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.

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: This study aimed to evaluate the diagnostic performance of the STANDARD F Influenza A/B FIA test (SD Biosensor Inc., Korea) for the rapid detection of influenza A virus in comparison with the Sofia Influenza A+B FIA (Quidel Corp., USA) and SD BIOLINE Influenza Ag A/B/A(H1N1) (Standard Diagnostic, Inc., Korea) tests. Methods: A total of 227 non-duplicated nasopharyngeal aspirates submitted for real-time RT-PCR analysis were included in the study. We used the three commercial tests in remnant samples from routine assays, according to the manufacturer’s instructions. We analyzed the diagnostic performance, including sensitivity and specificity, of the three tests. Results: Real-time RT-PCR analysis showed that 67 (29.5%) samples were positive and 160 (70.5%) were negative for influenza A virus, and that all the specimens were negative for influenza B. The overall sensitivity and specificity for influenza A virus detection were 50.7% and 100% for the STANDARD F, 50.7% and 100% for the Sofia, and 29.9% and 100% for the SD BIOLINE tests, respectively. The STANDARD F and SD BIOLINE tests showed negative results for influenza B virus in all specimens, whereas the Sofia test showed two false-positive results. Conclusion The STANDARD F Influenza A/B test showed a good diagnostic performance and may be useful for the rapid diagnosis of influenza A.

Background/Aims: Some cases of gastric low-grade dysplasia (LGD) and high-grade dysplasia (HGD) on forceps biopsy (FB) are diagnosed as gastric cancer (GC) after endoscopic resection (ER). This study aims to evaluate the clinical outcomes of ER for gastric LGD and HGD on pretreatment FB and to identify the factors that predict pathologic upstaging to GC. Methods: Patients who underwent ER for LGD and HGD on pretreatment FB from March 2005 to February 2018 in 14 hospitals in South Korea were enrolled, and the patients’ medical records were reviewed retrospectively. Results: This study included 2,150 cases of LGD and 1,534 cases of HGD diagnosed by pretreatment FB. In total, 589 of 2,150 LGDs (27.4%) were diagnosed as GC after ER. Helicobacter pylori infection, smoking history, tumor location in the lower third of the stomach, tumor size >10 mm, depressed lesion, and ulceration significantly predicted GC. A total of 1,115 out of 1,534 HGDs (72.7%) were diagnosed with GC after ER. Previous history of GC, H. pylori infection, smoking history, tumor location in the lower third of the stomach, tumor size >10 mm, depressed lesion, and ulceration were significantly associated with GC. As the number of risk factors predicting GC increased in both LGD and HGD on pretreatment FB, the rate of upstaging to GC after ER increased. Conclusions A substantial proportion of LGDs and HGDs on pretreatment FB were diagnosed as GC after ER. Accurate ER procedures such as endoscopic submucosal dissection should be recommended in cases of LGD and HGD with factors predicting pathologic upstaging to GC.

The purpose of this study was to evaluate the structural characteristics of the thread length of orthodontic mini-screws and the effects of insertion and removal torques according to the formation of the cutting flute. Two types of mini-screws were made, with a thread length of 6.0 mm and a thread length of 3.3 mm. In order to examine the effect of flute formation, the experiment group was divided into a miniscrew test group with flute formation and an experiment group without flute formation. To evaluate the effect of flute formation, two flutes were formed at 180°on the circumference, and at the tip of the mini screw, up to 4 mm for thread length of 6.0 mm and 2.4 mm for thread length of 3.3 mm. A biomechanical test block formed of 2 mm cortical bone and 10 mm cancellous bone was used to eliminate the influence of the difference in cortical bone thickness and bone density according to the insertion site. 1 mm diameter guide hole was drilled on the test block and the mini-screw was placed vertically. Using a 0.1 N·cm precision digital torque gauge, the maximum torque value was recorded at this time by embedding it to the top of the screw under a static load of 1.2 kg and the value when it was removed in the opposite direction. The insertion torque values for the 6.0 mm and 3.3 mm length mini screws were (29.53±1.84) N·cm and (26.84±2.15) N·cm, and the removal torque values are (14.50±1.37) N·cm and (13.15±2.89) N·cm, respectively.There were no statistically significant differences (P>0.05). The flute of 6.0 mm mini-screws had no statistically significant difference in both insertion and removal torque values and increased to (30.13±1.97) N·cm and (18.65±1.10) N·cm (P>0.05). In experiments with 3.3 mm mini-screws, the insertion and removal torque values decreased to (20.99±3.94) N·cm and (11.32±2.03) N·cm, respectively, showing a statistically significant decrease only in the insertion torque values (P<0.05). The insertion and removal torque values of the mini-screw were not significantly increased even when the screw length was doubled, and the flute formation effect was different with the screw length.

