Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Objectives: The coronavirus disease (COVID-19) pandemic has had various effects on mankind, especially children and adolescents.Because children and adolescents spend a lot of time at school, COVID-19 has had a great impact on school mental health. In this study, we investigated the effect of prolonged COVID-19 on school mental health. Methods: We prepared self-report questionnaires for depression (Children’s Depression Inventory, CDI), anxiety (Korean version of the Penn State Worry Questionnaire for Children; Generalized Anxiety Disorder-7, GAD-7), and post-traumatic stress (Primary Care Post-traumatic Stress Disorder, PC-PTSD) for administering to students aged between 7 and 18 years, recruited by a COVID-19 psychological prevention support group in the Gwangmyeong Mental Health Welfare Center for 2 years, in 2020 and 2021. Results: For children aged 7–12 years, there was no significant difference between the years 2020 and 2021 in the assessment of depression, anxiety, and post-traumatic stress. Conversely, for adolescents aged 13–18 years, there was a significant increase in the scale scores (CDI, PC-PTSD, and GAD-7). Conclusion Prolonged COVID-19 might have had a significant impact on the mental health of adolescents who spent a lot of time at school. When comparing the years 2020 and 2021, middle and high school students were more affected by COVID-19 than elementary school students.

Background/Aims: While distal radial artery (DRA) access is increasingly being used for diagnostic coronary angiography, limited information is available regarding DRA size. We aimed to determine the DRA reference diameters of Korean patients and identify the predictors of DRA diameter < 2.3 mm. Methods: The outer bilateral DRA diameters were assessed using a linear ultrasound probe in 1,162 consecutive patients who underwent transthoracic echocardiography. The DRA diameter was measured by the perpendicular angle in the dorsum of the hand, and the average values were compared by sex. DRA diameter < 2.3 mm was defined as unsuitable for routine diagnostic coronary angiography using a 5 Fr introducer sheath. Results: The mean DRA diameters were 2.31 ± 0.43 mm (right) and 2.35 ± 0.45 mm (left). The DRA was smaller in women than men (right: 2.15 ± 0.38 mm vs. 2.43 ± 0.44 mm, p < 0.001; left: 2.18 ± 0.39 mm vs. 2.47 ± 0.45 mm, p < 0.001). The DRA diameter was approximately 20% smaller than the radial artery diameter. A total of 630 (54.2%) and 574 (49.4%) patients had DRA diameter < 2.3 mm in the right and left hands, respectively. Female sex, low body mass index (BMI), and low body surface area (BSA) were significant predictors of DRA diameter < 2.3 mm. Conclusions We provided reference DRA diameters for Korean patients. Approximately 50% of the studied patients had DRA diameter < 2.3 mm. Female sex, low BMI, and low BSA remained significant predictors of DRA diameter < 2.3 mm.

Background: The clinical features of pediatric rhabdomyolysis differ from those of the adults with rhabdomyolysis; however, multicenter studies are lacking. This study aimed to investigate the characteristics of pediatric rhabdomyolysis and reveal the risk factors for acute kidney injury (AKI) in such cases. Methods: This retrospective study analyzed the medical records of children and adolescents diagnosed with rhabdomyolysis at 23 hospitals in South Korea between January 2007 and December 2016. Results: Among 880 patients, those aged 3 to 5 years old composed the largest subgroup (19.4%), and all age subgroups were predominantly male. The incidence of AKI was 11.3%. Neurological disorders (53%) and infection (44%) were the most common underlying disorder and cause of rhabdomyolysis, respectively. The median age at diagnosis in the AKI subgroup was older than that in the non-AKI subgroup (12.2 years vs. 8.0 years). There were no significant differences in body mass index, myalgia, dark-colored urine, or the number of causal factors between the two AKI-status subgroups. The multivariate logistic regression model indicated that the following factors were independently associated with AKI: multiorgan failure, presence of an underlying disorder, strong positive urine occult blood, increased aspartate aminotransferase and uric acid levels, and reduced calcium levels. Conclusions Our study revealed characteristic clinical and laboratory features of rhabdomyolysis in a Korean pediatric population and highlighted the risk factors for AKI in these cases. Our findings will contribute to a greater understanding of pediatric rhabdomyolysis and may enable early intervention against rhabdomyolysis-induced AKI.

