Objective: To investigate the detailed anatomy of the terminal crest (crista terminalis) and its junctional regions with the pectinate muscles and intercaval area to provide the yardstick for structural normality.
Design: 97 human necropsy hearts were studied from patients who were not known to have medical histories of atrial arrhythmias. The dimensions of the terminal crest were measured in width and thickness from epicardium to endocardium, at the four points known to be chosen as sites of ablation.
Results: The pectinate muscles originating from the crest and extending along the wall of the appendage towards the vestibule of the tricuspid valve had a non-uniform trabecular pattern in 80% of hearts. Fine structure of the terminal crest studied using light and scanning electron microscopy consisted of much thicker and more numerous fibrous sheaths of endomysium with increasing age of the patient. 36 specimens of 45 (80%) specimens studied by electron microscopy had a predominantly uniform longitudinal arrangement of myocardial fibres within the terminal crest. In contrast, in all specimens, the junctional areas of the terminal crest with the pectinate muscles and with the intercaval area had crossing and non-uniform architecture of myofibres.
Conclusions: The normal anatomy of the muscle fibres and connective tissue in the junctional area of the terminal crest/pectinate muscles and terminal crest/intercaval bundle favours non-uniform anisotropic properties.
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http://dx.doi.org/10.1136/heart.88.4.406 | DOI Listing |
Elife
December 2024
Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, United States.
Two major ligand-receptor signaling axes - endothelin Edn3 and its receptor Ednrb, and glial-derived neurotrophic factor (GDNF) and its receptor Ret - are required for migration of enteric nervous system (ENS) progenitors to the hindgut. Mutations in either component cause colonic aganglionosis, also called Hirschsprung disease. Here, we have used Wnt1Cre and Pax2Cre in mice to show that these driver lines label distinct ENS lineages during progenitor migration and in their terminal hindgut fates.
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November 2024
Multiscale Reaction Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
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January 2025
Department of Physiology, College of Medicine, China Medical University, Taichung 404, Taiwan. Electronic address:
Tetrabromobisphenol A (TBBPA), a brominated flame retardant (BFR), has been implicated as the neurotoxic effects in mammalian. However, the exact mechanisms underlying TBBPA-induced neurotoxicity remain unclear. In the present study, Neuro-2a cells, a mouse neural crest-derived cell line, were used to examine the mechanism of TBBPA-induced neuronal cytotoxicity.
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January 2025
Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan.
Human parvovirus B19 (B19V) causes fetal hydrops in pregnant women. Despite the significant impact of this virus, effective vaccines remain unclear. In this study, we successfully engineered B19V protein nanoparticles by fusing the N-terminal receptor-binding domain corresponding to 5-80 amino acids of VP1 with two distinct types of self-assembling protein nanoparticles.
View Article and Find Full Text PDFChembiochem
November 2024
Modality Research Laboratories 1, Research Unit, Research Division, Kyowa Kirin Co., Ltd., 3-6-6 Asahi, Machida, Tokyo, 194-8533, Japan.
Position-specific nucleoside sugar modifications have been shown to improve the translational activity and stability of chemically synthesized mRNA. For pharmaceutical applications of chemically modified mRNAs, a rapid purification methodology is imperative to identify the optimal modification pattern. However, while the chemical synthesis of mRNAs can be accomplished by splint ligation of oligonucleotide fragments, the current purification method for ligated mRNAs based on denaturing polyacrylamide gel electrophoresis tends to be time consuming.
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