Vaccination with tumor peptide epitopes associated with MHC class I molecules is an attractive approach directed at inducing tumor-specific CTLs. However, challenges remain in improving the therapeutic efficacy of peptide epitope vaccines, including the low immunogenicity of peptide epitopes and insufficient stimulation of innate immune components in vivo. To overcome this, we aimed to develop and test an innovative strategy that elicits potent CTL responses against tumor epitopes. The essential feature of this strategy is vaccination using tumor epitope-loaded nanoparticles (NPs) in combination with polyinosinic-polycytidylic acid (poly-IC) and anti-PD1 mAb. Carboxylated NPs were prepared using poly(lactic-co-glycolic acid) and poly(ethylene/maleic anhydride), covalently conjugated with anti-H-2K b mAbs, and then attached to H-2K b molecules isolated from the tumor mass (H-2 b ). Native peptides associated with the H-2K b molecules of H-2K b -attached NPs were exchanged with tumor peptide epitopes. Tumor peptide epitope-loaded NPs efficiently induced tumor-specific CTLs when used to immunize tumor-bearing mice as well as normal mice. This activity of the NPs significantly was increased when co-administered with poly-IC.Accordingly, the NPs exerted significant anti-tumor effects in mice implanted with EG7-OVA thymoma or B16-F10 melanoma, and the anti-tumor activity of the NPs was significantly increased when applied in combination with poly-IC. The most potent anti-tumor activity was observed when the NPs were co-administered with both poly-IC and anti-PD1 mAb.Immunization with tumor epitope-loaded NPs in combination with poly-IC and anti-PD1 mAb in tumor-bearing mice can be a powerful means to induce tumor-specific CTLs with therapeutic anti-tumor activity.

Background/Aims: While switching strategies of P2Y12 receptor inhibitors (RIs) have sometimes been used in acute myocardial infarction (AMI) patients, the current status of in-hospital P2Y12RI switching remains unknown. Methods: Overall, 8,476 AMI patients who underwent successful revascularization from Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) were divided according to in-hospital P2Y12RI strategies, and net adverse cardiovascular events (NACEs), defined as a composite of cardiac death, non-fatal myocardial infarction (MI), stroke, or thrombolysis in myocardial infarction (TIMI) major bleeding during hospitalization were compared. Results: Patients with in-hospital P2Y12RI switching accounted for 16.5%, of which 867 patients were switched from clopidogrel to potent P2Y12RI (C-P) and 532 patients from potent P2Y12RI to clopidogrel (P-C). There were no differences in NACEs among the unchanged clopidogrel, the unchanged potent P2Y12RIs, and the P2Y12RI switching groups. However, compared to the unchanged clopidogrel group, the C-P group had a higher incidence of non-fatal MI, and the P-C group had a higher incidence of TIMI major bleeding. In clinical events of in-hospital P2Y12RI switching, 90.9% of non-fatal MI occurred during pre-switching clopidogrel administration, 60.7% of TIMI major bleeding was related to pre-switching P2Y12RIs, and 71.4% of TIMI major bleeding was related to potent P2Y12RIs. Only 21.6% of the P2Y12RI switching group switched to P2Y12RIs after a loading dose (LD); however, there were no differences in clinical events between patients with and without LD. Conclusions In-hospital P2Y12RI switching occurred occasionally, but had relatively similar clinical outcomes compared to unchanged P2Y12RIs in Korean AMI patients. Non-fatal MI and bleeding appeared to be mainly related to pre-switching P2Y12RIs.

