In our department, all patients with advanced carcinoma of the oropharynx and hypopharynx are treated by retropharyngeal (RP) node dissection in addition to primary resection and standard neck dissection. Records of 42 patients (11 oropharynx, 29 hypopharynx and 2 retromandibula) who received RP node dissection from 1992 to 1996 in our department were examined for metastasis to RI' nodes and for preoperative radiographic diagnosis (MRI or CT). The criteria for radiographic involvement of RP nodes are as follows: a diameter greater than 10mm on axial images or central necrosis within the nodal substance. Of the 42 patients, 6 (14.3%) had pathologically positive RP nodes and of those 6 patients, 5 were able to be diagnosed preoperatively by either CT scan or MRI.Results of radiographic diagnosis (MRI or CT) were as follows: by CT scan the sensitivity, specificity and accuracy were all 100% and by MRI the sensitivity, specificity and accuracy were 83.3%, 100% and 97.0% respectively. It is our conclusion that preoperative radiographic diagnosis (MRI or CT) is very useful and effective for diagnosis of metastasis to RP nodes.

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The Clarion cochlear implant was developed in the USA and received FDA approval in August 1996. It consists of an implantable cochlear stimulator (ICS), speech processor with headpiece, and in addition, a clinician's programming system and portable cochlear implant tester. One of the features of the device is its stimulationcoding process for which two methods of continuous interleaved sampling (CIS) and compressed analogue (CA) are applicable. Regardless of which is used, stimulation can be provided over 8 channels. The device was used in 2 cases. Both patients were operated on in October 1996, and 16 electrodes in 8 pairs were mounted in the cochlea. Mapping, performed 3 weeks after the operation, showed good speech perception in both patients with only a cochlear implant in the "open-set " status. CIS was used as the stimulation coding method. CA has yet to be applied.

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A statistical analysis was performed on 4f) patients with squamous cell carcinoma of the tongue and mouth floor, which could be followed for 6 months or more after initial treatment in the Department of Otorhinolaryngology, School of Medicine, Keio University during the 1a years from 1983 to 1996, The 5 year survival rate determined by the Kaplan Nleier method for each stage was 10000 for Stage I, 77.8% for Stage II, 60.0% for Stage III and 34.4% for Stage IV. Thirteen suffered a relapse after initial treatment and patients with relapses among them have all survived after the subsequent salvage surgery. In contrast, in nine patients with cervical relapse, however, the 5 year survival rate was 11.1% with an unfavorable prognosis. This confirmed that suppressing cervical relapses is important for treating tongue and floor mouth cancers. The treatment strategy in our department is characteristic of positive enforcement of prophylactic neck dissection in the surgery and introduction of neoadjuvant chemotherapy (NAC) in the chemotherapy. Prophylactic neck dissection was performed in the 17 patients and no relapse was observed on the side of prophylactic neck dissection. NAC was performed on 26 patients in consideration of suppressed minute metastases and preserved function and 24 determinable cases were statistically analyzed. Among patients who had received NAC, the oral function was successfully preserved without surgical intervention in six patients both patients who showed complete response (CR) and four out of 14 patients who had a partial response (PR) following NAC. This may indicate that the oral function could be preserved in those patients who exhibited CR following NAC, but that preservation could be difficult in patients who exhibited PR. In addition, concerning the accumulated 5-year survival rate in relation to the effect of NAC, responders (CR+ PR) accounted for 90.9% and non-responders (no change+progressive disease following NAC) for 15.0% with a very good outcome noted in the responder group. These figures suggest that responders may have a significantly good prognosis in the multivariant analysis including additional background factors before treatment as well. Accordingly, the present therapeutic measures for non responders must be reexamined and performed more carefully and accurately as compared with those for responders.

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The expression of RB and bcl 2 proteins was investigated in 135 thyroid carcinomas (130 papillary carcinomas and five follicular carcinomas) by the imrnunohistocheniical technique with RI3 and hcl-2 monoclonal antibodies. The results were as follows: 1) RB protein nuclear staining was shown in 117 of the 135 thyroid carcinomas (87%). Bcl-2 protein staining was shown in 82 of the carcinomas (61%). 2) There was a higher incidence of recurrence in RB-negative cases than in RB-positive cases (X2 test p=0.001). But there is no significant relationship between the incidence of recurrence and the results of bcl 2 staining (X2 test p=0.287). 3) The expression of RB protein was related to age and clinical N and M categories. Bcl 2 protein expression was related to clinical T categories. 4) The 10-year overall survival rate for RB -positive patients was higher than that for negative patients (log-rank test p<0.0001). But the survival rate was not associated with bcl 2 expression (log rank test p=0.3). Our results suggest that assessment of RB protein expression by the immunohistochemical technique may be useful to determine the possibility of recurrence and to predict the outcome of thyroid carcinomas. We think that assessment of RB protein expression by the immunohistochemical technique can be applied as a more sensitive prognostic factor.

