ABSTRACT
Objective:To investigate the optimal keV value of a novel dual-layer spectral detector CT virtual monoenergetic images (VMI) for displaying esophageal cancer lesions and to evaluate its diagnostic efficacy for preoperative T staging of esophageal cancer.Methods:The data of 50 patients with esophageal carcinoma in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School from October 2019 to August 2020 were retrospectively analyzed. There were 42 males and 8 females, aged 49-78(65±7) years. All patients underwent novel dual-layer spectral detector CT chest enhanced scan before treatment, the conventional CT images and 40-200 keV VMI were reconstructed. One-way ANOVA and Kruskal-Wallis H rank sum test were used to compare the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) among conventional CT images and 40-200 keV VMI.The 5-grade grading method were applied for subjective evaluation, and the Friedman test was used to compare the differences in the subjective evaluation of image quality in each group.Spearman test was used to analyze the correlation of images at different energy levels with SNR and CNR. Fisher exact test was used to compare the accuracy of conventional CT and optimal keV value images for preoperative diagnosis of T staging of esophageal cancer. Results:There were significant differences in SNR and CNR among conventional CT images and 40-200 keV VMI images ( P<0.001), and the SNR and CNR of 40 keV images were superior to those of conventional CT images and 70-200 keV VMI images ( P<0.05). The energy level of 40-200 keV VMI was negatively correlated with SNR and CNR (SNR: r=-1.000, P<0.001; CNR: r =-1.000, P<0.001). The overall difference in subjective image quality scores among conventional CT images and 40-200 keV VMI was statistically significant (χ 2=498.37, P<0.001), of which the subjective image quality of 40-60 keV VMI was superior to that of conventional CT images ( P<0.05). The accuracy of preoperative diagnosis of T-stage of esophageal cancer was 62.9% (22/35) for both 40 keV VMI and conventional CT images. Conclusion:The novel dual-layer spectral detector CT of 40 keV VMI has the best display of esophageal cancer, and the accuracy of preoperative diagnosis of T staging is similar to that of conventional CT.
ABSTRACT
Solanum lycopersicum phenylalanine ammonia-lyase 5 (SlPAL5) gene regulates the metabolism of phenolic compounds. The study of transcription factors that regulate the expression of SlPAL5 gene is of great significance to elucidate the regulatory mechanism underlying the biosynthesis of phenolic compounds in tomato fruit induced by UV-C irradiation. Here, yeast one-hybrid library of tomato fruit was constructed, and the yeast one-hybrid technology was used to screen the transcription factors that regulate the expression of SlPAL5, the key gene related to the synthesis of phenolic compounds in tomato fruit. As a result, a transcription factor, SlERF7, was obtained and sequenced, followed by the blast homology analysis. Further experiments confirmed that SlERF7 interacted with the promoter of SlPAL5 gene. In addition, UV-C irradiation significantly increased the expression level of SlERF7. These results indicate that SlERF7, which is regulated by UV-C irradiation, might be involved in regulating the transcription of SlPAL5, which provided foundations for further studying the regulation mechanism of the biosynthesis of phenolic compounds in tomato fruit induced by UV-C irradiation.