Objectives: . Particulate matter (PM) is a risk factor for various diseases. Recent studies have established an association between otitis media (OM) and PM exposure. To confirm this relationship, we developed a novel exposure model designed to control the concentration of PM, and we observed the effects of PM exposure on the Eustachian tube (ET) and middle ear mucosa of rats. Methods: . Forty healthy, 10-week-old, male Sprague-Dawley rats were divided into 3-day, 7-day, 14-day exposure, and control groups (each, n=10). The rats were exposed to incense smoke as the PM source for 3 hours per day. After exposure, bilateral ETs and mastoid bullae were harvested, and histopathological findings were compared using microscopy and transmission electron microscopy (TEM). The expression levels of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor (VEGF) in the middle ear mucosa of each group were compared using real-time reverse transcription polymerase chain reaction (RT-PCR). Results: . In the ET mucosa of the exposure group, the goblet cell count significantly increased after PM exposure (P=0.032). In the middle ear mucosa, subepithelial space thickening, increased angio-capillary tissue, and inflammatory cell infiltration were observed. Moreover, the thickness of the middle ear mucosa in the exposure groups increased compared to the control group (P<0.01). The TEM findings showed PM particles on the surface of the ET and middle ear mucosa, and RT-PCR revealed that messenger RNA (mRNA) expression of IL-1β significantly increased in the 3-day and 7-day exposure groups compared to the control group (P=0.035). VEGF expression significantly increased in the 7-day exposure group compared to the control and 3-day exposure groups (P<0.01). Conclusion . The ET and middle ear mucosa of rats showed histopathologic changes after acute exposure to PM that directly reached the ET and middle ear mucosa. Therefore, acute exposure to PM may play a role in the development of OM.

Background: Korea recently established 70 emergency medical service areas. However, there are many concerns that medical resources for stroke could not be evenly distributed through the country. We aimed to compare the treatment quality and outcomes of acute stroke among the emergency medical service areas. Methods: This study analyzed the data of 28,800 patients admitted in 248 hospitals which participated in the 8th acute stroke quality assessment by Health Insurance Review and Assessment Service. Individual hospitals were regrouped into emergency service areas according to the address of the location. Assessment indicators and fatality were compared by the service areas. We defined the appropriate hospital by the performance of intravenous thrombolysis. Results: In seven service areas, there were no hospitals which received more than 10 stroke patients for 6 months. In nine service areas, there were no patients who underwent intravenous thrombolysis (IVT). Among 167 designated emergency medical centers, 50 hospitals (29.9%) responded that IVT was impossible 24 hours a day. There are 97 (39.1%) hospitals that meet the definitions of appropriate hospital. In 23 service areas (32.9%) had no appropriate or feasible hospitals. The fatality of service areas with stroke centers were 6.9% within 30 days and 15.6% within 1 year from stroke onset than those without stroke centers (7.7%, 16.9%, respectively). Conclusions There was a wide regional gap in the medical resource and the quality of treatments for acute stroke among emergency medical service areas in Korea. The poststroke fatality rate of the service areas which have stroke centers or appropriate hospitals were significantly low.

OBJECTIVES: We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea. METHODS: In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022. RESULTS: In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%. CONCLUSIONS The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.

Background and Objectives: Currently, safety pharmacological tests for the central nervous system depend on animal behavioral analysis. However, due to the subjectivity of behavioral analysis and differences between species, there is a limit to appropriate nervous system toxicity assessment, therefore a new neurotoxicity assessment that can simulate the human central nervous system is required. Methods: and Results: In our study, we developed an in vitro neurotoxicity assessment focusing on neuronal function. To minimize the differences between species and fast screening, hiPSC-derived neurons and a microelectrode array (MEA) that could simultaneously measure the action potentials of the neuronal networks were used. After analyzing the molecular and electrophysiological characters of our neuronal network, we conducted a neurotoxicity assessment on neurotransmitters, neurotoxicants, illicit drugs, and new psychoactive substances (NPS). We found that most substances used in our experiments responded more sensitively to our MEA-based neurotoxicity assessment than to the conventional neurotoxicity assessment. Also, this is the first paper that evaluates various illicit drugs and NPS using MEA-based neurotoxicity assessment using hiPSC-derived neurons. Conclusions Our study expanded the scope of application of neurotoxicity assessment using hiPSC-derived neurons to NPS, and accumulated evaluation data of various toxic substances for hiPSC-derived neurons.

