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Heart physiology

Shereen M Hamza, John E Hall
Renal sympathetic nerves contribute significantly to both physiological and pathophysiological phenomena. Evaluating renal sympathetic nerve activity (RSNA) is of great interest in many areas of research such as chronic kidney disease, hypertension, heart failure, diabetes and obesity. Unequivocal assessment of the role of the sympathetic nervous system is thus imperative for proper interpretation of experimental results and understanding of disease processes. RSNA has been traditionally measured in anesthetized rodents, including mice...
February 14, 2018: Journal of Visualized Experiments: JoVE
Jennifer F Buckman, Evgeny G Vaschillo, Maria Fonoberova, Igor Mezić, Marsha E Bates
OBJECTIVE: It has been nearly 15 years since Kazdin and Nock published methodological and research recommendations for understanding mechanisms of change in child and adolescent therapy. Their arguments and enthusiasm for research on mechanisms of behavior change (MOBCs) resonated across disciplines and disorders, as it shined a light on the crucial importance of understanding how and for whom treatments instigate behavior change and how therapeutic mechanisms might be extended to "situations and settings of everyday life...
March 2018: Journal of Studies on Alcohol and Drugs
Horng-Ruey Chua, Weng-Kin Wong, Venetia Huiling Ong, Dipika Agrawal, Anantharaman Vathsala, Hui-Ming Tay, Amartya Mukhopadhyay
PURPOSE: To evaluate 1-year mortality in patients with septic acute kidney injury (AKI) and to determine association between initial AKI recovery patterns ( reversal within 5 days, beyond 5 days but recovery, or nonrecovery) and chronic kidney disease (CKD) progression. METHODS: Prospective observational study, with retrospective evaluation of initial nonconsenters, of critically ill patients with septic AKI. RESULTS: We studied 207 patients (age, mean [SD]: 64 [16] years, 39% males), of which 56 (27%), 18 (9%), and 9 (4%) died in intensive care unit (ICU), post-ICU in hospital, and posthospitalization, respectively...
January 1, 2018: Journal of Intensive Care Medicine
Sheikh Mohammad Shavik, Zhenxiang Jiang, Seungik Baek, Lik Chuan Lee
While it has long been recognized that bi-directional interaction between the heart and the vasculature plays a critical role in the proper functioning of the cardiovascular system, a comprehensive study of this interaction has largely been hampered by a lack of modeling framework capable of simultaneously accommodating high-resolution models of the heart and vasculature. Here, we address this issue and present a computational modeling framework that couples finite element (FE) models of the left ventricle (LV) and aorta to elucidate ventricular-arterial coupling in the systemic circulation...
2018: Frontiers in Physiology
Cory S Inman, Kelly R Bijanki, David I Bass, Robert E Gross, Stephan Hamann, Jon T Willie
The amygdala is a key structure mediating emotional processing. Few studies have used direct electrical stimulation of the amygdala in humans to examine stimulation-elicited physiological and emotional responses, and the nature of such effects remains unclear. Determining the effects of electrical stimulation of the amygdala has important theoretical implications for current discrete and dimensional neurobiological theories of emotion, which differ substantially in their predictions about the emotional effects of such stimulation...
March 15, 2018: Neuropsychologia
Connor M Pettem, Jennifer M Briens, David M Janz, Lynn P Weber
Selenium (Se) is considered an essential trace element, involved in important physiological and metabolic functions for all vertebrate species. Fish require dietary concentrations of 0.1-0.5 μg Se/g dry mass (d.m.) to maintain normal physiological and selenoprotein function, however concentrations exceeding 3 μg/g d.m. have been shown to cause toxicity. As Se is reported to have a narrow margin between essentiality and toxicity, there is growing concern surrounding the adverse effects of elevated Se exposure caused by anthropogenic activities...
March 8, 2018: Aquatic Toxicology
Shinako Masuda, Katsuhisa Matsuura, Tatsuya Shimizu
Fibroblasts not only play key roles under physiological and pathological conditions in various tissues and organs including the heart but also are indispensable for fabricating bioengineered cardiac tissues and their functions through cell-cell interactions. Because tissue functions and cells surrounding fibroblasts in vivo are different among tissues, the properties of fibroblasts might be different according to their tissue origin. Understanding the molecular mechanisms of fibroblasts may lead to fabrication of bioengineered tissues close to biological tissues...
