systems both in high-income and low and middle-income countries to deliver adequate care to those in need, with efficient use of resources.We developed a health service model for primary prevention of CVD suitable for implementation in the Nairobi slums, based on best practices from public health and the private sectors. The model consists of four key intervention elements focusing on increasing awareness, incentives for promoting access to screening and treatment, and improvement of long-term adherence to prescribed medications. More than 5,000 slum dwellers aged ≥35 years and above have been screened in the study resulting in more than 1000 diagnosed with hypertension and referred to the clinic.Some marginalized groups in high-income countries like African migrants in the Netherlands also have low rates of awareness, treatment and control of hypertension as the slum population in Nairobi. The parallel between both groups is that they have a combination of risky lifestyle, are prone to chronic diseases such as hypertension, have limited knowledge about hypertension and its complications, and a tendency to stay away from clinics partly due to cultural beliefs in alternative forms of treatment, and lack of trust in health providers. Based on these similarities it was suggested by several policymakers that the model from Nairobi can be applied to other vulnerable populations such as African migrants in high-income countries. The model can be contextualized to the local situation by adapting the key steps of the model to the local settings.The involvement and support of African communities' infrastructures and health care staff is crucial, and the most important enabler for successful implementation of the model in migrant communities in high-income countries. Once these stakeholders have expressed their interest, the impact of the adapted intervention can be measured through an implementation research approach including collection of costs from health care providers' perspective and health effects in the target population, similar to the study design for Nairobi. PMID:25890177

  14. High-Dose Menaquinone-7 Supplementation Reduces Cardiovascular Calcification in a Murine Model of Extraosseous Calcification

    PubMed Central

    Scheiber, Daniel; Veulemans, Verena; Horn, Patrick; Chatrou, Martijn L.; Potthoff, Sebastian A.; Kelm, Malte; Schurgers, Leon J.; Westenfeld, Ralf

    2015-01-01

    Cardiovascular calcification is prevalent in the aging population and in patients with chronic kidney disease (CKD) and diabetes mellitus, giving rise to substantial morbidity and mortality. Vitamin K-dependent matrix Gla-protein (MGP) is an important inhibitor of calcification. The aim of this study was to evaluate the impact of high-dose menaquinone-7 (MK-7) supplementation (100 µg/g diet) on the development of extraosseous calcification in a murine model. Calcification was induced by 5/6 nephrectomy combined with high phosphate diet in rats. Sham operated animals served as controls. Animals received high or low MK-7 diets for 12 weeks. We assessed vital parameters, serum chemistry, creatinine clearance, and cardiac function. CKD provoked increased aortic (1.3 fold; p < 0.05) and myocardial (2.4 fold; p < 0.05) calcification in line with increased alkaline phosphatase levels (2.2 fold; p < 0.01). MK-7 supplementation inhibited cardiovascular calcification and decreased aortic alkaline phosphatase tissue concentrations. Furthermore, MK-7 supplementation increased aortic MGP messenger ribonucleic acid (mRNA) expression (10-fold; p < 0.05). CKD-induced arterial hypertension with secondary myocardial hypertrophy and increased elastic fiber breaking points in the arterial tunica media did not change with MK-7 supplementation. Our results show that high-dose MK-7 supplementation inhibits the development of cardiovascular calcification. The protective effect of MK-7 may be related to the inhibition of secondary mineralization of damaged vascular structures. PMID:26295257

  15. High-Dose Menaquinone-7 Supplementation Reduces Cardiovascular Calcification in a Murine Model of Extraosseous Calcification.

    PubMed

    Scheiber, Daniel; Veulemans, Verena; Horn, Patrick; Chatrou, Martijn L; Potthoff, Sebastian A; Kelm, Malte; Schurgers, Leon J; Westenfeld, Ralf

    2015-08-01

    Cardiovascular calcification is prevalent in the aging population and in patients with chronic kidney disease (CKD) and diabetes mellitus, giving rise to substantial morbidity and mortality. Vitamin K-dependent matrix Gla-protein (MGP) is an important inhibitor of calcification. The aim of this study was to evaluate the impact of high-dose menaquinone-7 (MK-7) supplementation (100 µg/g diet) on the development of extraosseous calcification in a murine model. Calcification was induced by 5/6 nephrectomy combined with high phosphate diet in rats. Sham operated animals served as controls. Animals received high or low MK-7 diets for 12 weeks. We assessed vital parameters, serum chemistry, creatinine clearance, and cardiac function. CKD provoked increased aortic (1.3 fold; p < 0.05) and myocardial (2.4 fold; p < 0.05) calcification in line with increased alkaline phosphatase levels (2.2 fold; p < 0.01). MK-7 supplementation inhibited cardiovascular calcification and decreased aortic alkaline phosphatase tissue concentrations. Furthermore, MK-7 supplementation increased aortic MGP messenger ribonucleic acid (mRNA) expression (10-fold; p < 0.05). CKD-induced arterial hypertension with secondary myocardial hypertrophy and increased elastic fiber breaking points in the arterial tunica media did not change with MK-7 supplementation. Our results show that high-dose MK-7 supplementation inhibits the development of cardiovascular calcification. The protective effect of MK-7 may be related to the inhibition of secondary mineralization of damaged vascular structures. PMID:26295257

  16. Effects of cyclooxygenase inhibition on cardiovascular function in a hypercholesterolemic swine model of chronic ischemia

    PubMed Central

    Chu, Louis M.; Robich, Michael P.; Bianchi, Cesario; Feng, Jun; Liu, Yuhong; Xu, Shu-Hua; Burgess, Thomas

    2012-01-01

    The cardiovascular effects of cyclooxygenase (COX) inhibition remain controversial, especially in the setting of cardiovascular comorbidities. We examined the effects of nonselective and selective COX inhibition on cardiovascular function in a hypercholesterolemic swine model of chronic ischemia. Twenty-four intact male Yorkshire swine underwent left circumflex ameroid constrictor placement and were subsequently given either no drug (HCC; n = 8), a nonselective COX inhibitor (440 mg/day naproxen; HCNS; n = 8), or a selective COX-2 inhibitor (200 mg/day celecoxib; HCCX; n = 8). After 7 wk, myocardial functional was measured and myocardium from the nonischemic ventricle and ischemic area-at-risk (AAR) were analyzed. Regional function as measured by segmental shortening was improved in the AAR of HCCX compared with HCC. There was no significant difference in perfusion to the nonischemic ventricle between groups, but myocardial perfusion in the AAR was significantly improved in the HCCX group compared with controls at rest and during pacing. Endothelium-dependent microvessel relaxation was diminished by ischemia in HCC animals, but both naproxen and celecoxib improved vessel relaxation in the AAR compared with controls, and also decreased the vasoconstrictive response to serotonin. Thromboxane levels in the AAR were decreased in both HCNS and HCCX compared with HCC, whereas prostacyclin levels were decreased only in HCNS, corresponding to a decrease in prostacyclin synthase expression. Chronic ischemia increased apoptosis in Troponin T negative cells and intramyocardial fibrosis, both of which were reduced by celecoxib administration in the AAR. Capillary density was decreased in both the HCNS and HCCX groups. Protein oxidative stress was decreased in both HCNS and HCCX, whereas lipid oxidative stress was decreased only in the HCCX group. Thus nonselective and especially selective COX inhibition may have beneficial myocardial effects in the setting of hypercholesterolemia and chronic ischemia. Whether these effects modulate cardiovascular risk in patients taking these drugs remains to be seen, but evidence to date suggests that they do not. PMID:22037194

  17. [Cardiovascular medicine in the German diagnosis-related group--(G-DRG) system 2005].

    PubMed

    Fürstenberg, T; Bunzemeier, H; Roeder, N; Reinecke, H

    2005-05-01

    The German diagnosis-related Group (G-DRG) System has recently been published in its third version. From 2005 on, this system will be the definite measure for the budgets of nearly all german hospitals. The preliminary phase with no budget reduction or redistribution being made and in which an inappropriate classification system had no negative impact on reimbursement has, thus, come to an end. At present, many hospitals are struggling in an economic competition about the independence or maintenance of the hospital or several sub-departments. The changes in the classification system with regard to a marked increase in the number of G DRGs, a modified grouping-logic, more properly determined reductions and extra charges for low and high outlier as well as the introduction of further additional charges contribute thereby to a better covering of services and treatments of cardiovascular patients. However, while many of the known problems have been eliminated, there are still weaknesses in the G-DRG System even concerning cardiovascular medicine. The G-DRG System has to be adapted continuously with consultation of the clinical expertise of the respective medical societies. The most important new aspects and changes in the G-DRG System 2005 and the accompanied execution regulations are explained with special view on cardiology. PMID:15868366

  18. Activation of the central histaminergic system mediates arachidonic-acid-induced cardiovascular effects.

    PubMed

    Altinbas, Burcin; Topuz, Bora Burak; İlhan, Tuncay; Yilmaz, Mustafa Sertac; Erdost, Hatice; Yalcin, Murat

    2014-08-01

    The aim of this study was to explain the involvement of the central histaminergic system in arachidonic acid (AA)-induced cardiovascular effects in normotensive rats using hemodynamic, immunohistochemistry, and microdialysis studies. Intracerebroventricularly (i.c.v.) administered AA (0.25, 0.5, and 1.0 μmol) induced dose- and time-dependent increases in mean arterial pressure and decreased heart rate in conscious normotensive Sprague-Dawley rats. Central injection of AA (0.5 μmol) also increased posterior hypothalamic extracellular histamine levels and produced strong COX-1 but not COX-2 immunoreactivity in the posterior hypothalamus of rats. Moreover, the cardiovascular effects and COX-1 immunoreactivity in the posterior hypothalamus induced by AA (0.5 μmol; i.c.v.) were almost completely blocked by the H2 receptor antagonist ranitidine (50 and 100 nmol; i.c.v.) and partially blocked by the H1 receptor blocker chlorpheniramine (100 nmol; i.c.v.) and the H3-H4 receptor antagonist thioperamide (50 and 100 nmol; i.c.v.). In conclusion, these results indicate that centrally administered AA induces pressor and bradycardic responses in conscious rats. Moreover, we suggest that AA may activate histaminergic neurons and increase extracellular histamine levels, particularly in the posterior hypothalamus. Acting as a neurotransmitter, histamine is potentially involved in AA-induced cardiovascular effects under normotensive conditions. PMID:25065747

  19. Recent insights and therapeutic perspectives of angiotensin-(1-9) in the cardiovascular system.

    PubMed

    Ocaranza, Maria Paz; Michea, Luis; Chiong, Mario; Lagos, Carlos F; Lavandero, Sergio; Jalil, Jorge E

    2014-11-01

    Chronic RAS (renin-angiotensin system) activation by both AngII (angiotensin II) and aldosterone leads to hypertension and perpetuates a cascade of pro-hypertrophic, pro-inflammatory, pro-thrombotic and atherogenic effects associated with cardiovascular damage. In 2000, a new pathway consisting of ACE2 (angiotensin-converting enzyme2), Ang-(1-9) [angiotensin-(1-9)], Ang-(1-7) [angiotensin-(1-7)] and the Mas receptor was discovered. Activation of this novel pathway stimulates vasodilation, anti-hypertrophy and anti-hyperplasia. For some time, studies have focused mainly on ACE2, Ang-(1-7) and the Mas receptor, and their biological properties that counterbalance the ACE/AngII/AT1R (angiotensin type 1 receptor) axis. No previous information about Ang-(1-9) suggested that this peptide had biological properties. However, recent data suggest that Ang-(1-9) protects the heart and blood vessels (and possibly the kidney) from adverse cardiovascular remodelling in patients with hypertension and/or heart failure. These beneficial effects are not modified by the Mas receptor antagonist A779 [an Ang-(1-7) receptor blocker], but they are abolished by the AT2R (angiotensin type 2 receptor) antagonist PD123319. Current information suggests that the beneficial effects of Ang-(1-9) are mediated via the AT2R. In the present review, we summarize the biological effects of the novel vasoactive peptide Ang-(1-9), providing new evidence of its cardiovascular-protective activity. We also discuss the potential mechanism by which this peptide prevents and ameliorates the cardiovascular damage induced by RAS activation. PMID:25029123

  20. [The cardiovascular system function of the cosmonauts of the 6th prime expedition on the Mir station].

    PubMed

    Poliakov, V V; Anashkin, O D; Alferova, I V; Turchaninova, V F; Golubchikova, Z A; Poliakova, A P; Liamin, V R; Turbasov, V D; Nalizhity?, V M; Kulev, A P

    1992-01-01

    Medical results of inflight cardiovascular measurements made in the 6th prime crew at rest and during provocative graded bicycle exercises and LBNP tests are presented. The methods of electrocardiography, tetrapolar rheography, kinetocardiography, arteriovenous pulsography and tacho-oscillography have been used to examine the cosmonauts. Together with regular cardiovascular changes typical of microgravity effect the individual peculiarities of developing the control mechanisms are noted. Thus in one of the cosmonauts a number of symptoms responsible for a decreased venous return. As a whole the functional state of the cardiovascular system on all flight stages was characterized by a sufficiently high physiological level. PMID:1297492

  1. Cardiovascular modeling in pulmonary arterial hypertension: focus on mechanisms and treatment of right heart failure using the CircAdapt model.

    PubMed

    Lumens, Joost; Delhaas, Tammo

    2012-09-15

    In recent years, increased understanding of cardiovascular system dynamics has led to the development of mathematical models of the heart and circulation. Models that enable realistic simulation of ventricular mechanics and interactions under a range of conditions have the potential to provide an ideal method with which to investigate the effects of pulmonary arterial hypertension and its treatment on cardiac mechanics and hemodynamics. Such mathematical models have the potential to contribute to a personalized, patient-specific treatment approach and allow more objective diagnostic decision-making, patient monitoring, and assessment of treatment outcome. This review discusses the development of mathematical models of the heart and circulation, with particular reference to the closed-loop CircAdapt model, and how the model performs under both normal and pathophysiological (pulmonary hypertensive) conditions. PMID:22921031

  2. Methods for establishing a surveillance system for cardiovascular diseases in Indian industrial populations.

    PubMed Central

    Reddy, K. S.; Prabhakaran, D.; Chaturvedi, V.; Jeemon, P.; Thankappan, K. R.; Ramakrishnan, L.; Mohan, B. V. M.; Pandav, C. S.; Ahmed, F. U.; Joshi, P. P.; Meera, R.; Amin, R. B.; Ahuja, R. C.; Das, M. S.; Jaison, T. M.

    2006-01-01

    OBJECTIVE: To establish a surveillance network for cardiovascular diseases (CVD) risk factors in industrial settings and estimate the risk factor burden using standardized tools. METHODS: We conducted a baseline cross-sectional survey (as part of a CVD surveillance programme) of industrial populations from 10 companies across India, situated in close proximity to medical colleges that served as study centres. The study subjects were employees (selected by age and sex stratified random sampling) and their family members. Information on behavioural, clinical and biochemical determinants was obtained through standardized methods (questionnaires, clinical measurements and biochemical analysis). Data collation and analyses were done at the national coordinating centre. FINDINGS: We report the prevalence of CVD risk factors among individuals aged 20-69 years (n = 19 973 for the questionnaire survey, n = 10 442 for biochemical investigations); mean age was 40 years. The overall prevalence of most risk factors was high, with 50.9% of men and 51.9% of women being overweight, central obesity was observed among 30.9% of men and 32.8% of women, and 40.2% of men and 14.9% of women reported current tobacco use. Self-reported prevalence of diabetes (5.3%) and hypertension (10.9%) was lower than when measured clinically and biochemically (10.1% and 27.7%, respectively). There was marked heterogeneity in the prevalence of risk factors among the study centres. CONCLUSION: There is a high burden of CVD risk factors among industrial populations across India. The surveillance system can be used as a model for replication in India as well as other developing countries. PMID:16799730

  3. Development of Diagnostic Reference Levels Using a Real-Time Radiation Dose Monitoring System at a Cardiovascular Center in Korea.

    PubMed

    Kim, Jungsu; Seo, Deoknam; Choi, Inseok; Nam, Sora; Yoon, Yongsu; Kim, Hyunji; Her, Jae; Han, Seonggyu; Kwon, Soonmu; Park, Hunsik; Yang, Dongheon; Kim, Jungmin

    2015-12-01

    Digital cardiovascular angiography accounts for a major portion of the radiation dose among the examinations performed at cardiovascular centres. However, dose-related information is neither monitored nor recorded systemically. This report concerns the construction of a radiation dose monitoring system based on digital imaging and communications in medicine (DICOM) data and its use at the cardiovascular centre of the University Hospitals in Korea. The dose information was analysed according to DICOM standards for a series of procedures, and the formulation of diagnostic reference levels (DRLs) at our cardiovascular centre represents the first of its kind in Korea. We determined a dose area product (DAP) DRL for coronary angiography of 75.6 Gy cm(2) and a fluoroscopic time DRL of 318.0 s. The DAP DRL for percutaneous transluminal coronary intervention was 213.3 Gy cm(2), and the DRL for fluoroscopic time was 1207.5 s. PMID:25700616

  4. Matching index of refraction using a diethyl phthalate/ethanol solution for in vitro cardiovascular models

    NASA Astrophysics Data System (ADS)

    Miller, P.; Danielson, K.; Moody, G.; Slifka, A.; Drexler, E.; Hertzberg, J.

    2006-09-01

    Experiments studying cardiovascular geometries require a working fluid that matches the high index of refraction of glass and silicone, has a low viscosity, and is safe and inexpensive. A good candidate working fluid is diethyl phthalate (DEP), diluted with ethanol. Measurements were made of index of refraction and viscosity of varied dilutions at a range of temperatures, and empirical models are proposed. Material compatibility tests showed that only specific formulations of ABS, acrylic, vinyl and PVC are compatible. A silicone elastomer additionally tested negative for change in compliance with DEP exposure.

  5. Integrated Metabolomics and Genomics: Systems Approaches to Biomarkers and Mechanisms of Cardiovascular Disease

    PubMed Central

    Shah, Svati H.; Newgard, Christopher B.

    2015-01-01

    The genetic architecture underlying the heritability of cardiovascular disease (CVD) is incompletely understood. Metabolomics is an emerging technology platform that has shown early success in identifying biomarkers and mechanisms of common, chronic diseases. Integration of metabolomics, genetics and other ‘omics’ platforms in a systems biology approach holds potential for elucidating novel genetic markers and mechanisms for CVD. We review important studies that have utilized metabolomic profiling in cardiometabolic diseases, approaches for integrating metabolomics with genetics and other molecular profiling platforms, and key studies showing the potential for such studies in deciphering CVD genetics, biomarkers and mechanisms. PMID:25901039

  6. Study of nanosensor systems for hypertension associated cerebrovascular and cardiovascular disorders

    NASA Astrophysics Data System (ADS)

    Ramasamy, Mouli; Varadan, Vijay K.

    2015-04-01

    Hypertension and hypertension associated cerebrovascular and cardiovascular diseases are on a rise. At-least 970 million people in the world and Seventy percent of the American adults are affected by high blood pressure, also known as hypertension. Even though blood pressure monitoring systems are readily available, the number of people being affected has been increasing. Most of the blood pressure monitoring systems require cumbersome approaches. Even the noninvasive techniques have not lowered the number of people affected nor did at-least increase the user base of these systems. Uncontrolled or untreated hypertension may lead to various cerebrovascular disorders including stroke, hypertensive crisis, lacunar infarcts intracerebral damage, microaneurysm, and cardiovascular disorders including heart failure, myocardial infraction, and ischemic heart disease. Hypertension is rated as the one of the most important causes of premature death in spite of the technical advances in biomedical technology. This paper briefs a review of the widely adopted blood pressure monitoring methods, research techniques, and finally, proposes a concept of implementing nanosensors and wireless communication for real time non-invasive blood pressure monitoring.

  7. Space Weather and the State of Cardiovascular System of a Healthy Human Being

    NASA Astrophysics Data System (ADS)

    Samsonov, S. N.; Manykina, V. I.; Krymsky, G. F.; Petrova, P. G.; Palshina, A. M.; Vishnevsky, V. V.

    The term "space weather" characterizes a state of the near-Earth environmental space. An organism of human being represents an open system so the change of conditions in the environment including the near-Earth environmental space influences the health state of a human being.In recent years many works devoted to the effect of space weather on the life on the Earth, and the degree of such effect has been represented from a zero-order up to apocalypse. To reveal a real effect of space weather on the health of human being the international Russian- Ukrainian experiment "Geliomed" is carried out since 2005 (http://geliomed.immsp.kiev.ua) [Vishnevsky et al., 2009]. The analysis of observational set of data has allowed to show a synchronism and globality of such effect (simultaneous manifestation of space weather parameters in a state of cardiovascular system of volunteer groups removed from each other at a distance over 6000 km). The response of volunteer' cardiovascular system to the changes of space weather parameters were observed even at insignificant values of the Earth's geomagnetic field. But even at very considerable disturbances of space weather parameters a human being healthy did not feel painful symptoms though measurements of objective physiological indices showed their changes.

  8. Reproduction of continuous flow left ventricular assist device experimental data by means of a hybrid cardiovascular model with baroreflex control.

    PubMed

    Fresiello, Libera; Zieliński, Krzysztof; Jacobs, Steven; Di Molfetta, Arianna; Pałko, Krzysztof Jakub; Bernini, Fabio; Martin, Michael; Claus, Piet; Ferrari, Gianfranco; Trivella, Maria Giovanna; Górczyńska, Krystyna; Darowski, Marek; Meyns, Bart; Kozarski, Maciej

    2014-06-01

    Long-term mechanical circulatory assistance opened new problems in ventricular assist device-patient interaction, especially in relation to autonomic controls. Modeling studies, based on adequate models, could be a feasible approach of investigation. The aim of this work is the exploitation of a hybrid (hydronumerical) cardiovascular simulator to reproduce and analyze in vivo experimental data acquired during a continuous flow left ventricular assistance. The hybrid cardiovascular simulator embeds three submodels: a computational cardiovascular submodel, a computational baroreflex submodel, and a hydronumerical interface submodel. The last one comprises two impedance transformers playing the role of physical interfaces able to provide a hydraulic connection with specific cardiovascular sites (in this article, the left atrium and the ascending/descending aorta). The impedance transformers are used to connect a continuous flow pump for partial left ventricular support (Synergy Micropump, CircuLite, Inc., Saddlebrooke, NJ, USA) to the hybrid cardiovascular simulator. Data collected from five animals in physiological, pathological, and assisted conditions were reproduced using the hybrid cardiovascular simulator. All parameters useful to characterize and tune the hybrid cardiovascular simulator to a specific hemodynamic condition were extracted from experimental data. Results show that the simulator is able to reproduce animal-specific hemodynamic status both in physiological and pathological conditions, to reproduce cardiovascular left ventricular assist device (LVAD) interaction and the progressive unloading of the left ventricle for different pump speeds, and to investigate the effects of the LVAD on baroreflex activity. Results in chronic heart failure conditions show that an increment of LVAD speed from 20 000 to 22 000 rpm provokes a decrement of left ventricular flow of 35% (from 2 to 1.3 L/min). Thanks to its flexibility and modular structure, the simulator is a platform potentially useful to test different assist devices, thus providing clinicians additional information about LVAD therapy strategy. PMID:24117988

  9. Model-based parameter estimation using cardiovascular response to orthostatic stress

    NASA Technical Reports Server (NTRS)

    Heldt, T.; Shim, E. B.; Kamm, R. D.; Mark, R. G.

    2001-01-01

    This paper presents a cardiovascular model that is capable of simulating the short-term (< or approximately equal to 3 min) transient hemodynamic response to gravitational stress and a gradient-based optimization method that allows for the automated estimation of model parameters from simulated or experimental data. We perform a sensitivity analysis of the transient heart rate response to determine which parameters of the model impact the heart rate dynamics significantly. We subsequently include only those parameters in the estimation routine that impact the transient heart rate dynamics substantially. We apply the estimation algorithm to both simulated and real data and showed that restriction to the 20 most important parameters does not impair our ability to match the data.

  10. Cardiovascular Dysfunction Following Burn Injury: What We Have Learned from Rat and Mouse Models.

    PubMed

    Guillory, Ashley N; Clayton, Robert P; Herndon, David N; Finnerty, Celeste C

    2016-01-01

    Severe burn profoundly affects organs both proximal and distal to the actual burn site. Cardiovascular dysfunction is a well-documented phenomenon that increases morbidity and mortality following a massive thermal trauma. Beginning immediately post-burn, during the ebb phase, cardiac function is severely depressed. By 48 h post-injury, cardiac function rebounds and the post-burn myocardium becomes tachycardic and hyperinflammatory. While current clinical trials are investigating a variety of drugs targeted at reducing aspects of the post-burn hypermetabolic response such as heart rate and cardiac work, there is still a paucity of knowledge regarding the underlying mechanisms that induce cardiac dysfunction in the severely burned. There are many animal models of burn injury, from rodents, to sheep or swine, but the majority of burn related cardiovascular investigations have occurred in rat and mouse models. This literature review consolidates the data supporting the prevalent role that β-adrenergic receptors play in mediating post-burn cardiac dysfunction and the idea that pharmacological modulation of this receptor family is a viable therapeutic target for resolving burn-induced cardiac deficits. PMID:26729111

  11. Cardiovascular Dysfunction Following Burn Injury: What We Have Learned from Rat and Mouse Models

    PubMed Central

    Guillory, Ashley N.; Clayton, Robert P.; Herndon, David N.; Finnerty, Celeste C.

    2016-01-01

    Severe burn profoundly affects organs both proximal and distal to the actual burn site. Cardiovascular dysfunction is a well-documented phenomenon that increases morbidity and mortality following a massive thermal trauma. Beginning immediately post-burn, during the ebb phase, cardiac function is severely depressed. By 48 h post-injury, cardiac function rebounds and the post-burn myocardium becomes tachycardic and hyperinflammatory. While current clinical trials are investigating a variety of drugs targeted at reducing aspects of the post-burn hypermetabolic response such as heart rate and cardiac work, there is still a paucity of knowledge regarding the underlying mechanisms that induce cardiac dysfunction in the severely burned. There are many animal models of burn injury, from rodents, to sheep or swine, but the majority of burn related cardiovascular investigations have occurred in rat and mouse models. This literature review consolidates the data supporting the prevalent role that β-adrenergic receptors play in mediating post-burn cardiac dysfunction and the idea that pharmacological modulation of this receptor family is a viable therapeutic target for resolving burn-induced cardiac deficits. PMID:26729111

  12. The cardiovascular effects of salidroside in the Goto-Kakizaki diabetic rat model.

    PubMed

    Alameddine, A; Fajloun, Z; Bourreau, J; Gauquelin-Koch, G; Yuan, M; Gauguier, D; Derbre, S; Ayer, A; Custaud, M A; Navasiolava, N

    2015-04-01

    Many factors, including hyperglycemia, hypertension, obesity, dyslipidemia, and a sedentary lifestyle, contribute to a high prevalence of cardiovascular disease. Specific vascular impairment treatments in the context of diabetes and vascular risk need to be improved. Salidroside is the primary active component of Rhodiola rosea and has documented antioxidative, cardioprotective, and vasculoprotective properties. The aim of this study was to test the hypothesis that salidroside has protective effects against hyperglycemia, hypertension, and vasodilation impairment in the Goto-Kakizaki (GK) rat model of diabetes. We evaluated cardiovascular parameters (e.g., daytime/nighttime systolic and diastolic blood pressure, heart rate, and activity), metabolic parameters (e.g., body weight, food and water consumption, serum fructosamine level, glucose tolerance), eNOS / phospho-eNOS expression level and in vitro vascular reactivity of aorta and second-order mesenteric arteries in Wistar-Kyoto (control) and GK (diabetic) rats treated with salidroside (40 mg/kg) or placebo (water) for 5 weeks. GK rats showed hypertension, marked glucose intolerance, and impaired endothelium-dependent and endothelium-independent vasodilation capacity. Salidroside showed beneficial effects on endothelial and non-endothelial vasodilation and likely acts on the endothelium and smooth muscle cells through the soluble guanylyl cyclase pathway. Despite its vascular effects, salidroside had no effect on blood pressure and heart rate in GK and control rats, it did not improve glucose metabolism or limit hypertension in the GK model of type 2 diabetes. PMID:25903955

  13. Improving patient outcomes from acute cardiovascular events through regionalized systems of care.

    PubMed

    Edwards, J Matthew; Carr, Brendan G

    2010-11-01

    ST-segment elevation myocardial infarction (STEMI), cardiac arrest, and ischemic stroke are a diverse group of cardiovascular illnesses linked by the necessity for timely intervention in order to maximize patient outcomes. Despite the known efficacies of therapies, such as emergent percutaneous coronary intervention (PCI), rapid administration of tissue plasminogen activator, and induction of therapeutic hypothermia after cardiac arrest, translating these discoveries into standard practice nationwide has proven difficult to achieve. Significant regional variations in practice are commonplace, and facilities with higher patient volumes of STEMI, cardiac arrest, and ischemic stroke consistently have better outcomes compared with lower-volume facilities. Such disparities in emergency care led the Institute of Medicine in 2006 to describe the existing emergency care system as "at the breaking point," and to call for "coordinated, regionalized, and accountable" systems of care. An effective and equitable regionalized emergency care system would resemble the existing US trauma system in some respects, with transparent and standard triage guidelines, cooperation between local and regional emergency medical service systems, and an integrated network of referring and receiving facilities. Emerging technologies, such as telemedicine, will likely play a significant role. Regionalized referral systems, such as designated PCI centers and designated stroke centers, are in existence, but have largely been reactive and local, and no mechanism is in place to ensure equitable distribution of such facilities across all geographic regions. As scientific advances in the treatment of these conditions continue to evolve, so too must the system of care that provides these therapies. Evidence suggests that regionalized systems of care for acute cardiovascular events may increase compliance with existing life-saving guidelines and improve patient outcomes. PMID:21068527

  14. Development of a multivariable model to predict vulnerability in older American patients hospitalised with cardiovascular disease

    PubMed Central

    Bell, Susan P; Schnelle, John; Nwosu, Samuel K; Schildcrout, Jonathan; Goggins, Kathryn; Cawthon, Courtney; Mixon, Amanda S; Vasilevskis, Eduard E; Kripalani, Sunil

    2015-01-01

    Objectives To identify vulnerable cardiovascular patients in the hospital using a self-reported function-based screening tool. Participants Prospective observational cohort study of 445 individuals aged ≥65 years admitted to a university medical centre hospital within the USA with acute coronary syndrome and/or decompensated heart failure. Methods Participants completed an inperson interview during hospitalisation, which included vulnerable functional status using the Vulnerable Elders Survey (VES-13), sociodemographic, healthcare utilisation practices and clinical patient-specific measures. A multivariable proportional odds logistic regression model examined associations between VES-13 and prior healthcare utilisation, as well as other coincident medical and psychosocial risk factors for poor outcomes in cardiovascular disease. Results Vulnerability was highly prevalent (54%) and associated with a higher number of clinic visits, emergency room visits and hospitalisations (all p<0.001). A multivariable analysis demonstrating a 1-point increase in VES-13 (vulnerability) was independently associated with being female (OR 1.55, p=0.030), diagnosis of heart failure (OR 3.11, p<0.001), prior hospitalisations (OR 1.30, p<0.001), low social support (OR 1.42, p=0.007) and depression (p<0.001). A lower VES-13 score (lower vulnerability) was associated with increased health literacy (OR 0.70, p=0.002). Conclusions Vulnerability to functional decline is highly prevalent in hospitalised older cardiovascular patients and was associated with patient risk factors for adverse outcomes and an increased use of healthcare services. PMID:26316650

  15. Comparing the cardiovascular therapeutic indices of glycopyrronium and tiotropium in an integrated rat pharmacokinetic, pharmacodynamic and safety model.

