Assessment of the Membranous Labyrinth in Infants Using a Heavily T2-weighted 3D FLAIR Sequence without Contrast Agent Administration.

BACKGROUND AND PURPOSE: Imaging is fundamental to assessing the acoustic pathway in infants with congenital deafness. We describe our depiction of the membranous labyrinth in infants using the heavily T2-weighted 3D FLAIR sequence without a contrast agent. MATERIALS AND METHODS: We retrospectively reviewed 10 infants (20 ears) (median term equivalent age: 2 weeks; IQR: 1-5 weeks) who had undergone brain MR imaging including a noncontrast heavily T2-weighted 3D FLAIR scan of the temporal bone. For each ear, 3 observers analyzed, in consensus, the saccule, the utricle, and the 3 ampullae, assessing the visibility (score 0, not appreciable; score 1, visible without well-defined boundaries; score 2, visible with well-defined boundaries) and morphology ("expected" or "unexpected" compared with adults). The heavily T2-weighted 3D FLAIR sequence was scored for overall quality (score 0, inadequate; score 1, adequate but with the presence of image degradation; score 2, adequate). RESULTS: Six (60%) MR examinations were considered adequate (score 1 or 2). The saccule was visible in 10 ears (83.3%) with an expected morphology in 9 ears (90%). In 1 ear of an infant with congenital deafness, the saccule showed an unexpected morphology. The utricle was visible as expected in 12 ears (100%). The lateral ampulla was visible in 5 ears (41.6%), the superior ampulla was visible in 6 ears (50.0%), and the posterior ampulla was visible in 6 ears (50.0%), always with expected morphology (100%). CONCLUSIONS: MR imaging can depict the membranous labyrinth in infants using heavily T2-weighted 3D FLAIR without an injected contrast agent, but the sequence acquisition time reduces its feasibility in infants undergoing MR studies during natural sleep.

Controlling the reproducibility of Coulomb blockade phenomena for gold nanoparticles on an organic monolayer/silicon system.

Two types of highly ordered organic layers were prepared on silicon modified with an amine termination for binding gold nanoparticles (AuNPs). These two grafted organic monolayers (GOMs), consisting of alkyl chains with seven or 11 carbon atoms, were grafted on oxide-free Si(111) surfaces as tunnel barriers between the silicon electrode and the AuNPs. Three kinds of colloidal AuNPs were prepared by reducing HAuCl4 with three different reactants: citrate (Turkevich synthesis, diameter ∼16 nm), ascorbic acid (diameter ∼9 nm), or NaBH4 (Natan synthesis, diameter ∼7 nm). Scanning tunnel spectroscopy (STS) was performed in a UHV STM at 40 K, and Coulomb blockade behaviour was observed. The reproducibility of the Coulomb behavior was analysed as a function of several chemical and physical parameters: size, crystallinity of the AuNPs, influence of surrounding surfactant molecules, and quality of the GOM/Si interface (degree of oxidation after the full processing). Samples were characterized with scanning tunneling microscope, STS, atomic force microscope, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy (XPS), and high resolution transmission electronic microscope. We show that the reproducibility in observing Coulomb behavior can be as high as ∼80% with the Natan synthesis of AuNPs and GOMs with short alkyl chains.

Electron transfers in a TiO2-containing MOR zeolite: synthesis of the nanoassemblies and application using a probe chromophore molecule.

New assemblies constituted by a microporous matrix of mordenite (MOR) zeolite on which TiO2 nanoclusters are deposited were synthesized using ionic oxalate complexes and TiCl3 titanium precursors. The samples were used to investigate the transfer of electrons produced by spontaneous or photo-induced ionization of a guest molecule (t-stilbene, t-St) occluded in the porous volume towards the conduction band of a conductive material placed nearby, in the pores or at least close to their entrance. The reaction mechanisms were compared in these Ti-rich solids and in a Ti-free mordenite sample. The characterization by XRD, N2 physisorption, TEM, XPS and DRIFT spectroscopy of the supramolecular TiO2/MOR systems before t-St adsorption showed the preservation of the crystalline structure after Ti addition and thermal activation treatments. They also revealed that titanium is mainly located at the external surface of the zeolite grains, in the form of highly dispersed and/or aggregated anatase. After incorporation of the guest molecule in the new assemblies, diffuse reflectance UV-visible and EPR spectroscopies indicate that the electron transfer processes are similar with and without TiO2 but strongly stabilized t-St˙(+) radicals are detected in the TiO2-MOR samples whereas such species were never detected earlier in TiO2-free mordenite using these techniques. The stabilization process is found to be more efficient in the sample prepared with TiCl3 as the precursor than with titanium oxalates. It is proposed that the proximity of TiO2 with the formed t-St˙(+) radicals provokes the stabilization of the radical through capture of the ejected electron by the semi-conductor and that confinement effects can also play a role.

