Complex Aneurysm: The Unpredictable Pathological Entity.

BACKGROUND: Surgical treatment of complex aneurysms often requires the execution of a revascularization procedure. Even if avoiding the concomitant trapping of the aneurysm during the bypass procedure (waiting for the subsequent endovascular or spontaneous closure) permits one to verify the graft's patency and patient's adaptation to increased flow, the hemodynamic changes induced by the bypass may cause the aneurysmal rupture. Whether or not to perform the concomitant trapping of the aneurysm still remains a dilemma. Here we illustrate our management protocol through the critical analysis of some illustrative cases of our series. MATERIALS AND METHODS: Between 1990 and 2016, 48 of 157 patients affected by complex aneurysms underwent a revascularization procedure. In 19 cases (1990-1997) only a bypass procedure was performed. Spontaneous or endovascular closure was obtained within the first postoperative week once the graft patency had been verified (staged revascularization strategy). In the remaining 29 cases. The total amount of cases is 48. 19 cases staged revascularization strategy. 29 cases single stage revascularization strategy. RESULTS: In the staged revascularization era, one patient died because of the rupture of the aneurysm before its closure.In the single-stage era no further cases of rebleeding were observed. Neurologic status of this group was unvaried or improved. CONCLUSIONS: Given the unpredictable response of complex aneurysms to the hemodynamic changes induced by the revascularization, in our opinion it is always preferable to perform complete or at least incomplete trapping of the aneurysm during the bypass procedure.

Fourth cranial nerve: surgical anatomy in the subtemporal transtentorial approach and in the pretemporal combined inter-intradural approach through the fronto-temporo-orbito-zygomatic craniotomy. A cadaveric study.

Despite the recent progress in surgical technology in the last decades, the surgical treatment of skull base lesions still remains a challenge. The purpose of this study was to assess the anatomy of the tentorial and cavernous segment of the fourth cranial nerve as it appears in two different surgical approaches to the skull base: subtemporal transtentorial approach and pretemporal fronto-orbito-zygomatic approach. Four human cadaveric fixed heads were used for the dissection. Using both sides of each cadaveric head, we made 16 dissections: 8 with subtemporal transtentorial technique and 8 with pretemporal fronto-orbito-zygomatic approach. The first segment that extends from the initial point of contact of the fourth cranial nerve with the tentorium (point Q) to its point of entry into its dural channel (point D) presents an average length of 13.5 mm with an extremely wide range and varying between 3.20 and 9.3 mm. The segment 2, which extends from point D to the point of entry into the lateral wall of the cavernous sinus, presents a lesser interindividual variability (mean 10.4 mm, range 15.1-5.9 mm). A precise knowledge of the surgical anatomy of the fourth cranial nerve and its neurovascular relationships is essential to safely approach. The recognition of some anatomical landmarks allows to treat pathologies located in regions of difficult surgical access even when there is an important subversion of the anatomy.

The etiology of low-grade gliomas: pathological and clinical considerations about radiation-induced low-grade gliomas.

The only environmental factor undoubtedly linked to an increased risk of brain tumors (including gliomas) is therapeutic X-rays. We aim to conduct a detailed study of radiation-induced low-grade gliomas, in order to better understand the pathogenesis of such gliomas. Furthermore, we want do prove whether or not there are significant differences, according to clinical features and biological behavior, between this type of tumor and general low-grade gliomas. We analyzed the existent literature of low-grade radiation-induced glioma case reports and other epidemiological reports based on the experience of the senior author. We were able to collect 20 cases of such gliomas. Demographic data and previous X-ray details, along with latency intervals of all patients are provided. The amount of radiation able to cause mutations is not necessarily very high, as tumors occur even after low doses of radiation (as 3-5 GY). The incidence of this kind of tumors may be underestimated and may rise in the future. Care must be taken when observing patients who were irradiated more than 10 years before, especially in the recent years in which access to radiosurgical and radiation therapies has increased in the general population for treating many cerebral pathologies. Radiation-induced low-grade gliomas appear to be different from general gliomas only in terms of age in which they occur. In terms of clinical and biological behavior, there seem to be no differences, even though exceptional cases are reported.

Neurotrophic gene polymorphisms and response to psychological therapy.

Therapygenetics, the study of genetic determinants of response to psychological therapies, is in its infancy. Here, we investigate whether single-nucleotide polymorphisms in nerve growth factor (NGF) (rs6330) and brain-derived neutrotrophic factor (BDNF) (rs6265) genes predict the response to cognitive behaviour therapy (CBT). Neurotrophic genes represent plausible candidate genes: they are implicated in synaptic plasticity, response to stress, and are widely expressed in brain areas involved in mood and cognition. Allelic variation at both loci has shown associations with anxiety-related phenotypes. A sample of 374 anxiety-disordered children with white European ancestry was recruited from clinics in Reading, UK, and in Sydney, Australia. Participants received manualised CBT treatment and DNA was collected from buccal cells using cheek swabs. Treatment response was assessed at post-treatment and follow-up time points. We report first evidence that children with one or more copies of the T allele of NGF rs6330 were significantly more likely to be free of their primary anxiety diagnosis at follow-up (OR = 0.60 (0.42-0.85), P = 0.005). These effects remained even when other clinically relevant covariates were accounted for (OR = 0.62 (0.41-0.92), P = 0.019). No significant associations were observed between BDNF rs6265 and response to psychological therapy. These findings demonstrate that knowledge of genetic markers has the potential to inform clinical treatment decisions for psychotherapeutic interventions.

Retention of the tetragonal to orthorhombic structural transition in F-substituted SmFeAsO: a new phase diagram for SmFeAs(O(1-x)F(x)).

In this Letter we propose a new phase diagram for the SmFeAs(O(1-x)F(x)) system, based on careful analysis of synchrotron powder diffraction data, SQUID, and muon spin rotation measurements. The tetragonal to orthorhombic structural transition is slightly affected by F content and is retained for the superconducting samples, even at optimal doping. These findings relate the AFM transition on a different ground with respect to the structural one and suggests that orbital ordering could be the driving force for symmetry breaking.

Selective liquid phase hydrogenation of citral on Au/Fe2O3 catalysts.

Gold supported on iron oxide hydrogenates citral (an alpha,beta-unsaturated aldehyde) to the corresponding alpha,beta-unsaturated alcohols (geraniol and nerol) with a selectivity higher than 95%.