The purpose of this study was to evaluate the structural characteristics of the thread length of orthodontic mini-screws and the effects of insertion and removal torques according to the formation of the cutting flute. Two types of mini-screws were made, with a thread length of 6.0 mm and a thread length of 3.3 mm. In order to examine the effect of flute formation, the experiment group was divided into a miniscrew test group with flute formation and an experiment group without flute formation. To evaluate the effect of flute formation, two flutes were formed at 180°on the circumference, and at the tip of the mini screw, up to 4 mm for thread length of 6.0 mm and 2.4 mm for thread length of 3.3 mm. A biomechanical test block formed of 2 mm cortical bone and 10 mm cancellous bone was used to eliminate the influence of the difference in cortical bone thickness and bone density according to the insertion site. 1 mm diameter guide hole was drilled on the test block and the mini-screw was placed vertically. Using a 0.1 N·cm precision digital torque gauge, the maximum torque value was recorded at this time by embedding it to the top of the screw under a static load of 1.2 kg and the value when it was removed in the opposite direction. The insertion torque values for the 6.0 mm and 3.3 mm length mini screws were (29.53±1.84) N·cm and (26.84±2.15) N·cm, and the removal torque values are (14.50±1.37) N·cm and (13.15±2.89) N·cm, respectively.There were no statistically significant differences (P>0.05). The flute of 6.0 mm mini-screws had no statistically significant difference in both insertion and removal torque values and increased to (30.13±1.97) N·cm and (18.65±1.10) N·cm (P>0.05). In experiments with 3.3 mm mini-screws, the insertion and removal torque values decreased to (20.99±3.94) N·cm and (11.32±2.03) N·cm, respectively, showing a statistically significant decrease only in the insertion torque values (P<0.05). The insertion and removal torque values of the mini-screw were not significantly increased even when the screw length was doubled, and the flute formation effect was different with the screw length.

This study was performed to evaluate the effect of cyclic precalcification treatment on the improvement of bioactivity of Ti-6Al-4V mini-screws. The cutted plate-shaped specimens of 10 mm × 10 mm dimensions, and a mini-screw with a diameter of 1.6 mm × 6.0 mm in length were used. Anodic oxidation treatment was carried out in a glycerol electrolyte solution containing 20 wt% H2O and 1.5 wt% NH 4F. Voltage of 20 V with current density of 20 mA/cm2 was applied for 1 hour to form a nanotube TiO2 layer. Afterwards, to improve the bioactivity, specimens were immersed in 0.5 vol% silica aqueous solution at 37 ℃ for 5 minutes, and then cyclic precalcification treatment with 0.05 M NH 4H2PO4and 0.01 M Ca(OH)2 solution at 90 ℃ was repeated with 20 times. Based on surface treatment the experimental groups were divided into three groups, namely untreated group (UT), anodized and heat-treated group (AH), and anodized, silica-treated, cyclic precalcified and heat-treated group (ASPH). There were TiO2 nanotubes completely self-aligned and formed in a dense structure on the surface after anodic oxidation treatment. A fine granular cluster layer of hydroxyapatite and octacalcium phosphate were formed on the surface after the cyclic precalcification treatment. As a result of immersion test in the simulated body fluid (SBF), bioactivity was confirmed to be improved by the precipitation of protrusions appearing at the initial stage of formation of hydroxyapatite.

We experienced an extremely rare case of proximal epithelioid sarcoma (PES) of the vulva in a 77-year-old woman. After history taking and physical examination, the patient was tentatively diagnosed as having Bartholin’s cyst in the right labium. Based on histopathological and immunohistochemical (IHC) findings, however, a final diagnosis of PES of the vulva was made. After receiving CyberKnife treatment, the patient survived but with recurrent episodes and poor prognosis. In conclusion, our case indicates that patients with PES of the vulva should be appropriately managed with radiotherapy after a differential diagnosis based on histopathological and IHC findings.

We experienced an extremely rare case of proximal epithelioid sarcoma (PES) of the vulva in a 77-year-old woman. After history taking and physical examination, the patient was tentatively diagnosed as having Bartholin’s cyst in the right labium. Based on histopathological and immunohistochemical (IHC) findings, however, a final diagnosis of PES of the vulva was made. After receiving CyberKnife treatment, the patient survived but with recurrent episodes and poor prognosis. In conclusion, our case indicates that patients with PES of the vulva should be appropriately managed with radiotherapy after a differential diagnosis based on histopathological and IHC findings.