Drill-induced damage was given to the auditory ossicle (incus) of guinea pigs, and permeability of HRP through strial vessels and the route of permeation of HRP to extracapillary spaces was examined.
The leakage of HRP from strial vessels was examined in different vibration times. Between 10-second vibration and 30-second vibration between 10 seconds and 60 seconds, and between 30 seconds and 60 seconds, the capillary permeability of HRP through strial vessels was significantly different in all cases. This reveals that leakage of HRP from strial capillaries depends upon drill vibration time. And it was found that the destruction of intermediate cells of stria vascularis also depends on drill vibration time.
As the route of permeation of HRP (a macromolecular protein) out of the blood vessel, two routes have been reported : a route by micropinocytosis in physiologically normal cases, and a route through opened interendothelial space in nonphysiological cases. The route of leakage we observed in the present study was through microtubules in vascular blood vessel : this route is different from the above two routes. When some damages occur in endothelial cells due to vibration, some channels which are usually closed, may open.

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A case of primary meningioma in the left anterior ethmoidal sinus is reported. Primary meningioma of the nasal cavity and paranasal sinuses is very rare. The patient is a 21-year-old woman with proptosis as the complication. There was no diplopia or other nasal symptoms. CT scan and MRI of the paranasal sinus showed a tumor localizing in the ethmoidal sinus.
The tumor was histologically diagnosed as meningioma and was surgically removed by the endonasal endoscopic approach under local anesthesia. There has been no recurrence for 9 months.

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Although it has recently been reported that ossicular anomalies are sometimes found in cases with congenital cholesteatoma, there are no reports regarding congenital cholesteatoma associated with inner ear anomalies. To our knowledge, this is the first report of two cases operated on for congenital middle ear cholesteatoma associated with inner ear anomalies. Case 1 was a two-year-old boy with profound deafness diagnosed as having congenital cholesteatoma and a hypoplastic bony labyrinth in the left ear. At the time of ear surgery, pearly cholesteatoma was found in the anteroinferior part of the mesotympanum and, in addition, fixation of the stapes was noted. Case 2 was a four-year-old boy diagnosed as having congenital cholesteatoma with normal bone conduction on the right ear. His opposite ear, however, showed profound sensorineural hearing loss, and temporal bone CT disclosed a Mondini-type inner ear anomaly in that ear. The cholesteatoma was successfully removed without affecting hearing. We conclude that temporal bone CT examination is needed to rule out the presence of congenital cholesteatoma in patients with not only conductive deafness but also sensorineural hearing loss, showing an intact eardrum.

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Three cases of benign disease presenting maxillary bone destruction are reported. In all cases we performed biopsy of the maxillary sinus by exploratory antrotomy for the purpose of definitive diagnosis. Pathological findings showed proliferating plasma cells and lymphocytes, and diffuse fibrosis. In these proliferating cells, atypia could not be seen. In all cases pathological diagnosis was non-specific inflammation. When a clinically malignant disease is suspected but pathologically no malignancy is found, the disease is generally called inflammatory pseudotumor. It is considered that these three cases can be called inflammatory pseudotumor in a wide sense. Mycosis is one which requires differential diagnosis. Because PAS and Grocott staining of these specimens tested negative, mycosis was excluded. In all cases maxillary radical operation was performed, and there has been no recurrence until now.

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The efficacy of induction chemotherapy on locally advanced head and neck cancer was evaluated clinically and histologically. From June 1992 to May 1996, at Yokohama City University, thirty-eight patients were treated for the first time for locally advanced head and neck cancer with induction chemotherapy consisting of cisplatin, 5-fluorouracil plus methotrexate, leucovorin or cyclophosphamide. Three (8%) of the 38 showed clinically complete response (CR) for both the primary tumor and neck lymph node metastasis. Response rate was 29%. After the chemotherapy, all patients underwent radical surgery. Five (13%) of the 38 had no histologic evidence of residual tumor in the surgically resected specimen. Three of the 5 histologically CR cases were also clinically CR, but the other 2 cases were 1 clinically partial response (PR) and 1 no change (NC). Patients who achieved histologically CR showed longer survival time than patients who were subsequently found to have residual tumor in their surgically resected specimen. The sensitivity and specificity of clinical evaluation were 40% and 97%. To improve the sensitivity of clinical evaluation, it is necessary to perform biopsies on the tumor site even after chemotherapy.

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Arteriovenous malformation (abbreviated as AVM hereafter) is defined as appearance of AV fistula as a remnant of the vascular system during the developmental stage, and this AV fistula without capillary bed provides a direct communication route between peripheral artery and venous vessels. AVM rarely occurs in the head and neck area. As we experienced one case of AVM occuring in the masseter, we will report it in this paper with some findings. A 38-year-old male visited our department in October 1995 with a chief complaint of pulsating tumor in the left cheek, which he had noticed since 1988. CT and MRI revealed a tumorous lesion rich in vascular tangle with the mandibular artery as the main supplying blood vessel. Under the diagnosis of AVM, it was resected surgically in Feburuary 1996. AVM is often treated by 1) operation, 2) occlusion of the supplying blood vessel, and 3) ligation. Occlusion is effective for prevention of massive bleeding associated with operation. However, since colateral blood vessels are formed after occlusion of the blood vessel, occlusion alone is difficult to eliminate the lesion, and thus total resection is needed.

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The frontal sinus cyst is a disease that is difficult to treat, because there are many cases that repeat recurrence even if they are operated. We evaluated 28 cases (30 sides) of the frontal sinus cyst who were operated in the past 6 years. The frontal sinus cyst is classified base on causes as follows : idiopathic cyst, postoperative cyst, traumatic cyst. The postoperative cysts are observed most frequently. There are few traumatic cysts. As for the rate of postoperative improvement in symptoms, endonasal sinus surgery is better than external incision operation. The rate of postoperative patency of the duct was high in cases who had undergone endonasal sinus surgery and silicon tube insertion to the duct. Therefore, in operation of a frontal sinus cyst, we should first select endonasal sinus surgery. In patients in whom endonasal sinus surgery is impossibe, we should perform external incision operation concomitantly with endonasal sinus surgery and place a silicon tube to the duct for 6 months at the shortest.

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In order to compare the accuracy of four infrared tympanic thermometers (ITTs), two infrared standards with 37°C and 40°C were measured ten times consecutively at every try, and measured more than one thousand times for one year, respectively. For 37°C standard, readings within 37 ± 0.1°C were 54, 52, 28, and 0%, respectively. Standard deviations were from 0.14 to 0.39°C. For 40°C, readings within 40 ± 0.2°C were 61, 50, 49, and 0%, respectively. Standard deviations were from 0.21 to 0.37°C. For every try, three ITTs showed the lowest reading at the first reading, and one ITT showed the highest reading at or after the fourth reading. In three ITTs, there was 0.6°C difference between the highest reading and the lowest one at every try, however, another ITT with the largest standard deviation, that difference was more than one centigrade.

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[in Japanese]

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