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: Sebocytes are the main cells involved in the pathogenesis of acne by producing lipids and inflammatory cytokines. Although palmitic acid (PA) has been suggested to induce an inflammatory reaction, its effect on sebocytes remains to be elucidated. Objective: In the present study, we investigated whether PA promotes inflammasome-mediated inflammation of sebocytes both in vivo and in vitro. Methods: We intradermally injected PA into the mice ears. And, we treated cultured human sebocytes with PA. Inflammasome-mediated inflammation was verified by immunohistochemistry, Western blot and ELISA. Results: PA-treated mice developed an inflammatory response associated with increased interleukin (IL)-1β expression in the sebaceous glands. When PA was added to cultured human sebocytes, caspase-1 activation and IL-1β secretion were significantly enhanced. In addition, NLRP3 knockdown attenuated IL-1β production by sebocytes stimulated with PA. PA-mediated inflammasome activation required reactive oxygen species. Conclusion These findings indicate that PA activates the NLRP3 inflammasome before induction of an inflammatory response in sebocytes. Thus, PA may play a role in the inflammation of acne

BACKGROUND: Hand eczema is one of the most common skin disorders and negatively affects quality of life. However, a large-scale multicenter study investigating the clinical features of patients with hand eczema has not yet been conducted in Korea. OBJECTIVE: To identify the prevalence of various hand diseases, which is defined as all cutaneous disease occurring in hands, and to investigate the clinical features of patients with hand eczema and the awareness about hand eczema in the general population and to compare the prevalence of hand eczema between health care providers and non-health care providers. METHODS: To estimate the prevalence of hand diseases, we analyzed the medical records of patients from 24 medical centers. Patients were assessed by online and offline questionnaires. A 1,000 from general population and 913 hand eczema patients answered the questionnaire, for a total of 1,913 subjects. RESULTS: The most common hand disease was irritant contact dermatitis. In an online survey, the lifetime prevalence of hand eczema was 31.2%. Hand eczema was more likely to occur in females (66.0%) and younger (20~39 years, 53.9%). Health care providers and housewives were the occupations most frequently associated with hand eczema. Winter (33.6%) was the most common season which people experienced aggravation. The 63.0% and 67.0% answered that hand eczema hinders their personal relationship and negatively affects daily living activities, respectively. CONCLUSION: Hand eczema is a very common disease and hinders the quality of life. The appropriate identification of hand eczema is necessary to implement effective and efficient treatment.
Activities of Daily Living ; Dermatitis, Contact ; Eczema* ; Female ; Hand* ; Health Personnel ; Humans ; Korea* ; Medical Records ; Occupations ; Prevalence ; Quality of Life ; Seasons ; Skin ; Surveys and Questionnaires

BACKGROUND: S100A8 is differentially expressed in various cell types and is associated with a number of malignant disorders. S100A8 may affect tumor biology. However, its role in cutaneous squamous cell carcinoma (SCC) is not well established. OBJECTIVE: This study aims to investigate the relationship between S100A8 and cutaneous SCC development. METHODS: We performed immunohistochemical staining to detect S100A8 expression in facial skin specimens of premalignant actinic keratosis (AK), malignant SCC, and normal tissues. In addition, we utilized postconfluence and high calcium-induced differentiation in a culture system model. Furthermore, we constructed a recombinant adenovirus expressing GFP-tagged S100A8 to investigate the role of S100A8 in SCC cell differentiation. RESULTS: S100A8 was significantly overexpressed in human cutaneous SCC compared to that in normal and AK tissues. S100A8 was gradually upregulated in SCC cells in a post-confluence-induced differentiation model. Overexpression of S100A8 in SCC cells induced by adenoviral transduction led to increased expression levels of differentiation markers, such as loricrin, involucrin, and filaggrin. S100A8 overexpression also increased loricrin and involucrin luciferase activity. CONCLUSION: S100A8 regulates cutaneous SCC differentiation and induces well-differentiated SCC formation in skin.
Adenoviridae ; Antigens, Differentiation ; Biology ; Carcinoma, Squamous Cell* ; Cell Differentiation ; Humans ; Keratosis, Actinic ; Luciferases ; Skin

