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Sympathetic system

Hadis Biglari, Reza Sameni
Fetal motility is a widely accepted indicator of the well-being of a fetus. In previous research, it has be shown that fetal motion (FM) is coherent with fetal heart rate accelerations and an indicator for active/rest cycles of the fetus. The most common approach for FM and fetal heart rate (FHR) assessment is by Doppler ultrasound (DUS). While DUS is the most common approach for studying the mechanical activities of the heart, noninvasive fetal electrocardiogram (ECG) and magnetocardiogram (MCG) recording and processing techniques have been considered as a possible competitor (or complement) for the DUS...
October 24, 2016: Physiological Measurement
A Puzserova, I Bernatova
Stress is considered a risk factor associated with the development of various civilization diseases including cardiovascular diseases, malignant tumors and mental disorders. Research investigating mechanisms involved in stress-induced hypertension have attracted much attention of physicians and researchers, however, there are still ambiguous results concerning a causal relationship between stress and long-term elevation of blood pressure (BP). Several studies have observed that mechanisms involved in the development of stress-induced hypertension include increased activity of sympathetic nervous system (SNS), glucocorticoid (GC) overload and altered endothelial function including decreased nitric oxide (NO) bioavailability...
October 24, 2016: Physiological Research
George L Bakris, John M Burkart, Eric D Weinhandl, Peter A McCullough, Michael A Kraus
Hypertension is a cardinal feature of end-stage renal disease (ESRD). Hypertensive nephropathy is the primary cause of ESRD for nearly 30% of patients, and the prevalence of hypertension is >85% in new patients with ESRD. In contemporary hemodialysis (HD) patients, mean predialysis systolic blood pressure (SBP) is nearly 150mmHg, and about 70%, 50%, and 40% use β-blockers, calcium channel blockers, and renin-angiotensin system inhibitors, respectively. Predialysis SBP generally exhibits a U-shaped association with mortality risk...
November 2016: American Journal of Kidney Diseases: the Official Journal of the National Kidney Foundation
Bruce J Ellis, Albertine J Oldehinkel, Esther Nederhof
The adaptive calibration model (ACM) is a theory of developmental programing focusing on calibration of stress response systems and associated life history strategies to local environmental conditions. In this article, we tested some key predictions of the ACM in a longitudinal study of Dutch adolescent males (11-16 years old; N = 351). Measures of sympathetic, parasympathetic, and adrenocortical activation, reactivity to, and recovery from social-evaluative stress validated the four-pattern taxonomy of the ACM via latent profile analysis, though with some deviations from expected patterns...
October 24, 2016: Development and Psychopathology
Zuzana Visnovcova, Michal Mestanik, Michal Gala, Andrea Mestanikova, Ingrid Tonhajzerova
The aim of this study was to evaluate potential changes in the electrodermal activity (EDA) to enable the detection of variations in the sympathetic nervous system during mental load and recovery period. Several EDA parameters were used: SCA (skin conductance amplitude), frequency of NS-EDR (nonspecific electrodermal responses), SIE (symbolic information entropy), and ApEn (approximate entropy). The cohort consisted of 50 healthy students (average age: 23.33±0.24yr., 25 women). The stress profile consisted of five phases: baseline (P1), Stroop test (P2), recovery (P3), mental arithmetic test (P4), and recovery (P5)...
October 14, 2016: Computers in Biology and Medicine
Muhammad Abid Azam, Joel Katz, Vina Mohabir, Paul Ritvo
BACKGROUND: Current research suggests that associations between headache conditions (migraine, tension) and imbalances in the autonomic nervous system (ANS) are due to stress-related dysregulation in the activity of the parasympathetic-sympathetic branches. Mindfulness meditation has demonstrated effectiveness in reducing pain-related distress, and in enhancing heart rate variability-a vagal-mediated marker of ANS balance. This study examined HRV during cognitive stress and mindfulness meditation in individuals with migraine and tension headaches...
October 18, 2016: International Journal of Psychophysiology
Brun Jean-Frédéric, Varlet-Marie Emmanuelle, Fédou Christine, Raynaud de Mauverger Eric
We investigated to what extent a prediction of the 'ideal' hematocrit based on individual hemorheological profile with an equation of viscosity is relevant in trained athletes, and how the agreement between theoretical and actual values is modified by changes in training volume and performance. Elite soccer players (national level: 18-32 yr, weight 61-83 kg, body mass index 20.9-25.8 kg/m2) were seen twice at one year interval. Hemorheologic parameters were measured with the MT90 viscometer and the Myrenne aggregometer the theoretical bell-shaped curve of hematocrit/viscosity ratio as a function of hematocrit was reconstructed with Quemada's equation using actual plasma viscosity and red cell rigidity to predict hematocrit/viscosity at various hematocrit levels...
