Conclusions: The small number of reported cases indicates either the rarity of this complication or unawareness of its existence. The true incidence of this complication is probably under-reported. Orthopedic and vascular surgeons should be aware of this potentially fatal problem. Prevention remains the best treatment. Once encountered, a variety of techniques are available to manage this complication
with reasonable outcome.”
“At the developing vertebrate neuromuscular junction, postsynaptic localization of the acetylcholine receptor (AChR) is regulated by agrin signaling via the muscle specific kinase (MuSK) and requires an intracellular Selleckchem S63845 scaffolding protein called rapsyn. In addition to its structural role, rapsyn is also necessary for agrin-induced tyrosine phosphorylation of the AChR, which regulates some aspects of receptor localization. Here, we learn more have investigated the molecular mechanism by which rapsyn mediates AChR phosphorylation at the rodent neuromuscular junction. In a heterologous COS cell system, we show that MuSK and rapsyn induced phosphorylation of beta subunit tyrosine 390 (Y390) and delta subunit Y393, as in muscle cells. Mutation of beta Y390 or delta Y393
did not inhibit MuSK/rapsyn-induced phosphorylation of the other subunit in COS cells, and mutation of beta Y390 did not inhibit agrin-induced phosphorylation of the delta subunit in So18 muscle cells; thus, their phosphorylation occurs independently, downstream of MuSK activation. In COS cells, we further show that MuSK-induced phosphorylation of the beta subunit was mediated by rapsyn, as MuSK plus rapsyn increased beta Y390 phosphorylation more than rapsyn alone and MuSK alone had no effect. Intriguingly, MuSK also induced
tyrosine phosphorylation of rapsyn itself. We then used deletion mutants to map the rapsyn domains responsible for activation of cytoplasmic tyrosine kinases that phosphorylate the AChR subunits. We found that rapsyn C-terminal domains (amino acids 212-412) are both necessary and sufficient for activation the of tyrosine kinases and induction of cellular tyrosine phosphorylation. Moreover, deletion of the rapsyn RING domain (365-412) abolished MuSK-induced tyrosine phosphorylation of the AChR beta subunit. Together, these findings suggest that rapsyn facilitates AChR phosphorylation by activating or localizing tyrosine kinases via its C-terminal domains. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Aortic pseudoaneurysm following lumbar laminectomy is a rare but potentially life-threatening complication. We report a case of a 49-year-old female patient who developed a pulsatile abdominal mass and pain following a lumbar laminectomy procedure. An aortic pseudoaneurysm was diagnosed which was successfully treated with endovascular stent-graft exclusion. This report represents the first case of endovascular exclusion of a laminectomy-related aortic pseudoaneurysm.