Functional Connectivity Change Associated With Apolipoprotein E Allotypes Precedes Structural Connectivity and Neurodegeneration in Cognitive Normal Older Adults Without Cerebral Aβ Deposition

Objective@#Apolipoprotein E (APOE) gene is known to influence cerebral functional connectivity (FC) in Alzheimer’s disease continuum. We investigated association between APOE allotypes and FC, structural connectivity, and cortical thickness in amyloid-PET negative cognitive normal older adults (CN). @*Methods@#A total of 188 CN (37 had ε2/ε2 or ε2/ε3 [ε2 group], 113 had ε3/ε3 [ε3 group], and 38 had ε3/ε4 or ε4/ε4 [ε4 group]) were recruited. Voxel-based morphometry and cortical thickness analysis were used to investigate differences in cortical thickness between three APOE allotypes. To investigate integrity of structural connectivity, we analyzed diffusion weighted imaging using fractional anisotropy and mean diffusivity. In terms of FC, differences of FC in default mode network (DMN) among APOE allotypes were measured using functional magnetic resonance imaging. @*Results@#There were no significant differences in age, sex, education, cerebral beta-amyloid (Aβ) deposition severity, or neuropsychological profiles. No significant differences were found in cortical thickness and structural connectivity among the APOE allotypes. However, FC within the DMN was significantly lower in ε4 and ε2 carriers compared to ε3 homozygotes. @*Conclusion@#This study suggests that both ε4 and ε2 exhibit APOE-associated DMN FC changes before Aβ deposition, structural changes, and neurodegeneration.

Current evidence and the potential role of proton beam therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, and external beam radiation therapy has emerged as a promising approach for managing HCC. Proton beam therapy (PBT) offers dosimetric advantages over X-ray therapy, with superior physical properties known as the Bragg peak. PBT holds promise for reducing hepatotoxicity and allowing safe dose-escalation to the tumor. It has been tried in various clinical conditions and has shown promising local tumor control and survival outcomes. A recent phase III trial demonstrated the non-inferiority of PBT in local tumor control compared to current standard radiofrequency ablation in early-stage HCC. PBT also tended to show more favorable outcomes compared to transarterial chemoembolization in the intermediate stage, and has proven effective in-field disease control and safe toxicity profiles in advanced HCC. In this review, we discuss the rationale, clinical studies, optimal indication, and future directions of PBT in HCC treatment.

The Present of Peripheral Nerve Regeneration / 대한정형외과학회잡지

Substantial progress has been made in peripheral nerve surgery, owing to the advances in pathophysiological understanding, microsurgical techniques and the improvement of synthetic materials. Despite this, large gaps caused by trauma, tumor resection and congenital deformities show unsatisfactory results. While primary direct end-to-end tension-free nerve repair remains as the gold standard for surgical treatment, an autologous nerve graft is recommended for nerve gaps greater than 2 to 3 cm. Studies cite remarkable clinical reports with decellularized nerve allografts after overcoming the previous immune suppression and cost issues with allograft nerve transfers. New light is being shed regarding synthetic nerve conduits that combines various cytokines and growth factors. Stem cell studies applying biomolecular and biological engineering technologies also show good results. Despite this, further assessment are required for clinical application because these results are based primarily on animal studies.

Old Age, Female Sex, and Psychotropic Medications Predict Hyposalivation But Not Heart Rate Variability

Objective@#To explore risk factors for dry mouth and examine the clinical utility of the heart rate variability (HRV) test in the prediction of dry mouth. @*Methods@#Every outpatient, who underwent tests for both unstimulated salivary flow and HRV, was retrospectively reviewed. After excluding seven subjects, the demographics and clinical factors in 70 total patients were collected. Based on objective salivary flow rates, patients were classified into normal (≥0.2 mL/min) or hyposalivation groups (<0.2 mL/min), and inter-group comparisons were performed with a two-tailed statistical significance of 0.05. @*Results@#Patients with subjective dry mouth were significantly more likely to show hyposalivation. Advanced age, female sex, and current use of psychotropic medications were identified as risk factors for dry mouth. However, dry mouth was not associated with any HRV parameters. @*Conclusion@#HRV test did not demonstrate a clinical utility in predicting dry mouth. Because subjective dry mouth is significantly associated with objective hyposalivation, a simple probing question would be useful for early recognition of dry mouth. Clinical attention is required for patients meeting criteria of older age, female, and/or using psychotropic prescriptions. Prompt management of hyposalivation may improve quality of life and clinical outcome by enhanced treatment adherence.

