Publications by authors named "Armour J"

Objective: This study evaluated the effects of cessation of both conventional low-frequency (50 Hz) and high-frequency (10 kHz) spinal cord stimulation (SCS) on the cardiospinal neural network activity in pigs with myocardial infarction (MI). The objective is to provide an insight into the memory effect of SCS.

Materials And Methods: In nine Yorkshire pigs, chronic MI was created by delivering microspheres to the left circumflex coronary artery.

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Background: Post-traumatic stress disorder (PTSD) is common in military veterans and presents as distress, anxiety, or depression due to a traumatic event. Expressive therapies are an emerging intervention used to enhance the quality of life by addressing the cognitive, emotional, and behavioral aspects of individuals.

Methods: Five databases were searched from 2014 to 2022 with search terms addressing the expressive therapies of art, dance, drama, music, and writing, and military veterans with PTSD.

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Introduction: Myocardial ischemia disrupts the cardio-spinal neural network that controls the cardiac sympathetic preganglionic neurons, leading to sympathoexcitation and ventricular tachyarrhythmias (VTs). Spinal cord stimulation (SCS) is capable of suppressing the sympathoexcitation caused by myocardial ischemia. However, how SCS modulates the spinal neural network is not fully known.

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Stellate ganglia within the intrathoracic cardiac control system receive and integrate central, peripheral, and cardiopulmonary information to produce postganglionic cardiac sympathetic inputs. Pathological anatomical and structural remodeling occurs within the neurons of the stellate ganglion (SG) in the setting of heart failure (HF). A large proportion of SG neurons function as interneurons whose networking capabilities are largely unknown.

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Background: Immunoglobulin A (IgA) nephropathy is a disorder of the immune system affecting kidney function, and genome-wide association studies (GWAS) have defined numerous loci with associated variation, all implicating components of innate or adaptive immunity. Among these, single nucleotide polymorphisms (SNPs) in a region including the multiallelic copy number variation (CNV) of DEFA1A3 are associated with IgA nephropathy in both European and Asian populations. At present, the precise factors underlying the observed associations at DEFA1A3 have not been defined, although the key alleles differ between Asian and European populations, and multiple independent factors may be involved even within a single population.

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Neural control of the heart involves continuous modulation of cardiac mechanical and electrical activity to meet the organism's demand for blood flow. The closed-loop control scheme consists of interconnected neural networks with central and peripheral components working cooperatively with each other. These components have evolved to cooperate control of various aspects of cardiac function, which produce measurable "functional" outputs such as heart rate and blood pressure.

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Article Synopsis
  • Some people smell differently due to their skin bacteria, which makes them more or less appealing to mosquitoes.
  • Researchers studied how women's skin bacteria affect their attractiveness to a type of mosquito known as Anopheles coluzzii.
  • The results showed that those who are more attractive to mosquitoes had different types of skin bacteria compared to those who are less attractive, which could help improve ways to trap or control mosquitoes.
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Myocardial infarction causes pathological changes in the autonomic nervous system, which exacerbate heart failure and predispose to fatal ventricular arrhythmias and sudden death. These changes are characterized by sympathetic activation and parasympathetic dysfunction (reduced vagal tone). Reasons for the central vagal withdrawal and, specifically, whether myocardial infarction causes changes in cardiac vagal afferent neurotransmission that then affect efferent tone, remain unknown.

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This study investigates the associations between perceived parenting and borderline personality disorder (BPD) in adolescents. The relations between components of parenting and BPD features were explored. Participants (N = 270; mean age = 15.

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Cardiopulmonary sympathetic control is exerted via stellate ganglia (SG); however, little is known about how neuronal firing patterns in the stellate ganglion relate to dynamic physiological function in the heart and lungs. We performed continuous extracellular recordings from SG neurons using multielectrode arrays in chloralose-anesthetized pigs ( = 6) for 8-9 h. Respiratory and left ventricular pressures (RP and LVP, respectively) and the electrocardiogram (ECG) were recorded concomitantly.

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The purpose of this study was to define the mechanism by which cardiac neuraxial decentralization or spinal cord stimulation (SCS) reduces ischemia-induced ventricular fibrillation (VF). Direct measurements of norepinephrine (NE) levels in the left ventricular interstitial fluid (ISF) by microdialysis, in response to transient (15-minute) coronary artery occlusion (CAO), were performed in anesthetized canines. Responses were studied in animals with intact neuraxes and were compared with those in which the intrathoracic component of the cardiac neuraxes (stellate ganglia) or the intrinsic cardiac neuronal (ICN) system was surgically delinked from the central nervous system and those with intact neuraxes with preemptive SCS (T1-T3).

