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1.
RNA ; 2022 May 04.
Article in English | MEDLINE | ID: covidwho-1833463

ABSTRACT

The high mutation rate of SARS-CoV-2 largely complicates our control of the pandemic. Particularly, it is currently unclear why the spike (S) gene has extraordinarily high mutation rate among all SARS-CoV-2 genes. By analyzing the occurrence of fixed synonymous mutations between SARS-CoV-2 and RaTG13, and profiling the DAF (derived allele frequency) of polymorphic synonymous sites among millions of world-wide SARS-CoV-2 strains, we found that both fixed and polymorphic mutations show higher mutation rates in S gene than other genes. The majority of mutation is C-to-T, representing the APOBEC-mediated C-to-U deamination instead of the previously-proposed A-to-I deamination. Both in silico and in vivo evidences indicated that S gene is more likely to be single-stranded compared to other SARS-CoV-2 genes, agreeing with the APOBEC preference on ssRNA. We conclude that the single-stranded property of S gene makes itself a favorable target for C-to-U deamination, leading to its excessively high mutation rate compared to other non-S genes. In conclusion, APOBEC, rather than ADAR, is the "editor-in-chief" of SARS-CoV-2 RNAs. This work helps us understand the molecular mechanism underlying the mutation and evolution of SARS-CoV-2, and is believed to contribute to the control of the pandemic.

3.
Glob Health Res Policy ; 7(1): 12, 2022 Apr 29.
Article in English | MEDLINE | ID: covidwho-1817295

ABSTRACT

BACKGROUND: With the continuation of the COVID-19 pandemic, some COVID-19 patients have become reinfected with the virus. Viral gene sequencing has found that some of these patients were reinfected by the different and others by same strains. This has raised concerns about the effectiveness of immunity after infection and the reliability of vaccines. To this end, we conducted a systematic review to assess the characteristics of patients with reinfection and possible causes. METHODS: A systematic search was conducted across eight databases: PubMed, Embase, Web of Science, The Cochrane Library, CNKI, WanFang, VIP and SinoMed from December 1, 2019 to September 1, 2021. The quality of included studies were assessed using JBI critical appraisal tools and Newcastle-Ottawa Scale. RESULTS: This study included 50 studies from 20 countries. There were 118 cases of reinfection. Twenty-five patients were reported to have at least one complication. The shortest duration between the first infection and reinfection was 19 days and the longest was 293 days. During the first infection and reinfection, cough (51.6% and 43.9%) and fever (50% and 30.3%) were the most common symptoms respectively. Nine patients recovered, seven patients died, and five patients were hospitalized, but 97 patients' prognosis were unknown. B.1 is the most common variant strain at the first infection. B.1.1.7, B.1.128 and B.1.351 were the most common variant strains at reinfection. Thirty-three patients were infected by different strains and 9 patients were reported as being infected with the same strain. CONCLUSIONS: Our research shows that it is possible for rehabilitated patients to be reinfected by SARS-COV-2. To date, the causes and risk factors of COVID-19 reinfection are not fully understood. For patients with reinfection, the diagnosis and management should be consistent with the treatment of the first infection. The public, including rehabilitated patients, should be fully vaccinated, wear masks in public places, and pay attention to maintaining social distance to avoid reinfection with the virus.


Subject(s)
COVID-19 , Reinfection , COVID-19/epidemiology , Humans , Pandemics , Reinfection/epidemiology , Reproducibility of Results , SARS-CoV-2
4.
IEEE Trans Pattern Anal Mach Intell ; PP2022 Apr 26.
Article in English | MEDLINE | ID: covidwho-1806969

