Objective: To develop and validate a preoperative risk score incorporating carbohydrate antigen (CA) 19-9, CT, and fluorine-18-fluorodeoxyglucose ( 18F-FDG) PET/CT variables to predict recurrence-free survival (RFS) after upfront surgery in patients with resectable pancreatic ductal adenocarcinoma (PDAC). Materials and Methods: Patients with resectable PDAC who underwent upfront surgery between 2014 and 2017 (development set) or between 2018 and 2019 (test set) were retrospectively evaluated. In the development set, a risk-scoring system was developed using the multivariable Cox proportional hazards model, including variables associated with RFS. In the test set, the performance of the risk score was evaluated using the Harrell C-index and compared with that of the postoperative pathological tumor stage. Results: A total of 529 patients, including 335 (198 male; mean age ± standard deviation, 64 ± 9 years) and 194 (103 male; mean age, 66 ± 9 years) patients in the development and test sets, respectively, were evaluated. The risk score included five variables predicting RFS: tumor size (hazard ratio [HR], 1.29 per 1 cm increment; P < 0.001), maximal standardized uptake values of tumor ≥ 5.2 (HR, 1.29; P = 0.06), suspicious regional lymph nodes (HR, 1.43; P = 0.02), possible distant metastasis on 18F-FDG PET/CT (HR, 2.32; P = 0.03), and CA 19-9 (HR, 1.02 per 100 U/mL increment; P = 0.002). In the test set, the risk score showed good performance in predicting RFS (C-index, 0.61), similar to that of the pathologic tumor stage (C-index, 0.64; P = 0.17). Conclusion The proposed risk score based on preoperative CA 19-9, CT, and 18F-FDG PET/CT variables may have clinical utility in selecting high-risk patients with resectable PDAC.

South Korea implemented interventions to curb the spread of the novel coronavirus disease 2019 (COVID-19) pandemic with discovery of the first case in early 2020. Mathematical modeling designed to reflect the dynamics of disease transmission has been shown to be an important tool for responding to COVID-19. This study aimed to review publications on the structure, method, and role of mathematical models focusing on COVID-19 transmission dynamics in Korea. In total, 42 papers published between August 7, 2020 and August 21, 2022 were studied and reviewed. This study highlights the construction and utilization of mathematical models to help craft strategies for predicting the course of an epidemic and evaluating the effectiveness of control strategies. Despite the limitations caused by a lack of available epidemiological and surveillance data, modeling studies could contribute to providing scientific evidence for policymaking by simulating various scenarios.

Purpose: Implant-based breast reconstruction is the most common reconstruction method used after mastectomy in breast cancer patients. Many studies have compared the smooth round implants and textured anatomical implants. This study aimed to compare the complications, including capsular contracture, between these two implants used in direct-toimplant (DTI) breast reconstruction. Methods: This retrospective chart review was performed using a prospectively maintained database from a single center. We identified patients who underwent mastectomy with DTI single-stage breast reconstruction at our hospital between August 2011 and June 2021. The overall complications, including capsular contracture, postoperative infection, seroma, hematoma, implant rupture, implant exposure, rippling, implant malposition, and nipple necrosis, were analyzed. Results: In total, 340 breasts of 323 patients were reconstructed by the DTI approach using either textured anatomical (n = 203) or smooth round (n = 137) implants. The incidence of overall complications and capsular contracture was significantly lower with smooth round implants than with textured anatomical implants. Multivariate analysis showed that smooth round implants were associated with a reduced risk of overall complications (odds ratio [OR], 0.465; 95% confidence interval [CI], 0.265–0.813) and capsular contracture (OR, 0.475; 95% CI, 0.235–0.962). Particularly, smooth round implants were associated with a decreased risk of overall complications in patients not receiving adjuvant chemotherapy and a decreased risk of capsular contracture in patients with body mass index < 25 kg/m2 and in those not receiving adjuvant radiotherapy. Conclusion Smooth round implants demonstrated a decreased risk of overall complications and capsular contracture when compared with textured anatomical implants. These results may be utilized in counseling patients regarding the advantages and disadvantages of smooth round implants in DTI breast reconstruction.

