The protein that is coded by p53 gene is a multi-functional transcription factor involved in the control of cell cycle progression, in DNA integrity and especially in the apoptosis of cells with damaged DNA. Mutation of p53 is reported to be a determinant of the response to radiation therapy. For the treatment of early laryngeal cancer cases, radiation therapy shares a considerably large part of the therapeutic strategy. The response to the radiation therapy is frequently associated with the total prognosis and quality of life after the treatment of laryngeal cancer.
Mutation analysis of p53 in laryngeal cancer cases were performed in this study. Samples obtained from 14 laryngeal cancer cases were examined by SSCP analysis followed by sequence analysis of exon 4, 5, 6, 7 and 8 of p53. Three different point mutations, G245D, R249S and Y205C, were identified among 3 out of 14 (21.4%) laryngeal cancer cases, respectively. These three cases all demonstrated relatively poorer prognosis, showing radiation resistance, postoperative neck metastasis and lung metastasis. Although statistical evaluations was difficult due to the small number of examined samples, these preliminary results indicated the potential clinical impact of genetic diagnosis of p53 in selecting the proper therapeutic strategies for early laryngeal cancer.

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The malignant progression mechanism of precancerous whitish lesions of the vocal cords is still unclear. In this study, the differences of angiogenesis and extracellular matrices between keratosis, dysplasia and invasive carcinoma of the vocal cords were investigated using immunohistochemical staining with anti-CD34, which discerns endothelial cells, and type IV collagen monoclonal antibodies.
In vocal cord keratosis, only a few vessels with small diameters were observed under the basement membrane of the epithelium. An increased number of vessels were recognized around the dysplastic epithelium, downward papillary grow to the stroma. Interestingly, the basement membranes under the dysplastic epithelium and around the vessels were located very closely, suggesting some interaction between the two basement membranes. The double basement membranes were also observed in invasive carcinoma with exophytic growth. In addition, a type IV collagen staining was also seen around nests of carcinoma cells which had infiltrated into the stroma. These results suggest the important roles of the basement membrane and the extracellular matrix in the malignant progression and angiogenesis of the precancerous lesion of the vocal cords.

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160 patients with T1N0 and T2N0 squamous cell carcinoma of the larynx were evaluated at our hospital between 1988 and 1995. The data was retrospectively reviewed. 127 cases had carcinoma of the glottis and the others had supra-glottic carcinoma. 104 cases underwent primary radiotherapy and 56 cases received surgical treatment. The disease recured locally in thirty-two of the patients who had received radiotherapy.
The tumors involving the anterior commissure or infrahyoid epiglottis were poorly controlled by local radiotherapy. 56% of recurrent tumors after irradiation appeared in the anterior site of the larynx. Conservative surgery will be one of the acceptable initial treatments for carcinoma involving the anterior commissure or infrahyoid epiglottis.
The local control rate of radiotherapy for glottic carcinoma was 75%. Subsequent surgery was performed for twenty patients who had developed recurrent tumors. In nine cases of, local control was obtained with conservative surgery but in eleven cases a total laryngectomy was needed. In the cases that had gross residual tumors at the time of 40Gy, 69% of them could not obtain functional larynx. The possibility of larynx preservation will be suggested by the response to radiotherapy at the time of 40Gy.

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There is a close relationship between perception and the production of language. In order to examine that of the central nervous system in the brain, a PET study was performed on healthy adults. The auditory association area, the Broca's area, was extensively activated during listening to speech. Neural activity was also observed in the cerebellum, in addition to Broca's area, motor area, and the supplementary motor area during reading aloud with auditory feedback. However, little activity in the auditory association area was noted compared with that during passive listening. These results suggest that one's own speech is not processed for perception by the auditory association area during speaking. During reading aloud with distorted feedback of input speech, activity increased in the auditory association area and in the motor area but was reduced in the supplementary motor area. Through these observations, we have found two different speech modes; feedforward control managed primarily by the supplementary motor area and feedback control by the auditory association area. It is suggested that interactions among functional areas of the brain for speech take place through numerous trial and errors during the language acquisition period and while the neural network is established. A PET study on patients with various functional voice disorders was also performed. It showed distinct differences in the activities of functional areas compared with those of healthy adults. Investigation of central cortical processing in the brain is important to elucidate the pathogenesis of patients with hearing and speech disorders.