BACKGROUND AND OBJECTIVES: There is a paucity of data regarding the benefit of clopidogrel monotherapy after dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents (DES). This study compared outcome between clopidogrel versus aspirin as monotherapy after DES for acute myocardial infarction (MI). METHODS: From Korea Acute Myocardial Infarction Registry-National Institute of Health database, 1,819 patients treated with DES who were switched to monotherapy with clopidogrel (n=534) or aspirin (n=1,285) after uneventful 12-month DAPT were analyzed. The primary endpoint was net adverse clinical events (NACE), defined as a composite of death from any cause, MI, repeat percutaneous coronary intervention (PCI), stent thrombosis, ischemic stroke, or major bleeding during the period from 12 to 24 months. RESULTS: After adjustment using inverse probability of treatment weighting, patients who received clopidogrel, compared with those treated with aspirin, had a similar incidence of NACE (0.7% and 0.7%; hazard ratio, 1.06; 95% confidence interval, 0.31–3.60; p=0.923). The 2 groups had similar rates of death from any cause (0.1% in each group, p=0.789), MI (0.3% and 0.1%, respectively; p=0.226), repeat PCI (0.1% and 0.3%, respectively; p=0.548), stent thrombosis (0.1% and 0%, respectively; p=0.121), major bleeding (0.2% in each group, p=0.974), and major adverse cardiovascular and cerebrovascular events (0.5% in each group, p=0.924). CONCLUSIONS Monotherapy with clopidogrel, compared to aspirin, after DAPT showed similar clinical outcomes in patients with acute MI treated with DES.

BACKGROUND AND OBJECTIVES: There is a paucity of data regarding the benefit of clopidogrel monotherapy after dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents (DES). This study compared outcome between clopidogrel versus aspirin as monotherapy after DES for acute myocardial infarction (MI).METHODS: From Korea Acute Myocardial Infarction Registry-National Institute of Health database, 1,819 patients treated with DES who were switched to monotherapy with clopidogrel (n=534) or aspirin (n=1,285) after uneventful 12-month DAPT were analyzed. The primary endpoint was net adverse clinical events (NACE), defined as a composite of death from any cause, MI, repeat percutaneous coronary intervention (PCI), stent thrombosis, ischemic stroke, or major bleeding during the period from 12 to 24 months.RESULTS: After adjustment using inverse probability of treatment weighting, patients who received clopidogrel, compared with those treated with aspirin, had a similar incidence of NACE (0.7% and 0.7%; hazard ratio, 1.06; 95% confidence interval, 0.31–3.60; p=0.923). The 2 groups had similar rates of death from any cause (0.1% in each group, p=0.789), MI (0.3% and 0.1%, respectively; p=0.226), repeat PCI (0.1% and 0.3%, respectively; p=0.548), stent thrombosis (0.1% and 0%, respectively; p=0.121), major bleeding (0.2% in each group, p=0.974), and major adverse cardiovascular and cerebrovascular events (0.5% in each group, p=0.924).CONCLUSIONS: Monotherapy with clopidogrel, compared to aspirin, after DAPT showed similar clinical outcomes in patients with acute MI treated with DES.
Aspirin ; Drug-Eluting Stents ; Hemorrhage ; Humans ; Incidence ; Korea ; Myocardial Infarction ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors ; Stents ; Stroke ; Thrombosis

BACKGROUND/AIMS: Colorectal cancer incidence among patients aged ≤50 years is increasing. This study aimed to develop and validate an advanced colorectal neoplasm (ACRN) screening model for young adults aged <50 years in Korea. METHODS: This retrospective cross-sectional study included 59,575 consecutive asymptomatic Koreans who underwent screening colonoscopy between 2003 and 2012 at a single comprehensive health care center. Young Adult Colorectal Screening (YCS) score was developed as an optimized risk stratification model for ACRN using multivariate analysis and was internally validated. The predictive power and diagnostic performance of YCS score was compared with those of Asia-Pacific Colorectal Screening (APCS) and Korean Colorectal Screening (KCS) scores. RESULTS: 41,702 and 17,873 subjects were randomly allocated into the derivation and validation cohorts, respectively, by examination year. ACRN prevalence was 0.9% in both cohorts. YCS score comprised sex, age, alcohol, smoking, obesity, glucose metabolism abnormality, and family history of CRC, with score ranges of 0 to 10. In the validation cohort, ACRN prevalence was 0.6% in the low-risk tier (score, 0–4), 1.5% in the moderate-risk tier (score, 5–7), and 3.4% in the high-risk tier (score, 8–10). ACRN risk increased 2.5-fold (95% confidence interval [CI], 1.8–3.4) in the moderate-risk tier and 5.8-fold (95% CI, 3.4–9.8) in the high-risk tier compared with the low-risk tier. YCS score identified better balanced accuracy (53.9%) than APCS (51.5%) and KCS (50.7%) scores and had relatively good discriminative power (area under the curve=0.660). CONCLUSIONS: YCS score based on clinical and laboratory risk factors was clinically effective and beneficial for predicting ACRN risk and targeting screening colonoscopy in adults aged <50 years.
Adult ; Cohort Studies ; Colonoscopy ; Colorectal Neoplasms ; Comprehensive Health Care ; Cross-Sectional Studies ; Early Detection of Cancer ; Glucose ; Humans ; Incidence ; Korea ; Mass Screening ; Metabolism ; Multivariate Analysis ; Obesity ; Prevalence ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Smoke ; Smoking ; Young Adult

