Sung-Won Chae's research while affiliated with Korea Institute of Robots and Convergence and other places

Recently, reports of noise-induced hearing loss (NIHL) have sharply risen among workers in South Korea, almost 20-fold in 2022, compared to 2012. This is presumably because NIHL is combined with age-related hearing loss. For the correct diagnosis of NIHL, therefore, the effect of aging that contributes to threshold shifts is should be excluded, and that would require scrutinizing of various established methods. Additionally, international and domestic data from large cross-sectional studies may provide new insights in excluding the effect of age-related hearing loss in individuals in which threshold shifts occurred. This paper comprises the recommendations for the diagnosis and quantification of NIHL in a medico-legal context.

Objectives During the COVID-19 pandemic, various non-pharmaceutical interventions such as individual hygiene practices like hand washing, social distancing, and mandates for the use of masks in public spaces were implemented to reduce the spread of the disease. Otitis media (OM) is a common infectious disease. How the changed environment due to the COVID-19 pandemic has influenced the prevalence of infectious diseases like OM is not known. This study aimed to investigate how OM prevalence and trends changed during COVID-19 in Korea. Methods OM patient data from 2017 to 2021 were extracted from the Health Insurance Review and Assessment Service database. Patients diagnosed with disease code H66 (suppurative and unspecified otitis media) were selected for analysis. Data on OM prevalence, gender, region, medical institution, and number of ventilating-tube prescriptions were analyzed. All age groups were included, and ages were categorized into 5-year ranges Results The number of patients diagnosed with the OM disease code decreased continuously from 2017 to 2021 (1 598 205, 1 560 178, 1 520 948, 983 701, and 734 901). The average OM prevalence per 1000 persons decreased by 45.0% from 30.2 in 2017 to 2019 to 16.6 in 2020 to 2021. The change of OM prevalence was greater for the 0 to 5 age group than other age groups. The decrease in average prevalence per 1000 persons was greatest in the 0 to 5 age group (48.6% decrease from 358.2 in 2017-2019 to 184.1 in 2020-2021). The impact of environmental changes on ventilation-tube insertion was smaller than on OM prevalence. The average number of ventilating-tube insertions decreased by 28.1% from 27 311 in 2017 to 2019 to 19 650 in 2020 to 2021. Conclusions OM prevalence decreased by 45.0%, and the number of ventilating-tube insertions decreased by 28.1% in Korea during COVID-19.

Background and Objectives Cognitive behavioral therapy (CBT) is a treatment option for subjective tinnitus. There are many reports on its clinical efficacy, but the protocol has not been well established. The purpose of this study was to set an outpatient-based CBT protocol and evaluate its clinical efficacy for tinnitus.Subjects and Method A total of 85 chronic tinnitus patients was assessed in this prospective study. After evaluating for eligibility, 30 patients completed CBT based on a protocol of 5 weekly sessions in an outpatient setting. Therapeutic efficacy was assessed by Tinnitus Handicap Inventory (THI) questionnaires and visual analogue scale (VAS) for tinnitus. The initial scores were compared with the final scores, which were assessed a month after the fifth CBT session.Results The results showed that CBT reduced THI and VAS scores significantly ( p <0.05).Conclusion The results of the study suggest that an outpatient-based CBT protocol can be clinically beneficial for patients with tinnitus.

Middle ear tumors are diverse, but relatively uncommon. The most frequent tumor in the middle ear is glomus tumor, followed by others such as schwannoma and cholesteatoma. We experienced a case of Mucosa-associated lymphoid tissue hyperplasia as a middle ear tumor. The mass behind tympanic membrane appeared a hypervascular tumor, mimicking a glomus tumor, but the form of multiple separate masses in middle ear and mastoid cavity was the distinguishing feature that set it apart from a glomus tumor. Additionally, another characteristic was its tendency to easily shrink under pressure. This characteristic should be considered when encounter a hypervascular looking middle ear mass. Laryngoscope, 2023.