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Basic fibroblast growth factor (bFGF), which is a member of fibroblast growth factor family, has been demonstrated to play important roles in neural development and regeneration. In this study, we investigated the expression pattern of bFGF in the rat nucleus ambiguus (NA) following unilateral recurrent laryngeal nerve (RLN) injury and discussed the roles of bFGF on neural regeneration.
This study involved thirty-three rat subjects. In the first group (n=15), the left RLN was crushed with forceps at the location of the seventh tracheal ring. In the second group (n=15), the left RLN was resected for 5mm in length. The brainstems of rats were excised on the 1st, 3rd, 7th, 14th and 28th days after the procedure in both groups. In the normal group (n=3), rats served as controls. The brainstems were rapidly frozen and 20μ m-thick serial sections were cut on a cryostat. The sections were processed for immunohistochemical staining using anti-bFGF antibody. The expression of bFGF in the NA was quantitatively evaluated via an image analysis technique.
Although a weak expression of bFGF in the NA was identified in the normal group, the expression had increased in the crushed and resected groups. In particular, bFGF was expressed up to 7 times as much as in the untreated side on the 14th day following RLN resection.
These findings suggest that the expression of bFGF in the NA is promoted by RLN injury and that it is deeply associated with a regeneration of the injured nerve by preventing lesion-induced neural death.

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Five infants underwent tracheostomies during the past 4 years in our department. Their disease were severe laryngomalacia, bilateral recurrent laryngeal nerve palsy, birth asphyxia, holoprosencephaly and congenital myopathy. A vertical incision was made in the trachea through the second, third and fourth tracheal rings. Care was taken that tracheal cartilage was not resected. Stay sutures were used to distract the cut edge of the trachea. The tracheotomy tubes were cut to the desired length not to abrade the carina or rest within the right main stem bronchus. The specially designed fenestrated tracheotomy tubes with one way valves allowed voice to be produced. All four cases suffered from no complications. There was one case with tracheal granulation. Two cases did not encounter undue difficulty with deglutition and speech development.

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Type 2 Thyroplasty or midline lateralization thyroplasty was performed on 3 patients under local anesthesia with adductor spasmodic dysphonia (SD). The voice was restored to normal in all 3 patients without recurrence. The optimal separation of the incised thyroid ala at the midline was found to be 2-4mm.
Clinical manifestation of SD is diverse, and 3 patients with differing SD are under consideration for surgical indication. This type of laryngeal framework surgery emphasizes the surgical procedures that provide symptomatic treatment rather than radical treatment.

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Oropharyngeal swallowing disorder results from the disruption of the integrated mechanism of deglutition. This disruption occurs when the lower cranial nerves have been paralyzed due to a cerebrovascular accident or by a skull base lesion. In this article, we postoperatively evaluated the outcomes of 26 patients who had undergone surgical intervention for severe dysphagia caused by lower cranial nerve deficits. The ages of the patients ranged from 22 to 79 years, with an average of 58 years. Etiology of dysphagia consisted of cerebrovascular accidents in 14 cases, skull base lesions in 7, parapharyngeal space lesions in 2, and others in 3. Twenty-one patients had been entirely dependent on tube feeding or intravenous hyperalimentation preoperatively. The series of surgical procedures included cricopharyngeal myotomy (CPM) in 10 cases, CPM with laryngeal suspension (LS) in 6, CPM with vocal fold medialization (VFM) in 3, CPM with both LS and VFM in 6, and VFM in 1. Twenty-three patients (88%) had success in postoperative swallowing function improvement, and oral food intake was restored. Although structured swallowing rehabilitation is mandatory for patients with pharyngeal swallowing disorders, surgical strategies should be considered as a choice of treatment for patients with prolonged pharyngeal swallowing dysfunction.

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INTRODUCTION : The prerequisites of voice therapy include not only understanding how the patient can phorate and assessing his background well (i.e. problems in his daily life), but also recognizing the patient pathological condition and his state of recovery during therapy. These are considered requirements for effective voice therapy.
SUBJECT : We found good results using visual feedback to promote voice therapy. The patients were two males out of 229 cases who had visited our outpatient voice disorders clinic at the National Defense Medical College Hospital. The period of this study was between May of 1997 and October of 1998. The two patients were selected because they had suffered from voice disorders mainly due to ventricular dysphonia.
METHOD : Each patient was asked to phorate according to the instruction of voice therapist while he was shown his own laryngeal image on a VTR monitor from a flexible fiberscope inserted through his nose. Clinical and voice therapist could simultaneously recognize how the patient is phonating on another TV monitor.
CONCLUSION : Our method is considered to be useful in assisting voice therapy in terms of the following : It is possible to provide visual feedback of improvement to the patient himself; no special device is needed if we have a VTR monitor system and a flexible fiberscope.

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