ABSTRACT

In this paper, we contribute a new million-scale recognition benchmark, containing uncurated 4M identities/260M faces (WebFace260M) and cleaned 2M identities/42M faces (WebFace42M) training data, as well as an elaborately designed time-constrained evaluation protocol. Firstly, we collect 4M name lists and download 260M faces from the Internet. Then, a Cleaning Automatically utilizing Self-Training pipeline is devised to purify the tremendous WebFace260M, which is efficient and scalable. To our best knowledge, the cleaned WebFace42M is the largest public face recognition training set in the community. Referring to practical deployments, Face Recognition under Inference Time conStraint (FRUITS) protocol and a new test set with rich attributes are constructed. Moreover, we gather a large-scale masked face sub-set for biometrics assessment under COVID-19. For a comprehensive evaluation of face matchers, three recognition tasks are performed under standard, masked and unbiased settings, respectively. Equipped with this benchmark, we delve into million-scale face recognition problems. Enabled by WebFace42M, we reduce 40% failure rate on the challenging IJB-C set and rank the 3rd among 430 entries on NIST-FRVT. Even 10% data (WebFace4M) shows superior performance compared with the public training set. The proposed benchmark shows enormous potential on standard, masked and unbiased face recognition scenarios.

5.
Nat Med ; 28(5): 1031-1041, 2022 May.
Article in English | MEDLINE | ID: covidwho-1773989

ABSTRACT

Since its emergence in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused hundreds of millions of cases and continues to circulate globally. To establish a novel SARS-CoV-2 human challenge model that enables controlled investigation of pathogenesis, correlates of protection and efficacy testing of forthcoming interventions, 36 volunteers aged 18-29 years without evidence of previous infection or vaccination were inoculated with 10 TCID50 of a wild-type virus (SARS-CoV-2/human/GBR/484861/2020) intranasally in an open-label, non-randomized study (ClinicalTrials.gov identifier NCT04865237 ; funder, UK Vaccine Taskforce). After inoculation, participants were housed in a high-containment quarantine unit, with 24-hour close medical monitoring and full access to higher-level clinical care. The study's primary objective was to identify an inoculum dose that induced well-tolerated infection in more than 50% of participants, with secondary objectives to assess virus and symptom kinetics during infection. All pre-specified primary and secondary objectives were met. Two participants were excluded from the per-protocol analysis owing to seroconversion between screening and inoculation, identified post hoc. Eighteen (~53%) participants became infected, with viral load (VL) rising steeply and peaking at ~5 days after inoculation. Virus was first detected in the throat but rose to significantly higher levels in the nose, peaking at ~8.87 log10 copies per milliliter (median, 95% confidence interval (8.41, 9.53)). Viable virus was recoverable from the nose up to ~10 days after inoculation, on average. There were no serious adverse events. Mild-to-moderate symptoms were reported by 16 (89%) infected participants, beginning 2-4 days after inoculation, whereas two (11%) participants remained asymptomatic (no reportable symptoms). Anosmia or dysosmia developed more slowly in 15 (83%) participants. No quantitative correlation was noted between VL and symptoms, with high VLs present even in asymptomatic infection. All infected individuals developed serum spike-specific IgG and neutralizing antibodies. Results from lateral flow tests were strongly associated with viable virus, and modeling showed that twice-weekly rapid antigen tests could diagnose infection before 70-80% of viable virus had been generated. Thus, with detailed characterization and safety analysis of this first SARS-CoV-2 human challenge study in young adults, viral kinetics over the course of primary infection with SARS-CoV-2 were established, with implications for public health recommendations and strategies to affect SARS-CoV-2 transmission. Future studies will identify the immune factors associated with protection in those participants who did not develop infection or symptoms and define the effect of prior immunity and viral variation on clinical outcome.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Humans , Kinetics , Treatment Outcome , Viral Load , Young Adult
6.
Vaccine ; 40(20): 2848-2855, 2022 May 03.
Article in English | MEDLINE | ID: covidwho-1768584