A Nationwide Population-Based Study on the Association between Rosacea and Psychiatric Disorders: New Findings of Behavioral Disorders / 대한피부과학회지

Background@#Rosacea is a chronic skin inflammatory disorder that almost always occurs on the face, which can cause emotional stress and affect self-esteem. Rosacea is associated with psychiatric disorders, but there have been few studies on the relationship between rosacea and psychiatric disorders in Koreans. @*Objective@#We aimed to investigate the risk of psychiatric disorders in Korean patients with rosacea. @*Methods@#Data were obtained from the Korean National Health Insurance Service-National Sample Cohort. The database was collected according to the Korean Standard Classification of Diseases version 6, which is based on the International Classification of Diseases, 10th revision. This study was conducted with 595 patients diagnosed with rosacea from 2002 to 2013. A total of 2,380 controls were set by performing 1:4 matching for sex, age, and index year. @*Results@#The incidence of psychiatric disorders was higher in patients with rosacea (114/595, 19.16%) than in patients without rosacea (319/2,380, 13.40%), with a significant difference (p＜0.001). Among several types of psychiatric disorders, the prevalence of anxiety disorder and behavioral disorder was significantly higher in the rosacea patients than in patients without rosacea (p=0.008 and p=0.044, respectively). The adjusted hazard ratio for psychiatric disorders in patients with rosacea was 1.543 (95% confidence interval=1.238∼1.922, p＜0.001). @*Conclusion@#Rosacea is associated with many types of psychiatric disorders. Awareness of the psychological impact of rosacea might be helpful in improving patient quality of life.

Traumatic Posterior Chamber Intraocular Lens Dislocation into the Subconjunctival Space

Purpose@#Here we report a case of posterior chamber intraocular lens (IOL) dislocation into the subconjunctival space (pesudophacocele) following ocular trauma.Case summary: A 66-year-old male presented with ocular pain and decreased vision in the right eye following trauma with a metallic rod. The patient had a history of trabeculectomy, glaucoma drainage device implantation, transscleral cyclophotocoagulation, and cataract surgery for uveitic glaucoma and a cataract in the right eye. On examination, vision was hand movement, the intraocular pressure was 3 mmHg, and subconjunctival hemorrhage and hyphema were observed. After the resolution of hemorrhage, uveal tissue prolapse was seen nasally behind the corneal limbus and the IOL was found to be dislocated into the nasal subconjunctival space. There were no changes in the filtering bleb and tube compared to the pre-trauma status. The IOL was removed through a conjunctival incision because the patient refused any active treatment. @*Conclusions@#Pesudophacocele developed in a patient who had a history of glaucoma and cataract surgery in the injured eye. The IOL could not be assessed immediately after the trauma because of subconjunctival hemorrhage and hyphema. When the status of IOL is unclear or suspected to be dislocated after trauma, the possibility of pseudophacocele should be considered, in addition to the dislocation into the vitreous cavity.

Factors Associated with the Underuse of Sedatives and Neuromuscular Blocking Agents for Pediatric Emergency Endotracheal Intubation in Korea

