• BMB Reports
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• v.43 no.3
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• pp.151-157
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• 2010

$Ca^{2+}$ is a universal signalling molecule that affects a variety of cellular processes including cardiac development. The majority of intracellular $Ca^{2+}$ is stored in the endoplasmic and sarcoplasmic reticulum of muscle and non-muscle cells. Calreticulin is a well studied $Ca^{2+}$-buffering protein in the endoplasmic reticulum, and calreticulin deficiency is embryonic lethal due to impaired cardiac development. Despite calsequestrin being the most abundant $Ca^{2+}$-buffering protein in the sarcoplasmic reticulum, viability is maintained in embryos without calsequestrin and normal $Ca^{2+}$ release and contractile function is observed. The $Ca^{2+}$ homeostasis regulated by the endoplasmic and sarcoplasmic reticulum is critical for the development and proper function of the heart.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.107-113
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• 2005

Pharmacologic stress testing for myocardial perfusion imaging is a widely used noninvasive method for the evaluation of known or suspected coronary artery disease. The use of exercise for cardiac stress has been practiced for over 60 years and clinicians are familial with its using. However, there are inevitabe situations in which exorcise stress is inappropriate. A large number of patients with cardiac problems are unable to exercise to their full potential due to comorbidity such as osteoarthritis, vascular disease and pulmonary disease and a standard exercise stress test for myocardial perfusion imaging is suboptimal means for assessment of coronary artery disease. This problem has led to the development of the pharmacologic stress test and to a great increase in its popularity. All of the currently used pharmacologic agents have well-documented diagnostic value. This review deals the physiological actions, clinical protocols, safety, nuclear imaging applications of currently available stress agents and future development of new vasodilating agents.

• Proceedings of the KSMRM Conference
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• 2005.09a
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• pp.14-14
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• 2005

• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.537-544
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• 2005

We have examined distribution and expression of caveolin-3 (cav-3), one of three caveolin isoforms from 16-wks-old spontaneously hypertensive rats (SHR) compared with age-matched control wistar-kyoto (WKY) rats. The expression of cav-3 was increased, whereas expression of PKB/Akt and calcineurin (Cn) was not changed in cardiac tissues of SHR compared to WKY rats. Interestingly, expression of cav-3, PKB/Akt and Cn were decreased in plasma membrane fraction in SHR compared to WKY rats. In H9c2 cardiomyoblast cells treated with phenylephrine ($50{\mu}M$, 48hr) or isoproterenol ($10{\mu}M$, 48hr), the expression of cav-3 was markedly enhanced compared to nontreated cells. Upon immunofluorescence analysis, cav-3 was localized in plasma membrane of control H9c2 cells. However phenylephrine or isoproterenol treatment caused translocation of cav-3 to perinuclear region. These results suggest that cav-3 plays as positive regulators in the development of hypertrophy in cardiac tissues of SHR rats.

• The Journal of Korean Medicine
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• v.40 no.2
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• pp.94-105
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• 2019

Objectives: The correlation between medicinal herbal formulas and a risk of cardiotoxicity has been controversial. Thus, this study investigated cardiac safety assessment of 52 most commonly used medicinal herbal formulas. Methods: We evaluated the in vitro effects of medicinal herbal formulas on recombinant human embryonic kidney 293 (HEK 293) cell line expressing human ether-a-go-go-related gene (hERG) potassium channel. Results and Conclusion: Our results demonstrated that all of 52 medicinal herbal formulas did not show inhibition of hERG current in hERG-HEK 293 recombinant cells. In conclusion, these safety data suggest that 52 medicinal herbal formulas were not associated with an increased risk of cardiotoxicity in hERG-HEK 293 recombinant cells.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.100-100
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• 2003

