SARS-CoV-2 NSP13 interacts with host IRF3, blocking antiviral immune responses.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses an unprecedented threat to human health since late 2019. Notably, the progression of the disease is associated with impaired antiviral interferon (IFN) responses. Although multiple viral proteins were identified as potential IFN antagonists, the underlying molecular mechanisms remain to be fully elucidated. In this study, we firstly demonstrate that SARS-CoV-2 NSP13 protein robustly antagonizes IFN response induced by the constitutively active form of transcription factor IRF3 (IRF3/5D). This induction of IFN response by IRF3/5D is independent of the upstream kinase, TBK1, a previously reported NSP13 target, thus indicating that NSP13 can act at the level of IRF3 to antagonize IFN production. Consistently, NSP13 exhibits a specific, TBK1-independent interaction with IRF3, which, moreover, is much stronger than that of NSP13 with TBK1. Furthermore, the NSP13-IRF3 interaction was shown to occur between the NSP13 1B domain and IRF3 IRF association domain (IAD). In agreement with the strong targeting of IRF3 by NSP13, we then found that NSP13 blocks IRF3-directed signal transduction and antiviral gene expression, counteracting IRF3-driven anti-SARS-CoV-2 activity. These data suggest that IRF3 is likely to be a major target of NSP13 in antagonizing antiviral IFN responses and provide new insights into the SARS-CoV-2-host interactions that lead to viral immune evasion.

Management and implementation strategies of pre-screening triage in children during coronavirus disease 2019 pandemic in Guangzhou, China.

BACKGROUND: Emerging infectious diseases are a constant threat to the public's health and health care systems around the world. Coronavirus disease 2019 (COVID-2019), which was defined by the World Health Organization as pandemic, has rapidly emerged as a global health threat. Outbreak evolution and prevention of international implications require substantial flexibility of frontline health care facilities in their response. AIM: To explore the effect of the implementation and management strategy of pre-screening triage in children during COVID-19. METHODS: The standardized triage screening procedures included a standardized triage screening questionnaire, setup of pre-screening triage station, multi-point temperature monitoring, extensive screenings, and two-way protection. In order to ensure the implementation of the pre-screening triage, the prevention and control management strategies included training, emergency exercise, and staff protection. Statistical analysis was performed on the data from all the children hospitalized from January 20, 2020 to March 20, 2020 at solstice during the pandemic period. Data were obtained from questionnaires and electronic medical record systems. RESULTS: A total of 17561 children, including 2652 who met the criteria for screening, 192 suspected cases, and two confirmed cases without omission, were screened from January 20, 2020 to March 20, 2020 at solstice during the pandemic period. There was zero transmission of the infection to any medical staff. CONCLUSION: The effective strategies for pre-screening triage have an essential role in the prevention and control of hospital infection.

Brainstem folding in an influenza child with Dandy-Walker variant.

BACKGROUND: Influenza in children is a major cause of morbidity and mortality worldwide. Nervous system diseases are a factor relating to increased mortality rate. However, reports of how these underlying diseases contribute to the death of children with influenza are rare. CASE SUMMARY: A 4-year-old-girl developed type A influenza-related encephalopathy (IAE) with seizures, acute disorder of consciousness, and intracranial hypertension (cerebrospinal fluid pressure: 250 mmH2O), and the Dandy-Walker variant was found by her first magnetic resonance imaging (MRI) when admission. Three days later, she suddenly presented anisocoria, acute pulmonary edema, and coma, and the later MRI found that she had compressed brainstem, oblongata "Z-like folding", and swelling bilateral basal ganglia. After admission, the patient were tested for routine and special biomarkers and underwent neuroimaging and neuroelectrophysiology examinations as well as Oseltamivir and intravenous immunogloblin treatments. When predicting that unstable intracranial structures detected by MRI might have disastrous consequences in the progression of IAE, she was transferred into the pediatric intensive care unit and underwent continuous assessment of clinical condition while she did not have instability of basic vital signs; at the same time, her parents were fully informed about the risk and prognosis. Although she was ultimately dead from brain stem failure, the parents expressed understanding and did not trigger a doctor-patient conflict. CONCLUSION: In case of finding an unstable intracranial structure, intensive care should be given to IAE patient and their clinical condition should be monitored continuously.

Clinical manifestations of severe enterovirus 71 infection and early assessment in a Southern China population.

BACKGROUND: Enterovirus 71 (EV-A71) shows a potential of rapid death, but the natural history of the infection is poorly known. This study aimed to examine the natural history of EV-A71 infection. METHODS: This was a prospective longitudinal observational study performed between January 1st and October 31st, 2012, at three hospitals in Guangdong, China. Subjects with positive EV-A71 RNA laboratory test results were included. Disease progression was documented with MRI, autopsies, and follow-up. Symptoms/signs with potential association with risk of death were analyzed. RESULTS: Among the 288 patients, neurologic symptoms and signs were observed (emotional movement disorders, dyskinesia, involuntary movements, autonomic dysfunction, and disturbance of consciousness). Some of them occurred as initial symptoms. Myoclonic jerks/tremors were observed among >50% of the patients; nearly 40% of patients presented fatigue and 25% were with vomiting. Twenty-eight patients (9.7%) presented poor peripheral perfusion within 53.4 ± 26.1 h; 23 patients (8.0%) presented pulmonary edema and/or hemorrhage within 62.9 ± 28.6 h. Seventeen (5.9%) patients were in a coma. Seven (2.4%) patients died within 62.9 ± 28.6 h. Seventy-seven survivors underwent head and spinal cord MRI and 37.7% (29/77) showed abnormalities. Two fatal cases showed neuronal necrosis, softening, perivascular cuffing, colloid, and neuronophagia phenomenon in the brainstem. CONCLUSIONS: Patients with EV-A71 infection showed high complexity of symptoms and onset timing. Death risk may be indicated by autokinetic eyeball, eyeball ataxia, severe coma, respiratory rhythm abnormality, absent pharyngeal reflex, ultrahyperpyrexia, excessive tachycardia, pulmonary edema and/or hemorrhage, and refractory shock and ataxic respiration. Early assessment of these symptoms/signs is important for proper management.

