Tsunemasa Aiba

Taste disorders: a survey of the examination methods and treatments used in Japan

Conclusions. In Japan, the number of patients seeking treatment for taste disorders from otolaryngologists is ≈240 000/year, and this number has almost doubled in the last 13 years. Taste examinations are routinely conducted in almost all university hospitals; testing is not as common in private clinics. Administration of zinc is the main treatment for taste disorders in Japan. Objectives. To investigate the number of patients who visited otolaryngologists for treatment of taste disorders between 2000 and 2002. In addition to determining changes in the number of patients that had occurred in the 13 years since the last study in 1990, the survey also sought to find out what types of taste examination were used to diagnose taste disorders in Japan and what therapies were used to treat them. Material and methods. A questionnaire was mailed to 1559 members of the Japan Society of Stomato-pharyngology. Results. The average number of patients with taste disorders who visited otolaryngological clinics between 2000 and 2002 was 244 858/year. This number is 1.77-fold greater than the number of patients reported by the last study in 1990 (138 575). Electrogustometry was used in 99% of university hospitals and in 20% of private clinics. The filter-paper disk method was also used in 57% of university hospitals and in 27% of private clinics. The main treatment was zinc administration. Most doctors (70%) prescribed polaprezinc, a zinc-containing drug that is used to treat peptic ulcers. Of these doctors, 78% stated that it effectively treated taste disorders and 11% that it did not.

A zinc-containing compound, Polaprezinc, is effective for patients with taste disorders: randomized, double-blind, placebo-controlled, multi-center study.

Conclusions. The effect of a zinc-containing compound, Polaprezinc, was shown to clinically improve the disease conditions of idiopathic taste disorders with no serious side effects in a well controlled double-blinded clinical study. Objectives. The purpose of the present study was to evaluate the efficacy and safety of a zinc-containing compound in the treatment of patients with idiopathic taste disorders, including patients with low serum zinc, by a Good Clinical Practice (GCP)-compliant, randomized, placebo-controlled, double-blind, multi-center clinical study. Subjects and methods. A group of 109 patients suffering from taste disorders was assigned into placebo and three treatment groups. Each group of patients was given either placebo (n=28), or 17 mg (n=27), 34 mg (n=26) or 68 mg (n=28) of oral zinc, Polaprezinc preparations, daily for 12 weeks. Results. The group of patients given 68 mg zinc showed a significant improvement in their gustatory sensitivity compared with the placebo group. The most common side effects observed were increase in serum triglyceride and serum alkaline phosphatase, decrease in serum iron, and some gastrointestinal incidents, although they were not serious.

An Epidemiological Study of Postviral Olfactory Disorder

Postviral olfactory disorder develops after infection with the common cold, and is a relatively severe and prolonged disorder without rhino-sinusitis. This epidemiological study aimed to characterize its clinical pathology and determine the causative virus. Postviral olfactory disorder occurs most commonly in middle-aged women and is most prevalent in spring and summer. A comparison of the monthly frequency of the disorder with the incidence of isolation of various viruses suggest that the influenza virus, respiratory syncytial virus, and herpes virus are not causative viruses, while parainfluenza virus type 3 is most likely to be a causative virus. This conclusion is supported by immunological study and analysis of symptoms of the cold. All patients with postviral olfactory disorder had increased serum antibody titre for parainfluenza virus type 3. No prominent or specific symptoms of common cold were identified as a potential trigger of this syndrome in patient questionnaires.

Gamma knife radiosurgery for intracanalicular acoustic neuromas

In the present study we reviewed our long-term experience with radiosurgery for intracanalicular acoustic neuromas. The study involved 25 patients with unilateral intracanalicular acoustic neuromas. The treatment volume was 0.07 to 0.8 cm(3) (median: 0.27 cm(3)). The marginal radiation dose used for treatment was 12 Gy for all patients. The follow-up period ranged from 36 to 132 months (mean: 89 months). The actuarial rate of tumour growth control at 5 and 10 years after radiosurgery was 96%. Hearing preservation was achieved in 16 patients (64%) and improvement (>20 dB relative to presurgical values) was noted in one patient (4%). No patients experienced post-radiosurgery facial palsy or other cranial nerve deficits. Based on our study and long-term follow-up, radiosurgery can produce high rates of tumour growth control and hearing preservation for intracanalicular acoustic neuromas, and is an alternative to surgical resection given its low level of invasiveness. When determining treatment for intracanalicular acoustic neuromas, the conditions benign natural course and the likelihood of hearing preservation must be taken into account.

Nerve Growth Factor (NGF) and its Receptor in Rat Olfactory Epithelium

Nerve Growth Factor (NGF) is a bioactive protein that plays an important role in the genesis, differentiation, growth, maintenance and aging of the central and peripheral nervous systems. The purpose of this study was to explore the significance of NGF in the turnover, regeneration and maintenance of the olfactory epithelium. We tried to detect NGF and NGF-receptor in the olfactory epithelium of young and mature rats with an immunohistochemical technique. Immunoreactivity to NGF and NGF-receptor was detected in all specimens of olfactory epithelium. Immunoreactivity to NGF was positive in the olfactory nerve cells, especially in the cytoplasm and dendrites, in the basal cell layer, and on fibers piercing the olfactory epithelium. Immunoreactivity to NGF-receptor was positive in the basal cell layer and on fibers piercing the olfactory epithelium. These results suggest that NGF plays a role in the maintenance of olfactory nerve cells, and in the differentiation from the basal cell to the mature olfactory nerve cell, in both the young and the mature rat. In addition, the differences in the density of immunoreactive cells between different parts of the olfactory epithelium support the concept of an active and a quiescent zone in olfactory epithelium turnover.

