Considerations in the replacement of over-retained primary teeth with implant restorations in the esthetic zone: A case report.

OBJECTIVE: There exist several treatment planning and clinical challenges when treating over-retained primary teeth with dental implants-especially in the esthetic zone where the existing hard and soft tissue positions are not in harmony with adjacent dentition and do not serve as reliable landmarks for implant placement and restoration. In this report, we highlight some of the key aspects for achieving predictable treatment outcomes for implant restorations replacing over-retained primary teeth in the esthetic zone. CLINICAL CONSIDERATIONS: This clinical report describes the treatment of a patient who presented with over-retained deciduous canines consequent to congenitally missing maxillary lateral incisors. The deciduous canines were deemed hopeless, and subsequently replaced with immediately placed implants following a computer-guided protocol. The optimal implant positions were determined through a diagnostic wax-up correcting the existing gingival discrepancies with the adjacent teeth. Existing periapical infections were addressed utilizing a vestibular approach to minimize the postoperative recession and scarring and achieve a more predictable esthetic outcome. Final restorations were fabricated with all ceramic materials for optimal esthetics. CONCLUSION: When planning for implants to replace over-retained primary teeth, it is essential to visualize the desired contours of the final restorations and correct the level of the existing gingival discrepancies by planning the proper implant position and angulation in relation to the adjacent teeth and gingival positions. CLINICAL SIGNIFICANCE: Careful treatment planning coupled with a guided implant workflow allows for a successful surgical and esthetic outcome for the replacement of over-retained primary teeth with implant restorations.

Elderly Mortality and Exposure to Fine Particulate Matter and Ozone.

BACKGROUND: The effects on particulate matter (PM) and ozone on health are being reported by a number of studies. The effects of these air pollutants are likely to be stronger in the elderly population, but studies in this regard are scarce. The purpose of this study was to study the effects of PM ≤ 2.5 µ and ozone on chronic health effects of the elderly population. METHODS: In order to analyze the health status of the elderly population, National Statistical Office Mortality records were used. In this study, we calculated the number of deaths in Seoul of people who were 60 years or older between 2002 and 2012. The current study analyzed each disorder separately and the lag effect. PM and ozone were analyzed using the single exposure model, as well as the adjusted multi exposure model. RESULTS: In the single exposure analysis with PM2.5 as the exposure variable, with the increase of 10 µ/m³, the number of deaths increased by 1.0039 fold, and vascular disease 1.0053 fold. In the multi exposure model adjusting for ozone, the number of deaths increased by 1.0037 fold, and vascular disease 1.0049 fold. In the single exposure analysis with ozone as the exposure variable, with the increase of 10 ppb, the number of deaths increased by 1.0038 fold, and in the multi exposure model adjusting for PM2.5, the number of deaths increased by 1.0027 fold. These results differed depending on the period or season. There was a 5-day lag effect between PM2.5 and deaths in the multi exposure model, and 1.0028 fold when adjusted for ozone. There was a 1-day lag effect in single exposure models with ozone as the main variable, and 1.0027 fold increase in deaths. CONCLUSION: In our study, an increase in the number of deaths in the elderly population in accordance with the increase in the PM2.5 and ozone was found. The association found in our study could also influence socioeconomic burden. Future studies need to be performed in regards to younger population, as well as other air pollutants.

The effect of pre-existing medical conditions on heat stroke during hot weather in South Korea.

BACKGROUND: Heat stroke contributes considerably to morbidity and mortality in hot weather, but it is unclear whether pre-existing medical conditions increase the risk of heat stroke. The purpose of this study was to assess the association between heat stroke and pre-existing medical conditions in South Korea. METHODS: A case-control study was conducted using data from a nationwide surveillance system for heat illnesses in 2012. Individuals with heat stroke were identified and compared to control subjects with mild heat illness such as heat exhaustion, heat edema, heat cramps, and heat syncope. Categories of pre-existing medical conditions included cardio/cerebrovascular disease, respiratory disease, neuropsychiatric disorder, and diabetes mellitus. Associations between heat stroke and pre-existing medical conditions were assessed by multivariate logistic regression analyses. RESULTS: Of 968 eligible patients, 178 (18.4%) presented with heat stroke. Patients with pre-existing medical conditions were relatively greater in the heat stroke group than in the control group (40.4% and 23.9%, respectively). Neuropsychiatric disorder was associated with an increased odds of heat stroke after adjustment for covariates (adjusted odds ratio, 7.69; 95% CI, 4.06-14.54). There were no significant relationships between heat stroke and other medical conditions (cardio/cerebrovascular disease: 0.66, 0.40-1.06; respiratory disease: 1.44, 0.35-5.89; diabetes mellitus: 1.16, 0.58-2.34). CONCLUSIONS: Pre-existing neuropsychiatric disorder was associated with an increased risk of heat stroke. National strategies and clinical guidance for such patients should be initiated to prevent fatal events.

