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https://www.readbyqxmd.com/read/28460516/neuroendocrine-dysregulation-in-irritable-bowel-syndrome-patients-a-pilot-study
#1
Cristina Stasi, Massimo Bellini, Dario Gambaccini, Emiliano Duranti, Nicola de Bortoli, Bernardo Fani, Eleonora Albano, Salvatore Russo, Isabella Sudano, Giacomo Laffi, Stefano Taddei, Santino Marchi, Rosa Maria Bruno
Background/Aims: Irritable bowel syndrome (IBS) is a multifactorial disorder, involving dysregulation of brain-gut axis. Our aim was to evaluate the neuroendocrine activity in IBS. Methods: Thirty IBS and 30 healthy subjects were enrolled. Psychological symptoms were evaluated by questionnaires. Urinary 5-hydroxyindoleacetic acid (5-HIAA), plasma serotonin, endothelin, neuropeptide Y (NPY), plasma, and urinary cortisol levels were evaluated. Fourteen IBS subjects underwent microneurography to obtain multiunit recordings of efferent postganglionic muscle sympathetic nerve activity (MSNA)...
April 26, 2017: Journal of Neurogastroenterology and Motility
https://www.readbyqxmd.com/read/28428756/neck-circumference-is-associated-with-muscle-sympathetic-nerve-activity-in-overweight-and-obese-men-but-not-women
#2
Nora E Straznicky, Mariee T Grima, Carolina I Sari, Nina Eikelis, Paul J Nestel, John B Dixon, Gavin W Lambert, Markus P Schlaich, Sarah E Phillips, Elisabeth A Lambert
Background: Neck circumference (NC) is a predictor of cardiometabolic risk. The objective of this study was to explore the relationship of NC to muscle sympathetic nerve activity (MSNA) within an overweight and obese population. Methods: The study design was a retrospective cross-sectional analysis. Un-medicated persons (72 men, 53 postmenopausal women) aged 56 ± 1 years (mean ± SEM) with body mass index (BMI) 32.8 ± 0.4 kg/m(2), were studied. NC was measured together with traditional anthropometric measures, supine blood pressure, fasting blood lipids, insulin, and glucose...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28378458/sensitivity-to-ischaemia-of-single-sympathetic-nerve-fibres-innervating-the-dorsum-of-the-human-foot
#3
W J Z'Graggen, R Solà, N E Graf, J Serra, H Bostock
The aim of this study was to determine whether velocity recovery cycles (VRCs) could detect the effects of ischaemia on sympathetic nerve fibres. VRCs of human sympathetic nerve fibres of the superficial peroneal nerve innervating the dorsum of the foot were recorded by microneurography in 7 healthy volunteers. Sympathetic nerve fibres were identified by studying their response to manoeuvres increasing sympathetic outflow and by measuring activity-dependent slowing at 2 Hz stimulation. VRCs were assessed at rest, during 30 min of induced limb ischaemia and during 20 min of recovery after ischaemia...
April 4, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28364029/intact-blood-pressure-but-not-sympathetic-responsiveness-to-sympathoexcitatory-stimuli-in-a-patient-with-unilateral-carotid-body-resection
#4
Kathryn F Larson, Jacqueline K Limberg, Sarah E Baker, Michael J Joyner, Timothy B Curry
Despite rapidly growing interest in the therapeutic resection of the carotid body (CB) chemoreceptors, few physiologic studies exist on the consequences of unilateral CB resection. We present a case of an otherwise healthy postmenopausal female who underwent unilateral CB resection for a paraganglioma. Approximately 4 years postoperatively, she underwent analysis of her sympathetic and hemodynamic responses to hypoxia, lower body negative pressure, cold pressor test (CPT), and ischemic hand grip exercise and postexercise ischemia (IHE/PEI)...
April 2017: Physiological Reports
https://www.readbyqxmd.com/read/28350577/reliability-of-heart-rate-as-neuroadrenergic-marker-in-the-metabolic-syndrome
#5
Fosca Quarti Trevano, Gino Seravalle, Mario Macchiarulo, Paolo Villa, Carlo Valena, Raffaella Dell'Oro, Giuseppe Mancia, Guido Grassi
BACKGROUND: Metabolic syndrome is characterized by a pronounced sympathetic overactivity as documented by the marked increase in muscle sympathetic nerve traffic (MSNA) as well as in plasma norepinephrine values reported in this condition. Whether and to what extent heart rate (HR) reflects the abovementioned adrenergic alterations in metabolic syndrome remains largely undefined. It is also undefined the validity of the abovementioned adrenergic markers in reflecting the main features of the metabolic syndrome...
