Medicine and Health Sciences Commons^™

A Novel Multiscale Mathematical Model For Building Bone Substitute Materials For Children, Abdennasser Chekroun, Laurent Pujo-Menjouet, Jean-Philippe Berteau

Publications and Research

Bone is an engineering marvel that achieves a unique combination of stiffness and toughness exceeding that of synthesized materials. In orthopedics, we are currently challenged for the child population that needs a less stiff but a tougher bone substitute than adults. Recent evidence suggests that the relationship between inter-molecular connections that involve the two main bone building blocks, TropoCollagen molecules (TC) and carbonated Hydroxyapatite (cAp), and bone macroscopic mechanical properties, stiffness and toughness, are key to building bone substitute materials for children. The goal of our study is to establish how inter-molecular connections that occur during bone mineralization are related …

Spatial Relationship Between Bone Formation And Mechanical Stimulus Within Cortical Bone: Combining 3d Fluorochrome Mapping And Poroelastic Finite Element Modelling, Alessandra Carriero, A. F. Pereira, A. J. Wilson, S. Castagno, B. Javaheri, A. A. Pitsillides, M. Marenzana, S. J. Shefelbine

Publications and Research

Bone is a dynamic tissue and adapts its architecture in response to biological and mechanical factors. Here we investigate how cortical bone formation is spatially controlled by the local mechanical environment in the murine tibia axial loading model (C57BL/6). We obtained 3D locations of new bone formation by performing ‘slice and view’3D fluorochrome mapping of the entire bone and compared these sites with the regions of high fluid velocity or strain energy density estimated using a finite element model, validated with ex-vivo bone surface strain map acquired ex-vivo using digital image correlation. For the comparison, 2D maps of the average …

The Farnesoid X Receptor Negatively Regulates Osteoclastogenesis In Bone Remodeling And Pathological Bone Loss, Ting Zheng, Ju-Hee Kang, Jung-Sun Sim, Jung-Woo Kim, Jeong-Tae Koh, Chan Soo Shin, Hyungsik Lim, Mijung Yim

Publications and Research

Farnesoid X receptor (FXR, NR1H4) is a member of the nuclear receptor superfamily of ligand-activated transcription factors. Since the role of FXR in osteoclast differentiation remains ill-defined, we investigated the biological function of FXR on osteoclastogenesis, using FXR-deficient mice. We demonstrated that FXR deficiency increases osteoclast formation in vitro and in vivo. First, FXR deficiency was found to accelerate osteoclast formation via down-regulation of c-Jun N-terminal kinase (JNK) 1/2 expression. Increased expression of peroxisome proliferator-activated receptor (PPAR)γ and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC- 1)β seems to mediate the pro-osteoclastogenic effect of FXR deficiency via the JNK pathway. In …

Inflammation And Bone Mineral Density: A Mendelian Randomization Study, Jian V. Huang, C. Mary Schooling

Publications and Research

Osteoporosis is a common age-related disorder leading to an increase in osteoporotic fractures and resulting in significant suffering and disability. Inflammation may contribute to osteoporosis, as it does to many other chronic diseases. We examined whether inflammation is etiologically relevant to osteoporosis, assessed from bone mineral density (BMD), as a new potential target of intervention, or whether it is a symptom/biomarker of osteoporosis. We obtained genetic predictors of inflammatory markers from genome-wide association studies and applied them to a large genome wide association study of BMD. Using two-sample Mendelian randomization, we obtained unconfounded estimates of the effect of high-sensitivity C-reactive …

Remodeling Brain Activity By Repetitive Cervicothoracic Transspinal Stimulation After Human Spinal Cord Injury, Lynda M. Murray, Maria Knikou

Publications and Research

Interventions that can produce targeted brain plasticity after human spinal cord injury (SCI) are needed for restoration of impaired movement in these patients. In this study, we tested the effects of repetitive cervicothoracic transspinal stimulation in one person with cervical motor incomplete SCI on cortical and corticospinal excitability, which were assessed via transcranial magnetic stimulation with paired and single pulses, respectively. We found that repetitive cervicothoracic transspinal stimulation potentiated intracortical facilitation in flexor and extensor wrist muscles, recovered intracortical inhibition in the more impaired wrist flexor muscle, increased corticospinal excitability bilaterally, and improved voluntary muscle strength. These effects may have …

Non-Operative Management Of Hip Osteoarthritis, Ray Marks

Publications and Research

This paper reviews several non-operative and non-pharmacologic management strategies advocated for alleviating the pain and disability experienced by people with hip osteoarthritis. It analyzes whether painful debilitating hip osteoarthritis, which has no effective cure and is often progressive, may be affected positively by non-operative interventions designed to control osteoar- thritis pain. Finally, it provides an integrated plan of management for ameliorating hip osteoar- thritis pain and disability in light of this knowledge.

Utilizing Fast Spin Echo Mri To Reduce Image Artifacts And Improve Implant/Tissue Interface Detection In Refractory Parkinson’S Patients With Deep Brain Stimulators, Subhendra N. Sarkar, Pooja R. Sarkar, Efstathios Papavassiliou, Rafael Rojas

Publications and Research

Introduction. In medically refractory Parkinson’s disease (PD) deep-brain stimulation (DBS) is an effective therapeutic tool. Postimplantation MRI is important in assessing tissue damage and DBS lead placement accuracy. We wanted to identify which MRI sequence can detectDBS leads with smallest artifactual signal void, allowing better tissue/electrode edge conspicuity.

Methods. Using an IRB approved protocol 8 advanced PDpatientswere imagedwithinMRconditional safety guidelines at lowRF power (SAR ≤ 0.1 W/kg) in coronal plane at 1.5T by various sequences.The image slices were subjectively evaluated for diagnostic quality and the lead contact diameters were compared to identify a sequence least affected by metallic leads.

Results …

Therapeutic Ultrasound: Osteoarthritis Symptom-Modification And Potential For Disease Modification, Daniel J. Leong, Huagang Zhang, Lin Xu, Justin Tang, David M. Hirsh, John A. Hardin, Luis Cardoso, Chandan Guha, Neil J. Cobelli, Hui B. Sun

Publications and Research

Osteoarthritis (OA) is a degenerative joint disease and a leading cause of adult disability. While joint replacement surgery is a common treatment option for end-stage disease, non-surgical management is critical for preventing disability and maintaining quality of life. Although therapeutic ultrasound, which applies mechanical and may also apply thermal energy in the form of sound waves, is widely used to treat various musculoskeletal disorders such as bone fractures, tendinopathy, and muscle contusions, its symptom- and disease-modifying effects on osteoarthritis have not been clearly demonstrated. Recent clinical evidence indicates therapeutic ultrasound is capable of relieving OAassociated pain and improving function of …

Anxiety In Disabling Osteoarthritis: Implications For Research And Practice, Ray Marks

Publications and Research

No abstract provided.