Effect of human epidermal growth factor receptor 2 overexpression in metastatic colorectal cancer on standard chemotherapy outcomes.

Background: In metastatic colorectal cancer (mCRC), the prognostic relevance of the human epidermal growth factor receptor-2 (HER2) remains controversial. We evaluated the impact of HER2 overexpression on outcomes of standard chemotherapy in patients with mCRC. Methods: This retrospective study included patients with mCRC who received standard chemotherapy for mCRC and were tested for HER2 expression at Samsung Medical Center, Seoul, Korea, between January 15, 2017, and February 05, 2022. The HER2 test was performed using immunohistochemistry. We assessed the objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) according to HER2 status. All statistical analyses were performed using SPSS® version 25 (IBM, Armonk, NY, USA). Results: In total, 108 patients were included; 10 (9.3%) had HER2-positive tumors. The ORR for patients with mCRC receiving standard chemotherapy did not differ for HER2-positive and HER2-negative tumors. The median PFS for patients with mCRC with HER2-positive or HER2-tumors after receiving first-line chemotherapy was 18.52 months [95% confidence interval (CI): 4.355-32.695] or 10.95 months (95% CI: 9.317-12.585; P=0.417), respectively, and that after second-line chemotherapy was 7.08 months (95% CI: 6.801-7.363) or 5.34 months (95% CI: 4.433-6.255; P=0.837), respectively. Likewise, OS did not differ according to HER2 expression (median OS: HER2-positive tumors, 49.1 months (95% CI: 0.000-98.365); HER2-negative tumors, 37.7 months (95% CI: 27.111-48.366; P=0.410). Conclusions: The tumor response and survival of patients with mCRC after standard chemotherapy did not differ by HER2 expression. These findings suggest that the status of HER2 expression need not be considered when choosing regimens as the current first- and second-line treatments.

The Optimal Tumor Mutational Burden Cutoff Value as a Novel Marker for Predicting the Efficacy of Programmed Cell Death-1 Checkpoint Inhibitors in Advanced Gastric Cancer.

PURPOSE: The optimal tumor mutational burden (TMB) value for predicting treatment response to programmed cell death-1 (PD-1) checkpoint inhibitors in advanced gastric cancer (AGC) remains unclear. We aimed to investigate the optimal TMB cutoff value that could predict the efficacy of PD-1 checkpoint inhibitors in AGC. MATERIALS AND METHODS: Patients with AGC who received pembrolizumab or nivolumab between October 1, 2020, and July 27, 2021, at Samsung Medical Center in Korea were retrospectively analyzed. The TMB levels were measured using a next-generation sequencing assay. Based on receiver operating characteristic curve analysis, the TMB cutoff value was determined. RESULTS: A total 53 patients were analyzed. The TMB cutoff value for predicting the overall response rate (ORR) to PD-1 checkpoint inhibitors was defined as 13.31 mutations per megabase (mt/Mb) with 56% sensitivity and 95% specificity. Based on this definition, 7 (13.2%) patients were TMB-high (TMB-H). The ORR differed between the TMB-low (TMB-L) and TMB-H (8.7% vs. 71.4%, P=0.001). The progression-free survival and overall survival (OS) for 53 patients were 1.93 (95% confidence interval [CI], 1.600-2.268) and 4.26 months (95% CI, 2.992-5.532). The median OS was longer in the TMB-H (20.8 months; 95% CI, 2.292-39.281) than in the TMB-L (3.31 months; 95% CI, 1.604-5.019; P=0.049). CONCLUSIONS: The TMB cutoff value for predicting treatment response in AGC patients who received PD-1 checkpoint inhibitor monotherapy as salvage treatment was 13.31 mt/Mb. When applying the programmed death ligand-1 status to TMB-H, patients who would benefit from PD-1 checkpoint inhibitors can be selected.

Age-dependent resistance of a perennial herb, Aristolochia contorta against specialist and generalist leaf-chewing herbivores.