    PubMed

    Trifilieff, Alexandre; Ethell, Brian T; Sykes, David A; Watson, Kenny J; Collingwood, Steve; Charlton, Steven J; Kent, Toby C

    2015-08-15

    Long acting inhaled muscarinic receptor antagonists, such as tiotropium, are widely used as bronchodilator therapy for chronic obstructive pulmonary disease (COPD). Although this class of compounds is generally considered to be safe and well tolerated in COPD patients the cardiovascular safety of tiotropium has recently been questioned. We describe a rat in vivo model that allows the concurrent assessment of muscarinic antagonist potency, bronchodilator efficacy and a potential for side effects, and we use this model to compare tiotropium with NVA237 (glycopyrronium bromide), a recently approved inhaled muscarinic antagonist for COPD. Anaesthetized Brown Norway rats were dosed intratracheally at 1 or 6h prior to receiving increasing doses of intravenous methacholine. Changes in airway resistance and cardiovascular function were recorded and therapeutic indices were calculated against the ED50 values for the inhibition of methacholine-induced bronchoconstriction. At both time points studied, greater therapeutic indices for hypotension and bradycardia were observed with glycopyrronium (19.5 and 28.5 fold at 1h; >200 fold at 6h) than with tiotropium (1.5 and 4.2 fold at 1h; 4.6 and 5.5 fold at 6h). Pharmacokinetic, protein plasma binding and rat muscarinic receptor binding properties for both compounds were determined and used to generate an integrated model of systemic M2 muscarinic receptor occupancy, which predicted significantly higher M2 receptor blockade at ED50 doses with tiotropium than with glycopyrronium. In our preclinical model there was an improved safety profile for glycopyrronium when compared with tiotropium. PMID:26026369

  16. Cardiovascular Actions of Neurotrophins

    PubMed Central

    CAPORALI, ANDREA; EMANUELI, COSTANZA

    2010-01-01

    Neurotrophins were christened in consideration of their actions on the nervous system and, for a long time, they were the exclusive interest of neuroscientists. However, more recently, this family of proteins has been shown to possess essential cardiovascular functions. During cardiovascular development, neurotrophins and their receptors are essential factors in the formation of the heart and critical regulator of vascular development. Postnatally, neurotrophins control the survival of endothelial cells, vascular smooth muscle cells, and cardiomyocytes and regulate angiogenesis and vasculogenesis, by autocrine and paracrine mechanisms. Recent studies suggest the capacity of neurotrophins, via their tropomyosin-kinase receptors, to promote therapeutic neovascularization in animal models of hindlimb ischemia. Conversely, the neurotrophin low-affinity p75NTR receptor induces apoptosis of endothelial cells and vascular smooth muscle cells and impairs angiogenesis. Finally, nerve growth factor looks particularly promising in treating microvascular complications of diabetes or reducing cardiomyocyte apoptosis in the infarcted heart. These seminal discoveries have fuelled basic and translational research and thus opened a new field of investigation in cardiovascular medicine and therapeutics. Here, we review recent progress on the molecular signaling and roles played by neurotrophins in cardiovascular development, function, and pathology, and we discuss therapeutic potential of strategies based on neurotrophin manipulation. PMID:19126759

  17. Relation of Total and Cardiovascular Death Rates to Climate System, Temperature, Barometric Pressure, and Respiratory Infection.

    PubMed

    Schwartz, Bryan G; Qualls, Clifford; Kloner, Robert A; Laskey, Warren K

    2015-10-15

    A distinct seasonal pattern in total and cardiovascular death rates has been reported. The factors contributing to this pattern have not been fully explored. Seven locations (average total population 71,354,000) were selected where data were available including relatively warm, cold, and moderate temperatures. Over the period 2004 to 2009, there were 2,526,123 all-cause deaths, 838,264 circulatory deaths, 255,273 coronary heart disease deaths, and 135,801 ST-elevation myocardial infarction (STEMI) deaths. We used time series and multivariate regression modeling to explore the association between death rates and climatic factors (temperature, dew point, precipitation, barometric pressure), influenza levels, air pollution levels, hours of daylight, and day of week. Average seasonal patterns for all-cause and cardiovascular deaths were very similar across the 7 locations despite differences in climate. After adjusting for multiple covariates and potential confounders, there was a 0.49% increase in all-cause death rate for every 1°C decrease. In general, all-cause, circulatory, coronary heart disease and STEMI death rates increased linearly with decreasing temperatures. The temperature effect varied by location, including temperature's linear slope, cubic fit, positional shift on the temperature axis, and the presence of circulatory death increases in locally hot temperatures. The variable effect of temperature by location suggests that people acclimatize to local temperature cycles. All-cause and circulatory death rates also demonstrated sizable associations with influenza levels, dew point temperature, and barometric pressure. A greater understanding of how climate, temperature, and barometric pressure influence cardiovascular responses would enhance our understanding of circulatory and STEMI deaths. PMID:26297511

  18. Functional plasticity of the developing cardiovascular system: examples from different vertebrates.

    PubMed

    Pelster, Bernd; Gittenberger-de Groot, A C; Poelmann, R E; Rombough, Peter; Schwerte, Thorsten; Thompson, Michael B

    2010-01-01

    Technical advances that have made it possible to perform physiological measurements on very small organisms, including those in embryonic and larval stages, have resulted in the formation of the discipline of developmental physiology. The transparency and size of developing organisms in some areas permit insights into physiological processes that cannot be obtained with opaque, adult organisms. On the other hand, it is widely accepted that without eggs, there are no chickens, so physiological adaptations during early life are just as important to species survival as those manifested by adults. Physiological adaptations of early developmental stages, however, are not always the same as patterns known in adults; they often follow their own rules. The adaptability of early developmental stages demonstrates that development is not stereotyped and a phenotype is not just the result of genetic information and the expression of a certain series of genes. Environmental factors influence phenotype production, and this in turn results in flexibility and plasticity in physiological processes. This article comprises exemplary studies presented at the Fourth International Conference in Africa for Comparative Physiology and Biochemistry (Maasai Mara, Kenya, 2008). It includes a brief introduction into technical advances, discusses the developing cardiovascular system of various vertebrates, and demonstrates the flexibility and plasticity of early developmental stages. Fluid forces, oxygen availability, ionic homeostasis, and the chemical environment (including, e.g., hormone concentrations or cholesterol levels) all contribute to the shaping and performance of the cardiovascular system. PMID:20687830

  19. Energy harvesting from the cardiovascular system, or how to get a little help from yourself.

    PubMed

    Pfenniger, Alois; Jonsson, Magnus; Zurbuchen, Adrian; Koch, Volker M; Vogel, Rolf

    2013-11-01

    Human energy harvesting is envisioned as a remedy to the weight, the size, and the poor energy density of primary batteries in medical implants. The first implant to have necessarily raised the idea of a biological power supply was the pacemaker in the early 1960s. So far, review articles on human energy harvesting have been rather unspecific and no tribute has been given to the early role of the pacemaker and the cardiovascular system in triggering research in the field. The purpose of the present article is to provide an up-to-date review of research efforts targeting the cardiovascular system as an alternative energy source for active medical implants. To this end, a chronological survey of the last 14 most influential publications is proposed. They include experimental and/or theoretical studies based on electromagnetic, piezoelectric, or electrostatic transducers harnessing various forms of energy, such as heart motion, pressure gradients, and blood flow. Technical feasibility does not imply clinical applicability: although most of the reported devices were shown to harvest an interesting amount of energy from a physiological environment, none of them were tested in vivo for a longer period of time. PMID:23949656

  20. Three-dimensional optical coherence tomography of the embryonic murine cardiovascular system

    NASA Astrophysics Data System (ADS)

    Luo, Wei; Marks, Daniel L.; Ralston, Tyler S.; Boppart, Stephen A.

    2006-03-01

    Optical coherence tomography (OCT) is an emerging high-resolution real-time biomedical imaging technology that has potential as a novel investigational tool in developmental biology and functional genomics. In this study, murine embryos and embryonic hearts are visualized with an OCT system capable of 2-µm axial and 15-µm lateral resolution and with real-time acquisition rates. We present, to our knowledge, the first sets of high-resolution 2- and 3-D OCT images that reveal the internal structures of the mammalian (murine) embryo (E10.5) and embryonic (E14.5 and E17.5) cardiovascular system. Strong correlations are observed between OCT images and corresponding hematoxylin- and eosin-stained histological sections. Real-time in vivo embryonic (E10.5) heart activity is captured by spectral-domain optical coherence tomography, processed, and displayed at a continuous rate of five frames per second. With the ability to obtain not only high-resolution anatomical data but also functional information during cardiovascular development, the OCT technology has the potential to visualize and quantify changes in murine development and in congenital and induced heart disease, as well as enable a wide range of basic in vitro and in vivo research studies in functional genomics.

  1. Milan PM1 Induces Adverse Effects on Mice Lungs and Cardiovascular System

    PubMed Central

    Farina, Francesca; Sancini, Giulio; Longhin, Eleonora; Mantecca, Paride; Camatini, Marina; Palestini, Paola

    2013-01-01

    Recent studies have suggested a link between inhaled particulate matter (PM) exposure and increased mortality and morbidity associated with cardiorespiratory diseases. Since the response to PM1 has not yet been deeply investigated, its impact on mice lungs and cardiovascular system is here examined. A repeated exposure to Milan PM1 was performed on BALB/c mice. The bronchoalveolar lavage fluid (BALf) and the lung parenchyma were screened for markers of inflammation (cell counts, tumor necrosis factor-α (TNF-α); macrophage inflammatory protein-2 (MIP-2); heme oxygenase-1 (HO-1); nuclear factor kappa-light-chain-enhancer of activated B cells p50 subunit (NFκB-p50); inducible nitric oxide synthetase (iNOS); endothelial-selectin (E-selectin)), cytotoxicity (lactate dehydrogenase (LDH); alkaline phosphatase (ALP); heat shock protein 70 (Hsp70); caspase-8-p18), and a putative pro-carcinogenic marker (cytochrome 1B1 (Cyp1B1)). Heart tissue was tested for HO-1, caspase-8-p18, NFκB-p50, iNOS, E-selectin, and myeloperoxidase (MPO); plasma was screened for markers of platelet activation and clot formation (soluble platelet-selectin (sP-selectin); fibrinogen; plasminogen activator inhibitor 1 (PAI-1)). PM1 triggers inflammation and cytotoxicity in lungs. A similar cytotoxic effect was observed on heart tissues, while plasma analyses suggest blood-endothelium interface activation. These data highlight the importance of lung inflammation in mediating adverse cardiovascular events following increase in ambient PM1 levels, providing evidences of a positive correlation between PM1 exposure and cardiovascular morbidity. PMID:23509745

  2. Prediction models for cardiovascular disease risk in the general population: systematic review

    PubMed Central

    Hooft, Lotty; Schuit, Ewoud; Debray, Thomas P A; Collins, Gary S; Tzoulaki, Ioanna; Lassale, Camille M; Siontis, George C M; Chiocchia, Virginia; Roberts, Corran; Schlüssel, Michael Maia; Gerry, Stephen; Black, James A; Heus, Pauline; van der Schouw, Yvonne T; Peelen, Linda M; Moons, Karel G M

    2016-01-01

    Objective To provide an overview of prediction models for risk of cardiovascular disease (CVD) in the general population. Design Systematic review. Data sources Medline and Embase until June 2013. Eligibility criteria for study selection Studies describing the development or external validation of a multivariable model for predicting CVD risk in the general population. Results 9965 references were screened, of which 212 articles were included in the review, describing the development of 363 prediction models and 473 external validations. Most models were developed in Europe (n=167, 46%), predicted risk of fatal or non-fatal coronary heart disease (n=118, 33%) over a 10 year period (n=209, 58%). The most common predictors were smoking (n=325, 90%) and age (n=321, 88%), and most models were sex specific (n=250, 69%). Substantial heterogeneity in predictor and outcome definitions was observed between models, and important clinical and methodological information were often missing. The prediction horizon was not specified for 49 models (13%), and for 92 (25%) crucial information was missing to enable the model to be used for individual risk prediction. Only 132 developed models (36%) were externally validated and only 70 (19%) by independent investigators. Model performance was heterogeneous and measures such as discrimination and calibration were reported for only 65% and 58% of the external validations, respectively. Conclusions There is an excess of models predicting incident CVD in the general population. The usefulness of most of the models remains unclear owing to methodological shortcomings, incomplete presentation, and lack of external validation and model impact studies. Rather than developing yet another similar CVD risk prediction model, in this era of large datasets, future research should focus on externally validating and comparing head-to-head promising CVD risk models that already exist, on tailoring or even combining these models to local settings, and investigating whether these models can be extended by addition of new predictors. PMID:27184143

  3. An optical multi-sensing system for detection of cardiovascular toxicity.

    PubMed

    Koo, Kyo-in; Kim, Sang Bok; Kim, Keekyoung; Oh, Jonghyun

    2014-05-01

    A mini-microscope-based system for multisite detection of cardiovascular toxicity was developed. The mini-microscope consisted of an image sensor and lens module extracted from an inexpensive webcam. The flipped lens module enabled cells to be magnified and monitored during testing. The portability and compactness of this system enables short-term and potential long-term experimentation inside a conventional incubator. The toxicity test results demonstrated that the normalized beating rates of cardiac muscle cells selected from multiple regions increased over time when treated with 100 nM isoprenaline. The presented system could be a promising cost-effective cell-based testing tool for discovering and screening drugs. PMID:24563288

  4. Pharmacological study of cholinergic system on cardiovascular regulation in the cuneiform nucleus of rat.

    PubMed

    Shafei, Mohammad Naser; Niazmand, Saeed; Enayatfard, Lili; Hosseini, Mahmoud; Daloee, Mahdi Hasanzade

    2013-08-01

    In the present study the effect of cholinergic system of Cuneiform nucleus (CnF) on central regulation of cardiovascular system was investigated. Two doses of acetylcholine (Ach; 90 and 150 nmol), atropine (3 and 9 nmol) and hexamethonium (Hexa; 100 and 300 nmol) were microinjected into the CnF. The maximum changes of MAP and HR were compared with control group (independent t-test). Both doses of Ach significantly decreased MAP but had no significant effect on HR. Administration of atropine and Hexa by themselves did not alter the MAP or HR. However, both doses of atropine and higher dose of Hexa significantly attenuated the hypotensive effect of Ach with no significant effect on HR. Our results suggest the involvement of CnF cholinergic system only on central blood pressure regulation that strongly mediated by muscarinic receptors. PMID:23811029

  5. Design and implementation of multimedia display system for electronic cardiovascular conferences with radiological consultation services

    NASA Astrophysics Data System (ADS)

    Zhang, Jianguo; Stahl, Johannes N.; Li, Gaoping; Huang, H. K.; Liu, Jun; Li, Jian; Zhou, Peng

    2000-04-01

    We present a networked multimedia display system based on component technologies for the electronic cardiovascular conferences with radiological consultation services. The system consists of two parts: a data acquisition gateway and a multimedia display workstation. The acquisition gateway is used to collect digital data from difference modalities and authorize them in different sessions for conference presentation. The display workstation is used to display static/dynamic radiographic images, or video sequences, ECG and other text information. The display program is designed with functions of image processing, multimedia data manipulation and visualization. In addition, the workstation also integrates with a real time tele-consultation component for the necessary consultation between cardiologists and remote radiologists equipped with a tele-consultation workstation. Finally, we discuss the system clinical performance and the applications.

  6. Flipped classroom model improves graduate student performance in cardiovascular, respiratory, and renal physiology.

    PubMed

    Tune, Johnathan D; Sturek, Michael; Basile, David P

    2013-12-01

    The purpose of this study was to assess the effectiveness of a traditional lecture-based curriculum versus a modified "flipped classroom" curriculum of cardiovascular, respiratory, and renal physiology delivered to first-year graduate students. Students in both courses were provided the same notes and recorded lectures. Students in the modified flipped classroom were required to watch the prerecorded lectures before class and then attend class, where they received a quiz or homework covering material in each lecture (valued at 25% of the final grade) followed by a question and answer/problem-solving period. In the traditional curriculum, attending lectures was optional and there were no quizzes. Evaluation of effectiveness and student performance was achieved by having students in both courses take the same multiple-choice exams. Within a comparable group of graduate students, participants in the flipped course scored significantly higher (P ≤ 0.05) on the cardiovascular, respiratory, and weighted cumulative sections by an average of >12 percentage points. Exam averages for students in the flipped course also tended to be higher on the renal section by ∼11 percentage points (P = 0.06). Based on our experience and responses obtained in blinded student surveys, we propose that the use of homework and in-class quizzes were critical motivating factors that likely contributed to the increase in student exam performance. Taken together, our findings support that the flipped classroom model is a highly effective means in which to disseminate key physiological concepts to graduate students. PMID:24292907

  7. Sent to Destroy: The Ubiquitin Proteasome System Regulates Cell Signaling and Protein Quality Control in Cardiovascular Development and Disease

    PubMed Central

    Willis, Monte S.; Townley-Tilson, W.H. Davin; Kang, Eunice Y.; Homeister, Jonathon W.; Patterson, Cam

    2010-01-01

    The ubiquitin proteasome system (UPS) plays a crucial role in biological processes integral to the development of the cardiovascular system and cardiovascular diseases. The UPS prototypically recognizes specific protein substrates and places polyubiquitin chains on them for subsequent destruction by the proteasome. This system is in place to degrade not only misfolded and damaged proteins, but is essential also in regulating a host of cell signaling pathways involved in proliferation, adaptation to stress, regulation of cell size, and cell death. During the development of the cardiovascular system, the UPS regulates cell signaling by modifying transcription factors, receptors, and structural proteins. Later, in the event of cardiovascular diseases as diverse as atherosclerosis, cardiac hypertrophy, and ischemia reperfusion injury, ubiquitin ligases and the proteasome are implicated in protecting and exacerbating clinical outcomes. However, when misfolded and damaged proteins are ubiquitinated by the UPS, their destruction by the proteasome is not always possible due to their aggregated confirmations. Recent studies have discovered how these ubiquitinated misfolded proteins can be destroyed by alternative specific mechanisms. The cytosolic receptors p62, NBR, and HDAC6 recognize aggregated ubiquitinated proteins and target them for autophagy in the process of selective autophagy. Even the ubiquitination of multiple proteins within whole organelles that drive the more general macro-autophagy may be due, in part, to similar ubiquitin-driven mechanisms. In summary, the cross-talk between the UPS and autophagy highlight the pivotal and diverse roles the UPS plays in maintaining protein quality control and regulating cardiovascular development and disease. PMID:20167943

  8. Left Ventricular Gene Expression Profile of Healthy and Cardiovascular Compromised Rat Models Used in Air Pollution Studies

    EPA Science Inventory

    The link between pollutant exposure and cardiovascular disease (CVD) has prompted mechanistic research with animal models of CVD. We hypothesized that the cardiac gene expression patterns of healthy and genetically compromised, CVD-prone rat models, with or without metabolic impa...

  9. The Expanding Complexity of Estrogen Receptor Signaling in the Cardiovascular System.

    PubMed

    Menazza, Sara; Murphy, Elizabeth

    2016-03-18

    Estrogen has important effects on cardiovascular function including regulation of vascular function, blood pressure, endothelial relaxation, and the development of hypertrophy and cardioprotection. However, the mechanisms by which estrogen mediates these effects are still poorly understood. As detailed in this review, estrogen can regulate transcription by binding to 2 nuclear receptors, ERα and ERβ, which differentially regulate gene transcription. ERα and ERβ regulation of gene transcription is further modulated by tissue-specific coactivators and corepressors. Estrogen can bind to ERα and ERβ localized at the plasma membrane as well as G-protein-coupled estrogen receptor to initiate membrane delimited signaling, which enhances kinase signaling pathways that can have acute and long-term effects. The kinase signaling pathways can also mediate transcriptional changes and can synergize with the ER to regulate cell function. This review will summarize the beneficial effects of estrogen in protecting the cardiovascular system through ER-dependent mechanisms with an emphasis on the role of the recently described ER membrane signaling mechanisms. PMID:26838792

  10. System identification of closed-loop cardiovascular control mechanisms: diabetic autonomic neuropathy

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.; Mathias, J. M.; Mullen, T. J.; Cohen, R. J.; Freeman, R.

    1999-01-01

    We applied cardiovascular system identification (CSI) to characterize closed-loop cardiovascular regulation in patients with diabetic autonomic neuropathy (DAN). The CSI method quantitatively analyzes beat-to-beat fluctuations in noninvasively measured heart rate, arterial blood pressure (ABP), and instantaneous lung volume (ILV) to characterize four physiological coupling mechanisms, two of which are autonomically mediated (the heart rate baroreflex and the coupling of respiration, measured in terms of ILV, to heart rate) and two of which are mechanically mediated (the coupling of ventricular contraction to the generation of the ABP wavelet and the coupling of respiration to ABP). We studied 37 control and 60 diabetic subjects who were classified as having minimal, moderate, or severe DAN on the basis of standard autonomic tests. The autonomically mediated couplings progressively decreased with increasing severity of DAN, whereas the mechanically mediated couplings were essentially unchanged. CSI identified differences between the minimal DAN and control groups, which were indistinguishable based on the standard autonomic tests. CSI may provide a powerful tool for assessing DAN.

  11. Renin–angiotensin–aldosterone system blockade for cardiovascular diseases: current status

    PubMed Central

    Ma, Terry KW; Kam, Kevin KH; Yan, Bryan P; Lam, Yat-Yin

    2010-01-01

    Activation of the renin–angiotensin–aldosterone system (RAAS) results in vasoconstriction, muscular (vascular and cardiac) hypertrophy and fibrosis. Established arterial stiffness and cardiac dysfunction are key factors contributing to subsequent cardiovascular and renal complications. Blockade of RAAS has been shown to be beneficial in patients with hypertension, acute myocardial infarction, chronic systolic heart failure, stroke and diabetic renal disease. An aggressive approach for more extensive RAAS blockade with combination of two commonly used RAAS blockers [ACE inhibitors (ACEIs) and angiotensin receptor blockers (ARBs)] yielded conflicting results in different patient populations. Combination therapy is also associated with more side effects, in particular hypotension, hyperkalaemia and renal impairment. Recently published ONTARGET study showed ACEI/ARB combination therapy was associated with more adverse effects without any increase in benefit. The Canadian Hypertension Education Program responded with a new warning: ‘Do not use ACEI and ARB in combination’. However, the European Society of Cardiology in their updated heart failure treatment guidelines still recommended ACEI/ARB combo as a viable option. This apparent inconsistency among guidelines generates debate as to which approach of RAAS inhibition is the best. The current paper reviews the latest evidence of isolated ACEI or ARB use and their combination in cardiovascular diseases, and makes recommendations for their prescriptions in specific patient populations. PMID:20590619

  12. Chemical sympathectomy reveals pre- and postsynaptic effects of neuropeptide Y (NPY) in the cardiovascular system.

    PubMed

    Mabe, Y; Pérez, R; Tatemoto, K; Huidobro-Toro, J P

    1987-09-15

    Intravenous injection of neuropeptide Y (NPY) caused short-lasting dose-dependent pressor responses in anesthetized rats. NPY was equipotent with noradrenaline in producing proportional pressor effects. Chemical sympathectomy, following the administration of 100 mg/kg 6-hydroxydopamine (6-OHDA), significantly potentiated the systemic pressor effects elicited by NPY or noradrenaline. Pretreatment with 2 nmol NPY enhanced the noradrenaline-induced pressor response in control rats. NPY did not change the basal tension of isolated rat aortic strips but significantly potentiated the contractile activity induced by 16 nM noradrenaline. This effect of NPY was not observed in aortic strips from rats pretreated with 6-OHDA. The presence of pre- and postsynaptic sites of action for NPY in the cardiovascular system of the rat is discussed. PMID:3115818

  13. The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

    NASA Technical Reports Server (NTRS)

    Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

    1994-01-01

    Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

  14. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

    SciTech Connect

    Xie, Tianwu; Lee, Choonsik; Bolch, Wesley E.; Zaidi, Habib

    2015-06-15

    Purpose: Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. Methods: Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. Results: For most organs, {sup 201}Tl produces the highest absorbed dose whereas {sup 82}Rb and {sup 15}O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of {sup 82}Rb is 48% and 77% lower than that of {sup 99m}Tc-tetrofosmin (rest), respectively. Conclusions: {sup 82}Rb results in lower effective dose in adults compared to {sup 99m}Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.

  15. The Kallikrein-Kinin System as a Regulator of Cardiovascular and Renal Function

    PubMed Central

    Rhaleb, Nour-Eddine; Yang, Xiao-Ping; Carretero, Oscar A.

