名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成11年1月22日 片桐浩久氏の博士論文として提出された

A biomechanical study of intervertebral foraminal narrowing during simulated automotive head-forward and head-turned rear impacts. The objective of this study was to quantify foraminal width, height and area narrowing during head-forward and head-turned rear impacts, and evaluate the potential for nerve root and ganglion impingement. Muscle weakness and paresthesias, documented in whiplash patients, have been associated with neural compression within the cervical intervertebral foramen. Rotated head posture at the time of rear impact has been correlated with increased frequency and severity of chronic radicular symptoms, as compared to facing forward. No studies have quantified dynamic changes in foramen dimensions during head-forward or head-turned rear impacts. Six whole cervical spine specimens with muscle force replication and surrogate head underwent simulated whiplash at 3.5, 5, 6.5 and 8 g, following non-injurious baseline 2 g acceleration. Continuous dynamic foraminal width, height and area narrowing were recorded, and the peaks were determined during each impact and statistically compared to baseline narrowing. During head-forward rear impacts, significant increases (P<0.05) in average peak foraminal width narrowing above baseline were observed at C5-C6 beginning with 3.5 g impact. No significant increases in average peak foraminal height narrowing were observed, while average peak foraminal areas were significantly narrower than baseline at C4-C5 at 3.5, 5 and 6.5 g. During head-turned rear impacts, significant increases (P<0.05) in average peak foraminal width narrowing above baseline of up to 1.8 mm in the left C5-C6 foramen at 8 g were observed. Average peak dynamic foraminal height was significantly narrower than baseline at right C2-C3 foramen at 5 g and 6.5 g, while no significant increases in foraminal area were observed. Extrapolation of the present head-forward rear impact results indicated that the greatest potential for ganglia compression injury was at the lower cervical spine, C5-C6 and C6-C7. The present head-turned rear impact results indicated that the greatest potential ganglia compression injury exists at C5-C6 and C6-C7. Greater potential for ganglia compression injury exists at C3-C4 and C4-C5 due to head-turned rear impact, as compared to head-forward rear impact. Acute ganglia compression may produce a sensitized neural response to repeat compression leading to chronic radiculopathy following head-forward and head-turned rear impacts. Dynamic ganglion or nerve root compression may also lead to chronic radiculopathy.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 153-165).

Thesis (Ph. D.)--Case Western Reserve University, 2004. / [School of Medicine] Department of Neurosciences. Includes bibliographical references. Available online via OhioLINK's ETD Center.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 19, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Christian Lorson and Dr. Michael Garcia. Includes bibliographical references.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri--Columbia, 2002. / "December 2002." Typescript. Vita. Includes bibliographical references (leaves 143-155). Also available on the Internet.

Current treatments for spinal cord injury (SCI) are extremely limited due to the fact that the central nervous system lacks the intrinsic ability to regenerate, and constitutes a poor environment for regenerative axon growth. Nerve tissue engineering is an emerging field with the aim of repairing or creating new nerve tissues to promote functional recovery by using artificial tissue repair scaffolds. The design of a stable and consistent animal model of SCI is essential to study the effectiveness of scaffolds in promoting nervous system repair. In this study, a partial transection animal model was created with a three dimensional lesion at T8-T9 that disrupts axonal pathways unilaterally in the dorsal columns of the rat spinal cord. Alginate hydrogel scaffolds incorporating living Schwann cells were fabricated to evaluate the abilities of those scaffolds to foster axonal regeneration. The surgical technique was improved to provide better outcomes related to bleeding during surgery, weight control, neurological function and surgery duration. The survival rate of animals during the surgical procedure and post-surgery period was ultimately increased to 100%. Histology and immunohistochemistry results indicated that implanted alginate scaffolds may induce larger cavities and extenuate harmful inflammation responses, but that effect was ameliorated by inclusion of Schwann cells in the scaffold. However, neither plain alginate scaffolds nor scaffolds containing living Schwann cells were able to improve regeneration of identified axon tracts in the spinal dorsal columns. This research also employed a synchrotron based x-ray phase contrast imaging technique coupled with computed-tomography to visualize the low optical density structural features of scaffolds and spinal cord tissues in formaldehyde fixed specimens. The imaging results suggest that this is a promising method for analyzing the structure of tissue repair scaffolds within the spinal cord. This degree of structural characterization, potentially applicable to living tissue, is not afforded by other conventional image analysis techniques.

published_or_final_version / Pathology / Master / Master of Medical Sciences

published_or_final_version / Medicine / Master / Master of Medical Sciences