Floor plan - 2013 Annual Meeting - American Association for Hand ...

Targeted Motor Reinnervation of the Rabbit Rectus Abdominis: a Single Muscle Can Receive
and Distinguish Three Independent Nerve Inputs
Institution where the work was prepared: Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
Peter S. Kim, MD1; Kristina O'Shaughnessy, MD1; Todd A. Kuiken, MD, PhD2; Gregory A. Dumanian1; (1)Northwestern
University, Feinberg School of Medicine, (2)Rehabilitation Institute of Chicago
BACKGROUND:
Current myoelectric prostheses are limited at the patient-prosthetic interface, lacking means for intuitive, rapid simultaneous prosthetic
joint movements. Targeted motor reinnervation (TMR) is a new method of rerouting the signals in existing amputated nerves to surrounding
musculature which thereby amplifies these signals. Until now, nerve transfers for the improved control of myoelectric prostheses
have only been performed in humans. This study investigates the feasibility of TMR of the rabbit rectus abdominis (RA) as a means
to better study this surgical technique and to investigate areas for technical advances.
METHOD:
After approval by our institutional Animal Care and Use Committee, 3 New Zealand white rabbits underwent a forelimb amputation
with preservation of the proximal median, radial and ulnar nerves. In a second stage operation, an inferiorly based rectus abdominis
flap was created and transposed onto the ventral chest wall. A neurorrhaphy was made between the median, radial, ulnar nerves and
three motor nerves innervating 3 distinct muscle bellies of the RA. After 10 weeks, the electrophysiologic properties of the reinnervated
flap were investigated prior to harvest. Specific muscle bellies also underwent glycogen depletion to further demonstrate discrete,
segmental innervation of the RA muscle bellies.
RESULTS:
Of the 9 total TMRs performed in 3 rabbits, 7 were grossly successful. Except in one rabbit, each single muscle flap was able to be reinnervated
by three different nerves that previously had served the forelimb. Muscle surface electromyographic data demonstrate that
the innervation of the RA retains its segmental nature after TMR. A logarithmic loss of electromyographic amplitude was noted in signals
crossing into adjacent muscle outside the area of the active contraction. These results are similar to those observed in the uninjured
rabbit RA controls. Similarly, prolonged stimulation of a nerve reinnervating the RA results in the loss of glycogen isolated to the
territory of the muscle stimulated by that nerve.
CONCLUSION:
This study demonstrates that the RA can safely and reliably undergo TMR in the rabbit and that the reinnervated muscle bellies are
electrically discrete entities. Therefore, by using a clinically proven muscle flap, several myoneurosomes may be created to help drive
increasingly complex myoelectric prostheses and to further improve the patient-prosthetic interface.
Donor-Recipient Bone Marrow Cells Fusion as a Novel Therapy for CTA Transplants
Institution where the work was prepared: Cleveland Clinic, Cleveland, OH, USA
Wioleta Luszczek, PhD; Earl Poptic; Serdar Nasir; Aleksandra Klimczak; Lukasz Krokowicz; Maria Siemionow; Cleveland Clinic
INTRODUCTION:
The aim of this study was to create ex vivo, a new generation of chimeric cells by donor-recipient cell fusion.
METHODS:
Bone marrow cells (BMC) were isolated from ACI (RT1a) donors and LEW (RT1l) recipients. Following harvesting, donor and recipients
BMC were stained respectively with green PKH67-GL and red PKH26-GL dye. ACI (RT1a) and LEW (RT1l) stained BMC were fused by
standard Poly-(ethylene-glycol) method. Ex vivo fused chimeric cells (RT1a/RT1l) were purified by FACS-sorting sorting using doublefluorescent
dye. Efficacy of purification was evaluated by immunofluorescence microscopy. PCR-SSP (polymerase chain reactionsequence
specific primers) method was used to confirm chimerism. Colony-forming-units (CFU) assessed clonogenic potential.
Kariotype analysis was performed to confirm polyploidy of the fused chimertic cells. Purified chimeric cells (1.3x106– 2.0x106) were transplanted
by direct intraosseous injection to five naïve LEW recipients to assess engraftment and migratory potential.
RESULTS:
Chimerism in peripheral blood was evaluated by flow cytometry. Immunofluorescence proved the presence of fused donor-recipient
chimeric cells characterized by RT1a/RT1l phenotype which morphologicaly resembled heterokaryon and synkaryon. Kariotype confirmed
polyploidy of fused cells and CFU assay established clonogenic capacity. PCR study allowed for detection of MHC class I genes
characteristics for both the donor and the recipient in genetic material isolated from fused RT1a/RT1l cells. 7 day after transplantation
of fused chimeric cells total chimerism in blood ranged between 1.2-4.58% and at day 21, between 2.54-4.57%. Engraftment and migratory
potential of fused chimeric cells was confirmed by their presence in a bone marrow compartment of the recipients at day 21 posttransplant.
CONCLUSION:
Our study confirmed the feasibility of ex vivo creation of chimeric cells. This study reports for the first time successful engraftment of ex
vivo fused chimeric cells from fully MHC mismatch donors into naïve recipients. Moreover efficacy of cell fusion was confirmed by cells
engraftment followed by chimerism induction. This approach may be applied as a novel cell-based supportive therapy in solid organ
and CTA transplants.
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