PubMed · 6618421
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
K Miyasaka. 1983. [X-ray CT].. https://pubmed.ncbi.nlm.nih.gov/6618421/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Claudin-14 (CLDN14) is a key component of tight junctions (TJs) critical for maintaining paracellular barrier function. Variants of CLDN14 have been linked to Vein of Galen malformations (VOGMs), a rare cerebrovascular disorder; however, the molecular mechanisms underlying their pathogenicity remain unknown. Here, we investigate the mechanistic effects of two VOGM-associated mutations, A113P and V143M, using reinforcement-learning driven enhanced sampling molecular dynamics simulations combined with DiffNets-based deep learning and independent trajectory-wide structural analyses. Our analysis reveals that A113P induces broader structural disruption of CLDN14, perturbing paracellular sealing, pore symmetry, and inter-protomer communication, whereas V143M induces structural rearrangements centred around TM3 and the TM3-ECL2 region. In both cases, mutation-specific alterations are observed in structural stability and interfacial organization across oligomeric assemblies. Notably, these effects are qualitatively consistent across different modelled architectures, despite variability in local responses. In the absence of experimentally resolved structures, the structural perturbations reported here provide a mechanistic understanding of how VOGM-associated variants may influence CLDN14 structure and dynamics.
Narrow-band sounds are known to be associated with some intracranial aneurysms. Previously proposed theories for the mechanism of aneurysm sounds do not satisfactorily explain the small spectral widths of the sounds. A simple theory is proposed here which gives quantitatively correct predictions of the spectral widths and which also explains other salient features of aneurysm sounds. The physical features of the aneurysm are described in terms of lumped mechanical elements, and the interaction between the aneurysm vibration and the blood flow is recognized as having the characteristic features of a nonlinear feedback system. The resulting model, with the application of the method of describing function analysis commonly used in nonlinear control theory, yields predictions of steady oscillation frequencies and predictions of the ranges of arterial flow velocities for which substantial oscillations can be excited. An analysis of radiation losses associated with peristaltic waves indicates that aneurysms, in the absence of any nonlinearity, behave as low-quality factor resonators with resonator quality factors on the order of 1-10, much lower than those that would be inferred from the observed spectral widths of aneurysm sounds. Aneurysm sounds are predicted by the present nonlinear theory to have center frequencies on the order of 400 Hz and bandwidths corresponding to quality factors on the order of 40, in good agreement with in vivo observations. It is concluded that linear resonance theories are incapable of fully describing aneurysm sounds.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.