SCL-90-R and 16PF profiles of senior high school students with excessive internet use.

OBJECTIVE: To investigate the psychiatric symptomatology and personality characteristics of Korean senior high school students considered to use the Internet to excess. METHOD: We administered a questionnaire packet to students that included 4 measures. These measures included a questionnaire on Internet use patterns during the previous month, the Internet Addiction Test (IAT), the Symptom Checklist-90-R (SCL-90-R), and the Sixteen Personality Factor Questionnaire (16PF). A total of 328 students, aged 15 to 19 years, participated in the study. RESULTS: Students were divided into 4 Internet user groups according to their IAT total scores: nonusers (n = 59, 18.0%), minimal users (n = 155, 47.3%), moderate users (n = 98, 29.9%), and excessive users (n = 16, 4.9%). The SCL-90-R showed that the excessive users group, when compared with the other groups in this study, reported the highest levels of symptomatology. The 16PF also revealed that excessive users were easily affected by feeling, emotionally less stable, imaginative, absorbed in thought, self-sufficient, experimenting, and preferred their own decisions. CONCLUSIONS: This study suggests that senior high school students who use the Internet to excess report and subsequently exhibit significantly more psychiatric symptoms than students who use the Internet less frequently. In addition, excessive users appear to have a distinctive personality profile when compared with nonusers, minimal, and moderate users.

Age-related changes in sleep/wake patterns among Korean teenagers.

INTRODUCTION: As children go through the transition from childhood to adolescence, many shifts occur in sleep/wake patterns related to intrinsic and extrinsic developmental changes. These shifts have been shown to result in corresponding shifts in sleep phase (later sleep onset) and sleep deprivation among teenagers in Western societies. However, the effect of these developmental changes on the sleep habits of Korean teenagers has not been analyzed. This study aims to quantify age-related changes in sleep/wake patterns among Korean teenagers and elucidate cultural and other factors causing these changes. METHODS: The School Sleep Habits Survey was administered in homeroom classes to students in grades 5 to 12 (mean age: 13.7 +/- 2.4 years) selected via a 2-way stratification sampling method. The survey included items regarding usual sleep/wake patterns over the previous 2 weeks as well as measures of daytime sleepiness, sleep/wake-problem behavior, depressed mood, and morningness/eveningness. RESULTS: A total of 1457 students (52.9% male) completed the survey. The higher the grade, the later bedtime was found to be on both school days and weekends. There was a similar relationship between increasing grade and earlier wake time on school days, but higher grades were associated with later wake time on weekends. Total sleep time decreased by approximately 3 hours on school nights and 1 hour on weekend nights from grades 5 to 12. Adolescents were severely sleep deprived, with mean school-night total sleep times of 6.02, 5.62, and 4.86 hours for 10th-, 11th-, and 12th-graders, respectively. In the higher grades, there was a greater discrepancy between school nights and weekends in terms of bedtime and wake time, and the magnitude of weekend oversleep increased. Older students also reported more daytime sleepiness, more sleep/wake-problem behavior, more depressed mood, and more eveningness preference. The chief reasons students cited for their sleep deprivation differed across grades: Academic demands and entertainment (such as Internet and television) were reported by 5th- and 6th-graders, entertainment and then academic demands by 7th-, 8th-, and 9th-graders, and early school start time and academic demands by 10th-, 11th- and 12th-graders. CONCLUSIONS: This study clearly demonstrates that Korean adolescents do not get adequate sleep and that they have profound discrepancies in their sleep/wake patterns between school and weekend nights. Compared with previous studies from other countries, Korean students display even greater sleep deprivation and also more irregular sleep/wake patterns. This study also demonstrates that academic demands/stress and early school start time are the most important contributing factors for sleep deprivation among Korean adolescents. These findings stress the need to promote awareness of the magnitude of adolescent sleep deprivation and its detrimental effects in Korean society.

Fungal metabolites, asterric acid derivatives inhibit vascular endothelial growth factor (VEGF)-induced tube formation of HUVECs.

In the search for new naturally occurring anti-angiogenic compounds, we found that a culture broth of an unidentified fungal strain B90911 exerted inhibitory activity on capillary-like tube formation of human umbilical vein endothelial cells (HUVEC) in vitro. Four active compounds were isolated by bioassay-guided separation and their structures were identified to be sulochrin (1), methyl asterric acid (2), and two new asterric acid derivatives, 3-chloroasterric acid (3), and 3,5-dichloroasterric acid (4) by spectroscopic analyses. These compounds significantly inhibited the VEGF-induced tube formation of HUVEC, suggesting that asterric derivatives could be useful for further study as anti-angiogenic agents.