Background: s: This study was performed to analyze the main key words of newspaper articles related to COVID-19 in 2020 for each category of quarantine measures according to the epidemic period of COVID-19. Methods: We analyzed articles related to COVID-19 in three major newspapers of Korea between February 17 and December 31, 2020. We targeted the front page articles on mondays and thursdays. The analysis of the relationship between the two variables was confirmed through the chi-square test. Results: As a result of analyzing the main key words for each category of quarantine measures, non-pharmaceutical intervention were the most common at 54.3%, followed by 3Ts(test, tracing, treatment and vaccine) at 31.9%. In the category of non-pharmaceutical intervention, social distancing was the most common at 33.9%. In the categories such as 3Ts(test, tracing, treatment) and vaccine, diagnostic tests were the most common at 41.8%. Conclusions It was identified that non-pharmaceutical intervention were the most common, and there was a difference in the reporting of main key words by category of quarantine measures for each epidemic period related to COVID-19 in 2020.

Background and Objectives: Endoscopic prelacrimal recess approach (PLRA) was introduced to treat maxillary sinus inverted papilloma (IP) without sacrificing the inferior turbinate and nasolacrimal duct. This study aimed to compare surgical outcomes of prelacrimal recess approach with the conventional Caldwell-Luc approach (CLA) to remove IP of maxillary sinus and to evaluate the usefulness of the PLRA.Subjects and Method We retrospectively reviewed medical records of 51 patients who were treated in our institution for IP of nasal cavity and sinuses between March 2010 and June 2019. Twenty patients had maxillary sinus IP. Sixteen patients underwent endoscopic sinus surgery combined with either CLA (n=8) or PLRA (n=8). Demographic data, surgical technique, site of IP origin, intra- and postoperative complications, duration of follow-up, recurrence rate and pathologic diagnosis were reviewed. Results: IP was the pathologic diagnosis for all 16 cases. Gross total removal was achieved in all cases. The mean follow-up period was 20.1 months in CLA group and 12.5 months in PLRA group. There was one case of massive bleeding during operation requiring transfusion and postoperative ICU care in CLA group. On postoperative follow-up, two patients from the CLA group had recurrence during the follow-up period. One patient had numbness around the gingival area, another patient had transient wound dehiscence, and another had persistent oro-antral fistula. In PLRA group, one patient had periorbital swelling after blowing nose; otherwise, no other patient from the PLRA group developed subjective complaints after surgery. Conclusion Endoscopic prelacrimal recess approach showed lower complication rates and recurrence rates compared to CLA. PLRA is a safe and effective method for the excision of primary maxillary sinus IP.

Purpose: With changing fungal epidemiology and azole resistance in Aspergillus species, identifying fungal species and susceptibility patterns is crucial to the management of aspergillosis and mucormycosis. The objectives of this study were to evaluate performance of panfungal polymerase chain reaction (PCR) assays on formalin-fixed paraffin embedded (FFPE) samples in the identification of fungal species and in the detection of azole-resistance mutations in the Aspergillus fumigatus cyp51A gene at a South Korean hospital. Materials and Methods: A total of 75 FFPE specimens with a histopathological diagnosis of aspergillosis or mucormycosis were identified during the 10-year study period (2006–2015). After deparaffinization and DNA extraction, panfungal PCR assays were conducted on FFPE samples for fungal species identification. The identified fungal species were compared with histopathological diagnosis. On samples identified as A. fumigatus, sequencing to identify frequent mutations in the cyp51A gene [tandem repeat 46 (TR46), L98H, and M220 alterations] that confer azole resistance was performed. Results: Specific fungal DNA was identified in 31 (41.3%) FFPE samples, and of these, 16 samples of specific fungal DNA were in accord with a histopathological diagnosis of aspergillosis or mucormycosis; 15 samples had discordant histopathology and PCR results. No azole-mediating cyp51A gene mutation was noted among nine cases of aspergillosis. Moreover, no cyp51A mutations were identified among three cases with history of prior azole use. Conclusion Panfungal PCR assay with FFPE samples may provide additional information of use to fungal species identification. No azole-resistance mediating mutations in the A. fumigatus cyp51A gene were identified among FFPE samples during study period.

