Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4-6 h prior to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral parameters, especially when animals have altered circadian phenotype.
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http://dx.doi.org/10.1152/ajpregu.00599.2010 | DOI Listing |
JACC Case Rep
January 2025
Division of Cardiology, Electrophysiology Section, Adult Congenital Arrhythmia Clinic, Emory University, Atlanta, Georgia, USA.
Background: The atrial switch procedure is accompanied by a very high rate of sinus node dysfunction. Baffle stenosis is a common problem with transvenous pacemaker leads in this scenario.
Case Summary: We present a first-in-human case of a leadless pacer (LP) in the left atrium in a patient with prior atrial switch for transposition and sinus node dysfunction complicated by multiple abandoned leads, superior baffle occlusion, and failed extraction.
JACC Adv
February 2025
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Background: Clonal hematopoiesis of indeterminate potential (CHIP) has been linked to intensified systemic inflammation and represents a novel risk factor for atherosclerotic cardiovascular diseases, including aortic stenosis (AS).
Objectives: This study aimed to assess the clinical impact of CHIP in a cohort of severe AS patients undergoing transcatheter aortic valve implantation (TAVI).
Methods: We enrolled 110 severe AS patients in this retrospective study.
Objective: Fluoropyrimidine chemotherapy is a first-line treatment for many gastrointestinal (GI) cancers, however, cardiotoxicity concerns may limit administration in patients with pre-existing cardiovascular disease (CVD). This study investigated the association of pre-existing CVD with use of fluoropyrimidine chemotherapy in tumour-eligible GI cancer patients.
Methods And Analysis: National cancer registry data from the Virtual Cardio-Oncology Research Initiative from England between 2014 and 2018 was used to identify GI cancer patients eligible to receive fluoropyrimidine chemotherapy.
Surg Open Sci
August 2024
University of California, Irvine, Department of Surgery, Division of Trauma, Burns and Surgical Critical Care, Orange, CA, USA.
Background: There is a paucity of literature guiding trauma surgeons in the care of patients with active metastatic cancer (MC). Even less is known regarding outcomes for MC patients requiring emergent surgery after trauma. We hypothesized that trauma patients with active Metastatic Cancer (MC) have an increased mortality rate and undergo increased rates of withdrawal of care (WoC) within 72-hours following emergent operations, compared to similarly matched patients without MC.
View Article and Find Full Text PDFPeerJ
January 2025
Department of Endocrinology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
Background: The aim of this study was to investigate the impact of diabetes on mortality and adverse outcomes in COVID-19 patients and to analyse the associated risk factors.
Methods: This is a retrospective cohort study in 500 hospitalized patients with COVID-19 infection (214 with diabetes and 286 without diabetes) admitted to a tertiary hospital in China from December 2022 to February 2023. Demographic information, clinical characteristics and outcomes were collected.
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