Abstract: An improved demineralized bone matrix (DBM) or other matrix composition is provided that has been mixed with a stabilizing agent that acts as (1) a diffusion barrier, (2) a enzyme inhibitor, (3) a competitive substrate, or (4) a masking moiety. A diffusion barrier acts as a barrier so as to protect the osteoinductive factors found in DBM from being degraded by proteolytic and glycolytic enzymes at the implantation site. Stabilizing agents may be any biodegradable material such as starches, modified starches, cellulose, dextran, polymers, proteins, and collagen. As the stabilizing agents degrades or dissolves in vivo, the osteoinductive factors such as TGF-&bgr;, BMP, and IGF are activated or exposed, and the activated factors work to recruit cells from the preivascular space to the site of injury and to cause differentiation into bone-forming cells. The invention also provides methods of preparing, testing, and using the inventive improved osteodinductive matrix compositions.

Abstract: Spinal and other implants may be bone or synthetic material shaped as rings, C-shaped or rectangular and so on and also may have serrated wedge shaped top and bottom surfaces to match the disc space lordosis of adjacent ertebra and so on. The implants have one or more recesses aligned in an insertion direction at either or both outer peripheral sides of the implant. In a ring implant, e.g., formed from a transverse slice of the diaphysis of a long bone or otherwise, the recesses are aligned overlying the opposing sides of the ring parallel to the insertion direction, which sides are stronger than the more central region overlying and aligned with a central chamber in the implant. The alignment ith the opposing sides minimizes damage to the implant at the weaker more central region in response to implant insertion forces.

Abstract: A shaft synchronous balancing apparatus wherein a rotor to be balanced is rotated in conjunction with appropriate balance plane located transducers and a non-contacting shaft monitoring pick-up, for example of an optical variety. The latter pick-up derives a one times per revolution reference signal which is treated by a software driven process control system including dual timer-counters to evaluate the period of revolution, T, and to develop N incremental sampling pulses having a duration or time constant of T/N. Preferably, N is an even integer power of 2. Periodic updating of the duration of a time constant is developed utilizing only one software interrupt in conjunction with the two counter timers. A nulling technique for canceling offset at the signal treatment stages is provided which accommodates for the high amplification levels necessary at the front end of the system.