    2015-01-01

    Autocrine, paracrine, endocrine, and neuroendocrine hormonal systems help regulate cardiovascular and renal function. Any change in the balance among these systems may result in hypertension and target organ damage, whether the cause is genetic, environmental or a combination of the two. Endocrine and neuroendocrine vasopressor hormones such as the renin-angiotensin system (RAS), aldosterone, and catecholamines are important for regulation of blood pressure and pathogenesis of hypertension and target organ damage. While the role of vasodepressor autacoids such as kinins is not as well defined, there is increasing evidence that they are not only critical to blood pressure and renal function but may also oppose remodeling of the cardiovascular system. Here we will primarily be concerned with kinins, which are oligopeptides containing the aminoacid sequence of bradykinin. They are generated from precursors known as kininogens by enzymes such as tissue (glandular) and plasma kallikrein. Some of the effects of kinins are mediated via autacoids such as eicosanoids, nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF), and/or tissue plasminogen activator (†PA). Kinins help protect against cardiac ischemia and play an important part in preconditioning as well as the cardiovascular and renal protective effects of angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor blockers (ARB). But the role of kinins in the pathogenesis of hypertension remains controversial. A study of Utah families revealed that a dominant kallikrein gene expressed as high urinary kallikrein excretion was associated with a decreased risk of essential hypertension. Moreover, researchers have identified a restriction fragment length polymorphism (RFLP) that distinguishes the kallikrein gene family found in one strain of spontaneously hypertensive rats (SHR) from a homologous gene in normotensive Brown Norway rats, and in recombinant inbred substrains derived from these SHR and Brown Norway rats this RFLP cosegregated with an increase in blood pressure. However, humans, rats and mice with a deficiency in one or more components of the kallikrein-kinin-system (KKS) or chronic KKS blockade do not have hypertension. In the kidney, kinins are essential for proper regulation of papillary blood flow and water and sodium excretion. B2-KO mice appear to be more sensitive to the hypertensinogenic effect of salt. Kinins are involved in the acute antihypertensive effects of ACE inhibitors but not their chronic effects (save for mineralocorticoidsalt-induced hypertension). Kinins appear to play a role in the pathogenesis of inflammatory diseases such as arthritis and skin inflammation; they act on innate immunity as mediators of inflammation by promoting maturation of dendritic cells, which activate the body’s adaptive immune system and thereby stimulate mechanisms that promote inflammation. On the other hand, kinins acting via NO contribute to the vascular protective effect of ACE inhibitors during neointima formation. In myocardial infarction produced by ischemia/reperfusion, kinins help reduce infarct size following preconditioning or treatment with ACE inhibitors. In heart failure secondary to infarction, the therapeutic effects of ACE inhibitors are partially mediated by kinins via release of NO, while drugs that activate the angiotensin type 2 receptor act in part via kinins and NO. Thus kinins play an important role in regulation of cardiovascular and renal function as well as many of the beneficial effects of ACE inhibitors and ARBs on target organ damage in hypertension. PMID:23737209

  16. Role of the Renin-Angiotensin-Aldosterone System and Its Pharmacological Inhibitors in Cardiovascular Diseases: Complex and Critical Issues.

    PubMed

    Borghi, Claudio; Rossi, Francesco

    2015-12-01

    Hypertension is one of the major risk factor able to promote development and progression of several cardiovascular diseases, including left ventricular hypertrophy and dysfunction, myocardial infarction, stroke, and congestive heart failure. Also, it is one of the major driven of high cardiovascular risk profile in patients with metabolic complications, including obesity, metabolic syndrome and diabetes, as well as in those with renal disease. Thus, effective control of hypertension is a key factor for any preventing strategy aimed at reducing the burden of hypertension-related cardiovascular diseases in the clinical practice. Among various regulatory and contra-regulatory systems involved in the pathogenesis of cardiovascular and renal diseases, renin-angiotensin system (RAS) plays a major role. However, despite the identification of renin and the availability of various assays for measuring its plasma activity, the specific pathophysiological role of RAS has not yet fully characterized. In the last years, however, several notions on the RAS have been improved by the results of large, randomized clinical trials, performed in different clinical settings and in different populations treated with RAS inhibiting drugs, including angiotensin converting enzyme (ACE) inhibitors and antagonists of the AT1 receptor for angiotensin II (ARBs). These findings suggest that the RAS should be considered to have a central role in the pathogenesis of different cardiovascular diseases, for both therapeutic and preventive purposes, without having to measure its level of activation in each patient. The present document will discuss the most critical issues of the pathogenesis of different cardiovascular diseases with a specific focus on RAS blocking agents, including ACE inhibitors and ARBs, in the light of the most recent evidence supporting the use of these drugs in the clinical management of hypertension and hypertension-related cardiovascular diseases. PMID:26403596

  17. Influence of Space Weather on a Cardiovascular System of a Human Being During Various Solar Cycle Phases

    NASA Astrophysics Data System (ADS)

    Samsonov, S. N.; Manykina, V. I.; Krymsky, G. F.; Parshina, S. S.; Petrova, P. G.; Palshina, A. A.; Strekalovskaya, A. A.; Shadrina, L. P., Vishnevsky, V. V.

    The study of relationship of dynamics of space weather parameters to changes of cardiovascular system state of a human being was carried out by data of measurements of volunteer groups in October - December 2009 and March-April, 2011 by data of Yakutsk and Tixie carried out according to the program of Russian-Ukrainian "Geliomed" project. It is shown that during a phase of minimum (2009) and growth phase (2011) of the 11-year solar activity a distinction in the response of cardiovascular system of a human being connected with the level of geomagnetic activity, latitude of residing of a human being and his/her age is observed.

  18. Modeling Cardiovascular Diseases with Patient-Specific Human Pluripotent Stem Cell-Derived Cardiomyocytes.

    PubMed

    Burridge, Paul W; Diecke, Sebastian; Matsa, Elena; Sharma, Arun; Wu, Haodi; Wu, Joseph C

    2016-01-01

    The generation of cardiomyocytes from human induced pluripotent stem cells (hiPSCs) provides a source of cells that accurately recapitulate the human cardiac pathophysiology. The application of these cells allows for modeling of cardiovascular diseases, providing a novel understanding of human disease mechanisms and assessment of therapies. Here, we describe a stepwise protocol developed in our laboratory for the generation of hiPSCs from patients with a specific disease phenotype, long-term hiPSC culture and cryopreservation, differentiation of hiPSCs to cardiomyocytes, and assessment of disease phenotypes. Our protocol combines a number of innovative tools that include a codon-optimized mini intronic plasmid (CoMiP), chemically defined culture conditions to achieve high efficiencies of reprogramming and differentiation, and calcium imaging for assessment of cardiomyocyte phenotypes. Thus, this protocol provides a complete guide to use a patient cohort on a testable cardiomyocyte platform for pharmacological drug assessment. PMID:25690476

  19. A cardiovascular disease policy model that predicts life expectancy taking into account socioeconomic deprivation

    PubMed Central

    Lewsey, J D; Lawson, K D; Ford, I; Fox, K A A; Ritchie, L D; Tunstall-Pedoe, H; Watt, G C M; Woodward, M; Kent, S; Neilson, M; Briggs, A H

    2015-01-01

    Objectives A policy model is a model that can evaluate the effectiveness and cost-effectiveness of interventions and inform policy decisions. In this study, we introduce a cardiovascular disease (CVD) policy model which can be used to model remaining life expectancy including a measure of socioeconomic deprivation as an independent risk factor for CVD. Design A state transition model was developed using the Scottish Heart Health Extended Cohort (SHHEC) linked to Scottish morbidity and death records. Individuals start in a CVD-free state and can transit to three CVD event states plus a non-CVD death state. Individuals who have a non-fatal first event are then followed up until death. Taking a competing risk approach, the cause-specific hazards of a first event are modelled using parametric survival analysis. Survival following a first non-fatal event is also modelled parametrically. We assessed discrimination, validation and calibration of our model. Results Our model achieved a good level of discrimination in each component (c-statistics for men (women)—non-fatal coronary heart disease (CHD): 0.70 (0.74), non-fatal cerebrovascular disease (CBVD): 0.73 (0.76), fatal CVD: 0.77 (0.80), fatal non-CVD: 0.74 (0.72), survival after non-fatal CHD: 0.68 (0.67) and survival after non-fatal CBVD: 0.65 (0.66)). In general, our model predictions were comparable with observed event rates for a Scottish randomised statin trial population which has an overlapping follow-up period with SHHEC. After applying a calibration factor, our predictions of life expectancy closely match those published in recent national life tables. Conclusions Our model can be used to estimate the impact of primary prevention interventions on life expectancy and can assess the impact of interventions on inequalities. PMID:25324535

  20. Comparing the cardiovascular therapeutic indices of glycopyrronium and tiotropium in an integrated rat pharmacokinetic, pharmacodynamic and safety model

    SciTech Connect

    Trifilieff, Alexandre; Ethell, Brian T.; Sykes, David A.; Watson, Kenny J.; Collingwood, Steve; Charlton, Steven J.; Kent, Toby C.

    2015-08-15

    Long acting inhaled muscarinic receptor antagonists, such as tiotropium, are widely used as bronchodilator therapy for chronic obstructive pulmonary disease (COPD). Although this class of compounds is generally considered to be safe and well tolerated in COPD patients the cardiovascular safety of tiotropium has recently been questioned. We describe a rat in vivo model that allows the concurrent assessment of muscarinic antagonist potency, bronchodilator efficacy and a potential for side effects, and we use this model to compare tiotropium with NVA237 (glycopyrronium bromide), a recently approved inhaled muscarinic antagonist for COPD. Anaesthetized Brown Norway rats were dosed intratracheally at 1 or 6 h prior to receiving increasing doses of intravenous methacholine. Changes in airway resistance and cardiovascular function were recorded and therapeutic indices were calculated against the ED{sub 50} values for the inhibition of methacholine-induced bronchoconstriction. At both time points studied, greater therapeutic indices for hypotension and bradycardia were observed with glycopyrronium (19.5 and 28.5 fold at 1 h; > 200 fold at 6 h) than with tiotropium (1.5 and 4.2 fold at 1 h; 4.6 and 5.5 fold at 6 h). Pharmacokinetic, protein plasma binding and rat muscarinic receptor binding properties for both compounds were determined and used to generate an integrated model of systemic M{sub 2} muscarinic receptor occupancy, which predicted significantly higher M{sub 2} receptor blockade at ED{sub 50} doses with tiotropium than with glycopyrronium. In our preclinical model there was an improved safety profile for glycopyrronium when compared with tiotropium. - Highlights: • We use an in vivo rat model to study CV safety of inhaled muscarinic antagonists. • We integrate protein and receptor binding and PK of tiotropium and glycopyrrolate. • At ED{sub 50} doses for bronchoprotection we model systemic M{sub 2} receptor occupancy. • Glycopyrrolate demonstrates lower M{sub 2} occupancy at bronchoprotective doses. • Glycopyrrolate demonstrates an improved CV safety profile, versus tiotropium.

  1. Pharmacological Strategies to Retard Cardiovascular Aging.

    PubMed

    Alfaras, Irene; Di Germanio, Clara; Bernier, Michel; Csiszar, Anna; Ungvari, Zoltan; Lakatta, Edward G; de Cabo, Rafael

    2016-05-13

    Aging is the major risk factor for cardiovascular diseases, which are the leading cause of death in the United States. Traditionally, the effort to prevent cardiovascular disease has been focused on addressing the conventional risk factors, including hypertension, hyperglycemia, hypercholesterolemia, and high circulating levels of triglycerides. However, recent preclinical studies have identified new approaches to combat cardiovascular disease. Calorie restriction has been reproducibly shown to prolong lifespan in various experimental model animals. This has led to the development of calorie restriction mimetics and other pharmacological interventions capable to delay age-related diseases. In this review, we will address the mechanistic effects of aging per se on the cardiovascular system and focus on the prolongevity benefits of various therapeutic strategies that support cardiovascular health. PMID:27174954

  2. Effects of intrauterine growth restriction on sleep and the cardiovascular system: The use of melatonin as a potential therapy?

    PubMed

    Yiallourou, Stephanie R; Wallace, Euan M; Miller, Suzanne L; Horne, Rosemary Sc

    2016-04-01

    Intrauterine growth restriction (IUGR) complicates 5-10% of pregnancies and is associated with increased risk of preterm birth, mortality and neurodevelopmental delay. The development of sleep and cardiovascular control are closely coupled and IUGR is known to alter this development. In the long-term, IUGR is associated with altered sleep and an increased risk of hypertension in adulthood. Melatonin plays an important role in the sleep-wake cycle. Experimental animal studies have shown that melatonin therapy has neuroprotective and cardioprotective effects in the IUGR fetus. Consequently, clinical trials are currently underway to assess the short and long term effects of antenatal melatonin therapy in IUGR pregnancies. Given melatonin's role in sleep regulation, this hormone could affect the developing infants' sleep-wake cycle and cardiovascular function after birth. In this review, we will 1) examine the role of melatonin as a therapy for IUGR pregnancies and the potential implications on sleep and the cardiovascular system; 2) examine the development of sleep-wake cycle in fetal and neonatal life; 3) discuss the development of cardiovascular control during sleep; 4) discuss the effect of IUGR on sleep and the cardiovascular system and 5) discuss the future implications of melatonin therapy in IUGR pregnancies. PMID:26140865

  3. Role of altered intestinal microbiota in systemic inflammation and cardiovascular disease in chronic kidney disease.

    PubMed

    Mafra, Denise; Lobo, Julie C; Barros, Amanda F; Koppe, Laetitia; Vaziri, Nosratola D; Fouque, Denis

    2014-01-01

    The normal intestinal microbiota plays a major role in the maintenance of health and disease prevention. In fact, the alteration of the intestinal microbiota has been shown to contribute to the pathogenesis of several pathological conditions, including obesity and insulin resistance, among others. Recent studies have revealed profound alterations of the gut microbial flora in patients and animals with chronic kidney disease (CKD). Alterations in the composition of the microbiome in CKD may contribute to the systemic inflammation and accumulation of gut-derived uremic toxins, which play a central role in the pathogenesis of accelerated cardiovascular disease and numerous other CKD-associated complications. This review is intended to provide a concise description of the potential role of the CKD-associated changes in the gut microbiome and its potential role the pathogenesis of inflammation and uremic toxicity. In addition, the potential efficacy of pre- and pro-biotics in the restoration of the microbiome is briefly described. PMID:24762311

  4. Apelin, Elabela/Toddler, and biased agonists as novel therapeutic agents in the cardiovascular system.

    PubMed

    Yang, Peiran; Maguire, Janet J; Davenport, Anthony P

    2015-09-01

    Apelin and its G protein-coupled receptor (GPCR) have emerged as a key signalling pathway in the cardiovascular system. The peptide is a potent inotropic agent and vasodilator. Remarkably, a peptide, Elabela/Toddler, that has little sequence similarity to apelin, has been proposed as a second endogenous apelin receptor ligand and is encoded by a gene from a region of the genome previously classified as 'non-coding'. Apelin is downregulated in pulmonary arterial hypertension and heart failure. To replace the missing endogenous peptide, 'biased' apelin agonists have been designed that preferentially activate G protein pathways, resulting in reduced β-arrestin recruitment and receptor internalisation, with the additional benefit of attenuating detrimental β-arrestin signalling. Proof-of-concept studies support the clinical potential for apelin receptor biased agonists. PMID:26143239

  5. Apelin, Elabela/Toddler, and biased agonists as novel therapeutic agents in the cardiovascular system

    PubMed Central

    Yang, Peiran; Maguire, Janet J.; Davenport, Anthony P.

    2015-01-01

    Apelin and its G protein-coupled receptor (GPCR) have emerged as a key signalling pathway in the cardiovascular system. The peptide is a potent inotropic agent and vasodilator. Remarkably, a peptide, Elabela/Toddler, that has little sequence similarity to apelin, has been proposed as a second endogenous apelin receptor ligand and is encoded by a gene from a region of the genome previously classified as ‘non-coding’. Apelin is downregulated in pulmonary arterial hypertension and heart failure. To replace the missing endogenous peptide, ‘biased’ apelin agonists have been designed that preferentially activate G protein pathways, resulting in reduced β-arrestin recruitment and receptor internalisation, with the additional benefit of attenuating detrimental β-arrestin signalling. Proof-of-concept studies support the clinical potential for apelin receptor biased agonists. PMID:26143239

  6. The implication of protein malnutrition on cardiovascular control systems in rats

    PubMed Central

    Silva, Fernanda C.; de Menezes, Rodrigo C.; Chianca, Deoclécio A.

    2015-01-01

    The malnutrition in early life is associated with metabolic changes and cardiovascular impairment in adulthood. Deficient protein intake-mediated hypertension has been observed in clinical and experimental studies. In rats, protein malnutrition also increases the blood pressure and enhances heart rate and sympathetic activity. In this review, we discuss the effects of post-weaning protein malnutrition on the resting mean arterial pressure and heart rate and their variabilities, cardiovascular reflexes sensitivity, cardiac autonomic balance, sympathetic and renin-angiotensin activities and neural plasticity during adult life. These insights reveal an interesting prospect on the autonomic modulation underlying the cardiovascular imbalance and provide relevant information on preventing cardiovascular diseases. PMID:26388783

  7. Pharmacology of Aldosterone and the Effects of Mineralocorticoid Receptor Blockade on Cardiovascular Systems

    PubMed Central

    Yagi, Shusuke; Akaike, Masashi; Aihara, Ken-ichi; Fukuda, Daiju; Ishida, Masayoshi; Ise, Takayuki; Niki, Toshiyuki; Sumitomo-Ueda, Yuka; Yamaguchi, Koji; Iwase, Takashi; Taketani, Yoshio; Yamada, Hirotsugu; Soeki, Takeshi; Wakatsuki, Tetsuzo; Shimabukuro, Michio; Sata, Masataka

    2013-01-01

    It is well-known that aldosterone plays an important role in reabsorption of sodium and fluid, and in potassium excretion in kidneys via epithelial mineralocorticoid receptor (MR) activation. Recent studies have shown that aldosterone causes cardiovascular remodeling not only in a blood pressure-dependent manner, but also in a blood pressure-independent manner by decreasing nitric oxide bioavailability and modulating oxidative stress, leading to vascular inflammation. In addition, MR blockade does provide beneficial effects associated with cardiovascular protection, resulting in a reduction of cardiovascular morbidity and mortality. A growing body of evidence suggests that MR blockade is a promising therapeutic target to help prevent cardiovascular events. PMID:27122708

  8. Tenascin-C and mechanotransduction in the development and diseases of cardiovascular system

    PubMed Central

    Imanaka-Yoshida, Kyoko; Aoki, Hiroki

    2014-01-01

    Living tissue is composed of cells and extracellular matrix (ECM). In the heart and blood vessels, which are constantly subjected to mechanical stress, ECM molecules form well-developed fibrous frameworks to maintain tissue structure. ECM is also important for biological signaling, which influences various cellular functions in embryonic development, and physiological/pathological responses to extrinsic stimuli. Among ECM molecules, increased attention has been focused on matricellular proteins. Matricellular proteins are a growing group of non-structural ECM proteins highly up-regulated at active tissue remodeling, serving as biological mediators. Tenascin-C (TNC) is a typical matricellular protein, which is highly expressed during embryonic development, wound healing, inflammation, and cancer invasion. The expression is tightly regulated, dependent on the microenvironment, including various growth factors, cytokines, and mechanical stress. In the heart, TNC appears in a spatiotemporal-restricted manner during early stages of development, sparsely detected in normal adults, but transiently re-expressed at restricted sites associated with tissue injury and inflammation. Similarly, in the vascular system, TNC is strongly up-regulated during embryonic development and under pathological conditions with an increase in hemodynamic stress. Despite its intriguing expression pattern, cardiovascular system develops normally in TNC knockout mice. However, deletion of TNC causes acute aortic dissection (AAD) under strong mechanical and humoral stress. Accumulating reports suggest that TNC may modulate the inflammatory response and contribute to elasticity of the tissue, so that it may protect cardiovascular tissue from destructive stress responses. TNC may be a key molecule to control cellular activity during development, adaptation, or pathological tissue remodeling. PMID:25120494

  9. Proceedings of the Symposium Teaching Cardiovascular Physiology Outside the Lecture Hall.

    ERIC Educational Resources Information Center

    Michael, Joel A.; Rovick, Allen A., Eds.

    1983-01-01

    Provided are 10 papers presented during a symposium on teaching cardiovascular physiology outside the lecture hall. Topics addressed include a mechanical model of the cardiovascular system for effective teaching, separate course for experiments in cardiovascular physiology, selective laboratory (alternative to cookbook experiments), cardiovascular…

  10. Pressure half-time in aortic regurgitation: evaluation with Doppler in a cardiovascular hydromechanical simulator and in a computer model.

    PubMed

    Slørdahl, S A; Piene, H; Skjaerpe, T

    1990-01-01

    Doppler echocardiographic determination of pressure half-time has been proposed as a method of assessing the severity of aortic regurgitation. To evaluate this method, we assessed the relation between pressure half-time and simulated aortic regurgitant flow under various conditions in two models of the cardiovascular system. In a hydromechanical model we assessed the influence of total peripheral resistance and arterial compliance on the pressure half-time as measured by continuous wave Doppler echocardiography. In a computer model that used the half-time of the pressure gradient between the aorta and the left ventricle as an expression of pressure half-time, we assessed the influence of total peripheral resistance and arterial compliance and also the influence of left ventricular compliance on pressure half-time. In both models, although we found an inverse relation between regurgitant orifice area and pressure half-time, changing total peripheral resistance and arterial compliance (but not left ventricular compliance) within the physiologic range significantly altered the pressure half-times. We concluded that the influence of total peripheral resistance and arterial compliance limits the usefulness of Doppler echocardiographic determination of pressure half-time as a method of assessing the severity of aortic regurgitation. PMID:2310592

  11. Continuous-flow pump model study: the effect on pump performance of pump characteristics and cardiovascular conditions.

    PubMed

    Ferrari, Gianfranco; Kozarski, Maciej; Fresiello, Libera; Di Molfetta, Arianna; Zieliński, Krzysztof; Górczyńska, Krystyna; Pałko, Krzysztof J; Darowski, Marek

    2013-06-01

    This model study evaluates the effect of pump characteristics and cardiovascular data on hemodynamics in atrio-aortic VAD assistance. The model includes a computational circulatory sub-model and an electrical sub-model representing two rotary blood pumps through their pressure-flow characteristics. The first is close to a pressure generator-PG (average flow sensitivity to pressure variations, -0.047 l mmHg(-1)); the second is closer to a flow generator-FG (average flow sensitivity to pressure variations, -0.0097 l mmHg(-1)). Interaction with VAD was achieved by means of two interfaces, behaving as impedance transformers. The model was verified by use of literature data and VAD onset conditions were used as a control for the experiments. Tests compared the two pumps, at constant pump speed, in different ventricular and circulatory conditions: maximum ventricular elastance (0.44-0.9 mmHg cm(-3)), systemic peripheral resistance (781-1200 g cm(-4) s(-1)), ventricular diastolic compliance C p (5-10-50 cm(3) mmHg(-1)), systemic arterial compliance (0.9-1.8 cm(3) mmHg(-1)). Analyzed variables were: arterial and venous pressures, flows, ventricular volume, external work, and surplus hemodynamic energy (SHE). The PG pump generated the highest SHE under almost all conditions, in particular for higher C p (+50 %). PG pump flow is also the most sensitive to E max and C p changes (-26 and -33 %, respectively). The FG pump generally guarantees higher external work reduction (54 %) and flow less dependent on circulatory and ventricular conditions. The results are evidence of the importance of pump speed regulation with changing ventricular conditions. The computational sub-model will be part of a hydro-numerical model, including autonomic controls, designed to test different VADs. PMID:23463355

  12. SUBCHRONIC PULMONARY PATHOLOGY, IRON-OVERLOAD AND TRANSCRIPTIONAL ACTIVITY AFTER LIBBY AMPHIBOLE EXPOSURE IN RAT MODELS OF CARDIOVASCULAR DISEASE

    EPA Science Inventory

    Background: Surface-available iron (Fe) is proposed to contribute to asbestos-induced toxicity through the production of reactive oxygen species.Objective: Our goal was to evaluate the hypothesis that rat models of cardiovascular disease with coexistent Fe overload would be incre...

  13. The Apoe(-/-) mouse model: a suitable model to study cardiovascular and respiratory diseases in the context of cigarette smoke exposure and harm reduction.

    PubMed

    Lo Sasso, Giuseppe; Schlage, Walter K; Boué, Stéphanie; Veljkovic, Emilija; Peitsch, Manuel C; Hoeng, Julia

    2016-01-01

    Atherosclerosis-prone apolipoprotein E-deficient (Apoe(-/-)) mice display poor lipoprotein clearance with subsequent accumulation of cholesterol ester-enriched particles in the blood, which promote the development of atherosclerotic plaques. Therefore, the Apoe(-/-) mouse model is well established for the study of human atherosclerosis. The systemic proinflammatory status of Apoe(-/-) mice also makes them good candidates for studying chronic obstructive pulmonary disease, characterized by pulmonary inflammation, airway obstruction, and emphysema, and which shares several risk factors with cardiovascular diseases, including smoking. Herein, we review the results from published studies using Apoe(-/-) mice, with a particular focus on work conducted in the context of cigarette smoke inhalation studies. The findings from these studies highlight the suitability of this animal model for researching the effects of cigarette smoking on atherosclerosis and emphysema. PMID:27207171

  14. The brain renin-angiotensin system and cardiovascular responses to stress: insights from transgenic rats with low brain angiotensinogen.

    PubMed

    Arnold, Amy C; Sakima, Atsushi; Kasper, Sherry O; Vinsant, Sherry; Garcia-Espinosa, Maria Antonia; Diz, Debra I

    2012-12-15

    The renin-angiotensin system (RAS) has been identified as an attractive target for the treatment of stress-induced cardiovascular disorders. The effects of angiotensin (ANG) peptides during stress responses likely result from an integration of actions by circulating peptides and brain peptides derived from neuronal and glial sources. The present review focuses on the contribution of endogenous brain ANG peptides to pathways involved in cardiovascular responses to stressors. During a variety of forms of stress, neuronal pathways in forebrain areas containing ANG II or ANG-(1-7) are activated to stimulate descending angiotensinergic pathways that increase sympathetic outflow to increase blood pressure. We provide evidence that glia-derived ANG peptides influence brain AT(1) receptors. This appears to result in modulation of the responsiveness of the neuronal pathways activated during stressors that elevate circulating ANG peptides to activate brain pathways involving descending hypothalamic projections. It is well established that increased cardiovascular reactivity to stress is a significant predictor of hypertension and other cardiovascular diseases. This review highlights the importance of understanding the impact of RAS components from the circulation, neurons, and glia on the integration of cardiovascular responses to stressors. PMID:22984245

  15. The brain renin-angiotensin system and cardiovascular responses to stress: insights from transgenic rats with low brain angiotensinogen

    PubMed Central

    Arnold, Amy C.; Sakima, Atsushi; Kasper, Sherry O.; Vinsant, Sherry; Garcia-Espinosa, Maria Antonia

    2012-01-01

    The renin-angiotensin system (RAS) has been identified as an attractive target for the treatment of stress-induced cardiovascular disorders. The effects of angiotensin (ANG) peptides during stress responses likely result from an integration of actions by circulating peptides and brain peptides derived from neuronal and glial sources. The present review focuses on the contribution of endogenous brain ANG peptides to pathways involved in cardiovascular responses to stressors. During a variety of forms of stress, neuronal pathways in forebrain areas containing ANG II or ANG-(1–7) are activated to stimulate descending angiotensinergic pathways that increase sympathetic outflow to increase blood pressure. We provide evidence that glia-derived ANG peptides influence brain AT1 receptors. This appears to result in modulation of the responsiveness of the neuronal pathways activated during stressors that elevate circulating ANG peptides to activate brain pathways involving descending hypothalamic projections. It is well established that increased cardiovascular reactivity to stress is a significant predictor of hypertension and other cardiovascular diseases. This review highlights the importance of understanding the impact of RAS components from the circulation, neurons, and glia on the integration of cardiovascular responses to stressors. PMID:22984245

  16. Modelling the lymphatic system: challenges and opportunities

    PubMed Central

    Margaris, K. N.; Black, R. A.

