Publications by authors named "Hyun Kyo Lim"

Background And Objective: Medical image visualization is a requirement in many types of surgery such as orthopaedic, spinal, thoracic procedures or tumour resection to eliminate risk such as "wrong level surgery". However, direct contact with physical devices such as mice or touch screens to control images is a challenge because of the potential risk of infection. To prevent the spread of infection in sterile environments, a contagious infection-free medical interaction system has been developed for manipulating medical images.

View Article and Find Full Text PDF

Background: An increase in the frequency of surgeries among older individuals is observed in some countries. Hypotension is common and exaggerated in older patients and can lead to increased morbidity and mortality. Total intravenous anesthesia is commonly administered with propofol, while remimazolam has been suggested as an alternative to propofol because of advantages such as a more stable hemodynamic profile and less respiratory suppression.

View Article and Find Full Text PDF

In contemporary practice, intraoral scans and cone-beam computed tomography (CBCT) are widely adopted techniques for tooth localization and the acquisition of comprehensive three-dimensional models. Despite their utility, each dataset presents inherent merits and limitations, prompting the pursuit of an amalgamated solution for optimization. Thus, this research introduces a novel 3D registration approach aimed at harmonizing these distinct datasets to offer a holistic perspective.

View Article and Find Full Text PDF

Submental intubation is an effective alternative technique for airway management in patients with maxillofacial trauma. Compared with tracheostomy, it is less invasive, but has risks associated with potential airway compromise such as hypoxia due to tube obstruction, collapse, and kinking. To shorten procedure time and ensure a reinforced tube lumen, we used a laparoscopic trocar as a new device for submental intubation.

View Article and Find Full Text PDF

Background: Submental intubation has been the recommended airway management procedure for maxillofacial surgery since proposed by Altemir in 1986. We adopted various submental intubation modifications based on modified intubation protocols and report on the effectiveness and problems of each modified method.

Case: Among a total of 13 submental intubation cases during the last five years, five representative methods are described.

View Article and Find Full Text PDF

Although arginase primarily participates in the last reaction of the urea cycle, we have previously demonstrated that arginase II is an important cytosolic calcium regulator through spermine production in a p32-dependent manner. Here, we demonstrated that rhaponticin (RPT) is a novel medicinal-plant arginase inhibitor and investigated its mechanism of action on Ca-dependent endothelial nitric oxide synthase (eNOS) activation. RPT was uncompetitively inhibited for both arginases I and II prepared from mouse liver and kidney.

View Article and Find Full Text PDF

Background: Hysteroscopic surgery has been used in various gynecological fields. However, massive fluid overload can occur as a complication due to persistent infusion of media for uterine cavity distension. We present the case of a woman who developed cardiomyopathy with pulmonary edema and epistaxis during hysteroscopic surgery.

View Article and Find Full Text PDF

Dexmedetomidine is used for sedation during spinal anesthesia. The sympatholytic effect of dexmedetomidine may exacerbate hypotension and bradycardia with spinal anesthesia. This study investigated the effects of prophylactic intramuscular injection of ephedrine in preventing hypotension and bradycardia occurring through combined use of spinal anesthesia and dexmedetomidine.

View Article and Find Full Text PDF

The p32 protein plays a crucial role in the regulation of cytosolic Ca2+ concentrations ([Ca2+]c) that contributes to the Ca2+‑dependent signaling cascade. Using an adenovirus and plasmid p32‑overexpression system, the aim of the study was to evaluate the role of p32 in the regulation of [Ca2+] and its potential associated with Ca2+‑dependent endothelial nitric oxide synthase (eNOS) activation in endothelial cells. Using electron and confocal microscopic analysis, p32 overexpression was observed to be localized to mitochondria and the endoplasmic reticulum and played an important role in Ca2+ translocation, resulting in increased [Ca2+] in these organelles and reducing cytosolic [Ca2+] ([Ca2+]c).

View Article and Find Full Text PDF

Reinforcement learning has recently been studied in various fields and also used to optimally control IoT devices supporting the expansion of Internet connection beyond the usual standard devices. In this paper, we try to allow multiple reinforcement learning agents to learn optimal control policy on their own IoT devices of the same type but with slightly different dynamics. For such multiple IoT devices, there is no guarantee that an agent who interacts only with one IoT device and learns the optimal control policy will also control another IoT device well.

View Article and Find Full Text PDF

Although arginase II (ArgII) is abundant in mitochondria, Ca-accumulating organelles, the relationship between ArgII activity and Ca translocation into mitochondria and the regulation of cytosolic Ca signaling are completely unknown. We investigated the effects of ArgII activity on mitochondrial Ca uptake through mitochondrial p32 protein (p32m) and on CaMKII-dependent vascular smooth muscle cell (VSMC) contraction. Native low-density lipoprotein stimulation induced an increase in [Ca]m as measured by CoCl-quenched calcein-AM fluorescence, which was prevented by Arg inhibition in hAoSMCs and reduced in mAoSMCs from ArgII mice.