October 15, 2016: Clinical Hemorheology and Microcirculation
Javier Díez
Natriuretic peptides (NPs) promote diuresis, natriuresis and vasodilation in early chronic heart failure (CHF), countering renin-angiotensin-aldosterone system (RAAS) and sympathetic nervous system (SNS) overstimulation. Despite dramatic increases in circulating NP concentrations as CHF progresses, their effects become blunted. Increases in diuresis, natriuresis, and vasodilation after administration of exogenous atrial (ANP) or brain (BNP) natriuretic peptides are attenuated in patients with advanced CHF compared with controls...
October 21, 2016: European Journal of Heart Failure
Erik H Van Iterson, Courtney Gramm, Nicholas R Randall, Thomas P Olson
Although pathophysiologic links between postmenopause and healthy aging remain unclear, both factors are associated with increased blood pressure and sympathetic nerve activity (SNA) in women. Activation of polymodal musculoskeletal neural afferents originating within adventia of venules modulates SNA and blood pressure control during exercise in healthy adults. We hypothesized transient subsystolic regional circulatory occlusion (RCO) during exercise sensitizes these afferents leading to augmented systemic vascular resistance (SVR) mediated increased mean arterial pressure (MAP) in postmenopause versus premenopause...
October 7, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Xiuqing Tian, Rui Guo, Yujiao Zhang, Lingling Xu, Xianbing Liu, Yinglong Hou
OBJECTIVE: To observe the effects of sympathetic overactivity on the immune system involved in the imbalance of T helper (Th) lymphocytes, we investigated the correlation between autonomic dysregulation and the generation of regulatory T (Treg) and Th1 chemokines in patients with acute coronary syndrome (ACS). METHODS: Blood samples obtained from patients with coronary artery disease and controls were analyzed for levels of Th1 and Treg cells and their associated cytokines by flow cytometry...
October 21, 2016: Neuroimmunomodulation
Lin Huang, Lluis Capdevila
OBJECTIVE: This study analyzed the efficacy of aromatherapy in improving work performance and reducing workplace stress. SUBJECTS: The initial sample comprised 42 administrative university workers (Mage = 42.21 years, standard deviation = 7.12; 10 male). INTERVENTION: All sessions were performed in a university computer classroom. The participants were randomly assigned into an aromatherapy group (AG) and a control group (CG), and they were invited to participate in a specific session only once...
October 20, 2016: Journal of Alternative and Complementary Medicine: Research on Paradigm, Practice, and Policy
Florent Elefteriou
The bone marrow microenvironment is characterized by its multicellular nature, and perhaps less obviously by the high mobility of multiple transient and stationary cell lineages present in this environment. The trafficking of hematopoietic and mesenchymal cells between the bone marrow and blood compartments is regulated by a number of bone marrow-derived factors. It is suspected that transformed metastatic cells "hijack" these processes to engraft into the skeleton and eventually cause the skeletal complications associated with metastatic disease...
September 2016: Journal of Bone Oncology
Raoyrin Chanavirut, Pattarapong Makarawate, Ian A Macdonald, Naruemon Leelayuwat
BACKGROUND: Imbalances of the autonomic nervous (ANS), the cardiovascular system, and ionics might contribute to the manifestation of The Brugada Syndrome (BrS). Thus, this study has aimed to investigate the cardio-respiratory fitness and the responses of the ANS both at rest and during a sub-maximal exercise stress test, in BrS patients and in gender-matched and age-matched healthy sedentary controls. METHODS: Eleven BrS patients and 23 healthy controls were recruited in Khon Kaen, Thailand...
October 2016: Journal of Arrhythmia
Petra Rust, Cem Ekmekcioglu
Excessive dietary salt (sodium chloride) intake is associated with an increased risk for hypertension, which in turn is especially a major risk factor for stroke and other cardiovascular pathologies, but also kidney diseases. Besides, high salt intake or preference for salty food is discussed to be positive associated with stomach cancer, and according to recent studies probably also obesity risk. On the other hand a reduction of dietary salt intake leads to a considerable reduction in blood pressure, especially in hypertensive patients but to a lesser extent also in normotensives as several meta-analyses of interventional studies have shown...
