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1.
IEEE Rev Biomed Eng ; 14: 16-29, 2021.
Article in English | MEDLINE | ID: covidwho-1501334

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading rapidly around the world, resulting in a massive death toll. Lung infection or pneumonia is the common complication of COVID-19, and imaging techniques, especially computed tomography (CT), have played an important role in diagnosis and treatment assessment of the disease. Herein, we review the imaging characteristics and computing models that have been applied for the management of COVID-19. CT, positron emission tomography - CT (PET/CT), lung ultrasound, and magnetic resonance imaging (MRI) have been used for detection, treatment, and follow-up. The quantitative analysis of imaging data using artificial intelligence (AI) is also explored. Our findings indicate that typical imaging characteristics and their changes can play crucial roles in the detection and management of COVID-19. In addition, AI or other quantitative image analysis methods are urgently needed to maximize the value of imaging in the management of COVID-19.


Subject(s)
COVID-19/diagnosis , Artificial Intelligence , COVID-19/diagnostic imaging , Humans , Lung/diagnostic imaging , Lung/virology , Positron Emission Tomography Computed Tomography/methods , SARS-CoV-2/pathogenicity , Tomography, X-Ray Computed/methods , Ultrasonography/methods
2.
Cell ; 184(1): 184-193.e10, 2021 01 07.
Article in English | MEDLINE | ID: covidwho-1385213

ABSTRACT

Transcription of SARS-CoV-2 mRNA requires sequential reactions facilitated by the replication and transcription complex (RTC). Here, we present a structural snapshot of SARS-CoV-2 RTC as it transitions toward cap structure synthesis. We determine the atomic cryo-EM structure of an extended RTC assembled by nsp7-nsp82-nsp12-nsp132-RNA and a single RNA-binding protein, nsp9. Nsp9 binds tightly to nsp12 (RdRp) NiRAN, allowing nsp9 N terminus inserting into the catalytic center of nsp12 NiRAN, which then inhibits activity. We also show that nsp12 NiRAN possesses guanylyltransferase activity, catalyzing the formation of cap core structure (GpppA). The orientation of nsp13 that anchors the 5' extension of template RNA shows a remarkable conformational shift, resulting in zinc finger 3 of its ZBD inserting into a minor groove of paired template-primer RNA. These results reason an intermediate state of RTC toward mRNA synthesis, pave a way to understand the RTC architecture, and provide a target for antiviral development.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Cryoelectron Microscopy , RNA, Messenger/chemistry , RNA, Viral/chemistry , SARS-CoV-2/chemistry , Viral Replicase Complex Proteins/chemistry , Amino Acid Sequence , Coronavirus/chemistry , Coronavirus/classification , Coronavirus/enzymology , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Methyltransferases/metabolism , Models, Molecular , RNA Helicases/metabolism , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/metabolism , SARS-CoV-2/enzymology , Sequence Alignment , Transcription, Genetic , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism , Virus Replication
3.
Cell ; 184(13): 3474-3485.e11, 2021 06 24.
Article in English | MEDLINE | ID: covidwho-1240208

ABSTRACT

The capping of mRNA and the proofreading play essential roles in SARS-CoV-2 replication and transcription. Here, we present the cryo-EM structure of the SARS-CoV-2 replication-transcription complex (RTC) in a form identified as Cap(0)-RTC, which couples a co-transcriptional capping complex (CCC) composed of nsp12 NiRAN, nsp9, the bifunctional nsp14 possessing an N-terminal exoribonuclease (ExoN) and a C-terminal N7-methyltransferase (N7-MTase), and nsp10 as a cofactor of nsp14. Nsp9 and nsp12 NiRAN recruit nsp10/nsp14 into the Cap(0)-RTC, forming the N7-CCC to yield cap(0) (7MeGpppA) at 5' end of pre-mRNA. A dimeric form of Cap(0)-RTC observed by cryo-EM suggests an in trans backtracking mechanism for nsp14 ExoN to facilitate proofreading of the RNA in concert with polymerase nsp12. These results not only provide a structural basis for understanding co-transcriptional modification of SARS-CoV-2 mRNA but also shed light on how replication fidelity in SARS-CoV-2 is maintained.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/genetics , Exoribonucleases/genetics , Methyltransferases/genetics , SARS-CoV-2/genetics , Amino Acid Sequence , COVID-19/virology , Humans , RNA, Messenger/genetics , RNA, Viral/genetics , Sequence Alignment , Transcription, Genetic/genetics , Virus Replication/genetics
5.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(2): 147-151, 2020 Feb 29.
Article in Chinese | MEDLINE | ID: covidwho-250195

ABSTRACT

The SARS-CoV-2 epidemic starting in Wuhan in December, 2019 has spread rapidly throughout the nation. The control measures to contain the epidemic also produced influences on the transport and treatment process of patients with acute myocardial infarction (AMI), and adjustments in the management of the patients need to be made at this particular time. AMI is characterized by an acute onset with potentially fatal consequence, a short optimal treatment window, and frequent complications including respiratory infections and respiratory and circulatory failure, for which active on-site treatment is essential. To standardize the management and facilitate the diagnosis and treatment, we formulated the guidelines for the procedures and strategies for the diagnosis and treatment of AMI, which highlight 5 Key Principles, namely Nearby treatment, Safety protection, Priority of thrombolysis, Transport to designated hospitals, and Remote consultation. For AMI patients, different treatment strategies are selected based on the screening results of SARS-CoV-2, the time window of STEMI onset, and the vital signs of the patients. During this special period, the cardiologists, including the interventional physicians, should be fully aware of the indications and contraindications of thrombolysis. In the transport and treatment of AMI patients, the physicians should strictly observe the indications for patient transport with appropriate protective measurements of the medical staff.


Subject(s)
Coronavirus Infections , Myocardial Infarction , Pandemics , Pneumonia, Viral , Betacoronavirus , COVID-19 , Consensus , Coronavirus Infections/complications , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Humans , Myocardial Infarction/diagnosis , Myocardial Infarction/therapy , Pandemics/prevention & control , Pneumonia, Viral/complications , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Practice Guidelines as Topic , Remote Consultation , SARS-CoV-2 , Thrombolytic Therapy , Transportation of Patients
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