PURPOSE: Most of studies dealing with abfractions are limited to the buccal surfaces of the teeth. In this study, we analyzed the cause for abfraction by investigating the incidence of palatal side abfractions in maxillary posterior teeth. MATERIALS AND METHODS: We investigated a total of 3193 maxillary posterior teeth by an intraoral examination, model observation, and observation of virtual model fabricated using model scanning. We recorded the results and classified them depending on the type of teeth, age, gender, and side of arches. We also performed Chi-square test to evaluate the statistical significance among the groups (α = 0.05). RESULTS: The incidence of palatal side abfraction of the maxillary molars (10.8%) was higher than the premolars (6.8%), and among them, the incidence of the 1st molars (39.1%) were the highest. The incidence of palatal side abfraction increased with age and was statistically significant (P < 0.05). There was no statistical significance in the difference by gender (P > 0.05); in the case of arches, left arch showed higher incidence and it was statistically significant (P < 0.05). CONCLUSION Palatal side abfraction in maxillary posterior teeth was frequently observed in the maxillary 1st molars, and the incidence increased with age. This result suggests that the main reason for abfraction is due to occlusal force.

BACKGROUND/OBJECTIVES: Colorectal cancer (CRC) is the third most common cancer worldwide with a high recurrence rate. Oxaliplatin (OXA) resistance is one of the major reasons hindering CRC therapy. β-Carotene (BC) is a provitamin A and is known to have antioxidant and anticancer effects. However, the combined effect of OXA and BC has not been investigated. Therefore, this study investigated the anticancer effects and mechanism of the combination of OXA and BC on CRC.MATERIALS/METHODS: In the present study, the effects of the combination of OXA and BC on cell viability, cell cycle arrest, and cancer stemness were investigated using HCT116, HT29, OXA-resistant cells, and human CRC organoids. RESULTS: The combination of OXA and BC enhanced apoptosis, G 2,/sub> /M phase cell cycle arrest, and inhibited cancer cell survival in human CRC resistant cells and CRC organoids without toxicity in normal organoids. Cancer stem cell marker expression and self-replicating capacity were suppressed by combined treatment with OXA and BC. Moreover, this combined treatment upregulated apoptosis and the stem cell-related JAK/STAT signaling pathway. CONCLUSIONS Our results suggest a novel potential role of BC in reducing resistance to OXA, thereby enhances the anticancer effects of OXA. This enhancement is achieved through the regulation of cell cycle, apoptosis, and stemness in CRC.

BACKGROUND: Although physical activity is known to be beneficial to lung function, few studies have been conducted to investigate the correlation between physical activity and lung function in dusty areas. Therefore, the purpose of this study is to investigate the correlation between physical activity and lung function in a Korean cohort including normal and COPD-diagnosed participants. METHODS: Data obtained from the COPD in dusty areas (CODA) cohort was analyzed for the following factors: lung function, symptoms, and information about physical activity. Information on physical activity was valuated using questionnaires, and participants were categorized into two groups: active and inactive. The evaluation of the mean lung function, modified Medical Research Council dyspnea grade scores, and COPD assessment test scores was done based on the participant physical activity using a general linear model after adjusting for age, sex, smoking status, pack-years, height, and weight. In addition, a stratification analysis was performed based on the smoking status and COPD. RESULTS: Physical activity had a correlation with high forced expiratory volume in 1 second (FEV₁) among CODA cohort (p=0.03). While the active group exhibited significantly higher FEV₁ compared to one exhibited by the inactive group among past smokers (p=0.02), no such correlation existed among current smokers. There was no significant difference observed in lung function after it was stratified by COPD. CONCLUSION This study established a positive correlation between regular physical activity in dusty areas and lung function in participants.

BACKGROUND: Although physical activity is known to be beneficial to lung function, few studies have been conducted to investigate the correlation between physical activity and lung function in dusty areas. Therefore, the purpose of this study is to investigate the correlation between physical activity and lung function in a Korean cohort including normal and COPD-diagnosed participants. METHODS: Data obtained from the COPD in dusty areas (CODA) cohort was analyzed for the following factors: lung function, symptoms, and information about physical activity. Information on physical activity was valuated using questionnaires, and participants were categorized into two groups: active and inactive. The evaluation of the mean lung function, modified Medical Research Council dyspnea grade scores, and COPD assessment test scores was done based on the participant physical activity using a general linear model after adjusting for age, sex, smoking status, pack-years, height, and weight. In addition, a stratification analysis was performed based on the smoking status and COPD. RESULTS: Physical activity had a correlation with high forced expiratory volume in 1 second (FEV₁) among CODA cohort (p=0.03). While the active group exhibited significantly higher FEV₁ compared to one exhibited by the inactive group among past smokers (p=0.02), no such correlation existed among current smokers. There was no significant difference observed in lung function after it was stratified by COPD. CONCLUSION: This study established a positive correlation between regular physical activity in dusty areas and lung function in participants.
Cohort Studies ; Dyspnea ; Forced Expiratory Volume ; Linear Models ; Lung ; Motor Activity ; Pulmonary Disease, Chronic Obstructive ; Respiratory Function Tests ; Smoke ; Smoking

BACKGROUND/OBJECTIVES: Colorectal cancer (CRC) is the third most common cancer worldwide and has a high recurrence rate, which is associated with cancer stem cells (CSCs).β-carotene (BC) possesses antioxidant activity and several anticancer mechanisms. However, no investigation has examined its effect on colon cancer stemness.MATERIALS/METHODS: CD133 + CD44 + HCT116 and CD133+ CD44+ HT-29 cells were isolated and analyzed their self-renewal capacity by clonogenic and sphere formation assays.Expressions of several CSCs markers and Wnt/β-catenin signaling were examined. In addition, CD133+ CD44+ HCT116 cells were subcutaneously injected in xenograft mice and analyzed the effect of BC on tumor formation, tumor volume, and CSCs markers in tumors. RESULTS: BC inhibited self-renewal capacity and CSC markers, including CD44, CD133, ALDH1A1, NOTCH1, Sox2, and β-catenin in vitro. The effects of BC on CSC markers were confirmed in primary cells isolated from human CRC tumors. BC supplementation decreased the number and size of tumors and delayed the tumor-onset time in xenograft mice injected with CD133+ CD44+ HCT116 cells. The inhibitory effect of BC on CSC markers and the Wnt/β-catenin signaling pathway in tumors was confirmed in vivo as well. CONCLUSIONS These results suggest that BC may be a potential therapeutic agent for colon cancer by targeting colon CSCs.