Immunoreactive dynamics of tumor-infiltrating lymphocytes (TILs) within the tumor microenvironment in breast cancer are not well understood. This study aimed to investigate the spatiotemporal cellular dynamics of TILs in breast cancer models. Breast cancer cells were implanted into the dorsal skinfold chamber of BALB/c nude mice, and T lymphocytes were adoptively transferred. Longitudinal intravital imaging was performed, and the spatiotemporal dynamics of TILs were assessed. In the 4T1 model, TILs progressively exhibited increased motility, and their motility inside the tumor was significantly higher than that outside the tumor. In the MDA-MB-231 model, the motility of TILs progressively decreased after an initial increase. TIL motility in the MDA-MB-231 and MCF-7 models differed significantly, suggesting an association between programmed death-ligand 1 expression levels and TIL motility, which warrants further investigation. Furthermore, intravital imaging of TILs can be a useful method for addressing dynamic interactions between TILs and breast cancer cells.

Background and Objectives: The relationship between the hospital percutaneous coronary intervention (PCI) volumes and the in-hospital clinical outcomes of patients with acute myocardial infarction (AMI) remains the subject of debate. This study aimed to determine whether the in-hospital clinical outcomes of patients with AMI in Korea are significantly associated with hospital PCI volumes. Methods: We selected and analyzed 17,121 cases of AMI, that is, 8,839 cases of non-ST-segment elevation myocardial infarction and 8,282 cases of ST-segment elevation myocardial infarction, enrolled in the 2014 Korean percutaneous coronary intervention (K-PCI) registry. Patients were divided into 2 groups according to hospital annual PCI volume, that is, to a high-volume group (≥400/year) or a low-volume group (<400/year). Major adverse cardiovascular and cerebrovascular events (MACCEs) were defined as composites of death, cardiac death, non-fatal myocardial infarction (MI), stent thrombosis, stroke, and need for urgent PCI during index admission after PCI. Results: Rates of MACCE and non-fatal MI were higher in the low-volume group than in the high-volume group (MACCE: 10.9% vs. 8.6%, p=0.001; non-fatal MI: 4.8% vs. 2.6%, p=0.001, respectively). Multivariate regression analysis showed PCI volume did not independently predict MACCE. Conclusions Hospital PCI volume was not found to be an independent predictor of in-hospital clinical outcomes in patients with AMI included in the 2014 K-PCI registry.

Objective: Personal mobility vehicles (PMV) have been used widely as a means of replacing bicycles in recent yearsbecause of their convenience and high economic efficiency. On the other hand, accidents related to PMV are alsoincreasing, but there have been few studies in this area. This study examined the factors that increase the severity ofdamage and determine the characteristics of the PMV compared to the accidents on a bicycle. Methods: Retrospective observational studies were performed. The variables related to the accident were collected andanalyzed for patients who visited the emergency room due to a PMV and bicycle accident. Multivariate logistic regressionanalysis was used to determine the factors affecting the severity of the patients. The odds ratios were calculated andcompared between injuries related to PMV and bicycles. Results: A total of 1,124 patients (bicycles 1,017, PMV 107) were enrolled in this study. In multivariate regression analysis,the severity of PMV was higher (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.06-2.83) than that of a bicycle.The factors affecting the severity of the patients were age (OR, 1.02, 95% CI, 1.01-1.03), alcohol use (OR, 1,70; 95% CI,1.04-2.70), ambulance transport (OR, 2.46; 95% CI, 1.78-3.40), and wearing a helmet (OR, 2.06; 95% CI, 1.36-3.13). Conclusion PMV showed higher severity of damage than a bicycle. The PMV, which is a new transportation means, isinsufficient for the prevention of safety compared to bicycles where driving regulations and wearing protective equipmentare common. Additional studies on the precise mechanisms of injury and damage are expected to prevent accidents andreduce their severity.