Plants need to balance investments in growth and defense throughout their life to increase their fitness. To optimize fitness, levels of defense against herbivores in perennial plants may vary according to plant age and season. However, secondary plant metabolites often have a detrimental effect on generalist herbivores, while many specialists have developed resistance to them. Therefore, varying levels of defensive secondary metabolites depending on plant age and season may have different effects on the performance of specialist and generalist herbivores colonizing the same host plants. In this study, we analyzed concentrations of defensive secondary metabolites (aristolochic acids) and the nutritional value (C/N ratios) of 1st-, 2nd- and 3rd-year Aristolochia contorta in July (the middle of growing season) and September (the end of growing season). We further assessed their effects on the performances of the specialist herbivore Sericinus montela (Lepidoptera: Papilionidae) and the generalist herbivore Spodoptera exigua (Lepidoptera: Noctuidae). Leaves of 1st-year A. contorta contained significantly higher concentrations of aristolochic acids than those of older plants, with concentrations tending to decrease over the first-year season. Therefore, when first year leaves were fed in July, all larvae of S. exigua died and S. montela showed the lowest growth rate compared to older leaves fed in July. However, the nutritional quality of A. contorta leaves was lower in September than July irrespective of plant age, which was reflected in lower larval performance of both herbivores in September. These results suggest that A. contorta invests in the chemical defenses of leaves especially at a young age, while the low nutritional value of leaves seems to limit the performance of leaf-chewing herbivores at the end of the season, regardless of plant age.

The efficacy of immune checkpoint inhibitors in biliary tract cancer with KRAS mutation.

Background: With a 15% incidence, KRAS is one of the most common mutations in biliary tract cancer (BTC) and is a poor prognostic factor. Immune checkpoint inhibitors (ICIs) as salvage therapy have modest activity in BTC. Objectives: There are limited data on the efficacy of ICIs according to KRAS mutation in BTC. We evaluated the efficacy of ICIs in BTC patients with or without KRAS mutations. Design: Retrospective observational study. Methods: We conducted molecular profiling in BTC patients who received ICIs as salvage therapy. The expression of programmed death ligand 1 (PD-L1) on tumor cells was assessed using immunohistochemistry. The TruSightTM Oncology 500 assay from Illumina was used as a cancer panel. We analyzed overall survival (OS) and progression-free survival (PFS) of ICI in BTC patients according to KRAS mutation and PD-L1 expression. Results: A total of 62 patients were included in this analysis. The median age was 68.0 years; 47 patients (75.8%) received pembrolizumab and 15 (24.2%) received nivolumab as salvage therapy. All patients received gemcitabine plus cisplatin as the frontline therapy, and 53.2% received fluoropyrimidine plus oxaliplatin (FOLFOX) before ICI. The median number of lines of prior chemotherapy was 2.5. The KRAS mutation was found in 13 patients (19.1%), and 28 patients (45.2%) showed 1% or more of tumor cells out of visible tumor cells positive for PD-L1. There was no statistical correlation between KRAS mutation and PD-L1 expression. The median OS and PFS with ICI were 5.6 [interquartile range (IQR): 3.3-8.0] and 3.8 (IQR: 3.0-4.5) months, respectively. There were no statistically significant differences in PFS with ICIs according to KRAS mutation (mutant type versus wild type) and PD-L1 expression (positive versus negative). In subgroup analysis, patients with both KRAS mutation and PD-L1 positivity had longer PFS compared with patients with KRAS mutation and PD-L1 negativity (10.1 versus 2.6 months, p = 0.047). This finding was not shown in patients with wild-type KRAS. Conclusion: Our analysis suggested that PD-L1 expression might be a useful biomarker for ICIs in BTC patients with KRAS mutation but not in those with wild-type KRAS.

The role of ramucirumab plus paclitaxel as second-line therapy after failure of nivolumab plus doublet chemotherapy in patients with advanced gastric cancer.

