933 research outputs found

    Noise induced hearing loss: the role of oxidative stress

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    Introduction: Noise-induced hearing loss (NIHL) is a relevant source of hearing disability affecting the general population, and accounts for about 16% of all the reported cases of disabling hearing loss in the adult population worldwide. NIHL can follow workplace-related and recreational noise exposure, and can be influenced by individual factors such as age, sex, genetic predisposition and socio-economic factors. Objectives: The aim of this paper is to provide a quick overview of the principal ndings in noise induced hearing loss, focusing on the role of oxidative stress and antioxidant intervention. Review: Oxidative stress plays a central role in leading to a condition of NIHL. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) largely participate in cellular mechanisms that underlie mainly the outer hair cell death after noise exposure and lead to sensorineural hearing loss. The beneficial effects of antioxidant supplementation have been demonstrated by several experimental studies in animals, while the observed results in humans are mixed. Conclusion: NIHL still represents a widespread condition among the general population; with a higher prevalence in developing countries among workers, and in developed countries among young adults exposed to leisure noise. Extensive literature confirms that increasing antioxidant levels in the organ of Corti may be an appropriate approach towards understanding NIHL in humans by increasing the endogenous antioxidant response or by administering antioxidant molecules systemically or locally

    Hearing loss in Takayasu's arteritis: a role for hyperbaric oxygen therapy?

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    In the scientific community, there is growing interest regarding associated symptoms in Takayasu’s arteritis (TA), an autoimmune condition that mainly affects the medium and large arteries. Hearing loss (HL) is a rare complication of TA that is often overlooked and has severe consequences on the quality of life. HL mainly presents as sudden sensorineural hearing loss (SSNHL) and responds to corticosteroid therapy. In the authors’ opinion, the reasons for misdiagnosing HL in patients with TA are lack of evidence re- garding this rare complication and because TA involves large caliber arteries, instead of small vessels that are typical of the inner ear. We recently used HBOT for a 36-year-old woman with TA, who had two SSNHL episodes in different ears in an 11-month period and observed a significant improvement in the patient's hearing. Although this was a single case finding and HBOT was administered together with steroid therapy, the significant recovery of HL in both ears following this therapeutic approach may be worth sharing with the scientific community. In conclusion, we recommend that awareness for inner ear involvement in TA should increase and that HL should be considered a possible complication of TA and should be treated with corticosteroid therapy and, after collecting further evidence, HBOT

    Optimal management of Cogan’s syndrome: a multidisciplinary approach

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    Cogan's syndrome (CS) is a rare disorder characterized by nonsyphilitic interstitial keratitis (IK) and audio-vestibular symptoms. CS affects mainly young Caucasian adults, mostly during their first three decades of age, and may develop into typical and atypical variants. Typical CS manifests primarily with IK and hearing loss, whereas atypical CS usually presents with inflammatory ocular manifestations in association with audio-vestibular symptoms but mostly different Ménière-like symptoms and, more frequently, with systemic inflammation (70%), of which vasculitis is the pathogenic mechanism. CS is considered as an autoimmune- or immune-mediated disease supported mainly by the beneficial response to corticosteroids. Using well-developed assays, antibodies to inner ear antigens, anti-Hsp70, and antineutrophil cytoplasmic antibodies were found to be associated with CS. Corticosteroids represent the first line of treatment, and multiple immunosuppressive drugs have been tried with variable degrees of success. Tumor necrosis factor-alpha blockers and other biological agents are a recent novel therapeutic option in CS. Cochlear implantation is a valuable rescue surgical strategy in cases with severe sensorineural hearing loss unresponsive to intensive and/or innovative immunosuppressive regimens

    Bias extension test for pantographic sheets: numerical simulations based on second gradient shear energies

