Objectives: Dental amalgam, containing approximately 50% mercury, is removed during treatment and released into the environment via medical waste incineration or sewage. This study estimated the annual mercury emission from amalgam removal in South Korea. Methods: Data on simple restoration removal (2014-2018) were obtained from a dental hospital’s insurance claims and the Health Insurance Review and Assessment Service (HIRA). Amalgam removal rates were calculated and applied to national data. The average amalgam weight was 0.2 g (50% mercury). Results: Over 5 years, 4,668,490 amalgam restorations were removed. The estimated mercury emission was 466.84 kg total (mean 93.4±11.0 kg/year; 95% CI, 372.2–536.8 kg). Conclusions Approximately 93.4 kg of mercury is annually released from amalgam removal, equivalent to discarding 9-18 million mercury-containing fluorescent lamps. Despite declining amalgam use, systematic separation and disposal guidelines are urgently needed.

Objective: This study aimed to examine morphological changes and changes in the extracellular signal-regulated kinase (ERK) and cyclic AMP response element-binding protein (CREB) activity in the testes of bulls with cryptorchidism. Methods: Testes from the 18-month-old unilateral cryptorchid bulls, including the descended (normal) and undescended (cryptorchid) testes from each animal, were analyzed through gross examination, histology, immunohistochemistry (Ki-67, phosphorylated p-ERK, p-CREB), and Western blotting. Results: Cryptorchid testes were smaller and exhibited reduced epithelial thickness, although seminiferous tubule area remained unchanged. Expression of Ki-67, p-ERK, and p-CREB was significantly decreased, indicating impaired cell proliferation and signaling.Total ERK and CREB protein levels were unchanged, but phosphorylation levels were notably reduced in cryptorchid samples. Conclusions and Relevance: Our findings demonstrate that cryptorchidism alters testicular morphology and disrupts key signaling pathways, particularly those involved in cell growth and function. Such alterations may contribute to infertility and highlight the importance of early diagnosis and intervention in the context of reproductive management in livestock.

Objective: To propose standardized MRI-proton density fat fraction (PDFF) cutoff values for diagnosing hepatic steatosis, evaluated using contemporary PDFF measuring methods in a large population of healthy adults, using histologic fat fraction (HFF) as the reference standard. Materials and Methods: A retrospective search of electronic medical records between 2015 and 2018 identified 1063 adult donor candidates for liver transplantation who had undergone liver MRI and liver biopsy within a 7-day interval. Patients with a history of liver disease or significant alcohol consumption were excluded. Chemical shift imaging-based MRI (CS-MRI) PDFF and high-speed T2-corrected multi-echo MR spectroscopy (HISTO-MRS) PDFF data were obtained. By temporal splitting, the total population was divided into development and validation sets. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the MRI-PDFF method. Two cutoff values with sensitivity > 90% and specificity > 90% were selected to rule-out and rule-in, respectively, hepatic steatosis with reference to HFF ≥ 5% in the development set. The diagnostic performance was assessed using the validation set. Results: Of 921 final participants (624 male; mean age ± standard deviation, 31.5 ± 9.0 years), the development and validation sets comprised 497 and 424 patients, respectively. In the development set, the areas under the ROC curve for diagnosing hepatic steatosis were 0.920 for CS-MRI-PDFF and 0.915 for HISTO-MRS-PDFF. For ruling-out hepatic steatosis, the CS-MRI-PDFF cutoff was 2.3% (sensitivity, 92.4%; specificity, 63.0%) and the HISTO-MRI-PDFF cutoff was 2.6% (sensitivity, 88.8%; specificity, 70.1%). For ruling-in hepatic steatosis, the CS-MRI-PDFF cutoff was 3.5% (sensitivity, 73.5%; specificity, 88.6%) and the HISTO-MRI-PDFF cutoff was 4.0% (sensitivity, 74.7%; specificity, 90.6%). Conclusion In a large population of healthy adults, our study suggests diagnostic thresholds for ruling-out and ruling-in hepatic steatosis defined as HFF ≥ 5% by contemporary PDFF measurement methods.