Background: Adding nivolumab to fluoropyrimidines and platinum agents has been considered a new standard first-line treatment in previously untreated human epidermal growth factor receptor 2 (HER2)-negative advanced gastric cancer (AGC). However, there were few data on the role of ramucirumab plus paclitaxel as second-line treatment after failure of nivolumab plus doublet chemotherapy. Herein, we analyzed the efficacy and safety of second-line ramucirumab plus paclitaxel in AGC patients refractory to nivolumab plus chemotherapy. Methods: This analysis included AGC patients with ramucirumab plus paclitaxel as second-line therapy after failing to respond to nivolumab plus doublet chemotherapy [capecitabine plus oxaliplatin (XELOX) or 5-fluorouracil plus oxaliplatin (FOLFOX)] at Samsung Medical Center, Korea. Twenty patients who progressed on nivolumab plus chemotherapy as first-line therapy were treated with ramucirumab plus paclitaxel between December 2021 and September 2022. Results: The median age was 56 (range, 24-76) years, and 13 (65.0%) were men. Of the 20 patients, 15 (75.0%) patients received nivolumab plus capecitabine, and oxaliplatin, while 5 (25.0%) patients received nivolumab plus 5-fluorouracil, and oxaliplatin. Two showed a partial response (PR) to ramucirumab plus paclitaxel, a response rate of 10%. Patients with stable disease (SD) accounted for a disease control rate (DCR) of 55.0%. The median progression-free survival (PFS) to ramucirumab plus paclitaxel was 2.7 months [95% confidence interval (CI): 1.7-3.7]. Subgroup analysis showed that responders (n=7) to first-line therapy had a PFS of 6.9 months compared to 2.3 months in non-responders (n=13) to first-line therapy. The median overall survival (OS) was 6.3 months (95% CI: 5.5-8.3), representing 6.9 months (95% CI: not calculated) in responders and 6.3 months (95% CI: 3.7-8.9) in non-responders (P=0.401). Conclusions: This analysis suggested that ramucirumab plus paclitaxel as second-line therapy might be further studied in AGC patients after failure of nivolumab plus chemotherapy. A new second-line therapy is needed in AGC patients after nivolumab plus chemotherapy.

Effect of ramucirumab plus paclitaxel in advanced gastric cancer according to the status of programmed cell death-ligand 1 (PD-L1) expression.

Background: Ramucirumab, an anti-vascular endothelial growth factor receptor (VEGFR) monoclonal antibody (mAb), inhibits angiogenesis and reduces tumor activity. Programmed cell death-ligand 1 (PD-L1) might act upon VEGFR2 to induce cancer cell angiogenesis and metastasis. Herein, we investigated the efficacy of combining ramucirumab and paclitaxel according to the status of PD-L1 expression in patients with advanced gastric cancer (AGC). Methods: This analysis included AGC patients who received ramucirumab plus paclitaxel as 2nd line therapy between December 1, 2018, and February 28, 2022, at Samsung Medical Center. All patient data analyses included an evaluation of PD-L1 expression using the combined positive score (CPS). We analyzed the efficacy and the survival of patients according to their PD-L1 expression. Results: We included 117 patients in this analysis, and 80 patients (68.4%) had a PD-L1 CPS of one or more, 37 (31.6%) had five or more, and 19 (16.2%) had ten or more scores. Progression-free survival (PFS) and overall survival (OS) did not differ significantly between patients with a PD-L1 CPS of less than one and one or more {PD-L1 <1% vs. PD-L1 ≥1%; PFS: median 3.6 months [95% confidence interval (CI): 2.4-4.8 months] vs. median 4.1 months (95% CI: 3.5-4.7 months), P=0.93; PD-L1 <1% vs. PD-L1 ≥1%; OS: median 7.0 months (95% CI: 5.4-8.6 months) vs. median 8.1 months (95% CI: 6.4-9.8 months), P=0.32}. PFS and OS did not differ significantly between patients with a PD-L1 CPS of less than 5 and 5 or more [PD-L1 <5% vs. PD-L1 ≥5%; PFS: 3.9 months (95% CI: 3.3-4.5 months) vs. 4.4 months (95% CI: 3.0-5.8 months), P=0.57; OS: 7.4 months (95% CI: 6.5-8.3 months) vs. 10.0 months (95% CI: 1.1-18.9 months), P=0.07]. Interestingly, with a PD-L1 CPS cutoff of 10, PFS and OS did differ significantly [PD-L1 <10% vs. PD-L1 ≥10%; PFS: 3.8 months (95% CI: 3.3-4.3 months) vs. 5.7 months (95% CI: 4.1-7.3 months), P=0.05; OS: 7.2 months (95% CI: 6.5-7.9 months) vs. 18.9 months (95% CI: 6.5-31.3 months), P=0.04]. Conclusions: No biomarkers have been established to predict survival times after ramucirumab plus paclitaxel treatment. This analysis suggests that a PD-L1 CPS cutoff of 10 might be novel a biomarker to predict the survival of AGC patients treated with ramucirumab and paclitaxel.