Orbital and paranasal actinomycosis have not been commonly reported. We report a case of this uncommon infection, which was improved after endonasal endoscopic drainage and antibiotics. A 53-year-old woman with type 2 diabetes mellitus complained of inability to lift her right upper eyelid and painful swelling over the preceding two days. Broad-spectrum antibiotics did not resolve her lesion. In ophthalmic examination, decreased visual acuity, upper and medial gaze limitation, and a relative afferent pupillary defect of her right eye were observed. Computed tomography of the orbit showed aggravated orbital cellulitis, preseptal cellulitis, subperiosteal abscess, and maxillary and ethmoid sinusitis. After endonasal endoscopic drainage and systemic antibiotics, her clinical symptoms dramatically improved. Microbiological analysis of the maxillary excisional biopsy showed Actinomycosis. This case is of interest due to the rare orbital presentation of actinomycosis infection and the importance of appropriate surgical drainage and long-term antibiotics treatment in such cases. Because delayed diagnosis and treatment of rhino-orbital actinomycosis can cause permanent vision loss or intracranial abscess, it requires careful clinical attention.
Abscess* ; Actinomycosis* ; Anti-Bacterial Agents ; Biopsy ; Cellulitis ; Delayed Diagnosis ; Diabetes Mellitus, Type 2* ; Drainage ; Ethmoid Sinus ; Ethmoid Sinusitis ; Eyelids ; Female ; Humans ; Middle Aged ; Orbit* ; Orbital Cellulitis ; Pupil Disorders ; Visual Acuity

The Korea National Health and Nutrition Examination Survey (KNHANES) is a national program designed to assess the health and nutritional status of the noninstitutionalized population of South Korea. The KNHANES was initiated in 1998 and has been conducted annually since 2007. Starting in the latter half of 2008, ophthalmologic examinations were included in the survey in order to investigate the prevalence and risk factors of common eye diseases such as visual impairment, refractive errors, strabismus, blepharoptosis, cataract, pterygium, diabetic retinopathy, age-related macular degeneration, glaucoma, dry eye disease, and color vision deficiency. The measurements included in the ophthalmic questionnaire and examination methods were modified in the KNHANES IV, V, and VI. In this article, we provide detailed information about the methodology of the ophthalmic examinations in KNHANES in order to aid in further investigations related to major eye diseases in South Korea.
*Epidemiologic Methods ; Eye Diseases/*epidemiology ; Humans ; Nutrition Surveys/*statistics & numerical data ; Ophthalmology/*methods ; Prevalence ; Republic of Korea/epidemiology ; Risk Factors ; *Surveys and Questionnaires

BACKGROUND: Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin. OBJECTIVE: To evaluate the basic physiological role of PAR-2 in skin. METHODS: We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes. RESULTS: Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker. CONCLUSION: Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands.
Blotting, Western ; Bony Callus ; Calcium ; Carcinoma, Squamous Cell ; Cell Line ; Epidermis* ; Homeostasis ; Humans ; Inflammation ; Keratinocytes ; Melanosomes ; Pain Perception ; Receptor, PAR-2 ; Skin ; Sweat Glands* ; Sweat* ; Syringoma

OBJECTIVES: The investigation of the prevalence of pleural diseases in regards to those living within 1 km of 14 asbestos mines in Chungnam province. METHODS: We enrolled 4,057 residents (male: 1,887, female: 2,170) living within 1km of asbestos mines in Chungcheong province. They received checkups from Soonchunhyang Environmental Health Center for asbestos related diseases between March 2009 and December 2009. Chest X-rays were taken from all subjects and read by two experts according to International Labor Organization guidelines. Those subjects suspected of asbestos related lesions were further checked with HRCT(high-resolution computed tomography). The determination was done by two experts after reviewing the resulting data. RESULTS: The 4,057 exposed residents underwent the checkup, 859 of whom further underwent the HRCT(high-resolution computed tomography) check. The prevalence of pleural plaque was found to be 11.3% (29.2% non-occupational, 8.0% occupational) from the chest X-rays. The HRCT(high-resolution computed tomography) results revealed that 227 subjects (26.4%) out of the 859 positive subjects (110 (18.8%) non-occupational, 117 (42.9%) occupational) showed evidence of pleural plaque. The statistical analysis showed that the prevalence of pleural plaque increased with increases in age, residence time, and occupational family exposure to asbestos (p<0.05). CONCLUSIONS: We recommend better control of asbestos in the soil and mines. We also recommend that all affected residents living near asbestos mines receive medical checkups as mandated by the asbestos health damage relief policy.
Asbestos ; Environmental Exposure ; Environmental Health ; Humans ; Korea ; Pleural Diseases ; Prevalence ; Soil ; Thorax

