OBJECTIVES: Schizophrenia patients have deficits of prediction and learning related to dopaminergic dysfunction. It is hypothesized that there would be different characteristics in associative learning of reward approach and loss aversion between controls and patients. METHODS: Participants were 23 healthy participants and 20 out-patients fulfilling criteria for schizophrenia according DSM-IV-TR. Using a monetary incentive contingency reversal task, successful learning rates, numbers of trials and errors till learning, numbers of trials of maintaining learning, response times were measured. Characteristics of learning were compared between controls and patients. RESULTS: Physical anhedonia and PANSS negative symptom scores correlated with the number of trials while loss aversion was maintained. Overall correct response rates were decreased in patient group, particularly during reward approach learning. Patients required more trials and errors to learn reward approach than controls. There were no significant differences in learning performance and reaction times between groups during loss avoidance learning. CONCLUSION: These results support previous reports of deficits in reward-driven learning in schizophrenia. However, anhedonia and negative symptoms were associated with the preserved function of loss avoidance learning.
Anhedonia ; Avoidance Learning ; Humans ; Learning ; Motivation ; Outpatients ; Reaction Time ; Reinforcement (Psychology) ; Reward ; Schizophrenia

OBJECTIVE: We aimed to investigate the influence of area-level factors on adolescent suicide and to determine which variables differ according to age and sex.METHODS: We selected variables that were available for collection through an online database from 2005 to 2015 in the Korean Statistical Information Service and the Korea Labor Institute. We used administrative districts of Korea in 2017 for geographical classification. We examined the relationships between regional suicide rates and area-level variables in male and female subjects aged 10–14 years and 15–19 years. In addition, we analyzed area-level variables in adolescents aged 15–19 years according to sex.RESULTS: Our findings indicated that several area-level variables affected adolescent suicide rates, varying according to age and sex. Economic problems were shown to be more associated with suicide in male adolescents than in female adolescents. On the other hand, social fragmentation and health services were shown to be more associated with suicide in females.CONCLUSION: Suicide in adolescents was attributable to area-level factors such as economic status, social fragmentation, and community health services. By identifying area-level variables affecting adolescent suicide rates, we will be able to contribute to implement mental health policies related to adolescent suicide.
Adolescent ; Classification ; Community Health Services ; Female ; Hand ; Health Services ; Humans ; Information Services ; Korea ; Male ; Mental Health ; Suicide

BACKGROUND: The purpose of this study was to identify the characteristics of injuries of school-aged children transported via emergency medical services (EMS) that occurred in schools by comparing with injuries that occurred outside of school. METHODS: Data from the 119 EMS from 2012 to 2014 were analyzed. School and non-school injuries were analyzed in children 6 to 17 years of age. The epidemiologic characteristics were assessed according to school-age groups; low-grade primary (6–8 years), high-grade primary (9–13 years), middle (13–15 years) and high (15–17 years) school. Gender-stratified multivariable logistic regression analysis was conducted to estimate the risks of school injury in each age group. RESULTS: During the study period, a total of 167,104 children with injury were transported via 119 ambulances. Of these injuries, 13.3% occurred at schools. Boys accounted for 76.9% of school injuries and middle school children accounted for a significantly greater proportion (39.6%) of school injuries (P < 0.001). The most frequent mechanisms of injury at school were falls (43.8%). The peak times for school injury occurrence were lunch time (13:00–13:59) in all age groups. Multivariate regression identified the risky age groups as high-grade primary (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.09–1.20) and middle school-aged boys (OR, 1.82; 95% CI, 1.74–1.90) and middle school-aged girls (OR, 1.30; 95% CI, 1.21–1.40). CONCLUSION: Notable epidemiologic differences exist between in- and out-of-school injuries. The age groups at risk for school injuries differ by gender.
Accidental Falls ; Ambulances ; Child ; Emergencies* ; Emergency Medical Services* ; Epidemiology ; Female ; Humans ; Korea* ; Logistic Models ; Lunch

Background: Adverse lipid profiles are observed in postmenopausal women. However, there is insufficient evidence of the association between lipids and reproductive aging in Korean women. We aimed to characterize lipid changes with respect to timing relative to menopause in Korean middle-aged women. Methods: This study included 1,436 premenopausal women who had a natural menopause during the follow-up period (median = 15.76 years) from the Korean Genome and Epidemiology Study (KoGES) Ansan and Anseong cohort. Lipid levels were measured every 2 years, and the magnitudes of annual lipid changes and differences in the changes by premenopausal body mass index were estimated using piecewise linear mixed-effects models. Results: All lipid levels increased greatly from 3 or 5 years before menopause to 1 year after menopause in all women, regardless of their premenopausal body mass index. During the period, high-density lipoprotein cholesterol (HDL-C) levels increased at 0.42 mg/dL per year (95% confidence interval [CI], 0.29 to 0.55 mg/dL). Nevertheless, non-HDL-C levels simultaneously increased at 3.42 mg/dL per year (95% CI, 3.11 to 3.72 mg/dL), and an annual change in the non-HDL-C to HDL-C ratio was 0.05 (95% CI, 0.04 to 0.06). One year after menopause, changes in all lipid parameters significantly slowed down, except for the nonHDL-C to HDL-C ratio (P < 0.001 for all). The ratio continued to increase until 3 years after menopause, but thereafter, the change leveled off. Conclusion Women experienced remarkable increases in lipid levels during menopausal transition, highlighting the need for early intervention strategies for cardiovascular disease prevention in women.

