Preparation of a new monoclonal antibody against nucleocapsid protein of swine acute diarrhea syndrome coronavirus and identification of its linear antigenic epitope.

Swine acute diarrhea syndrome coronavirus (SADS-CoV), which causes severe diarrhea in newborn piglets, was first identified in Southern China in 2017. Since the Nucleocapsid (N) protein in SADS-CoV is highly conserved and plays a key role in virus replication, it is often used as a target protein in scientific research. In this study, the N protein of SADS-CoV was successfully expressed, and a new monoclonal antibody (mAb), 5G12, against the protein was generated successfully. The mAb 5G12 can be used to detect SADS-CoV strains by indirect immunofluorescence assay (IFA) and western blotting. The mAb 5G12 epitope was located to amino acids 11 EQAESRGRK 19 by evaluating the antibody for reactivity with a series of truncated N protein segments. The biological information analysis showed that the antigenic epitope had a high antigenic index and conservation. This study will help further understand the protein structure and function of SADS-CoV and in the establishment of specific SADS-CoV detection methods.

Establishment of a recombinase polymerase amplification (RPA) fluorescence assay for the detection of swine acute diarrhea syndrome coronavirus (SADS-CoV).

BACKGROUND: Swine acute diarrhea syndrome coronavirus (SADS-CoV) causes acute vomiting and diarrhea in piglets, leading to significant financial losses for the pig industry. Recombinase polymerase amplification (RPA) is a rapid nucleic acid amplification technology used under constant temperature conditions. The study established a real-time reverse transcription (RT)-RPA assay for early diagnosis of SADS-CoV.  RESULTS: The detection limit of the real-time RT-RPA was 74 copies/µL of SADS-CoV genomic standard recombinant plasmid in 95% of cases. The assay was performed in less than 30 min and no cross-reactions were observed with eight other common viruses that affect swine, including classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), pseudo rabies virus (PRV), swine influenza virus (SIV), seneca valley virus (SVA), transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV). The coefficient of variation (C.V.) values of the two standards dilutions and three positive clinical sample ranged from 2.95% to 4.71%. A total of 72 clinical fecal samples from swine with diarrheal symptoms were analyzed with the developed RT-RPA and quantitative RT-PCR. There was 98.61% agreement between the RT-RPA and the quantitative real-time PCR results. CONCLUSIONS: These results indicated that the developed RT-RPA assay had good specificity, sensitivity, stability and repeatability. The study successfully established a broadly reactive RT-RPA assay for SADS-CoV detection.

5-min mindfulness audio induction alleviates psychological distress and sleep disorders in patients with COVID-19.

BACKGROUND: Mindfulness meditation is beneficial to mitigate the negative effects of the coronavirus disease 2019 (COVID-19) pandemic in the general population, but no study examined such meditation in the COVID-19 patients themselves. AIM: To explore the short-term efficacy of mindfulness meditation in alleviating psychological distress and sleep disorders in patients with COVID-19. METHODS: This prospective study enrolled patients with mild COVID-19 treated at Wuhan Fangcang Hospital in February 2020. The patients were voluntarily divided into either a mindfulness or a conventional intervention group. The patients were evaluated before/after the intervention using the Short Inventory of Mindfulness Capability (SMI-C), Hospital Anxiety and Depression Scale (HADS), and Pittsburgh Sleep Quality Index (PSQI). RESULTS: Seventy-five participants were enrolled in this study, with 43 and 32 in the mindfulness and conventional groups, respectively. Before the intervention, there were no differences in SMI-C, HADS, or PSQI scores between the two groups. After the 2-wk intervention, the mindfulness level (from 30.16 ± 5.58 to 35.23 ± 5.95, P < 0.001) and sleep quality (from 12.85 ± 3.06 to 9.44 ± 3.86, P < 0.001) were significantly increased in the mindfulness group. There were no differences in the conventional group. After the intervention, the mindfulness level (35.23 ± 5.95 vs 31.17 ± 6.50, P = 0.006) and sleep quality (9.44 ± 3.86 vs 11.87 ± 4.06, P = 0.011) were significantly higher in the mindfulness group than in the conventional group. Depression decreased in the mindfulness group (from 14.15 ± 3.21 to 12.50 ± 4.01, P = 0.038), but there was no difference between the two groups. CONCLUSION: Short-term mindfulness meditation can increase the mindfulness level, improve the sleep quality, and decrease the depression of patients with COVID-19.

Imaging diagnosis and molecular detection for COVID-19

The purpose of this study is to provide a systematic theoretical basis and technical support for the effective diagnosis and effective surveillance of Post COVID-19 epidemic. We systematically reviewed the development of the epidemic, collected data, and analyzed the medical imaging diagnostic methods and molecular detection techniques for clinical diagnosis of COVID-19 infected patients and the experience gained in clinical practice since the outbreak of the epidemic. Studies have shown that clinical suspected cases should be comprehensively analyzed in combination with clinical characteristics such as epidemiological contact history and imaging findings, and viral nucleic acid testing should be performed on respiratory or blood samples of suspected cases infected with new coronavirus(SARS-CoV-2). In clinical practice, patients with suspected COVID-19 pneumonia do not exclude the possibility of false negative test results. Real-time fluorescent RT-PCR is required to detect viral nucleic acid positive in order to fully confirm the diagnosis.