Numerical Sensitivity Tests of Volatile Organic Compounds Emission to PM2.5 Formation during Heat Wave Period in 2018 in Two Southeast Korean Cities

A record-breaking severe heat wave was recorded in southeast Korea from 11 July to 15 August 2018, and the numerical sensitivity simulations of volatile organic compound (VOC) to secondarily generated particulate matter with diameter of less than 2.5 mu m (PM2.5) concentrations were studied in the Busan and Ulsan metropolitan areas in southeast Korea. A weather research and forecasting (WRF) model coupled with chemistry (WRF-Chem) was employed, and we carried out VOC emission sensitivity simulations to investigate variations in PM2.5 concentrations during the heat wave period that occurred from 11 July to 15 August 2018. In our study, when anthropogenic VOC emissions from the Comprehensive Regional Emissions Inventory for Atmospheric Transport Experiment-2015 (CREATE-2015) inventory were increased by approximately a factor of five in southeast Korea, a better agreement with observations of PM2.5 mass concentrations was simulated, implying an underestimation of anthropogenic VOC emissions over southeast Korea. The simulated secondary organic aerosol (SOA) fraction, in particular, showed greater dominance during high temperature periods such as 19-21 July, 2018, with the SOA fractions of 42.3% (in Busan) and 34.3% (in Ulsan) among a sub-total of seven inorganic and organic components. This is considerably higher than observed annual mean organic carbon (OC) fraction (28.4 +/- 4%) among seven components, indicating the enhancement of secondary organic aerosols induced by photochemical reactions during the heat wave period in both metropolitan areas. The PM2.5 to PM10 ratios were 0.69 and 0.74, on average, during the study period in the two cities. These were also significantly higher than the typical range in those cities, which was 0.5-0.6 in 2018. Our simulations implied that extremely high temperatures with no precipitation are significantly important to the secondary generation of PM2.5 with higher secondary organic aerosol fraction via photochemical reactions in southeastern Korean cities. Other possible relationships between anthropogenic VOC emissions and temperature during the heat wave episode are also discussed in this study

Alpha-tocopherol exerts protective function against the mucotoxicity of particulate matter in amphibian and human goblet cells

Exposure to particulate matter (PM) in ambient air is known to increase the risk of cardiovascular disorders and mortality. The cytotoxicity of PM is mainly due to the abnormal increase of reactive oxygen species (ROS), which damage cellular components such as DNA, RNA, and proteins. The correlation between PM exposure and human disorders, including mortality, is based on long-term exposure. In this study we have investigated acute responses of mucus-secreting goblet cells upon exposure to PM derived from a heavy diesel engine. To this end, we employed the mucociliary epithelium of amphibian embryos and human Calu-3 cells to examine PM mucotoxicity. Our data suggest that acute exposure to PM significantly impairs mucus secretion and results in the accumulation of mucus vesicles in the cytoplasm of goblet cells. RNA-seq analysis revealed that acute responses to PM exposure significantly altered gene expression patterns; however, known regulators of mucus production and the secretory pathway were not significantly altered. Interestingly, pretreatment with alpha-tocopherol nearly recovered the hyposecretion of mucus from both amphibian and human goblet cells. We believe this study demonstrates the mucotoxicity of PM and the protective function of alpha-tocopherol on mucotoxicity caused by acute PM exposure from heavy diesel engines

Results of immediate loading for implant restoration in partially edentulous patients: a 6-month preliminary prospective study using SinusQuick™ EB implant system

STATEMENT OF PROBLEM. Many dental clinicians are concerned about immediate loading of inserted implants. However, there have been few clinical studies surveying the success rates of immediate loading, based on Korean implant systems. PURPOSE. The aim of this study was to evaluate the outcome of immediate functional loading of the implant (SinusQuickTM EB, Neobiotech Co., Seoul, Korea) in partially edentulous maxilla or mandible. MATERIAL AND METHODS. Total 15 implants were placed. Within 2 weeks after implant insertion, provisional implant-supported fixed partial dentures were delivered to the patients. Quantitatively, marginal bone loss was measured at the time of immediate loading, after 3-months of continued loading and at the last follow-up. The mean follow-up period was 4.8 months. RESULTS. Mean marginal bone loss from implant surgery to early loading, 3-months follow-up and last follow-up was 0.03 ± 0.07 mm, 0.16 ± 0.17 mm and 0.29 ± 0.19 mm. No implant failed up to 6 months after insertion, resulting in a 100% survival rate. CONCLUSION. Immediate loading exhibited high success rate in partial edentulism for up to 6 months. Well-controlled long term clinical studies with large sample size are necessary to confirm this finding

