The kinin B1 and B2 receptors and TNFR1/p55 axis on neuropathic pain in the mouse brachial plexus.

Tumour necrosis factor (TNF) and kinins have been associated with neuropathic pain-like behaviour in numerous animal models. However, the way that they interact to cause neuron sensitisation remains unclear. This study assessed the interaction of kinin receptors and TNF receptor TNFR1/p55 in mechanical hypersensitivity induced by an intraneural (i.n.) injection of rm-TNF into the lower trunk of brachial plexus in mice. The i.n. injection of rm-TNF reduced the mechanical withdrawal threshold of the right forepaw from the 3rd to the 10th day after the injection, indicating that TNF1/p55 displays a critical role in the onset of TNF-elicited neuropathic pain. The connection between TNF1/p55 and kinin B1 and B2 receptors (B1R and B2R) was confirmed using both knockout mice and mRNAs quantification in the injected nerve, DRG and spinal cord. The treatment with the B2R antagonist HOE 140 or with B1R antagonist des-Arg9-Leu8-BK reduced both BK- and DABK-induced hypersensitivity. The experiments using kinin receptor antagonists and CPM inhibitor (thiorphan) suggest that BK does not only activate B2R as an orthosteric agonist, but also seems to be converted into DABK that consequently activates B1R. These results indicate a connection between TNF and the kinin system, suggesting a relevant role for B1R and B2R in the process of sensitisation of the central nervous systems by the cross talk between the receptor and CPM after i.n. injection of rm-TNF.

Evaluation of brachial plexus fascicles involvement on infraclavicular block: unfixed cadaver study.

BACKGROUND AND OBJECTIVES: This study shows how the diffusion of the anesthetic into the sheath occurs through the axillary infraclavicular space and hence proves the efficacy of the anesthetic block of the brachial plexus, and may thereby allow a consolidation of this pathway, with fewer complications, previously attached to the anesthesia. MATERIALS AND METHODS: 33 armpits of adult cadavers were analyzed and unfixed. We injected a solution of neoprene with latex dye in the infraclavicular space, based on the technique advocated by Gusmão et al., and put the corpses in refrigerators for three weeks. Subsequently, the specimens were thawed and dissected, exposing the axillary sheath along its entire length. RESULTS AND DISCUSSION: Was demonstrated involvement of all fasciculus of the plexus in 51.46%. In partial involvement was 30.30%, 18.24% of cases the acrylic was located outside the auxiliary sheath involving no issue. CONCLUSIONS: The results allow us to establish the infraclavicular as an effective and easy way to access plexus brachial, because the solution involved the fascicles in 81.76% partially or totally, when it was injected inside the axillary sheath. We believe that only the use of this pathway access in practice it may demonstrate the efficiency.

Estudo anatômico da abordagem posterior sub-escapular do plexo braquial / Anatomic's study posterior subscapulary approach of the brachial plexus

O tratamento cirúrgico das lesões do plexo braquial feito consenso atualmente, e o plexo é normalmenteabordado por via anterior ou trans-axilar. Os autores trabalharam a abordagem posterior sub-escapular doplexo braquial. Esta técnica foi desenvolvida no final do século XIX e utilizada no início deste século pararessecção da primeira costela.O objetivo deste trabalho é estudar as possibilidades de tratamento das lesões supra e infra-claviculares do plexo braquial pela via posterior sub-escapular. Para isso, foram realizadas 22 dissecções em cadáveres frescos,com exposição de todo o plexo braquial, incluindo seus ramos colaterais e terminais. A abordagem posterior sub-escapular constitui uma técnica relativamente simples de execução e merece ser conhecida pelos cirurgiões do plexo braquial.

The surgical treatment of brachial plexus injuries is commonsense now and the brachial plexus is approachedthru an anterior or trans-axillary way. The authors worked on a posterior subscapulary approach of the brachialplexus. This technique was developed at end of the XIX century to perform first rib resection. The aim of this work is study the possibility to treat upper and lower brachial plexus injuries thru posterior subscapular approach. To do this, 22 cadaveric dissections were performed, exposing the brachial plexusentirely, main and collateral branches included. The posterior subscapular approach is a simple technique and deserves to be known by brachial plexussurgeons.