Malignancy of the middle ear is rare and its estimated incidence is 0.18 cases per million people in the US, with its most common type being squamous cell carcinoma. Squamous cell carcinoma in situ is thought to be a precursor to squamous cell carcinoma, which is extremely rare in the middle ear. The pathology reports of squamous cell carcinoma have not been well-characterized as it has not been reported to date in Korea. Here, we report a case of squamous cell carcinoma in situ of the middle ear in a 66-year-old man, who presented with otorrhea and tympanic membrane perforation.
Aged ; Carcinoma in Situ ; Carcinoma, Squamous Cell ; Ear, Middle ; Epithelial Cells ; Humans ; Incidence ; Korea ; Pathology ; Tympanic Membrane Perforation

Vascular endothelial growth factor (VEGF) plays a pivotal role in pathologic ocular neovascularization and vascular leakage via activation of VEGF receptor 2 (VEGFR2). This study was undertaken to evaluate the therapeutic mechanisms and effects of the tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a VEGFR2 inhibitor, in the development of vascular permeability and choroidal neovascularization (CNV). In cultured human retinal microvascular endothelial cells (HRMECs), treatment with RLYE blocked VEGF-A-induced phosphorylation of VEGFR2, Akt, ERK, and endothelial nitric oxide synthase (eNOS), leading to suppression of VEGF-A-mediated hyper-production of NO. Treatment with RLYE also inhibited VEGF-A-stimulated angiogenic processes (migration, proliferation, and tube formation) and the hyperpermeability of HRMECs, in addition to attenuating VEGF-A-induced angiogenesis and vascular permeability in mice. The anti-vascular permeability activity of RLYE was correlated with enhanced stability and positioning of the junction proteins VE-cadherin, β-catenin, claudin-5, and ZO-1, critical components of the cortical actin ring structure and retinal endothelial barrier, at the boundary between HRMECs stimulated with VEGF-A. Furthermore, intravitreally injected RLYE bound to retinal microvascular endothelium and inhibited laser-induced CNV in mice. These findings suggest that RLYE has potential as a therapeutic drug for the treatment of CNV by preventing VEGFR2-mediated vascular leakage and angiogenesis.
Actins ; Animals ; Capillary Permeability ; Choroid ; Choroidal Neovascularization ; Claudin-5 ; Endothelial Cells ; Endothelium ; Humans ; Macular Degeneration ; Mice ; Nitric Oxide Synthase Type III ; Permeability ; Phosphorylation ; Receptors, Vascular Endothelial Growth Factor ; Retinaldehyde ; Vascular Endothelial Growth Factor A

BACKGROUND: The natural course of thyroid cancer nodules and benign nodules is different. This study was to compare the changes in size between thyroid cancer nodules and thyroid benign nodules. The risk factors associated with the changes of thyroid cancer nodules were assessed. METHODS: This study contains retrospective observational and prospective analysis. A total of 113 patients with 120 nodules were recruited in the cancer group, and 116 patients with 119 nodules were enrolled in the benign group. Thyroid ultrasonography was performed at least two times at more than 1-year interval. RESULTS: The mean follow-up durations were 29.5±18.8 months (cancer group) and 31.9±15.8 months (benign group) (P=0.32). The maximum diameter change in length was 0.36±0.97 mm/year in the cancer group and –0.04±0.77 mm/year in the benign group (P<0.01). The volume was significantly increased in the cancer group compared with the benign group (0.06±0.18 mL/year vs. 0.004±0.05 mL/year, respectively, P<0.01; 26.9%±57.9%/year vs. 1.7%±26.0%/year, P<0.01). Initial maximum diameter (β=0.02, P<0.01) and initial volume (β=0.13, P<0.01) were significantly associated with volume change (mL)/year. Initial maximum standardized uptake value did not predict the nodule growth. CONCLUSION: It is suggested that thyroid cancer nodules progress rapidly compared with benign nodules. Initial size and volume of nodule were independent risk factors for cancer nodule growth.
Biopsy, Fine-Needle ; Follow-Up Studies ; Humans ; Prospective Studies ; Retrospective Studies ; Risk Factors ; Thyroid Gland ; Thyroid Neoplasms ; Thyroid Nodule ; Tumor Burden ; Ultrasonography