L-ascorbic acid induces apoptosis in human laryngeal epidermoid Hep-2 cells by modulating the nuclear factor kappa-light-chain-enhancer of activated B cells/ mitogen-activated protein kinase/Akt signaling pathway

L-ascorbic acid (L-AA; vitamin C) induces apoptosis in cancer cells. This study aimed to elucidate the molecular mechanisms of L-AA-induced apoptosis in human laryngeal epidermoid carcinoma Hep-2 cells. L-AA suppressed the viability of Hep-2 cells and induced apoptosis, as shown by the cleavage and condensation of nuclear chromatin and increased number of Annexin V-positive cells. L-AA decreased Bcl-2 protein expression but upregulated Bax protein levels. In addition, cytochrome c release from the mitochondria into the cytosol and activation of caspase-9, -8, and -3 were enhanced by L-AA treatment. Furthermore, apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were translocated into the nucleus during apoptosis of L-AA-treated Hep-2 cells. L-AA effectively inhibited the constitutive nuclear factor-κB (NF-κB) activation and attenuated the nuclear expression of the p65 subunit of NF-κB. Interestingly, L-AA treatment of Hep-2 cells markedly activated Akt and mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase [JNK]) and and LY294002 (Akt inhibitor), SB203580 (p38 inhibitor) or SP600125 (a JNK inhibitor) decreased the levels of Annexin V-positive cells. These results suggested that L-AA induces the apoptosis of Hep-2 cells via the nuclear translocation of AIF and EndoG by modulating the Bcl- 2 family and MAPK/Akt signaling pathways.

L-ascorbic acid induces apoptosis in human laryngeal epidermoid Hep-2 cells by modulating the nuclear factor kappa-light-chain-enhancer of activated B cells/ mitogen-activated protein kinase/Akt signaling pathway

L-ascorbic acid (L-AA; vitamin C) induces apoptosis in cancer cells. This study aimed to elucidate the molecular mechanisms of L-AA-induced apoptosis in human laryngeal epidermoid carcinoma Hep-2 cells. L-AA suppressed the viability of Hep-2 cells and induced apoptosis, as shown by the cleavage and condensation of nuclear chromatin and increased number of Annexin V-positive cells. L-AA decreased Bcl-2 protein expression but upregulated Bax protein levels. In addition, cytochrome c release from the mitochondria into the cytosol and activation of caspase-9, -8, and -3 were enhanced by L-AA treatment. Furthermore, apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were translocated into the nucleus during apoptosis of L-AA-treated Hep-2 cells. L-AA effectively inhibited the constitutive nuclear factor-κB (NF-κB) activation and attenuated the nuclear expression of the p65 subunit of NF-κB. Interestingly, L-AA treatment of Hep-2 cells markedly activated Akt and mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase [JNK]) and and LY294002 (Akt inhibitor), SB203580 (p38 inhibitor) or SP600125 (a JNK inhibitor) decreased the levels of Annexin V-positive cells. These results suggested that L-AA induces the apoptosis of Hep-2 cells via the nuclear translocation of AIF and EndoG by modulating the Bcl- 2 family and MAPK/Akt signaling pathways.

The Effects of Entrance Examination Stress on Oral Health Behavior and Subjective Oral Health in Female High School Students / 치위생과학회지

Background@#The purpose of this study is to investigate the effects of entrance exam stress on oral health behaviors and subjective oral health status in female high school students. @*Methods@#A self-reported questionnaire was administered to 216 female high school students in the Gwangju area. We performed an independent t-test, one-way analysis of variance (ANOVA), Pearson’s correlation coefficient, and multiple regression analysis using the SPSS/WIN 21.0 program. @*Results@#The average of the entrance exam stress was 2.73, and among the sub-areas, the tension for exam/poor stress was the highest with 3.21. As a result of analysis of general characteristics and subjective oral health status, oral mucosal disease was lower in family income level (p＜0.05), bad breath was significantly higher with lower academic performance (p＜0.001) and family income level (p＜0.05). As a result of oral health behavior and subjective oral health status analysis, dental caries has more than 4 times of caries snacks (per week) (p＜0.05), bad breath was found to be more perceived when the average number of daily brushing was 2 or less (p＜0.01). Factors affecting subjective oral health status were that dental caries was a patients pressure stress (β=0.202); temporomandibular disorder (β=0.227), xerostomia (β=0.342), and oral mucosal disease (β=0.190) were insufficient spare time; bad breath was academic performance (lower) (β=0.231) and insufficient spare time (β=0.184). There was a statistically significant positive correlation between the subjective oral health status and the subarea of entrance exam stress, excluding future uncertainty stress. @*Conclusion@#It is considered that oral health education should be conducted to prevent oral diseases for students with high parental pressure and insufficient spare time stress as well as finding practical ways to reduce entrance stress.