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Ninety-one cases of oropharyngeal squamous cell carcinoma initially treated at Keio University Hospital between July 1981 and June 1996 were reviewed retrospectively. There were 83 males and 8 females, aged from 29 to 83 years old, with an average age of 62.7. The primary lesion was located in the lateral wall in 52 patients (57.1%), the superior wall in 23 (25.3%), the anterior wall in 1.4 (15.4%) and the posterior wall in 2 (2.2%). Double cancer was detected in 21 patients (23.1%).
The patients were divided into two groups according to the initial main treatment of the primary lesion without regard to chemotherapy : 72 patients (79. 1%) who received curative radiotherapy with or without salvage surgery, and 14 patients (15.4%) who underwent curative surgery with or without preoperative and/or postoperative radiation. The remaining 5 patients were treated by chemotherapy alone. Prior to the above tretments 50 patients (54.9%) received neoadjuvant chemotherapy (NAC).
Survival distributions were estimated by the Kaplan Nleier method as univariate analysis, and compared by the generalized Wilcoxon test. The overall five-year cumulative survival rate was 55.6%. The five-year survival rates according to stage (UICC classification, 1987) were as follows: stage 1 (11 cases), 70.7%; stage II (12 cases), 63. 6%; stage 111 (30 cases), 52.3% ; and stage IV (38 cases), 52.5%. Significant clinicopathological variables that influenced survival were: (1) T stage (p=0.0075); (2) age(p=0.0274) ; and (3) location of primary lesion (p= 0.0400). The results of multivariate analysis by Cox's proportional hazards model identified T stage as a significant independent prognostic factor.
Evaluation of the therapeutic modalities led to the following conclusions. (1) Differences in the initial treatments of the primary lesion were not reflected in the outcome, (2) Salvage surgery for residual or recurrent tumor contributed to improving the survival. The superior wall type, in particular, seemed to be a good indication for salvage surgery (3) Although the limitations of radiotherapy are not defined clearly, we have to determine the indications for radical resection of tumors resistant to radiotherapy with reconstruction. (4) The response rate of NAC reached 85.4%. but there were no significant differences in survival between the group that underwent NAC and the other group in any other subset analyses. (5) Among the patients who underwent NAC, the responder (CR+ PR) group showed a better five-year survival rate (61.3%) than the non-responder (NC+PD) group (42.9%), but the difference was not significant.

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In order to clarify the mechanism of positive scintigraphy with Tc pertechnetate in adenolymphomas of the parotid gland, 10 cases of adenolyrphoma were studied morphologically and from a functional view point. Salivary tissue obtained from normal parotid glands were also investigated for comparison with the tumor. In morphological studies, rapid tissue fixation by microwave irradiation produced very good results for examining mitochondria by high resolution light microscopy. A number of mitochondria were found both in the epithelial cells of adenolymphoma and in the striated duct cells of the parotid gland. In functional studies, the one-step method of enzymatic histochemistry was used for detecting Na K ATPase. Na K ATPase was found on the baso lateral side of the epithelial cells of adenolymphoma and the striated duct cells of the parotid gland, and this activity of Na K ATPase may enhance the accumulation of Tc pertechnetate in these cells. These observations may provide evidence for the bi-cellular theory which indicates that adenolymphoma originated from immature intercalated duct reserve cells.

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The vertebrate olfactory system is capable of recognizing and discriminating thousands of different odorant molecules. In vitro biochemical studies have shown that some odorants elicit an increase in the intercellular second messenger cyclic AMP, whereas other odorants cause an increase in the second messenger inositol triphosphate (IP3). If 1P3 plays an important role in the signal transduction, calcium binding protein will be needed. We investigated the expression of calretinin, which belongs to the E F hand family, in the neonatal and adult olfactory mucosa and olfactory bulb. Mice were sacrificed on postnatal day 1 (P1), day 3 (P3), day 10 (Pl0) and 12 weeks as adults. The olfactory mucosa of the nasal septum and the olfactory bulb were stained with anti-calretinin antibody at a I: 1000 dilution for 48 hours. The results were as follows. 1) Olfactory mucosa : In the P1 mouse, the olfactory nerves running in the submucosal layer and olfactory cells in the epithelium were positive. In the epithelium, immunopositive spots were seen exclusively in the upper half of the epithelium. In the P3, P10 and adult mice, these spots were seen throughout the olfactory cell layer. However, the basal cell layer and supporting cells were negative. 2) Olfactory bulb: In all stages, the olfactory nerve layer and the glomerular layer were strongly stained. In the external plexiform layer, many cells were positive. Their shape was bipolar and the size of the cell body was thought to be about 20um. They were thought to be tufted cells. However, there is a possibility that these cells are short axon cells in the external plexiform layer. In the granule layer, some granule cells were positive. In the PI mouse, the immunopositive spots were exclusively seen in the upper half of the epithelium. In contrast, in the P3 mouse, these spots were seen throughout the olfactory cell layer. Judging from our results, it is suspected that the important change in neurogenesis of olfactory cells occurred between P1 and P3. In the olfactory bulb, from PI to adult mice, cairetinin was positive in the olfactory nerve layer, the glomerulus and periglomerular cells. In contrast, mitral cells were negative. Most reports state that calcium binding protein appears in periglomerular cells. However, in the external plexiform layer, many cells were positive. As their shape was bipolar and the cell body was a little larger than the periglomerular cells, these cells were thought to be tufted cells.

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