ABSTRACT

Vaccines for SARS-CoV-2 have been hugely successful in alleviating hospitalization and deaths caused by the newly emerged coronavirus that is the cause of COVID. However, although the parentally administered vaccines are very effective at reducing severe disease, they do not induce sterilizing immunity. As the virus continues to circulate around the globe, it is still not clear how long protection will last, nor whether variants will emerge that escape vaccine immunity. Animal models can be useful to complement studies of antigenicity of novel variants and inform decision making about the need for vaccine updates. The Syrian golden hamster is the preferred small animal model for SARS-CoV-2 infection. Since virus is efficiently transmitted between hamsters, we developed a transmission challenge model that presents a more natural dose and route of infection than the intranasal challenge usually employed. Our studies demonstrate that an saRNA vaccine based on the earliest Wuhan-like virus spike sequence induced neutralizing antibodies in sera of immunized hamsters at similar titres to those in human convalescent sera or vaccine recipients. The saRNA vaccine was equally effective at abrogating clinical signs in animals who acquired through exposure to cagemates infected either with a virus isolated in summer 2020 or with a representative Alpha (B.1.1.7) variant isolated in December 2020. The vaccine also reduced shedding of infectious virus from the nose, further reinforcing its likely effectiveness at reducing onwards transmission. This model can be extended to test the effectiveness of vaccination in blocking infections with and transmission of novel variants as they emerge.


Subject(s)
COVID-19 , Viral Vaccines , Animals , COVID-19/prevention & control , COVID-19/therapy , COVID-19 Vaccines , Cricetinae , Humans , Immunization, Passive , SARS-CoV-2 , Vaccines, Synthetic
7.
Front Psychol ; 11: 583604, 2020.
Article in English | MEDLINE | ID: covidwho-1760252

ABSTRACT

Drawing on the job demands-resources (JD-R) model and event system theory (EST), this study constructed a moderated mediating model to investigate the direct effect of career calling on work fatigue, the mediating effect of role overload, and the moderating effect of COVID-19 event disruption in the above relationships. We administered an online questionnaire to 488 Chinese police officers who participated in frontline work to prevent and control the COVID-19 pandemic. The results showed a U-shaped curvilinear relationship of career calling with physical fatigue, mental fatigue, emotional fatigue, and role overload. Moreover, role overload partially mediated these curvilinear relationships. In addition, COVID-19 event disruption positively moderated the direct curvilinear effect of career calling on role overload, physical fatigue, and emotional fatigue, as well as the first stage of the mediating effect in the relationship between career calling and physical, mental, and emotional fatigue through role overload. Furthermore, the direct U-shaped curvilinear effects and the indirect effects were more significant when COVID-19 event disruption was high.

8.
Viruses ; 14(3)2022 03 13.
Article in English | MEDLINE | ID: covidwho-1742726

ABSTRACT

The prolonged duration of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has resulted in the continuous emergence of variants of concern (VOC, e.g., Omicron) and variants of interest (VOI, e.g., Lambda). These variants have challenged the protective efficacy of current COVID-19 vaccines, thus calling for the development of novel therapeutics against SARS-CoV-2 and its VOCs. Here, we constructed a novel fusion inhibitor-based recombinant protein, denoted as 5-Helix, consisting of three heptad repeat 1 (HR1) and two heptad repeat 2 (HR2) fragments. The 5-Helix interacted with the HR2 domain of the viral S2 subunit, the most conserved region in spike (S) protein, to block homologous six-helix bundle (6-HB) formation between viral HR1 and HR2 domains and, hence, viral S-mediated cell-cell fusion. The 5-Helix potently inhibited infection by pseudotyped SARS-CoV-2 and its VOCs, including Delta and Omicron variants. The 5-Helix also inhibited infection by authentic SARS-CoV-2 wild-type (nCoV-SH01) strain and its Delta variant. Collectively, our findings suggest that 5-Helix can be further developed as either a therapeutic or prophylactic to treat and prevent infection by SARS-CoV-2 and its variants.