Background: Depression is a global mental health concern that negatively affects individuals’ health and increases medical costs. This study aimed to assess whether early depression management is cost-beneficial and effective from the perspective of quality indicators. Methods: Data of patients newly diagnosed with depressive disorder between 2012 and 2014 as well as follow-up data until 2020 were extracted from the National Health Insurance Service database. Hospitalization, emergency room visits, and annual medical expenses were set as dependent variables to estimate the effect of depression and information on medical expenditures. Six quality indicators developed by the Health Insurance Review and Assessment Service comprised independent variables. Results: In total, 465,766 patients were included in this study. Patients who met the quality indicators were more likely to be hospitalized with a psychiatric diagnosis. Furthermore, patients who met the quality indicator of revisiting within 3 weeks of their first visit had greater psychiatric and overall expenses during the early treatment phase; however, the overall expenses gradually decreased over time. Conclusion High-quality initial treatment for depression can be cost-effective in the long term; however, further studies are needed to discern its immediate clinical effects.

Background/Aims: With increased life expectancy, the management of elderly hepatocellular carcinoma (HCC) patients became a crucial issue, yet it is still challenging due to comorbidities and high surgical risks. While surgical resection is considered as primary treatment for eligible HCC patients, systematic evidence on its outcomes in elderly patients remains scarce. In this review, we aimed to analyze the efficacy and safety outcomes of surgical resection in elderly HCC patients. Methods: The studies included in this meta-analysis were selected from Ovid-MEDLINE, OvidEmbase, CENTRAL, KoreaMed, KMbase, and KISS databases following a predefined protocol.Efficacy outcomes included overall survival and disease-free survival, while the safety outcomes included postoperative mortality and complications. Results: Patients in the elderly group (≥65 years) who underwent surgery exhibited non-inferior overall survival (hazard ratio [HR], 1.26; 95% confidence interval [CI], 0.92 to 1.74) and diseasefree survival (HR, 1.03; 95% CI, 0.99 to 1.08) compared to the non-elderly group. Overall postop-erative mortality exhibited no statistical difference (odds ratio [OR], 1.07; 95% CI, 0.87 to 1.31), but 30-day, 90-day, and in-hospital mortality were higher in the elderly group. The incidence of overall complications was higher in the elderly group (OR, 1.44; 95% CI, 1.22 to 1.69). Sensitivity analysis for the super elderly group (≥80 years) showed significantly higher in-hospital mortality compared to the non-super elderly group (OR, 2.51; 95% CI, 1.16 to 5.45). Conclusions The efficacy outcome of surgical resection in the elderly HCC patients was not worse than that in the non-elderly HCC patients, while in-hospital mortality and complications rates were higher. Therefore, surgical resection should be purposefully considered in the elderly population, with careful candidate selection.

BACKGROUND: Epstein-Barr virus (EBV) is known to be the causative agent of infectious mononucleosis and EBV-related malignancies. In this study, we compared the results of three real-time PCR kits for EBV DNA assays. METHODS: A total of 300 whole blood samples submitted for quantitative EBV PCR between January 2013 and September 2014 at Severance Hospital were included. The samples were tested by using the Artus EBV RG PCR Kit (Qiagen, Germany), AccuPower EBV Quantitative PCR Kit (Bioneer, Korea), and Real-Q EBV Kit (BioSewoom, Korea). Samples with discordant results between the three kits were confirmed by direct sequencing. RESULTS: The result concordance rate and kappa coefficient (K) were 86.3% and 0.69 for Artus-AccuPower, 93.3% and 0.85 for Artus-Real-Q, and 92.3% and 0.83 for AccuPower-Real-Q, respectively. The correlations between the three kits were found to be significant, with a correlation coefficient of r=0.854 for Artus-AccuPower, -0.802 for Artus-Real-Q, and -0.977 for AccuPower-Real-Q, respectively (P<0.0001). If the real-time PCR concordant results of 258 samples and the direct sequencing results of 42 real-time PCR discordant samples were assumed to be true, the sensitivity/specificity values were 0.921/0.976 for Artus, 0.902/0.965 for AccuPower, and 0.967/1.000 for Real-Q. CONCLUSIONS: The three real-time PCR kits showed excellent sensitivities and specificities. All these kits would be acceptable for clinical and therapeutic management of EBV. However, some discordant results between the kits indicate the need for caution in clinical diagnosis and staging. Further implementation of standardized methodology would be needed for EBV DNA assays.
Diagnosis ; DNA* ; Herpesvirus 4, Human* ; Infectious Mononucleosis ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction*