Localization of Aggregatibacter actinomycetemcomitans cytolethal distending toxin subunits during intoxication of live cells.

The cytolethal distending toxin (Cdt), produced by some clinically important Gram-negative bacterial species, is related to the family of AB-type toxins. Three heterologous proteins (CdtA, CdtB, and CdtC) and a genotoxin mode of action distinguish the Cdt from others in this toxin class. Crystal structures of several species-specific Cdts have provided a basis for predicting subunit interactions and functions. In addition, empirical studies have yielded significant insights into the in vivo interactions of the Cdt subunits. However, there are still critical gaps in information about the intoxication process. In this study, a novel protein tagging technology was used to localize the subunits in Chinese hamster ovary cells (CHO-K1). A tetracysteine motif was engineered in each subunit, and in subunits with mutations in predicted functional domains, to permit detection with the fluorescein arsenical hairpin binding (FlAsH) dye Lumio green. Live-cell imaging, in conjunction with confocal microscopy, was used to capture the locations of the individual subunits in cells intoxicated, under various conditions, with hybrid heterotrimers. Using this approach, we observed the following. (i) The CdtA subunit remains on the cell surface of CHO cells in association with cholesterol-containing and cholesterol-depleted membrane. (ii) The CdtB subunit is exclusively in the cytosol and, after longer exposure times, localizes to the nucleus. (iii) The CdtC subunit is present on the cell surface and, to a greater extent, in the cytosol. These observations suggest that CdtC, but not CdtA, functions as a chaperone for CdtB entry into cells.

Identification of the robust predictor for sepsis based on clustering analysis.

Sepsis is a life-threatening disorder with high incidence and mortality rate. However, the early detection of sepsis is challenging due to lack of specific marker and various etiology. This study aimed to identify robust risk factors for sepsis via cluster analysis. The integrative task of the automatic platform (i.e., electronic medical record) and the expert domain was performed to compile clinical and medical information for 2,490 sepsis patients and 16,916 health check-up participants. The subjects were categorized into 3 and 4 groups based on seven clinical and laboratory markers (Age, WBC, NLR, Hb, PLT, DNI, and MPXI) by K-means clustering. Logistic regression model was performed for all subjects including healthy control and sepsis patients, and cluster-specific cases, separately, to identify sepsis-related features. White blood cell (WBC), well-known parameter for sepsis, exhibited the insignificant association with the sepsis status in old age clusters (K3C3 and K4C3). Besides, NLR and DNI were the robust predictors in all subjects as well as three or four cluster-specific subjects including K3C3 or K4C3. We implemented the cluster-analysis for real-world hospital data to identify the robust predictors for sepsis, which could contribute to screen likely overlooked and potential sepsis patients (e.g., sepsis patients without WBC count elevation).

Causes of death and demographic characteristics of victims of meteorological disasters in Korea from 1990 to 2008.

BACKGROUND: Meteorological disasters are an important component when considering climate change issues that impact morbidity and mortality rates. However, there are few epidemiological studies assessing the causes and characteristics of deaths from meteorological disasters. The present study aimed to analyze the causes of death associated with meteorological disasters in Korea, as well as demographic and geographic vulnerabilities and their changing trends, to establish effective measures for the adaptation to meteorological disasters. METHODS: Deaths associated with meteorological disasters were examined from 2,045 cases in Victim Survey Reports prepared by 16 local governments from 1990 to 2008. Specific causes of death were categorized as drowning, structural collapse, electrocution, lightning, fall, collision, landslide, avalanche, deterioration of disease by disaster, and others. Death rates were analyzed according to the meteorological type, specific causes of death, and demographic and geographic characteristics. RESULTS: Drowning (60.3%) caused the greatest number of deaths in total, followed by landslide (19.7%) and structural collapse (10.1%). However, the causes of deaths differed between disaster types. The meteorological disaster associated with the greatest number of deaths has changed from flood to typhoon. Factors that raised vulnerability included living in coastal provinces (11.3 times higher than inland metropolitan), male gender (1.9 times higher than female), and older age. CONCLUSIONS: Epidemiological analyses of the causes of death and vulnerability associated with meteorological disasters can provide the necessary information for establishing future adaptation measures against climate change. A more comprehensive system for assessing disaster epidemiology needs to be established.