Background: We sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) and clinical outcomes following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient factors were related to range of motion (ROM) in each referencing system. Methods: This retrospective study included 130 consecutive patients (184 knees) with osteoarthritis who underwent primary posterior cruciate ligament (PCL)-substituting fixed-bearing TKA. The difference between preoperative and postoperative PCO and PCOR values were calculated. Clinical outcomes including ROM and Western Ontario and McMaster University (WOMAC) scores were evaluated. Furthermore, multiple linear regression analysis was performed to determine the factors related to postoperative ROM in each referencing system. Results: The postoperative PCO was greater in the AR group (28.4 mm) than in the PR group (27.4 mm), whereas the PCO was more consistently preserved in the PR group. The mean postoperative ROM after TKA was greater in the AR group (129°) than in the PR group (122°), whereas improvement in WOMAC score did not differ between the two groups. Preoperative ROM was the only factor related to postoperative ROM in both groups. Conclusions There was no difference in postoperative PCO in AR and PR group and the PCO was not associated with postoperative ROM. PCO was more consistently preserved after surgery in the PR group. The postoperative PCO and PCOR changes did not affect the postoperative ROM. Furthermore, similar clinical outcomes were achieved in the AR and PR groups.

Glass ionomer cement (GIC) is a tailor-made material that is used as a filling material in dentistry. GIC is cured by an acid-base reaction consisting of a glass filler and ionic polymers. When the glass filler and ionic polymers are mixed, ionic bonds of the material itself are formed. In addition, the extra polymer anion reacts with calcium in enamel or dentin to increase adhesion to the tooth tissue. GICs are widely used as adhesives for artificial crowns or orthodontic brackets, and are also used as tooth repair material, cavity liner, and filling materials. In this review, the current status of GIC research and development and its prospects for the future have been discussed in detail.

Background: To provide a long-term bacterial seal through the formation of reparative dentin bridge, calcium silicate-based pulp capping materials have been used at sites of pulpal exposure. The aim of this study was to evaluate the mineralization-inducing potentials of calcium silicate-based pulp capping materials (ProRoot MTA [PR], Biodentine [BD], and TheraCal LC [TC]) in human dental pulp cells (HDPCs). Methods: Specimens of test materials were placed in deionized water for various incubation times to measure the pH variation and the concentration of calcium released. The morphology of HDPCs cultured on the specimens was examined using a confocal laser scanning microscope (CLSM). Alizarin red S staining and alkaline phosphatase assays were used to evaluate mineralization-inducing potentials of the capping materials. Results: BD showed the highest calcium release in all test periods, followed by PR and TC. (p<0.05). All experimental groups showed high alkalinity after 1 day, except at 14 days. BD showed the highest cell viability compared with PR and TC after 1 and 3 days, while TC showed the lowest value (p<0.05). The CLSM analysis showed that cells were well adhered and expressed actin filaments for all pulp capping materials. Mineralization by PR and BD groups was higher than that by TC group based on alizarin red S staining. BD showed significantly higher alkaline phosphatase activity than PR and TC, while TC showed the lowest value (p<0.05). Conclusion Within the limitations of the in vitro study, BD had higher mineralization-inducing potential than PR and TC.

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15–1.17), overweight (OR, 1.36; 95% CI, 1.35–1.36), and obese (OR, 1.34; 95% CI, 1.33–1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14–1.16) and overweight (OR, 1.06; 95% CI, 1.06–1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61–0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡ ). Conclusion The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

PURPOSE: The use of prostate-specific antigen as a biomarker for prostate cancer (PC) has been controversial and is, therefore, not used by many countries in their national health screening programs. The biological characteristics of PC in East Asians including Koreans and Japanese are different from those in the Western populations. Potential lifestyle risk factors for PC were evaluated with the aim of developing a risk prediction model. MATERIALS AND METHODS: A total of 1,179,172 Korean men who were cancer free from 1996 to 1997, had taken a physical examination, and completed a lifestyle questionnaire, were enrolled in our study to predict their risk for PC for the next eight years, using the Cox proportional hazards model. The model’s performance was evaluated using the C-statistic and Hosmer–Lemeshow type chi-square statistics. RESULTS: The risk prediction model studied age, height, body mass index, glucose levels, family history of cancer, the frequency of meat consumption, alcohol consumption, smoking status, and physical activity, which were all significant risk factors in a univariate analysis. The model performed very well (C statistic, 0.887; 95% confidence interval, 0.879 to 0.895) and estimated an elevated PC risk in patients who did not consume alcohol or smoke, compared to heavy alcohol consumers (hazard ratio [HR], 0.78) and current smokers (HR, 0.73) (p < 0.001). CONCLUSION: This model can be used for identifying Korean and other East Asian men who are at a high risk for developing PC, as well as for cancer screening and developing preventive health strategies.
Alcohol Drinking ; Asian Continental Ancestry Group ; Body Height ; Decision Support Techniques ; Early Detection of Cancer ; Forecasting ; Glucose ; Humans ; Life Style* ; Male ; Mass Screening ; Meat ; Motor Activity ; Physical Examination ; Population Characteristics ; Proportional Hazards Models ; Prostate* ; Prostate-Specific Antigen ; Prostatic Neoplasms* ; Risk Factors ; Smoke ; Smoking