Purpose@#Rapid sequence intubation (RSI) using sedatives and neuromuscular blocking agents (NMBAs) is recommended for pediatric emergency endotracheal intubation (ETI), but is not frequently performed in Korea. This study aimed to verify factors associated with the underuse of RSI medications. @*Materials and Methods@#This multicenter retrospective study reviewed patients aged under 18 years who underwent an ETI within 24 hours of arrival at the emergency department between 2016 and 2019. Any cases of ETI during cardiopulmonary resuscitation were excluded. We investigated the characteristics of the patients, intubators, RSI medications, and outcomes. The study cases were classified into no-medication, sedative-only, and sedative-with-NMBA groups. Multivariable logistic regression analysis of RSI medication use was conducted. @*Results@#A total of 334 cases with a median age of 3.4 years were included in this study. Sedatives and NMBAs were used in 63.8% and 32.9%, respectively. In comparing the no-medication (n=121), sedative-only (n=103), and sedative-with-NMBA (n=110) groups, patient age (median; 1.0 year vs. 2.8 years vs. 11.3 years; p<0.001), underlying medical conditions (77.7% vs. 56.3% vs. 36.4%; p<0.001), and pediatricians as intubators (76.9% vs. 54.4% vs. 17.3%; p<0.001) were different. The factors that influenced sedatives with NMBA use were patient age [for a year increment; adjusted odds ratio (aOR), 1.182; 95% confidence interval (CI), 1.120– 1.249], no underlying medical conditions (aOR, 2.109; 95% CI, 1.093–4.070), and intubators other than pediatricians (aOR, 5.123; 95% CI, 2.257–11.626). @*Conclusion@#RSI accounted for 32.9% of pediatric emergency ETI in Korea. The underuse of RSI medications is associated with younger patient age, underlying medical conditions, and pediatricians as intubators.

Benign Concentric Annular Macular Dystrophy in a Young Woman

Purpose@#Here, we report a case of benign concentric annular macular dystrophy associated with a visual field defect.Case summary: A 34-year-old woman presented with a visual field defect that was not accompanied by a deterioration in visual acuity. The patient’s best-corrected visual acuity was 1.25 in both eyes. No signs of anterior chamber inflammation were observed, and fundoscopy showed annular hypopigmentation at the fovea in both eyes. Annular hyperfluorescence was observed on fluorescein angiography due to the window defect. Automated perimetry demonstrated an annular paracentral scotoma in both eyes. The standard electroretinogram was normal, whereas optical coherence tomography showed a loss at the inner and outer boundaries of the foveal photoreceptors. The patient had no history of chloroquine or hydroxychloroquine intake, which excluded Bull’s eye maculopathy. The patient was observed without treatment for 2 years and no change was observed in her visual acuity or the appearance of the fovea. @*Conclusions@#Benign concentric annular macular dystrophy should be considered in patients with annular hypopigmentation at the fovea without deterioration in the visual acuity of both eyes.

Two Schwannomas Derived from the Ulnar Nerve Confirmed by Ultrasonography

Schwannoma is a rare tumor from the peripheral nerve and is mainly found alone. Diagnosis is made by ultrasonography or magnetic resonance imaging, and magnetic resonance imaging is preferred to ultrasonography for differential diagnosis of mass. After diagnosis, treatment is performed through surgical excision. In this case, a very small-sized neuropathy-causing lesion was identified through ultrasonography with electrodiagnostic study, and the other mass in the same nerve was discovered by chance through ultrasonography. Both masses were identified as schwannoma originating from the ulnar nerve and were successfully excised. We confirmed the advantages of ultrasonography in the rare diagnosis and again showed that ultrasonography has a diagnostic value that is not inferior to magnetic resonance imaging. Also, cases of multiple schwannomas confined to the ulnar nerve are rare and have been rarely reported worldwide. Therefore, it is reported together with the previous reports.

Effect of fever or respiratory symptoms on leaving without being seen during the COVID-19 pandemic in South Korea

Objective@#Coronavirus disease 2019 (COVID-19) has notably altered the emergency department isolation protocol, imposing stricter requirements on probable infectious disease patients that enter the department. This has caused adverse effects, such as an increased rate of leave without being seen (LWBS). This study describes the effect of fever/respiratory symptoms as the main cause of isolation regarding LWBS after the COVID-19 pandemic. @*Methods@#We retrospectively analyzed emergency department visits before (March to July 2019) and after (March to July 2020) the COVID-19 pandemic. Patients were grouped based on existing fever or respiratory symptoms, with the LWBS rate as the primary outcome. Logistic regression analysis was used to identify the risk factors of LWBS. Logistic regression was performed using interaction terminology (fever/respiratory symptom patient [FRP] × post–COVID-19) to determine the interaction between patients with FRPs and the COVID-19 pandemic period. @*Results@#A total of 60,290 patients were included (34,492 in the pre–COVID-19, and 25,298 in the post–COVID-19 group). The proportion of FRPs decreased significantly after the pandemic (P < 0.001), while the LWBS rate in FRPs significantly increased from 2.8% to 19.2% (P < 0.001). Both FRPs (odds ratio, 1.76; 95% confidence interval, 1.59–1.84 (P < 0.001) and the COVID-19 period (odds ratio, 2.29; 95% confidence interval, 2.15–2.44; P < 0.001) were significantly associated with increased LWBS. Additionally, there was a significant interaction between the incidence of LWBS in FRPs and the COVID-19 pandemic period (P < 0.001). @*Conclusion@#The LWBS rate has increased in FRPs after the COVID-19 pandemic; additionally, the effect observed was disproportionate compared with that of nonfever/respiratory symptom patients.