Subject(s)
COVID-19 , Viral Envelope Proteins , COVID-19 Vaccines , Humans , Membrane Glycoproteins/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Envelope Proteins/metabolism
9.
Viruses ; 14(3)2022 03 06.
Article in English | MEDLINE | ID: covidwho-1732247

ABSTRACT

Our previous studies have shown that cholesterol-conjugated, peptide-based pan-coronavirus (CoV) fusion inhibitors can potently inhibit human CoV infection. However, only palmitic acid (C16)-based lipopeptide drugs have been tested clinically, suggesting that the development of C16-based lipopeptide drugs is feasible. Here, we designed and synthesized a C16-modified pan-CoV fusion inhibitor, EK1-C16, and found that it potently inhibited infection by SARS-CoV-2 and its variants of concern (VOCs), including Omicron, and other human CoVs and bat SARS-related CoVs (SARSr-CoVs). These results suggest that EK1-C16 could be further developed for clinical use to prevent and treat infection by the currently circulating MERS-CoV, SARS-CoV-2 and its VOCs, as well as any future emerging or re-emerging coronaviruses.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , COVID-19/drug therapy , Humans , Lipopeptides/pharmacology , Palmitic Acid/pharmacology , SARS-CoV-2
10.
Parasitology ; 149(2): 218-233, 2022 02.
Article in English | MEDLINE | ID: covidwho-1721322

ABSTRACT

Schistosomiasis has been subjected to extensive control efforts in the People's Republic of China (China) which aims to eliminate the disease by 2030. We describe baseline results of a longitudinal cohort study undertaken in the Dongting and Poyang lakes areas of central China designed to determine the prevalence of Schistosoma japonicum in humans, animals (goats and bovines) and Oncomelania snails utilizing molecular diagnostics procedures. Data from the Chinese National Schistosomiasis Control Programme (CNSCP) were compared with the molecular results obtained.Sixteen villages from Hunan and Jiangxi provinces were surveyed; animals were only found in Hunan. The prevalence of schistosomiasis in humans was 1.8% in Jiangxi and 8.0% in Hunan determined by real-time polymerase chain reaction (PCR), while 18.3% of animals were positive by digital droplet PCR. The CNSCP data indicated that all villages harboured S. japonicum-infected individuals, detected serologically by indirect haemagglutination assay (IHA), but very few, if any, of these were subsequently positive by Kato-Katz (KK).Based on the outcome of the IHA and KK results, the CNSCP incorporates targeted human praziquantel chemotherapy but this approach can miss some infections as evidenced by the results reported here. Sensitive molecular diagnostics can play a key role in the elimination of schistosomiasis in China and inform control measures allowing for a more systematic approach to treatment.


Subject(s)
Schistosoma japonicum , Schistosomiasis japonica , Schistosomiasis , Animals , Cattle , China/epidemiology , Humans , Longitudinal Studies , Prevalence , Real-Time Polymerase Chain Reaction , Schistosoma japonicum/genetics , Schistosomiasis/epidemiology , Schistosomiasis japonica/epidemiology , Schistosomiasis japonica/veterinary , Snails
11.
Viruses ; 14(3)2022 02 28.
Article in English | MEDLINE | ID: covidwho-1715781

ABSTRACT

The global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become more serious because of the continuous emergence of variants of concern (VOC), thus calling for the development of broad-spectrum vaccines with greater efficacy. Adjuvants play important roles in enhancing the immunogenicity of protein-based subunit vaccines. In this study, we compared the effect of three adjuvants, including aluminum, nanoparticle manganese and MF59, on the immunogenicity of three protein-based COVID-19 vaccine candidates, including RBD-Fc, RBD and S-trimer. We found that the nanoparticle manganese adjuvant elicited the highest titers of SARS-CoV-2 RBD-specific IgG, IgG1 and IgG2a, as well as neutralizing antibodies against infection by pseudotyped SARS-CoV-2 and its Delta variant. What is more, the nanoparticle manganese adjuvant effectively reduced the viral load of the authentic SARS-CoV-2 and Delta variant in the cell culture supernatants. These results suggest that nanoparticle manganese, known to facilitate cGAS-STING activation, is an optimal adjuvant for protein-based COVID-19 subunit vaccines.


