193 research outputs found

    Glutamate-evoked redox state alterations are involved in tissue transglutaminase upregulation in primary astrocyte cultures

    Get PDF
    AbstractThe aim of this study was to evaluate the involvement of oxidative stress in glutamate-evoked transglutaminase (TGase) upregulation in astrocyte cultures (14 DIV). A 24 h exposure to glutamate caused a dose-dependent depletion of glutathione intracellular content and increased the ROS production in cell cultures. These effects were receptor-mediated, as demonstrated by inhibition with GYKI 52466. The pre-incubation with glutathione ethyl ester or cysteamine recovered oxidative status and was effective in significantly reducing glutamate-increased tissue TGase. These data suggest that tissue TGase upregulation may be part of a biochemical response to oxidative stress induced by a prolonged exposure of astrocyte cultures to glutamate

    Multiparametric study of the February-April 2013 paroxysmal phase of Mt. Etna New South-East crater

    Get PDF
    Between January 2011 and April 2013, Mt. Etna's eruptive activity consisted of episodic intracrater strombolian explosions and paroxysms from Bocca Nuova, Voragine, and the New South-East (NSEC) summit craters, respectively. Eruptions from NSEC consisted of initial increasing strombolian activity and lava flow output, passing to short-lasting lava fountaining. In this study we present seismic, infrasound, radiometric, plume SO2 and HCl fluxes and geodetic data collected by the INGV monitoring system between May 2012 and April 2013. The multiparametric approach enabled characterization of NSEC eruptive activity at both daily and monthly time scales and tracking of magma movement within Mt. Etna's plumbing system. While seismic, infrasound and radiometric signals give insight on the energy and features of the 13 paroxysms fed by NSEC, SO2 and halogen fluxes shed light on the likely mechanisms triggering the eruptive phenomena. GPS data provided clear evidence of pressurization of Mt. Etna's plumbing system from May 2012 to middle February 2013 and depressurization during the February-April 2013 eruptive activity. Taking into account geochemical data, we propose that the paroxysms' sequence represented the climax of a waxing-waning phase of degassing that had started as early as December 2012, and eventually ended in April 2013. Integration of the multidisciplinary observations suggests that the February-April 2013 eruptive activity reflects a phase of release of a volatile-rich batch of magma that had been stored in the shallow volcano plumbing system at least 4 months before, and with the majority of gas released between February and March 2013

    Space-Time Evolution of Magma Storage and Transfer at Mt. Etna Volcano (Italy): the 2015-2016 Re-Awakening of Voragine Crater'

    Get PDF
    The eruptions of December 2015 and May 2016 at Voragine crater were among the most explosive recorded during the last two decades at Mt. Etna volcano. Here, we present data coming from geophysics (infrasound, LP, VLP, volcanic tremor, VT earthquakes, ground deformations) and petrology (textural and micro-analytical data on plagioclase and olivine crystals) to investigate the pre-eruptive magma storage and transfer dynamics leading to these exceptional explosive eruptions. Integration of all the available data has led us to constrain chemically, physically and kinetically the environments where magmas were stored before the eruption, and how they have interacted during the transfer en-route to the surface. Although the evolution and behavior of volcanic phenomena at the surface was rather similar, some differences in storage and transfer dynamics were observed for 2015 and 2016 eruptions. Specifically, the 2015 eruptions have been fed by magmas stored at shallow levels that were pushed upward as a response of magma injections from deeper environments, whereas evidence of chemical interaction between shallow and deep magmatic environments becomes more prominent during the 2016 eruptions. Main findings evidence the activation of magmatic environments deeper than those generally observed for other recent Etnean eruptions, with involvement of deep basic magmas that were brought to shallow crustal levels in very short timescales (∼1 month). The fast transfer from the deepest levels of the plumbing system of basic, undegassed magmas might be viewed as the crucial triggering factor leading to development of exceptionally violent volcanic phenomena even with only basic magma involved

    Cardiovascular alterations in adult GH deficiency

    Get PDF
    There is a growing body of evidence indicating that patients with adult GH deficiency (GHD) are characterized by a cluster of traditional and emerging cardiovascular risk factors and markers, which can significantly increase their cardiovascular morbidity and mortality possibly linked to aberrations in GH status. Patients with adult GHD present multiple different cardiovascular abnormalities. In addition, cardiovascular risk in adult GHD is increased due to altered body composition, abnormal lipid profile, insulin resistance and impaired glucose metabolism. Cardiovascular risk factors can be reversed, at least partially, after GH replacement. However, evidence on the effects of GH replacement on cardiovascular events and mortality is too limited in adult GHD patients. Aim of this review is to provide an at-a-glance overview of the role of the GH/IGF-I on the cardiovascular system and the state of art of the effects of GH replacement on cardiovascular system

    A rare case of pituitary macroadenoma with synchronous suprasellar meningioma.: Case report, surgical strategy and review of literature