Phentermine and Phendimetrazine-Induced Psychotic Disorder and Bipolar Disorder: A Case Series

Objectives@#Recently, weight loss has emerged as a national concern in South Korea, and this has resulted in an increase in the frequency of use of central nervous system (CNS)-stimulating appetite suppressants. This study aimed to collect cases of psychotic disorders and bipolar disorders triggered by phentermine and phendimetrazine and explore the clinical features and courses. @*Methods@#In this retrospective study, we analyzed the electronic medical records of patients and selected eight patients who developed psychotic symptoms and manic symptoms for the first time after taking phentermine and phendimetrazine. All cases were reviewed, and their clinical features and course were summarized. @*Results@#All eight patients developed psychotic symptoms, and one had accompanying manic symptoms. The final diagnosis was appetite-suppressant-induced psychotic disorder in four patients, schizophrenia in three, and appetite-suppressant-induced bipolar disorder in one. In addition, three patients were diagnosed as having substance-use disorder. The key psychotic symptoms of these patients were hallucinations and paranoia. @*Conclusions@#These case findings suggest that phentermine and phendimetrazine can cause psychotic disorder, bipolar disorder, or substance use disorder and that medical professionals and the public should practice caution when prescribing and using these drugs.

Reference Standards for Nerve Conduction Studies of Individual Nerves of Lower Extremity With Expanded Uncertainty in Healthy Korean Adults

Objective@#To develop a set of reference standards for tibial motor, common peroneal motor, sural sensory, and superficial peroneal sensory nerve conduction studies (NCSs) with expanded uncertainty in a healthy Korean population. @*Methods@#Standardized procedures were conducted for individual lower extremity NCSs of 199 healthy participants in their 20s (n=100) and 50s (n=99). Mean values and expanded uncertainties for parameters were analyzed with thorough consideration of multiple uncertainty factors under the International Guide to the Expression of Uncertainty in Measurement. In addition, side-to-side differences in onset latency, amplitude, and nerve conduction velocity (NCV) were analyzed. @*Results@#Mean (reference range) for distal onset latency, baseline to negative peak amplitude, NCV of tibial motor nerve in males in their 20s were 4.3 ms (3.1–5.4 ms), 7.1 mV (3.4–10.9 mV), and 50.7 m/s (42.2–59.3 m/s), respectively; sural sensory nerve baseline to negative peak amplitude in males in their 20s was 21.7 μV (8.3–35.2 μV). Including the aforementioned data, we present a vast dataset of normative mean values and expanded uncertainties for NCSs of the leg in a healthy Korean population. Furthermore, upper limits for normal side-to-side differences for onset latency, amplitude, and NCV of each nerve are suggested. @*Conclusion@#To our knowledge, this is the first study to present the reference standards of leg NCSs with consideration for multifactorial uncertainties in an Asian population. We expect these results to help practitioners make reliable and reproducible clinical decisions.

Patterns of Proton Beam Therapy Use in Clinical Practice between 2007 and 2019 in Korea / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Proton beam therapy (PBT) is a state-of-the-art technology employed in radiotherapy (RT) for cancer patients. This study characterized how PBT has been used in clinical practice in Korea. @*Materials and Methods@#Patients who received any type of RT between 2007 and 2019 were identified from the radiation oncology registry of the two PBT facilities operating in Korea (National Cancer Center and Samsung Medical Center). The chi-square test was used to identify patient- and treatment-related characteristics associated with the receipt of PBT. @*Results@#A total of 54,035 patients had been treated with some form of RT in the two institutions, of whom 5,398 received PBT (10.0%). The number of patients who receive PBT has gradually increased since PBT first started, from 162 patients in 2007 to 1,304 patients in 2019. Among all types of cancer, PBT use in liver cancer has been steadily increasing from 20% in 2008-2009 to 32% in 2018-2019. In contrast, that in prostate cancer has been continuously decreasing from 20% in 2008-2009 to < 10% in 2018-2019. Male sex, very young or old age, stage I-II disease, residency in non-capital areas, a definitive setting, a curative treatment aim, enrollment in a clinical trial, re-irradiation and insurance coverage were significantly associated with the receipt of PBT (all p < 0.05). @*Conclusion@#Since PBT started in Korea, the number of patients receiving PBT has increased to more than 1,000 per year and treatment indications have expanded. Liver cancer is the most common primary tumor among all PBT cases in Korea.