Subject(s)
COVID-19 , Viral Vaccines , Animals , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Immunity , Mice , Mice, Inbred BALB C , SARS-CoV-2 , Vaccines, Subunit
12.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-325440

ABSTRACT

According to WHO statistics, there are more than 204,617,027 confirmed COVID-19 cases including 4,323,247 deaths worldwide till August 12, 2021. During the coronavirus epidemic, almost everyone wears a facial mask. Traditionally, face recognition approaches process mostly non-occluded faces, which include primary facial features such as the eyes, nose, and mouth. Removing the mask for authentication in airports or laboratories will increase the risk of virus infection, posing a huge challenge to current face recognition systems. Due to the sudden outbreak of the epidemic, there are yet no publicly available real-world masked face recognition (MFR) benchmark. To cope with the above-mentioned issue, we organize the Face Bio-metrics under COVID Workshop and Masked Face Recognition Challenge in ICCV 2021. Enabled by the ultra-large-scale WebFace260M benchmark and the Face Recognition Under Inference Time conStraint (FRUITS) protocol, this challenge (WebFace260M Track) aims to push the frontiers of practical MFR. Since public evaluation sets are mostly saturated or contain noise, a new test set is gathered consisting of elaborated 2,478 celebrities and 60,926 faces. Meanwhile, we collect the world-largest real-world masked test set. In the first phase of WebFace260M Track, 69 teams (total 833 solutions) participate in the challenge and 49 teams exceed the performance of our baseline. There are second phase of the challenge till October 1, 2021 and on-going leaderboard. We will actively update this report in the future.

13.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325339

ABSTRACT

SARS-CoV-2 is more infectious and transmissible in humans than SARS-CoV, despite the genetic relatedness and sharing the same cellular receptor. We sought to assess whether human airway organoids can model SARS-CoV-2 infection in the human airway and elucidate the cellular basis underlying its higher transmissibility. We demonstrate that SARS-CoV-2 can establish a productive infection in human airway organoids, in which ciliated cell and basal cell are infected. Wildtype SARS-CoV-2 carrying a furin cleavage motif exhibits comparable replication kinetics to a mutant virus without the motif. Human airway organoids sustain higher replication of SARS-CoV-2 than SARS-CoV, whereas interferon response is more potently induced in the latter than the former. Overall, human airway organoids can model SARS-CoV-2 infection and recapitulate the disposable role of furin cleavage motif for virus transmission in humans. SARS-CoV-2 stealth growth and evasion of interferon response may underlie pre-symptomatic virus shedding in COVID-19 patients, leading to its high infectiousness and transmissibility.

14.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325338

ABSTRACT

The aim of this study was to retrospectively analyze chest thin-section high-resolution CT (HRCT) findings for 32 patients with Corona Virus Disease 2019 (COVID-19) and clarify the correlation between CT data and laboratory results. 30 patients presented with abnormal initial CT scans. Of 30 patients, COVID-19 showed the involvement of bilateral lungs in 24 (80%), involvement of more than two lobes in 24 (80%), ground-glass opacities without consolidation in 27 (90%), ground-glass opacities with consolidation in 23 (76.7%), opacities with irregular intralobular lines in 26 (86.7%), opacities with round morphology in 25 (83.3%), and peripheral distribution in 30 (100%). Pleural effusion or mediastinal lymphadenopathy was relatively rare manifestations. Rapidly progression of the disease demonstrated by increasing number and range of ground glass opacities and appearance of consolidations at follow-up CT images in two patients. The CT lung severity score and No. of lobes involved were negatively correlated with lymphocyte count( r =-0.363, P =0.041;r =-0.367, P =0.039, respectively). Chest HRCT of COVID-19 predominantly manifests multiple, round, ground glass opacities with irregular intralobular lines, and peripheral distribution of bilateral lungs. HRCT is a potential tool for early screening, assessing progress, and predicting disease severity of COVID-19.Authors Jie Zhou and Jie Cao contributed equally to this work and are co-first authors.