Glucocorticoids Prevent Enterovirus 71 Capsid Protein VP1 Induced Calreticulin Surface Exposure by Alleviating Neuronal ER Stress.

Severe hand-foot-and-mouth disease (HFMD) caused by Enterovirus 71 (EV71) always accompanies with inflammation and neuronal damage in the central nervous system (CNS). During neuronal injuries, cell surface-exposed calreticulin (Ecto-CRT) is an important mediator for primary phagocytosis of viable neurons by microglia. Our data confirmed that brainstem neurons underwent neuronophagia by glia in EV71-induced death cases of HFMD. EV71 capsid proteins VP1, VP2, VP3, or VP4 did not induce apoptosis of brainstem neurons. Interestingly, we found VP1-activated endoplasmic reticulum (ER) stress and autophagy could promote Ecto-CRT upregulation, but ER stress or autophagy alone was not sufficient to induce CRT exposure. Furthermore, we demonstrated that VP1-induced autophagy activation was mediated by ER stress. Meaningfully, we found dexamethasone treatment could attenuate Ecto-CRT upregulation by alleviating VP1-induced ER stress. Altogether, these findings identify VP1-promoted Ecto-CRT upregulation as a novel mechanism of EV71-induced neuronal cell damage and highlight the potential of the use of glucocorticoids to treat severe HFMD patients with CNS complications.

Intervention effect of pinelliae decoction for purging stomach-fire on malignant transformation of bone marrow mesenchymal stem cells in the gastric cancer microenvironment.

OBJECTIVE: The study aimed to simulate the microenvironment of gastric cancer to promote the malignant transformation of bone marrow mesenchymal stem cells (BMSCs) and further evaluate the effect of Pinelliae Decoction for Purging Stomach-Fire and its disassembled prescriptions on BMSCs. METHODS: Transwell co-culture was performed on the human gastric cancer cell strains BGC-823 and BMSCs to simulate the microenvironment of gastric cancer. The drug-containing serum prepared by Pinelliae Decoction for Purging Stomach-Fire and its disassembled prescriptions was used, and its influence on BMSCs with malignant transformation was observed. RESULTS: BMSCs were harvested successfully from the rat bone marrow, and flow cytometer identification indicated that CD44+/CD34- cells accounted for 70.64%. The co-culture of BGC-823 cells can induce malignant transformation of BMSCs. And the drug-containing serum can induce G2 phase arrest, inhibit cell proliferation, simultaneously inhibit TERT and c-myc expression, lower the cellular ability of chemotactic migration, inhibit the tumor-forming ability of BGC-823 in nude rats and promote the tumor apoptosis. CONCLUSION: The effective components of Pinelliae Decoction for Purging Stomach-Fire in gastric cancer treatment are pinelliae and dried ginger, and the main acting mechanism is to inhibit tumor cell proliferation and chemotactic migration and promote apoptosis.

[Variability of soil water soluble organic carbon content and its response to temperature change in green spaces along urban-to-rural gradient of Nanchang, China].

Topsoil of green space including typical forest, shrub and grassland were collected to measure their water soluble organic carbon ( WSOC) before and after incubation of 30 days at 5, 15, 25, 35 and, 45 °C. The results showed the average values of WSOC were higher in urban than in rural green spaces, but the percentage of WSOC to total organic carbon (TOC) showed an opposite trend. No significant changes were found among the three green space types in WSOC and WSOC/TOC. Response of WSOC in green space to incubation temperature was generally highest in urban sites, followed by suburban sites, and lowest in rural sites at the incubation temperature of 5 °C, but showed an opposite trend at the temperature of 45 °C. Response coefficient of WSOC to temperature change was lower in forest and shrub than in grassland, but increased along the urban-rural gradient. Further analysis showed that WSOC positively correlated with TOC, total nitrogen and available phosphorus, and the response coefficient of WSOC to temperature change negatively correlated with available phosphorus. In summary, exogenous substances input might lead to the accumulation of WSOC in urban green space, however, urban environment was helpful to maintain the stability of WSOC, which might be due to the enrichment of available phosphorus in urban sites.

[A study on the karyotype, C-banding and Ag-NORs in Rana nigromaculata].

The chromosome samples of Rana nigromaculata were prepared by peripheral blood lymphocyte cultured in vitro. Karyotype, C-banding and silver-staining nucleolus organizer regions (Ag-NORs) were observed on chromosomes samples. The result showed that: (1) the chromosome number of Rana nigromaculata is 26 (2n=26), i.e., 10 large and 16 small chromosomes, the large chromosomes are matched into 5 homologous pairs and small chromosomes are matched into 8 homologous pairs, and further indicates the karyotype of Rana nigromaculata is bi-modal; (2) Metaphases of female and male were observed separately, the chromosome of No.11 has a pronounced secondary constriction in the middle of long arms. But the position of secondary constriction in the aberrant type individuals is in the middle of long arms of the No.8; (3) it has only one obvious C-banding close to the telomere, which is located in the long arms of the No.5; (4) The chromosome No.11 is a pair of homologous chromosomes with Ag-NORs, and the position of Ag-NORs in female and male is identical.