1.A Novel Histone Deacetylase 6 Inhibitor, 4-FHA, Improves Scopolamine-Induced Cognitive and Memory Impairment in Mice
Jee-Yeon SEO ; Jisoo KIM ; Yong-Hyun KO ; Bo-Ram LEE ; Kwang-Hyun HUR ; Young Hoon JUNG ; Hyun-Ju PARK ; Seok-Yong LEE ; Choon-Gon JANG
Biomolecules & Therapeutics 2025;33(2):268-277
Although histone deacetylase 6 (HDAC6) is considered a therapeutic target for Alzheimer’s disease (AD), its role in cholinergic dysfunction in AD patients remains unclear. This study investigated the effects of (E)-3-(2-(4-fluorostyryl)thiazol-4-yl)-N-hydroxypropanamide (4-FHA), a new synthetic HDAC6 inhibitor, on cognitive and memory impairments in a scopolamine-induced-AD mouse model. Behaviorally, 4-FHA improved scopolamine-induced memory impairments in the Y-maze, passive avoidance, and Morris water maze tests. In addition, 4-FHA ameliorated scopolamine-induced cognitive impairments in the novel object recognition and place recognition tests. Furthermore, 4-FHA increased acetylation of α-tubulin (a major HDAC6 substrate); the expression of BDNF; and the phosphorylation of ERK 1/2, CREB, and ChAT in the hippocampus of scopolamine-treated mice. In summary, according to our data 4-FHA, an HDAC6 inhibitor, improved the cognitive and memory deficits of the AD mouse model by normalizing BDNF signaling and synaptic transmission, suggesting that 4-FHA might be a potential therapeutic candidate for AD.
2.A Novel Histone Deacetylase 6 Inhibitor, 4-FHA, Improves Scopolamine-Induced Cognitive and Memory Impairment in Mice
Jee-Yeon SEO ; Jisoo KIM ; Yong-Hyun KO ; Bo-Ram LEE ; Kwang-Hyun HUR ; Young Hoon JUNG ; Hyun-Ju PARK ; Seok-Yong LEE ; Choon-Gon JANG
Biomolecules & Therapeutics 2025;33(2):268-277
Although histone deacetylase 6 (HDAC6) is considered a therapeutic target for Alzheimer’s disease (AD), its role in cholinergic dysfunction in AD patients remains unclear. This study investigated the effects of (E)-3-(2-(4-fluorostyryl)thiazol-4-yl)-N-hydroxypropanamide (4-FHA), a new synthetic HDAC6 inhibitor, on cognitive and memory impairments in a scopolamine-induced-AD mouse model. Behaviorally, 4-FHA improved scopolamine-induced memory impairments in the Y-maze, passive avoidance, and Morris water maze tests. In addition, 4-FHA ameliorated scopolamine-induced cognitive impairments in the novel object recognition and place recognition tests. Furthermore, 4-FHA increased acetylation of α-tubulin (a major HDAC6 substrate); the expression of BDNF; and the phosphorylation of ERK 1/2, CREB, and ChAT in the hippocampus of scopolamine-treated mice. In summary, according to our data 4-FHA, an HDAC6 inhibitor, improved the cognitive and memory deficits of the AD mouse model by normalizing BDNF signaling and synaptic transmission, suggesting that 4-FHA might be a potential therapeutic candidate for AD.
3.A Novel Histone Deacetylase 6 Inhibitor, 4-FHA, Improves Scopolamine-Induced Cognitive and Memory Impairment in Mice
Jee-Yeon SEO ; Jisoo KIM ; Yong-Hyun KO ; Bo-Ram LEE ; Kwang-Hyun HUR ; Young Hoon JUNG ; Hyun-Ju PARK ; Seok-Yong LEE ; Choon-Gon JANG
Biomolecules & Therapeutics 2025;33(2):268-277
Although histone deacetylase 6 (HDAC6) is considered a therapeutic target for Alzheimer’s disease (AD), its role in cholinergic dysfunction in AD patients remains unclear. This study investigated the effects of (E)-3-(2-(4-fluorostyryl)thiazol-4-yl)-N-hydroxypropanamide (4-FHA), a new synthetic HDAC6 inhibitor, on cognitive and memory impairments in a scopolamine-induced-AD mouse model. Behaviorally, 4-FHA improved scopolamine-induced memory impairments in the Y-maze, passive avoidance, and Morris water maze tests. In addition, 4-FHA ameliorated scopolamine-induced cognitive impairments in the novel object recognition and place recognition tests. Furthermore, 4-FHA increased acetylation of α-tubulin (a major HDAC6 substrate); the expression of BDNF; and the phosphorylation of ERK 1/2, CREB, and ChAT in the hippocampus of scopolamine-treated mice. In summary, according to our data 4-FHA, an HDAC6 inhibitor, improved the cognitive and memory deficits of the AD mouse model by normalizing BDNF signaling and synaptic transmission, suggesting that 4-FHA might be a potential therapeutic candidate for AD.