BACKGROUND: Early identification and appropriate management of mild chronic renal failure has been increasingly recognized as an important opportunity to delay the progression of renal disease. Many physicians rely on serum creatinine (Scr) as a screening test for renal impairment; however, Scr levels can remain within the normal range even when renal function is significantly impaired in certain group of patients. METHODS: The subjects were 20, 245 persons who were enrolled a regular health check up program, Jan. 1997 to Jun. 2001, at Ajou University Hospital, Korea. We identified GFR below 60 mL/min/1.73 m2 as abnormal and found the percentage of patients with Scr value from 1.1 mg/dL to 1.4 mg/dL and their sex and age distribution, using GFRs calculated by Cockroft-Gault Equation, MDRD Equation, and Kang's Equation. RESULTS: Average Scr was 1.07+-0.13 mg/dL in male and 0.82+-0.11 mg/dL in female. Among 34 University hospital in metro Seoul area, 11 hospital used 1.4 mg/dL as normal upper limit of Scr and 7 hospital used 1.3 mg/dL. Taking normal Scr upper limit as 1.3 or 1.4 mg/dL, the frequency of GFR below 60 mL/min/1.73 m2 was 3.9-50% in males and 75-100% in females, although some differences existed according to the equation used. CONCLUSION: Currently used normal Scr upper limit 1.3, 1.4 mL/dL was found to be much too high and we concluded a downward adjustment is needed and one-time test is not adequate to conclude renal impairment but several regular tests are required.
Age Distribution ; Creatinine* ; Female ; Glomerular Filtration Rate ; Humans ; Kidney Failure, Chronic ; Korea ; Male ; Mass Screening ; Reference Values* ; Seoul

Xenotransplantation of porcine organs has the potential to overcome the acute shortage of human tissues and organs for human transplantation. Swine represents an ideal source of such organs owing to their anatomical and physiological similarities to human besides their plentiful supply. However, this procedure is also associated with a number of safety issues related to zoonotic infections. Among such zoonotically important pathogens, porcine endogenous viruses (PERVs) represent the most concerned virus as they persist asymptomatically and show germline transmission in pigs. They belong to gamma retroviruses and are of three types viruses: A, B and C. In the present study, PCR based cloning was performed with chromosomal DNA extracted from miniature pigs to analyze the envelope gene of PERVs. Amplified PCR fragments of about 1.5 Kb, covering the partial env gene, were cloned into pCR2.1-TOPO vectors and sequenced. A total of 51 env clones were obtained from two miniature pigs, types M149 and T1111. Phylogenetic analysis of these genes revealed the presence of only PERV type A and B in the proportion of 45% and 55%, respectively. Among these, 9 clones had the correct open reading frame: eight were PERV type A and one PERV type B. Since both these PERV types are polytropic and have the capacity to infect human cells, our data raise a concern that proviral PERVs might have the potential to generate infectious viruses during or after xenotransplantation in humans.
Clone Cells ; Cloning, Molecular* ; Cloning, Organism ; DNA ; Genes, env ; Humans ; Methods ; Open Reading Frames ; Polymerase Chain Reaction ; Retroviridae ; Swine* ; Transplantation, Heterologous ; Zoonoses

Xenotransplantation of porcine organs has the potential to overcome the acute shortage of human tissues and organs for human transplantation. Swine represents an ideal source of such organs owing to their anatomical and physiological similarities to human besides their plentiful supply. However, this procedure is also associated with a number of safety issues related to zoonotic infections. Among such zoonotically important pathogens, porcine endogenous viruses (PERVs) represent the most concerned virus as they persist asymptomatically and show germline transmission in pigs. They belong to gamma retroviruses and are of three types viruses: A, B and C. In the present study, PCR based cloning was performed with chromosomal DNA extracted from miniature pigs to analyze the envelope gene of PERVs. Amplified PCR fragments of about 1.5 Kb, covering the partial env gene, were cloned into pCR2.1-TOPO vectors and sequenced. A total of 51 env clones were obtained from two miniature pigs, types M149 and T1111. Phylogenetic analysis of these genes revealed the presence of only PERV type A and B in the proportion of 45% and 55%, respectively. Among these, 9 clones had the correct open reading frame: eight were PERV type A and one PERV type B. Since both these PERV types are polytropic and have the capacity to infect human cells, our data raise a concern that proviral PERVs might have the potential to generate infectious viruses during or after xenotransplantation in humans.
Clone Cells ; Cloning, Molecular* ; Cloning, Organism ; DNA ; Genes, env ; Humans ; Methods ; Open Reading Frames ; Polymerase Chain Reaction ; Retroviridae ; Swine* ; Transplantation, Heterologous ; Zoonoses