Identification of common and severe COVID-19: the value of CT texture analysis and correlation with clinical characteristics.

OBJECTIVE: To explore the value of CT texture analysis (CTTA) for determining coronavirus disease 2019 (COVID-19) severity. METHODS: The clinical and CT data of 81 patients with COVID-19 were retrospectively analyzed. The texture features were extracted using LK2.1. The two-sample t test or Mann-Whitney U test was used to find the significant features. Minimum redundancy and maximum relevance (MRMR) method was performed to find the features with maximum correlation and minimum redundancy. These features were then used to construct a radiomics texture model to discriminate the severe patients using multivariate logistic regression method. Besides, a clinical model was also built. ROC analyses were conducted to evaluate the performance of two models. The correlations of clinical features and textural features were analyzed using the Spearman correlation analysis. RESULTS: Of the total cases included, 60 were common and 21 were severe. (1) For textural features, 20 radiomics features selected by MRMR showed good performance in discriminating the two groups (AUC > 70%). (2) For clinical features, chi-square tests or Mann-Whitney U tests identified 16 clinical features as significant, and 12 were discriminative (p < 0.05) between two groups analyzed by univariate logistic analysis. Of these, 10 had an AUC > 70%. (3) Prediction models for textural features and clinical features were established, and both showed high predictive accuracy. The AUC values of textural features and clinical features were 0.93 (0.86-1.00) and 0.95 (0.95-0.99), respectively. (4) The Spearman correlation analysis showed that most textural and clinical features had above-moderate correlations with disease severity (> 0.4). CONCLUSION: Texture analysis can provide reliable and objective information for differential diagnosis of COVID-19. KEY POINTS: • CT texture analysis can well differentiate common and severe COVID-19 patients. • Some textural features showed above-moderate correlations with clinical factors. • CT texture analysis can provide useful information to judge the severity of COVID-19.

A correlation between acute kidney injury and myonecrosis after scheduled percutaneous coronary intervention.

Slight elevations in cardiac troponin I and T are frequently observed after percutaneous coronary intervention (PCI). Contrast-induced acute kidney injury (CI-AKI) is a complex syndrome induced by exposure to intravascular contrast media (CM). Currently, the relationships between the CM, pre-existing kidney insufficiency, CI-AKI, and myonecrosis after elective PCI are unclear. To investigate the relationship between CI-AKI and post-procedural myonecrosis (PMN) after PCI, we analyzed 327 non-ST-segment elevation acute coronary syndrome subjects undertaking elective PCI. The levels of cardiac troponins (cTns), cTnI and cTnT, at baseline and on at least one occasion 18-24 h after PCI were measured. We also recorded serum levels of creatinine (SCr) and the urine albumin:creatinine ratio (ACR) before coronary angiography, and 24-48 h and 48-72 h after contrast administration. A post-procedure increase in cTns was detected in 16.21% (53/327) of subjects with cTns levels >99th to 5×99th percentile upper reference limit (URL). Twenty-seven patients (8.26%) developed CI-AKI. CI-AKI occurred more often in subjects with PMN than in those without PMN (20.8% versus 5.8%, respectively, P=0.001). Multiple logistic regression analysis revealed that pre-existing microalbuminuria (MA) was an important independent predictor of PMN (OR: 3.31; 95% CI: 1.26-8.65, P=0.01). However, there was no correlation between the incidence of CI-AKI and PMN (OR: 2.38; 95% CI: 0.88-6.46, P=0.09). We conclude that pre-existing MA was not only an important independent predictor of CI-AKI but also of PMN.

Wwp2, an E3 ubiquitin ligase that targets transcription factor Oct-4 for ubiquitination.

The POU transcription factor Oct-4 is a master regulator affecting the fate of pluripotent embryonic stem cells. However, the precise mechanisms by which the activation and expression of Oct-4 are regulated still remain to be elucidated. We describe here a novel murine ubiquitin ligase, Wwp2, that specifically interacts with Oct-4 and promotes its ubiquitination both in vivo and in vitro. Remarkably, the expression of a catalytically inactive point mutant of Wwp2 abolishes Oct-4 ubiquitination. Moreover, Wwp2 promotes Oct-4 degradation in the presence of overexpressed ubiquitin. The degradation is blocked by treatment with proteasome inhibitor. Fusion of a single ubiquitin to Oct-4 inactivates its transcriptional activity in a heterologous Oct-4-driven reporter system. Furthermore, overexpression of Wwp2 in embryonic stem cells significantly reduces the Oct-4-transcriptional activities. Collectively, we demonstrate for the first time that Oct-4 can be post-translationally modified by ubiquitination and that this modification dramatically suppresses its transcriptional activity. These results reveal that the functional status of Oct-4, in addition to its expression level, dictates its transcriptional activity, and the results open up a new avenue to understand how Oct-4 defines the fate of embryonic stem cells.