Effect of self-learning media based on 360° virtual reality for learning periodontal instrument skills.

INTRODUCTION: Of 360° Virtual Reality (VR) is possibly produced and sufficiently effective as a consumer-friendly VR learning medium. Therefore, it is also expected to be useful in the dental practice field, as a self-learning medium for non-face-to-face skill training during the ongoing pandemic (COVID-19). Accordingly, this study was conducted to assess 360° VR self-learning media for a periodontal instrument operation. MATERIALS AND METHODS: We recruited 30 participants who had never experienced instrument training. We offered basic education and initial assessment (IA), then divided them into three groups: 1) PAPER: trained only with paper handouts; 2) 2D: trained with 2D video; 3) VR: trained with 360° VR. Each group performed self-learning and mid-term assessment (MA). Subjects then implemented home self-learning with the same media for one week, which was then followed by a final assessment (FA). RESULT: Analysis of IA-to-FA improvement scores showed that VR and 2D video were significantly higher than the PAPER groups. Meanwhile, analysis of MA-to-FA improvement scores showed that only VR was substantially higher than the PAPER group. Although VR and 2D video groups were not considerably different, VR scores were numerically higher than 2D video in all improvement score analyses. DISCUSSION: Both 2D video and 360° VR training were helpful to participants for an effective self-learning and also had good portability and accessibility as online-based learning methods. 360° VR showed higher learning efficiency than regular 2D video, possibly due to its autonomy, 360° visual information and physical and immersive characteristics, which positively affected self-training. CONCLUSION: Our findings showed the potential of 360° VR learning media and, further, suggest its usefulness as a novel self-learning method in future dental education.

Atorvastatin protects cardiomyocyte from doxorubicin toxicity by modulating survivin expression through FOXO1 inhibition.

BACKGROUND: Survivin has an anti-apoptotic effect against anthracycline-induced cardiotoxicity. Clinically, statin use is associated with a lower risk for heart failure in breast cancer patients with anthracycline chemotherapy. So, the purpose of our study was to investigate whether survivin mediates the protective effect of statin against anthracycline-induced cardiotoxicity. METHODS: Mice were treated once a week with 5 mg/kg doxorubicin for 4 weeks with or without atorvastatin 20 mg/kg every day then heart tissues were analyzed. Molecular and cellular biology analyses were performed with H9c2 cell lysates. RESULTS: Doxorubicin suppressed survivin expression via activation of FOXO1 in H9c2 cardiomyocytes. Whereas, atorvastatin inhibited FOXO1 by increasing phosphorylation and inhibiting nuclear localization. Doxorubicin induced FOXO1 binding to STAT3 and prevented STAT3 from interacting with Sp1. However, atorvastatin inhibited these interactions and stabilized STAT3/Sp1 transcription complex. Chromatin immunoprecipitation analysis demonstrated that doxorubicin decreased STAT3/Sp1 complex binding to survivin promoter, whereas atorvastatin stabilized this binding. In mouse model, atorvastatin rescued doxorubicin-induced reduction of survivin expression and of heart function measured by cardiac magnetic resonance imaging. CONCLUSIONS: Our study suggested a new pathophysiologic mechanism that survivin mediated protective effect of atorvastatin against doxorubicin-induced cardiotoxicity via FOXO1/STAT3/Sp1 transcriptional network.

The association between oral health literacy and oral health behaviors in North Korean defectors: a cross-sectional study.

BACKGROUND: The present study aimed to investigate the association between oral health literacy and oral health behaviors among North Korean defectors. METHODS: This study involved the collection of self-reported questionnaires from 123 North Korean defectors visited a dental clinic that offered complimentary services, to receive dental treatment in a metropolitan area of South Korea from December 2017 to April 2018. Oral health literacy was measured with the Test of Korean Functional Health Literacy in Dentistry (TOKFHLiD), which consists of 30 items concerning verbal oral health literacy and 42 items concerning functional oral health literacy (28 items for reading comprehension and 14 items for numeracy). In addition, the questionnaire contains 15 and 14 items related to demographic characteristics and oral health behaviors (interest, lifestyle, diet, prevention), respectively, for a total of 101 items. RESULTS: The mean oral health literacy score was 44 (out of a maximum possible score of 72). Oral health literacy and oral health behaviors were positively correlated (r = 0.526, P < 0.001), and oral health literacy also had a significant effect on oral health behaviors (Beta = 0.26, 95% CI: 0.04-0.33). However, although functional oral health literacy had a significant effect on oral health behaviors (Beta = 0.20, 95% CI: 0.01-0.43), verbal oral health literacy did not (Beta = 0.13, 95% CI: - 0.06-037). CONCLUSIONS: Educational interventions are needed to improve oral health literacy, and thus oral health behaviors, as a part of the health promotion measures undertaken to facilitate the stable adjustment of North Korean defectors in South Korean society.

