1.Quantification of Hemodynamic Parameters Using Four-Dimensional Flow MRI
Hojin HA ; Hyungkyu HUH ; Dong Hyun YANG ; Namkug KIM
Journal of the Korean Radiological Society 2019;80(2):239-258
MRI provides non-invasive and non-ionizing methods for the accurate anatomic depiction of the cardiovascular system. Based on the inherent flow sensitivity, MRI can be used to investigate hemodynamic features in patients with anatomical data within a single measurement. In particular, time-resolved and three-dimensional (3D) characterization of blood flow using 4D flow MRI has achieved considerable progress in recent years. The present article reviews the principle and procedures of 4D Flow MRI. Various fluid dynamic biomarkers for possible clinical usage are also described, including wall shear stress, turbulent kinetic energy, and relative pressure. Finally, this article provides an overview of the clinical applications of 4D Flow MRI in various cardiovascular regions.
2.Undeflatable balloon guide catheter (BGC) during endovascular procedure: Rescue strategy
Hyungkyu LEE ; Taejoon PARK ; Jinwook BAEK ; Seonghwan KIM ; Sangpyung LEE ; Kyoungsoo RYOU
Journal of Cerebrovascular and Endovascular Neurosurgery 2022;24(4):372-379
The use of a balloon guide catheter (BGC) in the endovascular management of acute ischemic stroke is known to improve the efficacy and efficiency of the procedure by reducing the risk of distal embolization. During the procedure, the balloon of the catheter causes a temporary arrest of cerebral blood flow. However, failure of the balloon to deflate during the BGC procedure can result in catastrophic complications, including aggravated hypoxic damage.
This paper aims to share the resolution and methodological analysis of our experience with BGC balloon deflation failure, which was confirmed by a reproducible experiment under similar conditions.
3.Novel anatomical guidelines for botulinum neurotoxin injection in the mentalis muscle:a review
Kyu-Ho YI ; Ji-Hyun LEE ; Hye-Won HU ; Hyun-Jun PARK ; Hyungkyu BAE ; Kangwoo LEE ; Hee-Jin KIM
Anatomy & Cell Biology 2023;56(3):293-298
The mentalis muscle is a paired muscle originating from the alveolar bone of the mandible. This muscle is the main target muscle for botulinum neurotoxin (BoNT) injection therapy, which aims to treat cobblestone chin caused by mentalis hyperactivity. However, a lack of knowledge on the anatomy of the mentalis muscle and the properties of BoNT can lead to side effects, such as mouth closure insufficiency and smile asymmetry due to ptosis of the lower lip after BoNT injection procedures. Therefore, we have reviewed the anatomical properties associated with BoNT injection into the mentalis muscle.An up-to-date understanding of the localization of the BoNT injection point according to mandibular anatomy leads to better injection localization into the mentalis muscle. Optimal injection sites have been provided for the mentalis muscle and a proper injection technique has been described. We have suggested optimal injection sites based on the external anatomical landmarks of the mandible. The aim of these guidelines is to maximize the effects of BoNT therapy by minimizing the deleterious effects, which can be very useful in clinical settings.
4.Sonographic observation of the paradoxical masseteric bulging and clinical implication of functional compartment
Kyu-Ho YI ; Hyungkyu BAE ; Soo-Bin KIM ; Woo-Ram KIM ; Won LEE ; Ji-Soo KIM ; Hee-Jin KIM
Anatomy & Cell Biology 2024;57(1):13-17
Masseter are commonly botulinum neurotoxin targeted muscle for facial contouring in aesthetic field. However, paradoxical masseteric bulging is common adverse effect that has not been discussed with ultrasonographic observations.Retrospective study has been conducted from October, 2021 to January, 2023, out of 324 patients have done blinded botulinum neurotoxin injection in the masseter at the middle and lower portion of the masseter with each side of 25 units (letibotulinum neurotoxin type A), 3 patients demonstrated paradoxical masseteric bulging has been reported and the image observed by ultrasonography by physician. Based on the observations made, we can infer that the function of the moving muscle involves twisting of the muscle fibers during contraction, along with the twisting of the deep inferior tendon, which causes the muscle to be divided into anterior and posterior compartments rather than into superficial and deep compartments of masseter. In ultrasonographic observe the skin surface of a patient with paradoxical masseteric bulging, it is observable that either the anterior or posterior part contracts significantly. The functional units of anterior and posterior compartment are observable as muscular contraction of inward movement of the muscle from either the anterior or posterior functional unit.