Effects of some commercial calamansi-containing beverages on the enamel surface / 대한구강보건학회지

OBJECTIVES: The aim of this study was to investigate the effects of some commercial calamansicontaining beverages on the sound surface of bovine teeth as well as the dental erosion inhibitory effects of calcium.METHODS: The pH and titratable acidity of six kinds of commercially available calamansi beverages were determined. Further, 3% calcium was added to the calamansi beverage Oranssi in the experimental group to confirm its dental erosion inhibitory effect. Jeju Samdasoo was used in the negative control group and Coca-Cola in the positive control group. After immersing the sound teeth specimens for 10 min, surface microhardness was measured using the Vickers hardness number (VHN), and surface changes in specimens were observed under a scanning electron microscope.RESULTS: The average pH of the commercial calamansi beverages was 2.54±0.22. After 10 min of treatment with each experimental beverage, the surface hardness difference (ΔVHN) was highest in the Coca-Cola group (−49.05±12.59), followed by the Oranssi calamansi group (−43.77±13.70), 3% calcium-added Oranssi calamansi group (−2.71±12.58), and Samdasoo group (14.03±20.79). There was no significant difference between the bottled water and calcium-added Oranssi calamansi groups or between the Coca-Cola and Oranssi calamansi groups (P>0.05). However, there was a significant difference in the surface hardness between the bottled water and CocaCola groups (P<0.05). On scanning electron microscopy, the Samdasoo group showed a smooth surface without any loss, but Coca-Cola and Oranssi calamansi groups showed a rough surface due to erosion. However, although fine cracks and porosities were seen in the calcium-added Oranssi calamansi group, surfaces in the group were much smoother than those in the Oranssi calamansi group.CONCLUSIONS: Calamansi beverages of low pH may cause corrosion of the tooth surface, and the addition of calcium to the calamansi beverages inhibits demineralization of the tooth surface. Therefore, it is necessary to consider the risk of dental erosion when drinking calamansi beverages of low pH.

Analysis of Factors Affecting Dental Hygiene Students' Attitudes toward Patient Safety and Performing Confidence / 치위생과학회지

The purpose of this study was to investigate the attitudes and performing confidence, and factors influencing patient safety of dental hygiene students. The questionnaire contained items on the subjects' general characteristics, attitudes, and performing confidence in relation to patient safety. The self-reported questionnaire was administered to 287 dental hygiene students in Gwangju and Jeonnam, Korea from September to November 2017. We performed an independent t-test, one-way ANOVA analysis, Pearson's correlation coefficient, and multiple regression analysis using IBM SPSS ver. 21.0 software. As a result of differences in attitude, and performing confidence according to the general characteristics, attitude toward patient safety scored 3.48 out of 5 points, and was more positive in students from 4-year colleges, with high major satisfaction, and in students who answered that they needed patient safety education. Performing confidence for patient safety scored 3.57 out of 5 points, and was statistically significantly higher in 4-year college students, with higher major satisfaction, amongst those with experience in patient safety education, and when patient safety education was needed before clinical practice or employment. There were positive correlations between attitude and performing confidence for patient safety. As a result of analyzing the factors influencing attitude and performing confidence for patient safety, attitudes were higher with higher performing confidence and performing confidence had the highest satisfaction rate of the major and patient safety education experience. Therefore, it is necessary to provide systematic education at universities reflecting the characteristics of dental medical institutions, as well as developing various education contents and education methods.

The Influence of Dental Hygienist Images and Career Advice among High School Teachers / 치위생과학회지

The purpose of this study was to investigate the influence of dental hygienist images and career advice among high school teachers. A self-reported questionnaire was administered to 212 high school teachers in Gwangju, South Korea. The questionnaire contained subject's general characteristics, images of dental hygienists, and career advice. We performed an independent t-test, the Kruskal-Wallis test, Pearson's correlation coefficient, multiple regression analysis, and logistic regression analysis using the IBM SPSS ver. 21.0 software. Using a five-point scale, the average of all the dental hygienist images was 3.50, with personal images receiving the most positive rating at 3.83 and social images receiving the least positive rating at 2.86. The images of dental hygienists were significantly more positive in instances where the subjects recognized the dental hygienist or received treatment within one year. There were positive correlations among different kinds of images. Through multiple regression analysis, occupational images were associated with business and social images. Business images were associated with occupational and personal images. Personal images were associated with business images, especially in cases where the subjects recognized the dental hygienist. Social images were associated with occupational images, especially in cases where subjects received treatment within one year. Through logistic regression analysis, career advice was associated with social and occupational images. Therefore, our study provides suggestions on how to enhance positive recognition of social images of dental hygienists.

Cariogenic Activity in Saliva of Korean Head and Neck Cancer Patients

The purpose of this study is to evaluate salivary flow rate, salivary pH, and cariogenic activity using unstimulated saliva of the head and neck cancer patients. Twenty three cancer patients (19 males, 4 females) who had undergone chemotherapy and radiation therapy and twenty four healthy volunteers (14 males, 10 females) as a control were included. Salivary flow rate, salivary pH, and cariogenic activity using unstimulated saliva were examined. Compared to saliva of the control group, salivary flow rate (p<0.001) and salivary pH (p<0.001) were significantly lower in head and neck cancer patients. The colony counts of Lactobacilli was higher in head and neck cancer patients (p<0.05) than in control group. These salivary factors and cariogenic activity can increase the prevalence of dental caries in head and neck cancer patients.

Prevalence of Oral Microbes in the Saliva of Oncological Patients

This study examined the prevalence of oral microbes in the saliva of oncological patients and healthy subjects. PCR was used to assess the frequency of oral microbes including 3 cariogenic bacteria, 5 periodontopathic bacteria and 4 Candida species in the saliva of 104 oncological patients and 52 healthy subjects. Among these microorganims, Streptococcus mutans, Fusobacterium nucleatum and Candida albicans were most frequently detected in both groups. There were no significant differences in the prevalence of cariogenic bacteria between the patient and healthy groups, whereas significant differences in the frequency of Porphyromonas gingivalis and Tannerella forsythia were observed between the two groups (p < 0.05). The prevalence of all five periodontopathogens was higher in the healthy group than in the patient group. The prevalence of C. albicans in patients was significantly higher than that of healthy group (p < 0.05). In conclusion, there were significant differences in the prevalence of P. gingivalis, T. forsythia and C. albicans between the oncological patient group and healthy group.