Spinal Cord Injury (SCI) often causes cell death, demyelination, axonal degeneration and cavitation, resulting in functional motor and sensory loss below the site of injury. In an attempt to overcome SCI, the regenerating neurons require a permissive environment to promote their ability to reconnect. We report a novel thiolated hyaluronic acid (HA) hydrogel scaffold that can be used to repair the injured spinal cord. More specifically, thiolated hyaluronic acid hydrogels with varying thiol concentrations were successfully synthesized. The amount of thiol groups was measured spectrophotometrically using Ellman’s test. HA gels with different crosslinking densities were synthesized and the water content of the hydrogels was determined. The thermal behavior of the HA gels were studied by DSC. The strength of the hydrogels with varying thiol group content was evaluated by a rheometer. In addition, in vitro enzymatic degradation was performed through submerge the hydrogels in 200U/ml of hyaluronidase solution and incubate at 37°C. According to the result of the present study, this novel hydrogel shows great potential to serve as a 3D cell-patterning scaffold which can be inserted into a hollow fiber channel that could be used to promote regeneration after the SCI.

Maturation of motor control, including movements that can be autonomously generated by spinal circuits, relies on the development of key inputs to spinal circuitry. In particular, the development of supraspinal, sensory and motor fibers come together to form organized spinal circuits capable of producing skilled movements that are volitionally controlled. Primitive reflexes such as the palmar grasp reflex (PGR) are known to disappear during development; presumably giving way to more volitional control of hand grasping. However, the underlying changes to the spinal circuitry responsible for this transition remain to be determined. dI3 INs, a class of dorsal spinal interneurons, have positioned themselves as key mediators of reflexive grasping in early development and grasping in adult mice. The first aim of the study focused on determining the developmental time point at which the PGR disappeared. Our studies demonstrated that the PGR was lost by the third week of development. The second aim of this study focused on identifying changes in sensory innervation, presynaptic inhibition and supraspinal excitation to dI3 INs that might account for the loss of this reflex. Our studies demonstrated that while sensory innervation remained constant during development, presynaptic inhibitory terminals onto sensory afferents were found to increase during development. In addition, we report that dI3 INs receive decreasing corticospinal (CST) input during development. While these developmental changes do not fully account for the disappearance of the PGR, they provide valuable insights into how a reflex centered on a particular population develops.

This work presents an alternative approach to the production of cellulose-based biomaterials. Instead of extracting, processing and regenerating plant and or bacteria-derived cellulose into a biomaterial, my work established a decellularization protocol to remove cellular plant content from plant tissue resulting in a scaffold composed of cellulose with the evolved architecture of the plant cell wall. Tracheophyte plants, including clubmosses, horsetails, and ferns, gymnosperms and angiosperms, have evolved distinct vascular structures that support the transport of water and nutrients in xylem and phloem that form the vascular bundles (VBs)1. This thesis took it’s inspiration from the dense, linearly arranged, parallel microchannels which include (VBs) in the stalks of Asparagus officinalis possess an architecture with striking similarities to biomaterial scaffolds intended to repair damaged tissue. My work demonstrated that the plant cell wall contains many of the ideal characteristics of a medical biomaterial. The scaffold is biocompatible with mammalian cells and maintains high viability even with cell densities comparable to commercially available scaffolds. The cellulose scaffold could be biochemically functionalized or cross-linked to control the scaffolds' surface biochemistry and mechanical properties. My in vivo model demonstrated that the lignocellulose scaffold did not elicit a foreign body response. The scaffold was permissive to host cell invasion, including active host fibroblast, leading to the deposition of host collagen extracellular matrix. Importantly, active blood vessels formed within the scaffold to support the population of host cells. The scaffold retained much of its original shape and provided an inert, pro-vascular long-term environment for host cells to invade. Taken together, this led to the hypothesis that the innate plant cell wall architecture could restore the function of injured tissue, specifically that the vascular bundles could be used to promote axonal regeneration in spinal cord injuries. Rats with complete spinal cord transection were implanted with cellulose scaffolds with vascular bundles. Animals that received plant-derived scaffolds demonstrated a significant improvement in motor function. This thesis defines a novel and parallel route for exploiting naturally occurring plant microarchitectures of the underlying crystalline cellulose scaffold.

