High-affinity binding to the SARS-CoV-2 spike trimer by a nanostructured, trivalent protein-DNA synthetic antibody (preprint)

Multivalency enables nanostructures to bind molecular targets with high affinity. Although antibodies can be generated against a wide range of antigens, their shape and size cannot be tuned to match a given target. DNA nanotechnology provides an attractive approach for designing customized multivalent scaffolds due to the addressability and programmability of the nanostructure shape and size. Here, we design a nanoscale synthetic antibody ("nano-synbody") based on a three-helix bundle DNA nanostructure with one, two, or three identical arms terminating in a mini-binder protein that targets the SARS-CoV-2 spike protein. The nano-synbody was designed to match the valence and distance between the three receptor binding domains (RBDs) in the spike trimer, in order to enhance affinity. The protein-DNA nano-synbody shows tight binding to the wild-type, Delta, and several Omicron variants of the SARS-CoV-2 spike trimer, with affinity increasing as the number of arms increases from one to three. The effectiveness of the nano-synbody was also verified using a pseudovirus neutralization assay, with the three-arm nanostructure inhibiting two Omicron variants against which the structures with only one or two arms are ineffective. The structure of the three-arm nano-synbody bound to the Omicron variant spike trimer was solved by negative-stain transmission electron microscopy reconstruction, and shows the protein-DNA nanostructure with all three arms attached to the RBD domains, confirming the intended trivalent attachment. The ability to tune the size and shape of the nano-synbody, as well as its potential ability to attach two or more different binding ligands, will enable the high-affinity targeting of a range of proteins not possible with traditional antibodies.

The social psychological impact of the COVID-19 pandemic on medical staff in China: A cross-sectional study.

BACKGROUND: The COVID-19 outbreak required the significantly increased working time and intensity for health professionals in China, which may cause stress signs. METHODS: From March 2-13 of 2020, 4,618 health professionals in China were included in an anonymous, self-rated online survey regarding their concerns on exposure to the COVID-19 outbreak. The questionnaires consisted of five parts: basic demographic information and epidemiological exposure; occupational and psychological impact; concerns during the episode; coping strategies; and the Huaxi Emotional-Distress Index (HEI). RESULTS: About 24.2% of respondents experienced high levels of anxiety or/and depressive symptoms since the COVID-19 outbreak. Respondents who worried about their physical health and those who had COVID-19 infected friends or close relatives were more likely to have high HEI levels, than those without these characteristics. Further, family relationship was found to have an independent protective effect against high HEI levels. Their main concerns were that their families would not be cared for and that they would not be able to work properly. Compared to respondents with clear emotional problems, those with somewhat hidden emotional issues adopted more positive coping measures. CONCLUSIONS: About a quarter of medical staff experienced psychological problems during the pandemic of COVID-19. The psychological impact of stressful events was related to worrying about their physical health, having close COVID-19 infected acquaintances and family relationship issues. Therefore, the psychological supprot for medical staff fighting in the COVID-19 pandemic may be needed.

Exploring the driving factors of haze events in Beijing during Chinese New Year holidays in 2020 and 2021 under the influence of COVID-19 pandemic.

Unexpected outbreak of the 2019 novel coronavirus (COVID-19) has profoundly altered the way of human life and production activity, which posed visible impacts on PM2.5 and its chemical species. The abruptly emergency reduction in human activities provided an opportunity to explore the synergetic impacts of multi-factors on shaping PM2.5 pollution. Here, we conducted two comprehensive observation measurements of PM2.5 and its chemical species from 1 January to 16 February in Beijing 2020 and the same lunar date in 2021, to investigate temporal variations and reveal the driving factors of haze before and after Chinese New Year (CNY). Results show that mean PM2.5 concentrations during the whole observation were 63.83 and 66.86 µg/m3 in 2020 and 2021, respectively. Higher secondary inorganic species were observed after CNY, and K+, Cl- showed three prominent peaks which associated closely with fireworks burnings from suburb Beijing and surroundings, verifying that they could be used as two representative tracers of fireworks. Further, we explored the impacts of meteorological conditions, regional transportation as well as chemical reactions on PM2.5. We found that unfavorable meteorological conditions accounted for 11.0 % and 16.9 % of PM2.5 during CNY holidays in 2020 and 2021, respectively. Regional transport from southwest and southeast (south) played an important role on PM2.5 during the two observation periods. Higher ratio of NO3-/SO42- were observed under high OX and low RH conditions, suggesting the major pathway of NO3- and SO42- formation could be photochemical process and aqueous-phase reaction. Additionally, nocturnal chemistry facilitated the formation of secondary components of both inorganic and organic. This study promotes understandings of PM2.5 pollution in winter under the influence of COVID-19 pandemic and provides a well reference for haze and PM2.5 control in future.