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    We consider a bi-dimensional sheet consisting of two orthogonal families of inextensible fibres. Using the representation due to Rivlin and Pipkin for admissible placements, i.e. placements preserving the lengths of the inextensible fibres, we numerically simulate a standard bias extension test on the sheet, solving a non-linear constrained optimization problem. Several first and second gradient deformation energy models are considered, depending on the shear angle between the fibres and on its gradient, and the results obtained are compared. The proposed numerical simulations will be helpful in designing a systematic experimental campaign aimed at characterizing the internal energy for physical realizations of the ideal pantographic structure presented in this paper

    Somatosensory tinnitus: current evidence and future perspectives

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    In some individuals, tinnitus can be modulated by specific maneuvers of the temporomandibular joint, head and neck, eyes, and limbs. Neuroplasticity seems to play a central role in this capacity for modulation, suggesting that abnormal interactions between the sensory modalities, sensorimotor systems, and neurocognitive and neuroemotional networks may contribute to the development of somatosensory tinnitus. Current evidence supports a link between somatic disorders and higher modulation of tinnitus, especially in patients with a normal hearing threshold. Patients with tinnitus who have somatic disorders seems to have a higher chance of modulating their tinnitus with somatic maneuvers; consistent improvements in tinnitus symptoms have been observed in patients with temporomandibular joint disease following targeted therapy for temporomandibular disorders. Somatosensory tinnitus is often overlooked by otolaryngologists and not fully investigated during the diagnostic process. Somatic disorders, when identified and treated, can be a valid therapeutic target for tinnitus; however, somatic screening of subjects for somatosensory tinnitus is imperative for correct selection of patients who would benefit from a multidisciplinary somatic approach

    P-spline smoothing for spatial data collected worldwide

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    Spatial data collected worldwide at a huge number of locations are frequently used in environmental and climate studies. Spatial modelling for this type of data presents both methodological and computational challenges. In this work we illustrate a computationally efficient non parametric framework to model and estimate the spatial field while accounting for geodesic distances between locations. The spatial field is modelled via penalized splines (P-splines) using intrinsic Gaussian Markov Random Field (GMRF) priors for the spline coefficients. The key idea is to use the sphere as a surrogate for the Globe, then build the basis of B-spline functions on a geodesic grid system. The basis matrix is sparse and so is the precision matrix of the GMRF prior, thus computational efficiency is gained by construction. We illustrate the approach on a real climate study, where the goal is to identify the Intertropical Convergence Zone using high-resolution remote sensing data

    Nasal manifestations in granulomatosis with polyangiitis: a case report and review of the literature

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    Granulomatosis with polyangiitis (GPA) is an anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides of medium and small arteries, characterized by necrotizing granulomatous inflammation of the upper and lower respiratory tract with coexist- ing glomerulonephritis. We report a case of GPA in a patient presenting with a six-month history of spontaneous epistaxis, nasal obstruction and frontal headache. Nasal endoscopy showed a large nasal septum perforation and an anterior translucid mass in the right nasal fossa. Findings were confirmed by computed tomography (CT) scan with contrast. The patient underwent func- tional transnasal endoscopic removal of the mass; histological examination showed tissue features suggestive of GPA; dosage of c-ANCA e p-ANCA antibodies confirmed GPA diagnosis. Nasal septum perforation has long been recognized as a feature of GPA, in which granulomatous destruction of nasal cartilage can result in perforation and saddle-nose deformity. Prompt diagno- sis of GPA is important to initiate therapy which may be life-saving and organ sparing

    A Composite Index to Measure the Italian "Enological Vocation"

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    Abstract The Italian wine industry is going through, during a general economic crisis, a period of strong growth and expansion in the world markets. The quality of products, characterized by tradition and innovation, has defeated the involution of the Italian entrepreneurial system. The variety of wines produced represents the peculiarities of the Italian territory. The aim of this paper is to measure a multidimensional phenomenon, the "Enological vocation" of the Italian provinces, through the use of a composite index. The results highlight both areas of the territory for which it is known the strong vocation and less known areas where you need to do further investigation
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