4.Integrated care at the emergency department: an investment for better health.
Steven Hoon Chin LIM ; Colin Eng Choon ONG ; Arron Seng Hock ANG ; Khai Pin LEE ; Jean Mui Hua LEE ; Venkataraman ANANTHARAMAN
Singapore medical journal 2025;66(2):102-107
It is crucial that policy makers, healthcare providers and relevant stakeholders understand how integrated care may be improved at our emergency departments (EDs) and what benefits that would bring. The potential that exists for right-siting care of special patient groups who could be managed in an ambulatory setting with the integration of a variety of hospital-based and community-based clinical support services is tremendous. This review describes the best practice and value of integrated care at the EDs. Local evidence is cited and compared with findings from overseas. The opportunities of care transition interventions among discharged patients are outlined, including that for paediatric patients, palliative care patients and patients with chronic diseases. This review also suggests ways to move forward to meet the aim of providing holistic care at EDs through integrated care programmes, innovation and research.
Humans
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Emergency Service, Hospital/organization & administration*
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Delivery of Health Care, Integrated
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Palliative Care
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Chronic Disease
5.DWN12088, A Prolyl-tRNA Synthetase Inhibitor, Alleviates Hepatic Injury in Nonalcoholic Steatohepatitis
Dong-Keon LEE ; Su Ho JO ; Eun Soo LEE ; Kyung Bong HA ; Na Won PARK ; Deok-Hoon KONG ; Sang-In PARK ; Joon Seok PARK ; Choon Hee CHUNG
Diabetes & Metabolism Journal 2024;48(1):97-111
Background:
Nonalcoholic steatohepatitis (NASH) is a liver disease caused by obesity that leads to hepatic lipoapoptosis, resulting in fibrosis and cirrhosis. However, the mechanism underlying NASH is largely unknown, and there is currently no effective therapeutic agent against it. DWN12088, an agent used for treating idiopathic pulmonary fibrosis, is a selective prolyl-tRNA synthetase (PRS) inhibitor that suppresses the synthesis of collagen. However, the mechanism underlying the hepatoprotective effect of DWN12088 is not clear. Therefore, we investigated the role of DWN12088 in NASH progression.
Methods:
Mice were fed a chow diet or methionine-choline deficient (MCD)-diet, which was administered with DWN12088 or saline by oral gavage for 6 weeks. The effects of DWN12088 on NASH were evaluated by pathophysiological examinations, such as real-time quantitative reverse transcription polymerase chain reaction, immunoblotting, biochemical analysis, and immunohistochemistry. Molecular and cellular mechanisms of hepatic injury were assessed by in vitro cell culture.
Results:
DWN12088 attenuated palmitic acid (PA)-induced lipid accumulation and lipoapoptosis by downregulating the Rho-kinase (ROCK)/AMP-activated protein kinase (AMPK)/sterol regulatory element-binding protein-1c (SREBP-1c) and protein kinase R-like endoplasmic reticulum kinase (PERK)/α subunit of eukaryotic initiation factor 2 (eIF2α)/activating transcription factor 4 (ATF4)/C/EBP-homologous protein (CHOP) signaling cascades. PA increased but DWN12088 inhibited the phosphorylation of nuclear factor-κB (NF-κB) p65 (Ser536, Ser276) and the expression of proinflammatory genes. Moreover, the DWN12088 inhibited transforming growth factor β (TGFβ)-induced pro-fibrotic gene expression by suppressing TGFβ receptor 1 (TGFβR1)/Smad2/3 and TGFβR1/glutamyl-prolyl-tRNA synthetase (EPRS)/signal transducer and activator of transcription 6 (STAT6) axis signaling. In the case of MCD-diet-induced NASH, DWN12088 reduced hepatic steatosis, inflammation, and lipoapoptosis and prevented the progression of fibrosis.
Conclusion
Our findings provide new insights about DWN12088, namely that it plays an important role in the overall improvement of NASH. Hence, DWN12088 shows great potential to be developed as a new integrated therapeutic agent for NASH.