    2012-01-01

    The lymphatic system is a vital part of the circulatory and immune systems, and plays an important role in homeostasis by controlling extracellular fluid volume and in combating infection. Nevertheless, there is a notable disparity in terms of research effort expended in relation to the treatment of lymphatic diseases in contrast to the cardiovascular system. While similarities to the cardiovascular system exist, there are considerable differences in their anatomy and physiology. This review outlines some of the challenges and opportunities for those engaged in modelling biological systems. The study of the lymphatic system is still in its infancy, the vast majority of the models presented in the literature to date having been developed since 2003. The number of distinct models and their variants are few in number, and only one effort has been made thus far to study the entire lymphatic network; elements of the lymphatic system such as the nodes, which act as pumps and reservoirs, have not been addressed by mathematical models. Clearly, more work will be necessary in combination with experimental verification in order to progress and update the knowledge on the function of the lymphatic system. As our knowledge and understanding of its function increase, new and more effective treatments of lymphatic diseases are bound to emerge. PMID:22237677

  17. The impact of high fructose on cardiovascular system: Role of α-lipoic acid.

    PubMed

    Saygin, M; Asci, H; Cankara, F N; Bayram, D; Yesilot, S; Candan, I A; Alp, H H

    2016-02-01

    The aim of this study was to evaluate the role of α-lipoic acid (α-LA) on oxidative damage and inflammation that occur in endothelium of aorta and heart while constant consumption of high-fructose corn syrup (HFCS). The rats were randomly divided into three groups with each group containing eight rats. The groups include HFCS, HFCS + α-LA treatment, and control. HFCS was given to the rats at a ratio of 30% of F30 corn syrup in drinking water for 10 weeks. α-LA treatment was given to the rats at a dose of 100 mg/kg/day orally for the last 6 weeks. At the end of the experiment, the rats were killed by cervical dislocation. The blood samples were collected for biochemical studies, and the aortic and cardiac tissues were collected for evaluation of oxidant-antioxidant system, tissue bath, and pathological examination. HFCS had increased the levels of malondialdehyde, creatine kinase MB, lactate dehydrogenase, and uric acid and showed significant structural changes in the heart of the rats by histopathology. Those changes were improved by α-LA treatment as it was found in this treatment group. Immunohistochemical expressions of tumor necrosis factor α and inducible nitric oxide synthase were increased in HFCS group, and these receptor levels were decreased by α-LA treatment. All the tissue bath studies supported these findings. Chronic consumption of HFCS caused several problems like cardiac and endothelial injury of aorta by hyperuricemia and induced oxidative stress and inflammation. α-LA treatment reduced uric acid levels, oxidative stress, and corrected vascular responses. α-LA can be added to cardiac drugs due to its cardiovascular protective effects against the cardiovascular diseases. PMID:25825413

  18. Nesfatin-1 and the Cardiovascular System: Central and Pheripheral Actions and Cardioprotection.

    PubMed

    Imbrogno, Sandra; Angelone, Tommaso; Cerra, Maria C

    2015-01-01

    Recently, the hypothalamic 82-aa peptide Nesfatin-1 received notable attention for its anorexigenic and anti-hyperglycemic properties. In mammalian hypothalamus, Nesfatin-1 is expressed, together with the precursor Nucleobindin 2 (NUCB2), in regions controlling water-food intake, body weight, and glucose homeostasis. The peptide is also peripherally expressed, as shown in the rat heart, in which it is present together with NUCB2. In addition to a central modulation of nutrition and energy balance, and of the nervous circuits responsible for blood pressure and heart rate control, Nesfatin-1 also acts peripherally on several districts, including the cardiovascular (CV) system. Accordingly, the peptide is regarded with interest as a multifunctional hormone not only linked to alimentary homeostasis. This review aims to analyze the literature on Nesfatin-1, with focus on its emerging CV activity. Few available studies show that the peptide affects energy metabolism of murine and human cardiomyocytes, by eliciting insulin-like effects. On the ex vivo rat heart, it directly depresses contractility and relaxation via cGMP, PKG and ERK1/2, and limits ischemia/reperfusion (I/R) damage, acting in post-conditioning protection. Nesfatin-1 actions are proposed to involve an unknown G-protein coupled receptor. However, in the rat heart, functional studies, co-immunoprecipitation and local sequence alignment analyses suggest an interaction with the Natriuretic Peptide Receptor-type A (NPR-A). These data open up novel perspectives to clarify not only the biological significance of the peptide, but also its putative biomedical potential in the presence of nutrition-dependent cardiovascular diseases. PMID:25850621

  19. Evaluation of a new fiber-optic pressure recording system for cardiovascular measurements in mice.

    PubMed

    Woldbaek, Per Reidar; Stromme, Taevje Andreas; Sande, Jørn Bodvar; Christensen, Geir; Tønnessen, Theis; Ilebekk, Arnfinn

    2003-11-01

    We have tested a new fiber-optic pressure recording system, Samba, with a thin fiber [outer diameter (OD) = 0.25 mm] and a pressure sensor (length and OD = 0.42 mm) attached to the end. The accuracy of the system tested in vitro was good, with a coefficient of variation of 2.54% at 100 mmHg. The drift was <0.45 mmHg/h, and the temperature sensitivity was approximately 0.07 mmHg/1 degrees C between 22 and 37 degrees C. The frequency response characteristics were similar to a 1.4-Fr Millar catheter (0-200 Hz). Introduction of the Samba sensor from the right carotid artery into the left ventricle in six mice caused no drop in mean aortic pressure, whereas introduction of a 1.4-Fr Millar catheter (OD = 0.47 mm; n = 6) caused a pressure drop from 91.6 +/- 9.2 to 65.1 +/- 6.2 mmHg; P < 0.05. Thus the Samba sensor system may represent a new alternative to assess hemodynamic variables in the murine cardiovascular system. PMID:12829434

  20. A Computational Model for Thrombus Formation in Response to Cardiovascular Implantable Devices

    NASA Astrophysics Data System (ADS)

    Horn, John; Ortega, Jason; Maitland, Duncan

    2014-11-01

    Cardiovascular implantable devices elicit complex physiological responses within blood. Notably, alterations in blood flow dynamics and interactions between blood proteins and biomaterial surface chemistry may lead to the formation of thrombus. For some devices, such as stents and heart valves, this is an adverse outcome. For other devices, such as embolic aneurysm treatments, efficient blood clot formation is desired. Thus a method to study how biomedical devices induce thrombosis is paramount to device development and optimization. A multiscale, multiphysics computational model is developed to predict thrombus formation within the vasculature. The model consists of a set of convection-diffusion-reaction partial differential equations for blood protein constituents involved in the progression of the clotting cascades. This model is used to study thrombus production from endovascular devices with the goal of optimizing the device design to generate the desired clotting response. This work was performed in part under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  1. First-Year Medical Students' Conceptual Understanding of and Resistance to Conceptual Change Concerning the Central Cardiovascular System

    ERIC Educational Resources Information Center

    Mikkila-Erdmann, Mirjamaija; Sodervik, Ilona; Vilppu, Henna; Kaapa, Pekka; Olkinuora, Erkki

    2012-01-01

    Medical students often have initial understanding concerning medical domains, such as the central cardiovascular system (CCVS), when they enter the study programme. These notions may to some extent be in conflict with scientific understanding, which can be seen as a challenge for medical teaching. Hence, the purpose of this study was to analyse…

  2. Effect of a botanical composition, UP446, on respiratory, cardiovascular and central nervous systems in beagle dogs and rats.

    PubMed

    Yimam, Mesfin; Lee, Young Chul; Jia, Qi

    2016-06-01

    Extensive safety evaluation of UP446, a botanical composition comprised of standardized extracts from roots of Scutellaria baicalensis and heartwoods of Acacia catechu, has been reported previously. Here we carried out additional studies to assess the effect of UP446 on respiratory, cardiovascular and central nervous (CNS) systems. A Functional observational battery (FOB) and whole body plethysmography system in rats and implanted telemetry in dogs were utilized to evaluate the potential CNS, respiratory and cardiovascular toxicity, respectively. UP446 was administered orally at dose levels of 800, 2000 and 5000 mg/kg to SpragueDawley rats and at 4 ascending dose levels (0, 250, 500 and 1000 mg/kg) to beagle dogs. No abnormal effects were observed on the cage side, open field, hand held, and sensori-motor observations suggestive of toxicity in respiratory, cardiovascular and central nervous (CNS) systems. Rectal temperatures were comparable for each treatment groups. Similarly, respiratory rate, tidal volume and minute volume were unaffected by any of the treatment groups. No UP446 related changes were observed on blood pressure, heart rate and electrocardiogram in beagle dogs at dose levels of 250, 500 and 1000 mg/kg. Some minor incidental, non-dose correlated changes were observed in the FOB assessment. These data suggest that UP446 has minimal or no pharmaco-toxicological effect on the respiratory, cardiovascular and central nervous systems. PMID:27012374

  3. Aircraft flight simulation of spacelab experiment using an implanted telemetry system to obtain cardiovascular data from the monkey

    NASA Technical Reports Server (NTRS)

    Mccutcheon, E. P.; Miranda, R.; Fryer, T. B.; Hodges, G.; Newson, B. D.; Pace, N.

    1977-01-01

    The utility of a multichannel implantable telemetry system for obtaining cardiovascular data was tested in a monkey with a CV-990 aircraft flight simulation of a space flight experiment. Valuable data were obtained to aid planning and execution of flight experiments using chronically instrumented animals.

  4. An Investigation of the Potential for a Computer-based Tutorial Program Covering the Cardiovascular System to Replace Traditional Lectures.

    ERIC Educational Resources Information Center

    Dewhurst, D. G.; Williams, A. D.

    1998-01-01

    Presents the results of a comparative study to evaluate the effectiveness of two interactive computer-based learning (CBL) programs, covering the cardiovascular system, as an alternative to lectures for first year undergraduate students at a United Kingdom University. Discusses results in relation to the design of evaluative studies and the future…

  5. A System-Level Investigation into the Mechanisms of Chinese Traditional Medicine: Compound Danshen Formula for Cardiovascular Disease Treatment

    PubMed Central

    Li, Xiuxiu; Xu, Xue; Wang, Jinan; Yu, Hua; Wang, Xia; Yang, Hongjun; Xu, Haiyu; Tang, Shihuan; Li, Yan; Yang, Ling; Huang, Luqi; Wang, Yonghua; Yang, Shengli

    2012-01-01

    Compound Danshen Formula (CDF) is a widely used Traditional Chinese Medicine (TCM) which has been extensively applied in clinical treatment of cardiovascular diseases (CVDs). However, the underlying mechanism of clinical administrating CDF on CVDs is not clear. In this study, the pharmacological effect of CDF on CVDs was analyzed at a systemic point of view. A systems-pharmacological model based on chemical, chemogenomics and pharmacological data is developed via network reconstruction approach. By using this model, we performed a high-throughput in silico screen and obtained a group of compounds from CDF which possess desirable pharmacodynamical and pharmacological characteristics. These compounds and the corresponding protein targets are further used to search against biological databases, such as the compound-target associations, compound-pathway connections and disease-target interactions for reconstructing the biologically meaningful networks for a TCM formula. This study not only made a contribution to a better understanding of the mechanisms of CDF, but also proposed a strategy to develop novel TCM candidates at a network pharmacology level. PMID:22962593

  6. Personalized Cardiovascular Disease Prediction and Treatment—A Review of Existing Strategies and Novel Systems Medicine Tools

    PubMed Central

    Björnson, Elias; Borén, Jan; Mardinoglu, Adil

    2016-01-01

    Cardiovascular disease (CVD) continues to constitute the leading cause of death globally. CVD risk stratification is an essential tool to sort through heterogeneous populations and identify individuals at risk of developing CVD. However, applications of current risk scores have recently been shown to result in considerable misclassification of high-risk subjects. In addition, despite long standing beneficial effects in secondary prevention, current CVD medications have in a primary prevention setting shown modest benefit in terms of increasing life expectancy. A systems biology approach to CVD risk stratification may be employed for improving risk-estimating algorithms through addition of high-throughput derived omics biomarkers. In addition, modeling of personalized benefit-of-treatment may help in guiding choice of intervention. In the area of medicine, realizing that CVD involves perturbations of large complex biological networks, future directions in drug development may involve moving away from a reductionist approach toward a system level approach. Here, we review current CVD risk scores and explore how novel algorithms could help to improve the identification of risk and maximize personalized treatment benefit. We also discuss possible future directions in the development of effective treatment strategies for CVD through the use of genome-scale metabolic models (GEMs) as well as other biological network-based approaches. PMID:26858650

  7. Continuous system modeling

    NASA Technical Reports Server (NTRS)

    Cellier, Francois E.

    1991-01-01

    A comprehensive and systematic introduction is presented for the concepts associated with 'modeling', involving the transition from a physical system down to an abstract description of that system in the form of a set of differential and/or difference equations, and basing its treatment of modeling on the mathematics of dynamical systems. Attention is given to the principles of passive electrical circuit modeling, planar mechanical systems modeling, hierarchical modular modeling of continuous systems, and bond-graph modeling. Also discussed are modeling in equilibrium thermodynamics, population dynamics, and system dynamics, inductive reasoning, artificial neural networks, and automated model synthesis.

  8. A reduced-dimensional model for near-wall transport in cardiovascular flows.

    PubMed

    Hansen, Kirk B; Shadden, Shawn C

    2016-06-01

    Near-wall mass transport plays an important role in many cardiovascular processes, including the initiation of atherosclerosis, endothelial cell vasoregulation, and thrombogenesis. These problems are characterized by large Péclet and Schmidt numbers as well as a wide range of spatial and temporal scales, all of which impose computational difficulties. In this work, we develop an analytical relationship between the flow field and near-wall mass transport for high-Schmidt-number flows. This allows for the development of a wall-shear-stress-driven transport equation that lies on a codimension-one vessel-wall surface, significantly reducing computational cost in solving the transport problem. Separate versions of this equation are developed for the reaction-rate-limited and transport-limited cases, and numerical results in an idealized abdominal aortic aneurysm are compared to those obtained by solving the full transport equations over the entire domain. The reaction-rate-limited model matches the expected results well. The transport-limited model is accurate in the developed flow regions, but overpredicts wall flux at entry regions and reattachment points in the flow. PMID:26298313

  9. Cardiovascular effects of thyroid disease.

    PubMed

    Sangster, Jodi K; Panciera, David L; Abbott, Jonathan A

    2013-07-01

    Thyroid hormones have many effects on cardiovascular function, and deficiency or excess of thyroid hormones can result in cardiac dysfunction. Abnormalities of the cardiovascular system are often identified during examination of hyperthyroid and hypothyroid patients. This article addresses the effects of thyroid hormones on the cardiovascular system and the clinical relevance of the cardiovascular response to thyroid dysfunction. In addition, treatment recommendations are presented. PMID:23677842

  10. Polyphenols: Benefits to the Cardiovascular System in Health and in Aging

    PubMed Central

    Khurana, Sandhya; Venkataraman, Krishnan; Hollingsworth, Amanda; Piche, Matthew; Tai, T. C.

    2013-01-01

    Numerous studies have demonstrated the importance of naturally occurring dietary polyphenols in promoting cardiovascular health and emphasized the significant role these compounds play in limiting the effects of cellular aging. Polyphenols such as resveratrol, epigallocatechin gallate (EGCG), and curcumin have been acknowledged for having beneficial effects on cardiovascular health, while some have also been shown to be protective in aging. This review highlights the literature surrounding this topic on the prominently studied and documented polyphenols as pertaining to cardiovascular health and aging. PMID:24077237

  11. Cardiovascular health promotion for children: a model for a Parish (County)-wide program (implementation and preliminary results).

    PubMed

    Berenson, Gerald S

    2010-01-01

    Cardiovascular (CV) risk factors in childhood result in a lifetime burden on the CV system. The Bogalusa Heart Study, a prevention program for children, addresses behaviors and lifestyles associated with CV risk. This prevention program utilizes the substructure of a Parish (County) that can be a model for other areas. All aspects in educating school children-the classroom, physical activity, cafeteria, teachers, and parents with community involvement-are included. The program requires cooperation of parents, schools, physicians, and political and business personnel. Their collaboration helps implement and sustain the program. Understanding the origin of coronary artery disease, hypertension, diabetes, and now the obesity epidemic shows the need to develop a framework for improving lifestyles and behaviors beginning in childhood. In addition to nutrition and exercise, the program addresses tobacco, alcohol, and drug use, and societal problems such as dropping out of school, violent behavior, and teenage pregnancy. An initial accomplishment is the entry into all elementary schools, representing approximately 7000 children. Early results show reduction in obesity, increased physical activity, improved decision making, and healthy attitudes. This public health model is inexpensive by utilizing prior research findings and integrating into community resources. Health education of children is an important aspect of preventive cardiology with a need for pediatric and adult cardiologists' involvement. PMID:20021623

  12. SUSCEPTIBILITY TO OZONE-INDUCED INJURY AND ANTIOXIDANT COMPENSATION IN RAT MODELS OF CARDIOVASCULAR DISEASE

    EPA Science Inventory

    Increased oxidative stress and compromised antioxidant status are common pathologic factors of cardiovascular diseases (CVD). It is hypothesized that individuals with chronic CVD are more susceptible to environmental exposures due to underlying oxidative stress. To determine the ...

  13. Whole Body Plethysmography Reveals Differential Ventilatory Responses to Ozone in Rat Models of Cardiovascular Disease

    EPA Science Inventory

    Increasingly, urban air pollution is recognized as an important determinant of cardiovascular disease. Host susceptibility to air pollution can vary due to genetic predisposition and underlying disease. To elucidate key factors of host ...

  14. ALTERATIONS OF FE HOMEOSTASIS IN RAT CARDIOVASCULAR DISEASE MODELS AND ITS CONTRIBUTION TO CARDIOPULMONARY TOXICITY

    EPA Science Inventory

    Introduction: Fe homeostasis can be disrupted in human cardiovascular diseases (CVD). We addressed how dysregulation of Fe homeostasis affected the pulmonary inflammation/oxidative stress response and disease progression after exposure to Libby amphibole (LA), an asbestifonn mine...

  15. Effects of thyroid hormone and thyroid dysfunction on the cardiovascular system.

    PubMed

    Kienle, R D; Bruyette, D; Pion, P D

    1994-05-01

    Thyroid disease is common in veterinary practice. The heart, especially the myocardium, is sensitive to thyroid hormone, and deficiencies or excesses can alter cardiovascular function. Observed changes result from direct effects upon the myocardium and indirect effects that result from effects upon the vasculature and peripheral tissues. Clinically significant cardiovascular abnormalities related to hypothyroidism are rare. If present, they are primarily manifest as reduced left ventricular pump function, as apparent echocardiographically, or arrhythmias. Hyperthyroidism is common in the cat and infrequently encountered in dogs. Clinically significant cardiovascular manifestations are common and often dramatic. Hyperdynamic systolic function and mild myocardial hypertrophy are common manifestations which may lead to overt congestive and high output heart failure. If signs of congestive heart failure or significant arrhythmias are not evident, specific therapy need only be directed toward restoration of the euthyroid state. In most cases the cardiovascular changes associated with thyroid dysfunction are completely reversible. PMID:8053109

  16. Dietary Maillard reaction products and their fermented products reduce cardiovascular risk in an animal model.

    PubMed

    Oh, N S; Park, M R; Lee, K W; Kim, S H; Kim, Y

    2015-08-01

    This study examined the effects of Maillard reaction products (MRP) and MRP fermented by lactic acid bacteria on antioxidants and their enhancement of cardiovascular health in ICR mouse and rat models. In previous in vitro studies, the selected lactic acid bacteria were shown to significantly affect the activity of MRP. The expression of genes (e.g., superoxide dismutase, catalase, and glutathione peroxidase) related to antioxidant activity was upregulated by Maillard-reacted sodium caseinate (cMRP), and cMRP fermented by Lactobacillus fermentum H9 (F-cMRP) synergistically increased the expression of catalase and superoxide dismutase when compared with the high-cholesterol-diet group. Bleeding time, the assay for determination of antithrombotic activity, was significantly prolonged by Maillard-reacted whey protein concentration (wMRP) and wMRP fermented by Lactobacillus gasseri H10 (F-wMRP), similar to the bleeding time of the aspirin group (positive control). In addition, the acute pulmonary thromboembolism-induced mice overcame severe body paralysis or death in both the wMRP and the F-wMRP groups. In the serum-level experiment, cMRP and F-cMRP significantly reduced the serum total and low-density lipoprotein cholesterol levels and triglycerides but had only a slight effect on high-density lipoprotein cholesterol. The levels of aspartate transaminase and alanine transaminase also declined in the cMRP and F-cMRP intake groups compared with the high-cholesterol-diet group. In particular, F-cMRP showed the highest reducing effects on triglycerides, aspartate transaminase, and alanine transaminase. Moreover, the expression of cholesterol-related genes in the F-cMRP group demonstrated greater effects than for the cMRP group in the level of cholesterol 7 α-hydroxylase (CYP7A1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), and low-density lipoprotein receptors compared with the high-cholesterol-diet group. The protective role of cMRP and F-cMRP in the high-cholesterol group may have been the result of an antioxidative defense mechanism that regulated cholesterol synthesis and metabolism. Therefore, F-cMRP and cMRP have the potential to play preventive and therapeutic roles in the management of cardiovascular disease. PMID:26004833

  17. Phenotypic differences in cardiovascular regulation in inbred rat models of aerobic capacity.

    PubMed

    Koch, L G; Britton, S L; Barbato, J C; Rodenbaugh, D W; DiCarlo, S E

    1999-08-31

    The Dark Aouti (DA) inbred strain of rats has superior aerobic treadmill running capacity compared with the Copenhagen (COP) strain of inbred rats. This difference in aerobic capacity provides a model to explore the genetic basis of variation in this trait. The present study evaluated intermediate phenotypic differences between 10 male COP inbred rats and 10 male DA inbred rats that might contribute to the difference in aerobic capacity between the strains. Five autonomically regulated cardiovascular variables were evaluated during rest or exercise by measuring the response to autonomic antagonists. The DA rat had enhanced autonomic function for the regulation of peripheral blood flow and cardiac output. Specifically, at rest the DA rats had significantly more sympathetic (123 +/- 8 vs. 99 +/- 7 beats/min) and parasympathetic (35 +/- 5 vs. 12 +/- 3 beats/min) tonus for heart rate control and more sympathetic support of blood pressure (70 +/- 7 vs. 38 +/- 6 mmHg) compared with the COP rats. During three graded levels of treadmill exercise the DA rats had higher blood pressures (16% on average) and higher heart rates (4% on average) relative to the COP rats. In addition, the DA rats had a 27% greater heart weight-to-body weight ratio compared with the COP strain of rats (3.63 +/- 0.08 vs. 2.85 +/- 0.07 g/kg). All five of these intermediate phenotypes could participate as variables causative of the difference in treadmill running capacity between the DA and COP strains of rats. PMID:11015562

  18. Cardiovascular and organ responses and adaptation responses to hypogravity in an experimental animal model.

    NASA Astrophysics Data System (ADS)

    Biondi, R.; Capodicasa, E.; Tassi, C.; Mezzasomal, L.; Benedetti, C.; Valiani, M.; Marconi, P.; Rossi, R.

    1995-10-01

    The head-down suspension (i.e antiorthostatic hypokinesia) rat is used to simulate weightlessness. However, little is known about cardiovascular and organ adaptation responses which, over a long time, can become pathologically significant. The purpose of this study was therefore to evaluate regional changes in the hematology parameters, Endotheline-1 (ET-1) concentration and urinary excretion of N-acetyl-β-D-glucosaminidase (EC 3.2.1.30) (NAG) in an experimental antiorthostatic rat model. The data indicate significant variations in the plasma ET-1 level in time, in the superior and inferior cava vessel blood of animals maintained for 10 days in hypogravity with respect to controls. These changes do not seem to be due to hemoconcentration. The increase in urinary NAG was observed during the first 24h of experiment, indicating renal stress, probably due to adverse blood flow variations within the organ. We conclude that the plasma ET-1 level changes could be responsible, overall for the blood flow variations in the kidney and renal stress could be the consequence of extended antiorthostatic hypokinesia. The ET-1 behaviour and urinary NAG excretion in rats exposed to antiorthostatic hypokjnetic hydynamia offer possibilities for understanding if these changes might be reversible or when they become pathological. This could give some relevant information about the effects of prolonged hypogravity during the space voyage.

  19. A CRISPR Path to Engineering New Genetic Mouse Models for Cardiovascular Research.

    PubMed

    Miano, Joseph M; Zhu, Qiuyu Martin; Lowenstein, Charles J

    2016-06-01

    Previous efforts to target the mouse genome for the addition, subtraction, or substitution of biologically informative sequences required complex vector design and a series of arduous steps only a handful of laboratories could master. The facile and inexpensive clustered regularly interspaced short palindromic repeats (CRISPR) method has now superseded traditional means of genome modification such that virtually any laboratory can quickly assemble reagents for developing new mouse models for cardiovascular research. Here, we briefly review the history of CRISPR in prokaryotes, highlighting major discoveries leading to its formulation for genome modification in the animal kingdom. Core components of CRISPR technology are reviewed and updated. Practical pointers for 2-component and 3-component CRISPR editing are summarized with many applications in mice including frameshift mutations, deletion of enhancers and noncoding genes, nucleotide substitution of protein-coding and gene regulatory sequences, incorporation of loxP sites for conditional gene inactivation, and epitope tag integration. Genotyping strategies are presented and topics of genetic mosaicism and inadvertent targeting discussed. Finally, clinical applications and ethical considerations are addressed as the biomedical community eagerly embraces this astonishing innovation in genome editing to tackle previously intractable questions. PMID:27102963

  20. The Impact of Arteriovenous Fistulae for Hemodialysis on the Cardiovascular System.

    PubMed

    Rao, Nitesh N; Dundon, Benjamin K; Worthley, Matthew I; Faull, Randall J

    2016-05-01

    An arteriovenous fistula (AVF) is critical for the provision of optimal chronic hemodialysis. Its creation causes significant hemodynamic alterations in cardiovascular parameters, and can result in progressive left and right heart failure. Despite successful kidney transplantation, many patients retain a functional AVF indefinitely, which may contribute to ongoing adverse cardiovascular outcomes. A similar high risk:benefit ratio may exist in peritoneal dialysis patients with "backup" AVF. PMID:26756565

  1. Options for new real-time image-processing architectures in cardiovascular systems

    NASA Astrophysics Data System (ADS)

    Albers, Rob; Boosten, Marcel; de With, Peter H. N.

    2007-03-01

    Low-dose X-ray imaging, diagnosis by image analysis and multi-modal medical imaging are example aspects that lead to more advanced image processing algorithms and the corresponding platforms on which they have to be executed. In this paper, we investigate the applicability of commercially available off-the-shelf components for a new computing platform. In the analysis, we will comply to some specific use cases. In cardiovascular minimal invasive surgery, physicians require low-latency imaging applications, as their actions must be directly visible on the screen. Typical image-processing algorithms in this domain are based on multi-resolution decomposition, noise reduction, image analysis and enhancement techniques. We have compared various solutions for possible processing architectures. The most interesting technology areas for constituting a new architecture are presented and we discuss the mapping of the use cases onto the various architectural proposals. Results show that a heterogeneous architecture gives the highest potential for current and upcoming image-processing applications. However, hardware and software solutions to support low-latency, high-bandwidth image streaming and an efficient concurrent distribution of functionality still need further development. This validates a clear direction for the future, which is based on modeling streaming computing architectures and special interconnect infrastructures.

  2. Autonomic control of cardiovascular system in pre- and postmenopausal women: a cross-sectional study

    PubMed Central

    Neufeld, Irina W.; Kiselev, Anton R.; Karavaev, Antoly S.; Prokhorov, Mikhail D.; Gridnev, Vladimir I.; Ponomarenko, Vladimir I.; Bezruchko, Boris P.

    2015-01-01

    Objective The aim of this cross-sectional study was to assess the features of autonomic control of the cardiovascular system in pre- and postmenopausal women. Material and Methods We studied 185 postmenopausal women aged 59.3±8.5 years (mean±SD) and 104 premenopausal women aged 45.1±5.8 years. Standard indices of heart rate variability (HRV) (mean heart rate, coefficient of variation, standard deviation of the NN interval (the time elapsing between two consecutive R waves in the electrocardiogram with normal sinus rhythm) (SDNN), square root of the mean squared differences of successive NN intervals (RMSSD), proportion derived by dividing RR50, the number of interval differences of successive NN intervals greater than 50 ms, by the total number of NN intervals (PNN50), and power of low frequency (LF) and high frequency (HF) bands in absolute values and percentages of total spectral power) and index S of synchronization between the 0.1-Hz rhythms in heart rate and photoplethysmogram were compared between these two groups at rest. We assessed the following sex hormones: estradiol, follicle stimulating hormone, dehydroepiandrosterone sulfate, and testosterone. Results Mean heart rate and power of LF and HF bands were significantly different (p<0.05) in pre- and postmenopausal women. The autonomic indices were similar in women with natural and surgical menopause. Some indices (coefficient of variation, SDNN, RMSSD, PNN50, and power of LF and HF bands) showed weak correlation with menopause time in women with natural menopause. In women with surgical menopause, a moderate statistically significant correlation was observed only between menopause time and S index (r=−0.41, p=0.039). In premenopausal women, only testosterone correlated weakly with coefficient of variation, SDNN, PNN50, RMSSD, and power of HF band. In postmenopausal women, no correlations were found. We did not find any significant relationship between autonomic indices and hot flashes, assessed by hot flash diary. Conclusion We did not find a clinically important relationship between cardiovascular autonomic control and menopausal status in women. PMID:25788843

  3. Cardiovascular System Response to Carbon Dioxide and Exercise in Oxygen-Enriched Environment at 3800 m

    PubMed Central

    Liu, Guohui; Liu, Xiaopeng; Qin, Zhifeng; Gu, Zhao; Wang, Guiyou; Shi, Weiru; Wen, Dongqing; Yu, Lihua; Luo, Yongchang; Xiao, Huajun

    2015-01-01

    Background: This study explores the responses of the cardiovascular system as humans exercise in an oxygen-enriched room at high altitude under various concentrations of CO2. Methods: The study utilized a hypobaric chamber set to the following specifications: 3800 m altitude with 25% O2 and different CO2 concentrations of 0.5% (C1), 3.0% (C2) and 5.0% (C3). Subjects exercised for 3 min three times, separated by 30 min resting periods in the above-mentioned conditions, at sea level (SL) and at 3800 m altitude (HA). The changes of heart rate variability, heart rate and blood pressure were analyzed. Results: Total power (TP) and high frequency power (HF) decreased notably during post-exercise at HA. HF increased prominently earlier the post-exercise period at 3800 m altitude with 25% O2 and 5.0% CO2 (C3), while low frequency power (LF) changed barely in all tests. The ratios of LF/HF were significantly higher during post-exercise in HA, and lower after high intensity exercise in C3. Heart rate and systolic blood pressure increased significantly in HA and C3. Conclusions: Parasympathetic activity dominated in cardiac autonomic modulation, and heart rate and blood pressure increased significantly after high intensity exercise in C3. PMID:26393634

  4. Labview Based ECG Patient Monitoring System for Cardiovascular Patient Using SMTP Technology

    PubMed Central

    Singh, Om Prakash; Mekonnen, Dawit; Malarvili, M. B.

