Yong-Hwan Shin

Histomorphometric Analysis of the Spine and Femur in Ovariectomized Rats Using Micro-Computed Tomographic Scan

Objective The purpose of this study was to evaluate the different patterns of bone loss between the lumbar spine and the femur after ovariectomy in rats. Methods Twenty-four female Sprague-Dawley rats underwent a sham operation (the sham group) or bilateral ovariectomy (the ovariectomized group). Four and eight weeks after operation, six rats from each of the two groups were euthanized. Serum biochemical markers of bone turnover including osteocalcin and alkaline phosphatase (ALP), which are sensitive biochemical markers of bone formation, and the telopeptide fragment of type I collagen C-terminus (CTX), which is a sensitive biochemical marker of bone resorption, were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae and femur were determined by micro-computed tomography. Results Ovariectomized rats were found to have higher osteocalcin, ALP and CTX levels than sham controls. Additionally, 8 weeks after ovariectomy in the OVX group, serum levels of osteocalcin, ALP and CTX were significantly higher than those of 4 weeks after ovariectomy. Bone loss after ovariectomy was more extensive in the 4th lumbar spine compared to the femur. Bone loss in the 4th lumbar spine was mainly caused by trabecular thinning, but in the femur, it was mainly caused by trabecular elimination. Conclusion The present study demonstrates different patterns of bone loss between the 4th lumbar spine and the femur in ovariectomized rats. Therefore, when considering animal models of osteoporosis, it is important that bone sites should be taken into account.

49.1: Fabrication of 23” PVA LCD Panel by Laser Ablation Process of ITO

We fabricated the world first 23” PVA LCD panel of which transparent electrode (ITO) was patterned by “laser ablation process”. Generally photo process is used to pattern the transparent electrode. To simplify this photo process we tried to develop laser ablation process to pattern the ITO. Current photo process is composed of 6 steps such as Coating the Photoresist, Baking, Exposure, Development, Etching, and Stripping. But we succeeded in simplifying this process by the laser ablation process. From this experiment, we could identify the possibility of laser ablation process which can be used on the patterning process of transparent electrodes.