Coleman, T. P. | Search bioRxiv

bioRxiv2022

Measurement of Cervical Neuronal Activity during Stress Challenge Using Novel Flexible Adhesive Surface Electrodes

This study introduces a flexible, adhesive-integrated electrode array that was developed to enable non-invasive monitoring of cervical nerve activity. The device uses silver-silver chloride as the electrode material of choice and combines it with a novel electrode array consisting of a customized biopotential data acquisition unit and integrated graphical user interface (GUI) for visualization of real-time monitoring. Preliminary testing demonstrated this novel electrode design can achieve a high signal to noise ratio during cervical neural recordings. To demonstrate the capability of the surface electrodes to detect changes in cervical neuronal activity, the cold-pressor test (CPT) and a timed respiratory challenge were employed as stressors to the autonomic nervous system. This sensor system recording, a new novel technique, was termed Cervical Electroneurography (CEN). By applying a custom spike sorting algorithm to the novel electrode measurements, neural activity was classified in two ways: 1) pre-to-post CPT, and 2) during a timed respiratory challenge. Unique to this work: 1) rostral to caudal channel position-specific (cephalad to caudal) firing patterns and 2) cross challenge biotype-specific change in average CEN firing, were observed with both CPT and the timed respiratory challenge. Future work is planned to develop an ambulatory CEN recording device that could provide immediate notification of autonomic nervous system activity changes that might indicate autonomic dysregulation in healthy subjects and clinical disease states.

physiology↗

bioRxiv2021

Csf1r-GCaMP5 Reporter Mice Reveal Immune Cell Communication in Vitro and in Vivo

Interconnected cells are responsible for emergent functions ranging from cognition in the brain to cyclic contraction in the heart. In electrically excitable cells, methods for studying cell communication are highly advanced, but in non-excitable cells, generalized methods for studying cell communication are less mature. Immune cells have generally been classified as non-excitable cells with diverse pathophysiologic roles that span every tissue in the body, yet little is known about their interconnectedness because assays are destructive and have low temporal resolution. In this work, we hypothesize that non-excitable immune cells are functionally interconnected in previously unrecognized cell communication networks. To test the hypothesis, we created a hematopoietic calcium reporter mouse (Csf1r-Cre x GCaMP5) and non-destructively quantified the spatiotemporal dynamics of intracellular calcium in vitro and in vivo. In vitro, bone marrow derived macrophages calcium reporters reveal that fatal immune stimulatory DNA-sensing induces rapid intercellular communication to neighboring cells. In vivo, using intravital microscopy through a dorsal window chamber in the context of MC38-H2B-mCherry tumors, Csf1r-GCaMP5 reporters exhibit spatiotemporal dynamics consistent with cell communication. We present a theoretical framework and analysis pipeline for identifying spatiotemporal locations of "excess synchrony" of calcium spiking as a means of inferring previously unrecognized cell communication events. Together, these methods provide a toolkit for investigating known and as-yet-undiscovered cell communication events in vitro and in vivo.

immunology↗

bioRxiv2020

Bedscales: A non-contact adherence-independent multi-person sensor for longitudinal physiologic monitoring in the home bed

Home health monitoring technologies promise to improve care and reduce costs, yet they are limited by the need for adherence to self-monitoring, usage of an app, or application of a wearable. While implantable sensors overcome the adherence barrier, they are expensive and require invasive procedures. Here, we describe a non-invasive, non-contact, adherence-independent sensor, that when placed beneath the legs of a patients home bed, longitudinally monitors total body weight, detailed respiratory signals, and ballistocardiograms for months, without requiring any active patient participation. Accompanying algorithms demix weight and respiratory signals when the bed is shared by a partner or a pet. Validation studies during overnight clinical sleep studies exhibit quantitative equivalence to commercial sensors and allow discrimination of obstructive and central sleep apneas. In-home studies discriminate atrial fibrillation from normal sinus rhythm. To demonstrate real-world feasibility, we performed 3 months of continuous in-home monitoring in a patient with heart failure as he awaited and recovered from coronary artery bypass surgery. By overcoming the adherence barrier, Bedscales has the potential to create a multidimensional picture of chronic disease, learn signatures of impending hospitalization, and enable optimization of care in the home. DisclosuresDrs. King and Coleman and Nicholas Harrington are inventors on a patent application describing the Bedscales technology. Dr. Kevin R. King discloses consulting relationships with Bristol Myers Squibb and Astrazeneca, Medimmune and is founder of Nightingale Labs. Dr. Deepak L. Bhatt discloses the following relationships - Advisory Board: Cardax, Cereno Scientific, Elsevier Practice Update Cardiology, Medscape Cardiology, PhaseBio, Regado Biosciences; Board of Directors: Boston VA Research Institute, Society of Cardiovascular Patient Care, TobeSoft; Chair: American Heart Association Quality Oversight Committee; Data Monitoring Committees: Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute, for the PORTICO trial, funded by St. Jude Medical, now Abbott), Cleveland Clinic (including for the ExCEED trial, funded by Edwards), Duke Clinical Research Institute, Mayo Clinic, Mount Sinai School of Medicine (for the ENVISAGE trial, funded by Daiichi Sankyo), Population Health Research Institute; Honoraria: American College of Cardiology (Senior Associate Editor, Clinical Trials and News, ACC.org; Vice-Chair, ACC Accreditation Committee), Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute; RE-DUAL PCI clinical trial steering committee funded by Boehringer Ingelheim; AEGIS-II executive committee funded by CSL Behring), Belvoir Publications (Editor in Chief, Harvard Heart Letter), Duke Clinical Research Institute (clinical trial steering committees, including for the PRONOUNCE trial, funded by Ferring Pharmaceuticals), HMP Global (Editor in Chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (Guest Editor; Associate Editor), Medtelligence/ReachMD (CME steering committees), Population Health Research Institute (for the COMPASS operations committee, publications committee, steering committee, and USA national co-leader, funded by Bayer), Slack Publications (Chief Medical Editor, Cardiology Todays Intervention), Society of Cardiovascular Patient Care (Secretary/Treasurer), WebMD (CME steering committees); Other: Clinical Cardiology (Deputy Editor), NCDR-ACTION Registry Steering Committee (Chair), VA CART Research and Publications Committee (Chair); Research Funding: Abbott, Afimmune, Amarin, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Chiesi, CSL Behring, Eisai, Ethicon, Ferring Pharmaceuticals, Forest Laboratories, Fractyl, Idorsia, Ironwood, Ischemix, Lilly, Medtronic, PhaseBio, Pfizer, PLx Pharma, Regeneron, Roche, Sanofi Aventis, Synaptic, The Medicines Company; Royalties: Elsevier (Editor, Cardiovascular Intervention: A Companion to Braunwalds Heart Disease); Site Co-Investigator: Biotronik, Boston Scientific, CSI, St. Jude Medical (now Abbott), Svelte; Trustee: American College of Cardiology; Unfunded Research: FlowCo, Merck, Novo Nordisk, Takeda. Dr. Akshay S. Desai discloses the following relationships - Research grants to Brigham and Womens Hospital to support clinical trial activities from Alnylam, AstraZeneca, and Novartis; Consulting fees from Abbott, Alnylam, AstraZeneca, Biofourmis, Boehringer-Ingelheim, Boston Scientific, Merck, Novartis, Relypsa, Regeneron. Dr. Owens reports consulting fees from Novartis, and research grants to UCSD from Snoozeal, Nitto Denko, and Masimo.

bioengineering↗