OBJECTIVE: Data mining extracts meaningful information from large datasets. In this study, text mining techniques were used to extract keywords from the Journal of the Korean Society of Emergency Medicine, and the change trend was examined. METHODS: The rvest package in R was used to extract all papers published in the Journal of the Korean Society of Emergency Medicine from 2006 to 2016 that could be searched online. Among them, 3,952 keywords were extracted and studied. Using the selected keywords, the corpus was formed by refining keywords that did not correspond to MeSH (Medical Subject Headings) or were misspelled and had similar meanings based on agreement of researchers. Using the refined keywords, the frequencies of the keywords in the first and second halves of the studies were calculated and visualized. RESULTS: Word Cloud revealed that emergency medical service and cardiopulmonary resuscitation (CPR) were most frequently mentioned in both the first and second halves of the studies. In the first half, ultrasonography, stroke, poisoning, injury, and education were frequently mentioned, while in the second half, poisoning, injury, stroke, acute, and tomography were frequently mentioned. A pyramid graph revealed that the frequencies of emergency medical service and CPR were commonly high. CONCLUSION: Core keywords of the Journal of the Korean Society of Emergency Medicine were analyzed for correlations and trends. Changes in study topics according to key topics of interest and period were visually identified.
Cardiopulmonary Resuscitation ; Data Mining ; Dataset ; Education ; Emergencies ; Emergency Medical Services ; Emergency Medicine ; Poisoning ; Stroke ; Ultrasonography

OBJECTIVES: The aim of this study was to develop a Mental Health Questionnaire for Adults (MHQ-A) and investigate its validity and reliability. METHODS: A 73-item questionnaire was developed or selected by seven psychiatrists and a clinical psychologist. The questionnaire was administered to 351 subjects in Seoul and Gyeonggi area. The construct validity was investigated by performing principal component analysis, and the reliability was assessed in terms of the internal consistency using Cronbach's alpha. RESULTS: Principal component analysis revealed 15 factors underlying the psychiatric disorder and symptom category. Taken together, these 15 factors accounted for 64.023% of the common variance. Cronbach's alpha was high, indicating that the reliability of the questionnaire was satisfactory. Every category showed a positive correlation with most psychological measures. CONCLUSION: These results indicate that the MHQ-A is a reliable and valid scale for assessing psychiatric disorders. Although there were many limitations, the present study has significance as the basis of future research.
Adult ; Gyeonggi-do ; Humans ; Mental Health ; Principal Component Analysis ; Psychiatry ; Psychology ; Reproducibility of Results ; Seoul

