scholarly journals Quantifying Redundant/Synergistic Interactions between Cardiorespiratory Reflexes and Cardiac Control Mechanisms During Light-to-Moderate Bicycle Exercise

2019 ◽  
Author(s):  
Alberto Porta ◽  
Beatrice Cairo ◽  
Vlasta Bari ◽  
Emanuele Vaini ◽  
Beatrice De Maria ◽  
...  
Keyword(s):  
Control Mechanisms ◽  
Bicycle Exercise ◽  
Synergistic Interactions ◽  
Cardiac Control ◽  
Cardiorespiratory Reflexes

Significance of neuro-cardiac control mechanisms governed by higher regions of the brain

2016 ◽  
Vol 199 ◽  
pp. 54-65 ◽  
Author(s):  
Peter Taggart ◽  
Hugo Critchley ◽  
Stefan van Duijvendoden ◽  
Pier D. Lambiase
Keyword(s):  
Control Mechanisms ◽  
Cardiac Control ◽  
The Brain

Heart rate variability at limiting stationarity: evidence of neuro-cardiac control mechanisms operating at ultra-low frequencies

2014 ◽  
Vol 35 (2) ◽  
pp. 309-322 ◽  
Author(s):  
A C Fisher ◽  
D Groves ◽  
A Eleuteri ◽  
P Mesum ◽  
D Patterson ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Control Mechanisms ◽  
Low Frequencies ◽  
Cardiac Control

Functional restitution of cardiac control in heart transplant patients

2002 ◽  
Vol 282 (3) ◽  
pp. R900-R908 ◽  
Author(s):  
Eran Toledo ◽  
Itzhak Pinhas ◽  
Dan Aravot ◽  
Yael Almog ◽  
Solange Akselrod
Keyword(s):  
High Frequency ◽  
Sinoatrial Node ◽  
Control Group ◽  
Control Mechanisms ◽  
Very High Frequency ◽  
Transplant Patients ◽  
Cardiac Control ◽  
Principal Finding ◽  
Noninvasive Characterization ◽  
The Time Domain

Cardiovascular control is fundamentally altered after heart transplantation (HT) because of surgical denervation of the heart. The main goal of this work was the noninvasive characterization of cardiac rate control mechanisms after HT and the understanding of their nature. We obtained 25 recordings from 13 male HT patients [age = 28–68 yr, time after transplant (TAT) = 0.5–62.5 mo]. The control group included 14 healthy men (age = 28–59 yr). Electrocardiogram, continuous blood pressure (BP), and respiration were recorded for 45 min in the supine position and then during active change of posture (CP) to standing. The signals were analyzed in the time domain [mean and variance of heart rate (HR) and rise time of HR in response to CP] and the frequency domain [low and high frequency (LF and HF)]. Our principal finding was the consistent pattern of evolution of the HR response to standing: from no response, via a slow response (>40 s, TAT > 6 wk), to a fast increase (<20 s, TAT > 24 mo). HR response correlated with TAT ( P < 0.001). LF correlated with HR response to CP ( P < 0.0001); HF and HR did not. An important finding was the presence of very-high-frequency peaks in the power spectrum of HR and BP fluctuations. Extensive arrhythmias tended to appear at the TAT that corresponds to the transition from slow to fast HR response to CP. Our results indicate a biphasic evolution in cardiac control mechanisms from lack of control to a first-order control loop followed by partial sympathetic reinnervation and, finally, the direct effect of the old sinoatrial node on the pacemaker cell of the new sinoatrial node. There was no indication of vagal reinnervation.

Human enterocytic apoptosis and survival: Differentiation state-specific control mechanisms

2001 ◽  
Vol 120 (5) ◽  
pp. A502-A502
Author(s):  
R GAUTHIER ◽  
J DROLET ◽  
J REED ◽  
A VEZINA ◽  
P VACHON
Keyword(s):  
Control Mechanisms ◽  
Specific Control

Do Executive Motor-Control Mechanisms Regulate Monetary Choice and Gambling?