Peripheral Nerve Regeneration Using a Nerve Conduit with Olfactory Ensheathing Cells in a Rat Model

BACKGROUND@#Autologous nerve grafts are the gold standard treatment for peripheral nerve injury treatment. However, this procedure cannot avoid sacrificing other nerves as a major limitation. The aim of the present study was to evaluate the potential of olfactory ensheathing cells (OECs) embedded in a nerve conduit. @*METHODS@#A 10-mm segment of the sciatic nerve was resected in 21 rats, and the nerve injury was repaired with one of the following (n = 7 per group): autologous nerve graft, poly (ε-caprolactone) (PCL) conduit and OECs, and PCL conduit only. The consequent effect on nerve regeneration was measured based on the nerve conduction velocity (NCV), amplitude of the compound muscle action potential (ACMAP), wet muscle weight, histomorphometric analysis, and nerve density quantification. @*RESULTS@#Histomorphometric analysis revealed nerve regeneration and angiogenesis in all groups. However, there were significant differences (p  0.05). No significant results in NCV, wet muscle weight, and nerve density quantification were observed among the 3 groups. @*CONCLUSION@#A PCL conduit with OECs enhances the regeneration of injured peripheral nerves, offering a good alternative to autologous nerve grafts.

Usefulness of the Icare ic200 Rebound Tonometer in Korean

Purpose@#To evaluate the efficacy of the Icare ic200 in clinical practice by comparing the intraocular pressure (IOP) measured with the Icare ic200 rebound tonometer to the IOP measured with the Goldmann applanation tonometer (GAT). @*Methods@#A total of 294 eyes of 294 Korean patients were included. IOP was measured with the Icare ic200 and then measured again with a GAT in all patients. We evaluated the degree of IOP agreement between the two tonometers and analyzed the diagnostic ability of the Icare ic200 for a reading ≥ 22 mmHg with the GAT. We also analyzed whether clinical factors including biometry affected the difference in IOP measured by the two tonometers. @*Results@#The IOP values measured with the Icare ic200 and GAT were strongly correlated (r = 0.875, p < 0.001). The IOP measured with the Icare ic200 was lower than the IOP measured with GAT. The mean difference was 3.07 ± 2.67 mmHg, and 95.24% of patients were distributed within the 95% limits of agreement (-2.16 to 8.30 mmHg) on Bland-Altman plots. The diagnostic ability of the Icare ic200 for IOP ≥ 22 mmHg was 0.959 (area under the receiver operating characterisitic). In multivariate regression analyses, older age (β = 0.034, p = 0.020) and greater corneal curvature (β = 0.213, p = 0.030) were correlated with larger IOP differences between the two tonometers. @*Conclusions@#Although the Icare ic200 was more consistent than the GAT with reasonable diagnostic ability for ≥ 22 mmHg, the IOP measured 3 mmHg lower than the GAT. Therefore, the Icare ic200 might be more useful as a screening test to increase IOP rather than replacing GAT in clinical practice.

