Purpose: To evaluate the test-retest reliability of a contour-based stereoacuity test using a head-mounted display (HMD) and compare it with other stereotests. Methods: Thirty-two healthy adults aged 23-47 years were recruited from a tertiary hospital between August 2017 and July 2018. Two separate contour-based circles (crossed disparity: 135-1,350 arcsecs) were generated on a high-resolution phone display (Galaxy S7; Samsung, Seoul, Korea) using an HMD (Galaxy Gear VR). Two images were independently projected to each eye as graded circles with a random dot background. The results of the new HMD stereotest were compared to those of the standard Randot and TNO stereotests. The test-retest reliability was assessed using the Bland-Altman plot and Cohen’s kappa statistics. Results: Among the 32 study participants, 17 (53%) were males and the mean age was 30.1 ± 4.8 years (range: 23-47). The mean stereoacuity was 160.3 ± 53.5 arcsecs in the first HMD stereotest (HMD1), 28.4 ± 12.5 arcsecs in the Randot stereotest, 96.1 ± 83.5 arcsecs in the TNO stereotest, and 143.3 ± 47.7 arcsecs in the second HMD stereotest (HMD2). The Bland-Altman plot showed a mean difference of 0.042 (-0.189 to +0.272, 95% limits of agreement) between HMD1 and HMD2. The reliability analysis showed an intraclass correlation coefficient of 0.499 (p = 0.022) and agreement of 81.25% in Cohen’s kappa statistics (Cohen’s kappa index = 0.119, p = 0.017). Conclusions The HMD stereotest without monocular cues showed fair test-retest reliability and reproducibility. Further studies using a high resolution display are needed to confirm the validity of the HMD stereotest.

Purpose: This study aimed to investigate the perceptions and behaviors of Korean women of reproductive age in regards to contraception counseling. Materials and Methods: The study sample was collected in Korea and comprised 1011 women aged 20–44 years and 150 obstetrics and gynecology (OB/GYN) doctors. Participants completed online questionnaires assessing their current methods of contraception, knowledge of and satisfaction with contraceptive methods, and willingness to learn about and use other contraceptive methods. Results: Women used condoms (74.2%), natural methods (cycle control or withdrawal, 52.4%), and combined oral contraceptives (COCs) (36.9%) more frequently than long-acting reversible contraception (LARC) methods, such as hormone-releasing intrauterine system (IUS) (4.5%), copper-intrauterine devices (3.3%), and subdermal implants (1.4%). Although the proportion of women who used LARC was low, those who used hormone-releasing IUS or subdermal implants reported high levels of satisfaction. The findings revealed discordant results between women and OB/GYN doctors regarding the initiation and quality of information provided by doctors about contraception and overall satisfaction with counseling. Most women (83.1%) expressed a desire to have more information about various contraceptive methods. More than 60% of women reported a willingness to use LARC, such as hormone-releasing IUS or subdermal implants, when provided with detailed information in counseling. Conclusion The majority of Korean women are familiar with condoms and natural methods, but lack knowledge about alternative contraceptive methods, including LARC. Women who used LARC reported higher levels of satisfaction than those who used other methods.

Purpose: This study aimed to investigate the perceptions and behaviors of Korean women of reproductive age in regards to contraception counseling. Materials and Methods: The study sample was collected in Korea and comprised 1011 women aged 20–44 years and 150 obstetrics and gynecology (OB/GYN) doctors. Participants completed online questionnaires assessing their current methods of contraception, knowledge of and satisfaction with contraceptive methods, and willingness to learn about and use other contraceptive methods. Results: Women used condoms (74.2%), natural methods (cycle control or withdrawal, 52.4%), and combined oral contraceptives (COCs) (36.9%) more frequently than long-acting reversible contraception (LARC) methods, such as hormone-releasing intrauterine system (IUS) (4.5%), copper-intrauterine devices (3.3%), and subdermal implants (1.4%). Although the proportion of women who used LARC was low, those who used hormone-releasing IUS or subdermal implants reported high levels of satisfaction. The findings revealed discordant results between women and OB/GYN doctors regarding the initiation and quality of information provided by doctors about contraception and overall satisfaction with counseling. Most women (83.1%) expressed a desire to have more information about various contraceptive methods. More than 60% of women reported a willingness to use LARC, such as hormone-releasing IUS or subdermal implants, when provided with detailed information in counseling. Conclusion The majority of Korean women are familiar with condoms and natural methods, but lack knowledge about alternative contraceptive methods, including LARC. Women who used LARC reported higher levels of satisfaction than those who used other methods.