Purpose: Neuroinflammation is considered an important pathway associated with several diseases that result in cognitive decline. 18F-THK5351 positron emission tomography (PET) signals might indicate the presence of neuroinflammation, as well as Alzheimer’s disease-type tau aggregates. β-amyloid (Aβ)-negative (Aβ–) amnestic mild cognitive impairment (aMCI) may be associated with non-Alzheimer’s disease pathophysiology. Accordingly, we investigated associations between 18F-THK5351 PET positivity and cognitive decline among Aβ– aMCI patients. Materials and Methods: The present study included 25 amyloid PET negative aMCI patients who underwent a minimum of two follow-up neuropsychological evaluations, including clinical dementia rating-sum of boxes (CDR-SOB). The patients were classified into two groups: 18F-THK5351-positive and -negative groups. The present study used a linear mixed effects model to estimate the effects of 18F-THK5351 PET positivity on cognitive prognosis among Aβ– aMCI patients. Results: Among the 25 Aβ– aMCI patients, 10 (40.0%) were 18F-THK5351 positive. The patients in the 18F-THK5351-positive group were older than those in the 18F-THK5351-negative group (77.4±2.2 years vs. 70.0±5.5 years; p<0.001). There was no difference between the two groups with regard to the proportion of apolipoprotein E ε4 carriers. Interestingly, however, the CDR-SOB scores of the 18F-THK5351-positive group deteriorated at a faster rate than those of the 18F-THK5351-negative group (B=0.003, p=0.033). Conclusion The results of the present study suggest that increased 18F-THK5351 uptake might be a useful predictor of poor prognosis among Aβ– aMCI patients, which might be associated with increased neuroinflammation (ClinicalTrials.gov NCT02656498).

Background: Atopic dermatitis (AD) is a heterogeneous disease with different age of onset, disease course, clinical symptoms, severity, and risk of comorbidity. The characteristics of children with AD also vary by age or country. However, little is known about the clinical characteristics of AD in Korean school-aged children and adolescents. Furthermore, there are few studies on phenotypic differences according to onset age. This study aimed to explore the clinical characteristics and phenotypes according to onset age and severity of AD in children and adolescents in Korea. Methods: AD patients aged 6–18 years who presented to 18 hospitals nationwide were surveyed.The patients were examined for disease severity by pediatric allergy specialists, and data on history of other allergic diseases, familial allergy history, onset age, trigger factors, lesion sites,treatment history and quality of life were collected. The results of the patient’s allergy test were also analyzed. The patients were classified into infancy-onset (< 2 years of age), preschoolonset (2–5 years of age), and childhood-onset (≥ 6 years of age) groups. Study population was analyzed for clinical features according to onset-age groups and severity groups. Results: A total of 258 patients with a mean age of 10.62 ± 3.18 years were included in the study. Infancy-onset group accounted for about 60% of all patients and presented significantly more other allergic diseases, such as allergic rhinitis and asthma (P = 0.002 and P = 0.001, respectively). Food allergy symptoms and diagnoses were highly relevant to both earlier onset and more severe group. Inhalant allergen sensitization was significantly associated with both infancy-onset group and severe group (P = 0.012 and P = 0.024, respectively). A family history of food allergies was significantly associated with infancyonset group (P = 0.036). Severe group was significantly associated with a family history of AD, especially a paternal history of AD (P = 0.048 and P = 0.004, respectively). Facial (periorbital, ear, and cheek) lesions, periauricular fissures, hand/foot eczema, and xerosis were associated with infancy-onset group. The earlier the onset of AD, the poorer the quality of life (P = 0.038). Systemic immunosuppressants were used in only 9.6% of the patients in the severe group. Conclusion This study analyzed the clinical features of AD in Korean children and adolescents through a multicenter nationwide study and demonstrated the phenotypic differences according to onset age and severity. Considering the findings that the early-onset group is more severe and accompanied by more systemic allergic diseases, early management should be emphasized in young children and infants.