15.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-325227

ABSTRACT

Objectives: To evaluate the frequency and time course of RHS on CT in patient with COVID-19 pneumonia. Materials: and methods A total of 147 patients with COVID-19 pneumonia were divided into mild, moderate, severe and critical categories. The number, location, shape, wall appearance of RHS on CT were analyzed. Other parenchymal abnormalities include GGO, consolidation and linear opacity were also recorded. Results: RHS was observed in 37 (25.2%) of 147 patients and it was more common in patients with moderate disease than severe or critical disease (31.3% vs. 13.0%, P = 0.019). Time from symptom onset to appearance of RHS was 9 ± 5 days in moderate patients and 14 ± 8 days in severe/critical patients. A total of 64 RHS lesions were identified and the majority of lesions were located in peripheral aspect of lungs (55, 85.9%) and lower lobes (52, 81.2%). All lesions with RHS were round or oval-shaped. The rim of RHS were smooth in 54 (84.4%) and irregular in 10 (15.6%). Follow-up CT scans of 27 patients (50 lesions) showed 43(86%) lesions gradually resolved or developed into GGO and linear opacities and 7(14%) lesions remained unchanged appearance. Conclusions: RHS occurred sooner after symptom onset and with higher frequency in patients with moderate compared to those with severe or critical disease. RHS may represent a favorable prognostic sign in COVID-19 pneumonia. Key Points • 37 (25.2%) of 147 patients with COVID-19 pneumonia had RHS on at least one CT• RHS was more prevalent in patients with moderate disease than those with severe or critical disease• RHSs (78.4%) mostly occurred within 2 weeks after symptom onset

16.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-325157

ABSTRACT

Battling a widespread pandemic is an arms race between our mitigation efforts, e.g., social distancing or vaccination, and the pathogen's evolving persistence. This is being observed firsthand during the current COVID-19 crisis, as novel mutations challenge our global vaccination race. To address this, we introduce here a general framework to model epidemic spreading under pathogen evolution, finding that mutations can fundamentally alter the projection of the spread. Specifically, we detect a new pandemic phase - the mutated phase - in which, despite the fact that the pathogen is initially non-pandemic (R0 < 1), it may still spread due to the emergence of a critical mutation. The boundaries of this phase portray a balance between the epidemic and the evolutionary time-scales. If the mutation rate is too low, the pathogen prevalence decays prior to the appearance of a critical mutation. On the other hand, if mutations are too rapid, the pathogen evolution becomes volatile and, once again, it fails to spread. Between these two extremes, however, we observe a broad range of conditions in which an initially sub-pandemic pathogen will eventually gain prevalence. This is especially relevant during vaccination, which creates, as it progresses, increasing selection pressure towards vaccine-resistance. To overcome this, we show that vaccination campaigns must be accompanied by fierce mitigation efforts, to suppress the potential rise of a resistant mutant strain.

17.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-324830

ABSTRACT

Highly pathogenic coronaviruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 1,2 , Middle East respiratory syndrome coronavirus (MERS-CoV) 3,4 , and SARS-CoV-1 5 vary in their transmissibility and pathogenicity. However, infection by all three viruses result in substantial apoptosis in cell culture 6-8 and in patient samples 9-11 , suggesting a potential link between apoptosis and the pathogenesis of coronaviruses. To date, the underlying mechanism of how apoptosis modulates coronavirus pathogenesis is unknown. Here we show that a cysteine-aspartic protease of the apoptosis cascade, caspase-6, serves as an essential host factor for efficient coronavirus replication. We demonstrate that caspase-6 cleaves coronavirus nucleocapsid (N) proteins, generating N fragments that serve as interferon (IFN) antagonists, thus facilitating virus replication. Inhibition of caspase-6 substantially attenuates the lung pathology and body weight loss of SARS-CoV-2-infected golden Syrian hamsters and improves the survival of mouse-adapted MERS-CoV (MERS-CoV MA )-infected human DPP4 knock-in (hDPP4 KI) mice. Overall, our study reveals how coronaviruses exploit a component of the host apoptosis cascade to facilitate their replication. These results further suggest caspase-6 as a potential target of intervention for the treatment of highly pathogenic coronavirus infections including COVID-19 and MERS.

