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Objective:To investigate the differences in outcomes of surgical strategies and prognosis of patients with acute type A aortic dissection(ATAAD) during the period of COVID-19 Omicron variant epidemic compared with the non-epidemic period.Methods:Clinical data were retrospectively collected from ATAAD patients during the COVID-19 Omicron variant epidemic(December 7, 2022 to January 10, 2023) and during the non-epidemic period(December 7, 2019 to January 10, 2020) to compare the differences in surgical strategies, perioperative mortality, and perioperative complication rates in ATAAD patients during the two different periods.Results:There were 14 patients in the COVID-19 infected group and 43 patients in the control group. Patients in the infected group had a shorter mean aortic clamp time[(89.71±16.27)min vs.(110.09±28.99)min, P<0.01], a significantly higher postoperative mortality rate relative to the control group(21.43% vs. 2.33%, P=0.02), a significantly longer length of stay in the ICU(3 days vs. 2 days, P=0.04) and the duration of intubation time(34 h vs. 14 h, P<0.01), and the incidence of adverse events, mainly cerebral infarction, was higher in infected group(28.57% vs. 6.98%, P=0.03). Conclusion:During the COVID-19 Omicron variant strain epidemic, our center preferred a more conservative surgical strategy in COVID-19 infected patients. Although the COVID-19 infection increased the postoperative mortality and complication rate of ATAAD, patients still achieve a more satisfactory outcome. Therefore, surgical treatment should be timely performed for ATAAD patients.
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Objective:To develop a rapid, simple and cost-effective quantitative TaqMan RT-PCR (RT-qPCR) that could be used as an alternative to sequencing for the detection of Omicron variants and to evaluate its performance.Methods:Primers and TaqMan probes targeting the conserved domains of SARS-CoV-2 ORF1ab and the high-frequency mutation sites in the S gene of Omicron variants were designed. Then a RT-qPCR for the detection of Omicron variants was established. The consistency of the method was verified using samples identified by whole-genome sequencing. The specificity and sensitivity of the method were also evaluated.Results:The established RT-qPCR could distinguish Omicron variants from early epidemic A strains and Alpha and Delta variants of SARS-CoV-2, and the results were consistent with those of whole-genome sequencing with a coincidence rate of 100% (28/28). There was no cross-reactivity with other six respiratory viruses or coxsackievirus group A16. For RNA standards, this method showed good linearity in the range of 10 9-10 3 copies/μl with a correlation coefficient ( R2) greater than 0.99 and detection sensitivity of 10 3 copies/μl. Conclusions:The RT-qPCR designed in this study for Omicron variant detection had good sensitivity and specificity and could be easily performed in laboratories, which would greatly facilitate the monitoring of Omicron variants.
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Via an insufficient coat protein complex I (COPI) retrieval signal, the majority of SARS-CoV-2 spike (S) is resident in host early secretory organelles and a tiny amount is leaked out in cell surface. Only surface-exposed S can be recognized by B cell receptor (BCR) or anti-S therapeutic monoclonal antibodies (mAbs) that is the trigger step for B cell activation after S mRNA vaccination or infected cell clearance by S mAbs. Now, a drug strategy to promote S host surface exposure is absent. Here, we first combined structural and biochemical analysis to characterize S COPI sorting signals. A potent S COPI sorting inhibitor was then invented, evidently capable of promoting S surface exposure and facilitating infected cell clearance by S antibody-dependent cellular cytotoxicity (ADCC). Importantly, with the inhibitor as a probe, we revealed Omicron BA.1 S is less cell surface exposed than prototypes because of a constellation of S folding mutations, possibly corresponding to its ER chaperone association. Our findings not only suggest COPI is a druggable target against COVID-19, but also highlight SARS-CoV-2 evolution mechanism driven by S folding and trafficking mutations.
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@#Objective To optimize the culture conditions of four vaccine candidates of severe acute respiratory symptom coronavirus 2(SARS-CoV-2) Omicron variants BA.1,BA.1.1,BA.2 and BA.5 in Vero cells.Methods The harvest time(24,48,72 and 96 h) and MOI(0.01,0.001,0.0001 and 0.000 01) of four Omicron variants cultured in Vero cells were optimized by using cytopathic effect(CPE),viral nucleic acid copy number and viral titer as evaluation indexes.Results The optimum harvest time of the four Omicron variants BA.1,BA.1.1,BA.2 and BA.5 in Vero cells was 72 h,and the optimum MOI was 0.001～0.000 01,0.001～0.000 01,0.01～0.000 01 and 0.01～0.000 01,respectively.Conclusion The culture conditions of four Omicron variants in Vero cells were optimized,which laid a foundation of the development of SARS-CoV-2 Omicron variant inactivated vaccine based on Vero cells.