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Background To develop an effective model of predicting fatal outcomes in the severe coronavirus disease 2019 (COVID-19) patients. Methods Between February 20, 2020 and April 4, 2020, consecutive confirmed 2541 COVID-19 patients from three designated hospitals were enrolled in this study. All patients received chest computed tomography (CT) and serological examinations at admission. Laboratory tests included routine blood tests, liver function, renal function, coagulation profile, C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), and arterial blood gas. The SaO2 was measured using pulse oxygen saturation in room air at resting status. Independent high-risk factors associated with death were analyzed using Cox proportional hazard model. A prognostic nomogram was constructed to predict the survival of severe COVID-19 patients. Results There were 124 severe patients in the training cohort, and there were 71 and 76 severe patients in the two independent validation cohorts, respectively. Multivariate Cox analysis indicated that age ≥ 70 years (HR = 1.184, 95% CI 1.061–1.321), panting (breathing rate ≥ 30/min) (HR = 3.300, 95% CI 2.509–6.286), lymphocyte count 9/L (HR = 2.283, 95% CI 1.779–3.267), and interleukin-6 (IL-6) > 10 pg/ml (HR = 3.029, 95% CI 1.567–7.116) were independent high-risk factors associated with fatal outcome. We developed the nomogram for identifying survival of severe COVID-19 patients in the training cohort (AUC = 0.900, 95% CI 0.841–0.960, sensitivity 95.5%, specificity 77.5%); in validation cohort 1 (AUC = 0.811, 95% CI 0.763–0.961, sensitivity 77.3%, specificity 73.5%); in validation cohort 2 (AUC = 0.862, 95% CI 0.698–0.924, sensitivity 92.9%, specificity 64.5%). The calibration curve for probability of death indicated a good consistence between prediction by the nomogram and the actual observation. The prognosis of severe COVID-19 patients with high levels of IL-6 receiving tocilizumab were better than that of those patients without tocilizumab both in the training and validation cohorts, but without difference (P = 0.105 for training cohort, P = 0.133 for validation cohort 1, and P = 0.210 for validation cohort 2). Conclusions This nomogram could help clinicians to identify severe patients who have high risk of death, and to develop more appropriate treatment strategies to reduce the mortality of severe patients. Tocilizumab may improve the prognosis of severe COVID-19 patients with high levels of IL-6.

Ischaemic stroke is a severe disease worldwide. Restoration of blood flow after ischaemic stroke leads to cerebral ischaemia–reperfusion injury (CIRI). Various operations, such as cardiac surgery with deep hypothermic circulatory arrest, predictably cause cerebral ischaemia. Diabetes is related to the occurrence of perioperative stroke and exacerbates neurological impairment after stroke. Therefore, the choice of anaesthetic drugs has certain clinical significance for patients with diabetes. Isoflurane (ISO) exerts neuroprotective and anti-neuroinflammatory effects in patients without diabetes. However, the role of ISO in cerebral ischaemia in the context of diabetes is still unknown. Toll-like receptor 4 (TLR4) and NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome activation play important roles in microglia-mediated neuroinflammatory injury. In this study, we treated a diabetic middle cerebral artery occlusion mouse model with ISO. We found that diabetes exacerbated cerebral ischaemia damage and that ISO exerted neuroprotective effects in diabetic mice. Then, we found that ISO decreased TLR4-NLRP3 inflammasome activation in microglia and the excessive autophagy induced by CIRI in diabetic mice. The TLR4-specific agonist CRX-527 reversed the neuroprotective effects of ISO. In summary, our study indicated that ISO exerts neuroprotective effects against the neuroinflammation and autophagy observed during diabetic stroke via the TLR4-NLRP3 signalling pathway.

Additional file 3: Supplemental Table 1 Comparison of Baseline characteristics between severe patients and non-severe patients n(%). WBC. White blood cell; PLT. Platelet; CRP. C-reactive protein; PCT. Procalcitonin; IL-6. Interleukin-6; SaO2. Oxygen saturation; TBIL. Total bilirubin; ALT. Alanine aminotransferase; AST. Aspartate aminotransferase; LDH. Lactate dehydrogenase; γ-GT. γ-glutamyl transpeptadase; Cr. Creatinine; CT. Computed tomography. Supplemental Table 2 Baseline characteristics of the patients [n(%)]. aAges are shown as median (range). WBC. White blood cell; PLT. Platelet; CRP. C-reactive protein; PCT. Procalcitonin; IL-6. Interleukin-6; SaO2. Oxygen saturation; TBIL. Total bilirubin; ALT. Alanine aminotransferase; AST. Aspartate aminotransferase; LDH. Lactate dehydrogenase; γ-GT. γ-glutamyl transpeptadase; Cr. Creatinine; CT. Computed tomography

The effects of gentiopicroside (Gent), an active component derived from the traditional Chinese medicine Gentiana macrophylla, on lipopolysaccharide-induced astrocyte activation and subsequent neuronal damage were investigated. Gent significantly inhibited the release of tumor necrosis factor-α, interleukin-1β, nitric oxide, and prostaglandin E, as well as expressions of inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-induced primary astrocytes. Furthermore, Gent relieved neurotoxicity from astrocyte-mediated inflammatory injury. Mechanism studies indicated that Gent significantly suppressed nuclear factor-κB nuclear translocation and down-regulated c-Jun-N-terminal kinase/stress-activated protein kinase mitogen-activated protein kinase phosphorylation levels with little influence on elevated p-p38 levels. Taken together, our findings suggested Gent could prevent the neurotoxicity related to astrocyte-mediated inflammatory injury by inhibition of nuclear factor-κB and mitogen-activated protein kinase signaling pathways. The study also indicated that neuronal injury could be prevented by promptly modulating inflammatory responses of astrocytes.