Background: Many chronic obstructive pulmonary disease (COPD) patients receiving monotherapy continue to experience symptoms, exacerbations and poor quality of life. This study aimed to assess the efficacy and safety of direct switch from once-daily tiotropium (TIO) 18 μg to indacaterol/glycopyrronium (IND/GLY) 110/50 μg once-daily in COPD patients in Korea. Methods: This was a randomized, open-label, parallel group, 12-week trial in mild-to-moderate COPD patients who received TIO 18 μg once-daily for ≥12 weeks prior to study initiation. Patients aged ≥40 years, with predicted postbronchodilator forced expiratory volume in 1 second (FEV1) ≥50%, post-bronchodilator FEV1/forced vital capacity <0.7 and smoking history of ≥10 pack-years were included. Eligible patients were randomized in a 1:1 ratio to either IND/GLY or TIO. The primary objective was to demonstrate superiority of IND/GLY over TIO in pre-dose trough FEV1 at week 12. Secondary endpoints included transition dyspnea index (TDI) focal score, COPD assessment test (CAT) total score, and rescue medication use following the 12-week treatment, and safety assessment. Results: Of the 442 patients screened, 379 were randomized and 347 completed the study. IND/GLY demonstrated superiority in pre-dose trough FEV1 versus TIO at week 12 (least squares mean treatment difference [Δ], 50 mL; p=0.013). Also, numerical improvements were observed with IND/GLY in the TDI focal score (Δ, 0.31), CAT total score (Δ, –0.81), and rescue medication use (Δ, –0.09 puffs/day). Both treatments were well tolerated by patients. Conclusion A direct switch from TIO to IND/GLY provided improvements in lung function and other patient-reported outcomes with an acceptable safety profile in patients with mild-to-moderate airflow limitation.

Food allergy is an immune-mediated adverse reaction that occurs mainly by food ingestion. Some children with food allergies manifest fatal symptoms like anaphylaxis. Oral immunotherapy (OIT) may offer an effective therapeutic modality for persistent and severe forms of food allergies. We report our experience with OIT in 3 patients with IgE-mediated hen’s egg allergy. Our treatment strategy consists of 1–3 days of initial escalation, 47 to 65 weeks of build-up phase, and 1 year of maintenance phase. Lactobacillus plantarum CJLP133, 1×1010 colony-forming unit/day was taken during OIT. As a result, 1 patient achieved successful desensitization, and 1 patient reached maintenance therapy, but did not obtain desensitization. In addition, 1 patient withdrew from treatment due to anxiety symptoms. Despite the limited number of patients, we experienced and herein presented 3 cases of OIT in egg allergy. More trials of OIT need to be performed as a treatment option in Korean children with food allergies.

PURPOSE: Comorbidities have been considered a mortality risk factor in pediatric critical care patients. We studied the characteristics and prognostic factors of children without comorbidities who were admitted to the intensive care unit (ICU) due to respiratory failure. METHODS: We reviewed the medical charts of patients (< 18 years) admitted to the ICU for respiratory support in a single tertiary center between January 2006 and December 2016. Patients with comorbidities and perioperative statuses were excluded. RESULTS: Of the 4,712 ICU patients, 73 (1.5%) were included in this study. The median age was 31 months (8–57) and 51 (69.9%) were boys. Twenty-nine patients (39.7%) presented with pneumonia, 14 (19.2%) with acute respiratory distress syndrome (ARDS), and 11 (15.1%) with obstructive airway disease. The median duration of ICU hospitalization was 5 days (2–14.5), and 45 of the 73 patients (61.6%) needed mechanical ventilation. Mortality was 13.7% (10/73). None of the patients with pneumonia or obstructive airway disease died. The most frequent cause of death was ARDS (5 of 10, 50%). In adjusted analysis, the extent of extrapulmonary organ dysfunction was significantly associated with mortality (odds ratio, 2.89; 95% confidence interval, 1.17–7.11; P=0.023). CONCLUSION: The mortality rate of previously healthy pediatric patients needing respiratory support in the ICU should not be negligible. Multiple organ dysfunctions might be a significant risk factor for mortality in such patients.
Cause of Death ; Child* ; Comorbidity ; Critical Care* ; Hospitalization ; Humans ; Intensive Care Units* ; Mortality ; Pneumonia ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Respiratory Insufficiency ; Risk Factors

