The L-type calcium channel (LTCC) provides trigger Ca(2+) for sarcoplasmic reticulum Ca-release, and LTCC function is influenced by interacting proteins including the LTCC distal COOH terminus (DCT) and calmodulin. DCT is proteolytically cleaved and reassociates with the LTCC complex to regulate calcium channel function. DCT reduces LTCC barium current (I(Ba,L)) in reconstituted channel complexes, yet the contribution of DCT to LTCC Ca(2+) current (I(Ca,L)) in cardiomyocyte systems is unexplored. This study tests the hypothesis that DCT attenuates cardiomyocyte I(Ca,L). We measured LTCC current and Ca(2+) transients with DCT coexpressed in murine cardiomyocytes. We also heterologously coexpressed DCT and Ca(V)1.2 constructs with truncations corresponding to the predicted proteolytic cleavage site, Ca(V)1.2Δ1801, and a shorter deletion corresponding to well-studied construct, Ca(V)1.2Δ1733. DCT inhibited I(Ba,L) in cardiomyocytes, and in human embryonic kidney (HEK) 293 cells expressing Ca(V)1.2Δ1801 and Ca(V)1.2Δ1733. Ca(2+)-CaM relieved DCT block in cardiomyocytes and HEK cells. The selective block of I(Ba,L) combined with Ca(2+)-CaM effects suggested that DCT-mediated blockade may be relieved under conditions of elevated Ca(2+). We therefore tested the hypothesis that DCT block is dynamic, increasing under relatively low Ca(2+), and show that DCT reduced diastolic Ca(2+) at low stimulation frequencies but spared high frequency Ca(2+) entry. DCT reduction of diastolic Ca(2+) and relief of block at high pacing frequencies and under conditions of supraphysiological bath Ca(2+) suggests that a physiological function of DCT is to increase the dynamic range of Ca(2+) transients in response to elevated pacing frequencies. Our data motivate the new hypothesis that DCT is a native reverse use-dependent inhibitor of LTCC current.
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http://dx.doi.org/10.1152/ajpheart.00396.2012 | DOI Listing |
Prostate Int
December 2024
Department of Internal Urology, College of Medicine, Seoul National University, Seoul, Korea.
Background: To compare the efficacy and toxicity of docetaxel treatment regimens in metastatic castration-resistant prostate cancer (mCRPC).
Methods: We retrospectively analyzed 162 patients diagnosed with mCRPC who underwent docetaxel chemotherapy between 2009 and 2020. The patients were divided into three groups according to the dosage and interval of docetaxel (DCT) chemotherapy regimen: 30 mL/m weekly, 50 mL/m biweekly (every 2 weeks), and 75 mL/m triweekly (every 3 weeks).
Sci Rep
December 2024
School of Electronic and Nanoscale Engineering, University of Glasgow, Glasgow, G12 8QQ, UK.
In the era of the Internet of Things (IoT), the transmission of medical reports in the form of scan images for collaborative diagnosis is vital for any telemedicine network. In this context, ensuring secure transmission and communication is necessary to protect medical data to maintain privacy. To address such privacy concerns and secure medical images against cyberattacks, this research presents a robust hybrid encryption framework that integrates quantum, and classical cryptographic methods.
View Article and Find Full Text PDFMar Drugs
November 2024
Research Institute of Basic Sciences, Incheon National University, Incheon 22012, Republic of Korea.
, a salt-tolerant plant, has demonstrated antioxidant effects, the ability to prevent prostate enlargement, antifungal properties, and skin moisturizing benefits. This study aimed to explore the anti-melanogenic potential of the 70% ethanol extract of (TME) along with its ethyl acetate (TME-EA) and water (TME-A) fractions. TME (10-200 µg/mL), TME-EA (1-15 µg/mL), and TME-A (100-1000 µg/mL) were prepared and applied to B16F10 cells with or without α-MSH for 72 h.
View Article and Find Full Text PDFRes Sports Med
December 2024
High Institute of Sport and Physical Education, University of Sfax, Sfax, Tunisia.
This study examined the effect of a 40-min nap (N40) the day after a night session of the Loughborough Intermittent Shuttle Test (LIST), before, during and after Ramadan. In a randomized crossover design, fifteen male soccer players completed the LIST in the evening (2100h), followed by either a N40 or no nap (N0) the next day, at 1400h. Performance on the 5-m shuttle run test (5mSRT), digit cancellation test (DCT), and subjective measures (i.
View Article and Find Full Text PDFEClinicalMedicine
January 2025
Department of Pulmonology, Semmelweis University, Budapest, Hungary.
Background: Idiopathic pulmonary fibrosis (IPF) is a progressive, deadly lung disease with several factors, including respiratory tract infections (RTI), for disease worsening. There's no comprehensive data on RTI incidence in IPF patients across different therapies, including antifibrotic (nintedanib or pirfenidone), investigative or placebo treatments.
Methods: A systematic search of databases Medline, EMBASE, Cochrane Central, Web of Science and Scopus was conducted on September 30th 2024 (PROSPERO registration number: CRD42023484213).
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