Purpose: This study examined the effects of training using the slime on the hand function and problem behavior in adults with intellectual disabilities. Methods: Five adults with intellectual disabilities who were judged as Level 1 or Level 2 were selected. The training consisted of one session (50 min)/day, one day/week for 10 weeks (preparatory activities: 5 min, slime activities: 40 min, finishing activities: 5 min) The functions of the hand (Purdue Pegboard Test [PPT], grip strength test [GST]) and problem behavior (Korean Behavior Problems Inventory [K-BPI]) were assessed three times (first assessment; pre, second assessment; post-5 weeks, third assessment; post-10 weeks). Wilcoxon signed-rank tests were used to analyze changes in the subjects’ performance before and after the intervention. Results: In the PPT, the use of the non-dominant hand was increased significantly (p<0.05). No significant differences were observed in the remaining results, but the mean value increased. In addition, although the problem behavior was not statistically significant, an increase in the problem behavior score was noted. Conclusion The training using the slime for adults with intellectual disabilities is effective in hand function improvement and reducing problem behavior.

Background: The use of intraoperative neuromonitoring (IONM) in thyroid surgery to preserve recurrent laryngeal nerve (RLN) function has been widely accepted. We aimed to evaluate the usefulness of IONM in reoperation for recurrent thyroid cancer patients to help identify the RLN and prevent vocal cord palsy (VCP). Methods: We analyzed 121 consecutive patients (with IONM group, 48 patients; without IONM group, 73 patients) who underwent reoperation for recurrent thyroid cancer after total thyroidectomy from January 2009 to March 2019 in our institution without VCP due to previous operations. Data including age, sex, number of previous operations, histologic subtype of the malignancy at the initial operation, operation time, RLNs at risk, difficulty of RLN identification, surgical procedure, VCP, and other postoperative complications were reviewed. Vocal cord movement evaluations were performed preoperatively and at 2 weeks postoperatively to evaluate RLN function. In patients with VCP, additional evaluations were performed. VCP exceeding 12 months after surgery was considered permanent VCP. Results: VCP was observed in six (12.5%) and 16 (21.9%) patients with and without IONM (P=0.189). Transient and permanent VCP were found in three (6.3%) and three (6.3%) patients with IONM (P=0.098 and P=0.982, respectively) versus in 12 (16.4%) and four (5.5%) patients without IONM. Conclusion The incidence of transient VCP seems to be lower in reoperations with IONM; however, there was no statistical significances. Further study will be needed to ascertain the efficacy of IONM in reoperation for recurrent thyroid cancer patients.

Purpose: This study examined the effects of training using the slime on the hand function and problem behavior in adults with intellectual disabilities. Methods: Five adults with intellectual disabilities who were judged as Level 1 or Level 2 were selected. The training consisted of one session (50 min)/day, one day/week for 10 weeks (preparatory activities: 5 min, slime activities: 40 min, finishing activities: 5 min) The functions of the hand (Purdue Pegboard Test [PPT], grip strength test [GST]) and problem behavior (Korean Behavior Problems Inventory [K-BPI]) were assessed three times (first assessment; pre, second assessment; post-5 weeks, third assessment; post-10 weeks). Wilcoxon signed-rank tests were used to analyze changes in the subjects’ performance before and after the intervention. Results: In the PPT, the use of the non-dominant hand was increased significantly (p<0.05). No significant differences were observed in the remaining results, but the mean value increased. In addition, although the problem behavior was not statistically significant, an increase in the problem behavior score was noted. Conclusion The training using the slime for adults with intellectual disabilities is effective in hand function improvement and reducing problem behavior.