PURPOSE: The aim of this study is to report on preliminary data regarding the prevalence of major eye diseases in Korea. METHODS: We obtained data from the Korea National Health and Nutrition Examination Survey, a nation-wide cross-sectional survey and examinations of the non-institutionalized civilian population in South Korea (n = 14,606), conducted from July 2008 to December 2009. Field survey teams included an ophthalmologist, nurses, and interviewers, traveled with a mobile examination unit and performed interviews and ophthalmologic examinations. RESULTS: The prevalence of visual impairment, myopia, hyperopia and astigmatism in participants over 5 years of age was 0.4 +/- 0.1%, 53.7 +/- 0.6%, 10.7 +/- 0.4%, and 58.0 +/- 0.6%, respectively. The prevalence of strabismus and blepharoptosis in participants over 3 years of age was 1.5 +/- 0.1% and 11.0 +/- 0.8%, respectively. In participants over 40 years of age, the prevalence of cataract, pterygium, early and late age-related macular degeneration, diabetic retinopathy and glaucoma was 40.2 +/- 1.3%, 8.9 +/- 0.5%, 5.1 +/- 0.3%, 0.5 +/- 0.1%, 13.4 +/- 1.5%, and 2.1 +/- 0.2%, respectively. CONCLUSIONS: This is the first nation-wide epidemiologic study conducted in South Korea for assessment of the prevalence of eye diseases by both the Korean Ophthalmologic Society and the Korea Center for Disease Control and Prevention. This study will provide preliminary information for use in further investigation, prevention, and management of eye diseases in Korea.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Cross-Sectional Studies ; Eye Diseases/*epidemiology ; Female ; Humans ; Male ; Middle Aged ; Nutrition Surveys/*statistics & numerical data ; Prevalence ; Republic of Korea/epidemiology ; Young Adult

BACKGROUND: Although many anti-diabetic drugs have been used to control hyperglycemia for decades, the efficacy of commonly-used oral glucose-lowering agents in Korean type 2 diabetic patients has yet to be clearly demonstrated. METHODS: We evaluated the efficacy of glimepiride, metformin, and rosiglitazone as initial treatment for drug-naive type 2 diabetes mellitus patients in a 48-week, double-blind, randomized controlled study that included 349 Korean patients. Our primary goal was to determine the change in HbA1c levels from baseline to end point. Our secondary goal was to evaluate changes in fasting plasma glucose (FPG) levels, body weight, frequency of adverse events, and the proportion of participants achieving target HbA1c levels. RESULTS: HbA1c levels decreased from 7.8% to 6.9% in the glimepiride group (P<0.001), from 7.9% to 7.0% in the metformin group (P<0.001), and from 7.8% to 7.0% (P<0.001) in the rosiglitazone group. Glimepiride and rosiglitazone significantly increased body weight and metformin reduced body weight during the study period. Symptomatic hypoglycemia was more frequent in the glimepiride group and diarrhea was more frequent in the metformin group. CONCLUSION: The efficacy of glimepiride, metformin, and rosiglitazone as antidiabetic monotherapies in drug-naive Korean type 2 diabetic patients was similar in the three groups, with no statistical difference. This study is the first randomized controlled trial to evaluate the efficacy of commonly-used oral hypoglycemic agents in Korean type 2 diabetic patients. An additional subgroup analysis is recommended to obtain more detailed information.
Body Weight ; Diabetes Mellitus, Type 2 ; Diarrhea ; Fasting ; Glucose ; Humans ; Hyperglycemia ; Hypoglycemia ; Hypoglycemic Agents ; Metformin ; Plasma ; Sulfonylurea Compounds ; Thiazolidinediones