Purpose. As motor vehicle accidents and violence cause the majority of spinal cord injuries (SCI) sustained in the USA and people with SCI will likely struggle with emotional issues related to the offender, the purpose of this exploratory study was to examine potential salutary effects of forgiveness among people with SCI incurred traumatically. Specifically, we hypothesized that forgiveness would have positive associations with health-related outcomes. Method. A community-based sample of 140 adults (19-82 years of age) with SCI completed a self-report survey regarding dispositional forgiveness of self and others, health behavior, health status, and life satisfaction. Hierarchical multiple regression analyses were employed to examine the relationships in question. Results. After controlling for demographic variables, forgiveness of self was significantly associated with health behavior and life satisfaction (uniquely accounting for 7% and 13% of the variance, respectively) and forgiveness of others was significantly associated with health status (uniquely accounting for 9% of the variance). Conclusion.Results suggest that forgiveness may play a role in the health and life satisfaction of people with traumatic SCI, with the benefit depending on the type of forgiveness offered.

This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).

by Wai-Ying Li. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 87-94). / ABSTRACT --- p.i / CONTENTS --- p.iii / Chapter CHAPTER I. --- INTRODUCTION / Chapter A. --- Plasticity of central nervous system --- p.1 / Chapter B. --- The response of spinal cord after injury --- p.2 / Chapter C. --- Sprouting in the corticospinal tracts --- p.3 / Chapter D. --- Influential factors of sprouting in CNS --- p.5 / Chapter E. --- The objective of the present study --- p.6 / Chapter CHAPTER II. --- THE NORMAL RAT CORTICOSPINAL TRACTS --- p.9 / Chapter CHAPTER III. --- MATERIALS AND METHODS / Chapter A. --- The experimental model --- p.15 / Chapter B. --- Retrograde fluorescing tracer study to confirm sprouting --- p.16 / Chapter C. --- Protagol silver study to detect axonal sprouting --- p.19 / Chapter D. --- Chromatolysis study to prove the sprouting --- p.22 / Chapter E. --- Degenerating silver study to detect where sprouting might have come from --- p.25 / Chapter F. --- Cytochrome oxidase study to evaluate the cytochemical change of the motor neurons after hemisection --- p.28 / Chapter G. --- Labelled uptake studies to assay the biochemical changes after hemisection --- p.31 / Chapter H. --- The Raman spectroscopy study to detect proteins change after hemisection --- p.33 / Chapter I. --- Study on preferential growth sprouts into spinal cord or peripheral nerve --- p.35 / Chapter J. --- Study on target specificity of sprouting fibers --- p.37 / Chapter K. --- Study on the behavior of the hemisected rats --- p.39 / Chapter CHAPTER IV. --- RESULTS / Chapter A. --- Examination of the sprouting / Chapter 1. --- Results of the retrograde fluorescent tracer study --- p.50 / Chapter 2. --- Result of protagol silver study --- p.51 / Chapter 3. --- Result of chromatolysis study --- p.52 / Chapter 4. --- Result of degenerating silver study --- p.52 / Chapter B. --- Estimation of biochemical changes / Chapter 1. --- Result of cytochemical changes --- p.53 / Chapter 2. --- Result of labelled uptake study --- p.54 / Chapter 3. --- Result of Ramam spectroscopy study --- p.54 / Chapter C. --- Result on preferential growth of sprouts into the spinal cord or peripheral nerve --- p.55 / Chapter D. --- Result of target specificity study --- p.55 / Chapter E. --- Changes in the walking ability --- p.56 / Chapter CHAPTER V. --- Conclusion and discussion / Chapter A. --- Evaluation of the sprouting --- p.77 / Chapter B. --- Estimation on the source of sprouting --- p.79 / Chapter C. --- Evaluation of promoting effect of peripheral nerve --- p.79 / Chapter D. --- Evaluation of target specificity of sprouting --- p.80 / Chapter E. --- Analysis of functional activity of sprouting --- p.80 / Chapter F. --- Factors influencing sprouting --- p.81 / REFERENCES --- p.87 / ACKNOWLEDGEMENT --- p.95

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Centre for Neuroscience. Title from pdf file main screen (viewed on October 11, 2009). Includes bibliographical references.

Thesis (Ph.D.)--McMaster University, 2004. / Includes bibliographical references (p. 106-123). Also available via World Wide Web.