Editorial: Coronavirus disease 2019 (COVID-19) - advances in epidemiology, diagnostics, treatments, host-directed therapies, pathogenesis, vaccines, and ongoing challenges

In silico evaluation of the inhibitory potential of nucleocapsid inhibitors of SARS-CoV-2: a binding and energetic perspective

The COVID-19 outbreak brought on by the SARS-CoV-2 virus continued to infect a sizable population worldwide. The SARS-CoV-2 nucleocapsid (N) protein is the most conserved RNA-binding structural protein and is a desirable target because of its involvement in viral transcription and replication. Based on this aspect, this study focused to repurpose antiviral compounds approved or in development for treating COVID-19. The inhibitors chosen are either FDA-approved or are currently being studied in clinical trials against COVID-19. Initially, they were designed to target stress granules and other RNA biology. We have utilized structure-based molecular docking and all-atom molecular dynamics (MD) simulation approach to investigate in detail the binding energy and binding modes of the different anti-N inhibitors to N protein. The result showed that five drugs including Silmitasterib, Ninetanidinb, Ternatin, Luteolin, Fedratinib, PJ34, and Zotatafin were found interacting with RNA binding sites as well as to predicted protein interface with higher binding energy. Overall, drug binding increases the stability of the complex with maximum stability found in the order, Silmitasertib > PJ34 > Zotatatafin. In addition, the frustration changes due to drug binding brings a decrease in local frustration and this decrease is mainly observed in α-helix, β3, β5, and β6 strands and are important for drug binding. Our in-silico data suggest that an effective interaction occurs for some of the tested drugs and prompt their further validation to reduce the rapid outspreading of SARS-CoV-2.Communicated by Ramaswamy H. Sarma.

Predictors and clinical outcomes of silent hypoxia in COVID-19 patients, a single-center retrospective cohort study

Background

Patients with COVID-19 usually present with fever and respiratory symptoms such as cough, sputum production, and dyspnea. However, they may suffer from severe hypoxemia without a clinical correlation with the respiratory symptoms, also known as silent or apathetic hypoxia. The aim of the study was to assess the predictors and clinical outcomes of COVID-19 patients without dyspnea.

Methods

A single-center retrospective cohort study, based on data extracted from the electronic hospital information system, with COVID-19 patients over a 10-month period in Riyadh, Saudi Arabia.

Results

Of the COVID-19 patients presenting at the Emergency Department with a SpO₂ < 90%, 13% had silent hypoxia. The majority of the patients required BiPAP, 34% were intubated and 60% were admitted to an intensive care unit. There was no association between dyspnea and gender, age group, body mass index, or comorbidity. Cough, fever, and chronic cardiac diseases were predictive for dyspnea in a regression analysis. There was no difference in the clinical outcome between patients with silent dyspnea or dyspnea. Age and obesity were significantly associated with a decrease in survival, and an increase in the initial SpO₂ increased survival.

Conclusion

Patients with cardiac disease are more likely to present with silent hypoxia. The SpO₂ saturation in COVID-19 may be an independent predictor of survival. Silent hypoxia in COVID-19 patients does not appear to have an association with increase in mortality.