[Immunological abnormalities in patients with etiology unknown sensorineural hearing loss].

An immunological study was carried out in 50 patients with etiology unknown sensorineural hearing loss, including the following: 12 low tone deafness, 7 sudden deafness, 8 unilateral deafness, 7 idiopathic bilateral progressive sensorineural hearing loss and 14 other bilateral sensorineural hearing loss. Twenty-five out of 50 of the cases demonstrated immunological abnormalities. A full array immunological tests were performed with the following results. High immnunoglobulin titers showed in 18 out of 50 cases. Six cases were positive for antinuclear antibody. The anti-DNA antibody assay revealed high titers in 2 cases. Also, anti-rheumatoid factor antibody assay showed high titers in 6 cases while abnormal values of complements in serum were detected in 6 cases, though an immune complex was demonstrated in only one case. Also, it was noted that six patients with immunological abnormalities have autoimmune diseases. The above results indicated that some cases of etiology unknown sensorineural hearing loss may have an immunological link.

Audiological assessment before and after fractionated stereotactic irradiation for vestibular schwannoma.

PURPOSE: To find the audiological outcome after LINAC-based fractionated stereotactic irradiation (STI). MATERIALS AND METHODS: Twenty-four patients with vestibular schwannoma treated by fractionated STI between 1991 and 1997 had measurable hearing before STI and were followed audiologically for more than 6 months. The pure tone average (PTA) was measured by averaging the air-conduction threshold for five main frequencies (250-4000 Hz) before and periodically after STI in the 24 patients. Several possible prognostic factors for hearing preservation (defined as a PTA change at the last follow-up of less than 10 dB) were investigated. The median follow-up time was 22 months, ranging from 5 to 69 months. The irradiation schedule was 36 Gy in 20 fractions in 5 weeks to 44 Gy in 22 fractions in 6 weeks followed by 4 Gy/1 fraction boost. RESULTS: The pure tone average before STI was distributed from 7 to 73 dB. Fifty percent of patients showed a change in PTA of less than 10 dB, 79.2% of patients showed a change in PTA of less than 20 dB and 20.8% of patients showed a change in PTA of more than 21 dB at the last follow-up. Only one patient (4%) became deaf. Cases with a sudden loss of hearing were more likely to experience hearing preservation than those with gradual loss of hearing (P<0.05). The mean age was younger in patients whose hearing was preserved (P<0.05). Poor pretreatment PTA appeared to linearly correspond to the changes in PTA (regression coefficient 0.78). The size of the tumor was not related to the change in PTA. No relationship was observed between the maximum or peripheral dose and the PTA change. The real benefit of stereotactic boost after small-field fractionated irradiation was not certain. CONCLUSION: Fractionated STI produced a hearing preservation rate compatible with meticulously collimated multi-spots single fraction irradiation. Further follow-up is required to confirm the long-term benefits of fractionation.

[Unilateral multiple tumorous lesions of the parotid gland].

Multifocal tumors within the same parotid gland are very rare. We treated 13 patients with multiple tumorous lesions within the unilateral parotid gland. We evaluated the multiple nodules by CT-sialography or magnetic resonance imaging (MRI). These imagings showed clearly two or more distinct nodular-appearing lesions. Recurrent pleomorphic adenoma (6 patients) was predominant, followed by Whartin's tumor (3 patients). The other lesions were two differential parenchymal tumors (polymorphous low grade adenoma/adenoma) within the same gland, a malignant lymphoma, a squamous cell carcinoma metastatic to the gland, and a tuberculous lesion. On palpitation, 9 of the patients had an unilateral tumor, one a palpable parotid mass in the gland, and the other four had two or more tumors in the unilateral gland. The patients with intra-parotid lymph node and metastatic lesions had extra-parotid cervical adenopathy. The clinical features and the differential diagnosis of the unilateral multiple tumorous lesions of the parotid gland are discussed.

S-phase cells in the guinea pig endolymphatic sac.

S-phase (the period of DNA synthesis) cells in the endolymphatic sac (ES) were investigated by immunohistochemical methods. Monoclonal antibodies against 5-bromo-2'-deoxyuridine (BrdUrd) and proliferating cell nuclear antigen (PCNA) were used. After administration of BrdUrd i.p., guinea pigs were sacrificed with acid formalin and the decalcified temporal bones examined immunohistochemically. Scattered cells labelled with anti-BrdUrd or anti-PCNA antibodies were detected within the ES whereas labelled cells were not found in either the cochlea or the vestibule. From the morphological findings, these labelled cells within the ES epithelium were considered to be epithelial cells and the sub-epithelial stained cells looked like fibroblastic cells. Some labelled resident floating cells were found in the ES lumen. Our results reveal that the ES, where resident cells proliferate, is the sole site of the cell-renewing system in the inner ear of an adult animal.

