Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients.The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold.Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cellmediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

This study offers a comprehensive overview of brain organoids for researchers. It combines expert opinions with technical summaries on organoid definitions, characteristics, culture methods, and quality control. This approach aims to enhance the utilization of brain organoids in research. Brain organoids, as three-dimensional human cell models mimicking the nervous system, hold immense promise for studying the human brain. They offer advantages over traditional methods, replicating anatomical structures, physiological features, and complex neuronal networks. Additionally, brain organoids can model nervous system development and interactions between cell types and the microenvironment. By providing a foundation for utilizing the most human-relevant tissue models, this work empowers researchers to overcome limitations of two-dimensional cultures and conduct advanced disease modeling research.

Background and Objectives: The association between bilirubin and atrial fibrillation (AF) has been evaluated previously in observational studies but with contradictory results. This study evaluated the causal association between serum bilirubin level and AF using Mendelian randomization (MR) analysis. Methods: This cross-sectional study includes 8,977 participants from the Dong-gu Study.In the observational analysis, multivariate logistic regression was performed to evaluate the association between bilirubin and prevalent AF. To evaluate the causal association between bilirubin and AF, MR analysis was conducted by using the UGT1A1 rs11891311 and rs4148323 polymorphisms as instrumental variables. Results: Elevated serum bilirubin levels were associated with an increased risk for AF in observational analysis (total bilirubin: odds ratio [OR], 1.31; 95% confidence interval [95% CI], 1.15–1.48 per 1 standard deviation [SD]; direct bilirubin: OR, 1.31; 95% CI, 1.18–1.46 per 1 SD), whereas the genetically predicted serum bilirubin levels in MR analysis did not show this association (total bilirubin: OR, 1.02; 95% CI, 0.67–1.53 per 1 SD; direct bilirubin: OR, 1.03; 95% CI, 0.61–1.73 per 1 SD). Conclusions Genetically predicted bilirubin levels were not associated with prevalent AF.Thus, the observational association between serum bilirubin levels and AF may be noncausal and affected by reverse causality or unmeasured confounding.

Background: The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. Results: K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. Conclusion Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Objective: The purpose of this study was to compare the physical work intensity of emergency medicine (EM) and non-EM residents during a 24-hour work duty cycle using a smartwatch. Methods: This study was conducted for a month from 7 May to 4 June 2021. A total of 27 residents submitted their consent to be recruited as subjects for the study. We distributed a smartwatch to each of the participants and measured their physical work intensity. Twenty non-EM residents wore a smartwatch for a week. Also, seven EM residents wore a watch during the time they were on 24-hour duty for the whole research period. After finishing their 24-hour duty, participants took off the smartwatch and stopped recording their physical activities. Sixty-five samples were matched for comparison between the non-EM and EM residents. Each of the samples comprised a pair of 24-hour records of EM and non-EM residents. The data were matched to ensure the same date and grade and thus control the variables. Results: The results of this study showed that the maximum heart rate of the EM residents was 129.7±3.8 beats/min, which was higher than that of the non-EM residents. A comparison of the sleep hours during the 24-hour duty showed that the average sleep time of the EM residents was 156.9±84.8 minutes, which was significantly lower than that of the non-EM residents. However, calorie consumption, moving distance, and step count during the 24-hour duty cycle showed no significant difference between the EM and non-EM residents. Conclusion The maximum heart rate was higher among EM residents during their 24-hour work duty compared to the non-EM residents. In addition, the sleep time of the EM residents was significantly lower than that of the non-EM residents.

Hepatocellular carcinoma (HCC) is a cytotoxic chemotherapy-resistant tumor and most HCCs arise in a background of liver cirrhosis of various causes. Although the IMBrave150 trial showed remarkable advancements in the treatment of unresectable HCC with atezolizumab plus bevacizumab (AteBeva), therapeutic outcomes were unsatisfactory in more than half of the patients. Accordingly, many ongoing trials combine conventional modalities with new drugs such as immune checkpoint inhibitors for better treatment outcomes, and they are expected to benefit patients with limited responses to conventional treatment. Here, two patients with advanced stage HCC with preserved liver function and good performance status showed partial response after treatment with combination or sequential therapy of AteBeva, hepatic arterial infusion chemotherapy, radiation therapy, and transarterial chemoembolization. These findings indicate the efficacy of multidisciplinary treatment against advanced HCC. Additional studies are required to establish optimal treatment strategies.