March 27, 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28323975/muscle-sympathetic-nerve-activity-is-associated-with-elements-of-the-plasma-lipidomic-profile-in-young-asian-adults
#6
Nina Eikelis, Elisabeth A Lambert, Sarah Phillips, Carolina Ika Sari, Piyushkumar A Mundra, Jacquelyn M Weir, Kevin Huynh, Mariee T Grima, Nora E Straznicky, John B Dixon, Markus P Schlaich, Peter J Meikle, Gavin W Lambert
Background: Asian subjects are at increased cardio-metabolic risk at comparatively lower body mass index (BMI) compared with white subjects. Sympathetic nervous system activation and dyslipidemia, both characteristics of increased adiposity, appear to be related. We therefore analyzed the association of muscle sympathetic nerve activity (MSNA) with the plasma lipidomic profile in young adult Asian and white subjects. Methods: Blood samples were collected from 101 participants of either Asian or white background (age, 18 to 30 years; BMI, 28...
June 1, 2017: Journal of Clinical Endocrinology and Metabolism
https://www.readbyqxmd.com/read/28303912/new-technologies-for-the-assessment-of-neuropathies
#7
REVIEW
Roberto Gasparotti, Luca Padua, Chiara Briani, Giuseppe Lauria
Technical advances are rapidly changing the clinical and instrumental approach to peripheral nerve diseases. Magnetic resonance neurography, diffusion tensor imaging and nerve ultrasonography are increasingly entering the diagnostic workup of peripheral neuropathies as tools that complement neurophysiology and enable investigation of proximal structures, such as plexuses and roots. Progress in the design of magnetic resonance scanners and sequences, and the development of high-frequency ultrasound probes mean that high-resolution peripheral nerve imaging is possible, enabling detailed examination of nerve size, morphology and internal fascicular structure that can integrate nerve conduction studies into clinical practice...
March 17, 2017: Nature Reviews. Neurology
https://www.readbyqxmd.com/read/28289073/sympathetic-nervous-activity-in-patients-with-acute-coronary-syndrome-a-comparative-study-of-inflammatory-biomarkers
#8
COMPARATIVE STUDY
Humberto G Moreira, Rony L Lage, Daniel G Martinez, Larissa Ferreira-Santos, Maria U P B Rondon, Carlos E Negrão, José C Nicolau
Previous studies have shown that both sympathetic hyperactivity and enhanced inflammatory responses are associated with poor outcomes in patients with acute coronary syndrome (ACS). Whether there is a correlation between these two characteristics remains unclear. Thirty-four patients with uncomplicated ACS were evaluated; their mean age was 51.7±7.0 years, 79.4% were male, and 94.1% had myocardial infarction (MI). On the fourth day of hospitalization, they underwent muscle sympathetic nerve activity (MSNA) analysis (microneurography), as well as ultrasensitive C-reactive protein (usCRP), interleukin-6 (IL-6), and lipoprotein-associated phospholipase A2 (Lp-PLA2) activity measurements...
May 1, 2017: Clinical Science (1979-)
https://www.readbyqxmd.com/read/28263787/precise-coding-of-ankle-angle-and-velocity-by-human-calf-muscle-spindles
#9
Ryan M Peters, Brian H Dalton, Jean-Sébastien Blouin, J Timothy Inglis
Human standing balance control requires the integration of sensory feedback to produce anticipatory, stabilizing ankle torques. However, the ability of human triceps surae muscle spindles to provide reliable sensory feedback regarding the small, slow ankle movements that occur during upright standing has recently come under question. We performed microneurography to directly record axon potentials from single muscle spindle afferents in the human triceps surae during servo-controlled movement of the ankle joint...
March 2, 2017: Neuroscience
https://www.readbyqxmd.com/read/28248904/serum-uric-acid-and-the-relationship-with-subclinical-organ-damage-in-adults
#10
Elisabeth A Lambert, Mariam Hachem, Robyn Hemmes, Nora E Straznicky, Nina Eikelis, Carolina I Sari, Markus P Schlaich, Gavin W Lambert, John B Dixon
AIMS: Elevated serum uric acid (SUA) is often present in conditions associated with increased cardiovascular risk yet it is not recognized as a marker of risk. We evaluated whether SUA was associated with evidence of early markers of cardiovascular risk factor including subclinical early organ damage, sympathetic tone and metabolic profile in a healthy population with a high prevalence of obesity. MATERIAL AND METHODS: Data from 281 patients (175 women and 106 men, mean age: 35...