Metaplastic Carcinoma with Extensive Chondroid Differentiation in the Breast (Chondroid Carcinoma)

Metaplastic breast carcinoma is very rare, and metaplastic carcinoma with chondroid differentiation is even rarer. Here, we report a case of metaplastic carcinoma with extensive chondroid differentiation mimicking chondrosarcoma that was challenging to diagnose. The tumor was characterized by an abundant chondromyxoid matrix. The definitive area of classic invasive ductal carcinoma was minimal. The peripheral portion of the tumor showed increased cellularity with pleomorphism and definitive invasive growth. Tumor cells in the chondrosarcomatous areas were diffusely immunoreactive for S-100 protein, patchy positive for cytokeratin, but negative for epithelial membrane antigen (EMA). Tumor cells in carcinomatous areas were diffusely positive for cytokeratin, S-100 protein, and patchy positive for EMA. In both areas, tumor cells were negative for smooth muscle actin (SMA) and CD34, while oncoprotein p53 was overexpressed. When pathologists encounter breast tumors with chondroid differentiation, careful sampling and immunohistochemistry for cytokeratin and SMA are most helpful to differentiate metaplastic carcinoma from malignant phyllodes tumor and malignant adenomyoepithelioma

Metastatic hepatocellular carcinoma presenting as facial nerve palsy and facial pain

Facial nerve palsy due to temporal bone metastasis of hepatocellular carcinoma (HCC) has rarely been reported. We experienced a rare case of temporal bone metastasis of HCC that initially presented as facial nerve palsy and was diagnosed by surgical biopsy. This patient also discovered for the first time that he had chronic hepatitis B and C infections due to this facial nerve palsy. Radiation therapy greatly relieved the facial pain and facial nerve palsy. This report suggests that hepatologists should consider metastatic HCC as a rare but possible cause of new-onset cranial neuropathy in patients with chronic viral hepatitis

Trib2 regulates the pluripotency of embryonic stem cells and enhances reprogramming efficiency

Embryonic stem (ES) cells are pluripotent cells characterized by self-renewability and differentiation potential. Induced pluripotent stem (iPS) cells are ES cell-equivalent cells derived from somatic cells by the introduction of core reprogramming factors. ES and iPS cells are important sources for understanding basic biology and for generating therapeutic cells for clinical applications. Tribbles homolog 2 (Trib2) functions as a scaffold in signaling pathways. However, the relevance of Trib2 to the pluripotency of ES and iPS cells is unknown. In the present study, we elucidated the importance of Trib2 in maintaining pluripotency in mouse ES cells and in generating iPS cells from somatic cells through the reprogramming process. Trib2 expression decreased as ES cells differentiated, and Trib2 knockdown in ES cells changed their colony morphology while reducing the activity of alkaline phosphatase and the expression of the pluripotency marker genes Oct4, Sox2, Nanog and Klf4. Trib2 directly interacted with Oct4 and elevated Oct4 promoter activity. During the generation of iPS cells, Trib2 knockdown decreased the reprogramming efficiency of mouse embryonic fibroblasts, whereas Trib2 overexpression significantly increased their reprogramming efficiency. In summary, our results suggest that Trib2 is important for maintaining self-renewal in ES cells and for pluripotency induction during the reprogramming process

Effects of a Postnatal Care Program on Self-efficacy, Self-management, and Glycemic Control in Women with Gestational Diabetes Mellitus

PURPOSE: To examine effects of a postnatal care program on self-efficacy, self-management, and glycemic control in women with gestational diabetes mellitus (GDM). METHODS: A non-equivalent control group non-synchronized quasi-experimental design was used. Sixty-two women with GDM were enrolled and assigned to either an experimental group (n=30) or a control group (n=32). The experimental group received an intervention which was postnatal care program for women with GDM. The postnatal care program for GDM included an individual education with leaflet and mobile web-based video with three times of telephone counseling. Effects of the intervention were measured with self-efficacy, self-management questionnaire, and a 75 g oral glucose tolerance test (75g OGTT). Statistical significance was examined using independent t-test and χ2-test. RESULTS: Although there was no significant difference in 75g OGTT (χ2=.11, p=.748) or self-management (t=−1.28, p=.206), there was a statistically significant increase in self-efficacy (t=−2.02, p=.048) in the experimental group compared to that in the control group. CONCLUSION: A postnatal care program is needed for women with GDM to improve their self-efficacy. Further studies are warranted to improve self-management and glycemic control through tailored education for GDM postpartum women