5.Sonographic observation of the paradoxical masseteric bulging and clinical implication of functional compartment
Kyu-Ho YI ; Hyungkyu BAE ; Soo-Bin KIM ; Woo-Ram KIM ; Won LEE ; Ji-Soo KIM ; Hee-Jin KIM
Anatomy & Cell Biology 2024;57(1):13-17
Masseter are commonly botulinum neurotoxin targeted muscle for facial contouring in aesthetic field. However, paradoxical masseteric bulging is common adverse effect that has not been discussed with ultrasonographic observations.Retrospective study has been conducted from October, 2021 to January, 2023, out of 324 patients have done blinded botulinum neurotoxin injection in the masseter at the middle and lower portion of the masseter with each side of 25 units (letibotulinum neurotoxin type A), 3 patients demonstrated paradoxical masseteric bulging has been reported and the image observed by ultrasonography by physician. Based on the observations made, we can infer that the function of the moving muscle involves twisting of the muscle fibers during contraction, along with the twisting of the deep inferior tendon, which causes the muscle to be divided into anterior and posterior compartments rather than into superficial and deep compartments of masseter. In ultrasonographic observe the skin surface of a patient with paradoxical masseteric bulging, it is observable that either the anterior or posterior part contracts significantly. The functional units of anterior and posterior compartment are observable as muscular contraction of inward movement of the muscle from either the anterior or posterior functional unit.
6.Sonographic observation of the paradoxical masseteric bulging and clinical implication of functional compartment
Kyu-Ho YI ; Hyungkyu BAE ; Soo-Bin KIM ; Woo-Ram KIM ; Won LEE ; Ji-Soo KIM ; Hee-Jin KIM
Anatomy & Cell Biology 2024;57(1):13-17
Masseter are commonly botulinum neurotoxin targeted muscle for facial contouring in aesthetic field. However, paradoxical masseteric bulging is common adverse effect that has not been discussed with ultrasonographic observations.Retrospective study has been conducted from October, 2021 to January, 2023, out of 324 patients have done blinded botulinum neurotoxin injection in the masseter at the middle and lower portion of the masseter with each side of 25 units (letibotulinum neurotoxin type A), 3 patients demonstrated paradoxical masseteric bulging has been reported and the image observed by ultrasonography by physician. Based on the observations made, we can infer that the function of the moving muscle involves twisting of the muscle fibers during contraction, along with the twisting of the deep inferior tendon, which causes the muscle to be divided into anterior and posterior compartments rather than into superficial and deep compartments of masseter. In ultrasonographic observe the skin surface of a patient with paradoxical masseteric bulging, it is observable that either the anterior or posterior part contracts significantly. The functional units of anterior and posterior compartment are observable as muscular contraction of inward movement of the muscle from either the anterior or posterior functional unit.
7.Protein Kinase C Activates ATP-sensitive Potassium Channels in Rabbit Ventricular Myocytes.
Nari KIM ; Jae Boum YOUM ; Hyun JOO ; Hyungkyu KIM ; Euiyong KIM ; Jin HAN
The Korean Journal of Physiology and Pharmacology 2005;9(4):187-193
Several signal transduction pathways have been implicated in ischemic preconditioning induced by the activation of ATP-sensitive K+ (KATP) channels. We examined whether protein kinase C (PKC) modulated the activity of KATP channels by recording KATP channel currents in rabbit ventricular myocytes using patch-clamp technique and found that phorbol 12, 13-didecanoate (PDD) enhanced pinacidil-induced KATP channel activity in the cell-attached configuration; and this effect was prevented by bisindolylmaleimide (BIM). KATP channel activity was not increased by 4alpha-PDD. In excised inside-out patches, PKC stimulated KATP channels in the presence of 1 mM ATP, and this effect was abolished in the presence of BIM. Heat-inactivated PKC had no effect on channel activity. PKC-induced activation of KATP channels was reversed by PP2A, and this effect was not detected in the presence of okadaic acid. These results suggest that PKC activates KATP channels in rabbit ventricular myocytes.
Adenosine Triphosphate
;
Ischemic Preconditioning
;
KATP Channels*
;
Muscle Cells*
;
Okadaic Acid
;
Patch-Clamp Techniques
;
Protein Kinase C*
;
Protein Kinases*
;
Signal Transduction
8.Changes of Cytosolic Ca2+ under Metabolic Inhibition in Isolated Rat Ventricular Myocytes.