April 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28230704/muscle-metaboreflex-control-of-sympathetic-activity-in-obstructive-sleep-apnea
#11
Linda M Ueno-Pardi, Renan S Guerra, Thiago T Goya, Rosyvaldo F Silva, Elisangela M Gara, Marta F Lima, Thais S Nobre, Maria J N N Alves, Ivani C Trombetta, Geraldo Lorenzi-Filho
PURPOSE: Previous studies report abnormal muscle metaboreflex control of muscle sympathetic nerve activity (MSNA) in obesity, hypertension, and heart failure. We hypothesized that obstructive sleep apnea (OSA) is associated with augmented metaboreflex control of MSNA. METHODS: Thirty-one sedentary individuals with no comorbidities (age = 52 ± 1 yr, body mass index = 28 ± 1 kg·m) without (control, n = 14) and with OSA (n = 17) defined by polysomnography, underwent echocardiography...
July 2017: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/28228418/folic-acid-supplementation-increases-cutaneous-vasodilator-sensitivity-to-sympathetic-nerve-activity-in-older-adults
#12
Anna E Stanhewicz, Jody L Greaney, Lacy M Alexander, W Larry Kenney
During heat stress, blunted increases in skin sympathetic nervous system activity (SSNA) and reductions in end-organ vascular responsiveness contribute to the age-related reduction in reflex cutaneous vasodilation. In older adults, folic acid supplementation improves the cutaneous vascular conductance (CVC) response to passive heating; however, the influence of folic acid supplementation on SSNA:CVC transduction is unknown. Fourteen older adults (66±1yrs, 8M/6F) ingested folic acid (5mg·day(-1)) or placebo for 6 weeks in a randomized, double-blind, crossover design...
February 22, 2017: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
https://www.readbyqxmd.com/read/28162847/c-tactile-afferents-cutaneous-mediators-of-oxytocin-release-during-affiliative-tactile-interactions
#13
REVIEW
Susannah C Walker, Paula D Trotter, William T Swaney, Andrew Marshall, Francis P Mcglone
Low intensity, non-noxious, stimulation of cutaneous somatosensory nerves has been shown to trigger oxytocin release and is associated with increased social motivation, plus reduced physiological and behavioural reactivity to stressors. However, to date, little attention has been paid to the specific nature of the mechanosensory nerves which mediate these effects. In recent years, the neuroscientific study of human skin nerves (microneurography studies on single peripheral nerve fibres) has led to the identification and characterisation of a class of touch sensitive nerve fibres named C-tactile afferents...
January 19, 2017: Neuropeptides
https://www.readbyqxmd.com/read/28123010/optimal-delineation-of-single-c-tactile-and-c-nociceptive-afferents-in-humans-by-latency-slowing
#14
Roger H Watkins, Johan Wessberg, Helena Backlund Wasling, James P Dunham, Håkan Olausson, Richard D Johnson, Rochelle Ackerley
C-mechanoreceptors in humans comprise a population of unmyelinated afferents exhibiting a wide range of mechanical sensitivities. C-mechanoreceptors are putatively divided into those signaling gentle touch (C-tactile afferents, CTs) and nociception (C-mechanosensitive nociceptors, CMs), giving rise to positive and negative affect, respectively. We sought to distinguish, compare, and contrast the properties of a population of human C-mechanoreceptors to see how fundamental the divisions between these putative subpopulations are...
April 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28100923/reductions-in-central-arterial-compliance-with-age-are-related-to-sympathetic-vasoconstrictor-nerve-activity-in-healthy-men
#15
Hirofumi Tanaka, Frank A Dinenno, Douglas R Seals
The compliance of large elastic arteries in the cardiothoracic circulation declines, whereas sympathetic nervous system activity increases markedly with advancing age in adult humans. We tested the hypothesis that the reduction in compliance of the large elastic arteries with age is associated with elevations in sympathetic tone to vascular smooth muscle in 16 young and 17 older adults. Carotid arterial compliance (via ultrasonography) was 45% lower in healthy older compared with young men (P<0.001), and was inversely related to sympathetic nerve activity (via microneurography) (r=-0...
