1.Carbon monoxide activation of delayed rectifier potassium currents of human cardiac fibroblasts through diverse pathways
Hyemi BAE ; Taeho KIM ; Inja LIM
The Korean Journal of Physiology and Pharmacology 2022;26(1):25-36
To identify the effect and mechanism of carbon monoxide (CO) on delayed rectifier K+ currents (IK) of human cardiac fibroblasts (HCFs), we used the wholecell mode patch-clamp technique. Application of CO delivered by carbon monoxidereleasing molecule-3 (CORM3) increased the amplitude of outward K+ currents, and diphenyl phosphine oxide-1 (a specific IK blocker) inhibited the currents. CORM3-induced augmentation was blocked by pretreatment with nitric oxide synthase blockers (L-NG-monomethyl arginine citrate and L-NG-nitro arginine methyl ester).Pretreatment with KT5823 (a protein kinas G blocker), 1H-[1,-2,-4] oxadiazolo-[4,-3-a] quinoxalin-1-on (ODQ, a soluble guanylate cyclase blocker), KT5720 (a protein kinase A blocker), and SQ22536 (an adenylate cyclase blocker) blocked the CORM3 stimulating effect on IK . In addition, pretreatment with SB239063 (a p38 mitogen-activated protein kinase [MAPK] blocker) and PD98059 (a p44/42 MAPK blocker) also blocked the CORM3’s effect on the currents. When testing the involvement of S-nitrosylation, pretreatment of N-ethylmaleimide (a thiol-alkylating reagent) blocked CO-induced IKactivation and DL-dithiothreitol (a reducing agent) reversed this effect. Pretreatment with 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)-21H,23H porphyrin manganese (III) pentachloride and manganese (III) tetrakis (4-benzoic acid) porphyrin chloride (superoxide dismutase mimetics), diphenyleneiodonium chloride (an NADPH oxidase blocker), or allopurinol (a xanthine oxidase blocker) also inhibited CO-induced IK activation. These results suggest that CO enhances IK in HCFs through the nitric oxide, phosphorylation by protein kinase G, protein kinase A, and MAPK, S-nitrosylation and reduction/oxidation (redox) signaling pathways.
2.Carbon monoxide activates large-conductance calcium-activated potassium channels of human cardiac fibroblasts through various mechanisms
Hyemi BAE ; Taeho KIM ; Inja LIM
The Korean Journal of Physiology and Pharmacology 2021;25(3):227-237
Carbon monoxide (CO) is a cardioprotectant and potential cardiovascular therapeutic agent. Human cardiac fibroblasts (HCFs) are important determinants of myocardial structure and function. Large-conductance Ca 2+ -activated K+ (BK) channel is a potential therapeutic target for cardiovascular disease. We investigated whether CO modulates BK channels and the signaling pathways in HCFs using whole-cell mode patch-clamp recordings. CO-releasing molecules (CORMs; CORM-2 and CORM-3) significantly increased the amplitudes of BK currents IBK. The CO-induced stimulating effects on IBK were blocked by pre-treatment with specific nitric oxide synthase (NOS) blockers (L-N G -monomethyl arginine citrate and L-N G -nitroarginine methyl ester). 8-bromo-cyclic GMP increased IBK. KT5823 (inhibits PKG) or ODQ (inhibits soluble guanylate cyclase) blocked the CO-stimulating effect on IBK. Moreover, 8-bromo-cyclic AMP also increased IBK, and pre-treatment with KT5720 (inhibits PKA) or SQ22536 (inhibits adenylate cyclase) blocked the CO effect. Pre-treatment with Nethylmaleimide (a thiol-alkylating reagent) also blocked the CO effect on IBK, and DLdithiothreitol (a reducing agent) reversed the CO effect. These data suggest that CO activates IBK through NO via the NOS and through the PKG, PKA, and S-nitrosylation pathways.