Objective: This study aimed to determine the serum Dickkopf 1 (DKK1) levels in ankylosing spondylitis (AS) patients and decipher the mechanism of tumor necrosis factor (TNF)-mediated DKK1 regulation in human AS enthesis cells. Methods: The sera were obtained from 103 patients with AS and 30 healthy controls (HCs). The enthesis of facet joints were obtained from 4 AS patients and 5 controls. The serum levels of DKK1 were measured using ELISA and compared between AS and HCs. The impact of TNF on DKK1 expression in human primary spinal enthesis cells was evaluated using various molecular biology techniques and bone formation indicators. Results: AS patients showed higher serum DKK1 levels than HCs after adjusting for age (917.4 [615.3∼1,310.0] pg/mL vs. 826.2 [670.3∼927.8] pg/mL, p=0.043). TNF treatment promoted bone formation and DKK1 expression in both control enthesis cells and those of AS. This enhanced bone formation by TNF was pronounced in AS-enthesis than those of controls. Mechanically, TNF induced NF-κB activation upregulates the DKK1 transcript level. While, NF-κB inhibitor led to downregulate DKK1 expression in the enthesis. Besides, DKK1 overexpression promoted bone formation in enthesis. Conclusion TNF induced DKK1 expression in the enthesis through NF-κB activation. TNF-induced DKK1 expression may play a bone formation in the radiologic progression of ankylosing spondylitis.

Objective: This study aimed to determine the serum Dickkopf 1 (DKK1) levels in ankylosing spondylitis (AS) patients and decipher the mechanism of tumor necrosis factor (TNF)-mediated DKK1 regulation in human AS enthesis cells. Methods: The sera were obtained from 103 patients with AS and 30 healthy controls (HCs). The enthesis of facet joints were obtained from 4 AS patients and 5 controls. The serum levels of DKK1 were measured using ELISA and compared between AS and HCs. The impact of TNF on DKK1 expression in human primary spinal enthesis cells was evaluated using various molecular biology techniques and bone formation indicators. Results: AS patients showed higher serum DKK1 levels than HCs after adjusting for age (917.4 [615.3∼1,310.0] pg/mL vs. 826.2 [670.3∼927.8] pg/mL, p=0.043). TNF treatment promoted bone formation and DKK1 expression in both control enthesis cells and those of AS. This enhanced bone formation by TNF was pronounced in AS-enthesis than those of controls. Mechanically, TNF induced NF-κB activation upregulates the DKK1 transcript level. While, NF-κB inhibitor led to downregulate DKK1 expression in the enthesis. Besides, DKK1 overexpression promoted bone formation in enthesis. Conclusion TNF induced DKK1 expression in the enthesis through NF-κB activation. TNF-induced DKK1 expression may play a bone formation in the radiologic progression of ankylosing spondylitis.

Cadmium ; Electronic Cigarettes ; Female ; Humans ; Korea ; Male ; Nutrition Surveys ; Odds Ratio ; Smoke ; Smoking ; Tobacco ; Tobacco Products

PURPOSE: To investigate ocular fatigue after the use of a head-mounted display (HMD)-type virtual reality device.METHODS: Healthy adult volunteers were examined for ocular fatigue before and after watching videos for 10 min with an HMD-type virtual reality device. Subjective ocular fatigue was measured using a questionnaire. Objective fatigue was measured using the critical flicker fusion frequency (CFF), high frequency component of accommodative microfluctuation, and accommodation amplitude. The accommodation amplitude was measured using the push-up method and the dynamic measurement mode of the autorefractometer. Changes in the spherical equivalent were also measured.RESULTS: The questionnaire-based subjective ocular fatigue increased (p = 0.020) after use of the HMD device. In the dominant eye, the high frequency component of accommodative microfluctuation increased (p < 0.05). The accommodation amplitude using the push-up method was decreased in the nondominant eye (p = 0.007), and temporary myopia was observed (p < 0.05). However, there was no increase in ocular fatigue in the CFF or the accommodation amplitude using the dynamic measurement mode, which showed no significant difference before and after using the HMD device (p > 0.05).CONCLUSIONS: A subjective test and some objective tests suggested that use of the HMD-type virtual reality display increased ocular fatigue. However, no increase in ocular fatigue was measured using CFF nor in the accommodation amplitude using the dynamic measurement mode which was a limitation of the study. More studies with the aim to alleviate ocular fatigue after using HMD-type virtual reality devices are therefore needed.
Adult ; Asthenopia ; Fatigue ; Flicker Fusion ; Humans ; Methods ; Myopia ; Volunteers

