OBJECTIVE: This study was designed to evaluate the feasibility and clinical implications of CT angiography (CTA) in patients with acute ischemic stroke. METHODS: From August 2004 to July 2005, 24 cases of acute ischemic stroke were prospectively included in this study. We checked location of ischemic parenchymal lesion, location of vascular occlusion, degree of collateral supply, and presence of other accompanying vascular lesions on CT and CTA, and assessed the usefulness of CTA by comparing the findings with those of diffusionweighted MR imaging and digital subtraction angiography. RESULTS: Average time required for performing CT and CTA and getting reconstructed images was 30 minutes. Location of the parenchymal lesions and the corresponding occluded or stenosed artery could be clarified in 16 cases (67%) and 20 cases (83%), respectively. There were 13 cases of severe stenosis and 7 cases of occlusion. In 7 cases of major arterial occlusion, degree of collateral circulation could be assessed as good in 5, and moderate in 2. Incidental unruptured intracranial aneurysms were identified in 5 cases. CONCLUSION: CTA could provide valuable information regarding locations of parenchymal lesion and vascular occlusion, degree of collateral supply, and presence of accompanying intracranial aneurysm in cases of acute ischemic stroke without significant time delay, thereby guiding therapeutic plan.
Angiography* ; Angiography, Digital Subtraction ; Arteries ; Collateral Circulation ; Constriction, Pathologic ; Humans ; Intracranial Aneurysm ; Magnetic Resonance Imaging ; Prospective Studies ; Stroke*

Background: As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results: In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

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.