Mayumi K. Yoshioka

Individual Differences in the Permeability of the Round Window: Evaluating the Movement of Intratympanic Gadolinium Into the Inner Ear

Objective: Many recent studies have reported on intratympanic gentamicin therapy for the treatment of intractable Ménières disease. Intratympanic administration of steroids has also been used to treat sudden sensorineural hearing loss. These intratympanic drug therapies are based on the assumption that the drug administered intratympanically enters the inner ear through the round window membrane. We used magnetic resonance imaging (MRI) to evaluate whether and how intratympanically administered gadolinium (Gd) enters the inner ear. Methods: GD hydrate was injected intratympanically through the tympanic membrane using a 23-G needle into 61 ears of 55 patients with inner ear diseases. The injected Gd was diluted 8-fold in saline for injection into 58 ears and 16-fold for 3 ears. Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging was performed using a 3-Tesla MRI unit 1 day after the intratympanic injection. Results: In 53 of 61 ears, the Gd-containing inner ear was detected well as a high signal on 3D-FLAIR imaging. However, Gd was not visible in 2 ears with Ménières disease and in 1 ear with profound deafness. The concentration of Gd in the perilymph was lower in 4 ears with Ménières disease and 1 ear with delayed endolymphatic hydrops than after intratympanic administration of the 16-fold Gd dilution. Conclusion: Round window permeability was absent in 5% of ears, and 13% of ears had poor round window permeability. These results should be considered when planning intratympanic drug administration therapy to treat inner ear diseases.

Clinical significance of endolymphatic imaging after intratympanic gadolinium injection

Conclusion: Using three-dimensional real inversion recovery (3D-real IR) and three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI), various degrees of endolymphatic hydrops were observed in the basal and upper turns of the cochlea and in the vestibular apparatus after intratympanic gadolinium (Gd) injection. MRI may contribute to our understanding of inner ear diseases and may be a useful addition to intratympanic drug therapy in the management of inner ear diseases. Objective: To evaluate 3D-real IR MRI and 3D-FLAIR MRI with clinical symptoms and signs in patients with inner ear disease. Patients and methods: Gd was diluted in saline and injected intratympanically in 73 patients with inner ear disease. The endolymphatic space was evaluated with 3-Tesla MRI at 1 day after the intratympanic Gd injection. Results: 3D-real IR MRI was generally better than 3D-FLAIR MRI in discriminating between the perilymphatic space and endolymphatic space in the cochlear turns and in the vestibular apparatus. However, when Gd concentration was insufficient in the perilymph, it was more difficult to visualize the Gd with 3D-real IR MRI than with 3D-FLAIR MRI. Endolymphatic hydrops was observed using MRI in patients with ‘probable’ Ménières disease based on the criteria.

Impacts of a warming marginal sea on torrential rainfall organized under the Asian summer monsoon.

Monsoonal airflow from the tropics triggers torrential rainfall over coastal regions of East Asia in summer, bringing flooding situations into areas of growing population and industries. However, impacts of rapid seasonal warming of the shallow East China Sea ECS and its pronounced future warming upon extreme summertime rainfall have not been explored. Here we show through cloudresolving atmospheric model simulations that observational tendency for torrential rainfall events over western Japan to occur most frequently in July cannot be reproduced without the rapid seasonal warming of ECS. The simulations also suggest that the future ECS warming will increase precipitation substantially in such an extreme event as observed in midJuly 2012 and also the likelihood of such an event occurring in June. A need is thus urged for reducing uncertainties in future temperature projections over ECS and other marginal seas for better projections of extreme summertime rainfall in the surrounding areas.

Future increase of supertyphoon intensity associated with climate change

Increases of tropical cyclone intensity with global warming have been demonstrated by historical data studies and theory. This raises great concern regarding future changes in typhoon intensity. The present study addressed the problem to what extent supertyphoons will become intense in the global warming climate of the late 21st century. Very high resolution downscale experiments using a cloud-resolving model without convective parameterizations were performed for the 30 most intense typhoons obtained from the 20 km mesh global simulation of a warmer climate. Twelve supertyphoons occurred in the downscale experiments, and the most intense supertyphoon attained a central pressure of 857 hPa and a wind speed of 88 m s−1. The maximum intensity of the supertyphoon was little affected by uncertainties that arise from experimental settings. This study indicates that the most intense future supertyphoon could attain wind speeds of 85–90 m s−1 and minimum central pressures of 860 hPa.

The impact of arterial sclerosis on hearing with and without occupational noise exposure: A population-based aging study in males

OBJECTIVES Arterial sclerosis contributes to inadequate blood supply to multiple organs, suggesting that general atherosclerosis may play an important role in the inner ear. Since noise is a major etiology for hearing loss, the aim of this study was to evaluate both the respective and the combined effects of arterial sclerosis and occupational noise exposure on hearing after accounting for age in middle-aged and elderly men. METHODS The evaluation was conducted using 773 subjects from a population-based sample of 1189 men, aged 40-83 years. The impact of carotid atherosclerosis (CA) or retinal arteriolosclerosis (RA) on hearing was assessed according to history of occupational noise exposure (Noise) obtained in a questionnaire. Differences in the mean pure-tone thresholds at each frequency, between the CA (+) and CA (-) groups or between the RA (+) and RA (-) groups, based on noise exposure were compared using the general linear model (GLM) Procedure in SAS, with adjustments for age. Then, the main effect of CA or RA, and the interactive effect of noise and either CA or RA on pure-tone threshold at seven frequencies were analyzed using an analysis of covariance (ANCOVA), after adjusting for age. RESULTS In the Noise (+) group, a statistically significant deterioration in hearing was found in the CA (+) group compared with the CA (-) group at 500 and 1000 Hz. The results in RA were significant at even lower frequencies than in CA. In the results from ANCOVA, the significant main effect of CA was shown in the pure-tone threshold at 8000 Hz, but not in the analysis of RA. A significant interactive effect of either CA or RA and Noise was observed in hearing at the range from 125 to 1000 Hz. CONCLUSIONS The present study suggests that the impact of arterial sclerosis on hearing is limited but significantly hazardous in middle-aged and elderly men, and that arterial sclerosis exacerbates the deleterious effects of noise on hearing. Early recognition of arterial sclerosis might be contributory to the hearing prognosis after middle age, especially for noise-exposed men.