Impact of meteorological variation on hospital visits of patients with tree pollen allergy.

BACKGROUND: Climate change could affect allergic diseases, especially due to pollen. However, there has been no epidemiologic study to demonstrate the relationship between meteorological factors, pollen, and allergic patients. We aimed to investigate the association between meteorological variations and hospital visits of patients with tree pollen allergy. METHODS: The study subjects were adult patients who received skin prick tests between April and July from 1999 to 2008. We reviewed the medical records for the test results of 4,715 patients. Patients with tree pollen allergy were defined as those sensitized to more than 1 of 12 tree pollen allergens. We used monthly means of airborne tree pollen counts and meteorological factors: maximum/average/minimum temperature, relative humidity, and precipitation. We analyzed the correlations between meteorological variations, tree pollen counts, and the patient numbers. Multivariable logistic regression analyses were used to investigate the associations between meteorological factors and hospital visits of patients. RESULTS: The minimum temperature in March was significantly and positively correlated with tree pollen counts in March/April and patient numbers from April through July. Pollen counts in March/April were also correlated with patient numbers from April through July. After adjusting for confounders, including air pollutants, there was a positive association between the minimum temperature in March and hospital visits of patients with tree pollen allergy from April to July(odds ratio, 1.14; 95% CI 1.03 to 1.25). CONCLUSIONS: Higher temperatures could increase tree pollen counts, affecting the symptoms of patients with tree pollen allergy, thereby increasing the number of patients visiting hospitals.

Incidences of Waterborne and Foodborne Diseases After Meteorologic Disasters in South Korea.

BACKGROUND: Climate change could increase the number of regions affected by meteorologic disasters. Meteorologic disasters can increase the risk of infectious disease outbreaks, including waterborne and foodborne diseases. Although many outbreaks of waterborne diseases after single disasters have been analyzed, there have not been sufficient studies reporting comprehensive analyses of cases occurring during long-term surveillance after multiple disasters, which could provide evidence of whether meteorologic disasters cause infectious disease outbreaks. OBJECTIVES: This study aimed to assess the nationwide short-term changes in waterborne and foodborne disease incidences after a meteorologic disaster. METHODS: We analyzed cases after all 65 floods and typhoons between 2001 and 2009 using the Korean National Emergency Management Agency's reports. Based on these data, we compared the weekly incidences of Vibrio vulnificus septicemia (VVS), shigellosis, typhoid fever, and paratyphoid fever before, during, and after the disasters, using multivariate Poisson regression models. We also analyzed the interactions between disaster characteristics and the relative risk of each disease. FINDINGS: Compared with predisaster incidences, the incidences of VVS and shigellosis were 2.49-fold (95% confidence interval, 1.47-4.22) and 3.10-fold (95% confidence interval, 1.21-7.92) higher, respectively, the second week after the disaster. The incidences of VVS and shigellosis peaked the second week postdisaster and subsequently decreased. The risks of typhoid and paratyphoid fever did not significantly increase throughout the 4 weeks postdisaster. The daily average precipitation interacted with VVS and shigellosis incidences, whereas disaster type only interacted with VVS incidence patterns. CONCLUSIONS: The incidences of VVS and shigellosis were associated with meteorologic disasters, and disaster characteristics were associated with the disease incidence patterns postdisaster. These findings provide important comprehensive evidence to develop and support policies for managing and protecting public health after meteorologic disasters.

Dependency on Smartphone Use and Its Association with Anxiety in Korea.

OBJECTIVE: South Korea has the highest rate of smartphone ownership worldwide, which is a potential concern given that smartphone dependency may have deleterious effects on health. We investigated the relationship between smartphone dependency and anxiety. METHODS: Participants included 1,236 smartphone-using students (725 men and 511 women) from six universities in Suwon, South Korea. Participants completed measures of smartphone use, smartphone dependency, anxiety, and general characteristics (i.e., demographic, health-related, and socioeconomic characteristics). To measure smartphone dependency and anxiety, we used questionnaires of Yang's test developed from Young's Internet Addiction Test and Zung's Self-Rating Anxiety Scale. We used multiple logistic regression to determine the association between smartphone dependency and anxiety after adjusting for relevant factors. RESULTS: On a scale from 25 to 100, with higher scores on the smartphone dependency test indicating greater dependency, women were significantly more dependent on smartphones than were men (mean smartphone dependency score: 50.7 vs. 56.0 for men and women, respectively, p<0.001). However, the amount of time spent using smartphones and the purpose of smartphone use affected smartphone dependency in both men and women. Particularly, when daily use time increased, smartphone dependency showed an increasing trend. Compared with times of use <2 hours vs. ≥6 hours, men scored 46.2 and 56.0 on the smartphone dependency test, while women scored 48.0 and 60.4, respectively (p<0.001). Finally, for both men and women, increases in smartphone dependency were associated with increased anxiety scores. With each one-point increase in smartphone dependency score, the risk of abnormal anxiety in men and women increased by 10.1% and 9.2%, respectively (p<0.001). CONCLUSION: Among this group of university students in South Korea, smartphone dependency appeared to be associated with increased anxiety. Standards for smartphone use might help prevent deleterious health effects.

