Background/Aims: Although anti-hepatitis C virus (HCV) assay is widely used to screen for HCV infection, it has a high false-positive (FP) rate in low-risk populations. We investigated the accuracy of anti-HCV signal-to-cutoff (S/CO) ratio to distinguish true-positive (TP) from FP HCV infection. Methods: We retrospectively analyzed 77,571 patients with anti-HCV results. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of anti-HCV S/CO ratio in anti-HCV positive patients. Results: Overall, 1,126 patients tested anti-HCV positive; 34.7% of patients were FP based on HCV RNA and/or recombinant immunoblot assay (RIBA) results. The age and sex-adjusted anti-HCV prevalence was 1.22%. We identified significant differences in serum aspartate transaminase and alanine transaminase levels, anti-HCV S/CO ratio, and RIBA results between groups (viremia vs. non-viremia, TP vs. FP). Using ROC curves, the optimal cutoff values of anti-HCV S/CO ratio for HCV viremia and TP were 8 and 5, respectively. The area under the ROC curve, sensitivity, specificity, positive and negative predictive values were 0.970 (95% CI, 0.959–0.982, p < 0.001), 99.7%, 87.5%, 87.4%, and 99.7%, respectively, for predicting HCV viremia at an anti-HCV S/CO ratio of 8 and 0.987 (95% CI, 0.980–0.994, p < 0.001), 95.3%, 94.7%, 97.1%, and 91.4%, respectively, for TP HCV infection at an anti-HCV S/CO ratio of 5. No patients with HCV viremia had an anti-HCV S/CO ratio below 5. Conclusions The anti-HCV S/CO ratio is highly accurate for discriminating TP from FP HCV infection and should be considered when diagnosing HCV infections.

Purpose: The purpose of this study was to develop a Korean Adult Patients Delirium Screening Tool (K-APDS) for those admitted to general wards, and to verify its reliability and validity. Methods: For the development of the tool, 12 items were derived through the results of literature review and focus group interviews with general ward nurses, and the content validity was confirmed by experts. To verify the reliability and validity of the developed tool, 317 adult patients who were admitted to general wards of three tertiary general hospitals from October to November 2022 were evaluated by the attending nurse and data were collected. Results: After factor analysis for construct validity verification, two factors were extracted, which explained 60.1% of the total variance. After the validation of the control group, the difference in the delirium incidence scores calculated using the K-APDS between the delirium group and non-delirium group was very significant (Z=-10.82, p<.001).To verify the criterion validity, K-APDS, Delirium Observation Screening, and Pearson's correlation coefficient were checked and found to be .94 (p<.001). The predictive validity test reported that the sensitivity was 91.1%, specificity was 82.4%, positive predictive value was 52.6%, and negative predictive value was 97.8%. The reliability of K-APDS was found to be high with Cronbach’s ⍺=.91. Conclusion K-APDS can screen for delirium with 2 or more points, excellent validity and reliability have been verified. Therefore, this tool could be applied immediately in the clinical field, and will contribute to the early detection of delirium, enabling rapid interventions.

A case of persistent Ralstonia mannitolilytica bacteremia in the neonatal intensive care unit prompted source investigation due to its rarity. After an extensive investigation, a contaminated ultrasonic nebulizer was identified as the source, and the infection was controlled by removing the source. This study emphasizes the importance of further investigations, even in single cases of rare pathogens.

Background: Nilotinib is a tyrosine kinase inhibitor approved by the Ministry of Food and Drug Safety for frontline and 2nd line treatment of Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). This study aimed to confirm the safety and efficacy of nilotinib in routine clinical practice within South Korea. Methods: An open-label, multicenter, single-arm, 12-week observational post-marketing surveillance (PMS) study was conducted on 669 Korean adult patients with Ph + CML from December 24, 2010, to December 23, 2016. The patients received nilotinib treatment in routine clinical practice settings. Safety was evaluated by all types of adverse events (AEs) during the study period, and efficacy was evaluated by the complete hematological response (CHR) and cytogenetic response. Results: During the study period, AEs occurred in 61.3% (410 patients, 973 events), adverse drug reactions (ADRs) in 40.5% (271/669 patients, 559 events), serious AEs in 4.5% (30 patients, 37 events), and serious ADRs in 0.7% (5 patients, 8 events). Furthermore, unexpected AEs occurred at a rate of 6.9% (46 patients, 55 events) and unexpected ADRs at 1.2% (8 patients, 8 events). As for the efficacy results, CHR was achieved in 89.5% (442/494 patients), and minor cytogenetic response or major cytogenetic response was achieved in 85.8% (139/162 patients). Conclusion This PMS study shows consistent results in terms of safety and efficacy compared with previous studies. Nilotinib was well tolerated and efficacious in adult Korean patients with Ph + CML in routine clinical practice settings.

