Suggestion audiometry for non-organic hearing loss (pseudohypoacusis) in children.

Pertaining to non-organic hearing loss in children, three goals should be attained: detection of this disease, determination of true hearing levels and information about the possible cause. Recently, objective tests have been used principally for children with non-organic hearing loss; however, these lack the simplicity and convenience of traditional audiometry. A new method, which is referred to as suggestion audiometry, since it is suggested to the patient that hearing will be improved as a result of the test procedure, was developed for the purpose of simultaneously achieving the above-stated three goals. The subjects were 20 patients aged 8-16 years suspected of demonstrating non-organic hearing loss and whose apparent hearing loss had been identified by school hearing examinations. Suggestion pure tone audiometry was useful for the detection of non-organic hearing loss and suggestion speech audiometry was valuable for the determination of true hearing levels. The subjects were classified into four groups according to the test results. We discuss causes of the disease based on the classification of the subjects obtained from this test procedure.

Variable-speech-rate audiometry for hearing aid evaluation.

A new hearing aid evaluation method using variable-speech-rate audiometry (VSRA) was developed. VSRA was newly created based on the Japanese speech audiometry authorized by the Japan Audiological Society. The ordinary speech audiometry can not reveal a temporal factor in word discrimination ability of the hearing impaired. Since, with VSRA, we can compare several performance-intensity curves obtained from different speech-rate speech audiometries, the impact on the auditory system of each patient by the fast or slow speech rate could be easily determined. Taking the temporal factor of the auditory systems into consideration by using VSRA, hearing aid evaluation was performed for a master hearing aid with three types of signal processing and fitting for 36 hearing impaired subjects. Then hearing aid evaluation was performed using VSRA for a newly developed portable multi-function digital hearing aid with two types of signal processing and analog hearing aids which had been used by hearing-impaired patients. As a result, VSRA was useful for hearing aid evaluation, in particular, for cases when ordinary normal speech rate audiometry does not provide a significant difference in word discrimination scores. In addition, using VSRA revealed that amplitude compression is more effective for improvement of word discrimination than linear amplification.

[Voice restoration and clinical outcome in patients undergoing laryngectomy with voice prostheses].

Since the introduction of the tracheoesophageal fistula (TEF) technique for restoration of voice in 1983, we performed voice restoration using primary tracheoesophageal fistula in 83 patients undergoing laryngectomy. The success rate for voice restoration with TEF was 80.6% (good voice; 69.8%, fair voice; 10.8%). Thirty-one patients out of 51 patients who have been followed for over 3 years had 34 problems with TEF (15 granulations of TEF, 7 difficulties in insertion of voice prostheses, 4 stenoses of the tracheal stoma, 5 other reasons). However, most patients could use TEF by following appropriate procedures. Our results suggest that the Blom Singer TEF procedure is a safe, simple and effective means of alaryngeal communication.

Long-term observation after soft posterior meatal wall reconstruction in ears with cholesteatoma.

We performed tympanoplasty with reconstruction of the soft posterior meatal wall for the prevention of post-operative retraction pocket formation. Our method is characterized by the reconstruction of the soft posterior meatal wall, non-obliteration with permanent or temporary materials, including Gelfoam, no use of a Palva flap and the use of fibrin glue for attaching the fascia to the posterior meatal skin. None of the patients experienced post-operative narrow-neck retraction pocket formation, and whenever aeration of the middle ear was disturbed, a balloon-like retraction was observed. Not all the posterior meatal walls retracted. The final position of the posterior meatal wall varied among the subjects. No serious cavity or hearing problems have occurred since surgery. Due to the strong possibility of post-operative retraction pocket formation in cases with a large balloon-like retraction, we rejected adopting the canal wall up technique or hard posterior meatal wall reconstruction.

[Transsubmucosal maxilloethmoid sinus surgery through inferior turbinate (swinging of nasolacrimal duct and inferior turbinate)].

We recently devised a new technique for endonasal surgery, which simplifies maxillary antrotomy and ethmoidectomy, and dilates the middle nasal meatus widely enough to allow easier postoperative observation. Surgery is initiated by an incision similar to the one used for submucosal resection of the inferior turbinate. The bony inferior turbinate is resected, and the nasolacrimal duct is freed from the bone. Subsequently, the maxillary and ethmoidal sinuses are excenterated, with swinging of the membranaceous inferior turbinate and the nasolacrimal duct. Postoperative observation confirmed satisfactory results.

Inhibition of tumor-induced angiogenesis by sulfated chitin derivatives.

The effect of antimetastatic sulfated chitin derivatives (SCM-chitin III) on angiogenesis induced by B16-BL6 cells was examined in syngeneic mice. SCM-chitin III caused a marked decrease of the number of vessels toward tumor mass (angiogenic response) without affecting the tumor cell growth when coinjected with tumor cells (on day 0), or injected into tumor site on day 1 or 3 after tumor inoculation. In contrast, carboxymethyl chitin as well as heparin had no effect. Invasion of endothelial cells through reconstituted basement membrane (Matrigel) toward tumor-conditioned media was significantly inhibited by SCM-chitin III in a Transwell chamber assay. SCM-chitin III also inhibited the haptotactic migration of endothelial cells to fibronectin-substrate, but did not inhibit the chemotactic activity in tumor conditioned media in vitro. SCM-chitin III did not directly affect the viability and the growth of tumor cells and endothelial cells in vitro. These results suggest that inhibition of lung tumor metastasis by SCM-chitin III may in part be due to the inhibition of tumor-associated angiogenesis.