Combined Intravitreal Bevacizumab and Laser Photocoagulation to Treat Retinal Arterial Macroaneurysms

Purpose@#To investigate the effects of intravitreal bevacizumab injection combined with laser photocoagulation in patients with retinal microaneurysms. @*Methods@#We retrospectively reviewed the medical records of 21 eyes of 21 patients who underwent intravitreal bevacizumab injection and/or laser photocoagulation to treat retinal macroaneurysms. Eleven eyes received the combination therapy (CT) and 10 eyes monotherapy (MT) (either bevacizumab injection or laser photocoagulation). Changes in visual acuity, central macular thickness, macroaneurysm size and location, blood pressure, and the lipid level were compared between the two groups. @*Results@#The mean patient age was 74.0 ± 10.5 years and the mean study period 7.0 ± 5.3 months. The mean macroaneurysm diameter of the CT group was 480.00 ± 292.30 μm and that of the MT group 328.75 ± 87.09 μm. The diameter was significantly larger in the CT group (p = 0.002). The initial visual acuities were 0.91 ± 0.66 and 0.88 ± 0.83 in the CT and MT groups, respectively. At the 4-month follow-up, the visual acuities were 0.33 ± 0.26 and 0.17 ± 0.29 in the CT and MT groups, respectively, and had significantly improved only in the CT group (p = 0.042). The initial central macular thicknesses were 441.82 ± 226.81 and 541.63 ± 401.97 μm in the CT and MT groups, respectively. At the 4-month follow-up, the figures were 293.60 ± 46.10 and 269.00 ± 48.34 μm in the CT and MT groups, respectively, and had significantly decreased only in the CT group (p = 0.043). Compared to the initial findings, the proportion of patients whose final visual acuities improved by more than two lines were 73% and 40%, respectively, thus significantly higher in the CT group (p < 0.001). @*Conclusions@#Combined intravitreal bevacizumab injection and laser photocoagulation treatment of retinal macroaneurysms improve visual acuity and decrease macular thickness.

A Recognition Survey by Psychiatry Residents Regarding the Quality of Psychotherapy Training and Psychotherapy Competencies in Korea / 신경정신의학

Objectives@#This study surveyed the quality of psychotherapy training and psychotherapy competencies during residency in Korea. @*Methods@#A questionnaire developed by The Committee of Residency Training of the Korean Neuropsychiatric Association was completed by fourth-year residents of Korean psychiatry (n=120). The questionnaire examined their demographic characteristics, their experience of clinical psychotherapy training, their degree of satisfaction in the quality of psychotherapy training, and self-rated competence regarding the six types of psychotherapies, including supportive psychotherapy, cognitive behavioral therapy, interpersonal psychotherapy, psychoanalytic psychotherapy, group psychotherapy, and family psychotherapy. @*Results@#The degree of satisfaction of the residents with the psychotherapy training was diverse among the types of psychotherapy and contents of training. Across all types of psychotherapies, the satisfaction levels of the quantity and quality of supervision education were low, except for psychoanalytic psychotherapy. Overall, more than 70% of residents were not satisfied with the theoretical education, clinical practice, and supervision education in three types of psychotherapies, including interpersonal psychotherapy, group psychotherapy, and family psychotherapy. A positive correlation was found between the degree of satisfaction with the quality of training experience and self-rated competence of psychotherapy. Specifically, the self-rated competence of psychotherapy was more highly correlated with the experience of clinical cases and supervision than theoretical education @*Conclusion@#This study showed the quantitative and qualitative status of psychotherapy training in Korean psychiatry residency programs, and the satisfaction level of psychotherapy education was low except for psychoanalytic psychotherapy. There is a strong need for the improvement of psychotherapy training programs in Korea.

Respiratory Protection Effect of Earloop-type KF94 Masks according to the Wearing Method in COVID-19 Pandemic: a Randomized, Open-label Study

Background@#Ear-loop-type Korean Filter 94 masks (KF94 masks, equivalent to the N95 and FFP2) are broadly used in health care settings in Korea for the coronavirus disease 2019 pandemic. @*Methods@#A prospective randomized open-label study was designed to identify differences in the fitting performance between mask wearing methods in three different types of KF94 mask with ear loops between January to March 2021. General-fitting involved wearing an earloop-type KF94 mask, and tight-fitting involved wearing a mask aided by a clip connecting the ear loops. Each of the 30 participants wore three types of masks according to a randomly assigned order in both methods and performed a total of six quantitative fit tests (QNFTs) according to the occupational safety and health administration protocol. @*Results@#All fit factors (FFs) measured by the QNFT were significantly higher for tight-fitting method with the clip in all KF94 masks (P < 0.001). However, the total FFs were very low, with a median (interquartile range) of 6 (3–23) and 29 (9–116) for general-fitting and tight-fitting, respectively. When wearing tightly, the horizontal 3-fold type mask with adjustable ear-loop length had the highest FF, with a median of 125, and the QNFT pass rate (FF ≥ 100) increased significantly from 4 (13%) to 18 (60%). @*Conclusion@#Even with sufficient filter efficiency, ear-loop-type-KF94 masks do not provide adequate protection. However, in relatively low-risk environments, wearing a face-seal adjustable KF94 mask and tight wearing with a clip can improve respiratory protection for healthcare workers.