Hearing impairment, the third largest health burden worldwide, currently lacks definitive treatments or preventive drugs. This study compared the effects of hydrophilic and lipophilic statin on hearing loss using a common database model. This retrospective multicenter study was conducted in three hospitals in South Korea (Anam, Guro, Ansan). We enrolled patients with hyperlipidemia with an initial hearing loss diagnosis. Data were collected during January 1, 2022–December 31, 2021 using the Observational Health Data Science and Informatics open-source software and Common Data Model database. The primary outcome was the occurrence of first-time hearing loss following a hyperlipidemia diagnosis, as documented in the Common Data Model cohort database. The measures of interest were hearing loss risk between hydrophilic and lipophilic statin use. Variables were compared using propensity score matching, Cox proportional regression, and meta-analysis. Among 37,322 patients with hyperlipidemia, 13,751 (7669 men and 6082 women) and 23,631 (11,390 men and 12,241 women) were treated with hydrophilic and lipophilic statins, respectively. After propensity score matching, according to the Kaplan–Meier curve, hearing loss risk did not significantly differ among the hospitals. The hazard ratio (HR) of the male patients from Anam (0.29, [95% confidence interval (CI), 0.05–1.51]), Guro (HR, 0.56, [95% CI 0.18–1.71]), and Ansan (hazard ratio, 0.29, [95% CI 0.05–1.51]) hospitals were analyzed using Cox proportional regression. Overall effect size (HR, 0.40, [95% CI 0.18–0.91]) was estimated using meta-analysis, which indicated that hearing loss risk among hydrophilic statin users was less than that among lipophilic statin users and was statistically significant. Men in the hydrophilic statin group had a lower risk of hearing impairment than those in the lipophilic statin group.

Background Human mesenchymal stem cells (MSCs) are therapeutic for clinical applications because of their excellent immunomodulatory and multiple lineage differentiation abilities at tissue injury sites. However, insufficient number of cells and lack of regenerative properties during in vitro expansion still limit the clinical applicability of MSC therapies. Here, we demonstrated a preconditioning strategy with trophoblast stem cell-derived extracellular vesicles (TSC-EVs) to boost the proliferation and regenerative capacity of MSCs. Methods We employed cell proliferation analyses such as CCK8 and BrdU assays to determine the proliferation-promoting role of TSC-EVs on MSCs. Osteogenic effects of TSC-EVs on MSCs were assessed by alkaline phosphatase (ALP) activity, calcium assays, and calvarial bone defect animal models. For skin regenerative effects, skin wound mice model was exploited to analyze wound-healing rate in this study, as well as immunofluorescence and histological staining evaluates. We also performed the small RNA profiling and RNA-sequencing analyzes to understand the cellular mechanism of TSC-EVs on MSCs. Results TSC-EVs significantly promoted MSC proliferation under xeno-free conditions and facilitated the therapeutic effects of MSCs, including osteogenesis, anti-senescence, and wound healing. Transcriptomic analysis also provided evidence that specific microRNAs in TSC-EVs and differentially expressed genes (DEGs) in TSC-EV-treated MSCs showed the possibility of TSC-EVs triggering the regenerative abilities of MSCs with cytokine interaction. Hence, we found that NGF/Akt signaling mediated the regenerative effects of TSC-EVs on MSCs as a particular cellular signaling pathway. Conclusion The results of this study demonstrated the functional properties of TSC-EVs on MSCs for MSC-based therapeutic applications, suggesting that TSC-EVs may serve as a potential preconditioning source for MSC therapy in the clinical field of regenerative medicine. Graphical abstract

Trophoblasts play an important role in the regulation of the development and function of the placenta. Our recent study demonstrated the skin regeneration capacity of trophoblast-derived extracellular vesicles (EV). Here, we aimed to determine the potential of trophoblast-derived conditioned medium (TB-CM) in enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs). We found that TB-CM promoted the osteogenic differentiation of MSCs in a dose-dependent manner. Furthermore, it inhibited adipogenesis of MSCs. We also found that the primary trophoblast-derived conditioned medium (PTB-CM) significantly enhanced the proliferation and osteogenic differentiation of human MSCs. Our study demonstrated the regulatory mechanisms underlying the TB-CM-induced osteogenesis in MSCs. An upregulation of genes associated with cytokines/chemokines was observed. The treatment of MSCs with TB-CM stimulated osteogenesis by activating several biological processes, such as mitogen-activated protein kinase (MAPK) and bone morphogenetic protein 2 (BMP2) signaling. This study demonstrated the proliferative and osteogenic efficacies of the trophoblast-derived secretomes, suggesting their potential for use in clinical interventions for bone regeneration and treatment.