Adaptive Resources Allocation CUSUM for Binomial Count Data Monitoring with Application to COVID-19 Hotspot Detection (preprint)

In this paper, we present an efficient statistical method (denoted as "Adaptive Resources Allocation CUSUM") to robustly and efficiently detect the hotspot with limited sampling resources. Our main idea is to combine the multi-arm bandit (MAB) and change-point detection methods to balance the exploration and exploitation of resource allocation for hotspot detection. Further, a Bayesian weighted update is used to update the posterior distribution of the infection rate. Then, the upper confidence bound (UCB) is used for resource allocation and planning. Finally, CUSUM monitoring statistics to detect the change point as well as the change location. For performance evaluation, we compare the performance of the proposed method with several benchmark methods in the literature and showed the proposed algorithm is able to achieve a lower detection delay and higher detection precision. Finally, this method is applied to hotspot detection in a real case study of county-level daily positive COVID-19 cases in Washington State WA) and demonstrates the effectiveness with very limited distributed samples.

JAK-STAT signaling as an ARDS therapeutic target: status and future trends (preprint)

Acute respiratory distress syndrome (ARDS) is an acute respiratory disease which is characterized by non-cardiogenic pulmonary oedema. It has a high mortality rate and lacks effective pharmacotherapy. As the outbreak of COVID worldwide, the mortality of ARDS has increased correspondingly, which makes it urgent to find effective targets and strategies for the treatment of ARDS. Recent clinical trials of Janus kinase (JAK) inhibitors in treating COVID induced ARDS have shown a positive outcome, which makes the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway a potential therapeutic target for treating ARDS. Here, we review the complex cause of ARDS, the molecular pathway of JAK/STAT involved in ARDS pathology, and the progress that has been made in strategies of targeting JAK/STAT to treat ARDS Specially, JAK/STAT signaling directly participates in the progression of ARDS or collude with other pathways to aggravate ARDS. We summarize JAK and STAT inhibitors with ARDS treatment benefits, including inhibitors in clinical trials and pre-clinical studies and natural products, and discuss the side effects of the current JAK inhibitors to reveal the future trends in designing of JAK inhibitors, which will help to develop effective treatment strategies for ARDS in the future.

Comparative study of hematological and radiological feature of severe/critically ill patients with COVID-19, influenza A H7N9, and H1N1 pneumonia.