Purpose: Neutrophils contribute to thrombosis. However, there is limited information on the temporal course of neutrophil recruitment in thrombosis, the contribution of neutrophils to thrombus growth, and the characteristics of stroke patients with neutrophil-rich thrombi. Materials and Methods: After inducing carotid artery thrombosis in Institute of Cancer Research mice using ferric chloride, aged thrombi were produced by ligating the distal portion of the carotid artery in mice for 0.5, 1, 2, 3, 6, or 24 h. For thrombus analysis in stroke patients, we used registry data and thrombi that were obtained during intra-arterial thrombectomy. Immunohistochemistry was performed to determine thrombus composition. Results: In the thrombi of 70 mice, Ly6G positive cell counts (neutrophils) and histone H3-positive cell counts increased in a time-dependent manner (both p<0.001). Ly6G-positive cell count was strongly correlated with histone H3-positive cell counts (r=0.910, p<0.001), but not with thrombus size (p=0.320). In 75 stroke patients, atrial fibrillation and cardioembolism were more frequent in the higher neutrophil group (32/37, 86.5%) than in the lower neutrophil group (19/38, 50%) (p=0.002). The median erythrocyte fraction was higher [52.0 (interquartile range 39.9−57.8)] in the higher neutrophil group than in the lower neutrophil group [40.3 (interquartile range 23.5−53.2)]. The fraction of neutrophils was positively correlated with that of erythrocytes (R=0.35, p=0.002). Conclusion Neutrophils were recruited and increased in arterial thrombosis in a time-dependent manner; however, they were not associated with the growth of formed thrombi. Neutrophil fractions in the thrombi of stroke patients appeared to be associated with atrial fibrillation and erythrocyte fraction.

Purpose: Neutrophils contribute to thrombosis. However, there is limited information on the temporal course of neutrophil recruitment in thrombosis, the contribution of neutrophils to thrombus growth, and the characteristics of stroke patients with neutrophil-rich thrombi. Materials and Methods: After inducing carotid artery thrombosis in Institute of Cancer Research mice using ferric chloride, aged thrombi were produced by ligating the distal portion of the carotid artery in mice for 0.5, 1, 2, 3, 6, or 24 h. For thrombus analysis in stroke patients, we used registry data and thrombi that were obtained during intra-arterial thrombectomy. Immunohistochemistry was performed to determine thrombus composition. Results: In the thrombi of 70 mice, Ly6G positive cell counts (neutrophils) and histone H3-positive cell counts increased in a time-dependent manner (both p<0.001). Ly6G-positive cell count was strongly correlated with histone H3-positive cell counts (r=0.910, p<0.001), but not with thrombus size (p=0.320). In 75 stroke patients, atrial fibrillation and cardioembolism were more frequent in the higher neutrophil group (32/37, 86.5%) than in the lower neutrophil group (19/38, 50%) (p=0.002). The median erythrocyte fraction was higher [52.0 (interquartile range 39.9−57.8)] in the higher neutrophil group than in the lower neutrophil group [40.3 (interquartile range 23.5−53.2)]. The fraction of neutrophils was positively correlated with that of erythrocytes (R=0.35, p=0.002). Conclusion Neutrophils were recruited and increased in arterial thrombosis in a time-dependent manner; however, they were not associated with the growth of formed thrombi. Neutrophil fractions in the thrombi of stroke patients appeared to be associated with atrial fibrillation and erythrocyte fraction.

Background: Recently developed imaging techniques, such as cone beam computed tomography (CBCT) and CAD/CAM technology, have facilitated reliable implant planning and implant surgical guide production by 3D printing. This study compared the accuracy of implant-guided surgery using the R2GATE® program with CBCT before and after surgery. Patients and methods: The study included patients who visited the Department of Oral and Maxillofacial Surgery at Chonnam National University Hospital from September 2021 to March 2022. Twenty-four implants were placed in eleven patients. Using R2GATE® Windows (Megagen implant, Daegu, Korea) software, implant placement was planned. The difference was measured by the CBCT before and after surgery. The cervical and apical distance and angular deviation of the implants were measured. Statistical analysis was performed using an independent t-test, Pearson correlation, and multiple regression analyses. Results: The three-dimensional linear distance difference between the planned implant and the placed implant was 0.97 ± 0.37 mm at the cervical and 1.13 ± 0.36 mm at the apical. The difference in angle deviation between the planned implant and the placed implant was 3.42 ± 2.12°. Among the variables affecting the accuracy of implant placement, a statistically significant difference was found when using a tissue-supported implant guide, implant diameter and implant length. Conclusion Based on these results, using the R2GATE® program is useful to use an implant digital surgical guide, and it will be used in various clinic.