Background and Objectives The purpose of this study was to compare the preferred gain and the National Acoustic Laboratories Nonlinear 2nd edition (NAL-NL2) gain value in Korean language hearing aid users.Subjects and Method In this retrospective study, preferred gain and NAL-NL2 gain data were obtained from 199 monaural hearing aids users who were satisfied with their hearing aid devices. The gain value data were collected from three different sound levels at various frequencies. Several factors were also evaluated to determine a potential impact on the preferred gain.Results The preferred gain was significantly higher than the NAL-NL2 target gain (p=0.01). This difference was highest with the gain measured with a medium-level sound (65 dB) with 1 kHz tone. There was a tendency of reduced preferred gain with the increased age of the participant (p=0.049).Conclusion The results indicate that Korean hearing aid users require more gain than the NAL-NL2 target gain. Linguistic characteristics, age, degree of hearing loss, and many other factors may be implicated in this result.

Nasopharyngeal swabs have been widely to prevent the spread of coronavirus disease 2019 (COVID-19). Nasopharyngeal COVID-19 testing is a generally safe and well-tolerated procedure, but numerous complications have been reported in the media. Therefore, the present study aimed to review and document adverse events and suggest procedural references to minimize preventable but often underestimated risks. A total of 27 articles were selected for the review of 842 related documents in PubMed, Embase, and KoreaMed. The complications related to nasopharyngeal COVID-19 testing were reported to be rarely happened, ranging from 0.0012 to 0.026%. Frequently documented adverse events were retained swabs, epistaxis, and cerebrospinal fluid leakage, often associated with high-risk factors, including severe septal deviations, pre-existing skull base defects, and previous sinus or transsphenoidal pituitary surgery. Appropriate techniques based on sufficient anatomical knowledge are mandatory for clinicians to perform nasopharyngeal COVID-19 testing. The nasal floor can be predicted by the line between the nostril and external ear canal. For safe testing, the angle of swab insertion in the nasal passage should remain within 30° of the nasal floor. The swab was gently inserted along the nasal septum just above the nasal floor to the nasopharynx and remained on the nasopharynx for several seconds before removal. Forceful insertion should be attempted, and alternative examinations should be considered, especially in vulnerable patients. In conclusion, patients and clinicians should be aware of rare but possible complications and associated high-risk factors. The suggested procedural pearls enable more comfortable and safe nasopharyngeal COVID-19 testing for both clinicians and patients.

Vagus nerve stimulation (VNS) is considered a potential method for anti-inflammation due to the involvement of the VN in the cholinergic anti-inflammatory pathway (CAP) formation of a connection between the central nervous system and peripheral immune cells that help relieve inflammation. However, whether a non-invasive transcutaneous auricular VNS (taVNS) modulates the inflammation levels via altering the parameter of taVNS is poorly understood. This study aimed to determine the differential inhibitory effects of taVNS on lipopolysaccharide (LPS)-induced systemic inflammation using electrical stimulation parameters such as pulse frequency and time. The taVNS-promoted CAP activity significantly recovered LPS-induced tissue injuries (lung, spleen, and intestine) and decreased inflammatory cytokine levels and tissue-infiltrated immune cells. Interestingly, the anti-inflammatory capacity of taVNS with 15 Hz was much higher than that of taVNS with 25 Hz. When a cytokine array was used to investigate the changes of inflammation and immune response-related cytokines/chemokines expression in taVNS with 15 Hz or 25 Hz treatment in LPS-induced endotoxemia in mice, most of the expression of cytokines/chemokines associated with pro-inflammation was severely decreased in taVNS with 15 Hz compared to 25 Hz. This study demonstrated that the taVNS parameter could differentially modulate the inflammation levels of animals, suggesting the importance of taVNS parameter selection for use in feasible interventions for acute inflammation treatment.