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Aberrant afferent signaling drives adverse remodeling of the cardiac nervous system in ischemic heart disease. The study objective was to determine whether thoracic spinal dorsal column stimulation (SCS) modulates cardiac afferent sensory transduction of the ischemic ventricle. In anesthetized canines ( = 16), extracellular activity generated by 62 dorsal root ganglia (DRG) soma (T1-T3), with verified myocardial ischemic (MI) sensitivity, were evaluated with and without 20-min preemptive SCS (T1-T3 spinal level; 50 Hz, 90% motor threshold).

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Objective: In a 2014 publication, evidence was presented supporting the association of BMI with the copy number of the salivary amylase 1 (AMY1) gene, with an unprecedented effect size of -0.15 kg/m (SE 0.02) per copy of AMY1.

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Mechanisms behind development of premature ventricular contraction (PVC)-induced cardiomyopathy remain unclear. PVCs may adversely modulate the autonomic nervous system to promote development of heart failure. Afferent neurons in the inferior vagal (nodose) ganglia transduce cardiac activity and modulate parasympathetic output.

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We designed and implemented a novel automated negative non-invasive prenatal test (NIPT) result disclosure process using a proprietary, HIPAA-compliant web-based portal. High-risk pregnant patients who opted for NIPT from 04/2017 to 12/2018 were given the option to receive their negative result through the automated process. Patients were required to watch a brief educational video and answer evaluative questions before downloading their result.

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The objective of this pilot-scale study was to investigate the effectiveness of incorporating ozone (O) and advanced oxidation (hydrogen peroxide/ozone: HO/O) in combination with biofiltration for taste and odour control, organic carbon removal, and disinfection byproduct (DBP) precursor reduction. Implementation of O and HO/O with and without biofiltration was investigated at pilot-scale in terms of geosmin, 2-methylisoborneol (MIB), and DBP precursor removal efficiency. Two media types (granular activated carbon and anthracite) were compared in conjunction with investigating the impact of pre-oxidation with O (2 mg/L) and varying HO/O mass ratios (0.

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A clinical pathologist whose outstanding contribution to the profession was to invent the first reliable clinical biochemistry analyser for use in practice.

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Background: Autonomic regulation therapy involving either vagus nerve stimulation (VNS) or spinal cord stimulation (SCS) represents emerging bioelectronic therapies for heart disease. The objective of this study was to determine if VNS and/or SCS modulate primary cardiac afferent sensory transduction of the ischemic myocardium.

Methods: Using extracellular recordings in 19 anesthetized canines, of 88 neurons evaluated, 36 ventricular-related nodose ganglia sensory neurons were identified by their functional activity responses to epicardial touch, chemical activation of their sensory neurites (epicardial veratridine) and great vessel (descending aorta or inferior vena cava) occlusion.

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Key Points: The evoked cardiac response to bipolar cervical vagus nerve stimulation (VNS) reflects a dynamic interaction between afferent mediated decreases in central parasympathetic drive and suppressive effects evoked by direct stimulation of parasympathetic efferent axons to the heart. The neural fulcrum is defined as the operating point, based on frequency-amplitude-pulse width, where a null heart rate response is reproducibly evoked during the on-phase of VNS. Cardiac control, based on the principal of the neural fulcrum, can be elicited from either vagus.

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The cardiac nervous system continuously controls cardiac function whether or not pathology is present. While myocardial infarction typically has a major and catastrophic impact, population studies have shown that longer-term risk for recurrent myocardial infarction and the related potential for sudden cardiac death depends mainly upon standard atherosclerotic variables and autonomic nervous system maladaptations. Investigative neurocardiology has demonstrated that autonomic control of cardiac function includes local circuit neurons for networked control within the peripheral nervous system.

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Background: Variability in premature ventricular contraction (PVC) coupling interval (CI) increases the risk of cardiomyopathy and sudden death. The autonomic nervous system regulates cardiac electrical and mechanical indices, and its dysregulation plays an important role in cardiac disease pathogenesis. The impact of PVCs on the intrinsic cardiac nervous system, a neural network on the heart, remains unknown.

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Background: Salivary amylase in humans is encoded by the copy variable gene AMY1 in the amylase gene cluster on chromosome 1. Although the role of salivary amylase is well established, the consequences of the copy number variation (CNV) at AMY1 on salivary amylase protein production are less well understood. The amylase gene cluster is highly structured with a fundamental difference between odd and even AMY1 copy number haplotypes.

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The human amylase gene cluster includes the human salivary (AMY1) and pancreatic amylase genes (AMY2A and AMY2B), and is a highly variable and dynamic region of the genome. Copy number variation (CNV) of AMY1 has been implicated in human dietary adaptation, and in population association with obesity, but neither of these findings has been independently replicated. Despite these functional implications, the structural genomic basis of CNV has only been defined in detail very recently.

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Humans have more copies of amylase genes than other primates. It is still poorly understood, however, when the copy number expansion occurred and whether its spread was enhanced by selection. Here we assess amylase copy numbers in a global sample of 480 high coverage genomes and find that regions flanking the amylase locus show notable depression of genetic diversity both in African and non-African populations.

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