Pluripotent embryonic stem (ES) cells differentiate spontaneously into beating cardiomyocytes via embryo-like aggregates. We describe the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. To induce cardiomyocytic differentiation, mES03 cells were dissociated and allowed to aggregate (EB formation) at the presence of 0 75% dimethyl sulfoxide (DMSO) for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EBs were plated onto gelatin-coated dish for differentiation. Spontaneously contracting colonies which appeared in approximately 4-5 days upon differentiation. Expression of cardiac-specific genes were determined by RT-PCR. Rebust expression of myosin light chain (MLC-2V), cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta(\beta$-MHC), cardiac transcription factor GATA4 and skeletal muscle-specific ${\alpha}_1$-subunit of the L-type calcium channel (${\alpha}_1 CaCh_{sm}$) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel (${\alpha}_1$CaCh) were revealed at a low level. Strikingly, the expression of atrial natriuretic factor (ANF) was not detected. When spontaneous contracting cell masses were examined their electrophysiological features by patch-clamp technique, it showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes displayed biochemical and electrophysiological properties of cardiomyocytes and DMSO enhanced development of cardiomyocytes in 4+/4- method.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.54-62
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• 1990

The thermodiluton is a standard method to measure cardiac output in clinical medicine. However it has many disadvantages such as expensive instrument and measurement, limited number of measurement, pain, safety problem, and side-effect due to insertion of catheter into heart. Electrical Impedance Cardiography has no such disadvantages and that it can continuously monitor stroke volume, contractility of cardiac muscle, and systolic time interval (STI) as well as cardiac output. While this impedance technique has been widely used and vigorously studied adroad, it is not introduced yet in Korea. Thus an Impedance Cardiograph has been developed in order to introduce this new technique. Its accuracy also has been verified by simultaneous measurement of cardiac output with the thermodilution technique. Finally changes of cardiac function during exercise were also measured.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.132-139
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• 1989

We have designed a real-time Cardiac digital substraction angiography system (C-DSA) and tested the system for the diagnosis of Cardiac patients. The system was developed by interfacing a radiographic angiography system to a computerized motional image analysis system. This new cardiac DSA can perform the real time processing of averaging and subtraction of the 32 image frames to measure the volume changes of the left ventricle after elimination of motional artrifacts, caused by the heart contraction of beats per minute in average. Each frame has a resolution of 512 x 512 pixels and 256 gray levels. Two image data with maximal and minimal volume were moved to the interfaced IBM PC computer system by high speed computer link line for computation of the heart's contraction parameters. First, the boundary of the left ventricule was detected using a dynamic programming of the gray levels, and its volume was computered to determine the parameters, such as the maximal volume of end-diastolic volume (EDV), the minimal volume of end systolic volume (ESV), and ejection fraction (EF).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.959-964
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• 2013

This study materialized the new module which enables to measure more precise data than the existing modules in order to examine the cardiac disorder critical patient's state by using Swan-Ganz Catheter. There was bolus type CO(Cardiac Output) module which measured CO by measuring the blood changes in temperature and recovery time by injecting cold sap into the heart in the past, but recently, it is not used in most of hospitals due to limit of difficulty of continuous monitoring for the patients. To overcome this limit, the continuous cardiac output measurement platform was materialized to enable the continuous monitoring for patients. The wasted cost issues because of introducing the expensive imported equipment to observe the critical patient`s state with abnormal cardiopulmonary function in the hospitals can be solved by using this new module, and the problem of existing modules should be supplemented for more accurate diagnosis by collecting more precise data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1417-1426
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• 2011

Radiofrequency ablation through cardiac catheterization is one of minimally invasive intervention procedures used in drug resistant arrhythmia treatment. To facilitate more accurate and precise catheter navigation, systems for robotic cardiac catheter navigation have been developed and commercialized. The authors have been developing a novel robotic catheter navigation system. The system is a network-based master-slave configuration 3-DOF (Degree-Of-Freedom) robotic manipulator for operation with conventional cardiac ablation catheter. The catheter manipulation motion is composed of the translation (forward/backward) and the roll movements of the catheter and knob rotation for the catheter tip articulation. The master manipulator comprises an operator handle compartment for the knob and the roll movement input, and a base platform for the translation movement input. The slave manipulator implements a robotic catheter platform in which conventional cardiac catheter is mounted and the 3-DOF motions of the catheter are controlled. The system software that runs on a realtime OS based PC, implements the master-slave motion synchronization control in the robot system. The master-slave motion synchronization performance tested with step, sinusoidal and arbitrarily varying motion commands showed satisfactory results with acceptable level of steady state error. The developed system will be further improved through evaluation of safety and performance in in vitro and in vivo tests.