RESUMO
Introduction: African swine fever (ASF) is an infectious disease that causes considerable economic losses in pig farming. The agent of this disease, African swine fever virus (ASFV), is a double-stranded DNA virus with a capsid membrane and a genome that is 170-194 kb in length encoding over 150 proteins. In recent years, several live attenuated strains of ASFV have been studied as vaccine candidates, including the SY18ΔL7-11. This strain features deletion of L7L, L8L, L9R, L10L and L11L genes and was found to exhibit significantly reduced pathogenicity in pigs, suggesting that these five genes play key roles in virulence. Methods: Here, we constructed and evaluated the virulence of ASFV mutations with SY18ΔL7, SY18ΔL8, SY18ΔL9, SY18ΔL10, and SY18ΔL11L. Results: Our findings did not reveal any significant differences in replication efficiency between the single-gene deletion strains and the parental strains. Pigs inoculated with SY18ΔL8L, SY18ΔL9R and SY18ΔL10L exhibited clinical signs similar to those inoculated with the parental strains. Survival rate of pigs inoculated with 103.0TCID50 of SY18ΔL7L was 25%, while all pigs inoculated with 103.0TCID50 of SY18ΔL11L survived, and 50% inoculated with 106.0TCID50 SY18ΔL11L survived. Discussion: The results indicate that L8L, L9R and L10L do not affect ASFV SY18 virulence, while the L7L and L11L are associated with virulence.
RESUMO
Background: When patients with type A acute aortic dissection (TAAAD) present with changes to their ST-segment, diagnostic and treatment delays increase significantly. The performance of transthoracic echocardiography (TTE) screening of TAAAD in patients with ST-segment elevated myocardial infarction (STEMI) is yet to be validated. Methods: The diagnostic performance of TTE alone and combined with the aortic dissection risk score (ADRS) in TAAAD was evaluated. In this retrospective study (ChiCTR, No. 2000031291), TTE was reviewed to detect direct/indirect signs of TAAAD. The ADRS of each patient was calculated according to guidelines. Case adjudication was based on advanced imaging and surgery. Results: Among a total of 442 patients, TAAAD was diagnosed in 146 (33.0%). The presence of direct TTE signs had a sensitivity of 43.0% [95% confidence interval (CI): 35.0% to 52.0%] and specificity of 97.0% (95% CI: 95.0% to 99.0%), and the presence of any TTE sign had a sensitivity of 97.0% (95% CI: 93.0% to 99.0%) and specificity of 78.0% (95% CI: 73.0% to 82.0%) for TAAAD. The additive value of TTE was most evident in patients with low clinical probability for TAAAD (ADRS ≤1). The presence of ADRS ≤1 plus an absence of direct TTE signs for TAAAD rule-out had a sensitivity of 98.4% (95% CI: 96.1% to 99.6%). Conclusions: The use of TTE adds value in the screening of TAAAD in STEMI patients. In patients with low clinical probability for TAAAD, direct TTE signs can be used to rapidly identify those who require advanced imaging.