6.Study Design and Protocol for a Randomized Controlled Trial to Assess Long-Term Efficacy and Safety of a Triple Combination of Ezetimibe, Fenofibrate, and Moderate-Intensity Statin in Patients with Type 2 Diabetes and Modifiable Cardiovascular Risk Factors (ENSEMBLE)
Nam Hoon KIM ; Juneyoung LEE ; Suk CHON ; Jae Myung YU ; In-Kyung JEONG ; Soo LIM ; Won Jun KIM ; Keeho SONG ; Ho Chan CHO ; Hea Min YU ; Kyoung-Ah KIM ; Sang Soo KIM ; Soon Hee LEE ; Chong Hwa KIM ; Soo Heon KWAK ; Yong‐ho LEE ; Choon Hee CHUNG ; Sihoon LEE ; Heung Yong JIN ; Jae Hyuk LEE ; Gwanpyo KOH ; Sang-Yong KIM ; Jaetaek KIM ; Ju Hee LEE ; Tae Nyun KIM ; Hyun Jeong JEON ; Ji Hyun LEE ; Jae-Han JEON ; Hye Jin YOO ; Hee Kyung KIM ; Hyeong-Kyu PARK ; Il Seong NAM-GOONG ; Seongbin HONG ; Chul Woo AHN ; Ji Hee YU ; Jong Heon PARK ; Keun-Gyu PARK ; Chan Ho PARK ; Kyong Hye JOUNG ; Ohk-Hyun RYU ; Keun Yong PARK ; Eun-Gyoung HONG ; Bong-Soo CHA ; Kyu Chang WON ; Yoon-Sok CHUNG ; Sin Gon KIM
Endocrinology and Metabolism 2024;39(5):722-731
Background:
Atherogenic dyslipidemia, which is frequently associated with type 2 diabetes (T2D) and insulin resistance, contributes to the development of vascular complications. Statin therapy is the primary approach to dyslipidemia management in T2D, however, the role of non-statin therapy remains unclear. Ezetimibe reduces cholesterol burden by inhibiting intestinal cholesterol absorption. Fibrates lower triglyceride levels and increase high-density lipoprotein cholesterol (HDL-C) levels via peroxisome proliferator- activated receptor alpha agonism. Therefore, when combined, these drugs effectively lower non-HDL-C levels. Despite this, few clinical trials have specifically targeted non-HDL-C, and the efficacy of triple combination therapies, including statins, ezetimibe, and fibrates, has yet to be determined.
Methods:
This is a multicenter, prospective, randomized, open-label, active-comparator controlled trial involving 3,958 eligible participants with T2D, cardiovascular risk factors, and elevated non-HDL-C (≥100 mg/dL). Participants, already on moderate-intensity statins, will be randomly assigned to either Ezefeno (ezetimibe/fenofibrate) addition or statin dose-escalation. The primary end point is the development of a composite of major adverse cardiovascular and diabetic microvascular events over 48 months.
Conclusion
This trial aims to assess whether combining statins, ezetimibe, and fenofibrate is as effective as, or possibly superior to, statin monotherapy intensification in lowering cardiovascular and microvascular disease risk for patients with T2D. This could propose a novel therapeutic approach for managing dyslipidemia in T2D.
7.Tract Implantation of Thyroid Carcinoma After Transoral Thyroidectomy
Minhyung LEE ; Dong Hoon SHIN ; Hyun Jung LEE ; Jin-Choon LEE
Korean Journal of Otolaryngology - Head and Neck Surgery 2024;67(3):177-182
Transoral thyroidectomy is a promising technique because of its superior postoperative cosmesis. Although tract implantation after remote-access thyroidectomy is extremely rare, it can result in poor outcomes. A 45-year-old female presented with multiple palpable nodules in the anterior neck after a transoral thyroidectomy for which thyroid function tests, CT, ultrasonography, and fine-needle aspiration were performed. The thyroid function test results were normal. CT and ultrasonography revealed multiple, well-defined nodules at levels Ia and VI along the tracks left by the endoscopic instrument inserted during transoral thyroidectomy. Fineneedle aspiration revealed a microfollicular structure derived from thyroid tissue without evidence of atypia. Wash-out fluid from the nodules revealed elevated thyroglobulin levels. Initially, the patient was hesitant about surgical removal, but the nodules grew larger, so surgical removal was performed. Final histopathological examination revealed follicular thyroid carcinoma. The patient was recommended extensive resection but was lost to follow-up.
