BackgroundStress involves alterations of brain functioning that may precipitate to mood disorders. The neurotrophin Brain Derived Neurotrophic Factor (BDNF) has recently been involved in stress-induced adaptation. BDNF is a key regulator of neuronal plasticity and adaptive processes. Regulation of BDNF is complex and may reflect not only stress-specific mechanisms but also hormonal and emotional responses. For this reason we used, as an animal model of stress, a fish whose brain organization is very similar to that of higher vertebrates, but is generally considered free of emotional reactions.ResultsWe provide a comprehensive characterization of BDNF gene in the Dicentrarchus labrax and its transcriptional, translational and post-translational regulation following acute stress. While total BDNF mRNA levels are unchanged, BDNF transcripts 1c and 1d resulted down regulated after acute stress. Acute stress induces also a significant increase in proBDNF levels and reduction in mature BDNF suggesting altered regulation of proBDNF proteolytic processing. Notably, we provide here the first evidence that fishes possess a simplified proteolytic regulation of BDNF since the pro28Kda form, generated by the SKI-1 protease in mammals, is absent in fishes because the cleavage site has first emerged in reptilians. Finally, we show that the proBDNF/totBDNF ratio is a highly predictive novel quantitative biomarker to detect stress in fishes with sensitivity = 100%, specificity = 87%, and Negative Predictive Value = 100%.ConclusionThe high predictivity of proBDNF/totBDNF ratio for stress in lower vertebrates indicates that processing of BDNF is a central mechanism in adaptation to stress and predicts that a similar regulation of pro/mature BDNF has likely been conserved throughout evolution of vertebrates from fish to man.
Background: The endovascular techniques has widely changed the treatment of intracranial aneurysms. However surgery still represent the best therapeutic option in case of broad-based and complex lesions. The combined use of endoscopic and microsurgical techniques (EAM) may improve surgical results.Objective: The purpose of our study is to evaluate the advantages and limits of EAM for intracranial aneurysms.Methods: Between January 2002 and December 2012, 173 patients, harboring 206 aneurysms were surgically treated in our department with the EAM technique. One hundred and fifty-seven aneurysms were located in the anterior circulation and 49 were in the posterior circulation. Standard tailored approaches, based on skull base surgery principles, were chosen. The use of the endoscope included three steps: initial inspection, true operative time, and final inspection. For each procedure, an intraoperative video and an evaluation schedule were prepared, to report surgeons’ opinions about the technique itself. In the first cases, we always used the endoscope during surgical procedures in order to get an adequate surgical training. Afterwards we became aware in selecting cases in which to apply the endoscopy, as we started to become familiar with its advantages and limits.Results: After clipping, all patients were undergone postoperative cerebral angiography. No surgical mortality related to EAM were observed. Complications directly related to endoscopic procedures were rare.Conclusion: Our retrospective study suggests that endoscopic efficacy for aneurysms is only scarcely influenced by the preoperative clinical condition (Hunt–Hess grade), surgical timing, presence of blood in the cisterns (Fisher grade) and/or hydrocephalus. However the most important factors contributing to the efficacy of EAM are determined by the anatomical locations and sizes of the lesions. Furthermore, the advantages are especially evident using dedicated scopes and holders, after an adequate surgical training to increase the learning curve.
Background:Facial nerve schwannomas include only 0.8% of all intrapetrous mass lesions, and schwannomas originating exclusively from the greater petrosal nerve (GPN) are extremely rare. To date, only 13 reports have been described. In this case, the tumor was thought to originate from the GPN on the basis of clinical, radiological, and operative findings.Case Description:A 23-year-old girl presented an acute left facial palsy, a disturbance in tear secretion of the ipsilateral eye, and a left-sided conductive hypoacusia. Computed tomography (CT) scan and magnetic resonance imaging (MRI) showed an extradural mass in the left middle fossa. A subtemporal approach was performed and the lesion, originating from the proximal portion of the GPN, was excised. The post-operative course was satisfactory, except for a xerophtalmia, which was treated with artificial teardrops.Conclusion:GPN schwannomas can originate anywhere alongside the course of the nerve, from its proximal segment near the facial hiatus to its distal segment near the foramen lacerum. For these reasons, it requires differential diagnosis with trigeminal nerve schwannomas or with injuries arising from the geniculate ganglion, because it can be easily confused with those lesions. However, in less severe cases, an early diagnosis can be able to preserve the function of the facial nerve by reducing iatrogenic injuries caused by surgical maneuvers.
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