Published papers

We reported a 68-year-old female with Creutzfelt-Jakob disease (CJD) presenting hyperparathyroidism. She was suspected as Creutzfelt-Jakob like syndrome at her initial visit to our hospital because of progressive dementia and high level of serum calcium. Finally she was diagnosed as having CJD by the clinical symptoms including progressive dementia and myoclonus and the characteristic patterns of brain CT and electroencephalogram (EEG). CJD presents a variety of symptoms including progressive dementia, apathy and myoclonus. Hyperparathyroidism and toxicity of lithium, delirium and bismuth have been reported to induce similar symptoms of CJD, which are called Creutzfelt-Jakob like syndrome. Therefore, the diagnosis of CJD would be difficult in cases with CJD accompanied with Creutzfelt-Jakob like syndrome. It is rare for otolaryngologists to examine patients with dementia like CJD. However, we have to keep CJD in mind in the diagnosis of hyperparathyroidism. Copyright (C) 2000 Elsevier Science Ireland Ltd.

We examined neuroprotective effects of an adenoviral vector encoding glial cell line-derived neurotrophic factor (AxCAhGDNF) on the lesioned adult rat motoneurons in the nucleus ambiguus. After vagal nerve avulsion, AxCAhGDNF, AxCALacZ (adenovirus encoding β-galactosidase gene) or PBS was inoculated into the jugular foramen. Four days after the avulsion and treatment with AxCALacZ, the animals expressed β-galactosidase activity in the lesioned motoneurons in the nucleus ambiguus. The animals avulsed and inoculated with AxCAhGDNF showed immunolabeling for GDNF in the nucleus ambiguus on the treated side and expression of virus-induced human GDNF mRNA transcripts in the brainstem tissue that contained the nucleus ambiguus of the treated side. The treatment with AxCAhGDNF after avulsion prevented the loss of lesioned motoneurons in the nucleus ambiguus, ameliorated the choline acetyltransferase immunoreactivity, and also suppressed the activity of nitric oxide synthase in these neurons. These results indicate that adenovirus-mediated GDNF gene transfer may prevent the degeneration of motoneurons in humans after either vagal nerve injury or recurrent laryngeal nerve injury.

The mouse serves as a valuable model for treatment leading to the prevention and therapy of inner ear disease. Transgenic correction of genetic inner ear disease in mice may help develop treatment for human genetic inner ear disease. In mutations involving hair cells (HCs) or supporting cells (SCs), it is necessary to insert the wild-type transgenes directly into these cells. We used inner ear explants to characterize the transgenic expression using adenovirus-mediated reporter genes (bacterial lacZ). The variable parameters were the age of the explants (P1-P5), the type of vector (first and advanced generation adenovirus) and the genotype of the mouse (wild-type versus shaker-2 mutant). Transduction of cochlear HCs was detected at P1 and in some of the P3 cochleae. Low efficiency transduction of SCs was observed in P1 explants, but the efficiency increased with age and reached high levels at P5. The pattern of transduction was similar regardless of the genotype and the type of vector used. The data demonstrate that differentiating HCs and SCs in mouse explants can be transduced by adenovirus vectors, suggesting that cultures of mouse ears are a valuable model for developing inner ear gene therapy protocols.

In hearing preservation surgery for the treatment of vestibular schwannoma (VS), one of the important factors is the determination of the origin of VS. In this study, we investigated the diagnostic significance of using an MRI obtained by the three-dimensional Fourier transform fast spin-echo technique (3D-reconstructed MRI) in order to determine the origin of VS. The subjects consisted of 20 patients with mainly intra-canalicular sized VS who underwent tumor removal at our hospital. The origin of VS was determined from the 3D-reconstructed MRI findings and the results of the caloric test. These findings were then compared with the surgical findings. In 15 out of 20 patients, the MRI findings closely corresponded to the surgical ones, while the origin of VS hardly could be detected when a tumor filled up to the fundus acoustics on the MRI findings of the axial sections. On the other hand, 6 out of 15 patients (40%) whose tumor originated from the inferior vestibular nerve showed canal paresis. In conclusion, 3D-reconstructed MRI is considered to be helpful in obtaining more precise information regarding the origin of VS compared to the caloric test.

Objective and Study Design: The authors conducted a prospective, randomized, double-blinded clinical trial for the purpose of elucidating the effects of prostaglandin E1 (PGE1) on idiopathic sudden sensorineural hearing loss. Setting and Patients: With the approval of the institute ethics committee, a total of 57 consecutive patients with diagnoses of idiopathic sudden sensorineural hearing loss were included in the study. The patients in the PGE1 group received continuous infusion containing 60 μg PGE1 and 100 mg hydrocortisone for 7 days, and the patients in the placebo group were treated with continuous infusion containing an inactive placebo and 100 mg hydrocortisone. Results: No significant differences were observed in the improvements of pure-tone average and subjective symptoms between the PGE1 and the placebo groups. However, the hearing improvement at high frequencies (4 kHz and 8 kHz) was significantly higher in the PGE1 group than in the placebo group, especially in the patients with severe tinnitus. Conclusions: These results failed to prove a beneficial effect of PGE1 in the treatment of idiopathic sudden sensorineural hearing loss. Further studies will be needed to clarify the pharmacologic actions of PGE1 in the cochlea.