Xuanfei Baidu Decoction regulates NETs formation via CXCL2/CXCR2 signaling pathway that is involved in acute lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening symptoms in Coronavirus Disease 2019 (COVID-19) patients. Xuanfei Baidu Decoction (XFBD) is a recommend first-line traditional Chinese medicine (TCM) formula therapeutic strategy for COVID-19 patients. Prior studies demonstrated the pharmacological roles and mechanisms of XFBD and its derived effective components against inflammation and infections through multiple model systems, which provided the biological explanations for its clinical use. Our previous work revealed that XFBD inhibited macrophages and neutrophils infiltration via PD-1/IL17A signaling pathway. However, the subsequent biological processes are not well elucidated. Here, we proposed a hypothesis that XFBD can regulate the neutrophils-mediated immune responses, including neutrophil extracellular traps (NETs) formation and the generation of platelet-neutrophil aggregates (PNAs) after XFBD administration in lipopolysaccharide (LPS)-induced ALI mice. The mechanism behind it was also firstly explained, that is XFBD regulated NETs formation via CXCL2/CXCR2 axis. Altogether, our findings demonstrated the sequential immune responses of XFBD after inhibiting neutrophils infiltration, as well as shedding light on exploiting the therapy of XFBD targeting neutrophils to ameliorate ALI during the clinical course.

A versatile integrated tube for rapid and visual SARS-CoV-2 detection.

The coronavirus disease 2019 (COVID-19) caused by novel severe acute respiratory coronavirus 2 (SARS-CoV-2) has been rapidly spreading worldwide. Rapid and widespread testing is essential to promote early intervention and curb the ongoing COVID-19 pandemic. Current gold standard reverse transcription-polymerase chain reaction (RT-PCR) for detecting SARS-CoV-2 is restricted to professional laboratories and well-trained personnel, thus, limiting its widespread use in resource-limited conditions. To overcome these challenges, we developed a rapid and convenient assay using a versatile integrated tube for the rapid and visual detection of SARS-CoV-2. The reaction conditions of the method were optimized using SARS-CoV-2 RNA standards and the sensitivity and specificity were further determined. Finally, it was verified on clinical specimens. The assay was completed within 40 min, and the result was visible by the naked eye. The limits of detection (LODs) for the target ORF1ab and N genes were 50 copies/µl. No cross-reactivity was observed with the RNA standard samples of four respiratory viruses or clinical samples of common respiratory viral infections. Ninety SARS-CoV-2 positive and 30 SARS-CoV-2 negative patient specimens were analyzed. We compared these results to both prior and concurrent RT-PCR evaluations. As a result, the overall sensitivity and specificity for detection SARS-CoV-2 were 94.5 and 100.0%, respectively. Conclusion: The integrated tube assay has the potential to provide a simple, specific, sensitive, one-pot, and single-step assay for SARS-CoV-2.

A versatile integrated tube for rapid and visual SARS-CoV-2 detection

The coronavirus disease 2019 (COVID-19) caused by novel severe acute respiratory coronavirus 2 (SARS-CoV-2) has been rapidly spreading worldwide. Rapid and widespread testing is essential to promote early intervention and curb the ongoing COVID-19 pandemic. Current gold standard reverse transcription-polymerase chain reaction (RT-PCR) for detecting SARS-CoV-2 is restricted to professional laboratories and well-trained personnel, thus, limiting its widespread use in resource-limited conditions. To overcome these challenges, we developed a rapid and convenient assay using a versatile integrated tube for the rapid and visual detection of SARS-CoV-2. The reaction conditions of the method were optimized using SARS-CoV-2 RNA standards and the sensitivity and specificity were further determined. Finally, it was verified on clinical specimens. The assay was completed within 40 min, and the result was visible by the naked eye. The limits of detection (LODs) for the target ORF1ab and N genes were 50 copies/μl. No cross-reactivity was observed with the RNA standard samples of four respiratory viruses or clinical samples of common respiratory viral infections. Ninety SARS-CoV-2 positive and 30 SARS-CoV-2 negative patient specimens were analyzed. We compared these results to both prior and concurrent RT-PCR evaluations. As a result, the overall sensitivity and specificity for detection SARS-CoV-2 were 94.5 and 100.0%, respectively. Conclusion The integrated tube assay has the potential to provide a simple, specific, sensitive, one-pot, and single-step assay for SARS-CoV-2.

An integrated dual-layer microfluidic platform for multiple respiratory viruses screening.

