Radiology “Hits Refresh” with Artificial Intelligence

Publication date: Available online 6 April 2018
Source:Academic Radiology
Author(s): Srini Tridandapani




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Musculoskeletal Radiology Fellowship Application and Selection Process

Publication date: Available online 6 April 2018
Source:Academic Radiology
Author(s): Jennifer L. Demertzis, Jonathan C. Baker, Michael V. Friedman, Charles S. Resnik, Theodore T. Miller, David A. Rubin
Rational and ObjectivesThis study aimed to assess resident, fellow, and fellowship director perceptions of the musculoskeletal (MSK) radiology fellowship application process.Materials and MethodsA task group constructed three surveys with questions about current and "ideal" fellowship application and selection processes. Surveys were distributed to MSK fellowship directors, who were also asked to give separate surveys to current fellows. US and Canadian radiology residency directors were asked to distribute surveys to current R3 and R4 residents. Responses were tabulated and analyzed.ResultsResponses were received from 47 MSK fellowship directors, 73 MSK fellows, and 147 residents. Fellowship directors and fellows reported that most fellowship offers occur between July and September of the R3 year, although 19% of directors made offers as early as the R2 year. Of the 43 director respondents, 31 (72%) noted "pressure from other programs" as the main driving force behind their policies, but 28 (65%) felt that their timelines were "too early." A formal match was supported by 55% of responding fellowship directors, 57% of fellows, and 61.9% of residents, citing "fairness" as a major justification.ConclusionsMSK radiology fellowship selection occurs as early as the R2 year, before many residents have had substantial exposure to different subspecialties. An "arms race" has developed with programs moving their timelines earlier in response to the actions of other programs, presumably to avoid missing the best candidates. Although a majority of respondents would support a formalized match to increase fairness, there is not universal agreement that it would be the best approach.



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A Deep Boltzmann Machine-Driven Level Set Method for Heart Motion Tracking Using Cine MRI Images

Publication date: Available online 6 April 2018
Source:Medical Image Analysis
Author(s): Jian Wu, Thomas R. Mazur, Su Ruan, Chunfeng Lian, Nalini Daniel, Hilary Lashmett, Laura Ochoa, Imran Zoberi, Mark A. Anastasio, H. Michael Gach, Sasa Mutic, Maria Thomas, Hua Li
Heart motion tracking for radiation therapy treatment planning can result in effective motion management strategies to minimize radiation-induced cardiotoxicity. However, automatic heart motion tracking is challenging due to factors that include the complex spatial relationship between the heart and its neighboring structures, dynamic changes in heart shape, and limited image contrast, resolution, and volume coverage. In this study, we developed and evaluated a deep generative shape model-driven level set method to address these challenges. The proposed heart motion tracking method makes use of a heart shape model that characterizes the statistical variations in heart shapes present in a training data set. This heart shape model was established by training a three-layered deep Boltzmann machine (DBM) in order to characterize both local and global heart shape variations. During the tracking phase, a distance regularized level-set evolution (DRLSE) method was applied to delineate the heart contour on each frame of a cine MRI image sequence. The trained shape model was embedded into the DRLSE method as a shape prior term to constrain an evolutional shape to reach the desired heart boundary. Frame-by-frame heart motion tracking was achieved by iteratively mapping the obtained heart contour for each frame to the next frame as a reliable initialization, and performing a level-set evolution. The performance of the proposed motion tracking method was demonstrated using thirty-eight coronal cine MRI image sequences.

Graphical abstract

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Intestinal CART is a regulator of GIP and GLP-1 secretion and expression

Publication date: Available online 6 April 2018
Source:Molecular and Cellular Endocrinology
Author(s): L. Shcherbina, A. Lindqvist, A.-H. Thorén Fischer, E. Ahlqvist, E. Zhang, S.E. Falkmer, E. Renström, J. Koffert, H. Honka, N. Wierup
Impaired incretin effect is a culprit in Type 2 Diabetes. Cocaine- and amphetamine-regulated transcript (CART) is a regulatory peptide controlling pancreatic islet hormone secretion and beta-cell survival. Here we studied the potential expression of CART in enteroendocrine cells and examined the role of CART as a regulator of incretin secretion and expression.CART expression was found in glucose-dependent insulinotropic polypeptide (GIP)-producing K-cells and glucagon-like peptide-1 (GLP-1)-producing L-cells in human duodenum and jejunum and CART levels were increased 60 min after a meal in humans. CART expression was increased by fatty acids and GIP, but unaffected by glucose in GLUTag and STC-1 cells. Exogenous CART had no effect on GIP and GLP-1 expression and secretion in GLUTag or STC-1 cells, but siRNA-mediated silencing of CART reduced GLP-1 expression and secretion. Furthermore, acute administration of CART increased GIP and GLP-1 secretion during an oral glucose-tolerance test in mice. We conclude that CART is a novel constituent of human K- and L-cells with stimulatory actions on incretin secretion and that interfering with the CART system may be a therapeutic avenue for T2D.