The association between Antonovsky's sense of coherence and job stress among dental hygienists in Korea.

OBJECTIVE: High stress levels experienced by medical professionals are a well-established phenomenon in current literature. However, there are few studies focusing on stress experienced in the field of oral health or on the sense of coherence (SOC) that helps to actively respond to job stress. The purpose of this study was to analyse if there is an association between SOC and job stress among dental hygienists in Korea. METHODS: A cross-sectional study was conducted on a convenience sample of 441 dental hygienists in the Seoul Gyeonggi province, Korea. The independent variable was SOC which had three dimensions: comprehensibility, manageability and meaningfulness. The dependent variable was job stress, which was evaluated using the Korean Occupational Stress Scale Short Form. Confounding factors were age, marital status, educational background, type of hospital, and work experience. The chi-square test and t test measures were used for bivariate analysis. Multiple logistic regression analysis was performed to confirm the association between SOC and job stress. The collected data were statistically analysed using SPSS version 22.0. RESULTS: The SOC score showed a significant difference in relation to the job stress score. The SOC score was high when the job stress was low (P < .001). Overall SOC scores showed an inverse correlation with job stress. CONCLUSION: This study reports that a higher SOC is associated with lower job stress in Korean dental hygienists. Since a higher SOC in dental hygienists indicated that they could cope with job stress more positively, it is important to increase their SOC.

Prediction of itching diagnostic marker through RNA sequencing of contact hypersensitivity and skin scratching stimulation mice models.

Pruritus (itching) is classically defined as an unpleasant cutaneous sensation that leads to scratching behavior. Although the scientific criteria of classification for pruritic diseases are not clear, it can be divided as acute or chronic by duration of symptoms. In this study, we investigated whether skin injury caused by chemical (contact hypersensitivity, CHS) or physical (skin-scratching stimulation, SSS) stimuli causes initial pruritus and analyzed gene expression profiles systemically to determine how changes in skin gene expression in the affected area are related to itching. In both CHS and SSS, we ranked the Gene Ontology Biological Process terms that are generally associated with changes. The factors associated with upregulation were keratinization, inflammatory response and neutrophil chemotaxis. The Kyoto Encyclopedia of Genes and Genomes pathway shows the difference of immune system, cell growth and death, signaling molecules and interactions, and signal transduction pathways. Il1a , Il1b and Il22 were upregulated in the CHS, and Tnf, Tnfrsf1b, Il1b, Il1r1 and Il6 were upregulated in the SSS. Trpc1 channel genes were observed in representative itching-related candidate genes. By comparing and analyzing RNA-sequencing data obtained from the skin tissue of each animal model in these characteristic stages, it is possible to find useful diagnostic markers for the treatment of itching, to diagnose itching causes and to apply customized treatment.

Production of steviol from steviol glucosides using ß-glucosidase from a commercial pectinase, Sumizyme PX.

OBJECTIVE: To purify and characterize a specific enzyme from a commercial pectinase for the production of steviol from stevioside (Ste) without adding organic solvent and to improve steviol production. RESULTS: Commercial Sumizyme PX converted Ste to steviol with a yield of 98%. ß-Glucosidase from Sumizyme PX (ßglyPX) was purified in three steps with 12.5-fold purification and 51% yield. The specific activity of the purified ßglyPX was 141 U/mg. The molecular weight of ßglyPX was ~ 116 kDa on SDS-PAGE. Its optimum activity was at pH 3.5 and 65 °C. It was stable for 12 h up to 55 °C and for 24 h at pH 2-9.5. K m values of ßglyPX for pNPGal, oNPGlc, lactose, and Ste were 2.4, 0.7, 18, and 7.8 mM, respectively. The optimum conditions for steviol production were 55 °C, 900 U/ml, 80 mg Ste/ml, 12 h. CONCLUSION: ßglyPX contains great potential for industrial steviol production from Ste.

Inhibitory effect of flavonoids against NS2B-NS3 protease of ZIKA virus and their structure activity relationship.