Background: Although several characteristics of coronavirus disease 2019 (COVID-19), an ongoing pandemic disease, have been identified, data on the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. Methods: This prospective cohort study was conducted to analyze the infectivity of SARSCoV-2 based on data of all patients diagnosed with COVID-19 confirmed using real-time polymerase chain reaction test from January to April 2020 in Gyeonggi-do, the largest province in Korea. Results: Of the 502 patients, 298 consisting of 106 clusters with 5,909 contacts were included. Of these, 277 (93.0%) were symptomatic, and the most common symptoms were cough, fever, sputum, sore throat, and headache. A total of 94 patients (31.5%) had pneumonia, while 8 (2.7%) died during the follow-up period. The secondary attack rate (SAR) in the study population was 3.5% (204/5,909). In exposure settings, the SAR was higher in religious gathering (13.5% [95% confidence interval, 10.7–16.8%]), workplaces (8.49% [95% CI, 6.08–11.74%]), and schools (6.38% [95% CI, 3.39–11.69%]) than in health care facilities (1.92% [95% CI, 1.45–2.55%]). Sore throat at any period, dyspnea at diagnosis or any period, lower cycle threshold value in the lower respiratory tract samples, leukocytosis, and higher bilirubin levels were associated with higher infectivity of COVID-19. The presence of symptoms was not related to the infectivity. Conclusion In establishing the infection control strategies for COVID-19, the variables associated with high infectivity may be considered.

Background: The relationship between changes in anxiety levels and personal protective equipment (PPE) use is yet to be evaluated. The present study assessed this relationship among healthcare workers (HCWs) involved in the care of patients with coronavirus disease 2019 (COVID-19). Methods: An online survey was conducted in a municipal hospital with 195 nationally designated negative pressure isolation units in Korea. Anxiety level was measured using the self-rating anxiety scale (SAS), and changes in anxiety levels were assessed based on the time when COVID-19 vaccine was introduced in March 2021 in Korea. Monthly PPE usage between June 2020 and May 2021 was investigated. Results: The mean SAS score (33.25 ± 5.97) was within normal range and was lower than those reported in previous studies conducted before COVID-19 vaccination became available.Among the 93 HCWs who participated, 64 (68.8%) answered that their fear of contracting COVID-19 decreased after vaccination. The number of coveralls used per patient decreased from 33.6 to 0. However, a demand for more PPE than necessary was observed in situations where HCWs were exposed to body fluids and secretions (n = 38, 40.9%). Excessive demand for PPE was not related to age, working experience, or SAS score. Conclusion Anxiety in HCWs exposed to COVID-19 was lower than it was during the early period of the pandemic, and the period before vaccination was introduced. The number of coveralls used per patient also decreased although an excessive demand for PPE was observed.

BACKGROUND/AIMS: Colorectal cancer is associated with different anatomical, biological, and clinical characteristics. We determined the impact of the primary tumor location in patients with metastatic colorectal cancer (mCRC). METHODS: Demographic data and clinical information were collected from 1,115 patients from the Republic of Korea, who presented with mCRC between January 2009 and December 2011, using web-based electronic case report forms. Associations between the primary tumor location and the patient's clinical characteristics were assessed, and factors inf luencing overall survival were analyzed using Cox proportional hazards regression models. RESULTS: Of the 1,115 patients recruited to the study, 244 (21.9%) had right colon cancer, 483 (43.3%) had left colon cancer, and 388 (34.8%) had rectal cancer. Liver and lung metastases occurred more frequently in patients with left colon and rectal cancer (p = 0.005 and p = 0.006, respectively), while peritoneal and ovarian metastases occurred more frequently in patients with right and left colon cancer (p < 0.001 and p = 0.031, respectively). The median overall survival of patients with tumors originating in the right colon was significantly shorter than that of patients whose tumors had originated in the left colon or rectum (13.7 months [95% confidence interval (CI), 12.0 to 15.5] vs. 18.0 months [95% CI, 16.3 to 19.7] or 19.9 months [95% CI, 18.5 to 21.3], respectively; p = 0.003). Tumor resection, the number of metastatic sites, and primary tumor location correlated with overall survival in the univariate and multivariate analyses. CONCLUSIONS: Primary tumor location influences the metastatic sites and prognosis of patients with mCRC.
Colon ; Colonic Neoplasms ; Colorectal Neoplasms* ; Humans ; Liver ; Lung ; Multivariate Analysis ; Neoplasm Metastasis ; Prognosis ; Rectal Neoplasms ; Rectum ; Republic of Korea