8.Impact of a primary care partnership programme on accident and emergency attendances at a regional hospital in Singapore: a pilot study.
Hong Choon OH ; Srinath SRIDHARAN ; Mei Foon YAP ; Priscilla Sook Kheng GOH ; Lyndia Sze Hui LEE ; Narayan VENKATARAMAN ; Choon How HOW ; Hoon Chin LIM
Singapore medical journal 2023;64(8):534-537
9.Application of an Intraoperative Neuromonitoring System Using a Surface Pressure Sensor in Parotid Surgery: A Rabbit Model Study
Eui-Suk SUNG ; Hyun-Keun KWON ; Sung-Chan SHIN ; Young-Il CHEON ; Jung-Woo LEE ; Da-Hee PARK ; Seong-Wook CHOI ; Hwa-Bin KIM ; Hye-Jin PARK ; Jin-Choon LEE ; Jung-Hoon RO ; Byung-Joo LEE
Clinical and Experimental Otorhinolaryngology 2021;14(1):131-136
Objectives:
. Facial nerve monitoring (FNM) can be used to identify the facial nerve, to obtain information regarding its course, and to evaluate its status during parotidectomy. However, there has been disagreement regarding the efficacy of FNM in reducing the incidence of facial nerve palsy during parotid surgery. Therefore, instead of using electromyography (EMG) to identify the location and state of the facial nerve, we applied an intraoperative neuromonitoring (IONM) system using a surface pressure sensor to detect facial muscle twitching. The objective of this study was to investigate the feasibility of using the IONM system with a surface pressure sensor to detect facial muscle twitching during parotidectomy.
Methods:
. We evaluated the stimulus thresholds for the detection of muscle twitching in the orbicularis oris and orbicularis oculi, as well as the amplitude and latency of EMG and the surface pressure sensor in 13 facial nerves of seven rabbits, using the same stimulus intensity.
Results:
. The surface pressure sensor detected muscle twitching in the orbicularis oris and orbicularis oculi in response to a stimulation of 0.1 mA in all 13 facial nerves. The stimulus threshold did not differ between the surface pressure sensor and EMG.
Conclusion
. The application of IONM using a surface pressure sensor during parotidectomy is noninvasive, reliable, and feasible. Therefore, the IONM system with a surface pressure sensor to measure facial muscle twitching may be an alternative to EMG for verifying the status of the facial nerve.
10.Evaluation of Synergistic Effect of Combined Treatment with Linalool and Colistin on Multidrug-Resistant Acinetobacter baumannii to Expand Candidate for Therapeutic Option
Ung Jun KIM ; Choon Mee KIM ; Sook Jin JANG ; Seul Bi LEE ; Seong Sik CHO ; Seok Hoon JEONG ; Young Jin KO ; Seong Ho KANG ; Geon PARK ; Dong Min KIM ; Na Ra YOON ; Young Joon AHN ; Dong hoon LIM ; Joong Ki KOOK
Annals of Clinical Microbiology 2020;23(1):11-20
BACKGROUND:
Acinetobacter baumannii infection is a significant health problem worldwide due to increased drug resistance. The limited antimicrobial alternatives for the treatment of severe infections by multidrug-resistant A. baumannii (MDRAB) make the search for other therapeutic options more urgent. Linalool, the major oil compound in Coriandrum sativum, was recently found to have high antibacterial activity against A. baumannii. The purpose of this study was to investigate the synergistic effect of linalool and colistin combinations against MDRAB and extensively drug-resistant A. baumannii (XDRAB).
METHODS:
A total of 51 strains of A. baumannii clinical isolates, consisting of 10 MDRAB and 41 XDRAB were tested. We determined the minimum inhibitory concentration (MIC) of linalool for the test strains using the broth microdilution method and searched for interactions using the time-kill assay.
RESULTS:
The time-kill assay showed that the linalool and colistin combination displayed a high rate of synergy (92.1%) (by synergy criteria 2), low rate of indifference (7.8%), and a high rate of bactericidal activity (74.5%) in the 51 clinical isolates of A. baumannii. The synergy rates for the linalool and colistin combination against MDRAB and XDRAB were 96% and 92.1%, respectively. No antagonism was observed for the linalool and colistin combination.
CONCLUSION
The combination of linalool and colistin showed a high synergy rate, which may be beneficial for controlling MDRAB infections. Therefore, this combination is a good candidate for in vivo studies to assess its efficacy in the treatment of MDRAB infections.

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