Michitaka Iwanaga

Cyclin-D1-gene amplification is a more potent prognostic factor than its protein over-expression in human head-and-neck squamous-cell carcinoma.

To evaluate the prognostic significance of cyclin D1 protein/gene expressions in human head‐and‐neck squamous‐cell carcinoma (HNSCC), we examined amplification of the cyclin‐D1 gene (CCND1) by the differential PCR method and over‐expression of cyclin‐D1 protein by immunohistochemistry in 45 paraffin‐embedded sections from HNSCC. Amplification of CCND1 was found in 10 (22%) cases and over‐expression of cyclin D1 was found in 24 (53%) cases. CCND1 amplification was also found in 3 (25%) of 12 cases of dysplastic lesions adjacent to HNSCC. The overall 5‐year survival of patients with CCND1 amplification or with protein over‐production was significantly lower than that of patients without (p < 0.0001 and p < 0.05, respectively). However, with multivariate analysis, only amplification of CCND1 retained an independent prognostic value (p = 0.0018). These suggest that CCND1 amplification occurs at early stages of HNSCC tumorigenesis and is a more useful prognostic factor than over‐expression of cyclin D1 in HNSCC. Int. J. Cancer 74:576–581, 1997.© 1997 Wiley‐Liss, Inc.

Basic fibroblast growth factor combined with atelocollagen for closing chronic tympanic membrane perforations in 87 patients.

Objective: To present the clinical results of closing chronic tympanic membrane (TM) perforations using basic fibroblast growth factor (bFGF) combined with an atelocollagen/silicone bilayer membrane patch. Study Design: Closure of TM perforations in 87 patients was attempted using bFGF, which is thought to promote the regeneration of TM tissues by facilitating the growth of fibroblasts and collagen fibers. Methods: Under an operating microscope, the margin of the perforation was trimmed, and a piece of an atelocollagen/silicone bilayer membrane was placed in the perforation with the silicon layer facing outward and then infiltrated with 0.1 ml of trafermin. Data obtained from patient records included patient age, perforation size, and duration of treatment, with a focus on hearing improvement and complete TM closure. Results: The mean perforation size before treatment was 14.4%. Complete closure of the TM perforation was achieved in 80 patients (92.0%), whereas pinholes remained in 5 patients (8.7%), and small perforations were observed in 2 patients (2.3%). In the patients with complete closure, the TM perforations closed after an average 1.8 treatments, and hearing improved by 13.6 dB. Conclusion: This study demonstrated that bFGF combined with atelocollagen is effective for the conservative treatment of TM perforation.

Histologic Study of Homograft Cartilages Implanted in the Middle Ear

We examined conditions of the micro-sliced homograft cartilages implanted in the middle ear, implanted cartilages removed at revision surgery or implanted cartilages removed at the second stage of staged tympanoplasty, both macroscopically and histologically. Macroscopically, the appearance and shape of the cartilages remained unchanged, with no evidence of erosion. There was no evidence of any foreign body reaction or rejection phenomenon. In general, no marked histologic changes of the matrix tissues were found, although chondrocytes showed degenerative changes. There was partial absorption of cartilage and replacement by fibrous connective tissue when inflammatory changes occurred in the middle ear. It is concluded that implanted homograft cartilage maintains its stiffness for more than 6 months in a healthy, aerated middle ear and appears to be clinically useful for tympanoplasty.

Facial nerve neurinoma: Two cases located in the horizontal portion†

Two small facial neurinomas located in the horizontal portion were presented to demonstrate the clinical features, diagnostic evaluation, and surgical treatment. These two cases show the early state of facial neurinoma and suggest the mechanism of facial paralysis by facial neurinoma. Facial nerve decompression is recommended for Bells palsy unresponsive to the conservative therapy and recurrent facial palsy.

Soft tissue reaction to ceramic ossicular replacement prosthesis

Soft-tissue reaction to ceramic ossicular replacement prostheses (CORP) has been evaluated histologically in rabbits and humans. One week after implantation, severe inflammatory and foreign body reaction was observed in the fibrous connective tissue surrounding the prosthesis. Though some inflammatory response was seen after one month, after three months the CORP was surrounded by a layer of fibrous connective tissue without any foreign body giant cell, histiocyte or inflammatory cell infiltration. Our satisfactory clinical results in humans without placing a cartilage between the CORP and the fascia graft may be due to the excellent soft-tissue compatibility of CORP, as demonstrated in this study.

Tinnitus and/or hearing loss elicited by facial mimetic movement

Temporary tinnitus and/or hearing loss elicited by contraction of facial mimetic muscles are often observed on the affected side in patients recovering from facial nerve paralysis and in those with facial spasm. In order to clarify the mechanism of this phenomenon, changes in auditory threshold and middle ear compliance during voluntary contraction of mimetic muscles were investigated. The results suggest that this type of tinnitus and/or hearing loss is due to nonacoustic contraction of the stapedial muscle synchronous with contraction of mimetic muscles.

Use of Micro-Sliced Homograft Cartilage Plates in Tympanoplasty

We described our experiences in the use of micro-sliced septal cartilage homografts in tympanoplasty. The cartilage plates (0.1-0.5 mm thick) previously prepared with our method by use of a dermatome were used for the three purposes 1) to reconstruct the attic wall defect, 2) to prevent the retraction of the grafted fascia in myringoplasty, and 3) to prevent the displacement of the columella and the retraction of the grafted fascia in columella-type tympanoplasty. There have been no postoperative infections or extrusions in our 142 cases. These cartilage plates are considered to be very convenient in tympanoplasty.

Ossiculoplasty failure with ceramic ossicular replacement prosthesis

The stability of ceramic ossicular replacement prosthesis (CORP) in the middle ear was evaluated in 162 ears that had been followed for more than 18 months. The CORP extruded from 8 ears (4.9%) and was dislocated in 6 ears (3.7%). These failures were considered to be due mainly to postoperative tubal dysfunction and disease recurrence. CORP should not be used when such conditions can be anticipated.

Comparison of bacteria in the tympanic cavity and the mastoid antrum in chronic otitis media

Materials collected from the tympanic cavity before operation and from the mastoid antrum during operation of 58 discharging ears of patients with chronic otitis media were cultured, and the bacteria in these two cavities were compared. Staphylococcus aureus was the commonest organism in the tympanic cavity, and S epidermidis in the mastoid antrum. Anaerobic bacteria were found only in the mastoid antrum of patient with cholesteatoma. In 32 (55 per cent) of the 58 ears examined, bacteria were detected in both the tympanic and mastoid cavities. In 17 ears (53 per cent), the bacterial strains in the two cavities differed. The results indicate the necessity of bacteriologic examination of the mastoid cavity during operation to select antibiotics for postoperative treatment.

The fate of homologous nasal septal cartilages in tympanoplasty.

We have used homologous nasal septal cartilage for tympanoplasty for the last 8 years and obtained satisfactory results. In order to demonstrate the fate of homograft cartilage implanted into the middle ear, mucopolysaccharides have been studied by means of enzyme digestion. The matrix of normal septal cartilage was divided into three regions: 1) pericellular region; chondroitin sulfate B, 2) distal interstitial region; hyaluronic acid and chondroitin sulfates, 3) peripheral interstitial region; collagen. In preserved cartilage, chondroitin sulfate B was lacked out, but hyaluronic acid and collagen remained intact though the amount of mucopolysaccharides diminished slightly when compared with normal septal cartilage. Homograft cartilages evidenced depletion of mucopolysaccharides. Homograft cartilages should be used for the purposes mentioned, though not as material for columella, nor for reconstruction of large bone defect.