title: Pulsed focused ultrasound treatment of muscle mitigates paralysis-induced bone loss in the adjacent bone: a study in a mouse model.
abstract: Bone loss can result from bed rest, space flight, spinal cord injury or age-related hormonal changes. Current bone loss mitigation techniques include pharmaceutical interventions, exercise, pulsed ultrasound targeted to bone and whole body vibration. In this study, we attempted to mitigate paralysis-induced bone loss by applying focused ultrasound to the midbelly of a paralyzed muscle. We employed a mouse model of disuse that uses onabotulinumtoxinA-induced paralysis, which causes rapid bone loss in 5 d. A focused 2 MHz transducer applied pulsed exposures with pulse repetition frequency mimicking that of motor neuron firing during walking (80 Hz), standing (20 Hz), or the standard pulsed ultrasound frequency used in fracture healing (1 kHz). Exposures were applied daily to calf muscle for 4 consecutive d. Trabecular bone changes were characterized using micro-computed tomography. Our results indicated that application of certain focused pulsed ultrasound parameters was able to mitigate some of the paralysis-induced bone loss.
authors.affiliation: Department of Radiology, Seattle Children's Hospital, Seattle, Washington, USA; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA. Electronic address: sandra.poliachik@seattlechildrens.org.
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Poliachik
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA; Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Tatiana D
authors.initials: TD
authors.lastname: Khokhlova
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Yak-Nam
authors.initials: YN
authors.lastname: Wang
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Julianna C
authors.initials: JC
authors.lastname: Simon
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Bailey
mesh_terms: D000818:Animals; D018488:Bone Demineralization, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology* / Q000517:prevention & control*; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D010243:Paralysis / Q000150:complications*; D013977:Tibia / Q000000981:diagnostic imaging; D014464:Ultrasonic Therapy / Q000379:methods*; D014463:Ultrasonography; D055114:X-Ray Microtomography / Q000379:methods
keywords: Micro-computed tomography; Mitigation of trabecular bone loss; Mouse model of disuse; Musculoskeletal; Paralysis; Pulsed focused ultrasound