This study investigates whether personality characteristics and learning behaviors can predict medical students’ academic achievement in Korea, specifically in terms of successfully completing medical school without delays or achieving a high grade point average (GPA) in their final year. In May 2018, 316 medical students took the Multi-Dimensional Learning Strategy Test, 2nd edition, which provided data on their personality and learning behavioral characteristics. Their final year’s GPA and any delays in completing medical school were ascertained by reviewing all electronic academic records of each semester they had been enrolled. The combination of personality and learning behavioral characteristics was significantly associated with completing medical school without delays, even after adjusting for sex and admission path. A multiple logistic regression analysis showed that the adjusted odds ratios and 95% confidence intervals for completing medical school without delays were 1.52 (95% confidence interval [CI], 0.83–2.78) and 3.64 (95% CI, 1.70–7.82) for “others” and “both high” categories, respectively, when compared with the “both low” category. For 235 students who completed medical school without delays, their learning behavioral characteristics (scores) were significantly associated with their final year’s GPA even after adjusting for sex, admission path, and personality characteristics (scores) as determined by the multiple linear regression analysis. This study suggests that individual personality and learning behavior characteristics are predictors of medical students’ academic achievement. Therefore, interventions such as personalized counseling programs should be provided in consideration of such student characteristics.

Background: AML is a heterogeneous disease, and despite intensive therapy, recurrence is still high in AML patients who achieve the criterion for cytomorphologic remission (residual tumor burden [measurable residual disease, MRD]<5%). This study aimed to develop a targeted next-generation sequencing (NGS) panel to detect MRD in AML patients and validate its performance. Methods: We designed an error-corrected, targeted MRD-NGS panel without using physical molecular barcodes, including 24 genes. Fifty-four bone marrow and peripheral blood samples from 23 AML patients were sequenced using the panel. The panel design was validated using reference material, and accuracy was assessed using droplet digital PCR. Results: Dilution tests showed excellent linearity and a strong correlation between expected and observed clonal frequencies (R>0.99). The test reproducibly detected MRD in three dilution series samples, with a sensitivity of 0.25% for single-nucleotide variants. More than half of samples from patients with morphologic remission after one month of chemotherapy had detectable mutations. NGS-MRD positivity for samples collected after one month of chemotherapy tended to be associated with poor overall survival and progression-free survival. Conclusions Our highly sensitive and accurate NGS-MRD panel can be readily used to monitor most AML patients in clinical practice, including patients without gene rearrangement. In addition, this NGS-MRD panel may allow the detection of newly emerging clones during clinical relapse, leading to more reliable prognoses of AML.

Background and Objectives: Papillary thyroid carcinoma (PTC) with lateral neck lymph node metastasis is known as a major risk factor for tumor recurrence after surgical treatment. The aim of this study is to identify risk factors for loco-regional recurrence in patients with PTC with lateral neck lymph node metastasis, which has a high risk of recurrence.Subjects and Method This study involved 319 patients who underwent total thyroidectomy, central lymph node (LN) and lateral LN dissection due to PTC. The patients’ demographics and pathological factors, including lymph node metastasis were retrospectively reviewed. Univariate, multivariate and C-index with variable selection analyses were performed to identify factors associated with recurrence-free survival (RFS). Results: A mean follow-up of 101 months, 35 (10.9%) patients had a loco-regional recurrence. In multivariate analysis according to loco-regional recurrence, patients with a primary tumor of more than 4 cm, multifocality, vascular invasion, and bilateral lateral cervical metastasis were associated with worse RFS. In the variable selection analysis, lateral lymph node metastasis ratio was also statistically significant. Conclusion PTC with lateral neck lymph node metastasis included tumors larger than 4 cm. Multifocality, vascular invasion, high lateral lymph node metastasis ratio and bilateral neck lymph node metastasis are predictive factors of loco-regional recurrence, and these risk factors should be carefully followed-up after surgery.

Background: To deliver therapeutics into the brain, it is imperative to overcome the issue of the blood-brain-barrier (BBB). One of the ways to circumvent the BBB is to administer therapeutics directly into the brain parenchyma. To enhance the treatment efficacy for chronic neurodegenerative disorders, repeated administration to the target location is required. However, this increases the number of operations that must be performed. In this study, we developed the IntraBrain Injector (IBI), a new implantable device to repeatedly deliver therapeutics into the brain parenchyma. Methods: We designed and fabricated IBI with medical grade materials, and evaluated the efficacy and safety of IBI in 9 beagles. The trajectory of IBI to the hippocampus was simulated prior to surgery and the device was implanted using 3D-printed adaptor and surgical guides. Ferumoxytol-labeled mesenchymal stem cells (MSCs) were injected into the hippocampus via IBI, and magnetic resonance images were taken before and after the administration to analyze the accuracy of repeated injection. Results: We compared the planned vs. insertion trajectory of IBI to the hippocampus.With a similarity of 0.990 ± 0.001 (mean ± standard deviation), precise targeting of IBI was confirmed by comparing planned vs. insertion trajectories of IBI. Multiple administrations of ferumoxytol-labeled MSCs into the hippocampus using IBI were both feasible and successful (success rate of 76.7%). Safety of initial IBI implantation, repeated administration of therapeutics, and long-term implantation have all been evaluated in this study. Conclusion Precise and repeated delivery of therapeutics into the brain parenchyma can be done without performing additional surgeries via IBI implantation.

