Search

Your search keyword '"Ha, Jeong-mi"' showing total 20 results
Start Over Author "Ha, Jeong-mi"
20 results on '"Ha, Jeong-mi"'

10. The Role of the Alternative Complement Pathway in Early Graft Loss After Intraportal Porcine Islet Xenotransplantation

Author

Kang, Hee Jung, primary, Lee, Haneulnari, additional, Ha, Jeong-mi, additional, Lee, Jae-il, additional, Shin, Jun-Seop, additional, Kim, Ki-Yong, additional, Park, Ji Yoon, additional, Kim, Jung-Sik, additional, Min, Sang Il, additional, Park, Chung-Gyu, additional, Park, Seong Hoe, additional, and Kim, Sang Joon, additional

Published
2014
Full Text
View/download PDF

19. Simulation of Ca2-activated Cl−current of cardiomyocytes in rabbit pulmonary vein: implications of subsarcolemmal Ca2dynamics

Author

Leem, Chae Hun, Kim, Won Tae, Ha, Jeong Mi, Lee, Yoon Jin, Seong, Hyeon Chan, Choe, Han, Jang, Yeon Jin, Youm, Jae Boum, and Earm, Yung E

Abstract

In recent studies, we recorded transiently activated outward currents by the application of three-step voltage pulses to induce a reverse mode of Na–Ca2exchange (NCX). We found that these currents were mediated by a Ca2-activated Cl−current. Based on the recent reports describing the atrial Ca2transients, the Ca2transient at the subsarcolemmal space was initiated and then diffused into the cytosolic space. Because the myocardium in the pulmonary vein is an extension of the atrium, the Ca2-activated Cl−current may reflect the subsarcolemmal Ca2dynamics. We tried to predict the subsarcolemmal Ca2dynamics by simulating these current traces. According to recent reports on the geometry of atrial myocytes, we assumed that there were three compartments of sarcoplasmic reticulum (SR): a network SR, a junctional SR and a central SR. Based on these structures, we also divided the cytosolic space into three compartments: the junctional, subsarcolemmal and cytosolic spaces. Geometry information and cellular capacitance suggested that there were essentially no T-tubules in these cells. The basic physical data, such as the compartmental volumes, the diffusion coefficients and the stability coefficients of the Ca2buffers, were obtained from the literature. In the simulation, we incorporated the NCX, the L-type Ca2channel, the rapid activating outward rectifier Kchannel, the Na–Kpump, the SR Ca2-pump, the ryanodine receptor, the Ca2-activated Cl−channel and the dynamics of Na, K, Ca2and Cl−. In these conditions, we could successfully reconstruct the Ca2-activated Cl−currents. The simulation allowed estimation of the Ca2dynamics of each compartment and the distribution of the Ca2-activated Cl−channel and the NCX in the sarcolemma on the junctional or subsarcolemmal space.

Published
2006
Full Text
View/download PDF

20. A Novel Nicotinamide Adenine Dinucleotide Correction Method for Mitochondrial Ca(2+) Measurement with FURA-2-FF in Single Permeabilized Ventricular Myocytes of Rat.

Author

Lee JH, Ha JM, and Leem CH

Abstract

Fura-2 analogs are ratiometric fluoroprobes that are widely used for the quantitative measurement of [Ca(2+)]. However, the dye usage is intrinsically limited, as the dyes require ultraviolet (UV) excitation, which can also generate great interference, mainly from nicotinamide adenine dinucleotide (NADH) autofluorescence. Specifically, this limitation causes serious problems for the quantitative measurement of mitochondrial [Ca(2+)], as no available ratiometric dyes are excited in the visible range. Thus, NADH interference cannot be avoided during quantitative measurement of [Ca(2+)] because the majority of NADH is located in the mitochondria. The emission intensity ratio of two different excitation wavelengths must be constant when the fluorescent dye concentration is the same. In accordance with this principle, we developed a novel online method that corrected NADH and Fura-2-FF interference. We simultaneously measured multiple parameters, including NADH, [Ca(2+)], and pH/mitochondrial membrane potential; Fura-2-FF for mitochondrial [Ca(2+)] and TMRE for Ψm or carboxy-SNARF-1 for pH were used. With this novel method, we found that the resting mitochondrial [Ca(2+)] concentration was 1.03 µM. This 1 µM cytosolic Ca(2+) could theoretically increase to more than 100 mM in mitochondria. However, the mitochondrial [Ca(2+)] increase was limited to ~30 µM in the presence of 1 µM cytosolic Ca(2+). Our method solved the problem of NADH signal contamination during the use of Fura-2 analogs, and therefore the method may be useful when NADH interference is expected.

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results