Characteristics of COVID-19 outbreaks and risk factors for transmission at an army training center in South Korea from June to August 2021.

OBJECTIVES: It is crucial to establish the characteristics of coronavirus disease 2019 (COVID-19) outbreaks at army training centers to develop preventive measures. Therefore, this study aimed to determine the COVID-19 transmission patterns and risk factors in a sequence of outbreaks at an army training center from June to August 2021. METHODS: This study included 1,324 trainees at an army training center where outbreaks occurred from June to August 2021. The outbreak was qualitatively analyzed according to the period, attack rate, demographic characteristics, vaccination history, and living areas. An aerodynamic experiment was performed to evaluate aerosol transmission in living areas. RESULTS: Three outbreaks occurred at the army training center from June to August 2021. The first, second, and third outbreaks lasted for 32, 17, and 24 days, and the attack rates were 12.8%, 18.1%, and 8.9%, respectively. Confirmed cases were distributed in all age groups. Recruits and the unvaccinated were at higher risk for COVID-19. The aerodynamic experiment verified the possibility of aerosol transmission within the same living area. CONCLUSION: COVID-19 transmission at army training centers should be minimized through quarantine and post-admission testing during the latency period as part of integrated measures that include facility ventilation, vaccination, indoor mask-wearing, and social distancing.

Comparison of the Prevalence of Antibodies to SARS-CoV-2 in 9954 Recruits in the Korean Army Training Center with the General Korean Population of Equivalent Age Between September and November, 2020.

BACKGROUND Understanding the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be a useful tool when studying spread of the disease. This study aimed to compare the prevalence of antibodies to SARS-CoV-2 in 9954 recruits in the Korean Army Training Center with the general Korean population age <30 years between September and November, 2020. MATERIAL AND METHODS At the Korean Army Training Center, samples were taken from 9954 men from September to November, 2020. Participants were randomly enlisted healthy adult men. The data were compared with 4,205,265 samples from the Korean general population. Men age <30 years were used, as this is similar to the age range of the military recruits. RESULTS Among military recruits, 31 subjects (0.31%) were positive for the antibody, while the Korean male population had 3757 (0.09%) positive individuals. Among these 31 men, 13 were previously diagnosed by PCR, while 18 (58.06%) had no history related to the disease. Positive military recruits were mostly from 2 regional clusters. The first cluster was Daegu and Gyeongbuk areas (1.97% and 0.80%, respectively), which had an outbreak in March, 2020. The second cluster was Gyeonggi and Seoul, or capital areas (0.23% and 0.20%, respectively), which currently has high PCR positivity. Overall, seroprevalence was 3.49 times higher in study subjects. CONCLUSIONS The high seroprevalence of antibodies to SARS-CoV-2 between September and November 2020 in a densely populated military academy in Korea may have been an indicator for the resulting outbreak of COVID-19 in winter 2020-21, which highlights the importance of asymptomatic spread from the young and healthy to the general population.

A cystic artery arising from the middle hepatic artery detected during laparoscopic cholecystectomy: a case report.

We herein report a case in which a cystic artery arising from the middle hepatic artery (MHA) was encountered during cholecystectomy. A 42-year-old man visited the outpatient department complaining of chronic epigastric pain and a laparoscopic cholecystectomy was decided upon. During the preoperative evaluation, an interesting finding was observed on computed tomography. The patient had a cystic artery arising from the MHA. An MHA derived from the hilum of the proper hepatic artery runs along the medial border of the gallbladder and enters segment IV. In the operative field, the MHA that entered segment IV was observed. Dissecting downward along the MHA, a cystic artery was observed around the cystic duct. The cystic artery and duct were isolated and each was separately ligated and cut. Rare anatomical variations of the cystic artery, as in this case, can be a pitfall inducing complications during cholecystectomy.

Acalculous cholecystitis associated with Hantaan virus: A case report.

Acute acalculous cholecystitis (AAC) still remains one of the most elusive diagnoses and occurs in various conditions. Although AACs caused by viral infections are rare, various viruses have been revealed to cause AAC. Here we present a case in which a man suffered from AAC caused by a Hantaan virus infection. A 35-year-old man was referred to the emergency room for myalgia and fever that began 4 days ago. He suffered oliguria and abdominal pain for 2 days. At the time of his visit to the emergency room, he experienced a fever that spiked up to 38.3℃. An initial blood sample objectified the following pathologic results: white blood cells - 10260/µl; C-reactive protein - 6.76 mg/dl; total bilirubin - 1.7 mg/dl; AST - 90 IU/L; ALT - 233 IU/L. In the computed tomography, bilateral perirenal fluid collections and bilateral flexural effusion were shown and acute hepatopathy and cholecystopathy were also shown. Because there was no definite tenderness around the patient's right upper quadrant from physical examination and his cholecystopathy looked like it was from secondary change according to acute hepatopathy, we decided to perform conservative care without surgical treatment. The following day, in viral antibody test, Hantaan virus antibody was detected. After conservative management, the patient's condition improved and his laboratory findings were stable. The patient was discharged on the 10th day at the hospital stay without any symptoms. The Hantaan virus infection should be suspected as a causative agent of AAC, especially when there is abnormal liver function tests and abdominal pain.

