Segments are fundamental units in animal development which are made of distinct cell lineages separated by boundaries. Although boundaries show limited plasticity during their formation for sharpening, cell lineages make compartments that become tightly restricted as development goes on. Here, we characterize a unique case of breaking of the segment boundary in late drosophila embryos. During dorsal closure, specific cells from anterior compartments cross the segment boundary and enter the adjacent posterior compartments. This cell mixing behaviour is driven by an anterior-to-posterior reprogramming mechanism involving de novo expression of the homeodomain protein Engrailed. Mixing is accompanied by stereotyped local cell intercalation, converting the segment boundary into a relaxation compartment important for tension-release during morphogenesis. This process of lineage switching and cell remodelling is controlled by JNK signalling. Our results reveal plasticity of segment boundaries during late morphogenesis and a role for JNK-dependent developmental reprogramming in this process.
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http://dx.doi.org/10.1371/journal.pbio.1000390 | DOI Listing |
Ann Surg Oncol
December 2024
Center for Liver and Pancreatobiliary Cancer, National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
Background: Conventional right hepatectomy typically involves resection of the right hemiliver, often including partial removal of the caudate lobe. However, recent advancements, particularly in indocyanine green (ICG) fluorescence imaging, have allowed for more accurate identification of anatomical boundaries between liver segments. In this context, we present a refined technique for real anatomical right hepatectomy that preserves the caudate lobe, offering enhanced surgical precision and several distinct advantages over traditional methods.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, 01605, USA.
Multicellular spheroids embedded in 3D hydrogels are prominent in vitro models for 3D cell invasion. Yet, quantification methods for spheroid cell invasion that are high-throughput, objective and accessible are still lacking. Variations in spheroid sizes and the shapes of the cells within render it difficult to objectively assess invasion extent.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
December 2024
Aix Marseille Université, Université Gustave Eiffel, LBA, Marseille, France. Electronic address:
This study proposes a method for assessing the transverse toughness of human long-bone cortical tissue. The method is based on a three-point bending test of pre-notched femur diaphysis segments, post-processed using the compliance method coupled with numerical simulations. Given the cracking nature of bone and if cracking processes remain confined to the crack tip, it is assumed that the compliance method can be used.
View Article and Find Full Text PDFComput Biol Med
December 2024
Faculty of Chemical & Petroleum Engineering, University of Tabriz, Tabriz, Iran. Electronic address:
Background And Objectives: The liver, a vital metabolic organ, is always susceptible to various diseases that ultimately lead to fibrosis, cirrhosis, acute liver failure, chronic liver failure, and even cancer. Optimal and specific medicine delivery in various diseases, hepatectomy, shunt placement, and other surgical interventions to reduce liver damage, transplantation, optimal preservation, and revival of the donated organ all rely on a complete understanding of perfusion and mass transfer in the liver. This study aims to simulate the computational fluid dynamics of perfusion and the temporal-spatial distribution of a medicine in a healthy liver to evaluate the hemodynamic characteristics of flow and medicine transport with the purpose of more effective liver treatment.
View Article and Find Full Text PDFJ Imaging
December 2024
Faculty of Sustainable Design Engineering, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada.
This study introduced a novel approach to 3D image segmentation utilizing a neural network framework applied to 2D depth map imagery, with Z axis values visualized through color gradation. This research involved comprehensive data collection from mechanically harvested wild blueberries to populate 3D and red-green-blue (RGB) images of filled totes through time-of-flight and RGB cameras, respectively. Advanced neural network models from the YOLOv8 and Detectron2 frameworks were assessed for their segmentation capabilities.
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