3.Carbon monoxide activates large-conductance calcium-activated potassium channels of human cardiac fibroblasts through various mechanisms
Hyemi BAE ; Taeho KIM ; Inja LIM
The Korean Journal of Physiology and Pharmacology 2021;25(3):227-237
Carbon monoxide (CO) is a cardioprotectant and potential cardiovascular therapeutic agent. Human cardiac fibroblasts (HCFs) are important determinants of myocardial structure and function. Large-conductance Ca 2+ -activated K+ (BK) channel is a potential therapeutic target for cardiovascular disease. We investigated whether CO modulates BK channels and the signaling pathways in HCFs using whole-cell mode patch-clamp recordings. CO-releasing molecules (CORMs; CORM-2 and CORM-3) significantly increased the amplitudes of BK currents IBK. The CO-induced stimulating effects on IBK were blocked by pre-treatment with specific nitric oxide synthase (NOS) blockers (L-N G -monomethyl arginine citrate and L-N G -nitroarginine methyl ester). 8-bromo-cyclic GMP increased IBK. KT5823 (inhibits PKG) or ODQ (inhibits soluble guanylate cyclase) blocked the CO-stimulating effect on IBK. Moreover, 8-bromo-cyclic AMP also increased IBK, and pre-treatment with KT5720 (inhibits PKA) or SQ22536 (inhibits adenylate cyclase) blocked the CO effect. Pre-treatment with Nethylmaleimide (a thiol-alkylating reagent) also blocked the CO effect on IBK, and DLdithiothreitol (a reducing agent) reversed the CO effect. These data suggest that CO activates IBK through NO via the NOS and through the PKG, PKA, and S-nitrosylation pathways.
4.Stimulatory Effects of KPR-A148 on Osteoblast Differentiation and Bone Regeneration
Soomin LIM ; Ju Ang KIM ; Taeho LEE ; Doohyun LEE ; Sang Hyeon NAM ; Jiwon LIM ; Eui Kyun PARK
Tissue Engineering and Regenerative Medicine 2019;16(4):405-413
BACKGROUND: Xanthine derivatives have been used to treat a variety of medical conditions including respiratory disease and neural degeneration. However, few studies have reported their effects on bone regeneration. Therefore, we investigated the effects of KPR-A148, a synthetic xanthine derivative on osteoblast differentiation in vitro and bone regeneration in vivo. METHODS: The cytotoxicity of KPR-A148 was evaluated using MC3T3-E1 cells by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltertrazolium bromide assay. The effects of KPR-A148 on osteoblast differentiation were examined by alkaline phosphatase staining, Alizarin red S staining, and real-time PCR of osteoblast differentiation marker genes. To investigate the effects of KPR-A148 on in vivo bone regeneration, a KPR-A148-containing collagen sponge was implanted into a mouse calvarial defect and KPR-A148 was injected twice, weekly. Bone regeneration was evaluated quantitatively by micro-CT and qualitatively by hematoxylin and eosin, as well as Masson's Trichrome staining. RESULTS: KPR-A148 did not show toxicity in the MC3T3-E1 cells and promoted osteoblast differentiation in a concentration-dependent manner. 10 µM of KPR-A148 showed the most significant effect on alkaline phospatase staining and matrix mineralization. KPR-A148 increased the expression of osteoblast marker genes in both the early and late stages of differentiation. In addition, KPR-A148 significantly induced new bone formation in the calvarial defect model. CONCLUSION: These results demonstrate that KPR-A148 strongly induces osteoblast differentiation and new bone formation. Therefore, it could be used as a potential therapeutic agent for regenerating bone following its destruction by disease or trauma.
Alkaline Phosphatase
;
Animals
;
Bone Regeneration
;
Collagen
;
Eosine Yellowish-(YS)
;
Hematoxylin
;
In Vitro Techniques
;
Mice
;
Miners
;
Osteoblasts
;
Osteogenesis
;
Porifera
;
Real-Time Polymerase Chain Reaction
;
Xanthine
5.Validity Analysis of Korean Triage and Acuity Scale
Inhye LEE ; Ohhyun KIM ; Changsun KIM ; Jaehoon OH ; Taeho LIM ; Jinwoong LEE ; Suck Ju CHO ; Seong Youn HWANG ; Joonbum PARK
Journal of the Korean Society of Emergency Medicine 2018;29(1):13-20
PURPOSE: The Korean Triage and Acuity Scale (KTAS), which was developed in 2012 due to the need for a single triage tool for emergency patients in Korea, has since become nationalized. Although five years has passed, there has been limited evidence of its validation. Therefore, this study was conducted to analyze the validity of the new triage system. METHODS: We conducted a multicenter prospective study. Data were collected from seven hospitals and 42,187 patients were classified using the KTAS from April 1, 2013 to July 6, 2014. We analyzed whether the indirect severity variables showed meaningful differences according to KTAS levels. The variables consisted of disposition from emergency room, length of stay, numbers of consultations, examination of computed tomography, emergency room costs, and performance of emergent interventions. RESULTS: From KTAS level 1 to 5, a decreasing trend in the length of stay in emergency room, frequency of consultation with other departments, admission, computed tomography rate, emergency intervention rate, and emergency room costs was observed. Upon binominal logistic regression, disposition from emergency room and emergent intervention rate showed the highest odds ratio with statistical significance. CONCLUSION: The results of this study demonstrated that KTAS is a valid emergency triage tool that reflects the severity of the patient with indirect indicators. The results of this study will be useful as a reference for quality control of KTAS.