2011 ◽  
Author(s):  
Frederick Verbruggen ◽  
Rachel Adams ◽  
Chris Chambers
Keyword(s):  
Motor Control ◽  
Control Mechanisms

The relationship between integrated EMG and oxygen uptake during treadmill and bicycle exercise

1976 ◽  
Author(s):  
T. Fukunaga ◽  
K. Yuasa ◽  
M. Kobayashi ◽  
T. Miyagawa ◽  
H. Fujimatsu ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Bicycle Exercise ◽  
Integrated Emg ◽  
The Relationship

The Center for International Biomedical Communications Research

1966 ◽  
Vol 05 (03) ◽  
pp. 142-146
Author(s):  
A. Kent ◽  
P. J. Vinken
Keyword(s):  
Information Needs ◽  
English Language ◽  
Medical Information ◽  
Biomedical Literature ◽  
Information Storage ◽  
Control Mechanisms ◽  
University Of Pittsburgh ◽  
The World ◽  
The University ◽  
Excerpta Medica Foundation

A joint center has been established by the University of Pittsburgh and the Excerpta Medica Foundation. The basic objective of the Center is to seek ways in which the health sciences community may achieve increasingly convenient and economical access to scientific findings. The research center will make use of facilities and resources of both participating institutions. Cooperating from the University of Pittsburgh will be the School of Medicine, the Computation and Data Processing Center, and the Knowledge Availability Systems (KAS) Center. The KAS Center is an interdisciplinary organization engaging in research, operations, and teaching in the information sciences.Excerpta Medica Foundation, which is the largest international medical abstracting service in the world, with offices in Amsterdam, New York, London, Milan, Tokyo and Buenos Aires, will draw on its permanent medical staff of 54 specialists in charge of the 35 abstracting journals and other reference works prepared and published by the Foundation, the 700 eminent clinicians and researchers represented on its International Editorial Boards, and the 6,000 physicians who participate in its abstracting programs throughout the world. Excerpta Medica will also make available to the Center its long experience in the field, as well as its extensive resources of medical information accumulated during the Foundation’s twenty years of existence. These consist of over 1,300,000 English-language _abstract of the world’s biomedical literature, indexes to its abstracting journals, and the microfilm library in which complete original texts of all the 3,000 primary biomedical journals, monitored by Excerpta Medica in Amsterdam are stored since 1960.The objectives of the program of the combined Center include: (1) establishing a firm base of user relevance data; (2) developing improved vocabulary control mechanisms; (3) developing means of determining confidence limits of vocabulary control mechanisms in terms of user relevance data; 4. developing and field testing of new or improved media for providing medical literature to users; 5. developing methods for determining the relationship between learning and relevance in medical information storage and retrieval systems’; and (6) exploring automatic methods for retrospective searching of the specialized indexes of Excerpta Medica.The priority projects to be undertaken by the Center are (1) the investigation of the information needs of medical scientists, and (2) the development of a highly detailed Master List of Biomedical Indexing Terms. Excerpta Medica has already been at work on the latter project for several years.

Control of Thrombin Mediated Cleavage of Protein S

1986 ◽  
Vol 56 (02) ◽  
pp. 151-154 ◽  
Author(s):  
Christina A Mitchell ◽  
Lena Hau ◽  
Hatem H Salem
Keyword(s):  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Surface Protein ◽  
Protein S ◽  
Intact Protein ◽  
Control Mechanisms ◽  
Physiological Control ◽  
Endothelial Cell Surface ◽  
Thrombin Cleavage ◽  
Cofactor Activity

SummaryThrombin has been shown to cleave the vitamin K dependent cofactor protein S with subsequent loss of its cofactor activity. This study examines the control mechanisms for thrombin cleavage of protein S.The anticoagulant activity of activated protein C (APC) is enhanced fourteen fold by the addition of protein S. Thrombin cleaved protein S is seven fold less efficient than the native protein, and this loss of activity is due to reduced affinity of cleaved protein S for APC or the lipid surface compared to the intact protein.In the absence of Ca++, protein S is very sensitive to minimal concentrations of thrombin. As little as 1.5 nM thrombin results in complete cleavage of 20 nM protein S in 10 min and loss of cofactor activity. Ca++, in concentrations greater than 0.5 mM, will inhibit this cleavage and in the presence of physiological Ca++ concentrations, no cleavage of protein S could be demonstrated in spite of high concentrations of thrombin (up to 1 μM) and prolonged incubations (up to two hours). The endothelial surface protein thrombomodulin is very efficient in inhibiting the cleavage of protein S by thrombin suggesting that any thrombin formed on the endothelial cell surface is unlikely to cleave protein S, thus allowing the intact protein to act as a cofactor to APC.We conclude that the inhibitory effects of Ca++ and thrombomodulin on thrombin mediated cleavage of protein S imply that this event, by itself, is unlikely to represent a physiological control of the activity of protein S.

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