Kiyohiro Fujino

Transplantation of bone marrow stromal cells into the cochlea of chinchillas.

This study aimed to evaluate the potential of bone marrow stromal cells for treatment of inner ear diseases. Autologous marrow cells labeled with DiI were implanted into the inner ear of five gentamicin-treated chinchillas. Histological analysis 3 weeks later revealed robust survival of grafted marrow cells in multiple regions within the cochlea. Marrow cells implanted in the basal turn of the cochlea migrated as far as the apical end or into the spiral ligament of the cochlea. Some grafted cells expressed a neuronal or glial cell marker, indicating their ability to differentiate into neuronal or glial cells. Survival, migrational mobility and differentiation of autologous marrow cells in damaged cochlea suggest their potential as transplants for treatment of various degenerative inner ear diseases.

Adenosquamous Carcinoma of the Larynx

Adenosquamous carcinoma (AX) is a rare malignant epithelial tumor characterized by the simultaneous presence of adenocarcinoma and squamous cell carcinoma. Less than 40 cases in the upper aerodigestive tract, and only 20 cases in the larynx, have been reported. This neoplasm is histopathologically similar to mucoepidermoid carcinoma and adenoid squamous cell carcinoma, but it is even more malignant and has poorer prognosis than these carcinomas. In this article, an extremely rare case of ASC arising in the larynx is reported, and the literature is reviewed. ministered. After the completion of this radiotherapy, the tumor vanished. However, 6 months later tumor recurrence at the primary site was noted. Total laryngectomy with bilateral neck dissection was performed. Macroscopic examination of the extirpated larynx showed that the tumor extended to the subglottic area in the submucosal layer and advanced out of the larynx through the cricothyroid membrane. The ultimate histological diagnosis was ASC. One lymph node metastasis of 1 cm in diameter was noted in the left paratracheal region. The histological diagnosis of this metastasis was adenocarcinoma. Five months postoperatively, the patient remained free of recurrence.

Intracapsular enucleation of vagus nerve-originated tumors for preservation of neural function.

Tumors arising from the cervical vagus nerve are relatively rare. Most of them are neurilemmomas, neurofibromas, and paragangliomas. In the management of neurilemmomas, because they are benign and encapsulated, intracapsular enucleation is often performed in an effort to preserve function of the nerve.1 In previous reports, however, postoperative nerve palsy frequently occurred, and in some cases the nerve function did not recover. On the other hand, there have been few attempts to preserve nerve function in the resection of neurofibromas.1 In this report, we performed intracapsular enucleation for 2 vagal tumors: neurilemmoma and neurofibroma. In both cases tumors were completely excised with nerve fibers preserved. In the first case, postoperative palsy did not occur. In the second case transient incomplete vocal cord palsy was observed, but the cord recovered in 6 months. During the ablation of tumors, we monitored nerve function using a nerve stimulator and avoided damaging nerve fibers as much as possible. This procedure may have helped us to preserve nerve function in the resection of not only a neurilemmoma but also a neurofibroma.

Non-organic hearing loss.

Conclusion. Most non-organic hearing loss (NOHL) patients were young females. The discrepancy between the results of pure tone audiometry and objective auditory testing suggests NOHL. The diagnostic problem is that objective audiometry is not included in routine examinations and we have to suspect NOHL in order to perform further examination. The correct diagnosis can be difficult in patients who present with unilateral sudden hearing loss or who also have moderate to profound organic hearing loss. Objective. Symptoms and results of auditory tests for NOHL patients were reviewed. Patients and methods. This study comprised 31 patients with NOHL. Age, symptoms, and the results of subjective and objective audiometry were collected. Results. Twenty-four patients were female and 7 were male. The age at attendance ranged from 7 to 39 years old, with an average age of 16.6 years. Eight patients received steroids before the correct diagnosis was made. Six of them presented with unilateral sudden hearing loss, and the other two patients had accompanying bilateral organic hearing loss.

Cochlear implants in post-lingually deafened patients

Conclusion. Post-lingually deafened patients had good speech intelligibility scores with cochlear implantation. The age at the operation, duration of deafness, and the number of electrodes outside the cochlea showed only weak correlation with the postoperative performance, which warrants cochlear implantation in elderly patients and patients with a long history of deafness and leaving dummy electrodes outside the cochlea. Patients with cochlear obstruction showed comparable performance to patients with an open cochlea. Objective. To evaluate the background and performance of post-lingually deafened cochlear implantation recipients. Patients and methods. Preoperative and intraoperative factors were collected for 109 cochlear implant subjects. Speech intelligibility scores were obtained and the effects of preoperative and intraoperative factors on postoperative performance were evaluated. Results. The average speech intelligibility score was 85.1% for vowels, 41.1% for consonant-vowel (CV) syllables, and 80.4% for phrases. The correlation coefficient between the age at the operation, the duration of deafness, and the number of electrodes outside the cochlea and the postoperative performance was between 0.03 and −0.27. Patients with cochlear obstruction and patients with open cochlea did not show significant differences in speech intelligibility tests. The onset of deafness (progressive vs sudden) did not have an effect on the speech intelligibility test.