OBJECTIVES: To determine the inhibitory activities of flavonoids against NS2B-NS3 protease of ZIKA virus (ZIKV NS2B-NS3pro) expressed in Escherichia coli BL21 (DE3) and their structure activity relationship. RESULTS: ZIKV NS2B-NS3pro was expressed in E. coli BL21(DE3) as a 35 kDa protein. It had a K m of 26 µM with the fluorogenic peptide Dabcyl-KTSAVLQSGFRKME-Edan. The purified ZIKV NS2B-NS3pro was used for inhibition and kinetic assays to determine the activities of 22 polyphenol compounds. These polyphenol compounds at 100 µM inhibited the activity of ZIKV NS2B-NS3pro by 6.2-88%. Seven polyphenol compounds had IC50 ranging from 22 ± 0.2 to 112 ± 5.5 µM. Myricetin showed a mixed type inhibitory pattern against ZIKV NS2B-NS3pro protease. Its IC50 value was 22 ± 0.2 µM with a K i value of 8.9 ± 1.9 µM. CONCLUSION: The chemical structure of a polyphenol compound and its inhibitory activity against ZIKV NS2B-NS3pro can be explored to develop highly selective inhibitors against ZIKV NS2B-NS3pro.

Socioeconomic status, food security, and chewing discomfort of Korean elders: results from the Korea National Health and Nutrition Examination Survey.

BACKGROUND/OBJECTIVES: The purpose of this study was to investigate the association between socioeconomic status and chewing discomfort and identify the role of food insecurity in the association's causal pathway in a representative sample of Korean elders. MATERIALS/METHODS: We conducted cross-sectional analyses of the Korea National Health and Nutrition Examination Survey (2013-2015) data for elders aged ≥ 65 years. Socioeconomic status indicators used included household income and education level. Chewing discomfort was assessed according to the self-reported presence of chewing problems. Food security was surveyed using a questionnaire based on the US Household Food Security Survey Module. RESULTS: The odds ratios of chewing discomfort in the 1st and 2nd income quartiles were 1.55 (95% confidence interval [CI], 1.15-2.10) and 1.40 (95% CI, 1.03-1.90), respectively, compared to participants in the highest income quartile. Participants with the lowest education level were 1.89 (95% CI, 1.30-2.75) times more likely to have chewing discomfort than those without chewing discomfort. After including food security in the final model, the logistic coefficients were attenuated in the income and education quartiles. CONCLUSIONS: Low socioeconomic status was associated with chewing discomfort. In addition, the results confirm that food insecurity can mediate the association between socioeconomic inequalities and chewing discomfort among the elderly.

The association between visual impairment and dental care utilization in the Korean elderly.

INTRODUCTION: Individuals with visual impairment cannot recognize early-stage oral diseases, thus fail to receive prompt treatment. AIMS: To evaluate the association between visual impairment and dental care utilization in patients aged ≥65 years. DESIGN: Retrospective analysis. MATERIALS AND METHODS: We analyzed annual pooled data collected by the Korean Health Panel between 2011 and 2014; a total of 1472 patients and 13,285 dental visits were analyzed. Visual impairment was categorized as follows: normal vision, moderate vision impairment, and severe vision impairment. Dental treatments were categorized as conservative, prosthodontic, implant, periodontal, surgical, preventive, or others. All data were statistically analyzed using a negative binomial regression. MAIN OUTCOME MEASURE: Frequency of dental care utilization. RESULTS: Approximately 50% of the subjects had visual impairment. The frequency of dental care utilization for patients with severe vision impairment was 41% less than patients with normal vision. The dental care utilization for implant treatment was two times higher and periodontal treatment was 1.7 times lower than the conservative treatments among patients who reported moderate and severe vision impairment, respectively. CONCLUSIONS: Visual impairment has a negative association with dental care utilization among older adults. It is imperative to implement systematic interventions to prevent visual impairment from becoming a barrier to dental care in this population.

Thymosin ß4 is associated with bone sialoprotein expression via ERK and Smad3 signaling pathways in MDPC-23 odontoblastic cells.

