Leonardo Dalla Giacomassa Rocha Thomaz

Technique for implanting intramuscular electrodes in the diaphragm by videolaparoscopy in pigs

PURPOSE To describe a novel approach for implanting intramuscular electrodes in the diaphragm through videolaparoscopy. METHODS We used twelve pigs for this videolaparoscopic technique, which permits at the same time to explore the diaphragm, to locate its motor points and to fix the electrodes in the diaphragm bilaterally. In this technique we used three trocars: one portal for a 10-mm 0° viewing angle laparoscope, one portal for the manipulation of structures and another for electrode implantation. RESULTS All animals survived the procedure without pneumothorax/capnothorax or other complication. Implanted electrodes provided an appropriate interface between the muscle and the electrical current generator, and electroventilation was satisfactorily generated in all animals. CONCLUSION This videolaparoscopic technique with three trocars enables the exploration and identification of motor points and an efficient fixation of one or two electrodes in each hemidiaphragm.

RC-3095, a selective gastrin-releasing peptide receptor antagonist, does not protect the lungs in an experimental model of lung ischemia-reperfusion injury.

RC-3095, a selective GRPR antagonist, has been shown to have anti-inflammatory properties in different models of inflammation. However, its protective effect on lungs submitted to lung ischemia-reperfusion injury has not been addressed before. Then, we administrated RC-3095 intravenously before and after lung reperfusion using an animal model of lung ischemia-reperfusion injury (LIRI) by clamping the pulmonary hilum. Twenty Wistar rats were subjected to an experimental model in four groups: SHAM, ischemia-reperfusion (IR), RC-Pre, and RC-Post. The final mean arterial pressure significantly decreased in IR and RC-Pre compared to their values before reperfusion (P < 0.001). The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation when compared to baseline (P = 0.005). Caspase-9 activity was significantly higher in the RC-Post as compared to the other groups (P < 0.013). No significant differences were observed in eNOS activity among the groups. The groups RC-Pre and RC-Post did not show any significant decrease in IL-1β (P = 0.159) and TNF-α (P = 0.260), as compared to IR. The histological score showed no significant differences among the groups. In conclusion, RC-3095 does not demonstrate a protective effect in our LIRI model. Additionally, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis.

Similarities in the surface area/volume ratio in the fibers of the recurrent laryngeal nerve can explain the symmetry in the vocal fold mobility?

We demonstrate in this paper that although there are statistical differences for all morphometric data [axon length, axon diameter, myelinated fiber diameter and degree of the myelination (g-Ratio)] between the fibers of recurrent laryngeal nerve right and left, the surface area/volume ratio in the fibers of both nerves is exactly the same (1/1.7). Thereby, this paper presents the hypothesis that this similarity between the nerves can actually trigger a considerable synchrony in mobility of the intrinsic muscles of the larynx that control of the vocal folds.