18.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324334

ABSTRACT

Segmentation of infected areas in chest CT volumes is of great significance for further diagnosis and treatment of COVID-19 patients. Due to the complex shapes and varied appearances of lesions, a large number of voxel-level labeled samples are generally required to train a lesion segmentation network, which is a main bottleneck for developing deep learning based medical image segmentation algorithms. In this paper, we propose a weakly-supervised lesion segmentation framework by embedding the Generative Adversarial training process into the Segmentation Network, which is called GASNet. GASNet is optimized to segment the lesion areas of a COVID-19 CT by the segmenter, and to replace the abnormal appearance with a generated normal appearance by the generator, so that the restored CT volumes are indistinguishable from healthy CT volumes by the discriminator. GASNet is supervised by chest CT volumes of many healthy and COVID-19 subjects without voxel-level annotations. Experiments on three public databases show that when using as few as one voxel-level labeled sample, the performance of GASNet is comparable to fully-supervised segmentation algorithms trained on dozens of voxel-level labeled samples.

19.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-323540

ABSTRACT

Background: COVID-19, a worldwideinfectious disease, has killed more than 420000 people, whichis extremely harmful. Methods: In this single-center retrospective study, we included the novel coronavirus pneumonia confirmed in our hospital. This study collected the basic information andclinical examination features. Results: The enrolled 704 patients were affirmed infected with 2019-nCoV by the test of throat swabs. There are 334 men and 369 women, and gender, age, combined with basic diseasesare distinct in diverse disease classification (p<0.05). From the symptom analysis, the proportion of fever over 38 degrees, dyspnea, fatigue, poor appetite and other symptoms is diverse in different types of diseases (p<0.05). As the severity of the disease increases, the median lymphocyte count decreases, C-reactive protein increase, erythrocyte sedimentation rateincrease, albumin decrease, pleural effusion increase, D-Dimer and NT-proBNP increase significantly (p<0.05).As the disease severity increases, the average value of MuLBSTA score obviously ascend (p<0.05), MuLBSTA scoring system predicts novel coronavirus pneumonia patients' prognosis is still insufficient, and may require additional indicators including anorexia, fatigue, C reactive protein, etc (p<0.05). Conclusion: The MuLBSTA evaluation system has certain value for the evaluation of the disease, but it needs to be improved.

20.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-321467

ABSTRACT

Mice are not susceptible to wildtype SARS-CoV-2 infection. Emerging SARS-CoV-2 variants including B.1.1.7, B.1.351, P.1, and P.3 contain mutations in spike, which have been suggested to associate with an increased recognition of mouse ACE2, raising the postulation that they may have evolved to expand species tropism to rodents. Here, we investigated the capacity of B.1.1.7 and other emerging SARS-CoV-2 variants in infecting mouse (Mus musculus) and rats (Rattus norvegicus) under in vitro and in vivo settings. Our results show that B.1.1.7 and P.3, but not B.1 or wildtype SARS-CoV-2, can utilize mouse and rat ACE2 for virus entry in vitro. High infectious virus titers, abundant viral antigen expression, and pathological changes are detected in the nasal turbinate and lung of B.1.1.7-inocluated mice and rats. Together, these results reveal that the current predominant circulating SARS-CoV-2 variant, B.1.1.7, has gained the capability to expand species tropism to rodents.

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