    Get PDF
    Synchronous tumours can be found all along the entire neuraxis, however, some lesions are far less likely to coexist. One of these extremely rare associations is between GH-pituitary adenomas and suprasellar meningiomas. A wide spectrum of transcranial and transsphenoidal approaches were described in the literature for either sellar, suprasellar and parasellar lesions, but no agreement has been reached for the cases of simultaneous occurring lesions. We present a rare case of a woman with GH-secreting pituitary adenoma and concomitant suprasellar meningioma. The strategy chosen was sequential transsphenoidal surgeries. However, after the first surgery, the remaining tumour mass did not mobilize as expected due to gravity, hence we decided to perform a transcranial subfrontal unilateral approach. Surprisingly, the second surgery revealed a different histopathological result. Association of a GH-pituitary adenoma and suprasellar meningioma is very rare, only 17 cases being reported in the relevant literature so far.  Different authors prefer different strategies, ranging from only transsphenoidal to simultaneous transsphenoidal and transcranial approaches, but no general consensus was established. In conclusion, the existence of synchronous tumours of the sellar region should be taken into account when imaging studies reveal an intracranial mass developing both sellar and suprasellar. The surgical strategy should be tailored to every specific patient and experience of the neurosurgeon

    Independent Transposon Exaptation Is a Widespread Mechanism of Redundant Enhancer Evolution in the Mammalian Genome

    Get PDF
    Many regulatory networks appear to involve partially redundant enhancers. Traditionally, such enhancers have been hypothesized to originate mainly by sequence duplication. An alternative model postulates that they arise independently, through convergent evolution. This mechanism appears to be counterintuitive to natural selection: Redundant sequences are expected to either diverge and acquire new functions or accumulate mutations and become nonfunctional. Nevertheless, we show that at least 31% of the redundant enhancer pairs in the human genome (and 17% in the mouse genome) indeed originated in this manner. Specifically, for virtually all transposon-derived redundant enhancer pairs, both enhancer partners have evolved independently, from the exaptation of two different transposons. In addition to conferring robustness to the system, redundant enhancers could provide an evolutionary advantage by fine-tuning gene expression. Consistent with this hypothesis, we observed that the target genes of redundant enhancers exhibit higher expression levels and tissue specificity as compared with other genes. Finally, we found that although enhancer redundancy appears to be an intrinsic property of certain mammalian regulatory networks, the corresponding enhancers are largely species-specific. In other words, the redundancy in these networks is most likely a result of convergent evolution

    Treatment of acute proximal humeral fractures in children with modular external fixator

    Get PDF
    Abstract Objective To evaluate the follow-up of the fractures treated by external fixator. Methods A total of 31 children aged 6–15 years with proximal humeral fractures Grade IV according to Neer–Horowitz classification were treated. The medium follow-up was 24 months. Results In all cases, a good stability of the fracture and a quick healing process were obtained. The mean time of follow-up was 24 months. The external fixation was removed after 6 weeks (5–8 weeks) on average. Constant shoulder score was proposed to all patients and the average result was 97.5 (84–100). Conclusions Advantages of the external fixation are rapid mobilization of the joint, low invasiveness, a single surgery and the possibility to correct any secondary displacement. It is important to underline that the positioning of external fixator should be implanted by expert surgeons and that the patients must cooperate during the entire process up to the time of the removal of the fixator

    Timing and severity of inhibitor development in recombinant versus plasma-derived factor VIII concentrates: a SIPPET analysis

    Get PDF
    Essentials Recombinant factor VIII (rFVIII) was contrasted with plasma-derived FVIII (pdFVIII). In previously untreated patients with hemophilia A, rFVIII led to more inhibitors than pdFVIII. Inhibitors with rFVIII developed earlier, and the peak rate was higher than with pdFVIII. Inhibitors with rFVIII were more severe (higher titre) than with pdFVIII. Summary: Background The development of neutralizing antibodies (inhibitors) against factor VIII (FVIII) is the most severe complication in the early phases of treatment of severe hemophilia A. Recently, a randomized trial, the Survey of Inhibitors in Plasma-Product Exposed Toddlers (SIPPET) demonstrated a 2-fold higher risk of inhibitor development in children treated with recombinant FVIII (rFVIII) products than with plasma-derived FVIII (pdFVIII) during the first 50 exposure days (EDs). Objective/Methods In this post-hoc SIPPET analysis we evaluated the rate of inhibitor incidence over time by every 5 EDs (from 0 to 50 EDs) in patients treated with different classes of FVIII product, made possible by a frequent testing regime. Results The highest rate of inhibitor development occurred in the first 10 EDs, with a large contrast between rFVIII and pdFVIII during the first 5 EDs: hazard ratio 3.14 (95% confidence interval [CI], 1.01\ue2\u80\u939.74) for all inhibitors and 4.19 (95% CI, 1.18\ue2\u80\u9314.8) for high-titer inhibitors. For patients treated with pdFVIII, the peak of inhibitor development occurred later (6\ue2\u80\u9310 EDs) and lasted for a shorter time. Conclusion These results emphasize the high immunologic vulnerability of patients during the earliest exposure to FVIII concentrates, with the strongest response to recombinant FVIII products
    • …
    corecore