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.

Thyroid surgery complications include voice change, vocal fold paralysis, and hypoparathyroidism. The voice status should be evaluated pre- and post-surgery. In patients with voice change, laryngeal visualization is needed.Intraoperative neuromonitoring helps reduce recurrent laryngeal nerve injury. The measurement of serum calcium, parathyroid hormone, and 25-hydroxyvitamin D levels is recommended to evaluate perioperative parathyroid function and prescribe supplementation preoperatively if necessary. For postoperative hypoparathyroidism, vitamin D and oral calcium supplementation are indicated based on serum parathyroid hormone and calcium levels and the severity of symptoms or signs of hypocalcemia. If long-term treatment is required, the appropriateness of treatment should be evaluated based on the disease itself and the consideration of potential benefits and harms from long-term replacement.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.

Background: To report the clinical manifestations of non-arteritic anterior ischemic optic neuropathy (NAION) cases after coronavirus disease 2019 (COVID-19) vaccination in Korea. Methods: This multicenter retrospective study included patients diagnosed with NAION within 42 days of COVID-19 vaccination. We collected data on vaccinations, demographic features, presence of vascular risk factors, ocular findings, and visual outcomes of patients with NAION. Results: The study included 16 eyes of 14 patients (6 men, 8 women) with a mean age of 63.5 ± 9.1 (range, 43–77) years. The most common underlying disease was hypertension, accounting for 28.6% of patients with NAION. Seven patients (50.0%) had no vascular risk factors for NAION. The mean time from vaccination to onset was 13.8 ± 14.2 (range, 1–41) days. All 16 eyes had disc swelling at initial presentation, and 3 of them (18.8%) had peripapillary intraretinal and/or subretinal fluid with severe disc swelling. Peripapillary hemorrhage was found in 50% of the patients, and one (6.3%) patient had peripapillary cotton-wool spots. In eight fellow eyes for which we were able to review the fundus photographs, the horizontal cup/ disc ratio was less than 0.25 in four eyes (50.0%). The mean visual acuity was logMAR 0.6 ± 0.7 at the initial presentation and logMAR 0.7 ± 0.8 at the final visit. Conclusion Only 64% of patients with NAION after COVID-19 vaccination have known vascular and ocular risk factors relevant to ischemic optic neuropathy. This suggests that COVID-19 vaccination may increase the risk of NAION. However, overall clinical features and visual outcomes of the NAION patients after COVID-19 vaccination were similar to those of typical NAION.

Objective: To compare the convenience and effectiveness of the existing lumbosacral orthoses (LSO) (classic LSO and Cybertech) and a newly developed LSO (V-LSO) by analyzing postoperative data. Methods: This prospective cohort study was performed from May 2019 to November 2019 and enrolled and analyzed 88 patients with degenerative lumbar spine disease scheduled for elective lumbar surgery. Three types of LSO that were provided according to the time of patient registration were applied for 6 weeks. Patients were randomized into the classic LSO group (n=31), Cybertech group (n=26), and V-LSO group (n=31). All patients were assessed using the Oswestry Disability Index (ODI) preoperatively and underwent plain lumbar radiography (anteroposterior and lateral views) 10 days postoperatively. Lumbar lordosis (LS angle) and frontal imbalance were measured with and without LSO. At the sixth postoperative week, a follow-up assessment with the ODI and orthosis questionnaire was conducted. Results: No significant differences were found among the three groups in terms of the LS angle, frontal imbalance, ODI, and orthosis questionnaire results. When the change in the LS angle and frontal imbalance toward the reference value was defined as a positive change with and without LSO, the rate of positive change was significantly different in the V-LSO group (LS angle: 41.94% vs. 61.54% vs. 83.87%; p=0.003). Conclusion The newly developed LSO showed no difference regarding its effectiveness and compliance when compared with the existing LSO, but it was more effective in correcting lumbar lordosis.

Background/Objectives: Extra-nodal extension (ENE) is one of the strongest prognosticators in oral cancers. Here we tried to evaluate clinicopathological factors associated with the presence of ENE.Materials & Methods: We retrospectively analyzed clinical information of 120 patients who diagnosed with oral cancer and received curative surgery at our hospital from Mar 2012 to Apr 2020. We comparatively analyzed clinicopathological factors associated with the presence of lymph node (LN) metastasis and ENE, respectively. Results: Variable factors of primary tumor characteristics such as lymphovascular invasion, perineural invasion, largest diameter of tumor, depth of invasion and maximum standardized uptake value were significantly associated with the presence of cervical LN metastasis. The largest diameter of tumor was statistically significant also in multivariate analysis for predicting the LN metastasis. Meanwhile, the association between primary tumor characteristics and the presence of ENE were not statistically significant except the primary tumor size. Importantly, factors associated with LN characteristics including the maximum diameter and number of metastatic LNs were significantly associated with ENE. Conclusion In this study, several factors affecting cervical LN metastasis and ENE in oral cancer patients were identified. The ENE seems to be influenced by the status of the metastatic LNs, such as the number of metastatic LNs, rather than the characteristics of the primary tumor itself.