Tinnitus and brain MRI findings in Japanese elderly

Conclusion. There is evidence of an inverse association between cerebral infarction and tinnitus in this study. The effects of cerebral infarction on tinnitus could be explained by a neurophysiological model of tinnitus. Objectives. We examined the relationship between tinnitus and brain MRI findings including cerebral infarction, brain atrophy, ventricular dilatation, and white matter lesions. Subjects and methods. This was a cross-sectional population-based study of 2193 subjects aged 41–82 years living in Aichi prefecture, Japan. Detailed questionnaires, pure tone audiometry, and brain MRI were performed. Results. After adjusting for potential confounders in a multiple logistic analysis, cerebral infarction was inversely associated with tinnitus (odds ratio (OR)=0.649, 95% confidence interval (CI)=0.477–0.884). Cerebral infarctions of the basal ganglia (OR=0.542), thalamus (OR=0.441), and pons (OR=0.319) were especially associated with tinnitus. Brain atrophy, ventricular dilatation, and white matter lesions had no significant effects on the prevalence of tinnitus.

10-KM MESH GLOBAL ATMOSPHERIC SIMULATIONS

Following the development of an atmospheric general circulation model that runs very efficiently on the Earth Simulator, three meso-scale resolving global 10-km mesh simulations were performed. Three meso-scale phenomena were chosen as simulation and research targets: They were the typhoon genesis, wintertime cyclogenesis and Baiu-Meiyu frontal zone. A brief summary of these results is given in this paper. Generally speaking, the results are realistic, and the figures of precipitation fields from the simulations may look like synthesized pictures from artificial satellites. The results are very encouraging and suggest the usefulness of such ultra-high resolution global simulations for studies on, for example, interaction between large-scale circulation and meso-scale disturbances. Also rationales for this kind of simulations are discussed.

Evidence for SST-Forced Anomalous Winds Revealed from Simultaneous Radiosonde Launches from Three Ships across the Kuroshio Extension Front

AbstractSimultaneous launches of radiosondes were conducted from three research vessels aligned meridionally across a sea surface temperature (SST) front on the flank of the Kuroshio Extension. The soundings carried out every 2 h over 5 days in early July 2012 provided a unique opportunity in capturing unambiguous data on anomalous easterly winds derived from a pronounced meridional SST gradient. The data indicate that a meridional contrast in surface heat fluxes from the underlying ocean enhanced the air temperature anomaly across the SST front, which was observed from the surface up to 300-m altitude. Correspondingly, high and low pressure anomalies that reached 800-m altitude formed on the north and south sides of the SST front, respectively. These temperature and pressure anomalies were maintained even during the passage of synoptic-scale disturbances. Although the free-tropospheric winds are overall westerly, winds below the 1000-m level were easterly due to geostrophic anomalies driven by the northw...

Significance of non-rotational wind stress in the seasonal variation of continental torque

The physical mechanism by which seasonally varying atmospheric wind stress exerted on thesea surface is communicated to the solid earth as oceanic pressure torque (continental torque)and bottom frictional torque is investigated with a linear shallow-water numerical model ofbarotropic oceans. The model has a realistic land’ocean distribution and is driven by a seasonallyvarying climatic wind stress. A novel way to decompose the wind stress into rotational andnon-rotational components is devised. The rotational component drives ocean circulations asclassical theories of wind-driven circulations demonstrate. The non-rotational component doesnot produce ocean circulations within the framework of a barotropic shallow-water model, butbalances with the pressure gradient force due to surface displacement in the steady state. Basedon this decomposition, it is shown that most of the continental torque which plays a majorrole in producing the seasonal variation of length of day (LOD) is caused by the non-rotationalcomponent of the wind stress. Both continental torque due to the wind-driven circulationproduced by the rotational component of the wind stress and the bottom frictional torque areof minor importance.

Coupling Strategy of Atmospheric-Oceanic General Circulation Model with Ultra High Resolution and its Performance on the Earth Simulator

Coupled global climate models (CGCM) provide the most powerful tool to reproduce main features of the observed climate. In stand-alone atmospheric and oceanic models, the computational efficiency has been progressed by tuning each of model codes respectively. Ordinarily supercomputers do not provide reasonable turnaround of CGCM run for century time scales at ultra high resolution. The great expense of running CGCM has been hesitated of development by limiting the number of calculations and by prohibiting the use of the reasonable resolution for satisfying physical requirement. The resource of the Earth Simulator might become to be able to carry out the huge scale simulation. Our objective here is to develop coupled global climate models for the Earth Simulator (CFES) with ultra high resolution to carry out century time integration within reasonable time without decrease of computational efficiency of the component models. It is composed of oceanic general circulation model for the Earth Simulator (OFES) and atmospheric general circulation model for the Earth Simulator (AFES). We provide a new coupling structure to transfer physical data from one component model to the other component through a coupler and back again. In the structure of coupling scheme, each component can run independently to avoid bias due to modeling the feedback timing. It allows us not to, worry about the sequential order of execution of component models. CFES was performed with fully paralleized implementation including I/O interaction throughout coupling scheme. Due to the parallelization, CFES was able to control concurrent performance by changing the number of nodes which employed each component of atmospheric and oceanic models.