Objective: When rescuers move from ambulance to resuscitation area, they press the chest with one-hand by the stretchers. The purpose of this study was to investigate the effect of one-hand chest compression on unfolded stretchers and analyze the characteristics of rescuers that affect compression. Methods: A manikin simulation study was planned. A total of 28 participants performed one-hand chest compression for one minute to a manikin on the unfolded stretchers. The depth of compression, the extent of recoil and compression frequency were measured, and the results were analyzed. Correlation analysis was done between participant characteristics and depth and frequency of compression. Linear regression analysis was done for variables with significant correlation. Results: Four participants were excluded due to wrist or shoulder pain. A total of 24 participants (13 male; 11 female) were enrolled. The mean depth of compression was 34.88±11.06 cm; the mean extent of recoil was 50.00±0 cm. The mean frequency of compression was 104.71±11.07 per minute. The extent of recoil and frequency of compression were satisfied with cardiopulmonary resuscitation (CPR) guidelines. The depth of compression was highly correlated with participants’ sex (r=-0.88), height (r=0.86), and weight (r=0.78). When adjusted for sex, the depth of compression increased as height and weight increased. Conclusion Mechanical chest compression device should be used when CPR is required while moving a cardiac arrest patient by the stretchers. If CPR needs to be done manually, moving distance should be minimized. Finally, a new type of stretcher that fits the body shape of Koreans should be developed.

Background and Objectives: De-escalation of dual-antiplatelet therapy through dose reduction of prasugrel improved net adverse clinical events (NACEs) after acute coronary syndrome (ACS), mainly through the reduction of bleeding without an increase in ischemic outcomes. Whether the benefits of de-escalation are sustained in highly thrombotic conditions such as ST-elevation myocardial infarction (STEMI) is unknown. We aimed to assess the efficacy and safety of de-escalation therapy in patients with STEMI or non-STsegment elevation ACS (NSTE-ACS). Methods: This is a pre-specified subgroup analysis of the HOST-REDUCE-POLYTECH-ACS trial. ACS patients were randomized to prasugrel de-escalation (5 mg daily) or conventional dose (10 mg daily) at 1-month post-percutaneous coronary intervention. The primary endpoint was a NACE, defined as a composite of all-cause death, non-fatal myocardial infarction, stent thrombosis, clinically driven revascularization, stroke, and bleeding events of grade ≥2 Bleeding Academic Research Consortium (BARC) criteria at 1 year. Results: Among 2,338 patients included in the randomization, 326 patients were diagnosed with STEMI. In patients with NSTE-ACS, the risk of the primary endpoint was significantly reduced with de-escalation (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.48– 0.89; p=0.006 for de-escalation vs. conventional), mainly driven by a reduced bleeding. However, in those with STEMI, there was no difference in the occurrence of the primary outcome (HR, 1.04; 95% CI, 0.48–2.26; p=0.915; p for interaction=0.271). Conclusions Prasugrel dose de-escalation reduced the rate of NACE and bleeding, without increasing the rate of ischemic events in NSTE-ACS patients but not in STEMI patients.

Background and Objectives: The aim of this study was to demonstrate the efficacy and safety of treatment with drug-coated balloon (DCB) in a large real-world population. Methods: Patients treated with DCBs were included in a multicenter observational registry that enrolled patients from 18 hospitals in Korea between January 2009 and December 2017. The primary outcome was target lesion failure (TLF) defined as a composite of cardiovascular death, target vessel myocardial infarction, and clinically indicated target lesion revascularization at 12 months. Results: The study included 2,509 patients with 2,666 DCB-treated coronary artery lesions (1,688 [63.3%] with in-stent restenosis [ISR] lesions vs. 978 [36.7%] with de novo lesions).The mean age with standard deviation was 65.7±11.3 years; 65.7% of the patients were men.At 12 months, the primary outcome, TLF, occurred in 179 (6.7%), 151 (8.9%), 28 (2.9%) patients among the total, ISR, and de novo lesion populations, respectively. A history of hypertension, diabetes, acute coronary syndrome, previous coronary artery bypass graft, reduced left ventricular ejection fraction, B2C lesion and ISR lesion were independent predictors of 12 months TLF in the overall study population. Conclusions This large multicenter DCB registry study revealed the favorable clinical outcome of DCB treatment in real-world practice in patient with ISR lesion as well as small de novo coronary lesion.