[Alterations in the distributions of the basement membrane components after secondary inner ear immune reaction in guinea pigs].

Alterations in the distributions of type IV collagen (C-IV), laminin (La), and fibronectin (Fib), which are important components of the basement membrane, in the inner ear following secondary endolymphatic sac immune response were studied immunohistologically using control animals for comparison. Endolymphatic hydrops developed following direct secondary keyhole limpet hemocyanin (KLH) challenge to the endolymphatic sac in systematically pre-sensitized animals. In the endolymphatic sacs of control animals, C-IV and La were localized continuously just under epithelial cells whereas Fib was present intermittently in subepithelial connective tissue. In the endolymphatic sac, following secondary KLH challenge, linear subepithelial localizations of C-IV and La were interrupted, thinner and more loosely aggregated with numerous inflammatory cellular infiltrates on days 2-4. Following these changes, endolymphatic hydrops in the cochlea developed and peaked on days 4-7. On days 1-7, Fib was strongly but sporadically localized in subepithelial cells. These results suggest that C-IV and La may play important roles in the regulation of endolymph whereas Fib may be related to the restoration of injured endolymphatic sac tissue in animals exposed to a secondary challenge.

[Immunohistochemical study of basement membrane in pleomorphic adenomas of the parotid gland: comparison between primary treated tumor and recurrent tumor].

We immunohistochemically investigated the distributions of components of the basement membrane (BM) (type IV collagen and laminin) and alpha smooth muscle actin in twelve primary pleomorphic adenomas of the parotid gland, as compared with six recurrent benign pleomorphic tumors (recurrent type). There were no differences between the two types of the tumor in the distributions of the BM components and actin, whereas the recurrent type of tumor have numerous myxochondroid areas histologically. The localization of type IV collagen in the tumor tissue was almost the same as that of laminin. Actin was identified in the occasional myoepithelial cell. In the tumor tissues, the components of BM were most densely localized in the areas surrounding solid clusters of epithelial cells, outer cells of glandular structures and occasional cells in the myxoid area, but the stroma of the myxochondroid areas did not take up stain. BM was densely defined between the tumor capsule and epithelial cells, but the tumor capsule was not bordered by myxochondroid areas with BM. These results suggest that loss of BM between the capsule and myxochondroid areas may be one of the causes of postoperative recurrence of pleomorphic adenomas.

Localization of type IV collagen and laminin in the guinea pig inner ear.

The distribution of type IV collagen (C-IV) and laminin, which are important components of the basement membrane (BM), was studied immunohistochemically in the inner ear of healthy Hartley guinea pigs. Antibodies against C-IV and laminin were used in this study. The distribution of C-IV in the inner ear was almost the same as that of laminin, but the extent of staining for laminin was less than that for C-IV in some sites. The sites of the inner ear in which these components were most densely localized were the areas surrounding the spiral ganglion cells and nerve fibers, the capillary vessels in the stria vascularis and the spiral prominence, and an area directly beneath the epithelium of the endolymphatic sac. Type IV collagen and laminin were also localized around the other vascular BM and the epithelial BM in the inner ear, but the tectorial membrane, the cupula of the crista ampulla, and the sensory epithelium did not take up stain. These results suggest that the vascular BM of the stria vascularis and spiral prominence, as well as the epithelial BM of the endolymphatic sac, may play an important role in fluid transport, and that the perineural BM of the inner ear might play an important role in the functional maintenance of the optimal environment of the inner ear nervous system.

Deposition of sprayed particles in the nasal cavity.

Therapeutic effects of topically applied steroids is closely related to the deposition of sprayed particles. To clarify deposition in the nasal cavity, model experiments were undertaken using the gas and powder sprays. Deposits on the moistened filter paper which covered the surface of a nose model were assessed by absorbance of the extracts. The influence of the shape and the effect of continuous suction from the posterior outlet were also studied. When the nasal cavity was kept straight without any abnormal protrusions, the gas spray deposited more than 90% of particles. The amount was significantly lowered in the model of a concave septum with hypertrophic turbinates. The powder spray deposited approximately 75% of the original dose. This amount was more than 90% of actually sprayed particles because some loss was inevitable in spraying the powder. In general, the shape of the cavity more affected the deposition of the gas spray than the powder spray. This difference was probably due to the spray angle and to the size and speed of the aerosol particles. It was concluded that the powder spray was preferable to the gas spray with regard to the deposition in the nasal cavity.