Thymosin ß4 (Tß4) regulates the expression of molecules associated with dentinogenesis, including bone sialoprotein (BSP). BSP regulates the initiation of mineralization and the direction of dentin growth. However, the association between Tß4 signaling and BSP expression in odontoblasts remains unclear. Therefore, the aim of the present study was to investigate Tß4 mRNA expression in odontoblasts during dentinogenesis and the association between the Tß4 signaling pathway and BSP expression in MDPC­23 odontoblastic cells. Expression and localization of Tß4 mRNA was determined by in situ hybridization during mouse tooth development. The effect of Tß4 signaling on BSP expression was investigated by reverse transcription polymerase chain reaction, western blot analysis, immunofluorescence and a luciferase reporter assay in the presence or absence of specific inhibitors of mitogen activated protein kinase kinase (PD98059) and mothers against decapentaplegic homolog 3 (Smad3; SIS3) in MDPC­23 cells. The expression of Tß4 mRNA in the odontoblast layer was highest at postnatal day 5, known as the advanced bell stage, when odontoblasts actively secrete dentin matrix proteins. Tß4 increased BSP mRNA and protein levels in MDPC­23 cells, but this was inhibited by PD98059 or SIS3 treatment. Tß4 increased levels of phosphorylated (p) extracellular signal­regulated kinase (ERK)1/2, pSmad3, pß­catenin, and runt­related transcription factor 2 (Runx2) protein, but these effects were inhibited by PD98059 or SIS3. Tß4 induced the nuclear translocation of Runx2 and pSmad3, while nuclear translocation of ß­catenin was decreased. Tß4 significantly increased BSP promoter activity, which was decreased by PD98059 or SIS3 treatment. Tß4 induced BSP expression in MDPC­23 cells via ERK and Smad3 signaling pathways, suggesting its role as a signaling molecule in odontoblasts for regulating BSP secretion during dentinogenesis.

Down regulation of Jag-1 in VSMCs contributes to impaired angiogenesis under high glucose condition: Experimental study using aortic rings of rats.

The major cause of diabetes-related mortality is the complications involving aberrant angiogenesis. To understand the underlying mechanisms of such altered-angiogenesis in diabetes, examining the interaction between endothelial cells (ECs) and neighboring smooth muscle cells (VSMCs) rather than mainly focusing on EC might provide us useful information. Thus, in the present study, we examined the effect of high glucose on the expression of Jag1, one of the key trans-activating ligands of Notch receptors known to be involved in EC-SMC interaction, as well as angiogenic process, in vascular smooth muscle cells (VSMCs) to elucidate possible role of EC-VSMC interaction in diabetes-related angiopathy. Our data indicate that high glucose condition decreases the expression of Jag1 in VSMCs possibly by increasing Jag1-targeting micro RNAs (miRNAs) such as miR-21, and exogenous Jag1-simulating peptides increase proliferation and migration of ECs under high glucose condition in vitro. Ex vivo study using aortic rings from normal and streptozotocin (STZ)-treated diabetic mouse demonstrated that exogenous Jag1-simulating peptides increases EC sprouting of aortic rings from diabetic mouse under high glucose condition. Our data suggest that EC-VSMC interaction is altered under high glucose condition and restoring EC-VSMC interaction can be a feasible therapeutic target for treating diabetes-related angiopathy.

Evaluation of the Xpert Clostridium difficile assay for the diagnosis of Clostridium difficile infection.

Infection with Clostridium difficile is a growing concern because of the increasing prevalence and spread of nosocomial infections. Emergence of the hypervirulent 027/NAP1/BI strain is also notable. Existing diagnostic methods have low sensitivity or are time-consuming. Therefore, establishing a rapid and accurate microbiological diagnostic assay is needed. We evaluated the Xpert C. difficile assay (Xpert CD assay; Cepheid, USA) to detect toxigenic C. difficile. This assay is a real-time multiplex PCR assay that can be used to detect toxigenic C. difficile strains and differentiate the C. difficile presumptive 027/NAP1/BI strain. A total of 253 loose stool specimens were collected and toxigenic cultures, VIDAS C. difficile A & B assays (VIDAS CDAB assay; bioMérieux, France), and the Xpert CD assay were performed. In comparison to toxigenic cultures, the sensitivity, specificity, and positive and negative predictive values were 100%, 94.6%, 83.1%, and 100%, respectively, for the Xpert CD assay and 40.8%, 98.0%, 100%, and 88.9%, respectively, for VIDAS CDAB assay. Because of the low prevalence of the PCR ribotype 027 in Korea, the evaluation of the usefulness of the Xpert CD assay for screening for the 027 strain was limited. The Xpert CD assay provides great sensitivity in diagnosing toxigenic C. difficile infection. In addition, this method has excellent usability because it is simple and fast.