Publications by authors named "Hee-Chul Han"

Article Synopsis
  • The COVID-19 Vaccine Safety Research Center (CoVaSC) was created in South Korea to investigate potential links between COVID-19 vaccines and adverse events during the pandemic, with backing from health authorities.
  • Traditional methods for determining causality in medical events faced limitations, prompting an update of a causality assessment framework by the National Academies of Sciences, Engineering, and Medicine (NASEM) in 2024, which uses a weight-of-evidence approach.
  • This updated framework evaluates both epidemiological evidence from population studies and mechanistic evidence from biological studies, allowing for a comprehensive conclusion on causality, categorized from "convincingly supports" to "inadequate to accept or reject."
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Article Synopsis
  • - The COVID-19 Vaccine Safety Research Committee (CoVaSC) was formed in November 2021 to gather independent data on adverse events related to COVID-19 vaccinations, led by Korea's National Academy of Medicine and requested by the Korea Disease Control and Prevention Agency.
  • - In September 2022, the COVID-19 Vaccine Safety Research Center was established, restructuring CoVaSC into four specialized departments focused on research, communication, and policy regarding vaccine safety.
  • - The center has conducted comprehensive studies on 27 adverse events, involving collaboration between experts and regular updates to the public, while planning to enhance its research efforts and maintain transparency in its findings.
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  • * An educational program was created, involving online and offline materials, group studies, poster submissions, and presentations, aiming to enhance student attitudes towards organ donation.
  • * Results showed a significant increase in positive attitudes toward organ donation (from 74.7% to 97.7%), willingness to donate (from 76.8% to 96.5%), and acceptance of brain death as a determination of death (from 61.6% to 89.5%) following the program.
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The cholinergic system has been found to make an anti-inflammatory effect through the cholinergic anti-inflammatory pathway (CAIP), which suppresses the production of pro-inflammatory cytokines by secreting acetylcholine, a major neurotransmitter. However, no studies have been conducted on the effects of CAIP on joint pain and inflammation. In this study, we investigated the effects of muscarinic acetylcholine receptors (mAChRs) in knee arthritis.

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With the introduction of coronavirus disease 2019 (COVID-19) vaccines, the Korea Disease Control and Prevention Agency (KDCA) commissioned the National Academy of Medicine of Korea to gather experts to independently assess post-vaccination adverse events. Accordingly, the COVID-19 Vaccine Safety Research Committee (CoVaSC) was launched in November 2021 to perform safety studies and establish evidence for policy guidance. The CoVaSC established 3 committees for epidemiology, clinical research, and communication.

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Background: There is no national survey on medical school faculty members' burnout in Korea. This study aimed to investigate burnout levels and explore possible factors related to burnout among faculty members of Korean medical schools.

Methods: An anonymous online questionnaire was distributed to 40 Korean medical schools from October 2020 to December 2020.

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Background Context: Low back pain is one of the most common musculoskeletal disorders. Although, the pathology of intervertebral disc (IVD) degeneration has been modeled using various biological methods, these models are inadequate for simulating similar pathologic states in humans.

Purpose: This study investigated whether monosodium iodoacetate (MIA) injection into the IVD of rats could generate a reliable model of IVD degeneration.

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Methylene blue (MB) is a cationic thiazine dye, widely used as a biological stain and chemical indicator. Growing evidence have revealed that MB functions to restore abnormal vasodilation and notably it is implicated even in pain relief. Physicians began to inject MB into degenerated disks to relieve pain in patients with chronic discogenic low back pain (CDLBP), and some of them achieved remarkable outcomes.

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Purpose: This study explored how the Korean Medical Colleges responded to the coronavirus disease 2019 (COVID-19) pandemic and the medical deans' perspectives on what and how these adaptions influence the present and the future of medical education.

Methods: An email survey combining short and open-ended questions was distributed to all 40 Korean school deans in May 2020. Thirty-seven deans out of 40 medical schools in Korea (92.

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Methylene blue (MB) is a blue cationic thiazine dye and currently used in different medical settings. Notably, there have been several attempts to introduce MB for attenuating pain in the last decade. Some clinical studies reported remarkable results, which, however, have been much debated.

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Obesity is a significant risk factor for various metabolic diseases and is closely related to non-alcoholic fatty liver disease (NAFLD) characterized by inflammation and oxidative stress. Clusterin is a multi-functional protein that is up-regulated in the pathogenesis of various metabolic diseases, including obesity and NAFLD. Our previous studies indicated that hepatocyte-specific overexpression of clusterin alleviates methionine choline-deficient (MCD) diet-induced non-alcoholic steatohepatitis (NASH) by activating nuclear factor erythroid 2-related factor 2 (Nrf2).

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Salt sensitivity of blood pressure (SSBP) is a trait carrying strong prognostic implications for various cardiovascular diseases. To test the hypothesis that excessive maternal salt intake causes SSBP in offspring through a mechanism dependent upon arginine-vasopressin (AVP), we performed a series of experiments using offspring of the rat dams salt-loaded during pregnancy and lactation with 1.5% saline drink ("experimental offspring") and those with normal perinatal salt exposure ("control offspring").

