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Prolonged SARS-CoV-2 RNA shedding and recurrence of PCR-positive tests have been widely reported in patients after recovery, yet these patients most commonly are non-infectious1-14. Here we investigated the possibility that SARS-CoV-2 RNAs can be reverse-transcribed and integrated into the human genome and that transcription of the integrated sequences might account for PCR-positive tests. In support of this hypothesis, we found chimeric transcripts consisting of viral fused to cellular sequences in published data sets of SARS-CoV-2 infected cultured cells and primary cells of patients, consistent with the transcription of viral sequences integrated into the genome. To experimentally corroborate the possibility of viral retro-integration, we describe evidence that SARS-CoV-2 RNAs can be reverse transcribed in human cells by reverse transcriptase (RT) from LINE-1 elements or by HIV-1 RT, and that these DNA sequences can be integrated into the cell genome and subsequently be transcribed. Human endogenous LINE-1 expression was induced upon SARS-CoV-2 infection or by cytokine exposure in cultured cells, suggesting a molecular mechanism for SARS-CoV-2 retro-integration in patients. This novel feature of SARS-CoV-2 infection may explain why patients can continue to produce viral RNA after recovery and suggests a new aspect of RNA virus replication.
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Objective To explore and compare the prognostic ability of the serum level of M2BPGi and MRI imaging technology for hepatic fibrosis. Methods 118 patients who were diagnosed as hepatitis C were enrolled from March 2014 to March 2015 in our hospital.Their baseline data were recorded,and they were texted by imaging examination of MRI.Then all patients were followed-up 2 years.The patients were divided into hepatic fibrosis group and control group according to the follow-up results.Univariate analysis and Cox model were used to show that the prognostic factors influencing the prognosis of hepatic fibrosis in patients;meanwhile,the statistical significance factors were calculated by ROC curve.Results The serological markers of IV-C,HA and serum level of M2BPGi in hepatic fibrosis group were higher than those in control group,but its ADC values of liver was lower than those in control group,and the difference was statistically significant(P < 0.05). COX regression analysis showed that the difference of M2BPGi(RR = 4.282,P = 0.003)and ADC values(RR = 0.654,P = 0.004). The ROC analysis of the hepatic fibrosis group and the control group showed that the AUC of the combination was 0.865,the sensitivity and specificity were 95.2%,60.5%,respectively.Conclusion The clinical value the com-bined prognostic of them is of high prognostic efficacy,which is hopeful to be used as an auxiliary prognostic meth-od in clinic.
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PurposeTo evaluate the motion correction algorithm (snapshot freeze, SSF) and multi-cycle reconstruction on the imaging quality and interpretation of coronary CT angiography (CCTA).Materials and Methods Sixty patients with suspected coronary heart disease were divided into two groups according to the heart rate. Twenty-ifve patients with heart rate ≤65 beats per minute underwent prospectively ECG-gated CCTA on gemstone CT. Image quality and interpretability of standard (STD) and SSF reconstructions at 75% R-R interval were compared. Thirty-five patients with heart rate>65 beats per minute underwent retrospective ECG-gated CCTA. Image quality and interpretability of STD and SSF reconstructions at 45% and 75% R-R interval were compared. The image qualities and interpretability were assessed based on coronary artery segment, coronary artery bifurcation and overall coronary artery.Results For 25 patients with prospectively ECG gated CCTA, SSF reconstructions showed higher interpretability than STD reconstructions on per-segment level [96.3% (341/354)vs 90.7% (321/354),P0.05). For 35 patients with retrospective ECG-gate CCTA, SSF reconstructions at 45% R-R interval showed higher interpretability (P0.05). Image qualities with SSF were higher than that with single and double sector STD reconstructions (P0.05). There were signiifcant different for LAD, LCX and RCA on both 45% and 75% R-R interval images (P<0.01,P<0.001). Conclusion SSF may improve the image quality and interpretability of CCTA images using prospectively and retrospective ECG-gated techniques, especially for improving the image quality.