Risk factors for transmission in a COVID-19 cluster infection in a high school in the Republic of Korea

Objectives@#This study aimed to examine the scale, characteristics, risk factors, and modes of transmission in a coronavirus disease 2019 (COVID-19) outbreak at a high school in Seoul, Republic of Korea. @*Methods@#An epidemiological survey was conducted of 1,118 confirmed cases and closecontacts from a COVID-19 outbreak at an educational facility starting on May 31, 2021. Indepth interviews, online questionnaires, flow evaluations, and CCTV analyses were used todevise infection prevention measures. Behavioral and spatial risk factors were identified, and statistical significance was tested. @*Results@#Among 3rd-year students, there were 33 confirmed COVID-19 cases (9.6%). Students who used a study room in the annex building showed a statistically significant 4.3-foldelevation in their relative risk for infection compared to those who did not use the study room. Moreover, CCTV facial recognition analysis confirmed that 17.8% of 3rd-year students did not wear masks and had the lowest percentage of mask-wearers by grade. The air epidemiological survey conducted in the study room in the annex, which met the 3 criteria for a closed space, confirmed that there was only 10% natural ventilation due to the poor ventilation system. @*Conclusion@#To prevent and manage the spread of COVID-19 in educational facilities, advance measures that consider the size, operation, and resources of each school are crucial. In addition, various survey methodologies should be used in future studies to quickly analyze a wider range of data that can inform an evidence-based quarantine response.

Unbalanced Redox With Autophagy in Cardiovascular Disease

Precise redox balance is essential for the optimum health and physiological function of the human body. Furthermore, an unbalanced redox state is widely believed to be part of numerous diseases, ultimately resulting in death. In this review, we discuss the relationship between redox balance and cardiovascular disease (CVD). In various animal models, excessive oxidative stress has been associated with increased atherosclerotic plaque formation, which is linked to the inflammation status of several cell types. However, various antioxidants can defend against reactive oxidative stress, which is associated with an increased risk of CVD and mortality. The different cardiovascular effects of these antioxidants are presumably due to alterations in the multiple pathways that have been mechanistically linked to accelerated atherosclerotic plaque formation, macrophage activation, and endothelial dysfunction in animal models of CVD, as well as in in vitro cell culture systems. Autophagy is a regulated cell survival mechanism that removes dysfunctional or damaged cellular organelles and recycles the nutrients for the generation of energy. Furthermore, in response to atherogenic stress, such as the generation of reactive oxygen species, oxidized lipids, and inflammatory signaling between cells, autophagy protects against plaque formation. In this review, we characterize the broad spectrum of oxidative stress that influences CVD, summarize the role of autophagy in the content of redox balance-associated pathways in atherosclerosis, and discuss potential therapeutic approaches to target CVD by stimulating autophagy.

The Role of Macrophage Lipophagy in Reverse Cholesterol Transport

Macrophage cholesterol efflux is a central step in reverse cholesterol transport, which helps to maintain cholesterol homeostasis and to reduce atherosclerosis. Lipophagy has recently been identified as a new step in cholesterol ester hydrolysis that regulates cholesterol efflux, since it mobilizes cholesterol from lipid droplets of macrophages via autophagy and lysosomes. In this review, we briefly discuss recent advances regarding the mechanisms of the cholesterol efflux pathway in macrophage foam cells, and present lipophagy as a therapeutic target in the treatment of atherosclerosis.

Microbiology and Epidemiology of Infectious Spinal Disease

OBJECTIVE: Infectious spinal disease is regarded as an infection by a specific organism that affects the vertebral body, intervertebral disc and adjacent perivertebral soft tissue. Its incidence seems to be increasing as a result of larger proportion of the older patients with chronic debilitating disease, the rise of intravenous drug abuser, and the increase in spinal procedure and surgery. In Korea, studies assessing infectious spinal disease are rare and have not been addressed in recent times. The objectives of this study are to describe the epidemiology of all kind of spinal infectious disease and their clinical and microbiological characteristics as well as to assess the diagnostic methodology and the parameters related to the outcomes. METHODS: A retrospective study was performed in all infectious spinal disease cases presenting from January 2005 to April 2010 to three tertiary teaching hospitals within a city of 1.5 million in Korea. Patient demographics, risk factors, clinical features, and outcomes were assessed. Risk factors entailed the presence of diabetes, chronic renal failure, liver cirrhosis, immunosuppressants, remote infection, underlying malignancy and previous spinal surgery or procedure. We comparatively analyzed the results between the groups of pyogenic and tuberculous spinal infection. SPSS version 14 statistical software was used to perform the analyses of the data. The threshold for statistical significance was established at p<0.05. RESULTS: Ninety-two cases fulfilled the inclusion criteria and were reviewed. Overall, patients of tuberculous spinal infection (TSI) and pyogenic spinal infection (PSI) entailed 20 (21.7%) and 72 (78.3%) cases, respectively. A previous spinal surgery or procedure was the most commonly noted risk factor (39.1%), followed by diabetes (15.2%). The occurrence of both pyogenic and tuberculous spondylitis was predominant in the lumbar spine. Discs are more easily invaded in PSI. At initial presentation, white cell blood count and C-reactive protein levels were higher in PSI compared to TSI (p<0.05). Etiological agents were identified in 53.3%, and the most effective method for identification of etiological agents was tissue culture (50.0%). Staphyococcus aureus was the most commonly isolated infective agent associated with pyogenic spondylitis, followed by E. coli. Surgical treatment was performed in 31.5% of pyogenic spondylitis and in 35.0% of tuberculous spondylitis cases. CONCLUSION: Many previous studies in Korea usually reported that tuberculous spondylitis is the predominant infection. However, in our study, the number of pyogenic infection was 3 times greater than that of tuberculous spinal disease. Etiological agents were identified in a half of all infectious spinal disease. For better outcomes, we should try to identify the causative microorganism before antibiotic therapy and make every effort to improve the result of culture and biopsy.