May 2017: Hypertension Research: Official Journal of the Japanese Society of Hypertension
https://www.readbyqxmd.com/read/28077660/muscle-spindles-in-human-tibialis-anterior-encode-muscle-fascicle-length-changes
#16
James Day, Leah R Bent, Ingvars Birznieks, Vaughan G Macefield, Andrew G Cresswell
Muscle spindles provide exquisitely sensitive proprioceptive information regarding joint position and movement. Through passively driven length changes in the muscle-tendon unit (MTU), muscle spindles detect joint rotations because of their in-parallel mechanical linkage to muscle fascicles. In human microneurography studies, muscle fascicles are assumed to follow the MTU and, as such, fascicle length is not measured in such studies. However, under certain mechanical conditions, compliant structures can act to decouple the fascicles, and, therefore, the spindles, from the MTU...
April 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28057441/non-invasive-approach-for-the-assessment-of-sympathetic-baroreflex-function-a-feasibility-study
#17
Bartłomiej Paleczny, Agnieszka Siennicka, Piotr Ponikowski, Beata Ponikowska
BACKGROUND: Evaluation of sympathetic baroreflex (sBR) function in humans requires intra-neural recording of muscle sympathetic nerve activity (MSNA) by microneurography. AIMS: We proposed noninvasive approach for the evaluation of sBR function by applying the threshold-analysis (traditionally, based on MSNA) to systemic vascular resistance (SVR) measurement by photoplethysmography. METHODS & RESULTS: In nine healthy subjects (5M; age: 25±5y), the threshold-analysis was calculated twice: using MSNA and SVR...
December 29, 2016: Autonomic Neuroscience: Basic & Clinical
https://www.readbyqxmd.com/read/28055999/-role-of-the-sympathetic-nervous-system-in-vasovagal-syncope-and-rationale-for-beta-blockers-and-norepinephrine-transporter-inhibitors
#18
Manlio F Márquez, Jorge Rafael Gómez-Flores, Jesús A González-Hermosillo, Teresita de Jesús Ruíz-Siller, Manuel Cárdenas
Vasovagal or neurocardiogenic syncope is a common clinical situation and, as with other entities associated with orthostatic intolerance, the underlying condition is a dysfunction of the autonomic nervous system. This article reviews various aspects of vasovagal syncope, including its relationship with orthostatic intolerance and the role of the autonomic nervous system in it. A brief history of the problem is given, as well as a description of how the names and associated concepts have evolved. The response of the sympathetic system to orthostatic stress, the physiology of the baroreflex system and the neurohumoral changes that occur with standing are analyzed...
December 29, 2016: Medwave
https://www.readbyqxmd.com/read/28029639/sleep-disordered-breathing-exacerbates-muscle-vasoconstriction-and-sympathetic-neural-activation-in-patients-with-systolic-heart-failure
#19
Denise M L Lobo, Patricia F Trevizan, Edgar Toschi-Dias, Patricia A Oliveira, Rafael B Piveta, Dirceu R Almeida, Charles Mady, Edimar A Bocchi, Geraldo Lorenzi-Filho, Holly R Middlekauff, Carlos E Negrão
BACKGROUND: Sleep-disordered breathing (SDB) is common in patients with heart failure (HF), and hypoxia and hypercapnia episodes activate chemoreceptors stimulating autonomic reflex responses. We tested the hypothesis that muscle vasoconstriction and muscle sympathetic nerve activity (MSNA) in response to hypoxia and hypercapnia would be more pronounced in patients with HF and SDB than in patients with HF without SDB (NoSBD). METHODS AND RESULTS: Ninety consecutive patients with HF, New York Heart Association functional class II-III, and left ventricular ejection fraction ≤40% were screened for the study...
November 2016: Circulation. Heart Failure
https://www.readbyqxmd.com/read/27956555/the-influence-of-aetiology-on-the-benefits-of-exercise-training-in-patients-with-heart-failure
#20
Ligia M Antunes-Correa, Linda M Ueno-Pardi, Patricia F Trevizan, Marcelo R Santos, Carlos Henrique P da Silva, Fábio Gm Franco, Maria Janieire Nn Alves, Maria Urbana Pb Rondon, Carlos E Negrao
Background Exercise training improves neurovascular control and functional capacity in heart failure (HF) patients. However, the influence of the aetiology on these benefits is unknown. We compared the effects of exercise training on neurovascular control and functional capacity in idiopathic, ischaemic and hypertensive HF patients. Design Subjects consisted of 45 exercise-trained HF patients from our database (2000-2015), aged 40-70 years old, functional class II/III and ejection fraction ≤40%, and they were divided into three groups: idiopathic ( n = 11), ischaemic ( n = 18) and hypertensive ( n = 16)...
March 2017: European Journal of Preventive Cardiology
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