BACKGROUND: We evaluated the changes in mean arterial pressure (MAP) and heart rate (HR), and the anesthetic and hemostatic effects, after injection of 2% lidocaine containing various concentrations of epinephrine in rats and mice to determine the appropriate concentration of epinephrine in various anesthetic mixtures. METHODS: Rats and mice were randomly allocated to experimental groups: 2% lidocaine without epinephrine (L0), 2% lidocaine with epinephrine 1:200,000 (L200), 1:100,000 (L100), and 1:80,000 (L80). Changes in MAP and HR after administration of the anesthetic mixture were evaluated using a physiological recording system in rats. Onset and duration of local anesthesia was evaluated by pricking the hind paw of mice. A spectrophotometric hemoglobin assay was used to quantify the hemostatic effect. RESULTS: MAP increased in response to epinephrine in a dose-dependent manner; it was significantly higher in the L80 group than in the L0 group at 5 min post-administration. The HR was relatively lower in the L0 group than in the L80 group. The time required for onset of action was < 1 min in all evaluation groups. The duration of action and hemostatic effect of the local anesthetic were significantly better in the L200, L100, and L80 groups than in the L0 group. CONCLUSION: L200 demonstrated relatively stable MAP and HR values with satisfactory efficacy and hemostatic effect. L200 might be a better local anesthetic for dental patients in terms of anesthetic efficacy and safety.
Anesthesia, Local ; Anesthetics, Local ; Animals ; Arterial Pressure ; Epinephrine ; Heart Rate ; Hemostasis ; Humans ; Lidocaine ; Mice ; Rats

OBJECTIVE: In pectus excavatum patients, Nuss procedure provides excellent cosmetic results, but it cause hypoxemia and hypercarbia by the reduction of alveolar ventilation due to severe thorax expansion and pain after operation. This study was designed to evaluate the effect of different oxygen flow rates via a nasal cannula in recovery room after correction of pectus excavatum by Nuss procedure. METHODS: Forty patients (3–12 years old) undergoing pectus excavatum repair were randomly assigned and divided into two groups. Patients were given 200 mL/kg/min flow of 100% oxygen (group 1) and 100 mL/kg/min flow of oxygen (group 2) via nasal cannula in the recovery room. Arterial blood gas analysis and peripheral oxygen saturation were measured at arrival and after 5, 10, 15, and 30 minutes in the recovery room. RESULTS: In group 1 compared with group 2, decrease of PaCO2 (partial pressure of CO2 in arterial blood) accumulation was observed in 5, 10, and 15 minutes. Arterial oxygen pressure (PaO2) difference was not significant between the group. But, in comparison within groups, PaO2 level was significantly higher at 5, 10, 15, and 30 minutes than just after arrival at the recovery room. In both group, heart rate and systolic blood pressure were no significant difference. CONCLUSION: We recommend that 200 mL/kg/min flow of 100% oxygen should be administered to patients who were taken Nuss procedure for prevention of hypoxemia and hypercarbia in recovery rooms.
Anoxia ; Blood Gas Analysis ; Blood Pressure ; Catheters* ; Funnel Chest* ; Heart Rate ; Humans ; Oxygen* ; Recovery Room* ; Thorax ; Ventilation