Currently, the coronavirus disease 2019 (COVID-19) caused by the outbreak of a novel coronavirus (SARS-CoV-2) is spreading rapidly worldwide. Due to the high incidence of influenza coinciding with SARS-CoV-2, rapid detection is crucial to prevent spreading. Here, we present an integrated dual-layer microfluidic platform for specific and highly sensitive SARS-CoV-2, influenza viruses A (FluA) H1N1, H3N2, and influenza virus B (FluB) simultaneous detection. The platform includes a dual microchip (Dµchip) and a portable detection device for real-time fluorescence detection, temperature control and online communication. The Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) and Cas12a cleavage were performed on the Dµchip. The limit of detection (LoD) of the Dµchip assay was 10 copies for SARS-CoV-2, FluA H1N1, H3N2, and FluB RNAs. The Dµchip assay yielded no cross-reactivity against other coronaviruses, so it was suitable for the screening of multiple viruses. Moreover, the positive percentage agreement (PPA) and negative percentage agreement (NPA) of the assay were 97.9% and 100%, respectively, in 75 clinical samples compared to data from RT-PCR-based assays. Furthermore, the assay allowed the detection SARS-CoV-2 and influenza viruses in spiked samples. Overall, the present platform would provide a rapid method for the screening of multiple viruses in hospital emergency, community and primary care settings and facilitate the remote diagnosis and outbreak control of the COVID-19.

A Linkage-specific Sialic Acid Labeling Strategy Reveals Different Site-specific Glycosylation Patterns in SARS-CoV-2 Spike Protein Produced in CHO and HEK Cell Substrates.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus utilizes the extensively glycosylated spike (S) protein protruding from the viral envelope to bind to angiotensin-converting enzyme-related carboxypeptidase (ACE2) as its primary receptor to mediate host-cell entry. Currently, the main recombinant S protein production hosts are Chinese hamster ovary (CHO) and human embryonic kidney (HEK) cells. In this study, a recombinant S protein truncated at the transmembrane domain and engineered to express a C-terminal trimerization motif was transiently produced in CHO and HEK cell suspensions. To further evaluate the sialic acid linkages presenting on S protein, a two-step amidation process, employing dimethylamine and ammonium hydroxide reactions in a solid support system, was developed to differentially modify the sialic acid linkages on the glycans and glycopeptides from the S protein. The process also adds a charge to Asp and Glu which aids in ionization. We used MALDI-TOF and LC-MS/MS with electron-transfer/higher-energy collision dissociation (EThcD) fragmentation to determine global and site-specific N-linked glycosylation patterns. We identified 21 and 19 out of the 22 predicted N-glycosites of the SARS-CoV-2 S proteins produced in CHO and HEK, respectively. It was found that the N-glycosite at 1,158 position (N1158) and at 122, 282 and 1,158 positions (N122, N282 and N1158) were absent on S from CHO and HEK cells, respectively. The structural mapping of glycans of recombinant human S proteins reveals that CHO-Spike exhibits more complex and higher sialylation (α2,3-linked) content while HEK-Spike exhibits more high-mannose and a small amount of α2,3- and α2,6-linked sialic acids. The N74 site represents the most abundant glycosite on both spike proteins. The relatively higher amount of high-mannose abundant sites (N17, N234, N343, N616, N709, N717, N801, and N1134) on HEK-Spike suggests that glycan-shielding may differ among the two constructs. HEK-Spike can also provide different host immune system interaction profiles based on known immune system active lectins. Collectively, these data underscore the importance of characterizing the site-specific glycosylation of recombinant human spike proteins from HEK and CHO cells in order to better understand the impact of the production host on this complex and important protein used in research, diagnostics and vaccines.

Impact of Expressing Cells on Glycosylation and Glycan of the SARS-CoV-2 Spike Glycoprotein.

The spike glycoprotein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the first point of contact for the virus to recognize and bind to host receptors, is the focus of biomedical research seeking to effectively prevent and treat coronavirus disease (COVID-19). The mass production of spike glycoproteins is usually carried out in different cell systems. Studies have been shown that different expression cell systems alter protein glycosylation of hemagglutinin and neuraminidase in the influenza virus. However, it is not clear whether the cellular system affects the spike protein glycosylation. In this work, we investigated the effect of an expression system on the glycosylation of the spike glycoprotein and its receptor-binding domain. We found that there are significant differences in the glycosylation and glycans attached at each glycosite of the spike glycoprotein obtained from different expression cells. Since glycosylation at the binding site and adjacent amino acids affects the interaction between the spike glycoprotein and the host cell receptor, we recognize that caution should be taken when selecting an expression system to develop inhibitors, antibodies, and vaccines.

Effect of methylprednisolone in severe and critical COVID-19: Analysis of 102 cases.