PURPOSE: Severe combined immunodeficiency (SCID) is the most serious form of primary immunodeficiency. Infants with SCID are susceptible to life-threatening infections. To establish newborn screening for SCID in Korea, we performed a screening test for T-cell receptor excision circle (TREC) and κ-deleting recombination excision circle (KREC) in neonates and investigated the awareness of SCID among their parents. METHODS: Collections of dried blood spots from neonates and parent surveys were performed at the Samsung Medical Center and Cheil General Hospital & Women's Healthcare Center in Korea. The amplification crossing point (Cp) value <37.0 was defined as TREC/KRECpositive based on cutoff values from measuring multiplex real-time polymerase chain reaction. A Cp value >39.0 was defined as negative. RESULTS: For TREC/KREC screening, 141 neonates were enrolled; 63 (44.7%) were male. One hundred forty neonates (99.3%) had positive TREC/KREC results at the time of the initial test; 82.3% and 75.9% were positive and 17.0% and 23.4% were weakly positive for TREC and KREC, respectively. In one neonate (0.7%), the initial TREC/KREC test result was negative. However, repeated tests obtained and confirmed a positive result. For an awareness survey, 168 parents were engaged. Only 2% of parents (3/168) knew that the newborn screening test for SCID had been introduced and performed in other countries. Eighty-four percent of parents (141/168) replied that nationwide newborn SCID screening should be performed in Korean newborns. CONCLUSIONS: In this study, newborn SCID screening was performed along with assessment of public awareness of the SCID test in Korea. The study results showed that newborn SCID screening can be readily applied for clinical use at a relatively low cost in Korea.
Delivery of Health Care ; Hospitals, General ; Humans ; Infant ; Infant, Newborn* ; Korea* ; Male ; Mass Screening* ; Neonatal Screening ; Parents ; Pilot Projects* ; Real-Time Polymerase Chain Reaction ; Receptors, Antigen, T-Cell* ; Recombination, Genetic* ; Severe Combined Immunodeficiency* ; Surveys and Questionnaires ; T-Lymphocytes*

PURPOSE: This study aimed to evaluate the prognostic significance of smoking status in muscle invasive bladder cancer (MIBC) and non-MIBC in recurrence-free (RFS), progression-free (PFS), disease-free survival (DFS), and cancer-specific survival (CSS). MATERIALS AND METHODS: We retrospectively evaluated 541 patients with MIBC and non-MIBC who were surgically treated during 2002–2013. Smoking status was defined as never smokers (NS; n=160, 30%), former smokers (FS; smoking cessation for ≥1 year, n=176, 33%), and current smokers (CS; >100 cigarettes, n=198, 37%). We statistically compared these groups' clinicopathological facCtors for the predictive factors for RFS and PFS for non-MIBC (NMIBC) and DFS for MIBC, and CSS using multivariate model. RESULTS: The CS, FS, and NS groups exhibited insignificantly different pathological staging, grades, and immunohistological characteristics (p>0.05). Among the 441 patients with NMIBC, pathologic tumor size was a significant risk factor for RFS (1–3 cm: hazard ratio [HR], 1.88; >3 cm: HR, 2.21; p < 0.05); age (HR, 1.06), intravesical therapy (HR, 0.25), and high-grade cancer (HR, 8.33) significant for PFS; and age (HR, 1.08), intravesical instillation (HR, 0.26), and smoking status (FS: HR, 0.40; CS: HR, 0.44) significant for CSS (p < 0.05). The 93 patients with MIBC had no significant risk factors for DFS, although their significant risk factors for CSS were age (HR, 1.05), female sex (HR, 2.64), and carcinoma in situ (HR, 4.72) (p < 0.05). CONCLUSIONS: Smoking status only significantly affected CSS in patients with NMIBC.
Administration, Intravesical ; Carcinoma in Situ ; Disease-Free Survival ; Female ; Humans ; Muscles ; Prognosis ; Retrospective Studies* ; Risk Factors ; Smoke* ; Smoking Cessation ; Smoking* ; Tobacco Products ; Urinary Bladder Neoplasms* ; Urinary Bladder*