Influence of the site of small bowel resection on intestinal epithelial cell apoptosis

Massive small bowel resection (SBR) results in a significant increase in intestinal epithelial cell (EC) proliferation as well as apoptosis. Because the site of SBR (proximal (P) vs. distal (D)) affects the degree of intestinal adaptation, we hypothesized that different rates of EC apoptosis would also be found between P-SBR and D-SBR models. Wild-type C57BL/6J mice underwent: (1) 60% P-SBR, (2) 60% D-SBR, or (3) SHAM-operation (transaction–reanastomosis) at the mid-gut point. Mice were sacrificed after 7 days. EC apoptosis was measured by TUNEL staining. EC-related apoptotic gene expression including intrinsic and extrinsic pathways was measured with reverse transcriptase-polymerase chain reaction. Bcl-2 and bax protein expression were analyzed by Western immunobloting. Both models of SBR led to significant increases in villus height and crypt depth; however, the morphologic adaptation was significantly higher after P-SBR compared to D-SBR ( P <0.01). Both models of SBR led to significant increases in enterocyte apoptotic rates compared to respective sham levels; however, apoptotic rates were 2.5-fold higher in ileal compared to jejunal segments ( P <0.01). P-SBR led to significant increases in bax (pro-apoptotic) and Fas expression, whereas D-SBR resulted in a significant increase in TNF-α expression ( P <0.01). EC apoptosis seems to be an important component of intestinal adaptation. The significant difference in EC apoptotic rates between proximal and distal intestinal segments appeared to be due to utilization of different mechanisms of action.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47176/1/383_2005_Article_1576.pd

Osseointegrated amputation prostheses and implanted electrodes

The load transfer from the external prosthesis to the residual limb via the socket can cause significant stress on the soft tissues, leading to irritation and skin ulcers. Osseointegrated bone-anchored prostheses systems create a direct structural and functional connection between the prosthesis and residual skeleton. Up to date, standardized implant systems, surgical techniques, and postoperative rehabilitation protocols have been developed for osseointegrated prostheses for the rehabilitation of amputees (OPRA), which has resulted in better functionality, fewer complications, and a better quality of life for implant recipients. The OPRA implant systems can now incorporate neuromuscular electrodes to facilitate myoelectric control and sensory feedback, which is especially important for upper extremity amputees. The latest development, called the osseointegrated human-machine gateway, allows for permanent implantation of neuromuscular electrodes, which provide long-term stable signals for myoelectric control, independent of limb position or environmental conditions, as well as artificial sensory feedback. In addition, the modular design of this system allows any part to be upgraded or replaced with minimal disturbance to the other components. The osseointegrated implants and the human-machine gateway represent frontiers in amputee rehabilitation