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.

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.

Purpose: We investigated the predictive factors for acute urinary retention (AUR) after transperineal template-guided mapping biopsy (TTMB). Materials and Methods: We retrospectively reviewed the records of 459 patients who had undergone TTMB between May 2017 and July 2020. Overall complications after TTMB were analyzed and categorized according to the Clavien-Dindo classification. Factors that were likely to affect AUR were analyzed using a logistic regression model. Results: Overall complications after TTMB were observed in 95 of the 459 patients (20.7%), of which AUR was the most commonly reported (17.4%, n=80), followed by hematuria (3.1%, n=14). Hematuria in one patient was categorized as Clavien-Dindo grade IIIa. All remaining complications were Clavien-Dindo grade I. In the multivariate regression model, age ≥65 (odds ratio, 2.44; 95% confidence interval [CI], 1.42–4.17; p=0.001), prostate volume ≥30 mL (odds ratio, 3.72; 95% CI, 1.19–11.62; p<0.02), and number of biopsy cores ≥30 (odds ratio, 2.89; 95% CI, 1.29–6.43; p=0.01) were identified as the predictors for AUR after TTMB. Conclusions AUR is the most common complication after TTMB. Age ≥65 years, prostate volume ≥30 mL, and number of biopsy cores ≥30 were significant predictors of AUR following TTMB.

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.

Purpose: Internal hernia after gastrectomy is a rare but potentially life-threatening condition without surgical intervention. Clinical risk factors of internal hernia should, hence, be reviewed after gastrectomy.From 2008 to 2018, patients who underwent gastrectomy for gastric cancer were investigated. Methods: Abdominal computed tomography (CT) was used to screen for internal hernia, and surgical exploration was performed to confirm the diagnosis. Using retrospective statistical analysis, the incidence, characteristics, and risk factors were identified, and the characteristics of the internal hernia group were reviewed. Results: The overall incidence of internal hernia was 0.9%. From statistical analysis, it was found that laparoscopic surgery was almost five times riskier than open gastrectomy (odds ratio [OR], 4.947; 95% confidence interval [CI], 1.308–18.710; p = 0.019). Body mass index < 25 kg/m2 (OR, 4.596; 95% CI, 1.056– 20.004; p = 0.042) and proximal gastrectomy (OR, 4.238; 95% CI, 1.072–16.751; p = 0.039) were also associated with internal hernia. Among 20 patients with internal hernia, 12 underwent laparotomy, and five had their bowels removed due to ischemia. All patients with bowel resected had suffered from short bowel syndrome. Conclusion Suspecting an internal hernia should be an important step when a patient with a history of laparoscopic gastrectomy visits for medical care. When suspected, emergent screening through CT scan and surgical intervention should be considered as soon as possible to prevent lifetime complications accordingly.

Purpose: We investigated the predictive factors for acute urinary retention (AUR) after transperineal template-guided mapping biopsy (TTMB). Materials and Methods: We retrospectively reviewed the records of 459 patients who had undergone TTMB between May 2017 and July 2020. Overall complications after TTMB were analyzed and categorized according to the Clavien-Dindo classification. Factors that were likely to affect AUR were analyzed using a logistic regression model. Results: Overall complications after TTMB were observed in 95 of the 459 patients (20.7%), of which AUR was the most commonly reported (17.4%, n=80), followed by hematuria (3.1%, n=14). Hematuria in one patient was categorized as Clavien-Dindo grade IIIa. All remaining complications were Clavien-Dindo grade I. In the multivariate regression model, age ≥65 (odds ratio, 2.44; 95% confidence interval [CI], 1.42–4.17; p=0.001), prostate volume ≥30 mL (odds ratio, 3.72; 95% CI, 1.19–11.62; p<0.02), and number of biopsy cores ≥30 (odds ratio, 2.89; 95% CI, 1.29–6.43; p=0.01) were identified as the predictors for AUR after TTMB. Conclusions AUR is the most common complication after TTMB. Age ≥65 years, prostate volume ≥30 mL, and number of biopsy cores ≥30 were significant predictors of AUR following TTMB.

PURPOSE: To analyze postoperative complications for gastric cancer patients undergoing laparoscopic gastrectomy in single institution over long period of time. METHODS: The data of 1332 consecutive patients undergoing laparoscopic gastrectomy for gastric cancer at a single institution from January 2007 to December 2015 were reviewed. The patients were classified into the early or late surgery group; the initial 100 cases were classified as the initial group. We compared between the two groups and analyzed risk factors for postoperative complications. RESULTS: A total of 265 postoperative complications occurred in 223 patients (16.7%). Major complications occurred in 38 patients (2.9%) including 1 death (0.1%). Operative time and hospital stay were significantly shorter in the late group. Blood loss was greater in the initial group. Sex, comorbidity, tumor location, D2 LND, operative method, non B-I anastomosis, co-resection, long operative time, and blood loss were significant risk factors for overall postoperative complication. In the multivariate analysis, male sex, comorbidity, D2 lymph node dissection, total or proximal gastrectomy, non B-I anastomosis, co-resection, operative time and blood loss were associated with postoperative overall complications. CONCLUSION: Sex, co-morbidity, D2 LND, operative method, co-resection, operative time and blood loss revealed as the risk factor of overall postoperative complication. And there was no significant differences of risk factor related to postoperative complication between initial and maturation surgical period. This suggests that beginners also can safely perform laparoscopic gastrectomy through the appropriate patient selection.
Comorbidity ; Gastrectomy* ; Humans ; Laparoscopy ; Length of Stay ; Lymph Node Excision ; Male ; Methods ; Multivariate Analysis ; Operative Time ; Patient Selection ; Postoperative Complications* ; Risk Factors ; Stomach Neoplasms*