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Aims: Abundant evidence indicates that oestrogen (E2) plays a protective role against hypertension. Yet, the mechanism underlying the antihypertensive effect of E2 is poorly understood. In this study, we sought to determine the mechanism through which E2 inhibits salt-dependent hypertension.

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Objective: Drug injections and surgery are popular treatments for knee joint osteoarthritis. However, these treatments are invasive, and new noninvasive treatments with similar or better efficacy are needed. Here, we evaluated the application of 4.

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Peripheral group III metabotropic glutamate receptors (mGluRs) function to modulate pain signaling in inflammatory states. Here, we established in vivo experimental settings, including dynamic weight bearing test and in vivo single nerve recording, to elucidate how the group III mGluRs contribute to inhibiting pain transmission at the peripheral sensory nerve terminal in inflammatory states (1 and 3 days) elicited by Complete Freund's Adjuvant (CFA). As a result, CFA-induced nociceptive behaviors were significantly alleviated after administration of 100 and 200 μM L-AP4 (l-2-amino-4-phosphonobutylate; group III mGluR agonist).

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Introduction: Lengthened immobilization may prevent muscle shortening, and help maintain normal muscle length. However, its apoptotic effects remain unclear. We evaluated the effects of long-term immobilization on apoptotic proteins.

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Diabetes mellitus (DM) is associated with increased plasma levels of arginine-vasopressin (AVP), which may aggravate hyperglycemia and nephropathy. However, the mechanisms by which DM may cause the increased AVP levels are not known. Electrophysiological recordings in supraoptic nucleus (SON) slices from streptozotocin (STZ)-induced DM rats and vehicle-treated control rats revealed that γ-aminobutyric acid (GABA) functions generally as an excitatory neurotransmitter in the AVP neurons of STZ rats, whereas it usually evokes inhibitory responses in the cells of control animals.

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The systemic administration of opioids can be used for their strong analgesic effect. However, extensive activation of opioid receptors (ORs) beyond the targeted tissue can cause dysphoria, pruritus, and constipation. Therefore, selective activation of peripheral ORs present in the afferent fibers of the targeted tissue can be considered a superior strategy in opioid analgesia to avoid potential adverse effects.

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Background: Recent evidence indicates that histamine, acting on histamine 1 receptor (H1R), resets the circadian clock in the mouse suprachiasmatic nucleus (SCN) by increasing intracellular Ca(2+) concentration ([Ca(2+)]i) through the activation of CaV1.3 L-type Ca(2+) channels and Ca(2+)-induced Ca(2+) release from ryanodine receptor-mediated internal stores.

Results: In the current study, we explored the underlying mechanisms with various techniques including Ca(2+)- and Cl(-)-imaging and extracellular single-unit recording.

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Chamaecyparis obtusa essential oil (COE) has been widely used to treat allergic diseases and was suggested to exert anti-inflammatory, antioxidant, and antimicrobial effects. This study evaluated the effects of COE on pain-related behavior and pro-inflammatory cytokines in rats with carrageenan (CGN)-induced arthritis. Reduced dynamic weight load on inflamed joint in voluntarily walking rats was used as the behavior test for arthritic pain; 10% COE-treated group was significantly attenuated pain (6-8 h post-CGN injection) compared to VEH (mineral oil)-treated group.

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Histamine, a neurotransmitter/neuromodulator implicated in the control of arousal state, exerts a potent phase-shifting effect on the circadian clock in the rodent suprachiasmatic nucleus (SCN). In this study, the mechanisms by which histamine resets the circadian clock in the mouse SCN were investigated. As a first step, Ca(2+) -imaging techniques were used to demonstrate that histamine increases intracellular Ca(2+) concentration ([Ca(2+) ]i ) in acutely dissociated SCN neurons and that this increase is blocked by the H1 histamine receptor (H1R) antagonist pyrilamine, the removal of extracellular Ca(2+) and the L-type Ca(2+) channel blocker nimodipine.

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Background: Increased secretion of oxytocin and arginine vasopressin (AVP) from hypothalamic magnocellular neurosecretory cells (MNCs) is a key physiological response to lactation. In the current study, we sought to test the hypothesis that the GABAA receptor-mediated inhibition of MNCs is altered in lactating rats.

Results: Gramicidin-perforated recordings in the rat supraoptic nucleus (SON) slices revealed that the reversal potential of GABAA receptor-mediated response (EGABA) of MNCs was significantly depolarized in the lactating rats as compared to virgin animals.

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Neuropathic pain is a devastating chronic condition and is often induced in the upper limb following nerve injury or damage. Various drugs or surgical methods have been used to manage neuropathic pain; however, these are frequently accompanied by undesirable side effects. Transcutaneous electrical nerve stimulation (TENS) is a safe and non-invasive intervention that has been used to alleviate different types of pain in the clinic, but it is unclear whether TENS can improve chronic neuropathic pain in the upper limb.

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Objective: To determine whether a single trial of interferential current therapy (ICT) can immediately alleviate spasticity and improve balance and gait performance in patients with chronic stroke.

Design: Randomized, placebo-controlled clinical trial.

Setting: Inpatient rehabilitation in a local center.

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