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coronary and Kv

Rong Yang, Yu Liu, Xiaomin Hou, Yanying Fan, Jie Li, Min Chen, Yan Wang, Xuanping Zhang, Mingsheng Zhang
Acute coronary arterial spasm is contributory to ethanol-induced heart ischemic events. The present experiments were designed to study contractive effect of ethanol in isolated rat coronary arteries (RCAs) stimulated mildly with vasoconstrictors and involvement of voltage-gated potassium (KV ) channels and mitogen-activated protein kinases (MAPKs) of rat coronary arterial smooth muscle cell (RCASMC) in the spasm. The vascular tension was recorded with a wire myograph. KV currents of single freshly isolated RCASMC were assessed with patch clamp...
July 24, 2018: European Journal of Pharmacology
Jin Ryeol An, Hye Won Kim, Hongliang Li, Mi Seon Seo, Won-Kyo Jung, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Amy L Firth, Il-Whan Choi, Won Sun Park
This study examined the inhibitory effect of flecainide, a class 1c antiarrhythmic agent (Na+ channel blocker), on voltage-dependent K+ (Kv) channels in smooth muscle cells isolated from coronary arteries. Flecainide decreased the vascular Kv channel current in a dose-dependent manner with an IC50 value of 5.90 ± 0.87 μM and a Hill coefficient of 0.77 ± 0.06. Although the steady-state activation curve was not affected by flecainide, it shifted the steady-state inactivation curves toward a more negative potential...
July 20, 2018: Clinical and Experimental Pharmacology & Physiology
Robert Novotný, Dáša Slížová, Jaroslav Hlubocký, Otakar Krs, Jaroslav Špatenka, Jan Burkert, Radovan Fiala, Petr Mitáš, Pavel Mĕricka, Miroslav Špaček, Zuzana Hlubocka, Jaroslav Lindner
BACKGROUND: The aim of our experimental work was to assess the impact and morphological changes that arise during different thawing protocols on human aortic valve (AV) leaflets resected from cryopreserved aortic root allografts (CARAs). OBJECTIVES: Two thawing protocols were tested: 1. CARAs were thawed at a room temperature (23°C); 2. CARAs were placed directly into a water bath at a temperature of 37°C. After all the samples were thawed, non-coronary AV leaflets were sampled from each specimen and fixed in a 4% formaldehyde solution before they were sent for morphological analysis...
July 5, 2018: Advances in Clinical and Experimental Medicine: Official Organ Wroclaw Medical University
Tilman Hickethier, Bettina Baeßler, Jan Robert Kroeger, Dirk Müller, David Maintz, Guido Michels, Alexander C Bunck
Background Advanced knowledge-based iterative model reconstructions (IMR) became recently available for routine computed tomography (CT). Using more realistic physical models it promises improved image quality and potential radiation dose reductions, both possibly beneficial for non-invasive assessment of coronary stents. Purpose To evaluate the influence of different IMR settings at different radiation doses on stent lumen visualization in comparison to filtered back projection (FBP) and first-generation (hybrid) iterative reconstruction (HIR)...
January 1, 2018: Acta Radiologica
Hongliang Li, Sung Eun Shin, Jin Ryeol An, Mi Seon Seo, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Amy L Firth, Dae-Sung Lee, Mi-Jin Yim, Jeong Min Lee, Grace Choi, Il-Whan Choi, Won Sun Park
We investigated the effect of the tricyclic antidepressant clomipramine on voltage-dependent K+ (Kv) channels in native rabbit coronary arterial smooth muscle cells. Our results showed that clomipramine inhibited vascular Kv channels in a concentration-dependent manner, with an IC50 value of 8.61 ± 4.86 μM and a Hill coefficient (n) of 0.58 ± 0.07. The application of 10 μM clomipramine did not affect the activation curves of the Kv channels; however, the inactivation curves of the Kv channels were shifted toward a more negative potential...
May 2018: Journal of Pharmacological Sciences
Nienke G Eijsvoogel, Babs M F Hendriks, Hugo B Park, Sibel Altintas, Casper Mihl, Barbora Horehledova, Bastiaan L J H Kietselaer, Harry J G M Crijns, Joachim E Wildberger, Marco Das
Modern high-performance computed tomography (CT) scanners with improved scan acquisition times now allow for routine assessment of cardiac pathologies on chest CTs, which can result in numerous incidental cardiac findings. The CaPaCT study, an observer blinded, single-centre study, aims to assess the visibility, management and possible clinical impact of incidental cardiac pathologies that are now becoming visible on standard chest CTs. A total of 217 consecutive patients referred for a chest CT on a high-performance third-generation dual-source CT scanner will be included...