March 2, 2018: Biomaterials
Olivier Villemain, Mafalda Correia, Elie Mousseaux, Jérome Baranger, Samuel Zarka, Ilya Podetti, Gilles Soulat, Thibaud Damy, Albert Hagège, Mickael Tanter, Mathieu Pernot, Emmanuel Messas
OBJECTIVES: The goal of our study was to investigate the potential of myocardial shear wave imaging (SWI) to quantify the diastolic myocardial stiffness (MS) (kPa) noninvasively in adult healthy volunteers (HVs) and its physiological variation with age, and in hypertrophic cardiomyopathy (HCM) populations with heart failure and preserved ejection function (HFpEF). BACKGROUND: MS is an important prognostic and diagnostic parameter of the diastolic function. MS is affected by physiological changes but also by pathological alterations of extracellular and cellular tissues...
March 9, 2018: JACC. Cardiovascular Imaging
Sonia L Betancourt Cuellar, Diana Palacio, Marcelo F Benveniste, Brett W Carter, Gregory Gladish
Positron emission tomography (PET) computed tomography (CT) with 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) has been established as an effective modality for evaluation of cancer. Interpretations of patterns of physiologic18 F-FDG uptake by the heart is particularly difficult given the wide normal variations of18 F-FDG metabolic activity observed. Atypical patterns of focal or diffuse physiologic cardiac18 F-FDG uptake and post-therapeutic effects after radiation therapy, systemic diseases, or cardiomyopathy may also be confused with malignant disease on18 F-FDG PET/CT...
February 6, 2018: Current Problems in Diagnostic Radiology
Margherita Ruoppolo, Marianna Caterino, Lucia Albano, Rita Pecce, Maria Grazia Di Girolamo, Daniela Crisci, Michele Costanzo, Luigi Milella, Flavia Franconi, Ilaria Campesi
Sex differences affect several diseases and are organ-and parameter-specific. In humans and animals, sex differences also influence the metabolism and homeostasis of amino acids and fatty acids, which are linked to the onset of diseases. Thus, the use of targeted metabolite profiles in tissues represents a powerful approach to examine the intermediary metabolism and evidence for any sex differences. To clarify the sex-specific activities of liver, heart and kidney tissues, we used targeted metabolomics, linear discriminant analysis (LDA), principal component analysis (PCA), cluster analysis and linear correlation models to evaluate sex and organ-specific differences in amino acids, free carnitine and acylcarnitine levels in male and female Sprague-Dawley rats...
March 16, 2018: Scientific Reports
Julia Pietilä, Elina Helander, Ilkka Korhonen, Tero Myllymäki, Urho M Kujala, Harri Lindholm
BACKGROUND: Sleep is fundamental for good health, and poor sleep has been associated with negative health outcomes. Alcohol consumption is a universal health behavior associated with poor sleep. In controlled laboratory studies, alcohol intake has been shown to alter physiology and disturb sleep homeostasis and architecture. The association between acute alcohol intake and physiological changes has not yet been studied in noncontrolled real-world settings. OBJECTIVE: The aim of this study was to assess the effects of alcohol intake on the autonomic nervous system (ANS) during sleep in a large noncontrolled sample of Finnish employees...
March 16, 2018: JMIR Mental Health
Sarah K Schäfer, Frank R Ihmig, Karen A Lara H, Frank Neurohr, Stephan Kiefer, Marlene Staginnus, Johanna Lass-Hennemann, Tanja Michael
BACKGROUND: Specific phobias are among the most common anxiety disorders. Exposure therapy is the treatment of choice for specific phobias. However, not all patients respond equally well to it. Hence, current research focuses on therapeutic add-ons to increase and consolidate the effects of exposure therapy. One potential therapeutic add-on is biofeedback to increase heart rate variability (HRV). A recent meta-analysis shows beneficial effects of HRV biofeedback interventions on stress and anxiety symptoms...
March 16, 2018: Trials
Qiyu Lu, Yi Sun, Yuyin Duan, Bin Li, Jianming Xia, Songhua Yu, Guimin Zhang
BACKGROUND: Valvular heart disease is a leading cause of cardiovascular mortality, especially in China. More than a half of valvular heart diseases are caused by acute rheumatic fever. microRNA is involved in many physiological and pathological processes. However, the miRNA profile of the rheumatic valvular heart disease is unknown. This research is to discuss microRNAs and their target gene pathways involved in rheumatic heart valve disease. METHODS: Serum miRNA from one healthy individual and four rheumatic heart disease patients were sequenced...
