Objective: During recent years, the amplitude and the maximal systolic velocity of the mitral annulus motion (MAM) have been established as indices of the left ventricular systolic function and the maximal diastolic velocity of the annulus motion has been suggested as an index of diastolic function. The main aims of the present study were to investigate the feasibility of these techniques in rabbits and to investigate age-related changes concerning these variables.
Methods: Twenty-one New Zealand white rabbits were investigated by echocardiographic M-mode and pulsed tissue Doppler. One subgroup (I) included 11 still-growing, 3.0 +/- 0.2 month-old, animals and another group (II) included 10 young grown up rabbits, 12.1 +/- 1.5 months old.
Results: The amplitude (4.8 +/- 0.6 and 3.5 +/- 0.3 mm, respectively) and maximal systolic (98 +/- 14 and 66 +/- 7 mm/s, respectively) and diastolic (111 +/- 21 and 80 +/- 12 mm/s, respectively) velocities of the MAM were significantly (P < 0.001) higher in group I than in group II, despite a bigger heart in the animals in the latter group. A coefficient of variation of <5% was found for both inter- and intraobserver variability for both amplitude and velocities.
Conclusions: The amplitude and velocities of MAM are easily recorded in rabbits with excellent reproducibility and the changes with age seem to be very similar to those in humans. These noninvasive M-mode and tissue Doppler methods are therefore suitable for the investigation of left ventricular function in experimental studies in rabbits.
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http://dx.doi.org/10.1111/j.0742-2822.2004.03111.x | DOI Listing |
Electromagn Biol Med
January 2025
Department of Mathematics, University of Gour Banga, Malda, India.
Electromagn Biol Med
January 2025
Department of Applied Mathematics, University of Calcutta, Kolkata, India.
The current investigation explores tri-hybrid mediated blood flow through a ciliary annular model, designed to emulate an endoscopic environment. The human circulatory system, driven by the metachronal ciliary waves, is examined in this study to understand how ternary nanoparticles influence wave-like flow dynamics in the presence of interfacial nanolayers. We also analyze the effect of an induced magnetic field on Ag-Cu-/blood flow within the annulus, focusing on thermal radiation, heat sources, buoyancy forces and ciliary motion.
View Article and Find Full Text PDFClin Biomech (Bristol)
December 2024
Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, Ontario, Canada; Department of Health Sciences, Wilfrid Laurier University, Waterloo, Ontario, Canada. Electronic address:
Background: Vertebral fractures in young populations are associated with intervertebral disc disorders later in life. However, damage to the annulus fibrosus has been observed in rapidly loaded spines even without the subsequent occurrence of a fracture. Therefore, it may not be the fracture event that compromises the disc, but rather the manner in which the disc is loaded.
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November 2024
Department of Neurosurgery, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, United States.
J Clin Neurosci
February 2025
Laser Additive Manufacturing Laboratory, Laser Technology Division, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013, India.
Osseointegration along with better mimicry of natural bone behaviour addresses the long-term performance of artificial intervertebral disc prosthesis. Here the effect of a novel artificial intervertebral disc geometry on stress, deformation and strain on lumbar segments to restore movement of the spine was investigated. The process involved, using CT image data, and solid modelling, simulation-driven design and finite element (FE) analysis, hexahedral mesh sensitivity analysis, implant placements.
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