OBJECTIVES: This study aimed to explore clinical indexes for management of severe/critically ill patients with COVID-19, influenza A H7N9, and H1N1 pneumonia by comparing hematological and radiological characteristics. METHODS: Severe/critically ill patients with COVID-19, H7N9, and H1N1 pneumonia were retrospectively enrolled. The demographic data, clinical manifestations, hematological parameters, and radiological characteristics were compared. RESULTS: In this study, 16 cases of COVID-19, 10 cases of H7N9, and 13 cases of H1N1 who met severe/critically ill criteria were included. Compared with COVID-19, H7N9 and H1N1 groups had more chronic diseases (80% and 92.3% vs. 25%, p < 0.05), higher APACHE Ⅱ scores (16.00 ± 8.63 and 15.08 ± 6.24, vs. 5.50 ± 2.58, p < 0.05), higher mortality rates (40% and 46.2% vs. 0%, p < 0.05), significant lymphocytopenia (0.59 ± 0.31 × 109 /L and 0.56 ± 0.35 × 109 /L vs. 0.97 ± 0.33 × 109 /L, p < 0.05), and elevated neutrophil-to-lymphocyte ratio (NLR; 14.67 ± 6.10 and 14.64 ± 10.36 vs. 6.29 ± 3.72, p < 0.05). Compared with the H7N9 group, ground-glass opacity (GGO) on chest CT was common in the COVID-19 group (p = 0.028), while pleural effusion was rare (p = 0.001). CONCLUSIONS: The NLR can be used as a clinical parameter for the predication of risk stratification and outcome in COVID-19 and influenza A pneumonia. Manifestations of pleural effusion or GGO in chest CT may be helpful for the identification of different viral pneumonia.

Risk factors and prediction nomogram model for psychosocial and behavioural problems among children and adolescents during the COVID-19 pandemic: A national multicentre study: Risk Factors of Childhood Psychosocial Problems.

BACKGROUND: We aimed to explore the risk profiles attributable to psychosocial and behavioural problems during the coronavirus disease 2019 pandemic. To this end, we created a risk-prediction nomogram model. METHODS: A national multicentre study was conducted through an online questionnaire involving 12,186 children (6-11 years old) and adolescents (12-16 years old). Respondents' psychosocial and behavioural functioning were assessed using the Achenbach Child Behaviour Checklist (CBCL). Data were analysed using STATA software and R-language. RESULTS: The positive detection rate of psychological problems within Wuhan was greater than that outside Wuhan for schizoid (P = 0.005), and depression (P = 0.030) in children, and for somatic complaints (P = 0.048), immaturity (P = 0.023), and delinquent behaviour (P = 0.046) in adolescents. After graded multivariable adjustment, seven factors associated with psychological problems in children and adolescents outside Wuhan were parent-child conflict (odds ratio (OR): 4.94, 95% confidence interval (95% CI): 4.27-5.72), sleep problems (OR: 4.05, 95% CI: 3.77-4.36), online study time (OR: 0.41, 95% CI: 0.37-0.47), physical activity time (OR: 0.510, 95% CI: 0.44-0.59), number of close friends (OR: 0.51, 95% CI: 0.44-0.6), time spent playing videogames (OR: 2.26, 95% CI: 1.90-2.69) and eating disorders (OR: 2.71, 95% CI: 2.35-3.11) (all P < 0.001). Contrastingly, within Wuhan, only the first four factors, namely, parent-child conflict (5.95, 2.82-12.57), sleep problems (4.47, 3.06-6.54), online study time (0.37, 0.22-0.64), and physical activity time (0.42, 0.22-0.80) were identified (all P < 0.01). Accordingly, nomogram models were created with significant attributes and had decent prediction performance with C-indexes over 80%. LIMITATION: A cross-sectional study and self-reported measures. CONCLUSIONS: Besides the four significant risk factors within and outside Wuhan, the three additional factors outside Wuhan deserve special attention. The prediction nomogram models constructed in this study have important clinical and public health implications for psychosocial and behavioural assessment.

Psychosocial and behavioral problems of children and adolescents in the early stage of reopening schools after the COVID-19 pandemic: a national cross-sectional study in China.