Psychological Distress in Young Adult Males with Atopic Dermatitis: A Cross-Sectional Study.

The relationship between atopic dermatitis (AD) and psychological distress has been well established for children and adolescents. However, it is unclear whether this relationship exists in young adults. This study aimed to assess the relationship between AD and psychological distress in young male adults in South Korea. A cross-sectional study was conducted using regional conscription data from 2008 to 2012. A dermatologist diagnosed AD based on historical and clinical features, and determined severity using the eczema area and severity index. A psychiatrist used medical records, an interview, and a psychological test to examine psychological distress (depression, anxiety, and somatization). The relationship between psychological distress and AD was assessed by multivariate logistic regression analyses. Among the 120,508 conscripts, 1517 (1.2%) presented with AD. The odds of having each type of psychological distress were significantly greater for individuals with AD compared with those without AD. The adjusted odds ratios for depression, anxiety, and somatization were 1.79 (95% CI 1.40-2.29), 1.38 (95% CI 1.08-1.76), and 1.75 (95% CI 1.40-2.20), respectively. Moderate-to-severe AD was significantly related to depression and somatization to a greater extent compared with mild AD. Depression, anxiety, and somatization are strongly and independently associated with AD in young adult males. Early treatment of skin inflammation might modify the risk of psychiatric problems. Prospective cohort studies are needed to verify causal relationships.

Sources of polycyclic aromatic hydrocarbon exposure in non-occupationally exposed Koreans.

Urinary 1-hydroxypyrene (1-OHP), an exposure biomarker for polycyclic aromatic hydrocarbons (PAHs), was used to identify potential sources of PAH exposure for 660 Koreans who were not occupationally exposed to PAHs (65% male; 35% female; mean age, 36.5 +/- 11.1 years). In this study, 74% of subjects had detectable levels of urinary 1-OHP, with a concentration range of 0.001-3.796 microg/L (median, 0.079 microg/L). A backward elimination was conducted: five variables were selected with a significance level for removal of P < or = 0.1. The results of this study showed that residence in areas with relatively poor environmental conditions (Seoul and Suwon) was strongly associated with high concentrations of urinary 1-OHP (P = 0.007), while consumption of fried chicken and length of time spent outdoors had marginal positive associations with urinary 1-OHP levels (P = 0.06 and P = 0.09, respectively). Compared with the above three factors, tobacco smoking and urinary cotinine levels were poorly associated with urinary 1-OHP (P = 0.16 and 0.23, respectively). Pear consumption had an inverse association with urinary 1-OHP levels (P < 0.01). Individual variations in urinary 1-OHP concentrations were evaluated by considering the subjects' age, sex, and genetic polymorphisms in enzymes involved in the metabolism of PAHs. Among the individual variations, GSTT1-present subjects showed higher 1-OHP levels than GSTT1-absent subjects in cities having 10-microm particulate matter (PM(10)) levels and population density lower than those of Seoul and Suwon (P < 0.05). These epidemiological results suggest that the above factors that should be considered in preventing PAH exposure.

Influence of GSTM1 genotype on association between aromatic DNA adducts and urinary PAH metabolites in incineration workers.