    2015-01-01

    This paper leads to developing a Labview based ECG patient monitoring system for cardiovascular patient using Simple Mail Transfer Protocol technology. The designed device has been divided into three parts. First part is ECG amplifier circuit, built using instrumentation amplifier (AD620) followed by signal conditioning circuit with the operation amplifier (lm741). Secondly, the DAQ card is used to convert the analog signal into digital form for the further process. Furthermore, the data has been processed in Labview where the digital filter techniques have been implemented to remove the noise from the acquired signal. After processing, the algorithm was developed to calculate the heart rate and to analyze the arrhythmia condition. Finally, SMTP technology has been added in our work to make device more communicative and much more cost-effective solution in telemedicine technology which has been key-problem to realize the telediagnosis and monitoring of ECG signals. The technology also can be easily implemented over already existing Internet. PMID:27006940

  5. Labview Based ECG Patient Monitoring System for Cardiovascular Patient Using SMTP Technology.

    PubMed

    Singh, Om Prakash; Mekonnen, Dawit; Malarvili, M B

    2015-01-01

    This paper leads to developing a Labview based ECG patient monitoring system for cardiovascular patient using Simple Mail Transfer Protocol technology. The designed device has been divided into three parts. First part is ECG amplifier circuit, built using instrumentation amplifier (AD620) followed by signal conditioning circuit with the operation amplifier (lm741). Secondly, the DAQ card is used to convert the analog signal into digital form for the further process. Furthermore, the data has been processed in Labview where the digital filter techniques have been implemented to remove the noise from the acquired signal. After processing, the algorithm was developed to calculate the heart rate and to analyze the arrhythmia condition. Finally, SMTP technology has been added in our work to make device more communicative and much more cost-effective solution in telemedicine technology which has been key-problem to realize the telediagnosis and monitoring of ECG signals. The technology also can be easily implemented over already existing Internet. PMID:27006940

  6. Impact of Bisphenol A on the Cardiovascular System — Epidemiological and Experimental Evidence and Molecular Mechanisms

    PubMed Central

    Gao, Xiaoqian; Wang, Hong-Sheng

    2014-01-01

    Bisphenol A (BPA) is a ubiquitous plasticizing agent used in the manufacturing of polycarbonate plastics and epoxy resins. There is well-documented and broad human exposure to BPA. The potential risk that BPA poses to the human health has attracted much attention from regulatory agencies and the general public, and has been extensively studied. An emerging and rapidly growing area in the study of BPA’s toxicity is its impact on the cardiovascular (CV) system. Recent epidemiological studies have shown that higher urinary BPA concentration in humans is associated with various types of CV diseases, including angina, hypertension, heart attack and coronary and peripheral arterial disease. Experimental studies have demonstrated that acute BPA exposure promotes the development of arrhythmias in female rodent hearts. Chronic exposure to BPA has been shown to result in cardiac remodeling, atherosclerosis, and altered blood pressure in rodents. The underlying mechanisms may involve alteration of cardiac Ca2+ handling, ion channel inhibition/activation, oxidative stress, and genome/transcriptome modifications. In this review, we discuss these recent findings that point to the potential CV toxicity of BPA, and highlight the knowledge gaps in this growing research area. PMID:25153468

  7. The renin angiotensin system in the development of cardiovascular disease: role of aliskiren in risk reduction.

    PubMed

    Verdecchia, Paolo; Angeli, Fabio; Mazzotta, Giovanni; Gentile, Giorgio; Reboldi, Gianpaolo

    2008-01-01

    An association has been shown between plasma renin activity (PRA) and the risk of cardiovascular disease. There is also evidence that angiotensin II exerts detrimental effects on progression and instabilization of atherosclerotic plaque. The renin-angiotensin system (RAS) can be inhibited through inhibition of angiotensin I (Ang I) generation from angiotensinogen by direct renin inhibitors, inhibition of angiotensin II (Ang II) generation from angiotensin I by angiotensin-converting enzyme inhibitors and finally by direct inhibition of the action of Ang II receptor level. Aliskiren, the first direct renin inhibitor to reach the market, is a low-molecular-weight, orally active, hydrophilic nonpeptide. Aliskiren blocks Ang I generation, while plasma renin concentration increases because the drugs blocks the negative feed-back exerted by Ang II on renin synthesis. Because of its long pharmacological half-life, aliskiren is suitable for once-daily administration. Its through-to-peak ratio approximates 98% for the 300 mg/day dose. Because of its mechanism of action, aliskiren might offer the additional opportunity to inhibit progression of atherosclerosis at tissue level. Hypertension is an approved indication for this drug, which is also promising for the treatment of heart failure. The efficacy of this drug in reducing major clinical events is being tested in large ongoing clinical trials. PMID:19183745

  8. Incidence of and Risk Factors for Adverse Cardiovascular Events Among Patients With Systemic Lupus Erythematosus

    PubMed Central

    Magder, Laurence S.; Petri, Michelle

    2012-01-01

    Patients with systemic lupus erythematosus (SLE) are at excess risk of cardiovascular events (CVEs). There is uncertainty regarding the relative importance of SLE disease activity, medications, or traditional risk factors in this increased risk. To gain insight into this, the authors analyzed data from a cohort of 1,874 patients with SLE who were seen quarterly at a single clinical center (April 1987–June 2010) using pooled logistic regression analysis. In 9,485 person-years of follow-up, the authors observed 134 CVEs (rate = 14.1/1,000 person-years). This was 2.66 times what would be expected in the general population based on Framingham risk scores (95% confidence interval: 2.16, 3.16). After adjustment for age, CVE rates were not associated with duration of SLE. However, they were associated with average past levels of SLE disease activity and recent levels of circulating anti-double-stranded DNA. Past use of corticosteroids (in the absence of current use) was not associated with CVE rates. However, persons currently using 20 mg/day or more of corticosteroids had a substantial increase in risk even after adjustment for disease activity. Thus, consistent with findings in several recent publications among cohorts with other diseases, current use of corticosteroids was associated with an increased risk of CVEs. These results suggest a short-term impact of corticosteroids on CVE risk. PMID:23024137

  9. Spectrofluorimetric methods of stability-indicating assay of certain drugs affecting the cardiovascular system

    NASA Astrophysics Data System (ADS)

    Moussa, B. A.; Mohamed, M. F.; Youssef, N. F.

    2011-01-01

    Two stability-indicating spectrofluorimetric methods have been developed for the determination of ezetimibe and olmesartan medoxomil, drugs affecting the cardiovascular system, and validated in the presence of their degradation products. The first method, for ezetimibe, is based on an oxidative coupling reaction of ezetimibe with 3-methylbenzothiazolin-2-one hydrazone hydrochloride in the presence of cerium (IV) ammonium sulfate in an acidic medium. The quenching effect of ezetimibe on the fluorescence of excess cerous ions is measured at the emission wavelength, λem, of 345 nm with the excitation wavelength, λex, of 296 nm. Factors affecting the reaction were carefully studied and optimized. The second method, for olmesartan medoxomil, is based on measuring the native fluorescence intensity of olmesartan medoxomil in methanol at λem = 360 nm with λex = 286 nm. Regression plots revealed good linear relationships in the assay limits of 10-120 and 8-112 g/ml for ezetimibe and olmesartan medoxomil, respectively. The validity of the methods was assessed according to the United States Pharmacopeya guidelines. Statistical analysis of the results exposed good Student's t-test and F-ratio values. The introduced methods were successfully applied to the analysis of ezetimibe and olmesartan medoxomil in drug substances and drug products as well as in the presence of their degradation products.

  10. Development of Anatomophysiologic Knowledge Regarding the Cardiovascular System: From Egyptians to Harvey

    PubMed Central

    Bestetti, Reinaldo Bulgarelli; Restini, Carolina Baraldi A.; Couto, Lucélio B.

    2014-01-01

    Our knowledge regarding the anatomophysiology of the cardiovascular system (CVS) has progressed since the fourth millennium BC. In Egypt (3500 BC), it was believed that a set of channels are interconnected to the heart, transporting air, urine, air, blood, and the soul. One thousand years later, the heart was established as the center of the CVS by the Hippocratic Corpus in the medical school of Kos, and some of the CVS anatomical characteristics were defined. The CVS was known to transport blood via the right ventricle through veins and the pneuma via the left ventricle through arteries. Two hundred years later, in Alexandria, following the development of human anatomical dissection, Herophilus discovered that arteries were 6 times thicker than veins, and Erasistratus described the semilunar valves, emphasizing that arteries were filled with blood when ventricles were empty. Further, 200 years later, Galen demonstrated that arteries contained blood and not air. With the decline of the Roman Empire, Greco-Roman medical knowledge about the CVS was preserved in Persia, and later in Islam where, Ibn Nafis inaccurately described pulmonary circulation. The resurgence of dissection of the human body in Europe in the 14th century was associated with the revival of the knowledge pertaining to the CVS. The main findings were the description of pulmonary circulation by Servetus, the anatomical discoveries of Vesalius, the demonstration of pulmonary circulation by Colombo, and the discovery of valves in veins by Fabricius. Following these developments, Harvey described blood circulation. PMID:25590934

  11. Effects of zinc-deficient diets on the cardiovascular system in rabbits

    SciTech Connect

    Carter, J.W.; Koo, S.I.

    1986-03-05

    The authors used male New Zealand white rabbits to study the effects of zinc-deficient diets on the cardiovascular system. These 10 week-old rabbits were fed semi-purified diets containing either 50 ppm or less than 1 ppm zinc for 12 weeks. Serum samples were analyzed at 3,6,9 and 12 weeks. Body weight and food consumption were measured weekly. At necropsy the liver and heart were removed and weighed. Then the heart was perfused at 100 mm Hg with 10% buffered formalin via the ascending aorta. Coronary arteries were block-dissected and processed for light microscopy. Food consumption and body weights were not significantly altered throughout the study. Relative heart weights were not different; however, the relative liver weight of the zinc-deficient group was elevated by 11%. Neither total serum cholesterol or HDL-cholesterol were changed at any time. After 6 weeks treatment, serum zinc levels were depressed by 29% in the zinc-deficient group; no changes were observed for serum copper or calcium. Morphometric analysis of coronary arteries revealed a decreased combined thickness of the tunica intima and tunica media and a decreased area per unit length in the left coronary circumflex arteries of zinc-deficient rabbits. Significant changes reported here are probably related to possible alterations in lipoproteins metabolism and will be investigated in future studies.

  12. The cardiovascular system and the biochemistry of grafts used in heart surgery.

    PubMed

    Aydin, Suna; Aydin, Suleyman; Nesimi Eren, Mehmet; Sahin, Ibrahim; Yilmaz, Musa; Kalayci, Mehmet; Gungor, Orhan

    2013-01-01

    Blood is pumped into the cardiac muscle through arteries called the coronary arteries. Over time, the accumulation of cholesterol, coagulation factors, and cells on the walls of these arteries causes the walls to thicken and lose their elasticity, resulting in the development of atherosclerosis. When the blood supply of the heart is diminished by atherosclerosis, it can be restored by bypass surgery, in which atherosclerosis-free vein and/or artery grafts taken from another area of the body are used to replace the atherosclerotic vessels. These biological grafts used in surgery differ in biochemical composition and long-term patency. Although the great saphenous vein (GSV) has been the most popular graft material in revascularization for years, it has recently been superseded by the internal mammarian artery (IMA), which has a lower incidence of recurrence of atherosclerosis. The aim of the present review is briefly to address the structure of the cardiovascular system and blood vessels, and then, in the light recent data, to present the biochemical compositions and individual advantages of the graft materials used to restore an impaired blood supply to the heart. PMID:24324924

  13. Thyroid hormone and cardiovascular system: from basic concepts to clinical application.

    PubMed

    Iervasi, Giorgio; Nicolini, Giuseppina

    2013-04-01

    Experimental and clinical findings strongly support the concept that thyroid hormone (TH) plays a fundamental role in the cardiovascular (CV) homeostasis. CV diseases represent a major public health care and economic problem being one of the principal causes of morbidity, mortality and hospitalization. In particular, chronic heart failure (HF) is one of the most common reasons for general practitioners consultations in people >65-70 years old. TH derangement may have a key role in the evolution process of HF. In HF, the main and earlier alteration of the thyroid function is referred to as "low-T3" syndrome characterized by the reduction in serum total T3 and free T3 with normal levels of thyroxine (T4) and thyrotropin (TSH). This syndrome may affect till one-third of advanced HF patients. The main goal of this mini-review is to examine the main pathophysiological and clinical links between an altered thyroid metabolism and CV diseases, namely HF during progression of disease from organ specific to systemic disorder. PMID:23435988

  14. A comparative analysis of alternative approaches for quantifying nonlinear dynamics in cardiovascular system.

    PubMed

    Chen, Yun; Yang, Hui

    2013-01-01

    Heart rate variability (HRV) analysis has emerged as an important research topic to evaluate autonomic cardiac function. However, traditional time and frequency-domain analysis characterizes and quantify only linear and stationary phenomena. In the present investigation, we made a comparative analysis of three alternative approaches (i.e., wavelet multifractal analysis, Lyapunov exponents and multiscale entropy analysis) for quantifying nonlinear dynamics in heart rate time series. Note that these extracted nonlinear features provide information about nonlinear scaling behaviors and the complexity of cardiac systems. To evaluate the performance, we used 24-hour HRV recordings from 54 healthy subjects and 29 heart failure patients, available in PhysioNet. Three nonlinear methods are evaluated not only individually but also in combination using three classification algorithms, i.e., linear discriminate analysis, quadratic discriminate analysis and k-nearest neighbors. Experimental results show that three nonlinear methods capture nonlinear dynamics from different perspectives and the combined feature set achieves the best performance, i.e., sensitivity 97.7% and specificity 91.5%. Collectively, nonlinear HRV features are shown to have the promise to identify the disorders in autonomic cardiovascular function. PMID:24110259

  15. Development of anatomophysiologic knowledge regarding the cardiovascular system: from Egyptians to Harvey.

    PubMed

    Bestetti, Reinaldo Bulgarelli; Restini, Carolina Baraldi A; Couto, Lucélio B

    2014-12-01

    Our knowledge regarding the anatomophysiology of the cardiovascular system (CVS) has progressed since the fourth millennium BC. In Egypt (3500 BC), it was believed that a set of channels are interconnected to the heart, transporting air, urine, air, blood, and the soul. One thousand years later, the heart was established as the center of the CVS by the Hippocratic Corpus in the medical school of Kos, and some of the CVS anatomical characteristics were defined. The CVS was known to transport blood via the right ventricle through veins and the pneuma via the left ventricle through arteries. Two hundred years later, in Alexandria, following the development of human anatomical dissection, Herophilus discovered that arteries were 6 times thicker than veins, and Erasistratus described the semilunar valves, emphasizing that arteries were filled with blood when ventricles were empty. Further, 200 years later, Galen demonstrated that arteries contained blood and not air. With the decline of the Roman Empire, Greco-Roman medical knowledge about the CVS was preserved in Persia, and later in Islam where, Ibn Nafis inaccurately described pulmonary circulation. The resurgence of dissection of the human body in Europe in the 14th century was associated with the revival of the knowledge pertaining to the CVS. The main findings were the description of pulmonary circulation by Servetus, the anatomical discoveries of Vesalius, the demonstration of pulmonary circulation by Colombo, and the discovery of valves in veins by Fabricius. Following these developments, Harvey described blood circulation. PMID:25590934

  16. Impact of bisphenol a on the cardiovascular system - epidemiological and experimental evidence and molecular mechanisms.

    PubMed

    Gao, Xiaoqian; Wang, Hong-Sheng

    2014-08-01

    Bisphenol A (BPA) is a ubiquitous plasticizing agent used in the manufacturing of polycarbonate plastics and epoxy resins. There is well-documented and broad human exposure to BPA. The potential risk that BPA poses to the human health has attracted much attention from regulatory agencies and the general public, and has been extensively studied. An emerging and rapidly growing area in the study of BPA's toxicity is its impact on the cardiovascular (CV) system. Recent epidemiological studies have shown that higher urinary BPA concentration in humans is associated with various types of CV diseases, including angina, hypertension, heart attack and coronary and peripheral arterial disease. Experimental studies have demonstrated that acute BPA exposure promotes the development of arrhythmias in female rodent hearts. Chronic exposure to BPA has been shown to result in cardiac remodeling, atherosclerosis, and altered blood pressure in rodents. The underlying mechanisms may involve alteration of cardiac Ca2+ handling, ion channel inhibition/activation, oxidative stress, and genome/transcriptome modifications. In this review, we discuss these recent findings that point to the potential CV toxicity of BPA, and highlight the knowledge gaps in this growing research area. PMID:25153468

  17. Development of Anatomophysiologic Knowledge Regarding the Cardiovascular System: From Egyptians to Harvey.

    PubMed

    Bestetti, Reinaldo Bulgarelli; Restini, Carolina Baraldi A; Couto, Lucélio B

    2014-10-10

    Our knowledge regarding the anatomophysiology of the cardiovascular system (CVS) has progressed since the fourth millennium BC. In Egypt (3500 BC), it was believed that a set of channels are interconnected to the heart, transporting air, urine, air, blood, and the soul. One thousand years later, the heart was established as the center of the CVS by the Hippocratic Corpus in the medical school of Kos, and some of the CVS anatomical characteristics were defined. The CVS was known to transport blood via the right ventricle through veins and the pneuma via the left ventricle through arteries. Two hundred years later, in Alexandria, following the development of human anatomical dissection, Herophilus discovered that arteries were 6 times thicker than veins, and Erasistratus described the semilunar valves, emphasizing that arteries were filled with blood when ventricles were empty. Further, 200 years later, Galen demonstrated that arteries contained blood and not air. With the decline of the Roman Empire, Greco-Roman medical knowledge about the CVS was preserved in Persia, and later in Islam where, Ibn Nafis inaccurately described pulmonary circulation. The resurgence of dissection of the human body in Europe in the 14th century was associated with the revival of the knowledge pertaining to the CVS. The main findings were the description of pulmonary circulation by Servetus, the anatomical discoveries of Vesalius, the demonstration of pulmonary circulation by Colombo, and the discovery of valves in veins by Fabricius. Following these developments, Harvey described blood circulation. PMID:25317863

  18. Image-Based Computational Fluid Dynamics in Blood Vessel Models: Toward Developing a Prognostic Tool to Assess Cardiovascular Function Changes in Prolonged Space Flights

    NASA Technical Reports Server (NTRS)

    Chatzimavroudis, George P.; Spirka, Thomas A.; Setser, Randolph M.; Myers, Jerry G.

    2004-01-01

    One of NASA's objectives is to be able to perform a complete, pre-flight, evaluation of cardiovascular changes in astronauts scheduled for prolonged space missions. Computational fluid dynamics (CFD) has shown promise as a method for estimating cardiovascular function during reduced gravity conditions. For this purpose, MRI can provide geometrical information, to reconstruct vessel geometries, and measure all spatial velocity components, providing location specific boundary conditions. The objective of this study was to investigate the reliability of MRI-based model reconstruction and measured boundary conditions for CFD simulations. An aortic arch model and a carotid bifurcation model were scanned in a 1.5T Siemens MRI scanner. Axial MRI acquisitions provided images for geometry reconstruction (slice thickness 3 and 5 mm; pixel size 1x1 and 0.5x0.5 square millimeters). Velocity acquisitions provided measured inlet boundary conditions and localized three-directional steady-flow velocity data (0.7-3.0 L/min). The vessel walls were isolated using NIH provided software (ImageJ) and lofted to form the geometric surface. Constructed and idealized geometries were imported into a commercial CFD code for meshing and simulation. Contour and vector plots of the velocity showed identical features between the MRI velocity data, the MRI-based CFD data, and the idealized-geometry CFD data, with less than 10% differences in the local velocity values. CFD results on models reconstructed from different MRI resolution settings showed insignificant differences (less than 5%). This study illustrated, quantitatively, that reliable CFD simulations can be performed with MRI reconstructed models and gives evidence that a future, subject-specific, computational evaluation of the cardiovascular system alteration during space travel is feasible.

  19. Ghrelin and Cardiovascular Diseases

    PubMed Central

    Zhang, Gaigai; Yin, Xinhua; Qi, Yongfen; Pendyala, Lakshmana; Chen, Jack; Hou, Dongming; Tang, Chaoshu

    2010-01-01

    Ghrelin, a newly discovered bioactive peptide, is a natural endogenous ligand of the growth hormone (GH) secretagogue receptor and initially identified as a strong stimulant for the release of GH. Subsequent research has shown that ghrelin and its various receptors are ubiquitous in many other organs and tissues. Moreover, they participate in the regulation of appetite, energy, bodyweight, metabolism of glucose and fat, as well as modulation of gastrointestinal, cardiovascular, pulmonary, immune functions and cell proliferation/apoptosis. Increasing evidence has demonstrated that ghrelin has a close relationship with cardiovascular system. Ghrelin and its receptors are widely distributed in cardiovascular tissues, and there is no doubt that the effects of ghrelin in the cardiovascular system are mediated not only via its growth-hormone-releasing effect but also by its direct effects on the heart. Exogenous administration of ghrelin can dilate peripheral blood vessels, constrict coronary artery, improve endothelial function, as well as inhibit myocardial cell apoptosis. So, ghrelin may have cardiovascular protective effect, including lowering of blood pressure, regulation of atherosclerosis, and protection from ischemia/reperfusion injury as well as improving the prognosis of myocardial infarction and heart failure. Some of these new functions of ghrelin may provide new potential therapeutic opportunities for ghrelin in cardiovascular medicine. In this paper, we will review the existing evidence for cardiovascular effects of ghrelin, including the cardiovascular function, the variations in ghrelin plasma levels in pathophysiologicalogical conditions, the possible protective mechanisms of ghrelin, as well as its future potential therapeutic roles. PMID:21286280

  20. Systemic inflammation and cardiovascular risk factors predict rapid progression of atherosclerosis in rheumatoid arthritis

    PubMed Central

    del Rincón, Inmaculada; Polak, Joseph F; O’Leary, Daniel H; Battafarano, Daniel F; Erikson, John M; Restrepo, Jose F; Molina, Emily; Escalante, Agustín

    2014-01-01

    Objective To estimate atherosclerosis progression and identify influencing factors in rheumatoid arthritis (RA). Methods We used carotid ultrasound to measure intima-media thickness (IMT) in RA patients, and ascertained cardiovascular (CV) risk factors, inflammation markers and medications. A second ultrasound was performed approximately 3 years later. We calculated the progression rate by subtracting the baseline from the follow-up IMT, divided by the time between the two scans. We used logistic regression to identify baseline factors predictive of rapid progression. We tested for interactions of erythrocyte sedimentation rate (ESR) with CV risk factors and medication use. Results Results were available for 487 RA patients. The mean (SD) common carotid IMT at baseline was 0.571 mm (0.151). After a mean of 2.8 years, the IMT increased by 0.050 mm (0.055), p≤0.001, a progression rate of 0.018 mm/year (95% CI 0.016 to 0.020). Baseline factors associated with rapid progression included the number of CV risk factors (OR 1.27 per risk factor, 95% CI 1.01 to 1.61), and the ESR (OR 1.12 per 10 mm/h, 95% CI 1.02 to 1.23). The ESR×CV risk factor and ESR×medication product terms were significant, suggesting these variables modify the association between the ESR and IMT progression. Conclusions Systemic inflammation and CV risk factors were associated with rapid IMT progression. CV risk factors may modify the role of systemic inflammation in determining IMT progression over time. Methotrexate and antitumour necrosis factor agents may influence IMT progression by reducing the effect of the systemic inflammation on the IMT. PMID:24845391

  1. Evaluation of the Educational Value of YouTube Videos About Physical Examination of the Cardiovascular and Respiratory Systems

    PubMed Central

    2013-01-01

    Background A number of studies have evaluated the educational contents of videos on YouTube. However, little analysis has been done on videos about physical examination. Objective This study aimed to analyze YouTube videos about physical examination of the cardiovascular and respiratory systems. It was hypothesized that the educational standards of videos on YouTube would vary significantly. Methods During the period from November 2, 2011 to December 2, 2011, YouTube was searched by three assessors for videos covering the clinical examination of the cardiovascular and respiratory systems. For each video, the following information was collected: title, authors, duration, number of viewers, and total number of days on YouTube. Using criteria comprising content, technical authority, and pedagogy parameters, videos were rated independently by three assessors and grouped into educationally useful and non-useful videos. Results A total of 1920 videos were screened. Only relevant videos covering the examination of adults in the English language were identified (n=56). Of these, 20 were found to be relevant to cardiovascular examinations and 36 to respiratory examinations. Further analysis revealed that 9 provided useful information on cardiovascular examinations and 7 on respiratory examinations: scoring mean 14.9 (SD 0.33) and mean 15.0 (SD 0.00), respectively. The other videos, 11 covering cardiovascular and 29 on respiratory examinations, were not useful educationally, scoring mean 11.1 (SD 1.08) and mean 11.2 (SD 1.29), respectively. The differences between these two categories were significant (P<.001 for both body systems). The concordance between the assessors on applying the criteria was 0.89, with a kappa score >.86. Conclusions A small number of videos about physical examination of the cardiovascular and respiratory systems were identified as educationally useful; these videos can be used by medical students for independent learning and by clinical teachers as learning resources. The scoring system utilized by this study is simple, easy to apply, and could be used by other researchers on similar topics. PMID:24225171

  2. Communication system modeling

    NASA Technical Reports Server (NTRS)

    Holland, L. D.; Walsh, J. R., Jr.; Wetherington, R. D.

    1971-01-01

    This report presents the results of work on communications systems modeling and covers three different areas of modeling. The first of these deals with the modeling of signals in communication systems in the frequency domain and the calculation of spectra for various modulations. These techniques are applied in determining the frequency spectra produced by a unified carrier system, the down-link portion of the Command and Communications System (CCS). The second modeling area covers the modeling of portions of a communication system on a block basis. A detailed analysis and modeling effort based on control theory is presented along with its application to modeling of the automatic frequency control system of an FM transmitter. A third topic discussed is a method for approximate modeling of stiff systems using state variable techniques.