Background: Endoscope-assisted surgery is a surgical method that has been used in oral and maxillofacial surgical fields. It provides good illumination, clear, and magnified visualization of the operative field. The purpose of this article is to describe the early clinical experiences to conduct minimally invasive surgery with endoscope-assisted enucleation of cysts on the jaw. It appears that this approach may be a superior alternative to the conventional approach. Methods: In this study, 24 patients (9 females, 15 males, average age 41.5) underwent endoscope-assisted cyst enucleation under general anesthesia. All operations were done by one surgeon. The cases were classified depending on whether bone penetration occurred at the cyst site. The cystic lesions were enucleated using an endoscope with a 0°, 1.9 mm diameter, or a 30°, 2.7 mm diameter. Two bony windows were used for the insertion of a syringe for irrigation, curettes, suction tips, sinus blades, surgical drills, and an endoscope. An additional small channel was made for the insertion of endoscopic instruments. Results: The 24 patients who underwent cyst enucleation were regularly observed for 3 to 12 months to evaluate for complications. Although some patients experienced swelling and numbness, these symptoms did not persist, and the patients soon returned to normal and there was no sign of recurrence. Conclusions The results of this study have suggested the possibility of minimally invasive surgery with endoscopes when it comes to cyst removal in the oral and maxillofacial region. Nevertheless, this study has limitations designed as a preliminary report focusing on the feasibility of endoscope-assisted cyst enucleation in the oral and maxillofacial regions.

Coronavirus disease 2019 (COVID-19) is a global pandemic that had affected more than eight million people worldwide by June 2020. Given the importance of the presence of diabetes mellitus (DM) for host immunity, we retrospectively evaluated the clinical characteristics and outcomes of moderate-to-severe COVID-19 in patients with diabetes.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is associated with an increased risk for dementia. The effects of hypoglycemia on dementia are controversial. Thus, we evaluated whether hypoglycemia increases the risk for dementia in senior patients with T2DM. METHODS: We used the Korean National Health Insurance Service Senior cohort, which includes >10% of the entire senior population of South Korea. In total, 5,966 patients who had ever experienced at least one episode of hypoglycemia were matched with those who had not, using propensity score matching. The risk of dementia was assessed through a survival analysis of matched pairs. RESULTS: Patients with underlying hypoglycemic events had an increased risk for all-cause dementia, Alzheimer's dementia (AD), and vascular dementia (VaD) compared with those who had not experienced a hypoglycemic event (hazard ratio [HR], 1.254; 95% confidence interval [CI], 1.166 to 1.349; P<0.001 for all-cause dementia; HR, 1.264; 95% CI, 1.162 to 1.375; P<0.001 for AD; HR, 1.286; 95% CI, 1.110 to 1.490; P<0.001 for VaD). According to number of hypoglycemic episodes, the HRs of dementia were 1.170, 1.201, and 1.358 in patients with one hypoglycemic episode, two or three episodes, and more than three episodes, respectively. In the subgroup analysis, hypoglycemia was associated with an increased risk for dementia in both sexes with or without T2DM microvascular or macrovascular complications. CONCLUSION Our findings suggest that patients with a history of hypoglycemia have a higher risk for dementia. This trend was similar for AD and VaD, the two most important subtypes of dementia.

Purpose: Acute respiratory distress syndrome (ARDS) is characterized by its acute onset of symptoms such as bilateral pulmonary infiltrates, severe hypoxemia, and pulmonary edema. Many patients with ARDS survive in the acute phase, but then die from significant lung fibrosis. Methods: The effect of combination therapy with polydeoxyribonucleotide (PDRN) and pirfenidone on ARDS was investigated using human lung epithelial A549 cells. ARDS environment was induced by treatment with lipopolysaccharide and transforming growth factor (TGF)-β. Enzyme-linked immunoassay for connective tissue growth factor (CTGF) and hydroxyproline were conducted. Western blot for collagen type I, fibroblast growth factor (FGF), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 was performed. Results: In this study, 8-μg/mL PDRN enhanced cell viability. Combination therapy with PDRN and pirfenidone and pirfenidone monotherapy suppressed expressions of CTGF and hydroxyproline and inhibited expressions of collagen type I and FGF. Combination therapy with PDRN and pirfenidone and PDRN monotherapy suppressed expression of TNF-α and IL-1β. Conclusions The combination therapy with PDRN and pirfenidone exerted stronger therapeutic effect against lipopolysaccharide and TGF-β-induced ARDS environment compared to the PDRN monotherapy or pirfenidone monotherapy. The excellent therapeutic effect of combination therapy with PDRN and pirfenidone on ARDS was shown by promoting the rapid anti-inflammatory effect and inhibiting the fibrotic processes.