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Reduced bioavailability and plant uptake of polycyclic aromatic hydrocarbons from soil slurry amended with biochars pyrolyzed under various temperatures

Abstract

Biochar has high potential for organic pollutant immobilization due to its powerful sorption capacity. Nevertheless, potential risks may exist when biochar-sorbed organic pollutants are bioavailable. A direct plant exposure assay in combination with an organic solvent extraction experiment was carried out in this study to investigate the bioavailability of polycyclic aromatic hydrocarbons (PAHs) with the application of pine needle biochars pyrolyzed under different temperatures (100, 300, 400, and 700 °C; referred as P100–P700 accordingly). Biochar reduced solvent extractability and plant uptake of PAHs including naphthalene (Naph), acenaphthene (Acen), phenanthrene (Phen), and pyrene (Pyr), especially for three- and four-ring PAHs (Phen and Pyr) with high-temperature biochar. Plant uptake assay validates with organic solvent extraction for bioavailability assessment. Sorption of PAHs to biochars reduced plant uptake of PAHs in roots and shoots by lowering freely dissolved PAHs. Aging process reduced the bioavailability of PAHs that were bound to biochar. High pyrolysis temperature can be recommended for biochar preparation for purpose of effectively immobilizing PAHs, whereas application of moderate-temperature biochar for PAH immobilization should concern the potential risks of desorption and bioavailability of PAHs.

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The expression of fgfr3 in the zebrafish head

Publication date: Available online 6 April 2018
Source:Gene Expression Patterns
Author(s): Joanna K. Ledwon, Sergey Y. Turin, Arun K. Gosain, Jolanta M. Topczewska
Fibroblast growth factor (FGF) signaling is essential for many developmental processes and plays a pivotal role in skeletal homeostasis, regeneration and wound healing. FGF signals through one of five tyrosine kinase receptors: Fgfr1a, -1b, −2, −3, −4. To characterize the expression of zebrafish fgfr3 from the larval stage to adulthood, we used RNAscope in situ hybridization on paraffin sections of the zebrafish head. Our study revealed spatial and temporal distribution of fgfr3 transcript in chondrocytes of the head cartilages, osteoblasts involved in bone formation, ventricular zone of the brain, undifferentiated mesenchymal cells of the skin, and lens epithelium of the eye. In general, the expression pattern of zebrafish fgfr3 is similar to the expression observed in higher vertebrates.



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Electroconvulsive seizures influence dendritic spine morphology and BDNF expression in a neuroendocrine model of depression

Publication date: Available online 6 April 2018
Source:Brain Stimulation
Author(s): Kristen. R. Maynard, John W. Hobbs, Sumita Rajpurohit, Keri Martinowich
BackgroundElectroconvulsive therapy (ECT) is a rapid and effective treatment for major depressive disorder. Chronic stress-induced depression causes dendrite atrophy and deficiencies in brain-derived neurotrophic factor (BDNF), which are reversed by anti-depressant drugs. Electroconvulsive seizures (ECS), an animal model of ECT, robustly increase BDNF expression and stimulate dendritic outgrowth.ObjectiveThe present study aims to understand cellular and molecular plasticity mechanisms contributing to the efficacy of ECS following chronic stress-induced depression.MethodsWe quantify Bdnf transcript levels and dendritic spine density and morphology on cortical pyramidal neurons in mice exposed to vehicle or corticosterone and receiving either Sham or ECS treatment.ResultsECS rescues corticosterone-induced defects in spine morphology and elevates Bdnf exon 1 and exon 4-containing transcripts in cortex.ConclusionsDendritic spine remodeling and induction of activity-induced BDNF in the cortex represent important cellular and molecular plasticity mechanisms underlying the efficacy of ECS for treatment of chronic stress-induced depression.



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