  3. A Molecular Communication System Model for Particulate Drug Delivery Systems.

    PubMed

    Chahibi, Youssef; Pierobon, Massimiliano; Song, Sang Ok; Akyildiz, Ian F

    2013-12-01

    The goal of a drug delivery system (DDS) is to convey a drug where the medication is needed, while, at the same time, preventing the drug from affecting other healthy parts of the body. Drugs composed of micro- or nano-sized particles (particulate DDS) that are able to cross barriers which prevent large particles from escaping the bloodstream are used in the most advanced solutions. Molecular communication (MC) is used as an abstraction of the propagation of drug particles in the body. MC is a new paradigm in communication research where the exchange of information is achieved through the propagation of molecules. Here, the transmitter is the drug injection, the receiver is the drug delivery, and the channel is realized by the transport of drug particles, thus enabling the analysis and design of a particulate DDS using communication tools. This is achieved by modeling the MC channel as two separate contributions, namely, the cardiovascular network model and the drug propagation network. The cardiovascular network model allows to analytically compute the blood velocity profile in every location of the cardiovascular system given the flow input by the heart. The drug propagation network model allows the analytical expression of the drug delivery rate at the targeted site given the drug injection rate. Numerical results are also presented to assess the flexibility and accuracy of the developed model. The study of novel optimization techniques for a more effective and less invasive drug delivery will be aided by this model, while paving the way for novel communication techniques for Intrabody communication networks. PMID:23807425

  4. Understanding the Causes and Implications of Endothelial Metabolic Variation in Cardiovascular Disease through Genome-Scale Metabolic Modeling

    PubMed Central

    McGarrity, Sarah; Halldórsson, Haraldur; Palsson, Sirus; Johansson, Pär I.; Rolfsson, Óttar

    2016-01-01

    High-throughput biochemical profiling has led to a requirement for advanced data interpretation techniques capable of integrating the analysis of gene, protein, and metabolic profiles to shed light on genotype–phenotype relationships. Herein, we consider the current state of knowledge of endothelial cell (EC) metabolism and its connections to cardiovascular disease (CVD) and explore the use of genome-scale metabolic models (GEMs) for integrating metabolic and genomic data. GEMs combine gene expression and metabolic data acting as frameworks for their analysis and, ultimately, afford mechanistic understanding of how genetic variation impacts metabolism. We demonstrate how GEMs can be used to investigate CVD-related genetic variation, drug resistance mechanisms, and novel metabolic pathways in ECs. The application of GEMs in personalized medicine is also highlighted. Particularly, we focus on the potential of GEMs to identify metabolic biomarkers of endothelial dysfunction and to discover methods of stratifying treatments for CVDs based on individual genetic markers. Recent advances in systems biology methodology, and how these methodologies can be applied to understand EC metabolism in both health and disease, are thus highlighted. PMID:27148541

  5. Does early intensive multifactorial therapy reduce modelled cardiovascular risk in individuals with screen-detected diabetes? Results from the ADDITION-Europe cluster randomized trial

    PubMed Central

    Black, J A; Sharp, S J; Wareham, N J; Sandbæk, A; Rutten, G E H M; Lauritzen, T; Khunti, K; Davies, M J; Borch-Johnsen, K; Griffin, S J; Simmons, R K

    2014-01-01

    Aims Little is known about the long-term effects of intensive multifactorial treatment early in the diabetes disease trajectory. In the absence of long-term data on hard outcomes, we described change in 10-year modelled cardiovascular risk in the 5 years following diagnosis, and quantified the impact of intensive treatment on 10-year modelled cardiovascular risk at 5 years. Methods In a pragmatic, cluster-randomized, parallel-group trial in Denmark, the Netherlands and the UK, 3057 people with screen-detected Type 2 diabetes were randomized by general practice to receive (1) routine care of diabetes according to national guidelines (1379 patients) or (2) intensive multifactorial target-driven management (1678 patients). Ten-year modelled cardiovascular disease risk was calculated at baseline and 5 years using the UK Prospective Diabetes Study Risk Engine (version 3β). Results Among 2101 individuals with complete data at follow up (73.4%), 10-year modelled cardiovascular disease risk was 27.3% (sd 13.9) at baseline and 21.3% (sd 13.8) at 5-year follow-up (intensive treatment group difference –6.9, sd 9.0; routine care group difference –5.0, sd 12.2). Modelled 10-year cardiovascular disease risk was lower in the intensive treatment group compared with the routine care group at 5 years, after adjustment for baseline cardiovascular disease risk and clustering (–2.0; 95% CI –3.1 to –0.9). Conclusions Despite increasing age and diabetes duration, there was a decline in modelled cardiovascular disease risk in the 5 years following diagnosis. Compared with routine care, 10-year modelled cardiovascular disease risk was lower in the intensive treatment group at 5 years. Our results suggest that patients benefit from intensive treatment early in the diabetes disease trajectory, where the rate of cardiovascular disease risk progression may be slowed. PMID:24533664

  6. Independent Study Strategies for Learning about the Cardiovascular System from Text: A Comparison of Self-explanation and Drawing

    NASA Astrophysics Data System (ADS)

    Lam, Diane Phuong Nghinh

    Representations, such as figures and drawings, are aspects of biology that are key to learning, teaching, and communicating scientific ideas. While many studies have investigated undergraduate students' abilities to interpret representations generated by science experts, much remains to be understood about how student-generated representations (i.e., drawings) can support learning. Prior research suggests that theoretical mechanisms to explain how drawing aids learning may parallel those that explain how self-explanation aids learning, an area of educational research that has been extensively studied. As such, this research draws from the self-explanation literature to explore the similarities and differences between the use of drawing and self-explaining as independent study strategies for learning about the cardiovascular system (CVS) from text. We found that students who were asked to draw as they studied the CVS text performed better than students asked to self-explain on multiple learning measures. Their mental models, as interpreted from their drawings of the system, were significantly more accurate, and their responses to questions about structures and pathways within the system were more accurate. Further analyses of self-explanations and drawings revealed that the number of goal-oriented self-explanations a student generated was a significant predictor of their assessment scores, especially on questions about functions. Meanwhile, the number of passage-specific images a learner generated in their drawing was predictive of assessment scores, especially on questions about structures. Finally, findings from case studies identified attributes of self-explanations and drawings that may make them more meaningful for learning, such as self-explaining for the purposes of understanding how parts of the system connect together, and drawing to highlight the main ideas of the text. Findings from this study suggest that drawing is generally more effective than self-explanation for learning about the CVS, and should be promoted as a useful strategy for learning biology from text.

  7. Fuel delivery system model

    SciTech Connect

    Ricci, G.; Verma, A.

    1996-09-01

    A fuel delivery system hydraulic model has been developed by coupling a distributed hydraulic network model with lumped models for the various components of the fuel system like the injectors, regulators, accumulators, etc. The resulting governing equations are linearized around the nominal system pressure and integrated using a fourth order Runge-Kutta algorithm with a variable time-stepping scheme. The model assumes isothermal behavior, negligible frictional losses and single-phase flow. The goal of the model is to study small signal type perturbations around the operating system pressure. Typical outputs from exercising the model are presented. The model can be used to study fuel pressure and velocity transients throughout the system and to design the various fuel system components in a system context.

  8. Cardiovascular Deconditioning

    NASA Technical Reports Server (NTRS)

    Charles, John B.; Fritsch-Yelle, Janice M.; Whitson, Peggy A.; Wood, Margie L.; Brown, Troy E.; Fortner, G. William

    1999-01-01

    Spaceflight causes adaptive changes in cardiovascular function that may deleteriously affect crew health and safety. Over the last three decades, symptoms of cardiovascular changes have ranged from postflight orthostatic tachycardia and decreased exercise capacity to serious cardiac rhythm disturbances during extravehicular activities (EVA). The most documented symptom of cardiovascular dysfunction, postflight orthostatic intolerance, has affected a significant percentage of U.S. Space Shuttle astronauts. Problems of cardiovascular dysfunction associated with spaceflight are a concern to NASA. This has been particularly true during Shuttle flights where the primary concern is the crew's physical health, including the pilot's ability to land the Orbiter, and the crew's ability to quickly egress and move to safety should a dangerous condition arise. The study of astronauts during Shuttle activities is inherently more difficult than most human research. Consequently, sample sizes have been small and results have lacked consistency. Before the Extended Duration Orbiter Medical Project (EDOMP), there was a lack of normative data on changes in cardiovascular parameters during and after spaceflight. The EDOMP for the first time allowed studies on a large enough number of subjects to overcome some of these problems. There were three primary goals of the Cardiovascular EDOMP studies. The first was to establish, through descriptive studies, a normative data base of cardiovascular changes attributable to spaceflight. The second goal was to determine mechanisms of cardiovascular changes resulting from spaceflight (particularly orthostatic hypotension and cardiac rhythm disturbances). The third was to evaluate possible countermeasures. The Cardiovascular EDOMP studies involved parallel descriptive, mechanistic, and countermeasure evaluations.

  9. Characteristics and popular topics of latest researches into the effects of air particulate matter on cardiovascular system by bibliometric analysis.

    PubMed

    Jia, Xiaofeng; Guo, Xinbiao; Li, Haicun; An, Xinying; Zhao, Yingguang

    2013-03-01

    In recent years, many epidemiological and toxicological studies have investigated the adverse effects of air particulate matter (PM) on the cardiovascular system. However, it is difficult for the researchers to have a timely and effective overall command of the latest characteristics and popular topics in such a wide field. Different from the previous reviews, in which the research characteristics and trends are empirically concluded by experts, we try to have a comprehensive evaluation of the above topics for the first time by bibliometric analysis, a quantitative tool in information exploration. This study aims to introduce the bibliometric method into the field of PM and cardiovascular system. The articles were selected by searching PubMed/MEDLINE (from 2007 to 2012) using Medical Subject Headings (MeSH) terms "particulate matter" and "cardiovascular system". A total of 935 eligible articles and 1895 MeSH terms were retrieved and processed by the software Thomson Data Analyzer (TDA). The bibliographic information and the MeSH terms of these articles were classified and analyzed to summarize the research characteristics. The top 200 high-frequency MeSH terms (the cumulative frequency percentage was 74.2%) were clustered for popular-topic conclusion. We summarized the characteristics of published articles, of researcher collaborations and of the contents. Ten clusters of MeSH terms are presented. Six popular topics are concluded and elaborated for reference. Our study presents an overview of the characteristics and popular topics in the field of PM and cardiovascular system in the past five years by bibliometric tools, which may provide a new perspective for future researchers. PMID:23480197

  10. Protein Biomarkers of New-Onset Cardiovascular Disease: A Prospective Study from the Systems Approach to Biomarker Research in Cardiovascular Disease (SABRe CVD) Initiative

    PubMed Central

    Yin, Xiaoyan; Subramanian, Subha; Hwang, Shih-Jen; O’Donnell, Christopher J.; Fox, Caroline S.; Courchesne, Paul; Muntendam, Pieter; Adourian, Aram; Juhasz, Peter; Larson, Martin G.; Levy, Daniel

    2014-01-01

    Objective Incorporation of novel plasma protein biomarkers may improve current models for prediction of atherosclerotic cardiovascular disease (ASCVD) risk. Approach and Results We utilized discovery mass spectrometry (MS) to determine plasma concentrations of 861 proteins in 135 myocardial infarction (MI) cases and 135 matched controls. We then measured 59markers by targeted MS in 336 ASCVD case-control pairs. Associations with MI or ASCVD were tested in single marker and multimarker analyses adjusted for established ASCVD risk factors. Twelve single markers from discovery MS were associated with MI incidence (at p<0.01) adjusting for clinical risk factors. Seven proteins in aggregate (cyclophilin A, CD5 antigen-like, cell surface glycoprotein MUC18, collagen-alpha 1 [XVIII] chain, salivary alpha-amylase 1, C-reactive protein, and multimerin-2) were highly associated with MI (p<0.0001) and significantly improved its prediction compared to a model with clinical risk factors alone (C-statistic of 0.71 vs. 0.84). Through targeted MS, twelve single proteins were predictors of ASCVD (at p<0.05) after adjusting for established risk factors. In multimarker analyses, four proteins in combination (alpha-1-acid glycoprotein 1, paraoxonase 1, tetranectin, and CD5 antigen-like, predicted incident ASCVD (p<0.0001) and moderately improved the C-statistic from the model with clinical covariates alone (C-statistic of 0.69 vs. 0.73). Conclusions Proteomics profiling identified single and multimarker protein panels that are associated with new onset ASCVD and may lead to a better understanding of underlying disease mechanisms. Our findings include many novel protein biomarkers that, if externally validated, may improve risk assessment for MI and ASCVD. PMID:24526693

  11. Mathematical circulatory system model

    NASA Technical Reports Server (NTRS)

    Lakin, William D. (Inventor); Stevens, Scott A. (Inventor)

    2010-01-01

    A system and method of modeling a circulatory system including a regulatory mechanism parameter. In one embodiment, a regulatory mechanism parameter in a lumped parameter model is represented as a logistic function. In another embodiment, the circulatory system model includes a compliant vessel, the model having a parameter representing a change in pressure due to contraction of smooth muscles of a wall of the vessel.

  12. Space radiation and cardiovascular disease risk

    PubMed Central

    Boerma, Marjan; Nelson, Gregory A; Sridharan, Vijayalakshmi; Mao, Xiao-Wen; Koturbash, Igor; Hauer-Jensen, Martin

    2015-01-01

    Future long-distance space missions will be associated with significant exposures to ionizing radiation, and the health risks of these radiation exposures during manned missions need to be assessed. Recent Earth-based epidemiological studies in survivors of atomic bombs and after occupational and medical low dose radiation exposures have indicated that the cardiovascular system may be more sensitive to ionizing radiation than was previously thought. This has raised the concern of a cardiovascular disease risk from exposure to space radiation during long-distance space travel. Ground-based studies with animal and cell culture models play an important role in estimating health risks from space radiation exposure. Charged particle space radiation has dense ionization characteristics and may induce unique biological responses, appropriate simulation of the space radiation environment and careful consideration of the choice of the experimental model are critical. Recent studies have addressed cardiovascular effects of space radiation using such models and provided first results that aid in estimating cardiovascular disease risk, and several other studies are ongoing. Moreover, astronauts could potentially be administered pharmacological countermeasures against adverse effects of space radiation, and research is focused on the development of such compounds. Because the cardiovascular response to space radiation has not yet been clearly defined, the identification of potential pharmacological countermeasures against cardiovascular effects is still in its infancy. PMID:26730293

  13. Space radiation and cardiovascular disease risk.

    PubMed

    Boerma, Marjan; Nelson, Gregory A; Sridharan, Vijayalakshmi; Mao, Xiao-Wen; Koturbash, Igor; Hauer-Jensen, Martin

    2015-12-26

    Future long-distance space missions will be associated with significant exposures to ionizing radiation, and the health risks of these radiation exposures during manned missions need to be assessed. Recent Earth-based epidemiological studies in survivors of atomic bombs and after occupational and medical low dose radiation exposures have indicated that the cardiovascular system may be more sensitive to ionizing radiation than was previously thought. This has raised the concern of a cardiovascular disease risk from exposure to space radiation during long-distance space travel. Ground-based studies with animal and cell culture models play an important role in estimating health risks from space radiation exposure. Charged particle space radiation has dense ionization characteristics and may induce unique biological responses, appropriate simulation of the space radiation environment and careful consideration of the choice of the experimental model are critical. Recent studies have addressed cardiovascular effects of space radiation using such models and provided first results that aid in estimating cardiovascular disease risk, and several other studies are ongoing. Moreover, astronauts could potentially be administered pharmacological countermeasures against adverse effects of space radiation, and research is focused on the development of such compounds. Because the cardiovascular response to space radiation has not yet been clearly defined, the identification of potential pharmacological countermeasures against cardiovascular effects is still in its infancy. PMID:26730293

  14. MRI-Based Computational Fluid Dynamics in Experimental Vascular Models: Toward the Development of an Approach for Prediction of Cardiovascular Changes During Prolonged Space Missions

    NASA Technical Reports Server (NTRS)

    Spirka, T. A.; Myers, J. G.; Setser, R. M.; Halliburton, S. S.; White, R. D.; Chatzimavroudis, G. P.

    2005-01-01

    A priority of NASA is to identify and study possible risks to astronauts health during prolonged space missions [l]. The goal is to develop a procedure for a preflight evaluation of the cardiovascular system of an astronaut and to forecast how it will be affected during the mission. To predict these changes, a computational cardiovascular model must be constructed. Although physiology data can be used to make a general model, a more desirable subject-specific model requires anatomical, functional, and flow data from the specific astronaut. MRI has the unique advantage of providing images with all of the above information, including three-directional velocity data which can be used as boundary conditions in a computational fluid dynamics (CFD) program [2,3]. MRI-based CFD is very promising for reproduction of the flow patterns of a specific subject and prediction of changes in the absence of gravity. The aim of this study was to test the feasibility of this approach by reconstructing the geometry of MRI-scanned arterial models and reproducing the MRI-measured velocities using CFD simulations on these geometries.

  15. Cardiovascular group

    NASA Technical Reports Server (NTRS)

    Blomqvist, Gunnar

    1989-01-01

    As a starting point, the group defined a primary goal of maintaining in flight a level of systemic oxygen transport capacity comparable to each individual's preflight upright baseline. The goal of maintaining capacity at preflight levels would seem to be a reasonable objective for several different reasons, including the maintenance of good health in general and the preservation of sufficient cardiovascular reserve capacity to meet operational demands. It is also important not to introduce confounding variables in whatever other physiological studies are being performed. A change in the level of fitness is likely to be a significant confounding variable in the study of many organ systems. The principal component of the in-flight cardiovascular exercise program should be large-muscle activity such as treadmill exercise. It is desirable that at least one session per week be monitored to assure maintenance of proper functional levels and to provide guidance for any adjustments of the exercise prescription. Appropriate measurements include evaluation of the heart-rate/workload or the heart-rate/oxygen-uptake relationship. Respiratory gas analysis is helpful by providing better opportunities to document relative workload levels from analysis of the interrelationships among VO2, VCO2, and ventilation. The committee felt that there is no clear evidence that any particular in-flight exercise regimen is protective against orthostatic hypotension during the early readaptation phase. Some group members suggested that maintenance of the lower body muscle mass and muscle tone may be helpful. There is also evidence that late in-flight interventions to reexpand blood volume to preflight levels are helpful in preventing or minimizing postflight orthostatic hypotension.

  16. Strain differences in antioxidants in rat models of cardiovascular disease exposed to ozone.

    PubMed

    Hatch, Gary E; Crissman, Kay; Schmid, Judy; Richards, Judy E; Ward, William O; Schladweiler, Mette C; Ledbetter, Allen D; Kodavanti, Urmila P

    2015-01-01

    We examined the hypothesis that antioxidant substances and enzymes in lung, heart and in bronchoalveolar lavage fluid (BALF) are altered in response to O3 in cardiovascular disease and/or metabolic syndrome (CVD)-prone rat models. CVD strains [spontaneously hypertensive (SH), SH stroke-prone (SHSP), SHHF/Mcc heart failure obese (SHHF), insulin-resistant JCR:LA-cp obese (JCR) and Fawn-Hooded hypertensive (FHH)] were compared with normal strains [Wistar, Sprague-Dawley (SD) and Wistar Kyoto (WKY)]. Total glutathione (GSH + GSSG or GSx), reduced ascorbate (AH2), uric acid (UA) and antioxidant enzymes were determined in lung, heart and BALF immediately (0 h) or 20-h post 4-h nose-only exposure to 0.0, 0.25, 0.5 and 1.0 ppm O3. Basal- and O3-induced antioxidant substances in tissues varied widely among strains. Wistar rats had a robust O3-induced increase in GSx and AH2 in the lung. Two CVD strains (JCR and SHHF) had high basal levels of AH2 and GSx in BALF as well as high basal lung UA. Across all strains, high BALF GSx was only observed when high BALF AH2 was present. CVD rats tended to respond less to O3 than normal. High-basal BALF AH2 levels were associated with decreased O3 toxicity. In summary, large differences were observed between both normal and CVD rat strains in low-molecular weight antioxidant concentrations in lung, BALF and heart tissue. Wistar (normal) and JCR and SHHF (CVD) rats appeared to stand out as peculiar in terms of basal- or O3-induced changes. Results elucidate interactions among antioxidants and air pollutants that could enhance understanding of cardiopulmonary disease. PMID:26667331

  17. Projected Impact of Salt Restriction on Prevention of Cardiovascular Disease in China: A Modeling Study

    PubMed Central

    Liu, Jing; Coxson, Pamela G.; Penko, Joanne; Goldman, Lee; Bibbins-Domingo, Kirsten; Zhao, Dong

    2016-01-01

    Objectives To estimate the effects of achieving China’s national goals for dietary salt (NaCl) reduction or implementing culturally-tailored dietary salt restriction strategies on cardiovascular disease (CVD) prevention. Methods The CVD Policy Model was used to project blood pressure lowering and subsequent downstream prevented CVD that could be achieved by population-wide salt restriction in China. Outcomes were annual CVD events prevented, relative reductions in rates of CVD incidence and mortality, quality-adjusted life-years (QALYs) gained, and CVD treatment costs saved. Results Reducing mean dietary salt intake to 9.0 g/day gradually over 10 years could prevent approximately 197 000 incident annual CVD events [95% uncertainty interval (UI): 173 000–219 000], reduce annual CVD mortality by approximately 2.5% (2.2–2.8%), gain 303 000 annual QALYs (278 000–329 000), and save approximately 1.4 billion international dollars (Int$) in annual CVD costs (Int$; 1.2–1.6 billion). Reducing mean salt intake to 6.0 g/day could approximately double these benefits. Implementing cooking salt-restriction spoons could prevent 183 000 fewer incident CVD cases (153 000–215 000) and avoid Int$1.4 billion in CVD treatment costs annually (1.2–1.7 billion). Implementing a cooking salt substitute strategy could lead to approximately three times the health benefits of the salt-restriction spoon program. More than three-quarters of benefits from any dietary salt reduction strategy would be realized in hypertensive adults. Conclusion China could derive substantial health gains from implementation of population-wide dietary salt reduction policies. Most health benefits from any dietary salt reduction program would be realized in adults with hypertension. PMID:26840409

  18. Applications of SPICE for modeling miniaturized biomedical sensor systems

    NASA Technical Reports Server (NTRS)

    Mundt, C. W.; Nagle, H. T.

    2000-01-01

    This paper proposes a model for a miniaturized signal conditioning system for biopotential and ion-selective electrode arrays. The system consists of three main components: sensors, interconnections, and signal conditioning chip. The model for this system is based on SPICE. Transmission-line based equivalent circuits are used to represent the sensors, lumped resistance-capacitance circuits describe the interconnections, and a model for the signal conditioning chip is extracted from its layout. A system for measurements of biopotentials and ionic activities can be miniaturized and optimized for cardiovascular applications based on the development of an integrated SPICE system model of its electrochemical, interconnection, and electronic components.

  19. A farnesyltransferase inhibitor prevents both the onset and late progression of cardiovascular disease in a progeria mouse model.

    PubMed

    Capell, Brian C; Olive, Michelle; Erdos, Michael R; Cao, Kan; Faddah, Dina A; Tavarez, Urraca L; Conneely, Karen N; Qu, Xuan; San, Hong; Ganesh, Santhi K; Chen, Xiaoyan; Avallone, Hedwig; Kolodgie, Frank D; Virmani, Renu; Nabel, Elizabeth G; Collins, Francis S

    2008-10-14

    Hutchinson-Gilford progeria syndrome (HGPS) is the most dramatic form of human premature aging. Death occurs at a mean age of 13 years, usually from heart attack or stroke. Almost all cases of HGPS are caused by a de novo point mutation in the lamin A (LMNA) gene that results in production of a mutant lamin A protein termed progerin. This protein is permanently modified by a lipid farnesyl group, and acts as a dominant negative, disrupting nuclear structure. Treatment with farnesyltransferase inhibitors (FTIs) has been shown to prevent and even reverse this nuclear abnormality in cultured HGPS fibroblasts. We have previously created a mouse model of HGPS that shows progressive loss of vascular smooth muscle cells in the media of the large arteries, in a pattern that is strikingly similar to the cardiovascular disease seen in patients with HGPS. Here we show that the dose-dependent administration of the FTI tipifarnib (R115777, Zarnestra) to this HGPS mouse model can significantly prevent both the onset of the cardiovascular phenotype as well as the late progression of existing cardiovascular disease. These observations provide encouraging evidence for the current clinical trial of FTIs for this rare and devastating disease. PMID:18838683

  20. Analysis of cardiovascular regulation.

    PubMed

    Wilhelm, F H; Grossman, P; Roth, W T

    1999-01-01

    Adequate characterization of hemodynamic and autonomic responses to physical and mental stress can elucidate underlying mechanisms of cardiovascular disease or anxiety disorders. We developed a physiological signal processing system for analysis of continuously recorded ECG, arterial blood pressure (BP), and respiratory signals using the programming language Matlab. Data collection devices are a 16-channel digital, physiological recorder (Vitaport), a finger arterial pressure transducer (Finapres), and a respiratory inductance plethysmograph (Respitrace). Besides the conventional analysis of the physiological channels, power spectral density and transfer functions of respiration, heart rate, and blood pressure variability are used to characterize respiratory sinus arrhythmia (RSA), 0.10-Hz BP oscillatory activity (Mayer-waves), and baroreflex sensitivity. The arterial pressure transducer waveforms permit noninvasive estimation of stroke volume, cardiac output, and systemic vascular resistance. Time trends in spectral composition of indices are assessed using complex demodulation. Transient dynamic changes of cardiovascular parameters at the onset of stress and recovery periods are quantified using a regression breakpoint model that optimizes piecewise linear curve fitting. Approximate entropy (ApEn) is computed to quantify the degree of chaos in heartbeat dynamics. Using our signal processing system we found distinct response patterns in subgroups of patients with coronary artery disease or anxiety disorders, which were related to specific pharmacological and behavioral factors. PMID:11143335

  1. NEP systems model

    NASA Technical Reports Server (NTRS)

    Gilland, Jim; George, Jeffrey A.

    1993-01-01

    Various aspects of nuclear electric propulsion (NEP) systems analysis and modeling are discussed. The following specific topics are covered: (1) systems analysis challenges; (2) goals for NEP systems analysis; (3) the Nuclear Propulsion Office approach; and (4) NEP subsystem model development. The discussion is presented in vugraph form.

  2. Cardiovascular reactivity after blockade of angiotensin AT1 receptors in the experimental model of tilting test in conscious rats

    PubMed Central

    Bedette, D; Santos, R A S; Fontes, M A P

    2008-01-01

    Background and purpose: Studies have shown that the angiotensin II AT1 receptor antagonist, losartan, accentuates the hypotensive response in the orthostatic stress test (tilt) performed in anaesthetized rats. The same effect was not reported with other AT1 antagonists. The aim of this study was to re-evaluate the effects of AT1 receptor blockade on the cardiovascular response to tilt in a model developed for conscious rats. Experimental approach: Rats (n=5–7 per group) were instrumented for infusion of drugs and recording of cardiovascular parameters and, after recovery, placed in a plastic tube positioned over the tilt board. The tilt test was conducted by raising the head side of the tilt board from horizontal position to 75° head up position for 15 min. Key results: Compared with control group (NaCl 0.9%, 1 ml kg−1), oral treatment with 1 mg kg−1 per day of losartan or telmisartan did not alter the blood pressure response during tilt. With the 10 mg kg−1 dose, both antagonists altered the blood pressure response during tilt (mean maximum changes −11±3 mm Hg; P<0.01). A post-tilt hypotension was observed with both doses in losartan and telmisartan groups (−13±1 and −9±2 mm Hg, respectively; P<0.01). Conclusions and implications: The present results indicate that the effect of losartan on the cardiovascular reactivity to tilt shares a similar profile to that of other AT1 antagonists. Evidence discussed addresses the importance of using a conscious model for testing the influence of antihypertensive drugs on the cardiovascular reactivity to orthostatic challenges. PMID:18193073

  3. Social and physical environments and disparities in risk for cardiovascular disease: the healthy environments partnership conceptual model.

    PubMed

    Schulz, Amy J; Kannan, Srimathi; Dvonch, J Timothy; Israel, Barbara A; Allen, Alex; James, Sherman A; House, James S; Lepkowski, James

    2005-12-01

    The Healthy Environments Partnership (HEP) is a community-based participatory research effort investigating variations in cardiovascular disease risk, and the contributions of social and physical environments to those variations, among non-Hispanic black, non-Hispanic white, and Hispanic residents in three areas of Detroit, Michigan. Initiated in October 2000 as a part of the National Institute of Environmental Health Sciences' Health Disparities Initiative, HEP is affiliated with the Detroit Community-Academic Urban Research Center. The study is guided by a conceptual model that considers race-based residential segregation and associated concentrations of poverty and wealth to be fundamental factors influencing multiple, more proximate predictors of cardiovascular risk. Within this model, physical and social environments are identified as intermediate factors that mediate relationships between fundamental factors and more proximate factors such as physical activity and dietary practices that ultimately influence anthropomorphic and physiologic indicators of cardiovascular risk. The study design and data collection methods were jointly developed and implemented by a research team based in community-based organizations, health service organizations, and academic institutions. These efforts include collecting and analyzing airborne particulate matter over a 3-year period; census and administrative data; neighborhood observation checklist data to assess aspects of the physical and social environment; household survey data including information on perceived stressors, access to social support, and health-related behaviors; and anthropometric, biomarker, and self-report data as indicators of cardiovascular health. Through these collaborative efforts, HEP seeks to contribute to an understanding of factors that contribute to racial and socioeconomic health inequities, and develop a foundation for efforts to eliminate these disparities in Detroit. PMID:16330371

  4. Social and Physical Environments and Disparities in Risk for Cardiovascular Disease: The Healthy Environments Partnership Conceptual Model

    PubMed Central

    Schulz, Amy J.; Kannan, Srimathi; Dvonch, J. Timothy; Israel, Barbara A.; Allen, Alex; James, Sherman A.; House, James S.; Lepkowski, James

    2005-01-01

    The Healthy Environments Partnership (HEP) is a community-based participatory research effort investigating variations in cardiovascular disease risk, and the contributions of social and physical environments to those variations, among non-Hispanic black, non-Hispanic white, and Hispanic residents in three areas of Detroit, Michigan. Initiated in October 2000 as a part of the National Institute of Environmental Health Sciences’ Health Disparities Initiative, HEP is affiliated with the Detroit Community–Academic Urban Research Center. The study is guided by a conceptual model that considers race-based residential segregation and associated concentrations of poverty and wealth to be fundamental factors influencing multiple, more proximate predictors of cardiovascular risk. Within this model, physical and social environments are identified as intermediate factors that mediate relationships between fundamental factors and more proximate factors such as physical activity and dietary practices that ultimately influence anthropomorphic and physiologic indicators of cardiovascular risk. The study design and data collection methods were jointly developed and implemented by a research team based in community-based organizations, health service organizations, and academic institutions. These efforts include collecting and analyzing airborne particulate matter over a 3-year period; census and administrative data; neighborhood observation checklist data to assess aspects of the physical and social environment; household survey data including information on perceived stressors, access to social support, and health-related behaviors; and anthropometric, biomarker, and self-report data as indicators of cardiovascular health. Through these collaborative efforts, HEP seeks to contribute to an understanding of factors that contribute to racial and socioeconomic health inequities, and develop a foundation for efforts to eliminate these disparities in Detroit. PMID:16330371

  5. CARDIOVASCULAR DISEASES, SUSCEPTIBILITY TO OXIDATIVE INJURY AND COMPENSATORY MECHANISMS: INSIGHTS FROM RODENT MODELS

    EPA Science Inventory

    Cardiovascular diseases (CVD) are the number one cause for human mortality and nearly 25% of the population develops chronic CVD at an age of 65 years or older. Environmental and genetic interactions govern pathogenesis. Increased oxidative stress and compromised antioxidant stat...