Magnetic Resonance Imaging for Diagnosis of Congenital Anosmia

Magnetic Resonance Imaging (MRI) was performed on 9 patients who lacked a sense of smell since birth. Seven of them, including two patients with Kallmann syndrome, exhibited abnormality of the olfactory bulb, olfactory tract, olfactory sulcus, or rectus gyrus, with some variation among patients in type and degree of abnormality. The other two patients exhibited normal olfactory pathway morphology, and for them the possibility of acquired sensorineural anosmia could not be ruled out. MRI is useful for determining whether patients with congenital anosmia have olfactory pathway anomalies. Many patients with congenital anosmia and hypoplasty or aplasty of the olfactory pathway nevertheless had no gonadal or endocrinological disorders. Key words: anomaly, gonadal disorder, Kallmann syndrome, olfactory bulb, olfactory tract, olfactory sulcus, rectus gyrus.

Effect of Zinc Sulfate on Sensorineural Olfactory Disorder

We administered zinc sulfate to patients with sensorineural (post-viral, post-traumatic, or unknown aetiology) olfactory disorder and examined its effects. The patients were divided into three groups by method of treatment: zinc sulfate only, combination of zinc sulfate and the usual therapy, or the usual therapy. For disorders of post-viral and unknown aetiologies, there were no significant differences in improvement among the three groups. However, for post-traumatic olfactory disorder, the zinc sulfate groups had significantly higher improvement rates than did the group that received the usual therapy. The difference between post-traumatic and post-viral olfactory disorders in the effect of zinc sulfate therapy appeared to depend on the pathology of the associated lesions. In cases of post-traumatic olfactory disorder, regenerative capacity is retained in the olfactory epithelium because the blast cells of olfactory receptor cells remain intact. However, for post-viral olfactory disorder, the lack of olfactory receptor cells and blast cells due to viral infection results in loss of regenerative capacity. We also determined pre-treatment serum zinc concentrations in those patients who planned to be treated with zinc sulfate. Pre-treatment serum zinc concentration was not significantly related to improvement rates.

Further examination of infants referred from newborn hearing screening.

Objectives Universal newborn hearing screening (UNHS) is considered beneficial and is accepted worldwide. However, some problems remain, and administrative systematization has yet to be established in many countries. This study assessed the hearing screening of referred newborn infants and discusses the problems that remain. Materials and methods Over the two years from July 2001 to June 2003, 98 ears of 49 infants were judged as a “referral” from a newborn hearing screening program, and were subsequently referred to our hospital for further examination using conventional ABR and other audiological tests. The methodology used for hearing screening varied between practitioners and hospitals that utilized both different recording apparatus for AABR and/or automated DPOAEs and independent protocols. Results Conventional ABR identified 21 infants with bilateral normal hearing, 12 with unilateral hearing loss, and 16 with bilateral hearing loss, and a total correspondence rate of 40.8% (20 out of 49 infants). In a comparative analysis, 26 ears out of 98 (26.5%) were determined as false-positive, seven out of 98 as false-negative (7.1%), and there was a total correspondence rate of 66.3% (65 out of 98 ears). Five of the seven false-negative cases who were referred with unilateral hearing loss exhibited moderate to profound bilateral hearing loss (moderate; one infant, severe to profound; four infants). Of the 16 infants with bilateral hearing loss, nine with more than moderate loss had hearing aids fitted at our hospital or related educational institution before most were six months old. Conclusions Our results suggest the accuracy of newborn hearing screening remains an issue, but may be improved by an experienced examiner and better protocols including a two-stage process and altered timing of screening. Other ongoing health care programs need to monitor for signs of hearing loss even in the “passed” infants because of possible false-negatives and delayed-onset hearing loss. Improvement is needed in both the intervention systems and diagnostic follow-up of hospitals. Early public support is also required for infants with either severe to profound or moderate hearing loss. From the viewpoint of test conditions and puerperal parental psychological problems, it is considered that the timing of screening needs further discussion. Here it is suggested that screening should be performed within the first three months of infants life but not be limited to before hospital discharge, and incorporated into the routine health care program for one-month-old infants without reducing efficiency.

Apoptosis in the normal olfactory epithelium of the adult guinea pig

Among nerve cells of vertebrates, the olfactory epithelia are uncommon in their capacity for cell turnover. Apoptosis is well known to play a key role in maintaining homeostasis in continuously renewing tissues. We examined whether true apoptosis occurred in the normal olfactory epithelia of healthy adult guinea pigs using nucleic acid labeling. Subsequently, apoptosis was recognized in olfactory nerve cells, indicating that apoptosis might play a role in turnover of the olfactory epithelium.

Influence of Experimental Rhino-sinusitis on Olfactory Epithelium

The pathology of olfactory epithelium in rhino-sinusitis caused by experimental bacterial infection was studied by scanning electron microscopy. Masses of non-ciliated or microvillous cells were observed on the marginal region of olfactory epithelium as spotted or insular lesions 1 week after onset of inflammation. These masses sporadically contained respiratory ciliated cells which might have replaced cells of olfactory epithelium during recovery from inflammatory damage. Prolonged inflammation with repeated flare-ups promoted the transformation to the respiratory ciliated epithelium at the margin of the olfactory epithelium and made the boundary between olfactory and respiratory epithelium intricate and obscure. The present study suggests that repeated infection with aging could be responsible for a decreased olfactory region.