OBJECTIVES: The aim of this study was to develop a brief schema questionnaire for adults (BSQ-A) and investigate its validity and reliability. METHODS: A 36-item questionnaire was developed or selected by six psychiatrists. The questionnaire was administered to 209 subjects in Seoul and Gyeonggi area. The construct validity was investigated by performing principal component analysis, and the reliability was assessed in terms of the internal consistency using Cronbach's alpha. RESULTS: The principal component analysis revealed 18 factors underlying 18 early maladaptive schemas (EMSs). These 18 factors accounted for 87.488% of the common variance. The Cronbach's alpha was high, indicating that the reliability of the questionnaire was satisfactory. Every schema showed a positive correlation with most psychological measures. CONCLUSION: The results indicate that the BSQ-A is a reliable and valid scale for assessing EMSs. Although there are many limitations, the present study is expected to form the basis of future research.
Adult ; Gyeonggi-do ; Humans ; Principal Component Analysis ; Psychiatry ; Reproducibility of Results ; Seoul

OBJECTIVE: Data on the intensity of statin therapy for patients with acute myocardial infarction (MI) and very low baseline low-density lipoprotein (LDL) cholesterol level are lacking. We sought to assess the impact of statin intensity in patients with acute MI and LDL cholesterol <70 mg/dL. METHODS: A total of 1,086 patients with acute MI and baseline LDL cholesterol <70 mg/dL from the Korea Acute Myocardial Infarction Registry-National Institute of Health database were divided into less intensive statin (expected LDL reduction <40%, n=302) and more intensive statin (expected LDL reduction ≥40%, n=784) groups. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCEs), a composite of cardiac death, MI, revascularization occurring at least 30 days after admission, and stroke, at 12 months. RESULTS: After 1:2 propensity matching, differences were not observed between less intensive (n=302) and more intensive statin (n=604) groups in incidence of cardiac death (0.3% vs. 0.3%) and hemorrhagic stroke (0.3% vs. 0.5%, p=0.727) at 12 months. Compared with the less intensive statin group, the more intensive statin group showed lower target-vessel revascularization (4.6% vs. 1.8%, p=0.027) and MACCE (11.6% vs. 7.0%, p=0.021). Major bleeding was not different between less intensive and more intensive statin groups (1.0% vs. 2.6%, p=0.118). CONCLUSION: More intensive statin therapy was associated with significantly lower major adverse cardiovascular events in patients with acute MI and very low LDL cholesterol compared with less intensive statin therapy.
Cholesterol ; Cholesterol, LDL ; Death ; Hemorrhage ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Incidence ; Korea ; Lipoproteins ; Myocardial Infarction ; Stroke

BACKGROUND/AIMS: Although cardiovascular (CV) risk factors are well established, some patients experience acute myocardial infarction (AMI) even without any risk factors. METHODS: We analyzed total 11,390 patients (63.6 ± 12.6 years old, 8,401 males) with AMI enrolled in Korea Acute Myocardial Infarction Registry-National Institute of Health from November, 2011 to December, 2015. Patients were divided into two groups according to the presence of any CV risk factors (group I, without risk factors, n = 1,420 [12.5%]; group II, with risk factors, n = 9,970 [87.5%]). In-hospital outcomes were defined as in-hospital mortality and complications. One-year clinical outcomes were defined as the composite of major adverse cardiac events (MACE). RESULTS: Group I was older (67.3 ± 11.6 years old vs. 63.0 ± 12.7 years old, p < 0.001) and had higher prevalence of female gender (36.2% vs. 24.8%, p < 0.001) than the group II. Group I experienced less previous history of angina pectoris (7.0% vs. 9.4%, p = 0.003) and the previous history of cerebrovascular accidents (3.4% vs. 6.9%, p < 0.001). In-hospital mortality (2.6% vs. 3.0%, p = 0.450) and complications (20.6% vs. 20.0%, p = 0.647) were no differences between the groups. And 1 year clinical outcomes (5.7% vs. 5.1%, p = 0.337) were no differences between the groups. In multivariate logistic regression analysis, serum creatinine level (hazard ratio, 1.35; 95% confidence interval, 1.05 to 1.75; p = 0.021) were independent predictors of 1 year MACE in patients without any CV risk factors. CONCLUSIONS Elderly female patients were prone to develop AMI even without any modifiable CV risk factors. We suggest that more intensive care is needed in AMI patients without any CV risk factors who have high serum creatinine levels.