  6. The Development of a Model for Adult Education in Nutrition and Cardiovascular Disease.

    ERIC Educational Resources Information Center

    Walker, Susan K.; Villano, Maurice W.

    Two nutrition education modules were developed on cardiovascular disease and fat-controlled diet consisting of a self-instruction leader's guide and teaching package to conduct learning sessions for the participants. The sessions consisted of an audio-visual presentation, situations related to the module topic, group discussion, role-playing,…

  7. Flipped Classroom Model Improves Graduate Student Performance in Cardiovascular, Respiratory, and Renal Physiology

    ERIC Educational Resources Information Center

    Tune, Johnathan D.; Sturek, Michael; Basile, David P.

    2013-01-01

    The purpose of this study was to assess the effectiveness of a traditional lecture-based curriculum versus a modified "flipped classroom" curriculum of cardiovascular, respiratory, and renal physiology delivered to first-year graduate students. Students in both courses were provided the same notes and recorded lectures. Students in the…

  8. The Development of a Model for Adult Education in Nutrition and Cardiovascular Disease.

    ERIC Educational Resources Information Center

    Walker, Susan K.; Villano, Maurice W.

    Two nutrition education modules were developed on cardiovascular disease and fat-controlled diet consisting of a self-instruction leader's guide and teaching package to conduct learning sessions for the participants. The sessions consisted of an audio-visual presentation, situations related to the module topic, group discussion, role-playing,

  9. Examination of Susceptibility to Libby Amphibole Asbestos-Induced Injury in Rat Models of Cardiovascular Disease

    EPA Science Inventory

    Although cardiovascular disease (CVD) is considered a risk factor for the exacerbation of air pollution health effects, no studies have been done assessing the influence of the disease on the development of lung injury induced by asbestos exposure. In this study we examined lung ...

  10. Flipped Classroom Model Improves Graduate Student Performance in Cardiovascular, Respiratory, and Renal Physiology

    ERIC Educational Resources Information Center

    Tune, Johnathan D.; Sturek, Michael; Basile, David P.

    2013-01-01

    The purpose of this study was to assess the effectiveness of a traditional lecture-based curriculum versus a modified "flipped classroom" curriculum of cardiovascular, respiratory, and renal physiology delivered to first-year graduate students. Students in both courses were provided the same notes and recorded lectures. Students in the

  11. Modeling of geothermal systems

    SciTech Connect

    Bodvarsson, G.S.; Pruess, K.; Lippmann, M.J.

    1985-03-01

    During the last decade the use of numerical modeling for geothermal resource evaluation has grown significantly, and new modeling approaches have been developed. In this paper we present a summary of the present status in numerical modeling of geothermal systems, emphasizing recent developments. Different modeling approaches are described and their applicability discussed. The various modeling tasks, including natural-state, exploitation, injection, multi-component and subsidence modeling, are illustrated with geothermal field examples. 99 refs., 14 figs.

  12. [The production of nitro esters active at the level of the cardiovascular system].

    PubMed

    Dănilă, G; Ungureanu, M; Dorneanu, V; Lupaşcu, D

    1996-01-01

    In order to obtain new compounds with cardiovascular activity, some esters of nitric acid with ethanolamine were synthesised, using some aromatic acids, acexamic acid, the natural methylxanthines-theophylline and theobromine. The melting points, yields and solubility of the new compounds were determined, and the chemical structures were confirmed by elemental analysis C, H, N, and by spectral analysis in KBr. PMID:9455471

  13. Role of the Sympathetic Nervous System in Stress-Mediated Cardiovascular Disease.

    PubMed

    Hering, Dagmara; Lachowska, Kamila; Schlaich, Markus

    2015-10-01

    A high incidence of acute cardiovascular events and sudden cardiac death following unexpected acute emotional stress or a natural catastrophic disaster has been well-documented over the past decades. Chronic psychosocial factors have been shown to be directly linked to the development of hypertension, cardiovascular disease and stroke. Activation of various neurogenic pathways is an important mediator of acute and chronic stress-induced hypertension and heart disease. Heightened sympathetic activation has been shown to be a critical contributor linking psychogenic effects on cardiovascular regulation to serious and often fatal CV outcomes. Accordingly, several therapeutic approaches that attenuate autonomic imbalance via modulation of increased sympathetic outflow by either non-pharmacological or interventional means have been shown to alleviate clinical symptoms. Likewise stress reduction per se achieved with transcendental medicine has been linked to improved patient outcomes. Therapies that oppose adrenergic activity and/or have the potential to attenuate negative emotions are likely to reduce cardiovascular risk and its adverse consequences attributable to chronic mental stress. PMID:26318888

  14. System Advisor Model

    Energy Science and Technology Software Center (ESTSC)

    2010-03-01

    The System Advisor Model (SAM) is a performance and economic model designed to facilitate decision making for people involved in the renewable energy industry, ranging from project managers and engineers to incentive program designers, technology developers, and researchers.

  15. Investigations of the Cardiovascular and Respiratory Systems on Board the International Space Station: Experiments Puls and Pneumocard

    NASA Astrophysics Data System (ADS)

    Baranov, V. M.; Baevsky, R. M.; Drescher, J.; Tank, J.

    parameters describing the results of the function of these systems like heart rate, arterial pressure, cardiac output, or breathing frequency, concentration of O2 and CO2 , etc. Missing significant changes of these parameters during weightlessness supports the hypothesis that adaptational and compensatory mechanisms are sufficient and guarantee cardiovascular homeostasis under changing environmental conditions. characteristic changes of the vegetative balance and of the activity of different regulatory elements at the brainstem and subcortical level. This changes guaranteed the adaptation to long term weightlessness. However, it remains unclear to what extent the different levels are involved. Moreover, the criteria describing the efficacy of cardiorespiratory interaction for the different functional states are not defined yet. The investigation of this problems is highly relevant in order to improve the medical control, especially if considering that the disruption of regulatory systems mostly precedes dangerous destruction of homeostasis. cardiovascular and respiratory function on Board the International Space Station (ISS) aiming to obtain new insights into the interaction between different regulatory elements. "Puls" is measures ECG, photoplethysmogram (PPG), and the pneumotachogram (PTG). The ECG is used to measure time series of R-R intervals and to analyse HRV. PPG is used to define the pulse wave velocity, phases of the cardiac cycle, and an estimate of the filling of finger vessels. The variability of these parameters is also calculated and compared to HRV. The analysis of the PTG allows to describe the interaction of the regulatory parameters of the cardiovascular and respiratory systems. Hence, an important feature of the experiment "Puls" is the investigation of regulatory mechanisms rather than of cardiovascular homeostasis. cardiography) and left ventricular contractility (seismocardiography) will be obtained. This expansion is of major importance because, it allows us to get deeper insight into regulatory mechanisms of the cardiorespiratory system and into the state of cardiovascular homeostasis. have the same size (90 x 60 x 20 mm), identical technology, and identical interfaces with the computer. the onboard experiment and to store the obtained data; 2) "Editor": to archive and dearchive the obtained data, to edit them and to insert necessary comments and markers; 3) "Earth": to edit and analyse the data under laboratory conditions.The subprogram "Earth" is an original software package for data analysis, peak detection, calculation of a variety of parameters, time series forming and editing, statistical and spectral time series analysis. Furthermore, a specialized data base is designated for storing of the biosignals, results of analysis, information about the investigated subjects and comments of simple autonomic function tests will allow to assess different elements of the regulatory mechanisms. Special interest will be given to respiratory tests in order to evaluate the interaction between the cardiovascular system and respiration. volunteers and in patients with different cardiovascular diseases. The results were used to establish normal values and criteria for the prognosis of pathologic changes. These materials will be used at valuation the data obtained during researches on ISS. respiratory systems onboard the ISS are the following: 1) definition of the most important parameters, which can be measured simple and reliable during weightlessness; 2) development of miniaturized devices which can be kept on the astronauts body and which could be used in future as an autonomic system of operational medical control; 3) development of original software packages which allow to detect prognostic changes of the regulatory pattern preceding diseases and based on time series analysis of a large number of cardiorespiratory parameters.

  16. Sheep (Ovis aries) as a Model for Cardiovascular Surgery and Management before, during, and after Cardiopulmonary Bypass

    PubMed Central

    DiVincenti, Louis; Westcott, Robin; Lee, Candice

    2014-01-01

    Because of its similarity to humans in important respects, sheep (Ovis aries) are a common animal model for translational research in cardiovascular surgery. However, some unique aspects of sheep anatomy and physiology present challenges to its use in these complicated experiments. In this review, we discuss relevant anatomy and physiology of sheep and discuss management before, during, and after procedures requiring cardiopulmonary bypass to provide a concise source of information for veterinarians, technicians, and researchers developing and implementing protocols with this model. PMID:25255065

  17. Effect of titanium dioxide nanoparticles on the cardiovascular system after oral administration.

    PubMed

    Chen, Zhangjian; Wang, Yun; Zhuo, Lin; Chen, Shi; Zhao, Lin; Luan, Xianguo; Wang, Haifang; Jia, Guang

    2015-12-01

    Titanium dioxide nanoparticles (TiO2 NPs) have been widely used in various consumer products, especially food and personal care products. Compared to the well-characterized adverse cardiovascular effect of inhaled ambient ultrafine particles, research on the health response to orally administrated TiO2 NPs is still limited. In our study, we performed an in vivo study in Sprague-Dawley rats to understand the cardiovascular effect of TiO2 NPs after oral intake. After daily gastrointestinal administration of TiO2 NPs at 0, 2, 10, 50 mg/kg for 30 and 90 days, heart rate (HR), blood pressure, blood biochemical parameters and histopathology of cardiac tissues was assessed to quantify cardiovascular damage. Mild and temporary reduction of HR and systolic blood pressure as well as an increase of diastolic blood pressure was observed after daily oral administration of TiO2 NPs for 30 days. Injury of cardiac function was observed after daily oral administration of TiO2 NPs for 90 days as reflected in decreased activities of lactate dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (HBDH) and creatine kinase (CK). Increased white blood cells count (WBC) and granulocytes (GRN) in blood as well as increased concentrations of tumor necrosis factor α (TNF α) and interleukin 6 (IL-6) in the serum indicated inflammatory response initiated by TiO2 NPs exposure. It was hypothesize that cardiac damage and inflammatory response are the possible mechanisms of the adverse cardiovascular effects induced by orally administrated TiO2 NPs. Data from our study suggested that even at low dose of TiO2 NPs can induce adverse cardiovascular effects after 30 days or 90 days of oral exposure, thus warranting concern for the dietary intake of TiO2 NPs for consumers. PMID:26387441

  18. Testosterone and Cardiovascular Disease

    PubMed Central

    Tambo, Amos; Roshan, Mohsin H.K.; Pace, Nikolai P.

    2016-01-01

    Cardiovascular disease [CVD] is a leading cause of mortality accounting for a global incidence of over 31%. Atherosclerosis is the primary pathophysiology underpinning most types of CVD. Historically, modifiable and non-modifiable risk factors were suggested to precipitate CVD. Recently, epidemiological studies have identified emerging risk factors including hypotestosteronaemia, which have been associated with CVD. Previously considered in the realms of reproductive biology, testosterone is now believed to play a critical role in the cardiovascular system in health and disease. The actions of testosterone as they relate to the cardiac vasculature and its implication in cardiovascular pathology is reviewed. PMID:27014372

  19. 25-Hydroxyvitamin D and Cardiovascular Disease in Patients With Systemic Lupus Erythematosus: Data From a Large International Inception Cohort

    PubMed Central

    LERTRATANAKUL, APINYA; WU, PEGGY; DYER, ALAN; UROWITZ, MURRAY; GLADMAN, DAFNA; FORTIN, PAUL; BAE, SANG-CHEOL; GORDON, CAROLINE; CLARKE, ANN; BERNATSKY, SASHA; HANLY, JOHN G.; ISENBERG, DAVID; RAHMAN, ANISUR; MERRILL, JOAN; WALLACE, DANIEL J.; GINZLER, ELLEN; KHAMASHTA, MUNTHER; BRUCE, IAN; NIVED, OLA; STURFELT, GUNNAR; STEINSSON, KRISTJAN; MANZI, SUSAN; DOOLEY, MARY ANNE; KALUNIAN, KENNETH; PETRI, MICHELLE; ARANOW, CYNTHIA; van VOLLENHOVEN, RONALD; STOLL, THOMAS; RAMSEY-GOLDMAN, ROSALIND

    2016-01-01

    Objective An association between 25-hydroxyvitamin D (25[OH]D; vitamin D) deficiency and increased cardiovascular (CV) risk factors and CV disease (CVD) has been shown in general population studies. Vitamin D deficiency has been noted in systemic lupus erythematosus (SLE), and CVD is a major cause of morbidity and mortality in SLE. The objectives of this study were to estimate the associations of 25(OH)D levels with CV risk factors and to determine whether low baseline 25(OH)D levels predict future CV events in patients participating in an international inception cohort. Methods Data were collected on 890 participants, including demographics, SLE activity and damage assessments, CV risk factors and events, medications, laboratory assessments of 25(OH)D levels, and inflammatory markers. Multiple logistic and Cox regressions were used to estimate the associations of baseline 25(OH)D levels with baseline CV risk factors and CVD events. The models were adjusted for age, sex, race, season, and country, with and without body mass index. Results Patients in the higher quartiles of 25(OH)D were less likely to have hypertension and hyperlipidemia and were more likely to have lower C-reactive protein levels and lower Systemic Lupus Erythematosus Disease Activity Index 2000 scores at baseline when compared with the first quartile. Vitamin D levels were not independently associated with CVD event incidence; however, hazard ratios for CVD event incidence decreased with successively higher quartiles. Conclusion Lower baseline 25(OH)D levels are associated with higher risk for CV risk factors and more active SLE at baseline. There may be a trend toward a lower likelihood of CVD events in those with higher baseline 25(OH)D levels. PMID:24470118

  20. Modeling of dynamic cardiovascular responses during G-transition-induced orthostatic stress in pitch and roll rotations.

    PubMed

    Melek, William W; Lu, Ziren; Kapps, Alex; Cheung, Bob

    2002-12-01

    Dynamic and fuzzy models for a typical subject's cardiovascular response to the orthostatic stress have been developed based on experimental data. In our original study (Cheung et al., 1999), arterial blood pressure (BP) time-series data were obtained using a man-rated tilt table that applies gigahertz-acceleration transitions from +0.861 Gz [head-up (HU)] to -0.707 G [head-down (HD)] and back to +0.861 Gz (HU) using either pitch or roll rotations (Cheung et al., 1999). G transitions of different duration and onset rates are common in fighter maneuvers. Based on these data, two types of predictive models have been developed in this paper: 1) second-order discrete-time models that predict BP dynamics during pitch and roll rotations and 2) fuzzy logic models that predict important variations in a subject's cardiovascular dynamics induced by HU-to-HD and HD-to-HU transitions. These two types of models assist in providing an operationally important predictive view on the characteristics of BP responses to orthostatic stress induced by pitch and roll rotations of a fighter jet pilot. The new models are being currently utilized in the design of operational recommendations for more G-tolerant operational flight regimes (e.g., split-S tactical maneuver) than the ones currently in use for modern combat aircraft. PMID:12549730

  1. Sympathetic nervous system activity and cardiovascular homeostatis during head-up tilt in patients with spinal cord injuries.

    PubMed

    Houtman, S; Oeseburg, B; Hughson, R L; Hopman, M T

    2000-08-01

    The relationship between sympathetic nervous system activity and cardiovascular responses to head-up tilt in patients with spinal cord injuries and in able-bodied subjects was studied. Twenty-seven adults, nine in each of the three groups (tetraplegia, paraplegia, and able-bodied subjects) were tilted 70 degrees, head up, for 12 minutes after 20 minutes supine rest. Differences between steady-state measurements of mean arterial pressure, stroke volume, and sympathetic nervous system activity were estimated in both positions. Sympathetic nervous system activity was reflected by the low-frequency peak of the blood pressure variability spectrum. From supine rest to head-up tilt, low-frequency power increased in able-bodied subjects (median, 0.42 mm Hg2, p = 0.003), which was different (p = 0.015) from patients with tetraplegia and paraplegia (-0.15 and -0.10 mm Hg2, respectively). Stroke volume and mean arterial pressure decreased in patients with tetraplegia (-40% and -9 mm Hg, respectively; p = 0.008, both variables) more than in able-bodied subjects (-33%, 11 mm Hg, respectively) or patients with paraplegia (-24%, 8 mm Hg, respectively). Results indicated increased sympathetic nervous system activity during head-up tilt in able-bodied subjects, but not in patients with paraplegia or tetraplegia, whereas patients with tetraplegia, but not paraplegia, showed poorer cardiovascular homeostasis than able-bodied subjects. This suggests that patients with paraplegia maintained cardiovascular homeostasis during head-up tilt without increased sympathetic nervous system activity. PMID:11029019

  2. Cardiovascular Events in Systemic Lupus Erythematosus: A Nationwide Study in Spain From the RELESSER Registry.

    PubMed

    Fernández-Nebro, Antonio; Rúa-Figueroa, Íñigo; López-Longo, Francisco J; Galindo-Izquierdo, María; Calvo-Alén, Jaime; Olivé-Marqués, Alejandro; Ordóñez-Cañizares, Carmen; Martín-Martínez, María A; Blanco, Ricardo; Melero-González, Rafael; Ibáñez-Rúan, Jesús; Bernal-Vidal, José Antonio; Tomero-Muriel, Eva; Uriarte-Isacelaya, Esther; Horcada-Rubio, Loreto; Freire-González, Mercedes; Narváez, Javier; Boteanu, Alina L; Santos-Soler, Gregorio; Andreu, José L; Pego-Reigosa, José M

    2015-07-01

    This article estimates the frequency of cardiovascular (CV) events that occurred after diagnosis in a large Spanish cohort of patients with systemic lupus erythematosus (SLE) and investigates the main risk factors for atherosclerosis. RELESSER is a nationwide multicenter, hospital-based registry of SLE patients. This is a cross-sectional study. Demographic and clinical variables, the presence of traditional risk factors, and CV events were collected. A CV event was defined as a myocardial infarction, angina, stroke, and/or peripheral artery disease. Multiple logistic regression analysis was performed to investigate the possible risk factors for atherosclerosis. From 2011 to 2012, 3658 SLE patients were enrolled. Of these, 374 (10.9%) patients suffered at least a CV event. In 269 (7.4%) patients, the CV events occurred after SLE diagnosis (86.2% women, median [interquartile range] age 54.9 years [43.2-66.1], and SLE duration of 212.0 months [120.8-289.0]). Strokes (5.7%) were the most frequent CV event, followed by ischemic heart disease (3.8%) and peripheral artery disease (2.2%). Multivariate analysis identified age (odds ratio [95% confidence interval], 1.03 [1.02-1.04]), hypertension (1.71 [1.20-2.44]), smoking (1.48 [1.06-2.07]), diabetes (2.2 [1.32-3.74]), dyslipidemia (2.18 [1.54-3.09]), neurolupus (2.42 [1.56-3.75]), valvulopathy (2.44 [1.34-4.26]), serositis (1.54 [1.09-2.18]), antiphospholipid antibodies (1.57 [1.13-2.17]), low complement (1.81 [1.12-2.93]), and azathioprine (1.47 [1.04-2.07]) as risk factors for CV events. We have confirmed that SLE patients suffer a high prevalence of premature CV disease. Both traditional and nontraditional risk factors contribute to this higher prevalence. Although it needs to be verified with future studies, our study also shows-for the first time-an association between diabetes and CV events in SLE patients. PMID:26200625

  3. NASA'S Standard Measures During Bed Rest: Adaptations in the Cardiovascular System

    NASA Technical Reports Server (NTRS)

    Lee, Stuart M. C.; Feiveson, Alan H.; Martin, David S.; Cromwell, Roni L.; Platts, Steven H.; Stenger, Michael B.

    2016-01-01

    Bed rest is a well-accepted analog of space flight that has been used extensively to investigate physiological adaptations in a larger number of subjects in a shorter amount of time than can be studied with space flight and without the confounding effects associated with normal mission operations. However, comparison across studies of different bed rest durations, between sexes, and between various countermeasure protocols have been hampered by dissimilarities in bed rest conditions, measurement protocols, and testing schedules. To address these concerns, NASA instituted standard bed rest conditions and standard measures for all physiological disciplines participating in studies conducted at the Flight Analogs Research Unit (FARU) at the University of Texas-Medical Branch. Investigators for individual studies employed their own targeted study protocols to address specific hypothesis-driven questions, but standard measures tests were conducted within these studies on a non-interference basis to maximize data availability while reducing the need to implement multiple bed rest studies to understand the effects of a specific countermeasure. When possible, bed rest standard measures protocols were similar to tests nominally used for medically-required measures or research protocols conducted before and after Space Shuttle and International Space Station missions. Specifically, bed rest standard measures for the cardiovascular system implemented before, during, and after bed rest at the FARU included plasma volume (carbon monoxide rebreathing), cardiac mass and function (2D, 3D and Doppler echocardiography), and orthostatic tolerance testing (15- or 30-minutes of 80 degree head-up tilt). Results to-date indicate that when countermeasures are not employed, plasma volume decreases and the incidence of presyncope during head-up tilt is more frequent even after short-duration bed rest while reductions in cardiac function and mass are progressive as bed rest duration increases. Additionally, while plasma volume loss can be corrected and cardiac mass can be prevented with properly applied countermeasures, orthostatic tolerance is more difficult to protect when supine exercise is the only countermeasure. Similar results have been observed after space flight. Plasma volume, cardiac chamber volume, and orthostatic tolerance recover relatively quickly with resumption of ambulation and normal activity levels after bed rest but restoration of cardiac mass is prolonged.

  4. Integrated Workforce Modeling System

    NASA Technical Reports Server (NTRS)

    Moynihan, Gary P.

    2000-01-01

    There are several computer-based systems, currently in various phases of development at KSC, which encompass some component, aspect, or function of workforce modeling. These systems may offer redundant capabilities and/or incompatible interfaces. A systems approach to workforce modeling is necessary in order to identify and better address user requirements. This research has consisted of two primary tasks. Task 1 provided an assessment of existing and proposed KSC workforce modeling systems for their functionality and applicability to the workforce planning function. Task 2 resulted in the development of a proof-of-concept design for a systems approach to workforce modeling. The model incorporates critical aspects of workforce planning, including hires, attrition, and employee development.

  5. Long‐Term Renal Denervation Normalizes Disrupted Blood Pressure Circadian Rhythm and Ameliorates Cardiovascular Injury in a Rat Model of Metabolic Syndrome

    PubMed Central

    Katayama, Tetsuji; Sueta, Daisuke; Kataoka, Keiichiro; Hasegawa, Yu; Koibuchi, Nobutaka; Toyama, Kensuke; Uekawa, Ken; MingJie, Ma; Nakagawa, Takashi; Maeda, Masanobu; Ogawa, Hisao; Kim‐Mitsuyama, Shokei

    2013-01-01

    Background Although renal denervation significantly reduces blood pressure in patients with resistant hypertension, the role of the renal nerve in hypertension with metabolic syndrome is unknown. We investigated the impact of long‐term renal denervation on SHR/NDmcr‐cp(+/+) (SHRcp) rats, a useful rat model of metabolic syndrome, to determine the role of the renal nerve in hypertension with metabolic syndrome. Methods and Results SHRcp rats were divided into (1) a renal denervation (RD) group and (2) a sham operation group (control) to examine the effects of long‐term RD on blood pressure circadian rhythm, renal sodium retention‐related molecules, the renin‐angiotensin‐aldosterone system, metabolic disorders, and organ injury. RD in SHRcp rats not only significantly reduced blood pressure but also normalized blood pressure circadian rhythm from the nondipper to the dipper type, and this improvement was associated with an increase in urinary sodium excretion and the suppression of renal Na+‐Cl− cotransporter upregulation. RD significantly reduced plasma renin activity. RD significantly prevented cardiovascular remodeling and impairment of vascular endothelial function and attenuated cardiovascular oxidative stress. However, RD failed to ameliorate obesity, metabolic disorders, and renal injury and failed to reduce systemic sympathetic activity in SHRcp rats. Conclusions By including the upregulation of the Na+‐Cl− cotransporter, the renal sympathetic nerve is involved in the disruption of blood pressure circadian rhythm as well as hypertension in metabolic syndrome. Thus, RD seems to be a useful therapeutic strategy for hypertension with metabolic syndrome. PMID:23974905

  6. At the heart of the matter: the endocannabinoid system in cardiovascular function and dysfunction.

    PubMed

    Montecucco, Fabrizio; Di Marzo, Vincenzo

    2012-06-01

    Starting from the well-documented effects of marijuana smoking on heart rate and blood pressure, the cardiovascular effects of Δ⁹-tetrahydrocannabinol (THC, the main psychotropic ingredient of Cannabis) and endocannabinoids [THC endogenous counterparts that activate cannabinoid receptor type 1 (CB₁) and 2 (CB₂)] have been thoroughly investigated. These studies were mostly aimed at establishing the molecular bases of the hypotensive actions of THC, endocannabinoids and related molecules, but also evaluated their therapeutic potential in cardiac injury protection, metabolic cardiovascular risk factors and atherosclerotic plaque vulnerability. The results of these investigations, reviewed here, also served to highlight some of the most peculiar aspects of endocannabinoid signaling, such as redundancy in endocannabinoid targets and the often dualistic role of CB₁ and CB₂ receptors during pathological conditions. PMID:22503477

  7. Controversies in Cardiovascular Research: Induced pluripotent stem cell-derived cardiomyocytes – boutique science or valuable arrhythmia model?

    PubMed Central

    Knollmann, Björn C

    2013-01-01

    As part of the series on Controversies in Cardiovascular Research, the article reviews the strengths and limitations of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) as models of cardiac arrhythmias. Specifically, the article attempts to answer the following questions: Which clinical arrhythmias can be modeled by iPSC-CM? How well can iPSC-CM model adult ventricular myocytes? What are the strengths and limitations of published iPSC-CM arrhythmia models? What new mechanistic insight has been gained? What is the evidence that would support using iPSC-CM to personalize anti-arrhythmic drug therapy? The review also discusses the pros and cons of using the iPSC-CM technology for modeling specific genetic arrhythmia disorders such as long QT syndrome, Brugada Syndrome or Catecholaminergic Polymorphic Ventricular Tachycardia. PMID:23569106

  8. From form to function: the role of Nox4 in the cardiovascular system

    PubMed Central

    Chen, Feng; Haigh, Stephen; Barman, Scott; Fulton, David J. R.