Emergencies
;
Emergency Service, Hospital
;
Health Resources
;
Humans
;
Korea
;
Length of Stay
;
Logistic Models
;
Odds Ratio
;
Prospective Studies
;
Quality Control
;
Referral and Consultation
;
Triage
6.Korean Triage and Acuity Scale (KTAS).
Journal of the Korean Society of Emergency Medicine 2017;28(6):547-551
The number of patients visiting the emergency room (ER) is increasing every year. The Korean Triage and Acuity Scale (KTAS) was developed in Korea in 2012 to help reduce the congestion of the ER at the hospital level and improve the safety of patients. From January 2016, KTAS has been implemented in emergency medical (EM) centers. KTAS evaluates patients who visit the ER by the following process: impression evaluation, infection confirmation, primary symptom selection, and primary/secondary considerations. KTAS prioritizes patients according to the level, and if necessary, sets a time for which the patient can wait safely with the aim to see a doctor within that time. KTAS has the characteristics of both severity and acuity, so there can be some discrepancy between the KTAS level and disposition. All EM centers conducted the KTAS classification from March to November, 2016. An analysis of the results of the KTAS classification showed no distortion in the classification from the beginning of KTAS introduction. In the near future, it is hoped to develop a KTAS-based transport protocol reflecting the regional medical resources and cultures at the pre-hospital stage, and establish an effective EM system, including medical basis and policy consideration.
Classification
;
Emergencies
;
Emergency Medical Services
;
Emergency Service, Hospital
;
Estrogens, Conjugated (USP)
;
Hope
;
Humans
;
Korea
;
Patient Safety
;
Triage*
7.Effects of hydrogen peroxide on voltage-dependent K+ currents in human cardiac fibroblasts through protein kinase pathways.
Hyemi BAE ; Donghee LEE ; Young Won KIM ; Jeongyoon CHOI ; Hong Jun LEE ; Sang Wook KIM ; Taeho KIM ; Yun Hee NOH ; Jae Hong KO ; Hyoweon BANG ; Inja LIM
The Korean Journal of Physiology and Pharmacology 2016;20(3):315-324
Human cardiac fibroblasts (HCFs) have various voltage-dependent K+ channels (VDKCs) that can induce apoptosis. Hydrogen peroxide (H2O2) modulates VDKCs and induces oxidative stress, which is the main contributor to cardiac injury and cardiac remodeling. We investigated whether H2O2 could modulate VDKCs in HCFs and induce cell injury through this process. In whole-cell mode patch-clamp recordings, application of H2O2 stimulated Ca2+-activated K+ (K(Ca)) currents but not delayed rectifier K+ or transient outward K+ currents, all of which are VDKCs. H2O2-stimulated K(Ca) currents were blocked by iberiotoxin (IbTX, a large conductance K(Ca) blocker). The H2O2-stimulating effect on large-conductance K(Ca) (BK(Ca)) currents was also blocked by KT5823 (a protein kinase G inhibitor) and 1 H-[1, 2, 4] oxadiazolo-[4, 3-a] quinoxalin-1-one (ODQ, a soluble guanylate cyclase inhibitor). In addition, 8-bromo-cyclic guanosine 3', 5'-monophosphate (8-Br-cGMP) stimulated BK(Ca) currents. In contrast, KT5720 and H-89 (protein kinase A inhibitors) did not block the H2O2-stimulating effect on BK(Ca) currents. Using RT-PCR and western blot analysis, three subtypes of K(Ca) channels were detected in HCFs: BK(Ca) channels, small-conductance K(Ca) (SK(Ca)) channels, and intermediate-conductance K(Ca) (IK(Ca)) channels. In the annexin V/propidium iodide assay, apoptotic changes in HCFs increased in response to H2O2, but IbTX decreased H2O2-induced apoptosis. These data suggest that among the VDKCs of HCFs, H2O2 only enhances BK(Ca) currents through the protein kinase G pathway but not the protein kinase A pathway, and is involved in cell injury through BK(Ca) channels.
