Biomedical Engineering and Bioengineering Commons^™

Evaluation Of Tracing Techniques In The Rat Spinal Cord Using A Custom Matlab Application., Rachel M. Zalla

Electronic Theses and Dissertations

The objective of this research project is to evaluate the efficiency of traditional chemical tracing compared to dual-viral tracing for labeling long ascending propriospinal neurons (LAPNs) in the uninjured rat spinal cord, and to develop a MATLAB program which will accurately quantify this labeling.

To evaluate chemical tracing, Fluoro-Ruby (FR) was injected at the level of the axon terminals, and the number of ipsilateral labeled cell bodies at lumbar level was quantified. Similarly, two dual-viral systems were evaluated, by either injecting retro-AAV-Cre or HiRet-Lenti-Cre unilaterally in combination with a Cre-dependent adeno-associated virus. The HiRet-Lenti and FR groups labeled significantly greater …

Quantification Of Collagen Organization Using Fractal Dimensions And Fourier Transforms, Kayt E. Frisch, Sarah E. Duenwald-Kuehl, Hirohito Kobayashi, Connie S. Chamberlain, Roderic S. Lakes, Ray Vanderby Jr.

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Collagen fibers and fibrils that comprise tendons and ligaments are disrupted or damaged during injury. Fibrillogenesis during healing produces a matrix that is initially quite disorganized, but remodels over time to resemble, but not replicate, the original roughly parallel microstructure. Quantification of these changes is traditionally a laborious and subjective task. In this work we applied two automated techniques, fast Fourier transformation (FFT) and fractal dimension analysis (FA) to quantify the organization of collagen fibers or fibrils. Using multi-photon images of collagen fibers obtained from rat ligament we showed that for healing ligaments, FA differentiates more clearly between the different …

The Influence Of Macrophage Depletion On Ligament Healing, Connie S. Chamberlain, Ellen M. Leiferman, Kayt E. Frisch, Sijian Wang, Xipei Yang, Nico Van Rooijen, Geoff S. Baer, Stacey L. Brickson, Ray Vanderby

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Despite a complex cascade of cellular events to reconstruct damaged extracellular matrix (ECM), ligament healing results in a mechanically inferior, scar-like tissue. During normal healing, the number of macrophages significantly increases within the wound site. Then, granulation tissue expands into any residual, normal ligamentous tissue (creeping substitution), resulting in a larger region of healing, greater mechanical compromise, and an inefficient repair process. To study the effects of macrophages on the repair process, bilateral, surgical rupture of their medial collateral ligaments (MCLs) was done on rats. Treatment animals received liposome-encapsulated clodronate, 2 days before rupture to ablate phagocytosing macrophages. Ligaments were …