This study aims to explore the psychosocial and behavioral problems of children and adolescents in the early stage of reopening schools. In this national cross-sectional study, a total of 11072 students from China were naturally divided into two groups based on their schooling status: reopened schools (RS) and home schooling (HS) group. The psychosocial and behavioral functioning were measured by Achenbach Child Behaviour Checklist (CBCL) and compared in these two groups. Multivariable logistic regression analyses were conducted to explore the independent predictors associated with the psychosocial and behavioral problems. Our results showed that the students in the RS group had more adverse behaviors than that of HS group. The RS group had the higher rates of parent-offspring conflict, prolonged homework time, increased sedentary time and sleep problems (all p < 0.001). When separate analyses were conducted in boys and girls, the RS group had the higher scores for (1) overall behavioral problems (p = 0.02 and p = 0.01), internalizing (p = 0.02 and p = 0.02) and externalizing (p = 0.02 and p = 0.004) behaviors in the 6-11 age group; (2) externalizing (p = 0.049 and p = 0.006) behaviors in the 12-16 age group. Multivariable regression showed parent-offspring conflict and increased sedentary time were the most common risk factors, while physical activity and number of close friends were protective factors for behavior problems in RS students (p < 0.01 or 0.05). The present study revealed that students' psychosocial and behavioral problems increased in the early stage of schools reopened unexpectedly. These findings suggest that close attention must be paid and holistic strategies employed in the school reopening process of post-COVID-19 period.

Heterogeneous nuclear ribonucleoprotein A2B1, a novel drug target for hepatitis B virus infection (preprint)

HBV infection is a major global health burden that needs novel immunotherapeutic approaches. Herein, we show that heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) is a novel drug target for HBV infection. We reveal the new target with highly selective probes of PAC5, a natural sesquiterpene derivative. PAC5 show potent anti-HBV activity in vivo and in vitro. Further studies on its mode of action indicate that PAC5 binds to the residue Asp49 and a deep groove in the RNA recognition motif1 (RRM1) region of hnRNPA2B1. PAC5-bound hnRNPA2B1 is activated, dimerized, and translocated to the cytoplasm where it activates the TBK1-IRF3 pathway, leading to the production of type I interferons (IFNs). Furthermore, PAC5 also suppresses other viral replications, such as SARS-CoV-2 and vesicular stomatitis virus (VSV). Our results indicate that PAC5 is the first small molecule agonist of hnRNPA2B1, a drug target potentially valid for broad-spectrum viral infections, providing a novel strategy for viral immunotherapy.

Drivers and mediators of healthcare workers' anxiety in one of the most affected hospitals by COVID-19: a qualitative analysis.

OBJECTIVE: To report the driving and mediating factors of healthcare workers' anxiety during the COVID-19 pandemic. DESIGN: Qualitative indepth interview study. SETTING: The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. PARTICIPANTS: 53 healthcare workers who were or were not diagnosed with COVID-19. RESULTS: During the COVID-19 pandemic, healthcare workers were initially not sufficiently psychologically prepared. Then they suffered from severe anxiety and apprehension during the peak stage, regardless of whether they were infected with SARS-CoV-2 or not. These negative emotions were exacerbated by four drivers, namely infection risk, supplies, isolation and media. As the epidemic gradually came under control, healthcare workers experienced less anxiety from these factors, but became concerned about their low financial status. To reduce anxiety, healthcare workers diverted their attention from the risk of infection through personal entertainment and religious beliefs and focused on treating their patients. Furthermore, assistance from other people, including colleagues, families, friends, patients and society, helped protect healthcare workers from anxiety. CONCLUSIONS: Personal and social support can relieve healthcare workers' anxiety to some extent during the different stages of an epidemic. Both protective equipment and financial allowance motivate healthcare workers to focus on patient care, although the latter matters more as the epidemic comes under control.

Recommendations for the Diagnosis, Prevention, and Control of Coronavirus Disease-19 in Children-The Chinese Perspectives.

Ever since SARS-CoV-2 began infecting people by the end of 2019, of whom some developed severe pneumonia (about 5%), which could be fatal (case fatality ~3.5%), the extent and speed of the COVID-19 outbreak has been phenomenal. Within 2.5 months (by March 18, 2020) over 191,127 COVID-19 patients have been identified in 161 countries. By then, over 700 pediatric patients were confirmed to have COVID-19 in China, with only about 58 diagnosed elsewhere. By now, there are thousands of children and adolescents infected. Chinese pediatricians would like to share their experience on how these patients were managed in China and the key recommendations that had guided them in meeting the evolving challenges. A group of experts were summoned by the Chinese Pediatric Society and Editorial Board of Chinese Journal of Pediatrics to extract informative data from a survey on confirmed COVID-19 pediatric patients in China. Consensus on diagnosis, management, and prevention of pediatric COVID-19 were drawn up based on the analysis of such data plus insights gained from the past SARS and MERS coronavirus outbreaks. Relevant cumulating experiences from physicians managing adult patients, expedited reports on clinical and scientific COVID-19 and SARS-CoV-2 data, and the National Health Committee guidelines on COVID-19 management were integrated into this proposal.