Apoptosis
;
Blotting, Western
;
Cyclic AMP-Dependent Protein Kinases
;
Cyclic GMP-Dependent Protein Kinases
;
Fibroblasts*
;
Guanosine
;
Guanylate Cyclase
;
Humans*
;
Hydrogen Peroxide*
;
Hydrogen*
;
Oxidative Stress
;
Phosphotransferases
;
Potassium Channels, Calcium-Activated
;
Protein Kinases*
8.Public Safety Communication and Networking Technologies for Disaster Response and Medical Assistance.
Sangwoo LEE ; Sunwoo KIM ; Taeho LIM
Hanyang Medical Reviews 2015;35(3):141-145
Future major disasters require the development of socially transparent and rational-decision-making procedures. Recent reports indicate that the frequency of human disasters are decreasing while natural disasters and social disasters are becoming more frequent. The creation of a disaster communication network, which is essential in protecting the life and property as well as providing a sense of societal security. Standards for a modern disaster communication network must be developed at the national level, with national state support for a 3rd generation partnership project such as a Public Safety-LTE that allows the construction of an effective national disaster network plan. Compliance and certification standards to ensure interoperability of communications and other equipment are necessary for the creation of a modern national disaster network that allows more efficient management of disaster situations. It can be expected that our efforts and example can help other countries to build a standard protocol for managing the national disasters.
Certification
;
Compliance
;
Disaster Planning
;
Disasters*
;
Humans
;
Medical Assistance*
;
Telecommunications
;
Telemedicine
9.Emergency Medical Services in Disasters.
Hanyang Medical Reviews 2015;35(3):136-140
Disasters, or mass casualty incidents, occurring in modern history differ from those occurring in even the recent past. In previous times, disasters were mostly the result of natural causes such as earthquakes or floods. Currently, multiple casualty incidents are often the result of human actions such as vehicular accidents involving many vehicles with multiple operators, passengers and collateral victims, terror attacks and acts of war, radiation accidents, toxic chemical releases, and pandemic infectious agent exposures. Especially, events involving accidental and intentional exposures of chemical, biological, radiological/nuclear materials, often abbreviated as CBR or CBRN events present unique challenges to the healthcare system in caring for the victims. In these mass casualty incidents, a fully comprehensive, coordinated team response involving many different components of the community healthcare system need to be mobilized to effectively meet the modern challenge of CBRN events. Necessary components of a modern emergency response include training for prompt triage, decontamination, detoxification, emergency medical treatment, as well as providing appropriate transport to the proper medical treatment facility. Meeting these challenges requires maintaining ongoing communications between agencies charged with meeting the disaster to allow acquisition of information and location for the patients, transfer the information to both the Central Medical Emergency Response Center and the designated hospital. While sharing this information was problematic in the past, modern wireless communications and information technologies provide convenient means for the rapid sharing of important patient data and current situational details. Finally, improving modern disaster response requires the development of a disaster response plan, ongoing training in implementing the plan including disaster scenario simulation, and budgeting to acquire the necessary equipment involved for the emergency response personnel to meet the presenting crisis.
Budgets
;
Community Health Services
;
Decontamination
;
Delivery of Health Care
;
Disasters*
;
Earthquakes
;
Emergencies*
;
Emergency Medical Service Communication Systems
;
Emergency Medical Services*
;
Floods
;
History, Modern 1601-
;
Humans
;
Mass Casualty Incidents
;
Pandemics
;
Radioactive Hazard Release
;
Transportation of Patients
;
Triage
10.Disaster Medicine in Korea.
Hanyang Medical Reviews 2015;35(3):121-123
No abstract available.
Disaster Medicine*
;
Disasters*
;
Korea*

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