Objectives: ：This study investigate to identify the stability of temperament and personality characteristics of patients including Posttraumatic Stress Disorder (PTSD) patients. Methods: ：The number of subjects was 102, of which 33 were PTSD patients and 69 were non-PTSD patients. To demonstrate the change in individual temperament and personality characteristics, Temperament and Character Inventory (TCI) were administered repeatedly on the subjects. Repeated measures ANOVA and simple main effects analysis were conducted. Results: ：When analysed by dividing the subjects into PTSD groups and non-PTSD groups, the differences between the primary and secondary tests did not appear in the non-PTSD groups, but the differences between the primary and secondary tests were significant in Harm Avoidance (HA), Reward Dependence (RD), Self-Directedness (SD), Cooperativeness (C). In addition, it was noted that the time and group interaction effects of HA, RD, SD and C were significant, and that the main effects of time of HA, RD, SD and C were significant. Conclusions ：This study is meaningful in that in the course of experience and recovery of traumatic events,we have clinically confirmed that changes in the temperament, known as stable variables, are possible.

Objectives: ：This study investigate to identify the stability of temperament and personality characteristics of patients including Posttraumatic Stress Disorder (PTSD) patients. Methods: ：The number of subjects was 102, of which 33 were PTSD patients and 69 were non-PTSD patients. To demonstrate the change in individual temperament and personality characteristics, Temperament and Character Inventory (TCI) were administered repeatedly on the subjects. Repeated measures ANOVA and simple main effects analysis were conducted. Results: ：When analysed by dividing the subjects into PTSD groups and non-PTSD groups, the differences between the primary and secondary tests did not appear in the non-PTSD groups, but the differences between the primary and secondary tests were significant in Harm Avoidance (HA), Reward Dependence (RD), Self-Directedness (SD), Cooperativeness (C). In addition, it was noted that the time and group interaction effects of HA, RD, SD and C were significant, and that the main effects of time of HA, RD, SD and C were significant. Conclusions ：This study is meaningful in that in the course of experience and recovery of traumatic events,we have clinically confirmed that changes in the temperament, known as stable variables, are possible.

BACKGROUND: We investigated the association between blood concentration of cadmium and smoking status including use of electronic cigarettes (E-cigars). METHODS: We used data from the Korea National Health and Nutritional Survey 2013 and 2016. A total of 4,744 participants (2,162 men and 2,582 women) were included and were categorized into five groups (Non-smokers, E-cigar non-users in past-smokers, E-cigar users in past-smokers, E-cigar non-users in cigarette-smokers and E-cigar users in cigarette-smokers). Cadmium blood concentration was categorized into tertiles. All sampling and weight variables were stratified, and analysis to account for the complex sampling design was conducted. RESULTS: In both genders, the geometric cadmium concentration was significantly different according to smoking status (both genders, analysis of variance P value < 0.001). In men, E-cigar users were significantly higher than the non-smokers (P value = past-smokers, 0.017; cigarette-smokers, < 0.001) when fully adjusted. Compared with non-smokers, fully-adjusted odds ratios (95% confidence intervals) for the highest cadmium tertiles of E-cigar non-users in cigarette-smokers and E-cigar users in cigarette-smokers were 6.56 (3.55–12.11) and 5.68 (1.96–16.50) in men and 2.74 (1.42–5.29) and 1.29 (0.10–17.44) in women. CONCLUSION Conventional cigarette smoking in men and women and E-cigar use in men are associated with higher risk of elevated blood cadmium level. Preventive management of cadmium exposure monitoring in conventional cigarette-smokers and E-cigar users may be needed.