March 16, 2018: BMC Cardiovascular Disorders
Thorsten Tjardes, Markus Luecking
Introduction: To achieve the aim of zero preventable deaths on the battlefield a deeper understanding of uncontrolled hemorrhage from junctional or proximal extremity sources is mandatory. While tourniquet application to the extremities has drastically reduced morbidity and mortality, there is still room for improvement regarding the timing of tourniquet placement as the available evidence clearly points out a tight correlation between timing of tourniquet application and outcome. To save as many lives as possible the "point of no return" regarding the circulatory breakdown due to hemorrhage, colloquially addressed as platinum 5 min, needs to be determined...
March 14, 2018: Military Medicine
David Hasler, Dominik Obrist
The flow field past a prosthetic aortic valve comprises many details that indicate whether the prosthesis is functioning well or not. It is, however, not yet fully understood how an optimal flow scenario would look, i.e. which subtleties of the fluid dynamics in place are essential regarding the durability and compatibility of a prosthetic valve. In this study, we measured and analyzed the 3D flow field in the vicinity of a bio-prosthetic heart valve in function of the aortic root size. The measurements were conducted within aortic root phantoms of different size, mounted in a custom-built hydraulic setup, which mimicked physiological flow conditions in the aorta...
2018: PloS One
Sarah Herzog, Wendy D'Andrea, Jonathan DePierro, Vivian Khedari
There is need for further work clarifying attention-physiology interactions by degree of exposure to early victimization, as it is clear that cumulative trauma in childhood, that is, polyvictimization, may have lasting effects on the stress response that differ from those of acute traumatization. The present study examined relationships between baseline and task-related physiology (indexed by respiratory sinus arrhythmia [RSA] and heart rate [HR], respectively), and attention biases (via the dot probe task), in 63 community-dwelling adult women stratified on the basis of self-reported exposure to multiple types of childhood interpersonal victimization (i...
May 2018: Journal of Trauma & Dissociation
Oscar H L Bing
Ammonia plays a central role in the life and death of all living organisms and has been studied for over one hundred years. Ammonia is necessary for growth and development but it is toxic in excess and, as a result, differing methods of ammonia neutralization have evolved. Following physiological and pathological stress to the heart, tissue ammonia levels rise. Local ammonia neutralization may be inadequate and excess ammonia may exert its toxic effects. Phenylbutyrate (PBA), which is FDA approved for the treatment of elevated blood ammonia in urea cycle disorders, provides an accessory pathway for ammonia clearance...
March 16, 2018: American Journal of Physiology. Heart and Circulatory Physiology
Barbara Wiśniowska, Sebastian Polak
The current study is an example of drug-disease interaction modeling where a drug induces a condition which can affect the pharmacodynamics of other concomitantly taken drugs. The electrophysiological effects of hypokaliemia and heart rate changes induced by the antiasthmatic drugs were simulated with the use of the cardiac safety simulator. Biophysically detailed model of the human cardiac physiology-ten Tusscher ventricular cardiomyocyte cell model-was employed to generate pseudo-ECG signals and QTc intervals for 44 patients from four clinical studies...
March 15, 2018: Journal of Pharmacokinetics and Pharmacodynamics
Kasper Meidahl Petersen, Søren Bøgevig, Jens Juul Holst, Filip Krag Knop, Mikkel Bring Christensen
Context: Glucagon's effects on hemodynamic parameters - most notably heart rate and cardiac contractility - are overlooked. The glucagon receptor is a central target in novel and anticipated type 2 diabetes therapies and hemodynamic consequences of glucagon signaling have therefore become increasingly important. In this review we summarize and evaluate published studies on glucagon pharmacology with focus on clinical hemodynamic effects in humans. Evidence acquisition: PubMed, EMBASE and the Cochrane library were searched for clinical studies concerning hemodynamic effects of glucagon (no year restriction)...
March 13, 2018: Journal of Clinical Endocrinology and Metabolism
Luqing Wei, Hong Chen, Guo-Rong Wu
The neurovisceral integration model has shown a key role of the amygdala in neural circuits underlying heart rate variability (HRV) modulation, and suggested that reciprocal connections from amygdala to brain regions centered on the central autonomic network (CAN) are associated with HRV. To provide neuroanatomical evidence for these theoretical perspectives, the current study used covariance analysis of MRI-based gray matter volume (GMV) to map structural covariance network of the amygdala, and then determined whether the interregional structural correlations related to individual differences in HRV...
2018: Frontiers in Human Neuroscience
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