Chondroblastoma of the temporal bone

Chondroblastomas are highly destructive tumors that are derived from immature cartilage cells. The occurrence of this tumor in the temporal bone or skull base is uncommon. Approximately 70 cases have previously been reported, several of which have involved the temporomandibular joint (TMJ). We report here the case of a 67-year-old woman who presented with right-sided mixed hearing loss, a right external auditory canal mass, ear fullness, otalgia, blood-stained otorrhea, and pain around the TMJ, associated with difficulty in opening the mouth. CT and MRI revealed a mass involving the TMJ, infratemporal fossa, and pterygopalatine fossa. The patient underwent tumor resection via an infratemporal fossa approach type B. Gross total tumor removal was achieved, with no facial nerve paralysis or other complications observed after surgery. No recurrence or residual tumors were observed on CT and MRI, even after 7.5 years of follow-up. We conclude that temporal bone chondroblastomas are extremely rare and aggressive, but the outcome after appropriate surgical treatment is favorable. From the review, it may be particularly important to deal with tumors that involve the TMJ, which could affect the long-term outcomes, as well as tumor recurrence. © 2011 Informa Healthcare

p53 Mediates the Accelerated Onset of Senescence of Endothelial Progenitor Cells in Diabetes

Adverse metabolic factors, including oxidized small and dense low density lipoprotein (ox-dmLDL) can contribute to the reduced number and the impaired functions of circulating endothelial progenitors (EPC) in diabetic patients. To elucidate the molecular mechanisms involved, EPC from normal donors were cultured in the presence of ox-dmLDL. Under these experimental conditions EPC undergo to senescent-like growth arrest. This effect is associated with Akt activation, p21 expression, p53 accumulation, and retinoblastoma protein dephosphorylation and with a reduced protective effect against oxidative damage. Moreover, depletion of endogenous p53 expression by small interfering RNA demonstrates that the integrity of this pathway is essential for senescence to occur. Activation of the Akt/p53/p21 signaling pathway and accelerated onset of senescence are also detectable in EPC from diabetic patients. Finally, diabetic EPC depleted of endogenous p53 do not undergo to senescence-growth arrest and acquire the ability to form tube-like structures in vitro. These observations identify the activation of the p53 signaling pathway as a crucial event that can contribute to the impaired neovascularization in diabetes

Current trends on subtotal petrosectomy with cochlear implantation in recalcitrant chronic middle ear disorders

Objective. To establish the safety and effectiveness of subtotal petrosectomy with cochlear implantation in patients affected by chronic middle ear disorders to refractory to previous surgical treatments. Methods. A multicentre, retrospective study was conducted on patients affected by recalcitrant chronic middle ear disorders who underwent cochlear implantation in combi-nation with subtotal petrosectomy. Patients’ details were collected from databases of 11 Italian tertiary referral centres. Additionally, a review of the most updated literature was carried out. Results. 55 patients were included with a mean follow-up time of 44 months. Cholestea-toma was the most common middle ear recurrent pathology and 50.9% of patients had an open cavity. 80% of patients underwent a single stage surgery. One case of explantation for device failure was reported among the 7 patients with post-operative complications. Conclusions. Subtotal petrosectomy with cochlear implantation is a benchmark for management of patients with recalcitrant chronic middle ear disorders. A single stage procedure is the most recommended strategy. Optimal follow-up is still debated. Further studies are required to investigate the role of this surgery in paediatric patients. © Società Italiana di Otorinolaringoiatria e Chirurgia Cervico-Facciale

Kinetic Properties and Electron Paramagnetic Resonance Spectra of the Nitric Oxide Derivative of Hemoglobin Components of Trout (Salmo irideus)

The binding of nitric oxide to hemoglobin components of trout (Salmo irideus), i.e., Hb trout I and Hb trout IV, has been studied by optical and electron paramagnetic resonance spectroscopy. Kinetic studies show that the Root effect in Hb trout IV is operative also for NO, since a large increase in the dissociation velocity constant (j(4)) is observed as the pH is decreased below 7. Moreover, the time course of the displacement of NO by CO is heterogeneous, suggesting that α and β chains may have different j(4) values. Low-temperature X-band electron paramagnetic resonance spectra have been recorded with Hb trout I and IV saturated with NO at different pH values. The spectra of Hb trout IV are strongly pH-dependent. The high-pH form (pH 8.1) shows axial symmetry and no resolved hyperfine splitting, while the low-pH form is rhombic with a hyperfine splitting of 6.5 G in the g(z) region. The latter form reflects a more distorted site with a more significant delocalization of the unpaired electron on the proximal histidine; both features indicate a destabilization of the ligand binding at low pH. On the other hand, spectra of Hb trout I are axial at both pH values, with hyperfine splitting of 16.5 G, indicating that the site is not distorted and interacts with the ligand very strongly at either pH

Long-term clinical outcomes of cochlear implantation in children with symptomatic epilepsy

Objectives: To describe long-term clinical outcomes of cochlear implantation in deaf children with symptomatic epilepsy. Materials and methods: A retrospective data analysis review of patients implanted at the Cochlear Implant Center of the University of Parma, Italy, was performed, searching for implanted children with a confirmed diagnosis of symptomatic epilepsy. Clinical data, imaging findings, pre- and post-operative epilepsy pattern and EEG traces were analyzed; communicative skills were assessed using the Profile of Actual Linguistic Skills. Results: Search retrieved two patients affected by profound bilateral sensorineural hearing loss and symptomatic epilepsy (associated respectively with methylmalonic acidemia and cerebral palsy). After careful parental counselling both patients were offered and underwent cochlear implantation. Activation and use of cochlear implant did not determine substantial changes of pre-existing seizure pattern and EEG traces. Both patients showed substantial development of their communicative abilities. Conclusions: Cochlear implantation in children with symptomatic epilepsy did not determine variations in seizure pattern or EEG traces. Both patients experienced substantial benefit from cochlear implantation

Meningiomas Intrinsic to the Geniculate Ganglion

Geniculate ganglion meningiomas are extremely rare lesions—only 14 cases have been reported in the literature. Two new cases of these tumors are described. On computed tomography and magnetic resonance imaging, both lesions appeared centered on the area of the geniculate ganglion, extending to the tympanic cleft and eroding the middle cranial fossa floor. The first case was treated through a middle cranial fossa approach. Because the tumor was so large in the second case, a subtotal petrosectomy was used. The authors review the literature to clarify the clinical and radiological characteristics of these tumors and their surgical treatment