Kindergartens Reopening in the Period of Regular Epidemic Prevention and Control, Benefitial or Harmful?

In the period of regular epidemic prevention and control of Coronavirus disease 2019 (COVID-19) in our country, work resumption has been fully advanced. But there are still new sporadic local cases and imported cases across the country. In this situation, whether kindergartens reopening will increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread still remains uncertain. We reviewed two pediatric patients with moderate COVID-19, collected the epidemiologic information and monitored the cycle threshold value of rectal specimen and the viral loads, and discussed the transmission of SARS-CoV-2 in pediatric patients and the virulence of feces in children with moderate COVID-19, in order to analyze the risk of kindergartens reopening.

Prediction and analysis of Corona Virus Disease 2019.

The outbreak of Corona Virus Disease 2019 (COVID-19) in Wuhan has significantly impacted the economy and society globally. Countries are in a strict state of prevention and control of this pandemic. In this study, the development trend analysis of the cumulative confirmed cases, cumulative deaths, and cumulative cured cases was conducted based on data from Wuhan, Hubei Province, China from January 23, 2020 to April 6, 2020 using an Elman neural network, long short-term memory (LSTM), and support vector machine (SVM). A SVM with fuzzy granulation was used to predict the growth range of confirmed new cases, new deaths, and new cured cases. The experimental results showed that the Elman neural network and SVM used in this study can predict the development trend of cumulative confirmed cases, deaths, and cured cases, whereas LSTM is more suitable for the prediction of the cumulative confirmed cases. The SVM with fuzzy granulation can successfully predict the growth range of confirmed new cases and new cured cases, although the average predicted values are slightly large. Currently, the United States is the epicenter of the COVID-19 pandemic. We also used data modeling from the United States to further verify the validity of the proposed models.

Prevention of COVID-19 infection in a pediatric oncology ward in Wuhan.

OBJECTIVE: To assess the screening and isolation measures for preventing coronavirus disease 2019 (COVID-19) infection from newly admitted patients into a pediatric oncology ward. METHODS: We retrospectively analyzed 44 patients with established hematologic malignancies admitted for chemotherapy from January 23 to March 27, 2020 in the Department of Pediatric Hematology of Tongji Hospital, Wuhan. Every patient and their caregivers were well educated on personal protection and put it into effect at home and in hospital. Screening for COVID-19 of all the patients and caregivers before admission was performed. Both clinical features and screening results including chest computerized tomography (CT); nucleic acid testing of nasopharyngeal, oropharyngeal or anal swabs; and quantitative antibodies (IgM and IgG) detecting of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of these patients were described. RESULTS: The results of nucleic acid and antibodies (IgM and IgG) testing of all the 44 inpatients and their caregivers were negative. Abnormal chest CT images were observed in six symptomatic patients, while chest CT images of their caregivers did not show the changes related to viral pneumonia. These symptomatic patients all recovered after antibacterial combined with antifungal treatment, but without any antiviral agents. CONCLUSIONS: COVID-19 infection could be prevented in pediatric patients with malignancies if proper protective measures were implemented. For patients presenting suspicious symptoms, comprehensive examinations should be carried out.

Screening of SARS-CoV-2 in 299 Hospitalized Children with Hemato-oncological Diseases: A Multicenter Survey in Hubei, China.