Transplantation of neural stem cells into explants of rat inner ear.

Damage and loss of hair cells in the inner ear is the most frequent cause of hearing loss and balance disorders. Mammalian hair cells do not regenerate in the conventional ways. To regenerate the hair cell in the mammalian inner ear we transplanted neural stem cells into explants of rat inner ear. The stem cells integrated successfully into the sensory epithelium of the vestibular organs, but not into the organ of Corti. This method is useful to investigate efficient ways to transplant stem cells into the inner ear.

International Articles: International Case ReportsIntracapsular enucleation of vagus nerve-originated tumors for preservation of neural function

Tumors arising from the cervical vagus nerve are relatively rare. Most of them are neurilemmomas, neurofibromas, and paragangliomas. In the management of neurilemmomas, because they are benign and encapsulated, intracapsular enucleation is often performed in an effort to preserve function of the nerve.1 In previous reports, however, postoperative nerve palsy frequently occurred, and in some cases the nerve function did not recover. On the other hand, there have been few attempts to preserve nerve function in the resection of neurofibromas.1 In this report, we performed intracapsular enucleation for 2 vagal tumors: neurilemmoma and neurofibroma. In both cases tumors were completely excised with nerve fibers preserved. In the first case, postoperative palsy did not occur. In the second case transient incomplete vocal cord palsy was observed, but the cord recovered in 6 months. During the ablation of tumors, we monitored nerve function using a nerve stimulator and avoided damaging nerve fibers as much as possible. This procedure may have helped us to preserve nerve function in the resection of not only a neurilemmoma but also a neurofibroma.

Induction of cell proliferation and beta-catenin expression in rat utricles in vitro.

Limited regenerative response occurs in mammalian vestibular epithelia, although vestibular hair cell regeneration in mammals has been demonstrated under a variety of experimental conditions. Beta-catenin is known to play an important role in both cell–cell adhesion and signal transduction associated with cell proliferation. This study evaluated cell proliferation activity in mammalian vestibular epithelia in organotypic culture and examined the involvement of β-catenin in cell proliferation in vestibular epithelia. After 72 h of culture, utricles with or without induction of cell proliferation were examined. Cell proliferation was induced by brief exposure to forskolin and supplementation with fetal bovine serum. Cell proliferation activity was assessed by bromodeoxyuridine (BrdU) labeling. Immunohistochemistry was employed for analysis of cellular distribution of β-catenin. In utricles cultured without induction of cell proliferation, BrdU labeling was not found in vestibular epithelia. Expression of β-catenin was found in the area corresponding to the distribution of adherens junctions in vestibular epithelia. However, BrdU labeling was identified in sensory epithelia of utricles following induction of cell proliferation, although the number of BrdU-positive cells in sensory epithelia was very limited. Accumulation of β-catenin was occasionally found in proliferating cells in sensory epithelia; however, it was not always found in BrdU-positive cells. The present findings suggest that β-catenin may play a role in the induction of cell proliferation in mammal vestibular epithelia.

Clinical characteristics of delayed endolymphatic hydrops: long-term results of hearing and efficacy of hyperbaric oxygenation therapy

Conclusion. Diuretics significantly improved hearing in patients with contralateral-type DEH, whereas they did not inpatients with ipsilateral-type DEH. Objective. We report a review of 26 cases of DEH treated in recent 6 years. Patients and methods. The study group comprised 22 contralateral and 4 ipsilateral types of DEH. The efficacy of diuretics on the improvement in hearing was examined quantitatively. The efficacy of hyperbaric oxygenation therapy (HBO) on hearing was examined in six patients. Results. The general properties of these cases were similar to those reported previously, except for the high proportion of patients with contralateral-type DEH. Diuretics significantly improved the hearing of patients with contralateral-type DEH. In contrast, no significant improvement by diuretics was noted in ipsilateral-type DEH.

Bilateral congenital ossicular chain disruption mimicking otosclerosis

A rare case of bilateral congenital ossicular chain disruption whose history and findings mimicked those of otosclerosis is reported. A 54-year-old male consulted us for slowly progressing hearing loss. Audiogram showed bilateral intermediate mixed hearing loss. The stapedial reflex was negative and the tympanogram was normal A-type. Based on the diagnosis of otosclerosis, stapes surgery was planned for the left side. Surgical findings revealed normal mobility of the stapes and a small disruption at the incudostapedial joint with connection of intact mucosa. The disruption was repaired with auto-bone columella. The patients hearing improved after surgery. The surgery for the other side was performed successively, and similar ossicular disruption was observed. The mechanisms of findings that misled the preoperative diagnosis are discussed.