Deep Convolutional Neural Networks for Thyroid Tumor Grading using Ultrasound B-mode Imagesa)
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
Authors: Shao, Juntao; Zheng, Jingjing; Zhang, Bing
Abstract
The performances of deep convolutional neural network (DCNN) modeling and transfer learning (TF) for thyroid tumor grading using ultrasound imaging were evaluated. This retrospective study included input patient data (ultrasound B-mode image sets) assigned to the training group (115 participants) or testing group (28 participants). DCNN (ResNet50) and TF (ResNet50, ResNet101, ResNet152, VGG16, Inception V3, and DenseNet201), which trains a convolutional neural network that has been pre-trained on ImageNet, were used for image classification based on thyroid tumor grade. Supervised training was performed by using the DCNN or TF model to minimize the difference between the output data and clinical grading. The performances of the DCNN and TF models were assessed in the testing dataset with receiver operating characteristic analyses. Results showed that TF based on Resnet50 and VGG16 had better performance than DCNN (ResNet50) in differentiating thyroid tumor with areas under the receiver operating characteristic (AUCs) curve more than 0.8. However, TF based on ResNet101, ResNet152, InceptionV3, and Densenet201 had equal or worse performances than DCNN (ResNet50) in grading thyroid tumor with AUCs less than 0.5. TF based on ResNet50 and VGG16 had a superior performance compared to DCNN (ResNet50) model for grading thyroid tumors based on ultrasound images.
Mediator complex subunit Med19 binds directly GATA transcription factors and is required with Med1 for GATA-driven gene regulationin vivo
JOURNAL OF BIOLOGICAL CHEMISTRY
Authors: Immarigeon, Clement; Bernat-Fabre, Sandra; Guillou, Emmanuelle; Verger, Alexis; Prince, Elodie; Benmedjahed, Mohamed A.; Payet, Adeline; Couralet, Marie; Monte, Didier; Villeret, Vincent; Bourbon, Henri-Marc; Boube, Muriel
Abstract
The evolutionarily conserved multiprotein Mediator complex (MED) serves as an interface between DNA-bound transcription factors (TFs) and the RNA Pol II machinery. It has been proposed that each TF interacts with a dedicated MED subunit to induce specific transcriptional responses. But are these binary partnerships sufficient to mediate TF functions? We have previously established that the Med1 Mediator subunit serves as a cofactor of GATA TFs inDrosophila, as shown in mammals. Here, we observe mutant phenotype similarities between another subunit, Med19, and theDrosophilaGATA TF Pannier (Pnr), suggesting functional interaction. We further show that Med19 physically interacts with the Drosophila GATA TFs, Pnr and Serpent (Srp),in vivoandin vitrothrough their conserved C-zinc finger domains. Moreover, Med19 loss of function experimentsin vivoorin celluloindicate that it is required for Pnr- and Srp-dependent gene expression, suggesting general GATA cofactor functions. Interestingly, Med19 but not Med1 is critical for the regulation of all tested GATA target genes, implying shared or differential use of MED subunits by GATAs depending on the target gene. Lastly, we show a direct interaction between Med19 and Med1 by GST pulldown experiments indicating privileged contacts between these two subunits of the MED middle module. Together, these findings identify Med19/Med1 as a composite GATA TF interface and suggest that binary MED subunit-TF partnerships are probably oversimplified models. We propose several mechanisms to account for the transcriptional regulation of GATA-targeted genes.