The SARS-CoV-2 infection status of hospitalized children was surveyed in the department of pediatric hematology and oncology in three different hospitals of epidemic areas in Hubei, China. A cross-sectional study was performed to investigate the clinical characteristics, lung CT scan, SARS-CoV-2 nucleic acid test and serum antibodies of hospitalized children with hemato-oncological diseases from January 23 to April 24, 2020. 299 children were enrolled in this study, including 176 males (58.9%) and 123 females (41.1%), aged from 2 months to 16 years. 255 cases (85.3%) received chemotherapy or other immunosuppressive therapies, and there were 44 cases (14.7%) of other benign diseases. Nucleic acid test was performed on 258 children (86.3%) and one case was positive. 163 cases (54.5%) were tested for serum antibodies, and all of them were negative. Lung CT scan was performed on 247 children (82.6%), and 107 of them showed infectious changes. Only one case (0.33%) of COVID-19 was diagnosed in the group. The prevalence rate of COVID-19 in enrolled children with hemato-oncological diseases in Hubei was 0.33%. Immunosuppressed patients are not prone to produce related antibodies. Comprehensive protective measures and ward management can reduce the risk of SARS-CoV-2 infection in the group patients.

Are They Just Two Children COVID-19 Cases Confused With Flu?

COVID-19, an emerging infectious disease, has quickly spread all over the world. All human populations are susceptible to this disease. Here we present two pediatric COVID-19 cases, both of whom exhibited negative SARS-CoV-2 nucleic acid tests upon nasopharyngeal swab and were initially diagnosed with influenza A infection. COVID-19 was later confirmed in both patients by serum antibodies of SARS-CoV-2 and nucleic acid test on stool samples. Because children are susceptible to many respiratory pathogens, especially influenza, we concluded that children can be coinfected with multiple pathogens, and more attention should be paid to the exploration of SARS-CoV-2 during the pandemic of COVID-19. This report shows the possibility of misdiagnosis or missed diagnosis of children with COVID-19. We suggest that highly suspected pediatric COVID-19 cases with negative nucleic acid tests on nasopharyngeal swabs should be further checked by performing a nucleic acid test on stool samples and testing serum for antibodies against SARS-CoV-2.

ß-sitosterol ameliorates influenza A virus-induced proinflammatory response and acute lung injury in mice by disrupting the cross-talk between RIG-I and IFN/STAT signaling.

ß-Sitosterol (24-ethyl-5-cholestene-3-ol) is a common phytosterol Chinese medical plants that has been shown to possess antioxidant and anti-inflammatory activity. In this study we investigated the effects of ß-sitosterol on influenza virus-induced inflammation and acute lung injury and the molecular mechanisms. We demonstrate that ß-sitosterol (150-450 µg/mL) dose-dependently suppresses inflammatory response through NF-κB and p38 mitogen-activated protein kinase (MAPK) signaling in influenza A virus (IAV)-infected cells, which was accompanied by decreased induction of interferons (IFNs) (including Type I and III IFN). Furthermore, we revealed that the anti-inflammatory effect of ß-sitosterol resulted from its inhibitory effect on retinoic acid-inducible gene I (RIG-I) signaling, led to decreased STAT1 signaling, thus affecting the transcriptional activity of ISGF3 (interferon-stimulated gene factor 3) complexes and resulting in abrogation of the IAV-induced proinflammatory amplification effect in IFN-sensitized cells. Moreover, ß-sitosterol treatment attenuated RIG-I-mediated apoptotic injury of alveolar epithelial cells (AEC) via downregulation of pro-apoptotic factors. In a mouse model of influenza, pre-administration of ß-sitosterol (50, 200 mg·kg-1·d-1, i.g., for 2 days) dose-dependently ameliorated IAV-mediated recruitment of pathogenic cytotoxic T cells and immune dysregulation. In addition, pre-administration of ß-sitosterol protected mice from lethal IAV infection. Our data suggest that ß-sitosterol blocks the immune response mediated by RIG-I signaling and deleterious IFN production, providing a potential benefit for the treatment of influenza.