Background: Patients with Parkinson's disease can show brief normalization of motor activity in response to intense external stimuli - a phenomenon known as paradoxical kinesis. The purpose of the present study was to examine the effect of alarming auditory signals on the level of viscoelastic stiffness of skeletal muscles as an indicator of parkinsonian rigidity.
Methods: Myotonometry was used to determine the changes of viscoelastic stiffness of skeletal muscles in ten patients in an advanced stage of Parkinson's disease, treated with deep brain stimulation, and ten healthy controls. The measurements were repeated and compared during the stimulation-on and stimulation-off periods, with and without auditory alarming signals.
Findings: The mean values of stiffness measured in the stimulation-off phase (370.4 N/m) were significantly higher than the values obtained in the stimulation-on phase (339.2 N/m) (q = 6.05; P < 0.01) but also in the stimulation-off with alarming signals phase (349.6 N/m) (q = 4.04; P < 0.05). In the normal controls, exposure to the auditory alarming signals did not change the values of viscoelastic stiffness.
Interpretation: These findings demonstrate that the phenomenon of paradoxical kinesis is associated with the changes of muscular rigidity in parkinsonian patients. Results from the study may help to establish new strategies for addressing motor disabilities in patients with Parkinson's disease.
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http://dx.doi.org/10.1016/j.clinbiomech.2019.01.008 | DOI Listing |
Adv Healthc Mater
January 2025
Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, College of Bioengineering, Chongqing, 400044, P. R. China.
Decellularized artificial blood vessels prepared using physical and chemical methods often exhibit limitations, including poor mechanical performance, susceptibility to inflammation and calcification, and reduced patency. Cross-linking techniques can enhance the stiffness, as well as anti-inflammatory and anti-calcification properties of decellularized vessels. However, conventional cross-linking methods fail to effectively alleviate residual stress post-decellularization, which significantly impacts the patency and vascular remodeling following the implantation of artificial vessels.
View Article and Find Full Text PDFSmall
January 2025
Leicester Institute for Pharmaceutical Innovation, Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester, LE1 9BH, UK.
Guiding molecular assembly of peptides into rationally engineered nanostructures remains a major hurdle against the development of functional peptide-based nanomaterials. Various non-covalent interactions come into play to drive the formation and stabilization of these assemblies, of which electrostatic interactions are key. Here, the atomistic mechanisms by which electrostatic interactions contribute toward controlling self-assembly and lateral association of ultrashort β-sheet forming peptides are deciphered.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 2R3, Canada.
This study presents an experimental investigation of the quasi-static and dynamic behavior of a quasi-isotropic carbon-fiber-reinforced composite subjected to in-plane compressive loading. The experiments were performed at strain rates ranging from 4×10-5 to ∼1200 s-1 to quantifythe strain-rate-dependent response, failure propagation, and damage morphology using advanced camera systems. Fiber bridging, kink band formation, dominance of interlaminar failure, and inter-fiber failure fracture planes are evidenced through post-mortem analysis.
View Article and Find Full Text PDFBiomedicines
December 2024
Dementia and Multiple Sclerosis Unit, Neurology Service, Reina Sofia University Hospital, 14004 Cordoba, Spain.
: To compare the lumbopelvic muscle mechanical properties (MMPs) of women with and without multiple sclerosis (MS) and explore relationships between these properties and sociodemographic/clinical characteristics. : This cross-sectional observational study included 22 women with MS and 22 age- and BMI-matched women without MS. MMPs (frequency, stiffness, decrement, relaxation, and creep) of pelvic floor and lumbar paravertebral muscles were assessed using a MyotonPRO device.
View Article and Find Full Text PDFCirc Res
January 2025
Department of Integrative Pathophysiology, Medical Faculty Mannheim, DZHK Partnersite Mannheim-Heidelberg, University of Heidelberg, Germany (S.L.).
This review examines the giant elastic protein titin and its critical roles in heart function, both in health and disease, as discovered since its identification nearly 50 years ago. Encoded by the TTN (titin gene), titin has emerged as a major disease locus for cardiac disorders. Functionally, titin acts as a third myofilament type, connecting sarcomeric Z-disks and M-bands, and regulating myocardial passive stiffness and stretch sensing.
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