Impact of the COVID-19 Outbreak on Trends in Emergency Department Utilization in Children: a Multicenter Retrospective Observational Study in Seoul Metropolitan Area, Korea

Background@#Understanding the changes in emergency department (ED) visit patterns during the coronavirus disease 2019 (COVID-19) outbreak is important for effectively operating EDs during the pandemic. We aimed to analyze the changes in pediatric ED visits during the COVID-19 pandemic and examine the relationship between the number of ED visits and the stringency of government social distancing measures. @*Methods@#This multicenter retrospective study used data of pediatric (age < 18 years) ED visits in Seoul metropolitan area from June 1, 2018, to May 31, 2020. Patient demographics, ED results, and diagnoses were compared during the COVID-19 period and the previous year.To evaluate the effect of the stringency of social distancing measures on the number of ED visits, a Poisson regression model was developed with month, year, and the average monthly Government Response Stringency Index (GRSI) as fixed effects. @*Results@#In total, 190,732 patients were included. The number of pediatric ED visits during the COVID-19 period was 58.1% lower than in the previous year. There were disproportionate decreases in the numbers of ED visits for children in early childhood (66.5%), low-acuity children (55.2-63.8%), those who did not use an ambulance (59.0%), and those visiting the ED for noninjury complaints (64.9%). The proportion of admissions increased from 11.9% to 16.6%. For every 10-point increase in the GRSI, there was a 15.1% decrease in monthly ED visits. @*Conclusion@#A striking decrease in pediatric ED visits was observed during the COVID-19 outbreak, the scale which was associated with the stringency of government policies.Changes in the number and characteristics of children visiting the ED should be considered to facilitate the effective operation of EDs during the pandemic.

Partial Virological Response after 2 Years of Entecavir Therapy Increases the Risk of Hepatocellular Carcinoma in Patients with Hepatitis B Virus-Associated Cirrhosis

Background/Aims@#The clinical significance of partial virological response (PVR) in patients undergoing antiviral therapy is not well known. This study investigated whether PVR after 2 years of entecavir (ETV) therapy is associated with hepatocellular carcinoma (HCC) development in cirrhotic patients. @*Methods@#A total of 472 naïve patients with hepatitis B virus (HBV)-associated cirrhosis who were treated with ETV for at least 2 years were retrospectively enrolled. Clinical characteristics, laboratory data, PVR, and noninvasive fibrosis markers (aspartate aminotransferase to platelet ratio and FIB-4 index) at 2 years after ETV commencement were analyzed for HCC risk. @*Results@#After excluding those who developed HCC within 2 years of ETV therapy, 359 patients (mean age, 51±10 years; male 64.3%) were examined. During a median follow-up of 82 months, 80 patients developed HCC. In the univariate analysis, older age (hazard ratio [HR], 1.056; p<0.001), PVR (HR, 2.536; p=0.002), higher aspartate aminotransferase (HR, 1.018; p=0.005), lower albumin level (HR, 0.463; p<0.001), lower platelet count (HR, 0.993; p=0.01), and higher FIB-4 index (HR, 1.141; p<0.001) at 2 years after ETV commencement were risk factors for HCC. In the multivariate analysis, older age (HR, 1.046; 95% confidence interval [CI], 1.022 to 1.072; p<0.001), PVR (HR, 2.358; 95% CI, 1.310 to 4.245; p=0.004), and higher FIB-4 index (HR, 1.103; 95% CI, 1.035 to 1.177; p=0.003) were independent risk factors. @*Conclusions@#PVR and higher FIB-4 index after 2 years of ETV therapy were independent risk factors for HCC. Therefore, efforts to accomplish a complete virological response and reduce the FIB-4 index should be made.