2018: European radiology experimental
Chunhong Wang, Yuliang Liao, Haibin Chen, Xin Zhen, Jianhong Li, Yikai Xu, Linghong Zhou
Previous studies have shown that employing the low dose computed tomography (CT) technique based on low tube potential reduces the radiation dose required for the coronary artery examination protocol. However, low tube potential may adversely influence the CT number of plaque composition. Therefore, we aimed to determine whether quantitative atherosclerotic plaque analysis by a multi-slice, low radiation dose CT protocol using 80 kilovolts (kV) yields results comparable to those of the standard 120 kV protocol...
August 2018: International Journal of Cardiovascular Imaging
Moritz H Albrecht, Matthew W Bickford, U Joseph Schoepf, Christian Tesche, Domenico De Santis, Marwen Eid, Brian E Jacobs, Taylor M Duguay, Bernhard T Schmidt, Christian Canstein, Akos Varga-Szemes, Doris Leithner, Simon Martin, Thomas J Vogl, Carlo N De Cecco
PURPOSE: To investigate the effect of an iterative beam-hardening correction algorithm (iBHC) on artifact reduction and image quality in coronary CT angiography (cCTA) with low tube voltage. MATERIAL AND METHODS: Thirty-six patients (17 male, mean age, 57.3 ± 14.5 years) were prospectively enrolled in this IRB-approved study and underwent 70-kV cCTA using a third-generation dual-source CT scanner. Images were reconstructed using a standard algorithm (Bv36) both with and without the iBHC technique...
April 2018: European Journal of Radiology
Shihe Liu, Qing Fu, Hualong Yu, Chuanyu Zhang, Qing Yang, Yabin Hu, Wenjian Xu
BACKGROUND: 640-slice coronary CT angiography is becoming an accurate and reliable method of diagnosing coronary heart disease. However, how to reduce the radiation dosage while ensuring the clinically acceptable image quality remains a quite challenging issue. OBJECTIVE: To evaluate the effect of low tube voltage on radiation dosage under 640-slice coronary CT angiography (CCTA). METHODS: Four hundred patients (236 males, 164 females) with coronary heart disease and underwent CCTA using DCVT were classified into A1 (tube voltage: 120 kV; exposure phase window: 30-80%), B1 (120 kV; 70-80%), A2 (100 kV; 30-80%) and B2 group (100 kV; 70-80%), respectively...
2018: Journal of X-ray Science and Technology
Hong Seon Lee, Young Joo Suh, Kyunghwa Han, Jin Young Kim, Suyon Chang, Dong Jin Im, Yoo Jin Hong, Hye-Jeong Lee, Jin Hur, Young Jin Kim, Byoung Wook Choi
BACKGROUND: Reduced image quality from increased X-ray scatter and image noise can be problematic when coronary computed tomography angiography (CCTA) imaging is performed in obese patients. The aim of this study was to compare the image quality and radiation dose obtained using automatic tube potential selection with tube current modulation (APSCM) with those obtained using a body mass index (BMI)-based protocol for CCTA in obese patients. METHODS: A total of 203 consecutive obese (BMI > 30 kg/m2) patients were retrospectively enrolled, of whom 96 underwent CCTA with APSCM and 107 underwent a BMI-based protocol...
2018: PloS One
Yoshinori Nishijima, Ankush Korishettar, Dawid S Chabowski, Sheng Cao, Xiaodong Zheng, David D Gutterman, David X Zhang
OBJECTIVES: KV channels are important regulators of vascular tone, but the identity of specific KV channels involved and their regulation in disease remain less well understood. We determined the expression of KV 1 channel subunits and their role in cAMP-mediated dilation in coronary resistance arteries from subjects with and without CAD. METHODS: HCAs from patients with and without CAD were assessed for mRNA and protein expression of KV 1 channel subunits with molecular techniques and for vasodilator response with isolated arterial myography...
January 2018: Microcirculation: the Official Journal of the Microcirculatory Society, Inc
Sung Eun Shin, Hongliang Li, Jin Ryeol An, Mi Seon Seo, Sung Hun Na, Won-Kyo Jung, Amy L Firth, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Il-Whan Choi, Won Sun Park
We describe the effect of a tricyclic antidepressant drug desipramine on voltage-dependent K+ (Kv) currents in freshly isolated rabbit coronary arterial smooth muscle cells using a conventional whole-cell patch clamp technique. Application of desipramine rapidly decreased the Kv current amplitude in a concentration-dependent manner, with an IC50 value of 5.91 ± 0.18 μM and a Hill coefficient of 0.61 ± 0.09. The steady-state inactivation curves of the Kv channels were not affected by desipramine. However, desipramine shifted the steady-state inactivation curves toward a more negative potential...
June 2018: Cardiovascular Toxicology
Marc M Dwenger, Vahagn Ohanyan, Manuel F Navedo, Matthew A Nystoriak
Smooth muscle voltage-gated potassium (Kv) channels are important regulators of microvascular tone and tissue perfusion. Recent studies indicate that Kv1 channels represent a key component of the physiological coupling between coronary blood flow and myocardial oxygen demand. While the mechanisms by which metabolic changes in the heart are transduced to alter coronary Kv1 channel gating and promote vasodilation are unclear, a growing body of evidence underscores a pivotal role of Kv1 channels in sensing the cellular redox status...