October 19, 2016: Advances in Experimental Medicine and Biology
Martin Jastroch, Sylvain Giroud, Perry Barrett, Fritz Geiser, Gerhard Heldmaier, Annika Herwig
Endothermic mammals and birds require intensive energy turnover to sustain high body temperatures and metabolic rates. To cope with energetic bottlenecks associated with the change of seasons, and to minimise energy expenditure, complex mechanisms and strategies, such as daily torpor and hibernation, are used. During torpor metabolic depression and low body temperatures save energy. However, these bouts of torpor lasting for hours to weeks are interrupted by active 'euthermic' phases with high body temperatures...
October 18, 2016: Journal of Neuroendocrinology
Michael Böhm, Christian Ukena, Sebastian Ewen, Dominik Linz, Ina Zivanovic, Uta Hoppe, Krzysztof Narkiewicz, Luis Ruilope, Manuela Negoita, Roland Schmieder, Bryan Williams, Uwe Zeymer, Andreas Zirlik, Guiseppe Mancia, Felix Mahfoud
OBJECTIVES: Renal denervation (RDN) can reduce sympathetic activity and blood pressure (BP) in patients with hypertension. The effects on resting and ambulatory heart rate (HR), also regulated by the sympathetic nervous system, are not established. METHODS: Herein, we report 12-month outcomes from the Global SYMPLICITY Registry on office and ambulatory HR and BP in patients with uncontrolled hypertension (n = 846). RESULTS: HR declined in correlation with the HR at baseline and at 12 months, in particular, in patients in the upper tertile of HR (>74 bpm)...
October 15, 2016: Journal of Hypertension
Michael G Ziegler, Milos Milic
PURPOSE OF REVIEW: The sympathetic nervous system (SNS) mediates short-term increases in blood pressure. Evidence that psychosocial stress leads to chronic hypertension is mixed. The SNS activation found in obstructive sleep apnea (OSA), caregiving for a severely demented spouse, and obesity more specifically address whether SNS activation might lead to the metabolic syndrome and hypertension. RECENT FINDINGS: Obesity is associated with both increased SNS electrical activity and plasma norepinephrine...
October 15, 2016: Current Opinion in Nephrology and Hypertension
Keisuke Shinohara, Xuebo Liu, Donald A Morgan, Deborah R Davis, Maria Luisa S Sequeira-Lopez, Martin D Cassell, Justin L Grobe, Kamal Rahmouni, Curt D Sigmund
The renin-angiotensin system (RAS) in the brain is a critical determinant of blood pressure, but the mechanisms regulating RAS activity in the brain remain unclear. Expression of brain renin (renin-b) occurs from an alternative promoter-first exon. The predicted translation product is a nonsecreted enzymatically active renin whose function is unknown. We generated a unique mouse model by selectively ablating the brain-specific isoform of renin (renin-b) while preserving the expression and function of the classical isoform expressed in the kidney (renin-a)...
October 17, 2016: Hypertension
Byeong-Keuk Kim
Catheter-based renal sympathetic denervation (RDN) has opened the new world in the treatment of resistant or refractory hypertension. However, SYMPLICITY HTN-3, 2:1 randomization, blinded and sham-controlled study did not show a significant reduction of systolic blood pressure (BP) in patients with resistant hypertension 6 months after RDN as compared with a sham control. After that, substudy investigating the predictors of BP responses in SYMPLICITY HTN-3 trial was reported; racial difference and optimal medical treatment were issued for the optimal denervation therapy...
September 2016: Journal of Hypertension
Mohan Raizada
Hypertension (HTN) is the most prevalent modifiable risk for cardiovascular disease (CVD) and disorders directly influencing CVD (i.e. obesity, diabetes, chronic kidney disease, obstructive sleep apnea, etc.). About one billion people worldwide have HTN, with American adults having 90% lifetime risk of developing HTN. Despite aggressive campaign for lifestyle changes and advances in drug therapy, HTN remains an immense health, emotional, and economic challenge. This is due, in part, to the fact that ∼50% of HTN patients' blood pressure remains uncontrolled and ∼20% of HTN patients are resistant to or require > antihypertensive drugs...
September 2016: Journal of Hypertension
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