Involvement of cell-cell and cell-matrix interactions in bone destruction induced by metastatic MDA-MB-231 human breast cancer cells in nude mice.

To clarify the mechanisms of bone destruction associated with bone metastases, we studied an animal model in which inoculation of MDA-MB-231 human breast cancer cells into the left cardiac ventricle of female nude mice causes osteolytic lesions in bone using morphological techniques. On the bone surfaces facing the metastatic tumor cells, there existed many tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts. TRAP-positive mononuclear osteoclast precursor cells were also observed in the tumor nests.

[Observations on three dimensional images for cracks of doweled teeth--comparison of images from specimen sections and dental tomograms from small three dimensional X-ray CT].

Purpose: Intraoral views of teeth with dowel and post hole taken by small three-dimensional X-ray CT (3DX) were compared with three-dimensional images from specimen sections of the same extracted teeth. This comparison shows the usefulness of 3DX for examination of cracked teeth in the oral cavity.

Materials And Methods: After taking dental tomographic images using 3DX for fractured teeth in the oral cavity, the fractured teeth were extracted and three-dimensional images for them and their cracks were obtained from a set of photographed sections.