January 2018: Microcirculation: the Official Journal of the Microcirculatory Society, Inc
Hong Zhang, Yanhe Ma, Jun Lyu, Yapeng Yang, Wei Yuan, Zhenchun Song
BACKGROUND The aim of this study was to evaluate the image quality and radiation dose of CT coronary angiography (CTCA) with low kV, low concentration contrast agent, and iterative reconstruction. MATERIAL AND METHODS Ninety cases were randomly divided into 3 groups according to contrast agent concentration: group A 270 mg/ml (100 kV), group B 350 mg/ml (120 kV), and group C 370 mg/ml (120 kV), with 30 cases per group. Tube current was 200-250 mAs. Collimator width was 128×0.6 mm. Rotation speed was 0.27 s...
October 20, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Hongliang Li, Sung Eun Shin, Mi Seon Seo, Jin Ryeol An, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Il-Whan Choi, Dae-Sung Lee, Mi-Jin Yim, Jeong Min Lee, In Duk Jung, Amy L Firth, Il Yong Han, Won Sun Park
Amitriptyline, a tricyclic antidepressant (TCA) drug, is widely used in treatment of psychiatric disorders. However, the side effects of amitriptyline on vascular K+ channels remain to be determined. Therefore, we investigated the effect of the tricyclic antidepressant and serotonin reuptake inhibitor amitriptyline on voltage-dependent K+ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells, using the whole-cell patch clamp technique. The Kv current amplitudes were inhibited by amitriptyline in a concentration-dependent manner, with an apparent IC50 value of 2...
February 2018: Clinical and Experimental Pharmacology & Physiology
Mohamed Marwan, Michaela Hell, Annika Schuhbäck, Sören Gauss, Daniel Bittner, Tobias Pflederer, Stephan Achenbach
BACKGROUND: The factors influencing genesis of atherosclerosis at specific regions within the coronary arterial system are currently uncertain. Local mechanical factors such as shear stress as well as metabolic factors, including inflammatory mediators released from epicardial fat, have been proposed. We analyzed computed tomographic (CT) attenuation of pericoronary adipose tissue in normal versus atherosclerotic coronary segments as defined by intravascular ultrasound (IVUS). PATIENTS AND METHODS: We evaluated the data sets of 29 patients who were referred for invasive coronary angiography and in whom IVUS of 1 coronary vessel was performed for clinical reasons...
September 2017: Journal of Computer Assisted Tomography
Daryoush Khoramian, Soroush Sistani
GOAL: To estimate and compare the radiation dose associated with coronary computed tomography angiography (CCTA) examinations on two multi-detector CT scanners (MDCT), 64-MDCT and 128-MDCT, in daily practice. METHODS: Scan parameters of 90 patients undergoing retrospective electrocardiographic gating spiral CCTA exam were recorded during a period on a single-source 64-MDCT and a dual-source 128-MDCT, and average scan parameters were derived that were used for dosimetry...
December 2017: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
Yuko Kawaguchi, Shinichiro Fujimoto, Kazuhisa Takamura, Etsuro Kato, Shoko Suda, Rie Matsumori, Makoto Hiki, Kanako K Kumamaru, Hiroyuki Daida
Radiation exposure remains a concern in the use of coronary CT angiography (CCTA). Full reconstruction (Full) and reconstruction using advanced patient motion correction (APMC) could obtain a lower radiation dose using low tube current scanning in a 320-row Area Detector CT (320-ADCT). The radiation dose for an imaging protocol using Full and APMC in daily practice was estimated. A total of 209 patients who underwent CCTA in 1 rotation scanning with 100 kv and adaptive iterative dose reduction 3D in 320-ADCT were enrolled...
March 2018: International Journal of Cardiovascular Imaging
Davide Ippolito, Davide Fior, Cammillo Talei Franzesi, Luca Riva, Alessandra Casiraghi, Sandro Sironi
BACKGROUND: Effective radiation dose in coronary CT angiography (CTCA) for coronary artery bypass graft (CABG) evaluation is remarkably high because of long scan lengths. Prospective electrocardiographic gating with iterative reconstruction can reduce effective radiation dose. OBJECTIVES: To evaluate the diagnostic performance of low-kV CT angiography protocol with prospective ecg-gating technique and iterative reconstruction (IR) algorithm in follow-up of CABG patients compared with standard retrospective protocol...
December 2017: La Radiologia Medica
Yibo Sun, Yanqing Hua, Mingpeng Wang, Dingbiao Mao, Xiu Jin, Cheng Li, Kailei Shi, Jianrong Xu
RATIONALE AND OBJECTIVES: The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography. MATERIALS AND METHODS: Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5...
December 2017: Academic Radiology
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