Ginkgo biloba extract (GbE) enhances the anti-atherogenic effect of cilostazol by inhibiting ROS generation

In this study, the synergistic effect of 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone (cilostazol) and Ginkgo biloba extract (GbE) was examined in apolipoprotein E (ApoE) null mice. Co-treatment with GbE and cilostazol synergistically decreased reactive oxygen species (ROS) production in ApoE null mice fed a high-fat diet. Co-treatment resulted in a significantly decreased atherosclerotic lesion area compared to untreated ApoE mice. The inflammatory cytokines and adhesion molecules such as monocyte chemoattractant-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and VCAM-1 which can initiate atherosclerosis were significantly reduced by the co-treatment of cilostazol with GbE. Further, the infiltration of macrophages into the intima was decreased by co-treatment. These results suggest that co-treatment of GbE with cilostazol has a more potent anti-atherosclerotic effect than treatment with cilostazol alone in hyperlipidemic ApoE null mice and could be a valuable therapeutic strategy for the treatment of atherosclerosis.

Intentional Sparing of Daughter Sac from Coil Packing in the Embolization of Aneurysms Causing the Third Cranial Nerve Palsy : Initial Clinical and Radiological Results

OBJECTIVE: Cerebral aneurysms which cause oculomotor nerve [cranial nerve (CN) III] palsy, are frequently found with a daughter sac of the aneurysm dome. We assumed that CN III might be compressed by the daughter sac and it would be more helpful not to fill the daughter sac with coils than vice versa during endosaccular embolization for recovering from CN III palsy, because it may give a greater chance for the daughter sac to shrink by itself later. We reviewed the initial results of our experiences of such cases. METHODS: Among 9 aneurysms accompanied by CN III palsy, 7 (6 unruptured, 1 ruptured) showed a daughter sac. We tried to fill the main dome completely and spare the daughter sac from coil filling to increase the possibility of decompression. We evaluated the short-term effectiveness of this concept using medical records and angiograms. RESULTS: After initial embolization, all of CN III palsy caused by unruptured aneurysms (6/6) resolved completely after various periods (3-90 days) of time. No adverse effects were noted during and after the procedures except for one case of harmless coil stretching during coil filling using double microcatheter. CONCLUSION: During the coil embolization of the cerebral aneurysm causing CN III palsy, sparing the daughter sac from coil packing while tightly packing the main dome, can be helpful in increasing the effectiveness of decompression. However, a long-term follow-up will be required.

Clinical Analysis of Intracranial Mirror-image Aneurysms: A 20-year Single Center Experience / 대한뇌혈관외과학회지

OBJECTIVE: Detection of intracranial multiple aneurysms, including mirror-image aneurysms, have recently been increasing with the development of diagnostic techniques. However, studies of mirror-image aneurysms have been rare in South Korea. Thus, we intend to report our hospital's experience with mirror-image aneurysms during the past 20 years along with a review of relevant literature. METHODS: We analyzed medical records and image data from patients with cerebral aneurysms who had been admitted to our institution from January 1988 to June 2007. We divided the patients into three groups and investigated the clinical patterns of mirror-image aneurysms (Group 1). We then compared them with patients exhibiting non-mirror multiple aneurysms (Group 2) and the patients with solitary aneurysms (Group 3). We also statistically analyzed the age, sex, smoking habits, medical histories, and prognoses of the patients. RESULTS: Mirror-image aneurysms were found in 62 (5.1%) of the 1,209 patients admitted for cerebral aneurysms over the past 20 years. Of the mirror-image aneurysms, 48% were located in the posterior communicating artery (PcoA), and 40% were in the middle cerebral artery (MCA). Ruptures of aneurysms occurred slightly more frequently on the right side and when the aneurysm was larger and its shape was more irregular. Women, particularly menopausal women aged 50 and older, were shown to be at higher risk. Smoking was also a risk factor. However, there were no significant differences in prognoses among the three groups. CONCLUSION: We should pay attention to the possibility of mirror-image or multiple aneurysms when diagnosing and treating menopausal women and smokers, particularly if the cerebral aneurysm is located in the MCA or PcoA.

Intradural Mature Teratoma in the Lumbar Spine found in Adult

Intradural spinal teratoma is a very rare entity, more prevalent in childhood, and may be associated with dysraphic defects. Moreover, mature teratoma in adult is extremely rare. The authors report on a 56-year-old man with right leg motor weakness and numbness and sensation of incomplete voiding. The lumbar radiograph showed spina bifida in L4, L5, and S1. Magnetic resonance image(MRI) showed a 6.4-cm intradural cystic mass on the L2 and L3 levels of the spinal canal and tethering of the spinal cord. We performed a total laminectomy at L2, L3, and partial laminectomy at L4 and removed the mass completely. Histopathologic diagnosis was mature teratoma. The patient's complaints were improved after the surgery.