View Article and Find Full Text PDF

The contractility of vascular smooth muscle cells (VSMCs) controls the lumen diameter of vessels, thus serving a role in regulating blood pressure and organ blood flow. Although arginases are known to have numerous effects in the biological activities of VSMCs, the effects of arginase II on the constriction of VSMCs has not yet been investigated. When conducting a natural products screen for an inhibitor against arginase, the present study identified that a relatively high concentration of resveratrol (RSV) exhibited arginase inhibitory activity.

View Article and Find Full Text PDF

Background Arginase II activity contributes to reciprocal regulation of endothelial nitric oxide synthase ( eNOS ). We tested the hypotheses that arginase II activity participates in the regulation of Ca/Ca/calmodulin-dependent kinase II / eNOS activation, and this process is dependent on mitochondrial p32. Methods and Results Downregulation of arginase II increased the concentration of cytosolic Ca ([Ca]c) and decreased mitochondrial Ca ([Ca]m) in microscopic and fluorescence-activated cell sorting analyses, resulting in augmented eNOS Ser1177 phosphorylation and decreased eNOS Thr495 phosphorylation through Ca/Ca/calmodulin-dependent kinase II .

View Article and Find Full Text PDF

Purpose: Vascular smooth muscle cell (VSMC) proliferation induced by native low-density lipoprotein (nLDL) stimulation is dependent on superoxide production from activated NADPH oxidase. The present study aimed to investigate whether the novel arginase inhibitor limonin could suppress nLDL-induced VSMC proliferation and to examine related mechanisms.

Materials And Methods: Isolated VSMCs from rat aortas were treated with nLDL, and cell proliferation was measured by WST-1 and BrdU assays.

View Article and Find Full Text PDF

Acidic electrolyzed water is an innovative sanitizer having a wide-spectrum of applications in food industry, and healthcare industry but little is known on its effect and mechanism in wound healing. The study was conducted to identify the effect and mechanism of slightly acidic electrolyzed water (SAEW) on cutaneous wounds in hairless mice. SAEW (pH: 5-6.

View Article and Find Full Text PDF

Background: Laparoscopic upper abdominal surgery can cause spontaneous respiration due to diaphragmatic stimulation and intra-abdominal CO inflation. Therefore, sufficient muscle relaxation is necessary for a safe surgical environment.

Methods: We investigated if the combination of rocuronium and cisatracurium can counteract the delayed onset of cisatracurium's action and delayed recovery of muscle relaxation and whether the dosage of rocuronium, which is metabolized hepatically, can be reduced.

View Article and Find Full Text PDF

Rubinstein-Taybi syndrome is characterized by mental retardation, atypical facial features, broad thumbs and toes, and scoliosis. Polycystic ovaries are associated with chronic anovulation and abnormal uterine bleeding. A 15-year old female patient was diagnosed with Rubinstein-Taybi Syndrome, and had prolonged abnormal uterine bleeding for 2 years, accompanied by a polycystic ovary.

View Article and Find Full Text PDF

Cerebral salt wasting syndrome is a hyponatremic and hypovolemic condition caused by intracranial disorders, such as head injury, subarachnoid hemorrhage, brain tumor, and brain operations. We report a case of a 5-year-old girl that had cerebral salt wasting syndrome with marked polyuria who showed transient oliguria during general anesthesia. The patient had undergone an operation for traumatic intracranial hemorrhage three months prior and has had marked polyuria and hyponatremia since then.

View Article and Find Full Text PDF

Esophageal perforation is a very rare occurrence because accidental swallowing of foreign bodies is uncommon in adults. Thus, perforation due to swallowing of a foreign body and subsequent development of mediastinitis is rarely encountered by physicians. We experienced such a case and described an adult male patient who had perforated esophagus after accidentally swallowing a mussel shell.

View Article and Find Full Text PDF

Purpose: Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism.

Materials And Methods: Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured.

View Article and Find Full Text PDF

Lymphangioma is a congenital malformation of lymphatic system and often involves the oral cavity. When lymphangioma is located on the mouth floor and enlarges, it can compress the airway and make intubation difficult. The GlideScope(®) video laryngoscope is sometimes used in routine intubation, but is most commonly used in difficult or failed intubation.

View Article and Find Full Text PDF

Although uncommon, anaphylactic reactions during surgery are very dangerous and can result in serious morbidity. Various anesthetics can trigger anaphylactic reactions, and incidents with cephalosporin antibiotics are on the rise. In the case presented, an 84-year-old woman scheduled for calcaneus fracture surgery, was injected with cefbuperazone as a prophylactic antibiotic.

View Article and Find Full Text PDF

Cardiovascular disease is the prime cause of morbidity and mortality and the population ages that may contribute to increase in the occurrence of cardiovascular disease. Arginase upregulation is associated with impaired endothelial function in aged vascular system and thus may contribute to cardiovascular disease. According to recent research, Korean Red Ginseng water extract (KRGE) may reduce cardiovascular disease risk by improving vascular system health.

View Article and Find Full Text PDF

Purpose: This study investigated whether hormones and pain perception are associated with exam anxiety, and also whether exam anxiety is affected by seasonal differences in testosterone and cortisol levels.

Materials And Methods: Forty-six healthy males were recruited from a medical college. Anxiety was induced by having participants perform the Objective Structured Clinical Examination.

View Article and Find Full Text PDF