Background and Objectives: Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. Methods: Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. Results: mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). Conclusions Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

Background and Objectives: Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. Methods: Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. Results: mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). Conclusions Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

Objectives: This study examined associations among social capital indicators (social participation and generalized trust) at the individual level and alcohol use, which was quantified using Alcohol Use Disorders Identification Test (AUDIT) scores. Methods: In total, there were 8800 participants in community health interviews, including 220 adults sampled systematically from a resident registration database of each of 40 sub-municipal administrative units of local (city or county) governments. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated using polychotomous logistic regression. Results: The aORs for abstainers versus people with AUDIT scores of 0-7, based on 3 questions on generalized trust, in comparison to those with no positive responses, were 1.15 (95% CI, 0.99 to 1.34) for 1 positive response, 1.16 (95% CI, 0.98 to 1.37) for 2 positive responses; and 1.39 (95% CI, 1.20 to 1.61) for 3 positive responses. The aORs for abstainers versus people with AUDIT scores of 0-7, in comparison to participation in no organizations, were 0.61 (95% CI, 0.54 to 0.69) for participation only in informal organizations; 2.16 (95% CI, 1.57 to 2.99) for participation only in religious organizations; 2.41 (95% CI, 1.10 to 5.29) for participation only in volunteer organizations; and 0.65 (95% CI, 0.57 to 0.74) for participation in formal organizations. Participants in formal social organizations, regardless of their participation in informal organizations, were more likely to have AUDIT scores of 8-15 (aOR, 1.29; 95% CI, 1.04 to 1.60) or ≥16 (aOR, 1.65; 95% CI, 1.22 to 2.23) than to have scores of 0-7. Conclusions Our findings may have implications for health policy to reduce alcohol problems.

OBJECTIVES: The purpose of this study was to investigate the role of self-esteem as a moderator of the factors influencing suicidality among middle-schoolers. METHODS: Moderated multiple regression analysis was applied to assess the influence of happiness, depression, and hostility on suicidality and to determine the degree to which self-esteem served as a moderator of those relationships. Data were collected from 268 students at a middle school in Busan, Korea, using a self-administered structured questionnaire. RESULTS: Happiness, depression, and hostility had significant direct effects on suicidality. Self-esteem showed no direct effect, but had a significant moderating effect on the relationship between hostility and suicidal behavior. CONCLUSIONS: These results suggest that various interventions, such as counseling programs, should be designed to alleviate hostility and depression and to enhance happiness and self-esteem among early adolescents.
Adolescent ; Busan ; Counseling ; Depression ; Happiness ; Hostility ; Humans ; Korea

BACKGROUND AND OBJECTIVES: This study aims to evaluate that usefulness of the endoscopic ear surgery (EES) through the systematic review. SUBJECTS AND METHOD: We searched literatures in literature databases (MEDLINE, EMBASE, Cochrane Library, etc.). Inclusion criteria is 1) studies of patients with chronic otitis media, otitis media with effusion, cholesteatoma, conductive hearing loss, mixed hearing loss etc. 2) studies in which a transcanal endoscopic surgery was performed; and 3) studies in which one or more of the appropriate medical outcomes have been reported. We excluded that 1) non-human studies and pre-clinical studies; 2) non-original articles, for example, non-systematic reviews; editorial, letter and opinion pieces; 3) research not published in Korean and English; and 4) grey literature. Finally, 65 articles were selected and those results were analyzed. RESULTS: The safety of the EES was reported in 61 articles. Some studies reported damaged facial nerve or perilymph gusher but these are the complications that can arise due to the characteristics of the disease and not due to the EES and other reported complications were of similar or lower level in the intervention group rather than the microscopy group. The effectiveness of the EES was reported in 23 articles. The EES tended to show improved effects in terms of graft uptake status, cholesteatoma removal, and hearing improvement although effective outcomes of most studies reported no significant difference between EES and microscopic ear surgery. CONCLUSION: EES is a safe and effective technique and as it is less invasive than the microscopic ear surgery.
Cholesteatoma ; Ear ; Endoscopes ; Facial Nerve ; Hearing ; Hearing Loss, Conductive ; Hearing Loss, Mixed Conductive-Sensorineural ; Humans ; Methods ; Microscopy ; Otitis Media ; Otitis Media with Effusion ; Otologic Surgical Procedures ; Perilymph ; Transplants

BACKGROUND AND OBJECTIVES: This study aims to evaluate that usefulness of the endoscopic ear surgery (EES) through the systematic review.SUBJECTS AND METHOD: We searched literatures in literature databases (MEDLINE, EMBASE, Cochrane Library, etc.). Inclusion criteria is 1) studies of patients with chronic otitis media, otitis media with effusion, cholesteatoma, conductive hearing loss, mixed hearing loss etc. 2) studies in which a transcanal endoscopic surgery was performed; and 3) studies in which one or more of the appropriate medical outcomes have been reported. We excluded that 1) non-human studies and pre-clinical studies; 2) non-original articles, for example, non-systematic reviews; editorial, letter and opinion pieces; 3) research not published in Korean and English; and 4) grey literature. Finally, 65 articles were selected and those results were analyzed. RESULTS: The safety of the EES was reported in 61 articles. Some studies reported damaged facial nerve or perilymph gusher but these are the complications that can arise due to the characteristics of the disease and not due to the EES and other reported complications were of similar or lower level in the intervention group rather than the microscopy group. The effectiveness of the EES was reported in 23 articles. The EES tended to show improved effects in terms of graft uptake status, cholesteatoma removal, and hearing improvement although effective outcomes of most studies reported no significant difference between EES and microscopic ear surgery. CONCLUSION EES is a safe and effective technique and as it is less invasive than the microscopic ear surgery.