    2012-01-01

    The NADPH oxidase (Nox) family of proteins is comprised of seven members, including Noxes1–5 and the Duoxes 1 and 2. Nox4 is readily distinguished from the other Nox isoforms by its high level of expression in cardiovascular tissues and unique enzymatic properties. Nox4 is constitutively active and the amount of reactive oxygen species (ROS) contributed by Nox4 is primarily regulated at the transcriptional level although there is recent evidence for post-translational control. Nox4 emits a different pattern of ROS and its subcellular localizations, tissue distribution and influence over signaling pathways is different from the other Nox enzymes. Previous investigations have revealed that Nox4 is involved in oxygen sensing, vasomotor control, cellular proliferation, differentiation, migration, apoptosis, senescence, fibrosis, and angiogenesis. Elevated expression of Nox4 has been reported in a number of cardiovascular diseases, including atherosclerosis, pulmonary fibrosis, and hypertension, cardiac failure and ischemic stroke. However, many important questions remain regarding the functional significance of Nox4 in health and disease, including the role of Nox4 subcellular localization and its downstream targets. The goal of this review is to summarize the recent literature on the genetic and enzymatic regulation, subcellular localization, signaling pathways, and the role of Nox4 in cardiovascular disease states. PMID:23125837

  9. The impact of gender on cardiovascular system calcification in very elderly patients with severe aortic stenosis.

    PubMed

    Liyanage, Luckmini; Lee, Nam Ju; Cook, Tessa; Herrmann, Howard C; Jagasia, Dinesh; Litt, Harold; Han, Yuchi

    2016-01-01

    There is an established sex difference in cardiovascular disease among pre-menopausal women and age-matched men, with men having greater susceptibility to cardiovascular and coronary artery disease. Cardiovascular calcification may be linked to the atherosclerotic process and resulting disease, but the sex difference regarding coronary artery disease susceptibility and calcification is incompletely understood. We thought to measure calcium volume in different chest vascular beds in very elderly men and women with severe aortic stenosis (AS). Computed tomography scans of 94 patients with severe AS were calcium volume scored on Aquarius iNtuition Terarecon (Terarecon Inc., CA, USA) work stations. Coronary beds, aortic valve, mitral valve apparatus, and the thoracic aorta were examined. A significant sex difference in the mean total calcium volume of the coronary arteries was found in elderly (p = 0.001), with men having greater levels of calcification. There is also a significant sex difference in the amount of aortic valve calcium (p = 0.003). Furthermore, aortic and coronary calcification was independently correlated with sex. This study demonstrates a significant sex impact on calcification in the coronary beds and aortic valve in elderly patients with severe AS. PMID:26319217

  10. Multiple adipose depots increase cardiovascular risk via local and systemic effects

    PubMed Central

    Karastergiou, Kalypso; Fried, Susan K.

    2014-01-01

    Adipose tissue modifies the development of cardiovascular disease in a complex manner: obesity is a major risk factor, but particularly when accompanied with a central fat distribution. For that reason the characteristics of visceral adipose tissue attracted the majority of research interest thus far and measurement of waist circumference is now recommended for everyday clinical practice. However, the direct, causative role of visceral fat in cardiometabolic disease remains to be established. Epidemiological and clinical studies show that accumulation of fat subcutaneously, in the gluteo-femoral area, is protective for cardiovascular disease, but the exact molecular mechanisms remain again unclear. In the last few years, imaging allowed the study of smaller fat depots that may interact locally with important tissues: epicardial fat with the myocardium, perivascular fat with the vessel wall and the developing atherosclerotic plaque, renal sinus fat with the renal artery. Unraveling the heterogeneous fat distribution and metabolic phenotypes in human obesity will facilitate optimal assessment of cardiovascular risk in overweight and obese individuals. PMID:23982264

  11. The Earth System Model

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark; Rood, Richard B.; Hildebrand, Peter; Raymond, Carol

    2003-01-01

    The Earth System Model is the natural evolution of current climate models and will be the ultimate embodiment of our geophysical understanding of the planet. These models are constructed from components - atmosphere, ocean, ice, land, chemistry, solid earth, etc. models and merged together through a coupling program which is responsible for the exchange of data from the components. Climate models and future earth system models will have standardized modules, and these standards are now being developed by the ESMF project funded by NASA. The Earth System Model will have a variety of uses beyond climate prediction. The model can be used to build climate data records making it the core of an assimilation system, and it can be used in OSSE experiments to evaluate. The computing and storage requirements for the ESM appear to be daunting. However, the Japanese ES theoretical computing capability is already within 20% of the minimum requirements needed for some 2010 climate model applications. Thus it seems very possible that a focused effort to build an Earth System Model will achieve succcss.

  12. Mechanism of tissue-selective drug action in the cardiovascular system.

    PubMed

    Barrett, Terrance D; Triggle, David J; Walker, Michael J A; Maurice, Donald H

    2005-04-01

    Analysis of the human genome project tells us that there may be as few as 3000 genes that are likely to be good drug targets. Although the number of targets is still very large, these data have been interpreted by some to mean that the pharmaceutical industry may someday run out of novel drug targets. Despite the doom and gloom of such analysis, there is considerable reason for optimism. Drugs may exhibit selectivity of action beyond that predicted by target expression alone. Drugs that act at a single molecular target may have very different pharmacology and, as a result, different therapeutic uses. Three well-characterized model systems are highlighted to illustrate this point. The first model system is exemplified by nifedipine and verapamil, both of which act on L-type calcium channels. Both drugs are used to treat hypertension, but only verapamil can be used to produce atrioventricular block in patients with atrial fibrillation. The second model system describes the therapeutic exploitation of unusual conditions that occur in the ischemic myocardium to produce drugs that are more effective for suppressing ischemia-induced arrhythmias. The third model system discusses the mechanisms through which phosphodiesterase-5 (PDE5) inhibitors act selectively to facilitate penile erection while having little effect in the non-penile vasculature that also expresses PDE5. PMID:15821157

  13. Introducing a model of cardiovascular prevention in Nairobi's slums by integrating a public health and private-sector approach: the SCALE-UP study

    PubMed Central

    van de Vijver, Steven; Oti, Samuel; Tervaert, Thijs Cohen; Hankins, Catherine; Kyobutungi, Catherine; Gomez, Gabriela B.; Brewster, Lizzy; Agyemang, Charles; Lange, Joep

    2013-01-01

    Introduction Cardiovascular disease (CVD) is a leading cause of death in sub-Saharan Africa (SSA), with annual deaths expected to increase to 2 million by 2030. Currently, most national health systems in SSA are not adequately prepared for this epidemic. This is especially so in slum settlements where access to formal healthcare and resources is limited. Objective To develop and introduce a model of cardiovascular prevention in the slums of Nairobi by integrating public health and private sector approaches. Study design Two non-profit organizations that conduct public health research, Amsterdam Institute for Global Health and Development (AIGHD) and African Population and Health Research Center (APHRC), collaborated with private-sector Boston Consulting Group (BCG) to develop a service delivery package for CVD prevention in slum settings. A theoretic model was designed based on the integration of public and private sector approaches with the focus on costs and feasibility. Results The final model includes components that aim to improve community awareness, a home-based screening service, patient and provider incentives to seek and deliver treatment specifically for hypertension, and adherence support. The expected outcomes projected by this model could prove potentially cost effective and affordable (1 USD/person/year). The model is currently being implemented in a Nairobi slum and is closely followed by key stakeholders in Kenya including the Ministry of Health, the World Health Organization (WHO), and leading non-governmental organizations (NGOs). Conclusion Through the collaboration of public health and private sectors, a theoretically cost-effective model was developed for the prevention of CVD and is currently being implemented in the slums of Nairobi. If results are in line with the theoretical projections and first impressions on the ground, scale-up of the service delivery package could be planned in other poor urban areas in Kenya by relevant policymakers and NGOs. PMID:24149078

  14. Autophagy in cardiovascular biology

    PubMed Central

    Lavandero, Sergio; Chiong, Mario; Rothermel, Beverly A.; Hill, Joseph A.

    2015-01-01

    Cardiovascular disease is the leading cause of death worldwide. As such, there is great interest in identifying novel mechanisms that govern the cardiovascular response to disease-related stress. First described in failing hearts, autophagy within the cardiovascular system has been widely characterized in cardiomyocytes, cardiac fibroblasts, endothelial cells, vascular smooth muscle cells, and macrophages. In all cases, a window of optimal autophagic activity appears to be critical to the maintenance of cardiovascular homeostasis and function; excessive or insufficient levels of autophagic flux can each contribute to heart disease pathogenesis. In this Review, we discuss the potential for targeting autophagy therapeutically and our vision for where this exciting biology may lead in the future. PMID:25654551

  15. Model-Based Systems

    NASA Technical Reports Server (NTRS)

    Frisch, Harold P.

    2007-01-01

    Engineers, who design systems using text specification documents, focus their work upon the completed system to meet Performance, time and budget goals. Consistency and integrity is difficult to maintain within text documents for a single complex system and more difficult to maintain as several systems are combined into higher-level systems, are maintained over decades, and evolve technically and in performance through updates. This system design approach frequently results in major changes during the system integration and test phase, and in time and budget overruns. Engineers who build system specification documents within a model-based systems environment go a step further and aggregate all of the data. They interrelate all of the data to insure consistency and integrity. After the model is constructed, the various system specification documents are prepared, all from the same database. The consistency and integrity of the model is assured, therefore the consistency and integrity of the various specification documents is insured. This article attempts to define model-based systems relative to such an environment. The intent is to expose the complexity of the enabling problem by outlining what is needed, why it is needed and how needs are being addressed by international standards writing teams.

  16. Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age

    PubMed Central

    Mohiuddin, Mohammad W.; Rihani, Ryan J.; Laine, Glen A.

    2012-01-01

    The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance (Ctot) and increases in total peripheral resistance (Rtot) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity (cph) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in cph do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system model that includes realistic pulse wave transmission to determine whether increases in cph cause increased PP with age. First, we made the realistic arterial system model age dependent by altering cardiac output (CO), Rtot, Ctot, and cph to mimic the reported changes in these parameters from age 30 to 70. Then, cph was theoretically maintained constant, while Ctot, Rtot, and CO were altered. The predicted increase in PP with age was similar to the observed increase in PP. In a complementary approach, Ctot, Rtot, and CO were theoretically maintained constant, and cph was increased. The predicted increase in PP was negligible. We found that increases in cph have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in Ctot. PMID:22561301

  17. Utility of established cardiovascular disease risk score models for the 10-year prediction of disease outcomes in women.

    PubMed

    Goh, Louise G H; Dhaliwal, Satvinder S; Lee, Andy H; Bertolatti, Dean; Della, Phillip R

    2013-04-01

    Cardiovascular disease (CVD) is a major cause of mortality globally. In absolute numbers, more women die from CVD than men do. CVD mortality risk differs between genders, reflecting the different distribution of modifiable risk factors and severity of CVD outcomes. This study reviews six established risk score models and their applicability to the female population. These models are assessed against two criteria: discrimination and calibration. Sensitivity, specificity and positive- and negative-predictive values are also examined. The risk score models are found to be limited in applicability, requiring recalibration beyond their study population. Relevant risk factors to predict CVD mortality for women, such as measures of obesity, physical activity, alcohol consumption, use of antihypertensive medication, chronic kidney disease and coronary artery calcium are generally not incorporated in these models. PMID:23570356

  18. Selected System Models

    NASA Astrophysics Data System (ADS)

    Schmidt-Eisenlohr, F.; Puñal, O.; Klagges, K.; Kirsche, M.

    Apart from the general issue of modeling the channel, the PHY and the MAC of wireless networks, there are specific modeling assumptions that are considered for different systems. In this chapter we consider three specific wireless standards and highlight modeling options for them. These are IEEE 802.11 (as example for wireless local area networks), IEEE 802.16 (as example for wireless metropolitan networks) and IEEE 802.15 (as example for body area networks). Each section on these three systems discusses also at the end a set of model implementations that are available today.

  19. Laser Doppler flowmetry signals to quantify effects of isoflurane on the peripheral cardiovascular system of healthy rats

    NASA Astrophysics Data System (ADS)

    Humeau, Anne; Fizanne, Lionel; Roux, Jérôme; Asfar, Pierre; Cales, Paul; Rousseau, David; Chapeau-Blondeau, François

    2007-12-01

    The optical Doppler effect resulting from interactions between laser light photons and red blood cells of the microcirculation is used to characterize the influence of isoflurane, an halogenated volatile anesthetic, on the peripheral cardiovascular system. After having recorded laser Doppler flowmetry blood perfusion signals on isoflurane-induced anesthetized healthy rats, wavelet analyses show a significant decrease of the myogenic and neurogenic activities when isoflurane dose increases from 1.5% to 3%. Moreover, the approximate entropy shows a weak decrease of signal irregularity when dose of isoflurane increases. These findings demonstrate the usefulness of the optical Doppler effect in physiological and pharmacological applications.

  20. Exercise improves cardiovascular control in a model of dislipidemia and menopause.

    PubMed

    Heeren, Marcelo Velloso; De Sousa, Leandro Eziquiel; Mostarda, Cristiano; Moreira, Edson; Machert, Henrique; Rigatto, Katya Vianna; Wichi, Rogrio Brando; Irigoyen, M C; De Angelis, Ktia

    2009-02-20

    The present study investigated the effects of exercise training on arterial pressure, baroreflex sensitivity, cardiovascular autonomic control and metabolic parameters on female LDL-receptor knockout ovariectomized mice. Mice were divided into two groups: sedentary and trained. Trained group was submitted to an exercise training protocol. Blood cholesterol was measured. Arterial pressure (AP) signals were directly recorded in conscious mice. Baroreflex sensitivity was evaluated by tachycardic and bradycardic responses to AP changes. Cardiovascular autonomic modulation was measured in frequency (FFT) and time domains. Maximal exercise capacity was increased in trained as compared to sedentary group. Blood cholesterol was diminished in trained mice (191+/-8mg/dL) when compared to sedentary mice (250+/-9mg/dL, p<0.05). Mean AP and HR were reduced in trained group (101+/-3mmHg and 535+/-14bpm, p<0.05) when compared with sedentary group (125+/-3mmHg and 600+/-12bpm). Exercise training induced improvement in bradycardic reflex response in trained animals (-4.24+/-0.62bpm/mmHg) in relation to sedentary animals (-1.49+/-0.15bpm/mmHg, p<0.01); tachycardic reflex responses were similar between studied groups. Exercise training increased the variance (34+/-8 vs. 6.6+/-1.5ms(2) in sedentary, p<0.005) and the high-frequency band (HF) of the pulse interval (IP) (53+/-7% vs. 26+/-6% in sedentary, p<0.01). It is tempting to speculate that results of this experimental study might represent a rationale for this non-pharmacological intervention in the management of cardiovascular risk factors in dyslipidemic post-menopause women. PMID:19181466

  1. Dynamic prediction model and risk assessment chart for cardiovascular disease based on on-treatment blood pressure and baseline risk factors

    PubMed Central

    Teramukai, Satoshi; Okuda, Yasuyuki; Miyazaki, Shigeru; Kawamori, Ryuzo; Shirayama, Masayuki; Teramoto, Tamio

    2016-01-01

    For patients with hypertension, an individual risk prediction tool for cardiovascular disease based on on-treatment blood pressure is needed and would be useful. The objective of this study was to establish a 3-year risk prediction model for cardiovascular disease based on data from 13 052 patients with no history of cardiovascular disease in the Olmesartan Mega study to determine the relationship between Cardiovascular Endpoints and Blood Pressure Goal Achievement study. To develop dynamic prediction models including on-treatment blood pressure, a Cox proportional hazard model using the sliding landmarking method with three landmark points (6, 12 and 18 months from baseline) was used. The prediction model included blood pressure (<130/85 mm Hg, ⩾130/85  to <140/90 mm Hg, ⩾140/90 to <160/100 mm Hg and ⩾160/100 mm Hg) as a time-dependent covariate and well-known baseline risk factors (sex, age, smoking, family history of coronary artery disease and diabetes) as covariates. The 3-year risk assessment chart was constructed using the combination of all risk factors in the prediction model, and six different colors were displayed on each chart corresponding to the predicted probability of cardiovascular disease. Judging from the chart, if an elderly man with diabetes and other risk factors had a blood pressure of <130/85 mm Hg at 6 months, the risk of cardiovascular disease would be 8.0%, whereas the risk would be 8.6% if he had a blood pressure of ⩾130/85 to <140/90 mm Hg. The risk assessment chart developed from the large-scale observational study data would help physicians to more easily assess the cardiovascular disease risk for hypertensive patients on antihypertensive treatments. PMID:26606874

  2. Dynamic prediction model and risk assessment chart for cardiovascular disease based on on-treatment blood pressure and baseline risk factors.

    PubMed

    Teramukai, Satoshi; Okuda, Yasuyuki; Miyazaki, Shigeru; Kawamori, Ryuzo; Shirayama, Masayuki; Teramoto, Tamio

    2016-02-01

    For patients with hypertension, an individual risk prediction tool for cardiovascular disease based on on-treatment blood pressure is needed and would be useful. The objective of this study was to establish a 3-year risk prediction model for cardiovascular disease based on data from 13 052 patients with no history of cardiovascular disease in the Olmesartan Mega study to determine the relationship between Cardiovascular Endpoints and Blood Pressure Goal Achievement study. To develop dynamic prediction models including on-treatment blood pressure, a Cox proportional hazard model using the sliding landmarking method with three landmark points (6, 12 and 18 months from baseline) was used. The prediction model included blood pressure (<130/85 mm Hg, ⩾130/85  to <140/90 mm Hg, ⩾140/90 to <160/100 mm Hg and ⩾160/100 mm Hg) as a time-dependent covariate and well-known baseline risk factors (sex, age, smoking, family history of coronary artery disease and diabetes) as covariates. The 3-year risk assessment chart was constructed using the combination of all risk factors in the prediction model, and six different colors were displayed on each chart corresponding to the predicted probability of cardiovascular disease. Judging from the chart, if an elderly man with diabetes and other risk factors had a blood pressure of <130/85 mm Hg at 6 months, the risk of cardiovascular disease would be 8.0%, whereas the risk would be 8.6% if he had a blood pressure of ⩾130/85 to <140/90 mm Hg. The risk assessment chart developed from the large-scale observational study data would help physicians to more easily assess the cardiovascular disease risk for hypertensive patients on antihypertensive treatments. PMID:26606874

  3. Multiscale Cloud System Modeling

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Moncrieff, Mitchell W.

    2009-01-01

    The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

  4. Canister Model, Systems Analysis

    Energy Science and Technology Software Center (ESTSC)

    1993-09-29

    This packges provides a computer simulation of a systems model for packaging nuclear waste and spent nuclear fuel in canisters. The canister model calculates overall programmatic cost, number of canisters, and fuel and waste inventories for the Idaho Chemical Processing Plant (other initial conditions can be entered).

  5. Flexible system modeling

    SciTech Connect

    Maragno, M.; Schmid, C.; Schmieg, M.

    1995-04-01

    Stability analysis calculations are typically based on predefined system models, where, in the majority of cases, the well known IEEE definitions for controllers, prime movers, and other associated devices and functions are in use. for planning purposes, this approach might be acceptable, since predefined sets of parameters will allow a favorable and reasonable behavior of the analyzed system to be achieved, thus representing the possibly implementable system behavior. However, this approach is often also applied for system operation analysis purposes, for which typical IEEE models are applicable only in few cases. In quite a number of cases, even manufacturers who perform highly accurate system modeling studies have been asked to deliver block diagrams and parameters according to a list of available IEEE models. Utilities and consultants with an in-depth knowledge and tradition of conducting system operation performance and optimization studies have frequently requested adequate and accurate procedures and tools to tackle this special field of power system analysis appropriately. This need to solve complex operation analysis and special component planning problems has prompted the development of adequate methods and tools at DIgSILENT Systems in cooperation with FICHTNER C.E. This article focuses on various possibilities to approach this problem and to report on the applied strategies and methods. Comprehensive examples are given to demonstrate the capabilities of the implemented procedures.

  6. Systems Modelling and Control.

    ERIC Educational Resources Information Center

    Kershenbaum, L. S.; And Others

    1980-01-01

    Describes aims, objectives content, and instructional strategies of a course in systems modelling and control at Imperial College, England. Major problem areas include multivariable control system design, estimation and filtering, and the design and use of adaptive "self-tuning" regulators. (Author/JN)

  7. Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age.

    PubMed

    Mohiuddin, Mohammad W; Rihani, Ryan J; Laine, Glen A; Quick, Christopher M

    2012-07-01

    The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance (C(tot)) and increases in total peripheral resistance (R(tot)) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity (c(ph)) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in c(ph) do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system model that includes realistic pulse wave transmission to determine whether increases in c(ph) cause increased PP with age. First, we made the realistic arterial system model age dependent by altering cardiac output (CO), R(tot), C(tot), and c(ph) to mimic the reported changes in these parameters from age 30 to 70. Then, c(ph) was theoretically maintained constant, while C(tot), R(tot), and CO were altered. The predicted increase in PP with age was similar to the observed increase in PP. In a complementary approach, C(tot), R(tot), and CO were theoretically maintained constant, and c(ph) was increased. The predicted increase in PP was negligible. We found that increases in c(ph) have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in C(tot). PMID:22561301

  8. Effects of thyroid hormone on. beta. -adrenergic responsiveness of aging cardiovascular systems

    SciTech Connect

    Tsujimoto, G.; Hashimoto, K.; Hoffman, B.B.

    1987-03-01

    The authors have compared the effects of ..beta..-adrenergic stimulation on the heart and peripheral vasculature of young (2-mo-old) and older (12-mo-old) rats both in the presence and absence of triiodothyronine (T/sub 3/)-induced hyperthyroidism. The hemodynamic consequences of T/sub 3/ treatment were less prominent in the aged hyperthyroid rats compared with young hyperthyroid rats (both in intact and pithed rats). There was a decrease in sensitivity of chronotropic responsiveness to isoproterenol in older pithed rats, which was apparently reversed by T/sub 3/ treatment. The number and affinity of myocardial ..beta..-adrenergic receptor sites measured by (/sup 125/I)cyanopindolol were not significantly different in young and older control rats; also, ..beta..-receptor density increased to a similar extent in both young and older T/sub 3/-treated rats. The ability of isoproterenol to relax mesenteric arterial rings, markedly blunted in older rats, was partially restored by T/sub 3/ treatment without their being any change in isoproterenol-mediated relaxation in the arterial preparation from young rats. The number and affinity of the ..beta..-adrenergic receptors measured in the mesenteric arteries was unaffected by either aging or T/sub 3/ treatment. The data suggest that effects of thyroid hormone and age-related alterations of cardiovascular responsiveness to ..beta..-adrenergic stimulation are interrelated in a complex fashion with a net result that the hyperkinetic cardiovascular manifestations in hyperthyroidism are attenuated in the older animals.

  9. Cardiovascular System Changes and Related Risk Factors in Acromegaly Patients: A Case-Control Study

    PubMed Central

    Guo, Xiaopeng; Gao, Lu; Zhang, Shuo; Li, Yilin; Wu, Yue; Fang, Ligang; Deng, Kan; Yao, Yong; Lian, Wei; Wang, Renzhi; Xing, Bing

    2015-01-01

    Background. Cardiovascular complications are known to be the main determinants of reduced life expectancy and decreased quality of life in acromegaly patients. Our study aimed to provide insight into the cardiovascular changes that occur in acromegaly patients and to investigate the correlative risk factors. Methods. A total of 108 patients definitively diagnosed with acromegaly and 108 controls matched for age and gender were recruited into study and control groups, respectively. Standard echocardiography was performed on all of the participants, and data were collected and analyzed. Results. All acromegaly patients presented with structural cardiac changes, including a larger heart cavity, thicker myocardial walls, and increased great vessel diameters compared with the control group. Additionally, the acromegaly patients presented with reduced diastolic function. Aging and increased body mass index (BMI) were correlated with myocardial hypertrophy and diastolic dysfunction; a longer disease duration was correlated with larger great vessel diameters. Conclusions. Ageing and increased BMI are independent risk factors for acromegalic cardiomyopathy, and a long disease duration results in the expansion of great vessels. Increased efforts should be made to diagnose acromegaly at an early stage and to advise acromegaly patients to maintain a healthy weight. PMID:26600803

  10. Modelling the Traffic System

    NASA Astrophysics Data System (ADS)

    Važan, Pavel; Jurovatá, Dominika; Hrčka, Lukáš; Danek, Maroš

    2014-12-01

    The paper presents the simulation study results of the traffic system in the city of Hlohovec. The authors describe the process of building the model in Witness 2013c simulator. The individual entities of simulation model are explained in details, as the Witness simulator is primarily suitable for manufacture or service simulation and not for traffic system simulation. The goal of this paper is to analyse the traffic system and to suggest the changes for improving the traffic in the city of Hlohovec. All proposed measures will bring about 20% improvement of traffic when compared to the current state.

  11. Model deformation system

    NASA Technical Reports Server (NTRS)

    Holmes, H. K.

    1983-01-01

    The development of a system to measure model deflections encountered in the National Transonic Facility is discussed. The goal is to be able to measure peak deflections of up to 3 in. with accuracies to within 0.0025 in. over an area 1 m square as the model pitches through an included angle of 30 deg. Stereophotogrammetric techniques are being implemented, with the initial system being an extension of standard techniques. A second system, which will be all electronic, is under development. Both techniques require targets to be strategically placed on the model. Active targets are being developed for location in the model in order to maximize the signal-to-noise ratio and to approximate a point source. Image processing techniques and stereophotogrammetric data reduction programs are being implemented to perform the data reduction tasks.

  12. Association between Floods and Acute Cardiovascular Diseases: A Population-Based Cohort Study Using a Geographic Information System Approach

    PubMed Central

    Vanasse, Alain; Cohen, Alan; Courteau, Josiane; Bergeron, Patrick; Dault, Roxanne; Gosselin, Pierre; Blais, Claudia; Bélanger, Diane; Rochette, Louis; Chebana, Fateh

    2016-01-01

    Background: Floods represent a serious threat to human health beyond the immediate risk of drowning. There is few data on the potential link between floods and direct consequences on health such as on cardiovascular health. This study aimed to explore the impact of one of the worst floods in the history of Quebec, Canada on acute cardiovascular diseases (CVD). Methods: A cohort study with a time series design with multiple control groups was built with the adult population identified in the Quebec Integrated Chronic Disease Surveillance System. A geographic information system approach was used to define the study areas. Logistic regressions were performed to compare the occurrence of CVD between groups. Results: The results showed a 25%–27% increase in the odds in the flooded population in spring 2011 when compared with the population in the same area in springs 2010 and 2012. Besides, an increase up to 69% was observed in individuals with a medical history of CVD. Conclusion: Despite interesting results, the association was not statistically significant. A possible explanation to this result can be that the population affected by the flood was probably too small to provide the statistical power to answer the question, and leaves open a substantial possibility for a real and large effect. PMID:26828511

  13. Critical Infrastructure Modeling System

    Energy Science and Technology Software Center (ESTSC)

    2004-10-01

    The Critical Infrastructure Modeling System (CIMS) is a 3D modeling and simulation environment designed to assist users in the analysis of dependencies within individual infrastructure and also interdependencies between multiple infrastructures. Through visual cuing and textual displays, a use can evaluate the effect of system perturbation and identify the emergent patterns that evolve. These patterns include possible outage areas from a loss of power, denial of service or access, and disruption of operations. Method ofmore » Solution: CIMS allows the user to model a system, create an overlay of information, and create 3D representative images to illustrate key infrastructure elements. A geo-referenced scene, satellite, aerial images or technical drawings can be incorporated into the scene. Scenarios of events can be scripted, and the user can also interact during run time to alter system characteristics. CIMS operates as a discrete event simulation engine feeding a 3D visualization.« less

  14. Critical Infrastructure Modeling System

    SciTech Connect

    2004-10-01

    The Critical Infrastructure Modeling System (CIMS) is a 3D modeling and simulation environment designed to assist users in the analysis of dependencies within individual infrastructure and also interdependencies between multiple infrastructures. Through visual cuing and textual displays, a use can evaluate the effect of system perturbation and identify the emergent patterns that evolve. These patterns include possible outage areas from a loss of power, denial of service or access, and disruption of operations. Method of Solution: CIMS allows the user to model a system, create an overlay of information, and create 3D representative images to illustrate key infrastructure elements. A geo-referenced scene, satellite, aerial images or technical drawings can be incorporated into the scene. Scenarios of events can be scripted, and the user can also interact during run time to alter system characteristics. CIMS operates as a discrete event simulation engine feeding a 3D visualization.

  15. Model performance evaluation (validation and calibration) in model-based studies of therapeutic interventions for cardiovascular diseases : a review and suggested reporting framework.

    PubMed

    Haji Ali Afzali, Hossein; Gray, Jodi; Karnon, Jonathan

    2013-04-01

    Decision analytic models play an increasingly important role in the economic evaluation of health technologies. Given uncertainties around the assumptions used to develop such models, several guidelines have been published to identify and assess 'best practice' in the model development process, including general modelling approach (e.g., time horizon), model structure, input data and model performance evaluation. This paper focuses on model performance evaluation. In the absence of a sufficient level of detail around model performance evaluation, concerns regarding the accuracy of model outputs, and hence the cr