Waste incinerating workers are exposed to various pyrolysis products including polycyclic aromatic hydrocarbons (PAHs). We examined their PAH exposure by assessing urinary 1-hydroxypyrene glucuronide (1-OHPG), as a measure of internal dose, and aromatic DNA adducts in peripheral white blood cells (WBCs), as a measure of biological effect dose. The potential effect of genetic polymorphisms of three enzymes involved in PAH metabolisms (i.e., CYP1A1, GSTM1, and GSTT1) on these exposure markers was also investigated.Twenty-nine employees including workers incinerating industrial wastes and 21 non-exposed on-site controls were recruited from a company handling industrial wastes in South Korea. Sixteen ambient PAHs were determined by GC/MSD (NIOSH method) from personal breathing zone samples of nine subjects working near incinerators. Urinary 1-OHPG was assayed by synchronous fluorescence spectroscopy (SFS) after immunoaffinity purification using monoclonal antibody 8E11. Aromatic DNA adducts in peripheral WBC were measured by the nuclease P1-enhanced post-labelling assay. Genotypes were assessed by PCR-based methods. Information on smoking habits and use of personal protective equipment were collected by self-administered questionnaire. Urinary 1-OHPG levels were significantly higher in workers handling industrial wastes than in those with presumed lower exposure to PAHs (P=0.006, by Kruskal-Wallis test). A statistically significant dose-response increase in 1-OHPG levels was seen with the number of cigarettes consumed per day (r=0.686, P<0.001). Smoking and GSTM1 genotype were significant predictors for log-transformed 1-OHPG by multiple regression analysis (overall model R(2)=0.565, P<0.001), whereas smoking was the only significant predictor for log-transformed aromatic DNA adducts (overall model R(2)=0.249, P=0.201). Aromatic DNA adducts were significantly correlated with log-transformed urinary 1-OHPG level (r=0.31, P=0.04). However, the partial correlation coefficient adjusting for age, sex, and cigarette consumption was not significant (r=0.15, P=0.17). The significant association exists only in individuals with the GSTM1 null genotype (Pearson's correlation coefficient, r=0.52, P=0.01; partial correlation coefficient adjusting for age, sex, and cigarette consumption, r=0.36, P=0.04). Our results suggest that the significant increase in urinary 1-OHPG in the exposed workers is due to higher prevalence of smokers among them, and that the association between urinary PAH metabolites and aromatic DNA adducts in workers of industrial waste handling may be modulated by GSTM1 genotype. These results remain to be confirmed in future larger studies.

Health survey on workers and residents near the municipal waste and industrial waste incinerators in Korea.

Hazardous substances, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) also have been detected in Municipal Solid Waste (MSW) and industrial waste incinerators in Korea. In this study, we estimated the exposure status of these hazardous substances and their heath effects in workers and residents near the MSW incinerators and residents near the industrial waste incinerators. We interviewed 13 workers and 16 residents from the area around the two MSW incinerators, and further 10 residents from the area around one industrial waste incinerator, which is suspected to emit higher hazardous substances. During the interview we collected information including sociodemographic information, personal habits, work history, detailed gynecologic and other medical history. Blood samples from 45 subjects were also collected for analysis of PCDDs and PCDFs, which were analyzed by HRGC-HRMS (High Resolution Gas Chromatography-High Resolution Mass Spectrometer). In addition to a questionnaire survey, urinary concentrations of 8-hydroxydeoxyguanosine (8-OH-dG) and malondialdehyde (MDA) were measured as oxidative injury biomarkers. Urinary concentrations of 8-OH-dG were determined by in vitro ELISA (JAICA, Fukuroi, Japan). MDA were determined by HPLC using adduct with TBA (thiobarbituric acid). The PCDD/F concentrations in residents from the area around industrial waste incinerator were higher than those in workers and residents from the area around MSW incinerator. The average toxic equivalency (TEQ) concentrations of PCDD/Fs in residents from the area around industrial waste incinerator were 53.4 pg I-TEQs/g lipid. The average TEQ concentrations of PCDD/Fs in workers and residents near MSW incinerator were 12.2 pg I-TEQs/g lipid. Estimated daily intake (EDI) of each person was calculated, and the EDI of all workers and residents near MSW incinerator were within the tolerable daily intake range. But for only 30% of 10 people near the industrial waste incinerator were the EDI within the tolerable daily intake range (1-4 pg I-TEQ/kg bw/day) suggested by WHO (1997). The oxidative stress of residents near the industrial waste incinerator was higher than that in workers and residents from the area around MSW incinerator. This oxidative stress may have been caused by hazardous substances, such as PCDD/Fs emitted by incinerators. The residents from the area around industrial waste incinerator were exposed to hazardous substances such as PCDD/ Fs. Proper protection strategies against these hazardous chemicals are needed.