Neurofilament-histomorphometry comparison in the evaluation of unmyelinated axon regeneration following peripheral nerve injury: An alternative to electron microscopy.

Background: Currently, assessment of unmyelinated axon regeneration is limited to electron microscopy (EM), which is expensive, time consuming and not universally available. This study presents a protocol to estimate the number of unmyelinated axons in a regenerating peripheral nerve without the need for electron microscopy.

New Method: The common peroneal nerve of Sprague-Dawley rats was transected, repaired and regenerated for 4 weeks.

ErbB2 blockade with Herceptin (trastuzumab) enhances peripheral nerve regeneration after repair of acute or chronic peripheral nerve injury.

Objective: Attenuation of the growth supportive environment within the distal nerve stump after delayed peripheral nerve repair profoundly limits nerve regeneration. Levels of the potent Schwann cell mitogen neuregulin and its receptor ErbB2 decline during this period, but the regenerative impact of this change is not completely understood. Herein, the ErbB2 receptor pathway is inhibited with the selective monoclonal antibody Herceptin (trastuzumab) to determine its significance in regulating acute and chronic regeneration in a rat hindlimb.

Side-To-Side Nerve Bridges Support Donor Axon Regeneration Into Chronically Denervated Nerves and Are Associated With Characteristic Changes in Schwann Cell Phenotype.

Background: Chronic denervation resulting from long nerve regeneration times and distances contributes greatly to suboptimal outcomes following nerve injuries. Recent studies showed that multiple nerve grafts inserted between an intact donor nerve and a denervated distal recipient nerve stump (termed "side-to-side nerve bridges") enhanced regeneration after delayed nerve repair.

Objective: To examine the cellular aspects of axon growth across these bridges to explore the "protective" mechanism of donor axons on chronically denervated Schwann cells.

Long-term outcomes following lower extremity sarcoma resection and reconstruction with vascularized fibula flaps in children.

Background: Limb salvage operations in patients with bony oncologic defects carry technical challenges and may require long recoveries. This study aimed to evaluate functional outcomes, donor-site morbidity, and complications in lower limb bony oncologic defects reconstructed with vascularized fibula flaps in children.

Methods: The authors performed a retrospective review of consecutive pediatric patients undergoing this procedure between 1994 and 2012.

Molecular weight characterization of PRG4 proteins using multi-angle laser light scattering (MALLS).

Objectives: Alternative splicing and variable post-translational modifications result in proteoglycan 4 (PRG4) proteins with historically reported apparent molecular weights (Ma) ranging from 150 to 400 kDa. The objectives of this study were to (1) identify and determine the weight averaged molecular weights (M(W)'s) of PRG4 proteins purified from medium with transforming growth factor-beta 1 (TGF-β1) conditioned by mature bovine articular cartilage explants and (2) to examine the effect of reduction and alkylation (RA) on PRG4.

Methods: Non-reduced (NR) and RA preparations of PRG4 were separated using high performance liquid chromatography-size-exclusion chromatography with an in-line multi-angle laser light scattering (MALLS) detector, which was used for absolute determination of PRG4 M(W).