The Effect of Lactic Acid Concentration on Cell Morphology and Phenotype in Cultured Intervertebral Disc Cell of Rabbit / 대한척추외과학회지

STUDY DESIGN: Changes of morphology and phenotype of cultured cells in media added lactate were observed. OBJECTIVES: To evaluate the effect of lactate on morphology and phenotype of cultured intervertebral disc cell. SUMMARY OF LITERATURE REVIEW: It was reported that lactate and pH were important factor in the degeneration of intervertebral disc. However the effect of lactate on morphology and phenotype of cultured intervertebral disc cell have not been studied. MATERIALS AND METHODS: Cells were dissociated enzymatically from rabbit nucleus pulposus. After attaining monolayer growth, the cells were incubated in media added 2mM or 5mM lactate. Total cell counts and morphological changes of the cells were periodically observed. Changes in cell phenotype were investigated by use of anti-collagen antibody stain. RESULTS: The cell groups added no lactate and 2mM lactate showed no difference in cell counts, morphology and phenotype. The cell group added 5mM lactate showed a reduction in final cell Counts and highel'ratio of fibroblastic cell in total population. Anti-collagen I Ab stained the Intra-and extra-cellular area of fibroblastic cells and intracellular area of chondrocytic cells. CONCLUSIONS: The current study suggests that high concentration of lactate inhibit intervertebral disc cell proliferation and accelerate morphological and phenotypical change to fibroblastic cell.

Intramedullary Nailing with Knowles Pin for the Clavicle Shaft Fracture / 대한정형외과학회잡지

In the review of a series of 71 clavicle shaft fracture that were treated with open reduction and internal fixation, we tried a direct comparison between two fixation modes, that is, the fixation with plate and screws (54 cases) and the intramedullary nailing with Knowles pin (17 cases). The average time to healing was not significantly different between the two group; 10.8 weeks after the plating and 11.7 weeks with Knowles pinning. The rate of successful healing within four months after the surgery were also high in both groups: one delayed union and one nonunion in the plate group, and one delayed union in the Knowles pin group. There was one loosening in the Knowles pin group, which needed reoperation. Intramedullary fixation has several advantages compared with fixation with a plate and screws. It can be performed through a shorter incision: less dissection of soft tissue is needed: and, after healing, the pin is easily removed through a small incision under local anesthesia.