Spine
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Comparative Study
Human anulus fibrosis and nucleus pulposus cells of the intervertebral disc: effect of degeneration and culture system on cell phenotype.
Human intervertebral disc cells were harvested from patients with adolescent idiopathic scoliosis (AIS) and from donors with degenerative disc disease. Anulus fibrosis (AF) was separated from nucleus pulposus (NP), and cells were cultured separately in two different cell culture models. ⋯ These results provide a better understanding of how the phenotype of human healthy and degenerative disc cells is influenced by in vitro expansion. This may be useful for future tissue engineering purposes.
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Comparative Study
Effects of degeneration on the biphasic material properties of human nucleus pulposus in confined compression.
The biphasic compressive material properties of normal and degenerate human nucleus pulposus tissue were measured in confined compression. ⋯ Swelling is the primary load-bearing mechanism in both nondegenerate and degenerate nucleus pulposus. Knowledge of the biphasic material properties of the nucleus pulposus will aid the development of new treatment strategies for disc degeneration aimed at restoring mechanical function of the intervertebral disc.
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Comparative Study
Biomechanical assessment of the pediatric cervical spine under bending and tensile loading.
Cadaveric head-neck complexes from pediatric donors aged 2-12 years were subjected to a test battery consisting of nondestructive flexion-extension bending, nondestructive tensile step-and-hold tests, and tensile distraction loading to failure. ⋯ The current study provides valuable new information on the response and tolerance of the pediatric cervical spine to quasi-static flexion-extension and tensile distraction loading.
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Computer modeling and parametric analysis were used to determine the effect of reflex contraction of the neck muscles in the unaware occupant in whiplash. ⋯ Because reflex contraction did not substantially alter spinal kinematics, muscle contraction likely does not initiate in sufficient time to mitigate whiplash injuries that may occur during the retraction phase.
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Comparative Study
De novo osteogenesis from human ligamentum flavum by adenovirus-mediated bone morphogenetic protein-2 gene transfer.
In vitro and in vivo experiment using degenerated human ligamentum flavum (LF) and Type 5 adenovirus construct with bone morphogenetic protein-2 (BMP-2) cDNA. ⋯ Human LF cells transduced with Ad/BMP-2 exhibited the expression of osteogenic phenotype and bone nodule formation. Additionally, genetically modified human LF with BMP-2 cDNA clearly demonstrated de novo osteogenesis, which supports the concept that biologically modified LF can be a substitute for autogenous bone graft in spinal fusion surgery.