Sunghyun KANG ; Nari KIM ; Hyun JOO ; Jae Boum YOUM ; Won Sun PARK ; Mohamed WARDA ; Hyungkyu KIM ; Dang Van CUONG ; Taeho KIM ; Euiyong KIM ; Jin HAN
The Korean Journal of Physiology and Pharmacology 2005;9(5):291-298
To characterize cytosolic Ca2+ fluctuations under metabolic inhibition, rat ventricular myocytes were exposed to 200microM 2, 4-dinitrophenol (DNP), and mitochondrial Ca2+, mitochondrial membrane potential (delta psi m), and cytosolic Ca2+ were measured, using Rhod-2 AM, TMRE, and Fluo-4 AM fluorescent dyes, respectively, by Laser Scanning Confocal Microscopy (LSCM). Furthermore, the role of sarcolemmal Na+/Ca2+ exchange (NCX) in cytosolic Ca2+ efflux was studied in KB-R7943 and Na+-free normal Tyrode's solution (143 mM LiCl ). When DNP was applied to cells loaded with Fluo-4 AM, Fluo-4 AM fluorescence intensity initially increased by 70+/-10% within 70+/-10 s, and later by 400+/-200% at 850+/-46 s. Fluorescence intensity of both Rhod-2 AM and TMRE were initially decreased by DNP, coincident with the initial increase of Fluo-4 AM fluorescence intensity. When sarcoplasmic reticulum (SR) Ca2+ was depleted by 1microM thapsigargin plus 10microM ryanodine, the initial increase of Fluo-4 AM fluorescence intensity was unaffected, however, the subsequent progressive increase was abolished. KB-R7943 delayed both the first and the second phases of cytosolic Ca2+ overload, while Na+-free solution accelerated the second. The above results suggest that: 1) the initial rise in cytosolic Ca2+ under DNP results from mitochondrial depolarization; 2) the secondary increase is caused by progressive Ca2+ release from SR; 3) NCX plays an important role in transient cytosolic Ca2+ shifts under metabolic inhibition with DNP.
Animals
;
Caffeine
;
Cytosol*
;
Fluorescence
;
Fluorescent Dyes
;
Membrane Potential, Mitochondrial
;
Microscopy, Confocal
;
Mitochondria
;
Muscle Cells*
;
Rats*
;
Ryanodine
;
Sarcoplasmic Reticulum
;
Thapsigargin
9.Energy Metabolism in Human Pluripotent Stem and Differentiated Cells Compared Using a Seahorse XF96 Extracellular Flux Analyzer
Hyun Kyu KIM ; Yena SONG ; Minji KYE ; Byeongho YU ; Sang Beom PARK ; Ji Hyeon KIM ; Sung-Hwan MOON ; Hyungkyu CHOI ; Jong-Seok MOON ; Jae Sang OH ; Man Ryul LEE
International Journal of Stem Cells 2024;17(2):194-203
Evaluating cell metabolism is crucial during pluripotent stem cell (PSC) differentiation and somatic cell reprogramming as it affects cell fate. As cultured stem cells are heterogeneous, a comparative analysis of relative metabolism using existing metabolic analysis methods is difficult, resulting in inaccuracies. In this study, we measured human PSC basal metabolic levels using a Seahorse analyzer. We used fibroblasts, human induced PSCs, and human embryonic stem cells to monitor changes in basal metabolic levels according to cell number and determine the number of cells suitable for analysis. We evaluated normalization methods using glucose and selected the most suitable for the metabolic analysis of heterogeneous PSCs during the reprogramming stage. The response of fibroblasts to glucose increased with starvation time, with oxygen consumption rate and extracellular acidification rate responding most effectively to glucose 4 hours after starvation and declining after 5 hours of starvation. Fibroblasts and PSCs achieved appropriate responses to glucose without damaging their metabolism 2∼4 and 2∼3 hours after starvation, respectively. We developed a novel method for comparing basal metabolic rates of fibroblasts and PSCs, focusing on quantitative analysis of glycolysis and oxidative phosphorylation using glucose without enzyme inhibitors. This protocol enables efficient comparison of energy metabolism among cell types, including undifferentiated PSCs, differentiated cells, and cells undergoing cellular reprogramming, and addresses critical issues, such as differences in basal metabolic levels and sensitivity to normalization, providing valuable insights into cellular energetics.