Surgical decompression of a caudal vertebral disc extrusion by dorsal laminectomy.

A 3.5-year-old female spayed Beagle cross was presented to our emergency and referral facility for the complaint of acute onset paralysis of the tail. A full physical and neurological examination was performed which confirmed the absence of motor function in the tail. Signs of superficial and deep pain sensation to the tail remained intact. Orthogonal view survey radiographs identified mineralization superimposed over the intervertebral foramen of the first and second caudal vertebrae. A dorsal laminectomy was performed for surgical decompression of the caudal nerve roots. On the fourth postoperative day, the patient exhibited good motor function of the tail. Neurological improvement continued and 11 days postoperatively the patient demonstrated normal neurological function, free range-of-motion of the tail, and it did not exhibit any signs of pain. Follow-up examination was performed 76 days after surgery, at which time the patient exhibited normal neurological function and signs of a pain-free range-of-motion on manipulation of its tail.

[Computerized modification of Fukuda test]. / Rivisitazione del test di Fukuda mediante misure di elaborazione computerizzate.

OBJECTIVES: To study a new method to apply to Fukuda test in order to overcome the interpretational difficulty associated with a subjective evaluation of the exam. MATERIALS AND METHODS: During the exam, the patient wears a specially-designed headpiece, with a band at the back fitted with a sensor accommodating both a gyroscope and a bi-axial accelerometer. When asked to step in place, he does so in the Romberg position, eyes closed, successively rotating his head to the right and to the left. RESULTS: On analyzing the data obtained through the laterality variable (right/left oscillation) and time variable, it resulted that the difference between the averages referring to the laterality variable of right-handed and left-handed subjects was statistically significant (P = 0.001), while the difference between the averages of the time variable was not. CONCLUSIONS: To be able to propose an evaluation of the clinical validity of the test, further research must be carried out on pathological subjects, thus verifying the applicability of the method to the full.

Syphilitic aneurysm of the abdominal aorta.

A case of syphilitic aneurysm of the abdominal aorta is described. This unusual finding may be misdiagnosed as "inflammatory" abdominal aortic aneurysm, another condition associated with an intense periaortic inflammatory reaction. The authors discuss the differential diagnostic problems and the surgical technique advisable in these cases.

Tension-free hernioplasty: technical remarks and personal experience.

The authors report their experience with 463 tension free hernioplasty procedures for inguinal and femoral hernias. The surgical technique included the insertion of both a polypropylene plug and a polypropylene mesh, and was carried out mostly in local anesthesia (84.2%) using bupivacaine 0.25% for ileoinguinal and ileohypogastric blockage and mepivacaine 0.5% for local infiltration. There was no major intraoperative complication; local postoperative complications were rare (10%) and easily managed; postoperative pain was frequently observed (66%), though mild and transient; resumption of working activity occurred within a month in 96.6% of cases; there were only 3 post-operative recurrences (respectively, at 1, 6 and 12 months). The authors conclude that the tension free hernioplasty is a simple, rapid, low-cost and effective technique, easily performed under local anesthesia.

Suicide and custody.

Custodial settings are recognized as an important context both with respect to suicide and self-harm and for HIV prevention and care. This article examines briefly what is known about suicide and self harm in relation to custody, emphasizing the increased risk of suicide and self-harm with suicidal intent among certain subgroups within the custodial population. Subsequently the discussion focuses on the current lack of information as regards HIV prevalence in custodial settings and on HIV related policy and practice in custody. The writer attempts to draw out the implications for HIV related suicide in custody, arguing for a rethinking of traditional approaches to suicide in the light of the new stresses arising from the advent of HIV and AIDS in custody.