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Bioterrorism: The inevitable future?

Interview with Donald Henderson.

PPP: The Key to Defence Against Bioterrorsim.

Soft tissues (e.g., tendon, skin, cartilage) change their dimensions and properties in response to applied mechanical stress/strain, which is called remodeling. Experimental studies using tissue cultures were performed to understand the biomechanical properties of collagen fascicles under mechanical loads. Collagen fascicles were dissected from sheep Achilles tendons and loaded under 1, 2, and 3 kg for 2, 4, and 6 days under culture. The mechanical properties of collagen fascicles after being loaded into the culture media were determined using tensile tester, and resultant stress–strain curves, tangent modulus, tensile strength, and strain at failure values were compared with those in a non-loaded and non-cultured control group of fascicles. The tangent modulus and tensile strength of the collagen fascicles increased with the increasing remodeling load after two days of culture. However, these values gradually decreased with the increasing culture period compared with the control group. According to the results obtained in this study, the mechanical properties of collagen fascicles were improved by loading at two days of culture, most likely due to the remodeling of collagen fibers. However, after a period of remodeling, local strains on the collagen fibrils increased, and finally, the collagen fibrils broke down, decreasing the mechanical properties of the tissue.

The interplay between neoplastic cells and multinucleate osteoclast-like giant cells found in giant cell tumor has been considered as a model of the cellular interactions that occur during bone resorption in both primary and metastatic neoplasms. This chapter describes the tissue culture techniques of giant cell tumor of bone. The main proliferating cells maintained in culture are the spindle-shaped stromal-like mononuclear cells, which represent the neoplastic component of this tumor.