Regulation of Airway Inflammation by G-protein Regulatory Motif Peptides of AGS3 protein.

Respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and lung infections have critical consequences on mortality and morbidity in humans. The aims of the present study were to examine the mechanisms by which CXCL12 affects MUC1 transcription and airway inflammation, which depend on activator of G-protein signaling (AGS) 3 and to identify specific molecules that suppress CXCL12-induced airway inflammation by acting on G-protein-coupled receptors. Herein, AGS3 suppresses CXCL12-mediated upregulation of MUC1 and TNFα by regulating Gαi. We found that the G-protein regulatory (GPR) motif peptide in AGS3 binds to Gαi and downregulates MUC1 expression; in contrast, this motif upregulates TNFα expression. Mutated GPR Q34A peptide increased the expression of MUC1 and TGFß but decreased the expression of TNFα and IL-6. Moreover, CXCR4-induced dendritic extensions in 2D and 3D matrix cultures were inhibited by the GPR Q34A peptide compared with a wild-type GPR peptide. The GPR Q34A peptide also inhibited CXCL12-induced morphological changes and inflammatory cell infiltration in the mouse lung, and production of inflammatory cytokines in bronchoalveolar lavage (BAL) fluid and the lungs. Our data indicate that the GPR motif of AGS3 is critical for regulating MUC1/Muc1 expression and cytokine production in the inflammatory microenvironment.

Laparoscopic radical antegrade modular pancreatosplenectomy.

Although laparoscopic distal pancreatectomy is widely accepted for benign or borderline malignant pancreatic diseases, its application for pancreatic ductal adenocarcinoma (PDAC) remains controversial. Several recent reports have shown that laparoscopic surgery, for the treatment of PDAC, is associated with similar postoperative complications and survival outcomes compared with open surgery, and offers several advantages, particularly shorter hospital stay and less blood loss. However, potential risk of bias cannot be excluded because these results were obtained in retrospective studies. More importantly, it is unclear whether the extent of surgical resection is comparable between laparoscopic and open distal pancreatectomy. The aim of this video article is to show the technical feasibility of laparoscopic surgery to reproduce open radical antegrade modular pancreatosplenectomy (RAMPS) in terms of the extent of surgical resection.

Silencing of MUC8 by siRNA increases P2Y2-induced airway inflammation.

Mucin hypersecretion and overproduction are frequent manifestations of respiratory disease. Determining the physiological function of airway mucin is presently considered more important than identifying the relevant signaling pathways. The lack of a full-length human mucin 8 (MUC8) cDNA sequence has hindered the generation of a Muc8 knockout mouse line. Thus, the precise physiological functions of MUC8 are unclear. Herein, we investigated the function of MUC8 using a small-interfering RNA (siRNA)-mediated genetic silencing approach in human airway epithelial cells. Herein, intracellular IL-1α production was stimulated by an ATP/P2Y2 complex. While ATP/P2Y2 increased IL-1α secretion in a time-dependent manner, treatment with P2Y2-specific siRNA significantly decreased IL-1α secretion. Moreover, ATP increased P2Y2-mediated upregulation of MUC8 expression; however, IL-1α significantly decreased the extent to which ATP/P2Y2 upregulated MUC8 expression. Interestingly, treatment with MUC8-specific siRNA decreased the production of anti-inflammatory cytokines (TGF-ß and IL-1 receptor antagonist) and increased the production of inflammatory cytokines (IL-1α and IL-6) in our system. In addition, siRNA-mediated knockdown of MUC8 expression dramatically increased the secretion of inflammatory chemokines and resulted in an approximately threefold decrease in cell chemotaxis. We propose that MUC8 may function as an anti-inflammatory mucin that participates in inflammatory response by attracting immune cells/cytokines to the site of inflammation. Our results provide new insight into the physiological function of MUC8 and enhance our understanding of mucin overproduction during airway inflammation.