BACKGROUND: The coronavirus disease 2019 (COVID-19) outbreak has brought great challenges to public health. Aggravation of COVID-19 is closely related to the secondary systemic inflammatory response. Glucocorticoids are used to control severe diseases caused by the cytokine storm, owing to their anti-inflammatory effects. However, glucocorticoids are a double-edged sword, as the use of large doses has the potential risk of secondary infection and long-term serious complications, and may prolong virus clearance time. Nonetheless, the risks and benefits of glucocorticoid adjuvant therapy for COVID-19 are inconclusive. AIM: To determine the effect of methylprednisolone in severe and critically ill patients with COVID-19. METHODS: This single-center retrospective study included 102 adult COVID-19 patients admitted to a ward of a designated hospital in Wuhan, Hubei Province from January to March 2020. All patients received general symptomatic treatment and organ function support, and were given different respiratory support measures according to their conditions. In case of deterioration, considering the hyperinflammatory state of the patients, methylprednisolone was intravenously administered at 0.75-1.5 mg/kg/d, usually for less than 14 d. Patient vital signs and oxygenation were closely monitored, in combination with imaging and routine blood tests such as C-reactive protein, biochemical indicators (liver and kidney function, myocardial enzymes, electrolytes, etc.), and coagulation function. Patient clinical outcomes were discharge or death. RESULTS: A total of 102 severe and critically ill COVID-19 patients were included in this study. They were divided into treatment (69, 67.6%) and control groups (33, 32.4%) according to methylprednisolone use. Comparison of baseline data between the two groups showed that the treatment group patients had higher aspartic acid aminotransferase, globulin, hydroxybutyrate dehydrogenase, and lactate dehydrogenase. There was no significant difference in other baseline data between the two groups. With regard to prognosis, 29 (78.4%) patients in the treatment group died as opposed to 40 (61.5%) in the control group. The mortality was higher in the treatment group than in the control group; however, according to the log-rank test and the Kaplan-Meier survival curve, the difference in mortality between both groups was insignificant (P = 0.655). The COX regression equation was used to correct the variables with differences, and the results showed that methylprednisolone treatment did not improve prognosis. CONCLUSION: Methylprednisolone treatment does not improve prognosis in severe and critical COVID-19 patients.

Current status of and factors influencing anxiety and depression in front-line medical staff supporting Wuhan in containing the novel coronavirus pneumonia epidemic.

AIM: This research aimed to shed light on the relationship between the sociodemographic characteristics of front-line medical workers and their anxiety and depression, to provide the basis and reference for targeted mental health education and for relevant departments to formulate appropriate policies during the COVID-19 outbreak. METHODS: This study adopted a convenient sampling method and examined the psychological status of 150 front-line medical workers from Zhejiang Province with questionnaire surveys using the Hamilton Anxiety and Depression Scale. RESULTS: The participants had severe anxiety and depression; the top three items under the category of anxiety were genitourinary symptoms, behavior at interview, and respiratory symptoms, whereas the top three items under depression were feelings of guilt, weight loss, and retardation. Among all personal data, the following factors influenced anxiety, in decreasing order: degree of suspicion of being infected when showing associated symptoms, degree of fear of yourself and your family being infected, and the affiliated hospital (p < .05). As for depression, the factors were the degree of suspicion of being infected when showing associated symptoms and the degree of fear of yourself and your family being infected (p < .05). CONCLUSION: This study revealed that front-line medical staff presented symptoms of anxiety and depression when dealing with the COVID-19 outbreak and the factors influencing their psychological stress. Guiding policies and psychological interventions is crucial to maintaining their psychological well-being. Different measures may be implemented to solve this problem.

Predictive value of serum cystatin C for risk of mortality in severe and critically ill patients with COVID-19.

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) has rapidly evolved into a global pandemic. COVID-19 is clinically categorized into mild, moderate, severe, and critical illness. Acute kidney injury is an independent risk factor for poor prognosis in patients with. Serum cystatin C (sCys C) is considered a more sensitive biomarker for early renal insufficiency than conventional indicators of renal function. Early detection of risk factors that affect the prognosis of severe and critically ill patients while using active and effective treatment measures is very important and can effectively reduce the potential mortality rate. AIM: To determine the predictive value of sCys C for the prognosis of patients with COVID-19. METHODS: The clinical data of 101 severe and critically ill patients with COVID-19 at a designated hospital in Wuhan, Hubei Province, China were analyzed retrospectively. According to the clinical outcome, the patients were divided into a discharge group (64 cases) and a death group (37 cases). The general information, underlying diseases, and laboratory examination indexes of the two groups were compared. Multivariate Cox regression was used to explore the relationship between sCys C and prognosis. The receiver operating characteristic (ROC) curve was used to demonstrate the sensitivity and specificity of sCys C and its optimal cut-off value for predicting death. RESULTS: There were significant differences in age, sCys C, creatinine, C-reactive protein, serum albumin, creatine kinase-MB, alkaline phosphatase, lactate dehydrogenase, neutrophil count, and lymphocyte count between the two groups (P < 0.001). Multivariate logistic regression analysis showed that sCys C was an independent risk factor for death in patients with COVID-19 (Odds ratio = 1.812, 95% confidence interval [CI]: 1.300-2.527, P < 0.001). The area under the ROC curve was 0.755 (95%CI: 1.300-2.527), the cut-off value was 0.80, the specificity was 0.562, and the sensitivity was 0.865. CONCLUSION: sCys C is an independent risk factor for death in patients with COVID-19. Patients with a sCys C level of 0.80 mg/L or greater are at a high risk of death.